bluuebunny/crossref_metadata_2025_split huggingface dataset:
1H and 13C NMR assignments for new heterocyclic TAM leuco dyes, (2Z,2′E)‐2,2′‐(2‐phenyl propane‐1,3‐diylidene) bis(1,3,3‐trimethylindoline) derivatives. Part II
Authors: Keum Sam‐Rok , Roh Se‐Jung , Lee Min‐Hyung , Sauriol Francoise , Buncel Erwin 
Published: July 2008

AbstractThe 1H and 13C NMR spectra of the novel heterocyclic Leuco‐TAM dyes, (2Z, 2′E)‐2,2′‐(2‐phenyl propane‐1,3‐diylidene) bis(1,3,3‐trimethylindoline) derivatives 1–4 as precursors of triarylmethane (TAM)+ (Malachite Green FB‐analog) dyes were completely assigned by 1D and 2D NMR experiments, including DEPT, COSY, HSQC, HMBC, and NOESY. Especially, the diastereotopic gem‐dimethyl protons at the C3 and C3′ positions of the FB rings were definitively assigned. The (Z,E) isomers adopt the energetically favored three‐bladed propeller conformation in solution. Copyright © 2008 John Wiley & Sons, Ltd.
A preliminary study of soft cheese degradation in different packaging conditions by 1H‐NMR
Authors: Lamanna Raffaele , Piscioneri Ilario , Romanelli Valeria , Sharma Neeta 
Published: July 2008

AbstractThis preliminary work deals with the influence of packaging on the degradation of an Italian soft cheese studied by NMR. The NMR profiles of aqueous cheese extracts were acquired as a function of time during storage of cheese inside and outside the original package. From the NMR spectra 15 metabolites are quantified and used in a kinetic degradation model and in a multivariate algorithm in order to evaluate the changes in the metabolic composition of cheese stored under different conditions. Copyright © 2008 John Wiley & Sons, Ltd.
Structure elucidation of an unprecedented alkaloid and a new limonoid from Xylocarpus granatum
Authors: Cui Jianxin , Ouyang Jie , Deng Zhiwei , Lin Wenhan 
Published: July 2008

AbstractAn unprecedented new limonoid‐based alkaloid, granatoine (1), and a new phragmalin, xylocarpin L (2), along with xyloccensin Y were isolated as minor components from the fruits of the Chinese mangrove plant Xylocarpus granatum. Their structures were elucidated by extensive spectroscopic data (1D and 2D NMR) analysis. A possible biogenetic pathway for granatoine was also depicted. Copyright © 2008 John Wiley & Sons, Ltd.
NMR studies of novel Schiff bases derived from L‐α‐amino methyl esters and 3‐hydroxypyridin‐4‐carboxaldehyde
Authors: Perona Almudena , Sanz Dionisia , Claramunt Rosa M. , Elguero José 
Published: July 2008

AbstractSchiff bases of 3‐hydroxypyridin‐4‐carboxaldehyde and L‐α‐amino esters as well as those derived from the structurally related amines lacking the ester function have been synthesised. In two cases a tetrahydro‐1H‐imidazo[4,5‐c]pyridine was formed as a by‐product. 1H, 13C, 15N‐NMR spectral data and density functional theory (DFT) calculations established the structure of all compounds. Copyright © 2008 John Wiley & Sons, Ltd.
Pyruvate and oxygen consumption throughout the growth and development of murine oocytes
Authors: Harris Sarah E. , Leese Henry J. , Gosden Roger G. , Picton Helen M. 
Published: July 2008

