bluuebunny/crossref_metadata_2025 huggingface dataset:
Method to Predict Isthmus Location in Ventricular Tachycardia Caused by Reentry with a Double‐Loop Pattern
Authors: CIACCIO EDWARD J. , TOSTI ALEXIS C. , SCHEINMAN MELVIN M.
Published: May 2005

Background: During electrophysiologic study, induction and mapping of clinical reentrant ventricular tachycardia can be difficult. Hence, analysis of sinus‐rhythm electrograms for reentry localization is of potential clinical relevance. Herein is described a method of sinus‐rhythm electrogram shape analysis, that does not require arbitrary threshold values, for localization of double‐loop reentrant circuits that drive clinical tachycardias.

Methods and Results: Reentrant ventricular tachycardia was induced by premature stimulation in 23 postinfarction canine hearts 4–5 days after left anterior descending (LAD) ligation. Sinus‐rhythm activation maps were constructed from bipolar electrograms acquired at 196–312 sites in the epicardial border zone. The timing of all electrogram peak deflections during one cycle of sinus rhythm was determined, and the mean (MPD) and deviation (DPD) were taken, respectively, as estimates of the time of activation wavefront crossing, and the duration of local electrical activity. These variables were then mapped on a computerized grid. The line of most uniform and sharp MPD gradient predicted the propagation direction through the double‐loop reentrant circuit isthmus that would occur upon tachycardia induction. The sharpest transitions in DPD bounding this line predicted the positions of arcs of block that would border the reentrant circuit isthmus during tachycardia. The actual and estimated isthmuses overlapped by a mean of 84.1 ± 3.8%. In six experiments lacking inducible reentrant tachycardia, no line of sharp MPD gradient was present in the MPD maps.

Conclusions: Analysis of multiple sinus‐rhythm deflections can localize the reentrant ventricular tachycardia isthmus without introduction of arbitrary threshold points and peak choices that may lead to error.
Study of magnetoresistance of epitaxial magnetite films grown on vicinal MgO (100) substrate
Authors: Sofin R. G. S. , Arora S. K. , Shvets I. V.
Published: May 2005

The magnetoresistance (MR) studies of magnetite thin films deposited on vicinal MgO substrates show an enhanced MR along the miscut direction as compared to the direction perpendicular to it. The MR anisotropy increases with the decrease in temperature and peaks at the Verwey transition. The increase in magnetoresistance and anisotropy behavior is attributed to the formation of a greater number of out-of-plane shifted antiphase boundaries due to the step edges on vicinal MgO substrates. These local electronic and spin structure modifications at the APBs introduce additional spin scattering and are responsible for the increase in MR along the miscut.
Single sheet tester efficiency macromagnetic analysis
Authors: Antonelli E. , Cardelli E. , Faba A.
Published: May 2005

We present here a macromagnetic numerical analysis of single sheet testers, as measuring systems for grain oriented laminated Si–Fe steels. The modeling is in time domain, and hysteresis, anisotropy and nonlinearity are suitably taken into account. The curves B(H), and the specific losses, as measured by the magnetic frame, are predicted, and compared with the local “true” values. The numerical analysis allows us to extrapolate some remarks about the efficiency and the accuracy of the measuring frame versus the applied magnetic field, the induced magnetic induction, and the rating frequency.
Three-dimensional micromagnetic finite element simulations including eddy currents
Authors: Hrkac G. , Kirschner M. , Dorfbauer F. , Suess D. , Ertl O. , Fidler J. , Schrefl T.
Published: May 2005

We developed a micromagnetic eddy current method that allows arbitrary geometries, requires no mesh outside the ferromagnet, and uses a stable integration scheme. We simultaneously solve the Landau–Lifshitz–Gilbert equation and the quasistatic Maxwell equations using a hybrid finite element/boundary element method (FEM/BEM). The eddy current field is directly calculated from the space time behavior of the magnetization rate of change. The boundary conditions of the eddy current field at infinity are taken into account using a FEM/BEM scheme. The resulting system of differential algebraic equations is solved using a backward differentiation method.
Comparison between three-dimensional (3D) equivalent magnetic circuit network method and 3D finite element method for magnetic-field computation
Authors: Chun Yon Do , Oh Jae-Eung , Fujishima Yasushi , Wakao Shinji , Lee Ju , Cho Yun-Hyun
Published: May 2005

In this article, in order to investigate the merits of three-dimensional (3D) equivalent magnetic circuit network (EMCN) method, a 3D standard benchmark model proposed by the Institute of Electrical Engineers of Japan is analyzed. We also examine the accuracy of analysis results, the computer storage, and the computation time through the systematical comparison between 3D EMCN method and 3D finite element method based on hexahedral edge element. The incomplete Cholesky conjugate gradient method was selected for the solver. From the results, we can confirm the usefulness of 3D EMCN method.
Nature of the reversible paramagnetism to ferromagnetism state in cobalt-doped titanium dioxide
Authors: Manivannan A. , Glaspell G. , Dutta P. , Seehra M. S.
Published: May 2005

We report that Co0.1Ti0.9O2−δ prepared by the sol-gel technique is a paramagnet following the Curie–Weiss law: χ=χ0+C∕(T+θ) with θ≃5K. However, hydrogenation at 673 K in H2∕Ar(5%∕95%) gas converts a part of the paramagnetic (P) sample to room temperature ferromagnet (RTFM) and reheating the sample at 573 K in air converts it back to a paramagnet completely. This reversible P⇄RTFM transition has been observed for additional cycles by alternately heating in air and H2∕Ar. It is argued that this RTFM is intrinsic and it is due to Co2+–Co2+ exchange interaction mediated by oxygen holes which are produced by hydrogenation but eliminated by oxidation.
Classical and quantum mechanics of diatomic molecules in tilted fields
Authors: Arango Carlos A. , Kennerly William W. , Ezra Gregory S.
Published: May 2005

