bluuebunny/crossref_metadata_2025_split huggingface dataset:
Injector‐internal thermal desorption from edible oils. Part 2: Chromatographic optimization for the analysis of migrants from food packaging material
Authors: Fiselier Katell , Biedermann Maurus , Grob Koni 
Published: September 2005

AbstractInjector‐internal thermal desorption from edible oil or fat is a convenient sample preparation technique for the analysis of solutes in lipids or extracts from fatty foods. The injector temperature is selected to vaporize the solutes of interest while minimizing evaporation of the bulk material of the oil. This technique has been in routine use for pesticides for some time. Now its potential is explored for migrants from food contact materials, such as packaging, into simulant D (olive oil) or fatty/oily food, which means extending the range of application towards less volatile compounds. The performance for high boiling components was investigated for diisodecyl phthalate (DIDP) and diundecyl phthalate (DUP). Since the injector temperature needs to be as high as 260°C, some bulk material of the oil enters the column and must be removed after every analysis. This is achieved by a coated precolumn backflushed towards the end of each analysis. Desorption of the solutes is particularly efficient in the initial phase, when a thin sample film is spread on the liner wall, and is largely determined by the diffusion speed in the oil after the latter has contracted to droplets. An increased carrier gas flow rate during the splitless period supports the transfer into the column. It is concluded that the technique is attractive for migrant analysis, with DUP being at the upper limit of the boiling point.
Growth of Large Polymer Extended‐Chain Single Crystals in a Poly(ethylene terephthalate)/Bisphenol A Polycarbonate Blend under High Pressure
Authors: Lu Jun , Huang Rui , Li Liangbin , Luo Jianbin 
Published: September 2005

AbstractSummary: High‐quality synthetic polymer extended‐chain single crystals with c‐axis thickness exceeding 100 µm are obtained in a polyethylene terephthalate/polycarbonate (PET/PC) blend rapidly. Some crystals comprise of PET, while others are made up by the copolymers with PET and PC blocks. The fast growth of large crystals is attributed to the mechanisms including transesterification, segment nucleation, and chain‐sliding diffusion, which is a self‐assembling process induced by chemical reactions in multiphase polymer system at high pressure. Similar to the role of enzyme in biosystem, the PC plays as a macromolecular catalyst. This process provides a new direction to grow large polymer single crystals and suggests that self‐assembly under high pressure is a promising method to create materials with new structures and properties.SEI for a wedge‐shaped extended‐chain single crystal grown in a PET/PC blend at 200 MPa, 623 K for 6 h.magnified imageSEI for a wedge‐shaped extended‐chain single crystal grown in a PET/PC blend at 200 MPa, 623 K for 6 h.
Tegaserod (Zelnorm) for the treatment of constipation in Parkinson's disease
Authors: Sullivan Kelly L. , Staffetti Joseph F. , Hauser Robert A. , Dunne Peter B. , Zesiewicz Theresa A. 
Published: September 2005

AbstractWe performed a double‐blind randomized placebo‐controlled pilot study to determine the efficacy of tegaserod (Zelnorm) in treating constipation in 15 patients with Parkinson's disease (PD). There was a trend for improvement in the Subject's Global Assessment (SGA) of satisfaction with bowel habits (NS) and the total SGA (including abdominal discomfort, bothersome constipation, and satisfaction; NS). © 2005 Movement Disorder Society
The generalized Thomas–Fermi singular boundary value problems for neutral atoms
Authors: Agarwal Ravi P. , O'Regan Donal , Palamides Panos K. 
Published: September 2005

AbstractThis paper presents an upper and lower solution theory for singular boundary value problems modelling the Thomas–Fermi equation, subject to a boundary condition corresponding to the neutral atom with Bohr radius equal to its existence interval. Furthermore, we derive sufficient conditions for the existence–construction of the above‐mentioned upper–lower solutions. Copyright © 2005 John Wiley & Sons, Ltd.
W2, p estimates of the heat equation in Ω⊂ℝn and the restrictions on ∂Ω
Authors: Waters Gavin , Wang Lihe 
Published: September 2005

