Sum-rule corrections: a route to error cancellations in correlation matrix renormalisation theory

NASA Astrophysics Data System (ADS)

Liu, C.; Liu, J.; Yao, Y. X.; Wang, C. Z.; Ho, K. M.

2017-03-01

We recently proposed the correlation matrix renormalisation (CMR) theory to efficiently and accurately calculate ground state total energy of molecular systems, based on the Gutzwiller variational wavefunction (GWF) to treat the electronic correlation effects. To help reduce numerical complications and better adapt the CMR to infinite lattice systems, we need to further refine the way to minimise the error originated from the approximations in the theory. This conference proceeding reports our recent progress on this key issue, namely, we obtained a simple analytical functional form for the one-electron renormalisation factors, and introduced a novel sum-rule correction for a more accurate description of the intersite electron correlations. Benchmark calculations are performed on a set of molecules to show the reasonable accuracy of the method.

Sum-rule corrections: A route to error cancellations in correlation matrix renormalisation theory

DOE PAGES

Liu, C.; Liu, J.; Yao, Y. X.; ...

2017-01-16

Here, we recently proposed the correlation matrix renormalisation (CMR) theory to efficiently and accurately calculate ground state total energy of molecular systems, based on the Gutzwiller variational wavefunction (GWF) to treat the electronic correlation effects. To help reduce numerical complications and better adapt the CMR to infinite lattice systems, we need to further refine the way to minimise the error originated from the approximations in the theory. This conference proceeding reports our recent progress on this key issue, namely, we obtained a simple analytical functional form for the one-electron renormalisation factors, and introduced a novel sum-rule correction for a moremore » accurate description of the intersite electron correlations. Benchmark calculations are performed on a set of molecules to show the reasonable accuracy of the method.« less

Sum-rule corrections: A route to error cancellations in correlation matrix renormalisation theory

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

Liu, C.; Liu, J.; Yao, Y. X.

Here, we recently proposed the correlation matrix renormalisation (CMR) theory to efficiently and accurately calculate ground state total energy of molecular systems, based on the Gutzwiller variational wavefunction (GWF) to treat the electronic correlation effects. To help reduce numerical complications and better adapt the CMR to infinite lattice systems, we need to further refine the way to minimise the error originated from the approximations in the theory. This conference proceeding reports our recent progress on this key issue, namely, we obtained a simple analytical functional form for the one-electron renormalisation factors, and introduced a novel sum-rule correction for a moremore » accurate description of the intersite electron correlations. Benchmark calculations are performed on a set of molecules to show the reasonable accuracy of the method.« less

Convergence to equilibrium of renormalised solutions to nonlinear chemical reaction–diffusion systems

NASA Astrophysics Data System (ADS)

Fellner, Klemens; Tang, Bao Quoc

2018-06-01

The convergence to equilibrium for renormalised solutions to nonlinear reaction-diffusion systems is studied. The considered reaction-diffusion systems arise from chemical reaction networks with mass action kinetics and satisfy the complex balanced condition. By applying the so-called entropy method, we show that if the system does not have boundary equilibria, i.e. equilibrium states lying on the boundary of R_+^N, then any renormalised solution converges exponentially to the complex balanced equilibrium with a rate, which can be computed explicitly up to a finite-dimensional inequality. This inequality is proven via a contradiction argument and thus not explicitly. An explicit method of proof, however, is provided for a specific application modelling a reversible enzyme reaction by exploiting the specific structure of the conservation laws. Our approach is also useful to study the trend to equilibrium for systems possessing boundary equilibria. More precisely, to show the convergence to equilibrium for systems with boundary equilibria, we establish a sufficient condition in terms of a modified finite-dimensional inequality along trajectories of the system. By assuming this condition, which roughly means that the system produces too much entropy to stay close to a boundary equilibrium for infinite time, the entropy method shows exponential convergence to equilibrium for renormalised solutions to complex balanced systems with boundary equilibria.

Boomerang RG flows in M-theory with intermediate scaling

NASA Astrophysics Data System (ADS)

Donos, Aristomenis; Gauntlett, Jerome P.; Rosen, Christopher; Sosa-Rodriguez, Omar

2017-07-01

We construct novel RG flows of D=11 supergravity that asymptotically approach AdS 4 × S 7 in the UV with deformations that break spatial translations in the dual field theory. In the IR the solutions return to exactly the same AdS 4 × S 7 vacuum, with a renormalisation of relative length scales, and hence we refer to the flows as `boomerang RG flows'. For sufficiently large deformations, on the way to the IR the solutions also approach two distinct intermediate scaling regimes, each with hyperscaling violation. The first regime is Lorentz invariant with dynamical exponent z = 1 while the second has z = 5/2. Neither ofthe two intermediatescaling regimesare associatedwith exact hyperscaling violation solutions of D = 11 supergravity. The RG flow solutions are constructed using the four dimensional N = 2 STU gauged supergravity theory with vanishing gauge fields, but non-vanishing scalar and pseudoscalar fields. In the ABJM dual field theory the flows are driven by spatially modulated deformation parameters for scalar and fermion bilinear operators.

Hierarchical parallelisation of functional renormalisation group calculations - hp-fRG

NASA Astrophysics Data System (ADS)

Rohe, Daniel

2016-10-01

The functional renormalisation group (fRG) has evolved into a versatile tool in condensed matter theory for studying important aspects of correlated electron systems. Practical applications of the method often involve a high numerical effort, motivating the question in how far High Performance Computing (HPC) can leverage the approach. In this work we report on a multi-level parallelisation of the underlying computational machinery and show that this can speed up the code by several orders of magnitude. This in turn can extend the applicability of the method to otherwise inaccessible cases. We exploit three levels of parallelisation: Distributed computing by means of Message Passing (MPI), shared-memory computing using OpenMP, and vectorisation by means of SIMD units (single-instruction-multiple-data). Results are provided for two distinct High Performance Computing (HPC) platforms, namely the IBM-based BlueGene/Q system JUQUEEN and an Intel Sandy-Bridge-based development cluster. We discuss how certain issues and obstacles were overcome in the course of adapting the code. Most importantly, we conclude that this vast improvement can actually be accomplished by introducing only moderate changes to the code, such that this strategy may serve as a guideline for other researcher to likewise improve the efficiency of their codes.

Calculating the renormalisation group equations of a SUSY model with Susyno

NASA Astrophysics Data System (ADS)

Fonseca, Renato M.

2012-10-01

Susyno is a Mathematica package dedicated to the computation of the 2-loop renormalisation group equations of a supersymmetric model based on any gauge group (the only exception being multiple U(1) groups) and for any field content. Program summary Program title: Susyno Catalogue identifier: AEMX_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEMX_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 30829 No. of bytes in distributed program, including test data, etc.: 650170 Distribution format: tar.gz Programming language: Mathematica 7 or higher. Computer: All systems that Mathematica 7+ is available for (PC, Mac). Operating system: Any platform supporting Mathematica 7+ (Windows, Linux, Mac OS). Classification: 4.2, 5, 11.1. Nature of problem: Calculating the renormalisation group equations of a supersymmetric model involves using long and complicated general formulae [1, 2]. In addition, to apply them it is necessary to know the Lagrangian in its full form. Building the complete Lagrangian of models with small representations of SU(2) and SU(3) might be easy but in the general case of arbitrary representations of an arbitrary gauge group, this task can be hard, lengthy and error prone. Solution method: The Susyno package uses group theoretical functions to calculate the super-potential and the soft-SUSY-breaking Lagrangian of a supersymmetric model, and calculates the two-loop RGEs of the model using the general equations of [1, 2]. Susyno works for models based on any representation(s) of any gauge group (the only exception being multiple U(1) groups). Restrictions: As the program is based on the formalism of [1, 2], it shares its limitations. Running time can also be a significant restriction, in particular for models with many fields. Unusual features: Susyno contains functions that (a) calculate the Lagrangian of supersymmetric models and (b) calculate some group theoretical quantities. Some of these functions are available to the user and can be freely used. A built-in help system provides detailed information. Running time: Tests were made using a computer with an Intel Core i5 760 CPU, running under Ubuntu 11.04 and with Mathematica 8.0.1 installed. Using the option to suppress printing, the one- and two-loop beta functions of the MSSM were obtained in 2.5 s (NMSSM: 5.4 s). Note that the running time scales up very quickly with the total number of fields in the model. References: [1] S.P. Martin and M.T. Vaughn, Phys. Rev. D 50 (1994) 2282. [Erratum-ibid D 78 (2008) 039903] [arXiv:hep-ph/9311340]. [2] Y. Yamada, Phys. Rev. D 50 (1994) 3537 [arXiv:hep-ph/9401241].

Unification of gauge and Yukawa couplings

NASA Astrophysics Data System (ADS)

Abdalgabar, Ammar; Khojali, Mohammed Omer; Cornell, Alan S.; Cacciapaglia, Giacomo; Deandrea, Aldo

2018-01-01

The unification of gauge and top Yukawa couplings is an attractive feature of gauge-Higgs unification models in extra-dimensions. This feature is usually considered difficult to obtain based on simple group theory analyses. We reconsider a minimal toy model including the renormalisation group running at one loop. Our results show that the gauge couplings unify asymptotically at high energies, and that this may result from the presence of an UV fixed point. The Yukawa coupling in our toy model is enhanced at low energies, showing that a genuine unification of gauge and Yukawa couplings may be achieved.

Nonperturbative finite-temperature Yang-Mills theory

NASA Astrophysics Data System (ADS)

Cyrol, Anton K.; Mitter, Mario; Pawlowski, Jan M.; Strodthoff, Nils

2018-03-01

We present nonperturbative correlation functions in Landau-gauge Yang-Mills theory at finite temperature. The results are obtained from the functional renormalisation group within a self-consistent approximation scheme. In particular, we compute the magnetic and electric components of the gluon propagator, and the three- and four-gluon vertices. We also show the ghost propagator and the ghost-gluon vertex at finite temperature. Our results for the propagators are confronted with lattice simulations and our Debye mass is compared to hard thermal loop perturbation theory.

Large trilinear At soft supersymmetry breaking coupling from 5D MSSM

NASA Astrophysics Data System (ADS)

Abdalgabar, Ammar; Cornell, A. S.

2015-10-01

The possibility of generating a large trilinear At soft supersymmetry breaking coupling at low energies through renormalisation group evolution in the 5D MSSM is investigated. Using the power law running in five dimensions and a compactification scale in the 10-103 TeV range, we show that gluino mass may drive a large enough At to reproduce the measured Higgs mass and have a light stop superpartner below ∼ 1 TeV, as preferred by the fine tuning argument for the Higgs mass.

Inertial Spontaneous Symmetry Breaking and Quantum Scale Invariance

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

Ferreira, Pedro G.; Hill, Christopher T.; Ross, Graham G.

Weyl invariant theories of scalars and gravity can generate all mass scales spontaneously, initiated by a dynamical process of "inertial spontaneous symmetry breaking" that does not involve a potential. This is dictated by the structure of the Weyl current,more » $$K_\\mu$$, and a cosmological phase during which the universe expands and the Einstein-Hilbert effective action is formed. Maintaining exact Weyl invariance in the renormalised quantum theory is straightforward when renormalisation conditions are referred back to the VEV's of fields in the action of the theory, which implies a conserved Weyl current. We do not require scale invariant regulators. We illustrate the computation of a Weyl invariant Coleman-Weinberg potential.« less

The Φ43 and Φ63 matricial QFT models have reflection positive two-point function

NASA Astrophysics Data System (ADS)

Grosse, Harald; Sako, Akifumi; Wulkenhaar, Raimar

2018-01-01

We extend our previous work (on D = 2) to give an exact solution of the ΦD3 large- N matrix model (or renormalised Kontsevich model) in D = 4 and D = 6 dimensions. Induction proofs and the difficult combinatorics are unchanged compared with D = 2, but the renormalisation - performed according to Zimmermann - is much more involved. As main result we prove that the Schwinger 2-point function resulting from the ΦD3 -QFT model on Moyal space satisfies, for real coupling constant, reflection positivity in D = 4 and D = 6 dimensions. The Källén-Lehmann mass spectrum of the associated Wightman 2-point function describes a scattering part | p|2 ≥ 2μ2 and an isolated broadened mass shell around | p|2 =μ2.

On a radiative origin of the Standard Model from trinification

NASA Astrophysics Data System (ADS)

Camargo-Molina, José Eliel; Morais, António P.; Pasechnik, Roman; Wessén, Jonas

2016-09-01

In this work, we present a trinification-based grand unified theory incorporating a global SU(3) family symmetry that after a spontaneous breaking leads to a left-right symmetric model. Already at the classical level, this model can accommodate the matter content and the quark Cabbibo mixing in the Standard Model (SM) with only one Yukawa coupling at the unification scale. Considering the minimal low-energy scenario with the least amount of light states, we show that the resulting effective theory enables dynamical breaking of its gauge group down to that of the SM by means of radiative corrections accounted for by the renormalisation group evolution at one loop. This result paves the way for a consistent explanation of the SM breaking scale and fermion mass hierarchies.

Classical and quantum aspects of Yang-Baxter Wess-Zumino models

NASA Astrophysics Data System (ADS)

Demulder, Saskia; Driezen, Sibylle; Sevrin, Alexander; Thompson, Daniel C.

2018-03-01

We investigate the integrable Yang-Baxter deformation of the 2d Principal Chiral Model with a Wess-Zumino term. For arbitrary groups, the one-loop β-functions are calculated and display a surprising connection between classical and quantum physics: the classical integrability condition is necessary to prevent new couplings being generated by renormalisation. We show these theories admit an elegant realisation of Poisson-Lie T-duality acting as a simple inversion of coupling constants. The self-dual point corresponds to the Wess-Zumino-Witten model and is the IR fixed point under RG. We address the possibility of having supersymmetric extensions of these models showing that extended supersymmetry is not possible in general.

A class of renormalised meshless Laplacians for boundary value problems

NASA Astrophysics Data System (ADS)

Basic, Josip; Degiuli, Nastia; Ban, Dario

2018-02-01

A meshless approach to approximating spatial derivatives on scattered point arrangements is presented in this paper. Three various derivations of approximate discrete Laplace operator formulations are produced using the Taylor series expansion and renormalised least-squares correction of the first spatial derivatives. Numerical analyses are performed for the introduced Laplacian formulations, and their convergence rate and computational efficiency are examined. The tests are conducted on regular and highly irregular scattered point arrangements. The results are compared to those obtained by the smoothed particle hydrodynamics method and the finite differences method on a regular grid. Finally, the strong form of various Poisson and diffusion equations with Dirichlet or Robin boundary conditions are solved in two and three dimensions by making use of the introduced operators in order to examine their stability and accuracy for boundary value problems. The introduced Laplacian operators perform well for highly irregular point distribution and offer adequate accuracy for mesh and mesh-free numerical methods that require frequent movement of the grid or point cloud.

Multi-scale modeling of diffusion-controlled reactions in polymers: renormalisation of reactivity parameters.

PubMed

Everaers, Ralf; Rosa, Angelo

2012-01-07

The quantitative description of polymeric systems requires hierarchical modeling schemes, which bridge the gap between the atomic scale, relevant to chemical or biomolecular reactions, and the macromolecular scale, where the longest relaxation modes occur. Here, we use the formalism for diffusion-controlled reactions in polymers developed by Wilemski, Fixman, and Doi to discuss the renormalisation of the reactivity parameters in polymer models with varying spatial resolution. In particular, we show that the adjustments are independent of chain length. As a consequence, it is possible to match reactions times between descriptions with different resolution for relatively short reference chains and to use the coarse-grained model to make quantitative predictions for longer chains. We illustrate our results by a detailed discussion of the classical problem of chain cyclization in the Rouse model, which offers the simplest example of a multi-scale descriptions, if we consider differently discretized Rouse models for the same physical system. Moreover, we are able to explore different combinations of compact and non-compact diffusion in the local and large-scale dynamics by varying the embedding dimension.

Large-cell renormalisation and systems of dimensionality larger than the upper marginal dimension

NASA Technical Reports Server (NTRS)

Nakanishi, H.

1984-01-01

A recent argument dismissing the applicability of large-cell renormalization schemes to systems whose dimensionality is larger than the upper marginal dimension is critically discussed. In this connection, new large-cell renormalization results for the random walk for a dimensionality of 3 and 4 are presented which indicate convergence to the correct results.

Determination of the strong coupling constant \\varvec{α _s (m_Z)} in next-to-next-to-leading order QCD using H1 jet cross section measurements

NASA Astrophysics Data System (ADS)

Andreev, V.; Baghdasaryan, A.; Begzsuren, K.; Belousov, A.; Bertone, V.; Bolz, A.; Boudry, V.; Brandt, G.; Brisson, V.; Britzger, D.; Buniatyan, A.; Bylinkin, A.; Bystritskaya, L.; Campbell, A. J.; Cantun Avila, K. B.; Cerny, K.; Chekelian, V.; Contreras, J. G.; Cvach, J.; Currie, J.; Dainton, J. B.; Daum, K.; Diaconu, C.; Dobre, M.; Dodonov, V.; Eckerlin, G.; Egli, S.; Elsen, E.; Favart, L.; Fedotov, A.; Feltesse, J.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Gehrmann, T.; Ghazaryan, S.; Goerlich, L.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Grebenyuk, A.; Greenshaw, T.; Grindhammer, G.; Gwenlan, C.; Haidt, D.; Henderson, R. C. W.; Hladkỳ, J.; Hoffmann, D.; Horisberger, R.; Hreus, T.; Huber, F.; Huss, A.; Jacquet, M.; Janssen, X.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kiesling, C.; Klein, M.; Kleinwort, C.; Kogler, R.; Kostka, P.; Kretzschmar, J.; Krücker, D.; Krüger, K.; Landon, M. P. J.; Lange, W.; Laycock, P.; Lebedev, A.; Levonian, S.; Lipka, K.; List, B.; List, J.; Lobodzinski, B.; Malinovski, E.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meyer, A. B.; Meyer, H.; Meyer, J.; Mikocki, S.; Morozov, A.; Müller, K.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Niehues, J.; Nowak, G.; Olsson, J. E.; Ozerov, D.; Pascaud, C.; Patel, G. D.; Perez, E.; Petrukhin, A.; Picuric, I.; Pirumov, H.; Pitzl, D.; Plačakytė, R.; Polifka, R.; Rabbertz, K.; Radescu, V.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Šálek, D.; Sankey, D. P. C.; Sauter, M.; Sauvan, E.; Schmitt, S.; Schoeffel, L.; Schöning, A.; Sefkow, F.; Shushkevich, S.; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, A.; Steder, M.; Stella, B.; Straumann, U.; Sutton, M. R.; Sykora, T.; Thompson, P. D.; Traynor, D.; Truöl, P.; Tsakov, I.; Tseepeldorj, B.; Valkárová, A.; Vallée, C.; Van Mechelen, P.; Vazdik, Y.; Wegener, D.; Wünsch, E.; Žáček, J.; Zhang, Z.; Žlebčík, R.; Zohrabyan, H.; Zomer, F.

2017-11-01

The strong coupling constant α _s is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of α _s (m_Z) at the Z-boson mass m_Z are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be α _s (m_Z) =0.1157 (20)_exp (29)_th. Complementary, α _s (m_Z) is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value α _s (m_Z) =0.1142 (28)_tot obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.

Chiral fermions in asymptotically safe quantum gravity

NASA Astrophysics Data System (ADS)

Meibohm, J.; Pawlowski, J. M.

2016-05-01

We study the consistency of dynamical fermionic matter with the asymptotic safety scenario of quantum gravity using the functional renormalisation group. Since this scenario suggests strongly coupled quantum gravity in the UV, one expects gravity-induced fermion self-interactions at energies of the Planck scale. These could lead to chiral symmetry breaking at very high energies and thus to large fermion masses in the IR. The present analysis which is based on the previous works (Christiansen et al., Phys Rev D 92:121501, 2015; Meibohm et al., Phys Rev D 93:084035, 2016), concludes that gravity-induced chiral symmetry breaking at the Planck scale is avoided for a general class of NJL-type models. We find strong evidence that this feature is independent of the number of fermion fields. This finding suggests that the phase diagram for these models is topologically stable under the influence of gravitational interactions.

Chiral fermions in asymptotically safe quantum gravity.

PubMed

Meibohm, J; Pawlowski, J M

2016-01-01

We study the consistency of dynamical fermionic matter with the asymptotic safety scenario of quantum gravity using the functional renormalisation group. Since this scenario suggests strongly coupled quantum gravity in the UV, one expects gravity-induced fermion self-interactions at energies of the Planck scale. These could lead to chiral symmetry breaking at very high energies and thus to large fermion masses in the IR. The present analysis which is based on the previous works (Christiansen et al., Phys Rev D 92:121501, 2015; Meibohm et al., Phys Rev D 93:084035, 2016), concludes that gravity-induced chiral symmetry breaking at the Planck scale is avoided for a general class of NJL-type models. We find strong evidence that this feature is independent of the number of fermion fields. This finding suggests that the phase diagram for these models is topologically stable under the influence of gravitational interactions.

Bridging a gap between continuum-QCD and ab initio predictions of hadron observables

DOE PAGES

Binosi, Daniele; Chang, Lei; Papavassiliou, Joannis; ...

2015-03-01

Within contemporary hadron physics there are two common methods for determining the momentum- dependence of the interaction between quarks: the top-down approach, which works toward an ab initiocomputation of the interaction via direct analysis of the gauge-sector gap equations; and the bottom-up scheme, which aims to infer the interaction by fitting data within a well-defined truncation of those equations in the matter sector that are relevant to bound-state properties. We unite these two approaches by demonstrating that the renormalisation-group-invariant running-interaction predicted by contemporary analyses of QCD’s gauge sector coincides with that required in order to describe ground-state hadron observables usingmore » a nonperturbative truncation of QCD’s Dyson–Schwinger equations in the matter sector. This bridges a gap that had lain between nonperturbative continuum-QCD and the ab initio prediction of bound-state properties.« less

Extra dimension searches at hadron colliders to next-to-leading order-QCD

NASA Astrophysics Data System (ADS)

Kumar, M. C.; Mathews, Prakash; Ravindran, V.

2007-11-01

The quantitative impact of NLO-QCD corrections for searches of large and warped extra dimensions at hadron colliders are investigated for the Drell-Yan process. The K-factor for various observables at hadron colliders are presented. Factorisation, renormalisation scale dependence and uncertainties due to various parton distribution functions are studied. Uncertainties arising from the error on experimental data are estimated using the MRST parton distribution functions.

The electronic cigarette: a knight in shining armour or a Trojan horse?

PubMed

Schluger, Neil W

2014-10-01

Electronic cigarettes have caused a sharp debate in the public health community, with some promoting them as a means of harm reduction for tobacco users and some taking a strong stand against them because of fear of renormalising smoking behaviour and interrupting tobacco control progress. People with mental health problems smoke at high rates and e-cigarettes seem a potentially attractive method of cessation in this population, and their use should be studied carefully.

Loop amplitudes in an extended gravity theory

NASA Astrophysics Data System (ADS)

Dunbar, David C.; Godwin, John H.; Jehu, Guy R.; Perkins, Warren B.

2018-05-01

We extend the S-matrix of gravity by the addition of the minimal three-point amplitude or equivalently adding R3 terms to the Lagrangian. We demonstrate how Unitarity can be used to simply examine the renormalisability of this theory and determine the R4 counter-terms that arise at one-loop. We find that the combination of R4 terms that arise in the extended theory is complementary to the R4 counter-term associated with supersymmetric Lagrangians.

Spectroscopy of a one-dimensional V-shaped quantum well with a point impurity

NASA Astrophysics Data System (ADS)

Fassari, S.; Gadella, M.; Glasser, M. L.; Nieto, L. M.

2018-02-01

We consider the one-dimensional Hamiltonian with a V-shaped potential H0 = 1/2 [ -d2/dx2 + | x | ], decorated with a point impurity of either δ-type, or local δ‧-type or even nonlocal δ‧-type, thus yielding three exactly solvable models. We analyse the behaviour of the change in the energy levels when an interaction of the type - λ δ(x) or - λ δ(x -x0) is switched on. In the first case, even energy levels, pertaining to antisymmetric bound states, remain invariant with respect to λ even though odd energy levels, pertaining to symmetric bound states, decrease as λ increases. In the second, all energy levels decrease when the factor λ increases. A similar study has been performed for the so-called nonlocal δ‧ interaction, requiring a coupling constant renormalisation, which implies the replacement of the form factor λ by a renormalised form factor β. In terms of β, odd energy levels are unchanged. However, we show the existence of level crossings: after a fixed value of β the energy of each even level, with the natural exception of the first one, becomes lower than the constant energy of the previous odd level. Finally, we consider an interaction of the type - λδ(x) + μδ‧(x) , and analyse in detail the discrete spectrum of the resulting self-adjoint Hamiltonian.

["Junk-food"-intervention in poisoning delusion].

PubMed

Schwerthöffer, Dirk; Bäuml, Josef

2007-11-01

Case report about a 29-year old US-American patient who suddenly flew to Germany due to a schizoaffektive disorder. During a stay in our psychiatric hospital she refused food, liquid and medication because of fear of being poisoned. After four days her general condition had worsened rapidly so that parenteral nutrition was discussed. Surprisingly her poisoning delusion could be overcome by offering American "Junk-Food". From this moment on compliance in taking of medication improved too, so that renormalisation of her condition was achieved.

The electronic cigarette: a knight in shining armour or a Trojan horse?†

PubMed Central

Schluger, Neil W.

2014-01-01

Electronic cigarettes have caused a sharp debate in the public health community, with some promoting them as a means of harm reduction for tobacco users and some taking a strong stand against them because of fear of renormalising smoking behaviour and interrupting tobacco control progress. People with mental health problems smoke at high rates and e-cigarettes seem a potentially attractive method of cessation in this population, and their use should be studied carefully. PMID:25285216

Measuring multi-configurational character by orbital entanglement

NASA Astrophysics Data System (ADS)

Stein, Christopher J.; Reiher, Markus

2017-09-01

One of the most critical tasks at the very beginning of a quantum chemical investigation is the choice of either a multi- or single-configurational method. Naturally, many proposals exist to define a suitable diagnostic of the multi-configurational character for various types of wave functions in order to assist this crucial decision. Here, we present a new orbital-entanglement-based multi-configurational diagnostic termed Zs(1). The correspondence of orbital entanglement and static (or non-dynamic) electron correlation permits the definition of such a diagnostic. We chose our diagnostic to meet important requirements such as well-defined limits for pure single-configurational and multi-configurational wave functions. The Zs(1) diagnostic can be evaluated from a partially converged, but qualitatively correct, and therefore inexpensive density matrix renormalisation group wave function as in our recently presented automated active orbital selection protocol. Its robustness and the fact that it can be evaluated at low cost make this diagnostic a practical tool for routine applications.

PIXE analysis of Italian ink drawings of the XVI century

NASA Astrophysics Data System (ADS)

Zucchiatti, A.; Climent-Font, A.; Enguita, O.; Fernandez-Jimenez, M. T.; Finaldi, G.; Garrido, C.; Matillas, J. M.

2005-10-01

The composition of inks in a group of 24 drawings of ten XVI century Italian painters, has been determined by PIXE at the external micro-beam line of the Centro de Micro Análisis de Materiales of the Universidad Autónoma de Madrid. Ink elemental thicknesses have been determined by comparison with a set of certified thin standards. A comprehensive comparison of inks has also been performed by renormalisation of spectra and definition of an ink-to-ink distance. The elemental compositions and the ink-to-ink distances give consistent results that are generally in line with the appearance of the drawings and add relevant instrumental information to the stylistic observation, revealing for example the presence of retouches and additions in different parts of a drawing. Cluster analysis performed on a subgroup of 13 artefacts from the Genoese painter Luca Cambiaso and his school has revealed a partition that separates neatly the work of the master from that of his followers.

SO(10) × S 4 grand unified theory of flavour and leptogenesis

NASA Astrophysics Data System (ADS)

de Anda, Francisco J.; King, Stephen F.; Perdomo, Elena

2017-12-01

We propose a Grand Unified Theory of Flavour, based on SO(10) together with a non-Abelian discrete group S 4, under which the unified three quark and lepton 16-plets are unified into a single triplet 3'. The model involves a further discrete group ℤ 4 R × ℤ 4 3 which controls the Higgs and flavon symmetry breaking sectors. The CSD2 flavon vacuum alignment is discussed, along with the GUT breaking potential and the doublet-triplet splitting, and proton decay is shown to be under control. The Yukawa matrices are derived in detail, from renormalisable diagrams, and neutrino masses emerge from the type I seesaw mechanism. A full numerical fit is performed with 15 input parameters generating 19 presently constrained observables, taking into account supersymmetry threshold corrections. The model predicts a normal neutrino mass ordering with a CP oscillation phase of 260°, an atmospheric angle in the first octant and neutrinoless double beta decay with m ββ = 11 meV. We discuss N 2 leptogenesis, which fixes the second right-handed neutrino mass to be M 2 ≃ 2 × 1011 GeV, in the natural range predicted by the model.

Running of the charm-quark mass from HERA deep-inelastic scattering data

DOE PAGES

Gizhko, A.; Geiser, A.; Moch, S.; ...

2017-11-07

Combined HERA data on charm production in deep-inelastic scattering have previously been used to determine the charm-quark running mass m c(m c) in the MS¯ renormalisation scheme. Here, the same data are used as a function of the photon virtuality Q 2 to evaluate the charm-quark running mass at different scales to one-loop order, in the context of a next-to-leading order QCD analysis. Lastly, the scale dependence of the mass is found to be consistent with QCD expectations.

Running of the charm-quark mass from HERA deep-inelastic scattering data

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

Gizhko, A.; Geiser, A.; Moch, S.

Combined HERA data on charm production in deep-inelastic scattering have previously been used to determine the charm-quark running mass m c(m c) in the MS¯ renormalisation scheme. Here, the same data are used as a function of the photon virtuality Q 2 to evaluate the charm-quark running mass at different scales to one-loop order, in the context of a next-to-leading order QCD analysis. Lastly, the scale dependence of the mass is found to be consistent with QCD expectations.

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

Dulat, Falko; Lionetti, Simone; Mistlberger, Bernhard

We present an analytic computation of the Higgs production cross section in the gluon fusion channel, which is differential in the components of the Higgs momentum and inclusive in the associated partonic radiation through NNLO in perturbative QCD. Our computation includes the necessary higher order terms in the dimensional regulator beyond the finite part that are required for renormalisation and collinear factorisation at N 3LO. We outline in detail the computational methods which we employ. We present numerical predictions for realistic final state observables, specifically distributions for the decay products of the Higgs boson in the γγ decay channel.

Granger causal time-dependent source connectivity in the somatosensory network

NASA Astrophysics Data System (ADS)

Gao, Lin; Sommerlade, Linda; Coffman, Brian; Zhang, Tongsheng; Stephen, Julia M.; Li, Dichen; Wang, Jue; Grebogi, Celso; Schelter, Bjoern

2015-05-01

Exploration of transient Granger causal interactions in neural sources of electrophysiological activities provides deeper insights into brain information processing mechanisms. However, the underlying neural patterns are confounded by time-dependent dynamics, non-stationarity and observational noise contamination. Here we investigate transient Granger causal interactions using source time-series of somatosensory evoked magnetoencephalographic (MEG) elicited by air puff stimulation of right index finger and recorded using 306-channel MEG from 21 healthy subjects. A new time-varying connectivity approach, combining renormalised partial directed coherence with state space modelling, is employed to estimate fast changing information flow among the sources. Source analysis confirmed that somatosensory evoked MEG was mainly generated from the contralateral primary somatosensory cortex (SI) and bilateral secondary somatosensory cortices (SII). Transient Granger causality shows a serial processing of somatosensory information, 1) from contralateral SI to contralateral SII, 2) from contralateral SI to ipsilateral SII, 3) from contralateral SII to contralateral SI, and 4) from contralateral SII to ipsilateral SII. These results are consistent with established anatomical connectivity between somatosensory regions and previous source modeling results, thereby providing empirical validation of the time-varying connectivity analysis. We argue that the suggested approach provides novel information regarding transient cortical dynamic connectivity, which previous approaches could not assess.

Critical Two-Point Function for Long-Range O( n) Models Below the Upper Critical Dimension

NASA Astrophysics Data System (ADS)

Lohmann, Martin; Slade, Gordon; Wallace, Benjamin C.

2017-12-01

We consider the n-component |φ|^4 lattice spin model (n ≥ 1) and the weakly self-avoiding walk (n=0) on Z^d, in dimensions d=1,2,3. We study long-range models based on the fractional Laplacian, with spin-spin interactions or walk step probabilities decaying with distance r as r^{-(d+α )} with α \\in (0,2). The upper critical dimension is d_c=2α . For ɛ >0, and α = 1/2 (d+ɛ ), the dimension d=d_c-ɛ is below the upper critical dimension. For small ɛ , weak coupling, and all integers n ≥ 0, we prove that the two-point function at the critical point decays with distance as r^{-(d-α )}. This "sticking" of the critical exponent at its mean-field value was first predicted in the physics literature in 1972. Our proof is based on a rigorous renormalisation group method. The treatment of observables differs from that used in recent work on the nearest-neighbour 4-dimensional case, via our use of a cluster expansion.

Towards a multiconfigurational method of increments

NASA Astrophysics Data System (ADS)

Fertitta, E.; Koch, D.; Paulus, B.; Barcza, G.; Legeza, Ö.

2018-06-01

The method of increments (MoI) allows one to successfully calculate cohesive energies of bulk materials with high accuracy, but it encounters difficulties when calculating dissociation curves. The reason is that its standard formalism is based on a single Hartree-Fock (HF) configuration whose orbitals are localised and used for the many-body expansion. In situations where HF does not allow a size-consistent description of the dissociation, the MoI cannot be guaranteed to yield proper results either. Herein, we address the problem by employing a size-consistent multiconfigurational reference for the MoI formalism. This leads to a matrix equation where a coupling derived by the reference itself is employed. In principle, such an approach allows one to evaluate approximate values for the ground as well as excited states energies. While the latter are accurate close to the avoided crossing only, the ground state results are very promising for the whole dissociation curve, as shown by the comparison with density matrix renormalisation group benchmarks. We tested this two-state constant-coupling MoI on beryllium rings of different sizes and studied the error introduced by the constant coupling.

Next-to-minimal SOFTSUSY

NASA Astrophysics Data System (ADS)

Allanach, B. C.; Athron, P.; Tunstall, Lewis C.; Voigt, A.; Williams, A. G.

2014-09-01

We describe an extension to the SOFTSUSY program that provides for the calculation of the sparticle spectrum in the Next-to-Minimal Supersymmetric Standard Model (NMSSM), where a chiral superfield that is a singlet of the Standard Model gauge group is added to the Minimal Supersymmetric Standard Model (MSSM) fields. Often, a Z3 symmetry is imposed upon the model. SOFTSUSY can calculate the spectrum in this case as well as the case where general Z3 violating (denoted as =) terms are added to the soft supersymmetry breaking terms and the superpotential. The user provides a theoretical boundary condition for the couplings and mass terms of the singlet. Radiative electroweak symmetry breaking data along with electroweak and CKM matrix data are used as weak-scale boundary conditions. The renormalisation group equations are solved numerically between the weak scale and a high energy scale using a nested iterative algorithm. This paper serves as a manual to the NMSSM mode of the program, detailing the approximations and conventions used. Catalogue identifier: ADPM_v4_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADPM_v4_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 154886 No. of bytes in distributed program, including test data, etc.: 1870890 Distribution format: tar.gz Programming language: C++, fortran. Computer: Personal computer. Operating system: Tested on Linux 3.x. Word size: 64 bits Classification: 11.1, 11.6. Does the new version supersede the previous version?: Yes Catalogue identifier of previous version: ADPM_v3_0 Journal reference of previous version: Comput. Phys. Comm. 183 (2012) 785 Nature of problem: Calculating supersymmetric particle spectrum and mixing parameters in the next-to-minimal supersymmetric standard model. The solution to the renormalisation group equations must be consistent with boundary conditions on supersymmetry breaking parameters, as well as on the weak-scale boundary condition on gauge couplings, Yukawa couplings and the Higgs potential parameters. Solution method: Nested iterative algorithm and numerical minimisation of the Higgs potential. Reasons for new version: Major extension to include the next-to-minimal supersymmetric standard model. Summary of revisions: Added additional supersymmetric and supersymmetry breaking parameters associated with the additional gauge singlet. Electroweak symmetry breaking conditions are significantly changed in the next-to-minimal mode, and some sparticle mixing changes. An interface to NMSSMTools has also been included. Some of the object structure has also changed, and the command line interface has been made more user friendly. Restrictions: SOFTSUSY will provide a solution only in the perturbative regime and it assumes that all couplings of the model are real (i.e. CP-conserving). If the parameter point under investigation is non-physical for some reason (for example because the electroweak potential does not have an acceptable minimum), SOFTSUSY returns an error message. Running time: A few seconds per parameter point.

Erratum to: Measurement of jet multiplicity distributions in $$\\mathrm {t}\\overline{\\mathrm {t}}$$ production in pp collisions at $$\\sqrt{s} = 7\\,\\text {TeV} $$

DOE PAGES

Chatrchyan, Serguei

2015-05-19

Table 4 was incorrectly captioned in the originally published version. The correct caption is ‘Normalised differential tt - production cross section as a function of the number of additional jets with p T > 30 GeV in the lepton+jets channel. Furthermore, the statistical, systematic, and total uncertainties are also shown. Finally, the main experimental and model systematic uncertainties are displayed: JES and the combination of renormalisation and factorisation scales, jet-parton matching threshold, and hadronisation (in the table “Q 2/Match./Had.”)’.

Higgs-differential cross section at NNLO in dimensional regularisation

DOE PAGES

Dulat, Falko; Lionetti, Simone; Mistlberger, Bernhard; ...

2017-07-05

We present an analytic computation of the Higgs production cross section in the gluon fusion channel, which is differential in the components of the Higgs momentum and inclusive in the associated partonic radiation through NNLO in perturbative QCD. Our computation includes the necessary higher order terms in the dimensional regulator beyond the finite part that are required for renormalisation and collinear factorisation at N 3LO. We outline in detail the computational methods which we employ. We present numerical predictions for realistic final state observables, specifically distributions for the decay products of the Higgs boson in the γγ decay channel.

Numerical Coupling and Simulation of Point-Mass System with the Turbulent Fluid Flow

NASA Astrophysics Data System (ADS)

Gao, Zheng

A computational framework that combines the Eulerian description of the turbulence field with a Lagrangian point-mass ensemble is proposed in this dissertation. Depending on the Reynolds number, the turbulence field is simulated using Direct Numerical Simulation (DNS) or eddy viscosity model. In the meanwhile, the particle system, such as spring-mass system and cloud droplets, are modeled using the ordinary differential system, which is stiff and hence poses a challenge to the stability of the entire system. This computational framework is applied to the numerical study of parachute deceleration and cloud microphysics. These two distinct problems can be uniformly modeled with Partial Differential Equations (PDEs) and Ordinary Differential Equations (ODEs), and numerically solved in the same framework. For the parachute simulation, a novel porosity model is proposed to simulate the porous effects of the parachute canopy. This model is easy to implement with the projection method and is able to reproduce Darcy's law observed in the experiment. Moreover, the impacts of using different versions of k-epsilon turbulence model in the parachute simulation have been investigated and conclude that the standard and Re-Normalisation Group (RNG) model may overestimate the turbulence effects when Reynolds number is small while the Realizable model has a consistent performance with both large and small Reynolds number. For another application, cloud microphysics, the cloud entrainment-mixing problem is studied in the same numerical framework. Three sets of DNS are carried out with both decaying and forced turbulence. The numerical result suggests a new way parameterize the cloud mixing degree using the dynamical measures. The numerical experiments also verify the negative relationship between the droplets number concentration and the vorticity field. The results imply that the gravity has fewer impacts on the forced turbulence than the decaying turbulence. In summary, the proposed framework can be used to solve a physics problem that involves turbulence field and point-mass system, and therefore has a broad application.

An observational study of retail availability and in-store marketing of e-cigarettes in London: potential to undermine recent tobacco control gains?

PubMed Central

Hsu, Robert; Myers, Allison E; Ribisl, Kurt M; Marteau, Theresa M

2013-01-01

Objectives E-cigarette companies and vendors claim the potential of e-cigarettes to help smokers reduce or quit tobacco use. E-cigarettes also have the potential to renormalise smoking. The purpose of this study was to describe the availability and in-store marketing of e-cigarettes in London, UK stores selling tobacco and alcohol. Design Observational study. Setting Small and large stores selling alcohol and tobacco in London, UK. Primary and secondary outcome measures The number of stores selling e-cigarettes, the number of stores with an interior or exterior e-cigarette advertisement, the number of stores with an e-cigarette point-of-sale movable display, store size, deprivation index score for store's corresponding lower super output area. Results Audits were completed in 108 of 128 selected stores. 62 of the audited stores (57%) sold e-cigarettes. E-cigarette availability was unrelated to store size. There was a statistically non-significant trend towards increased availability in more deprived areas (p=0.069). 31 of the 62 stores (50%) selling e-cigarettes had a point-of-sale movable display, with all but one found in small stores. Two small stores had interior advertisements and eight had exterior advertisements. No advertisements were observed in large stores. Conclusions This audit revealed widespread availability of e-cigarettes and in-store marketing in London, UK. Even if e-cigarettes prove to be an effective cessation aid, their sale and use are resulting in an increasing public presence of cigarette-like images and smoking behaviour. After decades of work to denormalise smoking, these findings raise the question of whether e-cigarettes are renormalising smoking. PMID:24366581

Generic calculation of two-body partial decay widths at the full one-loop level

NASA Astrophysics Data System (ADS)

Goodsell, Mark D.; Liebler, Stefan; Staub, Florian

2017-11-01

We describe a fully generic implementation of two-body partial decay widths at the full one-loop level in the SARAH and SPheno framework compatible with most supported models. It incorporates fermionic decays to a fermion and a scalar or a gauge boson as well as scalar decays into two fermions, two gauge bosons, two scalars or a scalar and a gauge boson. We present the relevant generic expressions for virtual and real corrections. Whereas wave-function corrections are determined from on-shell conditions, the parameters of the underlying model are by default renormalised in a \\overline{ {DR}} (or \\overline{ {MS}}) scheme. However, the user can also define model-specific counter-terms. As an example we discuss the renormalisation of the electric charge in the Thomson limit for top-quark decays in the standard model. One-loop-induced decays are also supported. The framework additionally allows the addition of mass and mixing corrections induced at higher orders for the involved external states. We explain our procedure to cancel infrared divergences for such cases, which is achieved through an infrared counter-term taking into account corrected Goldstone boson vertices. We compare our results for sfermion, gluino and Higgs decays in the minimal supersymmetric standard model (MSSM) against the public codes SFOLD, FVSFOLD and HFOLD and explain observed differences. Radiatively induced gluino and neutralino decays are compared against the original implementation in SPheno in the MSSM. We exactly reproduce the results of the code CNNDecays for decays of neutralinos and charginos in R-parity violating models. The new version SARAH 4.11.0 by default includes the calculation of two-body decay widths at the full one-loop level. Current limitations for certain model classes are described.

A system dynamics modelling approach to assess the impact of launching a new nicotine product on population health outcomes.

PubMed

Hill, Andrew; Camacho, Oscar M

2017-06-01

In 2012 the US FDA suggested the use of mathematical models to assess the impact of releasing new nicotine or tobacco products on population health outcomes. A model based on system dynamics methodology was developed to project the potential effects of a new nicotine product at a population level. A model representing traditional smoking populations (never, current and former smokers) and calibrated using historical data was extended to a two-product model by including electronic cigarettes use statuses. Smoking mechanisms, such as product initiation, switching, transition to dual use, and cessation, were represented as flows between smoking statuses (stocks) and the potential effect of smoking renormalisation through a feedback system. Mortality over a 50-year period (2000-2050) was the health outcome of interest, and was compared between two scenarios, with and without e-cigarettes being introduced. The results suggest that by 2050, smoking prevalence in adults was 12.4% in the core model and 9.7% (including dual users) in the counterfactual. Smoking-related mortality was 8.4% and 8.1%, respectively. The results suggested an overall beneficial effect from launching e-cigarettes and that system dynamics could be a useful approach to assess the potential population health effects of nicotine products when epidemiological data are not available. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

The Chiral Separation Effect in quenched finite-density QCD

NASA Astrophysics Data System (ADS)

Puhr, Matthias; Buividovich, Pavel

2018-03-01

We present results of a study of the Chiral Separation Effect (CSE) in quenched finite-density QCD. Using a recently developed numerical method we calculate the conserved axial current for exactly chiral overlap fermions at finite density for the first time. We compute the anomalous transport coeffcient for the CSE in the confining and deconfining phase and investigate possible deviations from the universal value. In both phases we find that non-perturbative corrections to the CSE are absent and we reproduce the universal value for the transport coeffcient within small statistical errors. Our results suggest that the CSE can be used to determine the renormalisation factor of the axial current.

Zimmermann's forest formula, infrared divergences and the QCD beta function

NASA Astrophysics Data System (ADS)

Herzog, Franz

2018-01-01

We review Zimmermann's forest formula, which solves Bogoliubov's recursive R-operation for the subtraction of ultraviolet divergences in perturbative Quantum Field Theory. We further discuss a generalisation of the R-operation which subtracts besides ultraviolet also Euclidean infrared divergences. This generalisation, which goes under the name of the R*-operation, can be used efficiently to compute renormalisation constants. We will discuss several results obtained by this method with focus on the QCD beta function at five loops as well as the application to hadronic Higgs boson decay rates at N4LO. This article summarizes a talk given at the Wolfhart Zimmermann Memorial Symposium.

Orbital optimisation in the perfect pairing hierarchy: applications to full-valence calculations on linear polyacenes

NASA Astrophysics Data System (ADS)

Lehtola, Susi; Parkhill, John; Head-Gordon, Martin

2018-03-01

We describe the implementation of orbital optimisation for the models in the perfect pairing hierarchy. Orbital optimisation, which is generally necessary to obtain reliable results, is pursued at perfect pairing (PP) and perfect quadruples (PQ) levels of theory for applications on linear polyacenes, which are believed to exhibit strong correlation in the π space. While local minima and σ-π symmetry breaking solutions were found for PP orbitals, no such problems were encountered for PQ orbitals. The PQ orbitals are used for single-point calculations at PP, PQ and perfect hextuples (PH) levels of theory, both only in the π subspace, as well as in the full σπ valence space. It is numerically demonstrated that the inclusion of single excitations is necessary also when optimised orbitals are used. PH is found to yield good agreement with previously published density matrix renormalisation group data in the π space, capturing over 95% of the correlation energy. Full-valence calculations made possible by our novel, efficient code reveal that strong correlations are weaker when larger basis sets or active spaces are employed than in previous calculations. The largest full-valence PH calculations presented correspond to a (192e,192o) problem.

Non-universal Z‧ from fluxed GUTs

NASA Astrophysics Data System (ADS)

Crispim Romao, Miguel; King, Stephen F.; Leontaris, George K.

2018-07-01

We make a first systematic study of non-universal TeV scale neutral gauge bosons Z‧ arising naturally from a class of F-theory inspired models broken via SU (5) by flux. The phenomenological models we consider may originate from semi-local F-theory GUTs arising from a single E8 point of local enhancement, assuming the minimal Z2 monodromy in order to allow for a renormalisable top quark Yukawa coupling. We classify such non-universal anomaly-free U(1) ‧ models requiring a minimal low energy spectrum and also allowing for a vector-like family. We discuss to what extent such models can account for the anomalous B-decay ratios RK and RK*.

Charge dynamics of the antiferromagnetically ordered Mott insulator

NASA Astrophysics Data System (ADS)

Han, Xing-Jie; Liu, Yu; Liu, Zhi-Yuan; Li, Xin; Chen, Jing; Liao, Hai-Jun; Xie, Zhi-Yuan; Normand, B.; Xiang, Tao

2016-10-01

We introduce a slave-fermion formulation in which to study the charge dynamics of the half-filled Hubbard model on the square lattice. In this description, the charge degrees of freedom are represented by fermionic holons and doublons and the Mott-insulating characteristics of the ground state are the consequence of holon-doublon bound-state formation. The bosonic spin degrees of freedom are described by the antiferromagnetic Heisenberg model, yielding long-ranged (Néel) magnetic order at zero temperature. Within this framework and in the self-consistent Born approximation, we perform systematic calculations of the average double occupancy, the electronic density of states, the spectral function and the optical conductivity. Qualitatively, our method reproduces the lower and upper Hubbard bands, the spectral-weight transfer into a coherent quasiparticle band at their lower edges and the renormalisation of the Mott gap, which is associated with holon-doublon binding, due to the interactions of both quasiparticle species with the magnons. The zeros of the Green function at the chemical potential give the Luttinger volume, the poles of the self-energy reflect the underlying quasiparticle dispersion with a spin-renormalised hopping parameter and the optical gap is directly related to the Mott gap. Quantitatively, the square-lattice Hubbard model is one of the best-characterised problems in correlated condensed matter and many numerical calculations, all with different strengths and weaknesses, exist with which to benchmark our approach. From the semi-quantitative accuracy of our results for all but the weakest interaction strengths, we conclude that a self-consistent treatment of the spin-fluctuation effects on the charge degrees of freedom captures all the essential physics of the antiferromagnetic Mott-Hubbard insulator. We remark in addition that an analytical approximation with these properties serves a vital function in developing a full understanding of the fundamental physics of the Mott state, both in the antiferromagnetic insulator and at finite temperatures and dopings.

BOOK REVIEW: Supersymmetry: Theory, Experiment and Cosmology

NASA Astrophysics Data System (ADS)

Jones, Tim

2008-06-01

This volume presents a comprehensive introduction to supersymmetry, concentrating mainly on the Minimal Supersymmetric Standard Model (MSSM) and its possible embedding in a grand unified theory, but also including material on supergravity, non-perturbative aspects of supersymmetry, string theory and cosmology. There is an excellent self-contained appendix on the standard model which could be read first; other appendices provide introductions to spinor representations of the Lorentz group, superfields, and cosmology, and there is a short appendix listing the MSSM renormalisation group beta-functions. The appendices in fact occupy over a quarter of the volume. Substantial knowledge of quantum field theory is required of the reader; and also a working knowledge of group theory as employed in the construction of particle physics models: while there is some useful material on this in the section on grand unification, an appendix on it might perhaps have been a useful addition. Supersymmetry is introduced via the particle physicist's concern with the hierarchy problem and developed in the component formalism beginning with the Wess Zumino model and proceeding to supersymmetric gauge theories. The treatment is detailed and authoritative; the author has 25 years of high-level research experience in the area and it shows. The level of presentation is high, and difficult concepts are explained clearly. The examples and associated hints are excellent. One topic I would have liked to see more on is the renormalisation of supersymmetric theories; presentation of the explicit calculation of the anomalous dimension of a chiral superfield (gamma) at one loop for at least the Wess Zumino model might perhaps have been pedagogically useful. Associated, perhaps, with this omission is an inconsistency in the definition of gamma; the sign of gamma in the treatment in section 8.3.2 clearly differs from its sign in the appendix section E.3. In the text the formalism of supersymmetry is developed mainly in terms of four-component Majorana spinors, while use of two-component spinors is relegated to the appendices, where the author valiantly presents results in a manner facilitating translation between different conventions, which is very useful. In the main text, however, the reader might even be led to feel that the Wess Zumino model actions for a Majorana fermion on the one hand and a chiral fermion on the other are different theories, whereas in fact one can of course be rewritten as the other. I feel that the two-component formalism could have been profitably introduced at an earlier stage and used more consistently. The book concludes with discussions of two 'challenges' to supersymmetry, as presented by the flavour problem and the cosmological constant. These are full of interesting and (indeed) challenging material, at the frontier of present-day research. This is an excellent and up-to-date book, and very timely vis-à-vis the Large Hadron Collider. It would make an excellent graduate text for graduate students in particle theory. 'Road-maps' for high energy experimentalists and cosmologists are also provided; however for experimentalists a text with more in the way of, for example, explicit calculations of cross-sections would probably be more useful. To summarise: minor quibbles aside, a fine book with a wealth of exciting material, and to be thoroughly recommended to any theoretically-inclined graduate student who has done a field theory course and wants to really get to grips with any aspect of supersymmetry.

UNO DMRG CASCI calculations of effective exchange integrals for m-phenylene-bis-methylene spin clusters

NASA Astrophysics Data System (ADS)

Kawakami, Takashi; Sano, Shinsuke; Saito, Toru; Sharma, Sandeep; Shoji, Mitsuo; Yamada, Satoru; Takano, Yu; Yamanaka, Shusuke; Okumura, Mitsutaka; Nakajima, Takahito; Yamaguchi, Kizashi

2017-09-01

Theoretical examinations of the ferromagnetic coupling in the m-phenylene-bis-methylene molecule and its oligomer were carried out. These systems are good candidates for exchange-coupled systems to investigate strong electronic correlations. We studied effective exchange integrals (J), which indicated magnetic coupling between interacting spins in these species. First, theoretical calculations based on a broken-symmetry single-reference procedure, i.e. the UHF, UMP2, UMP4, UCCSD(T) and UB3LYP methods, were carried out with a GAUSSIAN program code under an SR wave function. From these results, the J value by the UHF method was largely positive because of the strong ferromagnetic spin polarisation effect. The J value by the UCCSD(T) and UB3LYP methods improved an overestimation problem by correcting the dynamical electronic correlation. Next, magnetic coupling among these spins was studied using the CAS-based method of the symmetry-adapted multireference methods procedure. Thus, the UNO DMRG CASCI (UNO, unrestricted natural orbital; DMRG, density matrix renormalised group; CASCI, complete active space configuration interaction) method was mainly employed with a combination of ORCA and BLOCK program codes. DMRG CASCI calculations in valence electron counting, which included all orbitals to full valence CI, provided the most reliable result, and support the UB3LYP method for extended systems.

Riding on irrelevant operators

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

De Rham, Claudia; Ribeiro, Raquel H., E-mail: Claudia.deRham@case.edu, E-mail: RaquelHRibeiro@case.edu

2014-11-01

We investigate the stability of a class of derivative theories known as P(X) and Galileons against corrections generated by quantum effects. We use an exact renormalisation group approach to argue that these theories are stable under quantum corrections at all loops in regions where the kinetic term is large compared to the strong coupling scale. This is the regime of interest for screening or Vainshtein mechanisms, and in inflationary models that rely on large kinetic terms. Next, we clarify the role played by the symmetries. While symmetries protect the form of the quantum corrections, theories equipped with more symmetries domore » not necessarily have a broader range of scales for which they are valid. We show this by deriving explicitly the regime of validity of the classical solutions for P(X) theories including Dirac-Born-Infeld (DBI) models, both in generic and for specific background field configurations. Indeed, we find that despite the existence of an additional symmetry, the DBI effective field theory has a regime of validity similar to an arbitrary P(X) theory. We explore the implications of our results for both early and late universe contexts. Conversely, when applied to static and spherical screening mechanisms, we deduce that the regime of validity of typical power-law P(X) theories is much larger than that of DBI.« less

Efficient electronic structure theory via hierarchical scale-adaptive coupled-cluster formalism: I. Theory and computational complexity analysis

NASA Astrophysics Data System (ADS)

Lyakh, Dmitry I.

2018-03-01

A novel reduced-scaling, general-order coupled-cluster approach is formulated by exploiting hierarchical representations of many-body tensors, combined with the recently suggested formalism of scale-adaptive tensor algebra. Inspired by the hierarchical techniques from the renormalisation group approach, H/H2-matrix algebra and fast multipole method, the computational scaling reduction in our formalism is achieved via coarsening of quantum many-body interactions at larger interaction scales, thus imposing a hierarchical structure on many-body tensors of coupled-cluster theory. In our approach, the interaction scale can be defined on any appropriate Euclidean domain (spatial domain, momentum-space domain, energy domain, etc.). We show that the hierarchically resolved many-body tensors can reduce the storage requirements to O(N), where N is the number of simulated quantum particles. Subsequently, we prove that any connected many-body diagram consisting of a finite number of arbitrary-order tensors, e.g. an arbitrary coupled-cluster diagram, can be evaluated in O(NlogN) floating-point operations. On top of that, we suggest an additional approximation to further reduce the computational complexity of higher order coupled-cluster equations, i.e. equations involving higher than double excitations, which otherwise would introduce a large prefactor into formal O(NlogN) scaling.

E-cigarettes, a safer alternative for teenagers? A UK focus group study of teenagers' views.

PubMed

Hilton, Shona; Weishaar, Heide; Sweeting, Helen; Trevisan, Filippo; Katikireddi, Srinivasa Vittal

2016-11-16

Concerns exist that e-cigarettes may be a gateway to traditional cigarettes and/or (re)normalise teenage smoking. This qualitative study explores how teenagers in the UK currently perceive e-cigarettes and how and why they do or do not use them. 16 focus groups were conducted across the UK between November 2014 and February 2015, with 83 teenagers aged 14-17. All discussions were digitally recorded, transcribed verbatim, imported into NVivo 10 and thematically analysed. Teenagers generally agreed that e-cigarettes are useful products for smokers, including teenage smokers, to quit or reduce traditional cigarette use. Concerns were expressed about lack of information on their precise ingredients and any unknown risks for users and bystanders. However, teenagers typically viewed e-cigarettes as substantially less harmful than traditional cigarettes. They perceived e-cigarettes as attractive, with products described as 'fun' and having 'great flavourings'. Seeing websites or social media featuring e-cigarettes, especially YouTube 'vaping tricks', prompted some experimentation and imitation. E-cigarettes were used in a variety of situations, including at parties or when they could not smoke traditional cigarettes. A very few participants suggested covert use was a possibility and that e-cigarettes might help maintain a fledgling nicotine habit. Teenagers support the use of e-cigarettes as smoking cessation aids for established adult smokers. However, they engage with these products differently from adults, with the novel hypothesis that covert use could potentially reinforce traditional cigarette smoking requiring further investigation. Policy responses should more clearly meet the needs of young people, as well as helping established adult smokers. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Resurgent transseries & Dyson–Schwinger equations

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

Klaczynski, Lutz, E-mail: klacz@mathematik.hu-berlin.de

2016-09-15

We employ resurgent transseries as algebraic tools to investigate two self-consistent Dyson–Schwinger equations, one in Yukawa theory and one in quantum electrodynamics. After a brief but pedagogical review, we derive fixed point equations for the associated anomalous dimensions and insert a moderately generic log-free transseries ansatz to study the possible strictures imposed. While proceeding in various stages, we develop an algebraic method to keep track of the transseries’ coefficients. We explore what conditions must be violated in order to stay clear of fixed point theorems to eschew a unique solution, if so desired, as we explain. An interesting finding ismore » that the flow of data between the different sectors of the transseries shows a pattern typical of resurgence, i.e. the phenomenon that the perturbative sector of the transseries talks to the nonperturbative ones in a one-way fashion. However, our ansatz is not exotic enough as it leads to trivial solutions with vanishing nonperturbative sectors, even when logarithmic monomials are included. We see our result as a harbinger of what future work might reveal about the transseries representations of observables in fully renormalised four-dimensional quantum field theories and adduce a tentative yet to our mind weighty argument as to why one should not expect otherwise. This paper is considerably self-contained. Readers with little prior knowledge are let in on the basic reasons why perturbative series in quantum field theory eventually require an upgrade to transseries. Furthermore, in order to acquaint the reader with the language utilised extensively in this work, we also provide a concise mathematical introduction to grid-based transseries.« less

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

Ellis, John; Olive, Keith A.; Velasco-Sevilla, Liliana

We consider supersymmetric grand unified theories with soft supersymmetry-breaking scalar masses m 0 specified above the GUT scale (super-GUTs) and patterns of Yukawa couplings motivated by upper limits on flavour-changing interactions beyond the Standard Model. If the scalar masses are smaller than the gaugino masses m 1/2, as is expected in no-scale models, the dominant effects of renormalisation between the input scale and the GUT scale are generally expected to be those due to the gauge couplings, which are proportional to m 1/2 and generation independent. In this case, the input scalar masses m 0 may violate flavour maximally, amore » scenario we call MaxSFV, and there is no supersymmetric flavour problem. As a result, we illustrate this possibility within various specific super-GUT scenarios that are deformations of no-scale gravity« less

Combining the GW formalism with the polarizable continuum model: A state-specific non-equilibrium approach

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

Duchemin, Ivan, E-mail: ivan.duchemin@cea.fr; Jacquemin, Denis; Institut Universitaire de France, 1 rue Descartes, 75005 Paris Cedex 5

We have implemented the polarizable continuum model within the framework of the many-body Green’s function GW formalism for the calculation of electron addition and removal energies in solution. The present formalism includes both ground-state and non-equilibrium polarization effects. In addition, the polarization energies are state-specific, allowing to obtain the bath-induced renormalisation energy of all occupied and virtual energy levels. Our implementation is validated by comparisons with ΔSCF calculations performed at both the density functional theory and coupled-cluster single and double levels for solvated nucleobases. The present study opens the way to GW and Bethe-Salpeter calculations in disordered condensed phases ofmore » interest in organic optoelectronics, wet chemistry, and biology.« less

Higgs production in association with a top-antitop pair in the Standard Model Effective Field Theory at NLO in QCD

DOE PAGES

Maltoni, Fabio; Vryonidou, Eleni; Zhang, Cen

2016-10-24

We present the results of the computation of the next-to-leading order QCD corrections to the production cross section of a Higgs boson in association with a top-antitop pair at the LHC, including the three relevant dimension-six operators (O tφ, O φG, O tG) of the standard model effective field theory. These operators also contribute to the production of Higgs bosons in loop-induced processes at the LHC, such as inclusive Higgs, Hj and HH production, and modify the Higgs decay branching ratios for which we also provide predictions. We perform a detailed study of the cross sections and their uncertainties atmore » the total as well as differential level and of the structure of the effective field theory at NLO including renormalisation group effects. Finally, we show how the combination of information coming from measurements of these production processes will allow to constrain the three operators at the current and future LHC runs. Finally, our results lead to a significant improvement of the accuracy and precision of the deviations expected from higher-dimensional operators in the SM in both the top-quark and the Higgs-boson sectors and provide a necessary ingredient for performing a global EFT fit to the LHC data at NLO accuracy.« less

Higgs production in association with a top-antitop pair in the Standard Model Effective Field Theory at NLO in QCD

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

Maltoni, Fabio; Vryonidou, Eleni; Zhang, Cen

We present the results of the computation of the next-to-leading order QCD corrections to the production cross section of a Higgs boson in association with a top-antitop pair at the LHC, including the three relevant dimension-six operators (O tφ, O φG, O tG) of the standard model effective field theory. These operators also contribute to the production of Higgs bosons in loop-induced processes at the LHC, such as inclusive Higgs, Hj and HH production, and modify the Higgs decay branching ratios for which we also provide predictions. We perform a detailed study of the cross sections and their uncertainties atmore » the total as well as differential level and of the structure of the effective field theory at NLO including renormalisation group effects. Finally, we show how the combination of information coming from measurements of these production processes will allow to constrain the three operators at the current and future LHC runs. Finally, our results lead to a significant improvement of the accuracy and precision of the deviations expected from higher-dimensional operators in the SM in both the top-quark and the Higgs-boson sectors and provide a necessary ingredient for performing a global EFT fit to the LHC data at NLO accuracy.« less

Maximal sfermion flavour violation in super-GUTs

DOE PAGES

Ellis, John; Olive, Keith A.; Velasco-Sevilla, Liliana

2016-10-20

We consider supersymmetric grand unified theories with soft supersymmetry-breaking scalar masses m 0 specified above the GUT scale (super-GUTs) and patterns of Yukawa couplings motivated by upper limits on flavour-changing interactions beyond the Standard Model. If the scalar masses are smaller than the gaugino masses m 1/2, as is expected in no-scale models, the dominant effects of renormalisation between the input scale and the GUT scale are generally expected to be those due to the gauge couplings, which are proportional to m 1/2 and generation independent. In this case, the input scalar masses m 0 may violate flavour maximally, amore » scenario we call MaxSFV, and there is no supersymmetric flavour problem. As a result, we illustrate this possibility within various specific super-GUT scenarios that are deformations of no-scale gravity« less

Towards a complete Δ(27) × SO(10) GUT of flavour

NASA Astrophysics Data System (ADS)

Björkeroth, Fredrik

2017-09-01

We propose a renormalisable model based on Δ(27) family symmetry with an SO(10) grand unified theory (GUT) leading to a novel form of spontaneous geometrical CP violation. The symmetries are broken close to the GUT breaking scale to yield the minimal supersymmetric standard model with standard R-parity. Low-scale Yukawa structure is dictated by the coupling of matter to Δ(27) antitriplets \\bar φ whose vacuum expectation values are aligned in the CSD3 directions by the superpotential. Light physical Majorana neutrinos masses emerge from the seesaw mechanism within SO(10). The model predicts a normal neutrino mass hierarchy with the best-fit lightest neutrino mass m 1 ∼ 0.3 meV, CP-violating oscillation phase δl ≈ 280° and the remaining neutrino parameters all within 1σ of their best-fit experimental values.

Percolation properties of 3-D multiscale pore networks: how connectivity controls soil filtration processes

NASA Astrophysics Data System (ADS)

Perrier, E. M. A.; Bird, N. R. A.; Rieutord, T. B.

2010-04-01

Quantifying the connectivity of pore networks is a key issue not only for modelling fluid flow and solute transport in porous media but also for assessing the ability of soil ecosystems to filter bacteria, viruses and any type of living microorganisms as well inert particles which pose a contamination risk. Straining is the main mechanical component of filtration processes: it is due to size effects, when a given soil retains a conveyed entity larger than the pores through which it is attempting to pass. We postulate that the range of sizes of entities which can be trapped inside soils has to be associated with the large range of scales involved in natural soil structures and that information on the pore size distribution has to be complemented by information on a Critical Filtration Size (CFS) delimiting the transition between percolating and non percolating regimes in multiscale pore networks. We show that the mass fractal dimensions which are classically used in soil science to quantify scaling laws in observed pore size distributions can also be used to build 3-D multiscale models of pore networks exhibiting such a critical transition. We extend to the 3-D case a new theoretical approach recently developed to address the connectivity of 2-D fractal networks (Bird and Perrier, 2009). Theoretical arguments based on renormalisation functions provide insight into multi-scale connectivity and a first estimation of CFS. Numerical experiments on 3-D prefractal media confirm the qualitative theory. These results open the way towards a new methodology to estimate soil filtration efficiency from the construction of soil structural models to be calibrated on available multiscale data.

Percolation properties of 3-D multiscale pore networks: how connectivity controls soil filtration processes

NASA Astrophysics Data System (ADS)

Perrier, E. M. A.; Bird, N. R. A.; Rieutord, T. B.

2010-10-01

Quantifying the connectivity of pore networks is a key issue not only for modelling fluid flow and solute transport in porous media but also for assessing the ability of soil ecosystems to filter bacteria, viruses and any type of living microorganisms as well inert particles which pose a contamination risk. Straining is the main mechanical component of filtration processes: it is due to size effects, when a given soil retains a conveyed entity larger than the pores through which it is attempting to pass. We postulate that the range of sizes of entities which can be trapped inside soils has to be associated with the large range of scales involved in natural soil structures and that information on the pore size distribution has to be complemented by information on a critical filtration size (CFS) delimiting the transition between percolating and non percolating regimes in multiscale pore networks. We show that the mass fractal dimensions which are classically used in soil science to quantify scaling laws in observed pore size distributions can also be used to build 3-D multiscale models of pore networks exhibiting such a critical transition. We extend to the 3-D case a new theoretical approach recently developed to address the connectivity of 2-D fractal networks (Bird and Perrier, 2009). Theoretical arguments based on renormalisation functions provide insight into multi-scale connectivity and a first estimation of CFS. Numerical experiments on 3-D prefractal media confirm the qualitative theory. These results open the way towards a new methodology to estimate soil filtration efficiency from the construction of soil structural models to be calibrated on available multiscale data.

E-cigarettes, a safer alternative for teenagers? A UK focus group study of teenagers' views

PubMed Central

Weishaar, Heide; Sweeting, Helen; Trevisan, Filippo; Katikireddi, Srinivasa Vittal

2016-01-01

Objective Concerns exist that e-cigarettes may be a gateway to traditional cigarettes and/or (re)normalise teenage smoking. This qualitative study explores how teenagers in the UK currently perceive e-cigarettes and how and why they do or do not use them. Design 16 focus groups were conducted across the UK between November 2014 and February 2015, with 83 teenagers aged 14–17. All discussions were digitally recorded, transcribed verbatim, imported into NVivo 10 and thematically analysed. Results Teenagers generally agreed that e-cigarettes are useful products for smokers, including teenage smokers, to quit or reduce traditional cigarette use. Concerns were expressed about lack of information on their precise ingredients and any unknown risks for users and bystanders. However, teenagers typically viewed e-cigarettes as substantially less harmful than traditional cigarettes. They perceived e-cigarettes as attractive, with products described as ‘fun’ and having ‘great flavourings’. Seeing websites or social media featuring e-cigarettes, especially YouTube ‘vaping tricks’, prompted some experimentation and imitation. E-cigarettes were used in a variety of situations, including at parties or when they could not smoke traditional cigarettes. A very few participants suggested covert use was a possibility and that e-cigarettes might help maintain a fledgling nicotine habit. Conclusions Teenagers support the use of e-cigarettes as smoking cessation aids for established adult smokers. However, they engage with these products differently from adults, with the novel hypothesis that covert use could potentially reinforce traditional cigarette smoking requiring further investigation. Policy responses should more clearly meet the needs of young people, as well as helping established adult smokers. PMID:27852721

The two and three-loop matter bispectrum in perturbation theories

NASA Astrophysics Data System (ADS)

Lazanu, Andrei; Liguori, Michele

2018-04-01

We evaluate for the first time the dark matter bispectrum of large-scale structure at two loops in the Standard Perturbation Theory and at three loops in the Renormalised Perturbation Theory (MPTBREEZE formalism), removing in each case the leading divergences in the integrals in order to make them infrared-safe. We show that the Standard Perturbation Theory at two loops can be employed to model the matter bispectrum further into the quasi-nonlinear regime compared to the one loop, up to kmax ~ 0.1 h/Mpc at z = 0, but without reaching a high level of accuracy. In the case of the MPTBREEZE method, we show that its bispectra decay at smaller and smaller scales with increasing loop order, but with smaller improvements decreases with loop order. At three loops, this model predicts the bispectrum accurately up to scales kmax ~ 0.17 h/Mpc at z = 0 and kmax ~ 0.24 h/Mpc at z = 1.

Gluon-fusion Higgs production in the Standard Model Effective Field Theory

NASA Astrophysics Data System (ADS)

Deutschmann, Nicolas; Duhr, Claude; Maltoni, Fabio; Vryonidou, Eleni

2017-12-01

We provide the complete set of predictions needed to achieve NLO accuracy in the Standard Model Effective Field Theory at dimension six for Higgs production in gluon fusion. In particular, we compute for the first time the contribution of the chromomagnetic operator {\\overline{Q}}_LΦ σ {q}_RG at NLO in QCD, which entails two-loop virtual and one-loop real contributions, as well as renormalisation and mixing with the Yukawa operator {Φ}^{\\dagger}Φ{\\overline{Q}}_LΦ {q}_R and the gluon-fusion operator Φ†Φ GG. Focusing on the top-quark-Higgs couplings, we consider the phenomenological impact of the NLO corrections in constraining the three relevant operators by implementing the results into the M adG raph5_ aMC@NLO frame-work. This allows us to compute total cross sections as well as to perform event generation at NLO that can be directly employed in experimental analyses.

A simple and accurate method for calculation of the structure factor of interacting charged spheres.

PubMed

Wu, Chu; Chan, Derek Y C; Tabor, Rico F

2014-07-15

Calculation of the structure factor of a system of interacting charged spheres based on the Ginoza solution of the Ornstein-Zernike equation has been developed and implemented on a stand-alone spreadsheet. This facilitates direct interactive numerical and graphical comparisons between experimental structure factors with the pioneering theoretical model of Hayter-Penfold that uses the Hansen-Hayter renormalisation correction. The method is used to fit example experimental structure factors obtained from the small-angle neutron scattering of a well-characterised charged micelle system, demonstrating that this implementation, available in the supplementary information, gives identical results to the Hayter-Penfold-Hansen approach for the structure factor, S(q) and provides direct access to the pair correlation function, g(r). Additionally, the intermediate calculations and outputs can be readily accessed and modified within the familiar spreadsheet environment, along with information on the normalisation procedure. Copyright © 2014 Elsevier Inc. All rights reserved.

Leading-twist parton distribution amplitudes of S-wave heavy-quarkonia

DOE PAGES

Ding, Minghui; Gao, Fei; Chang, Lei; ...

2015-12-08

Here, the leading-twist parton distribution amplitudes (PDAs) of ground-state 1S 0 and 3S 1 cc¯- and bb¯quarkonia are calculated using a symmetry-preserving continuum treatment of the meson bound-state problem which unifies the properties of these heavy-quark systems with those of light-quark bound-states, including QCD's Goldstone modes. Analysing the evolution of 1S 0 and 3S 1 PDAs with current-quark mass, m^ q, increasing away from the chiral limit, it is found that in all cases there is a value of m^ q for which the PDA matches the asymptotic form appropriate to QCD's conformal limit and hence is insensitive to changesmore » in renormalisation scale, ζ. This mass lies just above that associated with the s-quark. At current-quark masses associated with heavy-quarkonia, on the other hand, the PDAs are piecewise convex–concave–convex.« less

Controlled flavour changing neutral couplings in two Higgs Doublet models

NASA Astrophysics Data System (ADS)

Alves, Joao M.; Botella, Francisco J.; Branco, Gustavo C.; Cornet-Gomez, Fernando; Nebot, Miguel

2017-09-01

We propose a class of two Higgs doublet models where there are flavour changing neutral currents (FCNC) at tree level, but under control due to the introduction of a discrete symmetry in the full Lagrangian. It is shown that in this class of models, one can have simultaneously FCNC in the up and down sectors, in contrast to the situation encountered in the renormalisable and minimal flavour violating 2HDM models put forward by Branco et al. (Phys Lett B 380:119, 1996). The intensity of FCNC is analysed and it is shown that in this class of models one can respect all the strong constraints from experiment without unnatural fine-tuning. It is pointed out that the additional sources of flavour and CP violation are such that they can enhance significantly the generation of the Bbaryon asymmetry of the Universe, with respect to the standard model.

Hand-waving and interpretive dance: an introductory course on tensor networks

NASA Astrophysics Data System (ADS)

Bridgeman, Jacob C.; Chubb, Christopher T.

2017-06-01

The curse of dimensionality associated with the Hilbert space of spin systems provides a significant obstruction to the study of condensed matter systems. Tensor networks have proven an important tool in attempting to overcome this difficulty in both the numerical and analytic regimes. These notes form the basis for a seven lecture course, introducing the basics of a range of common tensor networks and algorithms. In particular, we cover: introductory tensor network notation, applications to quantum information, basic properties of matrix product states, a classification of quantum phases using tensor networks, algorithms for finding matrix product states, basic properties of projected entangled pair states, and multiscale entanglement renormalisation ansatz states. The lectures are intended to be generally accessible, although the relevance of many of the examples may be lost on students without a background in many-body physics/quantum information. For each lecture, several problems are given, with worked solutions in an ancillary file.

Axial vector Z‧ and anomaly cancellation

NASA Astrophysics Data System (ADS)

Ismail, Ahmed; Keung, Wai-Yee; Tsao, Kuo-Hsing; Unwin, James

2017-05-01

Whilst the prospect of new Z‧ gauge bosons with only axial couplings to the Standard Model (SM) fermions is widely discussed, examples of anomaly-free renormalisable models are lacking in the literature. We look to remedy this by constructing several motivated examples. Specifically, we consider axial vectors which couple universally to all SM fermions, as well as those which are generation-specific, leptophilic, and leptophobic. Anomaly cancellation typically requires the presence of new coloured and charged chiral fermions, and we argue that in a large class of models masses of these new states are expected to be comparable to that of the axial vector. Finally, an axial vector mediator could provide a portal between SM and hidden sector states, and we also consider the possibility that the axial vector couples to dark matter. If the dark matter relic density is set due to freeze-out via the axial vector, this strongly constrains the parameter space.

Dynamics of superconducting qubits in open transmission lines

NASA Astrophysics Data System (ADS)

Juan Jose, Garcia-Ripoll; Zueco, David; Porras, Diego; Peropadre, Borja

2014-03-01

The time and space resolved dynamics of a superconducting qubit with an Ohmic coupling to propagating 1D photons is studied, from weak coupling to the ultrastrong coupling regime (USC). A nonperturbative study based on Matrix Product States (MPS) shows the following results: (i) The ground state of the combined systems contains excitations of both the qubit and the surrounding bosonic field. (ii) An initially excited qubit equilibrates through spontaneous emission to a state, which under certain conditions, is locally close to that ground state, both in the qubit and the field. (iii) The resonances of the combined qubit-photon system match those of the spontaneous emission process and also the predictions of the adiabatic renormalisation. These results set the foundations for future studies and engineering of the interactions between superconducting qubits and propagating photons, as well as the design of photon-photon interactions based on artificial materials built from these qubits.

Transverse momentum in double parton scattering: factorisation, evolution and matching

NASA Astrophysics Data System (ADS)

Buffing, Maarten G. A.; Diehl, Markus; Kasemets, Tomas

2018-01-01

We give a description of double parton scattering with measured transverse momenta in the final state, extending the formalism for factorisation and resummation developed by Collins, Soper and Sterman for the production of colourless particles. After a detailed analysis of their colour structure, we derive and solve evolution equations in rapidity and renormalisation scale for the relevant soft factors and double parton distributions. We show how in the perturbative regime, transverse momentum dependent double parton distributions can be expressed in terms of simpler nonperturbative quantities and compute several of the corresponding perturbative kernels at one-loop accuracy. We then show how the coherent sum of single and double parton scattering can be simplified for perturbatively large transverse momenta, and we discuss to which order resummation can be performed with presently available results. As an auxiliary result, we derive a simple form for the square root factor in the Collins construction of transverse momentum dependent parton distributions.

Neutron radiation damage studies in the structural materials of a 500 MWe fast breeder reactor using DPA cross-sections from ENDF / B-VII.1

NASA Astrophysics Data System (ADS)

Saha, Uttiyoarnab; Devan, K.; Bachchan, Abhitab; Pandikumar, G.; Ganesan, S.

2018-04-01

The radiation damage in the structural materials of a 500 MWe Indian prototype fast breeder reactor (PFBR) is re-assessed by computing the neutron displacement per atom (dpa) cross-sections from the recent nuclear data library evaluated by the USA, ENDF / B-VII.1, wherein revisions were taken place in the new evaluations of basic nuclear data because of using the state-of-the-art neutron cross-section experiments, nuclear model-based predictions and modern data evaluation techniques. An indigenous computer code, computation of radiation damage (CRaD), is developed at our centre to compute primary-knock-on atom (PKA) spectra and displacement cross-sections of materials both in point-wise and any chosen group structure from the evaluated nuclear data libraries. The new radiation damage model, athermal recombination-corrected displacement per atom (arc-dpa), developed based on molecular dynamics simulations is also incorporated in our study. This work is the result of our earlier initiatives to overcome some of the limitations experienced while using codes like RECOIL, SPECTER and NJOY 2016, to estimate radiation damage. Agreement of CRaD results with other codes and ASTM standard for Fe dpa cross-section is found good. The present estimate of total dpa in D-9 steel of PFBR necessitates renormalisation of experimental correlations of dpa and radiation damage to ensure consistency of damage prediction with ENDF / B-VII.1 library.

[The effects of carbogen inhalation on microvascular within lateral wall of cochlear following acute acoustic trauma].

PubMed

Zhao, Jing; Sun, Jianjun; Kong, Weijia

2008-11-01

To explore the influence of carbogen on lateral wall microvascular of cochlear after acute acoustic trauma. Forty guinea pigs were divided into 4 groups: group A (noise damage), group B (carbogen inhalation), group C (noise damage + carbogen inhalation), and the control group without any treatment. The diameter of the column of RBCs (RBC column diameter, RBCCD), blood flow velocity (BFV) and blood flow states(BFS) in microvasculature were measured and described under microscope. The microvascular in group A demonstrated a blood flow in contrary direction, granuliform flow, and granular slow flow. The erythrocytes aggregated in the microvascular of the cochlea. The RBCCD decreased 12.1% compared with the control group (P < 0.05). The blood flow in group B showed a laminar flow or laminar granular flow, and the RBCCD increased 20.7% compared with the control group. The blood condition in group C was the same as the control group-laminar granular blood flow; the blood flow with contrary direction was less than group A, and the RBCCD was 17.4% lager than that of group A. Carbogen can dilate the RBCCD and increase the BFV in stria vascular. So carbogen can alleviate the harm from noise.

Observation of a hierarchy of modes in an interacting one-dimensional system

NASA Astrophysics Data System (ADS)

Ford, Christopher; Moreno, Maria; Jin, Yiqing; Tan, Wooi Kiat; Griffiths, Jon; Farrer, Ian; Jones, Geb; Anthore, Anne; Ritchie, David; Tsyplyatyev, Oleksandr; Schofield, Andrew

2015-03-01

Studying interacting fermions in 1D at high energy, we find a hierarchy in the spectral weights of the excitations theoretically and we observe evidence for second-level excitations experimentally. Diagonalising a model of fermions (without spin), we show that levels of the hierarchy are separated by powers of 2 /L2 , where  is a length-scale related to interactions and L is the system length. The first-level (strongest) excitations form a mode with parabolic dispersion, like that of a renormalised single particle. The second-level excitations produce a singular power-law line shape to the first-level mode and multiple power-laws at the spectral edge. We measure momentum-resolved tunneling of electrons (fermions with spin) from/to a wire formed within a GaAs heterostructure, which shows parabolic dispersion of the first-level mode and well-resolved spin-charge separation at low energy with appreciable interaction strength. We find structure resembling the second-level excitations, which dies away quite rapidly at high momentum.

Reference results for time-like evolution up to

NASA Astrophysics Data System (ADS)

Bertone, Valerio; Carrazza, Stefano; Nocera, Emanuele R.

2015-03-01

We present high-precision numerical results for time-like Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution in the factorisation scheme, for the first time up to next-to-next-to-leading order accuracy in quantum chromodynamics. First, we scrutinise the analytical expressions of the splitting functions available in the literature, in both x and N space, and check their mutual consistency. Second, we implement time-like evolution in two publicly available, entirely independent and conceptually different numerical codes, in x and N space respectively: the already existing APFEL code, which has been updated with time-like evolution, and the new MELA code, which has been specifically developed to perform the study in this work. Third, by means of a model for fragmentation functions, we provide results for the evolution in different factorisation schemes, for different ratios between renormalisation and factorisation scales and at different final scales. Our results are collected in the format of benchmark tables, which could be used as a reference for global determinations of fragmentation functions in the future.

Supersymmetric and non-supersymmetric models without catastrophic Goldstone bosons

NASA Astrophysics Data System (ADS)

Braathen, Johannes; Goodsell, Mark D.; Staub, Florian

2017-11-01

The calculation of the Higgs mass in general renormalisable field theories has been plagued by the so-called "Goldstone Boson Catastrophe," where light (would-be) Goldstone bosons give infra-red divergent loop integrals. In supersymmetric models, previous approaches included a workaround that ameliorated the problem for most, but not all, parameter space regions; while giving divergent results everywhere for non-supersymmetric models! We present an implementation of a general solution to the problem in the public code SARAH, along with new calculations of some necessary loop integrals and generic expressions. We discuss the validation of our code in the Standard Model, where we find remarkable agreement with the known results. We then show new applications in Split SUSY, the NMSSM, the Two-Higgs-Doublet Model, and the Georgi-Machacek model. In particular, we take some first steps to exploring where the habit of using tree-level mass relations in non-supersymmetric models breaks down, and show that the loop corrections usually become very large well before naive perturbativity bounds are reached.

Effect of age on cerebral blood flow during hypothermic cardiopulmonary bypass

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

Brusino, F.G.; Reves, J.G.; Smith, L.R.

1989-04-01

Cerebral blood flow was measured in 20 patients by xenon 133 clearance methodology during nonpulsatile hypothermic cardiopulmonary bypass to determine the effect of age on regional cerebral blood flow during these conditions. Measurements of cerebral blood flow at varying perfusion pressures were made in patients arbitrarily divided into two age groups at nearly identical nasopharyngeal temperature, hematocrit value, and carbon dioxide tension and with equal cardiopulmonary bypass flows of 1.6 L/min/m2. The range of mean arterial pressure was 30 to 110 mm Hg for group I (less than or equal to 50 years of age) and 20 to 90 mmmore » Hg for group II (greater than or equal to 65 years of age). There was no significant difference (p = 0.32) between the mean arterial pressure in group I (54 +/- 28 mm Hg) and that in group II (43 +/- 21 mm Hg). The range of cerebral blood flow was 14.8 to 29.2 ml/100 gm/min for group I and 13.8 to 37.5 ml/100 gm/min for group II. There was no significant difference (p = 0.37) between the mean cerebral blood flow in group I (21.5 +/- 4.6 ml/100 gm/min) and group II (24.3 +/- 8.1 ml/100 gm/min). There was a poor correlation between mean arterial pressure and cerebral blood flow in both groups: group I, r = 0.16 (p = 0.67); group II, r = 0.5 (p = 0.12). In 12 patients, a second cerebral blood flow measurements was taken to determine the effect of mean arterial pressure on cerebral blood flow in the individual patient. Changes in mean arterial pressure did not correlate with changes in cerebral blood flow (p less than 0.90). We conclude that age does not alter cerebral blood flow and that cerebral blood flow autoregulation is preserved in elderly patients during nonpulsatile hypothermic cardiopulmonary bypass.« less

Group Flow and Group Genius

ERIC Educational Resources Information Center

Sawyer, Keith

2015-01-01

Keith Sawyer views the spontaneous collaboration of group creativity and improvisation actions as "group flow," which organizations can use to function at optimum levels. Sawyer establishes ideal conditions for group flow: group goals, close listening, complete concentration, being in control, blending egos, equal participation, knowing…

The mode of emplacement of Neogene flood basalts in eastern Iceland: Facies architecture and structure of simple aphyric basalt groups

NASA Astrophysics Data System (ADS)

Óskarsson, Birgir V.; Riishuus, Morten S.

