bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of uterine torsion on mare and foal survival: a retrospective study, 1985–2005
Authors: CHANEY K. P. , HOLCOMBE S. J. , LEBLANC M. M. , HAUPTMAN J. G. , EMBERTSON R. M. , MUELLER P. O. E. , BEARD W. L. 
Published: March 2007

SummaryReasons for performing study: Anecdotal speculation suggests that prognosis for survival of mares and foals following correction of uterine torsion has improved over the past 30 years.Objectives: To determine statistically the outcome of uterine torsion according to duration of clinical signs, stage of gestation, parity, physical examination findings, method of correction, prognosis for survival and reproductive health of the mare, and prospects for the foal within the neonatal period.Methods: This retrospective study combined cases from 4 equine referral hospitals.Results: The stage of gestation at which uterine torsion occurred was a risk factor for survival of mare and foal. Overall mare survival was 53/63 (84%); when uterine torsion occurred at <320 days gestation, 36/37 (97%) of mares survived compared to 17/26 (65%) survival rate when uterine torsion occurred at ≥320 days gestation. Overall foal survival was 54% (29/54). When uterine torsion occurred at <320 days gestation, 21/29 (72%) foals survived compared to 8/25 (32%) when uterine torsion occurred at ≥320 days gestation. Thirty mares were discharged from the hospital carrying a viable fetus following uterine torsion correction and 25/30 (83%) of these mares delivered live foals that survived beyond the neonatal period.Conclusions: Prognosis for survival for mares and foals following uterine torsion is good and improves if torsion occurs <320 days compared to ≥320 days gestation.Clinical relevance: Gestational timing of uterine torsion should be considered when advising clients about the prognosis for survival of the mare and foal. The prognosis for a mare delivering a live foal is good if the mare is discharged from the hospital following uterine torsion correction with a viable fetus.
Mesenchymal stem cell therapy in equine musculoskeletal disease: scientific fact or clinical fiction?
Authors: TAYLOR S. E. , SMITH R. K. W. , CLEGG P. D. 
Published: March 2007

SummaryThe goal in the therapeutic use of mesenchymal stem cells (MSCs) in musculoskeletal disease is to harness the regenerative nature of these cells focussing on their potential to grow new tissues and organs to replace damaged or diseased tissue. Laboratory isolation of MSCs is now well established and has recently been demonstrated for equine MSCs. Stem cell science has attracted considerable interest in both the scientific and clinical communities because of its potential to regenerate tissues. Research into the use of MSCs in tissue regeneration in general reflects human medical needs, however, the nature, prevalence and prognosis of superficial digital flexor tendonitis has put equine veterinary science at the forefront of tendon regeneration research. Much has been investigated and learnt but it must be appreciated that in spite of this, the field is still relatively young and both communities must prepare themselves for considerable time and effort to develop the technology into a highly efficient treatments. The promise of functional tissue engineering to replace old parts with new fully justifies the interest. At present, however, it is important to balance the understanding of our current limitations with a desire to progress the technology.
Formation of poly‐vinyl‐alcohol structures by supercritical CO2
Authors: Reverchon E. , Cardea S. , Rapuano C. 
Published: March 2007

AbstractPoly‐vinyl‐alcohol (PVA) porous structures have been prepared using a supercritical phase inversion process in which supercritical carbon dioxide (SC‐CO2) acts as the nonsolvent. First, we tested the versatility of the SC‐CO2 phase inversion process, forming PVA/dimethylsulfoxide (DMSO) solutions with polymer concentrations ranging from 1 to 35% (w/w) and changing the process parameters. We worked at temperatures from 35 to 55°C and pressures from 100 to 200 bar obtaining different membranes morphologies: dense films, membranes with coexisting morphologies, and microparticles. However, we did not produce symmetric or asymmetric porous membranes. To obtain this result, we used casting solutions formed by adding acetone to DMSO with the aim of modifying the affinity between SC‐CO2 and the liquid solvent. In this series of experiments, we obtained asymmetric membranes with skin layer thicknesses lower than 10 μm. The results obtained in this work have been explained considering that the membranes formation mechanism is related to the kinetics of the process; i.e. the affinity between the solvent (mixture of solvents) and SC‐CO2. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Neue Erkenntnisse zum Verformungsverhalten des Frankfurter Tons
Authors: Dürrwang Rudolf , El‐Mossallamy Yasser , Reininger‐Behrenroth Maik 
Published: March 2007

