bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chiral separation of rac‐Ornidazole and detection of the impurity of (R)‐Ornidazole in (S)‐Ornidazole injection and raw material
Authors: Huang Jianquan , Cao Guoying , Hu Xin , Sun Chunhua , Zhang Junren 
Published: April 2006

Abstract(S)‐Ornidazole is a subject of research as an antifertility agent in male animals at present. However, there seems to be no relative report on chiral separation for rac‐Ornidazole, which has been used as an effective medicine for more than 30 years. In this article, the chiral separation of rac‐Ornidazole on a Chiralcel OB‐H column based on normal‐phase high‐performance liquid chromatography (NP‐HPLC) is investigated and the methodology for detection of impurity of (R)‐Ornidazole in (S)‐Ornidazole injection and raw material is established. The novel mobile phase is utilized by mixing n‐hexane, methanol and isopropyl alcohol (95:4:1, v/v/v) instead of the typical mobile phase of n‐hexane and isopropyl alcohol, although the methanol, which offers a good resolution factor for the enantiomeric separation in this system, is not recommended on the Chiralcel OB‐H column according to the instruction supplied by Daicel Chemical Ind., LTD (Japan). Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Cytokine‐induced killer cells against autologous CLL: Direct cytotoxic effects and induction of immune accessory molecules by interferon‐γ
Authors: Kornacker Martin , Moldenhauer Gerhard , Herbst Markus , Weilguni Edeltraud , Tita‐Nwa Freddy , Harter Christoph , Hensel Manfred , Ho Anthony D. 
Published: April 2006

AbstractCytokine‐induced killer cells (CIK cells), coexpressing CD3 and CD56, can be expanded from peripheral blood mononuclear cells by the timed addition of interferon‐γ (IFN‐γ), IL‐2 and OKT3. The effects of CIK cells on primary, autologous CLL cells are described. We used MACS to separate CD3+ cells for expansion of CIK cell effectors and CD19+ targets from peripheral blood of 16 CLL patients. Apoptosis was assessed by measuring annexinV staining in CLL cells. After incubation of autologous CIK with CLL, specific apoptosis in CLL cells was 15%. Coincubation with irradiated CIK cells for 48 hr before adding vital CIK cells resulted in an increased ICAM‐1 expression on CLL cells and an increase in apoptosis of CLL targets (30%). These effects were mediated by IFN‐γ secretion of CIK cells. In addition to their direct cytotoxic effect, CIK cells secrete IFN‐γ that modulates the expression of adhesion molecules on CLL cells, and this enhances apoptosis induction by cytotoxic effector cells. © 2006 Wiley‐Liss, Inc.
Interleukin‐6 induces both cell growth and VEGF production in malignant mesotheliomas
Authors: Adachi Yasuo , Aoki Chieko , Yoshio‐Hoshino Naoko , Takayama Koichi , Curiel David T. , Nishimoto Norihiro 
Published: April 2006

AbstractMalignant mesothelioma (MM), an incurable tumor, is reportedly an interleukin‐6 (IL‐6) secreting tumor. The pathological significance of IL‐6 overexpression in this tumor, however, has remained unclear. We investigated the biological functions of IL‐6 in mesotheliomas. Five mesothelioma cell lines were analyzed for IL‐6 production and IL‐6 receptor (IL‐6R) expression. Of them, 2 produced high levels of IL‐6, 2 produced intermediate levels and 1 cell line showed no secretion. All mesothelioma cell lines used in this study expressed very small amounts of IL‐6R mRNA. We compensated for this low level of IL‐6R expression in mesotheliomas by adding recombinant soluble IL‐6R (sIL‐6R) to mediate the IL‐6 signal. IL‐6 together with sIL‐6R was found to promote cell growth of H2052 and H226 MMs classified as high‐level IL‐6 producers in a dose‐dependent manner. Moreover, a humanized anti‐IL‐6R antibody (MRA) capable of blocking IL‐6 signaling suppressed the cell growth of mesotheliomas induced by IL‐6/sIL‐6R. These findings demonstrate that IL‐6 serves as an autocrine growth factor in the development of mesothelioma. In addition, IL‐6/sIL‐6R stimulation increased the expression of vascular endothelial growth factor (VEGF) in 4 out of 5 cell lines, and this induction was inhibited by MRA treatment. The involvement of the signal transducer and activator of transcription 3 (STAT3) pathway in both cell growth and VEGF induction by IL‐6/sIL‐6R was verified by dominant negative STAT3 transduction combined with adenovirus gene‐delivery methods. Although IL‐6 induces VEGF through the JAK2/STAT3 pathway, anti‐VEGF antibody could not inhibit the IL‐6‐induced cell growth observed in H2052 and H226. We concluded that IL‐6‐dependent growth does not occur via VEGF induction. These results suggest that treatment with anti‐IL‐6R antibody may constitute a potential molecular targeting therapy for MMs. © 2006 Wiley‐Liss, Inc.
Volatility dynamics and heterogeneous markets
Authors: McMillan David G. , Speight Alan E. H. 
Published: April 2006