AbstractThis is an alternative approach of finding the W2, p estimates of the heat equation in a domain, Ω⊂ℝn. Methods used in (Acta Math. Sin. 2003; 19(2):381–396) are expanded to the case of a bounded domain. As a result, milder restrictions are applied to ∂Ω than previously required by using the classical singular integral approach. Copyright © 2005 John Wiley & Sons, Ltd.
A ratio‐dependent eco‐epidemiological model of the Salton Sea
Authors: Kundu Kusumika , Chattopadhyay J. 
Published: September 2005

AbstractRatio‐dependent models set up a challenging issue for their rich dynamics incomparison to prey‐dependent models. Little attention has been paid so far to describe the importance of transmissible disease in ecological situation by considering ratio‐dependent models. In this paper, by assuming the predator response function as ratio‐dependent, we consider a model of a system of three non‐linear differential equations describing the time evolution of susceptible and infected Tilapia fish population and their predator, the Pelican. Existence and stability analysis of different equilibria of the system lead to different realistic thresholds in terms of system parameters. The condition for extinction of the species is also worked out. Our analytical and numerical studies may be helpful to chalk out suitable control strategies for minimizing the extinction of the Pelicans. We also suggest that supply of alternative food source for predator population may be used as a possible solution to save the predator from their extinction. Copyright © 2005 John Wiley & Sons, Ltd.
1H and 13C chemical shifts for 2‐aryl and 2‐N‐arylamino benzothiazole derivatives
Authors: Billeau S. , Chatel F. , Robin M. , Faure R. , Galy J.‐P. 
Published: September 2005

AbstractThe 1H and 13C NMR resonances for forty‐three 2‐aryl and 2‐N‐arylamino benzothiazole derivatives were completely assigned using a concerted application of one‐ and two‐dimensional experiments (DEPT, gs‐COSY, gs‐HMQC and gs‐HMBC). Copyright © 2005 John Wiley & Sons, Ltd.
Flow compensation in balanced SSFP sequences
Authors: Bieri O. , Scheffler K. 
Published: September 2005

AbstractIn balanced steady‐state free precession (b‐SSFP) sequences, uncompensated first‐order moments of encoding gradients induce a nonconstant phase evolution for moving spins within the excitation train, resulting in signal loss and image artifacts. To restore these flow‐related phase perturbations, “pairing” of consecutive phase‐encoding (PE) steps is compared with a fully flow‐compensated sequence using compensating gradient waveforms along all three encoding directions. In volunteer studies, the quality of images acquired with the “pairing” technique was comparable to that of images obtained with the fully flow‐compensated technique, regardless of the selected view‐ordering scheme used for data acquisition. Nevertheless, the results of phantom experiments indicate that the pairing technique becomes ineffective at flow velocities exceeding roughly 0.5–1 m/s. Consequently, the additional scan time required to null the first gradient moments in a flow‐compensated b‐SSFP sequence makes the “pairing” technique preferable for applications in which slow to moderate flow velocities can be expected. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Murine orthostatic response during prolonged vertical studies: Effect on cerebral blood flow measured by arterial spin‐labeled MRI
Authors: Foley Lesley M. , Hitchens T. Kevin , Kochanek Patrick M. , Melick John A. , Jackson Edwin K. , Ho Chien 
Published: September 2005

AbstractHigh‐field MRI scanners are, in principle, well suited for mouse studies; however, many high‐field magnets employ a vertical design that may influence the physiological state of the rodent. The purpose of this study was to investigate the orthostatic response of cerebral blood flow (CBF) in mice during a prolonged MR experiment in the vertical position. Arterial spin‐labeled (ASL) MRI was performed at 4.7‐Tesla with a 15‐cm gradient insert that allowed horizontal and vertical CBF measurements to be obtained with the same scanner. For mice in the head‐up (HU) vertical position, CBF decreased by approximately 40% compared to the horizontal position, although blood pressure did not differ. Furthermore, CBF values for vertically positioned mice treated with phenylephrine remained constant while blood pressure increased. These results support the conclusion that cerebral autoregulation was intact, albeit at a lower level. Since CBF recovers to near horizontal values by volume loading with saline, it appears that a decrease in central venous pressure (CVP) leading to an increase in sympathetic tone may be a contributing mechanism for lowered CBF. This suggests that using an HU vertical position for MRI in mice may have broader implications, especially for studies that rely on CBF (such as BOLD and fMRI). Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Acute blood–brain barrier opening in experimentally induced focal cerebral ischemia is preferentially identified by quantitative magnetization transfer imaging
Authors: Knight Robert A. , Nagesh Vijaya , Nagaraja Tavarekere N. , Ewing James R. , Whitton Polly A. , Bershad Eric , Fagan Susan C. , Fenstermacher Joseph D. 
Published: September 2005