We investigate the classical and quantum mechanics of diatomic molecules in noncollinear (tilted) static electric and nonresonant linearly polarized laser fields. The classical diatomic in tilted fields is a nonintegrable system, and we study the phase space structure for physically relevant parameter regimes for the molecule KCl. While exhibiting low-energy (pendular) and high-energy (free-rotor) integrable limits, the rotor in tilted fields shows chaotic dynamics at intermediate energies, and the degree of classical chaos can be tuned by changing the tilt angle. We examine the quantum mechanics of rotors in tilted fields. Energy-level correlation diagrams are computed, and the presence of avoided crossings quantified by the study of nearest-neighbor spacing distributions as a function of energy and tilting angle. Finally, we examine the influence of classical periodic orbits on rotor wave functions. Many wave functions in the tilted field case are found to be highly nonseparable in spherical polar coordinates. Localization of wave functions in the vicinity of classical periodic orbits, both stable and unstable, is observed for many states.
Microwave and millimeter-wave spectroscopy of the open-shell van der Waals complex Ar–HO2
Authors: Suma Kohsuke , Funato Wataru , Sumiyoshi Yoshihiro , Endo Yasuki
Published: May 2005

Pure rotational transitions of a rare gas atom–reactive open-shell triatom van der Waals complex Ar–HO2 have been observed by Fourier transform microwave spectroscopy. The transitions observed are of a type with Ka=0 and 1. Furthermore, by monitoring the change of the free induction decay signal of the a-type transitions, b-type transitions have been observed by a double resonance technique in the region 18–49 GHz. All these transitions provide us precise molecular constants. The r0 structure of Ar–HO2 has been determined by fixing the structure of the HO2 monomer. The determined structure is planar and almost T shaped, where the argon atom is slightly shifted to the hydrogen atom of HO2. The experimental data supplemented by high-level ab initio calculations indicate that the van der Waals bond of Ar–HO2 is relatively rigid. On the other hand, effects on the unpaired electron distribution by the complex formation are found to be fairly small, since the fine and hyperfine constants of Ar–HO2 are well explained by those of the HO2 monomer.
Non-Born–Oppenheimer molecular structure and one-particle densities for H2D+
Authors: Cafiero Mauricio , Adamowicz Ludwik
Published: May 2005

We show that the nonadiabatic (non-Born–Oppenheimer) ground state of a three-nuclei system can be effectively calculated with the use of an explicitly correlated Gaussian basis set with floating centers. Sample calculations performed for the H2D+ system with various basis set sizes show good convergence with respect to both the total energy and the expectation values of the internuclear distances (molecular geometry), the distances between the nuclei and the electrons, and between the electrons. We also provide a derivation of the formulas for one-particle density calculations and some density plots showing the spatial distribution of the H2D+ nuclear and electronic densities.
Steady supersonically rotating plasmas in the Maryland Centrifugal Experiment
Authors: Ellis R. F. , Case A. , Elton R. , Ghosh J. , Griem H. , Hassam A. , Lunsford R. , Messer S. , Teodorescu C.
Published: May 2005

The Maryland Centrifugal Experiment MCX [R. F. Ellis, A. B. Hassam, and S. Messer, Phys. Plasmas 8, 2057 (2000)] studies supersonic rotation and enhanced confinement produced by the application of an electric field perpendicular to an axial confining mirror magnetic field; radial shear in the rotation is predicted to stabilize magnetohydrodynamic (MHD) interchange modes. The MCX mirror field is 2.6 m in length, maximum mirror field 1.9 T, maximum midplane field 0.33 T; an inner coaxial core is driven by a 10 KV capacitor bank, producing the radial electric field which drives azimuthal rotation. MCX produces high density (n>1020m−3) fully ionized plasmas and has two operating modes. In the O (ordinary) mode the plasma rotates supersonically with azimuthal velocities in the range of 100 km/s for discharge times exceeding 8 ms. Ion temperatures are ∼30eV and momentum confinement times 100–200 μs. Sonic Mach numbers (uφ∕vti) in the range 1–2 and Alfvén Mach numbers (uφ∕vA)∼0.3 have been achieved for O mode discharges which remain steady for many milliseconds, much longer than MHD instability time scales; plasma lifetime is limited by the capacitance of the capacitor bank. MCX also has an enhanced mode of operation [higher rotation (HR) mode] with higher rotation velocities (>200km∕s), sonic Mach numbers greater than 3, Alfvén Mach numbers >∼0.5, and momentum confinement times of several hundred microseconds. HR mode occurs at higher B fields and lower discharge currents but is transient, transitioning to O mode after a few milliseconds. Both O and HR mode show spectroscopic evidence of radial velocity shear sufficient to satisfy the simplest criterion for MHD stability, but both modes also show significant fluctuations on magnetic probes.
One-dimensional particle-in-cell simulation of a current-free double layer in an expanding plasma
Authors: Meige Albert , Boswell Rod W. , Charles Christine , Turner Miles M.
Published: May 2005

