bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non‐myeloablative mixed chimerism approaches and tolerance, a split decision
Authors: Luo Bin , Chan William F. N. , Shapiro A. M. James , Anderson Colin C. 
Published: March 2007

AbstractStable mixed chimerism has been considered the most robust tolerance strategy. However, rejection of solid donor tissues by chimeras has been observed, a state termed split tolerance. Since new non‐myeloablative mixed chimerism approaches are being actively pursued, we sought to determine whether they lead to full tolerance or split tolerance and to define the mechanisms involved. Fully mismatched mixed chimeras generated by induction with various lymphocyte‐depleting antibodies along with either low‐dose irradiation or busulfan and temporary sirolimus, maintained stable mixed chimerism but nevertheless rejected donor skin grafts. Generation of stable mixed chimerism using antibody targeting CD40L, but not depleting antibodies to CD4 and CD8, could prevent split tolerance when skin grafts were given together with donor bone marrow. Minor antigen matching abrogated the ability of effector T cells to reject donor skin grafts. A CFSE killing assay indicated that chimeras were both directly and indirectly tolerant of donor hematopoietic cell antigens, suggesting that minor mismatches triggered a tissue‐specific response. Thus, split tolerance due to tissue‐restricted polymorphic antigens prevents full tolerance in a number of non‐myeloablative mixed chimerism protocols and a ‘tolerizing’ agent is required to overcome split tolerance. A model of the requirements for split tolerance is presented.
On watching the watchers: IDO and type I/II IFN
Authors: Puccetti Paolo 
Published: March 2007

AbstractA series of recent studies, including an article in this issue of the European Journal of Immunology, have demonstrated that the immunoregulatory pathway of tryptophan catabolism, initiated by the enzyme indoleamine 2,3‐dioxygenase (IDO), not only represents an effector mechanism of peripheral tolerance, but is also a critical participant in the promotion of an optimally protective immune response balanced between inflammation and tolerance. Although subjected to transcriptional regulation by type I/II IFN, IDO is itself required for the production of type I IFN in response to B7 signaling in CD19+ DC. Such a bidirectional feedback loop could be part of an integrated response for preventing excessive inflammation and autoimmunity.See accompanying article: http://dx.doi.org/10.1002/eji.200636690
Synthesis and Study of the Crystallographic and Magnetic Structure of HoFeMnO5
Authors: Muñoz Angel , Alonso José A. , Martínez‐Lope María J. , Martínez José L. 
Published: March 2007

AbstractA new oxide of stoichiometry HoFeMnO5 has been obtained by replacing Mn3+ cations by Fe3+ in the parent oxide HoMn2O5. The crystallographic and magnetic structures have been analyzed by neutron powder diffraction (NPD), which complements susceptibility and magnetization measurements. HoFeMnO5 is orthorhombic, belonging to the Pbam space group like the parent compound. The crystal structure contains infinite chains of edge‐sharing Mn4+O6 octahedra, interconnected by dimer units of Fe3+O5 square pyramids. In comparison with HoMn2O5, containing elongated Mn3+O6 pyramids, the Fe3+O5 units are flattened. The magnetization measurements show that HoFeMnO5 presents a long‐range magnetic order below TC ≈ 153 K. An NPD study shows that HoFeMnO5 adopts a collinear ferrimagnetic structure: each of the Mn4+ and Fe3+ sublattices are ferromagnetically coupled, and the coupling between the two sublattices is antiferromagnetic; the magnetic moments are oriented along the c direction. The Ho3+ cations also order below TC, but with a very small magnetic moment; the Ho3+ moments are parallel to the Fe3+ magnetic sublattice. At T = 2.7 K, the ordered magnetic moments for the Mn4+, Fe3+ and Ho3+ ions are 1.31(6), 3.20(10) and 0.36(7) μB, respectively. In comparison with ErFeMnO5, where Er3+ cations are fully ordered at low temperatures, in HoFeMnO5 there is a frustration concerning the long‐range order of the Ho3+ cations, which remain virtually paramagnetic over the whole temperature range.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Structural Chemistry of an n = 1 Member of the Ruddlesden–Popper Srn+1(Co0.5Ta0.5)nO3n+1 Homologous Series: Sr4CoTaO8
Authors: Boulahya Khalid , Parras Marina , González‐Calbet José María 
Published: March 2007

