bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phrenic nerve neurotization of the musculocutaneous nerve with end‐to‐side neurorrhaphy: A short report in a rabbit model
Authors: Stamatoukou Anna , Papadogeorgou Ellada , Zhang Zijie , Pavlakis Kitty , Zoubos Aristides B. , Soucacos Panayotis N. 
Published: April 2006

AbstractThis experimental study was performed to evaluate the efficacy of end‐to‐side coaptation between the musculocutaneous nerve and the phrenic nerve for brachial plexus injuries with nerve‐root avulsions. In an experimental rabbit model, neurotization of the musculocutaneous nerve with the phrenic nerve was compared using end‐to‐end and end‐to‐side neurorrhaphy. Preliminary results from electrophysiologic and histologic examinations indicate that end‐to‐side neurotization of the musculocutaneous nerve with the phrenic nerve is an effective means for musculocutaneous nerve repair. The effectiveness of the phrenic nerve is attributed to its large number of motor axons. © 2006 Wiley‐Liss, Inc. Microsurgery, 2006
1H and 13C NMR study of 5‐substituted‐4‐ (arylidene)amino‐2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐thiones and 6‐aryl‐3‐(D‐gluco‐ pentitol‐1‐yl)‐7H‐1,2,4‐triazolo[3,4‐b] [1,3,4]thiadiazines
Authors: Zhang Anjiang , Zhang Lixue , Lei Xinxiang 
Published: April 2006

AbstractFive 5‐substituted‐4‐(arylidene)amino‐2,4‐dihydro‐3H‐1, 2,4‐triazole‐3‐thiones (2a–2e) and seven 6‐aryl‐3‐(D‐gluco‐pentitol‐1‐yl)‐7H‐1,2,4‐triazolo[3,4‐b][1,3,4]thiadiazines (3a–3g) were synthesized. The complete 1H and 13C NMR chemical shift assignments were analyzed on one‐ and two‐dimensional NMR techniques, including DEPT, NOE‐DIF, COSY, gHMBC, and gHSQC. Copyright © 2006 John Wiley & Sons, Ltd.
Electronic structures of double perovskites Ba2MnMO6 (M = W and Re) from first‐principles studies
Authors: Cheng J. , Yang Z. Q. 
Published: April 2006

AbstractThe cover picture of the current issue refers to the work of J. Cheng and Z. Q. Yang which is featured as Editor's Choice [1]. Double perovskites, A2B′B″O6 (A is an alkaline earth; B′B″ sites are occupied alternately by transition metals) have recently attracted considerable attention due to the discovery of large low‐field room‐temperature magnetoresistance in this kind of materials. The authors study from first principles the electronic structure of two double perovskites, Ba2MnWO6 and Ba2MnReO6, using Density Functional Theory. The ground magnetic phases for the two compounds are found to be antiferromagnetic and ferrimagnetic, respectively, in agreement with experimental results. Ba2MnWO6 was predicted to have semiconductor band structure. For Ba2MnReO6, a finite energy gap can appear only when spin–orbital coupling together with on‐site Coulomb interactions on Re ions are taken into account. The results explain the curve of resistivity versus temperature for Ba2MnReO6.The first author J. Cheng works in the field of theoretical condensed matter physics from first‐principles calculations at the Surface Physics Laboratory, Fudan University, Shanghai, China.
Inhibition of nifedipine‐induced proliferation of cultured human gingival fibroblasts by Saiko, a Chinese herbal medicine
Authors: Hattori Toshimi , Matsunaga Shozo , Nakazono Youdai , Wang Pao‐Li 
Published: April 2006