2014-12-01

Simple flows (tabular) in the Neogene flood basalt sections of Iceland are described and their mode of emplacement assessed. The flows belong to three aphyric basalt groups: the Kumlafell group, the Hólmatindur group and the Hjálmadalur group. The groups can be traced over 50 km and originate in the Breiðdalur-Thingmuli volcanic zone. The groups have flow fields that display mixed volcanic facies architecture and can be classified after dominating type morphology. The Kumlafell and the Hólmatindur groups have predominantly simple flows of pāhoehoe and rubbly pāhoehoe morphologies with minor compound or lobate pāhoehoe flows. The Hjálmadalur group has simple flows of rubbly pāhoehoe, but also includes minor compound or lobate flows of rubble and 'a'ā. Simple flows are most common in the distal and medial areas from the vents, while more lobate flows in proximal areas. The simple flows are formed by extensive sheet lobes that are several kilometers long with plane-parallel contacts, some reaching thicknesses of ~ 40 m (aspect ratios < 0.01). They have overlapping contacts and are free of tubes and inflation structures. Their internal structure consists generally of a simple upper vesicular crust, a dense core and a thin basal vesicular zone. The brecciated flow-top is formed by clinker and crustal rubble, the clinker often welded or agglutinated. The simple flows erupted from seemingly short-lived fissures and have the characteristics of cooling-limited flows. We estimate the effusion rates to be ~ 105 m3/s for the simple flows of the Kumlafell and Hólmatindur groups and ~ 104 m3/s for the Hjálmadalur group. The longest flows advanced 15-20 km from the fissures, with lava streams of fast propagating flows inducing tearing and brecciation of the chilled crust. Compound or lobate areas appear to reflect areas of low effusion rates or the interaction of the lava with topographic barriers or wetlands, resulting in chaotic flowage. Slowing lobes with brecciated flow-tops developed into 'a'ā flows. The groups interdigitated with lava groups from the Reyðarfjörður volcanic zone to the east, and the exhumed Breiðdalur-Thingmuli volcanic zone which appear to have formed as a flank lineament parallel the main rift zone. Flood basalt volcanism in flank areas may support a mantle anomaly more pronounced and/or perhaps more widespread in the Neogene of Iceland than today. Eruptions of simple flows have not been observed in modern times and are significant for models of crustal accretion in Iceland and other Large Igneous Provinces.

Calibration of the Flow in the Test Section of the Research Wind Tunnel at DST Group

DTIC Science & Technology

2015-10-01

calibration of the flow in the test section of the Research Wind Tunnel at DST Group. The calibration was performed to establish the flow quality and to...of the Flow in the Test Section of the Research Wind Tunnel at DST Group Executive Summary The Defence Science and Technology Group (DST

Two-Year Outcomes with a Magnetically Levitated Cardiac Pump in Heart Failure.

PubMed

Mehra, Mandeep R; Goldstein, Daniel J; Uriel, Nir; Cleveland, Joseph C; Yuzefpolskaya, Melana; Salerno, Christopher; Walsh, Mary N; Milano, Carmelo A; Patel, Chetan B; Ewald, Gregory A; Itoh, Akinobu; Dean, David; Krishnamoorthy, Arun; Cotts, William G; Tatooles, Antone J; Jorde, Ulrich P; Bruckner, Brian A; Estep, Jerry D; Jeevanandam, Valluvan; Sayer, Gabriel; Horstmanshof, Douglas; Long, James W; Gulati, Sanjeev; Skipper, Eric R; O'Connell, John B; Heatley, Gerald; Sood, Poornima; Naka, Yoshifumi

2018-04-12

In an early analysis of this trial, use of a magnetically levitated centrifugal continuous-flow circulatory pump was found to improve clinical outcomes, as compared with a mechanical-bearing axial continuous-flow pump, at 6 months in patients with advanced heart failure. In a randomized noninferiority and superiority trial, we compared the centrifugal-flow pump with the axial-flow pump in patients with advanced heart failure, irrespective of the intended goal of support (bridge to transplantation or destination therapy). The composite primary end point was survival at 2 years free of disabling stroke (with disabling stroke indicated by a modified Rankin score of >3; scores range from 0 to 6, with higher scores indicating more severe disability) or survival free of reoperation to replace or remove a malfunctioning device. The noninferiority margin for the risk difference (centrifugal-flow pump group minus axial-flow pump group) was -10 percentage points. Of 366 patients, 190 were assigned to the centrifugal-flow pump group and 176 to the axial-flow pump group. In the intention-to-treat population, the primary end point occurred in 151 patients (79.5%) in the centrifugal-flow pump group, as compared with 106 (60.2%) in the axial-flow pump group (absolute difference, 19.2 percentage points; 95% lower confidence boundary, 9.8 percentage points [P<0.001 for noninferiority]; hazard ratio, 0.46; 95% confidence interval [CI], 0.31 to 0.69 [P<0.001 for superiority]). Reoperation for pump malfunction was less frequent in the centrifugal-flow pump group than in the axial-flow pump group (3 patients [1.6%] vs. 30 patients [17.0%]; hazard ratio, 0.08; 95% CI, 0.03 to 0.27; P<0.001). The rates of death and disabling stroke were similar in the two groups, but the overall rate of stroke was lower in the centrifugal-flow pump group than in the axial-flow pump group (10.1% vs. 19.2%; hazard ratio, 0.47; 95% CI, 0.27 to 0.84, P=0.02). In patients with advanced heart failure, a fully magnetically levitated centrifugal-flow pump was superior to a mechanical-bearing axial-flow pump with regard to survival free of disabling stroke or reoperation to replace or remove a malfunctioning device. (Funded by Abbott; MOMENTUM 3 ClinicalTrials.gov number, NCT02224755 .).

Flow enhancement of deformable self-driven objects by countercurrent

NASA Astrophysics Data System (ADS)

Mashiko, Takashi; Fujiwara, Takashi

2016-10-01

We report numerical simulations of the mixed flows of two groups of deformable self-driven objects. The objects belonging to the group A (B) have drift coefficient D =DA (DB), where a positive (negative) value of D denotes the rightward (leftward) driving force. For co-current flows (DA ,DB > 0), the result is rather intuitive: the net flow of one group (QA) increases if the driving force of the other group is stronger than its own driving force (i.e., DB >DA), and decreases otherwise (DB

Paleomagnetic correlation and ages of basalt flow groups in coreholes at and near the Naval Reactors Facility, Idaho National Laboratory, Idaho

USGS Publications Warehouse

Champion, Duane E.; Davis, Linda C.; Hodges, Mary K.V.; Lanphere, Marvin A.

2013-01-01

* The Jaramillo (Matuyama) flow group is found in corehole NRF 15, which is the deepest NRF corehole, and shows that the basalt flow group is thick in the subsurface at NRF. This flow group is thickest between the RWMC and INTEC and thins towards the ATRC and NRF.

Efficacy of Transcutaneous Electric Nerve Stimulation on Parotid Saliva Flow Rate in Relation to Age and Gender

PubMed Central

Dhillon, Manu; M Raju, Srinivasa; S Mohan, Raviprakash; Tomar, Divya

2016-01-01

Statement of the Problem Treatment with salivary substitutes and stimulation of salivary flow by either mechanical or pharmacologic methods has side effects and only provides symptomatic relief but no long-lasting results. Purpose To assess the effectiveness of extraoral transcutaneous electric nerve stimulation (TENS) as a mean of stimulating salivary function in healthy adult subjects; as well as to determine the gender and age-dependent changes in salivary flow rates of unstimulated and stimulated parotid saliva. Materials and Method Hundred patients were divided into two groups; Group I aged 20-40 and Group II aged ≥ 60 years. The TENS electrode pads were externally placed on the skin overlying the parotid glands. Unstimulated and stimulated parotid saliva was collected for 5 minutes each by using standardized collection techniques. Results Eighty seven of 100 subjects demonstrated increased salivary flow when stimulated via the TENS unit. Ten experienced no increase and 3 experienced a decrease. The mean unstimulated salivary flow rate was 0.01872 ml/min in Group I and 0.0088 ml/min in Group II. The mean stimulated salivary flow rate was 0.03084 ml/min (SD= 0.01248) in Group I, and 0.01556 ml/min (SD 0.0101) in Group II. After stimulation, the amount of salivary flow increased significantly in both groups (p< 0.001). Statistical comparison of the two groups revealed them to be significantly different (p< 0.001), with Group I producing more saliva. Gender-wise, no statistically significant difference was seen among the subjects in Group I (p = 0.148), and those in Group II (p= 0.448). Out of 12 subjects with 0 baseline flows, 7 continued to have no flow. Five subjects observed side effects, although minimal and transient. Conclusion The TENS unit was effective in increasing parotid gland salivary flow in healthy subjects. There was age-related but no gender-related variability in parotid salivary flow rate. PMID:27602390

Efficacy of Transcutaneous Electric Nerve Stimulation on Parotid Saliva Flow Rate in Relation to Age and Gender.

PubMed

Dhillon, Manu; M Raju, Srinivasa; S Mohan, Raviprakash; Tomar, Divya

2016-09-01

Treatment with salivary substitutes and stimulation of salivary flow by either mechanical or pharmacologic methods has side effects and only provides symptomatic relief but no long-lasting results. To assess the effectiveness of extraoral transcutaneous electric nerve stimulation (TENS) as a mean of stimulating salivary function in healthy adult subjects; as well as to determine the gender and age-dependent changes in salivary flow rates of unstimulated and stimulated parotid saliva. Hundred patients were divided into two groups; Group I aged 20-40 and Group II aged ≥ 60 years. The TENS electrode pads were externally placed on the skin overlying the parotid glands. Unstimulated and stimulated parotid saliva was collected for 5 minutes each by using standardized collection techniques. Eighty seven of 100 subjects demonstrated increased salivary flow when stimulated via the TENS unit. Ten experienced no increase and 3 experienced a decrease. The mean unstimulated salivary flow rate was 0.01872 ml/min in Group I and 0.0088 ml/min in Group II. The mean stimulated salivary flow rate was 0.03084 ml/min (SD= 0.01248) in Group I, and 0.01556 ml/min (SD 0.0101) in Group II. After stimulation, the amount of salivary flow increased significantly in both groups (p< 0.001). Statistical comparison of the two groups revealed them to be significantly different (p< 0.001), with Group I producing more saliva. Gender-wise, no statistically significant difference was seen among the subjects in Group I (p = 0.148), and those in Group II (p= 0.448). Out of 12 subjects with 0 baseline flows, 7 continued to have no flow. Five subjects observed side effects, although minimal and transient. The TENS unit was effective in increasing parotid gland salivary flow in healthy subjects. There was age-related but no gender-related variability in parotid salivary flow rate.

Evaluation of setting time and flow properties of self-synthesize alginate impressions

NASA Astrophysics Data System (ADS)

Halim, Calista; Cahyanto, Arief; Sriwidodo, Harsatiningsih, Zulia

2018-02-01

Alginate is an elastic hydrocolloid dental impression materials to obtain negative reproduction of oral mucosa such as to record soft-tissue and occlusal relationships. The aim of the present study was to synthesize alginate and to determine the setting time and flow properties. There were five groups of alginate consisted of fifty samples self-synthesize alginate and commercial alginate impression product. Fifty samples were divided according to two tests, each twenty-five samples for setting time and flow test. Setting time test was recorded in the s unit, meanwhile, flow test was recorded in the mm2 unit. The fastest setting time result was in the group three (148.8 s) and the latest was group fours). The highest flow test result was in the group three (69.70 mm2) and the lowest was group one (58.34 mm2). Results were analyzed statistically by one way ANOVA (α= 0.05), showed that there was a statistical significance of setting time while no statistical significance of flow properties between self-synthesize alginate and alginate impression product. In conclusion, the alginate impression was successfully self-synthesized and variation composition gives influence toward setting time and flow properties. The most resemble setting time of control group is group three. The most resemble flow of control group is group four.

Effect of stress, anxiety and depression on unstimulated salivary flow rate and xerostomia.

PubMed

Gholami, Neda; Hosseini Sabzvari, Behrous; Razzaghi, Alireza; Salah, Shilan

2017-01-01

Background. Unstimulated salivary flow rate can be influenced by different factors. This study was undertaken to evaluate the effect of stress, anxiety and depression on unstimulated salivary flow rate in adults. Methods. A total of 247 adult subjects, randomly selected from patients referring to Zanjan Dental School, were included in this investigation. The study procedures consisted of collecting salivary samples (in 5 minutes), completing a form for feeling of xerostomia and completing Depression Anxiety Stress Scale (DASS) Questionnaire to assess the severity of stress, anxiety and depression. Based on the results, the patients were categorized in four groups: Low salivary flow rate plus xerostomia (group 1, n=60), normal salivary flow rate plus xerostomia (group 2, n=59), low salivary flow rate without xerostomia (group 3, n=60) and normal salivary flow rate without xerostomia (control group, n=68). Results. The frequencies of subjects with severe and major depression in groups 1, 2 and 3 were 31.4%, 11.7% and 8.5%, respectively, with 4.4% in the control group. The frequencies of subjects with severe stress in groups 1, 2 and 3 were 21.7%, 3.3% and 11.9%, respectively, with 1.5% in the control group. The frequencies of patients with severe anxiety in groups 1, 2 and 3 were 50%, 30% and 61.1%, respectively, with 4.4% in the control group. Stress, anxiety and depression exhibited a statistically significant relationship with unstimulated salivary flow rate and xerostomia (P<0.05). Conclusion. Stress, anxiety and depression can influence unstimulated salivary flow rate and lead to xerostomia.

Protective environment for marrow transplant recipients. A prospective study

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

Buckner, C.D.; Clift, R.A.; Sanders, J.E.

1978-12-01

Laminar air flow isolation and decontamination procedures were evaluated in a prospective randomized study in patients with aplastic anemia or acute leukemia undergoing marrow transplantation from HLA-matched siblings. Patients transplanted in the laminar air flow group had significantly less septicemia and major local infections than did patients in the control group. Nineteen of 46 laminar air flow patients and six of 44 control patients are alive at present. In patients with aplastic anemia the survival was 13 of 17 in the laminar air flow group compared with four of 17 in the control group. In patients with acute leukemia themore » survival was six of 29 in the laminar air flow group versus two of 27 in the control group. These differences were not statistically significant. Death in both the laminar air flow and control groups was predominantly due to interstitial pneumonitis or recurrent leukemia, which were unaffected by isolation and decontamination.« less

Effects of perfluorohexane vapor on relative blood flow distribution in an animal model of surfactant-depleted lung injury

NASA Technical Reports Server (NTRS)

Hubler, Matthias; Souders, Jennifer E.; Shade, Erin D.; Polissar, Nayak L.; Bleyl, Jorg U.; Hlastala, Michael P.

2002-01-01

OBJECTIVE: To test the hypothesis that treatment with vaporized perfluorocarbon affects the relative pulmonary blood flow distribution in an animal model of surfactant-depleted acute lung injury. DESIGN: Prospective, randomized, controlled trial. SETTING: A university research laboratory. SUBJECTS: Fourteen New Zealand White rabbits (weighing 3.0-4.5 kg). INTERVENTIONS: The animals were ventilated with an FIO(2) of 1.0 before induction of acute lung injury. Acute lung injury was induced by repeated saline lung lavages. Eight rabbits were randomized to 60 mins of treatment with an inspiratory perfluorohexane vapor concentration of 0.2 in oxygen. To compensate for the reduced FIO(2) during perfluorohexane treatment, FIO(2) was reduced to 0.8 in control animals. Change in relative pulmonary blood flow distribution was assessed by using fluorescent-labeled microspheres. MEASUREMENTS AND MAIN RESULTS: Microsphere data showed a redistribution of relative pulmonary blood flow attributable to depletion of surfactant. Relative pulmonary blood flow shifted from areas that were initially high-flow to areas that were initially low-flow. During the study period, relative pulmonary blood flow of high-flow areas decreased further in the control group, whereas it increased in the treatment group. This difference was statistically significant between the groups (p =.02) as well as in the treatment group compared with the initial injury (p =.03). Shunt increased in both groups over time (control group, 30% +/- 10% to 63% +/- 20%; treatment group, 37% +/- 20% to 49% +/- 23%), but the changes compared with injury were significantly less in the treatment group (p =.03). CONCLUSION: Short treatment with perfluorohexane vapor partially reversed the shift of relative pulmonary blood flow from high-flow to low-flow areas attributable to surfactant depletion.

On global solutions of the random Hamilton-Jacobi equations and the KPZ problem

NASA Astrophysics Data System (ADS)

Bakhtin, Yuri; Khanin, Konstantin

2018-04-01

In this paper, we discuss possible qualitative approaches to the problem of KPZ universality. Throughout the paper, our point of view is based on the geometrical and dynamical properties of minimisers and shocks forming interlacing tree-like structures. We believe that the KPZ universality can be explained in terms of statistics of these structures evolving in time. The paper is focussed on the setting of the random Hamilton-Jacobi equations. We formulate several conjectures concerning global solutions and discuss how their properties are connected to the KPZ scalings in dimension 1  +  1. In the case of general viscous Hamilton-Jacobi equations with non-quadratic Hamiltonians, we define generalised directed polymers. We expect that their behaviour is similar to the behaviour of classical directed polymers, and present arguments in favour of this conjecture. We also define a new renormalisation transformation defined in purely geometrical terms and discuss conjectural properties of the corresponding fixed points. Most of our conjectures are widely open, and supported by only partial rigorous results for particular models.

A two-dimensional statistical framework connecting thermodynamic profiles with filaments in the scrape off layer and application to experiments

NASA Astrophysics Data System (ADS)

Militello, F.; Farley, T.; Mukhi, K.; Walkden, N.; Omotani, J. T.

2018-05-01

A statistical framework was introduced in Militello and Omotani [Nucl. Fusion 56, 104004 (2016)] to correlate the dynamics and statistics of L-mode and inter-ELM plasma filaments with the radial profiles of thermodynamic quantities they generate in the Scrape Off Layer. This paper extends the framework to cases in which the filaments are emitted from the separatrix at different toroidal positions and with a finite toroidal velocity. It is found that the toroidal velocity does not affect the profiles, while the toroidal distribution of filament emission renormalises the waiting time between two events. Experimental data collected by visual camera imaging are used to evaluate the statistics of the fluctuations, to inform the choice of the probability distribution functions used in the application of the framework. It is found that the toroidal separation of the filaments is exponentially distributed, thus suggesting the lack of a toroidal modal structure. Finally, using these measurements, the framework is applied to an experimental case and good agreement is found.

Effects of dorzolamide on choroidal blood flow, ciliary blood flow, and aqueous production in rabbits.

PubMed

Reitsamer, Herbert A; Bogner, Barbara; Tockner, Birgit; Kiel, Jeffrey W

2009-05-01

To determine the effects of topical dorzolamide (a carbonic anhydrase inhibitor) on choroidal and ciliary blood flow and the relationship between ciliary blood flow and aqueous flow. The experiments were performed in four groups of pentobarbital-anesthetized rabbits treated with topical dorzolamide (2%, 50 microL). In all groups, intraocular pressure (IOP) and mean arterial pressure (MAP) at the eye level were measured continuously by direct cannulation. In group 1, aqueous flow was measured by fluorophotometry before and after dorzolamide treatment. In group 2, aqueous flow was measured after dorzolamide at normal MAP and while MAP was held constant at 80, 55, or 40 mm Hg with occluders on the aorta and vena cava. In group 3, the same MAP levels were used, and ciliary blood flow was measured transsclerally by laser Doppler flowmetry (LDF). In group 4, choroidal blood flow was measured by LDF with the probe tip positioned in the vitreous over the posterior pole during ramp increases and decreases in MAP before and after dorzolamide. Dorzolamide lowered IOP by 19% (P < 0.01) and aqueous flow by 17% (P < 0.01), and increased ciliary blood flow by 18% (P < 0.01), which was associated with a significant reduction in ciliary vasculature resistance (-7%, P < 0.01). Dorzolamide shifted the relationship between ciliary blood flow and aqueous flow downward relative to the previously determined control relationship in the rabbit. Dorzolamide did not alter choroidal blood flow, choroidal vascular resistance, or the choroidal pressure flow relationship. Acute topical dorzolamide is a ciliary vasodilator and has a direct inhibitory effect on aqueous production, but it does not have a detectable effect on choroidal hemodynamics at the posterior pole in the rabbit.

Conceptualizing Group Flow: A Framework

ERIC Educational Resources Information Center

Duncan, Jana; West, Richard E.

2018-01-01

This literature review discusses the similarities in main themes between Csikszentmihályi theory of individual flow and Sawyer theory of group flow, and compares Sawyer's theory with existing concepts in the literature on group work both in education and business. Because much creativity and innovation occurs within groups, understanding group…

Paleomagnetic correlation of surface and subsurface basaltic lava flows and flow groups in the southern part of the Idaho National Laboratory, Idaho, with paleomagnetic data tables for drill cores

USGS Publications Warehouse

Champion, Duane E.; Hodges, Mary K.V.; Davis, Linda C.; Lanphere, Marvin A.

2011-01-01

Paleomagnetic inclination and polarity studies have been conducted on thousands of subcore samples from 51 coreholes located at and near the Idaho National Laboratory. These studies are used to paleomagnetically characterize and correlate successive stratigraphic intervals in each corehole to similar depth intervals in adjacent coreholes. Paleomagnetic results from 83 surface paleomagnetic sites, within and near the INL, are used to correlate these buried lava flow groups to basaltic shield volcanoes still exposed on the surface of the eastern Snake River Plain. Sample handling and demagnetization protocols are described as well as the paleomagnetic data averaging process. Paleomagnetic inclination comparisons between coreholes located only kilometers apart show comparable stratigraphic successions of mean inclination values over tens of meters of depth. At greater distance between coreholes, comparable correlation of mean inclination values is less consistent because flow groups may be missing or additional flow groups may be present and found at different depth intervals. Two shallow intersecting cross-sections, A-A- and B-B- (oriented southwest-northeast and northwest-southeast, respectively), drawn through southwest Idaho National Laboratory coreholes show the corehole to corehole or surface to corehole correlations derived from the paleomagnetic inclination data. From stratigraphic top to bottom, key results included the (1) Quaking Aspen Butte flow group, which erupted from Quaking Aspen Butte southwest of the Idaho National Laboratory, flowed northeast, and has been found in the subsurface in corehole USGS 132; (2) Vent 5206 flow group, which erupted near the southwestern border of the Idaho National Laboratory, flowed north and east, and has been found in the subsurface in coreholes USGS 132, USGS 129, USGS 131, USGS 127, USGS 130, USGS 128, and STF-AQ-01; and (3) Mid Butte flow group, which erupted north of U.S. Highway 20, flowed northwest, and has been found in the subsurface at coreholes ARA-COR-005 and STF-AQ-01. The high K20 flow group erupted from a vent that may now be buried south of U.S. Highway 20 near Middle Butte, flowed north, and is found in the subsurface in coreholes USGS 131, USGS 127, USGS 130, USGS 128, USGS 123, STF-AQ-01, and ARA-COR-005 ending near the Idaho Nuclear Technology and Engineering Center. The vent 5252 flow group erupted just south of U.S. Highway 20 near Middle and East Buttes, flowed northwest, and is found in the subsurface in coreholes ARA-COR-005, STF-AQ-01, USGS 130, USGS 128, ICPP 214, USGS 123, ICPP 023, USGS 121, USGS 127, and USGS 131. The Big Lost flow group erupted from a now-buried vent near the Radioactive Waste Management Complex, flowed southwest to corehole USGS 135, and northeast to coreholes USGS 132, USGS 129, USGS 131, USGS 127, USGS 130, STF-AQ-01, and ARA-COR-005. The AEC Butte flow group erupted from AEC Butte near the Advanced Test Reactor Complex and flowed south to corehole Middle 1823, northwest to corehole USGS 134, northeast to coreholes USGS 133 and NRF 7P, and south to coreholes USGS 121, ICPP 023, USGS 123, and USGS 128. Evidence of progressive subsidence of the axial zone of the ESRP is shown in these cross-sections, distorting the original attitudes of the lava flow groups and interbedded sediments. A deeper cross-section, C-C- (oriented west to east), spanning the entire southern Idaho National Laboratory shows correlations of the lava flow groups in the saturated part of the ESRP aquifer. Areally extensive flow groups in the deep subsurface (from about 100-800 meters below land surface) can be traced over long distances. In cross-section C-C-, the flow group labeled "Matuyama" can be correlated from corehole USGS 135 to corehole NPR Test/W-02, a distance of about 28 kilometers (17 miles). The flow group labeled "Matuyama 1.21 Ma" can be correlated from corehole Middle 1823 to corehole ANL-OBS-A-001, a distance of 26 kilometers (16 miles). Other flo

Pressure-flow specificity of inspiratory muscle training.

PubMed

Tzelepis, G E; Vega, D L; Cohen, M E; Fulambarker, A M; Patel, K K; McCool, F D

1994-08-01

The inspiratory muscles (IM) can be trained by having a subject breathe through inspiratory resistive loads or by use of unloaded hyperpnea. These disparate training protocols are characterized by high inspiratory pressure (force) or high inspiratory flow (velocity), respectively. We tested the hypothesis that the posttraining improvements in IM pressure or flow performance are specific to training protocols in a way that is similar to force-velocity specificity of skeletal muscle training. IM training was accomplished in 15 normal subjects by use of three protocols: high inspiratory pressure-no flow (group A, n = 5), low inspiratory pressure-high flow (group B, n = 5), and intermediate inspiratory pressure and flow (group C, n = 5). A control group (n = 4) did no training. Before and after training, we measured esophageal pressure (Pes) and inspiratory flow (VI) during single maximal inspiratory efforts against a range of external resistances including an occluded airway. Efforts originated below relaxation volume (Vrel), and peak Pes and VI were measured at Vrel. Isovolume maximal Pes-VI plots were constructed to assess maximal inspiratory pressure-flow performance. Group A (pressure training) performed 30 maximal static inspiratory maneuvers at Vrel daily, group B (flow training) performed 30 sets of three maximal inspiratory maneuvers with no added external resistance daily, and group C (intermediate training) performed 30 maximal inspiratory efforts on a midrange external resistance (7 mm ID) daily. Subjects trained 5 days/wk for 6 wk. Data analysis included comparison of posttraining Pes-VI slopes among training groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental study on interfacial area transport in downward two-phase flow

NASA Astrophysics Data System (ADS)

Wang, Guanyi

In view of the importance of two group interfacial area transport equations and lack of corresponding accurate downward flow database that can reveal two group interfacial area transport, a systematic database for adiabatic, air-water, vertically downward two-phase flow in a round pipe with inner diameter of 25.4 mm was collected to gain an insight of interfacial structure and provide benchmarking data for two-group interfacial area transport models. A four-sensor conductivity probe was used to measure the local two phase flow parameters and data was collected with data sampling frequency much higher than conventional data sampling frequency to ensure the accuracy. Axial development of local flow parameter profiles including void fraction, interfacial area concentration, and Sauter mean diameter were presented. Drastic inter-group transfer of void fraction and interfacial area was observed at bubbly to slug transition flow. And the wall peaked interfacial area concentration profiles were observed in churn-turbulent flow. The importance of local data about these phenomenon on flow structure prediction and interfacial area transport equation benchmark was analyzed. Bedsides, in order to investigate the effect of inlet conditions, all experiments were repeated after installing the flow straightening facility, and the results were briefly analyzed. In order to check the accuracy of current data, the experiment results were cross-checked with rotameter measurement as well as drift-flux model prediction, the averaged error is less than 15%. Current models for two-group interfacial area transport equation were evaluated using these data. The results show that two-group interfacial area transport equations with current models can predict most flow conditions with error less than 20%, except some bubbly to slug transition flow conditions and some churn-turbulent flow conditions. The disagreement between models and experiments could result from underestimate of inter-group void transfer.

Characterization of debris flows by rainstorm condition at a torrent on the Mount Yakedake volcano, Japan

NASA Astrophysics Data System (ADS)

Okano, Kazuyuki; Suwa, Hiroshi; Kanno, Tadahiro

2012-01-01

We analyzed rainstorm control on debris-flow magnitude and flow characteristics using the 14 sets of rainstorm and debris-flow data obtained from 1980 to 2005 at the Kamikamihorizawa Creek of Mount Yakedake. With the principal component analysis on five parameters of debris flows: frontal velocity, peak velocity, peak flow depth, peak discharge and total discharge, and with video-record of boulder-dams in motion, and the preceding rainfall intensities, we conclude that the 14 debris flows could be categorized into three groups. The flows in the first group have large hydraulic magnitude and massive and turbulent boulder-dams filled with slurry matrix. The flows in the second group have small hydraulic magnitude and boulder-dams scarcely filled with slurry matrix, and the dam is observed to alternate between stopping and starting. The flows in the third group have small hydraulic magnitude and boulder dams filled with slurry matrix. Analysis of hillslope hydrology and debris-flow data asserted that the antecedent rainfall conditions control not only the hydraulic magnitude of debris flows but also the boulder-dam features. Large rainstorms of high intensity and durations as short as 10 minutes induces fast and large storm runoff to the headwaters and the source reaches of debris flow, while rainstorms with durations as long as 24 h raises water content in the bottom deposits along the debris-flow growth reaches and generates substantial runoff from the tributaries. Classification of the three groups is done based on water availability to debris flows on the source and growth reaches at the occurrence of debris flow.

The Effect of Transcutaneous Electrical Nerve Stimulation of Sympathetic Ganglions and Acupuncture Points on Distal Blood Flow.

PubMed

Kamali, Fahimeh; Mirkhani, Hossein; Nematollahi, Ahmadreza; Heidari, Saeed; Moosavi, Elahesadat; Mohamadi, Marzieh

2017-04-01

Transcutaneous electrical nerve stimulation (TENS) is a widely-practiced method to increase blood flow in clinical practice. The best location for stimulation to achieve optimal blood flow has not yet been determined. We compared the effect of TENS application at sympathetic ganglions and acupuncture points on blood flow in the foot of healthy individuals. Seventy-five healthy individuals were randomly assigned to three groups. The first group received cutaneous electrical stimulation at the thoracolumbar sympathetic ganglions. The second group received stimulation at acupuncture points. The third group received stimulation in the mid-calf area as a control group. Blood flow was recorded at time zero as baseline and every 3 minutes after baseline during stimulation, with a laser Doppler flow-meter. Individuals who received sympathetic ganglion stimulation showed significantly greater blood flow than those receiving acupuncture point stimulation or those in the control group (p<0.001). Data analysis revealed that blood flow at different times during stimulation increased significantly from time zero in each group. Therefore, the application of low-frequency TENS at the thoracolumbar sympathetic ganglions was more effective in increasing peripheral blood circulation than stimulation at acupuncture points. Copyright © 2017 Medical Association of Pharmacopuncture Institute. Published by Elsevier B.V. All rights reserved.

BOOK REVIEW: Path Integrals in Field Theory: An Introduction

NASA Astrophysics Data System (ADS)

Ryder, Lewis

2004-06-01

In the 1960s Feynman was known to particle physicists as one of the people who solved the major problems of quantum electrodynamics, his contribution famously introducing what are now called Feynman diagrams. To other physicists he gained a reputation as the author of the Feynman Lectures on Physics; in addition some people were aware of his work on the path integral formulation of quantum theory, and a very few knew about his work on gravitation and Yang--Mills theories, which made use of path integral methods. Forty years later the scene is rather different. Many of the problems of high energy physics are solved; and the standard model incorporates Feynman's path integral method as a way of proving the renormalisability of the gauge (Yang--Mills) theories involved. Gravitation is proving a much harder nut to crack, but here also questions of renormalisability are couched in path-integral language. What is more, theoretical studies of condensed matter physics now also appeal to this technique for quantisation, so the path integral method is becoming part of the standard apparatus of theoretical physics. Chapters on it appear in a number of recent books, and a few books have appeared devoted to this topic alone; the book under review is a very recent one. Path integral techniques have the advantage of enormous conceptual appeal and the great disadvantage of mathematical complexity, this being partly the result of messy integrals but more fundamentally due to the notions of functional differentiation and integration which are involved in the method. All in all this subject is not such an easy ride. Mosel's book, described as an introduction, is aimed at graduate students and research workers in particle physics. It assumes a background knowledge of quantum mechanics, both non-relativistic and relativistic. After three chapters on the path integral formulation of non-relativistic quantum mechanics there are eight chapters on scalar and spinor field theory, followed by three on gauge field theories---quantum electrodynamics and Yang--Mills theories, Faddeev--Popov ghosts and so on.There is no treatment of the quantisation of gravity.Thus in about 200 pages the reader has the chance to learn in some detail about a most important area of modern physics. The subject is tough but the style is clear and pedagogic, results for the most part being derived explicitly. The choice of topics included is main-stream and sensible and one has a clear sense that the author knows where he is going and is a reliable guide. Path Integrals in Field Theory is clearly the work of a man with considerable teaching experience and is recommended as a readable and helpful account of a rather non-trivial subject.

Efficiency of the Thermal Jacket on the Delivered Temperature of Prewarmed Crystalloid Intravenous Fluid

DTIC Science & Technology

1989-01-01

intervals over a 60 minute period at flow rates of 100, 250, 500, 750, and 1,000 ml/hr. Analysis of variance showed a highly significant group effect with a...significant difference between all groups except Group 3 and Group 4. Analysis of - .riance aiso showed a highly significant flow rate effect on...as effective as the conventional method of delivering warmed fluids. Also, within the range of flow rates studied, faster flow rates tended to yield a

Vortex Rossby Waves in Asymmetric Basic Flow of Typhoons

NASA Astrophysics Data System (ADS)

Wang, Tianju; Zhong, Zhong; Wang, Ju

2018-05-01

Wave ray theory is employed to study features of propagation pathways (rays) of vortex Rossby waves in typhoons with asymmetric basic flow, where the tangential asymmetric basic flow is constructed by superimposing the wavenumber-1 perturbation flow on the symmetric basic flow, and the radial basic flow is derived from the non-divergence equation. Results show that, in a certain distance, the influences of the asymmetry in the basic flow on group velocities and slopes of rays of vortex Rossby waves are mainly concentrated near the radius of maximum wind (RMW), whereas it decreases outside the RMW. The distributions of radial and tangential group velocities of the vortex Rossby waves in the asymmetric basic flow are closely related to the azimuth location of the maximum speed of the asymmetric basic flow, and the importance of radial and tangential basic flow on the group velocities would change with radius. In addition, the stronger asymmetry in the basic flow always corresponds to faster outward energy propagation of vortex Rossby waves. In short, the group velocities, and thereby the wave energy propagation and vortex Rossby wave ray slope in typhoons, would be changed by the asymmetry of the basic flow.

A Fully Magnetically Levitated Circulatory Pump for Advanced Heart Failure.

PubMed

Mehra, Mandeep R; Naka, Yoshifumi; Uriel, Nir; Goldstein, Daniel J; Cleveland, Joseph C; Colombo, Paolo C; Walsh, Mary N; Milano, Carmelo A; Patel, Chetan B; Jorde, Ulrich P; Pagani, Francis D; Aaronson, Keith D; Dean, David A; McCants, Kelly; Itoh, Akinobu; Ewald, Gregory A; Horstmanshof, Douglas; Long, James W; Salerno, Christopher

2017-02-02

Continuous-flow left ventricular assist systems increase the rate of survival among patients with advanced heart failure but are associated with the development of pump thrombosis. We investigated the effects of a new magnetically levitated centrifugal continuous-flow pump that was engineered to avert thrombosis. We randomly assigned patients with advanced heart failure to receive either the new centrifugal continuous-flow pump or a commercially available axial continuous-flow pump. Patients could be enrolled irrespective of the intended goal of pump support (bridge to transplantation or destination therapy). The primary end point was a composite of survival free of disabling stroke (with disabling stroke indicated by a modified Rankin score >3; scores range from 0 to 6, with higher scores indicating more severe disability) or survival free of reoperation to replace or remove the device at 6 months after implantation. The trial was powered for noninferiority testing of the primary end point (noninferiority margin, -10 percentage points). Of 294 patients, 152 were assigned to the centrifugal-flow pump group and 142 to the axial-flow pump group. In the intention-to-treat population, the primary end point occurred in 131 patients (86.2%) in the centrifugal-flow pump group and in 109 (76.8%) in the axial-flow pump group (absolute difference, 9.4 percentage points; 95% lower confidence boundary, -2.1 [P<0.001 for noninferiority]; hazard ratio, 0.55; 95% confidence interval [CI], 0.32 to 0.95 [two-tailed P=0.04 for superiority]). There were no significant between-group differences in the rates of death or disabling stroke, but reoperation for pump malfunction was less frequent in the centrifugal-flow pump group than in the axial-flow pump group (1 [0.7%] vs. 11 [7.7%]; hazard ratio, 0.08; 95% CI, 0.01 to 0.60; P=0.002). Suspected or confirmed pump thrombosis occurred in no patients in the centrifugal-flow pump group and in 14 patients (10.1%) in the axial-flow pump group. Among patients with advanced heart failure, implantation of a fully magnetically levitated centrifugal-flow pump was associated with better outcomes at 6 months than was implantation of an axial-flow pump, primarily because of the lower rate of reoperation for pump malfunction. (Funded by St. Jude Medical; MOMENTUM 3 ClinicalTrials.gov number, NCT02224755 .).

A randomized prospective study of desflurane versus isoflurane in minimal flow anesthesia using “equilibration time” as the change-over point to minimal flow

PubMed Central

Mallik, Tanuja; Aneja, S; Tope, R; Muralidhar, V

2012-01-01

Background: In the administration of minimal flow anesthesia, traditionally a fixed time period of high flow has been used before changing over to minimal flow. However, newer studies have used “equilibration time” of a volatile anesthetic agent as the change-over point. Materials and Methods: A randomized prospective study was conducted on 60 patients, who were divided into two groups of 30 patients each. Two volatile inhalational anesthetic agents were compared. Group I received desflurane (n = 30) and group II isoflurane (n = 30). Both the groups received an initial high flow till equilibration between inspired (Fi) and expired (Fe) agent concentration were achieved, which was defined as Fe/Fi = 0.8. The mean (SD) equilibration time was obtained for both the agent. Then, a drift in end-tidal agent concentration during the minimal flow anesthesia and recovery profile was noted. Results: The mean equilibration time obtained for desflurane and isoflurane were 4.96 ± 1.60 and 16.96 ± 9.64 min (P < 0.001). The drift in end-tidal agent concentration over time was minimal in the desflurane group (P = 0.065). Recovery time was 5.70 ± 2.78 min in the desflurane group and 8.06 ± 31 min in the isoflurane group (P = 0.004). Conclusion: Use of equilibration time of the volatile anesthetic agent as a change-over point, from high flow to minimal flow, can help us use minimal flow anesthesia, in a more efficient way. PMID:23225926

Relationship between interatrial communication, ductus arteriosus, and pulmonary flow patterns in fetuses with transposition of the great arteries: prediction of neonatal desaturation.

PubMed

Vaujois, Laurence; Boucoiran, Isabelle; Preuss, Christophe; Brassard, Myriam; Houde, Christine; Fouron, Jean C; Raboisson, Marie-Josée

2017-09-01

The relationship between interatrial communication, ductus arteriosus, and pulmonary flow in transposition of the great arteries and intact ventricular septum may help predict postnatal desaturation. Echocardiographic data of 45 fetuses with transposition of the great arteries and intact ventricular septum and 50 age-matched controls were retrospectively reviewed. Interatrial communication, left and right ventricular output, flow in the ductus arteriosus, as well as effective pulmonary flow were measured. Patients were divided into two groups on the basis of postnatal saturations: group 1 had saturations ⩽50% and group 2 >50%. Of 45 fetuses, 13 (26.7%) were classified into group 1. Compared with fetuses in group 2, they had a smaller interatrial communication (2.9 versus 4.0 mm, p=0.004) and more retrograde diastolic flow in the ductus arteriosus (92 versus 23%, p=0.002). Both groups showed a significant decrease in ductal flow compared with controls. Patients in group 2 had a higher effective pulmonary flow compared with controls. There was a mild correlation between left ventricular output and size of the interatrial communication (Spearman's rank correlation 0.44). A retrograde diastolic flow is present in most of the fetuses with postnatal desaturation. Fetuses with transposition of the great arteries have a lower flow through the ductus arteriosus compared with controls. Fetuses without restrictive foramen ovale have higher effective pulmonary flow. Peripheral pulmonary vasodilatation due to higher oxygen saturation in pulmonary arteries in the case of transposition of the great arteries could be one possible cause.

Distribution of intrarenal blood flow consequent to left atrial balloon inflation.

PubMed

Passmore, J C; Stremel, R W; Hock, C E; Allen, R L; Bradford, W B

1985-01-01

The effects of inflation of a balloon within, and consequent distension of, the left atrium (LABI, left atrial balloon inflation) on total renal blood flow (RBF) and intrarenal blood flow distribution were measured and compared to values obtained from another group of dogs that were hemorrhaged (HEM) to the same level of hypotension as that produced by LABI, a mean systemic arterial pressure of 88 mm Hg. Kidney wt/kg, RBF/kg body wt, and urine flow were markedly reduced during the hemorrhage period in the HEM group when compared to values obtained during the experimental period for the LABI group. Data from the freeze-dissection (133Xe) analysis revealed that the percentage distribution of blood flow as renal outer cortical (OC) blood flow was less (26%) in the HEM group than in the LABI group (50%), this latter value being very similar to that of control dogs that experienced no hypotension (49%). LABI better maintains OC blood flow and urine flow when compared to HEM at the same systemic blood pressure, suggesting a role for cardiopulmonary receptors in reflex sympathetic control of renal blood flow distribution during hypotension.

Efficacy of a heat and moisture exchanger in inhalation anesthesia at two different flow rates.

PubMed

Yamashita, Koichi; Yokoyama, Takeshi; Abe, Hidehiro; Nishiyama, Tomoki; Manabe, Masanobu

2007-01-01

In general anesthesia with endotracheal intubation, a circle system with a heat and moisture exchanger (HME) and a low total flow is often used to prevent hypothermia and to maintain inspired gas humidity. The purpose of the present study was to compare the inspired gas humidity and body temperature, in general anesthesia with or without an HME at two different total flow rates. Eighty patients (American Society of Anesthesiologists [ASA] I or II) scheduled to undergo either orthopedic or head and neck surgery were studied. They were divided into four groups, of 20 patients each: total flow of 2 lxmin(-1) with (group HME2L) or without (group 2L) HME, and a total flow of 4 lxmin(-1) with (group HME4L) or without (group 4L) HME. The relative and absolute humidity and pharyngeal and inspired gas temperatures were measured for 2 h after endotracheal intubation. The relative humidity was not significantly different among groups 2L, HME2L, and HME4L. Group 4L had significantly lower absolute humidity than group 2L. The pharyngeal temperature did not decrease significantly for 2 h in any of the groups. During general anesthesia with a total flow of 2 lxmin(-1) in 2 h, HME might not be necessary, while with a total flow of 4 lxmin(-1), HME could be useful to maintain inspired gas humidity.

STUDIES ON THE ANOMALOUS VISCOSITY AND FLOW-BIREFRINGENCE OF PROTEIN SOLUTIONS

PubMed Central

Lawrence, A. S. C.; Miall, Margaret; Needham, Joseph; Shen, Shih-Chang

1944-01-01

1. An extensive investigation has been made of protein particle shape using the methods of flow-birefringence and anomalous viscosity measurement in the coaxial cell. 2. As a result of investigations on a number of proteins, it is concluded that they may be divided into four groups. Group A consists of those which show flow-anomaly both in the bulk phase and in the surface film. These also show flow-birefringence in the bulk phase. Examples: tobacco mosaic disease virus nucleoprotein; myosin. Though corpuscular proteins, they have elongated particles before denaturation. Group B consists of those which show flow-anomaly only (in the first instance) in the surface film, and no flow-birefringence in the bulk phase. They are probably close to spherical in shape in solution, but form elongated particles as they denature in the surface film. After this process has been completed, they may show flow-anomaly also in the bulk phase. Some proteins show flow-anomaly in the surface film immediately it forms, others only show it after a certain time has elapsed for the building up of the film. We designate the former as group B1 and the latter as group B2. Group B1, immediate surface film flow-anomaly. Examples: serum euglobulin, amphibian embryo euglobulin b. Group B2, slowly appearing surface film flow-anomaly. After the film has once been fully formed and then dispersed by shaking, the solution may have the properties of that of a protein in group B1; i.e., anomalous flow in the film may occur immediately on testing in the viscosimeter. Examples: avian ovalbumin, amphibian embryo pseudoglobulin. Group C consists of those proteins which show flow-anomaly neither in the bulk phase nor in the surface film, under the conditions used by us. They are probably close to spherical in shape. Examples: insulin, methaemoglobin, amphibian embryo euglobulin c, mucoproteins. 3. The theoretical significance of protein fibre molecules, whether native or formed by denaturation in the living cell, is discussed, especially in relation to experimental morphology and cytology. PMID:19873385

[Effects of the renal blood flow at different levels by transcutaneous electrical acupoint stimulation combined general anesthesia induced controlled hypotension].

PubMed

Fang, Jian-Qiao; Zhang, Le-Le; Shao, Xiao-Mei

2012-11-01

To observe the intervention of transcutaneous electrical acupoint stimulation (TEAS) on the renal blood flow at different levels of mean arterial pressure (MAP) in controlled hypotension. Forty-two male beagle dogs were randomly divided into seven groups, i. e., the general anesthesia group, the 50% controlled group, the 40% controlled group, the 30% controlled group, the 50% experimental group, the 40% experimental group, and the 30% experimental group, 6 in each group. Beagles in the general anesthesia group were not treated with controlled hypotension, and the target MAP was achieved in those of the rest groups and maintained for 60 min. In the experimental groups, TEAS was applied to bilateral Hegu (LI4), Zusanli (ST36), Sanyinjiao (SP6), and Quchi (LI11) at 2/100 Hz with the stimulation strength of (4 +/- 1) mA starting from the stability of their physiological conditions to 60 min of maintaining the target MAP level. The changes of the renal blood flow were monitored at different time points using laser Doppler. From starting pressure control to the target MAP level, the renal blood flow was significantly lower in the 30% controlled group than in the general anesthesia group and the basic level of the same group (P < 0.05), while there was no obvious change in the 30% experimental group. In maintaining the blood pressure, the renal blood flow was significantly lower in the 50% controlled group, the 40% controlled group, the 30% controlled group, and the 30% experimental group than in the general anesthesia group (P < 0.05), while there was no obvious change in the 50% experimental group or the 40% experimental group. By the end of blood pressure recovery, the renal blood flow restored to the basic level in the 50% controlled group, the 50% experimental group, and the 40% experimental group (P > 0.05), while it was not restored to the basic level in the 40% controlled group, the 30% controlled group, and the 30% experimental group (P < 0.05). TEAS combined general anesthesia in controlled hypotension could effectively improve the renal blood flow, thus protecting the kidney.

A Study Demonstrating the Quantitative Relationship Between Internal Thoracic Artery Length and Free Flow.

PubMed

Gode, Safa; Sen, Onur; Kadirogulları, Ersin; Reyhancan, Adem; Kyaruzi, Mugisha; Satılmısoglu, Muhammet Hulusi; Erkanlı, Korhan

2017-08-09

The left internal thoracic artery (LITA) is the most commonly used arterial bypass conduit in coronary artery bypass graft (CABG) patients and inadequate LITA flow can result in an increase in morbidity and mortality. In this study, we evaluated the effect of excision of the distal spasmodic segment of the LITA on the free flow in CABG patients. This study consisted of 47 patients who underwent elective CABG performed with or without other cardiac surgery, between July 2015 and December 2015. Excised LITA length was shorter than 15mm in group 1, between 15mm and 30mm in group 2 and longer than 30mm in group 3. Left ITA free flow was measured for 60seconds into a container before and after the distal LITA excision. The inter-measurement differences were calculated for the three groups. Thereafter, the comparison was performed in terms of free flow difference amongst the three groups. The mean difference of LITA free flow was 27.6±22.7ml/minute in group 1, 35.4±26.7ml/minute in group 2, and 52.6±26.1ml/minute in group 3. There were significant differences in terms of free flow difference between the groups (p=0.008). Also, differences were statistically significant in group 1 versus group 3 (p=0.003) and group 2 versus group 3 (p=0.038) in the intergroup comparisons. The distal part of the LITA has more spasmodic potential than other segments. This spasm may result in low flow of LITA grafts. Therefore, an as long as possible excision of the distal LITA segment may be required to avoid the spasmodic effect. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

The Influence of Insulin Dependent Diabetes Mellitus on Dental Caries and Salivary Flow

PubMed Central

Gupta, V. K.; Malhotra, Seema; Sharma, Vasuda; Hiremath, S. S.

2014-01-01

Objective. To assess whether or not there was any change in the dental caries and rate of salivary flow of patients with Insulin Dependent Diabetes Mellitus (IDDM) and the contribution of salivary flow to caries risk in IDDM. Setting. Department of Endocrinology, MS Ramaiah Hospital, Bangalore, India. Design. A comparative cross-sectional descriptive type. Materials and Methods. The sample consisted of two groups: 140 diabetic group (mean age 14.8 yr) and 140 nondiabetic group (mean age 13.7 yr). Dental caries by dmf(t) and dmf(s) indices for primary dentition and DMF(T) and DMF(S) indices was used in permanent dentition to assess the dental caries experience. Both stimulated and unstimulated salivary flow rate were assessed after collection of saliva. Results. In diabetic group 76% had carious lesion and in nondiabetic group 85.3% had carious lesion. Diabetics have lower mean DMFT, DMFS, dmft, and dmfs compared to the nondiabetic group. Diminished unstimulated and stimulated salivary flow rate in diabetic than nondiabetic group. Conclusions. The findings obtained conclude that even though there was reduced salivary flow rate in diabetic group the caries prevalence was low. PMID:26464864

The Influence of Insulin Dependent Diabetes Mellitus on Dental Caries and Salivary Flow.

PubMed

Gupta, V K; Malhotra, Seema; Sharma, Vasuda; Hiremath, S S

2014-01-01

Objective. To assess whether or not there was any change in the dental caries and rate of salivary flow of patients with Insulin Dependent Diabetes Mellitus (IDDM) and the contribution of salivary flow to caries risk in IDDM. Setting. Department of Endocrinology, MS Ramaiah Hospital, Bangalore, India. Design. A comparative cross-sectional descriptive type. Materials and Methods. The sample consisted of two groups: 140 diabetic group (mean age 14.8 yr) and 140 nondiabetic group (mean age 13.7 yr). Dental caries by dmf(t) and dmf(s) indices for primary dentition and DMF(T) and DMF(S) indices was used in permanent dentition to assess the dental caries experience. Both stimulated and unstimulated salivary flow rate were assessed after collection of saliva. Results. In diabetic group 76% had carious lesion and in nondiabetic group 85.3% had carious lesion. Diabetics have lower mean DMFT, DMFS, dmft, and dmfs compared to the nondiabetic group. Diminished unstimulated and stimulated salivary flow rate in diabetic than nondiabetic group. Conclusions. The findings obtained conclude that even though there was reduced salivary flow rate in diabetic group the caries prevalence was low.

Doppler sonographic screening of the flow in the basilar artery during head rotation reduces the risk for sudden infant death.

PubMed

Deeg, K-H; Reisig, A

2010-10-01

Position-dependent hypoperfusion of the brain stem may be a risk factor of sudden infant death. From 1998 to 2009 we performed Doppler sonographic flow measurements in the basilar artery of 18 194 newborns, 9322 boys and 8872 girls, in five different positions: the neutral position with the head in the midline and during head rotation to the left and right in a supine or prone position. The peak systolic and the time average flow velocity were measured from the flow profile. The flow velocities during head rotation were converted to % of the flow in the neutral position. A decrease in the velocities during head rotation below 50 % was thought to be abnormal. Biphasic flow, flow oscillating around the zero line or retrograde flow during rotation was considered to be pathological. Head rotations, which had caused abnormal and pathological flow, were avoided. The incidence of SIDS in our study group was evaluated and compared with the incidence in a control group of 3 519 newborns. In 17 929 newborns (98.54 %) the blood flow in the basilar artery was independent of head rotation and body position. In 204 newborns (1.12 %) we found an abnormal decrease under 50 %. Pathological flow alterations could be found in 61 patients (0.33 %). The overall incidence rate of SIDS in the study group was 0.055 ‰ (1:18 194). The incidence rate of SIDS in the control group was 1.14 ‰ (4:3519). The comparison of both groups showed a statistically significant (p < 0.0030) lower incidence rate in the study group. Hypoperfusion of the brain stem may be a significant risk factor of SIDS. © Georg Thieme Verlag KG Stuttgart · New York.

Graft flow assessment using a transit time flow meter in fractional flow reserve-guided coronary artery bypass surgery.

PubMed

Honda, Kentaro; Okamura, Yoshitaka; Nishimura, Yoshiharu; Uchita, Shunji; Yuzaki, Mitsuru; Kaneko, Masahiro; Yamamoto, Nobuko; Kubo, Takashi; Akasaka, Takashi

2015-06-01

To evaluate the relationship between preoperative severity of coronary stenosis occurring with fractional flow reserve (FFR), and the intraoperative bypass graft flow pattern. In all, 72 patients were enrolled in this retrospective study. The FFR value of the left anterior descending artery was evaluated, and data on "in situ" bypass grafting from the internal thoracic artery to the left anterior descending artery were assessed. Patients were divided into 3 groups according to preoperative FFR values (Group S: FFR < 0.70; group M: 0.70 ≤ FFR < 0.75; and group N: FFR ≥ 0.75). In groups S, M, and N, respectively, mean graft flow was 24.7 ± 10.6 mL/minute, 19.2 ± 14.0 mL/minute, and 16.0 ± 9.7 mL mL/minute; pulsatility index was 2.35 ± 0.6, 3.02 ± 1.1, and 5.51 ± 8.20; and number of patients with systolic reverse flow was 3 (6.8%), 5 (35.7%), and 4 (28.6%). Significant differences were observed in graft flow (P = .009), pulsatility index (P = .038), and proportion of systolic reverse flow (P = .023) among the 3 groups. In all patients, graft patency was confirmed with intraoperative fluorescence imaging; postoperative graft patency was confirmed with multislice computed tomography or coronary angiography in 69 patients (follow-up interval: 213 days). Early graft failure occurred in 1 patient. As coronary stenosis severity increased, graft flow increased, pulsatility index decreased, and proportion of patients with systolic reverse flow increased. In mild coronary artery stenosis, the chance of flow competition between the native coronary artery and the bypass graft increased. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Dynamic Modeling Strategy for Flow Regime Transition in Gas-Liquid Two-Phase Flows

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

Xia Wang; Xiaodong Sun; Benjamin Doup

In modeling gas-liquid two-phase flows, the concept of flow regimes has been widely used to characterize the global interfacial structure of the flows. Nearly all constitutive relations that provide closures to the interfacial transfers in two-phase flow models, such as the two-fluid model, are flow regime dependent. Current nuclear reactor safety analysis codes, such as RELAP5, classify flow regimes using flow regime maps or transition criteria that were developed for steady-state, fully-developed flows. As twophase flows are dynamic in nature, it is important to model the flow regime transitions dynamically to more accurately predict the two-phase flows. The present workmore » aims to develop a dynamic modeling strategy to determine flow regimes in gas-liquid two-phase flows through introduction of interfacial area transport equations (IATEs) within the framework of a two-fluid model. The IATE is a transport equation that models the interfacial area concentration by considering the creation of the interfacial area, fluid particle (bubble or liquid droplet) disintegration, boiling and evaporation, and the destruction of the interfacial area, fluid particle coalescence and condensation. For flow regimes beyond bubbly flows, a two-group IATE has been proposed, in which bubbles are divided into two groups based on their size and shapes, namely group-1 and group-2 bubbles. A preliminary approach to dynamically identify the flow regimes is discussed, in which discriminator s are based on the predicted information, such as the void fraction and interfacial area concentration. The flow regime predicted with this method shows good agreement with the experimental observations.« less

Pulse infusion thrombolysis (PIT) for large intracoronary thrombus: preventive effect against the 'no flow' phenomenon in revascularization therapy for acute myocardial infarction.

PubMed

Saito, T; Hokimoto, S; Ishibashi, F; Noda, K; Oshima, S

2001-02-01

Because large thrombus is a limitation for revascularization in acute myocardial infarction (AMI), the present study evaluated the effectiveness of pulse infusion thrombolysis (PIT) in patients with an AMI with a large (>15 mm) coronary thrombus, focusing on the occurrence of the 'no flow' phenomenon. The retrospective study compared patients treated before (1988-95; Group A, n=74) and after (1996-99; Group B, n=40) the use of PIT, using the following parameters: lesion success (<50% stenosis during 30-min observation), procedural success (lesion success plus TIMI grade 3 flow), procedural no flow (TIMI grade 0 flow during the procedure with 'back and forth movement' of contrast dye after lesion success), persistent no flow (consistent no flow without any flow improvement at the final visualization despite intensive treatment), reocclusion rate and in-hospital death. Group B was significantly better than Group A in procedural success (90% vs 66%; p=0.005), procedural 'no flow' (51% vs 15%; p<0.001), and persistent 'no flow' (34% vs 10%; p<0.05). Subgroup comparison was performed among the following groups: Direct-BA group (n=44): treated with mechanical angioplasty alone; ICT-BA group (n=40): treated with prior intracoronary thrombolysis and angioplasty; and PIT-BA group (n=30): treated with PIT and angioplasty. There were no differences in thrombus length and lesion success among these 3 groups. Procedural success was best achieved in PIT-BA: 97% vs 52% for Direct-BA (p=0.003) and 68% for ICT-BA (p=0.009). Procedural 'no flow' was least in PIT-BA: 50% vs 3.3% for Direct-BA (p=0.003) and 25% vs 3.3% for ICT-BA (p=0.042). Persistent 'no flow' was less frequent in PIT-BA than Direct-BA: 32% vs 3.3% (p=0.009). However, the difference between ICT-BA and Direct-BA was insignificant: 13% vs 3.3% (p=0.53). There were no differences in reocclusion rate and in-hospital death among the 3 subgroups. And there were no differences between Direct-BA and ICT-BA in any parameters. PIT was effective in preventing 'no flow' in the mechanical revasculalization for AMI especially those cases with a large thrombus.

Studies on the prevalence of reduced salivary flow rate in relation to general health and dental caries, and effect of iron supplementation.

PubMed

Flink, Håkan

2007-01-01

Reduced salivary flow is a condition that affects oral health. Its prevalence is unknown in young and middle-aged adults and there is no known treatment that permanently increases the salivary flow rate. Reduced salivary flow is related to dental caries, the most common oral disease. Reduced salivary flow is often found in individuals with insufficient food intake and thereby insufficient nutrition to the salivary glands. One nutrition related factor that has been proposed to effect salivary flow rate is iron deficiency. The aims of the thesis were to investigate i) the prevalence of reduced salivary flow rate in different age groups of adults, ii) the relationship between reduced salivary flow rate, general health and dental caries, iii) the influence of time of measurement on reduced salivary flow rate, and iv) if reduced salivary flow rates could be increased by iron supplementation. In Study I saliva was collected from 1427 individuals aged 20-69 years. A questionnaire was answered regarding subjective oral dryness, general diseases, use of drugs, BMI (Body Mass Index) and use of tobacco. In Study II saliva was collected from 48 patients with active caries and 48 caries-inactive patients. A blood sample was analysed for serum ferritin. In Study III the unstimulated salivary flow rate was tested at 7:30 and 11:30 a.m. in 108 individuals, age 15-46 years. The participants were allocated to one of three groups (very low < 0.1 mL/min, low 0.1-0.2 mL/min and normal > 0.2 mL/min) based on the the unstimulated salivary flow rate at 7:30 a.m. Different aspects of the perception of oral dryness were rated using Visual Analogue Scales. In Study IV a double-blind, randomized controlled trial was carried out on 50 individuals with a low unstimulated whole salivary flow rate and low serum ferritin. Half the individuals received 60 mg of iron orally twice a day for 3 months, while the other half received placebo. In Study I it was found that the prevalence of very low (< 0.1 mL/min) and low (0.10-0.19 mL/min) unstimulated salivary flow rate were similar for different age groups up to 50 years, ranging between 10.9-17.8% and 17.3-22.7%, respectively. Multiple logistic regression revealed that above age 50, female gender, 'having fewer than 20 teeth', and taking xerogenic drugs significantly increased the risk of very low unstimulated salivary flow rate. In Study II 32 individuals (67%) in the caries active group had low unstimulated salivary flow rate compared with 13 individuals (27%) in the caries inactive group. There was no difference in serum ferritin levels between the two groups. Study III showed for all groups a statistically significant increase in unstimulated salivary flow rate at 11:30 a.m. compared with 7:30 a.m., all of similar magnitude (0.08-0.09 mL/min). In the group with very low salivary flow rate, 70% at 11:30 a.m. exceeded the 0.1 mL/min limit. There were significant difference in perception of oral dryness between the normal group and both the low and the very low groups. In Study IV no statistically significant difference was found between the groups after treatment for the unstimulated flow rate and in the subjective assessments of oral dryness. The prevalence of reduced salivary flow rates is consistent and prevalent in younger and middle-aged adults (< 50 years). Very low salivary flow rates are related to high Body Mass Index (BMI) and diagnosed diseases in younger adults, but to medication in older adults. Reduced salivary flow rate in young adult women is related to caries. The time of measurement of salivary flow rates influences diagnosis of hyposalivation. Iron supplementation does not enhance salivary flow.

The NGC 1023 galaxy group: An anti-hubble flow?

NASA Astrophysics Data System (ADS)

Chernin, A. D.; Dolgachev, V. P.; Domozhilova, L. M.

2010-10-01

We discuss recently published data indicating that the nearby galaxy group NGC 1023 includes an inner, virialized, quasi-stationary component together with an outer component comprising a flow of dwarf galaxies falling toward the center of the system. The inner component is similar to the Local Group of galaxies, but the Local Group is surrounded by a receding set of dwarf galaxies forming the local Hubble flow, rather than a system of approaching dwarfs. This clear difference in the structures of these two systems, which are very similar in other respects, may be associated with the dark energy in which they are immersed. Self-gravity dominates in the inner component of the Local Group, while the anti-gravity created by the cosmic dark-energy background dominates in the surrounding Hubble flow. In contrast, self-gravity likewise dominates throughout the NGC 1023 Group, both in its central component and in the surrounding “anti-Hubble” flow. NGC 1023 as a whole is apparently in an ongoing state of formation and virialization. We expect that there exists a receding flow similar to the local Hubble flow at distances of 1.4-3 Mpc from the center of the group, where anti-gravity should become stronger than the gravity of the system.

Performance of a new carbon dioxide absorbent, Yabashi lime® as compared to conventional carbon dioxide absorbent during sevoflurane anesthesia in dogs.

PubMed

Kondoh, Kei; Atiba, Ayman; Nagase, Kiyoshi; Ogawa, Shizuko; Miwa, Takashi; Katsumata, Teruya; Ueno, Hiroshi; Uzuka, Yuji

2015-08-01

In the present study, we compare a new carbon dioxide (CO2) absorbent, Yabashi lime(®) with a conventional CO2 absorbent, Sodasorb(®) as a control CO2 absorbent for Compound A (CA) and Carbon monoxide (CO) productions. Four dogs were anesthetized with sevoflurane. Each dog was anesthetized with four preparations, Yabashi lime(®) with high or low-flow rate of oxygen and control CO2 absorbent with high or low-flow rate. CA and CO concentrations in the anesthetic circuit, canister temperature and carbooxyhemoglobin (COHb) concentration in the blood were measured. Yabashi lime(®) did not produce CA. Control CO2 absorbent generated CA, and its concentration was significantly higher in low-flow rate than a high-flow rate. CO was generated only in low-flow rate groups, but there was no significance between Yabashi lime(®) groups and control CO2 absorbent groups. However, the CO concentration in the circuit could not be detected (≤5ppm), and no change was found in COHb level. Canister temperature was significantly higher in low-flow rate groups than high-flow rate groups. Furthermore, in low-flow rate groups, the lower layer of canister temperature in control CO2 absorbent group was significantly higher than Yabashi lime(®) group. CA and CO productions are thought to be related to the composition of CO2 absorbent, flow rate and canister temperature. Though CO concentration is equal, it might be safer to use Yabashi lime(®) with sevoflurane anesthesia in dogs than conventional CO2 absorbent at the point of CA production.

Stratigraphy of the unsaturated zone and the Snake River Plain aquifer at and near the Idaho National Engineering Laboratory, Idaho

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

Anderson, S.R.; Liszewski, M.J.

1997-08-01

The unsaturated zone and the Snake River Plain aquifer at and near the Idaho National Engineering Laboratory (INEL) are made up of at least 178 basalt-flow groups, 103 sedimentary interbeds, 6 andesite-flow groups, and 4 rhyolite domes. Stratigraphic units identified in 333 wells in this 890-mile{sup 2} area include 121 basalt-flow groups, 102 sedimentary interbeds, 6 andesite-flow groups, and 1 rhyolite dome. Stratigraphic units were identified and correlated using the data from numerous outcrops and 26 continuous cores and 328 natural-gamma logs available in December 1993. Basalt flows make up about 85% of the volume of deposits underlying the area.

Surface roughness of flowable resin composites eroded by acidic and alcoholic drinks

PubMed Central

Poggio, Claudio; Dagna, Alberto; Chiesa, Marco; Colombo, Marco; Scribante, Andrea

2012-01-01

Aim: The aim of this study is to evaluate the surface roughness of four flowable resin composites following exposure to acidic and alcoholic drinks. Materials and Methods: SureFil SDR flow, TetricEvoFlow, Esthet-X Flow and Amaris Flow HT samples were immersed in artificial saliva, Coca Cola and Chivas Regal Whisky. Each specimen was examined using a Leica DCM 3D microscope: Arithmetical mean height of the surface profiles was measured (Sa). Results: Kruskal-Wallis test showed significant differences among various groups (P<0,001). Mann Whitney test was applied and control groups showed significantly lower Sa values than other groups (P=0,008). Coca Cola groups showed highest Sa values (P<0,021). No significant differences (P=0,14) in surface texture were found among the specimens of the different materials. No significant differences were found among TetricEvoFlow, Esthet-X Flow and Amaris Flow under control conditions nor after Coca Cola application. Under control condition and after Coca Cola application SureFil SDR flow showed significantly higher Sa values. Moreover, after whisky application Amaris Flow showed significantly lower Sa values then the other three groups that showed no significant differences among them. Conclusions: Acidic and alcoholic drinks eroded the surface roughness of all evaluated flowable resin composites. PMID:22557811

Influence of Dai-kenchu-to (DKT) on human portal blood flow.

PubMed

Ogasawara, Takashi; Morine, Yuji; Ikemoto, Tetsuya; Imura, Satoru; Fujii, Masahiko; Soejima, Yuji; Shimada, Mitsuo

2008-01-01

Dai-kenchu-to (DKT) is known as an herbal medicine used for postoperative ileus. However, no report exists about the effect of DKT on portal blood flow. The aim of this study is to clarify the influence of DKT on portal blood flow. To healthy volunteers (Healthy; n = 6), cirrhotic patients (Cirrhosis; n = 7) and liver-transplant patients (LTx; n = 3), DKT (2.5g) with 100mL of warm water was orally administrated in the DKT group, and only warm water was administrated in the control group. The portal blood flow rate (M-VEL: cm/sec.) and portal blood flow (Flow volume: mL/min.) was measured each time after administration using an ultrasonic Doppler method. Furthermore, the arterial blood pressure and heart rate was measured at the same time points. In the DKT group, a significant increase of M-VEL (120%) and flow volume (150%) 30 minutes after administration was observed in both Healthy and Cirrhosis in comparison with the control group. In LTx, there was also a significant increase of flow volume (128%) 30 minutes after administration. However, there was no change in average blood pressure and heart rate in all groups. DKT increases portal blood flow in early phase after oral administration without any significant changes in the blood pressure and heart rate.

Relationship between residual blood flow in the infarct-related artery and scintigraphic infarct size, myocardial salvage, and functional recovery in patients with acute myocardial infarction.

PubMed

Ndrepepa, Gjin; Kastrati, Adnan; Schwaiger, Markus; Mehilli, Julinda; Markwardt, Christina; Dibra, Alban; Dirschinger, Josef; Schömig, Albert

2005-11-01

In patients with acute myocardial infarction (AMI) before primary coronary stenting with adjunct glycoprotein IIb/IIIa receptor blockade, whether residual blood flow in the infarct-related artery (IRA) affects infarct size or myocardial salvage is not known. This study included 118 patients with ST-segment elevation AMI who received coronary stenting plus abciximab. SPECT studies were performed before and 7-14 d after stenting. Patients were divided into a group with initial Thrombolysis in Myocardial Infarction (TIMI) flow grade < or = 1 (77 patients) and a group with initial TIMI flow grade > 1 (41 patients). The initial median perfusion defect and (in brackets) the 25th and 75th percentiles were 29.1% [21.0%; 52.0%] of the left ventricle in patients with TIMI flow grade < or = 1, versus 16.5% [8.0%; 33.1%] of the left ventricle in patients with TIMI flow grade > 1 (P < 0.001). Baseline left ventricular ejection fraction (54.0% [45.0; 63.0] vs. 57.0% [40.0; 62.0], P = 0.623) or extension of hypokinetic region (28.0 [14.0; 41.0] hypokinetic chords vs. 24.0 [13.0; 39.0] hypokinetic chords, P = 0.643) did not differ significantly between the group with TIMI flow grade < or = 1 and the group with TIMI flow grade > 1. Final infarct size was 11.0% [6.1%; 23.5%] of the left ventricle in the group with TIMI flow grade < = 1, versus 6.0% [2.0%; 12.8%] of the left ventricle in the group with TIMI flow > 1 (P = 0.008). Salvage index was 0.58 [0.38; 0.76] in the group with TIMI flow grade < or = 1, versus 0.61 [0.36; 0.74] in the group with TIMI flow grade > 1 (P = 0.952). At the day 14 angiography, patients with TIMI flow grade > 1 had better left ventricular ejection fraction (61.0% [54.0%; 68.0%] vs. 56.5% [42.9%; 65.0%]; P = 0.03) and a smaller hypokinetic region (7 chords [0; 22.0] vs. 16 chords [2.5; 30.0]; P = 0.024) than did patients with TIMI flow grade < or = 1. Preserved blood flow in the IRA in patients with AMI is associated with a smaller area at risk, a smaller infarct, and better recovery of regional and global left ventricular function. The proportion of initial area at risk salvaged by coronary stenting does not seem to depend on residual blood flow in the IRA.

Qualitative Slow Blood Flow in Lower Extremity Deep Veins on Doppler Sonography: Quantitative Assessment and Preliminary Evaluation of Correlation With Subsequent Deep Venous Thrombosis Development in a Tertiary Care Oncology Center.

PubMed

Jensen, Corey T; Chahin, Antoun; Amin, Veral D; Khalaf, Ahmed M; Elsayes, Khaled M; Wagner-Bartak, Nicolaus; Zhao, Bo; Zhou, Shouhao; Bedi, Deepak G

2017-09-01

To determine whether the qualitative sonographic appearance of slow deep venous flow in the lower extremities correlates with quantitative slow flow and an increased risk of deep venous thrombosis (DVT) in oncology patients. In this Institutional Review Board-approved retrospective study, we reviewed lower extremity venous Doppler sonographic examinations of 975 consecutive patients: 482 with slow flow and 493 with normal flow. The subjective slow venous flow and absence of initial DVT were confirmed by 2 radiologists. Peak velocities were recorded at 3 levels. Each patient was followed for DVT development. The associations between DVT and the presence of slow venous flow were examined by the Fisher exact test; a 2-sample t test was used for peak velocity and DVT group comparisons. The optimal cutoff peak velocity for correlation with the radiologists' perceived slow flow was determined by the Youden index. Deep venous thrombosis development in the slow-flow group (21 of 482 [4.36%]) was almost doubled compared with patients who had normal flow (11 of 493 [2.23%]; P = .0456). Measured peak venous velocities were lower in the slow-venous flow group (P < .001). Patients with subsequent DVT did not have a significant difference in venous velocities compared with their respective patient groups. The sum of 3 venous level velocities resulted in the best cutoff for dichotomizing groups into normal versus slow venous flow. Qualitative slow venous flow in the lower extremities on Doppler sonography accurately correlates with quantitatively slower flow, and this preliminary evaluation suggests an associated mildly increased rate of subsequent DVT development in oncology patients. © 2017 by the American Institute of Ultrasound in Medicine.

The mode of emplacement of Neogene flood basalts in Eastern Iceland: The plagioclase ultraphyric basalts in the Grænavatn group

NASA Astrophysics Data System (ADS)

Óskarsson, Birgir V.; Andersen, Christina B.; Riishuus, Morten S.; Sørensen, Erik Vest; Tegner, Christian

2017-02-01

Plagioclase ultraphyric basalt lava with high fraction of solids have a mode of emplacement that is poorly understood. In this study we conduct detailed mapping of a PUB group in eastern Iceland, namely the Grænavatn group, and assess the group architecture, flow morphology and internal structure with additional constraints from petrography, petrology and crystal size distribution, to derive information on emplacement dynamics of plagioclase ultraphyric basalts. We also derive information on the plumbing system of the group with reference to the source of the macrocysts. The group is exposed in steep glacially carved fjords and can be traced for more than 70 km along strike. The flows have mixed architecture of simple and compound flows. Individual flow lobes have thicknesses in the range of 1-24 m and many reach widths and lengths exceeding 1000 m. The flows vary from rubbly to slabby pahoehoe, but are predominantly of pahoehoe type. The aspect ratio of the group and the nature of the flows indicate fissure-fed eruptions. The plagioclase macrocrysts (5-30 mm) are An-rich, exhibit bimodal size distribution and the modal proportions within the group varies from 15-40%. Clinopyroxene macrocrysts are also present ranging from 1-6%. The lowermost flow is thickest and carries the greatest crystal cargo load. The morphology of the lava flows suggests low viscous behavior, at odds with the high crystal content. The very calcic plagioclase macrocrysts (An80-85) are in disequilibrium with the groundmass and plagioclase microlaths therein (An50-70), meaning that the crystal-laden magmas quickly ascended from deeper crustal levels to the surface. The flows with highest crystal content may have maintained high temperatures by heat exchange with the primitive macrocrysts in the flows and developed non-Newtonian behavior such as shear thinning. Such conditions would have enabled the flows to advance rapidly during episodes with high effusion rates forming the simple flows, and subsequently maintained by insulated lobe-by-lobe emplacement. Occasionally surges disrupted the crust to form rubbly and slabby pahoehoe. A Herschel-Bulkley model is applied to the flows yielding effusion rates in the order of 103-104 m 3/s for the largest eruptions. Variation in crystal proportions within the group and individual flows is considered to be the result of magmas penetrating a crystal mush, followed by disaggregation and mobilization, sorting by flotation, mixing of magma batches and transportation of heterogeneous crystal-laden magmas to the surface with opportunities for staging en route.

Cine phase-contrast MRI evaluation of normal aqueductal cerebrospinal fluid flow according to sex and age.

PubMed

Unal, Ozkan; Kartum, Alp; Avcu, Serhat; Etlik, Omer; Arslan, Halil; Bora, Aydin

2009-12-01

The aim of this study was cerebrospinal flow quantification in the cerebral aqueduct using cine phase-contrast magnetic resonance imaging (MRI) technique in both sexes and five different age groups to provide normative data. Sixty subjects with no cerebral pathology were included in this study. Subjects were divided into five age groups: < or =14 years, 15-24 years, 25-34 years, 35-44 years, and > or =45 years. Phase, rephase, and magnitude images were acquired by 1.5 T MR unit at the level of cerebral aqueduct with spoiled gradient echo through-plane, which is a cine phase-contrast sequence. At this level, peak flow velocity (cm/s), average flow rate (cm/ s), average flow (L/min), volumes in cranial and caudal directions (mL), and net volumes (mL) were studied. There was a statistically significant difference in peak flow between the age group of < or =14 years and the older age groups. There were no statistically significant differences in average velocity, cranial and caudal volume, net volume, and average flow parameters among different age groups. Statistically significant differences were not detected in flow parameters between sexes. When using cine-phase contrast MRI in the cerebral aqueduct, only the peak velocity showed a statistically significant difference between age groups; it was higher in subjects aged < or =14 years than those in older age groups. When performing age-dependent clinical studies including adolescents, this should be taken into consideration.

Analysis of Pulsed Flow Modification Alternatives, Lower Missouri River, 2005

USGS Publications Warehouse

Jacobson, Robert B.

2008-01-01

The graphical, tabular, and statistical data presented in this report resulted from analysis of alternative flow regime designs considered by a group of Missouri River managers, stakeholders, and scientists during the summer of 2005. This plenary group was charged with designing a flow regime with increased spring flow pulses to support reproduction and survival of the endangered pallid sturgeon. Environmental flow components extracted from the reference natural flow regime were used to design and assess performance of alternative flow regimes. The analysis is based on modeled flow releases from Gavins Point Dam (near Yankton, South Dakota) for nine design alternatives and two reference scenarios; the reference scenarios are the run-of-the-river and the water-control plan implemented in 2004. The alternative designs were developed by the plenary group with the goal of providing pulsed spring flows, while retaining traditional social and economic uses of the river.

Syringe Pump Performance Maintained with IV Filter Use During Low Flow Rate Delivery for Pediatric Patients.

PubMed

Chau, Destiny F; Vasilopoulos, Terrie; Schoepf, Miriam; Zhang, Christina; Fahy, Brenda G

2016-09-01

Complex surgical and critically ill pediatric patients rely on syringe infusion pumps for precise delivery of IV medications. Low flow rates and in-line IV filter use may affect drug delivery. To determine the effects of an in-line filter to remove air and/or contaminants on syringe pump performance at low flow rates, we compared the measured rates with the programmed flow rates with and without in-line IV filters. Standardized IV infusion assemblies with and without IV filters (filter and control groups) attached to a 10-mL syringe were primed and then loaded onto a syringe pump and connected to a 16-gauge, 16-cm single-lumen catheter. The catheter was suspended in a normal saline fluid column to simulate the back pressure from central venous circulation. The delivered infusate was measured by gravimetric methods at predetermined time intervals, and flow rate was calculated. Experimental trials for initial programmed rates of 1.0, 0.8, 0.6, and 0.4 mL/h were performed in control and filter groups. For each trial, the flow rate was changed to double the initial flow rate and was then returned to the initial flow rate to analyze pump performance for titration of rates often required during medication administration. These conditions (initial rate, doubling of initial rate, and return to initial rate) were analyzed separately for steady-state flow rate and time to steady state, whereas their average was used for percent deviation analysis. Differences between control and filter groups were assessed using Student t tests with adjustment for multiplicity (using n = 3 replications per group). Mean time from 0 to initial flow (startup delay) was <1 minute in both groups with no statistical difference between groups (P = 1.0). The average time to reach steady-state flow after infusion startup or rate changes was not statistically different between the groups (range, 0.8-5.5 minutes), for any flow rate or part of the trial (initial rate, doubling of initial rate, and return to initial rate), although the study was underpowered to detect small time differences. Overall, the mean steady-state flow rate for each trial was below the programmed flow rate with negative mean percent deviations for each trial. In the 1.0-mL/h initial rate trial, the steady-state flow rate attained was lower in the filter than the control group for the initial rate (P = 0.04) and doubling of initial rate (P = 0.04) with a trend during the return to initial rate (P = 0.06), although this same effect was not observed when doubling the initial rate trials of 0.8 or 0.6 mL/h or any other rate trials compared with the control group. With low flow rates used in complex surgical and pediatric critically ill patients, the addition of IV filters did not confer statistically significant changes in startup delay, flow variability, or time to reach steady-state flow of medications administered by syringe infusion pumps. The overall flow rate was lower than programmed flow rate with or without a filter.

Methodology Development of a Gas-Liquid Dynamic Flow Regime Transition Model

NASA Astrophysics Data System (ADS)

Doup, Benjamin Casey

Current reactor safety analysis codes, such as RELAP5, TRACE, and CATHARE, use flow regime maps or flow regime transition criteria that were developed for static fully-developed two-phase flows to choose interfacial transfer models that are necessary to solve the two-fluid model. The flow regime is therefore difficult to identify near the flow regime transitions, in developing two-phase flows, and in transient two-phase flows. Interfacial area transport equations were developed to more accurately predict the dynamic nature of two-phase flows. However, other model coefficients are still flow regime dependent. Therefore, an accurate prediction of the flow regime is still important. In the current work, the methodology for the development of a dynamic flow regime transition model that uses the void fraction and interfacial area concentration obtained by solving three-field the two-fluid model and two-group interfacial area transport equation is investigated. To develop this model, detailed local experimental data are obtained, the two-group interfacial area transport equations are revised, and a dynamic flow regime transition model is evaluated using a computational fluid dynamics model. Local experimental data is acquired for 63 different flow conditions in bubbly, cap-bubbly, slug, and churn-turbulent flow regimes. The measured parameters are the group-1 and group-2 bubble number frequency, void fraction, interfacial area concentration, and interfacial bubble velocities. The measurements are benchmarked by comparing the prediction of the superficial gas velocities, determined using the local measurements with those determined from volumetric flow rate measurements and the agreement is generally within +/-20%. The repeatability four-sensor probe construction process is within +/-10%. The repeatability of the measurement process is within +/-7%. The symmetry of the test section is examined and the average agreement is within +/-5.3% at z/D = 10 and +/-3.4% at z/D = 32. Revised source/sink terms for the two-group interfacial area transport equations are derived and fit to area-averaged experimental data to determine new model coefficients. The average agreement between this model and the experiment data for the void fraction and interfacial area concentration is 10.6% and 15.7%, respectively. This revised two-group interfacial area transport equation and the three-field two-fluid model are used to solve for the group-1 and group-2 interfacial area concentration and void fraction. These values and a dynamic flow regime transition model are used to classify the flow regimes. The flow regimes determined using this model are compared with the flow regimes based on the experimental data and on a flow regime map using Mishima and Ishii's (1984) transition criteria. The dynamic flow regime transition model is shown to predict the flow regimes dynamically and has improved the prediction of the flow regime over that using a flow regime map. Safety codes often employ the one-dimensional two-fluid model to model two-phase flows. The area-averaged relative velocity correlation necessary to close this model is derived from the drift flux model. The effects of the necessary assumptions used to derive this correlation are investigated using local measurements and these effects are found to have a limited impact on the prediction of the area-averaged relative velocity.

The effects of flow on schooling Devario aequipinnatus: school structure, startle response and information transmission

PubMed Central

Chicoli, A.; Butail, S.; Lun, Y.; Bak-Coleman, J.; Coombs, S.; Paley, D.A.

2014-01-01

To assess how flow affects school structure and threat detection, startle response rates of solitary and small groups of giant danio Devario aequipinnatus were compared to visual looming stimuli in flow and no-flow conditions. The instantaneous position and heading of each D. aequipinnatus were extracted from high-speed videos. Behavioural results indicate that (1) school structure is altered in flow such that D. aequipinnatus orient upstream while spanning out in a crosswise direction, (2) the probability of at least one D. aequipinnatus detecting the visual looming stimulus is higher in flow than no flow for both solitary D. aequipinnatus and groups of eight D. aequipinnatus, however, (3) the probability of three or more individuals responding is higher in no flow than flow. Taken together, these results indicate a higher probability of stimulus detection in flow but a higher probability of internal transmission of information in no flow. Finally, results were well predicted by a computational model of collective fright response that included the probability of direct detection (based on signal detection theory) and indirect detection (i.e. via interactions between group members) of threatening stimuli. This model provides a new theoretical framework for analysing the collective transfer of information among groups of fishes and other organisms. PMID:24773538

Differences in aortic vortex flow pattern between normal and patients with stroke: qualitative and quantitative assessment using transesophageal contrast echocardiography.

PubMed

Son, Jang-Won; Hong, Geu-Ru; Hong, Woosol; Kim, Minji; Houle, Helene; Vannan, Mani A; Pedrizzetti, Gianni; Chung, Namsik

2016-06-01

The flow in the aorta forms a vortex, which is a critical determinant of the flow dynamics in the aorta. Arteriosclerosis can alter the blood flow pattern of the aorta and cause characteristic alterations of the vortex. However, this change in aortic vortex has not yet been studied. This study aimed to characterize aortic vortex flow pattern using transesophageal contrast echocardiography in normal and stroke patients. A total of 85 patients who diagnosed with ischemic stroke and 16 normal controls were recruited for this study. The 16 normal control subjects were designated as the control group, and the 85 ischemic stroke patients were designated as the stroke group. All subjects underwent contrast transesophageal echocardiography (TEE), and particle image velocimetry was used to assess aortic vortex flow. Qualitative and quantitative analyses of vortex flow morphology, location, phasic variation, and pulsatility were undertaken and compared between the groups. In the control group, multiple irregularly-shaped vortices were observed in a peripheral location in the descending thoracic aorta. In contrast, the stroke group had a single, round, merged, and more centrally located aortic vortex flow. In the quantitative analysis of vortex, vortex depth, which represents the location of the major vortex in the aorta, was significantly higher in the control group than in the stroke group (0.599 ± 0.159 vs. 0.522 ± 0.101, respectively, P = 0.013). Vortex relative strength, which is the pulsatility parameter of the vortex itself, was significantly higher in the stroke group than in the control group (0.367 ± 0.148 vs. 0.304 ± 0.087, respectively, P = 0.025). It was feasible to visualize and quantify the characteristic morphology and pulsatility of the aortic vortex flow using contrast TEE, and aortic vortex pattern significantly differed between normal and stroke patients.

Grouping of optic flow stimuli during binocular rivalry is driven by monocular information.

PubMed

Holten, Vivian; Stuit, Sjoerd M; Verstraten, Frans A J; van der Smagt, Maarten J

2016-10-01

During binocular rivalry, perception alternates between two dissimilar images, presented dichoptically. Although binocular rivalry is thought to result from competition at a local level, neighboring image parts with similar features tend to be perceived together for longer durations than image parts with dissimilar features. This simultaneous dominance of two image parts is called grouping during rivalry. Previous studies have shown that this grouping depends on a shared eye-of-origin to a much larger extent than on image content, irrespective of the complexity of a static image. In the current study, we examine whether grouping of dynamic optic flow patterns is also primarily driven by monocular (eye-of-origin) information. In addition, we examine whether image parameters, such as optic flow direction, and partial versus full visibility of the optic flow pattern, affect grouping durations during rivalry. The results show that grouping of optic flow is, as is known for static images, primarily affected by its eye-of-origin. Furthermore, global motion can affect grouping durations, but only under specific conditions. Namely, only when the two full optic flow patterns were presented locally. These results suggest that grouping during rivalry is primarily driven by monocular information even for motion stimuli thought to rely on higher-level motion areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

Older Adults' Engagement During an Intervention Involving Off-the-Shelf Videogame

PubMed Central

Marsiske, Michael; Leite, Walter L.; Yam, Anna; Thomas, Kelsey; Mann, William

2016-01-01

Abstract Objective: The overall goal of our current study was to examine older adults' experience of Flow (i.e., subjective engagement) during the course of a home-based cognitive training program. Materials and Methods: In this study, participants took part in a home-based training program. They were randomized to one of the two training groups. One group played an off-the-shelf videogame (i.e., Crazy Taxi), and the other group played a brain training game (i.e., Insight). Training consisted of 60 training sessions of 1 hour each, which were completed in 3 months (5 hours a week). After each training session, participants completed a Flow questionnaire to measure their engagement with the training. Results: The analysis was performed with a linear growth curve model. The results indicate that on average, there was no change in flow for the Insight group between time points. There was no difference between the initial flow status of the Insight group and the Crazy Taxi group. However, the interaction between group membership and time was statistically significant, indicating that the participants in the Crazy Taxi group increased their scores at each week at a rate that was 0.99 larger than those in the Insight group. Conclusion: The analyses revealed that both groups experienced increase in Flow over the period, but only participants in the Crazy Taxi group significantly improved in Flow. This has long-term implications since we would expect participation to go beyond 12 weeks in a real-world scenario. PMID:27310479

Older Adults' Engagement During an Intervention Involving Off-the-Shelf Videogame.