A one-dimensional particle-in-cell code using Monte Carlo collision techniques (MCC/PIC) for both ions and electrons is used to simulate our earlier experimental results which showed that a current-free electric double layer (DL) can form in a plasma expanding along a diverging magnetic field. These results differ from previous experimental or simulation systems where the double layers are driven by a current or by imposed potential differences. Both experiment and simulation show accelerated ions with energies up to about 60 eV on the low potential side of the plasma. A new numerical method is added to the conventional PIC scheme to simulate inductive electron heating, as distinct from the more common capacitively driven simulations. A loss process is introduced along the axis of the simulation to mimic the density decrease along the axis of an expanding plasma in a diverging magnetic field. The results from the MCC/PIC presented here suggest that the expansion rate compared to the ionization frequency is a critical parameter for the existence of the DL. For the DL to be absolutely current free, the source wall has to be allowed to charge: having both ends of the simulation at the same potential always resulted in a current flow. Also, the effect of the neutral pressure and of the size of the diffusion chamber are investigated. Finally we show that this particular type of DL has electrons in Boltzmann equilibrium and that it creates a supersonic ion beam.
Time-dependent plasma viscosity and poloidal flow damping with orbit squeezing in tokamaks
Authors: Shaing K. C.
Published: May 2005

In the vicinity of a magnetic island and in the zonal flow, the radial extent of the radial electric field layer is about the width of the ion poloidal gyroradius in tokamaks. Thus, the effects of the orbit squeezing become important in these situations and probably in other applications as well. It is shown that the poloidal flow damping rate in tokamaks is reduced approximately by a factor of ∣S∣ when the effects of orbit squeezing are taken into account. Here, S is the orbit-squeezing factor. Thus, the plasma confinement could be improved when the effects of the orbit squeezing are included in the turbulence simulations.
Velocity shear induced transition of magnetohydrodynamic to kinetic Alfvén waves
Authors: Chen Yao
Published: May 2005

It is found that in the linear shear flow after a certain time the noncompressive magnetohydrodynamic Alfvén wave with only k‖ develops large values of k⊥ and becomes the kinetic Alfvén wave with considerable compressibility, and velocity and magnetic field perturbations in the parallel direction (to the background magnetic field). It is found that the perturbation amplitudes of the above kinetic quantities increase continuously with time. The amplitudes are mostly determined by the ratios of the Alfvénic to ion gyrofrequency and of the thermal to magnetic pressure for a specified shear flow.
Relativistic shock formation in the presence of radial entropy gradients
Authors: Balasubramanian Koushik , Sujith R. I.
Published: May 2005

The nonlinear steepening of relativistic acoustic waves is investigated. The nonlinear evolution of a planar wave in a homentropic flow field is understood well through relativistic simple waves. However, in situations where the wave is nonplanar and the flow field is nonhomentropic, the concept of simple waves cannot be used. In the present paper, effect of entropy gradients on the nonlinear distortion of a spherical wave is analyzed using the wave front expansion technique. It is shown that the behavior of a relativistic wave in nonhomentropic environment is slightly different from the nonrelativistic wave. A closed form solution is obtained for the slope at the wave front. A general criterion for a compression wave to steepen into a shock is obtained. The distortion of compression and rarefaction waves is examined for some well known equations of state. However, the method used in this paper is general and can be easily extended to analyze shock formation in any fluid. Also, expressions for time and location of shock formation are obtained. The effects of gravity or self-gravity are not taken into account in this paper.
Measurements of classical transport of fast ions
Authors: Zhao L. , Heidbrink W. W. , Boehmer H. , McWilliams R. , Leneman D. , Vincena S.
Published: May 2005

To study the fast-ion transport in a well controlled background plasma, a 3-cm diameter rf ion gun launches a pulsed, ∼300eV ribbon shaped argon ion beam parallel to or at 15° to the magnetic field in the Large Plasma Device (LAPD) [W. Gekelman, H. Pfister, Z. Lucky, J. Bamber, D. Leneman, and J. Maggs, Rev. Sci. Instrum. 62, 2875 (1991)] at UCLA. The parallel energy of the beam is measured by a two-grid energy analyzer at two axial locations (z=0.32m and z=6.4m) from the ion gun in LAPD. The calculated ion beam slowing-down time is consistent to within 10% with the prediction of classical Coulomb collision theory using the LAPD plasma parameters measured by a Langmuir probe. To measure cross-field transport, the beam is launched at 15° to the magnetic field. The beam then is focused periodically by the magnetic field to avoid geometrical spreading. The radial beam profile measurements are performed at different axial locations where the ion beam is periodically focused. The measured cross-field transport is in agreement to within 15% with the analytical classical collision theory and the solution to the Fokker–Planck kinetic equation. Collisions with neutrals have a negligible effect on the beam transport measurement but do attenuate the beam current.
Dust-acoustic shock waves: Effect of plasma density gradient
Authors: Xiao De-long , Ma J. X. , Li Yang-fang
Published: May 2005

The propagation of dust-acoustic shock waves in an inhomogeneous collisional dusty plasma is studied, where the equilibrium plasma densities and dust charges are spatially nonuniform but the dust density is uniform. It is shown that, in such a plasma, the dust charge density can change continuously from tenuous to dense state. The effect of collisions of the dust with neutral gas causes the damping of the amplitude, while collisionless dissipation arising from nonadiabatic dust charge variation results in the formation of the shock structure. The amplitude is proportional to the square root of the phase velocity of the linear dust-acoustic wave but inversely proportional to the square root of the equilibrium dust charge number, both of them vary with spatial positions. Due to the inhomogeneity, the relationships among the amplitude, the Mach number, and the width (rise time) of the shock front do not follow the simple monotonic behavior as in the homogeneous cases.
Visible electroluminescence from silicon nanocrystals embedded in amorphous silicon nitride matrix
Authors: Chen Liang-Yih , Chen Wen-Hua , Hong Franklin Chau-Nan
Published: May 2005