AbstractSaiko is predominantly contained in Saireito, a Chinese herbal medicine. The present study was conducted to determine whether or not Saiko is involved in the inhibition by Saireito of nifedipine‐induced proliferation and collagen synthesis in gingival fibroblasts. Nifedipine (10 µm) significantly enhanced the proliferation starting on day 5 of the culture period. When added together with nifedipine, Saiko at concentrations of 0.05%–0.2% (w/v) dose‐dependently inhibited the nifedipine‐induced proliferation, and at the highest concentration tested (0.2%), Saiko inhibited the nifedipine‐induced proliferation by about 40%. Moreover, Saiko (0.2%) also inhibited the normal proliferation at days 11 and 14. Sole application of nifedipine (10 µm) augmented the release of bFGF, and Saiko concentration‐dependently reduced the level of bFGF in the nifedipine‐containing culture medium. Nifedipine (10 µm) increased the production of type I collagen to almost twice that of the control (normal medium), and Saiko at concentrations above 0.1% significantly reduced the nifedipineinduced production of collagen. In conclusion, the present findings demonstrate that Saiko inhibited the nifedipine‐induced proliferation of gingival fibroblasts by reducing the release of bFGF and that Saiko is involved in the Saireito‐induced inhibition of nifedipine‐stimulated proliferation and collagen synthesis in gingival fibroblasts. Copyright © 2006 John Wiley & Sons, Ltd.
Constrained simulated annealing for stability margin computation in a time‐delay system
Authors: Kim Kyungsup , Bae Jinho 
Published: April 2006

AbstractThe stability margin of a time‐delay system is formulated via factorization. This paper provides a numerical method for computing the stability margin of time‐delay linear time‐invariant systems with delay dependence by using a constrained simulated annealing algorithm. The constrained simulated annealing is used to solve a nonlinear continuous constrained optimization problem, which is derived from computing the stability margin of a delay system. Illustrative examples show that the established method can verify the stability for a class of time‐delay systems. Copyright © 2006 John Wiley & Sons, Ltd.
Detecting and monitoring change in models
Authors: Schaffernicht Martin 
Published: April 2006

AbstractSystem dynamics is often brought into connection with a double‐loop learning process. Learning has been the object of an increasing number of studies. However, inquiry has focused on using models rather than modeling, and there are huge differences in assessment approaches. If learning changes models then it can be inferred from comparing models. Here it is argued that monitoring learning from modeling is feasible and desirable. One possibility is to conceive of a model as a series of versions and compare their structure. One possible method for comparing model versions is presented. Copyright © 2006 John Wiley & Sons, Ltd.
Non-Boussinesq and penetrative convection in a cylindrical cell
Authors: Walden R. W. , Ahlers Guenter 
Published: April 2006

Measurements of Rayleigh numbers R and Nusselt numbers N have been made for a cylindrical cell having a radius to height ratio of 4·72 and containing liquid helium I. The upper surface of the cell was maintained at a constant temperature T2 near T0 = 2·178 K where the fluid density has a maximum. The heat input to the cell bottom was varied quasi-statically while the lower surface temperature T1 was recorded. The penetration parameter [Pscr ]≡(T1−T2)/(T1−T0) ranged between 0·1 and 3 for our experiments.For [Pscr ] < 1, the initial slope of N(R) for R near the critical Rayleigh number Rc was independent of [Pscr ]. For ${\cal P}\;{\mathop {\raise-2pt\hbox{$>$}}\limits^{\raise-8pt\hbox{$\sim$}}}\;1$, two hysteresis loops of N(R) were observed. One of them occurred very near Rc and is interpreted in terms of the inverted bifurcation associated with the onset of cellular convection of non-Boussinesq systems. The other, for R > Rc, is believed to correspond to the transition from cellular to two-dimensional flow. Near Rc and with [Pscr ] > 2 we also observed multistability, with the states believed to correspond to different numbers of convective cells.For large [Pscr ] the onset of time-dependent flow occurred much closer to Rc than is the case for Boussinesq systems.
Steady, supercritical flow in collapsible tubes. Part 2. Theoretical studies
Authors: Mcclurken Michael E. , Kececioglu Ifiyenia , Kamm Roger D. , Shapiro Ascher H. 
Published: April 2006