PubMed

Belchior, Patrícia; Marsiske, Michael; Leite, Walter L; Yam, Anna; Thomas, Kelsey; Mann, William

2016-06-01

The overall goal of our current study was to examine older adults' experience of Flow (i.e., subjective engagement) during the course of a home-based cognitive training program. In this study, participants took part in a home-based training program. They were randomized to one of the two training groups. One group played an off-the-shelf videogame (i.e., Crazy Taxi), and the other group played a brain training game (i.e., Insight). Training consisted of 60 training sessions of 1 hour each, which were completed in 3 months (5 hours a week). After each training session, participants completed a Flow questionnaire to measure their engagement with the training. The analysis was performed with a linear growth curve model. The results indicate that on average, there was no change in flow for the Insight group between time points. There was no difference between the initial flow status of the Insight group and the Crazy Taxi group. However, the interaction between group membership and time was statistically significant, indicating that the participants in the Crazy Taxi group increased their scores at each week at a rate that was 0.99 larger than those in the Insight group. The analyses revealed that both groups experienced increase in Flow over the period, but only participants in the Crazy Taxi group significantly improved in Flow. This has long-term implications since we would expect participation to go beyond 12 weeks in a real-world scenario.

Ischemia-reperfusion injury in the isolated rat lung. Role of flow and endogenous leukocytes.

PubMed

Seibert, A F; Haynes, J; Taylor, A

1993-02-01

Microvascular lung injury caused by ischemia-reperfusion (IR) may occur via leukocyte-dependent and leukocyte-independent pathways. Leukocyte-endothelial adhesion may be a rate-limiting step in IR lung injury. Leukocyte adhesion to microvascular endothelium occurs when the attractant forces between leukocyte and endothelium are greater than the kinetic energy of the leukocyte and the vascular wall shear rate. We hypothesized (1) that isolated, buffer-perfused rat lungs are not free of endogenous leukocytes, (2) that endogenous leukocytes contribute to IR-induced microvascular injury as measured by the capillary filtration coefficient (Kfc), and (3) that a reduction of perfusate flow rate would potentiate leukocyte-dependent IR injury. Sixty lungs were divided into four groups: (1) low-flow controls, (2) high-flow controls, (3) low-flow IR, and (4) high-flow IR. Microvascular injury was linearly related to baseline perfusate leukocyte concentrations at both low (r = 0.78) and high (r = 0.82) flow rates. Kfc in the high-flow IR group (0.58 +/- 0.03 ml/min/cm H2O/100 g) was less (p < 0.05) than Kfc in the low-flow IR group (0.82 +/- 0.07), and in both groups Kfc values were significantly greater than low-flow (0.34 +/- 0.03) and high-flow (0.31 +/- 0.01) control Kfc values after 75 min. Retention of leukocytes in the lung, evaluated by a tissue myeloperoxidase assay, was greatest in the low-flow IR group. We conclude (1) that isolated, buffer-perfused rat lungs contain significant quantities of leukocytes and that these leukocytes contribute to IR lung injury, and (2) that IR-induced microvascular injury is potentiated by low flow.

Ultrasound-guided axillary brachial plexus block versus local infiltration anesthesia for arteriovenous fistula creation at the forearm for hemodialysis in patients with chronic renal failure.

PubMed

Nofal, W H; El Fawal, S M; Shoukry, A A; Sabek, Eas; Malak, Wfa

2017-01-01

The primary failure rate for arteriovenous fistula (AVF) creation under local anesthesia for hemodialysis is about 30%. Axillary brachial plexus block (BPB) may improve blood flow through blood vessels used in fistula creation; it may improve the AVF blood flow and thus may reduce the primary failure rate after 3 months. Hundred and forty patients with chronic renal failure scheduled for AVF creation for hemodialysis were divided into two equal groups; Group 1 (AxBP-G) received ultrasound (US) guided axillary BPB, and Group 2 (LI-G) received local infiltration. We recorded the measurements of the brachial and radial arteries before and after anesthesia and the AVF blood flow in both groups at three different time points. Furthermore, the primary failure rate was recorded in each group and compared. After anesthesia, the mean radial artery blood flow in the AxBP-group was 3.52 ml/min more than the LI-group, and the brachial artery diameter was also 0.68 mm more than in the LI-group, both differences were statistically significant ( P < 0.05). There were significant increases ( P < 0.05) in the AVF blood flow in the AxBP-group more than the LI-group with mean differences of 29.6, 69.8, and 27.2 ml/min at 4 h, 1 week, and 3 months, respectively. The overall mean of AVF blood flow was 42.21 ml/min more in the AxBP group than the LI-group a difference which is statistically significant ( P < 0.001). The primary failure rate was 17% in the AxBP group versus 30% in the LI-group; however, this difference is not significant statistically ( P = 0.110). The US-guided axillary block increases AVF blood flow significantly more than local infiltration and nonsignificantly decreases the primary failure rate of the AVF after 3 months.

Effects of lornoxicam and intravenous ibuprofen on erythrocyte deformability and hepatic and renal blood flow in rats.

PubMed

Arpacı, Hande; Çomu, Faruk Metin; Küçük, Ayşegül; Kösem, Bahadır; Kartal, Seyfi; Şıvgın, Volkan; Turgut, Hüseyin Cihad; Aydın, Muhammed Enes; Koç, Derya Sebile; Arslan, Mustafa

2016-01-01

Change in blood supply is held responsible for anesthesia-related abnormal tissue and organ perfusion. Decreased erythrocyte deformability and increased aggregation may be detected after surgery performed under general anesthesia. It was shown that nonsteroidal anti-inflammatory drugs decrease erythrocyte deformability. Lornoxicam and/or intravenous (iv) ibuprofen are commonly preferred analgesic agents for postoperative pain management. In this study, we aimed to investigate the effects of lornoxicam (2 mg/kg, iv) and ibuprofen (30 mg/kg, iv) on erythrocyte deformability, as well as hepatic and renal blood flows, in male rats. Eighteen male Wistar albino rats were randomly divided into three groups as follows: iv lornoxicam-treated group (Group L), iv ibuprofen-treated group (Group İ), and control group (Group C). Drug administration was carried out by the iv route in all groups except Group C. Hepatic and renal blood flows were studied by laser Doppler, and euthanasia was performed via intra-abdominal blood uptake. Erythrocyte deformability was measured using a constant-flow filtrometry system. Lornoxicam and ibuprofen increased the relative resistance, which is an indicator of erythrocyte deformability, of rats (P=0.016). Comparison of the results from Group L and Group I revealed no statistically significant differences (P=0.694), although the erythrocyte deformability levels in Group L and Group I were statistically higher than the results observed in Group C (P=0.018 and P=0.008, respectively). Hepatic and renal blood flows were significantly lower than the same in Group C. We believe that lornoxicam and ibuprofen may lead to functional disorders related to renal and liver tissue perfusion secondary to both decreased blood flow and erythrocyte deformability. Further studies regarding these issues are thought to be essential.

Predictive ability and efficacy for shortening door-to-balloon time of a new prehospital electrocardiogram-transmission flow chart in patients with ST-elevation myocardial infarction - Results of the CASSIOPEIA study.

PubMed

Sakai, Toshiaki; Nishiyama, Osamu; Onodera, Masayuki; Matsuda, Shigekatsu; Wakisawa, Shinobu; Nakamura, Motoyuki; Morino, Yoshihiro; Itoh, Tomonori

2018-05-24

The purposes of this study were to create a new flow-chart of prehospital electrocardiography (ECG)-transmission, evaluate its predictive ability for ST-elevation myocardial infarction (STEMI) and shorten door-to-balloon time (DTBT). The new transmission flow-chart was created using symptoms from previous medical records of STEMI patients. A total of 4090 consecutive patients transferred emergently to our hospital were divided into two groups: those in ambulances with an ECG-transmission device with the new flow-chart (ECGT-FC) and those transferred without an ECG-transmission device (non-ECGT) groups. A STEMI group comprising walk-in patients during the same period was used as a control group. The predictive ability of STEMI and the effectiveness of shortening the DTBT by the new flow-chart of ECG-transmission was evaluated. In the ECGT-FC group, the prevalence of STEMI in the ECG-transmission by the new flow-chart were significantly higher than in the non-ECG-transmission patients (6.71% vs. 0.19%; p<0.001). The sensitivity and specificity of the new ECG-transmission flow-chart were 83.3% and 88.1%, respectively. The median DTBT was significantly shortened (p=0.045) and the prevalence of DTBT<90min was significantly higher in the ECGT-FC group (p=0.018) than the other groups. The sensitivity and specificity of the new flow-chart for ECG-transmission were high. The new flow-chart combined with an ECG-transmission device could detect STEMI efficiently and shorten DTBT. Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Barotrauma and microvascular injury in lungs of nonadult rabbits: effect of ventilation pattern.

PubMed

Peevy, K J; Hernandez, L A; Moise, A A; Parker, J C

1990-06-01

To study the pulmonary microvascular injury produced by ventilation barotrauma, the isolated perfused lungs of 4 to 6-wk-old New Zealand white rabbits were ventilated by one of the following methods: peak inspiratory pressure (PIP) 23 cm H2O, gas flow rate 1.1 L/min (group 1); PIP 27 cm H2O, gas flow rate 6.9 L/min (group 2); PIP 50 cm H2O, gas flow rate 1.9 L/min (group 3); or PIP 53 cm H2O, gas flow rate 8.3 L/min (group 4). Microvascular permeability was assessed using the capillary filtration coefficient (Kfc) before and 5, 30, and 60 min after a 15-min period of ventilation. Baseline Kfc was not significantly different between groups. A significant increase over the baseline Kfc was noted at 60 min in group 2 and in all postventilation Kfc values in groups 3 and 4 (p less than .05). Group 1 Kfc values did not change significantly after ventilation. At all post-ventilation times, values for Kfc were significantly greater in groups 3 and 4 than in group 1 (p less than .05). Group 4 Kfc values were significantly greater than those in group 2 at 5 and 30 min postventilation. These data indicate that high PIP, and to a lesser extent, high gas flow rates cause microvascular injury in the compliant nonadult lung and suggest that the combination of high PIP and high gas flow rates are the most threatening to microvascular integrity.

Comparison of Diaphragmatic Breathing Exercise, Volume and Flow Incentive Spirometry, on Diaphragm Excursion and Pulmonary Function in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Trial

PubMed Central

Anand, R.

2016-01-01

Objective. To evaluate the effects of diaphragmatic breathing exercises and flow and volume-oriented incentive spirometry on pulmonary function and diaphragm excursion in patients undergoing laparoscopic abdominal surgery. Methodology. We selected 260 patients posted for laparoscopic abdominal surgery and they were block randomization as follows: 65 patients performed diaphragmatic breathing exercises, 65 patients performed flow incentive spirometry, 65 patients performed volume incentive spirometry, and 65 patients participated as a control group. All of them underwent evaluation of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow Rate (PEFR), and diaphragm excursion measurement by ultrasonography before the operation and on the first and second postoperative days. With the level of significance set at p < 0.05. Results. Pulmonary function and diaphragm excursion showed a significant decrease on the first postoperative day in all four groups (p < 0.001) but was evident more in the control group than in the experimental groups. On the second postoperative day pulmonary function (Forced Vital Capacity) and diaphragm excursion were found to be better preserved in volume incentive spirometry and diaphragmatic breathing exercise group than in the flow incentive spirometry group and the control group. Pulmonary function (Forced Vital Capacity) and diaphragm excursion showed statistically significant differences between volume incentive spirometry and diaphragmatic breathing exercise group (p < 0.05) as compared to that flow incentive spirometry group and the control group. Conclusion. Volume incentive spirometry and diaphragmatic breathing exercise can be recommended as an intervention for all patients pre- and postoperatively, over flow-oriented incentive spirometry for the generation and sustenance of pulmonary function and diaphragm excursion in the management of laparoscopic abdominal surgery. PMID:27525116

Comparison of Diaphragmatic Breathing Exercise, Volume and Flow Incentive Spirometry, on Diaphragm Excursion and Pulmonary Function in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Trial.

PubMed

Alaparthi, Gopala Krishna; Augustine, Alfred Joseph; Anand, R; Mahale, Ajith

2016-01-01

Objective. To evaluate the effects of diaphragmatic breathing exercises and flow and volume-oriented incentive spirometry on pulmonary function and diaphragm excursion in patients undergoing laparoscopic abdominal surgery. Methodology. We selected 260 patients posted for laparoscopic abdominal surgery and they were block randomization as follows: 65 patients performed diaphragmatic breathing exercises, 65 patients performed flow incentive spirometry, 65 patients performed volume incentive spirometry, and 65 patients participated as a control group. All of them underwent evaluation of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow Rate (PEFR), and diaphragm excursion measurement by ultrasonography before the operation and on the first and second postoperative days. With the level of significance set at p < 0.05. Results. Pulmonary function and diaphragm excursion showed a significant decrease on the first postoperative day in all four groups (p < 0.001) but was evident more in the control group than in the experimental groups. On the second postoperative day pulmonary function (Forced Vital Capacity) and diaphragm excursion were found to be better preserved in volume incentive spirometry and diaphragmatic breathing exercise group than in the flow incentive spirometry group and the control group. Pulmonary function (Forced Vital Capacity) and diaphragm excursion showed statistically significant differences between volume incentive spirometry and diaphragmatic breathing exercise group (p < 0.05) as compared to that flow incentive spirometry group and the control group. Conclusion. Volume incentive spirometry and diaphragmatic breathing exercise can be recommended as an intervention for all patients pre- and postoperatively, over flow-oriented incentive spirometry for the generation and sustenance of pulmonary function and diaphragm excursion in the management of laparoscopic abdominal surgery.

PAI-1 4G/5G gene polymorphism is associated with angiographic patency in ST-elevation myocardial infarction patients treated with thrombolytic therapy.

PubMed

Ozkan, Bugra; Cagliyan, Caglar E; Elbasan, Zafer; Uysal, Onur K; Kalkan, Gulhan Y; Bozkurt, Mehmet; Tekin, Kamuran; Bozdogan, Sevcan T; Ozalp, Ozge; Duran, Mustafa; Sahin, Durmus Y; Cayli, Murat

2012-09-01

In this study, we examined the relationship between PAI-1 4G/5G polymorphism and patency of the infarct-related artery after thrombolysis in patients with ST-elevation myocardial infarction (STEMI). Acute STEMI patients who received thrombolytic therapy within first 12 h were included in our study. The PAI-1 4G/5G promoter region insertion/deletion polymorphism was studied from venous blood samples. Patients with the PAI-1 4G/5G gene polymorphism were included in group 1 and the others were included in group 2. Coronary angiography was performed in all patients in the first 24 h after receiving thrombolytic therapy. Thrombolysis in myocardial infarction (TIMI) 0-1 flow in the infarct-related artery was considered as 'no flow', TIMI 2 flow as 'slow flow', and TIMI 3 flow as 'normal flow'. A total of 61 patients were included in our study. Thirty patients (49.2%) were positive for the PAI-1 4G/5G gene polymorphism, whereas 31 of them (50.8%) were in the control group. There were significantly more patients with 'no flow' (14 vs. 6; P=0.02) and less patients with 'normal flow' (8 vs. 19; P=0.02) in group 1. In addition, time to thrombolytic therapy (TTT) was maximum in the 'no flow' group and minimum in the 'normal flow' group (P=0.005). In the logistic regression analysis, TTT (odds ratio: 0.9898; 95% confidence interval: 0.982-0.997; P=0.004) and the PAI-1 4G/5G gene polymorphism (odds ratio: 4.621; 95% confidence interval: 1.399-15.268; P<0.01) were found to be independently associated with post-thrombolytic 'no flow'. The PAI-1 4G/5G gene polymorphism and TTT are associated independently with 'no flow' after thrombolysis in patients with STEMI.

Impact of transient or persistent slow flow and adjunctive distal protection on mortality in ST-segment elevation myocardial infarction.

PubMed

Fujii, Toshiharu; Masuda, Naoki; Nakano, Masataka; Nakazawa, Gaku; Shinozaki, Norihiko; Matsukage, Takashi; Ogata, Nobuhiko; Yoshimachi, Fuminobu; Ikari, Yuji

2015-04-01

Routine use of distal protection for ST-segment elevation myocardial infarction (STEMI) is not recommended. The purpose of this study was to analyze the impact of slow flow on mortality after STEMI, and the efficacy of adjunctive distal protection following primary thrombus aspiration. We retrospectively analyzed 414 STEMI patients who underwent primary PCI. Distal protection was used following primary thrombus aspiration only when the operator judged the patient to be at high risk of slow flow. Patients were divided into 3 groups: those receiving no thrombus aspiration (A- Group), thrombus aspiration without distal protection (A+/D- Group) or a combination of aspiration with distal protection (A+/D+ Group). Slow flow/no reflow was characterized as transient or persistent. The A-, A+/D-, and A+/D+ Groups consisted of 28.5 % (n = 118), 44.4 % (n = 184), and 27.1 % (n = 112) of patients, respectively. All-cause mortality at 180 days was 6.8 % without slow flow, 14.1 % with transient and 44.4 % with persistent slow flow (P < 0.0001), but was similar whether or not distal protection was used among these groups complicated without slow flow (A-, 8.7 %; A+/D-, 6.3 %; A+/D+, 4.3 %; P = 0.5854). However, in cases complicated with transient or persistent slow flow, distal protection reduced all-cause mortality to 38.5 % (A-), 23.3 % (A+/D-), and 10.8 % (A+/D+) at 180 days (P = 0.0114). Our data confirm that routine distal protection is not to be recommended. However, it is suggested that it could reduce mortality of patients with slow flow. Predicting slow flow accurately before PCI, however, remains a challenge.

Changes in Retinal and Choroidal Vascular Blood Flow after Oral Sildenafil: An Optical Coherence Tomography Angiography Study.

PubMed

Berrones, David; Salcedo-Villanueva, Guillermo; Morales-Cantón, Virgilio; Velez-Montoya, Raul

2017-01-01

To describe changes in the retina and choroidal flow by optical coherence tomography angiography (OCT-A) after a single dose of oral sildenafil. A case-control study. Patients in the study group received 50 mg of oral sildenafil. Patients in the control group received a sham pill. Retinal and choroidal images were obtained at baseline (before pill ingestion) and 1 hour after ingestion. Central macular and choroidal thickness, choroidal and outer retina flow, and the retinal and choroidal vascular density were compared using a Mann-Whitney U test. Twenty eyes were enrolled into the study group and 10 eyes in the control group. There was a significant difference in central choroidal thickness and outer retina blood flow between groups after 1 hour of sildenafil ingestion ( p < 0.01). There were no differences in central macular thickness, choroidal flow, and retinal vascular density among groups. A single dose of oral sildenafil increases choroidal thickness, probably due to sildenafil-induced vasodilation.

Changes in Retinal and Choroidal Vascular Blood Flow after Oral Sildenafil: An Optical Coherence Tomography Angiography Study

PubMed Central

Berrones, David; Morales-Cantón, Virgilio

2017-01-01

Purpose To describe changes in the retina and choroidal flow by optical coherence tomography angiography (OCT-A) after a single dose of oral sildenafil. Method A case-control study. Patients in the study group received 50 mg of oral sildenafil. Patients in the control group received a sham pill. Retinal and choroidal images were obtained at baseline (before pill ingestion) and 1 hour after ingestion. Central macular and choroidal thickness, choroidal and outer retina flow, and the retinal and choroidal vascular density were compared using a Mann-Whitney U test. Results Twenty eyes were enrolled into the study group and 10 eyes in the control group. There was a significant difference in central choroidal thickness and outer retina blood flow between groups after 1 hour of sildenafil ingestion (p < 0.01). There were no differences in central macular thickness, choroidal flow, and retinal vascular density among groups. Conclusions A single dose of oral sildenafil increases choroidal thickness, probably due to sildenafil-induced vasodilation. PMID:29129998

Relationship between flow and incidence of thrombosis in polytetrafluoroethylene vascular grafts in free microvascular flaps in lambs.

PubMed

Paloma, V; Lasso, J M; Bazán, A; Serra, J M

1999-09-01

We have done an experimental study in lambs in which we investigated the influence of flow rate on free microvascular flaps using polytetrafluoroethylene (PTFE) vascular grafts. We set up five surgical groups in which blood flow was progressively increased through the PTFE vascular graft. In group I (venous autograft) we observed just one vascular thrombosis which was located at the site of the anastomosis. In group II (PTFE 3 x 10 mm) all the microvascular flaps became necrosed after the third postoperative day. In group III (PTFE 3 x 10 mm) necrosis also developed in all cases, but the anastomoses remained permeable no longer than eight days. In group IV (3 x 15 mm) the permeability in the microvascular free flaps was about 40% after 21 days, and in group V (3 x 10 mm) it reached 70%. To match graft flow rates with flap survival we did a regression analysis of flow rates for groups II, III, and V and the corresponding survival periods for the flaps. There was a clear and highly significant relationship (r = 0.717, p = 0.0001). In conclusion, it is necessary to maintain blood flow through the prosthesis at a rate higher than the thrombogenic threshold. When the flow rate in the vessels through the PTFE grafts was higher, the viability of the flaps was better. The ideal surgical technique should always be based on an arteriovenous fistula distal to the PTFE vascular graft. It is necessary to maintain blood flow through a prosthesis at a rate higher than the thrombogenic threshold.

Vaginal blood flow after radical hysterectomy with and without nerve sparing. A preliminary report.

PubMed

Pieterse, Q D; Ter Kuile, M M; Deruiter, M C; Trimbos, J B M Z; Kenter, G G; Maas, C P

2008-01-01

Radical hysterectomy with pelvic lymphadenectomy (RHL) for cervical cancer causes damage to the autonomic nerves, which are responsible for increased vaginal blood flow during sexual arousal. The aim of the study of which we now report preliminary data was to determine whether a nerve-sparing technique leads to an objectively less disturbed vaginal blood flow response during sexual stimulation. Photoplethysmographic assessment of vaginal pulse amplitude (VPA) during sexual stimulation by erotic films was performed. Subjective sexual arousal was assessed after each stimulus. Thirteen women after conventional RHL, 10 women after nerve-sparing RHL, and 14 healthy premenopausal women participated. Data were collected between January and August 2006. The main outcome measure was the logarithmically transformed mean VPA. To detect statistically significant differences in mean VPA levels between the three groups, a univariate analysis of variance was used. Mean VPA differed between the three groups (P= 0.014). The conventional group had a lower vaginal blood flow response than the control group (P= 0.016), which tended also to be lower than that of the nerve-sparing group (P= 0.097). These differences were critically dependent on baseline vaginal blood flow differences between the groups. The conventional group follows a vaginal blood flow pattern similar to postmenopausal women. Conventional RHL is associated with an overall disturbed vaginal blood flow response compared with healthy controls. Because it is not observed to the same extent after nerve-sparing RHL, it seems that the nerve-sparing technique leads to a better overall vaginal blood flow caused by less denervation of the vagina.

Effect of Postextubation High-Flow Nasal Cannula vs Noninvasive Ventilation on Reintubation and Postextubation Respiratory Failure in High-Risk Patients: A Randomized Clinical Trial.

PubMed

Hernández, Gonzalo; Vaquero, Concepción; Colinas, Laura; Cuena, Rafael; González, Paloma; Canabal, Alfonso; Sanchez, Susana; Rodriguez, Maria Luisa; Villasclaras, Ana; Fernández, Rafael

2016-10-18

High-flow conditioned oxygen therapy delivered through nasal cannulae and noninvasive mechanical ventilation (NIV) may reduce the need for reintubation. Among the advantages of high-flow oxygen therapy are comfort, availability, lower costs, and additional physiopathological mechanisms. To test if high-flow conditioned oxygen therapy is noninferior to NIV for preventing postextubation respiratory failure and reintubation in patients at high risk of reintubation. Multicenter randomized clinical trial in 3 intensive care units in Spain (September 2012-October 2014) including critically ill patients ready for planned extubation with at least 1 of the following high-risk factors for reintubation: older than 65 years; Acute Physiology and Chronic Health Evaluation II score higher than 12 points on extubation day; body mass index higher than 30; inadequate secretions management; difficult or prolonged weaning; more than 1 comorbidity; heart failure as primary indication for mechanical ventilation; moderate to severe chronic obstructive pulmonary disease; airway patency problems; or prolonged mechanical ventilation. Patients were randomized to undergo either high-flow conditioned oxygen therapy or NIV for 24 hours after extubation. Primary outcomes were reintubation and postextubation respiratory failure within 72 hours. Noninferiority margin was 10 percentage points. Secondary outcomes included respiratory infection, sepsis, and multiple organ failure, length of stay and mortality; adverse events; and time to reintubation. Of 604 patients (mean age, 65 [SD, 16] years; 388 [64%] men), 314 received NIV and 290 high-flow oxygen. Sixty-six patients (22.8%) in the high-flow group vs 60 (19.1%) in the NIV group were reintubation (absolute difference, -3.7%; 95% CI, -9.1% to ∞); 78 patients (26.9%) in the high-flow group vs 125 (39.8%) in the NIV group experienced postextubation respiratory failure (risk difference, 12.9%; 95% CI, 6.6% to ∞) [corrected]. Median time to reintubation did not significantly differ: 26.5 hours (IQR, 14-39 hours) in the high-flow group vs 21.5 hours (IQR, 10-47 hours) in the NIV group (absolute difference, -5 hours; 95% CI, -34 to 24 hours). Median postrandomization ICU length of stay was lower in the high-flow group, 3 days (IQR, 2-7) vs 4 days (IQR, 2-9; P=.048). Other secondary outcomes were similar in the 2 groups. Adverse effects requiring withdrawal of the therapy were observed in none of patients in the high-flow group vs 42.9% patients in the NIV group (P < .001). Among high-risk adults who have undergone extubation, high-flow conditioned oxygen therapy was not inferior to NIV for preventing reintubation and postextubation respiratory failure. High-flow conditioned oxygen therapy may offer advantages for these patients. clinicaltrials.gov Identifier: NCT01191489.

The ideal oxygen/nitrous oxide fresh gas flow sequence with the Anesthesia Delivery Unit machine.

PubMed

Hendrickx, Jan F A; Cardinael, Sara; Carette, Rik; Lemmens, Hendrikus J M; De Wolf, Andre M

2007-06-01

To determine whether early reduction of oxygen and nitrous oxide fresh gas flow from 6 L/min to 0.7 L/min could be accomplished while maintaining end-expired nitrous oxide concentration > or =50% with an Anesthesia Delivery Unit anesthesia machine. Prospective, randomized clinical study. Large teaching hospital in Belgium. 53 ASA physical status I and II patients requiring general endotracheal anesthesia and controlled mechanical ventilation. Patients were randomly assigned to one of 4 groups depending on the duration of high oxygen/nitrous oxide fresh gas flow (two and 4 L/min, respectively) before lowering total fresh gas flow to 0.7 L/min (0.3 and 0.4 L/min oxygen and nitrous oxide, respectively): one, two, three, or 5 minutes (1-minute group, 2-minute group, 3-minute group, and 5-minute group), with n = 10, 12, 13, and 8, respectively. The course of the end-expired nitrous oxide concentration and bellows volume deficit at end-expiration was compared among the 4 groups during the first 30 minutes. At the end of the high-flow period the end-expired nitrous oxide concentration was 35.6 +/- 6.2%, 48.4 +/- 4.8%, 53.7 +/- 8.7%, and 57.3 +/- 1.6% in the 4 groups, respectively. Thereafter, the end-expired nitrous oxide concentration decreased to a nadir of 36.1 +/- 4.5%, 45.4 +/- 3.8%, 50.9 +/- 6.1%, and 55.4 +/- 2.8% after three, 4, 6, and 8 minutes after flows were lowered in the 1- to 5-minute groups, respectively. A decrease in bellows volume was observed in most patients, but was most pronounced in the 2-minute group. The bellows volume deficit gradually faded within 15 to 20 minutes in all 4 groups. A 3-minute high-flow period (oxygen and nitrous oxide fresh gas flow of 2 and 4 L/min, respectively) suffices to attain and maintain end-expired nitrous oxide concentration > or =50% and ensures an adequate bellows volume during the ensuing low-flow period.

Intraoperative Portal Flow of Less Than 1 Liter per Minute After Orthotopic Liver Transplantation Is Not Associated Per Se With an Increased Rate of Early Graft Dysfunction.

PubMed

Gastaca, M; Prieto, M; Valdivieso, A; Ruiz, P; Ventoso, A; Palomares, I; Matarranz, A; Martinez-Indart, L; Ortiz de Urbina, J

2016-09-01

The aim of this study was to determine whether a portal flow of <1,000 mL/min in orthotopic liver transplantation (OLT) is associated with a higher incidence of early graft dysfunction (EGD) and graft loss. A retrospective study was performed of 540 OLTs carried out consecutively from December 2004 to December 2013. Patients were divided into 2 groups: group A, portal flow <1,000 mL/min; and group B, portal flow >1,000 mL/min. We studied the incidence of EGD and graft survival. A subanalysis was performed to define the minimum acceptable portal flow/100 g of liver weight to reduce the development EGD and graft loss. Group A included 29 patients and group B, 511 patients. Group A had significantly lower-weight donors and recipients, female recipients with cholestatic disease, lower MELD scores, and lower hepatic artery flow. EGD occurred in 7 patients in group A (24.1%) versus 101 patients in group B (19.8%; P = .43). No significant differences were found in 1- and 5-year graft survival. A portal flow of <80 mL/min/100 g of liver weight was related to a significantly higher risk of developing EGD (odds ratio, 4.35; 95% confidence interval [CI], 1.46-12.91; P = .008) and graft loss (hazard ratio, 4.05; 95% CI, 1.32-12.42; P = .014). Intraoperative portal flow of <1,000 mL/min in OLT was not related per se with a higher incidence of EGD or graft loss. Significantly higher risk of developing EGD and graft loss was associated with a portal flow of <80 mL/min/100 g of liver weight. Copyright © 2016 Elsevier Inc. All rights reserved.

Optic nerve head blood flow response to reduced ocular perfusion pressure by alteration of either the blood pressure or intraocular pressure.

PubMed

Wang, Lin; Cull, Grant A; Fortune, Brad

2015-04-01

To test the hypothesis that blood flow autoregulation in the optic nerve head has less reserve to maintain normal blood flow in the face of blood pressure-induced ocular perfusion pressure decrease than a similar magnitude intraocular pressure-induced ocular perfusion pressure decrease. Twelve normal non-human primates were anesthetized by continuous intravenous infusion of pentobarbital. Optic nerve blood flow was monitored by laser speckle flowgraphy. In the first group of animals (n = 6), the experimental eye intraocular pressure was maintained at 10 mmHg using a saline reservoir connected to the anterior chamber. The blood pressure was gradually reduced by a slow injection of pentobarbital. In the second group (n = 6), the intraocular pressure was slowly increased from 10 mmHg to 50 mmHg by raising the reservoir. In both experimental groups, optic nerve head blood flow was measured continuously. The blood pressure and intraocular pressure were simultaneously recorded in all experiments. The optic nerve head blood flow showed significant difference between the two groups (p = 0.021, repeat measures analysis of variance). It declined significantly more in the blood pressure group compared to the intraocular pressure group when the ocular perfusion pressure was reduced to 35 mmHg (p < 0.045) and below. There was also a significant interaction between blood flow changes and the ocular perfusion pressure treatment (p = 0.004, adjusted Greenhouse & Geisser univariate test), indicating the gradually enlarged blood flow difference between the two groups was due to the ocular perfusion pressure decrease. The results show that optic nerve head blood flow is more susceptible to an ocular perfusion pressure decrease induced by lowering the blood pressure compared with that induced by increasing the intraocular pressure. This blood flow autoregulation capacity vulnerability to low blood pressure may provide experimental evidence related to the hemodynamic pathophysiology in glaucoma.

Overexcitability and Optimal Flow in Talented Dancers, Singers, and Athletes

ERIC Educational Resources Information Center

Thomson, Paula; Jaque, S. Victoria

2016-01-01

Overexcitability (OE) and optimal flow are variables shared by talented individuals. This study demonstrated that the dancer (n = 86) and opera singer (n = 61) groups shared higher OE profiles compared to the athlete group (n = 50). Two self-report instruments assessed flow (global and subscales) and the five OE dimensions. All groups endorsed…

Two-body decays of gluino at full one-loop level in the quark-flavour violating MSSM.

PubMed

Eberl, Helmut; Ginina, Elena; Hidaka, Keisho

2017-01-01

We study the two-body decays of the gluino at full one-loop level in the Minimal Supersymmetric Standard Model with quark-flavour violation (QFV) in the squark sector. The renormalisation is done in the [Formula: see text] scheme. The gluon and photon radiations are included by adding the corresponding three-body decay widths. We discuss the dependence of the gluino decay widths on the QFV parameters. The main dependence stems from the [Formula: see text]-[Formula: see text] mixing in the decays to up-type squarks, and from the [Formula: see text]-[Formula: see text] mixing in the decays to down-type squarks due to the strong constraints from B-physics on the other quark-flavour-mixing parameters. The full one-loop corrections to the gluino decay widths are mostly negative and of the order of about -10%. The QFV part stays small in the total width but can vary up to -8% for the decay width into the lightest [Formula: see text] squark. For the corresponding branching ratio the effect is somehow washed out by at least a factor of two. The electroweak corrections can be as large as 35% of the SUSY QCD corrections.

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

Chakraborty, Bipasha; Davies, C. T. H.; Donald, G. C.

Here, we compare correlators for pseudoscalar and vector mesons made from valence strange quarks using the clover quark and highly improved staggered quark (HISQ) formalisms in full lattice QCD. We use fully nonperturbative methods to normalise vector and axial vector current operators made from HISQ quarks, clover quarks and from combining HISQ and clover fields. This allows us to test expectations for the renormalisation factors based on perturbative QCD, with implications for the error budget of lattice QCD calculations of the matrix elements of clover-staggeredmore » $b$-light weak currents, as well as further HISQ calculations of the hadronic vacuum polarisation. We also compare the approach to the (same) continuum limit in clover and HISQ formalisms for the mass and decay constant of the $$\\phi$$ meson. Our final results for these parameters, using single-meson correlators and neglecting quark-line disconnected diagrams are: $$m_{\\phi} =$$ 1.023(5) GeV and $$f_{\\phi} = $$ 0.238(3) GeV in good agreement with experiment. These results come from calculations in the HISQ formalism using gluon fields that include the effect of $u$, $d$, $s$ and $c$ quarks in the sea with three lattice spacing values and $$m_{u/d}$$ values going down to the physical point.« less

Correlation of the flow patterns among the four pulmonary veins as assessed by transesophageal echocardiography: influence of significant mitral regurgitation.

PubMed

Hwang, J J; Lin, J M; Hsu, K L; Lai, L P; Tseng, Y Z; Lee, Y T; Lien, W P

1999-01-01

To evaluate the correlation of the flow patterns of the four pulmonary veins as assessed by transesophageal echocardiography and the influence of significant mitral regurgitation on this correlation. Eighty-eight patients with normal sinus rhythm and variable underlying cardiovascular diseases underwent transthoracic and transesophageal echocardiographic studies. Doppler flow of the four pulmonary veins could not be adequately interpreted in 19 patients (22%). The left atrial dimension of these patients was significantly larger than that of the patients with complete study of the flow in the four pulmonary veins (49 +/- 6 vs. 43 +/- 7 mm; p < 0.05). Of the 69 patients with complete evaluation of the four pulmonary veins, 48 patients without significant mitral regurgitation were analyzed as group A, and the remaining 21 patients as group B. The peak systolic and diastolic forward flow velocities of the four pulmonary veins were measured and the ratio of peak systolic (S) to diastolic (D) flow velocity was calculated. Group A had a significantly larger S/D ratio in all four pulmonary veins than group B (p < 0.05 in each pulmonary vein measurement). There was good correlation of the flow pattern represented as S/D ratio between left upper and lower pulmonary veins (r = 0.90) and between right upper and lower pulmonary veins (r = 0.89) in group A. The correlation of the flow pattern among the four pulmonary veins deteriorated in group B. Pulmonary veins on the same side share rather similar flow patterns in comparison with pulmonary veins on the opposite sides. The correlation of flow patterns among the four pulmonary veins is good in subjects without significant mitral regurgitation, but it worsens in patients with significant mitral regurgitation. Therefore, cautious interpretation of flow patterns of the four pulmonary veins in patients with significant regurgitation is indicated for grading the severity of mitral regurgitation.

The effects of respiratory muscle training on peak cough flow in patients with Parkinson's disease: a randomized controlled study.

PubMed

Reyes, Alvaro; Castillo, Adrián; Castillo, Javiera; Cornejo, Isabel

2018-05-01

To compare the effects of an inspiratory versus and expiratory muscle-training program on voluntary and reflex peak cough flow in patients with Parkinson disease. A randomized controlled study. Home-based training program. In all, 40 participants with diagnosis of Parkinson's disease were initially recruited in the study and randomly allocated to three study groups. Of them, 31 participants completed the study protocol (control group, n = 10; inspiratory training group, n = 11; and expiratory training group, n = 10) Intervention: The inspiratory and expiratory group performed a home-based inspiratory and expiratory muscle-training program, respectively (five sets of five repetitions). Both groups trained six times a week for two months using a progressively increased resistance. The control group performed expiratory muscle training using the same protocol and a fixed resistance. Spirometric indices, maximum inspiratory pressure, maximum expiratory pressure, and peak cough flow during voluntary and reflex cough were assessed before and at two months after training. The magnitude of increase in maximum expiratory pressure ( d = 1.40) and voluntary peak cough flow ( d = 0.89) was greater for the expiratory muscle-training group in comparison to the control group. Reflex peak cough flow had a moderate effect ( d = 0.27) in the expiratory group in comparison to the control group. Slow vital capacity ( d = 0.13) and forced vital capacity ( d = 0.02) had trivial effects in the expiratory versus the control group. Two months of expiratory muscle-training program was more beneficial than inspiratory muscle-training program for improving maximum expiratory pressure and voluntary peak cough flow in patients with Parkinson's disease.

Relationship of long-term highly active antiretroviral therapy on salivary flow rate and CD4 Count among HIV-infected patients.

PubMed

Kumar, J Vijay; Baghirath, P Venkat; Naishadham, P Parameswar; Suneetha, Sujai; Suneetha, Lavanya; Sreedevi, P

2015-01-01

To determine if long-term highly active antiretroviral therapy (HAART) therapy alters salivary flow rate and also to compare its relation of CD4 count with unstimulated and stimulated whole saliva. A cross-sectional study was performed on 150 individuals divided into three groups. Group I (50 human immunodeficiency virus (HIV) seropositive patients, but not on HAART therapy), Group II (50 HIV-infected subjects and on HAART for less than 3 years called short-term HAART), Group III (50 HIV-infected subjects and on HAART for more than or equal to 3 years called long-term HAART). Spitting method proposed by Navazesh and Kumar was used for the measurement of unstimulated and stimulated salivary flow rate. Chi-square test and analysis of variance (ANOVA) were used for statistical analysis. The mean CD4 count was 424.78 ± 187.03, 497.82 ± 206.11 and 537.6 ± 264.00 in the respective groups. Majority of the patients in all the groups had a CD4 count between 401 and 600. Both unstimulated and stimulated whole salivary (UWS and SWS) flow rates in Group I was found to be significantly higher than in Group II (P < 0.05). Unstimulated salivary flow rate between Group II and III subjects were also found to be statistically significant (P < 0.05). ANOVA performed between CD4 count and unstimulated and stimulated whole saliva in each group demonstrated a statistically significant relationship in Group II (P < 0.05). There were no significant results found between CD4 count and stimulated whole saliva in each groups. The reduction in CD4 cell counts were significantly associated with salivary flow rates of HIV-infected individuals who are on long-term HAART.

Cyanotic congenital heart disease the coronary arterial circulation.

PubMed

Perloff, Joseph K

2012-02-01

The coronary circulation in cyanotic congenital heart disease (CCHD) includes the extramural coronary arteries, basal coronary blood flow, flow reserve, the coronary microcirculation, and coronary atherogenesis. Coronary arteriograms were analyzed in 59 adults with CCHD. Dilated extramural coronaries were examined histologically in six patients. Basal coronary blood flow was determined with N-13 positron emission tomography in 14 patients and in 10 controls. Hyperemic flow was induced by intravenous dipyridamole pharmacologic stress. Immunostaining against SM alpha-actin permitted microcirculatory morphometric analysis. Non-fasting total cholesterols were retrieved in 279 patients divided into four groups: Group A---143 cyanotic unoperated, Group B---47 rendered acyanotic by reparative surgery, Group C---41 acyanotic unoperated, Group D---48 acyanotic before and after operation. Extramural coronary arteries were mildly or moderately dilated to ectatic in 49/59 angiograms. Histologic examination disclosed loss of medial smooth muscle, increased medial collagen, and duplication of internal elastic lamina. Basal coronary flow was appreciably increased. Hyperemic flow was comparable to controls. Remodeling of the microcirculation was based upon coronary arteriolar length, volume and surface densities. Coronary atherosclerosis was absent in both the arteriograms and the necropsy specimens. Extramural coronary arteries in CCHD dilate in response to endothelial vasodilator substances supplemented by mural attenuation caused by medial abnormalities. Basal coronary flow was appreciably increased, but hyperemic flow was normal. Remodeling of the microcirculation was responsible for preservation of flow reserve. The coronaries were atheroma-free because of the salutory effects of hypocholesterolemia, hypoxemia, upregulated nitric oxide, low platelet counts, and hyperbilirubinrmia.

Assessing the Financial Condition of Provider-Sponsored Health Plans.

PubMed

McCue, Michael J

2015-06-01

The aim of this study was to assess the performance of health plans sponsored by provider organizations, with respect to plans generating strong positive cash flow relative to plans generating weaker cash flow. A secondary aim was to assess their capital adequacy. The study identified 24 provider-sponsored health plans (PSHPs) with an average positive cash flow margin from 2011 through 2013 at or above the top 75th percentile, defined as "strong cash flow PSHPs:" This group was compared with 72 PSHPs below the 75th percentile, defined as "weak cash flow PSHPs:" Atlantic Information Services Directory of Health Plans was used to identify the PSHPs. Financial ratios were computed from 2013 National Association of Insurance Commissioners Financial Filings. The study conducted a t test mean comparison between strong and weak cash flow PSHPs across an array of financial performance and capital adequacy measures. In 2013, the strong cash flow PSHPs averaged a cash-flow margin ratio of 6.6%. Weak cash flow PSHPs averaged a cash-flow margin of -0.4%. The net worth capital position of both groups was more than 4.5 times authorized capital. The operational analysis shows that strong cash-flow margin PSHPs are managing their medical costs to achieve this position. Although their medical loss ratio increased by almost 300 basis points from 2011 to 2013, it was still statistically significantly lower than the weaker cash flow PSHP group (P<.001). In terms of capital adequacy, both strong and weak cash-flow margin PSHP groups possessed sufficient capital to ensure the viability of these plans.

Simulator training and non-technical factors improve laparoscopic performance among OBGYN trainees.

PubMed

Ahlborg, Liv; Hedman, Leif; Nisell, Henry; Felländer-Tsai, Li; Enochsson, Lars

2013-10-01

To investigate how simulator training and non-technical factors affect laparoscopic performance among residents in obstetrics and gynecology. In this prospective study, trainees were randomized into three groups. The first group was allocated to proficiency-based training in the LapSimGyn(®) virtual reality simulator. The second group received additional structured mentorship during subsequent laparoscopies. The third group served as control group. At baseline an operation was performed and visuospatial ability, flow and self-efficacy were assessed. All groups subsequently performed three tubal occlusions. Self-efficacy and flow were assessed before and/or after each operation. Simulator training was conducted at the Center for Advanced Medical Simulation and Training, Karolinska University Hospital. Sterilizations were performed at each trainee's home clinic. Twenty-eight trainees/residents from 21 hospitals in Sweden were included. Visuospatial ability was tested by the Mental Rotation Test-A. Flow and self-efficacy were assessed by validated scales and questionnaires. Laparoscopic performance was measured as the duration of surgery. Visuospatial ability, self-efficacy and flow were correlated to the laparoscopic performance using Spearman's correlations. Differences between groups were analyzed by the Mann-Whitney U-test. No differences across groups were detected at baseline. Self-efficacy scores before and flow scores after the third operation were significantly higher in the trained groups. Duration of surgery was significantly shorter in the trained groups. Flow and self-efficacy correlate positively with laparoscopic performance. Simulator training and non-technical factors appear to improve the laparoscopic performance among trainees/residents in obstetrics and gynecology. © 2013 Nordic Federation of Societies of Obstetrics and Gynecology.

Flow of quasi-two dimensional water in graphene channels

NASA Astrophysics Data System (ADS)

Fang, Chao; Wu, Xihui; Yang, Fengchang; Qiao, Rui

2018-02-01

When liquids confined in slit channels approach a monolayer, they become two-dimensional (2D) fluids. Using molecular dynamics simulations, we study the flow of quasi-2D water confined in slit channels featuring pristine graphene walls and graphene walls with hydroxyl groups. We focus on to what extent the flow of quasi-2D water can be described using classical hydrodynamics and what are the effective transport properties of the water and the channel. First, the in-plane shearing of quasi-2D water confined between pristine graphene can be described using the classical hydrodynamic equation, and the viscosity of the water is ˜50% higher than that of the bulk water in the channel studied here. Second, the flow of quasi-2D water around a single hydroxyl group is perturbed at a position of tens of cluster radius from its center, as expected for low Reynolds number flows. Even though water is not pinned at the edge of the hydroxyl group, the hydroxyl group screens the flow greatly, with a single, isolated hydroxyl group rendering drag similar to ˜90 nm2 pristine graphene walls. Finally, the flow of quasi-2D water through graphene channels featuring randomly distributed hydroxyl groups resembles the fluid flow through porous media. The effective friction factor of the channel increases linearly with the hydroxyl groups' area density up to 0.5 nm-2 but increases nonlinearly at higher densities. The effective friction factor of the channel can be fitted to a modified Carman equation at least up to a hydroxyl area density of 2.0 nm-2. These findings help understand the liquid transport in 2D material-based nanochannels for applications including desalination.

Variability of computational fluid dynamics solutions for pressure and flow in a giant aneurysm: the ASME 2012 Summer Bioengineering Conference CFD Challenge.

PubMed

Steinman, David A; Hoi, Yiemeng; Fahy, Paul; Morris, Liam; Walsh, Michael T; Aristokleous, Nicolas; Anayiotos, Andreas S; Papaharilaou, Yannis; Arzani, Amirhossein; Shadden, Shawn C; Berg, Philipp; Janiga, Gábor; Bols, Joris; Segers, Patrick; Bressloff, Neil W; Cibis, Merih; Gijsen, Frank H; Cito, Salvatore; Pallarés, Jordi; Browne, Leonard D; Costelloe, Jennifer A; Lynch, Adrian G; Degroote, Joris; Vierendeels, Jan; Fu, Wenyu; Qiao, Aike; Hodis, Simona; Kallmes, David F; Kalsi, Hardeep; Long, Quan; Kheyfets, Vitaly O; Finol, Ender A; Kono, Kenichi; Malek, Adel M; Lauric, Alexandra; Menon, Prahlad G; Pekkan, Kerem; Esmaily Moghadam, Mahdi; Marsden, Alison L; Oshima, Marie; Katagiri, Kengo; Peiffer, Véronique; Mohamied, Yumnah; Sherwin, Spencer J; Schaller, Jens; Goubergrits, Leonid; Usera, Gabriel; Mendina, Mariana; Valen-Sendstad, Kristian; Habets, Damiaan F; Xiang, Jianping; Meng, Hui; Yu, Yue; Karniadakis, George E; Shaffer, Nicholas; Loth, Francis

2013-02-01

Stimulated by a recent controversy regarding pressure drops predicted in a giant aneurysm with a proximal stenosis, the present study sought to assess variability in the prediction of pressures and flow by a wide variety of research groups. In phase I, lumen geometry, flow rates, and fluid properties were specified, leaving each research group to choose their solver, discretization, and solution strategies. Variability was assessed by having each group interpolate their results onto a standardized mesh and centerline. For phase II, a physical model of the geometry was constructed, from which pressure and flow rates were measured. Groups repeated their simulations using a geometry reconstructed from a micro-computed tomography (CT) scan of the physical model with the measured flow rates and fluid properties. Phase I results from 25 groups demonstrated remarkable consistency in the pressure patterns, with the majority predicting peak systolic pressure drops within 8% of each other. Aneurysm sac flow patterns were more variable with only a few groups reporting peak systolic flow instabilities owing to their use of high temporal resolutions. Variability for phase II was comparable, and the median predicted pressure drops were within a few millimeters of mercury of the measured values but only after accounting for submillimeter errors in the reconstruction of the life-sized flow model from micro-CT. In summary, pressure can be predicted with consistency by CFD across a wide range of solvers and solution strategies, but this may not hold true for specific flow patterns or derived quantities. Future challenges are needed and should focus on hemodynamic quantities thought to be of clinical interest.

SPheno 3.1: extensions including flavour, CP-phases and models beyond the MSSM

NASA Astrophysics Data System (ADS)

Porod, W.; Staub, F.

2012-11-01

We describe recent extensions of the program SPhenoincluding flavour aspects, CP-phases, R-parity violation and low energy observables. In case of flavour mixing all masses of supersymmetric particles are calculated including the complete flavour structure and all possible CP-phases at the 1-loop level. We give details on implemented seesaw models, low energy observables and the corresponding extension of the SUSY Les Houches Accord. Moreover, we comment on the possibilities to include MSSM extensions in SPheno. Catalogue identifier: ADRV_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADRV_v2_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 154062 No. of bytes in distributed program, including test data, etc.: 1336037 Distribution format: tar.gz Programming language: Fortran95. Computer: PC running under Linux, should run in every Unix environment. Operating system: Linux, Unix. Classification: 11.6. Catalogue identifier of previous version: ADRV_v1_0 Journal reference of previous version: Comput. Phys. Comm. 153(2003)275 Does the new version supersede the previous version?: Yes Nature of problem: The first issue is the determination of the masses and couplings of supersymmetric particles in various supersymmetric models, the R-parity conserved MSSM with generation mixing and including CP-violating phases, various seesaw extensions of the MSSM and the MSSM with bilinear R-parity breaking. Low energy data on Standard Model fermion masses, gauge couplings and electroweak gauge boson masses serve as constraints. Radiative corrections from supersymmetric particles to these inputs must be calculated. Theoretical constraints on the soft SUSY breaking parameters from a high scale theory are imposed and the parameters at the electroweak scale are obtained from the high scale parameters by evaluating the corresponding renormalisation group equations. These parameters must be consistent with the requirement of correct electroweak symmetry breaking. The second issue is to use the obtained masses and couplings for calculating decay widths and branching ratios of supersymmetric particles as well as the cross sections for these particles in electron-positron annihilation. The third issue is to calculate low energy constraints in the B-meson sector such as BR(b s), MB s, rare lepton decays, such as BR(e), the SUSY contributions to anomalous magnetic moments and electric dipole moments of leptons, the SUSY contributions to the ρ parameter as well as lepton flavour violating Z decays. Solution method: The renormalisation connecting a high scale and the electroweak scale is calculated by the Runge-Kutta method. Iteration provides a solution consistent with the multi-boundary conditions. In case of three-body decays and for the calculation of initial state radiation Gaussian quadrature is used for the numerical solution of the integrals. Reasons for new version: Inclusion of new models as well as additional observables. Moreover, a new standard for data transfer had been established, which is now supported. Summary of revisions: The already existing models have been extended to include also CP-violation and flavour mixing. The data transfer is done using the so-called SLHA2 standard. In addition new models have been included: all three types of seesaw models as well as bilinear R-parity violation. Moreover, additional observables are calculated: branching ratios for flavour violating lepton decays, EDMs of leptons and of the neutron, CP-violating mass difference in the B-meson sector and branching ratios for flavour violating b-quark decays. Restrictions: In case of R-parity violation the cross sections are not calculated. Running time: 0.2 seconds on an Intel(R) Core(TM)2 Duo CPU T9900 with 3.06 GHz

Effects of chewing rate and reactive hyperemia on blood flow in denture-supporting mucosa during simulated chewing.

PubMed

Ogino, Takamichi; Ueda, Takayuki; Ogami, Koichiro; Koike, Takashi; Sakurai, Kaoru

2017-01-01

We examined how chewing rate and the extent of reactive hyperemia affect the blood flow in denture-supporting mucosa during chewing. The left palatal mucosa was loaded under conditions of simulated chewing or simulated clenching for 30s, and the blood flow during loading was recorded. We compared the relative blood flow during loading under conditions that recreated different chewing rates by combining duration of chewing cycle (DCC) and occlusal time (OT): fast chewing group, typical chewing group, slow chewing group and clenching group. The relationship between relative blood flow during simulated chewing and the extent of reactive hyperemia was also analyzed. When comparing the different chewing rate, the relative blood flow was highest in fast chewing rate, followed by typical chewing rate and slow chewing rate. Accordingly, we suggest that fast chewing increases the blood flow more than typical chewing or slow chewing. There was a significant correlation between the amount of blood flow during simulated chewing and the extent of reactive hyperemia. Within the limitations of this study, we concluded that slow chewing induced less blood flow than typical or fast chewing in denture-supporting mucosa and that people with less reactive hyperemia had less blood flow in denture-supporting mucosa during chewing. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Local expansion flows of galaxies: quantifying acceleration effect of dark energy

NASA Astrophysics Data System (ADS)

Chernin, A. D.; Teerikorpi, P.

2013-08-01

The nearest expansion flow of galaxies observed around the Local group is studied as an archetypical example of the newly discovered local expansion flows around groups and clusters of galaxies in the nearby Universe. The flow is accelerating due to the antigravity produced by the universal dark energy background. We introduce a new acceleration measure of the flow which is the dimensionless ``acceleration parameter" Q (x) = x - x-2 depending on the normalized distance x only. The parameter is zero at the zero-gravity distance x = 1, and Q(x) ∝ x, when x ≫ 1. At the distance x = 3, the parameter Q = 2.9. Since the expansion flows have a self-similar structure in normalized variables, we expect that the result is valid as well for all the other expansion flows around groups and clusters of galaxies on the spatial scales from ˜ 1 to ˜ 10 Mpc everywhere in the Universe.

Early infectious complications in allogeneic marrow transplant recipients with acute leukemia: effects of prophylactic measures.

PubMed

Buckner, C D; Clift, R A; Thomas, E D; Hersman, J; Sanders, J E; Stewart, P S; Wade, J C; Murphy, M; Counts, G; Meyers, J D

1983-01-01

One hundred eighty-two patients with acute leukemia underwent allogeneic marrow transplantation and received one of two forms of infection prophylaxis: isolation and decontamination procedures in laminar air flow rooms (90 patients) or prophylactic granulocyte transfusion from a single family member (92 patients). Infection acquisition and survival were analyzed from the time of admission to 100 days posttransplant. There were 20 major local infections in the laminar air flow group and 16 in the prophylactic granulocyte group. Of the patients in the laminar air flow group, 24 (27%) had 27 episodes of bacteremia, while 23 (25%) of the prophylactic granulocyte group had 25 episodes of bacteremia. There were no significant differences in infection acquisition between the two groups during the period of granulocytopenia or after engraftment. The mortality during the first 100 days was 28% for the laminar air flow group and 35% for the prophylactic granulocyte group. Thirteen patients (14%) in the laminar air flow group and five (5%) in the prophylactic granulocyte group died with bacterial or fungal infections. There were no statistically significant differences between the two groups in overall incidence of or mortality from interstitial pneumonitis which was the predominant cause of death. However, the subset of patients who were seronegative for cytomegalovirus antibody at the time of transplant and received granulocytes from seropositive donors had a significantly higher incidence of and mortality from cytomegalovirus interstitial pneumonitis.

Effects of Constant Flow vs. Constant Pressure Perfusion on Fluid Filtration in Severe Hypothermic Isolated Blood-Perfused Rat Lungs.

PubMed

Halsøy, Kathrine; Kondratiev, Timofey; Tveita, Torkjel; Bjertnaes, Lars J

2016-01-01

Victims of severe accidental hypothermia are prone to fluid extravasation but rarely develop lung edema. We hypothesize that combined hypothermia-induced increase in pulmonary vascular resistance (PVR) and a concomitant fall in cardiac output protect the lungs against edema development. Our aim was to explore in hypothermic-isolated blood-perfused rat lungs whether perfusion at constant pressure influences fluid filtration differently from perfusion at constant flow. Isolated blood-perfused rat lungs were hanging freely in a weight transducer for measuring weight changes (ΔW). Fluid filtration coefficient (Kfc), was determined by transiently elevating left atrial pressure (Pla) by 5.8 mmHg two times each during normothermia (37°C) and during hypothermia (15°C). The lung preparations were randomized to two groups. One group was perfused with constant flow (Constant flow group) and the other group with constant pulmonary artery pressure (Constant PPA group). Microvascular pressure (Pmv) was determined before and during elevation of Pla (ΔPmv) by means of the double occlusion technique. Kfc was calculated with the formula Kfc = ΔW/ΔPmv/min. All Kfc values were normalized to predicted lung weight (P LW ), which was based on body weight (BW) according to the formula: P LW  = 0.0053 BW - 0.48 and presented as Kfc PLW in mg/min/mmHg/g. At cessation, bronchoalveolar lavage (BAL) fluid/perfusate protein concentration (B/P) ratio was determined photometrically. Data were analyzed with parametric or non-parametric tests as appropriate. p  < 0.05 considered as significant. Perfusate flow remained constant in the Constant flow group, but was more than halved during hypothermia in the Constant PPA group concomitant with a more fold increase in PVR. In the Constant flow group, Kfc PLW and B/P ratio increased significantly by more than 10-fold during hypothermia concerted by visible signs of edema in the trachea. Hemoglobin and hematocrit increased within the Constant flow group and between the groups at cessation of the experiments. In hypothermic rat lungs perfused at constant flow, fluid filtration coefficient per gram P LW and B/P ratio increased more than 10-fold concerted by increased hemoconcentration, but the changes were less in hypothermic lungs perfused at constant PPA.

Male-Mediated Gene Flow in Patrilocal Primates

PubMed Central

Schubert, Grit; Stoneking, Colin J.; Arandjelovic, Mimi; Boesch, Christophe; Eckhardt, Nadin; Hohmann, Gottfried; Langergraber, Kevin; Lukas, Dieter; Vigilant, Linda

2011-01-01

Background Many group–living species display strong sex biases in dispersal tendencies. However, gene flow mediated by apparently philopatric sex may still occur and potentially alters population structure. In our closest living evolutionary relatives, dispersal of adult males seems to be precluded by high levels of territoriality between males of different groups in chimpanzees, and has only been observed once in bonobos. Still, male–mediated gene flow might occur through rare events such as extra–group matings leading to extra–group paternity (EGP) and female secondary dispersal with offspring, but the extent of this gene flow has not yet been assessed. Methodology/Principal Findings Using autosomal microsatellite genotyping of samples from multiple groups of wild western chimpanzees (Pan troglodytes verus) and bonobos (Pan paniscus), we found low genetic differentiation among groups for both males and females. Characterization of Y–chromosome microsatellites revealed levels of genetic differentiation between groups in bonobos almost as high as those reported previously in eastern chimpanzees, but lower levels of differentiation in western chimpanzees. By using simulations to evaluate the patterns of Y–chromosomal variation expected under realistic assumptions of group size, mutation rate and reproductive skew, we demonstrate that the observed presence of multiple and highly divergent Y–haplotypes within western chimpanzee and bonobo groups is best explained by successful male–mediated gene flow. Conclusions/Significance The similarity of inferred rates of male–mediated gene flow and published rates of EGP in western chimpanzees suggests this is the most likely mechanism of male–mediated gene flow in this subspecies. In bonobos more data are needed to refine the estimated rate of gene flow. Our findings suggest that dispersal patterns in these closely related species, and particularly for the chimpanzee subspecies, are more variable than previously appreciated. This is consistent with growing recognition of extensive behavioral variation in chimpanzees and bonobos. PMID:21747938

Determinants of expiratory flow limitation in healthy women during exercise.

PubMed

Dominelli, Paolo B; Guenette, Jordan A; Wilkie, Sabrina S; Foster, Glen E; Sheel, A William

2011-09-01

Expiratory flow limitation (EFL) can occur in healthy young women during exercise. We questioned whether the occurrence and severity of EFL were related to aerobic fitness or anatomical factors. Twenty-two healthy young (<40 yr) women performed a progressive cycle test to exhaustion. The subjects' maximum expiratory flow-volume curve was compiled from several effort-graded vital capacity maneuvers before and after exercise. The maximum expiratory flow-volume curve, along with inspiratory capacity maneuvers, was used to determine lung volumes and expiratory flows and to quantify EFL. To determine relative airway size, we used a ratio sensitive to both airway size and lung volume, called the dysanapsis ratio. The subjects were partitioned into two groups based upon the appearance of >5% EFL. Ten subjects showed EFL during exercise. Forced vital capacities (4.4 ± 0.4 vs 3.7 ± 0.4 L, P < 0.001) and forced expiratory flows for any given lung volume were significantly larger in the non-expiratory flow-limited (NEFL) group. The NEFL group's dysanapsis ratio was significantly larger than that of the EFL group (0.27 ± 0.06 vs 0.21 ± 0.04, respectively, P < 0.05), indicating larger airways in the NEFL group. There was no difference between the NEFL and EFL groups with respect to maximal aerobic capacity (50.8 ± 10.0 vs 46.7 ± 5.9 mL·kg(-1)·min(-1), respectively, P = 0.264). At peak exercise, the NEFL group had a significantly higher end-expiratory lung volume than the EFL group (40.1% ± 4.8% vs 33.7% ± 5.7% FVC, respectively, P < 0.05). We conclude that EFL in women can largely be explained by anatomical factors that influence the capacity to generate flow and volume during exercise rather than fitness per se.

Impact of chronic hypoxemia on blood flow to the brain, heart, and adrenal gland in the late-gestation IUGR sheep fetus.

PubMed

Poudel, Rajan; McMillen, I Caroline; Dunn, Stacey L; Zhang, Song; Morrison, Janna L

2015-02-01

In the fetus, there is a redistribution of cardiac output in response to acute hypoxemia, to maintain perfusion of key organs, including the brain, heart, and adrenal glands. There may be a similar redistribution of cardiac output in the chronically hypoxemic, intrauterine growth-restricted fetus. Surgical removal of uterine caruncles in nonpregnant ewe results in the restriction of placental growth (PR) and intrauterine growth. Vascular catheters were implanted in seven control and six PR fetal sheep, and blood flow to organs was determined using microspheres. Placental and fetal weight was significantly reduced in the PR group. Despite an increase in the relative brain weight in the PR group, there was no difference in blood flow to the brain between the groups, although PR fetuses had higher blood flow to the temporal lobe. Adrenal blood flow was significantly higher in PR fetuses, and there was a direct relationship between mean gestational PaO2 and blood flow to the adrenal gland. There was no change in blood flow, but a decrease in oxygen and glucose delivery to the heart in the PR fetuses. In another group, there was a decrease in femoral artery blood flow in the PR compared with the Control group, and this may support blood flow changes to the adrenal and temporal lobe. In contrast to the response to acute hypoxemia, these data show that there is a redistribution of blood flow to the adrenals and temporal lobe, but not the heart or whole brain, in chronically hypoxemic PR fetuses in late gestation. Copyright © 2015 the American Physiological Society.

Does an Open Recirculation Line Affect the Flow Rate and Pressure in a Neonatal Extracorporeal Life Support Circuit With a Centrifugal or Roller Pump?

PubMed

Wang, Shigang; Spencer, Shannon B; Woitas, Karl; Glass, Kristen; Kunselman, Allen R; Ündar, Akif

2017-01-01

The objective of this study is to evaluate the impact of an open or closed recirculation line on flow rate, circuit pressure, and hemodynamic energy transmission in simulated neonatal extracorporeal life support (ECLS) systems. The two neonatal ECLS circuits consisted of a Maquet HL20 roller pump (RP group) or a RotaFlow centrifugal pump (CP group), Quadrox-iD Pediatric oxygenator, and Biomedicus arterial and venous cannulae (8 Fr and 10 Fr) primed with lactated Ringer's solution and packed red blood cells (hematocrit 35%). Trials were conducted at flow rates ranging from 200 to 600 mL/min (200 mL/min increments) with a closed or open recirculation line at 36°C. Real-time pressure and flow data were recorded using a custom-based data acquisition system. In the RP group, the preoxygenator flow did not change when the recirculation line was open while the prearterial cannula flow decreased by 15.7-20.0% (P < 0.01). Circuit pressure, total circuit pressure drop, and hemodynamic energy delivered to patients also decreased (P < 0.01). In the CP group, the prearterial cannula flow did not change while preoxygenator flow increased by 13.6-18.8% (P < 0.01). Circuit pressure drop and hemodynamic energy transmission remained the same. The results showed that the shunt of an open recirculation line could decrease perfusion flow in patients in the ECLS circuit using a roller pump, but did not change perfusion flow in the circuit using a centrifugal pump. An additional flow sensor is needed to monitor perfusion flow in patients if any shunts exist in the ECLS circuit. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Impact of laminar flow velocity of different acids on enamel calcium loss.

PubMed

Attin, T; Becker, K; Wiegand, A; Tauböck, T T; Wegehaupt, F J

2013-03-01

The aim of the study was to evaluate the impact of flow velocity under laminar flow conditions of different acidic solutions on enamel erosion. A total of 240 bovine enamel specimens were prepared and allocated to 30 groups (n = 8 each). Samples of 18 groups were superfused in a flow chamber system with laminar flow behavior using 1 ml of citric acid or hydrochloric acid (HCl) of pH 2.0, 2.6 or 3.0. Flow rates in the sample chamber were adjusted to 10, 60 or 100 μl/min. To simulate turbulent flow behavior, samples of six groups were immersed in 1 ml of the respective solution, which was vortexed (15 min, 600 rpm). For simulating non-agitated conditions, specimens of the remaining six groups were immersed in 1 ml of the respective solution without stirring. Calcium in the solutions, released from the enamel samples, was determined using Arsenazo III method. For acidic solutions of pH 2.6 and 3.0, erosive potential of citric acid was equivalent to that of HCl at a flow of 100 μl/min. The same observation was made for the samples subjected to turbulent conditions at pH 3. At all other conditions, citric acid induced a significantly higher calcium loss than HCl. It is concluded that under slow laminar flow conditions, flow rate variations lead to higher erosive impact of citric acid compared to hydrochloric acid at pH 2.0, but not at pH ≥ 2.6 and increasing laminar flow or turbulent conditions. Erosive enamel dissolution under laminar flow conditions is a complex issue influenced by flow rate and acidic substrate.

Cyanotic Congenital Heart Disease The Coronary Arterial Circulation

PubMed Central

Perloff, Joseph K

2012-01-01

Background: The coronary circulation in cyanotic congenital heart disease (CCHD) includes the extramural coronary arteries, basal coronary blood flow, flow reserve, the coronary microcirculation, and coronary atherogenesis. Methods: Coronary arteriograms were analyzed in 59 adults with CCHD. Dilated extramural coronaries were examined histologically in six patients. Basal coronary blood flow was determined with N-13 positron emission tomography in 14 patients and in 10 controls. Hyperemic flow was induced by intravenous dipyridamole pharmacologic stress. Immunostaining against SM alpha-actin permitted microcirculatory morphometric analysis. Non-fasting total cholesterols were retrieved in 279 patients divided into four groups: Group A---143 cyanotic unoperated, Group B---47 rendered acyanotic by reparative surgery, Group C---41 acyanotic unoperated, Group D---48 acyanotic before and after operation. Results: Extramural coronary arteries were mildly or moderately dilated to ectatic in 49/59 angiograms. Histologic examination disclosed loss of medial smooth muscle, increased medial collagen, and duplication of internal elastic lamina. Basal coronary flow was appreciably increased. Hyperemic flow was comparable to controls. Remodeling of the microcirculation was based upon coronary arteriolar length, volume and surface densities. Coronary atherosclerosis was absent in both the arteriograms and the necropsy specimens. Conclusions: Extramural coronary arteries in CCHD dilate in response to endothelial vasodilator substances supplemented by mural attenuation caused by medial abnormalities. Basal coronary flow was appreciably increased, but hyperemic flow was normal. Remodeling of the microcirculation was responsible for preservation of flow reserve. The coronaries were atheroma-free because of the salutory effects of hypocholesterolemia, hypoxemia, upregulated nitric oxide, low platelet counts, and hyperbilirubinrmia. PMID:22845810

Effect of Isometric Hand Grip Exercises on Blood Flow and Placement of IV Catheters for Administration of Chemotherapy.

PubMed

Ozkaraman, Ayse; Yesilbalkan, Öznur Usta

2016-04-01

Complications may occur in the subcutaneous or subdermal tissues during IV administration of chemotherapy related to blood flow and catheter placement. Daily isometric hand grip exercises were evaluated for their effect on blood flow in the vessels of the nondominant arm before placement of IV catheters and the success rate of IV catheter placement on the first attempt. The study focused on patients with non-Hodgkin lymphoma receiving the first and second cycles of chemotherapy. The intervention group performed daily isometric hand grip exercises before chemotherapy with peripheral catheter insertion. The control group performed routine activities only. Blood flow was measured by ultrasound in the brachial artery (BA) and brachial vein (BV) of the nondominant arm before the first (T1) and second (T2) cycles of chemotherapy. Blood flow slightly increased in the intervention group at T2 compared to T1. In the control group, blood flow decreased in the BA and did not change in the BV at T2 compared to T1. The success rate for first-attempt placement of a peripheral IV catheter was the same for the intervention and control groups.

Temporary arterial shunts to maintain limb perfusion after arterial injury: an animal study

NASA Technical Reports Server (NTRS)

Dawson, D. L.; Putnam, A. T.; Light, J. T.; Ihnat, D. M.; Kissinger, D. P.; Rasmussen, T. E.; Bradley, D. V. Jr

1999-01-01

BACKGROUND: Temporary shunt placement can quickly restore perfusion after extremity arterial injury. This study examined the adequacy of limb blood flow with shunt use, non-heparin-bonded shunt patency over prolonged periods, and the safety of this technique. METHODS: Common iliac arteries were divided and 4.0-mm Silastic Sundt shunts placed in 16 anesthetized pigs. Eight (group I) had shunts placed immediately; eight others (group II) were shunted after an hour of limb ischemia and hemorrhagic shock. Physiologic parameters and femoral artery blood flow in both hindlimbs were continuously monitored. Limb lactic acid generation, oxygen utilization, and hematologic and metabolic effects were serially evaluated for 24 hours. RESULTS: Shunts remained patent in 13 of 16 pigs. Shunts thrombosed in two group I animals because of technical errors, but functioned well after thrombectomy and repositioning. Patency could not be maintained in one animal that died from shock. Flow in group I shunted limbs was 57 (+/-11 SD) % of control. For group II animals in shock, shunted limb flow initially averaged 46 +/- 15% of control, but 4 hours after shunt placement, the mean limb blood flow was the same as in group I. Increased oxygen extraction compensated for the lower flow. Lactic acid production was not increased in comparison to control limbs. CONCLUSION: Shunts provided adequate flow in this model of extremity trauma. Correctly placed shunts stayed patent for 24 hours, without anticoagulation, if shunt placement followed resuscitation.

Prospective evaluation of basal stromal Doppler studies in women with good ovarian reserve and infertility undergoing in vitro fertilization-embryo transfer treatment: patients with polycystic ovary syndrome versus ovulatory patients.

PubMed

Younis, Johnny S; Jadaon, Jimmy E; Haddad, Sami; Izhaki, Ido; Ben-Ami, Moshe

2011-04-01

To gain insight into the ovarian stromal blood flow in women with polycystic ovary syndrome (PCOS) as compared with women with normal ovulation, good ovarian reserve, and infertility and to evaluate the role of stromal flow in these patients to predict clinical pregnancy in an assisted reproductive technologies setting. A prospective observational cohort study. A university-affiliated reproductive medicine unit. Eighteen consecutive patients with PCOS (study) compared with 101 patients with normal ovulation and infertility (control), undergoing their first IVF-ET treatment at our unit. Women with low ovarian reserve were excluded a priori from evaluation. Basal ovarian reserve parameters and stromal flow studies were conducted as routinely performed in our unit, in a natural cycle before starting treatment. None. Basal ovarian endocrine, sonographic, and stromal flow studies were compared between the groups. After completion of treatment, the stromal flow studies were compared between conception and nonconception cycles. Patients' characteristics and basal ovarian reserve, including endocrine and sonographic parameters, were similar between the PCOS and control groups. Only antral follicle count and LH/FSH ratio were higher in the PCOS as compared with the control group, corresponding to 15.11 ± 6.05 versus 9.05 ± 4.77 and 1.14 ± 0.64 versus 0.79 ± 0.37, respectively. Basal stromal flow indices were similar between the PCOS group and the group with normal ovulation and good ovarian reserve. Clinical pregnancy rate per initiated cycle was 50.0% and 39.6% in the PCOS and control groups, respectively, with no significant difference. Flow indices were similar between conception cycles in the PCOS and control groups. As well, the indices did not differ significantly between conception and nonconception cycles within the PCOS and control groups. Basal ovarian stromal blood flow does not differ between women with PCOS and women with normal ovulation, good ovarian reserve, and infertility. Moreover, stromal flow has no predictive value, in these patients, for clinical pregnancy achievement in an IVF-ET setting. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Biological assessment of environmental flows for Oklahoma

USGS Publications Warehouse

Fisher, William L.; Seilheimer, Titus S.; Taylor, Jason M.

2012-01-01

Large-scale patterns in fish assemblage structure and functional groups are influenced by alterations in streamflow regime. In this study, we defined an objective threshold for alteration for Oklahoma streams using a combination of the expected range of 27 flow indices and a discriminant analysis to predict flow regime group. We found that fish functional groups in reference flow conditions had species that were more intolerant to flow alterations and preferences for stream habitat and faster flowing water. In contrast, altered sites had more tolerant species that preferred lentic habitat and slower water velocity. Ordination graphs of the presence and functional groups of species revealed an underlying geographical pattern roughly conforming to ecoregions, although there was separation between reference and altered sites within the larger geographical framework. Additionally, we found that reservoir construction and operation significantly altered fish assemblages in two different systems, Bird Creek in central Oklahoma and the Kiamichi River in southeastern Oklahoma. The Bird Creek flow regime shifted from a historically intermittent stream to one with stable perennial flows, and changes in fish assemblage structure covaried with changes in all five components of the flow regime. In contrast, the Kiamichi River flow regime did not change significantly for most flow components despite shifts in fish assemblage structure; however, most of the species associated with shifts in assemblage structure in the Kiamichi River system were characteristic of lentic environments and were likely related more to proximity of reservoirs in the drainage system than changes in flow. The spatial patterns in fish assemblage response to flow alteration, combined with different temporal responses of hydrology and fish assemblage structure at sites downstream of reservoirs, indicate that interactions between flow regime and aquatic biota vary depending on ecological setting. This supports the notion that regional variation in natural flow regimes could affect the development of flow recommendations.

Quantum Structure of Space and Time

NASA Astrophysics Data System (ADS)

Duff, M. J.; Isham, C. J.

2012-07-01

Foreword Abdus Salam; Preface; List of participants; Part I. Quantum Gravity, Fields and Topology: 1. Some remarks on gravity and quantum mechanics Roger Penrose; 2. An experimental test of quantum gravity Don N. Page and C. D. Geilker; 3. Quantum mechanical origin of the sandwich theorem in classical gravitation theory Claudio Teitelboim; 4. θ-States induced by the diffeomorphism group in canonically quantized gravity C. J. Isham; 5. Strong coupling quantum gravity: an introduction Martin Pilati; 6. Quantizing fourth order gravity theories S. M. Christensen; 7. Green's functions, states and renormalisation M. R. Brown and A. C. Ottewill; 8. Introduction to quantum regge calculus Martin Roček and Ruth Williams; 9. Spontaneous symmetry breaking in curved space-time D. J. Toms; 10. Spontaneous symmetry breaking near a black hole M. S. Fawcett and B. F. Whiting; 11. Yang-Mills vacua in a general three-space G. Kunstatter; 12. Fermion fractionization in physics R. Jackiw; Part II. Supergravity: 13. The new minimal formulation of N=1 supergravity and its tensor calculus M. F. Sohnius and P. C. West; 14. A new deteriorated energy-momentum tensor M. J. Duff and P. K. Townsend; 15. Off-shell N=2 and N=4 supergravity in five dimensions P. Howe; 16. Supergravity in high dimensions P. van Niewenhuizen; 17. Building linearised extended supergravities J. G. Taylor; 18. (Super)gravity in the complex angular momentum plane M. T. Grisaru; 19. The multiplet structure of solitons in the O(2) supergravity theory G. W. Gibbons; 20. Ultra-violet properties of supersymmetric gauge theory S. Ferrara; 21. Extended supercurrents and the ultra-violet finiteness of N=4 supersymmetric Yang-Mills theories K. S. Stelle; 22. Duality rotations B. Zumino; Part III. Cosmology and the Early Universe: 23. Energy, stability and cosmological constant S. Deser; 24. Phase transitions in the early universe T. W. B. Kibble; 25. Complete cosmological theories L. P. Grishchuk and Ya. B. Zeldovich; 26. The cosmological constant and the weak anthropic principle S. W. Hawking.

Self-Similar Compressible Free Vortices

NASA Technical Reports Server (NTRS)

vonEllenrieder, Karl

1998-01-01

Lie group methods are used to find both exact and numerical similarity solutions for compressible perturbations to all incompressible, two-dimensional, axisymmetric vortex reference flow. The reference flow vorticity satisfies an eigenvalue problem for which the solutions are a set of two-dimensional, self-similar, incompressible vortices. These solutions are augmented by deriving a conserved quantity for each eigenvalue, and identifying a Lie group which leaves the reference flow equations invariant. The partial differential equations governing the compressible perturbations to these reference flows are also invariant under the action of the same group. The similarity variables found with this group are used to determine the decay rates of the velocities and thermodynamic variables in the self-similar flows, and to reduce the governing partial differential equations to a set of ordinary differential equations. The ODE's are solved analytically and numerically for a Taylor vortex reference flow, and numerically for an Oseen vortex reference flow. The solutions are used to examine the dependencies of the temperature, density, entropy, dissipation and radial velocity on the Prandtl number. Also, experimental data on compressible free vortex flow are compared to the analytical results, the evolution of vortices from initial states which are not self-similar is discussed, and the energy transfer in a slightly-compressible vortex is considered.

[Microcirculatory blood and lymph flow examination in eyelid skin by laser Doppler flowmetry].

PubMed

Safonova, T N; Kintyukhina, N P; Sidorov, V V; Gladkova, O V; Reyn, E S

to study normal blood and lymph microcirculation of the upper and lower eyelids in different age groups. The study included 108 volunteers (216 eyes) aged from 20 to 80 years with no signs of changes in anterior segment structures, who were grouped by age ranges (20-30 years, 31-40 years, 41-50 years, 51-60 years, 61-70 years, and 71-80 years) into 6 groups equal in gender and quantitative composition. In all volunteers, microcirculation of the upper and lower eyelids was examined by laser Doppler flowmetry (LDF) ('LASMA MC-1' peripheral blood and lymph flow analyzer and 'LASMA MC' laser diagnostic complex, LASMA LLC). The average perfusion changes in blood and lymph flow as well as blood and lymph flow oscillations were analyzed. Blood and lymph flow in the microvasculature of the upper and lower eyelids is variable and depends on neither the age, nor gender of the test subject. On LDF-gram, every increase in amplitude of blood flow corresponds to a decrease in that of lymph flow. The non-invasive method of LDF expands our diagnostic capabilities as it enables assessment of not only blood, but also lymph flow. The data obtained can serve as a starting point for exploring microcirculation in different age groups in the presence of different pathological processes.

Ultrasound Mediated Microbubbles Destruction Augmented Sonolysis: An In Vitro and In Vivo Study.

PubMed

Cui, Hai; Zhu, Qiong; Gao, Yunhua; Xia, Hongmei; Tan, Kaibin; He, Ying; Liu, Zheng; Xu, Yali

2017-01-01

This study was aimed at exploring ultrasound mediated microbubbles destruction (UMMD) assisted sonolysis in both the in vitro and in vivo clots. Therapeutic ultrasound (TUS) and lipid microbubbles (MBs) were used in whole blood clots and divided into the control, TUS group, and TUS + MB group. Thrombolytic rates and microscopy were performed. Color Doppler flow imaging (CDFI) and angiography were performed to evaluate the recanalization rates and flow scores in femoral arterial thrombus (FAT) in rabbits. FAT were dyed with H&E. The average thrombolytic ratios of TUS + MB group were significantly higher than those of TUS group and the control group (both P < 0.05). Clots had different pathological changes. Recanalization rates and flow scores in TUS + MB group were significantly higher than the control and TUS group. Flow scores and recanalization ratios were grade 0 in 0% of the control group, grade I in 25% of TUS group, and grade II or higher in 87.5% of TUS + MB group after 30 min sonolysis. Both the in vitro and in vivo sonolysis can be significantly augmented by the introduction of MBs without thrombolytic agents, which might be induced by the enhanced cavitation via UMMD.

Analysis of endoscopic third ventriculostomy patency by MRI: value of different pulse sequences, the sequence parameters, and the imaging planes for investigation of flow void.

PubMed

Dinçer, Alp; Yildiz, Erdem; Kohan, Saeed; Memet Özek, M

2011-01-01

The aim of the study is to evaluate the efficiency of turbo spin-echo (TSE), three-dimensional constructive interference in the steady state (3D CISS) and cine phase contrast (Cine PC) sequences in determining flow through the endoscopic third ventriculostomy (ETV) fenestration, and to determine the effect of various TSE sequence parameters. The study was approved by our institutional review board and informed consent from all patients was obtained. Two groups of patients were included: group I (24 patients with good clinical outcome after ETV) and group II (22 patients with hydrocephalus evaluated preoperatively). The imaging protocol for both groups was identical. TSE T2 with various sequence parameters and imaging planes, and 3D CISS, followed by cine PC were obtained. Flow void was graded as four-point scales. The sensitivity, specificity, accuracy, positive and negative predictive values of sequences were calculated. Bidirectional flow through the fenestration was detected in all group I patients by cine PC. Stroke volumes through the fenestration in group I ranged 10-160.8 ml/min. There was no correlation between the presence of reversed flow and flow void grading. Also, there was no correlation between the stroke volumes and flow void grading. The sensitivity of 3D CISS was low, and 2 mm sagittal TSE T2, nearly equal to cine PC, provided best result. Cine PC and TSE T2 both have high confidence in the assessment of the flow through the fenestration. But, sequence parameters significantly affect the efficiency of TSE T2.

Cervical microleakage in Class II cavities restored with the Sonicsys approx system.

PubMed

Rominu, Mihai; Florita, Zeno; Lakatos, Sorin; Rominu, Roxana Otilia

2009-04-01

To investigate the cervical microleakage in Class II cavities restored with Sonicsys approx ceramic inserts and four resin-based materials. Forty noncarious and crack-free mandibular third molars were used. These teeth were randomly assigned to four groups each containing 10 teeth. No control group was created. On each tooth, one mesial boxlike cavity was prepared using the active head Sonicsys approx no. 3. The cervical margin of each cavity was in enamel about 1 mm coronal to the cementoenamel junction. According to manufacturer's instructions, the prepared cavities were restored using a Sonicsys approx ceramic inserts no.3 and four resin-based materials as follows: group 1, Tetric Flow; group 2, Admira Flow; group 3, Nexus 2; group 4, X-Flow. After finishing and polishing, all specimens were stored in distilled water for 7 days at 37 degrees C, thermocycled 1,000 cycles between 5 degrees and 55 degrees C, and stored for 24 hours in basic fuchsine 2%. All specimens were then embedded in clear acrylic resin and sectioned along a mesial-distal plane through the middle of the cervical margin. The cervical areas of the resulting sections were examined using an optical microscope to assess the dye penetration. The registered scores were analyzed using Kruskal-Wallis and Mann-Whitney U tests. Microleakage was detected in each experimental group. Kruskal-Wallis test revealed statistically significant differences among groups (P = .009, alpha = .01). The Mann-Whitney U test showed significant differences between Admira Flow group and Tetric Flow (P = .011, alpha = .05), Nexus 2 (P = .001, alpha = .01), and X-Flow (P = .004, alpha = .01), respectively. Within the limitations of this study, the extent of microleakage in the cervical area (enamel) of Class II cavities restored with Sonicsys approx ceramic inserts depends on the material used for luting. The highest leakage occurred when Admira flow was used.

Effects of intravitreal injection of ranibizumab on choroidal structure and blood flow in eyes with diabetic macular edema.

PubMed

Okamoto, Masahiro; Yamashita, Mariko; Ogata, Nahoko

2018-05-01

To determine the effects of an intravitreal injection of ranibizumab (IVR) on the choroidal structure and blood flow in eyes with diabetic macular edema (DME). Twenty-eight consecutive patients with DME who received an IVR and 20 non-diabetic, age-matched controls were followed for 1 month. The eyes with DME were divided into those with prior panretinal photocoagulation (PRP, n = 16) and those without prior PRP (no-PRP, n = 12). The enhanced depth imaging optical coherence tomography (EDI-OCT) scans and Niblack's image binarization were performed to determine the choroidal structure. The choroidal blood flow was determined by laser speckle flowgraphy. The subfoveal choroidal thickness at the baseline was significantly thicker in the no-PRP group than in the PRP-treated group. After IVR, the best-corrected visual acuity (BCVA) and central retinal thickness in eyes with DME were significantly improved compared to the baseline values. There were significant differences in the choroidal thickness, total choroidal area, and choroidal vascularity index between the groups after IVR. Choroidal vascular index and choroidal blood flow were significantly reduced only in the no-PRP group and not in the PRP-treated group. In addition, the correlation between the central retinal thickness and the choroidal blood flow was significant in the no-PRP group (r = 0.47, P < 0.05). A single IVR will reduce the central retinal thickness and improve the BCVA in eyes with DME in both the no-PRP and PRP-treated group. IVR affected the choroidal vasculature and blood flow significantly, and a significant correlation was found between the central retinal thickness and the choroidal blood flow in eyes without PRP.