AbstractPathologic changes in brain tissue during and after stroke may lead to injury of the blood–brain barrier (BBB) and subsequent hemorrhagic transformation (HT). In a rat model of HT, the apparent diffusion coefficient of water, cerebral blood flow, relaxation times, T1 and T2, and magnetization transfer (MT) related parameters (T1sat, Kfor and the MT ratio) were repetitively measured during 3 h of focal ischemia and 2 h of reperfusion (n = 8). Areas of BBB opening were identified by sequential assay of the transcapillary influx of Gd‐diethylenetriaminepentaacetic acid (Gd‐DTPA) by MRI and 14C‐α‐aminoisobutyric acid (AIB) by quantitative autoradiography. Ischemia‐injured regions of interest were identified from the MRI data and divided into those with and without BBB opening. Of the several MRI parameters measured, the T1sat in the caudate‐putamen and preoptic area during ischemia and the first 2 h of reperfusion correlated best with the regional pattern of BBB opening observed thereafter. These data suggest that an ipsilateral/contralateral T1sat ratio > 1.6 demarcates leakage of small molecules such as Gd‐DTPA and AIB across the BBB. As to clinical relevance, the quantitation of MT parameters in acute stroke may enable the early detection of areas of BBB opening and potential HT. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Simultaneous monitoring of temperature and T1: Methods and preliminary results of application to drug delivery using thermosensitive liposomes
Authors: Bos Clemens , Lepetit‐Coiffé Matthieu , Quesson Bruno , Moonen Chrit T. W. 
Published: September 2005

AbstractA method is presented to obtain temperature and longitudinal relaxivity measurements simultaneously and in near real‐time. Quantitative relaxivity values are obtained from the signal magnitude from fast Look‐Locker EPI data, whereas phase information from all signal samples on the recovery curve is combined to provide temperature values using the proton resonance frequency method. The utility of this technique is illustrated in an in vitro experiment with thermosensitive liposomes, which are studied as potential micro vehicles for local drug delivery. The method allowed measuring the evolution of relaxivity during RF‐heating of liposomes containing a paramagnetic contrast agent, demonstrating increase of liposome permeability near the phase transition temperature. Potential applications are monitoring of local drug delivery using thermosensitive liposomes, and confirmation of reaching the liposomes' threshold temperature during thermal therapy. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Field map estimation with a region growing scheme for iterative 3‐point water‐fat decomposition
Authors: Yu Huanzhou , Reeder Scott B. , Shimakawa Ann , Brittain Jean H. , Pelc Norbert J. 
Published: September 2005

AbstractRobust fat suppression techniques are required for many clinical applications. Multi‐echo water‐fat separation methods are relatively insensitive to B0 field inhomogeneity compared to the fat saturation method. Estimation of this field inhomogeneity, or field map, is an essential and important step, which is well known to have ambiguity. For an iterative water‐fat decomposition method recently proposed, ambiguities still exist, but are more complex in nature. They were studied by analytical expressions and simulations. To avoid convergence to incorrect field map solutions, an initial guess closer to the true field map is necessary. This can be achieved using a region growing process, which correlates the estimation among neighboring pixels. Further improvement in stability is achieved using a low‐resolution reconstruction to guide the selection of the starting pixels for the region growing. The proposed method was implemented and shown to significantly improve the algorithm's immunity to field inhomogeneity. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Numerical simulations of simple shear with non‐coaxial soil models
Authors: Yang Yunming , Yu H. S. 
Published: September 2005