Theories are developed to explain the experimental observations of steady, supercritical flow in compliant, partially collapsed tubes, presented in the companion paper (part 1).It is shown that the measured curves of area vs. distance are governed by a combination of (i) friction and gravity, which produce mean gradients of area, and (ii) longitudinal bending and tension forces, which produce standing waves of area superposed upon the mean gradients. The experiments confirm the one-dimensional theory for the mean gradients: (i) in the absence of gravity, friction causes a pressure rise and a positive mean gradient of area; (ii) a downward slope can cancel gravity and lead asymptotically to a uniform state having zero gradients of pressure and area.The inviscid dispersion relationship for area waves due to longitudinal bending and tension is developed, based on a simple, approximate model for the mechanics of the tube. The phase velocity increases as the wavelength decreases, hence the group velocity exceeds the phase velocity. Consequently, in steady flows that are supercritical with respect to the infinite-wavelength phase velocity, energy can propagate upstream and standing waves of area may appear.In the experiments of part 1, longitudinal tension predominated over longitudinal bending. The measured wavelengths of standing waves were found to be in general agreement with the dispersion relationship for tension-induced area waves. The observed streamwise growth of standing area waves is interpreted physically as the attenuation of waves radiating upstream from a source of disturbance such as a shock-like rapid increase of area. The rate of wave attenuation indicates that the skin-friction coefficient has a large out-of-phase oscillatory component. The observed steepness of shock transitions agrees with an approximate theory based on treating the forward portion of the shock as the rearward part of the standing wave train that the shock drives upstream.
Equilibrium shape and stability of a liquid cylinder in cross flow at low Weber numbers
Authors: Weihs D. , Frankel I. 
Published: April 2006

The cross-section shape and stability of a liquid cylinder moving perpendicularly to its axis in a gaseous medium is studied. Such liquid cylinders are formed during the break-up process of thin, rapidly moving liquid sheets, appearing in spray and atomization processes. The equilibrium shape is affected mainly by two factors: the dynamic-pressure distribution in the gas flow and the surface tension on the liquid boundary. The former tends to distort the liquid cross-section into an oval shape while the latter tends to restore the circular cross-section.A series expansion for the shape of the cylinder cross-section was determined by assuming incompressible potential flow, neglecting the effects of body forces and internal circulation in the liquid.The stability analysis shows that in the range of low Weber numbers the cylinder break-up is due to the divergence of varicose perturbations. The wavenumber of the most rapidly growing perturbation, its rate of growth and the maximal wavenumber for which varicose instability occurs, are all found to decrease as the Weber number grows, owing to a pressure distribution caused by the varicose distortion, which tends to reduce these perturbations.
Shock diffraction in channels with 90° bends
Authors: Edwards D. H. , Fearnley P. , Nettleton M. A. 
Published: April 2006

A study has been made of how initially planar shocks in air propagate around 90° bends in channels of nearly rectangular cross-section. In shallow bends for which the radius of curvature R is much greater than the radius r of the channel, the shock recovers from a highly curved profile at the start of the bend to regain planarity towards the end of the bend. This occurs on account of the acceleration of the triple point across the channel following its interaction with the expansion waves generated at the convex wall. In sharp bends the shock profiles retain their pronounced curvature for some distance downstream of the bend.At the start of a shallow bend (R/r ≈ 6) the shock at the concave wall, initial Mach number M0, accelerates to Mw = 1.15M0 and remains at this value until towards the end of the bend it begins to attenuate. At the convex wall, shocks of M0 > 1.7 attenuate to Mw = 0.7M0 and propagate at this value for some distance around the bend. In the early stages of a sharper bend (R/r ≈ 3) the shock at the concave wall strengthens to Mw = 1.3M0, remaining at this value for some distance downstream of the bend. At the convex wall the shock decelerates to 0.6M0.Whitham's (1974) ray theory is shown to predict with reasonable accuracy the Mach numbers of the wall shocks at both surfaces for both bends tested and the range of incident shock velocities used, 1.2 < M0 < 3. The agreement between the theory and experimental results is particularly close for stronger shocks propagating along the inner bend. Predictions from 3-shock theory (Courant & Friedrichs 1948) of the Mach number at the outer wall are consistently higher than those from Whitham's analysis. In turn, the latter tends to slightly overestimate the strength of the wall shock.A model is developed, based on an extension of Whitham's analysis, and is shown to predict the length of the Mach stem produced by shocks of M0 > 2 over the initial stages of the bend.
Turbulence structure in thermal convection and shear-free boundary layers
Authors: Hunt J. C. R. 
Published: April 2006