AbstractA layered perovskite related compound with the Sr4CoTaO8 composition was isolated. This material constitutes the n = 1 member of the recently reported [Srn+1(Co0.5Ta0.5)nO3n+1] Ruddlesden–Popper series. XRPD, SAED and HREM reveal that this compound crystallizes as a K2NiF4‐type with space group I4/mmm. The structure is formed by one Sr2CoTaO6 perovskite block that intergrows with one SrO rock salt layer; no ordering between the Co and Ta cations was established. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Indium Triflate‐Catalysed Addition of Thio Compounds to Camphene: A Novel Route to 2,3,3‐Trimethyl‐2‐thiobicyclo[2.2.1]heptane Derivatives
Authors: Weïwer Michel , Chaminade Xavier , Bayón J. Carles , Duñach Elisabet 
Published: March 2007

AbstractInIII triflate‐catalysed addition of thiols and thiocarboxylic acids to camphene under mild conditions has allowed the functionalisation of the alkene for the first time, with suppression of the classical rearrangement of the camphene terpene skeleton to isobornane structures. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Stereoselective Synthesis of 2‐Deoxyglycosides from Sulfanyl Alkenes by Consecutive “One Pot” Cyclization and Glycosylation Reactions
Authors: Rodríguez Miguel A. , Boutureira Omar , Matheu M. Isabel , Díaz Yolanda , Castillón Sergio 
Published: March 2007

Abstract2‐Deoxy‐2‐iodopyranosides 3, and 9–12 were synthesized from sulfanyl alkenes using a “one pot” consecutive cyclization–glycosylation process. Compared with the stepwise procedure, the “one pot” process gave significantly improved yields with similar or slightly lower selectivities. The “onepot” procedure was applied to the synthesis of 2,6‐dideoxy‐2‐iodoglycoside 22, which was successfully deiodinated to afford the 2,6‐dideoxyglycoside 23. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Directed Branched‐Regioselective Hydroformylation of 2‐Substituted Allylic o‐DPPB Esters
Authors: Breit Bernhard , Grünanger Christian U. , Abillard Olivier 
Published: March 2007

AbstractBranched‐regioselective hydroformylation of allylic o‐DPPB esters has been accomplished with mono‐ and disubstituted alkene functions in good to excellent yields and selectivities. Optimized reaction conditions allowed the reaction of even trisubstitued alkenic functions. These reactions occur as a result of a significant rate‐accelerating effect exerted by the catalyst‐directing o‐DPPB group, as exemplified by highly position‐, regio‐, and diastereoselective hydroformylation of the geranyl and neryl o‐DPPB esters.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Facile Access to Optically Active Ferrocenyl Derivatives with Direct Substitution of the Hydroxy Group Catalyzed by Indium Tribromide
Authors: Vicennati Paola , Cozzi Pier Giorgio 
Published: March 2007

AbstractFerrocene derivatives have found many different uses and applications in organometallic chemistry, material chemistry, and catalysis. We have shown that using a catalytic amount (5–10 mol‐%) of commercially available indium tribromide, at room temperature, many carbon nucleophiles, such as indoles, allylsilane, enolsilane, silyl ketene acetal, diketone, and trimethylsilylcyanide, smoothly react with different optically active ferrocenyl alcohol derivatives to afford the desired products in high yield, with retention of configuration. Also, many different N‐nucleophiles (azide, carbamates) and O‐nucleophiles (alcohols) react as well, again with retention of configuration. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Stochastic seismic response analysis of hysteretic multi‐degree‐of‐freedom structures
Authors: Wen Yi‐Kwei 
Published: March 2007