AbstractGrowing oocytes in vitro from the most immature stages until they are developmentally competent is a major goal of reproductive technology, requiring fundamental knowledge of metabolic processes. Carbohydrate metabolism and oxygen consumption have been analysed in a series of experiments designed to investigate important energy substrates for mouse oocytes and to reveal any qualitative or quantitative changes between the primordial and ovulatory follicle stages. Primordial follicles were incubated in groups in modified‐KSOM medium, whereas growing or ovulated oocytes were studied singly and, in both cases, the depletion or accumulation of metabolites in spent medium were analysed using ultramicrofluorometric assays. The rates of glucose (0.014 ± 0.006 pmol/hr) and pyruvate (0.028 ± 0.009 pmol/hr) consumption and l‐lactate (0.058 ± 0.023 pmol/hr) production by primordial follicles suggested that energy production was supported by a combination of metabolic pathways, including glycolysis. Pyruvate and oxygen consumption per oocyte increased two‐ and ninefold, respectively, between the primary and pre‐ovulatory stages (0.82 ± 0.1 and 1.67 ± 0.1 pmol pyruvate/hr, respectively and 1.4 ± 0.3 and 7 ± 0.6 pmol oxygen/hr) after which oxygen (12.7 ± 1.1 pmol/hr) utilisation nearly doubled. Oxygen consumption by fully grown oocytes was in excess of oxidation requirements for pyruvate. When pyruvate and oxygen consumption rates were normalised for oocyte cellular volume, which increased over 130‐fold during growth, oocyte metabolism was higher in primary follicles than at any subsequent stage, indicating that energy needs are greater during a developmental transition. To conclude, pyruvate and oxygen were consumed throughout oocyte development at increasing rates. When oocyte cellular volume was accounted for, oocytes from primary follicles displayed greatest metabolic rates. Mol. Reprod. Dev. 76: 231–238, 2009. © 2008 Wiley‐Liss, Inc.
The de Quervain's screening tool: Validity and reliability of a measure to support clinical diagnosis and management
Authors: Batteson Rachel , Hammond Alison , Burke Frank , Sinha Shiladitya 
Published: July 2008

AbstractBackground: Studies into the effectiveness of interventions for upper limb soft tissue disorders have been hampered by a lack of consistently used diagnostic criteria, meaning that comparison of research results is a problem. To aid homogeneous recruitment into a study of de Quervain's disease, a de Quervain's screening tool (DQST) was developed. This could also be used to facilitate clinical diagnosis and management in practice.Aims: To provide evidence for the content and construct validity and test–retest and inter‐rater reliability of the DQST.Method: The study was conducted in an acute care, outpatient hand unit in a district general hospital. Three convenience samples of: 59 people with de Quervain's disease; 18 with carpal tunnel syndrome (CTS) and 16 with osteoarthritis (OA) of the carpometacarpal (CMC) joint were recruited. The DQST diagnostic criteria were initially generated from a literature review. Content validity was then established by expert doctors with an interest in upper limb musculoskeletal disorders (n = 7) rating the relevance of the seven items included. The DQST was then tested in people either already diagnosed with, or reported as having some of the symptoms of, de Quervain's disease. Construct validity was tested with people with CTS or OA of the CMC joint.Results: The median DQST score was 5 (Interquartile range IQR = 4–6) out of a possible seven diagnostic criteria. Inter‐rater reliability was excellent (Intra‐class coefficient [ICC] = 0.85; 95% confidence interval [CI] = 0.75, 0.91). Test retest reliability was good (ICC = 0.64; 95% CI = 0.20, 0.87). Sensitivity (Se) and specificity (Sp) testing (Se = 1.00; Sp = 1.00) demonstrated that the DQST discriminated between people with de Quervain's disease, CTS or OA of the CMC joint.Conclusions: The DQST is a valid, reliable tool which could be of assistance in aiding correct diagnosis for recruitment to clinical trials and in clinical practice. Future research is recommended to further examine retest reliability with a larger sample size and to identify the commonest diagnostic criteria required for inclusion. Copyright © 2008 John Wiley & Sons, Ltd.
A survey of foot problems in juvenile idiopathic arthritis
Authors: Hendry G. , Gardner‐Medwin J. , Watt G.F. , Woodburn J. 
Published: July 2008