Coronary flow characteristics after a Bentall procedure with or without sinuses of Valsalva.

PubMed

de Paulis, Ruggero; Tomai, Fabrizio; Bertoldo, Fabio; Ghini, Anna S; Scaffa, Raffaele; Nardi, Paolo; Chiariello, Luigi

2004-07-01

The sinuses of Valsalva are known to contribute to the normal function of the aortic valve. Little is known about their role in promoting coronary artery blood flow. The aim of this study was to compare coronary artery flow characteristics among patients undergoing a Bentall operation by means of a conventional cylindrical Dacron conduit or with a new conduit with pseudosinuses of Valsalva or in patients retaining their natural sinuses of Valsalva after aortic valve and supracoronary ascending aorta replacement. One year after a Bentall procedure with a standard cylindrical Dacron conduit (7 patients, group A) or with the new conduit (7 patients, group B), or after aortic valve and ascending aortic replacement (control group, 7 patients, group C) coronary flow velocity reserve and diastolic to systolic time integral ratio at baseline and after maximal hyperemia (with 40 microg of adenosine) were assessed by using a 0.014-in. Doppler guidewire positioned in the middle portion of the left anterior descending coronary artery. All patients were in NYHA class I, sinus rhythm and free of coronary disease. Arterial blood pressures and heart rate were comparable among groups. Intracoronary Doppler measurements did not show any significant difference in coronary vascular reserve between the three groups (3.6+/-0.4 vs 3.1+/-0.7 vs 3.7+/-0.5, P = 0.2). A greater diastolic component at baseline was present in group B patients (5.5+/-1.9 vs 3.5+/-0.9 in group A and 3.7+/-0.9 in group C, P = 0.024). After maximal hyperemia the diastolic component increased slightly in group A patients (8%) while both in groups B and C significantly decreased (-15 and -20%, respectively) (P = 0.017). The presence of pseudosinuses of Valsalva does not influence coronary flow reserve. After maximal coronary vasodilation the increase in the systolic component of coronary flow is more evident in the presence of sinuses or pseudosinuses of Valsalva, thus suggesting that coronary flow pattern may be affected by the presence of sinuses.

Chemical constituents in groundwater from multiple zones in the eastern Snake River Plain aquifer, Idaho National Laboratory, Idaho, 2009-13

USGS Publications Warehouse

Bartholomay, Roy C.; Hopkins, Candice B.; Maimer, Neil V.

2015-01-01

Tritium concentrations in relation to basaltic flow units indicate the presence of wastewater influence in multiple basalt flow groups; however, tritium is most abundant in the South Late Matuyama flow group in the southern boundary wells. The concentrations of wastewater constituents in deep zones in wells Middle 2051, USGS 132, USGS 105, and USGS 103 support the concept of groundwater flow deepening in the southwestern corner of the INL, as indicated by the INL groundwater-flow model.

Relative ages of lava flows at Alba Patera, Mars

NASA Technical Reports Server (NTRS)

Schneeberger, Dale M.; Pieri, David C.

1987-01-01

Many large lava flows on the flanks of Alba Patera are astonishing in their volume and length. As a suite, these flows suggest tremendously voluminous and sustained eruptions, and provide dimensional boundary conditions typically a factor of 100 larger than terrestrial flows. One of the most striking features associated with Alba Patera is the large, radially oriented lava flows that exhibit a variety of flow morphologies. These include sheet flows, tube fed and tube channel flows, and undifferentiated flows. Three groups of flows were studied; flows on the northwest flank, southeast flank, and the intracaldera region. The lava flows discussed probably were erupted as a group during the same major volcanic episode as suggested by the data presented. Absolute ages are poorly constrained for both the individual flows and shield, due in part to disagreement as to which absolute age curve is representative for Mars. A relative age sequence is implied but lacks precision due to the closeness of the size frequency curves.

Information flow to assess cardiorespiratory interactions in patients on weaning trials.

PubMed

Vallverdú, M; Tibaduisa, O; Clariá, F; Hoyer, D; Giraldo, B; Benito, S; Caminal, P

2006-01-01

Nonlinear processes of the autonomic nervous system (ANS) can produce breath-to-breath variability in the pattern of breathing. In order to provide assess to these nonlinear processes, nonlinear statistical dependencies between heart rate variability and respiratory pattern variability are analyzed. In this way, auto-mutual information and cross-mutual information concepts are applied. This information flow analysis is presented as a short-term non linear analysis method to investigate the information flow interactions in patients on weaning trials. 78 patients from mechanical ventilation were studied: Group A of 28 patients that failed to maintain spontaneous breathing and were reconnected; Group B of 50 patients with successful trials. The results show lower complexity with an increase of information flow in group A than in group B. Furthermore, a more (weakly) coupled nonlinear oscillator behavior is observed in the series of group A than in B.

[Effect on tranquilizing and allaying excitement needling method on brain blood flow in the patients of insomnia of heart and spleen deficiency].

PubMed

Yan, Xing-ke; Zhang, Yan; Yu, Lu; Yue, Gong-lei; Li, Tie; Chen, Cheng; Cui, Hai-fu; Wang, Fu-chun

2010-02-01

To observe the therapeutic effect of tranquilizing and allaying excitement needling method on insomnia of heart and spleen deficiency and the effect of brain blood flow. Sixty cases were randomly divided into a tranquilizing and allaying excitement needling method group (observation group) and an eight confluence points selected group (control group), 30 cases in each group. The observation group was treated by acupuncture at Sishencong (EX-HN 1), Shenmen (HT 7), and Sanyinjiao (SP 6) with tranquilizing and allaying excitement needling method. The control group was treated by acupuncture at Shenmai (BL 62) and Zhaohai (KI 6). Their therapeutic effects and changes of brain blood flow were observed. The total effective rate was 93.3% (28/30) in the observation group which was better than 83.3% (25/30) in the control group (P < 0.05). After treatment, the peak velocity of systolic (Vp) and diastolic blood flow velocity (Vd) of middle cerebral artery, basilar artery and vertebral artery were increased in the both groups (P < 0.01, P < 0.05), with more obvious increase in the observation group (P < 0.01, P < 0.05), except the Vd of left vertebral artery. Both the tranquilizing and allaying excitement needling method and the eight confluence points selected needling method can improve the clinical signs and symptoms. Meanwhile, the therapeutic effect of acupuncture is related with improvement of brain blood flow. However, the tranquilizing and allaying excitement needling method has better therapeutic effect on insomnia of heart and spleen deficiency.

Continuous-flow cold therapy for outpatient anterior cruciate ligament reconstruction.

PubMed

Barber, F A; McGuire, D A; Click, S

1998-03-01

This prospective, randomized study evaluated continuous-flow cold therapy for postoperative pain in outpatient arthroscopic anterior cruciate ligament (ACL) reconstructions. In group 1, cold therapy was constant for 3 days then as needed in days 4 through 7. Group 2 had no cold therapy. Evaluations and diaries were kept at 1, 2, and 8 hours after surgery, and then daily. Pain was assessed using the VAS and Likert scales. There were 51 cold and 49 noncold patients included. Continuous passive movement (CPM) use averaged 54 hours for cold and 41 hours for noncold groups (P=.003). Prone hangs were done for 192 minutes in the cold group and 151 minutes in the noncold group. Motion at 1 week averaged 5/88 for the cold group and 5/79 the noncold group. The noncold group average visual analog scale (VAS) pain and Likert pain scores were always greater than the cold group. The noncold group average Vicodin use (Knoll, Mt. Olive, NJ) was always greater than the cold group use (P=.001). Continuous-flow cold therapy lowered VAS and Likert scores, reduced Vicodin use, increased prone hangs, CPM, and knee flexion. Continuous-flow cold therapy is safe and effective for outpatient ACL reconstruction reducing pain medication requirements.

Novel radiator for carbon dioxide absorbents in low-flow anesthesia.

PubMed

Hirabayashi, Go; Mitsui, Takanori; Kakinuma, Takayasu; Ogihara, Yukihiko; Matsumoto, Shohei; Isshiki, Atsushi; Yasuo, Watanabe

2003-01-01

During long-term low-flow sevoflurane anesthesia, dew formation and the generation of compound A are increased in the anesthesia circuit because of elevated soda lime temperature. The object of this study was to develop a novel radiator for carbon dioxide absorbents used for long durations of low-flow sevoflurane anesthesia. Eleven female swine were divided into two groups comprising a "radiator" group (n = 5) that used a novel radiator for carbon dioxide absorbents and a "control" group (n = 6) that used a conventional canister. Anesthesia was maintained with N2O, O2, and sevoflurane, and low-flow anesthesia was performed with fresh gas flow at 0.6 L/min for 12 hr. In the "control" group, the soda lime temperature reached more than 40 degrees C and soda lime dried up with severe dew formation in the inspiratory valve. In the "radiator" group, the temperature of soda lime stayed at 30 degrees C, and the water content of soda lime was retained with no dew formation in the inspiratory valve. In addition, compound A concentration was reduced. In conclusion, radiation of soda lime reduced the amounts of condensation formed and the concentration of compound A in the anesthetic circuit, and allowed long term low-flow anesthesia without equipment malfunction.

A clinical study to compare between resting and stimulated whole salivary flow rate and pH before and after complete denture placement in different age groups

PubMed Central

Muddugangadhar, B. C.; Sangur, Rajashekar; Rudraprasad, I. V.; Nandeeshwar, D. B.; Kumar, B. H. Dhanya

2015-01-01

Purpose: This study compared the flow rate and pH of resting (unstimulated) and stimulated whole saliva before and after complete denture placement in different age groups. Materials and Methods: Fifty healthy, non-medicated edentulous individuals of different age groups requiring complete denture prostheses were selected from the outpatient department. The resting (unstimulated) and stimulated whole saliva and pH were measured at three stages i.e., i)Before complete denture placement;ii)Immediately after complete denture placement; andiii)After 2 to 3 months of complete denture placement. Saliva production was stimulated by chewing paraffin wax. pH was determined by using a digital pH meter. Results: Statistically significant differences were seen in resting(unstimulated) and stimulated whole salivary flow rate and pH obtained before, immediately after, and after 2 to 3 months of complete denture placement. No statistically significant differences were found between the different age groups in resting (unstimulated) as well as stimulated whole salivary flow rate and pH. Conclusion: Stimulated whole salivary flow rates and pH were significantly higher than resting (unstimulated) whole salivary flow rates and pH obtained before, immediately after, and after 2 to 3 months of complete denture placement. No age related variations in whole salivary flow rate and pH were observed in healthy, non-medicated individuals. Clinical Implications: The assessment of salivary flow rate, pH in different age groups is of prognostic value, which is an important aspect to be considered in the practice of removable prosthodontics. PMID:26929540

A clinical study to compare between resting and stimulated whole salivary flow rate and pH before and after complete denture placement in different age groups.

PubMed

Muddugangadhar, B C; Sangur, Rajashekar; Rudraprasad, I V; Nandeeshwar, D B; Kumar, B H Dhanya

2015-01-01

This study compared the flow rate and pH of resting (unstimulated) and stimulated whole saliva before and after complete denture placement in different age groups. Fifty healthy, non-medicated edentulous individuals of different age groups requiring complete denture prostheses were selected from the outpatient department. The resting (unstimulated) and stimulated whole saliva and pH were measured at three stages i.e., i)Before complete denture placement;ii)Immediately after complete denture placement; andiii)After 2 to 3 months of complete denture placement. Saliva production was stimulated by chewing paraffin wax. pH was determined by using a digital pH meter. Statistically significant differences were seen in resting(unstimulated) and stimulated whole salivary flow rate and pH obtained before, immediately after, and after 2 to 3 months of complete denture placement. No statistically significant differences were found between the different age groups in resting (unstimulated) as well as stimulated whole salivary flow rate and pH. Stimulated whole salivary flow rates and pH were significantly higher than resting (unstimulated) whole salivary flow rates and pH obtained before, immediately after, and after 2 to 3 months of complete denture placement. No age related variations in whole salivary flow rate and pH were observed in healthy, non-medicated individuals. The assessment of salivary flow rate, pH in different age groups is of prognostic value, which is an important aspect to be considered in the practice of removable prosthodontics.

Effects of hypothyroidism on the skeletal muscle blood flow response to contractions.

PubMed

Bausch, L; McAllister, R M

2003-04-01

Hypothyroidism is associated with impaired blood flow to skeletal muscle under whole body exercise conditions. It is unclear whether poor cardiac and/or vascular function account for blunted muscle blood flow. Our experiment isolated a small group of hindlimb muscles and simulated exercise via tetanic contractions. We hypothesized that muscle blood flow would be attenuated in hypothyroid rats (HYPO) compared with euthyroid rats (EUT). Rats were made hypothyroid by mixing propylthiouracil in their drinking water (2.35 x 10-3 mol/l). Treatment efficacy was evidenced by lower serum T3 concentrations and resting heart rates in HYPO (both P<0.05). In the experimental preparation, isometric contractions of the lower right hindlimb muscles at a rate of 30 tetani/min were induced via sciatic nerve stimulation. Regional blood flows were determined by the radiolabelled microsphere method at three time points: rest, 2 min of contractions and 10 min of contractions. Muscle blood flow generally increased from rest ( approximately 5-10 ml/min per 100 g) through contractions for both groups. Further, blood flow during contractions did not differ between groups for any muscle (eg. red section of gastrocnemius muscle; EUT, 59.9 +/- 14.1; HYPO, 61.1 +/- 15.0; NS between groups). These findings indicate that hypothyroidism does not significantly impair skeletal muscle blood flow when only a small muscle mass is contracting. Our findings suggest that impaired blood flow under whole body exercise is accounted for by inadequate cardiac function rather than abnormal vascular function.

Collateral Flow and White Matter Disease in Patients with Internal Carotid Artery Occlusion.

PubMed

Ishikawa, Mami; Sugawara, Hitoshi; Nagai, Mutsumi; Kusaka, Gen; Tanaka, Yuichi; Naritaka, Heiji

2017-01-01

When an internal carotid artery (ICA) occludes, a patient may develop cerebral infarction (CI). We investigated whether CI caused by ICA occlusion (ICAO) is associated with collateral flow through the anterior and posterior communicating arteries (ACoA and PCoA). In 100 patients with ICAO, we investigated CI and white matter disease by performing an MRI and the anatomy of the ACoA and PCoA were investigated by performing magnetic resonance angiography. All patients were divided into the symptomatic CI group or the no-CI group. The collateral flow pathway was estimated by the anterior cerebral artery (ACA)-PCoA score and the collateral flow volume after ICAO was estimated by the middle cerebral artery (MCA) flow score, based on how well the MCA was visualized. Of 100 patients with ICAO, the symptomatic CI group included 36 patients. ACA-PCoA score and white matter disease grades were significantly higher in the CI group (indicating poor collateral flow). More than 80% of patients with an ACA-PCoA score of 4 (poor collateral) experienced symptomatic CI. Thirty-one symptomatic CI patients (86%) had an MCA flow score of 1 or 2 (decreased MCA flow). The ACA-PCoA score and white matter disease grade may suggest an increased risk of CI following ICAO. © 2016 S. Karger AG, Basel.

The effectiveness of high-flow regional cerebral perfusion in Norwood stage I palliation.

PubMed

Miyaji, Kagami; Miyamoto, Takashi; Kohira, Satoshi; Yoshii, Takeshi; Itatani, Kei-Ichi; Sato, Hajime; Inoue, Nobuyuki

2011-11-01

Regional cerebral perfusion (RCP) has been shown to provide cerebral circulatory support during Norwood procedure. In our institution, high-flow RCP (HFRCP) from the right innominate artery has been induced to keep sufficient cerebral and somatic oxygen delivery via collateral vessels. We studied the effectiveness of HFRCP to regional cerebral and somatic tissue oxygenation in Norwood stage I palliation. Seventeen patients, who underwent the Norwood procedure, were separated into two groups: group C (n=6) using low-flow RCP and group H (n=11) using HFRCP (mean flow: 54 vs 92mlkg(-1)min(-1), P<0.0001). The mean duration of RCP was 64±10min (range, 49-86min) under the moderate hypothermia. Chlorpromazine (3.0mgkg(-1)) was given to group H patients before and during RCP to increase RCP flow. The mean radial arterial pressure was kept <50mmHg during RCP. To clarify the effectiveness of HFRCP for cerebral and somatic tissue oxygenation, cerebral regional oxygen saturation (rSO(2)) and systemic venous oxygenation (SvO(2)) during RCP were compared between the two groups. Changes in the lactate level before and after RCP, and changes in the blood urea nitrogen (BUN), creatinine, lactate dehydrogenase (LDH), and creatinine kinase (CK) levels before and after surgery, were also compared between the groups. Mean rSO(2) was 82.9±9.0% in group H and 65.9±10.7% in group C (P<0.05). Mean SvO(2) during RCP was 98.2±4.3% in group H and 85.4±9.7% in group C (P<0.01). During RCP, lactate concentration significantly increased in group C compared with that in group H (P<0.001). After surgery, the LDH and CK levels significantly increased in group C compared with that in group H (P<0.05). Our study revealed that HFRCP preserved sufficient cerebral and somatic tissue oxygenation during the Norwood procedure. The reduction of vascular resistance of collateral vessels increased both cerebral and somatic blood flow, resulting in improved tissue oxygen delivery. Copyright © 2011 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Epidural anaesthesia restores pancreatic microcirculation and decreases the severity of acute pancreatitis

PubMed Central

Demirag, Alp; Pastor, Catherine M; Morel, Philippe; Jean-Christophe, Copin; Sielenkämper, Andreas W; Güvener, Nilgun; Mai, Gang; Berney, Thierry; Frossard, Jean-Louis; Bühler, Leo H

2006-01-01

AIM: To investigate the effect of epidural anaesthesia (EA) on pancreatic microcirculation during acute pancreatitis (AP). METHODS: AP was induced by injection of sodium taurocholate into the pancreatic duct of Sprague-Dawley rats. To realize EA, a catheter was introduced into the epidural space between T7 and T9 and bupivacaine was injected. Microcirculatory flow was measured by laser Doppler flowmetry. Arterial blood gas analyses were performed. At the end of the experiment (≤ 5 h), pancreas was removed for histology. The animals were divided into three groups: Group 1 (n = 9), AP without EA; Group 2 (n = 4), EA without AP; and Group 3 (n = 6), AP treated by EA. RESULTS: In Group 1, pancreatic microcirculatory flow prior to AP was 141 ± 39 perfusion units (PU). After AP, microcirculatory flow obviously decreased to 9 ± 6 PU (P < 0.05). Metabolic acidosis developed with base excess (BE) of - 14 ± 3 mmol/L. Histology revealed extensive edema and tissue necrosis. In Group 2, EA did not significantly modify microcirculatory flow. BE remained unchanged and histological analysis showed normal pancreatic tissue. In Group 3, AP initially caused a significant decrease in microcirculatory flow from 155 ± 25 to 11 ± 7 PU (P < 0.05). After initiation of EA, microcirculatory flow obviously increased again to 81 ± 31 PU (P < 0.05). BE was -6 ± 4 mmol/L, which was significantly different compared to Group 1 (P < 0.05). Furthermore, histology revealed less extensive edema and necrosis in pancreatic tissue in Group 3 than that in Group 1. CONCLUSION: AP caused dramatic microcirculatory changes within the pancreas, with development of metabolic acidosis and tissue necrosis. EA allowed partial restoration of microcirculatory flow and prevented development of tissue necrosis and systemic complications. Therefore, EA should be considered as therapeutic option to prevent evolution from edematous to necrotic AP. PMID:16521220

Mono- and polynucleation, atomistic growth, and crystal phase of III-V nanowires under varying group V flow

NASA Astrophysics Data System (ADS)

Dubrovskii, V. G.

2015-05-01

We present a refined model for the vapor-liquid-solid growth and crystal structure of Au-catalyzed III-V nanowires, which revisits several assumptions used so far and is capable of describing the transition from mononuclear to polynuclear regime and ultimately to regular atomistic growth. We construct the crystal phase diagrams and calculate the wurtzite percentages, elongation rates, critical sizes, and polynucleation thresholds of Au-catalyzed GaAs nanowires depending on the As flow. We find a non-monotonic dependence of the crystal phase on the group V flow, with the zincblende structure being preferred at low and high group V flows and the wurtzite structure forming at intermediate group V flows. This correlates with most of the available experimental data. Finally, we discuss the atomistic growth picture which yields zincblende crystal structure and should be very advantageous for fabrication of ternary III-V nanowires with well-controlled composition and heterointerfaces.

The effect of changing the contact surface area between pleural liquid and pleura on the turnover of pleural liquid.

PubMed

Nakamura, T; Hara, H; Ijima, F; Arai, T; Kira, S

1984-03-01

To study the dynamics of pleural liquid, 250 ml of saline labeled with markers were injected into the pleural cavity of anesthetized dogs. For 3 h, liquid volume and concentration of these markers were measured. In a control group of dogs, the turnover rate of pleural liquid was 19.6 +/- 5.6 ml/min and lymphatic flow was 0.58 +/- 0.07 ml/min. In a group of pneumonectomized dogs, the turnover rate and lymphatic flow fell to about one fourth of those in the control group. When the left pulmonary artery was occluded, the turnover rate was halved, but lymphatic flow was not significantly different from that in the control group. These results suggest that the turnover rate of pleural liquid is dependent on the area of contact between pleural liquid and pleura and on the blood flow of the pleura. In addition, it appears that changes in pleural liquid volume are dependent on lymphatic flow.

Quantitative assessment of cerebrospinal fluid hydrodynamics using a phase-contrast cine MR image in hydrocephalus.

PubMed

Kim, D S; Choi, J U; Huh, R; Yun, P H; Kim, D I

1999-09-01

This investigation was undertaken to characterize CSF flow at the level of the aqueduct of Sylvius with a phase-contrast cine MR pulse sequence in 28 healthy volunteers. Sixteen patients with obstructive hydrocephalus and 11 patients with normal pressure hydrocephalus (NPH) were investigated with the same sequence before and after CSF diversion. The peak CSF flow velocity and stroke volume in the aqueduct increased significantly in the NPH group and decreased significantly in the obstructive hydrocephalus group. After lumboperitoneal shunting in the NPH group, the retrograde flow of CSF was anterogradely converted and the peak flow velocities decreased somewhat. The clinical diagnosis of NPH was well correlated with the results of cine MRI. After endoscopic III ventriculostomy in the obstructive hydrocephalus group we noted increased CSF flow velocity with markedly increased stroke volume at the prepontine cistern. Phase-contrast cine MR is useful in evaluating CSF dynamics in patients with hyperdynamic aqueductal CSF or aqueductal obstruction.

Sheet flow and suspended sediment due to wave groups in a large wave flume

USGS Publications Warehouse

Dohmen-Janssen, C. M.; Hanes, D.M.

2005-01-01

A series of sand bed experiments was carried out in the Large Wave Flume in Hannover, Germany as a component of the SISTEX99 experiment. The experiments focussed on the dynamic sediment response due to wave group forcing over a flat sand bed in order to improve understanding of cross-shore sediment transport mechanisms and determine sediment concentrations, fluxes and net transport rates under these conditions. Sediment concentrations were measured within the sheet flow layer (thickness in the order of 10 grain diameters) and in the suspension region (thickness in the order of centimetres). Within the sheet flow layer, the concentrations are highly coherent with the instantaneous near-bed velocities due to each wave within the wave group. However, in the suspension layer concentrations respond much more slowly to changes in near-bed velocity. At several centimetres above the bed, the suspended sediment concentrations vary on the time scale of the wave group, with a time delay relative to the peak wave within the wave group. The thickness of the sheet flow changes with time. It is strongly coherent with the wave forcing, and is not influenced by the history or sequence of the waves within the group. The velocity of the sediment was also measured within the sheet flow layer some of the time (during the larger wave crests of the group), and the velocity of the fluid was measured at several cm above the sheet flow layer. The grain velocity and concentration estimates can be combined to estimate the sediment flux. The estimates were found to be consistent with previous measurements under monochromatic waves. Under these conditions, without any significant mean current, the sediment flux within the sheet flow layer was found to greatly exceed the sediment flux in the suspension layer. As a result, net transport rates under wave groups are similar to those under monochromatic waves. ?? 2004 Elsevier Ltd. All rights reserved.

COMIS -- an international multizone air-flow and contaminant transport model

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

Feustel, H.E.

1998-08-01

A number of interzonal models have been developed to calculate air flows and pollutant transport mechanisms in both single and multizone buildings. A recent development in multizone air-flow modeling, the COMIS model, has a number of capabilities that go beyond previous models, much as COMIS can be used as either a stand-alone air-flow model with input and output features or as an infiltration module for thermal building simulation programs. COMIS was designed during a 12 month workshop at Lawrence Berkeley National Laboratory (LBNL) in 1988-89. In 1990, the Executive Committee of the International Energy Agency`s Energy Conservation in Buildings andmore » Community Systems program created a working group on multizone air-flow modeling, which continued work on COMIS. The group`s objectives were to study physical phenomena causing air flow and pollutant (e.g., moisture) transport in multizone buildings, develop numerical modules to be integrated in the previously designed multizone air flow modeling system, and evaluate the computer code. The working group supported by nine nations, officially finished in late 1997 with the release of IISiBat/COMIS 3.0, which contains the documented simulation program COMIS, the user interface IISiBat, and reports describing the evaluation exercise.« less

Flow rate, pH and calcium concentration of saliva of children and adolescents with type 1 diabetes mellitus.

PubMed

Moreira, A R; Passos, I A; Sampaio, F C; Soares, M S M; Oliveira, R J

2009-08-01

Alterations in salivary parameters may increase the caries risk in diabetic children, but, contradictory data on this issue have been reported. The aims of this study were to compare salivary parameters (flow rate, pH and calcium concentration) between healthy and type 1 diabetes mellitus (T1DM) individuals. The sample consisted of 7- to 18-year-old individuals divided into two groups: 30 subjects with T1DM (group A) and 30 healthy control subjects (group B). Fasting glucose levels were determined. Unstimulated and stimulated saliva was collected. The pH of unstimulated saliva was measured with paper strips and an electrode. Calcium concentrations in stimulated saliva were determined with a selective electrode. Group A individuals had inadequate blood glucose control (HbA(1C) >9%), with means +/- SD unstimulated salivary flow rate of 0.15 +/- 0.1 mL/min compared to 0.36 +/- 0.2 mL/min for group B (P < 0.01). Stimulated salivary flow rate was similar by both groups and above 2.0 mL/min. Saliva pH was 6.0 +/- 0.8 for group A and significantly different from 7.0 +/- 0.6 for group B (P < 0.01). Salivary calcium was 14.7 +/- 8.1 mg/L for group A and significantly higher than 9.9 +/- 6.4 mg/L for group B (P < 0.01). Except for elevated calcium concentrations in saliva, salivary parameters favoring caries such as low saliva pH and unstimulated salivary flow rate were observed in T1DM individuals.

A new self-expandable aortic valved stent deployed above native leaflets for aortic insufficiency: an in vitro study.

PubMed

Huang, H; Zhou, Y; Shao, J; Cai, J; Mei, Y; Wang, Y

2012-12-01

The aim of this paper was to develop a new self-expandable aortic valved stent following the shape of the sinus of Valsalva, which can be deployed above native leaflets for aortic regurgitation, and study it's effect on coronary artery flow when orthotopic implantation in and above native leaflets. New self-expandable aortic valved stent consist of nitinol stent and bovine pericardium, and was designed following the shape of the sinus of Valsalva, the bovine pericardium was tailed as native leaflet. Thirty-six swine hearts were divided into three equal groups of twelve. In Group A (N.=12), the new self-expandable aortic valved stents deployed in native leaflets. In Group B (N.=12), the new self-expandable aortic valved stents deployed above native leaflets. In Group C (N.=12), the cylinder-like valved stents deployed only in native leaflets. The measurements of each coronary flow rate and endoscopic inspections were repeated post-implantation. In Group A and C, valve implantation in native leaflets resulted in a significant decrease in both left and right coronary flows. In Group B, no significant change in either right or left coronary flow was found after new self-expandable aortic valved stent placement. Endoscopic inspections showed that in group A and C the native leaflets sandwiched between valved stent and aortic wall, whereas, in group B the native leaflets were under the artificial leaflets. Two kinds of stents deployed in native leaflets affect left and right coronary flows significantly. No significant effect was found when the new self-expandable aortic valved stent deployed above native leaflets. This new self-expandable aortic valved stent can be deployed above the native leaflets, which avoids the obstruction of native leaflets on coronary flow.

Flow Experience in Design Thinking and Practical Synergies with Lego Serious Play

ERIC Educational Resources Information Center

Primus, Dirk J.; Sonnenburg, Stephan

2018-01-01

The flow experience can be an important precursor to high levels of creativity and innovation. Prior work has identified and conceptualized the key elements of the flow experience in cocreative activities as individual flow corridor, individual flow feeling, and group flow. Surprisingly, the flow experience is underrepresented in theory and…

Border information flow architecture

DOT National Transportation Integrated Search

2006-04-01

This brochure describes the Border Information Flow Architecture (BIFA). The Transportation Border Working Group, a bi-national group that works to enhance coordination and planning between the United States and Canada, identified collaboration on th...

Significance of measured intraoperative portal vein flows after thrombendvenectomy in deceased donor liver transplantations with portal vein thrombosis.

PubMed

Draoua, Mark; Titze, Nicole; Gupta, Amar; Fernandez, Hoylan T; Ramsay, Michael; Saracino, Giovanna; McKenna, Gregory; Testa, Giuliano; Klintmalm, Goran B; Kim, Peter T W

2017-08-01

Adequate portal vein (PV) flow in liver transplantation is essential for a good outcome, and it may be compromised in patients with portal vein thrombosis (PVT). This study evaluated the impact of intraoperatively measured PV flow after PV thrombendvenectomy on outcomes after deceased donor liver transplantation (DDLT). The study included 77 patients over a 16-year period who underwent PV thrombendvenectomy with complete flow data. Patients were classified into 2 groups: high PV flow (>1300 mL/minute; n = 55) and low PV flow (≤1300 mL/minute; n = 22). Postoperative complications and graft survival were analyzed according to the PV flow. The 2 groups were similar in demographic characteristics. Low PV flow was associated with higher cumulative rates of biliary strictures (P = 0.02) and lower 1-, 2-, and 5-year graft survival (89%, 85%, and 68% versus 64%, 55%, and 38%, respectively; P = 0.002). There was no difference in the incidence of postoperative PVT between the groups (1.8% versus 9.1%; P = 0.19). No biliary leaks or hepatic artery thromboses were reported in either group. By multivariate analyses, age >60 years (hazard ratio [HR], 3.04, 95% confidence interval [CI], 1.36-6.82; P = 0.007) and low portal flow (HR, 2.31; 95% CI, 1.15-4.65; P = 0.02) were associated with worse survival. In conclusion, PV flow <1300 mL/minute after PV thrombendvenectomy for PVT during DDLT was associated with higher rates of biliary strictures and worse graft survival. Consideration should be given to identifying reasons for low flow and performing maneuvers to increase PV flow when intraoperative PV flows are <1300 mL/minute. Liver Transplantation 23 1032-1039 2017 AASLD. © 2017 by the American Association for the Study of Liver Diseases.

DYNAMIC MODELING STRATEGY FOR FLOW REGIME TRANSITION IN GAS-LIQUID TWO-PHASE FLOWS

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

X. Wang; X. Sun; H. Zhao

In modeling gas-liquid two-phase flows, the concept of flow regime has been used to characterize the global interfacial structure of the flows. Nearly all constitutive relations that provide closures to the interfacial transfers in two-phase flow models, such as the two-fluid model, are often flow regime dependent. Currently, the determination of the flow regimes is primarily based on flow regime maps or transition criteria, which are developed for steady-state, fully-developed flows and widely applied in nuclear reactor system safety analysis codes, such as RELAP5. As two-phase flows are observed to be dynamic in nature (fully-developed two-phase flows generally do notmore » exist in real applications), it is of importance to model the flow regime transition dynamically for more accurate predictions of two-phase flows. The present work aims to develop a dynamic modeling strategy for determining flow regimes in gas-liquid two-phase flows through the introduction of interfacial area transport equations (IATEs) within the framework of a two-fluid model. The IATE is a transport equation that models the interfacial area concentration by considering the creation and destruction of the interfacial area, such as the fluid particle (bubble or liquid droplet) disintegration, boiling and evaporation; and fluid particle coalescence and condensation, respectively. For the flow regimes beyond bubbly flows, a two-group IATE has been proposed, in which bubbles are divided into two groups based on their size and shape (which are correlated), namely small bubbles and large bubbles. A preliminary approach to dynamically identifying the flow regimes is provided, in which discriminators are based on the predicted information, such as the void fraction and interfacial area concentration of small bubble and large bubble groups. This method is expected to be applied to computer codes to improve their predictive capabilities of gas-liquid two-phase flows, in particular for the applications in which flow regime transition occurs.« less

Analysis of transit time flow of the right internal thoracic artery anastomosed to the left anterior descending artery compared to the left internal thoracic artery

PubMed Central

Milani, Rodrigo; de Moraes, Daniela; Sanches, Aline; Jardim, Rodrigo; Lumikoski, Thais; Miotto, Gabriela; Santana, Vitor Hugo; Brofman, Paulo Roberto

2014-01-01

Introduction We evaluated with transit time flow the performance of the right and left thoracic arteries when used as a graft for the left anterior descending artery. Methods Fifty patients undergoing surgery for myocardial revascularization without cardiopulmonary bypass were divided into two groups. In group A patients received graft of right internal mammary artery to the anterior interventricular branch. In group B patients received graft of left internal mammary artery to the same branch. At the end of the operation the flow was assessed by measuring transit time. Results In group A, mean age was 60.6±9.49 years. The average height and weight of the group was 80.4±10.32 kg and 169.2±6.86 cm. The average number of grafts per patient in this group was 3.28±1.49. The mean flow and distal resistance obtained in right internal thoracic artery was 42.1±23.4 ml/min and 2.8±0.9 respectively. In group B, the mean age was 59.8±9.7 years. The average height and weight of this group was 77.7±14.22 kg and 166.0±8.2 cm. The average number of grafts per patient in this group was 3.08 ±0.82. The mean flow and distal resistance observed in this group was 34.2±19.1 ml/min and 2.0±0.7. There were no deaths in this series. Conclusion Right internal mammary artery presented a similar behavior to left internal mammary artery when anastomosed to the anterior interventricular branch of the left coronary artery. There was no statistical difference between the measured flow obtained between both arteries. PMID:25140463

The Holographic F Theorem

NASA Astrophysics Data System (ADS)

Taylor, Marika; Woodhead, William

2017-12-01

The F theorem states that, for a unitary three dimensional quantum field theory, the F quantity defined in terms of the partition function on a three sphere is positive, stationary at fixed point and decreases monotonically along a renormalization group flow. We construct holographic renormalization group flows corresponding to relevant deformations of three-dimensional conformal field theories on spheres, working to quadratic order in the source. For these renormalization group flows, the F quantity at the IR fixed point is always less than F at the UV fixed point, but F increases along the RG flow for deformations by operators of dimension between 3/2 and 5/2. Therefore the strongest version of the F theorem is in general violated.

[Changes of renal blood flow during organ-associated foot reflexology measured by color Doppler sonography].

PubMed

Sudmeier, I; Bodner, G; Egger, I; Mur, E; Ulmer, H; Herold, M

1999-06-01

Using colour Doppler sonography blood flow changes of the right kidney during foot reflexology were determined in a placebo-controlled, double-blind, randomised study. 32 healthy young adults (17 women, 15 men) were randomly assigned to the verum or placebo group. The verum group received foot reflexology at zones corresponding to the right kidney, the placebo group was treated on other foot zones. Before, during and after foot reflexology the blood flow of three vessels of the right kidney was measured using colour Doppler sonography. Systolic peak velocity and end diastolic peak velocity were measured in cm/s, and the resistive index, a parameter of the vascular resistance, was calculated. The resistive index in the verum group showed a highly significant decrease (p

Low basal salivary flow and burning mouth syndrome: new evidence in this enigmatic pathology.

PubMed

Spadari, Francesco; Venesia, Paolo; Azzi, Lorenzo; Veronesi, Giovanni; Costantino, Dario; Croveri, Fabio; Farronato, Davide; Tagliabue, Angelo; Tettamanti, Lucia

2015-03-01

Burning mouth syndrome remains a puzzling condition. One symptom commonly associated with the burning sensation is xerostomia. The current study measured basal and stimulated salivary flow in a group of burning mouth syndrome patients. Three groups of patients were recruited: 44 burning mouth syndrome patients, 27 oral lichen planus patients and 40 healthy patients. We chose to measure basal salivary flow and stimulated salivary flow in the three groups of patients using the 'spitting' method. Thus, the patients were asked to spit every minute for 5 min. Afterwards, they were asked to repeat the procedure a second time, but a drop of citric acid was positioned on their tongue every minute to stimulate salivary secretion. After 14 days, the same procedure was repeated for 15 min. Although there was no significant difference between the burning mouth syndrome group and the other two groups regarding the stimulated volumes, an important difference was found in the basal volumes, with the burning mouth syndrome patients showing lower values. The outcomes of our research demonstrate the presence of very low basal salivary flow in burning mouth syndrome patients compared with the other two groups, but the stimulated salivary flow was equal, if not higher, in the burning mouth syndrome patients. This study contributes new topics for further investigation of a solution to the very mysterious pathology represented by burning mouth syndrome. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Annual research briefs, 1993. [Center for Turbulence Research

NASA Technical Reports Server (NTRS)

1993-01-01

The 1993 annual progress reports of the Research Fellow and students of the Center for Turbulence Research are included. The first group of reports are directed towards the theory and application of active control in turbulent flows including the development of a systematic mathematical procedure based on the Navier Stokes equations for flow control. The second group of reports are concerned with the prediction of turbulent flows. The remaining articles are devoted to turbulent reacting flows, turbulence physics, experiments, and simulations.

Laser speckle flowgraphy for differentiating between nonarteritic ischemic optic neuropathy and anterior optic neuritis.

PubMed

Maekubo, Tomoyuki; Chuman, Hideki; Nao-I, Nobuhisa

2013-07-01

The aim of this study was to investigate the usefulness of laser speckle flowgraphy (LSFG) for the differentiation of acute nonarteritic ischemic optic neuropathy (NAION) from anterior optic neuritis (ON). To investigate blood flow in the optic disc under normal conditions, NAION, and anterior ON, we compared the tissue blood flow of the right eye with that of the left eye in the control group, and that of the affected eye with that of the unaffected eye in the NAION and anterior ON groups. In the normal control group, the tissue blood flow did not significantly differ between the right and left eyes. In the NAION group, all 6 patients had decreased optic disc blood flow in the NAION eye when compared with the unaffected eye. By contrast, in the anterior ON group, all 6 patients had increased optic disc blood flow in the anterior ON eye when compared with the unaffected eye. In the NAION group, the mean blur rate (MBR) of the affected eyes was 29.5 % lower than that of the unaffected eyes. In the anterior ON group, the MBR of the affected eyes was 15.9 % higher than that of the unaffected eyes. LSFG could be useful in differentiating between NAION and anterior ON. In addition, this imaging technique saves time and is noninvasive.

Correlation between unstimulated salivary flow, pH and streptococcus mutans, analysed with real time PCR, in caries-free and caries-active children.

PubMed

Abbate, G M; Borghi, D; Passi, A; Levrini, L

2014-03-01

Evaluate the correlations between unstimulated salivary flow, pH and level of S. mutans, analysed through real time PCR, in caries-free and caries-active children. Thirty healthy children were divided into 2 groups: test group (DMFT/dmft ≥ 3 and at least 1 active caries lesion) and control group (DMFT/dmft=0). Un-stimulated saliva was collected, pH was measured and S. mutans and total bacterial amount were evaluated with real-time PCR analysis. Unstimulated salivary flow in the test group was significantly lower (p = 0.0269) compared to group control. The level of S. mutans was higher in the test group (p = 0.176), and an inverse correlation was recorded between total bacterial amount and un-stimulated salivary flow (p = 0.063). In the control group a positive relationship was found between total bacterial amount and S. mutans (p = 0.045) and an inverse correlation between pH and S. mutans (p = 0.088). A t-test and a linear regression analysis were performed. A higher salivary flow and an increased salivary pH seem to represent protective factors against caries in children, while high levels of S. mutans are correlated with caries active lesions. Caries risk assessment should be performed considering all parameters involved in the development of the disease.

Comparative evaluation of the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and xylitol-containing chewing gum on salivary flow rate, pH and buffering capacity in children: An in vivo study.

PubMed

Hegde, Rahul J; Thakkar, Janhavi B

2017-01-01

This study aimed to compare and evaluate the changes in the salivary flow rate, pH, and buffering capacity before and after chewing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and xylitol-containing chewing gums in children. Sixty children aged between 8 and 12 years were selected for the study. They were randomly divided into Group 1 (CPP-ACP chewing gum) and Group 2 (xylitol-containing chewing gum) comprising thirty children each. Unstimulated and stimulated saliva samples at 15 and 30 min interval were collected from all children. All the saliva samples were estimated for salivary flow rate, pH, and buffering capacity. Significant increase in salivary flow rate, pH, and buffering capacity from baseline to immediately after spitting the chewing gum was found in both the study groups. No significant difference was found between the two study groups with respect to salivary flow rate and pH. Intergroup comparison indicated a significant increase in salivary buffer capacity in Group 1 when compared to Group 2. Chewing gums containing CPP-ACP and xylitol can significantly increase the physiochemical properties of saliva. These physiochemical properties of saliva have a definite relation with caries activity in children.

Relationship between aneurysm occlusion and flow diverting device oversizing in a rabbit model.

PubMed

Hodis, Simona; Ding, Yong-Hong; Dai, Daying; Lingineni, Ravi; Mut, Fernando; Cebral, Juan; Kallmes, David; Kadirvel, Ramanathan

2016-01-01

Implanted, actual flow diverter pore density is thought to be strongly influenced by proper matching between the device size and parent artery diameter. The objective of this study was to characterize the correlation between device sizing, metal coverage, and the resultant occlusion of aneurysms following flow diverter treatment in a rabbit model. Rabbit saccular aneurysms were treated with flow diverters (iso-sized to proximal parent artery, 0.5 mm oversized, or 1.0 mm oversized, respectively, n=6 for each group). Eight weeks after implantation, the angiographic degree of aneurysm occlusion was graded (complete, near-complete, or incomplete). The ostium of the explanted aneurysm covered with the flow diverter struts was photographed. Based on gross anatomic findings, the metal coverage and pore density at the ostium of the aneurysm were calculated and correlated with the degree of aneurysm occlusion. Angiographic results showed there were no statistically significant differences in aneurysm geometry and occlusion among groups. The mean parent artery diameter to flow diverter diameter ratio was higher in the 1.0 mm oversized group than in the other groups. Neither the percentage metal coverage nor the pore density showed statistically significant differences among groups. Aneurysm occlusion was inversely correlated with the ostium diameter, irrespective of the size of the device implanted. Device sizing alone does not predict resultant pore density or metal coverage following flow diverter implantation in the rabbit aneurysm model. Aneurysm occlusion was not impacted by either metal coverage or pore density, but was inversely correlated with the diameter of the ostium. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Betahistine metabolites, aminoethylpyridine, and hydroxyethylpyridine increase cochlear blood flow in guinea pigs in vivo.

PubMed

Bertlich, Mattis; Ihler, Fritz; Sharaf, Kariem; Weiss, Bernhard G; Strupp, Michael; Canis, Martin

2014-10-01

Betahistine is a histamine-like drug that is used in the treatment of Ménière's disease. It is commonly believed that betahistine increases cochlear blood flow and thus decreases the endolymphatic hydrops that is the cause of Ménière's. Despite common clinical use, there is little understanding of the kinetics or effects of its metabolites. This study investigated the effect of the betahistine metabolites aminoethylpyridine, hydroxyethylpyridine, and pyridylacetic acid on cochlear microcirculation. Guinea pigs were randomly assigned to one of the groups: placebo, betahistine, or equimolar amounts of aminoethylpyridine, hydroxyethylpyridine, or pyridylacetic acid. Cochlear blood flow and mean arterial pressure were recorded for three minutes before and 15 minutes after treatment. Thirty Dunkin-Hartley guinea pigs assigned to one of five groups with six guinea pigs per group. Betahistine, aminoethylpyridine, and hydroxyethylpyridine caused a significant increase in cochlear blood flow in comparison to placebo. The effect seen under aminoethylpyridin was greatest. The group treated with pyridylacetic acid showed no significant effect on cochlear blood flow. Aminoethylpyridine and hydroxyethylpyridine are, like betahistine, able to increase cochlear blood flow significantly. The effect of aminoethylpyridine was greatest. Pyridylacetic acid had no effect on cochlear microcirculation.

Cardiovascular control during whole body exercise

PubMed Central

Secher, Niels H.

2016-01-01

It has been considered whether during whole body exercise the increase in cardiac output is large enough to support skeletal muscle blood flow. This review addresses four lines of evidence for a flow limitation to skeletal muscles during whole body exercise. First, even though during exercise the blood flow achieved by the arms is lower than that achieved by the legs (∼160 vs. ∼385 ml·min−1·100 g−1), the muscle mass that can be perfused with such flow is limited by the capacity to increase cardiac output (42 l/min, highest recorded value). Secondly, activation of the exercise pressor reflex during fatiguing work with one muscle group limits flow to other muscle groups. Another line of evidence comes from evaluation of regional blood flow during exercise where there is a discrepancy between flow to a muscle group when it is working exclusively and when it works together with other muscles. Finally, regulation of peripheral resistance by sympathetic vasoconstriction in active muscles by the arterial baroreflex is critical for blood pressure regulation during exercise. Together, these findings indicate that during whole body exercise muscle blood flow is subordinate to the control of blood pressure. PMID:27311439

Cardiovascular control during whole body exercise.

PubMed

Volianitis, Stefanos; Secher, Niels H

2016-08-01

It has been considered whether during whole body exercise the increase in cardiac output is large enough to support skeletal muscle blood flow. This review addresses four lines of evidence for a flow limitation to skeletal muscles during whole body exercise. First, even though during exercise the blood flow achieved by the arms is lower than that achieved by the legs (∼160 vs. ∼385 ml·min(-1)·100 g(-1)), the muscle mass that can be perfused with such flow is limited by the capacity to increase cardiac output (42 l/min, highest recorded value). Secondly, activation of the exercise pressor reflex during fatiguing work with one muscle group limits flow to other muscle groups. Another line of evidence comes from evaluation of regional blood flow during exercise where there is a discrepancy between flow to a muscle group when it is working exclusively and when it works together with other muscles. Finally, regulation of peripheral resistance by sympathetic vasoconstriction in active muscles by the arterial baroreflex is critical for blood pressure regulation during exercise. Together, these findings indicate that during whole body exercise muscle blood flow is subordinate to the control of blood pressure. Copyright © 2016 the American Physiological Society.

To shunt or not to shunt? An experimental study comparing temporary vascular shunts and venous ligation as damage control techniques for vascular trauma.

PubMed

Marinho de Oliveira Góes Junior, Adenauer; de Campos Vieira Abib, Simone; de Seixas Alves, Maria Teresa; Venerando da Silva Ferreira, Paulo Sérgio; Carvalho de Andrade, Mariseth

2014-04-01

To evaluate vascular flow through temporary vascular shunts inserted into peripheral arteries and veins and the repercussion, on the arterial perfusion, of venous ligation and venous shunt insertion in an experimental model for damage control. Experimental study in pigs. Animals were distributed in 5 groups: group 1, right external iliac artery (EIA) shunting and right external iliac vein (EIV) ligation; group 2, right EIA shunting and right EIV shunting; group 3, right EIV ligation; group 4, right EIV shunting; group 5, no vascular shunting and no venous ligation. Flowmeters were used to measure vascular flow on right and left external iliac vessels, and blood samples were collected from the EIVs for biochemical analysis. A right anterior limb biopsy was performed before shock. Hemorrhagic shock was induced through the external right jugular vein, until the vascular flow through right iliac external artery shunt or right iliac external vein shunt (group 4) ceased or until the animal's death. After the end of the experiments, biopsies of bilateral hind limb were obtained for histologic analysis. For statistical analysis, Microsoft Office Excel 2007 and BioEstat 5.0 (2007) were used. In the absence of hemorrhagic shock, venous ligation (group 1) was associated with a 38.8% reduction (P < 0.05) and venous shunting with a 28.4% reduction on the vascular flow through the arterial shunt. When associated with hemorrhagic shock, the mean vascular flow on the right EIA was 13 mL/min and on the left EIA was 41.2 mL/min; on group 2, the right EIA flow was 8.5 mL/min and the left EIA flow was 8.1 mL/min. When associated with hemorrhagic shock, the pO2 was 25.8 mm Hg on right EIV and 33.8 mm Hg on the left EIV for group 1 (P < 0.05), whereas for group 2, the pO2 was 22.6 mm Hg on right EIV and 22.8 mm Hg on the left EIV. On group 1, serum potassium was 3.84 mEq/L on the right EIV and 3.96 mEq/L on the left EIV, whereas on group 2, it was 7.1 mEq/L on the right EIV and 5.88 mEq/L on the left EIV (P < 0.05). In the developed experimental model, venous shunting, when compared with venous ligation, offered less resistance to vascular flow through the arterial shunt and allowed a more efficient limb venous drainage than simple vein ligature. Copyright © 2014 Elsevier Inc. All rights reserved.

On the renormalisation of the diffusion asymptotics in the problem of reflection of a narrow optical beam from a biological medium

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

Appanov, A Yu; Barabanenkov, Yu N

2005-12-31

An analytic hybrid method is considered for solving the stationary radiation transfer equation in the problem on reflection of a narrow laser beam from biological media such as the 2% aqueous solution of intralipid and erythrocyte suspension with the volume concentration (hematocrit) H=0.41. The method is based on the reciprocity of the Green function in the radiation transfer theory and on the iteration solution of the integral equation for this function. As a result, the ray intensity is represented as a sum of two terms. The first of them describes the contribution of finite-order scattering to the intensity of amore » beam diffusely reflected from the medium. The second term contains the explicit analytic expression for a spatially distributed effective source of diffuse radiation emerging from the deep layers of the medium to the surface. This approach substantially improves the diffusion approximation for the problem under study and allows one to obtain the uniform asymptotics of the reflection coefficient at the specified interval of distances between the radiation source and detector on the medium surface with the relative error within {+-}6% for the 2% intralipid emulsion and erythrocyte suspension (H=0.41). (radiation scattering)« less

Nonperturbative comparison of clover and highly improved staggered quarks in lattice QCD and the properties of the Φ meson

DOE PAGES

Chakraborty, Bipasha; Davies, C. T. H.; Donald, G. C.; ...

2017-10-02

Here, we compare correlators for pseudoscalar and vector mesons made from valence strange quarks using the clover quark and highly improved staggered quark (HISQ) formalisms in full lattice QCD. We use fully nonperturbative methods to normalise vector and axial vector current operators made from HISQ quarks, clover quarks and from combining HISQ and clover fields. This allows us to test expectations for the renormalisation factors based on perturbative QCD, with implications for the error budget of lattice QCD calculations of the matrix elements of clover-staggeredmore » $b$-light weak currents, as well as further HISQ calculations of the hadronic vacuum polarisation. We also compare the approach to the (same) continuum limit in clover and HISQ formalisms for the mass and decay constant of the $$\\phi$$ meson. Our final results for these parameters, using single-meson correlators and neglecting quark-line disconnected diagrams are: $$m_{\\phi} =$$ 1.023(5) GeV and $$f_{\\phi} = $$ 0.238(3) GeV in good agreement with experiment. These results come from calculations in the HISQ formalism using gluon fields that include the effect of $u$, $d$, $s$ and $c$ quarks in the sea with three lattice spacing values and $$m_{u/d}$$ values going down to the physical point.« less

Visual adaptation alters the apparent speed of real-world actions.

PubMed

Mather, George; Sharman, Rebecca J; Parsons, Todd

2017-07-27

The apparent physical speed of an object in the field of view remains constant despite variations in retinal velocity due to viewing conditions (velocity constancy). For example, people and cars appear to move across the field of view at the same objective speed regardless of distance. In this study a series of experiments investigated the visual processes underpinning judgements of objective speed using an adaptation paradigm and video recordings of natural human locomotion. Viewing a video played in slow-motion for 30 seconds caused participants to perceive subsequently viewed clips played at standard speed as too fast, so playback had to be slowed down in order for it to appear natural; conversely after viewing fast-forward videos for 30 seconds, playback had to be speeded up in order to appear natural. The perceived speed of locomotion shifted towards the speed depicted in the adapting video ('re-normalisation'). Results were qualitatively different from those obtained in previously reported studies of retinal velocity adaptation. Adapting videos that were scrambled to remove recognizable human figures or coherent motion caused significant, though smaller shifts in apparent locomotion speed, indicating that both low-level and high-level visual properties of the adapting stimulus contributed to the changes in apparent speed.

Relationship between unstimulated salivary flow rate and saliva composition of healthy children in Taiwan.

PubMed

Wu, Katie P; Ke, Jyh-Yuh; Chung, Chia-Ying; Chen, Chia-Ling; Hwang, Tsong-Long; Chou, Ming-Yen; Wong, Alice M K; Hu, Ching-Fang; Lee, Yu-Cheng

2008-01-01

Saliva is one of the most important factors in regulating oral health, with flow rate and composition changing throughout development and during disease. In view of the shortage of data, the present study aimed to shed light on the relationship between unstimulated salivary flow rate and saliva composition of healthy children in Taiwan. Forty-four normal, healthy children from 3-14 years of age were divided into three age groups: pre-school, elementary school and junior-high school. All participants received salivary flow rate, pH and saliva composition analysis under unstimulated conditions. One-way ANOVA and Pearson's correlation were used. Statistical significance was set at p < 0.05. Our results suggest that, under unstimulated conditions, the salivary flow rate of the elementary school group was greater than that of the pre-school group (p < 0.05). No difference in pH was found among the three groups. Intergroup salivary calcium, phosphorus and amylase did not reach statistical difference. As the flow rate increased, the pH increased (r = 0.364, p < 0.05) but the protein level decreased (r = -0.473, p < 0.05). In addition, salivary protein was positively correlated to age (r = 0.479, p < 0.05) and negatively correlated to pH (r = -0.361, p < 0.01). Age-related increase in the unstimulated salivary flow rate of pre-school and elementary school groups was noted. As the flow rate increased, the pH increased but the protein level decreased. The information obtained may serve as reference values for the growing interest in saliva as a diagnostic tool, especially monitoring those with neurological or oral motor dysfunction.

High-definition flow Doppler ultrasonographic technique to assess hepatic vasculature compared with color or power Doppler ultrasonography: preliminary experience.

PubMed

Kim, Se Hyung; Lee, Jeong Min; Kim, Young Jun; Lee, Jae Young; Han, Joon Koo; Choi, Byung Ihn

2008-10-01

The purpose of this study was to introduce a new high-definition flow (HDF) Doppler technique and to compare its performance with those of color Doppler ultrasonography (CDU) and power Doppler ultrasonography (PDU) for assessment of hepatic vasculature in native and transplanted livers. High-definition flow was invented as a high-resolution bidirectional PDU technique. We obtained CDU, PDU, and HDF images of the hepatic artery (HA), portal vein (PV), and hepatic vein from 60 patients. They were divided into 2 groups: a liver transplantation group (group 1, n = 10) and a native liver group (group 2, n = 50). Two radiologists independently reviewed the cine images and graded them using a 4-point scale in terms of the clarity of the vessel margin and degree of depiction of the HA, flow filling, and flash artifacts. The degree of differentiation between the HA and PV was also evaluated. Flow directionality was recorded, and interobserver agreement was finally analyzed. Moderate to almost perfect agreement was achieved between radiologists for all parameters of each ultrasonographic technique. High-definition flow was significantly superior to both CDU and PDU with respect to all analyzed items except the degree of flash artifacts (P < .05). With regard to flash artifacts, CDU was significantly better than either PDU or HDF. High-definition flow provided directional information, as did CDU. The HDF technique provides better resolution for depicting hepatic vessels as well as their margins with less blooming compared with conventional Doppler ultrasonography in both native and transplanted liver. It also provides solid directional flow information. One point of concern, however, is the frequency of flash artifacts compared with that on CDU.

Severe aortic stenosis patients with preserved ejection fraction according to flow and gradient classification: Prevalence and outcomes.

PubMed

González Gómez, Ariana; Fernández-Golfín, Covadonga; Monteagudo, Juan Manuel; Izurieta, Carlos; Hinojar, Rocío; García, Ana; Casas, Eduardo; Jiménez-Nacher, José Julio; Moya, José Luis; Ruiz, Soledad; Zamorano, José Luis

2017-12-01

Clinicians often encounter patients with apparently discordant echocardiographic findings, severe aortic stenosis (SAS) defined by aortic valve area (AVA) despite a low mean gradient. A new classification according to flow state and pressure gradient has been proposed. We sought to assess the prevalence, characteristics and outcomes of patients with asymptomatic SAS with preserved left-ventricular ejection fraction (LVEF) according to flow and gradient. In total 442 patients with SAS (AVAi<0.6 cm2/m2) and LVEF ≥50% (mean age 80+11years, 54,5% female) were included. Patients were classified according to flow state (≥ or <35ml/m 2 ) and mean pressure gradient (≥ or <40mmHg): Low Flow/Low Gradient (LF/LG): 21.3%(n=94); Normal Flow/Low Gradient (NF/LG): 32.1%(n=142); Low Flow/High Gradient (LF/HG): 6.8%(n=30); Normal Flow/High Gradient (NF/HG): 39,8%(n=176). Mean follow-up time was 20.5months (SD=10.3). Primary combined endpoint was cardiovascular mortality and hospital admission for SAS related symptom, secondary endpoint was aortic valve replacement (AVR), comparing HG group to LF/LG group. During follow-up 17 (18%) of LF/LG patients and 21 (10.2%) of HG patients met the primary endpoint. A lower free of event survival (cardiovascular mortality and hospital admission) was observed in patients with LF/LG AS (Breslow, p=0.002). Significant differences were noted between groups with a lower AVR free survival in the LF/LG group compared to HG groups (Breslow, p=0.002). Our study confirms the high prevalence and worse prognosis of LF/LG SAS. Clinicians must be aware of this entity to ensure appropriate patient management. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

The Development of Patient Scheduling Groups for an Effective Appointment System

PubMed Central

2016-01-01

Summary Background Patient access to care and long wait times has been identified as major problems in outpatient delivery systems. These aspects impact medical staff productivity, service quality, clinic efficiency, and health-care cost. Objectives This study proposed to redesign existing patient types into scheduling groups so that the total cost of clinic flow and scheduling flexibility was minimized. The optimal scheduling group aimed to improve clinic efficiency and accessibility. Methods The proposed approach used the simulation optimization technique and was demonstrated in a Primary Care physician clinic. Patient type included, emergency/urgent care (ER/UC), follow-up (FU), new patient (NP), office visit (OV), physical exam (PE), and well child care (WCC). One scheduling group was designed for this physician. The approach steps were to collect physician treatment time data for each patient type, form the possible scheduling groups, simulate daily clinic flow and patient appointment requests, calculate costs of clinic flow as well as appointment flexibility, and find the scheduling group that minimized the total cost. Results The cost of clinic flow was minimized at the scheduling group of four, an 8.3% reduction from the group of one. The four groups were: 1. WCC, 2. OV, 3. FU and ER/UC, and 4. PE and NP. The cost of flexibility was always minimized at the group of one. The total cost was minimized at the group of two. WCC was considered separate and the others were grouped together. The total cost reduction was 1.3% from the group of one. Conclusions This study provided an alternative method of redesigning patient scheduling groups to address the impact on both clinic flow and appointment accessibility. Balance between them ensured the feasibility to the recognized issues of patient service and access to care. The robustness of the proposed method on the changes of clinic conditions was also discussed. PMID:27081406

History of Suction-Type Laminar-Flow Control with Emphasis on Flight Resrearch: Monographs in Aerospace History Number 13

NASA Technical Reports Server (NTRS)

Braslow, A. L.

1999-01-01

The paper contains the following sections: Foreword; Preface; Laminar-Flow Control Concepts and Scope of Monograph; Early Research on Suction-Type Laminar-Flow Control (Research from the 1930s through the War Years; Research from after World War II to the Mid-1960s); Post X-21 Research on Suction-Type Laminar-Flow Control; Status of Laminar-Flow Control Technology in the Mid-1990s; Glossary; Document 1-Aeronautics Panel, AACB, R&D Review, Report of the Subpanel on Aeronautic Energy Conservation/Fuels; Document 2-Report of Review Group on X-21A Laminar Flow Control Program; Document 3-Langley Research Center Announcement, Establishment of Laminar Flow Control Working Group; Document 4-Intercenter Agreement for Laminar Flow Control Leading Edge Glove Flights, LaRC and DFRC; Document 5-Flight Report NLF-144, of AFTIF-111 Aircraft with the TACT Wing Modified by a Natural Laminar Flow Glove; Document 6-Flight Record, F-16XL Supersonic Laminar Flow Control Aircraft; Index; and About the Author.

Comparative evaluation of fracture resistance of root canals obturated with four different obturating systems

PubMed Central

Punjabi, Mansi; Dewan, Ruchika Gupta; Kochhar, Rohit

2017-01-01

Aim and Objectives: The aim of this study is to evaluate and compare the fracture resistance of root canals obturated with four different obturating systems in endodontically treated teeth. Materials and Methods: One hundred and twenty single-rooted teeth were selected and decoronated at cementoenamel junction. Instrumentation of teeth (except control group) was done with Mtwo rotary files up to size 25/0.06 using a step-back technique. All teeth were divided into four experimental groups (n = 25) and two control groups (n = 10). In Group I (negative control), teeth were neither instrumented nor obturated, in Group II (positive control), instrumentation was done, but no obturation was performed, in Group III, obturation was done with cold lateral compaction technique, in Group IV, obturation was done with cold free-flow compaction technique, in Group V, obturation was done with warm vertical compaction technique, and in Group VI, obturation was done with injection-molded thermoplasticized technique. All prepared teeth were embedded in an acrylic resin block, and their fracture strength was measured using Universal Testing Machine. Statistical data were analyzed using one-way analysis of variance and Tukey's honestly significant difference test. Results: Negative control Group I showed highest fracture resistance and positive control Group II had lowest fracture resistance. Among experimental groups, cold free-flow compaction technique with GuttaFlow2 (Group IV) showed higher fracture resistance as compared to the Group III, Group V, and Group VI. Conclusion: GuttaFlow2 has the potential to strengthen the endodontically treated roots to a level that is similar to that of intact teeth. PMID:29430099

Comparative evaluation of fracture resistance of root canals obturated with four different obturating systems.

PubMed

Punjabi, Mansi; Dewan, Ruchika Gupta; Kochhar, Rohit

2017-01-01

The aim of this study is to evaluate and compare the fracture resistance of root canals obturated with four different obturating systems in endodontically treated teeth. One hundred and twenty single-rooted teeth were selected and decoronated at cementoenamel junction. Instrumentation of teeth (except control group) was done with Mtwo rotary files up to size 25/0.06 using a step-back technique. All teeth were divided into four experimental groups ( n = 25) and two control groups ( n = 10). In Group I (negative control), teeth were neither instrumented nor obturated, in Group II (positive control), instrumentation was done, but no obturation was performed, in Group III, obturation was done with cold lateral compaction technique, in Group IV, obturation was done with cold free-flow compaction technique, in Group V, obturation was done with warm vertical compaction technique, and in Group VI, obturation was done with injection-molded thermoplasticized technique. All prepared teeth were embedded in an acrylic resin block, and their fracture strength was measured using Universal Testing Machine. Statistical data were analyzed using one-way analysis of variance and Tukey's honestly significant difference test. Negative control Group I showed highest fracture resistance and positive control Group II had lowest fracture resistance. Among experimental groups, cold free-flow compaction technique with GuttaFlow2 (Group IV) showed higher fracture resistance as compared to the Group III, Group V, and Group VI. GuttaFlow2 has the potential to strengthen the endodontically treated roots to a level that is similar to that of intact teeth.

The effect of fertility stress on endometrial and subendometrial blood flow among infertile women.

PubMed

Dong, Yuezhi; Cai, Yanna; Zhang, Yu; Xing, Yurong; Sun, Yingpu

2017-03-04

To investigate the effect of fertility stress on endometrial and subendometrial blood flow among infertile women. This case-control study was conducted in The First Affiliated Hospital of Zhengzhou University. The fertility problem inventory (FPI) was adopted to evaluate fertility stress. Three-dimensional power Doppler ultrasonography (3D PD-US) was performed during the proliferative phase of the menstrual cycle (days 5-11) to measure endometrial thickness, pattern, endometrial and subendometrial volume (V), the vascularization index (VI), the flow index (FI) and the vascularization-FI (VFI) index. Then, 300 infertile women were separated into two groups (high-score group and low-score group) based on total FPI scores and 80 healthy women were selected as controls. No differences were found among all three groups with regard to general characteristics, endometrial thickness, pattern, endometrial and subendometrial V, VI and VFI. The endometrial and subendometrial FIs associated with different stress levels significantly differed among the three groups (F = 33.95, P < 0.001; F = 44.79, P < 0.001, respectively). The endometrial and subendometrial FIs in the control group were significantly higher than those in the high-score group and low-score groups. The endometrial and subendometrial FIs in the low-score group were significantly higher than those in the high-score group. The total FPI score was closely related to the endometrial and subendometrial FIs (r = -0.304, P < 0.001; r = -0.407, P < 0.001, respectively). Fertility stress was associated with endometrial and subendometrial flow index. Whether fertility stress might affect pregnancy outcome by reducing endometrial and subendometrial blood flow requires further research.

Heel blood flow during loading and off-loading in bedridden older adults with low and normal ankle-brachial pressure index: a quasi-experimental study.

PubMed

Masaki, Nami; Sugama, Junko; Okuwa, Mayumi; Inagaki, Misako; Matsuo, Junko; Nakatani, Tosio; Sanada, Hiromi

2013-07-01

The purpose of this study was to evaluate the differences in heel blood flow during loading and off-loading in bedridden adults older than 65 years. The patients were divided into three groups based on ankle-brachial pressure index (ABI) and transcutaneous oxygen tension (tcPO₂): (1) patients with an ABI ≥ 0.8 (Group A); (2) patients with an ABI < 0.8 and heel tcPO₂ ≥ 10 mmHg (Group B); and (3) patients with an ABI < 0.8 and heel tcPO₂ < 10 mmHg (Group C). Heel blood flow was monitored using tcPO₂ sensors. Data were collected with the heel (1) suspended above the bed surface (preload), (2) on the bed surface for 30 min (loading), and (3) again suspended above the bed surface for 60 min (off-loading). Heel blood flow during off-loading was assessed using three parameters: oxygen recovery index (ORI), total tcPO₂ for the first 10 min, and change in tcPO₂ after 60 min of off-loading. ORI in Group C (n = 8) was significantly shorter than in Groups A (n = 22) and B (n = 15). Total tcPO₂ for the first 10 min of off-loading in Group C was significantly less than that in Groups A and B. Change in tcPO₂ after 60 min of off-loading in Group C was less than in Group A. Based on these findings, additional preventive care against heel blood flow decrease in older adults with an ABI < 0.8 and heel tcPO₂ < 10 mmHg might be necessary after loading.

Effect of GnRH and hCG on progesterone concentration and ovarian and luteal blood flow in diestrous mares.

PubMed

Brito, L F C; Baldrighi, J M; Wolf, C A; Ginther, O J

2017-01-01

The objective of the present study was to investigate the effect of reproductive hormones (GnRH, hCG, LH and progesterone) on the regulation of corpus luteum (CL) and ovarian blood flow. Diestrous mares received a single treatment of saline, 100μg gonadorelin (GnRH), or 1500IU hCG 10days after ovulation. Plasma LH and progesterone concentrations, resistance index (RI) for ovarian artery blood-flow, and percentage of corpus luteum (CL) with color-Doppler signals of blood flow were determined immediately before treatment (hour 0) and at hours 0.25, 0.5, 1, 1.5, 2, 3, 4, 5, and 6. In the GnRH group, LH increased (P<0.0001) between hours 0 and 0.25 and then progressively decreased; concentration of LH was not affected in the saline and hCG groups. Progesterone concentration was not different among groups. In the GnRH group, RI tended (P<0.07) to decrease between hours 0 and 1.5 and increased (P<0.01) between hours 1.5 and 4. In the hCG group, two transient RI decreases (P<0.05) occurred before hour 2. The percentage change from hour 0 in the percentage of CL with blood-flow signals was greater at hour 0.5 in the GnRH group than in the saline group and was intermediate in the hCG group. The similarity among groups in progesterone concentration indicated that changes in progesterone were not involved in the GnRH and hCG stimulation of ovarian vascular perfusion. Effects of treatment might have been mediated through LH; however, since hCG biological activity is primarily LH-like, the differences in timing and degree of ovarian and luteal blood flow changes after GnRH or hCG administration in the present study suggest that GnRH might have a direct effect on ovarian blood vessels and vascular control. Copyright © 2016. Published by Elsevier B.V.

Flow diagram or prose: does the format of practice guidelines matter?

PubMed

Hardern, R D; Hodgson, L C; Hamer, D W

1998-06-01

The aim of this study was to compare the performance of two formats (prose and flow diagram) of the guidelines for management of paracetamol poisoning, and to assess the likely performance without access to the guidelines. A prospective questionnaire study of the management of seven hypothetical cases of paracetamol ingestion was carried out by accident and emergency senior house officers at a regional induction course. No differences were found between the two formats. The proportion of correct answers was 37% in the flow diagram and 31% in the prose group (95% confidence interval for the difference -8% to 20%). In the group with neither format of the guideline the proportion of correct answers was lower: 19% (95% confidence interval for the difference between this group and the group with flow charts 6.9% to 30.6%, for the difference between this group and the group with the prose format 0.4% to 24.8%). The time taken to answer the questions did not vary between the groups. These data do not support the exclusive use of either format. They suggest that management of paracetamol poisoning is less likely to be correct if staff do not have access to the guidelines.

Prevalence of tidal expiratory flow limitation in preschool children with and without respiratory symptoms: application of the negative expiratory pressure (NEP) method.

PubMed

JIRICKOVA, A; SULC, J; POHUNEK, P; KITTNAR, O; DOHNALOVA, A; KOFRANEK, J

2009-01-01

Negative expiratory pressure (NEP) applied at the mouth during tidal expiration provides a non-invasive method for detecting expiratory flow limitation. Forty-two children were studied, i.e. 25 children with different respiratory symptoms (R) and 17 without any respiratory symptoms (NR). Children were examined without any sedation. A preset NEP of -5 cm H(2)O was applied; its duration did not exceed duration of tidal expiration. A significance of FL was judged by determining of a flow-limited range (in % of tidal volume). FL was found in 48 % children of R group. No patient of the NR group elicited FL (P<0.001 R vs. NR). The frequency of upper airway collapses was higher in R group (12 children) than in NR group (5 children). In conclusion, a high frequency of tidal FL in the R group was found, while it was not present in NR group. A relatively high frequency of expiratory upper airway collapses was found in both groups, but it did not differ significantly. NEP method represents a reasonable approach for tidal flow limitation testing in non-sedated preschool children.

Salivary flow rate and xerostomia in patients with type I and II diabetes mellitus

PubMed Central

Hoseini, Amineh; Mirzapour, Ali; Bijani, Ali; Shirzad, Atena

2017-01-01

Background Diabetes mellitus is one of the most prevalent metabolic diseases, with complications such as decreased salivary flow rate and xerostomia. Objective This study aimed to determine the salivary flow rate and xerostomia in type I and II diabetic patients in comparison with healthy controls. Methods This case-control study was performed on diabetic patients of a private office in Babol, Iran, between May 2015 and October 2016. This study involved two study groups (type I and II diabetes, with 40 in each group) and two control groups (control I and II, with 35 in each group) which were age- and sex-matched with the related study groups. They were all selected through simple sampling. Unstimulated whole saliva was collected through Navazesh method and the salivary flow rate was measured (ml/min). Xerostomia was evaluated via Fox’s test. Moreover, the patients’ data were recorded including age, sex, disease duration, type of diabetes, fasting blood glucose (FBG) and HbA1C. The obtained data were statistically analyzed by using SPSS version 17. Independent-samples t-test, Chi-square, Pearson correlation and multiple comparison post-hoc tests were employed as appropriated. p<0.05 was considered significant. Results The mean salivary flow rate in type I diabetics (0.35±0.11 ml/min) was lower than that in control I (0.50±0.07 ml/min) (p=0.01). The same difference was observed between type II diabetics (0.37±0.13 ml/min) and control II groups (0.47±0.11 ml/min) (p=0.01). No significant difference was observed in the salivary flow rate between type I and II diabetics (p=0.345). Furthermore, xerostomia was higher in type I (2.70±2.50, 1.17±1.60) and II (2.65±2.20–1.62±1.50) diabetics compared with the related control groups (p=0.01), (p=0.02). Conclusion Type I, II diabetic patients revealed lower salivary flow rate and higher xerostomia compared with healthy controls. The salivary flow rate and xerostomia had inverse correlation. PMID:29038704

Salivary flow rate and xerostomia in patients with type I and II diabetes mellitus.

PubMed

Hoseini, Amineh; Mirzapour, Ali; Bijani, Ali; Shirzad, Atena

2017-09-01

Diabetes mellitus is one of the most prevalent metabolic diseases, with complications such as decreased salivary flow rate and xerostomia. This study aimed to determine the salivary flow rate and xerostomia in type I and II diabetic patients in comparison with healthy controls. This case-control study was performed on diabetic patients of a private office in Babol, Iran, between May 2015 and October 2016. This study involved two study groups (type I and II diabetes, with 40 in each group) and two control groups (control I and II, with 35 in each group) which were age- and sex-matched with the related study groups. They were all selected through simple sampling. Unstimulated whole saliva was collected through Navazesh method and the salivary flow rate was measured (ml/min). Xerostomia was evaluated via Fox's test. Moreover, the patients' data were recorded including age, sex, disease duration, type of diabetes, fasting blood glucose (FBG) and HbA1C. The obtained data were statistically analyzed by using SPSS version 17. Independent-samples t-test, Chi-square, Pearson correlation and multiple comparison post-hoc tests were employed as appropriated. p<0.05 was considered significant. The mean salivary flow rate in type I diabetics (0.35±0.11 ml/min) was lower than that in control I (0.50±0.07 ml/min) (p=0.01). The same difference was observed between type II diabetics (0.37±0.13 ml/min) and control II groups (0.47±0.11 ml/min) (p=0.01). No significant difference was observed in the salivary flow rate between type I and II diabetics (p=0.345). Furthermore, xerostomia was higher in type I (2.70±2.50, 1.17±1.60) and II (2.65±2.20-1.62±1.50) diabetics compared with the related control groups (p=0.01), (p=0.02). Type I, II diabetic patients revealed lower salivary flow rate and higher xerostomia compared with healthy controls. The salivary flow rate and xerostomia had inverse correlation.

Botulinum toxin A and B raise blood flow and increase survival of critically ischemic skin flaps.

PubMed

Schweizer, Dennis F; Schweizer, Riccardo; Zhang, Shengye; Kamat, Pranitha; Contaldo, Claudio; Rieben, Robert; Eberli, Daniel; Giovanoli, Pietro; Erni, Dominique; Plock, Jan A

2013-10-01

Botulinum toxin (BTX) A and B are commonly used for aesthetic indications and in neuromuscular disorders. New concepts seek to prove efficacy of BTX for critical tissue perfusion. Our aim was to evaluate BTX A and B in a mouse model of critical flap ischemia for preoperative and intraoperative application. BTX A and B were applied on the vascular pedicle of an axial pattern flap in mice preoperatively or intraoperatively. Blood flow, tissue oxygenation, tissue metabolism, flap necrosis rate, apoptosis assay, and RhoA and eNOS expression were endpoints. Blood-flow measurements 1 d after the flap operation revealed a significant reduction to 53% in the control group, while flow was maintained or increased in all BTX groups (103%-129%). Over 5 d all BTX groups showed significant increase in blood flow to 166-187% (P < 0.01). Microdialysis revealed an increase of glucose and reduced lactate/pyruvate ratio and glycerol levels in the flap tissue of all BTX groups. This resulted in significantly improved tissue survival in all BTX groups compared with the control group (62% ± 10%; all P < 0.01): BTX A preconditioning (84% ± 5%), BTX A application intraoperatively (88% ± 4%), BTX B preconditioning (91% ± 4%), and intraoperative BTX B treatment (92% ± 5%). This was confirmed by TUNEL assay. Immunofluorescence demonstrated RhoA and eNOS expression in BTX groups. All BTX applications were similarly effective, despite pharmacologic dissimilarities and different timing. In conclusion, we were able to show on a vascular, tissue, cell, and molecular level that BTX injection to the feeding arteries supports flap survival through ameliorated blood flow and oxygen delivery. Copyright © 2013 Elsevier Inc. All rights reserved.

Stress-strain analysis of jejunal contractility in response to flow and ramp distension in type 2 diabetic GK rats: effect of carbachol stimulation.

PubMed

Zhao, Jingbo; Chen, Pengmin; Gregersen, Hans

2013-09-27

Investigation of intestinal motility in a genetic model of GK rats abandons the possible neurotoxic effect of streptozotocin in streptozotocin-induced diabetic model. Seven GK male rats (GK group) and nine normal Wistar rats (Normal group) were used in the study. The motility experiments were carried out in an organ bath containing physiological Krebs solution. Before and after 10(-5)M carbachol application, the pressure and diameter changes of jejunum were obtained in relation to (1) basic contraction, (2) flow-induced contraction with different outlet resistance pressures and (3) contractions induced by ramp distension. The frequency and amplitude of contractions were analyzed from pressure-diameter curves. Distension-induced contraction thresholds and maximum contraction amplitude of basic and flow-induced contractions were calculated in terms of stress and strain. (1) The contraction amplitude increased to the peak value in less than 10s after adding carbachol. More than two peaks were observed in the GK group. (2) Carbachol decreased the pressure and stress threshold and Young's modulus in the GK group (P<0.01). (3) Carbachol increased the maximum pressure and stress of flow-induced contractions at most outlet pressure levels in both two groups (P<0.001). Furthermore, the flow-induced contractions were significantly bigger at low outlet pressure levels in GK group (P<0.05 and P<0.01). (4) The contraction frequency, the strain threshold and the maximum contraction strain did not differ between the two groups (P>0.05) and between before and after carbachol application (P>0.05). In GK diabetic rats, the jejunal contractility was hypersensitive to flow and distension stimulation after carbachol application. Copyright © 2013 Elsevier Ltd. All rights reserved.

School Mathematics Study Group, Unit Number Two. Chapter 3 - Informal Algorithms and Flow Charts. Chapter 4 - Applications and Mathematics Models.

ERIC Educational Resources Information Center

Stanford Univ., CA. School Mathematics Study Group.

This is the second unit of a 15-unit School Mathematics Study Group (SMSG) mathematics text for high school students. Topics presented in the first chapter (Informal Algorithms and Flow Charts) include: changing a flat tire; algorithms, flow charts, and computers; assignment and variables; input and output; using a variable as a counter; decisions…

Gas Flows in Rocket Motors. Volume 2. Appendix C. Time Iterative Solution of Viscous Supersonic Flow

DTIC Science & Technology

1989-08-01

by b!ock number) FIELD GROUP SUB- GROUP nozzle analysis, Navier-Stokes, turbulent flow, equilibrium S 20 04 chemistry 19. ABSTRACT (Continue on reverse... quasi -conservative formulations lead to unacrepilably large mass conservation errors. Along with the investigations of Navier-Stkes algorithins...Characteristics Splitting ................................... 125 4.2.3 Non -Iterative PNS Procedure ............................... 125 4.2.4 Comparisons of

Emergent supersymmetry in the marginal deformations of $$\\mathcal{N}=4$$ SYM

DOE PAGES

Jin, Qingjun

2016-10-24

Here, we study the one loop renormalization group flow of the marginal deformations ofmore » $$\\mathcal{N}=4$$ SYM theory using the a-function. We found that in the planar limit some non-supersymmetric deformations flow to the supersymmetric infrared fixed points described by the Leigh-Strassler theory. This means supersymmetry emerges as a result of renormalization group flow.« less

Eruptive history of the Karoo lava flows and their impact on early Jurassic environmental change

NASA Astrophysics Data System (ADS)

Moulin, M.; Fluteau, F.; Courtillot, V.; Marsh, J.; Delpech, G.; Quidelleur, X.; Gérard, M.

2017-02-01

This paper reports new paleomagnetic and geochronologic data from a 1500 m thick composite section belonging to the Drakensberg group, the thickest remnant of the Karoo lavas in Northern Lesotho. Flow-by-flow analysis of paleomagnetic directions reveals 21 magnetic directional groups, corresponding to single eruptive events, and 16 individual lava flows. The new age determinations of lava flows range from 180.1 ± 1.4 to 182.8 ± 2.6 Ma. These data, combined with previous results, allow us to propose that the main part of the Drakensberg group and the Karoo intrusive complex dated around 181-183 Ma may have been erupted over a period as short as 250 kyr and may have coincided with the two main phases of extinction in the Early Toarcian. This scenario agrees well with the discontinuous rhythm of environmental and biotic perturbations in the Late Pliensbachian-Toarcian interval.

Procrastination, Flow, and Academic Performance in Real Time Using the Experience Sampling Method.

PubMed

Sumaya, Isabel C; Darling, Emily

2018-01-01

The authors' aim was to first provide an alternative methodology in the assessment of procrastination and flow that would not reply on retrospective or prospective self-reports. Using real-time assessment of both procrastination and flow, the authors investigated how these factors impact academic performance by using the Experience Sampling Method. They assessed flow by measuring student self-reported skill versus challenge, and procrastination by measuring the days to completion of an assignment. Procrastination and flow were measured for six days before a writing assignment due date while students (n = 14) were enrolled in a research methods course. Regardless of status of flow, both the nonflow and flow groups showed high levels of procrastination. Students who experienced flow as they worked on their paper, in real time, earned significantly higher grades (M = 3.05 ± 0.30: an average grade of B) as compared with the nonflow group (M = 1.16 ± 0.33: an average grade of D; p = .007). Additionally, students experiencing flow were more accurate in predicting their grade (difference scores, flow M = 0.12 ± 0.33 vs. nonflow M = 1.39 ± 0.29; p = .015). Students in the nonflow group were nearly a grade and a half off in their prediction of their grade on the paper. To the authors' knowledge, the study is the first to provide experimental evidence showing differences in academic performance between students experiencing flow and nonflow students.

Flowing together: a longitudinal study of collective efficacy and collective flow among workgroups.

PubMed

Salanova, Marisa; Rodríguez-Sánchez, Alma M; Schaufeli, Wilmar B; Cifre, Eva

2014-01-01

The aim of this study is to extend the Channel Model of Flow (Csikszentmihalyi, 1975, 1990) at the collective level (workgroups) by including collective efficacy beliefs as a predictor of collective flow based on the Social Cognitive Theory (Bandura, 1997, 2001). A two-wave longitudinal lab study was conducted with 250 participants working in 52 small groups. Longitudinal results from Structural Equation Modeling with data aggregated at the group level showed, as expected, that collective efficacy beliefs predict collective flow over time, both being related reciprocally. Findings and their theoretical and practical implications in the light of Social Cognitive Theory are discussed.

Determination of pump flow rate during cardiopulmonary bypass in obese patients avoiding hemodilution.

PubMed

Santambrogio, Luisa; Leva, Cristian; Musazzi, Giorgio; Bruno, Piergiorgio; Vailati, Andrea; Zecchillo, Franco; Di Credico, Germano

2009-01-01

During cardiopulmonary bypass the pump flow is usually set on 2.4 L/min/m(2) of body surface area (BSA) to guarantee adequate tissue perfusion without differences for patient constitutional type. The present study attempts to evaluate the adequacy of pump flow rate in obese patients, considering the ideal weight instead of the real one, avoiding the overflow side effects and hemodilution. Obese patients with body mass index (BMI) > 30 presented for cardiac surgery were randomized in two groups: in one the cardiopulmonary bypass was led traditionally, in the other, pump flow rate was calculated on ideal BMI of 25. Demographics, preoperative tests, and monitoring data were registered. Mortality at hospital discharge and 30 days after were analyzed. The pump flow rate between the groups was different (4.46 vs. 4.87; p = 0.004); there were no differences in organ perfusion (SvO(2); diuresis) and mortality, but the study group presented fewer complications and blood transfusions. The BSA is widely used as the biometric unit to normalize physiologic parameters included pump flow rate, but it is disputable if this practice is correct also in obese patients. The study group, in which pump flow rate was set on ideal BSA, presented no difference in diuresis and mixed venous saturation but fewer complications and fewer perioperative blood transfusions.

The effect of light level, CO2 flow rate, and anesthesia on the stress response of mice during CO2 euthanasia.

PubMed

Powell, Karin; Ethun, Kelly; Taylor, Douglas K

2016-09-21

Euthanasia protocols are designed to mitigate the stress experienced by animals, and an environment that induces minimal stress helps achieve that goal. A protocol that is efficient and practical in a typical animal research facility is also important. Light intensity, isoflurane, and CO2 flow rate were studied for their impact on the stress response of mice during CO2 euthanasia. Behavior was observed and scored during euthanasia and serum corticosterone was measured immediately after death. Unsurprisingly, animals euthanized with a high-flow rate of CO2 became unconscious in the least amount of time, while animals euthanized with a low-flow rate required the most time to reach unconsciousness. There was a significant increase in anxious behaviors in animals in the isoflurane group (F1,12 = 6.67, P = 0.024), the high-flow rate CO2 group (F1,12 = 10.24, P = 0.007), and bright chamber group (F1,12 = 7.27, P = 0.019). Serum corticosterone was highest in the isoflurane group (124.72 ± 83.98 ng/ml), however there was no significant difference in corticosterone levels observed for the other study variables of light and flow-rate. A darkened chamber and low CO2 flow rates help to decrease stress experienced during CO2 euthanasia, while the use of isoflurane was observed to increase the stress response during euthanasia.