Visible electroluminescence from silicon nanocrystals (Si-NCs) embedded in amorphous silicon nitride (a-SiNx) films has been observed. The Si-NC∕a-SiNx films were deposited by evaporating silicon from electron gun into the inductively coupled plasma of nitrogen. The density of Si-NCs in the a-SiNx matrix was around 1012cm−2. Strong room temperature photoluminescence was observed in 2.8 and 3.0eV, different from literature values. The electroluminescence (EL) devices were fabricated with Si-NCs∕a-SiNx film as the active layer using the Al or Ca∕Ag cathode and the indium tin oxide anode. Through tunneling, the electrons and holes were respectively injected from the cathode and anode into Si-NCs and confined within Si-NCs for light emission by the high band gap a-SiNx matrix. For the device with Ca∕Ag cathode, the turn-on voltage was as low as 10V and the EL efficiency was about 1.6×10−1 Cd∕A. The EL spectra consisted of two broad peaks centered around 2.5 and 2.8eV. Our results demonstrate that Si-NCs∕a-SiNx nanocomposite films have potentials to be fabricated into electroluminescence devices using the low work function cathode.
Focused-ion-beam platinum nanopatterning for GaN nanowires: Ohmic contacts and patterned growth
Authors: Nam C. Y. , Kim J. Y. , Fischer J. E.
Published: May 2005

Nanopatterned Pt by Ga+ focused ion beam (FIB) decomposition of an organometallic precursor forms low resistance ohmic contacts on 40–70nm diameter GaN nanowires (NWs) grown by thermal reaction of Ga2O3 and NH3. With no intentional doping, the wires are presumed to be n type. Thus, the linear I-V behavior is surprising since evaporated Pt usually forms Schottky barriers on n GaN. Ohmic behavior was not obtained for 130–140 diameter wires, even with thicker Pt contacts. A second application of FIB Pt nanopatterning was demonstrated by position-selective growth of GaN NWs on Pt catalyst dots. NW locations and density are defined by the position, size, and thickness of the Pt deposit. Combining these techniques provides a versatile platform for nanostructure research and development.
G protein-dependent presynaptic inhibition mediated by AMPA receptors at the calyx of Held
Authors: Takago Hideki , Nakamura Yukihiro , Takahashi Tomoyuki
Published: May 2005

The α-amino-3-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) is an ionotropic receptor mediating excitatory synaptic transmission, but it can also interact with intracellular messengers. Here we report that, at the calyx of Held in the rat auditory brainstem, activation of AMPARs induced inward currents in the nerve terminal and inhibited presynaptic Ca
2+
currents (I
pCa
), thereby attenuating glutamatergic synaptic transmission. The AMPAR-mediated I
pCa
inhibition was disinhibited by a strong depolarizing pulse and occluded by the nonhydrolyzable GTP analog GTPγS loaded into the terminal. We conclude that functional AMPARs are expressed at the calyx of Held nerve terminal and that their activation inhibits voltage-gated Ca
2+
channels by an interaction with heterotrimeric GTP-binding proteins (G proteins). Thus, at a central glutamatergic synapse, presynaptic AMPARs have a metabotropic nature and regulate transmitter release by means of G proteins.
The domains of a cholesterol-dependent cytolysin undergo a major FRET-detected rearrangement during pore formation
Authors: Ramachandran Rajesh , Tweten Rodney K. , Johnson Arthur E.
Published: May 2005

FRET measurements were used to determine the domain-specific topography of perfringolysin O, a pore-forming toxin, on a membrane surface at different stages of pore formation. The data reveal that the elongated toxin monomer binds stably to the membrane in an “end-on” orientation, with its long axis approximately perpendicular to the plane of the membrane bilayer. This orientation is largely retained even after monomer association to form an oligomeric prepore complex. The domain 3 (D3) polypeptide segments that ultimately form transmembrane β-hairpins remain far above the membrane surface in both the membrane-bound monomer and prepore oligomer. Upon pore formation, these segments enter the bilayer, whereas D1 moves to a position that is substantially closer to the membrane. Therefore, the extended D2 β-structure that connects D1 to membrane-bound D4 appears to bend or otherwise reconfigure during the prepore-to-pore transition of the perfringolysin O oligomer.
Global divergence of microbial genome sequences mediated by propagating fronts
Authors: Vetsigian Kalin , Goldenfeld Nigel
Published: May 2005

We model the competition between homologous recombination and point mutation in microbial genomes, and present evidence for two distinct phases, one uniform, the other genetically diverse. Depending on the specifics of homologous recombination, we find that global sequence divergence can be mediated by fronts propagating along the genome, whose characteristic signature on genome structure is elucidated, and apparently observed in closely related
Bacillus
strains. Front propagation provides an emergent, generic mechanism for microbial “speciation,” and suggests a classification of microorganisms on the basis of their propensity to support propagating fronts.
Paraoxonase 1 Q192R (PON1-192) polymorphism is associated with reduced lipid peroxidation in healthy young men on a low-carotenoid diet supplemented with tomato juice
Authors: Bub Achim , Barth Stephan W. , Watzl Bernhard , Briviba Karlis , Rechkemmer Gerhard
Published: May 2005