AbstractAnalytical study of random vibration of non‐linear mutli‐degree‐of‐freedom (MDF) systems is generally difficult. This is particularly true for MDF inelastic systems due to the highly non‐linear and hereditary behaviour of the restoring force. On the other hand, to obtain the response statistics using a step‐by‐step Monte Carlo simulation requires a large sample, and it could be very costly. The purpose of this paper is to present a practical analytical‐empirical method for an MDF yielding system. The method is based on a substitute structure (SS) concept in which the SS parameters are determined from empirical results of single‐degree‐of‐freedom systems, i.e. each element in the system is replaced by a linear counterpart with ductility‐dependent stiffness and damping. Based on a linear random vibration response analysis, the statistics of the maximum response (ductility) of each element are obtained by iteration. Numerical examples are given for multi‐storey buildings with deteriorating (reinforced concrete frame) or non‐deteriorating (steel frame) restoring forces. Comparisons with empirical results are satisfactory qualitatively. The main advantage of this method is that it requires relatively insignificant computation time, e.g. 1 s of execution time on the IBM 360–75 system for an eight‐storey steel frame.
The effective period and damping of a class of hysteretic structures
Authors: Iwan Wilfred D. , Gates Nathan C. 
Published: March 2007

AbstractThis paper presents the results of a numerical investigation in which the maximum response of six hysteretic systems is calculated for an ensemble of twelve earthquakes. Inelastic response spectra are constructed for a range of response ductility. An effective linear period and damping are calculated for each system and ductility by determining those parameters which minimize an RMS response spectrum error. Conclusions are presented concerning the effects of deterioration, stiffness degradation, cracking and ductility on the effective linear system parameters.
Cyclic liquefaction strength of sands
Authors: Mostaghel N. , Habibagahi K. 
Published: March 2007

AbstractThrough an energy approach, a model is proposed to predict the cyclic liquefaction strength of saturated sands in terms of their static shear strengths. Plots of cyclic liquefaction strength versus relative density and also versus modified standard penetration resistance are presented for various uniformity coefficients and different numbers of stress cycles. The predicted cyclic liquefaction strength values are converted to cyclic stress ratios and compare favourably with Seed's empirical correlations.
Axisymmetric seismic response of a thick circular plate supporting many rods by modal synthesis
Authors: Lee Teh Hwei 
Published: March 2007

AbstractDynamic response of a thick, horizontal, circular plate supporting a large number of slender rods subjected to uniform boundary motion in the vertical direction has been studied by synthesizing component modes of continuous substructures. The excitation considered corresponds to the vertical component of boundary movement produced by earthquake disturbances and the axisymmetric response problem was solved. Mindlin theory was used to formulate the component equations of the plate which is treated as the main component in a modal synthesis technique. The slender rods, which are attached vertically to the plate, are handled as branch components. Vibration modes of a classical thin plate were used as the initial displacement functions for the Mindlin plate. These functions were subsequently modified by a component mode improvement process to obtain plate modes. System modes were generated by combining the improved plate modes with component modes of rods. Numerical results for the natural frequencies and time‐history response of the coupled system are compared with those given by a three‐dimensional finite element method.
Generation of spectrum compatible accelerograms
Authors: Iyengar R. Narayana , Rao P. Narasimha 
Published: March 2007

AbstractIn this paper a new method is presented for generating earthquake accelerograms which have pre‐established response spectra. The non‐stationary random nature and other salient features of the accelerograms can be taken care of by the procedure developed. The method leads to a sample spectrum which lies above the given spectrum. The generation of records to suit several spectra simultaneously can also be handled by this approach. The method is detailed first. This is followed by several numerical examples.
Analysis of three‐dimensional strong ground motions along principal axes, San Fernando earthquake
Authors: Kubo Tetsuo , Penzien Joseph 
Published: March 2007