The effect of cooling management on blood flow to the dominant follicle and estrous cycle length at heat stress.

PubMed

Honig, Hen; Ofer, Lior; Kaim, Moshe; Jacobi, Shamay; Shinder, Dima; Gershon, Eran

2016-07-15

The use of ultrasound imaging for the examination of reproductive organs has contributed substantially to the fertility management of dairy cows around the world. This method has many advantages such as noninvasiveness and immediate availability of information. Adding Doppler index to the ultrasound imaging examination, improved the estimation of blood volume and flow rate to the ovaries in general and to the dominant follicle in particular. The aim of this study was to examine changes in the blood flow to the dominant follicle and compare them to the follicular development throughout the cycle. We further set out to examine the effects of different types of cooling management during the summer on the changes in blood flow to the dominant follicle. For this purpose, 24 Israeli-Holstein dairy cows, under heat stress, were randomly assigned one of two groups: one was exposed to five cooling sessions per day (5CS) and the other to eight cooling sessions per day (8CS). Blood flow to the dominant follicle was measured daily using Doppler index throughout the estrous cycle. No differences in the preovulatory dominant follicle diameter were detected between the two cooling management regimens during the cycle. However, the length of the first follicular wave was significantly longer, whereas the second follicular wave was nonsignificantly shorter in the 5CS group as compared to the 8CS group. In addition, no difference in blood flow was found during the first 18 days of the cycle between the two groups. However, from Day 20 until ovulation a higher rate of blood flow was measured in the ovaries of cows cooled 8 times per day as compared to the 5CS group. No differences in progesterone levels were noted. Finally, the estrous cycle length was shorter in the 8CS group as compared to the 5CS group. Our data suggest that blood flow to the dominant follicle and estrous cycle length is affected by heat stress. Using the appropriate cooling management during heat stress can enhance the blood flow to the ovary and may contribute to improved fertility in dairy cows. Copyright © 2016 Elsevier Inc. All rights reserved.

Prevalence of xerostomia and the salivary flow rate in diabetic patients.

PubMed

Malicka, Barbara; Kaczmarek, Urszula; Skośkiewicz-Malinowska, Katarzyna

2014-01-01

Diabetes is a metabolic disease characterized by hyperglycemia, which results from relative or absolute insulin deficiency. One of the first oral symptoms of diabetes is xerostomia. The aim of the study was to determine the prevalence of the xerostomia symptoms and salivary flow rate in diabetic patients according to the type of diabetes, the level of metabolic control and the duration of the disease. The study involved 156 adult patients of both sexes including 34 patients with diabetes type 1 (group C1), 59 with diabetes type 2 (group C2), and 63 generally healthy individuals as two control groups, sex- and age-matched to the diabetic group. The patients suffering from both types of diabetes were additionally subdivided according to the level of metabolic control and the duration of the disease. Xerostomia was diagnosed with the use of a specially prepared questionnaire and Fox's test. Moreover, the salivary flow rate of resting mixed saliva was measured. In type 1 diabetics, a significantly lower salivary flow rate in comparison to the age-matched control group (0.38 ± 0.19 mL/min vs. 0.53 ± 0.20 mL/min, p < 0.01) was found. However in type 2 diabetics, a slight lower salivary flow rate was noticed (on average, 20% lower). Dry mouth was far more frequently diagnosed in type 1 diabetics than in the control group. In type 1 diabetics, in comparison to healthy subjects, a significantly lower resting flow rate of saliva and significantly higher prevalence of xerosomia were observed, but in type 2 diabetics, only a trend of such variability was observed.

The Effect of Pulsatile Versus Nonpulsatile Blood Flow on Viscoelasticity and Red Blood Cell Aggregation in Extracorporeal Circulation

PubMed Central

Ahn, Chi Bum; Kang, Yang Jun; Kim, Myoung Gon; Yang, Sung; Lim, Choon Hak; Son, Ho Sung; Kim, Ji Sung; Lee, So Young; Son, Kuk Hui; Sun, Kyung

2016-01-01

Background Extracorporeal circulation (ECC) can induce alterations in blood viscoelasticity and cause red blood cell (RBC) aggregation. In this study, the authors evaluated the effects of pump flow pulsatility on blood viscoelasticity and RBC aggregation. Methods Mongrel dogs were randomly assigned to two groups: a nonpulsatile pump group (n=6) or a pulsatile pump group (n=6). After ECC was started at a pump flow rate of 80 mL/kg/min, cardiac fibrillation was induced. Blood sampling was performed before and at 1, 2, and 3 hours after ECC commencement. To eliminate bias induced by hematocrit and plasma, all blood samples were adjusted to a hematocrit of 45% using baseline plasma. Blood viscoelasticity, plasma viscosity, hematocrit, arterial blood gas analysis, central venous O2 saturation, and lactate were measured. Results The blood viscosity and aggregation index decreased abruptly 1 hour after ECC and then remained low during ECC in both groups, but blood elasticity did not change during ECC. Blood viscosity, blood elasticity, plasma viscosity, and the aggregation index were not significantly different in the groups at any time. Hematocrit decreased abruptly 1 hour after ECC in both groups due to dilution by the priming solution used. Conclusion After ECC, blood viscoelasticity and RBC aggregation were not different in the pulsatile and nonpulsatile groups in the adult dog model. Furthermore, pulsatile flow did not have a more harmful effect on blood viscoelasticity or RBC aggregation than nonpulsatile flow. PMID:27298790

The Effect of Pulsatile Versus Nonpulsatile Blood Flow on Viscoelasticity and Red Blood Cell Aggregation in Extracorporeal Circulation.

PubMed

Ahn, Chi Bum; Kang, Yang Jun; Kim, Myoung Gon; Yang, Sung; Lim, Choon Hak; Son, Ho Sung; Kim, Ji Sung; Lee, So Young; Son, Kuk Hui; Sun, Kyung

2016-06-01

Extracorporeal circulation (ECC) can induce alterations in blood viscoelasticity and cause red blood cell (RBC) aggregation. In this study, the authors evaluated the effects of pump flow pulsatility on blood viscoelasticity and RBC aggregation. Mongrel dogs were randomly assigned to two groups: a nonpulsatile pump group (n=6) or a pulsatile pump group (n=6). After ECC was started at a pump flow rate of 80 mL/kg/min, cardiac fibrillation was induced. Blood sampling was performed before and at 1, 2, and 3 hours after ECC commencement. To eliminate bias induced by hematocrit and plasma, all blood samples were adjusted to a hematocrit of 45% using baseline plasma. Blood viscoelasticity, plasma viscosity, hematocrit, arterial blood gas analysis, central venous O2 saturation, and lactate were measured. The blood viscosity and aggregation index decreased abruptly 1 hour after ECC and then remained low during ECC in both groups, but blood elasticity did not change during ECC. Blood viscosity, blood elasticity, plasma viscosity, and the aggregation index were not significantly different in the groups at any time. Hematocrit decreased abruptly 1 hour after ECC in both groups due to dilution by the priming solution used. After ECC, blood viscoelasticity and RBC aggregation were not different in the pulsatile and nonpulsatile groups in the adult dog model. Furthermore, pulsatile flow did not have a more harmful effect on blood viscoelasticity or RBC aggregation than nonpulsatile flow.

Correlation between voluntary cough and laryngeal cough reflex flows in patients with traumatic brain injury.

PubMed

Lee, Sang Chul; Kang, Seong-Woong; Kim, Min Tae; Kim, Yong Kyun; Chang, Won Hyuk; Im, Sang Hee

2013-08-01

To correlate voluntary cough and laryngeal cough reflex (LCR) flows in patients with traumatic brain injury (TBI). Cross-sectional study. University rehabilitation hospital. Patients with TBI (n=25) and healthy controls (n=48). Not applicable. Peak cough flows (PCFs) and LCR flows were measured using a peak flow meter at the oral-nasal interface. The largest value of 3 attempts was recorded for PCF and LCR, respectively. LCR was elicited by 20% solution of pharmaceutic-grade citric acid dissolved in sterile .15M NaCl solution that was inhaled from a nebulizer. PCF was 447.4 ± 99.0 L/min in the control group and 211.7 ± 58.2 L/min in the patient group. LCR was 209.2 ± 63.8L/min in the control group and 170.0 ± 59.7 L/min in the patient group. Both PCF (P=.000) and LCR (P=.013) were significantly reduced in patients with TBI compared to that of the control group. LCR was strongly related to the PCF in both control (R=.645; P=.000) and patient (R=.711; P=.000) groups. As LCR can be measured as a numerical value and significantly correlates with PCF, LCR can be used to estimate cough ability of patients with TBI who cannot cooperate with PCF measurement. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Sex-dependent alterations in resting-state cerebral blood flow, amplitude of low-frequency fluctuations and their coupling relationship in schizophrenia.

PubMed

Ma, Xiaomei; Wang, Di; Zhou, Yujing; Zhuo, Chuanjun; Qin, Wen; Zhu, Jiajia; Yu, Chunshui

2016-04-01

We aimed to investigate sex-dependent alterations in resting-state relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling in patients with schizophrenia. Resting-state functional magnetic resonance imaging and three-dimensional pseudo-continuous arterial spin labeling imaging were performed to obtain resting-state amplitude of low-frequency fluctuations and relative cerebral blood flow in 95 schizophrenia patients and 99 healthy controls. Sex differences in relative cerebral blood flow and amplitude of low-frequency fluctuations were compared in both groups. Diagnostic group differences in relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling were compared in male and female subjects, respectively. In both healthy controls and schizophrenia patients, the males had higher relative cerebral blood flow in anterior brain regions and lower relative cerebral blood flow in posterior brain regions than did the females. Compared with multiple regions exhibiting sex differences in relative cerebral blood flow, only the left middle frontal gyrus had a significant sex difference in amplitude of low-frequency fluctuations. In the females, schizophrenia patients exhibited increased relative cerebral blood flow and amplitude of low-frequency fluctuations in the basal ganglia, thalamus and hippocampus and reduced relative cerebral blood flow and amplitude of low-frequency fluctuations in the frontal, parietal and occipital regions compared with those of healthy controls. However, there were fewer brain regions with diagnostic group differences in the males than in the females. Brain regions with diagnostic group differences in relative cerebral blood flow and amplitude of low-frequency fluctuations only partially overlapped. Only the female patients exhibited increased relative cerebral blood flow-amplitude of low-frequency fluctuations couplings compared with those of healthy females. The alterations in the relative cerebral blood flow and amplitude of low-frequency fluctuations in schizophrenia are sex-specific, which should be considered in future neuroimaging studies. The relative cerebral blood flow and amplitude of low-frequency fluctuations have different sensitivity in detecting changes in neuronal activity in schizophrenia and can provide complementary information. © The Royal Australian and New Zealand College of Psychiatrists 2015.

Cellular transport of l-arginine determines renal medullary blood flow in control rats, but not in diabetic rats despite enhanced cellular uptake capacity.

PubMed

Persson, Patrik; Fasching, Angelica; Teerlink, Tom; Hansell, Peter; Palm, Fredrik

2017-02-01

Diabetes mellitus is associated with decreased nitric oxide bioavailability thereby affecting renal blood flow regulation. Previous reports have demonstrated that cellular uptake of l-arginine is rate limiting for nitric oxide production and that plasma l-arginine concentration is decreased in diabetes. We therefore investigated whether regional renal blood flow regulation is affected by cellular l-arginine uptake in streptozotocin-induced diabetic rats. Rats were anesthetized with thiobutabarbital, and the left kidney was exposed. Total, cortical, and medullary renal blood flow was investigated before and after renal artery infusion of increasing doses of either l-homoarginine to inhibit cellular uptake of l-arginine or N ω -nitro- l-arginine methyl ester (l-NAME) to inhibit nitric oxide synthase. l-Homoarginine infusion did not affect total or cortical blood flow in any of the groups, but caused a dose-dependent reduction in medullary blood flow. l-NAME decreased total, cortical and medullary blood flow in both groups. However, the reductions in medullary blood flow in response to both l-homoarginine and l-NAME were more pronounced in the control groups compared with the diabetic groups. Isolated cortical tubular cells displayed similar l-arginine uptake capacity whereas medullary tubular cells isolated from diabetic rats had increased l-arginine uptake capacity. Diabetics had reduced l-arginine concentrations in plasma and medullary tissue but increased l-arginine concentration in cortical tissue. In conclusion, the reduced l-arginine availability in plasma and medullary tissue in diabetes results in reduced nitric oxide-mediated regulation of renal medullary hemodynamics. Cortical blood flow regulation displays less dependency on extracellular l-arginine and the upregulated cortical tissue l-arginine may protect cortical hemodynamics in diabetes. Copyright © 2017 the American Physiological Society.

Electrical stimulation of acupoint combinations against deep venous thrombosis in elderly bedridden patients after major surgery.

PubMed

Hou, Lili; Chen, Cuiping; Xu, Lei; Yin, Peihao; Peng, Wen

2013-04-01

To compare the effects of electrical stimulation of different acupoint combinations among postoperative bedridden elderly patients on hemorheology and deep venous blood flow velocity and investigate the.role of electrical stimulation against deep vein thrombosis (DVT). From November 2010 to October 2011, a total of 160 elderly bedridden patients after major surgery were divided into the conventional care group, invigorating and promoting Qi group, blood-activating and damp-eliminating group, and acupoint-combination stimulation group. Whole blood viscosity, plasma viscosity, D-dimer levels, lower limb skin temperature, lower limb circumference, and flow velocities of the external iliac vein, femoral vein, popliteal vein, and deep calf veins in all patients were documented and compared among the four groups. Whole blood viscosity, plasma viscosity, D-dimer levels, and lower limb circumference were significantly reduced in the blood-activating and damp-eliminating group compared with the conventional care group (P < 0.05) and were almost equal to those in the acupoint-combination stimulation group (P > 0.05). Lower limb venous flow velocities were accelerated in the invigorating and promoting Qi group compared with the other groups, excluding the acupoint-combination stimulation group (P < 0.05). Hemorheological indices in postoperative bedridden elderly patients were improved after combined electrical stimulation at Yinlingquan (SP 9) and Sanyinjiao (SP 6). Combined electrical stimulation at Zusanli (ST 36) and Taichong (LR 3), on the other hand, accelerated lower limb venous flow.

Influence Of Low Intensity Laser Therapy On Diabetic Polyneuropathy

NASA Astrophysics Data System (ADS)

Abdel-Raoof, N. A.; Elnhas, N. G.; Elsayed, I. M.

2011-09-01

Diabetic peripheral neuropathy is a consequence of diabetes-mediated impairment of blood flow, and resultant hypoxia of nerves that may develop within 10 years of the onset of diabetes in 40-50% of people with type 1 or type 2 diabetes. Low Intensity Laser Therapy (LILT) has been advocated for the treatment of chronic pain disorders as blood flow is an important determinant for pain relief. Comparing the effect of Helium-Neon Laser therapy versus Infrared laser therapy on blood vessels diameter and flow as well as level of sensation for neuropathy. Twenty diabetic patients suffering from neuropathy were enrolled in the study with age 45-55 years. They were assigned randomly into two equal groups in number; Group A underwent an application of He-Neon laser while Group B underwent an application of Infrared laser. Both groups received laser for 2 months. Blood flow velocity, and blood vessel diameter were investigated by using duplex Doppler ultrasound and peripheral neuropathy parameters were investigated by Semmes-Weinstein monofilament assessment. The results revealed that He-Neon laser as well as Infrared laser groups showed significant improvement in blood flow velocity, blood vessel diameter & neuropathy tested parameters after treatment but there was no significance difference between the two types of LILT. LILT is a safe, non-invasive and drug free method for improving blood flow & sensation in patients suffering from diabetic polyneuropathy in addition to preventing one of the most threatening microvascular complications of diabetes.

Improvement in symptoms and cochlear flow with pycnogenol in patients with Meniere's disease and tinnitus.

PubMed

Luzzi, R; Belcaro, G; Hu, S; Dugall, M; Hosoi, M; Cacchio, M; Ippolito, E; Corsi, M

2014-06-01

The aim of this supplement registry was to evaluate the efficacy of the Pycnogenol® in improving cochlear flow and symptoms in a 6-month follow-up for patients with Meniere's disease (MD), tinnitus and cochlear hypoperfusion. Main signs/symptoms were considered: Spontaneous vertigo, positional vertigo, hearing loss, tinnitus, pressure in the ear, unsteady gait, associated clinical problems, alterations in daily life. All subjects were managed with the best available management (BM); one group used the supplement Pycnogenol (150 mg/day). Cochlear flow and tinnitus were also evaluated. Out of 120 patients incuded in the registry, 55 used Pycnogenol and 52 (controls) were managed only with BM. There was a more significant improvement in all registry items at 3 and 6 months in the Pycnogenol group (P<0.05). The number of lost working days was lower in the Pycnogenol group. At 3 months, 45.4% of subjects using Pycnogenol were completely asymptomatic in comparison with 23.07% of controls. At 6 months 87.3% of the Pycnogenol subjects were asymptomatic compared with 34.6% of controls. Cochlear flow velocity was significantly better (higher flow, higher diastolic component) in the Pycnogenol group (P<0.05). The subjective tinnitus scale decreased in both groups (P<0.05); the decrease was more significant in Pycnogenol subjects (P<0.05) at 3 and 6 months. Symptoms of Meniere's disease, flow at cochlear level and tinnitus improved in Pycnogenol subjects in comparison with best management.

[Effects of Frankincense and Myrrh essential oil on transdermal absorption in vitro of Chuanxiong and penetration mechanism of skin blood flow].

PubMed

Zhu, Xiao-Fang; Luo, Jing; Guan, Yong-Mei; Yu, Ya-Ting; Jin, Chen; Zhu, Wei-Feng; Liu, Hong-Ning

2017-02-01

The aim of this paper was to explore the effects of Frankincense and Myrrh essential oil on transdermal absorption in vitro of Chuanxiong, and to investigate the possible penetration mechanism of their essential oil from the perspective of skin blood perfusion changes. Transdermal tests were performed in vitro with excised mice skin by improved Franz diffusion cells. The cumulative penetration amounts of ferulic acid in Chuanxiong were determined by HPLC to investigate the effects of Frankincense and Myrrh essential oil on transdermal permeation properties of Chuanxiong. Simultaneously, the skin blood flows were determined by laser flow doppler. The results showed that the cumulative penetration amount of ferulic acid in Chuanxiong was (8.13±0.76) μg•cm⁻² in 24 h, and was (48.91±4.87), (57.80±2.86), (63.34±4.56), (54.17±4.40), (62.52±7.79) μg•cm⁻² respectively in Azone group, Frankincense essential oil group, Myrrh essential oil, frankincense and myrrh singly extracted essential oil mixture group, and frankincense and myrrh mixed extraction essential oil group. The enhancement ratios of each essential oil groups were 7.68, 8.26, 7.26, 8.28, which were slightly greater than 6.55 in Azone group. In addition, as compared with the conditions before treatment, there were significant differences and obvious increasing trend in blood flow of rats in Frankincense essential oil group, Myrrh essential oil group, frankincense and myrrh singly extracted essential oil mixture group, and frankincense and myrrh mixed extraction essential oil group when were dosed at 10, 20, 30, 10 min respectively, indicating that the skin blood flows were increased under the effects of Frankincense and Myrrh essential oil to a certain extent. Thus, Frankincense and Myrrh essential oil had certain effect on promoting permeability of Chuanxiong both before and after drug combination, and may promote the elimination of drugs from epidermis to dermal capillaries through increase of skin blood flow, thus enhancing the transdermal permeation amounts of drugs. Copyright© by the Chinese Pharmaceutical Association.

Intramucosal–arterial PCO2 gap fails to reflect intestinal dysoxia in hypoxic hypoxia

PubMed Central

Dubin, Arnaldo; Murias, Gastón; Estenssoro, Elisa; Canales, Héctor; Badie, Julio; Pozo, Mario; Sottile, Juan P; Barán, Marcelo; Pálizas, Fernando; Laporte, Mercedes

2002-01-01

Introduction An elevation in intramucosal–arterial PCO2 gradient (ΔPCO2) could be determined either by tissue hypoxia or by reduced blood flow. Our hypothesis was that in hypoxic hypoxia with preserved blood flow, ΔPCO2 should not be altered. Methods In 17 anesthetized and mechanically ventilated sheep, oxygen delivery was reduced by decreasing flow (ischemic hypoxia, IH) or arterial oxygen saturation (hypoxic hypoxia, HH), or no intervention was made (sham). In the IH group (n = 6), blood flow was lowered by stepwise hemorrhage; in the HH group (n = 6), hydrochloric acid was instilled intratracheally. We measured cardiac output, superior mesenteric blood flow, gases, hemoglobin, and oxygen saturations in arterial blood, mixed venous blood, and mesenteric venous blood, and ileal intramucosal PCO2 by tonometry. Systemic and intestinal oxygen transport and consumption were calculated, as was ΔPCO2. After basal measurements, measurements were repeated at 30, 60, and 90 minutes. Results Both progressive bleeding and hydrochloric acid aspiration provoked critical reductions in systemic and intestinal oxygen delivery and consumption. No changes occurred in the sham group. ΔPCO2 increased in the IH group (12 ± 10 [mean ± SD] versus 40 ± 13 mmHg; P < 0.001), but remained unchanged in HH and in the sham group (13 ± 6 versus 10 ± 13 mmHg and 8 ± 5 versus 9 ± 6 mmHg; not significant). Discussion In this experimental model of hypoxic hypoxia with preserved blood flow, ΔPCO2 was not modified during dependence of oxygen uptake on oxygen transport. These results suggest that ΔPCO2 might be determined primarily by blood flow. PMID:12493073

[Low flow anaesthesia with isoflurane in the dog].

PubMed

Kramer, Sabine; Alyakine, Hassan; Nolte, Ingo

2005-01-01

The aim of the present study was to compare the safety of two low flow (LF) regimes [fresh gas flow (FGF) 20 ml/kg/min (group 2) and 14 ml/kg/min (group 3)] with the high flow (HF) technique (FGF 50 ml/kg/min; group 1) of isoflurane anaesthesia. Data were gathered from ninety dogs assigned for surgery under general anaesthesia with an expected duration of 75 minutes or longer. All dogs had an anaesthetic induction with 0,6 mg/kg I-methadone (maximum 25 mg) and 1 mg/kg diazepam (maximum 25 mg) i.v. Anaesthesia was maintained with isoflurane in a mixture of 50% O2 and 50% N2O as carrier gases, with controlled ventilation. The Monitoring included electrocardiogramm, body temperature, the temperature of in- and exspired gases, arterial oxygen saturation, arterial blood pressure as well as a continuous monitoring of inhaled and exhaled gas concentrations (O2, N2O, CO2, isoflurane). The consumption of isoflurane and carrier gases as well as the recovery times were evaluated for the three groups. The inspired oxygen concentrations always ranged above the minimum value of 30 Vol.-% during low flow anaesthesia. The arterial oxygen saturation ranged between 92-98%, the end tidal concentration of CO2 between 35 and 45 mmHg. Heart rate and arterial blood pressure were within normal limits. Recovery time was significantly shorter after LF than after HF anaesthesia. The highest decrease in body temperature occurred in the HF group 1 because of a significantly lower anaesthetic gas temperature. Despite this, LF anaesthesia resulted in a reduced consumption of carrier gases and volatiles. In conclusion, low flow anaesthesia with isoflurane is a safe technique and offers substantial economic advantages over high flow techniques and is moreover better tolerated by the patients.

[The treatment of hyperhomocysteinemia in patients on dialysis: folic acid or the high-flow polysulphonic membrane?].

PubMed

Lovcić, Vesna; Kes, Petar; Zeljko, Reiner; Kusec, Vesna

2006-06-01

The aim of the study was to determine the effects of high-flow and low-flow hemodialysis (HD), with simultaneous treatment with folic acid and vitamin B12, on total homocysteine (tHcy) concentration in plasma of dialyzed patients. The planned clinical observation included 46 patients of both sexes, aged 21-82, treated with bicarbonate dialysis for a mean of 4.7 years. The patients were divided into group A, subsequently dialyzed by use of high-flow polysulphonic membrane (AN 69ST, Nephral 300), and group B that continued to be dialyzed by use of low-flow diacetate membrane (Diacepal 14 and 16). The subjects in both groups received 30 mg of folic acid at the end of each dialysis (3 times a week), and 500 g of vitamin B12 at the end of every other dialysis. The method of stable isotopic dilution mass spectrometry was used to measure tHcy. Folic acid was determined by the test based on ion capture technology. Vitamin B12 was determined by MEIA. An increase in the concentration of tHcy was observed in 39/46 (85%) patients with a mean concentration of 24.76 +/- 11.04 micromol/L. The mean concentration of folic acid and vitamin B12 was within the normal limits. In the group dialyzed by high-flow dialyzer, the values of tHcy and folic acid decreased (18.74 +/- 2.95 micromol/L and 13.90 +/- 6.78 pmol/L) after hemodialysis, which was significant compared to the initial value (p<0.01 and p<0.05, respectively). At four weeks of treatment, tHcy concentration before HD showed a significant decrease both in the group dialyzed by high-flow dialyzer (15.10 +/- 4.26 mmol/L, p<0.01) and in the group dialyzed by low-flow dialyzer (12.54 +/- 3.87 micromol/L, p<0.01) compared to the measure before HD and before the treatment. There was no statistically significant difference (z -0.40, p>0.68) in the percentage of tHcy change between the group treated by high-flow dialyzer and the group treated by low-flow dialyzer in the measurements before HD and before the treatment with folic acid and vitamin B12, and after the treatment. There is a literature report on the concentration increase by 26 micromol/L, which is very similar to our result. The absence of long-term effect on predialysis concentration of tHcy in HD by high-flow membrane has also been described, because the decrease of tHcy is mantained until the uremic toxins, enzyme inhibitors that are necessary for the process of remethylation of Hcy, accumulated again. During high-flow HD, the folic acid concentration decreased by 23.05% on an average, consistent with other literature reports. Some reports support our observation that the dosage of folic acid required for tHcy decrease is 15-30 mg, and that the dosage higher than 60 mg does not significantly decrease tHcy concentration. Our study confirmed the reported observations that treatment with folic acid and vitamin B12 rather than high-flow dialyzer contributes to tHcy decrease. The study confirmed the high prevalence of hyperhomocysteinemia in patients on dialysis. The treatment with folic acid and vitamin B12 results in a significant decrease of tHcy. After individual HD by high-flow dialyzer, there is a significant, but temporary decrease of tHcy concentration in plasma. There is no significant difference in the efficiency on pre-dialysis tHcy concentration between the high-flow and low-flow dialyzer membrane. Because of the atherogenic effect of hyperhomocysteinemia, the treatment with folic acid and vitamin B12 should be accepted as an options to lower the risk factors for the rapid atherosclerosis in patients on dialysis, thus reducing the occurrence and fatality of cardiovascular diseases.

Correlation of Miocene flows of the Columbia River Basalt Group from the central Columbia River Plateau to the coast of Oregon and Washington

USGS Publications Warehouse

Wells, Ray E.; Simpson, R.W.; Bentley, R.D.; Beeson, Melvin H.; Mangan, Margaret T.; Wright, Thomas L.

1989-01-01

Nearly twenty flows of the Columbia River Basalt Group (CRBG) can be paleomagnetically and chemically correlated westward as far as 500 km from the Columbia Plateau in Washington, through the Columbia Gorge, to the Coast Range of Oregon and Washington. In the Coast Range near Cathlamet, Washington, the CRBG flow stratigraphy includes 10 flows of Grande Ronde Basalt (1 low-MgO R2 flow, 6 low-MgO N2 flows, 3 high-MgO N2 flows), 2 flows of Wanapum Basalt (both flows of Sand Hollow from the Frenchman Springs Member), and the Pomona Member of the Saddle Mountains Basalt. Elsewhere in the Coast Range, additional Grande Ronde Basalt flows, including flows of Winterwater or Umtanum, and additional Wanapum flows, including the flows of Ginkgo, have been reported. Thus at least 18 to 20 CRBG flows reached the coast region. Several of these distal flows have distinctive chemical and magnetic characteristics that are shared by nearby isolated intrusions in Coast Range sedimentary rocks, thus strongly supporting recent suggestions that these intrusions are invasive bodies fed by CRBG flows. Magnetization directions from several flows indicate 16 to 30° of clockwise rotation of the coast with respect to the plateau since middle Miocene time.

Evaluation of the effectiveness of low-dose aspirin and omega 3 in treatment of asymmetrically intrauterine growth restriction: A randomized clinical trial.

PubMed

Ali, Mohammed K; Amin, Maggy E; Amin, Ahmed F; Abd El Aal, Diaa Eldeen M

2017-03-01

To test the effect of aspirin and omega 3 on fetal weight as well as feto-maternal blood flow in asymmetrical intrauterine growth restriction (IUGR). This study is a clinically registered (NCT02696577), open, parallel, randomized controlled trial, conducted at Assiut Woman's Health Hospital, Egypt including 80 pregnant women (28-30 weeks) with IUGR. They were randomized either to group I: aspirin or group II: aspirin plus omega 3. The primary outcome was the fetal weight after 6 weeks of treatment. Secondary outcomes included Doppler blood flow changes in both uterine and umbilical arteries, birth weight, time and method of delivery and admission to NICU. The outcome variables were analyzed using paired and unpaired t-test. The estimated fetal weight increased significant in group II more than group I (p=0.00). The uterine and umbilical arteries blood flow increased significantly in group II (p<0.05). The birth weight in group II was higher than that observed in group I (p<0.05). The using of aspirin with omega 3 is more effective than using aspirin only in increasing fetal weight and improving utero-placental blood flow in IUGR. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Emplacement of Columbia River flood basalt

NASA Astrophysics Data System (ADS)

Reidel, Stephen P.

1998-11-01

Evidence is examined for the emplacement of the Umatilla, Wilbur Creek, and the Asotin Members of Columbia River Basalt Group. These flows erupted in the eastern part of the Columbia Plateau during the waning phases of volcanism. The Umatilla Member consists of two flows in the Lewiston basin area and southwestern Columbia Plateau. These flows mixed to form one flow in the central Columbia Plateau. The composition of the younger flow is preserved in the center and the composition of the older flow is at the top and bottom. There is a complete gradation between the two. Flows of the Wilbur Creek and Asotin Members erupted individually in the eastern Columbia Plateau and also mixed together in the central Columbia Plateau. Comparison of the emplacement patterns to intraflow structures and textures of the flows suggests that very little time elapsed between eruptions. In addition, the amount of crust that formed on the earlier flows prior to mixing also suggests rapid emplacement. Calculations of volumetric flow rates through constrictions in channels suggest emplacement times of weeks to months under fast laminar flow for all three members. A new model for the emplacement of Columbia River Basalt Group flows is proposed that suggests rapid eruption and emplacement for the main part of the flow and slower emplacement along the margins as the of the flow margin expands.

Propulsion and Energetics Panel Working Group 14 on Suitable Averaging Techniques in Non-Uniform Internal Flows

DTIC Science & Technology

1983-06-01

PANEL WORKING GROUP 14 on SUITABLE AVERAGING TECHNIQUES IN NON-UNIFORM INTERNAL FLOWS Edited by M.Pianko Office National d’Etudes et de...d’Etudes et de Recherches Aerospatiales Pratt and Whitney Government Products Division Rocketdyne Division of Rockwell International , Inc. Teledyne CAE...actions exerted by individual components on the gas flow must be known. These specific component effects are distributed internally within the

Flow Diversion versus Standard Endovascular Techniques for the Treatment of Unruptured Carotid-Ophthalmic Aneurysms.

PubMed

Di Maria, F; Pistocchi, S; Clarençon, F; Bartolini, B; Blanc, R; Biondi, A; Redjem, H; Chiras, J; Sourour, N; Piotin, M

2015-12-01

Over the past few years, flow diversion has been increasingly adopted for the treatment of intracranial aneurysms, especially in the paraclinoid and paraophthalmic carotid segment. We compared clinical and angiographic outcomes and complication rates in 2 groups of patients with unruptured carotid-ophthalmic aneurysms treated for 7 years by either standard coil-based techniques or flow diversion. From February 2006 to December 2013, 162 unruptured carotid-ophthalmic aneurysms were treated endovascularly in 138 patients. Sixty-seven aneurysms were treated by coil-based techniques in 61 patients. Flow diverters were deployed in 95 unruptured aneurysms (77 patients), with additional coiling in 27 patients. Complication rates, clinical outcome, and immediate and long-term angiographic results were retrospectively analyzed. No procedure-related deaths occurred. Four procedure-related thromboembolic events (6.6%) leading to permanent morbidity in 1 case (1.6%) occurred in the coiling group. Neurologic complications were observed in 6 patients (7.8%) in the flow-diversion group, resulting in 3.9% permanent morbidity. No statistically significant difference was found between complication (P = .9) and morbidity rates (P = .6). In the coiling group (median follow-up, 31.5 ± 24.5 months), recanalization occurred at 1 year in 23/50 (54%) aneurysms and 27/55 aneurysms (50.9%) at the latest follow-up, leading to retreatment in 6 patients (9%). In the flow-diversion group (mean follow-up, 13.5 ± 10.8 months), 85.3% (35/41) of all aneurysms were occluded after 12 months, and 74.6% (50/67) on latest follow-up. The retreatment rate was 2.1%. Occlusion rates between the 2 groups differed significantly at 12 months (P < .001) and at the latest follow-up (P < .005). Our retrospective analysis shows better long-term occlusion of carotid-ophthalmic aneurysms after use of flow diverters compared with standard coil-based techniques, without significant differences in permanent morbidity. © 2015 by American Journal of Neuroradiology.

Low flow anesthesia: Efficacy and outcome of laryngeal mask airway versus pressure–optimized cuffed–endotracheal tube

PubMed Central

El-Seify, Zeinab A; Khattab, Ahmed Metwally; Shaaban, Ashraf; Radojevic, Dobrila; Jankovic, Ivanka

2010-01-01

Background Low flow anesthesia can lead to reduction of anesthetic gas and vapor consumption. Laryngeal mask airway (LMA) has proved to be an effective and safe airway device. The aim of this study is to assess the feasibility of laryngeal mask airway during controlled ventilation using low fresh gas flow (1.0 L/min) as compared to endotracheal tube (ETT). Patients and Methods Fifty nine non-smoking adult patients; ASA I or II, being scheduled for elective surgical procedures, with an expected duration of anesthesia 60 minutes or more, were randomly allocated into two groups - Group I (29 patients) had been ventilated using LMA size 4 for females and 5 for males respectively; and Group II (30 patients) were intubated using ETT. After 10 minutes of high fresh gas flow, the flow was reduced to 1 L/min. Patients were monitored for airway leakage, end-tidal CO2(ETCO2), inspiratory and expiratory isoflurane and nitrous oxide fraction concentrations, and postoperative airway-related complications. Results Two patients in the LMA-group developed initial airway leakage (6.9%) versus no patient in ETT-group. Cough and sore throat were significantly higher in ETT patients. There were no evidences of differences between both groups regarding ETCO2, uptake of gases, nor difficulty in swallowing. Conclusion: The laryngeal mask airway proved to be effective and safe in establishing an airtight seal during controlled ventilation under low fresh gas flow of 1 L/min, inducing less coughing and sore throat during the immediate postoperative period than did the ETT, with continuous measurement and readjustment of the tube cuff pressure. PMID:20668559

[Macular choroidal blood flow in concurrent age-related macular degeneration and primary open-angle glaucoma].

PubMed

Panova, I E; Ermak, E M; Shaimova, T A; Shaimova, V A

2016-01-01

Ocular circulation disorders are an important factor in the development of primary open-angle glaucoma (POAG) and age-related macular degeneration (AMD). To date, however, there have been no studies on choroidal blood flow peculiarities in case of concurrent AMD and POAG. to determine distinctive features of choroidal blood flow characteristic of concurrent AMD and POAG and to assess their role in disease pathogenesis. Macular choroidal blood flow, including blood supply, was assessed in 54 patients (102 eyes) by means of Doppler ultrasound. Three groups were formed: group 1 - 38 eyes with both AMD and POAG; group 2 - 41 eyes with AMD and no signs of optic nerve pathology; and group 3 - 23 eyes with POAG and no signs of AMD. Groups 1 and 2 were subdivided into two subgroups each: А - atrophic AMD and B - macular drusen. The mean patient age was 78.7±8.4 years. The following parameters of choroidal blood flow were of interest: peak systolic velocity (Vps), end diastolic velocity (Ved), time-averaged maximum velocity (Vtamax), and resistance index (RI). Groups 1, 3, and 2A had an evident choroidal hypoperfusion in the macular area (decreased Vtamax) with uncompensated perfusion deficit, despite autoregulation efforts (decreased Vps, Ved, decreased or normal RI). Group 2B demonstrated a significantly higher rate of choroidal hyperperfusion (increased Vps, Ved, Vtamax, and RI). Concurrent AMD and POAG are notable for choroidal hypoperfusion in the macular area that leads to inadequate trophism of the neurosensory retina and can aggravate the course of AMD contributing to progression of its atrophic form.

[Economical benefit of continuous total intravenous anesthesia].

PubMed

Onaka, M; Yamamoto, H; Akatsuka, M; Mori, H

1999-05-01

Total intravenous anesthesia (TIVA) has been recommended in view of avoiding air pollution. However, intermittent administration of anesthetic agents has a large disadvantage of delayed emergence. We reported that continuous TIVA with propofol, ketamine, vecuronium and buprenorphine (PKBp) could bring rapid emergence. In this study, we calculated and compared the cost of anesthesia in the subjects who had undergone general anesthesia either with continuous PKBp or nitrous oxide-oxygen-sevoflurane. In group PKBp subjects, after induction with propofol, ketamine, vecuronium and buprenorphine, anesthesia was maintained with continuous intravenous administration of propofol corresponding to the patient's age using twice step down method; ketamine (240 micrograms.kg-1.h-1), vecuronium (80 micrograms.kg-1.h-1) and buprenorphine (0.4 microgram.kg-1.h-1). Group GOS subjects, after the same induction method, received nitrous oxide, sevoflurane and vecuronium. Moreover, the group GOS subjects were divided to two groups; the high flow GOS (N2O:O2:sevoflurane = 4 l:2 l:30 ml) and the low flow GOS (N2O:O2:sevoflurane = 2 l:1 l:15 ml). Continuous PKBp group showed lower cost than the high flow GOS group. The PKBp group showed lower cost than the low flow GOS group except in patients weighing more than 100 kg. Furthermore, we calculated the cost of continuous PKBp anesthesia in Japan, U.S.A. and U.K. The U.S.A. cost of PKBp was higher than the Japanese and the U.K., because the cost of ketamine in U.S.A. is higher than in the other countries. Continuous PKBp is more economical than the high flow GOS, and continuous PKBp in Japan is more economical than in U.S.A.

External and Turbomachinery Flow Control Working Group

NASA Technical Reports Server (NTRS)

Ahmadi, G.; Alstrom, B.; Colonius, T.; Dannenhoffer, J.; Glauser, M.; Helenbrook, B.; Higuchi, H.; Hodson, H.; Jha, R.; Kabiri, P.;

HYPERHYDRATION AND PAROTID FLOW IN MAN.

DTIC Science & Technology

Parotid fluid was collected without exogenous stimulation from five groups of 25 subjects each. Each group received a different amount of water...under conditions of forced ingestion. The increase in parotid flow rate brought about by water ingestion was highly significant. Doses of 1,000 ml. or

One-group interfacial area transport in vertical air-water bubbly flow

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

Wu, Q.; Kim, S.; Ishii, M.

In the two-fluid model for two-phase flows, interfacial area concentration is one of the most important closure relations that should be obtained from careful mechanistic modeling. The objective of this study is to develop a one-group interfacial area transport equation together with the modeling of the source and sink terms due to bubble breakage and coalescence. For bubble coalescence, two mechanisms are considered to be dominant in vertical two-phase bubbly flow. These are the random collisions between bubbles due to turbulence in the flow field, and the wake entrainment process due to the relative motion of the bubbles in themore » wake region of a seeding bubble. For bubble breakup, the impact of turbulent eddies is considered. These phenomena are modeled individually, resulting in a one-group interfacial area concentration transport equation with certain parameters to be determined from experimental data. Compared to the measured axial distribution of the interfacial area concentration under various flow conditions, these parameters are obtained for the reduced one-group, one-dimensional transport equation. The results indicate that the proposed models for bubble breakup and coalescence are appropriate.« less

Microvascular Blood Flow Improvement in Hyperglycemic Obese Adult Patients by Hypocaloric Diet.

PubMed

Mastantuono, T; Di Maro, M; Chiurazzi, M; Battiloro, L; Starita, N; Nasti, G; Lapi, D; Iuppariello, L; Cesarelli, M; D'Addio, G; Colantuoni, A

2016-11-01

The present study was aimed to assess the changes in skin microvascular blood flow (SBF) in newly diagnosed hyperglycemic obese subjects, administered with hypocaloric diet. Adult patients were recruited and divided in three groups: NW group (n=54), NG (n=54) and HG (n=54) groups were constituted by normal weight, normoglycemic and hyperglycemic obese subjects, respectively. SBF was measured by laser Doppler perfusion monitoring technique and oscillations in blood flow were analyzed by spectral methods under baseline conditions, at 3 and 6 months of dietary treatment. Under resting conditions, SBF was lower in HG group than in NG and NW ones. Moreover, all subjects showed blood flow oscillations with several frequency components. In particular, hyperglycemic obese patients revealed lower spectral density in myogenic-related component than normoglycemic obese and normal weight ones. Moreover, post-occlusive reactive hyperemia (PORH) was impaired in hyperglycemic obese compared to normoglycemic and normal weigh subjects. After hypocaloric diet, in hyperglycemic obese patients there was an improvement in SBF accompanied by recovery in myogenic-related oscillations and arteriolar responses during PORH. In conclusion, hyperglycemia markedly affected peripheral microvascular function; hypocaloric diet ameliorated tissue blood flow.

Microvascular Blood Flow Improvement in Hyperglycemic Obese Adult Patients by Hypocaloric Diet

PubMed Central

Mastantuono, T; Di Maro, M.; Chiurazzi, M.; Battiloro, L.; Starita, N.; Nasti, G.; Lapi, D.; Iuppariello, L.; Cesarelli, M.; D’Addio, G.; Colantuoni, A.

2016-01-01

The present study was aimed to assess the changes in skin microvascular blood flow (SBF) in newly diagnosed hyperglycemic obese subjects, administered with hypocaloric diet. Adult patients were recruited and divided in three groups: NW group (n=54), NG (n=54) and HG (n=54) groups were constituted by normal weight, normoglycemic and hyperglycemic obese subjects, respectively. SBF was measured by laser Doppler perfusion monitoring technique and oscillations in blood flow were analyzed by spectral methods under baseline conditions, at 3 and 6 months of dietary treatment. Under resting conditions, SBF was lower in HG group than in NG and NW ones. Moreover, all subjects showed blood flow oscillations with several frequency components. In particular, hyperglycemic obese patients revealed lower spectral density in myogenic-related component than normoglycemic obese and normal weight ones. Moreover, post-occlusive reactive hyperemia (PORH) was impaired in hyperglycemic obese compared to normoglycemic and normal weigh subjects. After hypocaloric diet, in hyperglycemic obese patients there was an improvement in SBF accompanied by recovery in myogenic-related oscillations and arteriolar responses during PORH. In conclusion, hyperglycemia markedly affected peripheral microvascular function; hypocaloric diet ameliorated tissue blood flow. PMID:27896221

Hydrodynamic schooling of flapping swimmers

NASA Astrophysics Data System (ADS)

Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

2015-10-01

Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing-wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. These results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.

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

Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.

Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing–wake interactions. Simulations show that swimming in amore » group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. Lastly, these results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.« less

Hydrodynamic schooling of flapping swimmers

DOE PAGES

Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; ...

2015-10-06

Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing–wake interactions. Simulations show that swimming in amore » group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. Lastly, these results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.« less

Sleep-Disordered Breathing Exacerbates Muscle Vasoconstriction and Sympathetic Neural Activation in Patients with Systolic Heart Failure.

PubMed

Lobo, Denise M L; Trevizan, Patricia F; Toschi-Dias, Edgar; Oliveira, Patricia A; Piveta, Rafael B; Almeida, Dirceu R; Mady, Charles; Bocchi, Edimar A; Lorenzi-Filho, Geraldo; Middlekauff, Holly R; Negrão, Carlos E

2016-11-01

Sleep-disordered breathing (SDB) is common in patients with heart failure (HF), and hypoxia and hypercapnia episodes activate chemoreceptors stimulating autonomic reflex responses. We tested the hypothesis that muscle vasoconstriction and muscle sympathetic nerve activity (MSNA) in response to hypoxia and hypercapnia would be more pronounced in patients with HF and SDB than in patients with HF without SDB (NoSBD). Ninety consecutive patients with HF, New York Heart Association functional class II-III, and left ventricular ejection fraction ≤40% were screened for the study. Forty-one patients were enrolled: NoSDB (n=13, 46 [39-53] years) and SDB (n=28, 57 [54-61] years). SDB was characterized by apnea-hypopnea index ≥15 events per hour (polysomnography). Peripheral (10% O 2 and 90% N 2 , with CO 2 titrated) and central (7% CO 2 and 93% O 2 ) chemoreceptors were stimulated for 3 minutes. Forearm and calf blood flow were evaluated by venous occlusion plethysmography, MSNA by microneurography, and blood pressure by beat-to-beat noninvasive technique. Baseline forearm blood flow, forearm vascular conductance, calf blood flow, and calf vascular conductance were similar between groups. MSNA was higher in the SDB group. During hypoxia, the vascular responses (forearm blood flow, forearm vascular conductance, calf blood flow, and calf vascular conductance) were significantly lower in the SDB group compared with the NoSDB group (P<0.01 to all comparisons). Similarly, during hypercapnia, the vascular responses (forearm blood flow, forearm vascular conductance, calf blood flow, and calf vascular conductance) were significantly lower in the SDB group compared with the NoSDB group (P<0.001 to all comparisons). MSNA were higher in response to hypoxia (P=0.024) and tended to be higher to hypercapnia (P=0.066) in the SDB group. Patients with HF and SDB have more severe muscle vasoconstriction during hypoxia and hypercapnia than HF patients without SDB, which seems to be associated with endothelial dysfunction and, in part, increased MSNA response. © 2016 American Heart Association, Inc.

A new model for the emplacement of Columbia River basalts as large, inflated pahoehoe lava flow fields

USGS Publications Warehouse

Self, S.; Thordarson, Th.; Keszthelyi, L.; Walker, G.P.L.; Hon, K.; Murphy, M.T.; Long, P.; Finnemore, S.

1996-01-01

Extensive flows of the Columbia River Basalt (CRB) Group in Washington, Oregon, and Idaho are dominantly inflated compound pahoehoe sheet lavas. Early studies recognized that CRB lavas are compound pahoehoe flows, with textures suggesting low flow velocities, but it was thought that the great thickness and extent of the major flows required very rapid emplacement as turbulent floods of lava over a period of days or weeks. However, small volume ( < 1 km3) compound pahoehoe flows on Kilauea, Hawai'i, demonstrate that such flows can thicken by at least an order of magnitude through gradual inflation and the same mechanism has been proposed for larger (10-20 km3) pahoehoe flows in Iceland. The vertical distribution of vesicles and other morphologic features within CRB lava flows indicate that they grew similarly by inflation. Small pahoehoe lobes at the base and top of many CRB pahoehoe lava flows indicate emplacement in a gradual, piecemeal manner rather than as a single flood. We propose that each thick CRB sheet flow was active for months to years and that each group of flows produced by a single eruption (a flow field) was emplaced slowly over many years. Copyright 1996 by the American Geophysical Union.

Methods for improved growth of group III nitride semiconductor compounds

DOEpatents

Melnik, Yuriy; Chen, Lu; Kojiri, Hidehiro

2015-03-17

Methods are disclosed for growing group III-nitride semiconductor compounds with advanced buffer layer technique. In an embodiment, a method includes providing a suitable substrate in a processing chamber of a hydride vapor phase epitaxy processing system. The method includes forming an AlN buffer layer by flowing an ammonia gas into a growth zone of the processing chamber, flowing an aluminum halide containing precursor to the growth zone and at the same time flowing additional hydrogen halide or halogen gas into the growth zone of the processing chamber. The additional hydrogen halide or halogen gas that is flowed into the growth zone during buffer layer deposition suppresses homogeneous AlN particle formation. The hydrogen halide or halogen gas may continue flowing for a time period while the flow of the aluminum halide containing precursor is turned off.

Crystalloids versus colloids for goal-directed fluid therapy in major surgery

PubMed Central

Hiltebrand, Luzius B; Kimberger, Oliver; Arnberger, Michael; Brandt, Sebastian; Kurz, Andrea; Sigurdsson, Gisli H

2009-01-01

Introduction Perioperative hypovolemia arises frequently and contributes to intestinal hypoperfusion and subsequent postoperative complications. Goal-directed fluid therapy might reduce these complications. The aim of this study was to compare the effects of goal-directed administration of crystalloids and colloids on the distribution of systemic, hepatosplanchnic, and microcirculatory (small intestine) blood flow after major abdominal surgery in a clinically relevant pig model. Methods Twenty-seven pigs were anesthetized and mechanically ventilated and underwent open laparotomy. They were randomly assigned to one of three treatment groups: the restricted Ringer lactate (R-RL) group (n = 9) received 3 mL/kg per hour of RL, the goal-directed RL (GD-RL) group (n = 9) received 3 mL/kg per hour of RL and intermittent boluses of 250 mL of RL, and the goal-directed colloid (GD-C) group (n = 9) received 3 mL/kg per hour of RL and boluses of 250 mL of 6% hydroxyethyl starch (130/0.4). The latter two groups received a bolus infusion when mixed venous oxygen saturation was below 60% ('lockout' time of 30 minutes). Regional blood flow was measured in the superior mesenteric artery and the celiac trunk. In the small bowel, microcirculatory blood flow was measured using laser Doppler flowmetry. Intestinal tissue oxygen tension was measured with intramural Clark-type electrodes. Results After 4 hours of treatment, arterial blood pressure, cardiac output, mesenteric artery flow, and mixed oxygen saturation were significantly higher in the GD-C and GD-RL groups than in the R-RL group. Microcirculatory flow in the intestinal mucosa increased by 50% in the GD-C group but remained unchanged in the other two groups. Likewise, tissue oxygen tension in the intestine increased by 30% in the GD-C group but remained unchanged in the GD-RL group and decreased by 18% in the R-RL group. Mesenteric venous glucose concentrations were higher and lactate levels were lower in the GD-C group compared with the two crystalloid groups. Conclusions Goal-directed colloid administration markedly increased microcirculatory blood flow in the small intestine and intestinal tissue oxygen tension after abdominal surgery. In contrast, goal-directed crystalloid and restricted crystalloid administrations had no such effects. Additionally, mesenteric venous glucose and lactate concentrations suggest that intestinal cellular substrate levels were higher in the colloid-treated than in the crystalloid-treated animals. These results support the notion that perioperative goal-directed therapy with colloids might be beneficial during major abdominal surgery. PMID:19302713

Temperature constraints on the Ginkgo flow of the Columbia River Basalt Group

NASA Astrophysics Data System (ADS)

Ho, Anita M.; Cashman, Katharine V.

1997-05-01

This study provides the first quantitative estimate of heat loss for a Columbia River Basalt Group flow. A glass composition-based geothermometer was experimentally calibrated for a composition representative of the 500-km-long Ginkgo flow of the Columbia River Basalt Group to measure temperature change during transport. Melting experiments were conducted on a bulk sample at 1 atm between 1200 and 1050 °C. Natural glass was sampled from the margin of a feeder dike near Kahlotus, Washington, and from pillow basalt at distances of 120 km (Vantage, Washington), 350 km (Molalla, Oregon), and 370 km (Portland, Oregon). Ginkgo basalt was also sampled at its distal end at Yaquina Head, Oregon (500 km). Comparison of the glass MgO content, K2O in plagioclase, and measured crystallinities in the experimental charges and natural samples tightly constrains the minimum flow temperature to 1085 ± 5 °C. Glass and plagioclase compositions indicate an upper temperature of 1095 ± 5 °C; thus the maximum temperature decrease along the flow axis of the Ginkgo is 20 °C, suggesting cooling rates of 0.02 0.04 °C/km. These cooling rates, substantially lower than rates observed in active and historic flows, are inconsistent with turbulent flow models. Calculated melt temperatures and viscosities of 240 750 Pa · s allow emplacement either as a fast laminar flow under an insulating crust or as a slower, inflated flow.

Improvement in cochlear flow in patients with tinnitus with the complex supplement Acustop: a product evaluation.

PubMed

Grossi, M G; Belcaro, G; Cesarone, M R; Dugall, M; Hosoi, M; Cacchio, M; Ippolito, E; Bavera, P

2011-09-01

Patients with tinnitus constitute a very large group without a real, specific therapeutic solution. With noninvasive, color duplex it is possible to measure flow in the cochlear artery and to follow duplex flow changes due to treatments in most patients. The aim of this preliminary evaluation was to study flow variations in patients with "mild-to-moderate" tinnitus, possibly associated to cochlear hypo-perfusion, after administration of Acustop (used as a food supplement). The aim was to improve cochlear flow decreasing the level of tinnitus. Patients with "mild-to-moderate", "idiopathic", monolateral tinnitus, present for at least 4 weeks were included; no vertigo or important hearing loss had been observed. The origin of tinnitus had been sudden (hours or days). The tinnitus was associated to a decrease in cochlear flow measured by color Duplex at the affected ear. A group of 42 patients was evaluated; 25 used Acustop; there were 17 controls (follow-up only). Groups were comparable for their clinical problem and other details. The average duration of treatment was 4 weeks. No side effects were observed and no drop-outs were recorded. Flow velocity at the level of the affected inner ear was significantly lower (both the diastolic and systolic components; P<0.05) in comparison with the other ear. This was considered an indication of the vascular origin of the tinnitus. With Acustop treatment there was a significant improvement in systolic (P<0.05) and diastolic flow velocity (P<0.05). The increase in flow velocity was not significant in controls. An analogue scale line was used to measure symptoms in the Acustop group: it was 8.2;2 at inclusion; it decreased to 3.1;1.5 at 4 weeks (P<0.05). The score was 8.4;2 in controls at inclusion; at 4 weeks the score was 7.1;2.2 (not significant). Tinnitus scale: the value at inclusion of the tinnitus scale in the Acustop group a was 8.5;1.1 versus 8.3;1.2 in controls. After 4 weeks the score was 3.1;1.1 (P<0.05) in the Acustop group vs 7.2 in controls; the difference between the two groups was significant; P<0.025). In conclusion, these results suggest that in selected patients with tinnitus and altered inner ear perfusion Acustop appears to be effective in relieving tinnitus possibly by improving cochlear flow. More studies should be planned to evaluate better the potential applications of Acustop in this very interesting field. This clinical problem affects a large number of patients, without a real therapeutic solution at the moment, decreasing their quality of life and their performing abilities.

Transcutaneous Electrical Nerve Stimulation Regulates Organ Blood Flow and Apoptosis during Controlled Hypotension in Dogs

PubMed Central

Zhang, Lele; Shao, Xiaomei; Zhou, Chuanlong; Guo, Xiaoqing; Jin, Ling; Lian, Linli; Yu, Xiaojing; Dong, Zhenhua; Mo, Yadi; Fang, Jianqiao

2014-01-01

Transcutaneous electrical nerve stimulation (TENS) is commonly used in clinical practice for alleviating pains and physiological disorders. It has been reported that TENS could counteract the ischemic injury happened in some vital organs. To determine the protective effect of TENS on internal organs during CH in dogs, target hypotension was maintained for 60 min at 50% of the baseline mean arterial pressure (MAP). The perfusion to the brain, liver, stomach, and kidney was recorded and apoptosis within these organs was observed. Results showed that when arriving at the target MAP, and during the maintaining stage for 10 min, perfusion to the stomach and liver in the CH+TENS group was much higher than in the CH group (P<0.05). Perfusion to the cerebral cortex greatly declined in both the controlled pressure groups when compared with the general anesthesia (GA) group (P<0.05). After withdrawing CH, the hepatic blood flow in both the CH and CH+TENS groups, and the gastric and cerebral cortical blood flow in the CH+TENS group, were rapidly increased. By the end of MAP restoration, gastric blood flow in the CH group was still low. At 72 h after applying CH, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells in stomach and kidney tissue from the CH group were significantly increased compared with those in the GA group (P<0.05). There was no significant difference in TUNEL-positive cells in the liver and hippocampus among the three groups. Our results demonstrated that CH with a 50% MAP level could cause lower perfusion to the liver, stomach, cerebral cortex, and kidney, with apoptosis subsequently occurring in the stomach and kidney. TENS combined GA is able to improve the blood flow to the liver, stomach, and reduce the apoptosis in the stomach and kidney. PMID:24732970

High dose naloxone does not improve cerebral or myocardial blood flow during cardiopulmonary resuscitation in pigs.

PubMed

Gervais, H W; Eberle, B; Hennes, H J; Grimm, W; Kilian, A; Konietzke, D; Massing, C; Dick, W

1997-06-01

In a prospective, randomized, placebo-controlled, double-blind trial we tested the hypothesis that naloxone given during cardiopulmonary resuscitation (CPR) enhances cerebral and myocardial blood flow. Twenty-one anesthetized, normoventilated pigs were instrumented for measurements of right atrial and aortic pressures, and regional organ blood flow (radiolabeled microspheres). After 5 min of untreated fibrillatory arrest, CPR was commenced using a pneumatic chest compressor/ventilator. With onset of CPR, an i.v. bolus of 40 micrograms/kg b.w. of epinephrine was given, followed by an infusion of 0.4 micrograms/kg per min. After 5 min of CPR, either naloxone, 10 mg/kg b.w. (group N, n = 11) or normal saline (group S, n = 10) was given i.v. Prior to, and after 1, 15, and 30 min of CPR, hemodynamic and blood flow measurements were obtained. After 30 min of CPR, mean arterial pressure was significantly higher in group N (26 +/- 5 vs. 13 +/- 3 mmHg, P < 0.05). Groups did not differ with respect to myocardial perfusion pressure or arterial blood gases at any time during the observation period. Regional brain and heart blood flows were not different between N and S at any point of measurement. We conclude that high-dose naloxone does not augment cerebral or myocardial blood flow during prolonged closed-chest CPR.

Intensive insulin treatment improves forearm blood flow in critically ill patients: a randomized parallel design clinical trial.

PubMed

Žuran, Ivan; Poredos, Pavel; Skale, Rafael; Voga, Gorazd; Gabrscek, Lucija; Pareznik, Roman

2009-01-01

Intensive insulin treatment of critically ill patients was seen as a promising method of treatment, though recent studies showed that reducing the blood glucose level below 6 mmol/l had a detrimental outcome. The mechanisms of the effects of insulin in the critically ill are not completely understood. The purpose of the study was to test the hypothesis that intensive insulin treatment may influence forearm blood flow independently of global hemodynamic indicators. The study encompassed 29 patients of both sexes who were admitted to the intensive care unit due to sepsis and required artificial ventilation as the result of acute respiratory failure. 14 patients were randomly selected for intensive insulin treatment (Group 1; blood glucose concentration 4.4-6.1 mmol/l), and 15 were selected for conventional insulin treatment (Group 2; blood glucose level 7.0 mmol/l-11.0 mmol/l). At the start of the study (t0, beginning up to 48 hours after admittance and the commencement of artificial ventilation), at 2 hours (t1), 24 hours (t2), and 72 hours (t3) flow in the forearm was measured for 60 minutes using the strain-gauge plethysmography method. Student's t-test of independent samples was used for comparisons between the two groups, and Mann-Whitney's U-test where appropriate. Linear regression analysis and the Pearson correlation coefficient were used to determine the levels of correlation. The difference in 60-minute forearm flow at the start of the study (t0) was not statistically significant between groups, while at t2 and t3 significantly higher values were recorded in Group 1 (t2; Group 1: 420.6 +/- 188.8 ml/100 ml tissue; Group 2: 266.1 +/- 122.2 ml/100 ml tissue (95% CI 30.9-278.0, P = 0.02); t3; Group 1: 369.9 +/- 150.3 ml/100 ml tissue; Group 2: 272.6 +/- 85.7 ml/100 ml tissue (95% CI 5.4-190.0, P = 0.04). At t1 a trend towards significantly higher values in Group 1 was noted (P = 0.05). The level of forearm flow was related to the amount of insulin infusion (r = 0.40). Compared to standard treatment, intensive insulin treatment of critically ill patients increases forearm flow. Flow increase was weakly related to the insulin dose, though not to blood glucose concentration. ISRCTN39026810.

Intensive insulin treatment improves forearm blood flow in critically ill patients: a randomized parallel design clinical trial

PubMed Central

2009-01-01

Introduction Intensive insulin treatment of critically ill patients was seen as a promising method of treatment, though recent studies showed that reducing the blood glucose level below 6 mmol/l had a detrimental outcome. The mechanisms of the effects of insulin in the critically ill are not completely understood. The purpose of the study was to test the hypothesis that intensive insulin treatment may influence forearm blood flow independently of global hemodynamic indicators. Methods The study encompassed 29 patients of both sexes who were admitted to the intensive care unit due to sepsis and required artificial ventilation as the result of acute respiratory failure. 14 patients were randomly selected for intensive insulin treatment (Group 1; blood glucose concentration 4.4-6.1 mmol/l), and 15 were selected for conventional insulin treatment (Group 2; blood glucose level 7.0 mmol/l-11.0 mmol/l). At the start of the study (t0, beginning up to 48 hours after admittance and the commencement of artificial ventilation), at 2 hours (t1), 24 hours (t2), and 72 hours (t3) flow in the forearm was measured for 60 minutes using the strain-gauge plethysmography method. Student's t-test of independent samples was used for comparisons between the two groups, and Mann-Whitney's U-test where appropriate. Linear regression analysis and the Pearson correlation coefficient were used to determine the levels of correlation. Results The difference in 60-minute forearm flow at the start of the study (t0) was not statistically significant between groups, while at t2 and t3 significantly higher values were recorded in Group 1 (t2; Group 1: 420.6 ± 188.8 ml/100 ml tissue; Group 2: 266.1 ± 122.2 ml/100 ml tissue (95% CI 30.9-278.0, P = 0.02); t3; Group 1: 369.9 ± 150.3 ml/100 ml tissue; Group 2: 272.6 ± 85.7 ml/100 ml tissue (95% CI 5.4-190.0, P = 0.04). At t1 a trend towards significantly higher values in Group 1 was noted (P = 0.05). The level of forearm flow was related to the amount of insulin infusion (r = 0.40). Conclusions Compared to standard treatment, intensive insulin treatment of critically ill patients increases forearm flow. Flow increase was weakly related to the insulin dose, though not to blood glucose concentration. Trial Registration Trial number: ISRCTN39026810. PMID:20003200

Inquiry and Flow in Science Education

ERIC Educational Resources Information Center

Gyllenpalm, Jakob

2018-01-01

Ellwood's and Abrams's paper, "Students's social interaction in inquiry-based science education: how experiences of flow can increase motivation and achievement," describes two groups of students and their experiences in an extended inquiry unit. For one of these, the Off-Campus group, several educational aspects were enhanced compared…

Fractional flow reserve vs. angiography in guiding management to optimize outcomes in non-ST-segment elevation myocardial infarction: the British Heart Foundation FAMOUS–NSTEMI randomized trial

PubMed Central

Layland, Jamie; Oldroyd, Keith G.; Curzen, Nick; Sood, Arvind; Balachandran, Kanarath; Das, Raj; Junejo, Shahid; Ahmed, Nadeem; Lee, Matthew M.Y.; Shaukat, Aadil; O'Donnell, Anna; Nam, Julian; Briggs, Andrew; Henderson, Robert; McConnachie, Alex; Berry, Colin; Hannah, Andrew; Stewart, Andrew; Metcalfe, Malcolm; Norrie, John; Chowdhary, Saqib; Clark, Andrew; Henderson, Robert; Balachandran, Kanarath; Berry, Colin; Baird, Gordon; O'Donnell, Anna; Sood, Arvind; Curzen, Nick; Das, Raj; Ford, Ian; Layland, Jamie; Junejo, Shahid; Oldroyd, Keith

2015-01-01

Aim We assessed the management and outcomes of non-ST segment elevation myocardial infarction (NSTEMI) patients randomly assigned to fractional flow reserve (FFR)-guided management or angiography-guided standard care. Methods and results We conducted a prospective, multicentre, parallel group, 1 : 1 randomized, controlled trial in 350 NSTEMI patients with ≥1 coronary stenosis ≥30% of the lumen diameter assessed visually (threshold for FFR measurement) (NCT01764334). Enrolment took place in six UK hospitals from October 2011 to May 2013. Fractional flow reserve was disclosed to the operator in the FFR-guided group (n = 176). Fractional flow reserve was measured but not disclosed in the angiography-guided group (n = 174). Fractional flow reserve ≤0.80 was an indication for revascularization by percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG). The median (IQR) time from the index episode of myocardial ischaemia to angiography was 3 (2, 5) days. For the primary outcome, the proportion of patients treated initially by medical therapy was higher in the FFR-guided group than in the angiography-guided group [40 (22.7%) vs. 23 (13.2%), difference 95% (95% CI: 1.4%, 17.7%), P = 0.022]. Fractional flow reserve disclosure resulted in a change in treatment between medical therapy, PCI or CABG in 38 (21.6%) patients. At 12 months, revascularization remained lower in the FFR-guided group [79.0 vs. 86.8%, difference 7.8% (−0.2%, 15.8%), P = 0.054]. There were no statistically significant differences in health outcomes and quality of life between the groups. Conclusion In NSTEMI patients, angiography-guided management was associated with higher rates of coronary revascularization compared with FFR-guided management. A larger trial is necessary to assess health outcomes and cost-effectiveness. PMID:25179764

Hepatic perfusion changes in mice livers with developing colorectal cancer metastases.

PubMed

Kruskal, Jonathan B; Thomas, Peter; Kane, Robert A; Goldberg, S Nahum

2004-05-01

To evaluate whether intrahepatic flow alterations occur during formation of hepatic colorectal cancer metastases and to identify possible causes of these alterations. Intravital imaging of exteriorized livers was performed in 72 live mice. Three groups of mice were studied: a sham-operated control group (n = 24), a group with nonmetastasizing subcutaneous gliomas (n = 24), and a group with developing hepatic CX-1 colon cancer metastases (n = 24). Microvascular flow parameters, leukocyte-endothelial interactions, and wall shear stress were directly measured in hepatic sinusoids and postsinusoidal venules at 2-day intervals prior to and during the development of metastases. The Kruskal-Wallis test was used initially to test for overall equality of medians in each data group. Single posttest comparisons of independent samples were performed with the Mann-Whitney test, with an overall statistical significance of .05. Prior to the development of visible colorectal cancer metastases, significant (P <.05) reductions occurred in sinusoidal and postsinusoidal flow and wall shear rates, coupled with increased leukocyte rolling and adherence. With tumor growth, flow was further compromised in 92% of tumors larger than 0.5 mm in diameter by extrinsic compression of sinusoids and portal venules and narrowing caused by adherent leukocytes. Significant intrahepatic flow alterations occur in mouse livers prior to growth of visible metastases and provide a rational explanation for elevation in the Doppler perfusion index that occurs prior to tumor formation.

Evaluation of Streamflow Requirements for Habitat Protection by Comparison to Streamflow Characteristics at Index Streamflow-Gaging Stations in Southern New England

USGS Publications Warehouse

Armstrong, David S.; Parker, Gene W.; Richards, Todd A.

2003-01-01

Streamflow characteristics and methods for determining streamflow requirements for habitat protection were investigated at 23 active index streamflow-gaging stations in southern New England. Fish communities sampled near index streamflow-gaging stations in Massachusetts have a high percentage of fish that require flowing-water habitats for some or all of their life cycle. The relatively unaltered flow condition at these sites was assumed to be one factor that has contributed to this condition. Monthly flow durations and low flow statistics were determined for the index streamflow-gaging stations for a 25- year period from 1976 to 2000. Annual hydrographs were prepared for each index station from median streamflows at the 50-percent monthly flow duration, normalized by drainage area. A median monthly flow of 1 ft3/s/mi2 was used to split hydrographs into a high-flow period (November–May), and a low-flow period (June–October). The hydrographs were used to classify index stations into groups with similar median monthly flow durations. Index stations were divided into four regional groups, roughly paralleling the coast, to characterize streamflows for November to May; and into two groups, on the basis of base-flow index and percentage of sand and gravel in the contributing area, for June to October. For the June to October period, for index stations with a high base-flow index and contributing areas greater than 20 percent sand and gravel, median streamflows at the 50-percent monthly flow duration, normalized by drainage area, were 0.57, 0.49, and 0.46 ft3/s/mi2 for July, August, and September, respectively. For index stations with a low base-flow index and contributing areas less than 20 percent sand and gravel, median streamflows at the 50-percent monthly flow duration, normalized by drainage area, were 0.34, 0.28, and 0.27 ft3/s/mi2 for July, August, and September, respectively. Streamflow variability between wet and dry years can be characterized by use of the interquartile range of median streamflows at selected monthly flow durations. For example, the median Q50 discharge for August had an interquartile range of 0.30 to 0.87 ft3/s/mi2 for the high-flow group and 0.16 to 0.47 ft3/s/mi2 for the low-flow group. Streamflow requirements for habitat protection were determined for 23 index stations by use of three methods based on hydrologic records, the Range of Variability Approach, the Tennant method, and the New England Aquatic-Base-Flow method. Normalized flow management targets determined by the Range of Variability Approach for July, August, and September ranged between 0.21 and 0.84 ft3/s/mi2 for the low monthly flow duration group, and 0.37 and 1.27 ft3/s/mi2 for the high monthly flow duration group. Median streamflow requirements for habitat protection during summer for the 23 index streamflow-gaging stations determined by the Tennant method, normalized by drainage area, were 0.81, 0.61, and 0.21 ft3/s/mi2 for the Tennant 40-, 30-, and 10-percent of the mean annual flow methods, representing good, fair, and poor stream habitat conditions in summer, according to Tennant. New England Aquatic-Base-Flow streamflow requirements for habitat protection during summer were determined from median of monthly mean flows for August for index streamflow-gaging stations having drainage areas greater than 50 mi2 . For five index streamflow-gaging stations in the low median monthly flow group, the average median monthly mean streamflow for August, normalized by drainage area, was 0.48 ft3/s/mi2. Streamflow requirements for habitat protection were determined for riffle habitats near 10 index stations by use of two methods based on hydraulic ratings, the Wetted-Perimeter and R2Cross methods. Hydraulic parameters required by these methods were simulated by calibrated HEC-RAS models. Wetted-Perimeter streamflow requirements for habitat protection, normalized by drainage area, ranged between 0.13 and 0.58 ft3/s/mi2, and had a median value of 0.37 ft3/s/mi2. Streamflow requirements determined by the R2Cross 3-of-3 criteria method ranged between 0.39 and 2.1 ft3/s/mi2 , and had a median of 0.84 ft3/s/mi2. Streamflow requirements determined by the R2Cross 2-of-3 criteria method, normalized by drainage area, ranged between 0.16 and 0.85 ft3/s/mi2 and had a median of 0.36 ft3/s/mi2 , respectively. Streamflow requirements determined by the different methods were evaluated by comparison to streamflow statistics from the index streamflow-gaging stations.

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

McManamay, Ryan A; Orth, Dr. Donald J; Davis, Dr, Mary

Generalized and quantitative relationships between flow and ecology are pivotal to developing environmental flow standards based on socially acceptable ecological conditions. Informing management at regional scales requires compiling sufficient hydrologic and ecological sources of information, identifying information gaps, and creating a framework for hypothesis development and testing. We compiled studies of empirical and theoretical relationships between flow and ecology in the South Atlantic region (SAR) of the United States to evaluate their utility for the development of environmental flow standards. Using database searches, internet searches, and agency contacts, we gathered 186 sources of information that provided a qualitative or quantitativemore » relationship between flow and ecology within states encompassing the SAR. A total of 109 of the 186 sources had sufficient information to support quantitative analyses. Ecological responses to natural changes in flow magnitude, frequency, and duration were highly variable regardless of the direction and magnitude of changes in flow. In contrast, the majority of ecological responses to anthropogenic-induced flow alterations were negative. Fish consistently showed negative responses to anthropogenic flow alterations whereas other ecological groups showed somewhat variable responses (e.g. macroinvertebrates and riparian vegetation) and even positive responses (e.g. algae). Fish and organic matter had sufficient sample sizes to stratify natural flow-ecology relationships by specific flow categories (e.g. high flow, baseflows) or by region (e.g. coastal plain, uplands). After stratifying relationships, we found that significant correlations existed between changes in natural flow and ecological responses. In addition, a regression tree explained 57% of the variation in fish responses to anthropogenic and natural changes in flow. Because of some ambiguity in interpreting the directionality in ecological responses, we utilized ecological gains or losses, where each represents a benefit or reduction to ecosystem services, respectively. Variables explained 49% of the variation in ecological gains and losses for all ecological groups combined. Altogether, our results suggested that the source of flow change and the ecological group of interest played primary roles in determining the direction and magnitude of ecological responses. Furthermore, our results suggest that developing broadly generalized relationships between ecology and changes in flow at a regional scale is unlikely unless relationships are placed within meaningful contexts, such as environmental flow components or by geomorphic setting.« less

Spatial variation of vessel grouping in the xylem of Betula platyphylla Roth.

PubMed

Zhao, Xiping

2016-01-01

Vessel grouping in angiosperms may improve hydraulic integration and increase the spread of cavitations through redundancy pathways. Although disputed, it is increasingly attracting research interest as a potentially significant hydraulic trait. However, the variation of vessel grouping in a tree is poorly understood. I measured the number of solitary and grouped vessels in the xylem of Betula platyphylla Roth. from the pith to the bark along the water flow path. The vessel grouping parameters included the mean number of vessels per vessel group (VG), percentage of solitary vessels (SVP), percentage of radial multiple vessels (MVP), and percentage of cluster vessels (CVP). The effects of cambial age (CA) and flow path-length (PL) on the vessel grouping were analyzed using a linear mixed model.VG and CVP increased nonlinearly, SVP decreased nonlinearly with PL. In trunks and branches, VG and CVP decreased nonlinearly, and SVP increased nonlinearly with CA. In roots, the parameters had no change with CA. MVP was almost constant with PL or CA. The results suggest that vessel grouping has a nonrandom variation pattern, which is affected deeply by cambial age and water flow path.

[Evaluation of transfection effectiveness using fluorescein-labelled oligonucleotides and entraster-R siRNA transfection into Plasmodium falciparum].

PubMed

Zhou, Hong-Chang; Gao, Yu-Hui; Shao, Sheng-Wen; Zhang, Hui; Zhang, Ting

2013-12-01

The cultured Plasmodium falciparum parasites were synchronized twice by 5% sorbitol treatment twice (8-hour window), and then incubated at 37 degrees C for 16 h. Parasites were transfected with fluorescein-labelled oligonucleotides (group A) or fluorescein-labelled oligonucleotides+Entranster-R siRNA transfection reagent (group B). After 5 h a part of parasites was evaluated by fluorescence microscopy and flow cytometry. The rest of parasites were washed with RPMI 1640 medium, and then incubated with 500 microl new medium containing 2% fresh erythrocytes for another 12 h, and detected by flow cytometry. The fluorescein-labelled oligonucleotides were localized in erythrocytes in group B, but nearly no fluorescence was observed for group A. Flow cytometry analysis indicated that the transfection efficiency of group B [(47.40 +/- 3.39)%] was higher than that of group A [(0.60 +/- 0.27)%]. In the second cell cycle, the transfection efficiency in group B was (26.85 +/- 2.90)%, while that of group A was nearly zero. The results indicated that Entranster-R siRNA transfection reagent may increase the oligonucleotides transfection efficiency.

An Evaluation of GuttaFlow2 in Filling Artificial Internal Resorption Cavities: An in vitro Study.

PubMed

Mohammad, Yara; Alafif, Hisham; Hajeer, Mohammad; Yassin, Oula

2016-06-01

Obturation of root canal with internal resorption represents a major challenge in Endodontics. In spite of that, usual obturation techniques are often employed without considering the best technique to solve this problem. The goal of this study was to investigate the ability of GuttaFlow2 in filling artificial internal resorption cavities. The study sample included 36 human upper central incisors that were prepared using Protaper system (F4). Internal resorption cavities were prepared by cutting each tooth at 7 mm from the apex and preparing hemispherical cavities on both the sides and then re-attaching them. The sample was randomly separated into three groups (n = 12 in each group). In the first group, thermal injection technique (Obtura II) was employed and served as the control group. In the second group, injection of cold free-flow obturation technique with a master cone (GF2-C) was employed, whereas in the third group injection of cold free-flow obturation without a master cone (GF2) was followed. The teeth were re-cut at the same level as before and examined under a stereomicroscope. Subsequently, the captured images were transferred to AutoCAD program to measure the percentage of total filling "TF," gutta-percha "G," sealer "S," and voids "V" out of the total surface of the cross sections. All materials showed high filling properties in terms of "total filling," ranging from 99.17% (for Obtura II) to 99.72% (for GF2-C). Regarding gutta-percha percentages of filling, they ranged from 83.15 to 83.93%, whereas those for the sealer ranged from 5.71 to 15.24%. GuttaFlow2 group with a master cone appeared to give the best results despite the insignificant differences among the three groups. The GuttaFlow2 with a master cone technique seemed to be a promising filling material and gave results similar to those observed with Obtura II. It is recommended for use to obturate internal resorption cavities in clinical practice due to its good adaptability to root canal walls, ease of handling, and application. Internal resorption defects can be successfully filled with GuttaFlow2 material when supplemented with a master cone, and the results are comparable with those obtained with the Obtura II technique.

Difference in vascular patterns between transosseous-equivalent and transosseous rotator cuff repair.

PubMed

Urita, Atsushi; Funakoshi, Tadanao; Horie, Tatsunori; Nishida, Mutsumi; Iwasaki, Norimasa

2017-01-01

Vascularity is the important factor of biologic healing of the repaired tissue. The purpose of this study was to clarify sequential vascular patterns of repaired rotator cuff by suture techniques. We randomized 21 shoulders in 20 patients undergoing arthroscopic rotator cuff repair into 2 groups: transosseous-equivalent repair (TOE group, n = 10) and transosseous repair (TO group, n = 11). Blood flow in 4 regions inside the cuff (lateral articular, lateral bursal, medial articular, and medial bursal), in the knotless suture anchor in the TOE group, and in the bone tunnel in the TO group was measured using contrast-enhanced ultrasound at 1 month, 2 months, 3 months, and 6 months postoperatively. The sequential vascular pattern inside the repaired rotator cuff was different between groups. The blood flow in the lateral articular area at 1 month, 2 months, and 3 months (P = .002, .005, and .025) and that in the lateral bursal area at 2 months (P = .031) in the TO group were significantly greater than those in the TOE group postoperatively. Blood flow was significantly greater for the bone tunnels in the TO group than for the knotless suture anchor in the TOE group at 1 month and 2 months postoperatively (P = .041 and .009). This study clarified that the sequential vascular pattern inside the repaired rotator cuff depends on the suture technique used. Bone tunnels through the footprint may contribute to biologic healing by increasing blood flow in the repaired rotator cuff. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Measurement of pressure and flow rates during irrigation of a root canal ex vivo with three endodontic needles.

PubMed

Boutsioukis, C; Lambrianidis, T; Kastrinakis, E; Bekiaroglou, P

2007-07-01

To monitor ex vivo intra-canal irrigation with three endodontic needles (25, 27 and 30 gauge) and compare them in terms of irrigant flow rate, intra-barrel pressure, duration of irrigation and volume of irrigant delivered. A testing system was constructed to allow measurement of selected variables with pressure and displacement transducers during ex vivo intra-canal irrigation with a syringe and three different needles (groups A, B, C) into a prepared root canal. Ten specialist endodontists performed the irrigation procedure. Each operator performed ten procedures with each needle. Data recorded by the transducers were analysed using Friedman's test, Wilcoxon Signed Rank test, Mann-Whitney U-test and Kendall's T(b) test. The level of significance was set to 95%. Significant differences were detected among the three needles for most variables. Duration of delivery and flow rates significantly decreased as the needle diameter increased, whilst pressure increased up to 400-550 kPa. Gender of the operator had a significant impact on the results. Experience of the operators (years) were negatively correlated to volume of irrigant (all groups), to the duration of delivery (groups A, B) and to the average flow rate (group A). Finer diameter needles require increased effort to deliver the irrigant and result in higher intra-barrel pressure. The syringe and needles used tolerated the pressure developed. Irrigant flow rate should be considered as a factor directly influencing flow beyond the needle. Wide variations of flow rate were observed among operators. Syringe irrigation appears difficult to standardize and control.

Functional Renormalization Group Flows on Friedman-Lemaître-Robertson-Walker backgrounds

NASA Astrophysics Data System (ADS)

Platania, Alessia; Saueressig, Frank

2018-06-01

We revisit the construction of the gravitational functional renormalization group equation tailored to the Arnowitt-Deser-Misner formulation emphasizing its connection to the covariant formulation. The results obtained from projecting the renormalization group flow onto the Einstein-Hilbert action are reviewed in detail and we provide a novel example illustrating how the formalism may be connected to the causal dynamical triangulations approach to quantum gravity.

Character of energy flow in air shower core

NASA Technical Reports Server (NTRS)

Mizushima, K.; Asakimori, K.; Maeda, T.; Kameda, T.; Misaki, Y.

1985-01-01

Energy per charged particle near the core of air showers was measured by 9 energy flow detectors, which were the combination of Cerenkov counters and scintillators. Energy per particle of each detector was normalized to energy at 2m from the core. The following results were obtained as to the energy flow: (1) integral frequency distribution of mean energy per particle (averaged over 9 detectors) is composed of two groups separated distinctly; and (2) showers contained in one group show an anisotropy of arrival direction.

Multiloop Functional Renormalization Group That Sums Up All Parquet Diagrams

NASA Astrophysics Data System (ADS)

Kugler, Fabian B.; von Delft, Jan

2018-02-01

We present a multiloop flow equation for the four-point vertex in the functional renormalization group (FRG) framework. The multiloop flow consists of successive one-loop calculations and sums up all parquet diagrams to arbitrary order. This provides substantial improvement of FRG computations for the four-point vertex and, consequently, the self-energy. Using the x-ray-edge singularity as an example, we show that solving the multiloop FRG flow is equivalent to solving the (first-order) parquet equations and illustrate this with numerical results.

Acute hyperfibrinogenemia impairs cochlear blood flow and hearing function in guinea pigs in vivo.

PubMed

Ihler, Fritz; Strieth, Sebastian; Pieri, Nicos; Göhring, Peter; Canis, Martin

2012-03-01

Impairment of microcirculation is a possible cause of sudden sensorineural hearing loss (SSNHL). Fibrinogen is known as a risk factor for both microvascular dysfunction and SSNHL. Therefore, the aim of this study was to investigate the effect of elevated serum levels of fibrinogen on cochlear blood flow and hearing function in vivo. One group of guinea pigs received two consecutive injections of 100 mg fibrinogen while a control group received equimolar doses of albumin. Measurements of cochlear microcirculation by intravital microscopy and of hearing thresholds by auditory brainstem response (ABR) recordings were carried out before, after first and after second injection. Ten healthy guinea pigs were randomly assigned to a treatment group or a control group of five animals each. Serum fibrinogen levels were elevated after the first and second injections of fibrinogen compared to basal values and control group respectively. Increasing levels of fibrinogen were paralleled by decreasing cochlear blood flow as well as increasing hearing thresholds. Hearing threshold correlated negatively with cochlear blood flow. The effect of microcirculatory impairment on hearing function could be explained by a malfunction of the cochlear amplifier. Further investigation is needed to quantify cochlear potentials under elevated serum fibrinogen levels.

Complex magnetohydrodynamic low-Reynolds-number flows.

PubMed

Xiang, Yu; Bau, Haim H

2003-07-01

The interaction between electric currents and a magnetic field is used to produce body (Lorentz) forces in electrolyte solutions. By appropriate patterning of the electrodes, one can conveniently control the direction and magnitude of the electric currents and induce spatially and temporally complicated flow patterns. This capability is useful, not only for fundamental flow studies, but also for inducing fluid flow and stirring in minute devices in which the incorporation of moving components may be difficult. This paper focuses on a theoretical and experimental study of magnetohydrodynamic flows in a conduit with a rectangular cross section. The conduit is equipped with individually controlled electrodes uniformly spaced at a pitch L. The electrodes are aligned transversely to the conduit's axis. The entire device is subjected to a uniform magnetic field. The electrodes are divided into two groups A and C in such a way that there is an electrode of group C between any two electrodes of group A. We denote the various A and C electrodes with subscripts, i.e., A(i) and C(i), where i=0,+/-1,+/-2, .... When positive and negative potentials are, respectively, applied to the even and odd numbered A electrodes, opposing electric currents are induced on the right and left hand sides of each A electrode. These currents generate transverse forces that drive cellular convection in the conduit. We refer to the resulting flow pattern as A. When electrodes of group C are activated, a similar flow pattern results, albeit shifted in space. We refer to this flow pattern as C. By alternating periodically between patterns A and C, one induces Lagrangian chaos. Such chaotic advection may be beneficial for stirring fluids, particularly in microfluidic devices. Since the flow patterns A and C are shifted in space, they also provide a mechanism for Lagrangian drift that allows net migration of passive tracers along the conduit's length.

The relationship of coronary flow to neutrophil/lymphocyte ratio in patients undergoing primary percutaneous coronary intervention

PubMed Central

Yuksel, Serkan; Gulel, Okan; Erbay, Ali Riza; Meric, Murat; Zengin, Halit; Museyibov, Muhtar; Yasar, Erdogan; Demircan, Sabri

2013-01-01

Purpose It has been known that inflammatory mechanisms play an important role in the coronary artery disease. Our aim in this study was to investigate the relationship between the neutrophil/lymphocyte (N/L) ratio and coronary flow velocity after primary percutaneous coronary intervention (PCI) in patients presenting with ST-segment elevation myocardial infarction (STEMI). Methods Two hundred and ten patients who had undergone primary PCI were included. The coronary flow velocities were evaluated using the recorded PCI procedures by Thrombolysis in Myocardial Infarction (TIMI) flow grades and corrected TIMI frame counts (cTFC) values. A value of >40 for the final cTFC was accepted as an index of insufficient coronary blood flow. The white blood cell subtypes and counts were determined in the blood samples obtained at the clinics. Results In 165 (78%) of the investigated patients, reperfusion was found to be sufficient (Group I) while in 45 (22%) of them (Group II) insufficient reperfusion was observed (Group II). In-hospital mortality was 7.2% (n=12) in Group I, whereas it was 17.7% (n=8) in Group II (P=0.033). Similarly, one-year mortality was higher in Group II (26.6%, n=12) than in Group I (13.3%, n=22) (P=0.031). N/L ratio was determined to be higher in Group I than in Group II (8.3±6.1 vs. 6.2±5.0; P=0.034). Also, N/L ratio was found as an independent predictor of severe no-reflow development (TIMI 0-1) and of one-year mortality (P=0.01 and P=0.047, respectively). Conclusions N/L ratio has been found to be an independent indicator for no-reflow development in patients who have undergone PCI for acute STEMI. This simple and low-cost parameter can provide useful information for the relevant risk evaluation in these patients. PMID:23825756

The effect of preoperative Lugol's iodine on intraoperative bleeding in patients with hyperthyroidism.