The HDL-bound enzyme paraoxonase (PON) protects LDL from oxidation and may therefore attenuate the development of atherosclerosis. We examined the effect of tomato and carrot juice consumption on PON1 activity and lipid peroxidation in healthy young volunteers with different PON1-192 genotypes (Q/R substitution at position 192). In this randomized cross-over study twenty-two healthy, non-smoking men on a low-carotenoid diet received 330 ml/d tomato juice (37·0 mg lycopene, 1·6 mg β-carotene) or carrot juice (27·1 mg β-carotene, 13·1 mg α-carotene) for 2 weeks. Intervention periods were preceded by 2-week low-carotenoid intake. We determined the PON1-192 genotype by restriction fragment length polymorphism–polymerase chain reaction (RFLP-PCR) and measuredex vivoLDL oxidation (lag time), plasma malondialdehyde and PON1 activity at the beginning and end of each intervention period. At baseline, lag time was higher (P<0·05) in QQ (111 (sd 9) min) than in QR/RR subjects (101 (sd 8) min). Neither tomato nor carrot juice consumption had significant effects on PON1 activity. However, tomato juice consumption reduced (P<0·05) plasma malondialdehyde in QR/RR (Δ: −0·073 (sd 0·11) μmol/l) as compared to QQ subjects (Δ:+0·047 (sd 0·13) μmol/l). Carrot juice had no significant effect on malondialdehyde irrespective of the PON1-192 genotype. Male volunteers with the QR/RR genotype showed an increased lipid peroxidation at baseline. Although tomato and carrot juice fail to affect PON1 activity, tomato juice intake reduced lipid peroxidation in healthy volunteers carrying the R-allele of the PON1-192 genotype and could thus contribute to CVD risk reduction in these individuals.
Nutritional regulation of proteases involved in fetal rat insulin secretion and islet cell proliferation
Authors: Kalbe L. , Leunda A , Sparre T , Meulemans C , Ahn M.-T , Orntoft T , Kruhoffer M , Reusens B , Nerup J , Remacle C
Published: May 2005

Epidemiological studies have indicated that malnutrition during early life may programme chronic degenerative disease in adulthood. In an animal model of fetal malnutrition, rats received an isoenergetic, low-protein (LP) diet during gestation. This reduced fetal β-cell proliferation and insulin secretion. Supplementation during gestation with taurine prevented these alterations. Since proteases are involved in secretion and proliferation, we investigated which proteases were associated with these alterations and their restoration in fetal LP islets. Insulin secretion and proliferation of fetal control and LP islets exposed to different protease modulators were measured. Lactacystin and calpain inhibitor I, but not isovaleryl-l-carnitine, raised insulin secretion in control islets, indicating that proteasome and cysteinyl cathepsin(s), but not μ-calpain, are involved in fetal insulin secretion. Insulin secretion from LP islets responded normally to lactacystin but was insensitive to calpain inhibitor I, indicating a loss of cysteinyl cathepsin activity. Taurine supplementation prevented this by restoring the response to calpain inhibitor I. Control islet cell proliferation was reduced by calpain inhibitor I and raised by isovaleryl-l-carnitine, indicating an involvement of calpain. Calpain activity appeared to be lost in LP islets and not restored by taurine. Most modifications in the mRNA expression of cysteinyl cathepsins, calpains and calpastatin due to maternal protein restriction were consistent with reduced protease activity and were restored by taurine. Thus, maternal protein restriction affected cysteinyl cathepsins and the calpain–calpastatin system. Taurine normalised fetal LP insulin secretion by protecting cysteinyl cathepsin(s), but the restoration of LP islet cell proliferation by taurine did not implicate calpains.
Novel tempeh (fermented soyabean) isoflavones inhibitin vivoangiogenesis in the chicken chorioallantoic membrane assay
Authors: Kiriakidis Serafim , Högemeier Oliver , Starcke Susanne , Dombrowski Frank , Hahne Jens Claus , Pepper Michael , Jha Hem Chandra , Wernert Nicolas
Published: May 2005

Anti-angiogenic strategies are emerging as an important tool for the treatment of cancer and inflammatory diseases. In the present investigation we isolated several isoflavones from a tempeh (fermented soyabean) extract. The isolated isoflavones were identified as 5,7,4′-trihydroxyisoflavone (genistein), 7,4′-dihydroxyisoflavone (daidzein), 6,7,4′-trihydroxyisoflavone (factor 2), 7,8,4′-trihydroxyisoflavone (7,8,4′-TriOH) and 5,7,3′,4′-tetrahydroxyisoflavone (orobol). The effects on angiogenesis of these isoflavones were evaluated in the chicken chorioallantoic membrane assay; their capacity to inhibit vascular endothelial growth factor-induced endothelial cell proliferation and expression of the Ets 1 transcription factor, known to be implicated in the regulation of new blood vessel formation, were also investigated. We found that all isoflavones inhibited angiogenesis, albeit with different potencies. Compared with negative controls, which slightly inhibitedin vivoangiogenesis by 6·30 %, genistein reduced angiogensis by 75·09 %, followed by orobol (67·96 %), factor 2 (56·77 %), daidzein (48·98 %) and 7,8,4′-TriOH (24·42 %). These compounds also inhibited endothelial cell proliferation, with orobol causing the greatest inhibition at lower concentrations. The isoflavones also inhibited Ets 1 expression, providing some insight into the molecular mechanisms of their action. Furthermore, the chemical structure of the different isoflavones suggests a structure–activity relationship. Our present findings suggest that the new isoflavones might be added to the list of low molecular mass therapeutic agents for the inhibition of angiogenesis.
Eight-year trends in food, energy and macronutrient intake in a sample of elderly German subjects
Authors: Jungjohann Svenja M. , Lührmann Petra M. , Bender Ralf , Blettner Maria , Neuhäuser-Berthold Monika
Published: May 2005