AbstractBackground: Evidence suggests that foot problems are common in juvenile idiopathic arthritis (JIA), with prevalence estimates over 90%. The aim of this survey was to describe foot‐related impairment and disability associated with JIA and foot‐care provision in patients managed under modern treatment paradigms, including disease‐modifying anti‐rheumatic drugs (DMARDs) and biologic therapies.Methods: The Juvenile Arthritis Foot Disability Index (JAFI), Child Health Assessment Questionnaire (CHAQ), and pain visual analogue scale (VAS) were recorded in 30 consecutive established JIA patients attending routine outpatient clinics. Foot deformity score, active/limited joint counts, walking speed, double‐support time (s) (DS) and step length symmetry index % (SI) were also measured. Foot‐care provision in the preceding 12 months was determined from medical records.Results: Sixty‐three per cent of children reported some foot impairment, with a median (range) JAFI subscale score of 1 (0–3); 53% reported foot‐related activity limitation, with a JAFI subscale score of 1 (0–4); and 60% reported participation restriction, with a JAFI subscale score of 1 (0–3). Other reported variables were CHAQ 0.38 (0–2), VAS pain 22 (0–79), foot deformity 6 (0–20), active joints 0 (0–7), limited joints 0 (0–31), walking speed 1.09 m/s (0.84–1.38 m/s), DS 0.22 s (0.08–0.26 s) and SI ±4.0% (±0.2–±31.0%). A total of 23/30 medical records were reviewed and 15/23 children had received DMARDS, 8/23 biologic agents and 20/23 multiple intra‐articular corticosteroid injections. Ten children received specialist podiatry care comprising footwear advice, orthotic therapy and silicone digital splints together with intrinsic muscle strengthening exercises.Conclusion: Despite frequent use of DMARD/biologic therapy and specialist podiatry‐led foot care, foot‐related impairment and disability persists in some children with JIA. Copyright © 2008 John Wiley & Sons, Ltd.
Effectiveness of an integrated outpatient care programme compared with present‐day standard care in early rheumatoid arthritis
Authors: Esselens Greet , Westhovens René , Verschueren Patrick 
Published: July 2008

AbstractObjectives: To investigate the effectiveness of an integrated care programme in daily practice compared with present‐day standard care for ambulatory early rheumatoid arthritis patients.Methods: In this cross‐sectional study, group A received programmed multidisciplinary outpatient care and group B standard rheumatologist‐centred care. Demographics, disease duration, initial and actual treatment, disease activity (Disease Activity‐28 Score), general health (Short Form‐36 [SF‐36]), functionality (Health Assessment Questionnaire [HAQ]), coping style (Utrecht's Coping List), illness perception (Dutch–Revised Illness Perception Questionnaire) and satisfaction about care were recorded.Results: Eight‐nine patients were included in group A and 102 in group B. Demographics, rheumatoid factor, antibodies against cyclic citrullinated peptides and disease duration were comparable. More patients in group A received initial combination therapy (35% versus 3%). Actual treatment regimens were comparable. More patients were in remission (69% versus 39%) or had low disease activity (80% versus 60%), mean HAQ‐scores were lower (0.52 versus 0.80), more patients had no functional impairment (38% versus 15%) and SF‐36 scores were higher in group A. Coping style and illness perception were similar, except for illness coherence. Satisfaction differed only for aspects typically favouring a care programme. Participation in a care programme independently predicted remission and absence of disability in a regression model, including gender and initial treatment as other predictors.Conclusion: Disease activity was better controlled and functionality and general health better preserved in patients following an outpatient care programme. This was partly due to the easier implementation of an intensive initial treatment strategy but apparently also to other aspects of organized pharmacological and non‐pharmacological care, to be defined in randomized, controlled studies. Copyright © 2008 John Wiley & Sons, Ltd.
Defeaturing: A posteriori error analysis via feature sensitivity
Authors: Turevsky Inna , Gopalakrishnan Sankara Hari , Suresh Krishnan 
Published: July 2008

AbstractIt is well known that small geometric features within a CAD model can significantly impact the computational cost, and often undermine the reliability, of finite element analysis. Engineers therefore resort to defeaturing or detail removal, wherein the offending features are suppressed prior to computational analysis. However, this results in a defeaturing‐induced analysis error.In this paper, we estimate this error in an a posteriori sense through the novel concept of feature sensitivity. The latter determines the first‐order change in quantities of interest when an arbitrary cluster of small geometric features is deleted from a model. A formal theory and a set of associated algorithms are provided to compute the feature sensitivity associated with a scalar elliptic partial differential equation. The theory is supported through numerical experiments in 2‐D, involving both internal and boundary features. Copyright © 2008 John Wiley & Sons, Ltd.
Bounds for quantities of interest and adaptivity in the element‐free Galerkin method
Authors: Vidal Yolanda , Parés Núria , Díez Pedro , Huerta Antonio 
Published: July 2008