AbstractAnhand des Bauvorhabens “Opernturm” von Tishman Speyer auf dem ehemaligen Gelände der Zürichversicherung “Zürichhaus” an der Alten Oper im Zentrum von Frankfurt am Main wird dargestellt, daß der Effekt der Entlastung/Wiederbelastung ausschließlich zeitabhängig ist. Dies wurde möglich, da erstmals in Frankfurt nach dem Abbruch der alten Zürichhäuser sechs Jahre vergingen, bis mit dem Neubau begonnen wurde. In diesem Zeitraum wurden die Hebungen der alten Gründung (Bestandskeller) und der Nachbarn (u.a. U‐Bahn) als Teil des Beweissicherungsverfahrens beobachtet. Weiterhin werden die Ergebnisse von Cross‐hole‐Messungen zur Bestimmung der dynamischen Baugrundsteifigkeit des Frankfurter Baugrunds dargestellt und diskutiert.
Enantioseparation and determination of 2,2‐dimethylcyclopropanecarboxamide and corresponding acid in the bioconversion broth by gas chromatography
Authors: Zheng Ren‐Chao , Zheng Yu‐Guo , Shen Yin‐Chu 
Published: March 2007

AbstractA simple and sensitive method employing gas chromatography was developed for the enantioseparation and determination of 2,2‐dimethylcyclopropanecarboxamide and its acid in the bioconversion broth. Samples were recovered in high yield by extracting the broth with equal volumes of ethyl acetate twice. Separation of the four enantiomers was performed on a gamma‐cyclodextrin based chiral column BGB‐175. The effect of column flow rate and temperature on the retention and resolution of the enantiomers was investigated. The proposed method exhibited good linearity, repeatability and precision, and was successfully used to monitor and control the bioconversion process of 2,2‐dimethylcyclopropanecarboxamide. Copyright © 2007 John Wiley & Sons, Ltd.
Study on Electrochemical Copolymerization of Aniline and 3‐Methylthiophene in HMIMBF4 Ionic Liquid and Its Properties
Authors: Zhang Ai‐Jian , Zhang Gui‐Rong , Yang Guang‐Da , Ao Feng‐Guo , Lu Jia‐Xing 
Published: March 2007

AbstractElectrochemical polymerization of aniline and 3‐methylthiophene has been accomplished in 1‐methylimidazium tetrafluoroborate (HMIMBF4) ionic liquid. Homopolymer and copolymers of aniline and 3‐methylthiophene were obtained successfully. The copolymer was studied by cyclic voltammetry and electrochemical impedance spectroscopy. The formation of copolymer has been confirmed by FT‐IR and UV spectra. The atomic force microscope (AFM) was used for microstructural analysis. Both the homopolymer and the copolymer had the catalytic activity for the hydroquinone.
Low‐Temperature Heat Capacities and Thermodynamic Properties of Hydrated Nickel L‐Threonate Ni(C4H7O5)2·2H2O(s)
Authors: Di You‐Ying , Xiao Qin , Tan Zhi‐Cheng , Gao Sheng‐Li , Chen San‐Ping , Sun Li‐Xian 
Published: March 2007

AbstractLow‐temperature heat capacities of the compound Ni(C4H7O5)2·2H2O(s) have been measured with an automated adiabatic calorimeter. A thermal decomposition or dehydration occurred in 350–369 K. The temperature, the enthalpy and entropy of the dehydration were determined to be (368.141±0.095) K, (18.809±0.088) kJ·mol−1 and (51.093±0.239) J·K−1·mol−1 respertively. The experimental values of the molar heat capacities in the temperature regions of 78–350 and 368–390 K were fitted to two polynomial equations of heat capacities (Cp,m) with the reduced temperatures (X), [X = f (T)], by a least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound were calculated on the basis of the fitted polynomials. The smoothed values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated with an interval of 5 K.
Determination of Inorganic Arsenic Species by Electrochemical Hydride Generation Atomic Absorption Spectrometry with Selective Electrochemical Reduction
Authors: Li Xun , Wang Zheng‐Hao 
Published: March 2007