Time trends in the food and the corresponding energy and macronutrient intake between 1994 and 2002 are investigated as part of the longitudinal study on nutrition and health status in an ageing population in Giessen, Germany (GISELA study). The dietary intake is assessed via a 3 d estimated dietary record especially developed and validated for this study. A total of 2135 records from 532 subjects, aged 60 years and over, are analysed separately according to sex and age groups (born 1904–1928 and born 1929–1942). Results show that the food, energy and macronutrient intake of the GISELA subjects stayed fairly stable over the study period. However, some significant changes in the consumption pattern are observed, predominantly in the women and the younger age groups, which correspond to the national trends in Germany. Most obvious changes observed among the GISELA subjects are the increased intake of water (between +21·05 and +41·61 ml/d per year) and vegetables (between +2·94 and +3·38 g/d per year) and a reduced consumption of coffee and tea (between −10·65 and −15·99 ml/d per year) as well as of meat (between −1·79 and −2·56 g/d per year). The healthier food choices and the ability to change food habits could be related to the relatively high health-awareness of the GISELA subjects compared to the federal average of equivalent age groups.
The Diet Quality Index-International (DQI-I): is it a useful tool to evaluate the quality of the Mediterranean diet?
Authors: Tur Josep A. , Romaguera Dora , Pons Antoni
Published: May 2005

The aim of this study was to assess whether the recently developed Diet Quality Index-International (DQI-I) could be used to evaluate diet quality of a Mediterranean population. A cross-sectional nutritional survey was carried out in the Balearic Islands (Spain) between 1999 and 2000. Dietary information (replicated 24 h recall and a food frequency questionnaire), and socio-demographic and lifestyle data were collected from a representative sample of the population (n 1200: 498 males and 702 females) aged 16–65 years (response rate 77·22 %). The DQI-I was developed according to the method defined by Kim et al. (2003), and focused on four major aspects of a high-quality diet (variety, adequacy, moderation and overall balance). The percentage of adherence to the Mediterranean dietary pattern (MDP) was also calculated and correlation analysis was carried out between the DQI-I score and the percentage of adherence to the MDP. The total score of the DQI-I reached 43 % of the possible score, indicating that the Balearic diet was a poor-quality diet. Correlation analysis between the DQI-I scores and adherence to the MDP showed that the DQI-I subcategories protein, iron and calcium adequacy were negatively correlated with the MDP. Furthermore, moderation in empty calorie food consumption and overall balance subcategories were not significantly correlated with the MDP. Due to some methodological factors and cultural biases, the proposed DQI-I scoring system is not useful to evaluate the quality of this Mediterranean-type diet. Further research is needed to develop a new diet quality index adapted to the MDP.
Hyperinsulinaemia, supplemental protein and branched-chain amino acids when combined can increase milk protein yield in lactating sows
Authors: Dunshea Frank R. , Bauman Dale E. , Nugent Elizabeth A. , Kerton Douglas J. , King Raymond H. , McCauley Ian
Published: May 2005

The aim of this study was to determine whether dietary supplementation with branched-chain amino acids, and the infusion of insulin and dextrose, would increase milk protein secretion in the sow. The experiment involved sixteen lactating sows fed either a normal lactation diet (162 g/kg crude protein, n 8) or a high-protein diet (230 g/kg crude protein, n 8) supplemented with branched-chain amino acids (valine, isoleucine and leucine). Sows were either infused with insulin and dextrose or not infused at all during mid (day 5–10) and late (day 17–22) lactation in a single reversal design. Blood samples were analysed for glucose, and the dextrose infusion rate was adjusted to maintain the blood glucose level within 15 % of pre-infusion levels. Milk (10·1 v. 11·1 kg/d; P=0·014) and\ lactose (628 v. 727 g/d; P=0·002) yield increased with insulin infusion, whereas milk protein content (5·0 % v. 5·5 %; P=0·007) was increased in diets supplemented with protein and branched-chain amino acids. Piglet growth was increased by feeding the higher-protein diet (237 v. 273 g/d; P=0·05) but not significantly increased by insulin infusion (245 v. 265 g/d; P=0·11). These effects were additive such that the combined treatment resulted in a 24 % (56 g/d; P<0·05) increase in piglet growth rate. These data demonstrate that increasing the dietary protein/branched-chain amino acid content can increase milk protein secretion but not milk yield. The infusion of insulin and dextrose increased milk and milk lactose yields, and tended to increase milk protein yield but not milk protein content. These effects are additive and translate to increased protein yield and piglet growth.
Expressing the glycaemic potency of foods
Authors: Monro John
Published: May 2005