This paper is a study of turbulence near rigid surfaces, in the absence of any mean shear. Different sources of turbulence are considered, including thermal convection and grid turbulence. It is shown that, if a rigid boundary is introduced into the flow, then for short times the linear theory of Hunt & Graham (1978) reveals the common structure of these flows near the boundary, if the parameters used are the rate of energy dissipation per unit mass ε and the distance z from the surface. Over longer times nonlinear effects develop, such as large eddies straining smaller eddies near the boundary. Some new estimates are suggested here and compared with the computations of Biringen & Reynolds (1981) and experiments of Thomas & Hancock (1977).It is shown that calculations based on the linear theory agree well with many measurements of the vertical profiles of turbulence in thermal convection layers, including those of the vertical variance, the low-frequency end of the spectrum of the vertical turbulence (w), the integral scale of w, and two-point cross-correlations of w. (The latter was a prediction, subsequently tested by atmospheric measurements.) Some discussion of the reasons for this agreement are suggested. The observations of the effects of mean-velocity gradients near the surface are also shown to be consistent with the theoretical arguments proposed here.
High-Reynolds-number viscous flow in collapsible tubes
Authors: Tutty O. R. 
Published: April 2006

This study is concerned with steady laminar high-Reynolds-number flow in collapsible tubes, where the position of the tube wall is a function (the tube law) only of the pressure exerted by the fluid on the wall. The system is controlled by two main parameters: the Reynolds number of the incoming flow, and the ‘compliance’, which characterizes the response of the wall to a change in fluid pressure. Restrictions are placed on these parameters so that the streamwise lengthscale is large, and, to the order worked, the pressure is uniform across the tube. Attention is restricted to (axi)symmetric systems.Channels are considered in most detail, the results for axisymmetric pipes being largely similar.For a model tube law the flow in the converging section of a channel is investigated in detail. Solutions are presented for certain of the parameter values. For some channels a singularity is found in the solution such that the channel width tends to zero at a finite distance downstream. No way was found to integrate past this singularity.For particular channels and pipes, solutions are found only for flows in which the mean fluid velocity is less than the propagation speed of frictionless waves. This is consistent with experimental results.
Cell-pattern sensitivity to box configuration in a saturated porous medium
Authors: Borkowska-Pawlak B. , Kordylewski W. 
Published: April 2006

Steady small-amplitude thermal convection in a fluid-saturated. infinitely extended porous layer is investigated theoretically in the wavenumber range 1/√2−1. It was shown that the point of multiple bifurcation Ra0 = (3/√2 + 2)π2, α0 = 2−0.25 leads to secondary bifurcation when the wavenumber decreases.As a result a new branch of a stable, complicated, three-dimensional flow in the square cell was discovered for α close to α0. This branch joins two adjacent branches of three-dimensional flows emanating from the trivial solution and causes their stability transition at the branching points.
On a submerged sphere in a viscous fluid excited by small-amplitude periodic motions
Authors: Jenkins S. A. , Inman D. L. 
Published: April 2006

Higher-order nonlinear corrections to the Stokes pendulum problem are calculated in perturbation schemes for small values of Reynolds numbers R(2) = umd0/2ν. Here the controlling lengthscale ½d0 is the displacement amplitude of the undisturbed periodic motion, um is the velocity amplitude and ν is the kinematic viscosity. Solutions for two general types of periodic motion are found; namely orbital motion as under deep water waves and oscillatory motion as under shallow water or acoustic waves. These solutions are found by matched asymptotic expansions using the fundamental irrotational oscillation to drive a thin Stokes a.c. boundary layer over the surface of the sphere. From the boundary layer several secondary motions are excited which die away in the neighbouring fluid. Among these are an orthogonal system of steady, rotational Eulerian streaming currents, and two outwardly radiating non-dispersive waves, one having the frequency of the fundamental but with a phase shift, the other appearing at the second harmonic.With these solutions the forces and torques on a fixed sphere were computed. One of the orthogonal components of the rotational streaming field was found to produce a rotary lift force which opposed virtual-mass forces and diminished the resultant force component in quadrature to the fundamental oscillation. The other streaming component contributed damping terms which, unlike leading-order Stokes drag, vary nonlinearly with the displacement amplitude. Steady and second-harmonic torques were found to act on the sphere about the horizontal axis transverse to the fundamental oscillation.
Characteristics of pressure-wave propagation in a compliant tube with a fully collapsed segment
Authors: Shimizu Masashi 
Published: April 2006