AbstractA new direct procedure for the determination of inorganic arsenic species was developed by electrochemical hydride generation atomic absorption spectrometry (EcHG‐AAS) with selective electrochemical reduction. The determination of inorganic arsenic species is based on the fact that As(III) shows significantly higher absorbance at low electrolytic currents than As(V) in 0.3 mol·L−1 H2SO4. The electrolytic current used for the determination of As(III) without considerable interferences of As(V) was 0.4 A, whereas the current for the determination of As(III) and As(V) was 1.2 A. For equal concentrations of As(III) and As(V) in a sample, the interferences of As(V) during the As(III) determination were smaller than 5%. The absorbance for As(V) could be calculated by subtracting that for As(III) measured at 0.4 A from the total absorbance for As(III) and As(V) measured at 1.2 A, and then the concentration of As(V) can be obtained by its calibration curve at 1.2 A. The methodology developed provided the detection limits of 0.3 and 0.6 ng·mL−1 for As(III) and As(V), respectively. The relative standard deviations were of 3.5% for 20 ng·mL−1 As(III) and 3.2% for 20 ng·mL−1 As(V). The method was successfully applied to determination of soluble inorganic arsenic species in Chinese medicine.
New Copper(II) and Nickel(II) Complexes of 4‐Morpholinoaceto‐ phenone Thiosemicarbazone: Structural, Electrochemical and Antimicrobial Studies
Authors: Bingol Haluk , Coskun Ahmet , Akgemci Emine Guler , Kaya Basturk , Atalay Tevfik 
Published: March 2007

Abstract4‐Morpholinoacetophenone thiosemicarbazone, MAPT, and its nickel(II) and copper(II) complexes have been prepared and characterized by elemental analysis, magnetic susceptibility, spectral methods (FT‐IR, 1H NMR) and cyclic voltammetry. Electrochemical behaviors of the complexes have been studied by cyclic voltammetry in DMF media showing metal centered reduction processes for both of them. The redox properties, nature of the electrode processes and the stability of the complexes were discussed. [Cu(MAPT)2]Cl2 complex shows Cu(II)/Cu(I) couple and quasi‐reversible wave associated with the Cu(III)/Cu(II) process. The reduction/oxidation potential values depend on the structures of complexes. Also, the antimicrobial activities of these complexes were determined against S. aureus, E. coli and B. subtilis.
Selective Synthesis of [2+2] Macrocyclic Schiff Bases from Chiral 1,4‐Diamines
Authors: Zhu Hai‐Bin , Hu Da‐Hua , Dong Hua‐Ze , Li Gen‐Xi , Gou Shao‐Hua 
Published: March 2007

Abstract[2+2] macrocyclic Schiff bases of three kinds have been synthesized from chiral 1,4‐diamines by use of different methods. Macrocyclic Schiff bases 1a–1c have been selectively obtained based on a non‐templated dilution method from chiral 1,4‐diamines a–c and dialdehyde DA1, whereas macrocycles 2a–2c have been selectively produced from reaction of diamines a–c and dialdehyde DA2 in the presence of boric acid as templates. Macrocyclic Schiff bases 3a–3c have been afforded in high selectivity from diamines a–c and dialdehyde DA3 by means of sodium‐template. All the titled compounds have been confirmed by 1H NMR and ESI‐MS analyses.
Studies on Aggregation Interaction between Reduced‐Denatured Egg White Lysozymes during Refolding Procedure in Urea Solution
Authors: Bian Liu‐Jiao , Liang Chang‐Li , Yang Xiao‐Yan , Liu Li 
Published: March 2007

AbstractThe aggregation interaction between reduced‐denatured egg white lysozymes during refolding procedure in urea solution was studied by means of reducing and non‐reducing protein electrophoreses. Results of non‐reducing sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE) of the supernatant and aggregate precipitate formed in refolding process show that except being refolded to native egg white lysozymes, the reduced‐denatured lysozymes can also form the aggregates with molecular weights (MW) being separately about 30.0 and 35.0 kD, while the reducing SDS‐PAGE and the refolding results in the presence of sodium dodecyl sulphate show that these aggregates are formed chiefly through the misconnection of disulfide bonds between the reduced‐denatured lysozymes, and the aggregate precipitates are formed through the non‐covalent interactions between the aggregates with molecular weight being about 30.0 kD. From the results of electrophoresis and size‐exclusion chromatographic analyses, it can be inferred that the aggregates with molecular weights being about 30.0 and 35.0 kD are bi‐molecular and tri‐molecular egg white lysozyme aggregates, respectively. And finally, a suggested refolding mechanism of reduced‐denatured egg white lysozymes in urea solution was presented.
Homopolymerization and Copolymerization of Adipic Anhydride with ε‐Caprolactone Catalyzed by Rare Earth Trisphenolate
Authors: Chen Feng , Zhu Wei‐Pu , Shen Zhi‐Quan 
Published: March 2007