The glycaemic index (GI) was introduced to guide food exchanges within equicarbohydrate food categories, and it expresses the glycaemic potency of the available carbohydrate component in a food relative to that of glucose. As GI is a relative value based on ‘available carbohydrate’ it cannot guide food choice for glycaemic control unless the foods are equal in available carbohydrate. Furthermore, GI cannot respond to food intake or to effects on food glycaemic potency of replacing glycaemic ingredients with non-glycaemic ingredients. The glycaemic glucose equivalent (GGE) overcomes these limitations of GI. The GGE content of an amount of food is the weight of glucose (g) that would induce a glycaemic response equal to that induced by the food. Few studies have compared GI and GGE as guides to food choice for glycaemic control, but in a direct test of the predictive validity of GGE in a group of foods of differing carbohydrate and GI, GGE predicted glycaemic potency well, whereas GI was unrelated to glycaemic effect. Furthermore, an information-processing model of the use of food information in food choice shows that GI has fundamental flaws when used outside the restriction of equicarbohydrate food exchange categories. As a general guide to food choices for the control of glycaemia GI does not satisfy the criteria predictive validity, accuracy, safety, ease of use, flexibility, sufficiency and compatability, whereas GGE does. GGE is also a scientifically precise and meaningful term with which to express glycaemic potency than is ‘glycaemic load’.
The biology of obesity
Authors: Trayhurn Paul
Published: May 2005

Obesity is a multidisciplinary area, the ‘biology’ of which encompasses: (1) the fundamental mechanisms of energy balance and its regulation; (2) the biological basis for the development of obesity; (3) adipose tissue function; (4) the biological description of the obese state; (5) the pathological consequences of obesity; (6) the physiological basis for treatment strategies. At a mechanistic level, important developments in recent years include the identification of novel neuroendocrine factors in the control of appetite (such as cocaine- and amphetamine-regulated transcript, the orexins, the endocannabinoids) and the discovery of new peripheral signals (such as leptin, ghrelin). Despite the identification of additional uncoupling proteins (UCP2, UCP3), mitochondrial uncoupling in brown adipose tissue through UCP1 remains the only major mechanism for adaptive thermogenesis. White adipose tissue (WAT) has now moved centre stage in energy balance and obesity research, and there are three main reasons: (1) it is the organ which defines obesity; (2) it is the source of a critical endocrine signal in the control of body weight; (3) it secretes a range of diverse protein factors, termed adipokines, some of which are directly implicated in the pathologies associated with obesity. WAT is now recognised as a key endocrine organ, communicating both with the brain and peripheral tissues through the adipokines. Obesity is characterised by mild inflammation, and WAT may be the main locus of the inflammatory state, producing cytokines, chemokines, acute-phase proteins and angiogenic factors. It has been suggested that inflammation in obesity is principally an adaptive response to hypoxia in clusters of adipocytes within the expanding adipose mass.
Central regulation of energy balance: inputs, outputs and leptin resistance
Authors: Arch Jonathan R. S.
Published: May 2005

The regulation of energy balance is complex and, in man, imprecise. Nevertheless, in many individuals intake and expenditure are balanced with <1% error with little or no conscious effect. Essential components of such a regulatory system are signals, leptin and insulin, that reflect the size of lipid stores. Leptin receptors signal via phosphatidylinositol 3-kinase (as do insulin receptors) and via the transcription factor signal transducer and activator of transcription-3 to activate various types of neurone. Obese rodents, and possibly man, are resistant to leptin; in some cases because of genetic or perinatal programming (primary resistance), but commonly in response to high leptin levels (secondary resistance). Secondary leptin resistance may be a result of reduced transport of leptin to the brain or down-regulation of leptin signalling. Signals that reflect lipid stores form the tonic homeostatic regulatory system. They interact with episodic homeostatic signals carried by neurones, hormones and metabolites to regulate meal size and frequency. They also interact with signals related to the palatability of food, biorhythms and learning. Many neurotransmitters and hormones mediate responses to more than one input (e.g. gastric and adipocyte leptin), but are nevertheless most involved with particular inputs (e.g. leptin with adipocyte fat stores). Feeding can be divided into appetitive (preparation for feeding) and consummatory phases, which can both be further subdivided. Different sets of neurotransmitters and hormones are involved at each stage. In the long term it may be possible to customise obesity therapies according to those inputs and outputs that are most disturbed and most amenable to intervention in individual subjects.
Decomposition of high-pressure (400 kPa) SF6–CO2, SF6–CO, SF6–N2–CO2and SF6–N2–CO mixtures under negative dc coronas
Authors: Casanovas A M , Casanovas J
Published: May 2005

Sulfur hexafluoride, SF6, is successfully employed by the electric power industry for gas insulated equipment. However, it is a potent greenhouse gas and mixtures of SF6with more friendly environmental gases have recently been proposed. It was demonstrated that SF6mixed with N2and/or CO2could be a good substitute for some insulation applications such as gas-insulated transmission lines (GILs).

Considering the possible occurrence of corona discharges in GILs, the decomposition of these gas mixtures under such stress must be studied. In this paper, the chemical stability under negative corona of SF6and SF6–N2(10 : 90) or (5 : 95) mixtures was investigated at 400 kPa on adding percentages of CO2up to 80%.

The corona discharges were generated at 23°C in a 340 cm3experimental cell between a stainless steel point connected to a high voltage source and a plane of aluminium. The gaseous decomposition products were assayed by gas chromatography at the end of each run carried out over a range of transported charges covering 8–17 C.