AbstractThis paper investigates the effects of a non‐coaxial model on simulated stress–strain behaviour of granular materials subject to simple shearing under various initial conditions. In most cases, a significant difference of predictions between coaxial and non‐coaxial modelling is found during the early stage in shearing. With the increase in shearing, non‐coaxial simulations approach and tend to coincide with coaxial simulations. It is also found that the roles of non‐coaxial modelling in simulating simple shear behaviour are considerably influenced by hardening rules, flow rules, initial static lateral pressure coefficients. In some cases, the non‐coaxial modelling gives a similar simulation as the coaxial modelling. In other cases, the non‐coaxial modelling decreases the hardening response or softening response of materials, compared with the coaxial modelling. Under certain conditions, the predicted peak strength of materials with non‐coaxial modelling is larger than that for coaxial modelling. Some of these observations can be attributed to the amount of principal stress rotation in various cases analysed. Others can be attributed to the difference between the directions of the non‐coaxial plastic flow and those for coaxial plastic flow. Copyright © 2005 John Wiley & Sons, Ltd.
Cross‐linking emulsion copolymerization of butyl acrylate with diallyl maleate
Authors: Bouvier‐Fontes Ludivine , Pirri Rosangela , Asua José M. , Leiza Jose R. 
Published: September 2005

AbstractThe emulsion copolymerization of butyl acrylate (BA) with a trifunctional cross‐linker, diallyl maleate (DAM), was investigated. The effect of the monomer feeding time and the amount of cross‐linker on the microstructural properties (branching, cross‐linking, gel formation, and sol MWD) of the seeded semicontinuous emulsion copolymerization of BA with DAM was investigated. It was found that the gel content was not significantly affected by increasing feeding time, but the level of quaternary carbons (an indication of the branching density) increased. On the other hand, increasing the amount of DAM in the feed composition caused gel content, level of quaternary carbons, and the cross‐linking density to increase. Interestingly, the level of quaternary carbons and the cross‐linking density sharply increased during the cooking period. The molecular weight of the sol decreased as DAM increased in the feed. In addition, the effect of process type, batch versus semibatch, was also considered and important differences in the level of quaternary carbons, cross‐linking, and gel content were found. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4684–4694, 2005
Hyperbranched fluorocopolymers by atom transfer radical self‐condensing vinyl copolymerization
Authors: Cheng Chong , Wooley Karen L. , Khoshdel Ezat 
Published: September 2005

AbstractHyperbranched fluorocopolymers were synthesized by the atom transfer radical self‐condensing vinyl copolymerization (ATR–SCVCP) of an inimer, either p‐chloromethylstyrene (CMS) or p‐bromomethylstyrene (BMS), with 2,3,4,5,6‐pentafluorostyrene (PFS), with 2,2′‐bipyridine together with CuCl or CuBr as the ligand/catalyst system. The reaction conditions were studied to provide for control over the copolymer compositions, molecular weights, degrees of branching, and properties, as characterized by 1H, 13C, and 19F NMR spectroscopy, gel permeation chromatography, elemental analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and solubility tests. Copolymers having number‐average molecular weights from 2.9 to 260 kDa and polydispersities (weight‐average molecular weight/number‐average molecular weight) from 1.8 to 4.8 were obtained. The molar fractions of PFS units increased with increases in the feed ratio of PFS to the inimer. The degrees of branching were typically about 30% with the feed of 1.0 or 2.0 equiv of PFS with respect to the inimer, although slight variations could be achieved through the variation of the inimer composition. Under similar reaction conditions with CuCl as the catalyst, ATR–SCVCP of BMS with PFS led to higher degrees of branching than ATR–SCVCP of CMS with PFS. Solubility tests indicated that the polymers prepared under conditions that avoided extensive biradical coupling were soluble in a broad range of organic solvents. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4754–4770, 2005
Tacticity of poly‐α‐olefins from poly‐1‐hexene to poly‐1‐octadecene
Authors: Galland Griselda Barrera , Da Silva Luciano Forgiarini , Nicolini Adriana 
Published: September 2005