PubMed

Yilmaz, Yeliz; Kamer, Kemal Erdinc; Ureyen, Orhan; Sari, Erdem; Acar, Turan; Karahalli, Onder

2016-08-01

To investigate the effect of preoperative Lugol's iodine on intraoperative bleeding in patients with hyperthyroidism. This controlled, randomized, prospective cohort was carried out on 40 patients who admitted for surgery due to hyperthyroidism. Cases were randomly assigned to receive either preoperative treatment with Lugol solution (Group 1) or no preoperative treatment with Lugol solution (Group 2). Group 3 (n = 10) consisted of healthy adults with no known history and signs of hyperthyroidism. Blood flow through the thyroid arteries of patients was measured by color flow Doppler ultrasonography. Free T3, free T4, TSH, thyroid volume and the resistance index of the four main thyroid arteries were measured in all patients. There was not a significant difference between gender, preoperative serum thyroid hormone levels, or thyroid gland volumes between groups 1 and 2. The mean blood flow of the patients in Group 1 was significantly lower than values in Group 2. When age, gender, thyroid hormone, TSH, thyroid volume, blood flow, and Lugol solution treatment were included as independent variables, Lugol solution treatment (OR, 7.40; 95% CI, 1.02-58.46; p = 0.001) was found to be the only significant independent determinant of intraoperative blood loss. Lugol solution treatment resulted in a 7.40-fold decrease in the rate of intraoperative blood loss. Preoperative Lugol solution treatment was found to be a significant independent determinant of intraoperative blood loss. Moreover, preoperative Lugol solution treatment decreased the rate of blood flow, and intraoperative blood loss during thyroidectomy.

Multiloop functional renormalization group for general models

NASA Astrophysics Data System (ADS)

Kugler, Fabian B.; von Delft, Jan

2018-02-01

We present multiloop flow equations in the functional renormalization group (fRG) framework for the four-point vertex and self-energy, formulated for a general fermionic many-body problem. This generalizes the previously introduced vertex flow [F. B. Kugler and J. von Delft, Phys. Rev. Lett. 120, 057403 (2018), 10.1103/PhysRevLett.120.057403] and provides the necessary corrections to the self-energy flow in order to complete the derivative of all diagrams involved in the truncated fRG flow. Due to its iterative one-loop structure, the multiloop flow is well suited for numerical algorithms, enabling improvement of many fRG computations. We demonstrate its equivalence to a solution of the (first-order) parquet equations in conjunction with the Schwinger-Dyson equation for the self-energy.

On new scaling group of transformation for Prandtl-Eyring fluid model with both heat and mass transfer

NASA Astrophysics Data System (ADS)

Rehman, Khalil Ur; Malik, Aneeqa Ashfaq; Malik, M. Y.; Tahir, M.; Zehra, Iffat

2018-03-01

A short communication is structured to offer a set of scaling group of transformation for Prandtl-Eyring fluid flow yields by stretching flat porous surface. The fluid flow regime is carried with both heat and mass transfer characteristics. To seek solution of flow problem a set of scaling group of transformation is proposed by adopting Lie approach. These transformations are used to step down the partial differential equations into ordinary differential equations. The reduced system is solved by numerical method termed as shooting method. A self-coded algorithm is executed in this regard. The obtain results are elaborated by means of figures and tables.

Precision tools and models to narrow in on the 750 GeV diphoton resonance

NASA Astrophysics Data System (ADS)

Staub, Florian; Athron, Peter; Basso, Lorenzo; Goodsell, Mark D.; Harries, Dylan; Krauss, Manuel E.; Nickel, Kilian; Opferkuch, Toby; Ubaldi, Lorenzo; Vicente, Avelino; Voigt, Alexander

2016-09-01

The hints for a new resonance at 750 GeV from ATLAS and CMS have triggered a significant amount of attention. Since the simplest extensions of the standard model cannot accommodate the observation, many alternatives have been considered to explain the excess. Here we focus on several proposed renormalisable weakly-coupled models and revisit results given in the literature. We point out that physically important subtleties are often missed or neglected. To facilitate the study of the excess we have created a collection of 40 model files, selected from recent literature, for the Mathematica package SARAH. With SARAH one can generate files to perform numerical studies using the tailor-made spectrum generators FlexibleSUSY and SPheno. These have been extended to automatically include crucial higher order corrections to the diphoton and digluon decay rates for both CP-even and CP-odd scalars. Additionally, we have extended the UFO and CalcHep interfaces of SARAH, to pass the precise information about the effective vertices from the spectrum generator to a Monte-Carlo tool. Finally, as an example to demonstrate the power of the entire setup, we present a new supersymmetric model that accommodates the diphoton excess, explicitly demonstrating how a large width can be obtained. We explicitly show several steps in detail to elucidate the use of these public tools in the precision study of this model.

Towards a complete A4 × SU(5) SUSY GUT

NASA Astrophysics Data System (ADS)

Björkeroth, Fredrik; de Anda, Francisco J.; de Medeiros Varzielas, Ivo; King, Stephen F.

2015-06-01

We propose a renormalisable model based on A 4 family symmetry with an SU(5) grand unified theory (GUT) which leads to the minimal supersymmetric standard model (MSSM) with a ℤ9 × ℤ6 symmetry provides the fermion mass hierarchy in both the quark and lepton sectors, while ℤ {4/ R } symmetry is broken to ℤ {2/ R }, identified as usual R-parity. Proton decay is highly sup-pressed by these symmetries. The strong CP problem is solved in a similar way to the Nelson-Barr mechanism. We discuss both the A 4 and SU(5) symmetry breaking sectors, including doublet-triplet splitting, Higgs mixing and the origin of the μ term. The model provides an excellent fit (better than one sigma) to all quark and lepton (including neu-trino) masses and mixing with spontaneous CP violation. With the A 4 vacuum alignments, (0, 1, 1) and (1, 3, 1), the model predicts the entire PMNS mixing matrix with no free pa-rameters, up to a relative phase, selected to be 2π/3 from a choice of the nine complex roots of unity, which is identified as the leptogenesis phase. The model predicts a normal neutrino mass hierarchy with leptonic angles θ{13/ ι } ≈ 8.7∘, θ{12/ ι } ≈ 34∘, θ{23/ ι } ≈ 46∘ and an oscillation phase δ ι ≈ - 87∘.

Vibrational renormalisation of the electronic band gap in hexagonal and cubic ice

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

Engel, Edgar A., E-mail: eae32@cam.ac.uk; Needs, Richard J.; Monserrat, Bartomeu

2015-12-28

Electron-phonon coupling in hexagonal and cubic water ice is studied using first-principles quantum mechanical methods. We consider 29 distinct hexagonal and cubic ice proton-orderings with up to 192 molecules in the simulation cell to account for proton-disorder. We find quantum zero-point vibrational corrections to the minimum electronic band gaps ranging from −1.5 to −1.7 eV, which leads to improved agreement between calculated and experimental band gaps. Anharmonic nuclear vibrations play a negligible role in determining the gaps. Deuterated ice has a smaller band-gap correction at zero-temperature of −1.2 to −1.4 eV. Vibrations reduce the differences between the electronic band gapsmore » of different proton-orderings from around 0.17 eV to less than 0.05 eV, so that the electronic band gaps of hexagonal and cubic ice are almost independent of the proton-ordering when quantum nuclear vibrations are taken into account. The comparatively small reduction in the band gap over the temperature range 0 − 240 K of around 0.1 eV does not depend on the proton ordering, or whether the ice is protiated or deuterated, or hexagonal, or cubic. We explain this in terms of the atomistic origin of the strong electron-phonon coupling in ice.« less

The neutral Higgs self-couplings in the (h)MSSM

NASA Astrophysics Data System (ADS)

Chalons, G.; Djouadi, A.; Quevillon, J.

2018-05-01

We consider the Minimal Supersymmetric extension of the Standard Model in the regime where the supersymmetric breaking scale is extremely large. In this MSSM, not only the Higgs masses will be affected by large radiative corrections, the dominant part of which is provided by the third generation quark/squark sector, but also the various self-couplings among the Higgs states. In this note, assuming that squarks are extremely heavy, we evaluate the next-to-leading order radiative corrections to the two neutral CP-even Higgs self-couplings λHhh and λhhh and to the partial decay width Γ (H → hh) that are most relevant at the LHC. The calculation is performed using an effective field theory approach that resums the large logarithmic squark contributions and allows to keep under control the perturbative expansion. Since the direct loop vertex corrections are generally missing in this effective approach, we have properly renormalised the effective theory to take them into account. Finally, we perform a comparison of the results in this effective MSSM with those obtained in a much simpler way in the so-called hMSSM approach in which the mass value for the lightest Higgs boson Mh = 125 GeV is used as an input. We show that the hMSSM provides a reasonably good approximation of the corrected self-couplings and H → hh decay rate and, hence, it can be used also in these cases.

E-cigarettes, vaping and performativity in the context of tobacco denormalisation.

PubMed

Lucherini, Mark; Rooke, Catriona; Amos, Amanda

2018-04-17

E-cigarettes are devices through which a nicotine solution is 'vapourised' and inhaled by the user. Unlike cigarettes, the process involves no tobacco combustion. However, the inhalation and exhalation of vapour is reminiscent of smoking and there is debate about the possible harms and benefits of e-cigarette use, including the 'renormalisation' of smoking. Despite these debates, there has been little exploration into the embodied and semiotic similarities between smoking and vaping. This paper views the practices of vaping and smoking through the lens of performativity that is, the accumulation of meaning associated with the habits over time and space. Through in-depth interviews, we explore how young adults from primarily disadvantaged areas in Scotland, understand the similarity in practices between smoking and vaping. Participants talked about financial barriers to using different types of e-cigarettes, and how their use reflected their views on smoking cessation. They also discussed the embodied similarities between smoking and vaping, with divergent opinions on whether this continuance of habit was beneficial or not, revealing still developing and ambiguous norms around performativity. The norms of vaping were also frequently discussed, with participants' experiences and views reflecting the contested position of vaping in an environment where cigarette smoking is denormalised. © 2018 The Authors. Sociology of Health & Illness published by John Wiley & Sons Ltd on behalf of Foundation for SHIL.

High Bolus Tirofiban vs Abciximab in Acute STEMI Patients Undergoing Primary PCI – The Tamip Study

PubMed Central

Balghith, Mohammed A.

2012-01-01

Background: Primary percutaneous coronary intervention (PCI) has been shown to be an effective therapy for patients with acute myocardial infarction (MI). Glycoprotein (GP) IIb/IIIa receptor blockers reduce thrombotic complications in patients undergoing PCI. Most available data relate to Reopro, which has been registered for this indication. GP IIb/IIIa reduce unfavorable outcome in U/A and non ST-elevation myocardial infarction (STEMI) patients. Only few studies focused on high dose Aggrastat for STEMI patients in the emergency department (ED) before PCI. The aim is to increase the patency during the time awaiting coronary angioplasty in patients with acute MI. Objectives: To study the effect of upfront high bolus dose (HDR) of tirofiban on the extent of residual ST segment deviation 1 hour after primary PCI and the incidence of TIMI 3 flow of the infarct-related artery (IRA). Materials and Methods: A randomized, open label, single center study in the ED. A total of 90 patients with acute ST-elevation MI, diagnosed clinically by ECG criteria (ST segment elevation of >2 mm in two adjacent ECG leads), and with an expectation that a patient will undergo primary PCI. Patients were aged 21-85 years and all received heparin 5000 u, aspirin 160 mg, and Plavix 600 mg. Patients were divided in two groups (group I: triofiban high bolus vs group II: Reopro) with 45 patients in each group. In group I, high bolus triofiban 25 mcg/kg over 3 min was started in the ED with maintenance infusion of 0.15 mcg/ kg/min continued for 12 hours and transferred to cath lab for PCI. Patients in group II were transferred to cath lab, where a standard dose of Reopro was given with a bolus of 0.25 mcg/kg and maintenance infusion of 0.125 mcg/kg/min over 12 hours. Results: ST segment resolution and TIMI flow were evaluated in both groups before and after PCI. Thirty-five patients (78%) enrolled in group I and 29 patients (64%) in group II had resolution of ST segment (P-value 0.24). Twenty-one patients (47% group I) vs 23 patients (51% group II) with P-value 0.83 achieved TIMI 0 flow. Twenty-four patients (53% group I) compared with 22 patients (49% group II) with P-value 0.83 had TIMI 1 to 3 flow before PCI. TIMI 3 flow was achieved in 40 patients (89% group I) compared with 38 patients (84% group II) with P-value 0.76. Conclusion: In this study there was a trend toward better ST segment resolution and patency of IRA (i.e., improved TIMI flow) in patients given high bolus dose Aggrastat in the ED. Larger studies are needed to confirm this finding. PMID:23181175

COMPARISON OF REAL-TIME MICROVASCULAR ABNORMALITIES IN PEDIATRIC AND ADULT SICKLE CELL ANEMIA PATIENTS

PubMed Central

Cheung, Anthony T.W.; Miller, Joshua W.; Craig, Sarah M.; To, Patricia L.; Lin, Xin; Samarron, Sandra L.; Chen, Peter C.Y.; Zwerdling, Theodore; Wun, Ted; Li, Chin-Shang; Green, Ralph

2010-01-01

The conjunctival microcirculation in 14 pediatric and 8 adult sickle cell anemia (SCA) patients was studied using computer-assisted intravital microscopy. The bulbar conjunctiva in SCA patients in both age groups exhibited a blanched/avascular appearance characterized by decreased vascularity. SCA patients from both age groups had many of the same abnormal morphometric {vessel diameter, vessel distribution, morphometry (shape), tortuosity, arteriole:venule (A:V) ratio, and hemosiderin deposits} and dynamic {vessel sludging/sludged flow, boxcar blood (trickled) flow and abnormal flow velocity} abnormalities. A severity index (SI) was computed to quantify the degree of vasculopathy for comparison between groups. The severity of vasculopathy differed significantly between the pediatric and adult patients (SI: 4.2 ± 1.8 vs 6.6 ± 2.4; p=0.028), indicative of a lesser degree of overall severity in the pediatric patients. Specific abnormalities that were less prominent in the pediatric patients included abnormal vessel morphometry and tortuosity. Sludged flow, abnormal vessel distribution, abnormal A:V ratio, and boxcar flow, appeared in high prevalence in both age groups. The results indicate that SCA microvascular abnormalities develop in childhood and the severity of vasculopathy likely progresses with age. Intervention and effective treatment/management modalities should target pediatric patients to ameliorate, slow down or prevent progressive microvascular deterioration. PMID:20872552

Blood flow of the right and left submandibular gland during unilateral carotid artery occlusion in rat: role of nitric oxide.

PubMed

Vág, J; Hably, C; Fazekas, A; Bartha, J

1999-01-01

The aim of the present study was to investigate the effect of unilateral carotid artery occlusion on the blood flow of submandibular gland in anesthetized rats and identify the role of nitric oxide (NO) in blood flow changes after the artery occlusion. L-NAME (N omega-nitro-L-arginine-methyl-ester; 10 mg/kg/day, per os) dissolved in tap water was used to block nitric oxide synthase. Glandular blood flow was measured using Sapirstein's indicator (86Rb) distribution technique. In the control animals the blood flow of left (ligated side) submandibular gland was lower than in the right (unligated side) one (right: 76.4+/-15.4 ml/min/100 g, 64.1+/-13.4 ml/min/100 g, p<0.01). The blood flow of submandibular glands decreased in NOS blocked group versus control. The vascular resistance after L-NAME treatment was elevated (control: 11+/-2.3 R/kg, L-NAME: 17.5+/-4.1 R/kg, p<0.001). In L-NAME group the difference between blood flow value of the left and right submandibular gland was significantly lower than in the control group (control: -16%, NAME: -8%, p<0.01). The maintenance of the blood flow in the left submandibular gland during ligation of the left common carotid artery could be due to the good vascular anastomotic system at these regions and adaptation of the submandibular vessels to the decreased perfusion pressure. Nitric oxide may have a role in the regulation of blood flow tinder this condition.

Testing random forest classification for identifying lava flows and mapping age groups on a single Landsat 8 image

NASA Astrophysics Data System (ADS)

Li, Long; Solana, Carmen; Canters, Frank; Kervyn, Matthieu

2017-10-01

Mapping lava flows using satellite images is an important application of remote sensing in volcanology. Several volcanoes have been mapped through remote sensing using a wide range of data, from optical to thermal infrared and radar images, using techniques such as manual mapping, supervised/unsupervised classification, and elevation subtraction. So far, spectral-based mapping applications mainly focus on the use of traditional pixel-based classifiers, without much investigation into the added value of object-based approaches and into advantages of using machine learning algorithms. In this study, Nyamuragira, characterized by a series of > 20 overlapping lava flows erupted over the last century, was used as a case study. The random forest classifier was tested to map lava flows based on pixels and objects. Image classification was conducted for the 20 individual flows and for 8 groups of flows of similar age using a Landsat 8 image and a DEM of the volcano, both at 30-meter spatial resolution. Results show that object-based classification produces maps with continuous and homogeneous lava surfaces, in agreement with the physical characteristics of lava flows, while lava flows mapped through the pixel-based classification are heterogeneous and fragmented including much "salt and pepper noise". In terms of accuracy, both pixel-based and object-based classification performs well but the former results in higher accuracies than the latter except for mapping lava flow age groups without using topographic features. It is concluded that despite spectral similarity, lava flows of contrasting age can be well discriminated and mapped by means of image classification. The classification approach demonstrated in this study only requires easily accessible image data and can be applied to other volcanoes as well if there is sufficient information to calibrate the mapping.

Physical training improves flow-mediated dilation in patients with the polymetabolic syndrome.

PubMed

Lavrencic, A; Salobir, B G; Keber, I

2000-02-01

Endothelial dysfunction that can be detected as impaired flow-mediated dilation by ultrasonography is an early event in atherogenesis and has been demonstrated in healthy subjects with risk factors for atherosclerosis many years before the appearance of atheromatous plaques. We examined the influence of physical training on flow-mediated dilation in patients with the polymetabolic syndrome. Twenty-nine asymptomatic men aged 40 to 60 years with the polymetabolic syndrome were randomly divided between the control group and the training group, which trained 3 times a week for 12 weeks. On high-resolution ultrasound images, the diameter of the brachial artery was measured at rest, after reactive hyperemia (causing flow-mediated, endothelium-dependent dilation), and after sublingual glyceryltrinitrate (causing endothelium-independent vasodilation) in all subjects before and after the training period. The training program induced an increase of 18% in physical fitness. Flow-mediated dilation increased from 5.3+/-2.8% to 7.3+/-2.7% (P<0. 05). There was no change in body mass index, blood pressure, insulin resistance, lipids, and big endothelin-1 in either group. Flow-mediated dilation measured before training was negatively correlated with resting heart rate, waist-to-hip ratio, and insulin resistance. Resting heart rate emerged as the only independent determinant, which explained 22% of the variation in flow-mediated dilation. In conclusion, our findings suggest that a 3-month physical training program, which improved maximal exercise capacity, enhances flow-mediated dilation in patients with the polymetabolic syndrome.

Three-Dimensional Upward Flame Spreading in Partial-Gravity Buoyant Flows

NASA Technical Reports Server (NTRS)

Sacksteder, Kurt R.; Feier, Ioan I.; Shih, Hsin-Yi; T'ien, James S.

2001-01-01

Reduced-gravity environments have been used to establish low-speed, purely forced flows for both opposed- and concurrent-flow flame spread studies. Altenkirch's group obtained spacebased experimental results and developed unsteady, two-dimensional numerical simulations of opposed-flow flame spread including gas-phase radiation, primarily away from the flammability limit for thin fuels, but including observations of thick fuel quenching in quiescent environments. T'ien's group contributed some early flame spreading results for thin fuels both in opposed flow and concurrent flow regimes, with more focus on near-limit conditions. T'ien's group also developed two- and three-dimensional numerical simulations of concurrent-flow flame spread incorporating gas-phase radiative models, including predictions of a radiatively-induced quenching limit reached in very low-speed air flows. Radiative quenching has been subsequently observed in other studies of combustion in very low-speed flows including other flame spread investigations, droplet combustion and homogeneous diffusion flames, and is the subject of several contemporary studies reported in this workshop. Using NASA aircraft flying partial-gravity "parabolic" trajectories, flame spreading in purely buoyant, opposed-flow (downward burning) has been studied. These results indicated increases in flame spread rates and enhanced flammability (lower limiting atmospheric oxygen content) as gravity levels were reduced from normal Earth gravity, and were consistent with earlier data obtained by Altenkirch using a centrifuge. In this work, experimental results and a three-dimensional numerical simulation of upward flame spreading in variable partial-gravity environments were obtained including some effects of reduced pressure and variable sample width. The simulation provides physical insight for interpreting the experimental results and shows the intrinsic 3-D nature of buoyant, upward flame spreading. This study is intended to link the evolving understanding of flame spreading in purely-forced flows to the purely-buoyant flow environment, particularly in the concurrent flow regime; provide additional insight into the existence of steady flame spread in concurrent flows; and stimulate direct comparisons between opposed- and concurrent-flow flame spread. Additionally, this effort is intended to provide direct practical understanding applicable to fire protection planning for the habitable facilities in partial gravity environments of anticipated Lunar and Martian explorations.

Neonatal piglet model of intraaortic balloon pumping: improved efficacy using echocardiographic timing.

PubMed

Minich, L L; Tani, L Y; Pantalos, G M; Bolland, B L; Knorr, B K; Hawkins, J A

1998-11-01

Pediatric intraaortic balloon pumping (IABP) has met with little success because of technical difficulty in tracking rapid heart rates. This study was designed to evaluate the efficacy of M-mode echocardiography for IABP timing in a neonatal piglet model. Two groups of piglets underwent mitral valve avulsion to create a model of shock. Group 1 (n = 8; mean weight, 7.7+/-1.8 kg) underwent IABP timed with both the ascending aortic pressure and M-mode echocardiogram. Group 2 (n = 6; mean weight, 7.5+/-1.4 kg) underwent two separate periods of IABP: one with echocardiographic timing and the second using standard timing points from the femoral arterial pressure tracing and electrocardiogram. Measurements included ascending aortic flow, left anterior descending arterial flow, ascending aortic pressure, left atrial pressure, and heart rate. Mitral valve avulsion produced a shock model with a significant decrease in mean aortic pressure and aortic flow and a significant increase in left atrial pressure and heart rate. Compared with the shock state, IABP in group 1 animals resulted in a significant increase in aortic flow (353+/-152 versus 454+/-109 mL/min; p < 0.05) and a significant decrease in left atrial pressure (23+/-6 versus 17+/-7 mm Hg; p < 0.05). Group 2 animals with echocardiogram-timed IABP had significantly increased aortic flow (365+/-106 versus 458+/-107 mL/min; p < 0.05) and mean aortic pressure (43+/-11 versus 52+/-8 mm Hg; p < 0.05). However, standard-timed IABP failed to show any improvement. In piglets with rapid heart rates, echocardiogram-timed IABP results in increased aortic flow and pressure and decreased left atrial pressure compared with standard-timed IABP.

[Low flow anaesthesia with isoflurane and sevoflurane in the dog].

PubMed

Kramer, Sabine; Alyakine, Hassan; Nolte, Ingo

2008-01-01

The aim of the present study was to compare the safety and efficacy of sevoflurane and isoflurane during low flow anaesthesia (fresh gas flow (FGF) 14 ml/kg/min) as well as to compare the consumption of both anaesthetics. Data were gathered from 60 dogs assigned for surgery under general anaesthesia with an expected duration of 75 minutes or longer. All dogs were induced with 0.6 mg/kg (maximum 25 mg) l-methadone and 1 mg/kg (maximum 25 mg) diazepam i.v.. Anaesthesia was maintained with isoflurane (group 1) or sevoflurane (group 2) in a mixture with 50% O2 and 50% N2O as carrier gases, under controlled ventilation. Monitoring included electrocardiogram, body temperature, the temperature of in- and exspired gases, arterial oxygen saturation, arterial blood pressure as well as a continuous monitoring of inhaled and exhaled gas concentrations (O2, N2O, CO2, isoflurane, sevoflurane). The consumption of isoflurane and sevoflurane as well as the dogs' recovery times were evaluated for both groups. In all groups the inspired oxygen concentrations ranged above the minimum value of 30 Vol% during low flow anaesthesia, with an arterial oxygen saturation above 97%. End tidal concentration of CO2, heart rate and arterial blood pressure were within the physiological ranges and showed no differences between the two groups. Recovery time was significantly shorter after sevoflurane compared to isoflurane anaesthesia, whilst the consumption of sevoflurane was higher than that of isoflurane. Sevoflurane appears to be as clinically safe as isoflurane in low flow anaesthesia. Even considering that sevoflurane is more expensive than isoflurane, the use of the low flow technique decreases the cost of anaesthesia due to the reduced volatile anaesthetic consumption.

Normal muscle oxygen consumption and fatigability in sickle cell patients despite reduced microvascular oxygenation and hemorheological abnormalities.

PubMed

Waltz, Xavier; Pichon, Aurélien; Lemonne, Nathalie; Mougenel, Danièle; Lalanne-Mistrih, Marie-Laure; Lamarre, Yann; Tarer, Vanessa; Tressières, Benoit; Etienne-Julan, Maryse; Hardy-Dessources, Marie-Dominique; Hue, Olivier; Connes, Philippe

2012-01-01

Although it has been hypothesized that muscle metabolism and fatigability could be impaired in sickle cell patients, no study has addressed this issue. We compared muscle metabolism and function (muscle microvascular oxygenation, microvascular blood flow, muscle oxygen consumption and muscle microvascular oxygenation variability, which reflects vasomotion activity, maximal muscle force and local muscle fatigability) and the hemorheological profile at rest between 16 healthy subjects (AA), 20 sickle cell-hemoglobin C disease (SC) patients and 16 sickle cell anemia (SS) patients. Muscle microvascular oxygenation was reduced in SS patients compared to the SC and AA groups and this reduction was not related to hemorhelogical abnormalities. No difference was observed between the three groups for oxygen consumption and vasomotion activity. Muscle microvascular blood flow was higher in SS patients compared to the AA group, and tended to be higher compared to the SC group. Multivariate analysis revealed that muscle oxygen consumption was independently associated with muscle microvascular blood flow in the two sickle cell groups (SC and SS). Finally, despite reduced muscle force in sickle cell patients, their local muscle fatigability was similar to that of the healthy subjects. Sickle cell patients have normal resting muscle oxygen consumption and fatigability despite hemorheological alterations and, for SS patients only, reduced muscle microvascular oxygenation and increased microvascular blood flow. Two alternative mechanisms can be proposed for SS patients: 1) the increased muscle microvascular blood flow is a way to compensate for the lower muscle microvascular oxygenation to maintain muscle oxygen consumption to normal values or 2) the reduced microvascular oxygenation coupled with a normal resting muscle oxygen consumption could indicate that there is slight hypoxia within the muscle which is not sufficient to limit mitochondrial respiration but increases muscle microvascular blood flow.

Repetitive shock wave therapy improves muscular microcirculation.

PubMed

Kisch, Tobias; Wuerfel, Waldemar; Forstmeier, Vinzent; Liodaki, Eirini; Stang, Felix H; Knobloch, Karsten; Mailaender, Peter; Kraemer, Robert

2016-04-01

Extracorporeal shock wave therapy (ESWT) is mainly applied in tendon as well as bone problems based on stem-cell activation and healing acceleration. The effect of ESWT on muscle tissue is much less understood to date. However, from a clinical perspective, muscle injuries are of distinct interest especially in elite athletes such as soccer players. A total of 26 rats were randomized into two groups. Group A received a single application of high-energetic focused ESWT (0.3 mJ/mm(2), 4 Hz, 1000 impulses, 10 J), whereas group B underwent the same procedure every 10 min for three sessions (3 × 0.3 mJ/mm(2), 4 Hz, 3 × 1000 impulses, totaling 30 J). Blood flow at a depth of 8 mm was measured continuously and noninvasively by a combined Laser-Doppler-Imaging and photospectrometric technique (Oxygen-to-see, O2C, LEA Medizintechnik, Germany). One minute after the application of high-energy ESWT blood flow in group A increased by 16.5% (P = 0.007). Thereafter, it decreased from minute 2 after application and remained significantly unchanged to baseline value until the end of the measuring period at 50 min (P = 0.550). Group B showed a similar significant increase in blood flow of 16.4% (P = 0.049) and a decrease afterward, too. After the second focused ESWT blood flow was boosted to 26.6% (P = 0.004), remaining significantly elevated until the third application was initiated. Muscular blood flow was increased to 29.8% after the third focused ESWT (P < 0.001), remaining significantly increased for another 10 min. Focused ESWT enhances blood flow in the muscle of rats. Moreover, repetitive ESWT extended this beneficial effect. Copyright © 2016 Elsevier Inc. All rights reserved.

Stratigraphy of the unsaturated zone and uppermost part of the Snake River Plain aquifer at test area north, Idaho National Engineering Laboratory, Idaho

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

Anderson, S.R.; Bowers, B.

1995-06-01

A complex sequence of basalt flows and sedimentary interbeds underlies Test Area North (TAN) at the Idaho National Engineering Laboratory in eastern Idaho. Wells drilled to depths of at least 500 feet penetrate 10 basalt-flow groups and 5 to 10 sedimentary interbeds that range in age from about 940,000 to 1.4 million years. Each basalt-flow group consists of one or more basalt flows from a brief, single or compound eruption. All basalt flows of each group erupted from the same vent, and have similar ages, paleomagnetic properties, potassium contents, and natural-gamma emissions. Sedimentary interbeds consist of fluvial, lacustrine, and eolianmore » deposits of clay, silt, sand, and gravel that accumulated for hundreds to hundreds of thousands of years during periods of volcanic quiescence. Basalt and sediment are elevated by hundreds of feet with respect to rocks of equivalent age south and cast of the area, a relation that is attributed to past uplift at TAN. Basalt and sediment are unsaturated to a depth of about 200 feet below land surface. Rocks below this depth are saturated and make up the Snake River Plain aquifer. The effective base of the aquifer is at a depth of 885 feet below land surface. Detailed stratigraphic relations for the lowermost part of the aquifer in the depth interval from 500 to 885 feet were not determined because of insufficient data. The stratigraphy of basalt-flow groups and sedimentary interbeds in the upper 500 feet of the unsaturated zone and aquifer was determined from natural-gamma logs, lithologic logs, and well cores. Basalt cores were evaluated for potassium-argon ages, paleomagnetic properties, petrographic characteristics, and chemical composition. Stratigraphic control was provided by differences in ages, paleomagnetic properties, potassium content, and natural-gamma emissions of basalt-flow groups and sedimentary interbeds.« less

Blood flow changes after unilateral carotid artery ligation monitored by optical coherence tomography

NASA Astrophysics Data System (ADS)

Ma, Yushu; Liang, Chengbo; Suo, Yanyan; Zhao, Yuqian; Wang, Yi; Xu, Tao; Wang, Ruikang; Ma, Zhenhe

2016-03-01

Unilateral carotid artery ligation which could induce adaptive improvement is a classic model that has been widely used to study pathology of ischemic disease. In those studies, blood flow is an important parameter to characterize the ischemia. Optical coherence tomography (OCT) is a powerful imaging modality which can provide depth resolved images in biological tissue with high spatial and temporal resolution. SPF rats was anesthetized with isoflurane and divided into two groups. In first group, bilateral carotid artery was surgically exposed, and then left carotid artery was ligated. Blood flow changes of the contralateral carotid artery was monitored using high speed spectral domain optical coherence tomography, including the absolute flow velocity and the flow volume. In the other group, skull window was opened at the ipsilateral cerebral cortex of ligation and blood supply of small artery was measured before and after the ligation. The measured results demonstrate the blood supply compensation process after unilateral carotid artery ligation. With the superiority of high resolution, OCT is an effective technology in monitoring results of carotid artery after ligation.

Behavior of neutral solutes in pressurized flow driven electrochromatography using a mixed stationary phase of ODS and anion-exchange.

PubMed

Kitagawa, Shinya; Tsuda, Takao

2003-05-02

The behavior of neutral sample solutes in pressurized flow driven electrochromatography using a mixed stationary phase, which consisted of ODS and anion-exchange (ODS-SAX), was studied. Applications of both positive and negative voltage on a column induced increases in retention factors of sample solutes. The direction of an electroosmotic flow under applications of positive and negative voltage were the same, therefore, the sign of the surface charge density under positive and negative voltage was opposite. We proposed a new equation for the relationship between applied voltage and surface charge density, and the practical electroosmotic flow conformed to this equation. Studying the electroosmotic flow using our proposed equation revealed that the applied negative voltage accelerates the protonation of the quaternary ammonium group and dissociation of the silanol group on packing materials. The retention behavior of a neutral solute was affected by the existence of the charged functional groups. We propose that this phenomenon is applicable to the control of the retention behavior of a sample solute using an electric field.

Comparison of Flow and Volume Incentive Spirometry on Pulmonary Function and Exercise Tolerance in Open Abdominal Surgery: A Randomized Clinical Trial.

PubMed

Kumar, Amaravadi Sampath; Alaparthi, Gopala Krishna; Augustine, Alfred Joseph; Pazhyaottayil, Zulfeequer Chundaanveetil; Ramakrishna, Anand; Krishnakumar, Shyam Krishnan

2016-01-01

Surgical procedures in abdominal area lead to changes in pulmonary function, respiratory mechanics and impaired physical capacity leading to postoperative pulmonary complications, which can affect up to 80% of upper abdominal surgery. To evaluate the effects of flow and volume incentive spirometry on pulmonary function and exercise tolerance in patients undergoing open abdominal surgery. A randomized clinical trial was conducted in a hospital of Mangalore city in Southern India. Thirty-seven males and thirteen females who were undergoing abdominal surgeries were included and allocated into flow and volume incentive spirometry groups by block randomization. All subjects underwent evaluations of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow (PEF). Preoperative and postoperative measurements were taken up to day 5 for both groups. Exercise tolerance measured by Six- Minute Walk Test during preoperative period and measured again at the time of discharge for both groups. Pulmonary function was analysed by post-hoc analysis and carried out using Bonferroni's 't'-test. Exercise tolerance was analysed by Paired 'T'-test. Pulmonary function (FVC, FEV1, and PEFR) was found to be significantly decreased in 1(st), 2(nd) and 3(rd) postoperative day when compared with preoperative day. On 4(th) and 5(th) postoperative day the pulmonary function (FVC, FEV1, and PEFR) was found to be better preserved in both flow and volume incentive spirometry groups. The Six-Minute Walk Test showed a statistically significant improvement in pulmonary function on the day of discharge than in the preoperative period. In terms of distance covered, the volume- incentive spirometry group showed a greater statistically significant improvement from the preoperative period to the time of discharge than was exhibited by the flow incentive spirometry group. Flow and volume incentive spirometry can be safely recommended to patients undergoing open abdominal surgery as there have been no adverse events recorded. Also, these led to a demonstrable improvement in pulmonary function and exercise tolerance.

Comparison of Flow and Volume Incentive Spirometry on Pulmonary Function and Exercise Tolerance in Open Abdominal Surgery: A Randomized Clinical Trial

PubMed Central

Kumar, Amaravadi Sampath; Augustine, Alfred Joseph; Pazhyaottayil, Zulfeequer Chundaanveetil; Ramakrishna, Anand; Krishnakumar, Shyam Krishnan

2016-01-01

Introduction Surgical procedures in abdominal area lead to changes in pulmonary function, respiratory mechanics and impaired physical capacity leading to postoperative pulmonary complications, which can affect up to 80% of upper abdominal surgery. Aim To evaluate the effects of flow and volume incentive spirometry on pulmonary function and exercise tolerance in patients undergoing open abdominal surgery. Materials and Methods A randomized clinical trial was conducted in a hospital of Mangalore city in Southern India. Thirty-seven males and thirteen females who were undergoing abdominal surgeries were included and allocated into flow and volume incentive spirometry groups by block randomization. All subjects underwent evaluations of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow (PEF). Preoperative and postoperative measurements were taken up to day 5 for both groups. Exercise tolerance measured by Six- Minute Walk Test during preoperative period and measured again at the time of discharge for both groups. Pulmonary function was analysed by post-hoc analysis and carried out using Bonferroni’s ‘t’-test. Exercise tolerance was analysed by Paired ‘T’-test. Results Pulmonary function (FVC, FEV1, and PEFR) was found to be significantly decreased in 1st, 2nd and 3rd postoperative day when compared with preoperative day. On 4th and 5th postoperative day the pulmonary function (FVC, FEV1, and PEFR) was found to be better preserved in both flow and volume incentive spirometry groups. The Six-Minute Walk Test showed a statistically significant improvement in pulmonary function on the day of discharge than in the preoperative period. In terms of distance covered, the volume- incentive spirometry group showed a greater statistically significant improvement from the preoperative period to the time of discharge than was exhibited by the flow incentive spirometry group. Conclusion Flow and volume incentive spirometry can be safely recommended to patients undergoing open abdominal surgery as there have been no adverse events recorded. Also, these led to a demonstrable improvement in pulmonary function and exercise tolerance. PMID:26894090

Effects of raloxifene on carotid blood flow resistance and endothelium-dependent vasodilation in postmenopausal women.

PubMed

Ceresini, Graziano; Marchini, Lorenzo; Rebecchi, Isabella; Morganti, Simonetta; Bertone, Luca; Montanari, Ilaria; Bacchi-Modena, Alberto; Sgarabotto, Maria; Baldini, Monica; Denti, Licia; Ablondi, Fabrizio; Ceda, Gian Paolo; Valenti, Giorgio

2003-03-01

Raloxifene is one of the most important selective estrogen receptor modulators currently employed for the treatment of postmenopausal osteoporosis. However, it has also been suggested that this compound affects the vascular system. We evaluated both carotid blood flow resistance and endothelium-dependent vasodilation in 50 healthy postmenopausal women randomly assigned to receive, in a double blind design, either raloxifene (60 mg per day; N=25 subjects) or placebo (N=25 subjects) for 4 months. Indices of carotid blood flow resistance, such as the pulsatility index (PI) and resistance index (RI), as well as the flow-mediated brachial artery dilation were measured both at baseline and at the end of treatment. Changes in PI were -1.86+/-2.24 and -2.15+/-2.22% after placebo and raloxifene treatment, respectively, with no significant differences between groups. Changes in RI were -0.77+/-1.72 and -1.81+/-1.54% after placebo and raloxifene treatment, respectively, with no significant differences between groups. At the end of the treatment period, the increments in artery diameter measured after the flow stimulus were 10.79+/-2.39 and 6.70+/-1.23% for placebo and raloxifene, respectively, with no significant differences between groups. These results demonstrate no significant effects of raloxifene on either carotid blood flow resistance or brachial artery flow-mediated dilation in postmenopausal women.

Increased plasma soluble adhesion molecules; ICAM-1, VCAM-1, and E-selectin levels in patients with slow coronary flow.

PubMed

Turhan, Hasan; Saydam, Gul Sevim; Erbay, Ali Riza; Ayaz, Selime; Yasar, Ayse Saatci; Aksoy, Yuksel; Basar, Nurcan; Yetkin, Ertan

2006-04-04

Inflammation has been reported to be a major contributing factor to many cardiovascular events. In the present study, we aimed to evaluate plasma soluble adhesion molecules; intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin as possible indicators of endothelial activation or inflammation in patients with slow coronary flow. Study population included 17 patients with angiographically proven normal coronary arteries and slow coronary flow in all three coronary vessels (group I, 11 male, 6 female, mean age=48+/-9 years), and 20 subjects with angiographically proven normal coronary arteries without associated slow coronary flow (group II, 11 male, 9 female, mean age=50+/-8 years). Coronary flow rates of all patients and control subjects were documented by Thrombolysis In Myocardial Infarction frame count (TIMI frame count). All patients in group I had TIMI frame counts greater than two standard deviation above those of control subjects (group II) and, therefore, were accepted as exhibiting slow coronary flow. Serum levels of ICAM-1, VCAM-1, and E-selectin were measured in all patients and control subjects using commercially available ELISA kits. Serum ICAM-1, VCAM-1, and E-selectin levels of patients with slow coronary flow were found to be significantly higher than those of control subjects with normal coronary flow (ICAM-1: 545+/-198 ng/ml vs. 242+/-113 ng/ml respectively, p<0.001, VCAM-1: 2040+/-634 ng/ml vs. 918+/-336 ng/ml respectively, p<0.001, E-selectin: 67+/-9 ng/ml vs. 52+/-8 ng/ml respectively, p<0.001). Average TIMI frame count was detected to be significantly correlated with plasma soluble ICAM-1 (r=0.550, p<0.001), VCAM-1 (r=0.569, p<0.001) and E-selectin (r=0.443, p=0.006). Increased levels of soluble adhesion molecules in patients with slow coronary flow may be an indicator of endothelial activation and inflammation and are likely to be in the causal pathway leading to slow coronary flow.

Towards a universal description of cohesive-particle flows

NASA Astrophysics Data System (ADS)

Lamarche, Casey; Liu, Peiyuan; Kellogg, Kevin; Lattanzi, Aaron; Hrenya, Christine

2017-11-01

A universal framework for describing cohesive granular flows seems unattainable based on prior works, making a fundamental continuum theory to predict such flows appear unachievable. For the first time, universal behavior of cohesive-grain flows is demonstrated by linking the macroscopic (many-grain) behavior to grain-grain interactions via two dimensionless groups: a generalized Bond number BoG - ratio of maximum cohesive force to the force driving flow - and a new Agglomerate number Ag - ratio of critical cohesive energy to the granular energy. Cohesive-grain flow is investigated in several systems, and universal behavior is determined via collapse of a cohesion-dependent output variable from each system with the appropriate dimensionless group. Universal behavior is observed using BoG for dense (enduring-contact-dominated) flows and Ag for dilute (collision-dominated) flows, as BoG accounts for the cohesive contact force and Ag for increased collisional dissipation due to cohesion. Hence, a new physical picture is presented, namely, BoG dominates in dense flows, where force chains drive momentum transfer, and Ag dominates in dilute systems, where the dissipative collisions dominate momentum transfer. Apparent discrepancies with past treatments are resolved. Dow Corning Corporation.

Effect of hindlimb unweighting on tissue blood flow in the rat

NASA Technical Reports Server (NTRS)

Mcdonald, K. S.; Delp, M. D.; Fitts, R. H.

1992-01-01

This study characterized distribution of blood flow in the rat during hindlimb unweighting (HU), and post-HU standing and exercise. The relationship between reduced hindlimb blood flow and the previously observed elevation in anaerobic metabolism observed with contractile activity in the atrophied soleus muscle was examined (Witzmann et al., 1992). Blood flow was measured during unweighting, normal standing, and running on a treadmill (15 m/min), after 15 days of HU or cage control. For another group blood flow was measured during preexercise treadmill standing and treadmill running. During unweighting, PE standing, and running no difference in soleus blood flow was observed between groups. Muscles composed mainly of fast twitch glycolytic fibers received greater blood flow during chronic unweighting. With exercise blood flow to visceral organs was reduced in control animals, a similar change was not seen in 15 day HU rats. These changes suggest a reduction in the ability of the sympathetic nervous system to distribute cardiac output after chronic HU. A reduction in blood flow to the soleus during exercise was not observed after HU and so does not explain the increased dependence of the atrophied soleus on anerobic energy production during contractile activity.

Effects of intravenous bolus injection of nicorandil on renal artery flow velocity assessed by color Doppler ultrasound.

PubMed

Shimamoto, Yukiko; Kubo, Takashi; Tanabe, Kazumi; Emori, Hiroki; Katayama, Yosuke; Nishiguchi, Tsuyoshi; Taruya, Akira; Kameyama, Takeyoshi; Orii, Makoto; Yamano, Takashi; Kuroi, Akio; Yamaguchi, Tomoyuki; Takemoto, Kazushi; Matsuo, Yoshiki; Ino, Yasushi; Tanaka, Atsushi; Hozumi, Takeshi; Terada, Masaki; Akasaka, Takashi

2017-01-01

Previous animal studies have shown that a potassium channel opener, nicorandil, provokes vasodilation in renal microvasculature and increases renal blood flow. We conducted a clinical study that aimed to evaluate the effect of nicorandil on renal artery blood flow in comparison with nitroglycerin by using color Doppler ultrasound. The present study enrolled 40 patients with stable coronary artery disease who had no renal arterial stenosis and renal parenchymal disease. The patients received intravenous administration of nicorandil (n=20) or nitroglycerin (n=20). Before and after the administration, renal artery blood flow velocity was measured by color-guided pulsed-wave Doppler. The peak-systolic, end-diastolic, and mean renal artery blood flow velocities before the administration were not different between the nicorandil group and the nitroglycerin group. The peak-systolic (79±15cm/s to 99±21cm/s, p<0.001; and 78±19cm/s to 85±19cm/s, p=0.004), end-diastolic (22±5cm/s to 28±8cm/s, p<0.001; and 24±6cm/s to 26±6cm/s, p=0.005) and mean (41±6cm/s to 49±9cm/s, p<0.001; and 43±9cm/s to 45±9cm/s, p=0.009) renal artery flow velocities increased significantly in either group. The nominal changes in the peak-systolic (20±10cm/s vs. 7±8cm/s, p<0.001), end-diastolic (5±4cm/s vs. 2±3cm/s, p=0.001), and mean (8±5cm/s vs. 2±2cm/s, p<0.001) renal artery blood flow velocities were significantly greater in the nicorandil group compared with the nitroglycerin group. Intravenous nicorandil increased renal artery blood flow velocity in comparison with nitroglycerin. Nicorandil has a significant effect on renal hemodynamics. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Combined AIE/EBE/GMRES approach to incompressible flows. [Adaptive Implicit-Explicit/Grouped Element-by-Element/Generalized Minimum Residuals

NASA Technical Reports Server (NTRS)

Liou, J.; Tezduyar, T. E.

1990-01-01

Adaptive implicit-explicit (AIE), grouped element-by-element (GEBE), and generalized minimum residuals (GMRES) solution techniques for incompressible flows are combined. In this approach, the GEBE and GMRES iteration methods are employed to solve the equation systems resulting from the implicitly treated elements, and therefore no direct solution effort is involved. The benchmarking results demonstrate that this approach can substantially reduce the CPU time and memory requirements in large-scale flow problems. Although the description of the concepts and the numerical demonstration are based on the incompressible flows, the approach presented here is applicable to larger class of problems in computational mechanics.

Continuous Metabolic Monitoring in Infant Cardiac Surgery: Toward an Individualized Cardiopulmonary Bypass Strategy.

PubMed

Torre, Salvatore; Biondani, Elisa; Menon, Tiziano; Marchi, Diego; Franzoi, Mauro; Ferrarini, Daniele; Tabbì, Rocco; Hoxha, Stiljan; Barozzi, Luca; Faggian, Giuseppe; Luciani, Giovanni Battista

2016-01-01

Cardiopulmonary bypass (CPB) in infants is associated with morbidity due to systemic inflammatory response syndrome (SIRS). Strategies to mitigate SIRS include management of perfusion temperature, hemodilution, circuit miniaturization, and biocompatibility. Traditionally, perfusion parameters have been based on body weight. However, intraoperative monitoring of systemic and cerebral metabolic parameters suggest that often, nominal CPB flows may be overestimated. The aim of the study was to assess the safety and efficacy of continuous metabolic monitoring to manage CPB in infants during open-heart repair. Between December 2013 and October 2014, 31 consecutive neonates, infants, and young children undergoing surgery using normothermic CPB were enrolled. There were 18 male and 13 female infants, aged 1.4 ± 1.7 years, with a mean body weight of 7.8 ± 3.8 kg and body surface area of 0.39 m(2) . The study was divided into two phases: (i) safety assessment; the first 20 patients were managed according to conventional CPB flows (150 mL/min/kg), except for a 20-min test during which CPB was adjusted to the minimum flow to maintain MVO2>70% and rSO2>45% (group A); (ii) efficacy assessment; the following 11 patients were exclusively managed adjusting flows to maintain MVO2>70% and rSO2>45% for the entire duration of CPB (group B). Hemodynamic, metabolic, and clinical variables were compared within and between patient groups. Demographic variables were comparable in the two groups. In group A, the 20-min test allowed reduction of CPB flows greater than 10%, with no impact on pH, blood gas exchange, and lactate. In group B, metabolic monitoring resulted in no significant variation of endpoint parameters, when compared with group A patients (standard CPB), except for a 10% reduction of nominal flows. There was no mortality and no neurologic morbidity in either group. Morbidity was comparable in the two groups, including: inotropic and/or mechanical circulatory support (8 vs. 1, group A vs. B, P = 0.07), reexploration for bleeding (1 vs. none, P = not significant [NS]), renal failure requiring dialysis (none vs. 1, P = NS), prolonged ventilation (9 vs. 4, P = NS), and sepsis (2 vs. 1, P = NS). The present study shows that normothermic CPB in neonates, infants, and young children can be safely managed exclusively by systemic and cerebral metabolic monitoring. This strategy allows reduction of at least 10% of predicted CPB flows under normothermia and may lay the ground for further tailoring of CPB parameters to individual patient needs. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Caries prevalence in chronic alcoholics and the relationship to salivary flow rate and pH.

PubMed

Dukić, Walter; Dobrijević, Tanja Trivanović; Katunarić, Marina; Lesić, Stjepanka

2013-03-01

The aim of this study was to investigate the dental status of alcoholics; to evaluate the relationship of unstimulated and stimulated saliva pH on their decayed/missing/filled teeth (DMFT); and to evaluate the relationship of unstimulated and stimulated salivary flow rate on their DMFT. A cross-sectional study was conducted in patients treated for alcohol dependency (n = 70; mean age 41.7 years) and a control group of non-alcoholics (n = 70; mean age 39.1 years). Examinations for dental caries were conducted using the World Health Organization (WHO) criteria and questionnaires. The correlation between nominal variables was determined using chi2 test (alpha = 0.05). The correlation between interval variables was determined using Pearson's correlation coefficient. The mean DMFT was similar in alcoholics (14.40) and the control group (13.44) (p > 0.05). There was a statistically significant correlation between alcoholism and unstimulated salivary flow rate (p < 0.05), but no relationship on DMFT was recorded. No statistically significant differences were found between alcoholics and controls in terms of stimulated salivary flow rate (p > 0.05) or stimulated salivary flow on DMFT (p > 0.05). There was a statistically significant correlation between alcoholism and the pH value of stimulated saliva (p < 0.01). There was no correlation between the amount of alcohol consumed and the number of carious lesions (p > 0.05). No major differences were found with respect to overall DMFT in alcoholics compared to the control group. Alcoholism and stimulated salivary flow rate showed no correlation. Unstimulated salivary flow rate as well as the pH values of both unstimulated and stimulated saliva, were lower in the alcoholic group.

The neurochemistry and social flow of singing: bonding and oxytocin

PubMed Central

Keeler, Jason R.; Roth, Edward A.; Neuser, Brittany L.; Spitsbergen, John M.; Waters, Daniel J. M.; Vianney, John-Mary

2015-01-01

Music is used in healthcare to promote physical and psychological well-being. As clinical applications of music continue to expand, there is a growing need to understand the biological mechanisms by which music influences health. Here we explore the neurochemistry and social flow of group singing. Four participants from a vocal jazz ensemble were conveniently sampled to sing together in two separate performances: pre-composed and improvised. Concentrations of plasma oxytocin and adrenocorticotropic hormone (ACTH) were measured before and after each singing condition to assess levels of social affiliation, engagement and arousal. A validated assessment of flow state was administered after each singing condition to assess participants' absorption in the task. The feasibility of the research methods were assessed and initial neurochemical data was generated on group singing. Mean scores of the flow state scale indicated that participants experienced flow in both the pre-composed (M = 37.06) and improvised singing conditions (M = 34.25), with no significant difference between conditions. ACTH concentrations decreased in both conditions, significantly so in the pre-composed singing condition, which may have contributed to the social flow experience. Mean plasma oxytocin levels increased only in response to improvised singing, with no significant difference between improvised and pre-composed singing conditions observed. The results indicate that group singing reduces stress and arousal, as measured by ACTH, and induces social flow in participants. The effects of pre-composed and improvised group singing on oxytocin are less clear. Higher levels of plasma oxytocin in the improvised condition may perhaps be attributed to the social effects of improvising musically with others. Further research with a larger sample size is warranted. PMID:26441614

Echocardiographic Assessment of the Alterations in Pulmonary Blood Flow Associated with Ketamine and Etomidate Administration in Children with Tetralogy of Fallot.

PubMed

Jha, Ajay K; Gharde, Parag; Chauhan, Sandeep; Kiran, Usha; Malhotra Kapoor, Poonam

2016-02-01

Despite widespread uses of ketamine, the clinical studies determining its effect on pulmonary blood flow in children with tetralogy of Fallot (TOF) are lacking. Furthermore, the quantification of pulmonary blood flow is not possible in these patients, because pulmonary artery catheter is contraindicated. Therefore, the purpose of this study was to evaluate the changes in pulmonary blood flow by intra-operative transesophageal echocardiography after ketamine or etomidate administration in children with TOF. Eleven children each in the two clinical variants of TOF (group A-moderate to severe cyanosis; group B-mild to minimal cyanosis) undergoing intracardiac repair were prospectively studied after endotracheal intubation. A single bolus dose of ketamine (2 mg/kg) and etomidate (0.3 mg/kg) was administered in a random order after 15 minute interval. Hemodynamic, arterial blood gas, and echocardiographic measurements were obtained at 7 consecutive times (T) points (baseline, 1, 2, 4, 6, 8, and 15 minutes after drug administration). Ketamine produced a significant reduction in VTI-T (velocity time integrals total of left upper pulmonary vein), RVOT-PG (right ventricular outflow tract peak gradient), and MG (mean gradient) in group A while those in group B had a significant increase in VTI-T, RVOT-PG, and RVOT-MG at time (T1, T2, T4, and T6; P = 0.00). This divergent behavior, however, was not observed with etomidate. Etomidate does not change pulmonary blood flow. However, ketamine produces divergent effects; it increases pulmonary blood flow in children with minimal cyanosis and decreases pulmonary blood flow in children with moderate to severe cyanosis. © 2015, Wiley Periodicals, Inc.

Feasibility study of hidden flow imaging based on laser speckle technique using multiperspectives contrast images

NASA Astrophysics Data System (ADS)

Abookasis, David; Moshe, Tomer

2014-11-01

This paper demonstrates the insertion of lens array in the front of a CCD camera in a laser speckle imaging (LSI) like-technique to acquire multiple speckle reflectance projections for imaging blood flow in an intact biological tissue. In some of LSI applications, flow imaging is obtained by thinning or removing of the upper tissue layers to access blood vessels. In contrast, with the proposed approach flow imaging can be achieved while the tissue is intact. In the system, each lens from an hexagonal lens array observed the sample from slightly different perspectives and captured with a CCD camera. In the computer, these multiview raw images are converted to speckled contrast maps. Then, a self-deconvolution shift-and-add algorithm is employed for processing yields high contrast flow information. The method is experimentally validated first with a plastic tube filled with scattering liquid running at different controlled flow rates hidden in a biological tissue and then extensively tested for imaging of cerebral blood flow in an intact rodent head experience different conditions. A total of fifteen mice were used in the experiments divided randomly into three groups as follows: Group 1 (n=5) consisted of injured mice experience hypoxic ischemic brain injury monitored for ~40 min. Group 2 (n=5) injured mice experience anoxic brain injury monitored up to 20 min. Group 3 (n=5) experience functional activation monitored up to ~35 min. To increase tissue transparency and the penetration depth of photons through head tissue layers, an optical clearing method was employed. To our knowledge, this work presents for the first time the use of lens array in LSI scheme.

Airport Network Flow Simulator

DOT National Transportation Integrated Search

1978-10-01

The Airport Network Flow Simulator is a FORTRAN IV simulation of the flow of air traffic in the nation's 600 commercial airports. It calculates for any group of selected airports: (a) the landing and take-off (Type A) delays; and (b) the gate departu...

Using Functional Flow Diagrams to Enhance Technical Systems Understanding.

ERIC Educational Resources Information Center

Satchwell, Richard E.

1997-01-01

A treatment group of 20 aviation students used training manuals that presented functional flow diagrams before schematic diagrams. Comparison of data from 10 controls on a card-sort task showed that functional flow diagrams enhanced understanding of technical systems. (SK)

Evaluation of small bowel blood flow in healthy subjects receiving low-dose aspirin

PubMed Central

Nishida, Urara; Kato, Mototsugu; Nishida, Mutsumi; Kamada, Go; Yoshida, Takeshi; Ono, Shouko; Shimizu, Yuichi; Asaka, Masahiro

2011-01-01

AIM: To investigate the relationship between low-dose aspirin-induced small bowel mucosal damage and blood flow, and the effect of rebamipide. METHODS: Ten healthy volunteers were enrolled in this study. The subjects were divided into two groups: a placebo group given low-dose aspirin plus placebo and a rebamipide group given low-dose aspirin plus rebamipide for a period of 14 d. Capsule endoscopy and contrast-enhanced ultrasonography were performed before and after administration of drugs. Areas under the curves and peak value of time-intensity curve were calculated. RESULTS: Absolute differences in areas under the curves were -1102.5 (95% CI: -1980.3 to -224.7, P = 0.0194) in the placebo group and -152.7 (95% CI: -1604.2 to 641.6, P = 0.8172) in the rebamipide group. Peak values of time intensity curves were -148.0 (95% CI: -269.4 to -26.2, P = 0.0225) in the placebo group and 28.3 (95% CI: -269.0 to 325.6, P = 0.8343) in the rebamipide group. Capsule endoscopy showed mucosal breaks only in the placebo group. CONCLUSION: Short-term administration of low-dose aspirin is associated with small bowel injuries and blood flow. PMID:21245996

Blood-flow change and recovery of sensibility in the maxillary dental pulp during and after maxillary distraction: a pilot study.

PubMed

Harada, Kiyoshi; Sato, Masaru; Omura, Ken

2004-11-01

To examine the change in blood flow and recovery of sensibility in the maxillary dental pulp during and after maxillary distraction. The subjects included 5 patients undergoing high Le Fort I osteotomy and maxillary distraction (D-group) and a reference group of 14 patients who underwent a common single-segment Le Fort I osteotomy, 1-stage maxillary advancement, and mandibular setback surgery (C-group). Eleven (D-group) and 54 (C-group) maxillary incisors were assessed preoperatively and at 1-7 days, 14 days, and 3 months postoperatively. Pulpal blood flow (PBF) was measured by laser Doppler flowmetry, and pulpal sensibility (PS) was investigated by electrodiagnostics. From postoperative days 1 to 5 (the latency period), the PBF tended to be higher in the D-group than in the C-group. From day 6 to 3 months postoperatively (during and after maxillary distraction), the PBF values of the 2 groups were similar. The PS remained negative up to 14 days postoperatively in both groups. However, at 3 months after the operation, a higher proportion (90.9%) of teeth in the D-group was positive for PS. These results suggest that maxillary distraction is a favorable technique for maintenance of PBF and recovery of PS in the maxillary teeth after surgery.

Effects of 4 weeks of low-load unilateral resistance training, with and without blood flow restriction, on strength, thickness, V wave, and H reflex of the soleus muscle in men.

PubMed

Colomer-Poveda, David; Romero-Arenas, Salvador; Vera-Ibáñez, Antonio; Viñuela-García, Manuel; Márquez, Gonzalo

2017-07-01

To test the effects of 4 weeks of unilateral low-load resistance training (LLRT), with and without blood flow restriction (BFR), on maximal voluntary contraction (MVC), muscle thickness, volitional wave (V wave), and Hoffmann reflex (H reflex) of the soleus muscle. Twenty-two males were randomly distributed into three groups: a control group (CTR; n = 8); a low-load blood flow restriction resistance training group (BFR-LLRT; n = 7), who were an inflatable cuff to occlude blood flow; and a low-load resistance training group without blood flow restriction (LLRT; n = 7). The training consisted of four sets of unilateral isometric LLRT (25% of MVC) three times a week over 4 weeks. MVC increased 33% (P < 0.001) and 22% (P < 0.01) in the trained leg of both BFR-LLRT and LLRT groups, respectively. The soleus thickness increased 9.5% (P < 0.001) and 6.5% (P < 0.01) in the trained leg of both BFR-LLRT and LLRT groups, respectively. However, neither MVC nor thickness changed in either of the legs tested in the CTR group (MVC -1 and -5%, and muscle thickness 1.9 and 1.2%, for the control and trained leg, respectively). Moreover, V wave and H reflex did not change significantly in all the groups studied (V wave /M wave ratio -7.9 and -2.6%, and H max /M max ratio -3.8 and -4%, for the control and trained leg, respectively). Collectively, the present data suggest that in spite of the changes occurring in soleus strength and thickness, 4 weeks of low-load resistance training, with or without BFR, does not cause any change in neural drive or motoneuronal excitability.

Fifth Graders' Flow Experience in a Digital Game-Based Science Learning Environment

ERIC Educational Resources Information Center

Zheng, Meixun; Spires, Hiller A.

2014-01-01

This mixed methods study examined 73 5th graders' flow experience in a game-based science learning environment using two gameplay approaches (solo and collaborative gameplay). Both survey and focus group interview findings revealed that students had high flow experience; however, there were no flow experience differences that were contingent upon…

New method of laser doppler flowmetry signal processing in pulp vitality evaluation after teeth cosmetic treatment

NASA Astrophysics Data System (ADS)

Todea, Carmen; Sarpe, Amalia; Vitez, Bogdan; Draganescu, Gheorghe

2014-01-01

The present study aims to assess the pulp vitality before and after different tooth bleaching procedures, in order to determine the changes in pulpal microcirculation and whether they are reversible or not. Twelve volunteers were included in this study. For each volunteer, the pulpal blood flow of maxillary teeth was assessed prior to treatment using Laser Doppler Flowmetry. The "in office" bleaching technique was used 6 anterior teeth, with two different gels, a conventional one chemically activated (Group I 3teeth) and another one activated using Nd:YAG laser (Group II-3 teeth). The bleaching agents were applied on counterpart teeth and, after obtaining a esthetic results for each tooth, the pulpal blood flow was assessed using Laser Doppler Flowmetry immediately after treatment and then after one day and one week. All data were collected and statistically analyzed. Immediately after treatment, the assessment showed an increase of pulpal blood flow, for both study groups, but higher in Group I as compared to Group II (p<0.005). The subsequent assessments showed a reduction of the pulpal blood flow with non - significant differences between the study groups (p<0.005).The results suggest that the tooth bleaching procedurere presents a safe treatment method, which does not lead to irreversible damage to the dental pulp, when used correctly.

Saliva composition in three selected groups with normal stimulated salivary flow rates, but yet major differences in caries experience and dental erosion.

PubMed

Bardow, Allan; Lykkeaa, Joan; Qvist, Vibeke; Ekstrand, Kim; Twetman, Svante; Fiehn, Niels-Erik

2014-08-01

It was hypothesized that, by comparing matched subjects with major differences in these dental diseases, but yet normal saliva flow rates, it would be possible to obtain data on the effect of saliva composition on dental disease isolated from the effect of the flow rate. Thus, the aim of the study was to compare the major physicochemical characteristics of stimulated whole saliva in three groups of 85 subjects, each with normal saliva flow rates and at least 24 remaining teeth. A group with very little dental disease (healthy), a group with dental erosion (erosion) and a group with very high caries experience (caries) were chosen. Furthermore, the aim was to determine whether differences among groups could also be found on an individual level. Although it was not possible to retrieve three groups whose members were completely identical, the present study points in the direction that, on a group level, subjects with very little dental disease seemed to have a more favorable physicochemical saliva composition with respect to higher calcium, phosphate, bicarbonate, pH, degree of saturation with respect to hydroxyapatite and a lower critical pH (p < 0.05 or less). However, on an individual level the explanatory power for the saliva composition was only 10% for caries experience and only 11% for dental erosion (p < 0.001). The compositional analyses performed in this study on stimulated whole saliva, including major physicochemical characteristics of saliva, will most likely have little predictive value for future dental caries and erosion in single individuals.

Renal Blood Flow, Glomerular Filtration Rate, and Renal Oxygenation in Early Clinical Septic Shock.

PubMed

Skytte Larsson, Jenny; Krumbholz, Vitus; Enskog, Anders; Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2018-06-01

Data on renal hemodynamics, function, and oxygenation in early clinical septic shock are lacking. We therefore measured renal blood flow, glomerular filtration rate, renal oxygen consumption, and oxygenation in patients with early septic shock. Prospective comparative study. General and cardiothoracic ICUs. Patients with norepinephrine-dependent early septic shock (n = 8) were studied within 24 hours after arrival in the ICU and compared with postcardiac surgery patients without acute kidney injury (comparator group, n = 58). None. Data on systemic hemodynamics and renal variables were obtained during two 30-minute periods. Renal blood flow was measured by the infusion clearance of para-aminohippuric acid, corrected for renal extraction of para-aminohippuric acid. Renal filtration fraction was measured by renal extraction of chromium-51 labeled EDTA. Renal oxygenation was estimated from renal oxygen extraction. Renal oxygen delivery (-24%; p = 0.037) and the renal blood flow-to-cardiac index ratio (-21%; p = 0.018) were lower, renal vascular resistance was higher (26%; p = 0.027), whereas renal blood flow tended to be lower (-19%; p = 0.068) in the septic group. Glomerular filtration rate (-32%; p = 0.006) and renal sodium reabsorption (-29%; p = 0.014) were both lower in the septic group. Neither renal filtration fraction nor renal oxygen consumption differed significantly between groups. Renal oxygen extraction was significantly higher in the septic group (28%; p = 0.022). In the septic group, markers of tubular injury were elevated. In early clinical septic shock, renal function was lower, which was accompanied by renal vasoconstriction, a lower renal oxygen delivery, impaired renal oxygenation, and tubular sodium reabsorption at a high oxygen cost compared with controls.

A cellular automation model accounting for bicycle's group behavior

NASA Astrophysics Data System (ADS)

Tang, Tie-Qiao; Rui, Ying-Xu; Zhang, Jian; Shang, Hua-Yan

2018-02-01

Recently, bicycle has become an important traffic tool in China, again. Due to the merits of bicycle, the group behavior widely exists in urban traffic system. However, little effort has been made to explore the impacts of the group behavior on bicycle flow. In this paper, we propose a CA (cellular automaton) model with group behavior to explore the complex traffic phenomena caused by shoulder group behavior and following group behavior on an open road. The numerical results illustrate that the proposed model can qualitatively describe the impacts of the two kinds of group behaviors on bicycle flow and that the effects are related to the mode and size of group behaviors. The results can help us to better understand the impacts of the bicycle's group behaviors on urban traffic system and effectively control the bicycle's group behavior.

Assessment of salivary calcium, phosphate, magnesium, pH, and flow rate in healthy subjects, periodontitis, and dental caries.

PubMed

Rajesh, K S; Zareena; Hegde, Shashikanth; Arun Kumar, M S

2015-01-01

This study was conducted to estimate and compare inorganic salivary calcium, phosphate, magnesium, salivary flow rate, and pH of unstimulated saliva and oral hygiene status of healthy subjects, subjects with periodontitis and dental caries, and to correlate salivary calcium level with number of intact teeth. The study population consisted of 48 systemically healthy subjects in the age group of 18-55 years, which was further divided into three groups: healthy, periodontitis, and dental caries. Oral hygiene index-simplified, probing pocket depth, clinical attachment level, the number of intact teeth, and active carious lesions were recorded. Estimation of inorganic salivary calcium, phosphate, and magnesium was performed spectrophotometrically using Vitros 5.1 FS. Statistical analysis was performed using the one-way analysis of variance test at 5% significance level. There was a statistically significant increase in inorganic salivary calcium, phosphate, pH, flow rate, and poor oral hygiene status in periodontitis group compared to dental caries and healthy group. Subjects with increased inorganic salivary calcium, phosphate, pH, flow rate, and poor oral hygiene are at a higher risk of developing periodontitis. Since there is increased remineralization potential, these subjects have more number of intact teeth compared to the dental caries group.

Assessment of salivary calcium, phosphate, magnesium, pH, and flow rate in healthy subjects, periodontitis, and dental caries

PubMed Central

Rajesh, K. S.; Zareena; Hegde, Shashikanth; Arun Kumar, M. S.

2015-01-01

Aim: This study was conducted to estimate and compare inorganic salivary calcium, phosphate, magnesium, salivary flow rate, and pH of unstimulated saliva and oral hygiene status of healthy subjects, subjects with periodontitis and dental caries, and to correlate salivary calcium level with number of intact teeth. Materials and Methods: The study population consisted of 48 systemically healthy subjects in the age group of 18-55 years, which was further divided into three groups: healthy, periodontitis, and dental caries. Oral hygiene index-simplified, probing pocket depth, clinical attachment level, the number of intact teeth, and active carious lesions were recorded. Estimation of inorganic salivary calcium, phosphate, and magnesium was performed spectrophotometrically using Vitros 5.1 FS. Statistical analysis was performed using the one-way analysis of variance test at 5% significance level. Results: There was a statistically significant increase in inorganic salivary calcium, phosphate, pH, flow rate, and poor oral hygiene status in periodontitis group compared to dental caries and healthy group. Conclusion: Subjects with increased inorganic salivary calcium, phosphate, pH, flow rate, and poor oral hygiene are at a higher risk of developing periodontitis. Since there is increased remineralization potential, these subjects have more number of intact teeth compared to the dental caries group. PMID:26681848

Speeding for fun? Exploring the speeding behavior of riders of heavy motorcycles using the theory of planned behavior and psychological flow theory.

PubMed

Chen, Ching-Fu; Chen, Cheng-Wen

2011-05-01

This paper focuses on a special segment of motorcyclists in Taiwan--riders of heavy motorcycles--and investigates their speeding behavior and its affecting factors. It extends the theory of planned behavior (TPB) to explore motorcyclist speeding behavior by including the variables of psychological flow theory. The levels of sensation-seeking and riding experience are also used as grouping variables to investigate group differences from the influences of their affecting factors on speeding behavior. The results reveal that the psychological flow variables have greater predictive power in explaining speeding behavior than the TPB variables, providing useful insights into the unique nature of this group of motorcyclists, who are more prone to engage in speeding. Group differences with regard to both sensation-seeking and rider experience in speeding behavior are highlighted, and the implications of the findings are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Efficacy of ProTaper Retreatment System in Root Canals Obturated with Gutta-Percha Using Two Different Sealers and GuttaFlow

PubMed Central

Siotia, Jaya; Acharya, Shashi Rashmi; Gupta, Sunil Kumar

2011-01-01

Objective. To compare the efficacy of ProTaper retreatment files in removing three different obturating materials. Study Design. Forty-five human, single-rooted premolars were divided into three experimental groups. Group 1 was obturated with gutta-percha and AH Plus sealer, Group 2 was obturated with gutta-percha and zinc oxide eugenol sealer, and Group 3 was obturated with GuttaFlow. Retreatment was done using the ProTaper universal rotary retreatment files. Root halves were visualized using magnifying loops at 3X magnification and optical stereomicroscope at 10X magnification. Images were analyzed using AutoCAD 2004 software to calculate area of the remaining debris in the canal. For statistical analysis were used variance test and ANOVA. Results. Total debris/canal area ratio between the three groups showed a statistically significant difference (P < 0.001). Conclusion. ProTaper retreatment system did not produce completely clean canals in any of the groups. However, it had the best efficacy towards removing silicon based obturating material GuttaFlow. PMID:22114598

The effect of topically administered latanoprost on the cochlear blood flow and hearing.

PubMed

Jang, Chul Ho; Cho, Yong Beom; Choi, Cheol Hee; Um, Jae-Young; Wang, Pa-Chun; Pak, Sok Cheon

2013-06-01

The application of intratympanic latanoprost (PGF2α analog) has been recently used to alleviate vertigo, disequilibrium and to improve hearing in Meniere's disease patients. However, there is no known report on the effect of topically applied latanoprost on hearing and cochlear hemodynamic parameters including cochlear blood flow (CBF) and vascular conductance. Our goal was to assess the influence of topically applied latanoprost on cochlear blood flow (CBF) and hearing. Twenty male Sprague-Dawley rats were randomly divided into the group A, 50 μl of latanoprost (1 ml containing 50 μg, n=10) and group B, 100 μl (1 ml containing 50 μg, n=10). Topical application of latanoprost was performed at the right side, and the left side was applied with phosphate buffered saline (PBS) as a negative control. Five rats at each group were used to measure cochlear blood flow (CBF). And the others at each group were used for hearing test by auditory brainstem response (ABR). After physiological examination, bullas were extracted. The changes of cochlear hair cells were observed by performing the field emission-scanning electron microscopy (FE-SEM). The CBF of both groups was found to be decreased compared to the PBS applied left side. Significant decrement of CBF was observed in group B compared to the group A. Significant elevation of hearing threshold at high frequencies was observed in both groups compared to the PBS applied group. However, inner and outer hair cells were intact. Topically administered latanoprost decreased the CBF and impaired hearing. Based on our findings, additional studies are required to evaluate the side effects of intratympanic latanoprost before its use in clinical practice. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Effects of a warm hand bath on the blood flow in the shoulder, skin and deep body temperature, autonomic nervous activity, and subjective comfort in healthy women: An experimental cross-over trial.

PubMed

Kudo, Yukiko; Sasaki, Makiko; Kikuchi, Yukiko; Sugiyama, Reiko; Hasebe, Makiko; Ishii, Noriko

2018-06-19

The present study was conducted in order to clarify the effects of a warm hand bath at 40°C for 10 min on the blood flow in the shoulder, skin and deep body temperature, autonomic nervous activity, and subjective comfort in healthy women. The study's participants were 40 healthy adult women who were randomly assigned to either a structured hand bath first and no hand bath second (Group A) or to no hand bath first and a hand bath second (Group B). The blood flow in the shoulder, skin and deep body temperature, autonomic nervous activity, and subjective comfort then were recorded in all the participants. A repeated-measures ANOVA revealed no significant difference in the blood flow in the right shoulder or deep body temperature between groups. The skin temperature of the hands, forearms, and arms was significantly increased, but not of the face and upper back. The skin temperature of the forearms was maintained at 0.5°C-1°C higher for 30 min in the hand bath group, compared with the no hand bath group. The hand bath group had a significantly higher heart rate while bathing and a significantly lower parasympathetic nerve activity level during bathing. No significant difference was seen in the sympathetic activity level between groups. The hand bath group had a significantly higher subjective comfort level. Hand baths can improve the level of subjective comfort and increase the heart rate and might affect autonomic nervous activity. The skin temperature of the forearms was maintained for 30 min in the hand bath group. © 2018 Japan Academy of Nursing Science.

When genes move farther than offspring: gene flow by male gamete dispersal in the highly philopatric bat species Thyroptera tricolor.

PubMed

Buchalski, M R; Chaverri, G; Vonhof, M J

2014-02-01

For species characterized by philopatry of both sexes, mate selection represents an important behaviour for inbreeding avoidance, yet the implications for gene flow are rarely quantified. Here, we present evidence of male gamete-mediated gene flow resulting from extra-group mating in Spix's disc-winged bat, Thyroptera tricolor, a species which demonstrates all-offspring philopatry. We used microsatellite and capture-recapture data to characterize social group structure and the distribution of mated pairs at two sites in southwestern Costa Rica over four breeding seasons. Relatedness and genetic spatial autocorrelation analyses indicated strong kinship within groups and over short distances (<50 m), resulting from matrilineal group structure and small roosting home ranges (~0.2 ha). Despite high relatedness among-group members, observed inbreeding coefficients were low (FIS  = 0.010 and 0.037). Parentage analysis indicated mothers and offspring belonged to the same social group, while fathers belonged to different groups, separated by large distances (~500 m) when compared to roosting home ranges. Simulated random mating indicated mate choice was not based on intermediate levels of relatedness, and mated pairs were less related than adults within social groups on average. Isolation-by-distance (IBD) models of genetic neighbourhood area based on father-offspring distances provided direct estimates of mean gamete dispersal distances (r^) > 10 roosting home range equivalents. Indirect estimates based on genetic distance provided even larger estimates of r^, indicating direct estimates were biased low. These results suggest extra-group mating reduces the incidence of inbreeding in T. tricolor, and male gamete dispersal facilitates gene flow in lieu of natal dispersal of young. © 2013 John Wiley & Sons Ltd.

Examination of Calcium Silicate Cements with Low-Viscosity Methyl Cellulose or Hydroxypropyl Cellulose Additive.

PubMed

Baba, Toshiaki; Tsujimoto, Yasuhisa

2016-01-01

The purpose of this study was to improve the operability of calcium silicate cements (CSCs) such as mineral trioxide aggregate (MTA) cement. The flow, working time, and setting time of CSCs with different compositions containing low-viscosity methyl cellulose (MC) or hydroxypropyl cellulose (HPC) additive were examined according to ISO 6876-2012; calcium ion release analysis was also conducted. MTA and low-heat Portland cement (LPC) including 20% fine particle zirconium oxide (ZO group), LPC including zirconium oxide and 2 wt% low-viscosity MC (MC group), and HPC (HPC group) were tested. MC and HPC groups exhibited significantly higher flow values and setting times than other groups ( p < 0.05). Additionally, flow values of these groups were higher than the ISO 6876-2012 reference values; furthermore, working times were over 10 min. Calcium ion release was retarded with ZO, MC, and HPC groups compared with MTA. The concentration of calcium ions was decreased by the addition of the MC or HPC group compared with the ZO group. When low-viscosity MC or HPC was added, the composition of CSCs changed, thus fulfilling the requirements for use as root canal sealer. Calcium ion release by CSCs was affected by changing the CSC composition via the addition of MC or HPC.

Examination of Calcium Silicate Cements with Low-Viscosity Methyl Cellulose or Hydroxypropyl Cellulose Additive

PubMed Central

Tsujimoto, Yasuhisa

2016-01-01

The purpose of this study was to improve the operability of calcium silicate cements (CSCs) such as mineral trioxide aggregate (MTA) cement. The flow, working time, and setting time of CSCs with different compositions containing low-viscosity methyl cellulose (MC) or hydroxypropyl cellulose (HPC) additive were examined according to ISO 6876-2012; calcium ion release analysis was also conducted. MTA and low-heat Portland cement (LPC) including 20% fine particle zirconium oxide (ZO group), LPC including zirconium oxide and 2 wt% low-viscosity MC (MC group), and HPC (HPC group) were tested. MC and HPC groups exhibited significantly higher flow values and setting times than other groups (p < 0.05). Additionally, flow values of these groups were higher than the ISO 6876-2012 reference values; furthermore, working times were over 10 min. Calcium ion release was retarded with ZO, MC, and HPC groups compared with MTA. The concentration of calcium ions was decreased by the addition of the MC or HPC group compared with the ZO group. When low-viscosity MC or HPC was added, the composition of CSCs changed, thus fulfilling the requirements for use as root canal sealer. Calcium ion release by CSCs was affected by changing the CSC composition via the addition of MC or HPC. PMID:27981048

Coronary Slow Flow is Associated with Depression and Anxiety

PubMed Central

Durmaz, Tahir; Keles, Telat; Erdogan, Kemal Esref; Ayhan, Huseyin; Bilen, Emine; Bayram, Nihal Akar; Akcay, Murat; Oz, Ozgur; Albayrak, Yakup; Ozdemir, Naci; Bozkurt, Engin

2014-01-01

Background There is an established relationship between depression/anxiety disorders and cardiovascular morbidity and mortality which has been previously documented. However, there has been no study evaluating coronary slow flow in association with depression and anxiety. Methods and Results A total of consecutive 90 patients were included in the study. All patients completed scoring scales for depression [Hamilton Rating Scale for Depression (HAMD)] and anxiety (STAI-1, State anxiety subscale of State-Trait Anxiety Inventory; STAI-2, Trait anxiety subscale of State-Trait Anxiety Inventory). Thereafter, they underwent selective coronary angiography and 2 groups were formed: coronary slow flow (n = 42), and normal coronary flow (n = 48). The two groups had comparable baseline characteristics. However, significant differences were found between coronary slow flow and normal coronary flow groups regarding depression (13.1 ± 8.2 and 6.9 ± 6.7, p < 0.001 for HAMD, respectively) and anxiety (46.2 ± 15.0 vs. 32.6 ± 9.9, p < 0.001 for STAI-1 and 51.0 ± 16.7 vs. 43.0 ± 10.7, p = 0.009 for STAI-2, respectively) scores. There were also significant positive correlations between depression/anxiety scores and TIMI frame counts of all major epicardial coronary arteries. In addition, after adjustment for smoking, hypertension, scoring scales, and the presence of depressive mood, all scoring scales and depressive mood were found to be independent risk factors for coronary slow flow in multivariable logistic regression analysis. Conclusions Significant association was found among coronary slow flow, depression/anxiety scores and depressive mood. PMID:27122789

The diagnostic plot analysis of artesian aquifers with case studies in Table Mountain Group of South Africa

NASA Astrophysics Data System (ADS)

Sun, Xiaobin; Xu, Yongxin; Lin, Lixiang

2015-05-01

Parameter estimates of artesian aquifers where piezometric head is above ground level are largely made through free-flowing and recovery tests. The straight-line method proposed by Jacob-Lohman is often used for interpretation of flow rate measured at flowing artesian boreholes. However, the approach fails to interpret the free-flowing test data from two artesian boreholes in the fractured-rock aquifer in Table Mountain Group (TMG) of South Africa. The diagnostic plot method using the reciprocal rate derivative is adapted to evaluate the artesian aquifer properties. The variation of the derivative helps not only identify flow regimes and discern the boundary conditions, but also facilitates conceptualization of the aquifer system and selection of an appropriate model for data interpretation later on. Test data from two free-flowing tests conducted in different sites in TMG are analysed using the diagnostic plot method. Based on the results, conceptual models and appropriate approaches are developed to evaluate the aquifer properties. The advantages and limitations of using the diagnostic plot method on free-flowing test data are discussed.

Relationship between platelet-to-lymphocyte ratio and coronary slow flow.

PubMed

Oylumlu, Muhammed; Doğan, Adnan; Oylumlu, Mustafa; Yıldız, Abdülkadir; Yüksel, Murat; Kayan, Fethullah; Kilit, Celal; Amasyalı, Basri

2015-05-01

The coronary slow flow phenomenon (CSFP), which is characterized by delayed distal vessel opacification in the absence of significant epicardial coronary disease, is an angiographic finding. The aim of this study is to investigate the association between platelet-to-lymphocyte ratio (PLR) and coronary blood flow rate. This is a retrospective observational study. It was based on two medical centers. A total of 197 patients undergoing coronary angiography were included in the study, 95 of whom were patients with coronary slow flow without stenosis in coronary angiography and 102 of whom had normal coronary arteries and normal flow. The PLR was higher in the coronary slow flow group compared with the control groups (p=0.001). In the correlation analysis, PLR showed a significant correlation with left anterior descending (LAD) artery thrombolysis in myocardial infarction (TIMI) frame count. After multiple logistic regression, high levels of PLR were independently associated with coronary slow flow, together with hemoglobin. PLR was higher in patients with CSFP, and we also showed that PLR was significantly and independently associated with CSFP.

The long flow to freedom

DOE PAGES

Aharony, Ofer; Razamat, Shlomo S.; Seiberg, Nathan; ...

2017-02-10

Two-dimensional field theories do not have a moduli space of vacua. Instead, it is common that their low-energy behavior is a sigma model with a target space. When this target space is compact its renormalization group flow is standard. When it is non-compact the continuous spectrum of operators can change the qualitative behavior. Here we discuss two-dimensional gauge theories with N = (2,2) supersymmetry. We focus on two specific theories, for which we argue that they flow to free chiral multiplets at low energies: the U(1) gauge theory with one flavor (two chiral superfields with charges plus and minus one)more » and a non-zero Fayet-Iliopoulos term, and pure SU( N) gauge theories. We argue that the renormalization group flow of these theories has an interesting order of limits issue. Holding the position on the target space fixed, the space flattens out under the renormalization group. On the other hand, if we first go to infinity on the target space and then perform the renormalization group, we always have a non-trivial space, e.g. a cone with a deficit angle. We explain how to interpret low-energy dualities between theories with non-compact target spaces. As a result, we expect a similar qualitative behavior also for other non-compact sigma models, even when they do not flow to free theories.« less

Flow and dissociation: examination of mean levels, cross-links, and links to emotional well-being across sports and recreational and pathological gambling.

PubMed

Wanner, Brigitte; Ladouceur, Robert; Auclair, Amélie V; Vitaro, Frank

2006-01-01

To examine whether flow (Csikszentmihalyi (1990). Flow: The psychology of optimal experience. NY: Harper & Row) and dissociation (Jacobs (1986). Journal of Gambling Behavior, 2, 15-31) are experienced across sports and recreational and pathological gambling, we assessed a sample of 511 college students (256 females and 255 males, M age = 19.54) that was comprised of 14 pathological gamblers, 21 non-addicted gamblers, and 476 athletes. The findings showed that both flow and dissociation lay on a continuum of subjective experiences across activity groups. Specifically, pathological gamblers experienced lower levels of flow than athletes, whereas recreational gamblers lay in between the previous groups in this regard. In contrast, pathological gamblers experienced higher mean levels of dissociation than athletes and recreational gamblers who, in turn, were similar in this regard. A LISREL model showed that flow was positively associated with general emotional well-being, whereas dissociation was negatively associated with well-being.