The presence of CO2in SF6and SF6–N2mixtures submitted to negative coronas leads to:

a considerable increase in the formation of the major compound group (SOF4+SO2F2),

formation of similar large quantities of COF2,

abundant production of CO with diluted SF6in nitrogen,

decreased formation of S2F10.
Long-Term Self-Renewal of Postnatal Muscle-derived Stem Cells
Authors: Deasy B. M. , Gharaibeh B. M. , Pollett J. B. , Jones M. M. , Lucas M. A. , Kanda Y. , Huard J.
Published: May 2005

The ability to undergo self-renewal is a defining characteristic of stem cells. Self-replenishing activity sustains tissue homeostasis and regeneration. In addition, stem cell therapy strategies require a heightened understanding of the basis of the self-renewal process to enable researchers and clinicians to obtain sufficient numbers of undifferentiated stem cells for cell and gene therapy. Here, we used postnatal muscle-derived stem cells to test the basic biological assumption of unlimited stem cell replication. Muscle-derived stem cells (MDSCs) expanded for 300 population doublings (PDs) showed no indication of replicative senescence. MDSCs preserved their phenotype (ScaI+/CD34+/desminlow) for 200 PDs and were capable of serial transplantation into the skeletal muscle of mdx mice, which model Duchenne muscular dystrophy. MDSCs expanded to this level exhibited high skeletal muscle regeneration comparable with that exhibited by minimally expanded cells. Expansion beyond 200 PDs resulted in lower muscle regeneration, loss of CD34 expression, loss of myogenic activity, and increased growth on soft agar, suggestive of inevitable cell aging attributable to expansion and possible transformation of the MDSCs. Although these results raise questions as to whether cellular transformations derive from cell culturing or provide evidence of cancer stem cells, they establish the remarkable long-term self-renewal and regeneration capacity of postnatal MDSCs.
A Unique Opportunity for an Intercultural Discussion on CAM and Liver Disease
Authors: Marotta Francesco
Published: May 2005

The meeting of the APASL, Asian Pacific Association for the Study of the Liver, was held in December 2004, in New Delhi, India. The meeting was held under the patronage of the APASL Committee and Board of Presidents of the National Liver Association and in conjunction with the annual conference of the Indian Association for the Study of Liver (INASL). The congress was designed to have a core meeting with three parallel sessions running throughout, dedicated research workshops and intensive breakfast sessions. This report concentrates on the two sessions devoted to complementary and alternative medicine (CAM) and shows the latest research in CAM for liver disease and the concerns of doctors about integrating CAM with more traditional treatments. With researchers and practitioners gathering from all over the world, it was a unique opportunity for an intercultural discussion on CAM and liver disease.
Isolation of CYP3A4 Inhibitors from the Black Cohosh (Cimicifuga racemosa)
Authors: Tsukamoto Sachiko , Aburatani Maki , Ohta Tomihisa
Published: May 2005

Recent investigation on drug interaction has shown that some foods and herbal medicines increase the oral availability of a variety of CYP3A4 substrates, which is caused by the reduction of CYP3A4 in intestinal epithelium. During the course of our investigation on CYP3A4 interaction, we found that the commercially available dietary supplement made from black cohosh (Cimicifuga racemosa) showed CYP3A4 inhibition. Black cohosh has been used for the treatment of menopausal and post‐menopausal symptoms as a dietary supplement. Bioassay‐guided isolation from the supplement afforded six active principles, which were identified as cycloartanoid triterpene glycosides.
Complementary and Alternative Medicine in Pakistan: Prospects and Limitations
Authors: Shaikh Babar T. , Hatcher Juanita
Published: May 2005

Despite all the marvelous advancements in modern medicine, traditional medicine has always been practiced. More than 70% of the developing world′s population still depends on the complementary and alternative systems of medicine (CAM). Cultural beliefs and practices often lead to self‐care or home remedies in rural areas and consultation with traditional healers. Evidence‐based CAM therapies have shown remarkable success in healing acute as well as chronic diseases. Alternative therapies have been utilized by people in Pakistan who have faith in spiritual healers, clergymen, hakeems, homeopaths or even many quacks. These are the first choice for problems such as infertility, epilepsy, psychosomatic troubles, depression and many other ailments. The traditional medicine sector has become an important source of health care, especially in rural and tribal areas of the country. The main reasons for consulting a CAM healer is the proximity, affordable fee, availability, family pressure and the strong opinion of the community. Pakistan has a very rich tradition in the use of medicinal plants for the treatment of various ailments. It necessitates the integration of the modern and CAM systems in terms of evidence‐based information sharing. The health‐seeking behavior of the people especially in developing countries calls for bringing all CAM healers into the mainstream by providing them with proper training, facilities and back‐up for referral. A positive interaction between the two systems has to be harnessed to work for the common goal of improving health of the people.

Corrigendum to
“Complementary and Alternative Medicine in Pakistan: Prospects and Limitations”dx.doi.org/10.1093/ecam/nel113
Taxonomy and phylogeny of the ascomycetous yeast genus Zygoascus, with proposal of Zygoascus meyerae sp. nov. and related anamorphic varieties
Authors: Smith Maudy Th. , Robert V. , Poot G. A. , Epping Wendy , de Cock A. W. A. M.
Published: May 2005

Physiological characters, mating compatibility, PCR-RAPD fingerprints, mol% G+C content, DNA–DNA relatedness, and large-subunit and internal transcribed spacer rRNA gene sequences of strains assigned to the genus Zygoascus were re-examined. On the basis of those data, and after phylogenetic analyses, an emendation of Zygoascus hellenicus (type material is a cross of CBS 6736T×CBS 5839T) is proposed, comprising two novel anamorphic varieties, Candida steatolytica var. steatolytica (CBS 6736T) and C. steatolytica var. inositophila (CBS 5839T). A novel teleomorphic species, Zygoascus meyerae sp. nov. (type material is a cross of CBS 4099T×CBS 7521T) is described, together with two novel anamorphic varieties corresponding to it, Candida hellenica var. hellenica (CBS 4099T) and C. hellenica var. acidophila (CBS 7115T).