AbstractRecent research has suggested that intra‐day volatility may possess a component structure, resulting either from the arrival of heterogeneous information or the actions of heterogeneous market agents. This paper reports direct evidence for the existence of such components in S&P500 index and DM/$ exchange rate data. Estimation of a FIGARCH model supports the contention that volatility dynamics result from multiple sources. Using a HARCH conditional variance model which defines volatility components over differing time horizons, confirmatory evidence of heterogeneous components is reported, in which context the impact of high‐frequency speculation and noise‐trading are particularly apparent. Copyright © 2006 John Wiley & Sons, Ltd.
The real exchange rate–real interest rate relation: evidence from tests for symmetric and asymmetric threshold cointegration
Authors: Sollis Robert , Wohar Mark E. 
Published: April 2006

AbstractThis paper investigates the existence of threshold cointegration between real exchange rates and real interest rate differentials. Unlike previous work, which generally fails to find evidence of a long‐run relationship employing linear models, we employ tests of the null hypothesis of no cointegration derived from nonlinear bivariate models that allow for threshold cointegration under the alternative hypothesis. For six of the countries in our sample our analysis reveals some evidence of a nonlinear long‐run relationship between real exchange rates and real interest rate differentials. Asymmetric mean reversion of the equilibrium error is found to be driven by the asymmetric short‐run adjustment of the real exchange rate to dis‐equilibrium. When threshold cointegration is found to exist, we find stronger mean reversion when the equilibrium error is negative relative to when it is positive. Copyright © 2006 John Wiley & Sons, Ltd.
Concentric‐needle single‐fiber electromyography for the diagnosis of myasthenia gravis
Authors: Benatar Michael , Hammad Mustafa , Doss‐Riney Heidi 
Published: April 2006

AbstractThe goal of this study was to estimate the accuracy of concentric‐needle single‐fiber electromyography (CN‐SFEMG) for the diagnosis of myasthenia gravis (MG). A consecutive series of patients referred for CN‐SFEMG was evaluated by an investigator blinded to the results of CN‐SFEMG in order to determine the presence or absence of MG using an independent reference standard. Sensitivity, specificity, predictive values, and likelihood ratios were calculated. The study population included 51 patients (21 with MG). CN‐SFEMG was normal in 34 patients (67%) and abnormal in 17 (33%). The sensitivity of CN‐SFEMG for the diagnosis of MG was 0.67 and the specificity was 0.96. The positive likelihood ratio was 16.8 and the negative likelihood ratio was 0.34. The positive and negative predictive values were 0.93 and 0.76, respectively. These results indicate that CN‐SFEMG showing abnormal jiggle is extremely useful for confirming the diagnosis of MG, but that CN‐SFEMG showing normal jiggle has limited utility in excluding the diagnosis. Muscle Nerve, 2006
Anionic grafting polymerization of propylene sulfide onto human hair in water
Authors: Morinaga Hisatoyo , Ochiai Bungo , Mori Hideharu , Endo Takeshi 
Published: April 2006

AbstractNatural human hair was modified by the graft polymerization of propylene sulfide in an aqueous medium. The amount of the polymer grafted onto the reduced hair was 0.15–0.19 g on 1.0 g of hair. The grafted polymer was isolated by the hydrolysis of the hair in the polymer‐grafted hair under basic conditions and was confirmed to be poly(propylene sulfide) by 1H NMR, 13C NMR, and Fourier transform infrared spectra. The number‐average molecular weights of the isolated polymers from the grafted products were 10,000–12,000. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3778–3786, 2006
Fertility of internal migrants: comparison between Austria and Poland
Authors: Kulu Hill 
Published: April 2006