Blood flow speed of the gastric conduit assessed by indocyanine green fluorescence

PubMed Central

Koyanagi, Kazuo; Ozawa, Soji; Oguma, Junya; Kazuno, Akihito; Yamazaki, Yasushi; Ninomiya, Yamato; Ochiai, Hiroki; Tachimori, Yuji

2016-01-01

Abstract Anastomotic leakage is considered as an independent risk factor for postoperative mortality after esophagectomy, and an insufficient blood flow in the reconstructed conduit may be a risk factor of anastomotic leakage. We investigated the clinical significance of blood flow visualization by indocyanine green (ICG) fluorescence in the gastric conduit as a means of predicting the leakage of esophagogastric anastomosis after esophagectomy. Forty patients who underwent an esophagectomy with gastric conduit reconstruction were prospectively investigated. ICG fluorescence imaging of the gastric conduit was detected by a near-infrared camera system during esophagectomy and correlated with clinical parameters or surgical outcomes. In 25 patients, the flow speed of ICG fluorescence in the gastric conduit wall was simultaneous with that of the greater curvature vessels (simultaneous group), whereas in 15 patients this was slower than that of the greater curvature vessels (delayed group). The reduced speed of ICG fluorescence stream in the gastric conduit wall was associated with intraoperative blood loss (P = 0.008). Although anastomotic leakage was not found in the simultaneous group, it occurred in 7 patients of the delayed group (P < 0.001). A flow speed of ICG fluorescence in the gastric conduit wall of 1.76 cm/s or less was determined by a receiver operating characteristic (ROC) curve, identified as a significant independent predictor of anastomotic leakage after esophagectomy (P = 0.004). This preliminary study demonstrates that intraoperative evaluation of blood flow speed by ICG fluorescence in the gastric conduit wall is a useful means to predict the risk of anastomotic leakage after esophagectomy. PMID:27472732

Penile blood flow by xenon-133 washout

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

Haden, H.T.; Katz, P.G.; Mulligan, T.

1989-06-01

Penile erectile failure is often attributed to abnormalities of vascular supply or drainage, but few direct measurements of penile blood flow have been made. We describe the xenon washout method for measurement of penile blood flow, and present the results obtained in a group of normal and impotent subjects. The procedure was performed with standard nuclear imaging equipment. Flaccid-state penile blood flow in the impotent patients studied was not significantly different from the normal group, suggesting that flaccid-state measurements may not be helpful in evaluation of erectile failure. However, this method can be used to measure penile venous outflow withmore » stimulated or induced erection, and may provide a method for detecting abnormal venous leakage.« less

Evaluation of Salivary Flow Rate, pH and Buffer in Pre, Post & Post Menopausal Women on HRT.

PubMed

D R, Mahesh; G, Komali; K, Jayanthi; D, Dinesh; T V, Saikavitha; Dinesh, Preeti

2014-02-01

Climateric is considered to be a natural phase of life which by definition is the period of life starting from decline in ovarian activity until after the end of ovarian function. It is accompanied by various health consequences that include the changes in saliva too. This study was carried out to evaluate the salivary flow rate, pH, buffering capacity in pre-menopausal, post-menopausal and post-menopausal women on HRT. (1) To evaluate the salivary flow rate, pH of resting saliva and stimulated saliva and buffer capacity of stimulated saliva in pre-menopausal, post-menopausal and post-menopausal women on Hormone Replacement Therapy (HRT). (2) To compare the above salivary findings between pre-menopausal, post-menopausal and post-menopausal women on HRT. The study was carried out on 60 patients. These patients were divided into three groups of 20 patients: Group 1: Pre-menopausal women (control), Group 2: post-menopausal women (case), Group 3: post-menopausal women on HRT (case). The control group consisted of 20 women volunteers, having regular ovulatory menstrual cycles with no known systemic illness and deleterious habits and Group 2 consists of 20 post-menopausal women and Group 3 will consist of 20 post-menopausal women on HRT. After clearing the mouth by swallowing, stimulated saliva was collected after chewing paraffin for 10 mins in to a glass centrifuge tube graded in 0.1 mL increments up to 10mL.in rare cases the collection time will be reduced or extended (5-15 min), salivary flow rate will be determined as ml/min, immediately after collection, pH was determined by dipping pH test paper directly into the sample of oral fluid, salivary buffer capacity was determined by using saliva check buffer kit (GC corporation). The data obtained was statistically evaluated using chi-square test, fisher exact test ANOVA analysis. In our study we found salivary flow rate significantly lower in the post-menopausal women in comparison with the menstruating women and also there was improvement in the flow rate in individuals who were on HRT, it was also observed that salivary pH of the post-menopausal group was significantly lower than that of the control group, statistically significant difference in buffer capacity values was found between the groups however buffer capacity values were higher in the post-menopausal group than the control group. From the above study it is clear that post-menopausal women will present with oral discomfort, while HRT can improve the same. Hence our role as physicians and health care providers is to incorporate preventive dental health care in post-menopausal women and clearly inform patients about both the benefits and the limitations of HRT.

Evaluation of stream flow effects on smolt survival in the Yakima River basin, Washington

USGS Publications Warehouse

Courter,; Garrison,; Kock, Tobias J.; Perry, Russell W.

2012-01-01

Yearling Chinook smolt survival and travel time estimates from 2012 suggest that migration rates and survival rates in the Roza Reach may be associated with stream flow, water temperature, release timing (i.e. migratory disposition), and fish size, but the extent to which each variable influenced survival is yet to be determined. The lowest survival rate (61%) and longest travel time (median 2.26 days) was observed in Release Group 1, which had the smallest size distribution and experienced the lowest flows, lowest temperatures, and earliest release date among the three groups. Release Groups 2 and 3 survived at 96% and 98% respectively and traveled through the Roza Reach in less than eight hours. The primary focus of years two and three of this study will be to collect data that minimizes the effect of confounding explanatory variables, so that flow effects on emigration survival can be quantified independent of these other influential factors.

Incarcerated Inguinal Hernia Mesh Repair: Effect on Testicular Blood Flow and Sperm Autoimmunity.

PubMed

Krnić, Dragan; Družijanić, Nikica; Štula, Ivana; Čapkun, Vesna; Krnić, Duška

2016-05-05

BACKGROUND The aim of our study was to determine an influence of incarcerated inguinal hernia mesh repair on testicular circulation and to investigate consequent sperm autoimmunity as a possible reason for infertility. MATERIAL AND METHODS This prospective study was performed over a 3-year period, and 50 male patients were included; 25 of these patients underwent elective open mesh hernia repair (Group I). Group II consisted of 25 patients who had surgery for incarcerated inguinal hernia. Doppler ultrasound evaluation of the testicular blood flow and blood samplings for antisperm antibodies (ASA) was performed in all patients before the surgery, on the second day, and 5 months after. Main outcome ultrasound measures were resistive index (RI) and pulsative index (PI), as their values are inversely proportional to testicular blood flow. RESULTS In Group I, RI, and PI temporarily increased after surgery and then returned to basal values in the late postoperative period. Friedman analysis showed a significant difference in RI and PI for all measurements in Group II (p<0.05), with a significant decrease between the preoperative, early, and late postoperative periods. All final values were within reference range, including ASA, despite significant increase of ASA in the late postoperative period. CONCLUSIONS Although statistically significant differences in values of testicular flow parameters and immunologic sensitization in observed time, final values remained within the reference ranges in all patients. Our results suggest that the polypropylene mesh probably does not cause any clinically significant effect on testicular flow and immunologic response in both groups of patients.

Multimodal pressure-flow method to assess dynamics of cerebral autoregulation in stroke and hypertension.

PubMed

Novak, Vera; Yang, Albert C C; Lepicovsky, Lukas; Goldberger, Ary L; Lipsitz, Lewis A; Peng, Chung-Kang

2004-10-25

This study evaluated the effects of stroke on regulation of cerebral blood flow in response to fluctuations in systemic blood pressure (BP). The autoregulatory dynamics are difficult to assess because of the nonstationarity and nonlinearity of the component signals. We studied 15 normotensive, 20 hypertensive and 15 minor stroke subjects (48.0 +/- 1.3 years). BP and blood flow velocities (BFV) from middle cerebral arteries (MCA) were measured during the Valsalva maneuver (VM) using transcranial Doppler ultrasound. A new technique, multimodal pressure-flow analysis (MMPF), was implemented to analyze these short, nonstationary signals. MMPF analysis decomposes complex BP and BFV signals into multiple empirical modes, representing their instantaneous frequency-amplitude modulation. The empirical mode corresponding to the VM BP profile was used to construct the continuous phase diagram and to identify the minimum and maximum values from the residual BP (BPR) and BFV (BFVR) signals. The BP-BFV phase shift was calculated as the difference between the phase corresponding to the BPR and BFVR minimum (maximum) values. BP-BFV phase shifts were significantly different between groups. In the normotensive group, the BFVR minimum and maximum preceded the BPR minimum and maximum, respectively, leading to large positive values of BP-BFV shifts. In the stroke and hypertensive groups, the resulting BP-BFV phase shift was significantly smaller compared to the normotensive group. A standard autoregulation index did not differentiate the groups. The MMPF method enables evaluation of autoregulatory dynamics based on instantaneous BP-BFV phase analysis. Regulation of BP-BFV dynamics is altered with hypertension and after stroke, rendering blood flow dependent on blood pressure.

[Sensitivity and specificity of the cerebral blood flow reactions to acupuncture in the newborn infants presenting with hypoxic ischemic encephalopathy].

PubMed

Filonenko, A V; Vasilenko, A M; Khan, M A

2015-01-01

To evaluate the effects of acupuncture integrated into the standard therapy, the condition of cerebral blood flow, and other syndromes associated with cerebral ischemia in the newborn infants. MATERIAL AND METHODS. A total of 131 pairs of puerperae and newborns with hypoxic ischemic encephalopathy were divided into four treatment groups. 34 children of the first group were given standard therapy (control), in the second group comprised of 33 mothers and children the standard treatment was supplemented by acupuncture, the third group included only 32 mothers given the acupuncture treatment alone, and the fourth group contained only 32 newborn infants treated by acupuncture. Each course of acupuncture treatment consisted of five sessions. Sensitivity and specificity of cerebral blood flow reactions were determined based on the results of the ROC-analysis and the area under the curve before and after the treatment. The treatment with the use of acupuncture greatly improved the cerebrospinal hemodynamics (p < 0.05). Other symptoms, viz. sleep disorders, vegetative reactivity and excitability were significantly reduced. The ROC analysis confirmed the effectiveness of acupuncture as a tool for the treatment of the impaired cerebral blood flow in the newborn babies. The high level of sensitivity (84.4-94.8%) associated with good specificity makes it possible to distinguish between the true positive and true negative cases. Acupuncture integrated into the treatment of "mother-baby" pairs presenting with hypoxic ischemic encephalopathy can be used to improve the initially low level of cerebral blood flow in neonates presenting with this condition.

Incarcerated Inguinal Hernia Mesh Repair: Effect on Testicular Blood Flow and Sperm Autoimmunity

PubMed Central

Krnić, Dragan; Družijanić, Nikica; Štula, Ivana; Čapkun, Vesna; Krnić, Duška

2016-01-01

Background The aim of our study was to determine an influence of incarcerated inguinal hernia mesh repair on testicular circulation and to investigate consequent sperm autoimmunity as a possible reason for infertility. Material/Methods This prospective study was performed over a 3-year period, and 50 male patients were included; 25 of these patients underwent elective open mesh hernia repair (Group I). Group II consisted of 25 patients who had surgery for incarcerated inguinal hernia. Doppler ultrasound evaluation of the testicular blood flow and blood samplings for antisperm antibodies (ASA) was performed in all patients before the surgery, on the second day, and 5 months after. Main outcome ultrasound measures were resistive index (RI) and pulsative index (PI), as their values are inversely proportional to testicular blood flow. Results In Group I, RI, and PI temporarily increased after surgery and then returned to basal values in the late postoperative period. Friedman analysis showed a significant difference in RI and PI for all measurements in Group II (p<0.05), with a significant decrease between the preoperative, early, and late postoperative periods. All final values were within reference range, including ASA, despite significant increase of ASA in the late postoperative period. Conclusions Although statistically significant differences in values of testicular flow parameters and immunologic sensitization in observed time, final values remained within the reference ranges in all patients. Our results suggest that the polypropylene mesh probably does not cause any clinically significant effect on testicular flow and immunologic response in both groups of patients. PMID:27149257

Renal embolic protection devices improve blood flow after stenting for atherosclerotic renal artery stenosis.

PubMed

Paul, Timir K; Lee, John H; White, Christopher J

2012-11-15

We sought to measure angiographic renal frame counts (RFC), as a quantitative angiographic assessment of renal blood flow, to evaluate microvascular compromise due to atheroembolism associated with RAS. Atheroembolism associated with renal artery stenting (RAS) has been implicated as a cause for worsening renal function following successful intervention. Use of a distal embolic protection device (EPD) during RAS has been shown to be safe with debris capture in a high percentage of cases. However, objective benefit for renal function with EPD has been difficult to demonstrate. A control group of 30 consecutive patients (33 kidneys) who underwent RAS without EPD were compared with 33 consecutive patients (33 kidneys) who underwent RAS with EPD using RFC measurement. The prestent and poststent mean RFC for the control group was 30.4 ± 12.1 vs. 23.7 ± 9.9 (P = 0.002) and for the EPD group it was 42.6 ± 12.6 vs. 28.3 ± 9.2 (P < 0.0001). The EPD group had a greater improvement in renal blood flow, manifested by a greater reduction of the RFC (Δ RFC) 14.2 ± 15.2 vs. 6.7 ± 11.7 (P = 0.03) compared with the control group. The use of an EPD was associated with a much larger improvement in renal blood flow (lower RFC) following RAS. This suggests that EPD's may be effective in preventing renal atheroembolic injury and that a controlled trial measuring the impact of EPD's on renal blood flow following RAS should be performed. Copyright © 2012 Wiley Periodicals, Inc.

Airway hyperresponsiveness, peak flow variability and inflammatory markers in non-asthmatic subjects with respiratory infections.

PubMed

Björnsson, Eythór; Lúdvíksdóttir, Dóra; Hedenström, Hans; Eriksson, Britt-Marie; Högman, Marieann; Venge, Per; Janson, Christer

2007-07-01

The aim of this study was to characterise non-asthmatic subjects with asthma-like symptoms during a common cold, particularly in relation to airway hyperresponsiveness (AHR). Subjects with acute respiratory infections and a group of controls (n = 20 + 20), age 20-65 years, underwent bronchial provocations with methacholine, adenosine and cold air. All were non-smokers and had no history of asthma or heart disease. Those with infection had asthma-like symptoms (>2). Measurements of exhaled nitric oxide (eNO), serum levels of eosinophil cationic protein (ECP), eosinophil peroxidase, myeloperoxidase and human neutrophil lipocalin were made at each provocation. A 17-day symptom and peak flow diary was calculated. No differences between the two groups were found, regarding responsiveness to methacholine, adenosine or cold air challenge, as well as the inflammatory markers measured. In the infected group, the mean (standard deviation) ECP was higher in those with AHR to methacholine or cold air [15.7 (6.5) and 11.4 (4.2) microg/L, respectively; P < 0.05]; furthermore, eNO was higher in the infected group [116 (54) and 88 (52) nL/min, respectively; P = 0.055]. The infected group had, at all times, more symptoms and higher peak flow, with a decrease in the symptoms (P = 0.02) and a tendency to change in peak flow variation (P = 0.06). AHR does not seem to be the main cause of asthma-like symptoms in adults with infectious wheezing. Peak flow variation and symptom prevalence during the post-infection period may imply airway pathology different from AHR.

Vortex Flow in the Right Atrium Surrogates Supraventricular Arrhythmia and Thrombus After Atriopulmonary Connection-Type Fontan Operation: Vortex Flow Analysis Using Conventional Cine Magnetic Resonance Imaging.

PubMed

Shiina, Yumi; Inai, Kei; Takahashi, Tatsunori; Shimomiya, Yamato; Ishizaki, Umiko; Fukushima, Kenji; Nagao, Michinobu

2018-02-01

We developed a novel imaging technique, designated as vortex flow (VF) mapping, which presents a vortex flow visually on conventional two-dimensional (2D) cine MRI. Using it, we assessed circumferential VF patterns and influences on RA thrombus and supraventricular tachycardia (SVT) in AP connection-type Fontan circulation. Retrospectively, we enrolled 27 consecutive patients (25.1 ± 9.2 years) and 7 age-matched controls who underwent cardiac MRI. Conventional cine images acquired using a 1.5-Tesla scanner were scanned for axial and coronal cross section of the RA. We developed "vortex flow mapping" to demonstrate the ratio of the circumferential voxel movement at each phase to the total movement throughout a cardiac cycle towards the RA center. The maximum ratio was used as a magnitude of vortex flow (MVF%) in RA cine imaging. We also measured percentages of strong and weak VF areas (VFA%). Furthermore, in 10 out of 27, we compared VF between previous CMR (3.8 ± 1.5 years ago) and latest CMR. Of the patients, 15 had cardiovascular complications (Group A); 12 did not (Group B). A transaxial image showed that strong VFA% in Group A was significantly smaller than that in Group B or controls. A coronal view revealed that strong VFA% was also smaller, and weak VFA% was larger in Group A than in Group B or controls (P < 0.05, and P < 0.05). Maximum MVF% in Group A was significantly smaller than in other groups (P < 0.001). Univariate logistic analyses revealed weak VFA% on a coronal image, and serum total bilirubin level as factors affecting cardiovascular complications (Odds ratio 1.14 and 66.1, 95% CI 1.004-1.30 and 1.59-2755.6, P values < 0.05 and < 0.05, respectively). Compared to the previous CMR, smaller maximum VMF%, smaller strong VFA%, and larger weak VFA% were identified in the latest CMR. Circumferentially weak VFA% on a coronal image can be one surrogate marker of SVT and thrombus in AP connection-type Fontan circulation. This simple VF assessment is clinically useful to detect blood stagnation.

Classification of reaches in the Missouri and lower Yellowstone Rivers based on flow characteristics

USGS Publications Warehouse

Pegg, Mark A.; Pierce, Clay L.

2002-01-01

Several aspects of flow have been shown to be important determinants of biological community structure and function in streams, yet direct application of this approach to large rivers has been limited. Using a multivariate approach, we grouped flow gauges into hydrologically similar units in the Missouri and lower Yellowstone Rivers and developed a model based on flow variability parameters that could be used to test hypotheses about the role of flow in determining aquatic community structure. This model could also be used for future comparisons as the hydrological regime changes. A suite of hydrological parameters for the recent, post-impoundment period (1 October 1966–30 September 1996) for each of 15 gauges along the Missouri and lower Yellowstone Rivers were initially used. Preliminary graphical exploration identified five variables for use in further multivariate analyses. Six hydrologically distinct units composed of gauges exhibiting similar flow characteristics were then identified using cluster analysis. Discriminant analyses identified the three most influential variables as flow per unit drainage area, coefficient of variation of mean annual flow, and flow constancy. One surprising result was the relative similarity of flow regimes between the two uppermost and three lowermost gauges, despite large differences in magnitude of flow and separation by roughly 3000 km. Our results synthesize, simplify and interpret the complex changes in flow occurring along the Missouri and lower Yellowstone Rivers, and provide an objective grouping for future tests of how these changes may affect biological communities. 

Simultaneous Moisture Content and Mass Flow Measurements in Wood Chip Flows Using Coupled Dielectric and Impact Sensors.

PubMed

Pan, Pengmin; McDonald, Timothy; Fulton, John; Via, Brian; Hung, John

2016-12-23

An 8-electrode capacitance tomography (ECT) sensor was built and used to measure moisture content (MC) and mass flow of pine chip flows. The device was capable of directly measuring total water quantity in a sample but was sensitive to both dry matter and moisture, and therefore required a second measurement of mass flow to calculate MC. Two means of calculating the mass flow were used: the first being an impact sensor to measure total mass flow, and the second a volumetric approach based on measuring total area occupied by wood in images generated using the capacitance sensor's tomographic mode. Tests were made on 109 groups of wood chips ranging in moisture content from 14% to 120% (dry basis) and wet weight of 280 to 1100 g. Sixty groups were randomly selected as a calibration set, and the remaining were used for validation of the sensor's performance. For the combined capacitance/force transducer system, root mean square errors of prediction (RMSEP) for wet mass flow and moisture content were 13.42% and 16.61%, respectively. RMSEP using the combined volumetric mass flow/capacitance sensor for dry mass flow and moisture content were 22.89% and 24.16%, respectively. Either of the approaches was concluded to be feasible for prediction of moisture content in pine chip flows, but combining the impact and capacitance sensors was easier to implement. In situations where flows could not be impeded, however, the tomographic approach would likely be more useful.

Effect of Hindlimb Unweighting on Tissue Blood Flow in the Rat

NASA Technical Reports Server (NTRS)

McDonald, K. S.; Delp, M. D.; Fitts, R. H.

1992-01-01

The purpose of this study was to characterize the distribution of blood flow in the rat during hindlimb unweighting (HU) and post-HU standing and exercise and examine whether the previously reported elevation in anaerobic metabolism observed with contractile activity in the atrophied soleus muscle was caused by a reduced hindlimb blood flow. After either 15 days of HU or cage control, blood flow was measured with radioactive microspheres during unweighting, normal standing, and running on a treadmill (15 m/min). In another group of control and experimental animals, blood flow was measured during preexercise (PE) treadmill standing and treadmill running (15 m/min). Soleus muscle blood flow was not different between groups during unweighting, PE standing, and running at 15 m/min. Chronic unweighting resulted in the tendency for greater blood flow to muscles composed of predominantly fast-twitch glycolytic fibers. With exercise, blood flow to visceral organs was reduced compared with PE values in the control rats, whereas flow to visceral organs in 15-day HU animals was unaltered by exercise. These higher flows to the viscera and to muscles composed of predominantly fast-twitch glycolytic fibers suggest an apparent reduction in the ability of the sympathetic nervous system to distribute cardiac output after chronic HU. In conclusion, because 15 days of HU did not affect blood flow to the soleus during exercise, the increased dependence of the atrophied soleus on anerobic energy production during contractile activity cannot be explained by a reduced muscle blood flow.

Relationship between the Direction of Ophthalmic Artery Blood Flow and Ocular Microcirculation before and after Carotid Artery Stenting.

PubMed

Ishii, Masashi; Hayashi, Morito; Yagi, Fumihiko; Sato, Kenichiro; Tomita, Goji; Iwabuchi, Satoshi

2016-01-01

When internal carotid artery stenosis is accompanied by ocular ischemic syndrome, intervention is recommended to prevent irreversible visual loss. In this study, we used laser speckle flowgraphy to measure the ocular microcirculation in the optic nerve head before and after carotid artery stenting (CAS) of 40 advanced internal carotid stenosis lesions from 37 patients. The aim was to investigate the relationship between ocular microcirculation and the direction of ophthalmic artery blood flow obtained by angiography. We found that there was a significant increase in blood flow after CAS ( P = 0.003). Peak systolic velocity as an indicator of the rate of stenosis was also significantly higher in the group with retrograde/undetected flow of the ophthalmic artery than in the group with antegrade flow ( P = 0.002). In all cases where retrograde flow of the ophthalmic artery was observed before stenting, the flow changed to antegrade after stenting. Through the use of laser speckle flowgraphy, this study found that CAS can improve ocular microcirculation. Furthermore, while patients displaying retrograde flow of the ophthalmic artery before stenting have a poor prognosis, CAS corrected the flow to antegrade, suggesting that visual loss can be prevented by improving the ocular microcirculation.

Exquisite Moments: Achieving Optimal Flow in Three Activity-Based Groups Regardless of Early-Childhood Adversity

ERIC Educational Resources Information Center

Thomson, Paula; Jaque, S. Victoria

2016-01-01

Flow experiences (also known as optimal performance) occur when people engage in activities they enjoy. The authors discuss such events in their study that examined a number of healthy, active individuals (performing artists, athletes, and others engaged in a range of recreational activities) and divided these into three groups based on adverse…

A Comparative Study on Quantitative Assessment of Blood Flow and Vascularization in Polycystic Ovary Syndrome Patients and Normal Women Using Three-Dimensional Power Doppler Ultrasonography.

PubMed

Garg, Nitasha; Khaira, Harkiran Kaur; Kaur, Manjot; Sinha, Smita

2018-04-01

To compare the quantitative assessment of blood flow and vascularization of ovaries in polycystic ovary syndrome patients and normal women using three-dimensional power Doppler ultrasonography. This cross-sectional quantitative study was conducted on women of reproductive age group (15-45 years) attending Gynaecology OPD AIMSR, Bathinda, Punjab. Thirty women were enrolled in polycystic ovarian syndrome (PCOS) group and 30 healthy women in control group. Women were categorized as polycystic ovary syndrome according to Rotterdam's criteria. The women with PCOS underwent transvaginal USG Doppler on day 6 of the cycle using 3D power Doppler USG equipment (GE Voluson E8), and vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were measured. The mean values of VI, FI and VFI measured by power Doppler ultrasonography were significantly increased ( P value = 0.000) in women with PCOS when compared with healthy women. This study suggests that blood flow and vascularization measured by 3D power Doppler ultrasonography in ovaries of polycystic ovary syndrome patients were significantly more than the ovaries of normal women.

Relationship between vertebral artery blood flow in different head positions and vertigo.

PubMed

Araz Server, Ela; Edizer, Deniz Tuna; Yiğit, Özgür; Yasak, Ahmet Görkem; Erdim, Çağrı

2018-01-01

To identify the vertebral artery blood flow in different head positions in patients with positional vertigo with no specific diagnosis. Patients with history of vestibular symptoms associated with changes in head position were enrolled into the study. Healthy volunteers were evaluated as control group. Doppler ultrasonography examination of the cervical segment of the vertebral arteries was performed under three different head positions: (i) supine position, (ii) head hyperextended and rotated to the right side and (iii) head hyperextended and rotated to the left side. In the study group, right and left vertebral artery blood flow was significantly lower in the ipsilateral hyperextended position compared to standard supine position (respectively p = .014; p = .001), but did not differ significantly when compared between the standard supine and contralateral hyperextended positions (respectively = .959; p = .669). In the control group, left and right vertebral artery blood flow did not differ significantly when the head was hyperextended to the right or left sides compared to standard supine position (p > .05). Our data demonstrated that the etiology of vestibular complaints in patients with undiagnosed positional vertigo might be related to impairment in vertebral artery blood flow according to head positions.

Salivary secretory IgA, pH, flow rates, mutans streptococci and Candida in children with rampant caries.

PubMed

Thaweboon, Sroisiri; Thaweboon, Boonyanit; Nakornchai, Siriruk; Jitmaitree, Sukritta

2008-09-01

The aim of this study was to determine the levels of secretory IgA (SIgA), pH, flow rates, mutans streptococci (MS) and Candida in saliva of children with rampant caries compared to those caries-free. Thirty children (age 62-123 months) were enrolled and divided into two groups: Group I, children with rampant caries, Group II, caries-free children. The average salivary flow rate was measured from the volume yielded within 5 minutes and the pH was determined using a pH-electrode. Measurement of SIgA was performed using an immunoassay kit. The levels of MS and Candida were determined by culture on Mitis-Salivarius Bacitracin agar and Sabouraud dextrose agar. It was found that children with rampant caries presented with significantly higher levels of salivary SIgA, MS and Candida. However, the mean values for salivary flow rates and pH were similar between the groups. The results reveal that children with rampant caries had significantly higher levels of SIgA, MS and Candida in their oral cavities. This finding tends to support the hypothesis that higher levels of salivary SIgA may reflect a past exposure of the host to cariogenic microorganisms.

Leptomeningeal metastases: a RANO proposal for response criteria

PubMed Central

Junck, Larry; Brandsma, Dieta; Soffietti, Riccardo; Rudà, Roberta; Raizer, Jeffrey; Boogerd, Willem; Taillibert, Sophie; Groves, Morris D.; Rhun, Emilie Le; Walker, Julie; van den Bent, Martin; Wen, Patrick Y.; Jaeckle, Kurt A.

2017-01-01

Abstract Leptomeningeal metastases (LM) currently lack standardization with respect to response assessment. A Response Assessment in Neuro-Oncology (RANO) working group with expertise in LM developed a consensus proposal for evaluating patients treated for this disease. Three basic elements in assessing response in LM are proposed: a standardized neurological examination, cerebral spinal fluid (CSF) cytology or flow cytometry, and radiographic evaluation. The group recommends that all patients enrolling in clinical trials undergo CSF analysis (cytology in all cancers; flow cytometry in hematologic cancers), complete contrast-enhanced neuraxis MRI, and in instances of planned intra-CSF therapy, radioisotope CSF flow studies. In conjunction with the RANO Neurological Assessment working group, a standardized instrument was created for assessing the neurological exam in patients with LM. Considering that most lesions in LM are nonmeasurable and that assessment of neuroimaging in LM is subjective, neuroimaging is graded as stable, progressive, or improved using a novel radiological LM response scorecard. Radiographic disease progression in isolation (ie, negative CSF cytology/flow cytometry and stable neurological assessment) would be defined as LM disease progression. The RANO LM working group has proposed a method of response evaluation for patients with LM that will require further testing, validation, and likely refinement with use. PMID:28039364

Expiratory flow limitation and operating lung volumes during exercise in older and younger adults.

PubMed

Smith, Joshua R; Kurti, Stephanie P; Meskimen, Kayla; Harms, Craig A

2017-06-01

We determined the effect of aging on expiratory flow limitation (EFL) and operating lung volumes when matched for lung size. We hypothesized that older adults will exhibit greater EFL and increases in EELV during exercise compared to younger controls. Ten older (5M/5W; >60years old) and nineteen height-matched young adults (10M/9W) were recruited. Young adults were matched for%predicted forced vital capacity (FVC) (Y-matched%Pred FVC; n=10) and absolute FVC (Y-matched FVC; n=10). Tidal flow-volume loops were recorded during the incremental exercise test with maximal flow-volume loops measured pre- and post-exercise. Compared to younger controls, older adults exhibited more EFL at ventilations of 26, 35, 51, and 80L/min. The older group had higher end-inspiratory lung volume compared to Y-matched%Pred FVC group during submaximal ventilations. The older group increased EELV during exercise, while EELV stayed below resting in the Y-matched%Pred FVC group. These data suggest older adults exhibit more EFL and increase EELV earlier during exercise compared to younger adults. Copyright © 2017 Elsevier B.V. All rights reserved.

Doppler color flow analysis of the uterine arteries before and after intrauterine device insertion: a prospective study.

PubMed

de Souza, Marco Aurélio Martins; Geber, Selmo

2006-02-01

An intrauterine device (IUD) is one of the most frequently used methods of birth control around the world. Although a relationship between its use and menstrual disorders has been well documented, only a few studies have tried to show whether there are any vascular modifications. The aim of our study was to evaluate the influence of an IUD on uterine artery blood flow using Doppler assessment. A total of 100 patients selected for IUD use were prospectively evaluated with Doppler analysis before and 30 days after insertion. The resistive index (RI) and pulsatility index (PI) were used to evaluate uterine artery vascular resistance. Patients were allocated in 2 groups according to whether they were (group 2) or were not (group 1) lactating. The PI and RI of the patients in groups 1 and 2 before and after IUD insertion were not statistically significantly different (P = .298 and .23). When we compared uterine artery blood flow indices before and after IUD insertion for groups 1 and 2 separately, we observed in group 1 that the mean +/- SD PI values were 2.45 +/- 0.62 and 2.55 +/- 0.55 (P = .38) and the RI values were 0.87 +/- 0.08 and 0.87 +/- 0.06 (P = .88) before and after IUD insertion, respectively. In group 2, the PI values were 2.31 +/- 0.55 and 2.37 +/- 0.69 (P = .68) and the RI values were 0.85 +/- 0.07 and 0.86 +/- 0.07 (P = .44) before and after IUD insertion. Finally, we used the mean blood flow indices of the uterine arteries of all patients to compare the effect of IUD insertion. Results were also not statistically significant when we compared PI and RI before and after IUD insertion. The presence of an IUD does not interfere with the vascular resistance of the uterine arteries that can be shown by Doppler flow assessments 1 month after insertion.

[Effects of electro-acupuncture at Zusanli point on gastric and intestinal blood flow in rats with acute necrotizing pancreatitis].

PubMed

Bai, Lu; Zhu, Lin; Tang, Wen-Fu; Wan, Mei-Hua; Huang, Wei; Chen, Guang-Yuan

2013-11-01

To investigate the effects of electro-acupuncture (EA) at Zusanli point on gastric and intestinal blood flow and serum endothelin-1(ET-1), nitricoxide(NO), thromboxaneB2 (TXB2), 6-keto-prostaglandin F1alpha (6-K-PGF1alpha) in rats with acute necrotizing pancreatitis (ANP). Thirty-six male Sprague Dawley (SD) rats were randomly divided into sham operation (sham), ANP and EA groups (n = 12). ANP model was induced by retrograde injection of 5% sodium taurocholate into pancreaticobiliary. EA was applied to Zusanli for 30 min at 2 h and 6 h after the operation in EA group. Gastric and intestinal mucosal blood flow was measured by laser doppler flowmetry (LDF) at 12 h and 24 h after operation, while the levels of serum ET-1, NO, TXB2 and 6-K-PGF1alpha were detected. The gastric and intestinal blood flow in ANP rats were significantly lower than those in the sham group (P < 0.05), but those of EA groups were higher than those in ANP groups (P < 0.05). The serum ET-1, NO and ET-1/NO levels in ANP group were increased when compared with SO group (P < 0.05). After the electro-acupuncture treatment at Zusanli point, the levels of ET-1, NO and ET-1/N were decreased, and there were significant differences of ET-1 (at 12 h, 24 h), NO (at 12 h) and ET-1/NO (at 24 h) between EA and ANP group (P < 0.05). The levels of serum TXB2, 6-K-PGF1alpha and TXB2/6-K-PGF1alpha in ANP group were also increased (P < 0.05), but those in EA group were decreased, and there were significant differences of TXB2 (at 12 h, 24 h), 6-K-PGF1alpha (at 12 h) and TXB2/6-K-PGF1alpha (at 24 h) compared with ANP groups (P < 0.05). Electro-acupuncture at Zusanli point can significantly improve the gastric and intestinal mucosa blood flow in ANP rats, which may be related to the regulation of serum ET-1, NO, TXB2, 6-K-PGF1alpha.

Age discrimination among basalt flows using digitally enhanced LANDSAT imagery. [Saudi Arabia

NASA Technical Reports Server (NTRS)

Blodget, H. W.; Brown, G. F.

1984-01-01

Digitally enhanced LANDSAT MSS data were used to discriminate among basalt flows of historical to Tertiary age, at a test site in Northwestern Saudi Arabia. Spectral signatures compared favorably with a field-defined classification that permits discrimination among five groups of basalt flows on the basis of geomorphic criteria. Characteristics that contributed to age definition include: surface texture, weathering, color, drainage evolution, and khabrah development. The inherent gradation in the evolution of geomorphic parameters, however, makes visual extrapolation between areas subjective. Therefore, incorporation of spectrally-derived volcanic units into the mapping process should produce more quantitatively consistent age groupings.

Effect of anti-vertigo granule on the opening number and blood flow of mouse ear capillary network

NASA Astrophysics Data System (ADS)

Li, Chongxian; Liu, Xiaobin; Li, Jun; Hao, Shaojun; Wang, Xidong; Li, Wenjun; Zhang, Zhengchen

2018-04-01

To observe the effects of anti-glare particles on the open number and blood flow in the auricle of mice with microcirculation disturbance model. Sixty mice, half male and half female, were randomly divided into 6 groups. The mice were given Kangxuan granule suspension, serum brain granule suspension and normal saline of the same volume, respectively, once a day. The mice were anesthetized by intraperitoneal injection of chloral hydrate at 1 hour after the last administration. The mouse was fixed on the observation platform and the auricle was placed on the transmission stage. BZ-2000 microcirculation microscope and microcirculation analysis system were used to observe the changes of blood velocity and capillary opening volume in auricle of mice before administration. The changes of blood velocity and capillaries opening volume of mouse auricle were observed 2 min after epinephrine injection into tail vein of mice. Bear fruit: Compared with those before epinephrine, the opening number of capillary reticulum of auricle in large dose Kangxuan granule group was significantly decreased (P<0.05), and in normal saline group and middle group. In the small dose Kangxuan granule group, the opening number of capillary network of auricle decreased significantly (P<0.01). Compared with the model group, the large dose Kangxuan granule group could significantly increase the opening number of the auricle capillary network in mice (P<0.01). Yangxuannao granule group could significantly increase the opening number of auricle capillary reticulum in mice (P<0.05), compared with the model group by Ridit test. Both Kangxuan granule group and Yangxuannao granule group could significantly improve the auricle hair of mice with microcirculation disorder. The blood flow in fine blood vessels (P<0.01). Kangxuan granule has a good effect on the opening number of capillary network of auricle and blood flow in mice with microcirculation disorder.

Ovarian parameters and ovarian blood flow of women living in the area of environmental crisis.

PubMed

Balmagambetova, Aru; Abdelazim, Ibrahim A; Bekmukhambetov, Erbol; Zhurabekova, Gulmira; Yehia, Amr H; AbuFaza, Mohannad

2016-05-01

Exposure to environmental hazards will destroy a number of ovarian primordial follicles, reduce ovarian reserve and subsequent reproductive ability. This study designed to evaluate ovarian parameters and ovarian blood flow of women living in the area of environmental crisis Shalkar city (Kazakhstan) compared to women living in Aktobe city (Kazakhstan). 220 women in their reproductive age studied and classified into two groups; study (Shalkar) group and control (Aktobe) group. Blood sample taken from studied women during follicular phase (day 3) for hormonal level evaluation including; follicle stimulating hormone (FSH) and anti-Mullerian hormone (AMH). Studied women evaluated using trans-vaginal ultrasound (TVS) to detect antral follicle count (AFC) during follicular scan and ovarian volume (OV), ovarian blood flow (OBF) using pulsatility index (PI) during follicular scan and luteal scan. Both ovaries AFC was significantly less in study (Shalkar) group compared to and control (Aktobe) group (p=0.0001). Mean ovarian volume was significantly less in Shalkar group in both follicular phase and luteal phase (5.86±0.23 and 6.19±0.22Cm(3); respectively) compared to Aktobe group (6.85±0.19 and 6.92±0.18Cm(3); respectively). In addition, mean ovarian pulsatility index was significantly high with subsequent decrease in ovarian blood flow in Shalkar group in both follicular phase and luteal phase (3.36±0.20 and 3.45±0.19Cm/s; respectively) compared to Aktobe group (2.96±0.16 and 2.92±0.15Cm/s; respectively). This study suggests definite environmental effect on ovarian parameters as indicated by decreased AFC, decreased both follicular and luteal OV and OBF in women living in environmental crisis Shalkar group compared to Aktobe group. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Generalizations of holographic renormalization group flows

NASA Astrophysics Data System (ADS)

Suh, Minwoo

The AdS/CFT correspondence conjectures the duality between type IIB supergravity on AdS5 × S5 and N = 4 super Yang-Mills theory. Mass deformations of N = 4 super Yang-Mills theory drive renormalization group (RG) flows. Holographic RG flows are described by domain wall solutions interpolating between AdS5 geometries at critical points of N = 8 gauged supergravity in five dimensions. In this thesis we study two directions of generalizations of holographic RG flows. First, motivated by the Janus solutions, we study holographic RG flows with dilaton and axion fields. To be specific, we consider the SU (3)-invariant flow with dilaton and axion fields, and discover the known supersymmetric Janus solution in five dimensions. Then, by employing the lift ansatz, we uplift the supersymmetric Janus solution of the SU(3)-invariant truncation with dilaton and axion fields to a solution of type IIB supergravity. We identify the uplifted solution to be one of the known supersymmetric Janus solution in type IIB supergravity. Furthermore, we consider the SU(2) × U(1)-invariant N = 2 and N = 1 supersymmetric flows with dilaton and axion fields. Second, motivated by the development in AdS/CMT, we study holographic RG flows with gauge fields. We consider the SU(3)-invariant flow with electric potentials or magnetic fields, and find first-order systems of flow equations for each case.

Abnormal early diastolic intraventricular flow 'kinetic energy index' assessed by vector flow mapping in patients with elevated filling pressure.

PubMed

Nogami, Yoshie; Ishizu, Tomoko; Atsumi, Akiko; Yamamoto, Masayoshi; Kawamura, Ryo; Seo, Yoshihiro; Aonuma, Kazutaka

2013-03-01

Recently developed vector flow mapping (VFM) enables evaluation of local flow dynamics without angle dependency. This study used VFM to evaluate quantitatively the index of intraventricular haemodynamic kinetic energy in patients with left ventricular (LV) diastolic dysfunction and to compare those with normal subjects. We studied 25 patients with estimated high left atrial (LA) pressure (pseudonormal: PN group) and 36 normal subjects (control group). Left ventricle was divided into basal, mid, and apical segments. Intraventricular haemodynamic energy was evaluated in the dimension of speed, and it was defined as the kinetic energy index. We calculated this index and created time-energy index curves. The time interval from electrocardiogram (ECG) R wave to peak index was measured, and time differences of the peak index between basal and other segments were defined as ΔT-mid and ΔT-apex. In both groups, early diastolic peak kinetic energy index in mid and apical segments was significantly lower than that in the basal segment. Time to peak index did not differ in apex, mid, and basal segments in the control group but was significantly longer in the apex than that in the basal segment in the PN group. ΔT-mid and ΔT-apex were significantly larger in the PN group than the control group. Multiple regression analysis showed sphericity index, E/E' to be significant independent variables determining ΔT apex. Retarded apical kinetic energy fluid dynamics were detected using VFM and were closely associated with LV spherical remodelling in patients with high LA pressure.

Direct visualization of pancreatic juice flow using unenhanced MRI with spin labeling can be aid in diagnosing chronic pancreatitis.

PubMed

Sugita, Reiji; Furuta, Akemi; Yamazaki, Tetsuro; Itoh, Kei; Fujita, Naotaka; Takahashi, Shoki

2014-05-01

The purpose of this study is to prospectively assess whether direct visualization of pancreatic juice flow using an unenhanced MRI technique with spin labeling can aid in the diagnosis of chronic pancreatitis. Ten healthy volunteers and 50 patients who were categorized as having no chronic pancreatitis (n = 11), early chronic pancreatitis (n = 7), or established chronic pancreatitis (n = 32) underwent MRI, including direct pancreatic juice visualization using a flow-out technique with a time-spatial labeling inversion pulse, comprising a nonselective inversion recovery pulse immediately followed by a spatially selective inversion labeling pulse. The mean velocities and volumes of pancreatic juice excretion were also obtained. Variance tests were used to evaluate the clinical groups with respect to the appearance rate and mean velocity; the Kruskal-Wallis test was used for volume. There were no significant differences between healthy volunteers and patients with no chronic pancreatitis. The appearance rate, mean velocity, and volume of pancreatic juice excretion tended to decrease with the degree of chronic pancreatitis. Although the difference in these values was statistically significant between the healthy group and the established chronic pancreatitis group, the values of the early group and other groups were not statistically significant. There was a significant correlation between the appearance rate of pancreatic juice and the clinical groups (τ = -0.4376, p = 0.0015). The measurement of directly visualized pancreatic juice flow may aid in establishing the diagnosis of chronic pancreatitis.

Effect of a single injection of gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) on testicular blood flow measured by color doppler ultrasonography in male Shiba goats

PubMed Central

SAMIR, Haney; SASAKI, Kazuaki; AHMED, Eman; KAREN, Aly; NAGAOKA, Kentaro; EL SAYED, Mohamed; TAYA, Kazuyoshi; WATANABE, Gen

2015-01-01

Although color Doppler ultrasonography has been used to evaluate testicular blood flow in many species, very little has been done in goat. Eight male Shiba goats were exposed to a single intramuscular injection of either gonadotropin-releasing hormone (GnRH group; 1 µg/kg BW) or human chorionic gonadotropin (hCG group; 25 IU/kg BW). Plasma testosterone (T), estradiol (E2) and inhibin (INH) were measured just before (0 hr) and at different intervals post injection by radioimmunoassay. Testis volume (TV) and Doppler indices, such as resistive index (RI) and pulsatility index (PI) of the supratesticular artery, were measured by B-mode and color Doppler ultrasonography, respectively. The results indicated an increase in testicular blood flow in both groups, as RI and PI decreased significantly (P<0.05), but this increase was significant higher and earlier in hCG group (1 hr) than in the GnRH group (2 hr). A high correlation was found for RI and PI with both T (RI, r= −0.862; PI, r= −0.707) and INH in the GnRH group (RI, r=0.661; PI, r=0.701). However, a significant (P<0.05) correlation was found between E2 and both RI (r= −0.610) and PI (r= −0.763) in hCG group. In addition, TV significantly increased and was highly correlated with RI in both groups (GnRH, r= −0.718; hCG, r= −0.779). In conclusion, hCG and GnRH may improve testicular blood flow and TV in Shiba goats. PMID:25715956

Oral manifestations of diabetes mellitus in complete denture wearers.

PubMed

Cristina de Lima, Danielle; Nakata, Gislaine Cristina; Balducci, Ivan; Almeida, Janete Dias

2008-01-01

The oral mucosa has been reported to show a variety of changes in subjects with diabetes mellitus. The purpose of this study was to compare diabetic and nondiabetic subjects wearing complete dentures with regard to salivary flow, salivary buffering capacity, denture retention, and oral mucosal lesions. Sixty subjects, 30 with and 30 without a diagnosis of diabetes, were matched for gender, race, and age. Salivary flow, salivary buffering capacity, glycemia, blood pressure, presence of mucosal lesions, denture retention, use of medications, and behavioral factors (controlled or uncontrolled diet, alcohol consumption, and smoking) reported by the subjects, were evaluated. For the salivary buffering capacity test, 1 mL of saliva was pipetted into a test tube containing 3 mL 0.005 N of hydrochloric acid, and the pH was measured with indicator strips. Group differences were statistically analyzed using the Student t test and the Mann-Whitney test for quantitative variables and the chi-square test for qualitative variables (alpha =.05). Mean (SD) salivary flow was 1.14 (0.87) mL/min in the nondiabetic subjects and 0.95 (0.61) mL/min in the diabetic subjects. Evaluation of self-reported denture retention revealed no significant difference between groups. Denture retention was observed in 66.7% (20/30) of the control group and in 50% (15/30) of the diabetic group. The prevalence of mucosal lesions was 90% (27/30) in the control group and 83.3% (25/30) in the diabetic group. Salivary buffering capacity was 5.80 (0.85) in the control group and 5.26 (0.83) in the diabetic group (P=.017). Within the limitations of this study, no significant differences were observed in salivary flow, denture retention, or oral lesions in diabetic and nondiabetic subjects.

Efficacy of blood flow restriction exercise during dialysis for end stage kidney disease patients: protocol of a randomised controlled trial.

PubMed

Clarkson, Matthew J; Fraser, Steve F; Bennett, Paul N; McMahon, Lawrence P; Brumby, Catherine; Warmington, Stuart A

2017-09-11

Exercise during haemodialysis improves strength and physical function. However, both patients and clinicians are time poor, and current exercise recommendations add an excessive time burden making exercise a rare addition to standard care. Hypothetically, blood flow restriction exercise performed during haemodialysis can provide greater value for time spent exercising, reducing this time burden while producing similar or greater outcomes. This study will explore the efficacy of blood flow restriction exercise for enhancing strength and physical function among haemodialysis patients. This is a randomised controlled trial design. A total of 75 participants will be recruited from haemodialysis clinics. Participants will be allocated to a blood flow restriction cycling group, traditional cycling group or usual care control group. Both exercising groups will complete 3 months of cycling exercise, performed intradialytically, three times per week. The blood flow restriction cycling group will complete two 10-min cycling bouts separated by a 20-min rest at a subjective effort of 15 on a 6 to 20 rating scale. This will be done with pressurised cuffs fitted proximally on the active limbs during exercise at 50% of a pre-determined limb occlusion pressure. The traditional cycling group will perform a continuous 20-min bout of exercise at a subjective effort of 12 on the same subjective effort scale. These workloads and volumes are equivalent and allow for comparison of a common blood flow restriction aerobic exercise prescription and a traditional aerobic exercise prescription. The primary outcome measures are lower limb strength, assessed by a three repetition maximum leg extension test, as well as objective measures of physical function: six-minute walk test, 30-s sit to stand, and timed up and go. Secondary outcome measures include thigh muscle cross sectional area, body composition, routine pathology, quality of life, and physical activity engagement. This study will determine the efficacy of blood flow restriction exercise among dialysis patients for improving key physiological outcomes that impact independence and quality of life, with reduced burden on patients. This may have broader implications for other clinical populations with similarly declining muscle health and physical function, and those contraindicated to higher intensities of exercise. Australian and New Zealand Clinical Trial Register: ACTRN12616000121460.

40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and...

Code of Federal Regulations, 2012 CFR

2012-07-01

... collected—PR. d,e Carbon Adsorber f a. Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) during carbon bed regeneration cycle(s), and 1. Record the total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle.2. Record and report the total...

40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

Code of Federal Regulations, 2012 CFR

2012-07-01

... collected—PR. d,e Carbon adsorber f a. Total regeneration steam flow or nitrogen flow, or pressure gauge or absolute) during carbon bed regeneration cycle(s), and 1. Record of total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle. 2. Record and report the total...

40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

Code of Federal Regulations, 2011 CFR

2011-07-01

... collected—PR. d,e Carbon adsorber f a. Total regeneration steam flow or nitrogen flow, or pressure gauge or absolute) during carbon bed regeneration cycle(s), and 1. Record of total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle. 2. Record and report the total...

40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and...

Code of Federal Regulations, 2010 CFR

2010-07-01

... collected—PR. d,e Carbon Adsorber f a. Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) during carbon bed regeneration cycle(s), and 1. Record the total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle.2. Record and report the total...

40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

Code of Federal Regulations, 2013 CFR

2013-07-01

... collected—PR. d,e Carbon adsorber f a. Total regeneration steam flow or nitrogen flow, or pressure gauge or absolute) during carbon bed regeneration cycle(s), and 1. Record of total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle. 2. Record and report the total...

40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

Code of Federal Regulations, 2010 CFR

2010-07-01

... collected—PR. d,e Carbon adsorber f a. Total regeneration steam flow or nitrogen flow, or pressure gauge or absolute) during carbon bed regeneration cycle(s), and 1. Record of total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle. 2. Record and report the total...

40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and...

Code of Federal Regulations, 2013 CFR

2013-07-01

... collected—PR. d,e Carbon Adsorber f a. Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) during carbon bed regeneration cycle(s), and 1. Record the total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle.2. Record and report the total...

40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and...

Code of Federal Regulations, 2011 CFR

2011-07-01

... collected—PR. d,e Carbon Adsorber f a. Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) during carbon bed regeneration cycle(s), and 1. Record the total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle.2. Record and report the total...

40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

Code of Federal Regulations, 2014 CFR

2014-07-01

... collected—PR. d e Carbon adsorber f a. Total regeneration steam flow or nitrogen flow, or pressure gauge or absolute) during carbon bed regeneration cycle(s), and 1. Record of total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle. 2. Record and report the total...

40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and...

Code of Federal Regulations, 2014 CFR

2014-07-01

... collected—PR. d e Carbon Adsorber f a. Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) during carbon bed regeneration cycle(s), and 1. Record the total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle.2. Record and report the total...

Conceptualizing how group singing may enhance quality of life with Parkinson's disease.

PubMed

Buetow, Stephen A; Talmage, Alison; McCann, Clare; Fogg, Laura; Purdy, Suzanne

2014-01-01

Abstract Purpose: Group singing could be a promising component of neurorehabilitative care. This article aims to conceptualize how group singing may enable people with Parkinson's disease (PD) to synchronize their movement patterns to musical rhythm and enhance quality of life. Spanning the medical and social sciences, the article draws conceptually on literature on PD, group singing and rhythm in music; personal experience; and reasoning. Conceptualizing PD in terms of disruptions to social and biological rhythms, we hypothesize how group singing may produce two socio-psychological states - connectedness and flow - that may entrain rhythm in people with PD. The states connect during group singing to elicit and enhance motor processes but may also reawaken after the group singing, through the recall and reactivation of the musical rhythms encoded during group singing. In people with PD, this continuity of flow is hypothesized to be conducive to rhythmic entrainment during and after group singing and in turn to reduced deficits in motor timing and emotional processing, and improvements in quality of life. Empirical studies are needed to test this hypothesis in people with movement disorders such as PD. Implications for Rehabilitation Musical rhythm in group singing may enhance quality of life, and rehabilitation, in people with PD. Use group singing to produce two socio-psychological states - connectedness and flow - that may yield these health benefits. Include people with PD in singing groups to facilitate perceptual exposure to familiar music with melodic distinctiveness and a regular beat.

Comparison between Saline Solution Containing Heparin versus Saline Solution in the Lock of Totally Implantable Catheters.

PubMed

Brito, Antonio Rafael de Oliveira; Nishinari, Kenji; Saad, Paulo Fernandes; Saad, Karen Ruggeri; Pereira, Monica Aparecida Tomé; Emídio, Suellen Cristina Dias; Yazbek, Guilherme; Bomfim, Guilherme Andre Zottele; Cavalcante, Rafael Noronha; Krutman, Mariana; Teivelis, Marcelo Passos; Pignataro, Bruno Soriano; Fonseca, Igor Yoshio Imagawa; Centofanti, Guilherme; Soares, Bruno Leonardo Freitas

2018-02-01

There are only 3 studies comparing the efficacy of 2 different types of lock used in totally implantable catheters regarding occlusion or reflux dysfunction. The present study contains the largest published casuistry (862 patients) and is the only one that analyzes 3 parameters: occlusion, reflux dysfunction, and flow dysfunction. This was a retrospective study of patients operated at a large oncology center and followed up in the outpatient clinic between 2007 and 2015. The patients were divided into 2 groups according to the type of lock: the Hep group (heparine), whose lock was composed of saline solution 0.9% with heparin (100 IU/mL) and the SS group (saline solution), whose lock was composed of saline solution 0.9%. The Hep group was composed of 270 patients (31%) and the SS group of 592 patients (69%). Regarding occlusion, there were 8 cases in the Hep group (2.96%) and 8 in the SS group (1.35%; P = 0.11); in relation to reflux dysfunction, there were 8 cases in the Hep group (2.96%) and 8 in the SS group (1.35%; P = 0.11); in relation to flow dysfunction, there was 1 case in the Hep group (0.37%) and 4 cases in the SS group (0.68%; P = 1). There was no statistically significant difference between the groups regarding occlusion, reflux dysfunction, and flow dysfunction. Copyright © 2017 Elsevier Inc. All rights reserved.

[Antegrade diastolic blood flow and classic reflux in varicose dilatation of the intersaphenous vein].

PubMed

Shaidakov, E V; Rosukhovsky, D A; Grigoryan, A G; Bulatov, V L; Ilyukhin, E A

2016-01-01

In the intersaphenous vein (ISV) there may take place the so-called "antegrade" or "paradoxical" reflux. This type of blood flow is revealed in a series of patients during muscular diastole and is a link of the pathogenesis of varicose disease, but has, as distinct from the "classical" reflux, an antegrade direction. An incompetent saphenopopliteal junction (SPJ) is a source of the antegrade diastolic blood flow (ADBF) through the ISV. Descriptions of possible variants of impaired blood flow through the ISV are fragmentary and their interpretations are controversial. Prevalence and pathogenesis of these disorders impairments have not yet been studied. A cross-sectional study: over 4 years three centres examined a total of 1,413 patients diagnosed with class C2-C6 varicose veins according the CEAP classification. All patients underwent ultrasound duplex scanning of lower limb veins. The ADBF was determined as a unidirectional antegrade blood flow with the duration of not more than 0.5 second, observed after the crus was relived of compression (in the diastole). Of the patients included into the study who had no varicose veins on the contralateral extremity with the ISV being spotted we sequentially selected 40 subjects including them into the Study Group for the analysis of blood flow and the diameter of the ISV in health. Impairments of blood flow in the ISV were revealed in 61 (4.8%) of 1,265 extremities included into the study: the "classical" reflux in 9 (14.8%) limbs, ADBF was revealed in 37 (60.7%) limbs, a combination of the "classical" blood flow and ADBF - in 15 (24.6%) limbs. Hence, the patients were subdivided into three groups. Studying the nature of blood flow through the ISV in the control group on 40 lower limbs revealed no blood flow disorders. The mean ISV diameter amounted to 1.68 mm (ME=1 mm). The ISV diameter was considerably higher in all studied groups as compared with the control one (p<0.0001). The diameter of the ISV in its proximal portion averagely amounted to 4.48 mm (SD 1.337 mm, SE 0.171 mm). The diameter in the distal portion amounted to 5.39 mm (SD 1.725 mm, SE 0.221 mm).

Creativity and Flow in Musical Composition: An Empirical Investigation

ERIC Educational Resources Information Center

MacDonald, Raymond; Byrne, Charles; Carlton, Lana

2006-01-01

Although an extensive literature exists on creativity and music, there is a lack of published research investigating possible links between musical creativity and Csikszentmihalyi's concept of flow or optimal experience. This article examines a group composition task to study the relationships between creativity, flow and the quality of the…

Application of nonlinear-regression methods to a ground-water flow model of the Albuquerque Basin, New Mexico

USGS Publications Warehouse

Tiedeman, C.R.; Kernodle, J.M.; McAda, D.P.

1998-01-01

This report documents the application of nonlinear-regression methods to a numerical model of ground-water flow in the Albuquerque Basin, New Mexico. In the Albuquerque Basin, ground water is the primary source for most water uses. Ground-water withdrawal has steadily increased since the 1940's, resulting in large declines in water levels in the Albuquerque area. A ground-water flow model was developed in 1994 and revised and updated in 1995 for the purpose of managing basin ground- water resources. In the work presented here, nonlinear-regression methods were applied to a modified version of the previous flow model. Goals of this work were to use regression methods to calibrate the model with each of six different configurations of the basin subsurface and to assess and compare optimal parameter estimates, model fit, and model error among the resulting calibrations. The Albuquerque Basin is one in a series of north trending structural basins within the Rio Grande Rift, a region of Cenozoic crustal extension. Mountains, uplifts, and fault zones bound the basin, and rock units within the basin include pre-Santa Fe Group deposits, Tertiary Santa Fe Group basin fill, and post-Santa Fe Group volcanics and sediments. The Santa Fe Group is greater than 14,000 feet (ft) thick in the central part of the basin. During deposition of the Santa Fe Group, crustal extension resulted in development of north trending normal faults with vertical displacements of as much as 30,000 ft. Ground-water flow in the Albuquerque Basin occurs primarily in the Santa Fe Group and post-Santa Fe Group deposits. Water flows between the ground-water system and surface-water bodies in the inner valley of the basin, where the Rio Grande, a network of interconnected canals and drains, and Cochiti Reservoir are located. Recharge to the ground-water flow system occurs as infiltration of precipitation along mountain fronts and infiltration of stream water along tributaries to the Rio Grande; subsurface flow from adjacent regions; irrigation and septic field seepage; and leakage through the Rio Grande, canal, and Cochiti Reservoir beds. Ground water is discharged from the basin by withdrawal; evapotranspiration; subsurface flow; and flow to the Rio Grande, canals, and drains. The transient, three-dimensional numerical model of ground-water flow to which nonlinear-regression methods were applied simulates flow in the Albuquerque Basin from 1900 to March 1995. Six different basin subsurface configurations are considered in the model. These configurations are designed to test the effects of (1) varying the simulated basin thickness, (2) including a hypothesized hydrogeologic unit with large hydraulic conductivity in the western part of the basin (the west basin high-K zone), and (3) substantially lowering the simulated hydraulic conductivity of a fault in the western part of the basin (the low-K fault zone). The model with each of the subsurface configurations was calibrated using a nonlinear least- squares regression technique. The calibration data set includes 802 hydraulic-head measurements that provide broad spatial and temporal coverage of basin conditions, and one measurement of net flow from the Rio Grande and drains to the ground-water system in the Albuquerque area. Data are weighted on the basis of estimates of the standard deviations of measurement errors. The 10 to 12 parameters to which the calibration data as a whole are generally most sensitive were estimated by nonlinear regression, whereas the remaining model parameter values were specified. Results of model calibration indicate that the optimal parameter estimates as a whole are most reasonable in calibrations of the model with with configurations 3 (which contains 1,600-ft-thick basin deposits and the west basin high-K zone), 4 (which contains 5,000-ft-thick basin de

Dose-response studies of Ropivacaine in blood flow of upper extremity after supraclavicular block: a double-blind randomized controlled study.

PubMed

Li, Ting; Ye, Qiguang; Wu, Daozhu; Li, Jun; Yu, Jingui

2017-12-02

The sympathetic block of upper limb leading to increased blood flow has important clinical implication in microvascular surgery. However, little is known regarding the relationship between concentration of local anesthetic and blood flow of upper limb. The aim of this dose-response study was to determine the ED 50 and ED 95 of ropivacaine in blood flow after supraclavicular block (SB). Patients undergoing upper limb surgery and supraclavicular block were randomly assigned to receive 30ml ropivacaine in concentrations of 0.125%(A Group), 0.2%(B Group), 0.25%(C Group), 0.375%(D Group), 0.5%(E Group), or 0.75%(F Group) (n=13 per group). All patients received supraclavicular block (SB). Time average maximum velocity (TAMAX), cross-sectional area (CSA) of brachial artery and skin temperatures (T s ) were measured repeatedly at the same marked points, they were taken at baseline (before block, t 0 ) and at 30min after SB (t 1 ). Blood flow(BF) = TAMAX× CSA×60 sec.. Relative blood flow (ΔBF) = BF t1 / BF t0 . Success of SB was assessed simultaneously. Supplementary anesthesia and other adverse events (AE) were recorded. Significant increase in TAMAX, CSA, BF and T s were seen in all concentration groups at t 1 comparing with t 0 (P<0.001). There was an upward trend of TAMAX, CSA, BF with the increasing concentration of ropivacaine except T s . There was no significant different of T s at t 1 among different concentration group. The dose-response formula of ropivacaine on ΔBF was Y=1+3.188/(1+10^((-2.451-X) × 1.730)) and ED 50 /ED 95 (95%CI) were 0.35/1.94%(0.25-0.45/0.83-4.52), and R 2 (coefficient of determination) =0.85. ED 50 /ED 95 (95%CI) values of sensory block were 0.18/0.33% (0.15-0.21/0.27-0.51), R 2 =0.904. The dose-response curve between SB ropivacaine and the changes of BF was determined. The ED 50 /ED 95 of ropivacaine of ΔBF are 0.35/1.94% (0.25-0.45/0.83-4.52). TAMAX, CSA and BF consistently increased with ropivacaine concentration. The maximal sympathetic block needs higher concentration than that complete sensation block needs which may benefit for microvascular surgery. Clinicaltrials.gov NCT02139982 . Retrospectively registered (Date of registration: May, 2014).

Effect of Low-Dose Aspirin on Midluteal Phase Uterine Artery Blood Flow in Patients With Recurrent Pregnancy Loss.

PubMed

Kang, Xiaomin; Wang, Tongfei; He, Liyin; Xu, Haijing; Liu, Zhilan; Zhao, Aimin

2016-12-01

The purpose of this study was to evaluate differences in uterine artery blood flow parameters and pregnancy outcomes, if any. An investigation was conducted to determine the effects of low-dose aspirin on uterine artery blood flow indices in patients with recurrent pregnancy loss. This observational study included 353 Chinese women with a history of recurrent pregnancy loss and 85 women without a history of recurrent pregnancy loss (control group) from Ren Ji Hospital. All patients were scanned transvaginally with transvaginal Doppler sonography 6 to 8 days after ovulation to measure the pulsatility index (PI), resistive index (RI), and systolic-to-diastolic ratio (S/D) of the left and right main uterine arteries. Low-dose aspirin at a dose of 50 mg/d was administered orally in patients with recurrent pregnancy loss for 2 months, and the blood flow indices were measured subsequently. The Student t test was used for analysis of the results, P < .05 was considered significant. The mean PI and S/D of the uterine arteries in the recurrent pregnancy loss group were significantly higher than in the control group. Although not statistically significant, the RI was higher in the recurrent pregnancy loss group than the control group. Moreover, the PI and S/D increased as the number of pregnancy losses increased. Significant enhancements of the PI and S/D were observed in patients with 4 or more consecutive abortions. After low-dose aspirin supplementation, patients with recurrent pregnancy loss showed a highly significant reduction in the PI and S/D. Uterine blood flow decreased during the luteal phase in patients with recurrent pregnancy loss. Low-dose aspirin induced a reversible increase in uterine blood flow and may be of therapeutic value. © 2016 by the American Institute of Ultrasound in Medicine.

Normal Muscle Oxygen Consumption and Fatigability in Sickle Cell Patients Despite Reduced Microvascular Oxygenation and Hemorheological Abnormalities

PubMed Central

Waltz, Xavier; Pichon, Aurélien; Lemonne, Nathalie; Mougenel, Danièle; Lalanne-Mistrih, Marie-Laure; Lamarre, Yann; Tarer, Vanessa; Tressières, Benoit; Etienne-Julan, Maryse; Hardy-Dessources, Marie-Dominique; Hue, Olivier; Connes, Philippe

2012-01-01

Background/Aim Although it has been hypothesized that muscle metabolism and fatigability could be impaired in sickle cell patients, no study has addressed this issue. Methods We compared muscle metabolism and function (muscle microvascular oxygenation, microvascular blood flow, muscle oxygen consumption and muscle microvascular oxygenation variability, which reflects vasomotion activity, maximal muscle force and local muscle fatigability) and the hemorheological profile at rest between 16 healthy subjects (AA), 20 sickle cell-hemoglobin C disease (SC) patients and 16 sickle cell anemia (SS) patients. Results Muscle microvascular oxygenation was reduced in SS patients compared to the SC and AA groups and this reduction was not related to hemorhelogical abnormalities. No difference was observed between the three groups for oxygen consumption and vasomotion activity. Muscle microvascular blood flow was higher in SS patients compared to the AA group, and tended to be higher compared to the SC group. Multivariate analysis revealed that muscle oxygen consumption was independently associated with muscle microvascular blood flow in the two sickle cell groups (SC and SS). Finally, despite reduced muscle force in sickle cell patients, their local muscle fatigability was similar to that of the healthy subjects. Conclusions Sickle cell patients have normal resting muscle oxygen consumption and fatigability despite hemorheological alterations and, for SS patients only, reduced muscle microvascular oxygenation and increased microvascular blood flow. Two alternative mechanisms can be proposed for SS patients: 1) the increased muscle microvascular blood flow is a way to compensate for the lower muscle microvascular oxygenation to maintain muscle oxygen consumption to normal values or 2) the reduced microvascular oxygenation coupled with a normal resting muscle oxygen consumption could indicate that there is slight hypoxia within the muscle which is not sufficient to limit mitochondrial respiration but increases muscle microvascular blood flow. PMID:23285055

Aortic Valve Stenosis Increases Helical Flow and Flow Complexity: A Study of Intra-Operative Cardiac Vector Flow Imaging.

PubMed

Hansen, Kristoffer Lindskov; Møller-Sørensen, Hasse; Kjaergaard, Jesper; Jensen, Maiken Brit; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

2017-08-01

Aortic valve stenosis alters blood flow in the ascending aorta. Using intra-operative vector flow imaging on the ascending aorta, secondary helical flow during peak systole and diastole, as well as flow complexity of primary flow during systole, were investigated in patients with normal, stenotic and replaced aortic valves. Peak systolic helical flow, diastolic helical flow and flow complexity during systole differed between the groups (p < 0.0001), and correlated to peak systolic velocity (R = 0.94, 0.87 and 0.88, respectively). The study indicates that aortic valve stenosis increases helical flow and flow complexity, which are measurable with vector flow imaging. For assessment of aortic stenosis and optimization of valve surgery, vector flow imaging may be useful. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Dark energy domination in the Virgocentric flow

NASA Astrophysics Data System (ADS)

Chernin, A. D.; Karachentsev, I. D.; Nasonova, O. G.; Teerikorpi, P.; Valtonen, M. J.; Dolgachev, V. P.; Domozhilova, L. M.; Byrd, G. G.

2010-09-01

Context. The standard ΛCDM cosmological model implies that all celestial bodies are embedded in a perfectly uniform dark energy background, represented by Einstein's cosmological constant, and experience its repulsive antigravity action. Aims: Can dark energy have strong dynamical effects on small cosmic scales as well as globally? Continuing our efforts to clarify this question, we now focus on the Virgo Cluster and the flow of expansion around it. Methods: We interpret the Hubble diagram from a new database of velocities and distances of galaxies in the cluster and its environment, using a nonlinear analytical model, which incorporates the antigravity force in terms of Newtonian mechanics. The key parameter is the zero-gravity radius, the distance at which gravity and antigravity are in balance. Results: 1. The interplay between the gravity of the cluster and the antigravity of the dark energy background determines the kinematical structure of the system and controls its evolution. 2. The gravity dominates the quasi-stationary bound cluster, while the antigravity controls the Virgocentric flow, bringing order and regularity to the flow, which reaches linearity and the global Hubble rate at distances ⪆15 Mpc. 3. The cluster and the flow form a system similar to the Local Group and its outflow. In the velocity-distance diagram, the cluster-flow structure reproduces the group-flow structure with a scaling factor of about 10; the zero-gravity radius for the cluster system is also 10 times larger. Conclusions: The phase and dynamical similarity of the systems on the scales of 1-30 Mpc suggests that a two-component pattern may be universal for groups and clusters: a quasi-stationary bound central component and an expanding outflow around it, caused by the nonlinear gravity-antigravity interplay with the dark energy dominating in the flow component.

Automated structure and flow measurement - a promising tool in nailfold capillaroscopy.

PubMed

Berks, Michael; Dinsdale, Graham; Murray, Andrea; Moore, Tonia; Manning, Joanne; Taylor, Chris; Herrick, Ariane L

2018-07-01

Despite increasing interest in nailfold capillaroscopy, objective measures of capillary structure and blood flow have been little studied. We aimed to test the hypothesis that structural measurements, capillary flow, and a combined measure have the predictive power to separate patients with systemic sclerosis (SSc) from those with primary Raynaud's phenomenon (PRP) and healthy controls (HC). 50 patients with SSc, 12 with PRP, and 50 HC were imaged using a novel capillaroscopy system that generates high-quality nailfold images and provides fully-automated measurements of capillary structure and blood flow (capillary density, mean width, maximum width, shape score, derangement and mean flow velocity). Population statistics summarise the differences between the three groups. Areas under ROC curves (A Z ) were used to measure classification accuracy when assigning individuals to SSc and HC/PRP groups. Statistically significant differences in group means were found between patients with SSc and both HC and patients with PRP, for all measurements, e.g. mean width (μm) ± SE: 15.0 ± 0.71, 12.7 ± 0.74 and 11.8 ± 0.23 for SSc, PRP and HC respectively. Combining the five structural measurements gave better classification (A Z  = 0.919 ± 0.026) than the best single measurement (mean width, A Z  = 0.874 ± 0.043), whilst adding flow further improved classification (A Z  = 0.930 ± 0.024). Structural and blood flow measurements are both able to distinguish patients with SSc from those with PRP/HC. Importantly, these hold promise as clinical trial outcome measures for treatments aimed at improving finger blood flow or microvascular remodelling. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Reversed aqueductal cerebrospinal fluid net flow in idiopathic normal pressure hydrocephalus.

PubMed

Yin, L K; Zheng, J J; Zhao, L; Hao, X Z; Zhang, X X; Tian, J Q; Zheng, K; Yang, Y M

2017-11-01

The changes of CSF flow dynamics in idiopathic normal pressure hydrocephalus (iNPH) are not fully elucidated. Most previous studies took the whole cardiac cycle as a unit. In this work, it is divided into systole and diastole phase and compared between iNPH patients and normal elderly and paid special attention to the change of netflow direction. Twenty iNPH patients according to international guideline and twenty healthy volunteers were included in this study and examined by MRI. Three categories of CSF flow parameters were measured: peak velocity (V peak ), stroke volume (SV), and minute flow volume (MinV) covering the whole cycle; peak velocity (V peak-s , V peak-d ) and flow volume (Vol s , Vol d ) of the systole and diastole, respectively; net flow. Evans index (EI) was also measured and compared statistically between the two groups. EI, V peak , SV, MinV, Vol s , Vol d , and V peak-d significantly increased in iNPH group (P<0.05). V peak-s of the two groups were not significantly different (P>0.05). The net flow of 16 iNPH patients (16/20) was in the caudo-cranial direction, while 15 volunteers (15/20) were in the opposite direction, which showed statistically significant differences (P=.001). INPH patients present hyperdynamic flow with increased velocity and volume both in systole and diastole phase. Degree of rising in diastole phase exceeds that of systole phase. The resulting reversal of netflow direction may play a key role in the occurrence of ventriculomegaly in iNPH patients. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Randomized, double-blind, placebo-controlled trial of saw palmetto in men with lower urinary tract symptoms.

PubMed

Gerber, G S; Kuznetsov, D; Johnson, B C; Burstein, J D

2001-12-01

To assess the effects of saw palmetto on urinary symptoms, sexual function, and urinary flow rate in men with lower urinary tract symptoms using a double-blind, randomized, placebo-controlled trial. The eligible patients were 45 years of age or older and had an International Prostate Symptom Score of 8 or greater. After a 1-month placebo run-in period, 85 men were randomized to receive saw palmetto or placebo for 6 months. Patients were evaluated using the International Prostate Symptom Score, a sexual function questionnaire, and by measurement of the urinary flow rate. The mean symptom score decreased from 16.7 to 12.3 in the saw palmetto group compared with 15.8 to 13.6 in the placebo group (P = 0.038). The quality-of-life score improved to a greater degree in the saw palmetto group, but this difference was not statistically significant. No change occurred in the sexual function questionnaire results in either group. The peak flow rate increased by 1.0 mL/s and 1.4 mL/s in the saw palmetto and placebo groups, respectively (P = 0.73). Saw palmetto led to a statistically significant improvement in urinary symptoms in men with lower urinary tract symptoms compared with placebo. Saw palmetto had no measurable effect on the urinary flow rates. The mechanism by which saw palmetto improves urinary symptoms remains unknown.

Use of flumes in measuring discharge

USGS Publications Warehouse

Kilpatrick, F.A.; Schneider, V.R.

1983-01-01

Flumes for measuring discharge are usually of two general groups-critical-flow flumes and supercritical-flow flumes. In this chapter, the underlying design principles for each group are discussed; the most commonly used flumes are described and their discharge ratings presented. There is also discussion of considerations in choosing and fitting the appropriate flume for a given situation as well as flume construction techniques and operational experiences.

Manual lymphatic drainage in chronic venous disease: a duplex ultrasound study.

PubMed

Dos Santos Crisóstomo, Rute Sofia; Candeias, Miguel Sandu; Ribeiro, Ana Margarida Martins; da Luz Belo Martins, Catarina; Armada-da-Silva, Paulo As

2014-12-01

To compare the effect of call-up and reabsorption maneuvers of manual lymphatic drainage on blood flow in femoral vein and great saphenous vein in patients with chronic venous disease and healthy controls. Forty-one subjects participated in this study (mean age: 42.68(15.23)), 23 with chronic venous disease (chronic venous disease group) with clinical classification C1-5 of clinical-etiological-anatomical-pathological (CEAP) and 18 healthy subjects (control group). Call-up and reabsorption maneuvers were randomly applied in the medial aspect of the thigh. The cross-sectional areas, as well as the peak and the mean blood flow velocity at femoral vein and great saphenous vein, were assessed by Duplex ultrasound at the baseline and during maneuvers. The venous flow volume changes were calculated. The venous flow volume in femoral vein and great saphenous vein increased during both manual lymphatic drainage maneuvers and in both groups (P < 0.05). The two maneuvers had a similar effect on femoral vein and great saphenous vein hemodynamics, and in both the chronic venous disease and control groups. As a result of the call-up maneuver, the flow volume augmentations, as a result of call-up maneuver, decreased with the severity of chronic venous disease in those patients measured by the clinical classification of CEAP (r = -0.64; P = 0.03). Manual lymphatic drainage increases the venous blood flow in the lower extremity with a magnitude that is independent from the specific maneuver employed or the presence of chronic venous disease. Therefore, manual lymphatic drainage may be an alternative strategy for the treatment and prevention of venous stasis complications in chronic venous disease. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Effect of three commercially available chewing gums on salivary flow rate and pH in caries-active and caries-free children: An in vivo study.

PubMed

Vantipalli, Usha Kiran; Avula, Sai Sankar Jogendra; Enuganti, Sridevi; Bandi, Sujatha; Kakarla, Pranitha; Kuravadi, Raja Vardhan

2017-01-01

Adequate salivary flow is an important requisite in the maintenance of oral health. Salivary flow increases in response to both gustatory (taste) and mechanical (chewing) stimuli. Hence, the aim of the present study was to know the efficacy of commercially available chewing gums (sugar free and sugared) on salivary flow rate (SFR) and pH in caries-active and caries-free children. One hundred school children aged between 10 and 12 years were divided into two groups on the basis of their caries status into caries free and caries active. Unstimulated saliva was collected before start of the study. Both groups were subjected to three commercially available chewing gums (2 sugar free, 1 sugared) on consecutive days, and saliva was collected at intervals of 2 min (T2), 10 min (T10), and 30 min (T30). The pH and flow rate of saliva samples were measured before and specified time intervals after gum chewing. In both the groups, gum chewing increased the SFR, significantly at T2, and gradually declined at T30 which was significantly higher than baseline values. The pH raised significantly at T2 and gradually declined at T30 which was significantly higher than baseline values with sugar-free gums, but with sugared gums, the pH raised slightly at T2 and dropped significantly at T30. However, no statistically significant differences in pH and flow rate were noticed in both the groups. Chewing of sugar-free gums in both caries-active and caries-free children may aid in reducing the incidence of dental caries.

Cerebral perfusion and oxygenation after the Norwood procedure: comparison of right ventricle-pulmonary artery conduit with modified Blalock-Taussig shunt.

PubMed

Kussman, Barry D; Gauvreau, Kimberlee; DiNardo, James A; Newburger, Jane W; Mackie, Andrew S; Booth, Karen L; del Nido, Pedro J; Roth, Stephen J; Laussen, Peter C

2007-03-01

The proposed physiologic advantage of the modified Norwood procedure using a right ventricle-pulmonary artery conduit to supply pulmonary blood flow, compared with a modified Blalock-Taussig shunt, is reduced runoff from the systemic-to-pulmonary circulation during diastole, resulting in a higher diastolic blood pressure and improved systemic perfusion. We hypothesized that the modified Norwood procedure is associated with improved cerebral perfusion and oxygenation. Transcranial Doppler sonography and near-infrared spectroscopy were performed in neonates undergoing the Norwood procedure with either a modified Blalock-Taussig shunt (n = 14) or right ventricle-pulmonary artery conduit (n = 13). Diastolic blood pressure was significantly higher in the right ventricle-pulmonary artery group at 6 hours after bypass (46 +/- 7 vs 40 +/- 4 mm Hg; P = .03), on postoperative day 1 (45 +/- 6 vs 37 +/- 5 mm Hg; P = .002), and on postoperative day 2 (46 +/- 7 vs 37 +/- 4 mm Hg; P = .001). Cerebral diastolic blood flow velocity did not differ significantly between groups at any time point or over time, but cerebral systolic blood flow velocity was higher over time in the Blalock-Taussig group (P = .01). No significant differences in regional cerebral oxygen saturation were found between groups at baseline or after bypass. Blood flow velocities and cerebral oxygen saturation did not differ significantly according to use of regional low-flow perfusion. The higher diastolic blood pressure after the modified Norwood procedure is not associated with higher cerebral blood flow velocities or regional cerebral oxygen saturation. This may imply an equal vulnerability to the cerebral injury associated with hemodynamic instability in the early postoperative period.

Bubble CPAP versus CPAP with variable flow in newborns with respiratory distress: a randomized controlled trial.

PubMed

Yagui, Ana Cristina Zanon; Vale, Luciana Assis Pires Andrade; Haddad, Luciana Branco; Prado, Cristiane; Rossi, Felipe Souza; Deutsch, Alice D Agostini; Rebello, Celso Moura

2011-01-01

To evaluate the efficacy and safety of nasal continuous positive airway pressure (NCPAP) using devices with variable flow or bubble continuous positive airway pressure (CPAP) regarding CPAP failure, presence of air leaks, total CPAP and oxygen time, and length of intensive care unit and hospital stay in neonates with moderate respiratory distress (RD) and birth weight (BW) ≥ 1,500 g. Forty newborns requiring NCPAP were randomized into two study groups: variable flow group (VF) and continuous flow group (CF). The study was conducted between October 2008 and April 2010. Demographic data, CPAP failure, presence of air leaks, and total CPAP and oxygen time were recorded. Categorical outcomes were tested using the chi-square test or the Fisher's exact test. Continuous variables were analyzed using the Mann-Whitney test. The level of significance was set at p < 0.05. There were no differences between the groups with regard to demographic data, CPAP failure (21.1 and 20.0% for VF and CF, respectively; p = 1.000), air leak syndrome (10.5 and 5.0%, respectively; p = 0.605), total CPAP time (median: 22.0 h, interquartile range [IQR]: 8.00-31.00 h and median: 22.0 h, IQR: 6.00-32.00 h, respectively; p = 0.822), and total oxygen time (median: 24.00 h, IQR: 7.00-85.00 h and median: 21.00 h, IQR: 9.50-66.75 h, respectively; p = 0.779). In newborns with BW ≥ 1,500 g and moderate RD, the use of continuous flow NCPAP showed the same benefits as the use of variable flow NCPAP.

Conversion of umbilical arterial Doppler waveforms to cardiac cycle triggering signals: a preparatory study for online motion-gated three-dimensional fetal echocardiography.

PubMed

Deng, J; Birkett, A G; Kalache, K D; Hanson, M A; Peebles, D M; Linney, A D; Lees, W R; Rodeck, C H

2001-01-01

To remove motion artefacts, a device was built to convert "noisy" umbilical arterial Doppler waveforms (UADWs) from an ultrasound (US) system into sharp ECG R-wave-like cardiac cycle triggering signals (CCTSs). These CCTSs were then used to gate a simultaneous (online) 3-D acquisition of sectional fetal echocardiograms from another US system. To test the conversion performance, a study was carried out in sheep fetal twins. Pulmonary arterial flow waveforms (PAFWs) from implanted probes were traced, in the meantime, to determine the reference cardiac cycle. Interference caused by running the two nonsynchronised US systems was controlled to three degrees (not-noticeable, moderate, and severe), together with high (> or = 40 cm/s) and low (< 40) flow velocities on UADWs. The conversion efficiency, assessed by the percentage of UADWs converted into CCTSs, was in the range of 83% to 100% for not-noticeable and moderate interference, and 0% to 71% for severe interference. The triggering accuracy, assessed by [(time lag mean between the onsets of PAFWs and corresponding CCTSs) -- (its 99% confidence level)] / the mean, was 90% to 96% for the not-noticeable interference high- and low-flow groups and for the moderate interference high-flow group; 19% to 93% for the moderate interference low-flow group; and from not obtainable up to 90% for the severe interference groups. The results show that UADWs can be used as a satisfactory online motion-gating source even in the presence of moderate interference. The major problems are from severe interference or moderate interference with low-flow velocity, which can be minimised/eliminated by the integration of the individual systems involved.

Comparative Evaluation of Flow Quantification across the Atrioventricular Valve in Patients with Functional Univentricular Heart after Fontan's Surgery and Healthy Controls: Measurement by 4D Flow Magnetic Resonance Imaging and Streamline Visualization.

PubMed

She, Hoi Lam; Roest, Arno A W; Calkoen, Emmeline E; van den Boogaard, Pieter J; van der Geest, Rob J; Hazekamp, Mark G; de Roos, Albert; Westenberg, Jos J M

2017-01-01

To evaluate the inflow pattern and flow quantification in patients with functional univentricular heart after Fontan's operation using 4D flow magnetic resonance imaging (MRI) with streamline visualization when compared with the conventional 2D flow approach. Seven patients with functional univentricular heart after Fontan's operation and twenty-three healthy controls underwent 4D flow MRI. In two orthogonal two-chamber planes, streamline visualization was applied, and inflow angles with peak inflow velocity (PIV) were measured. Transatrioventricular flow quantification was assessed using conventional 2D multiplanar reformation (MPR) and 4D MPR tracking the annulus and perpendicular to the streamline inflow at PIV, and they were validated with net forward aortic flow. Inflow angles at PIV in the patient group demonstrated wide variation of angles and directions when compared with the control group (P < .01). The use of 4D flow MRI with streamlines visualization in quantification of the transatrioventricular flow had smaller limits of agreement (2.2 ± 4.1 mL; 95% limit of agreement -5.9-10.3 mL) when compared with the static plane assessment from 2DFlow MRI (-2.2 ± 18.5 mL; 95% limit of agreement agreement -38.5-34.1 mL). Stronger correlation was present in the 4D flow between the aortic and trans-atrioventricular flow (R 2 correlation in 4D flow: 0.893; in 2D flow: 0.786). Streamline visualization in 4D flow MRI confirmed variable atrioventricular inflow directions in patients with functional univentricular heart with previous Fontan's procedure. 4D flow aided generation of measurement planes according to the blood flood dynamics and has proven to be more accurate than the fixed plane 2D flow measurements when calculating flow quantifications. © 2016 Wiley Periodicals, Inc.

Effect of sequential pneumatic compression therapy on venous blood velocity, refilling time, pain and quality of life in women with varicose veins: a randomized control study

PubMed Central

Yamany, Abeer; Hamdy, Bassant

2016-01-01

[Purpose] The aim of this study was to investigate the effects of sequential pneumatic compression therapy on venous blood flow, refilling time, pain level, and quality of life in women with varicose veins. [Subjects and Methods] Twenty-eight females with varicose veins were selected and randomly allocated to a control group, and experimental group. Maximum and mean venous blood velocities, the refilling time, pain by visual analog scale and quality of life by Aberdeen Varicose Veins Questionnaire were measured in all patients before and after six weeks of treatment. Both groups received lower extremity exercises; in addition, patients in the experimental group received sequential pneumatic compression therapy for 30 minutes daily, five days a week for six weeks. [Results] All measured parameters improved significantly in both groups, comparison of post treatment measurements between groups showed that the maximum and mean blood flow velocity, the pain level, and quality of life were significantly higher in the experimental group compared with the control group. On the other hand there was no significant difference between groups for refilling time. [Conclusion] Sequential pneumatic compression therapy with the applied parameters was an effective modality for increasing venous blood flow, reducing pain, and improving quality of women life with varicose veins. PMID:27512247

Microbial ingrowth around single- and multi-component adhesives studied in vitro.