AbstractAn orthogonal set of principal axes is defined for earthquake ground motions. These principal axes are obtained such that the corresponding variances of motion have maximum, minimum and intermediate values and the covariances equal zero. This indicates that the corresponding components of motion along the principal axes are uncorrelated with respect to each other. Since real earthquake accelerograms are assumed to be reasonably well represented by Gaussian random processes, the three components of motion along the principal axes are statistically independent of each other.Using these principal axes and applying the moving‐window technique to the ground accelerograms recorded during the San Fernando earthquake of 9 February 1971, time‐dependent characteristics of three‐dimensional ground motions along principal axes are determined. Results of the analysis indicate significant correlation between directions of principal axes and directions from the recording stations to the fault slip zone. It is concluded that three components of ground motion can be generated stochastically with statistical independence being maintained, provided they are assumed to be directed along principal axes.
Seismic motion and response prediction alternatives
Authors: Cornell C. Allin , Banon Hooshang , Shakal Anthony F. 
Published: March 2007

AbstractStatistical methods are available which predict the maximum response of simple oscillators given the peak acceleration (Ap), peak velocity (Vp) or peak displacement (Dp) of seismic ground motions. An alternative parameter, namely an ordinate (or ordinates) of the Fourier amplitude spectrum of ground motion acceleration, FS(f), may in fact be a preferred predictor of peak response, especially in a frequency range close to f. Other statistical methods (attenuation laws) use distance R and other parameters such as magnitude (M), Modified Mercalli epicentral Intensity (Io) and Modified Mercalli site Intensity (MMI or Is) to predict spectral velocity (Sv(f)), etc. In using such approaches, it is most desirable to know the total uncertainty in the predicted peak response of the system given the starting parameter values. An extensive strong motion data set is used to study these questions, The most direct prediction models are found to be preferable (have lower prediction dispersion) but data may not be available in all regions to permit their use.
An analytical theory of resonant scattering of SH waves by thin overground structures
Authors: Mei Chiang C. , Foda Mostafa A. 
Published: March 2007

AbstractScattering of SH waves in a half‐space with simple overground structures is studied analytically. For two‐dimensional structures, such as shells, shear walls and a slab‐bridge over a river, the method of matched asymptotics is used for sinusoidal waves long compared to the thickness of the structures. Resonance features are deduced analytically and calculated numerically for various incidences and other parameters.
Free vibration of frame shear wall structures on flexible foundations
Authors: Cheung Y. K. , Swaddiwudhipong S. 
Published: March 2007

AbstractThe finite strip method is used to study the effect of an elastic foundation on the natural frequencies of coupled frame shear wall structures. The solid wall in the structure is divided into several strip elements, the column is treated as a line element and the effect of the connecting beams is dealt with through the compatibility matrices which transfer their structural properties to the adjacent strip or line elements. The comparison functions which satisfy the boundary conditions of being free at the top and being spring supported at the bottom are used for the displacement field in the longitudinal direction. A series of numerical examples is presented to show the accuracy and applicability of the proposed method.
The deployment of strong‐motion earthquake instrument arrays
Authors: Iwan Wilfred D. 
Published: March 2007

AbstractThe International Workshop on Strong‐motion Earthquake Instrument Arrays was held during 2‐5 May 1978 in Honolulu, Hawaii. The goal of the workshop was to develop a workable plan for the possible future deployment of dense strong‐motion arrays with primary emphasis on ground motion studies. Topics considered by the workshop included: favourable array locations, the design of arrays for source mechanism and wave propagation studies, the design of arrays for local effects studies, array construction and operation, and implementation. This paper gives a summary of the recommendations and conclusions of the workshop.
Ground motion at canyons of arbitrary shape under incident sh waves
Authors: Sánchez‐Sesma Francisco J. , Rosenblueth Emilio 
Published: March 2007

AbstractA method for calculating the two‐dimensional scattering of incident SH waves by canyons of arbitrary shape is presented. The problem is formulated in terms of a Fredholm integral equation of the first kind with the integration path outside the boundary. Point‐source discretization and a least‐squares scheme are used. Numerical results are compared with the known analytic solution for a semi‐cylindrical canyon. Spatial variations of surface amplitudes are computed for triangular and half‐cycle sinusoidal canyons as well.
Earthquake response of underground pipelines
Authors: Hindy A. , Novak M. 
Published: March 2007