In order to model the fluid dynamics of Korotkoff sound generation when the artery under the cuff is fully collapsed during most of the heart cycle, the characteristics of pressure-wave propagation in a long silicone-rubber tube were studied experimentally. The central portion of this tube was designed to collapse to zero cross-sectional area as a result of high negative transmural pressure, thus simulating a collapsed artery. Propagation of a single half-sinusoidal pressure wave in and around this segment was studied in detail by pressure, velocity and tube-longitudinal-shape measurements.A very steep wave front (shock wave) capable of producing a short tapping sound was formed by an overtaking phenomenon in the fully collapsed tube segment and it propagated into the inflated tube distal to the collapsed segment. An empirical equation relating the flow rate penetrating into the collapsed segment, the incident-wave pressure and the external pressure Pc over the collapsed segment was obtained. This equation predicts that the pressure-wave propagation in a fully collapsed segment depends only on the flow rate into the collapsed segment.The initial internal pressure of the tube distal to the collapsed segment Pd is one independent variable in the high-cuff-pressure condition. The amplitude of the steep wave front and the shape of the pressure wave in the inflated tube distal to the collapsed segment are governed by Pc–Pd and the flow rate penetrating the collapsed segment. For the same flow rate, if Pc–Pd is lower than a critical value, the amplitude of the pressure in the distal tube decreases with increasing Pd because of positive pressure-wave reflection at the exit of the collapsed segment. On the other had, if Pc–Pd is higher than that value, no wave reflection occurs and the amplitude of the pressure wave is independent of Pd. In the latter case a severe constriction exists near the distal end of the collapsed segment, and flow occurs as two thin high-speed jets.
Effects of rac‐albuterol on arterial blood gases in patients with stable hypercapnic chronic obstructive pulmonary disease
Authors: Whale Christopher I. , Sovani Milind P. , Mortimer Kevin , Oborne Janet , Cooper Sue , Harrison Timothy W. , Tattersfield Anne E. 
Published: April 2006

AimsMany patients with chronic obstructive pulmonary disease (COPD) are treated with high dose β2‐adrenoceptor agonists, which can increase ventilation/perfusion mismatching, and tremor and cardiac output, thereby increasing oxygen uptake and carbon dioxide output (VCO2). Patients with severe COPD and hypercapnia may be unable to increase ventilation in response to increased VCO2, in which case arterial carbon dioxide tension (PaCO2) may rise. Our aim was to determine whether high dose nebulized rac‐albuterol could increase PaCO2 in patients with COPD, limited bronchodilator reversibilty and hypercapnia.MethodsWe compared 10 mg and 400 µg rac‐albuterol, given in two doses 1 h apart on nonconsecutive days, in a double‐blind randomized crossover study in 14 patients with severe COPD. PaCO2, arterial oxygen tension (PaO2) and heart rate were measured over 120 min and change from baseline was plotted against time to obtain an area under the curve.ResultsMean PaCO2 fell slightly over 120 min, with no difference between treatments (0.03 kPa h−1 (95% confidence interval 0.02, 0.04)) and only three subjects had an increase in PaCO2 after high dose rac‐albuterol. High dose rac‐albuterol caused a greater fall in PaO2[0.1 kPa h−1 (95% confidence interval 0, 0.2)] and increase in heart rate than the low dose, although the differences were small.ConclusionsUnder stable conditions most subjects with severe COPD and hypercapnia will have a fall in PaCO2 and PaO2 following 10 mg rac‐albuterol, suggesting that they maintain capacity to respond to any increase in VCO2 and prevent a rise in PaCO2.
Major determinant factors of the extent of interaction between grapefruit juice and calcium channel antagonists
Authors: Ohnishi Ayako , Ohtani Hisakazu , Sawada Yasufumi 
Published: April 2006

AimTo evaluate quantitatively the influence of bioavailability and plasma unbound fraction (fu) on the extent of interaction between grapefruit juice (GFJ) and calcium antagonists.MethodsThe extent of drug–GFJ interaction was evaluated from reported clinical interaction studies of 11 calcium antagonists. The relationship between extent of interaction and bioavailability or fu was analysed.ResultsThe following significant hyperbolic relationships were observed: [Extent] = 12.2/[bioavailability] + 1 and [Extent] = 0.718/[fu] + 1.ConclusionsBioavailability and fu are major determinant factors of calcium antagonist–GFJ interaction: a drug with smaller bioavailability or lower fu is likely to exhibit a more potent interaction, and vice versa.