PubMed

Preussker, S; Klimm, W; Pöschmann, M; Koch, R

2003-01-01

The aim of this study was to compare the in vitro microbial leakage in 4 micro-hybrid composites in combination with 4 single-component dental adhesives (Scotchbond 1/Z100 MP = group 1; Syntac Single-Component/Tetric Flow = group 3; OptiBond Solo/XRV Herculite = group 5; Solobond M/Arabesk Top = group 7) and 4 multi-component dental adhesives (Scotchbond Multi-Purpose/Z100 MP = group 2; Syntac/Tetric Flow = group 4; OptiBond FL/XRV Herculite = group 6; Solobond Plus/Arabesk Top = group 8). Ninety-four mixed standardized Class V cavities of human caries-free extracted premolars were filled with eight different composite adhesive systems using a one-layer (groups 1-4) or a two-layer technique (groups 5-8). After thermocycling and incubation in a broth culture of Streptococcus mutans and Lactobacillus acidophilus, followed by decalcification and staining, the extent and the type of microbial leakage were measured histologically. The extent of microbial leakage in the composite restorations was very low in all groups and there were no significant differences between adhesives. Z100 MP in combination with single- and multi-component adhesives showed a significantly higher microbial leakage than Tetric Flow systems (U test: p=0.037). XRV Herculite adhesive systems showed significantly less extensive microbial leakage than Arabesk Top adhesive systems (U test: p<0.001). The single-component dental adhesives achieved a marginal adaptation of composites comparable to that of multi-component adhesives in vitro. Copyright 2003 S. Karger AG, Basel

Anesthesia maintenance with 'induction dose only' sevoflurane during pediatric ophthalmic examination: comparison with standard low-flow technique through a randomized controlled trial.

PubMed

Datta, Priyankar K; Sinha, Renu; Ray, Bikash Ranjan; Jambunathan, Venkateswaran; Kundu, Riddhi

2017-02-01

Sevoflurane is preferred for pediatric day care procedures. However, financial and environmental costs remain major limitations. Induction dose of sevoflurane could itself be sufficient for maintaining anesthesia with low fresh gas flow during short noninvasive procedures. Fifty children, aged 1-5 years, scheduled for ophthalmic examination under anesthesia, were randomized into two groups. All children were induced with 8% sevoflurane in O 2 : N 2 O (40 : 60). In the Group S, anesthesia was maintained with 2% sevoflurane at 1 l·min -1 fresh gas flow [O 2 : N 2 O = 50 : 50]. In Group L, the sevoflurane vaporizer was turned off and fresh gas flow was reduced to 0.5 l·min -1 [O 2 : N 2 O = 50 : 50]. HR, BP, MAC, BIS, total sevoflurane consumption, ocular deviation, body movement, time to laryngeal mask airway removal (T WO ), and airway complications were compared between the groups. Rescue propofol bolus was used, if needed. Median duration of examination was 14 min (IQR = 9-17) in Group S and 15 min (IQR = 10-17) in Group L. Sevoflurane consumption was lower in the Group L (7 ml) compared to Group S (9 ml) [median difference = 2 ml, P < 0.001, 95% CI = 0.96-3.04]. T WO was lower in Group L (86 s) compared to Group S (131 s) [median difference = 45 s, P = 0.002, 95% CI = 19.85-70.15]. There was no difference in hemodynamic parameters, incidence of ocular deviation, movement or airway complications, and need for rescue propofol. Induction dose of sevoflurane is, in itself, adequate for maintaining anesthesia for short noninvasive ophthalmic examinations lasting approximately 15 min. This method significantly reduces sevoflurane consumption and cost. © 2016 John Wiley & Sons Ltd.

Low prevalence of collateral cerebral circulation in the circle of Willis in patients with severe carotid artery stenosis and recent ischemic stroke.

PubMed

Badacz, Rafał; Przewłocki, Tadeusz; Karch, Izabela; Pieniążek, Piotr; Rosławiecka, Agnieszka; Mleczko, Szymon; Brzychczy, Andrzej; Trystuła, Mariusz; Żmudka, Krzysztof; Kabłak-Ziembicka, Anna

2015-01-01

The circle of Willis is thought to play a key role in development of collateral flow in patients with internal carotid artery stenosis (ICAS). To assess flow in the circle of Willis in patients with recent ischemic stroke (IS). The study included 371 patients, 102 symptomatic with severe ICAS and recent IS (within the last 3 months) (group I) and 269 asymptomatic with severe ICAS (group II). Flow in the middle (MCA), anterior (ACA) and posterior (PCA) cerebral arteries and pattern of the cross-flow through anterior (ACoA) and posterior (PCoA) communicating arteries were assessed with transcranial color-coded Doppler ultrasonography (TCCD). The ACoA or PCoA was less prevalent in group I than in group II (54% vs. 78%, p < 0.001 and 20% vs. 42%, p < 0.001, respectively), resulting in lower peak-systolic velocity (PSV) in the MCA in group I vs. group II (p = 0.015). Any collateral pathway was present in 67% of patients in group I, compared to 86% in group II (p < 0.001). Both PSV and end-diastolic (EDV) flow velocity in the ACA were lower in patients with recent IS, compared to asymptomatic subjects (71 ±24 cm/s vs. 86 ±34 cm/s, p < 0.001 and 32 ±12 cm/s vs. 37 ±17 cm/s, p = 0.038, respectively). Presence of ACoA or PCoA and higher PSV in the MCA and ACA were associated with significant risk reduction of IS (RR = 0.28 (95% CI = 0.16-0.49, p < 0.001), RR = 0.28 (95% CI = 0.15-0.52, p < 0.001), RR = 0.97 (95% CI = 0.96-0.99, p < 0.001), RR = 0.99 (95% CI = 0.98-0.99, p < 0.032), respectively). However, ROC curves failed to show reliable MCA or ACA PSV cut-offs for IS risk assessment. The ACoA and PCoA seem to play a key role in the evaluation of IS risk in subjects with severe ICAS.

Ultrasound and color-flow Doppler evaluation for the diagnosis of subclinical hyperthyroidism.

PubMed

Cirillo, L; Casella, C; D'Adda, F; Cappelli, C; Salerni, B

2014-03-01

Clinical significance, population screening and management of subclinical hyperthyroidism (SHyper) are still debated. Although the diagnosis of subclinical hyperthyroidism is, by definition, purely a biochemical one a conventional gray-scale sonography and, more recently, color-flow Doppler sonography (CFDS) have proven to be useful in obtaining information about thyroid morphology and function in thyroid disease, such as SHyper. The objective of this study was to evaluate, using CFDS, the presence and significance of changes in intrathyroidal blood flow and velocity in patients affected by SHyper and, to evalutate the potential diagnostic role of CFDS in mild thyroid disease in absence of a significant alteration in the serum level of circulating thyroid hormones. In this study, patients with SHyper (the case group) and euthyroid patients (the control group) were enrolled. All patients from the two groups who were affected by multinodular goiter as preoperative diagnosis, underwent total thyroidectomy. In both groups preoperative examination included a conventional grey-scale sonography, followed by CFDS. Quantitative flow evaluation was performed measuring the maximal peak systolic velocity (PSV) at the level of intrathyroid arteries and inferior thyroid artery. Patients with SHyper showed an increased thyroid vascularization both intranodular and peripheral and the mean PSV values were higher in case patients than in control subjects. We have shown that significant changes in thyroid vascularity and blood flow velocity are already present in patients with SHyper. CFDS is a suitable technique to identify SHyper.

Bubble Continuous Positive Airway Pressure Enhances Lung Volume and Gas Exchange in Preterm Lambs

PubMed Central

Pillow, J. Jane; Hillman, Noah; Moss, Timothy J. M.; Polglase, Graeme; Bold, Geoff; Beaumont, Chris; Ikegami, Machiko; Jobe, Alan H.

2007-01-01

Rationale: The technique used to provide continuous positive airway pressure (CPAP) to the newborn may influence lung function and breathing efficiency. Objectives: To compare differences in gas exchange physiology and lung injury resulting from treatment of respiratory distress with either bubble or constant pressure CPAP and to determine if the applied flow influences short-term outcomes. Methods: Lambs (133 d gestation; term is 150 d) born via cesarean section were weighed, intubated, and treated with CPAP for 3 hours. Two groups were treated with 8 L/minute applied flow using the bubble (n = 12) or the constant pressure (n = 12) technique. A third group (n = 10) received the bubble method with 12 L/minute bias flow. Measurements at study completion included arterial blood gases, oxygraphy, capnography, tidal flow, multiple breath washout, lung mechanics, static pressure–volume curves, and bronchoalveolar lavage fluid protein. Measurements and Main Results: Birth weight and arterial gas variables at 15 minutes were comparable. Flow (8 or 12 L/min) did not influence the 3-hour outcomes in the bubble group. Bubble technique was associated with a higher pH, PaO2, oxygen uptake, and area under the flow–volume curve, and a decreased alveolar protein, respiratory quotient, PaCO2, and ventilation inhomogeneity compared with the constant pressure group. Conclusions: Compared with constant pressure technique, bubble CPAP promotes enhanced airway patency during treatment of acute postnatal respiratory disease in preterm lambs and may offer protection against lung injury. PMID:17431223

Clinical Outcomes of Transurethral Enucleation with Bipolar for Benign Prostatic Hypertrophy.

PubMed

Kawamura, Yoshiaki; Tokunaga, Masatoshi; Hoshino, Hideaki; Matsushita, Kazuo; Terachi, Toshiro

2015-12-20

This study compared outcomes of transurethral enucleation with bipolar (TUEB) with transurethral resection in saline (TURis). Thirty patients who underwent TURis were compared with 30 who underwent TUEB. Perioperative treatment outcomes, preoperative and 1-month postoperative International Prostrate Symptom Scores (IPSS), quality of life (QOL) index, maximum flow rate, average urinary flow, post- void residual urinary volume, and complications were compared. There were no significant differences in IPSS, measurements of urinary flow, or duration of catheterization. However, the improvement of QOL index after surgery was significantly greater in the TUEB group than the TURis group. The TUEB group had significantly longer surgical time, but tended to have greater enucleated tissue weight than the TURis group. There was no significant difference in enucleated tissue weight per unit time between the groups. The TUEB group also tended to have less hemoglobin decrease at postoperative day 1; this tendency was more prominent in patients with an estimated prostate volume of ≥ 50 ml. No significant differences in postoperative complications were observed. This study confirmed that the previously reported safety and efficacy of TUEB are comparable to those of TURis. TUEB appears especially safe for those with a large benign hypertrophic prostate.

Changes in Maxillary Canine Pulpal Blood Flow During Dentoalveolar Distraction Osteogenesis.

PubMed

Ersahan, Seyda; Sabuncuoglu, Fidan Alakus

2016-05-01

The aim of this study was to assess the effects of dentoalveolar distraction osteogenesis (DD) on the pulpal blood flow (PBF) of maxillary canines. A laser Doppler flowmeter (LDF) was used to measure PBF in maxillary canines of 10 patients undergoing DD (study group) and 10 nonsurgical subjects who received no orthodontic treatment (control group). PBF was measured at baseline, at 4 and 7 days postoperatively, at the end of distraction and at the end of consolidation in the study group and at similar time-points in nonsurgical control subjects. Data were analyzed using paired and Student t tests, with the significance level set at 0.05. Study findings showed that baseline PBF values did not differ significantly between groups. PBF in the control group did not vary over time; however, in the study group, an initial decrease in PBF was observed at 4 days postoperatively and was followed by a gradual increase to preoperative levels at the end of distraction. During the DD latency period, there appears to be a short-lived ischemic phase when perfusion of pulp tissue declines; however, blood-flow returns to normal by the end of distraction.

Simultaneous moisture content and mass flow measurements in wood chip flows using coupled dielectric and impact sensors

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

Pan, Pengmin; McDonald, Timothy; Fulton, John

An 8-electrode capacitance tomography (ECT) sensor was built and used to measure moisture content (MC) and mass flow of pine chip flows. The device was capable of directly measuring total water quantity in a sample but was sensitive to both dry matter and moisture, and therefore required a second measurement of mass flow to calculate MC. Two means of calculating the mass flow were used: the first being an impact sensor to measure total mass flow, and the second a volumetric approach based on measuring total area occupied by wood in images generated using the capacitance sensor’s tomographic mode. Testsmore » were made on 109 groups of wood chips ranging in moisture content from 14% to 120% (dry basis) and wet weight of 280 to 1100 g. Sixty groups were randomly selected as a calibration set, and the remaining were used for validation of the sensor’s performance. For the combined capacitance/force transducer system, root mean square errors of prediction (RMSEP) for wet mass flow and moisture content were 13.42% and 16.61%, respectively. RMSEP using the combined volumetric mass flow/capacitance sensor for dry mass flow and moisture content were 22.89% and 24.16%, respectively. Either of the approaches was concluded to be feasible for prediction of moisture content in pine chip flows, but combining the impact and capacitance sensors was easier to implement. As a result, in situations where flows could not be impeded, however, the tomographic approach would likely be more useful.« less

Simultaneous moisture content and mass flow measurements in wood chip flows using coupled dielectric and impact sensors

DOE PAGES

Pan, Pengmin; McDonald, Timothy; Fulton, John; ...

2016-12-23

An 8-electrode capacitance tomography (ECT) sensor was built and used to measure moisture content (MC) and mass flow of pine chip flows. The device was capable of directly measuring total water quantity in a sample but was sensitive to both dry matter and moisture, and therefore required a second measurement of mass flow to calculate MC. Two means of calculating the mass flow were used: the first being an impact sensor to measure total mass flow, and the second a volumetric approach based on measuring total area occupied by wood in images generated using the capacitance sensor’s tomographic mode. Testsmore » were made on 109 groups of wood chips ranging in moisture content from 14% to 120% (dry basis) and wet weight of 280 to 1100 g. Sixty groups were randomly selected as a calibration set, and the remaining were used for validation of the sensor’s performance. For the combined capacitance/force transducer system, root mean square errors of prediction (RMSEP) for wet mass flow and moisture content were 13.42% and 16.61%, respectively. RMSEP using the combined volumetric mass flow/capacitance sensor for dry mass flow and moisture content were 22.89% and 24.16%, respectively. Either of the approaches was concluded to be feasible for prediction of moisture content in pine chip flows, but combining the impact and capacitance sensors was easier to implement. As a result, in situations where flows could not be impeded, however, the tomographic approach would likely be more useful.« less

Architecture and emplacement of flood basalt flow fields: case studies from the Columbia River Basalt Group, NW USA

NASA Astrophysics Data System (ADS)

Vye-Brown, C.; Self, S.; Barry, T. L.

2013-03-01

The physical features and morphologies of collections of lava bodies emplaced during single eruptions (known as flow fields) can be used to understand flood basalt emplacement mechanisms. Characteristics and internal features of lava lobes and whole flow field morphologies result from the forward propagation, radial spread, and cooling of individual lobes and are used as a tool to understand the architecture of extensive flood basalt lavas. The features of three flood basalt flow fields from the Columbia River Basalt Group are presented, including the Palouse Falls flow field, a small (8,890 km2, ˜190 km3) unit by common flood basalt proportions, and visualized in three dimensions. The architecture of the Palouse Falls flow field is compared to the complex Ginkgo and more extensive Sand Hollow flow fields to investigate the degree to which simple emplacement models represent the style, as well as the spatial and temporal developments, of flow fields. Evidence from each flow field supports emplacement by inflation as the predominant mechanism producing thick lobes. Inflation enables existing lobes to transmit lava to form new lobes, thus extending the advance and spread of lava flow fields. Minimum emplacement timescales calculated for each flow field are 19.3 years for Palouse Falls, 8.3 years for Ginkgo, and 16.9 years for Sand Hollow. Simple flow fields can be traced from vent to distal areas and an emplacement sequence visualized, but those with multiple-layered lobes present a degree of complexity that make lava pathways and emplacement sequences more difficult to identify.

Simultaneous Moisture Content and Mass Flow Measurements in Wood Chip Flows Using Coupled Dielectric and Impact Sensors

PubMed Central

Pan, Pengmin; McDonald, Timothy; Fulton, John; Via, Brian; Hung, John

2016-01-01

An 8-electrode capacitance tomography (ECT) sensor was built and used to measure moisture content (MC) and mass flow of pine chip flows. The device was capable of directly measuring total water quantity in a sample but was sensitive to both dry matter and moisture, and therefore required a second measurement of mass flow to calculate MC. Two means of calculating the mass flow were used: the first being an impact sensor to measure total mass flow, and the second a volumetric approach based on measuring total area occupied by wood in images generated using the capacitance sensor’s tomographic mode. Tests were made on 109 groups of wood chips ranging in moisture content from 14% to 120% (dry basis) and wet weight of 280 to 1100 g. Sixty groups were randomly selected as a calibration set, and the remaining were used for validation of the sensor’s performance. For the combined capacitance/force transducer system, root mean square errors of prediction (RMSEP) for wet mass flow and moisture content were 13.42% and 16.61%, respectively. RMSEP using the combined volumetric mass flow/capacitance sensor for dry mass flow and moisture content were 22.89% and 24.16%, respectively. Either of the approaches was concluded to be feasible for prediction of moisture content in pine chip flows, but combining the impact and capacitance sensors was easier to implement. In situations where flows could not be impeded, however, the tomographic approach would likely be more useful. PMID:28025536

A new approach to determining symmetry groups of filtration properties of porous media in nonlinear filtration laws

NASA Astrophysics Data System (ADS)

Maksimov, V. M.; Dmitriev, N. M.; Dmitriev, M. N.

2017-04-01

Theoretical analysis of filtration properties of porous media for orthotropic and monoclinic symmetry groups has been carried out. It is shown how it is possible to establish a type of symmetry with the help of special laboratory investigations and to distinguish groups with orthotropic and monoclinic symmetry. It is established that the criterion for solving this problem is the use of nonlinear Darcy law at high flow velocities, where the effects of asymmetry of filtration properties manifest themselves upon a change in the flow direction.

Changes in phasic coronary blood flow velocity profile in relation to changes in hemodynamic parameters during stress in patients with aortic valve stenosis.

PubMed

Petropoulakis, P N; Kyriakidis, M K; Tentolouris, C A; Kourouclis, C V; Toutouzas, P K

1995-09-15

Alterations in phasic coronary flow profile have been demonstrated at rest in patients with aortic valve stenosis (AVS) but have never been studied under conditions of hemodynamic stress. Thirty-four patients with significant pure AVS (21 with exertional symptoms [group 1], 13 asymptomatic [group 2]) and 9 control subjects (group 3), all with normal coronary arteries, were studied successively at rest, during rapid atrial pacing, and after dobutamine infusion (5 to 30 micrograms.kg-1.min-1 i.v.) by proximal left anterior descending (LAD) intracoronary Doppler flow velocimetry concomitant with hemodynamic measurements. Systolic retrograde coronary flow velocity (CFV) was recorded only in patients with AVS, and its resting peak value was positively correlated with peak aortic pressure gradient (APG) (r = .63, P < .001). In group 1, there was lower aortic valve area (0.58 +/- 0.10 versus 0.75 +/- 0.08 cm2, P < .001) and higher resting APG and peak systolic retrograde CFV than in group 2, and also higher resting peak diastolic and mean CFV than in groups 2 and 3. In the two AVS groups, there were no changes from rest in APG and retrograde CFV at peak pacing rate; however, these parameters increased concomitantly and significantly at peak dobutamine stress. The ratio of the resting systolic to diastolic CFV curve area was inversely correlated with mean APG (r = -.54, P < .001); it was significantly lower in group 1 than in groups 2 and 3 (0.19 +/- 0.07 versus 0.29 +/- 0.10 and 0.30 +/- 0.04, respectively, both P < .005) and increased at peak pacing (group 1, to 0.29 +/- 0.14; group 2, to 0.39 +/- 0.12; group 3, to 0.38 +/- 0.07; all P < .001). At peak dobutamine stress, it decreased in patients with AVS (group 1, to 0.05 +/- 0.05; group 2, to 0.08 +/- 0.03; both P < .001) but did not change in group 3 (0.25 +/- 0.05). From rest to peak dobutamine stress, in both AVS groups there was increased retrograde systolic (group 1, 441 +/- 483%; group 2, 681 +/- 356%; both P < .001), decreased total systolic (group 1, -66 +/- 25%, P < .001; group 2, -19 +/- 24%; P = NS), and increased diastolic (group 1, 33.4 +/- 31.7%; group 2, 197.7 +/- 105.1%; both P < .001; group 1 versus group 2, P < .001) CFV curve area. In contrast, group 3 showed comparable increases in both systolic (143.5 +/- 44.4%) and diastolic (197.1 +/- 75.2%) CFV area (both P < .001). The stress-induced increases in the mean CFV and blood flow exceeded or were comparable with the concomitant increases in the estimated myocardial metabolic demand in groups 2 and 3 but were significantly lower in group 1. Stress-induced changes in LAD phasic CFV profile differ significantly between patients with and without AVS. In AVS, these changes are closely related to the concomitant stress-induced changes in hemodynamic parameters.

Improvement in cochlear flow with Pycnogenol® in patients with tinnitus: a pilot evaluation.

PubMed

Grossi, M G; Belcaro, G; Cesarone, M R; Dugall, M; Hosoi, M; Cacchio, M; Ippolito, E; Bavera, P

2010-06-01

The aim of this preliminary evaluation was to study the efficacy of Pycnogenol in improving cochlear flow in patients with mild-to-moderate tinnitus present for at least two weeks (without vertigo or important hearing loss), possibly associated with cochlear hypo-perfusion. Patients with mild-to-moderate, idiopatic, monolateral tinnitus present for at least 2 weeks were included; no vertigo or important hearing loss had been found in a specific examination. The origin of tinnitus had been sudden (hours or days). Fifty-eight patients used Pycnogenol: 24 used 150 mg/day (group A; mean age 43.2+/-4.3) and 34 patients 100 mg/day (group B: mean age 42.4+/-3.8). Controls included 24 patients (mean age 42.3+/-4.5). The groups were comparable for their clinical problem and age and sex. The average duration of treatment was 34.3+/-3.1 days. No side effects were observed and no drop-outs occurred. The variations in cochlear flow velocity (in cm/s at the cochlear artery), at inclusion and after four weeks of treatment indicated that flow velocity at the level of the affected ear was significantly lower (both the diastolic and systolic components; P<0.05) in comparison with the other ear. The treatment favored an improvement in systolic (P<0.05) and diastolic flow velocity (P<0.05) in the two treatment groups A+B. The increase in flow velocity was very limited and not significant in controls. These results suggest that in selected patients with tinnitus and altered perfusion, Pycnogenol is effective in a short period of time in relieving tinnitus symptoms by improving cochlear blood flow. The effect is more pronounced with higher Pycnogenol dosage. More studies should be planned to better evaluate the pathology and potential applications of Pycnogenol in a larger number of patients who are currently without a real therapeutic solution.

Regional muscle tissue saturation is an indicator of global inadequate circulation during cardiopulmonary bypass: a randomized porcine study using muscle, intestinal and brain tissue metabolomics.

PubMed

Thomassen, Sisse Anette; Kjærgaard, Benedict; Sørensen, Preben; Andreasen, Jan Jesper; Larsson, Anders; Rasmussen, Bodil Steen

2017-04-01

Muscle tissue saturation (StO 2 ) measured with near-infrared spectroscopy has generally been considered a measurement of the tissue microcirculatory condition. However, we hypothesized that StO 2 could be more regarded as a fast and reliable measure of global than of regional circulatory adequacy and tested this with muscle, intestinal and brain metabolomics at normal and two levels of low cardiopulmonary bypass blood flow rates in a porcine model. Twelve 80 kg pigs were connected to normothermic cardiopulmonary bypass with a blood flow of 60 mL/kg/min for one hour, reduced randomly to 47.5 mL/kg/min (Group I) or 35 mL/kg/min (Group II) for one hour followed by one hour of 60 mL/kg/min in both groups. Regional StO 2 was measured continuously above the musculus gracilis (non-cannulated leg). Metabolomics were obtained by brain tissue oxygen monitoring system (Licox) measurements of the brain and microdialysis perfusate from the muscle, intestinal mucosa and brain. A non-parametric statistical method was used. The systemic parameters showed profound systemic ischaemia during low CPB blood flow. StO 2 did not change markedly in Group I, but in Group II, StO 2 decreased immediately when blood flow was reduced and, furthermore, was not restored despite blood flow being normalized. Changes in the metabolomics from the muscle, colon and brain followed the changes in StO 2 . We found, in this experimental cardiopulmonary bypass model, that StO 2 reacted rapidly when the systemic circulation became inadequate and, furthermore, reliably indicate insufficient global tissue perfusion even when the systemic circulation was restored after a period of systemic hypoperfusion.

Multimodal pressure-flow method to assess dynamics of cerebral autoregulation in stroke and hypertension

PubMed Central

Novak, Vera; Yang, Albert CC; Lepicovsky, Lukas; Goldberger, Ary L; Lipsitz, Lewis A; Peng, Chung-Kang

2004-01-01

Background This study evaluated the effects of stroke on regulation of cerebral blood flow in response to fluctuations in systemic blood pressure (BP). The autoregulatory dynamics are difficult to assess because of the nonstationarity and nonlinearity of the component signals. Methods We studied 15 normotensive, 20 hypertensive and 15 minor stroke subjects (48.0 ± 1.3 years). BP and blood flow velocities (BFV) from middle cerebral arteries (MCA) were measured during the Valsalva maneuver (VM) using transcranial Doppler ultrasound. Results A new technique, multimodal pressure-flow analysis (MMPF), was implemented to analyze these short, nonstationary signals. MMPF analysis decomposes complex BP and BFV signals into multiple empirical modes, representing their instantaneous frequency-amplitude modulation. The empirical mode corresponding to the VM BP profile was used to construct the continuous phase diagram and to identify the minimum and maximum values from the residual BP (BPR) and BFV (BFVR) signals. The BP-BFV phase shift was calculated as the difference between the phase corresponding to the BPR and BFVR minimum (maximum) values. BP-BFV phase shifts were significantly different between groups. In the normotensive group, the BFVR minimum and maximum preceded the BPR minimum and maximum, respectively, leading to large positive values of BP-BFV shifts. Conclusion In the stroke and hypertensive groups, the resulting BP-BFV phase shift was significantly smaller compared to the normotensive group. A standard autoregulation index did not differentiate the groups. The MMPF method enables evaluation of autoregulatory dynamics based on instantaneous BP-BFV phase analysis. Regulation of BP-BFV dynamics is altered with hypertension and after stroke, rendering blood flow dependent on blood pressure. PMID:15504235

A uniform method for the simultaneous blood group phenotyping of Fya , Fyb , Jka , Jkb , S, s̅, P1, k applying lateral-flow technique.

PubMed

Caesar, A; Meyer, S; Trost, N; Neuenschwander, K; Geisen, C; Frey, B M; Gassner, C; Schwind, P

2018-02-01

A lateral flow assay for simultaneous blood group typing of ABO, RhD, C, E, c, e, Cw and K with stable end-point and without centrifugation is in routine use since several years (MDmulticard ® ). The typing of extended phenotype parameters belonging to the Duffy, Kidd, MNSs blood group systems and others, however, has not yet been demonstrated for this technique. Reliable detection of Fy x , a weak Fy b phenotype with a pronounced quantitative reduction of the number of Fy b antigens on the erythrocyte surface, remains a weakness of current serological blood grouping techniques. The performance characteristics of the following reagents were evaluated in donor and patient samples in lateral flow technology (MDmulticard ® ): Anti-Fy a , -Fy b , -Jk a , -Jk b , -S, -s̅, -P1 and -k. The sensitivity to detect Fy x was in addition evaluated with Fy x positive samples, which had been preselected by MALDI-TOF MS-based genotyping. All results obtained with the MDmulticard ® were in full accordance with those of the CE-certified reference products for all the eight reagent formulations used: Anti-Fy a , -Fy b , -Jk a , -Jk b , -S, -s̅, -P1 and -k. Also, all Fy x phenotypes of the selected population of 93 positive samples, originally identified by MALDI-TOF MS-based genotyping, were reliably detected by the lateral flow assay. Extended phenotype blood group parameters, including the serologically challenging Fy x phenotype, can be determined simultaneously, rapidly and accurately using the lateral flow (MDmulticard ® ) technology, even in cases when IgG class antibodies are the only source of diagnostic antibodies. © 2017 International Society of Blood Transfusion.

Regional Cerebral Blood Flow In Dementia: Receiver-Operating-Characteristic Analysis

NASA Astrophysics Data System (ADS)

Zemcov, Alexander; Barclay, Laurie; Sansone, Joseph; Blass, John P.; Metz, Charles E.

1985-06-01

The coupling of mentation to regional cerebral blood flow (rCBF) has prompted the application of the Xe-133 inhalation method of measuring rCBF in the differential diagnosis of the two most common dementing diseases, Alzheimer's disease and multi-infarct dementia (MID). In this study receiver-operating-characteristic (ROC) curve analysis was used to assess the effectiveness of a 32 detector Xe-133 inhalation system in discriminating between patients with Alzheimer's disease and normal controls, MID patients and normal controls and between patients with Alzheimer's disease and MID. The populations were clinically evaluated as 1) normal (age 63.1 + 13.1, n=23), 2) Alzheimer's disease (age 72.7 + 7.0, n=82), 3) MID (age 76.4 + 7.6, n=27): The mean flow values for all detectors were lowest for the Alzheimer's disease group, larger for the MID group and largest for the normal controls. The dynamic relationship between the correct identifications (true posi-tives) versus incorrect identifications (false positives) per detector for any 2 pairs of clinical groups varies as the cutoff value of flow is changed over the range of experimental blood flow values. Therefore a quantitative characterization of the "decision" or ROC curve (TP vs FP) for each detector and for each pair of clinical groups provides a measure of the overall diagnostic efficacy of the detector. Detectors directed approximately toward the speech, auditory and association cortices were most effective in disciminatinq between each of the dementia groups and the controls. Frontal detectors were diagnostically inefficient. The Xe-133 inhalation system provided virtually no diagnostic power in discriminating between the two forms of dementia, however. Therefore this imaging technology is most useful when assessing the general diagnostic state of dementia (Alz-heimer's disease and MID) from normal cognitive function.

Random regression models using different functions to model milk flow in dairy cows.

PubMed

Laureano, M M M; Bignardi, A B; El Faro, L; Cardoso, V L; Tonhati, H; Albuquerque, L G

2014-09-12

We analyzed 75,555 test-day milk flow records from 2175 primiparous Holstein cows that calved between 1997 and 2005. Milk flow was obtained by dividing the mean milk yield (kg) of the 3 daily milking by the total milking time (min) and was expressed as kg/min. Milk flow was grouped into 43 weekly classes. The analyses were performed using a single-trait Random Regression Models that included direct additive genetic, permanent environmental, and residual random effects. In addition, the contemporary group and linear and quadratic effects of cow age at calving were included as fixed effects. Fourth-order orthogonal Legendre polynomial of days in milk was used to model the mean trend in milk flow. The additive genetic and permanent environmental covariance functions were estimated using random regression Legendre polynomials and B-spline functions of days in milk. The model using a third-order Legendre polynomial for additive genetic effects and a sixth-order polynomial for permanent environmental effects, which contained 7 residual classes, proved to be the most adequate to describe variations in milk flow, and was also the most parsimonious. The heritability in milk flow estimated by the most parsimonious model was of moderate to high magnitude.

Comparison of Effects of Low-Flow Sevoflurane and Low-Flow Desflurane Anaesthesia on Renal Functions Using Cystatin C

PubMed Central

Duymaz, Gökçen; Yağar, Seyhan; Özgök, Ayşegül

2017-01-01

Objective Numerous studies have indicated nephrotoxic effects of sevoflurane because of its two bioproducts compound A and fluoride. Cystatin C (CyC) is a more sensitive biomarker than creatinine to show early and mild changes in kidney function. We designed this prospective randomised study to compare the effects of low-flow sevoflurane anaesthesia and low-flow desflurane anaesthesia on renal functions based on CyC levels. No studies have evaluated the effects of low-flow sevoflurane anaesthesia on renal functions based on CyC levels to date. Methods Thirty American Society of Anesthesiologists (ASA) physical status I–II patients who were scheduled for urological procedures were enrolled in this study. The patients were randomly assigned to 2 groups: low-flow sevoflurane anaesthesia or low-flow desflurane anaesthesia. Serum urea, creatinine and CyC levels were measured before the operation, just before extubation and 24 h after the operation. Creatinine clearance was calculated in the first 24-h urine sample. Results There were no significant differences in serum urea, creatinine and CyC levels or 24 h creatinine clearance between the groups. Conclusion Our study demonstrates with a more sensitive biomarker, CyC, that low-flow sevoflurane anaesthesia is safe in terms of the effects on renal function. PMID:28439441

Counting RG flows

DOE PAGES

Gukov, Sergei

2016-01-05

Here, interpreting renormalization group flows as solitons interpolating between different fixed points, we ask various questions that are normally asked in soliton physics but not in renormalization theory. Can one count RG flows? Are there different "topological sectors" for RG flows? What is the moduli space of an RG flow, and how does it compare to familiar moduli spaces of (supersymmetric) dowain walls? Analyzing these questions in a wide variety of contexts -- from counting RG walls to AdS/CFT correspondence -- will not only provide favorable answers, but will also lead us to a unified general framework that is powerfulmore » enough to account for peculiar RG flows and predict new physical phenomena. Namely, using Bott's version of Morse theory we relate the topology of conformal manifolds to certain properties of RG flows that can be used as precise diagnostics and "topological obstructions" for the strong form of the C-theorem in any dimension. Moreover, this framework suggests a precise mechanism for how the violation of the strong C-theorem happens and predicts "phase transitions" along the RG flow when the topological obstruction is non-trivial. Along the way, we also find new conformal manifolds in well-known 4d CFT's and point out connections with the superconformal index and classifying spaces of global symmetry groups.« less

Study flow diagrams in Cochrane systematic review updates: an adapted PRISMA flow diagram.

PubMed

Stovold, Elizabeth; Beecher, Deirdre; Foxlee, Ruth; Noel-Storr, Anna

2014-05-29

Cochrane systematic reviews are conducted and reported according to rigorous standards. A study flow diagram must be included in a new review, and there is clear guidance from the PRISMA statement on how to do this. However, for a review update, there is currently no guidance on how study flow diagrams should be presented. To address this, a working group was formed to find a solution and produce guidance on how to use these diagrams in review updates.A number of different options were devised for how these flow diagrams could be used in review updates, and also in cases where multiple searches for a review or review update have been conducted. These options were circulated to the Cochrane information specialist community for consultation and feedback. Following the consultation period, the working group refined the guidance and made the recommendation that for review updates an adapted PRISMA flow diagram should be used, which includes an additional box with the number of previously included studies feeding into the total. Where multiple searches have been conducted, the results should be added together and treated as one set of results.There is no existing guidance for using study flow diagrams in review updates. Our adapted diagram is a simple and pragmatic solution for showing the flow of studies in review updates.

Endothelin and vasopressin influence splanchnic blood flow distribution during and after cardiopulmonary bypass.

PubMed

Bomberg, Hagen; Bierbach, Benjamin; Flache, Stephan; Wagner, Isabell; Gläser, Lena; Groesdonk, Heinrich V; Menger, Michael D; Schäfers, Hans-Joachim

2013-02-01

Gastrointestinal blood flow can be compromised during and after cardiopulmonary bypass. Endothelin has been shown to be involved in the intestinal microcirculatory disturbance of sepsis. The aim of the present study was to analyze the involvement of the endothelin system on intestinal blood flow regulation during cardiopulmonary bypass and the effect of vasopressin given during cardiopulmonary bypass. A total of 24 pigs were studied in 4 groups (n = 6): group I, sham; group II, ischemia/reperfusion with 1 hour of superior mesenteric artery occlusion; group III, cardiopulmonary bypass for 1 hour; and group IV, 1 hour of cardiopulmonary bypass plus vasopressin administration, maintaining the baseline arterial pressure. All the pigs were reperfused for 90 minutes. During the experiment, the hemodynamics and jejunal microcirculation were measured continuously. The jejunal mucosal expression of endothelin-1 and its receptor subtypes A and B were determined using polymerase chain reaction. During cardiopulmonary bypass, superior mesenteric artery flow was preserved but marked jejunal microvascular impairment occurred compared with baseline (mucosal capillary density, 192.2 ± 5.4 vs 150.8 ± 5.1 cm/cm(2); P = .005; tissue blood flow, 501.7 ± 39.3 vs 332.3 ± 27.9 AU; P = .025). The expression of endothelin-1 after cardiopulmonary bypass (3.2 ± 0.4 vs 12.2 ± 0.8 RQ, P = .006) and endothelin subtype A (0.7 ± 0.2 vs 2.4 ± 0.6 RQ; P = .01) was significantly increased compared to the sham group. Vasopressin administration during cardiopulmonary bypass led to normal capillary density (189.9 ± 3.9 vs 178.0 ± 6.3; P = .1) and tissue blood flow (501.7 ± 39.3 vs 494.7 ± 44.4 AU; P = .4) compared with baseline. The expression of endothelin-1 (3.2 ± 0.4 vs 1.8 ± 0.3 RQ; P = .3) and endothelin subtype A (0.7 ± 0.2 vs 0.9 ± 0.2 RQ; P = .5) was not different from the sham group. Cardiopulmonary bypass leads to microvascular impairment of jejunal microcirculation, which is associated with the upregulation of endothelin-1 and endothelin subtype A. The administration of vasopressin minimizes these cardiopulmonary bypass-associated alterations. Copyright © 2013 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

A revised catalog of CfA galaxy groups in the Virgo/Great Attractor flow field

NASA Technical Reports Server (NTRS)

Nolthenius, Richard

1993-01-01

A new identification of groups and clusters in the CfAl Catalog of Huchra, et al. (1983) is presented, using a percolation algorithm to identify density enhancements. The procedure differs from that of the original Geller and Huchra (1983; GH) catalog in several important respects; galaxy distances are calculated from the Virgo-Great Attractor flow model of Faber and Burnstein (1988), the adopted distance linkage criteria is only approx. 1/4 as large as in the Geller and Huchra catalog, the sky link relation is taken from Nolthenius and White (1987), correction for interstellar extinction is included, and 'by-hand' adjustments to group memberships are made in the complex regions of Virgo/Coma I/Ursa Major and Coma/A1367 (to allow for varying group velocity dispersions and to trim unphysical 'spider arms'). Since flow model distances are poorly determined in these same regions, available distances from the IR Tully-Fisher planetary nebula luminosity function and surface brightness resolution methods are adopted if possible.

Effect of cevimeline on salivary components in patients with Sjögren syndrome.

PubMed

Suzuki, Kimihiro; Matsumoto, Mitsuyo; Nakashima, Masahiro; Takada, Kunio; Nakanishi, Takashi; Okada, Makoto; Ohsuzu, Fumitaka

2005-05-01

The aim of this study is to clarify the effects of cevimeline on various components in human saliva, such as immunoglobulin A (IgA), lysozyme, alpha-amylase and squamous cell carcinoma (SCC) antigen. Twelve female patients with Sjögren syndrome (SS) and 14 healthy women were enrolled. After the first saliva collection, one capsule (30 mg) of cevimeline was administered to each subject. Saliva was collected again after 90 min. The salivary flow rate and concentration of each component were measured. In both groups the salivary flow rate and amylase concentration were significantly increased by cevimeline. The lysozyme and IgA concentrations did not change significantly in both groups. The SCC antigen concentration did not change significantly in the SS group, but it decreased significantly in the control group. The secretion rates of amylase and IgA showed significant increases in both groups. The secretion rate of lysozyme significantly increased only in the control group, while the secretion rate of SCC significantly increased only in the SS group. Cevimeline augments not only the salivary flow rate but also the secretion rate of some digestive and/or defense factors from infections. It may be beneficial for SS patients to continue taking cevimeline to prevent oral infections, and other serious sequelae. Copyright (c) 2005 S. Karger AG, Basel.

Influence of Intradialytic Aerobic Training in Cerebral Blood Flow and Cognitive Function in Patients with Chronic Kidney Disease: A Pilot Randomized Controlled Trial.

PubMed

Stringuetta Belik, Fernanda; Oliveira E Silva, Viviana Rugolo; Braga, Gabriel Pereira; Bazan, Rodrigo; Perez Vogt, Barbara; Costa Teixeira Caramori, Jacqueline; Barretti, Pasqual; de Souza Gonçalves, Renato; Fortes Villas Bôas, Paulo José; Hueb, João Carlos; Martin, Luis Cuadrado; da Silva Franco, Roberto Jorge

2018-06-07

Changes in cerebral blood flow may play an important role in cognitive impairment among hemodialysis (HD) patients. Physical activity has a promising role in delaying cognitive impairment in general population, but there are only a few studies in HD to confirm this finding. We aimed to evaluate the effects of intradialytic aerobic training on cerebral blood flow and cognitive impairment in HD. This is a pilot, controlled, randomized trial. Fifteen patients underwent intradialytic aerobic training 3 times a week for 4 months. The control group was comprised of another 15 patients. Trained patients had a statistically significant improvement of cognitive impairment and basilar maximum blood flow velocity. The proportion of arteries with increased flow velocity was statistically significant between groups. Intradialytic aerobic training improves cognitive impairment and cerebral blood flow of patients in HD, suggesting a possible mechanism improving cognitive impairment by physical training in HD. These data still need to be confirmed by major trials. © 2018 S. Karger AG, Basel.

Improved brachial artery shear patterns and increased flow-mediated dilation after low-volume high-intensity interval training in type 2 diabetes.

PubMed

Ghardashi Afousi, Alireza; Izadi, Mohammad Reza; Rakhshan, Kamran; Mafi, Farnoosh; Biglari, Soheil; Gandomkar Bagheri, Habibalah

2018-06-22

What is the central question of this study? Endothelial function is impaired because of increased oscillatory and retrograde shear in patients with type 2 diabetes. It is unclear whether low-volume high-intensity interval training and continuous moderate intensity exercise can modulate oscillatory and retrograde shear, blood flow and flow-mediated arterial dilation in these patients. What is the main finding and its importance? We found that low-volume high-intensity interval training, by increasing anterograde shear and decreasing retrograde shear and oscillatory index, can increase nitric oxide production and consequently result in increased flow-mediated dilation and outward arterial remodelling in patients with type 2 diabetes. Atherosclerosis in patients with type 2 diabetes is characterized by endothelial dysfunction associated with impaired flow-mediated dilation (FMD) and increases retrograde and oscillatory shear. The present study investigated endothelium-dependent vasodilation and shear rate in patients with type 2 diabetes at baseline and follow-up after 12 weeks of low-volume high-intensity interval training (LV-HIIT) or continuous moderate intensity training (CMIT). Seventy five sedentary patients with type 2 diabetes and untreated pre- or stage I hypertension were randomly divided into LV-HIIT, CMIT and control groups. The LV-HIIT group intervention was 12 intervals of 1.5 min at 85%-90% HR max and 2 min at 55%-60% HR max . The CMIT group intervention was 42 min of exercise at 70% HR max for 3 sessions per week during 12 weeks. High-resolution Doppler ultrasound was used to measure FMD, arterial diameter, anterograde and retrograde blood flow and shear rate patterns. Brachial artery FMD increased significantly in the LV-HIIT group (3.83 ± 1.13 baseline, 7.39 ± 3.6% follow-up), whereas there were no significant increase in the CMIT group (3.45 ± 0.97 baseline, 4.81 ± 2.36% follow-up) compared to the control group (3.16 ± 0.78 baseline, 4.04 ± 1.28% follow-up) (P < 0.05). Retrograde shear in the LV-HIIT group decreased significantly (P < 0.05), and no significant decrease in retrograde shear was seen in the CMIT group. Anterograde shear after LV-HIIT increased significantly (P < 0.05) but was unchanged in the CMIT group. However, oscillatory shear index in both exercise groups decreased significantly (P = 0.029). Nitrite/nitrate (NOx) level increased in both exercise groups, but the increase was greater in the LV-HIIT group (P < 0.001). Our results indicate that by increasing NOx, HIIT decreases the oscillatory shear-induced improvement in FMD and outward artery remodelling in patients with T2D. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Evaluation of Salivary Flow Rate, pH and Buffer in Pre, Post & Post Menopausal Women on HRT

PubMed Central

D.R., Mahesh; G., Komali; K., Jayanthi; D., Dinesh; T.V., Saikavitha; Dinesh, Preeti

2014-01-01

Background: Climateric is considered to be a natural phase of life which by definition is the period of life starting from decline in ovarian activity until after the end of ovarian function. It is accompanied by various health consequences that include the changes in saliva too. This study was carried out to evaluate the salivary flow rate, pH, buffering capacity in pre-menopausal, post-menopausal and post-menopausal women on HRT. Aims and objectives: (1) To evaluate the salivary flow rate, pH of resting saliva and stimulated saliva and buffer capacity of stimulated saliva in pre-menopausal, post-menopausal and post-menopausal women on Hormone Replacement Therapy (HRT). (2) To compare the above salivary findings between pre-menopausal, post-menopausal and post-menopausal women on HRT. Materials and Methods: The study was carried out on 60 patients. These patients were divided into three groups of 20 patients: Group 1: Pre-menopausal women (control), Group 2: post-menopausal women (case), Group 3: post-menopausal women on HRT (case). The control group consisted of 20 women volunteers, having regular ovulatory menstrual cycles with no known systemic illness and deleterious habits and Group 2 consists of 20 post-menopausal women and Group 3 will consist of 20 post-menopausal women on HRT. After clearing the mouth by swallowing, stimulated saliva was collected after chewing paraffin for 10 mins in to a glass centrifuge tube graded in 0.1 mL increments up to 10mL.in rare cases the collection time will be reduced or extended (5-15 min), salivary flow rate will be determined as ml/min, immediately after collection, pH was determined by dipping pH test paper directly into the sample of oral fluid, salivary buffer capacity was determined by using saliva check buffer kit (GC corporation). The data obtained was statistically evaluated using chi-square test, fisher exact test ANOVA analysis. Results: In our study we found salivary flow rate significantly lower in the post-menopausal women in comparison with the menstruating women and also there was improvement in the flow rate in individuals who were on HRT, it was also observed that salivary pH of the post-menopausal group was significantly lower than that of the control group, statistically significant difference in buffer capacity values was found between the groups however buffer capacity values were higher in the post-menopausal group than the control group. Conclusion: From the above study it is clear that post-menopausal women will present with oral discomfort, while HRT can improve the same. Hence our role as physicians and health care providers is to incorporate preventive dental health care in post-menopausal women and clearly inform patients about both the benefits and the limitations of HRT. PMID:24701542

Correlation of the Deccan and Rajahmundry Trap lavas: Are these the longest and largest lava flows on Earth?

NASA Astrophysics Data System (ADS)

Self, S.; Jay, A. E.; Widdowson, M.; Keszthelyi, L. P.

2008-05-01

We propose that the Rajahmundry Trap lavas, found near the east coast of peninsular India , are remnants of the longest lava flows yet recognized on Earth (˜ 1000 km long). These outlying Deccan-like lavas are shown to belong to the main Deccan Traps. Several previous studies have already suggested this correlation, but have not demonstrated it categorically. The exposed Rajahmundry lavas are interpreted to be the distal parts of two very-large-volume pāhoehoe flow fields, one each from the Ambenali and Mahabaleshwar Formations of the Wai Sub-group in the Deccan Basalt Group. Eruptive conditions required to emplace such long flows are met by plausible values for cooling and eruption rates, and this is shown by applying a model for the formation of inflated pāhoehoe sheet flow lobes. The model predicts flow lobe thicknesses similar to those observed in the Rajahmundry lavas. For the last 400 km of flow, the lava flows were confined to the pre-existing Krishna valley drainage system that existed in the basement beyond the edge of the gradually expanding Deccan lava field, allowing the flows to extend across the subcontinent to the eastern margin where they were emplaced into a littoral and/or shallow marine environment. These lavas and other individual flow fields in the Wai Sub-group may exceed eruptive volumes of 5000 km 3, which would place them amongst the largest magnitude effusive eruptive units yet known. We suggest that the length of flood basalt lava flows on Earth is restricted mainly by the size of land masses and topography. In the case of the Rajahmundry lavas, the flows reached estuaries and the sea, where their advance was perhaps effectively terminated by cooling and/or disruption. However, it is only during large igneous province basaltic volcanism that such huge volumes of lava are erupted in single events, and when the magma supply rate is sufficiently high and maintained to allow the formation of very long lava flows. The Rajahmundry lava fields were emplaced around 65 Ma during the later times of Deccan volcanism, probably just after the K/T environmental crisis. However, many lava-forming eruptions of similar magnitude and style straddled the K/T boundary.

Correlation of the Deccan and Rajahmundry Trap lavas: Are these the longest and largest lava flows on Earth?

USGS Publications Warehouse

Self, S.; Jay, A.E.; Widdowson, M.; Keszthelyi, L.P.

2008-01-01

We propose that the Rajahmundry Trap lavas, found near the east coast of peninsular India, are remnants of the longest lava flows yet recognized on Earth (??? 1000??km long). These outlying Deccan-like lavas are shown to belong to the main Deccan Traps. Several previous studies have already suggested this correlation, but have not demonstrated it categorically. The exposed Rajahmundry lavas are interpreted to be the distal parts of two very-large-volume pa??hoehoe flow fields, one each from the Ambenali and Mahabaleshwar Formations of the Wai Sub-group in the Deccan Basalt Group. Eruptive conditions required to emplace such long flows are met by plausible values for cooling and eruption rates, and this is shown by applying a model for the formation of inflated pa??hoehoe sheet flow lobes. The model predicts flow lobe thicknesses similar to those observed in the Rajahmundry lavas. For the last 400??km of flow, the lava flows were confined to the pre-existing Krishna valley drainage system that existed in the basement beyond the edge of the gradually expanding Deccan lava field, allowing the flows to extend across the subcontinent to the eastern margin where they were emplaced into a littoral and/or shallow marine environment. These lavas and other individual flow fields in the Wai Sub-group may exceed eruptive volumes of 5000??km3, which would place them amongst the largest magnitude effusive eruptive units yet known. We suggest that the length of flood basalt lava flows on Earth is restricted mainly by the size of land masses and topography. In the case of the Rajahmundry lavas, the flows reached estuaries and the sea, where their advance was perhaps effectively terminated by cooling and/or disruption. However, it is only during large igneous province basaltic volcanism that such huge volumes of lava are erupted in single events, and when the magma supply rate is sufficiently high and maintained to allow the formation of very long lava flows. The Rajahmundry lava fields were emplaced around 65??Ma during the later times of Deccan volcanism, probably just after the K/T environmental crisis. However, many lava-forming eruptions of similar magnitude and style straddled the K/T boundary. ?? 2007 Elsevier B.V. All rights reserved.

Group solution for unsteady free-convection flow from a vertical moving plate subjected to constant heat flux

NASA Astrophysics Data System (ADS)

Kassem, M.

2006-03-01

The problem of heat and mass transfer in an unsteady free-convection flow over a continuous moving vertical sheet in an ambient fluid is investigated for constant heat flux using the group theoretical method. The nonlinear coupled partial differential equation governing the flow and the boundary conditions are transformed to a system of ordinary differential equations with appropriate boundary conditions. The obtained ordinary differential equations are solved numerically using the shooting method. The effect of Prandlt number on the velocity and temperature of the boundary-layer is plotted in curves. A comparison with previous work is presented.

Late-Pleistocene to precolumbian behind-the-arc mafic volcanism in the eastern Mexican Volcanic Belt; implications for future hazards

NASA Astrophysics Data System (ADS)

Siebert, Lee; Carrasco-Núñez, Gerardo

2002-06-01

An area of widespread alkaline-to-subalkaline volcanism lies at the northern end of the Cofre de Perote-Citlaltépetl (Pico de Orizaba) volcanic chain in the eastern Mexican Volcanic Belt (MVB). Two principal areas were active. About a dozen latest-Pleistocene to precolumbian vents form the 11-km-wide, E-W-trending Cofre de Perote vent cluster (CPVC) at 2300-2800 m elevation on the flank of the largely Pleistocene Cofre de Perote shield volcano and produced an extensive lava field that covers >100 km 2. More widely dispersed vents form the Naolinco volcanic field (NVF) in the Sierra de Chiconquiaco north of the city of Jalapa (Xalapa). Three generations of flows are delineated by cone and lava-flow morphology, degree of vegetation and cultivation, and radiocarbon dating. The flows lie in the behind-the-arc portion of the northeastern part of the MVB and show major- and trace-element chemical patterns transitional between intraplate and subduction zone environments. Flows of the oldest group originated from La Joya cinder cone (radiocarbon ages ˜42 000 yr BP) at the eastern end of the CPVC. This cone fed an olivine-basaltic flow field of ˜20 km 2 that extends about 14 km southeast to underlie the heavily populated northern outskirts of Jalapa, the capital city of the state of Veracruz. The Central Cone Group (CCG), of intermediate age, consists of four morphologically youthful cinder cones and associated vents that were the source of a lava field>27 km 2 of late-Pleistocene or Holocene age. The youngest group includes the westernmost flow, from Cerro Colorado, and a lava flow ˜2980 BP from the Rincón de Chapultepec scoria cone of the NVF. The latest eruption, from the compound El Volcancillo scoria cone, occurred about 870 radiocarbon years ago and produced two chemically and rheologically diverse lava flows that are among the youngest precolumbian flows in México and resemble paired aa-pahoehoe flows from Mauna Loa volcano. The El Volcancillo eruption initially produced the high effusion rate, short-duration Toxtlacuaya alkaline aa lava flow from the southeastern crater. This 12-km-long hawaiite (average 50.5% SiO 2) flow was followed by extrusion of the calc-alkaline Río Naolinco lava flow from the northwestern crater. This large-volume (˜1.3 km 3) tube-fed basaltic pahoehoe flow (average SiO 2 49%) traveled 50 km. Inferred effusion rates suggest emplacement over a decade-long period. Flows of all three age groups are transected by Highway 140 and the railway that form major transportation arteries between Jalapa and Puebla. This area has not previously been considered to be at volcanic risk, but volcanism here has continued into precolumbian time. Future eruptions of similar magnitude and location to those documented here could pose significant hazards to transportation corridors and to densely populated areas in and to the north of Jalapa. Slight variations in vent locations could produce future flows down one or more of more than a half dozen drainages with widely varying population densities.

Functional renormalization group for the U (1 )-T56 tensorial group field theory with closure constraint

NASA Astrophysics Data System (ADS)

Lahoche, Vincent; Ousmane Samary, Dine

2017-02-01

This paper is focused on the functional renormalization group applied to the T56 tensor model on the Abelian group U (1 ) with closure constraint. For the first time, we derive the flow equations for the couplings and mass parameters in a suitable truncation around the marginal interactions with respect to the perturbative power counting. For the second time, we study the behavior around the Gaussian fixed point, and show that the theory is nonasymptotically free. Finally, we discuss the UV completion of the theory. We show the existence of several nontrivial fixed points, study the behavior of the renormalization group flow around them, and point out evidence in favor of an asymptotically safe theory.

Ureteroscopic skills with and without Roboflex Avicenna in the K-box® simulator.

PubMed

Proietti, Silvia; Dragos, Laurian; Emiliani, Esteban; Butticè, Salvatore; Talso, Michele; Baghdadi, Mohammed; Villa, Luca; Doizi, Steeve; Giusti, Guido; Traxer, Olivier

2017-01-01

The aim of this study was to evaluate the acquisition of basic ureteroscopic skills with and without Roboflex Avicenna by subjects with no prior surgical training. Ten medical students were divided in two groups: Group 1 was trained with Roboflex Avicenna and Group 2 with flexible ureteroscope alone, using the K-box ® simulator model. Participants were scored on their ability to perform or not two exercises, recording the time. In addition, the participants were evaluated on the quality of their performance for the following parameters: respect of the surrounding environment, flow of the operation, orientation, vision centering and stability. The first exercise was completed only by three and four out of five of students in Group 1 and Group 2, respectively. Stability with the scope was significantly more accurate in the first group compared with the second (P = 0.02). There were no differences in timing, flow or orientation between groups. Although not significant, a tendency of respecting the surrounding tissue and maintaining centered vision was perceived more in the first group. As for the second exercise, there were no differences between groups in regard of orientation, flow, respecting the surrounding tissue, stability or the ability of maintaining centered vision. Although not significant, the second group had a tendency of performing the exercise faster. According to these preliminary results, the acquisition of basic ureteroscopic skills with and without robotic fURS in the K-box ® simulator, by subjects with no prior surgical training, is similar.

Solid-loaded flows: applications in technology

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

Molerus, O.

1983-01-01

The evaluation of experiments and the representation of the resulting data by nondimensional groups defined ad hoc largely governs the treatment of problems arising with solid-loaded flows in practice. Without doubt, this is a result of the very complex nature of solid-loaded flows and, consequently, empiricism tends to prevail, more or less. To overcome this situation, two sets of nondimensional groups, which take into consideration the translatory, as well as the rotary, motion of particles suspended in a fluid, are derived from the equations of motion of a solid body. The intuitive meaning of these nondimensional groups arises from theirmore » derivation. With respect to applications in engineering, the influence of the rotary motion of a particle on the motion of its center of gravity can thus be taken into account. As such, a common basis for the representation of the different phenomena observed with solid-loaded flows is established. The application of the above concepts to fluidization and hydraulic and pneumatic conveying proves their usefulness. New insights into well-known facts as well as new results demonstrate that taking the real nature of solid particles (i.e., those of finite dimensions) into consideration will provide a common and profound basis for the representation of different phenomena observed with solid-loaded flows in practice.« less

Comparative Evaluation of Sealing Ability of Three Newer Root Canal Obturating Materials Guttaflow, Resilon and Thermafil: An In Vitro Study

PubMed Central

H Bhandi, Shilpa; T S, Subhash

2013-01-01

Introduction: Microleakage continues to be a main reason for failure of root canal treatment where the challenge has been to achieve an adequate seal between the internal structure and the main obturating material. The objective of this study is to compare the sealing ability of 3 newer obturating materials GuttaFlow, Resilon/Epiphany system (RES) and Thermafil, using silver nitrate dye and observing under stereomicroscope. Methodology: Thirty single rooted teeth were divided into following groups. Group I : GuttaFlow ;Group II : Resilon /Epiphany sealer Group III : Thermafil with AH-Plus sealer. Teeth were decoronated and instrumented with profile rotary system and obturated with specified materials. Apical seal was determined by dye penetration method using silver nitrate. Then the specimens were transversely sectioned at each mm till 3 mm from the apex. Dye leakage was determined using stereomicroscope. Statistical analysis of the results was performed using Kruskall-Wallis test. Results: The results showed that Group II i.e., Resilon with Epiphany sealer showed the least amount of microleakage when compared to Group I i.e., GuttaFlow and Group III i.e., Thermafil with AH-plus sealer. Conclusion: Based on the results of this study it can be concluded that RES had higher sealing ability followed by Thermafil and GuttaFlow in vitro but further studies have to be carried out to make a direct correlation between these results and invivo situation. How to cite this article: Bhandi S H, Subhash T S. Comparative Evaluation of Sealing Ability of Three Newer Root Canal Obturating Materials Guttaflow, Resilon and Thermafil: An In Vitro Study. J Int Oral Health 2013; 5(1):54-65. PMID:24155579

Dark Energy Domination In The Virgocentric Flow

NASA Astrophysics Data System (ADS)

Byrd, Gene; Chernin, A. D.; Karachentsev, I. D.; Teerikorpi, P.; Valtonen, M.; Dolgachev, V. P.; Domozhilova, L. M.

2011-04-01

Dark energy (DE) was first observationally detected at large Gpc distances. If it is a vacuum energy formulated as Einstein's cosmological constant, Λ, DE should also have dynamical effects at much smaller scales. Previously, we found its effects on much smaller Mpc scales in our Local Group (LG) as well as in other nearby groups. We used new HST observations of member 3D distances from the group centers and Doppler shifts. We find each group's gravity dominates a bound central system of galaxies but DE antigravity results in a radial recession increasing with distance from the group center of the outer members. Here we focus on the much larger (but still cosmologically local) Virgo Cluster and systems around it using new observations of velocities and distances. We propose an analytic model whose key parameter is the zero-gravity radius (ZGR) from the cluster center where gravity and DE antigravity balance. DE brings regularity to the Virgocentric flow. Beyond Virgo's 10 Mpc ZGR, the flow curves to approach a linear global Hubble law at larger distances. The Virgo cluster and its outer flow are similar to the Local Group and its local outflow with a scaling factor of about 10; the ZGR for Virgo is 10 times larger than that of the LG. The similarity of the two systems on the scales of 1 to 30 Mpc suggests that a quasi-stationary bound central component and an expanding outflow applies to a wide range of groups and clusters due to small scale action of DE as well as gravity. Chernin, et al 2009 Astronomy and Astrophysics 507, 1271 http://arxiv.org/abs/1006.0066 http://arxiv.org/abs/1006.0555

Relationship among salivary carbonic anhydrase VI activity and flow rate, biofilm pH and caries in primary dentition.

PubMed

Frasseto, F; Parisotto, T M; Peres, R C R; Marques, M R; Line, S R P; Nobre Dos Santos, M

2012-01-01

This study aimed to determine the activity of carbonic anhydrase isoenzyme VI (CAVI) in the saliva of preschool children with caries and to investigate the relationship between caries and salivary CAVI activity, salivary flow rate and biofilm pH before and after a 20% sucrose rinse. Thirty preschool children aged 45.3-80.3 months were divided into two groups: a caries-free group and a caries group. Clinical examinations were conducted by one examiner (κ = 0.95) according to WHO criteria (dmfs) and early caries lesions. From each subject, CAVI activity, salivary flow rate and plaque pH were determined before and after a sucrose rinse. The results were submitted to Wilcoxon, Mann-Whitney and Spearman correlation tests (α = 0.05). The results showed that prerinse CAVI activity and its variation were higher in the saliva from caries children than from caries-free children. No difference was found between the two groups in postrinse salivary CAVI activity. After rinsing, biofilm pH differences were lower in both groups (p = 0.0012 and p = 0.0037 for the caries and caries-free groups, respectively). Also, after the sucrose rinse, salivary flow rate significantly increased in caries and caries-free groups (p = 0.0003, p = 0.0037). The variation of salivary CAVI activity was negatively correlated with caries (r = -0.501, p = 0.005). Child's age showed a positive correlation with caries (r = 0.456, p = 0.011). These results suggest that variation of salivary CAVI activity and child's age are associated with dental caries in preschool children. Copyright © 2012 S. Karger AG, Basel.

GPSS and Modeling of Computer Communication Networks.

DTIC Science & Technology

1982-04-01

chains are used to alter the normal "flows" of transactions in a user defined manner. Transaction "flow" may be controlled on the basis of group ...authors refer to loops and rings interchangeably, including those who have designed loop networks with distributed control mechanisms [8,9,10,11,121...that detailed simulation of character by character transmission does not take place; rather, [ control message--data message-- control message! groupings

Quantum corrections for spinning particles in de Sitter

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

Fröb, Markus B.; Verdaguer, Enric, E-mail: mbf503@york.ac.uk, E-mail: enric.verdaguer@ub.edu

We compute the one-loop quantum corrections to the gravitational potentials of a spinning point particle in a de Sitter background, due to the vacuum polarisation induced by conformal fields in an effective field theory approach. We consider arbitrary conformal field theories, assuming only that the theory contains a large number N of fields in order to separate their contribution from the one induced by virtual gravitons. The corrections are described in a gauge-invariant way, classifying the induced metric perturbations around the de Sitter background according to their behaviour under transformations on equal-time hypersurfaces. There are six gauge-invariant modes: two scalarmore » Bardeen potentials, one transverse vector and one transverse traceless tensor, of which one scalar and the vector couple to the spinning particle. The quantum corrections consist of three different parts: a generalisation of the flat-space correction, which is only significant at distances of the order of the Planck length; a constant correction depending on the undetermined parameters of the renormalised effective action; and a term which grows logarithmically with the distance from the particle. This last term is the most interesting, and when resummed gives a modified power law, enhancing the gravitational force at large distances. As a check on the accuracy of our calculation, we recover the linearised Kerr-de Sitter metric in the classical limit and the flat-space quantum correction in the limit of vanishing Hubble constant.« less

A study of Tycho's SNR at TeV energies with the HEGRA CT-System

NASA Astrophysics Data System (ADS)

Aharonian, F. A.; Akhperjanian, A. G.; Barrio, J. A.; Bernlöhr, K.; Börst, H.; Bojahr, H.; Bolz, O.; Contreras, J. L.; Cortina, J.; Denninghoff, S.; Fonseca, V.; Gonzalez, J. C.; Götting, N.; Heinzelmann, G.; Hermann, G.; Heusler, A.; Hofmann, W.; Horns, D.; Ibarra, A.; Jung, I.; Kankanyan, R.; Kestel, M.; Kettler, J.; Kohnle, A.; Konopelko, A.; Kornmeyer, H.; Kranich, D.; Krawczynski, H.; Lampeitl, H.; Lorenz, E.; Lucarelli, F.; Magnussen, N.; Mang, O.; Meyer, H.; Mirzoyan, R.; Moralejo, A.; Padilla, L.; Panter, M.; Plaga, R.; Plyasheshnikov, A.; Prahl, J.; Pühlhofer, G.; Rauterberg, G.; Röhring, A.; Rhode, W.; Rowell, G. P.; Sahakian, V.; Samorski, M.; Schilling, M.; Schröder, F.; Stamm, W.; Tluczykont, M.; Völk, H. J.; Wiedner, C.; Wittek, W.

2001-07-01

Tycho's supernova remnant (SNR) was observed during 1997 and 1998 with the HEGRA Čerenkov Telescope System in a search for gamma-ray emission at energies above ~ 1 TeV. An analysis of these data, ~ 65 hours in total, resulted in no evidence for TeV gamma-ray emission. The 3sigma upper limit to the gamma-ray flux (>1 TeV) from Tycho is estimated at 5.78x 10-13 photons cm-2 s-1, or 33 milli-Crab. We interpret our upper limit within the framework of the following scenarios: (1) that the observed hard X-ray tail is due to synchrotron emission. A lower limit on the magnetic field within Tycho may be estimated B>=22 mu G, assuming that the RXTE-detected X-rays were due to synchrotron emission. However, using results from a detailed model of the ASCA emission, a more conservative lower limit B>=6 mu G is derived. (2) The hadronic model of Drury and (3) the more recent time-dependent kinetic theory of Berezhko & Völk. Our upper limit lies within the range of predicted values of both hadronic models, according to uncertainties in physical parameters of Tycho, and shock acceleration details. In the latter case, the model was scaled to suit the parameters of Tycho and re-normalised to account for a simplification of the original model. We find that we cannot rule out Tycho as a potential contributor at an average level to the Galactic cosmic-ray flux.

Superconductivity, pseudo-gap, and stripe correlations in high-Tc cuprates

NASA Astrophysics Data System (ADS)

Zhang, Zailan; Denis, Sylvain; Lebert, Blair W.; Bertran, Francois; Le Fèvre, Patrick; Taleb-Ibrahimi, Amina; Castellan, John-Paul; Bolloc'h, David Le; Jacques, Vincent L. R.; Sidis, Yvan; Baptiste, Benoît; Decorse, Claudia; Berthet, Patrick; Perfetti, Luca; d'Astuto, Matteo

2018-05-01

Under-doped La-214 cuprates show a charge- and spin-modulation known as "stripes" [1]. These stripe modulations are (quasi)-static close to 1/8 hole doping where superconductivity is suppressed. The pseudo-gap phase of other cuprate compounds recently also revealed charge modulation, but interpreted rather as a charge density wave (CDW) [2-4], that possibly competes with superconductivity. In this context, to better understand the interplay between the stripe phase and the superconductivity, we use angle-resolved photoemission spectroscopy to study the electronic band structure and gap in La-214 cuprates near 1/8 doping (La2-x-yNdySrxCuO4 (x = 0.12; y = 0.0 & 0.4)) and compare with the previous results in the same system [5] and La1.86Ba0.14CuO4 [6]. Our data shows a loss of spectral intensity towards the end of the Fermi arcs, that is possibly due to a strong renormalisation, as already pointed out elsewhere [6], with a noisy but still measurable gap. On the nodal direction no gap is observed within our statistics, but a sizeable decrease in intensity with temperature. Moreover, we do not see any shadow band, but our Fermi surface can be well modelled with a single electron band calculation in the tight binding approximation, even very close to the 1/8 doping La2-x-yNdySrxCuO4 with and without Nd substitution.

The integrated bispectrum and beyond

NASA Astrophysics Data System (ADS)

Munshi, Dipak; Coles, Peter

2017-02-01

The position-dependent power spectrum has been recently proposed as a descriptor of gravitationally induced non-Gaussianity in galaxy clustering, as it is sensitive to the "soft limit" of the bispectrum (i.e. when one of the wave number tends to zero). We generalise this concept to higher order and clarify their relationship to other known statistics such as the skew-spectrum, the kurt-spectra and their real-space counterparts the cumulants correlators. Using the Hierarchical Ansatz (HA) as a toy model for the higher order correlation hierarchy, we show how in the soft limit, polyspectra at a given order can be identified with lower order polyspectra with the same geometrical dependence but with renormalised amplitudes expressed in terms of amplitudes of the original polyspectra. We extend the concept of position-dependent bispectrum to bispectrum of the divergence of the velocity field Θ and mixed multispectra involving δ and Θ in the 3D perturbative regime. To quantify the effects of transients in numerical simulations, we also present results for lowest order in Lagrangian perturbation theory (LPT) or the Zel'dovich approximation (ZA). Finally, we discuss how to extend the position-dependent spectrum concept to encompass cross-spectra. And finally study the application of this concept to two dimensions (2D), for projected galaxy maps, convergence κ maps from weak-lensing surveys or maps of CMB secondaries e.g. the frequency cleaned y-parameter maps of thermal Sunyaev-Zel'dovich (tSZ) effect from CMB surveys.

The integrated bispectrum and beyond

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

Munshi, Dipak; Coles, Peter, E-mail: D.Munshi@sussex.ac.uk, E-mail: P.Coles@sussex.ac.uk

2017-02-01

The position-dependent power spectrum has been recently proposed as a descriptor of gravitationally induced non-Gaussianity in galaxy clustering, as it is sensitive to the 'soft limit' of the bispectrum (i.e. when one of the wave number tends to zero). We generalise this concept to higher order and clarify their relationship to other known statistics such as the skew-spectrum, the kurt-spectra and their real-space counterparts the cumulants correlators. Using the Hierarchical Ansatz (HA) as a toy model for the higher order correlation hierarchy, we show how in the soft limit, polyspectra at a given order can be identified with lower ordermore » polyspectra with the same geometrical dependence but with renormalised amplitudes expressed in terms of amplitudes of the original polyspectra. We extend the concept of position-dependent bispectrum to bispectrum of the divergence of the velocity field Θ and mixed multispectra involving δ and Θ in the 3D perturbative regime. To quantify the effects of transients in numerical simulations, we also present results for lowest order in Lagrangian perturbation theory (LPT) or the Zel'dovich approximation (ZA). Finally, we discuss how to extend the position-dependent spectrum concept to encompass cross-spectra. And finally study the application of this concept to two dimensions (2D), for projected galaxy maps, convergence κ maps from weak-lensing surveys or maps of CMB secondaries e.g. the frequency cleaned y -parameter maps of thermal Sunyaev-Zel'dovich (tSZ) effect from CMB surveys.« less

Impact of continuous positive airway pressure (CPAP) on the respiratory capacity of chronic kidney disease patients under hemodialysis treatment.

PubMed

Xavier, Vivian Bertoni; Roxo, Renata Spósito; Miorin, Luiz Antônio; Dos Santos Alves, Vera Lúcia; Dos Santos Sens, Yvoty Alves

2015-06-01

Chronic kidney disease (CKD) patients on long-term dialysis present changes in pulmonary function and respiratory muscle strength, negatively influencing physical capacity. To analyze the impact of a continuous positive airway pressure (CPAP) protocol on the respiratory capacity of CKD patients under hemodialysis. A randomized clinical trial was conducted involving 40 CKD patients 19-83 years old divided into two groups: control (n = 20) and CPAP (n = 20). Subjects were assessed on the respiratory muscle function test, maximal respiratory pressures, peak flow and 6-min walk test, at baseline and again at the 2-month follow-up. CPAP group patients were submitted to CPAP protocol (PEEP: 5 cm H2O, flow: 15 L/min, FiO2: 33 %) three times per week during hemodialysis sessions. The CPAP group showed higher forced vital capacity, forced expiratory volume in one second, peak expiratory flow, maximal inspiratory pressure, peak flow, as well as lower systolic blood pressure, heart rate, respiratory rate and Borg scale, in addition to a longer distance travelled on the 6-min walk test, compared with the control group. The introduction of a CPAP protocol during hemodialysis sessions had a positive impact on pulmonary function and physical capacity in CKD patients.

Conservation laws of wave action and potential enstrophy for Rossby waves in a stratified atmosphere

NASA Technical Reports Server (NTRS)

Straus, D. M.

1983-01-01

The evolution of wave energy, enstrophy, and wave motion for atmospheric Rossby waves in a variable mean flow are discussed from a theoretical and pedagogic standpoint. In the absence of mean flow gradients, the wave energy density satisfies a local conservation law, with the appropriate flow velocity being the group velocity. In the presence of mean flow variations, wave energy is not conserved, but wave action is, provided the mean flow is independent of longitude. Wave enstrophy is conserved for arbitrary variations of the mean flow. Connections with Eiiassen-Palm flux are also discussed.

Conservation laws of wave action and potential enstrophy for Rossby waves in a stratified atmosphere

NASA Technical Reports Server (NTRS)

Straus, D. M.

1983-01-01

The evolution of wave energy, enstrophy, and wave motion for atmospheric Rossby waves in a variable mean flow are discussed from a theoretical and pedagogic standpoint. In the absence of mean flow gradients, the wave energy density satisfies a local conservation law, with the appropriate flow velocity being the group velocity. In the presence of mean flow variations, wave energy is not conserved, but wave action is, provided the mean flow is independent of longitude. Wave enstrophy is conserved for arbitrary variations of the mean flow. Connections with Eliassen-Palm flux are also discussed.

Microvascular Responsiveness to Pulsatile and Nonpulsatile Flow During Cardiopulmonary Bypass.

PubMed

O'Neil, Michael P; Alie, Rene; Guo, Linrui Ray; Myers, Mary-Lee; Murkin, John M; Ellis, Christopher G

2018-06-01

Pulsatile perfusion may offer microcirculatory advantages over conventional nonpulsatile perfusion during cardiopulmonary bypass (CPB). Here, we present direct visual evidence of microvascular perfusion and vasoreactivity between perfusion modalities. A prospective, randomized cohort study of 20 high-risk cardiac surgical patients undergoing pulsatile (n = 10) or nonpulsatile (n = 10) flow during CPB was conducted. Changes in sublingual mucosal microcirculation were assessed with orthogonal polarization spectral imaging along with near-infrared spectroscopic indices of thenar muscle tissue oxygen saturation (StO 2 ) and its recovery during a vascular occlusion test at the following time points: baseline (T 0 ), 30 minutes on CPB (T 1 ), 90 minutes on CPB (T 2 ), 1 hour after CPB (T 3 ), and 24 hours after CPB (T 4 ). On the basis of our scoring scale, a shift in microcirculatory blood flow occurred over time. The pulsatile group maintained normal perfusion characteristics, whereas the nonpulsatile group exhibited deterioration in perfusion during CPB (T 2 : 74.0% ± 5.6% versus 57.6% ± 5.0%) and after CPB (T 3 : 76.2% ± 2.7% versus 58.9% ± 5.2%, T 4 : 85.7% ± 2.6% versus 69.8% ± 5.9%). Concurrently, no important differences were found between groups in baseline StO 2 and consumption slope at all time points. Reperfusion slope was substantially different between groups 24 hours after CPB (T 4 : 6.1% ± 0.6% versus 3.7% ± 0.5%), indicating improved microvascular responsiveness in the pulsatile group versus the nonpulsatile group. Pulsatility generated by the roller pump during CPB improves microcirculatory blood flow and tissue oxygen saturation compared with nonpulsatile flow in high-risk cardiac surgical patients, which may reflect attenuation of the systemic inflammatory response and ischemia-reperfusion injury. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

A new clinical method for the assessment of penile endothelial function using the flow mediated dilation with plethysmography technique.

PubMed

Dayan, Lior; Greunwald, Illan; Vardi, Yoram; Jacob, Giris

2005-04-01

Penile endothelial function (EnF) is 1 of the major factors involved in the pathophysiology of erectile dysfunction. EnF assessment could offer crucial information on the etiology and degree of severity of cavernosal vascular pathology. In the present study we propose a new technique for the evaluation of penile EnF and test its applicability using strain gauge plethysmography. A total of 23 healthy subjects (13 younger and 10 older than 40 years) with no history of erectile dysfunction were studied. The flow mediated dilation technique was applied to the arm and penis in both age groups for the assessment of EnF. Baseline blood flow and the sequential flow recordings after rapid cessation of 5 minutes of ischemia were obtained in both organs. Baseline flow in the penis was significantly higher (approximately 3-fold) than that in the forearm and was not affected by age in either organ. Both measures of penile EnF, ie area under the flow-time curve (AUC) and maximal flow obtained after ischemia were significantly lower in the older group compared to the younger group (p <0.01 and p <0.02, respectively). Individual penile AUC and maximal flow were significantly correlated with age (r = 0.55, p <0.01 and r = 0.50, p <0.02, respectively). Finally a positive, significant correlation existed between penile and forearm AUC (p <0.05, r = 0.48). The implementation of the flow mediated dilation technique using mercury strain gauge plethysmography is simple and applicable for the assessment of penile EnF. Endothelial function parameters in the penis were found to correlate with those in the forearm, thus support for the validity of the technique is given. Further strength for the validity of this procedure in the penis comes from the comparison between the forearm and penis, and the relation to subject age.

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles.

PubMed

Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Diaz Berenstein, Laura; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2015-08-01

Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3-9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was p<0.05. A strong inverse correlation was noted between CBF and APC/shunt both on room air and with hypercarbia whether CBF was indexed to aortic flow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=-0.67--0.70 for all patients on room air, p<0.01 and R=-0.49--0.90 in hypercarbia, p<0.01). Correlations were not different between surgical stages. CBF was lower, and APCs/shunt flow was higher prior to BDG than in other stages. There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. NCT02135081. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Differential effects of total and partial sleep deprivation on salivary factors in Wistar rats.

PubMed

Lasisi, Dr T J; Shittu, S T; Meludu, C C; Salami, A A

2017-01-01

Aim of this study was to investigate the effects of sleep deprivation on salivary factors in rats. Animals were randomly assigned into three groups of 6 animals each as control, total sleep deprivation (TSD) and partial sleep deprivation (PSD) groups. The multiple platform method was used to induce partial and total sleep deprivation for 7days. On the 8th day, stimulated saliva samples were collected for the analysis of salivary lag time, flow rate, salivary amylase activity, immunoglobulin A secretion rate and corticosterone levels using ELISA and standard kinetic enzyme assay. Data were analyzed using ANOVA with Dunnett T3 post hoc tests. Salivary flow rate reduced significantly in the TSD group compared with the PSD group as well as the control group (p=0.01). The secretion rate of salivary IgA was significantly reduced in the TSD group compared with the control group (p=0.04). Salivary amylase activity was significantly elevated in the TSD group compared with the PSD group as well as control group (p<0.001). However, there were no significant changes in the salivary lag time and levels of corticosterone among the groups. These findings suggest that total sleep deprivation is associated with reduced salivary flow rate and secretion rate of IgA as well as elevated levels of salivary amylase activity in rats. However, sleep recovery of four hours in the PSD group produced ameliorative effects on the impaired functions of salivary glands. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative study of the concentration of salivary and blood glucose in type 2 diabetic patients.

PubMed

Vasconcelos, Ana Carolina U; Soares, Maria Sueli M; Almeida, Paulo C; Soares, Teresa C

2010-06-01

The objective of the present study was to comparatively evaluate the concentrations of blood and salivary glucose as well as salivary flow and xerostomia in type 2 diabetic and non-diabetic patients. The mean salivary glucose level in diabetic patients was 14.03 +/-16.76 mg/dl and 6.35 +/- 6.02 mg/dl (P = 0.036) in the control group. The mean capillary blood glucose level in diabetic patients was 213 +/- 88 mg/dl, while that in non-diabetic patients was 99 +/- 14 mg/dl (P = 0.000). The mean value for resting salivary flow was 0.21 +/- 0.16 ml/min in diabetic patients and 0.33 +/- 0.20 ml/min in the control group (P = 0.002). The stimulated salivary flow was lower in the group of diabetic patients, with a mean of 0.63 +/- 0.43 ml/min, whereas the control group showed a mean of 1.20 +/- 0.70 ml/min (P = 0.000). Of the diabetic patients, 45% exhibited hyposalivation, in contrast to 2.5% of the non-diabetic patients (P = 0.000). Xerostomia was reported in 12.5% of diabetic patients and 5% of non-diabetic patients (P = 0.23). We can conclude that salivary glucose concentration was significantly higher in the experimental group and that there was no correlation between salivary and blood glucose concentrations in diabetic patients. The total salivary flow was significantly reduced in diabetic patients and there was no significant difference as to the presence of xerostomia in both groups.

Changes in duration of action of rocuronium following decrease in hepatic blood flow during pneumoperitoneum for laparoscopic gynaecological surgery.

PubMed

Liu, Yang; Cao, Wen; Liu, Yu; Wang, Yun; Lang, Ren; Yue, Yun; Wu, An-Shi

2017-03-20

A moderate insufflation pressure and deep neuromuscular blockade (NMB) have been recommended in laparoscopic surgery in consideration of the possible reduction in splanchnic perfusion due to the CO 2 -pneumoperitoneum. Since the liver is the major organ for rocuronium metabolism, the question of whether NMB of rocuronium would change with the variation of liver perfusion during pneumoperitoneum during laparoscopic surgery merits investigation. In this prospective study, a total of sixty female patients scheduled for either selective laparoscopic gynaecological surgery (group laparoscopy) or laparotomy for gynaecological surgery (group control) were analyzed. Rocuronium was administered with closed-loop feedback infusion system, which was also applied to monitor NMB complied with good clinical research practice (GCRP). The onset time, clinical duration, and recovery index were measured. Hepatic blood flow was assessed by laparoscopic intraoperative ultrasonography before insufflation/after entering the abdominal cavity (T1), 5 min after insufflation in the Trendelenburg position/5 min after skin incision (T2), 15 min after insufflation in the Trendelenburg position/15 min after skin incision (T3), 30 min after insufflation in the Trendelenburg position/30 min after skin incision (T4), and 5 min after deflation/before closing the abdomen (T5) in group laparoscopy/group control respectively. The relationship between the clinical duration of rocuronium and portal venous blood flow was analyzed using linear or quadratic regression. The clinical duration and RI of rocuronium were both prolonged significantly in group laparoscopy (36.8 ± 8.3 min; 12.8 ± 5.5 min) compared to group control (29.0 ± 5.8 min; 9.8 ± 4.0 min) (P < 0.0001; P = 0.018). A significant decrease was found in portal venous blood flow during the entire pneumoperitoneum period in group laparoscopy compared with group control (P < 0.0001). There was a significant correlation between the clinical duration of rocuronium and portal venous blood flow (Y = 51.800-0.043X + (1.86E-005) X 2 ; r 2  = 0.491; P < 0.0001). Rocuronium-induced NMB during laparoscopic gynaecological surgery might be prolonged due to the decrease in portal venous blood flow induced by CO 2 -pneumoperitoneum. Less rocuronium could be required to achieve a desirable NMB in laparoscopic gynaecological surgery. ChiCTR. Registry number: ChiCTR-OPN-15007524 . Date of registration: December 4, 2015.

Does ligation of internal iliac artery for postpartum hemorrhage affect clitoral artery blood flow and postpartum sexual functions?

PubMed

Kaya, B; Usluogullari, B; Yurttutan, N; Sahan, M H; Güralp, O; Malik, E

2017-12-01

To investigate whether internal iliac artery ligation (IIAL) for postpartum hemorrhage (PPH) affects the sexual life in the postpartum period or significantly reduces the clitoral artery blood flow. The women who underwent IIAL due to PPH during cesarean section (CS) were compared with healthy postpartum women delivered by CS between October 2014 and February 2016 in the Gaziantep Women's Health and Maternity Hospital, Gaziantep, Turkey. Clitoral Doppler flow measurements and the Female Sexual Function Index questionnaire (FSFIQ) were performed in all women in the 3rd and 6th postpartum months. This study was registered at ClinicalTrials.gov with the identification number NCT02409602. Mean age, gravidity and parity, body mass index (BMI), first sexual intercourse after childbirth, and education years were similar in both groups. There was no statistically significant difference in the measurements of RI, PI, PSV, EDV, and S/D between the study and control groups in the 3rd month. Lack of statistical significance was also noted between the study and control groups values in the 6th month, as well as between the 3rd and 6th month's values within both the study group and the control group. Additionally, there were no statistically significant differences in the total FSFI scores including sexual desire, sexual arousal, lubrication, orgasm, sexual satisfaction, and pain domain scores between the study and control groups in the 3rd month; between the study and control groups 6th months; whereas all scores were higher in the 6th month compared to the 3rd month within each group. IIAL does not affect the blood flow of the dorsal clitoral artery between the 3rd and 6th months postpartum and between the women who underwent IIAL due to PPH and healthy postpartum women. The sexual function scores were significantly higher in the 6th month compared to the 3rd month in both groups. Copyright © 2017 Elsevier B.V. All rights reserved.

Identifying natural flow regimes using fish communities

NASA Astrophysics Data System (ADS)

Chang, Fi-John; Tsai, Wen-Ping; Wu, Tzu-Ching; Chen, Hung-kwai; Herricks, Edwin E.

2011-10-01

SummaryModern water resources management has adopted natural flow regimes as reasonable targets for river restoration and conservation. The characterization of a natural flow regime begins with the development of hydrologic statistics from flow records. However, little guidance exists for defining the period of record needed for regime determination. In Taiwan, the Taiwan Eco-hydrological Indicator System (TEIS), a group of hydrologic statistics selected for fisheries relevance, is being used to evaluate ecological flows. The TEIS consists of a group of hydrologic statistics selected to characterize the relationships between flow and the life history of indigenous species. Using the TEIS and biosurvey data for Taiwan, this paper identifies the length of hydrologic record sufficient for natural flow regime characterization. To define the ecological hydrology of fish communities, this study connected hydrologic statistics to fish communities by using methods to define antecedent conditions that influence existing community composition. A moving average method was applied to TEIS statistics to reflect the effects of antecedent flow condition and a point-biserial correlation method was used to relate fisheries collections with TEIS statistics. The resulting fish species-TEIS (FISH-TEIS) hydrologic statistics matrix takes full advantage of historical flows and fisheries data. The analysis indicates that, in the watersheds analyzed, averaging TEIS statistics for the present year and 3 years prior to the sampling date, termed MA(4), is sufficient to develop a natural flow regime. This result suggests that flow regimes based on hydrologic statistics for the period of record can be replaced by regimes developed for sampled fish communities.