AbstractThe ring‐opening polymerization of adipic anhydride and the ring‐opening copolymerization of adipic anhydride with ϵ‐caprolactone catalyzed by single component rare earth trisphenolate have been reported. The structure of the copolymer poly(CL‐b‐AA) has been characterized by SEC, 1H NMR and DSC.
A New Approach to C60‐Contanining Polyphosphazenes by Polymerization of Phosphonitrile Chloride Trimer in the Presence of C60
Authors: Li Zhen , Zeng Qi , Zhu Zhi‐Chao , Li Qian‐Qian , Li Zhong‐An , Qin Jin‐Gui 
Published: March 2007

AbstractA novel synthetic strategy was developed to prepare polyphosphazenes containing C60 moieties. Thus, the phosphonitrile chloride trimer underwent thermal ring‐opening polymerization (ROP) in the presence of C60 molecules to yield the reactive macromolecular intermediate, C60‐containing poly(dichlorophosphazene). And then, the other groups could be linked to the phosphazene backbone by nucleophilic substitution reaction of the chlorine atoms in this intermediate to produce a series of C60‐containing polyphosphazene. The polymer exhibits good solubility in common organic solvents and is thermally stable.
Amide‐Exchange‐Rate‐Edited NMR (AERE‐NMR) Experiment: A Novel Method for Resolving Overlapping Resonances
Authors: Liu Xue‐Hu , Lin Dong‐Hai 
Published: March 2007

AbstractThis paper describes an amide‐exchange‐rate‐edited (AERE) NMR method that can effectively alleviate the problem of resonance overlap for proteins and peptides. This method exploits the diversity of amide proton exchange rates and consists of two complementary experiments: (1) SEA (solvent exposed amide)‐type NMR experiments to map exchangeable surface residues whose amides are not involved in hydrogen bonding, and (2) presat‐type NMR experiments to map solvent inaccessibly buried residues or nonexchangeable residues located in hydrogen‐bonded secondary structures with properly controlled saturation transfer via amide proton exchanges with the solvent. This method separates overlapping resonances in a spectrum into two complementary spectra. The AERE‐NMR method was demonstrated with a sample of 15N/13C/2H(70%) labeled ribosome‐inactivating protein trichosanthin of 247 residues.
NMR Spectral Analysis and Modelling I. Basic Concepts and Fourier Transforms
Authors: Ziessow Dieter 
Published: March 2007

AbstractEssentially all high‐resolution NMR experiments are now carried out with pulse excitation. Basic concepts, such as signal induction and sense of rotation, are discussed using a rotating magnetic needle as an analogy. The typical signal, recorded immediately after the r.f. pulse is a superposition of many single‐line free‐induction‐decay signals, each of which is described by the expression, Uo, j‐cos(2πvjt +Φj)·dj(t). The frequency, vj, carries structural information and the amplitude Uo, j is proportional to the molecular concentration. The function dj(t) accounts for the decay, and the phase Φj depends on instrumental parameters and the mode of observation. It is the purpose of spectral analysis to determine these parameters from the measured composite signal. Fourier analysis, the most prominent approach, is introduced in a graphical and analytical manner based on the concept of complex harmonic waves exp(i2πvt). To facilitate understanding, the reverse process, namely Fourier synthesis, as well as the number e and its complex powers eix, are introduced in an elementary way. Part I concludes with a discussion of: a) the relationship between the attainable spectral resolution and its time length of signal observation, and b) the difference between the actual and predicted time signals within and outside the observation‐time window.
Phase‐Sensitive Detection. Part II: Quadrature Phase Detection
Authors: D. Traficante Daniel 
Published: March 2007