AbstractPrevious research has proposed four competing views on an individual's fertility following a move from one social context to another. Each view has received support but has also been challenged in the literature. This study contributes to the existing discussion on fertility by providing an analysis of the effects of internal migration on the fertility of post‐war Austrian and Polish female cohorts. The study is based on retrospective event‐history data and applies intensity regression to both single and simultaneous equations. The analysis shows, firstly, that natives in urban areas in general and in large cities in particular have lower fertility compared with non‐migrants in rural areas, both in Austria and Poland. Secondly, it reveals that people who move from one place to another adopt the fertility behaviour that dominates at the destination. Thirdly, we observe an elevated first‐birth risk for women who move because of union formation, and a short‐term postponement of childbearing for those who settle in a large city. The country comparison shows some differences in fertility variation across settlements, but overall the results are quite similar, despite the different post‐war societal contexts of the two countries. Copyright © 2006 John Wiley & Sons, Ltd.
The effects of boundary imperfections on convection in a saturated porous layer: near-resonant wavelength excitation
Authors: Rees D. A. S. , Riley D. S. 
Published: April 2006

Weakly nonlinear theory is used to study the porous-medium analogue of the classical Rayleigh-Bénard problem, i.e. Lapwood convection in a saturated porous layer heated from below. Two particular aspects of the problem are focused upon: (i) the effect of thermal imperfections on the stability characteristics of steady rolls near onset; and (ii) the evolution of unstable rolls.For Rayleigh-Bénard convection it is well known (see Busse and co-workers 1974, 1979, 1986) that the stability of steady two-dimensional rolls near onset is limited by the presence of cross-roll, zigzag and sideband disturbances; this is shown to be true also in Lapwood convection. We further determine the modifications to the stability boundaries when small-amplitude imperfections in the boundary temperatures are present. In practice imperfections would usually consist of broadband thermal noise, but it is the Fourier component with wavenumber close to the critical wavenumber for the perfect problem (i.e. in the absence of imperfections) which, when present, has the greatest effect due to resonant forcing. This particular case is the sole concern of the present paper; other resonances are considered in a complementary study (Rees & Riley 1989).For the case when the modulations on the upper and lower boundaries are in phase, asymptotic analysis and a spectral method are used to determine the stability of roll solutions and to calculate the evolution of the unstable flows. It is shown that steady rolls with spatially deformed axes or spatially varying wavenumbers evolve. The evolution of the flow that is unstable to sideband disturbances is also calculated when the modulations are π out of phase. Again rolls with a spatially varying wavenumber result.
Numerical simulation of boundary-layer transition and transition control
Authors: Laurien E. , Kleiser L. 
Published: April 2006

The laminar-turbulent transition process in a parallel boundary-layer with Blasius profile is simulated by numerical integration of the three-dimensional incompressible Navier-Stokes equations using a spectral method. The model of spatially periodic disturbances developing in time is used. Both the classical Klebanoff-type and the subharmonic type of transition are simulated. Maps of the three-dimensional velocity and vorticity fields and visualizations by integrated fluid markers are obtained. The numerical results are compared with experimental measurements and flow visualizations by other authors. Good qualitative and quantitative agreement is found at corresponding stages of development up to the one-spike stage. After the appearance of two-dimensional Tollmien-Schlichting waves of sufficiently large amplitude an increasing three-dimensionality is observed. In particular, a peak-valley structure of the velocity fluctuations, mean longitudinal vortices and sharp spike-like instantaneous velocity signals are formed. The flow field is dominated by a three-dimensional horseshoe vortex system connected with free high-shear layers. Visualizations by time-lines show the formation of A-structures. Our numerical results connect various observations obtained with different experimental techniques. The initial three-dimensional steps of the transition process are consistent with the linear theory of secondary instability. In the later stages nonlinear interactions of the disturbance modes and the production of higher harmonics are essential.We also study the control of transition by local two-dimensional suction and blowing at the wall. It is shown that transition can be delayed or accelerated by superposing disturbances which are out of phase or in phase with oncoming Tollmien-Schlichting instability waves, respectively. Control is only effective if applied at an early, two-dimensional stage of transition. Mean longitudinal vortices remain even after successful control of the fluctuations.
The generation and collapse of a foam layer at the roof of a basaltic magma chamber
Authors: Jaupart Claude , Vergniolle Sylvie 
Published: April 2006