AbstractA novel approach to implicit residual‐type error estimation in mesh‐free methods and an adaptive refinement strategy are presented. This allows computing upper and lower bounds of the error in energy norm with the ultimate goal of obtaining bounds for outputs of interest. The proposed approach precludes the main drawbacks of standard residual‐type estimators circumventing the need of flux‐equilibration and resulting in a simple implementation that avoids integrals on edges/sides of a domain decomposition (mesh). This is especially interesting for mesh‐free methods. The adaptive strategy proposed leads to a fast convergence of the bounds to the desired precision. Copyright © 2008 John Wiley & Sons, Ltd.
A combined global and local search method to deal with constrained optimization for continuous tabu search
Authors: Chen Xi , Yang Jing , Li Zhaohua , Tian Daqing , Shao Zhijiang 
Published: July 2008

AbstractHeuristic methods, such as tabu search, are efficient for global optimizations. Most studies, however, have focused on constraint‐free optimizations. Penalty functions are commonly used to deal with constraints for global optimization algorithms in dealing with constraints. This is sometimes inefficient, especially for equality constraints, as it is difficult to keep the global search within the feasible region by purely adding a penalty to the objective function. A combined global and local search method is proposed in this paper to deal with constrained optimizations. It is demonstrated by combining continuous tabu search (CTS) and sequential quadratic programming (SQP) methods. First, a nested inner‐ and outer‐loop method is presented to lead the search within the feasible region. SQP, a typical local search method, is used to quickly solve a non‐linear programming purely for constraints in the inner loop and provides feasible neighbors for the outer loop. CTS, in the outer loop, is used to seek for the global optimal. Finally, another local search using SQP is conducted with the results of CTS as initials to refine the global search results. Efficiency is demonstrated by a number of benchmark problems. Copyright © 2008 John Wiley & Sons, Ltd.
A polynomial dimensional decomposition for stochastic computing
Authors: Rahman Sharif 
Published: July 2008

AbstractThis article presents a new polynomial dimensional decomposition method for solving stochastic problems commonly encountered in engineering disciplines and applied sciences. The method involves a hierarchical decomposition of a multivariate response function in terms of variables with increasing dimensions, a broad range of orthonormal polynomial bases consistent with the probability measure for Fourier‐polynomial expansion of component functions, and an innovative dimension‐reduction integration for calculating the coefficients of the expansion. The new decomposition method does not require sample points as in the previous version; yet, it generates a convergent sequence of lower‐variate estimates of the probabilistic characteristics of a generic stochastic response. The results of five numerical examples indicate that the proposed decomposition method provides accurate, convergent, and computationally efficient estimates of the tail probability of random mathematical functions or the reliability of mechanical systems. Copyright © 2008 John Wiley & Sons, Ltd.
A singular‐value decomposition (SVD)‐based generalized finite difference (GFD) method for close‐interaction moving boundary flow problems
Authors: Ang S. J. , Yeo K. S. , Chew C. S. , Shu C. 
Published: July 2008

AbstractIn this paper, we present a study on a singular‐value decomposition (SVD)‐based generalized finite difference (GFD) method and a nodal selection scheme for moving body/boundary flow problems formulated on a hybrid Cartesian cum meshfree grid system. The present study shows that the SVD‐based method is more robust and accurate than the conventional least‐squares‐based GFD scheme. A nodal selection scheme is also introduced to overcome the problem of numerical instability associated with the clustering of computational nodes. Such nodal clustering occurs dynamically when moving bodies or boundaries approach within close proximity of each other, resulting in the overlap of their meshfree grids. The nodal scheme is applied to close‐interaction flow problems as exemplified by the squeezing action of a circular cylinder through a very narrow slot and the close proximity bypass interaction of two oscillating circular cylinders. Copyright © 2008 John Wiley & Sons, Ltd.
Locally enhanced Voronoi cell finite element model (LE‐VCFEM) for simulating evolving fracture in ductile microstructures containing inclusions
Authors: Hu Chao , Ghosh Somnath 
Published: July 2008