AbstractThe problems associated with the use of a single phase‐sensitive detector (PSD) in an NMR receiver are reviewed. These problems can be eliminated by the use of two PSDs, arranged in parallel. The references to the PSDs are derived from a single source, but one is phase‐shifted by 90° with respect to the other. This arrangement is called quadrature phase detection (QPD). The free‐induction decays (FIDs) obtained as outputs from the two PSDs are phase‐shifted by 90° with respect to one another, and are referred to as a “real” and an “imaginary” FID. The PSDs and the electronic components associated with them, including amplifiers and filters, are called the “real” and the “imaginary” channels. The FIDs from these channels can be processed so that the problems associated with the use of a single PSD are eliminated. In practice, however, a different set of problems emerges with the use of a QPD system because it is not possible to balance the two channels exactly. A procedure called CYCLOPS, which phase‐cycles both the transmitter and the receiver portion of the computer, can be used to overcome these difficulties.
Combined Rotation and Multiple Pulse Spectroscopy (CRAMPS)
Authors: P. Burum Douglas 
Published: March 2007

AbstractThe combined rotation and multiple pulse spectroscopy (CRAMPS) experiment is discussed from a practical point of view. Emphasis is given to the understanding of fundamental concepts and practical methods for obtaining optimum results. After a discussion of the basic theoretical concepts of coherent‐averaging theory, the effects of rf pulse errors are discussed. A detailed discussion of spectrometer hardware emphasizes features critical to the success of CRAMPS. A step‐by‐step procedure for spectrometer adjustment in preparation for CRAMPS is outlined. Finally, there is an overview of more sophisticated one‐ and two‐dimensional NMR experiments that incorporate CRAMPS.
Study of a stabilized mixed finite element with emphasis on its numerical performance for strain localization problems
Authors: Sánchez P. J. , Sonzogni V. E. , Huespe A. E. 
Published: March 2007

AbstractThe numerical performance of a stabilized mixed finite‐element formulation based on the pressure‐gradient‐projection method (PGP) using equal‐order (linear) interpolation is evaluated by solving solid mechanics problems, such as structural limit load determination and strain localization modelling. All of them present incompressibility kinematical constraints induced by the constitutive behaviour. This work is specially devised to obtain critical conclusions about the use of PGP model when the mechanical response is governed by strain‐softening macroscopic mechanisms. In this context, we report some detected limitations in the present formulation due to the existence of pathological mesh bias dependence once the strain localization process becomes dominant, and linear kinematics is used. An additional contribution is the numerical comparative analysis of two different strategies, for solving the complete linear equation system, addressed to a finite‐element parallel code. The numerical results are compared with the standard Galerkin formulation and with an alternative stabilized mixed finite‐element procedure (pressure stabilizing Petrov–Galerkin scheme). Copyright © 2007 John Wiley & Sons, Ltd.
Applications of three‐dimensional finite‐difference seismic modeling in oil field exploitation and simulation
Authors: Mufti Irshad R. , Fou Joseph T. 
Published: March 2007

AbstractTwo‐dimensional finite‐difference seismic models are excited by a line‐source which leads to incorrect amplitudes. Moreover, in a structurally complex environment with strong three‐dimensional (3‐D) features, the results obtained from such models are often incorrect and do not include any out‐of‐plane events. On the other hand, 3‐D models based on the ray‐theory approximation fail to provide vital information such as diffractions and interference patterns which can strongly influence the seismic expression associated with hydrocarbon reservoirs. We present the results of a study in which an approximate version of mapped surfaces was used to carry out a synthetic 3‐D finite‐difference survey. This followed the necessary adjustment of various horizons and it involved the calibration of synthetic sections by comparing them with the corresponding unmigrated real‐data sections. The simulation of reservoir characteristics was accomplished in reference to two key seismic horizons used in the model.
Terrain analysis from curvature profiles
Authors: Goldgof Dmitry B. , Huang Thomas S. , Lee Hua 
Published: March 2007

AbstractThis paper describes a new algorithm which uses Gaussian and mean curvature values of the terrain surface to extract feature points. These points are then used for recognition of particular subregions of the terrain and in estimating relative positions of these subregions in the terrain. The Gaussian and mean curvatures are chosen because they are invariant under rotation and translation. In the Gaussian and mean curvature images, the points of maximum and minimum curvatures are extracted and used for matching. The stability of the position of these points in the presence of noise and with resampling is investigated. The input for this algorithm is 3D digital terrain data. Curvature values are calculated from the data by fitting a quadratic surface over a square window and calculating directional derivatives of this surface. A method of surface fitting that is invariant to sensor‐centered coordinate system transformation is suggested and implemented. Real terrain data are used in our experiments. The algorithm is tested with and without the presence of noise, and its performance is described.