Basaltic volcanoes erupt in several different regimes which have not been explained. At Kilauea (Hawaii), eruption can take the form of either fire fountaining, where gas-rich jets propel lava clots to great heights in the atmosphere, or quiet effusive outflow of vesicular lava. Another regime is commonly observed at Stromboli, where large gas slugs burst intermittently at the vent. In an attempt to provide a unifying framework for these regimes, we investigate phenomena induced by degassing in a reservoir which empties into a small conduit. Laboratory experiments are done in a cylindrical tank topped by a thin vertical tube. Working liquids are silicone oils and glycerol solutions to investigate a range of viscosity and surface tension. Gas bubbles are generated at the tank bottom with known bubble diameter and total gas flux. The bubbles rise through the tank and accumulate in a foam layer at the roof. Depending on the behaviour of this foam layer, three different regimes can be distinguished: (i) steady horizontal flow of the foam leading to bubbly flow in the conduit; (ii) alternating regimes of foam build-up and collapse leading to the eruption of a single, large gas pocket; (iii) flow of the foam partially coalesced into larger gas pockets leading to intermittent slug flow in the conduit. These regimes have natural counterparts in basaltic volcanoes.A simple theory is proposed to explain regimes (i) and (ii). The bubbles in contact with the roof deform under the action of buoyancy forces, developing flat contact areas whose size increases as a function of foam thickness. Maximum deformation corresponds to a critical thickness hc = 2σ/ερlgR, where σ is the coefficient of surface tension, ρl the liquid density, g the acceleration due to gravity, R the bubble radius and ε the gas volume fraction in the foam. The foam thickness is determined by a balance between the input of bubbles from below and the output into the conduit, and is proportional to (μlQ/ε2 ρlg)¼, where μl is the liquid viscosity and Q the gas flux. A necessary and sufficient condition for collapse is that it exceeds the critical value hc. In a liquid of given physical properties, this occurs when the gas flux exceeds a critical value which depends on viscosity, surface tension and bubble size. Experimental determinations of the critical gas flux and of the time between two events of foam collapse are in agreement with this simple theory.
A numerical method for treating time-periodic boundary layers
Authors: Duck P. W. 
Published: April 2006

The development of an incompressible, laminar, pulsatile boundary layer over a semi-infinite flat plate is studied. Although the undisturbed free stream flow is taken to be non-reversing (following previous studies), sufficiently far downstream, the flow in part of the boundary layer must ultimately reverse direction during part of the cycle.A novel numerical (finite-difference) scheme is described, which builds in the time periodicity of the flow, and also takes into account the direction of the flow in deciding the form of the differencing in the streamwise direction. The effect of variations in numerical grid is investigated, and comparison is made with asymptotic formulae applicable close to and far from the leading edge of the plate, together with linearized (small oscillation) results obtained using the analysis of Ackerberg & Phillips (1972), which is shown to yield remarkably accurate results when compared with the solution for the full problem, even for quite large oscillation amplitudes.
Selection of convective planform orientation by boundary anisotropy
Authors: Pearlstein Arne J. , Oztekin Alparslan 
Published: April 2006

Thermal instability of a fluid layer confined between isotropic horizontal solid walls leads to convection cells having no preferred horizontal direction. For thermally anisotropic walls, we find that certain planform orientations are preferred, in that convection sets in at a smaller Rayleigh number (Ra) for some orientations than for others, thus providing a means by which a regular planform may be established in a large-aspect-ratio layer. We consider horizontal layers of two Boussinesq, Newtonian fluids separated by a rigid, thermally anisotropic plate of constant thickness. The upper and lower fluid layers are bounded above and below, respectively, by rigid, thermally anisotropic plates of arbitrary thickness. When the bounding surfaces are thermally anisotropic, the horizontal wavevector (a) of the resulting convective flow has two distinct components. Thus, instead of a neutral curve in the (Ra, a)-plane, there is a neutral surface, and Ra depends on both components of a, or alternatively, on |a| and the planform orientation angle Φrε[0, 2π]. In the isotropic case, the neutral surface is axisymmetric (i.e. invariant with respect to Φr consistent with the known dependence on |a| only.For anisotropic walls, axisymmetry is replaced by π- periodicity in the Φr direction, corresponding to invariance with respect to a 180° rotation, and the neutral surface has an even number of local minima. We study the dependence of Φr on the middle plate orientation (Φp) Several different Φr−Φp topologies are found. When the number of local minima exceeds two, discontinuous Φr−Φp plots may occur. The dependence of Φr on the thicknesses and conductivities of the plates and fluids and on the orientation of the plates is discussed, with special reference to the transitions between different Φr−Φp topologies.
Numerical simulation of liquid-metal MHD flows in rectangular ducts
Authors: Sterl A. 
Published: April 2006