AbstractSeismic response of underground pipelines is investigat́ed theoretically considering dynamic soil‐pipe interaction. A lumped mass model of the pipe is employed with the soil reactions derived from static and dynamic continuum theories. The soil is supposed to be homogeneous or composed of two different media separated by a vertical boundary. Axial and bending stresses in the pipe due to travelling waves are examined.An extensive parametric study indicates that the axial stresses in the pipe are much higher than bending stresses. In a homogeneous medium, soil‐pipe interaction reduces the stresses in the pipe compared to those calculated ignoring interaction. In a soil composed of two different media, the pipe stresses are highest close to the boundary and can exceed those predicted neglecting interaction.
On the coupled torsional and sway vibrations of a class of shear buildings
Authors: Wittrick W. H. , Horsington R. W. 
Published: March 2007

AbstractThis paper is concerned with the free vibrations of a restricted class of multi‐storey shear buildings in which inertial coupling exists between the torsional and the two sway vibrations. The restrictions imposed are that (a) the shear centres of all storeys lie on a vertical straight line, (b) the principal axes of shear are in the same directions in all storeys, (c) the centres of mass of all floors lie on another vertical straight line, (d) the radius of gyration about the shear centre of every floor mass is the same and (e) the ratios of the two shear stiffnesses to the torsional stiffness do not vary from storey to storey.In consequence of the last restriction it is proved that the 3n natural frequencies, normal modes and generalized masses, where n is the number of storeys, are expressible very simply in terms of products of the three natural frequencies, normal modes and generalized masses of the single‐storey, three‐dimensional building formed by removing everything above the first floor, with the n natural frequencies, normal modes and generalized masses of a certain n‐storey, two‐dimensional shear frame.In the special case of a uniform building, a simple closed form solution, valid for any number of storeys, is given.
The Santa Barbara earthquake of 13 august, 1978
Authors: Miller Richard K. 
Published: March 2007

AbstractAlthough the Santa Barbara earthquake was only a moderate seismic event, it was the most destructive earthquake in the United States in 1978 causing more than $7 million damage and at least 65 injuries. Reported Richter magnitudes ranged from 5–1 to 5–7, but estimates based on strong motion records yielded about 5–8. Due to the geologic features of the earthquake, the intensity of strong shaking was geographically asymmetrical, being much larger in the Goleta area north and west of the epicentre. Peak ground accelerations of 0–40 g were recorded near Goleta, while 0–23 g was recorded closer to the epicentre in Santa Barbara. The duration of strongest shaking was only about 2–3 s. The earthquake caused light cracking of shear walls in multi‐storey reinforced concrete structures, as well as damage to highway overcrossings, many mobile homes and to rooftop mechanical equipment. Presented in this paper are the results of preliminary investigations of the engineering features of this earthquake.
Dynamic response of single span highway bridges
Authors: Hutton S. G. , Cheung Y. K. 
Published: March 2007

AbstractThe dynamic response of single span simply supported bridge decks subjected to the passage of vehicles is examined. A modal analysis approach is adopted that is based upon a finite strip idealization of the deck. The vehicle is modelled as a rigid body supported at two points by a suspension idealization that accounts for the effect of tyre stiffness and the frictional nature of real suspension systems.Results are presented for an orthotropic slab deck and a box girder deck that illustrate the effects of (i) the initial precompression of the suspension system as the vehicle enters the span, (ii) the ratio of the vehicle's natural frequency to that of the bridge deck and (iii) a bridge deck surface profile that is not perfectly horizontal.
Base isolation systems for earthquake protection of multi‐storey shear structures
Authors: Lee D. M. , Medland I. C. 
Published: March 2007

AbstractThis paper is a study of the effectiveness of a wide range of bilinear hysteretic isolation systems in shielding multistorey 2‐D shear structures from earthquake excitations. Important parameters of the isolation system are identified and their effect on structure response noted. It is shown that isolation systems can be constructed which allow the structure proper to remain purely elastic even during very strong ground motions. It is further shown that the shear responses and base displacements of structures on these isolation systems can be accurately estimated from elastic response spectra of the forcing earthquakes.The philosophy of structure isolation is discussed and an introduction given to the physical devices currently available to provide it.