AbstractDuctile heterogeneous materials such as cast aluminum alloys undergo catastrophic failure that initiates with particle fragmentation, which evolves with void growth and coalescence in localized bands of intense plastic deformation and strain softening. The Voronoi cell finite element model (VCFEM), based on the assumed stress hybrid formulation, is unable to account for plastic strain‐induced softening. To overcome this shortcoming of material softening due to plastic strain localization, this study introduces a locally enhanced VCFEM (LE‐VCFEM) for modeling the very complex phenomenon of ductile failure in heterogeneous metals and alloys. In LE‐VCFEM, finite deformation displacement elements are adaptively added to regions of localization in the otherwise assumed stress‐based hybrid Voronoi cell finite element to locally enhance modeling capabilities for ductile fracture. Adaptive h‐refinement is used for the displacement elements to improve accuracy. Damage initiation by particle cracking is triggered by a Weibull model. The nonlocal Gurson–Tvergaard–Needleman model of porous plasticity is implemented in LE‐VCFEM to model matrix cracking. An iterative strain update algorithm is used for the displacement elements. The LE‐VCFEM code is validated by comparing with results of conventional FE codes and experiments with real materials. The effect of various microstructural morphological characteristics is also investigated. Copyright © 2008 John Wiley & Sons, Ltd.
Hyper‐reduction of mechanical models involving internal variables
Authors: Ryckelynck D. 
Published: July 2008

AbstractWe propose to improve the efficiency of the computation of the reduced‐state variables related to a given reduced basis. This basis is supposed to be built by using the snapshot proper orthogonal decomposition (POD) model reduction method. In the framework of non‐linear mechanical problems involving internal variables, the local integration of the constitutive laws can dramatically limit the computational savings provided by the reduction of the order of the model. This drawback is due to the fact that, using a Galerkin formulation, the size of the reduced basis has no effect on the complexity of the constitutive equations. In this paper we show how a reduced‐basis approximation and a Petrov–Galerkin formulation enable to reduce the computational effort related to the internal variables. The key concept is a reduced integration domain where the integration of the constitutive equations is performed. The local computations being not made over the entire domain, we extrapolate the computed internal variable over the full domain using POD vectors related to the internal variables. This paper shows the improvement of the computational saving obtained by the hyper‐reduction of the elasto‐plastic model of a simple structure. Copyright © 2008 John Wiley & Sons, Ltd.
Stress update algorithm for elastoplastic models with nonconvex yield surfaces
Authors: Pedroso Dorival M. , Sheng Daichao , Sloan Scott W. 
Published: July 2008

AbstractA stress update algorithm for elastoplastic models with nonconvex yield surfaces is presented. An explicit algorithm based on the Runge–Kutta embedded method of second‐order accuracy is developed. The crossing of the yield surface is properly taken into account by means of a robust intersection‐finding algorithm. This algorithm is based on a simple multiple‐root‐finding technique, which requires the yield function, evaluated along a given secant stress path, to be continuously differentiable to the second order. The accuracy of the intersection‐finding algorithm is illustrated through examples using simple yield functions similar to the ones adopted in models for unsaturated soils and the modified Cam clay model yield surface with a nonconvex Argyris et al. failure criterion. Isoerror surfaces and finite element simulations are used to investigate the accuracy and efficiency of the stress update algorithm. It is observed that although the algorithm for nonconvex surfaces is slower than its equivalent for convex surfaces, the accuracy can be controlled locally by means of specified tolerances. Copyright © 2008 John Wiley & Sons, Ltd.
Time‐dependent shape functions for modeling highly transient geothermal systems
Authors: van der Meer F. P. , Al‐Khoury R. , Sluys L. J. 
Published: July 2008

AbstractThis paper presents new time‐dependent finite element shape functions suitable for modeling high‐gradient transient conductive heat flow in geothermal systems. The shape functions are made adaptive by enhancing the approximation functions with time‐dependent variables, which may vary according to the transient process without adding extra degrees of freedom or applying mesh adaptation. Two different approaches are presented. First, an iterative method is proposed, in which an exponential approximation function, which is optimized continually during the transient process, is incorporated in the shape function. Second, an analytical method is suggested, in which an analytical solution of a simplified process is incorporated in the shape function, enabling an explicit update of the shape functions in each time step. A methodology for modeling the variation of temperature in one and two dimensions is introduced. The ability of the method to capture high‐gradient temperature profiles using relatively large elements is illustrated with numerical examples of cases in which equally large standard finite elements fail. Copyright © 2008 John Wiley & Sons, Ltd.