To design self-cooled liquid metal blankets for fusion reactors, one must know about the behaviour of MHD flows at high Hartmann numbers. In this work, finite difference codes are used to investigate the influence of Hartmann number M, interaction parameter N, wall conductance ratio c, and changing magnetic field, respectively, on the flow.As liquid-metal MHD flows are characterized by thin boundary layers, resolution of these layers is the limiting issue. Hartmann numbers up to 103 are reached in the two-dimensional case of fully developed flow, while in three-dimensional flows the limit is 102. However, the calculations reveal the main features of MHD flows at large M. They are governed by electric currents induced in the fluid. Knowing the paths of these currents makes it possible to predict the flow structure.Results are shown for two-dimensional flows in a square duct at different Hartmann numbers and wall conductivities. While the Hartmann number governs the thickness of the boundary layers, the wall conductivities are responsible for the pressure losses and the structure of the flows. The most distinct feature is the side layers where the velocities can exceed those at the centre by orders of magnitude.The three-dimensional results are also for a square duct. The main interest here is to investigate the redistribution of the fluid in a region where the magnetic field changes. Large axial currents are induced leading to the ‘M-shaped’ velocity profiles characteristic of MHD flow. So-called Flow Channel Inserts (FCI), of great interest in blanket design, are investigated. They serve to decouple the load carrying wall from the currents in the fluid. The calculations show that the FCI is indeed a suitable measure to reduce the pressure losses in the blanket.
Time-depeiident and time-averaged turbulence structure near the nose of a wing-body junction
Authors: Devenport William J. , Simpson Roger L. 
Published: April 2006

The behaviour of a turbulent boundary layer on a flat surface as it encounters the nose of a cylindrical wing mounted normal to that surface is being investigated. A three-component laser anemometer has been developed to measure this highly turbulent three-dimensional flow. Measurements of all the non-zero mean-velocity and Reynolds-stress components have been made with this instrument in the plane of symmetry upstream of the wing. These data have been used to estimate some of the component terms of the turbulence kinetic energy equation. Histograms of velocity fluctuations and short-time cross-correlations between the laser anemometer and a hot-wire probe have also been measured in the plane of symmetry. In all, these results reveal much of the time-dependent and time-averaged turbulence structure of the flow here.Separation occurs in the plane of symmetry because of the adverse pressure gradient imposed by the wing. In the time mean the resulting separated flow consists of two fairly distinct regions: a thin upstream region characterized by low mean backflow velocities and a relatively thick downstream region dominated by the intense recirculation of the mean junction vortex. In the upstream region the turbulence stresses develop in a manner qualitatively similar to those of a two-dimensional boundary layer separating in an adverse pressure gradient. In the vicinity of the junction vortex, though, the turbulence stresses are much greater and reach’ values many times larger than those normally observed in turbulent flows. These large stresses are associated with bimodal (double-peaked) histograms of velocity fluctuations produced by a velocity variation that is bistable. These observations are consistent with large-scale low-frequency unsteadiness of the instantaneous flow structure associated with the junction vortex. This unsteadiness seems to be produced by fluctuations in the momentum and vorticity of fluid from the outer part of the boundary layer which is recirculated as it impinges on the leading edge of the wing. Though we would expect these fluctuations to be produced by coherent structures in the boundary layer, frequencies of the large-scale unsteadiness are substantially lower than the passage frequency of such structures. It therefore seems that only a fraction of the turbulent structures are recirculated in this way.