AbstractA systematic study of the influence of the α‐olefin size, the catalyst stereospecificity and the reaction temperature was done on the catalytic activity and tacticity of poly‐α‐olefins from 1‐hexene to 1‐octadecene. The metallocenes used were rac‐Et[Ind2]ZrCl2 (1) and Me2C[Cp(9‐Flu)]ZrCl2 (2) to obtain isotactic and syndiotactic polyolefins. Some catalysts giving atactic polymers were also used in order to study all the possible 13C NMR pentades. Catalytic activities increased and isotacticity and syndiotacticity decreased with temperature, but no real trend was found with the α‐olefin size. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4744–4753, 2005
Control of thermal cross‐linking reactions and the degree of crystallinity of syndiotactic 1,2‐polybutadiene
Authors: Cai Jiali , Yu Qing , Zhang Xuequan , Lin Jiaping , Jiang Liansheng 
Published: September 2005

AbstractThermal stability, crystallization, morphological development, subsequently melting, and crystallinity control of a syndiotactic 1,2‐polybutadiene sample were carefully carried out by thermogravimetry (TGA), polarized optical microscopy (POM), differential scanning calorimetry (DSC), temperature‐modulated differential scanning calorimetry (TMDSC), and wide‐angle X‐ray diffraction (WAXD), respectively. The experiments indicate that thermal cross‐linking reaction rates under nitrogen protection and in air are different for this polymer at temperature above 155 °C. Under nitrogen protection, the thermal cross‐linking reaction rate is delayed and the mechanism of melt crystallization obtained from the DSC results is in good accordance with that from POM observation. TMDSC results indicate that melting–recrystallization–melting model is more proper to explain the double melting events of this sample. At the same time, the evolution of the degree of crystallinity as the function of the time was investigated by WAXD profiles for the samples firstly crystallized at 145 °C for 1 h and then kept at 163 °C mediated between the temperatures of the double peaks. It shows that as prolonging the annealing time at 163 °C thermal cross‐linking reactions possibly occur, leading to gradual reduction of the apparent crystallite sizes, evaluated by Scherrer equation and the degree of crystallinity. The changing sequence of the relative intensity of the stronger four diffraction peaks with time due to thermal cross‐linking reactions is (111)/(201) > (210) > (010) > (200)/(110). © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2885–2897, 2005
Multiscale dewetting of triblock copolymer thin film induced by solvent vapor
Authors: Zhu Jintao , Zhao Junchai , Liao Yonggui , Jiang Wei 
Published: September 2005

AbstractMultiscale dewetting of poly(styrene‐b‐ethylene/butylenes‐b‐styrene) (SEBS) triblock copolymer thin films induced by volatile solvent vapor treatment were observed in this study. Film rupture occurred at first and produced macroscopic holes. Near‐regular droplets (which represented a compromise between complete disorder and perfect order) could be formed at the last stage. The mechanism of solvent‐driven dewetting was discussed by comparing with that of thermal‐induced dewetting. Similar to thermal‐induced dewetting, the block copolymer thin films initially break up through the nucleation of holes that perforated the films. The rapid growing holes became unstable and formed nonequilibrium fingering patterns. The films exhibit autophobic or autodewetting phenomena. The velocity of the holes growth was nearly a constant (3.3 μm/min). The stages of the dewetting were quite similar to that found for homopolymer and block copolymer thin films dewetting on solid or liquid substrates under thermal treatment. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2874–2884, 2005
New synthesis of cis 5‐tert‐butyl‐L‐proline via cuprate. Evaluation as a cis proline mimetic in a biological active octapeptide
Authors: Aubry Carine , Oulyadi Hassan , Dutheuil Guillaume , Leprince Jerome , Vaudry Hubert , Pannecoucke Xavier , Quirion Jean‐Charles 
Published: September 2005

Abstractcis 5‐tert‐butyl‐L‐proline (Cbp) was prepared rapidly and efficiently by the addition of low‐valent tert‐butyl cuprate to an aminal derived from proline. [Cbp2, D‐Leu5]‐OP was then synthesized, showing a predominant cis peptide bond conformation, as confirmed by NMR. Copyright © 2005 European Peptide Society and John Wiley & Sons, Ltd.