bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synergistic Effect of Pybox Substituents and Lanthanide Cations in Reversing the Asymmetric Induction in the Catalysed Diels−Alder Reaction between 3‐Acryloyl‐1,3‐oxazolidin‐2‐one and Cyclopentadiene
Authors: Desimoni Giovanni , Faita Giuseppe , Guala Matilde , Laurenti Anna 
Published: June 2004

AbstractThe enantioselectivity in the pybox/lanthanide(III) triflate catalysed Diels−Alder reaction between cyclopentadiene and 3‐acryloyl‐1,3‐oxazolidin‐2‐one is profoundly influenced by the presence of a phenyl group in the 5′‐position of the ligand, since it sometimes amplifies, and sometimes reverses the enantioselectivity induced by the 4′‐substituent. The results can be summarised in three points. Of the catalysts derived from (4′R,5′R)‐4‐Me‐5‐Ph‐pybox (6), the ScIII‐based one is both strongly endo‐selective and strongly enantioselective. Several catalysts derived from (4′R,5′R)‐trans‐diphenyl‐pybox (9) give up to 50% yields of exo‐4 and, at least with PrIII and LaIII, induce excellent ee values in both endo and exo adducts. The (4′R,5′S)‐cis‐diphenyl‐pybox (8) is a novel and valuable ligand, since opposite enantiomers can be obtained with good selectivity simply by changing the cation from ScIII to LaIII. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Construction of a Fused Polycyclic Wall within the Cyclodextrin Belt To Ensure a Distorted Cavity: An Unusual trans‐Diequatorial Ring‐Opening Reaction of Cyclodextrin Epoxide Rings
Authors: Fujita Kahee , Fujioka Toshihiro , Shimada Hideaki , Ohta Kazuko , Yoshino Akitoshi , Okabe Yuji , Fukudome Makoto , Yuan De‐Qi 
Published: June 2004

AbstractIn the nucleophilic ring‐opening reaction of 2X,3X‐manno‐epoxides, the incoming nucleophiles attack the 3X‐C position of the epoxide almost exclusively. However, a quite unusual but very interesting reversed regioselectivity is observed when intramolecular hydroxy groups act as nucleophiles, that is, only the attack by 3X−1‐OH at the 2X‐C position of the epoxide is observed. The reaction affords the apparent trans‐diequatorial products and ensures an efficient construction of fused heterocycles within the cyclodextrin belt. In the case of 2I,3I:2II,3II‐di‐manno‐epoxy‐β‐cyclodextrin, a tandem‐type reaction is initiated by the attack by the 3VII‐OH group at the 2I‐C position to generate a fused pentacycle. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Preparation of Sugar Amino Acids by Claisen‐Johnson Rearrangement: Synthesis and Incorporation into Enkephalin Analogues
Authors: Montero Ana , Mann Enrique , Herradón Bernardo 
Published: June 2004

AbstractWe have developed a convenient route for the synthesis of an unsaturated branched sugar bearing a carboxylic acid and an amino group (masked as an azide group) by employing a totally stereoselective Claisen−Johnson rearrangement as the key step. Several Met‐ and Leu‐enkephalin analogues with different substitution patterns at the N‐ and C‐termini were prepared by incorporating this sugar amino acid (SAA) as a substitute for the central Gly−Gly fragment of the parent pentapeptides. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Model Compound of the Novel Organic Cofactor CTQ (Cysteine Tryptophylquinone) of Quinohemoprotein Amine Dehydrogenase
Authors: Murakami Yoko , Tachi Yoshimitsu , Itoh Shinobu 
Published: June 2004

AbstractA model compound of the novel organic cofactor CTQ (cysteine tryptophylquinone) of quinohemoprotein amine dehydrogenase (QH‐AmDH) has been synthesized for the first time by the Michael addition of phenylmethanethiol to the 3‐methyl‐6,7‐indolequinone derivative as a key step. The model compound replicates the characteristic absorption spectrum of native CTQ as well as its redox potential in the γ subunit of QH‐AmDH. Detailed structural and spectroscopic characterizations of the model compound have provided important insights into the substituent effects of the thioether group of CTQ. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A Polymer‐Supported Phosphoramide as a Lewis‐Base Catalyst for the Catalytic Aldol Reaction
Authors: Flowers Robert A. , Xu Xin , Timmons Cody , Li Guigen 
Published: June 2004

AbstractThe aldol reactions between trichlorosilyl enol ethers and aldehydes were catalyzed by an environmentally benign polymer‐supported phosphoramide organocatalyst. Eight examples are reported with moderate to good chemical yields and stereoselectivity. Significant rate enhancements were observed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Cover Picture: Synthesis of Phenylacetylene Dendrimers Having Sterically Congested Diazo Units and Characterization of Their Photoproducts (Eur. J. Org. Chem. 14/2004)
Authors: Itoh Tetsuji , Maemura Toshiyuki , Ohtsuka Yusuke , Ikari Yoshiyuki , Wildt Holger , Hirai Katsuyuki , Tomioka Hideo 
Published: June 2004

AbstractThe cover picture shows a phenylacetylene dendrimer having 12 diazo units, from which a dodecakiscarbene is generated. Diazo functional groups are usually labile and hence cannot be used as building blocks to prepare more complicated poly(diazo) compounds. We have shown that a diphenyldiazomethane prepared to generate a persistent triplet diphenylcarbene is also stable and can be used as a building block to construct poly(diazo) compounds, which can generate high‐spin polycarbenes. Details are discussed in the article by H. Tomioka et al. on page 2991 ff.
Experimental Investigation of Drying Behavior of Carrots in a Fluidized Bed with Energy Carrier
Authors: Hatamipour M.S. , Mowla D. 
Published: June 2004

AbstractA pilot scale fluidized bed dryer with inert particles as energy carrier was used to investigate the drying characteristics of carrot in this type of dryer. Glass beads, hollow steel balls and pieces of dry carrot were used as inert materials. The effects of sample diameter, inert material type, inert material diameter, amount of inert material, air velocity and temperature on the rate of drying were studied. It was found that the presence of inert particles enhances the rate of drying. The results of this study also revealed that, although the rate of drying increased with decreasing sample diameter, increasing of inert material thermal conductivity, and increasing of air temperature, but the inert material diameter and air velocity did not have any significant effect on the rate of drying. The independence of the rate of drying on air velocity in well fluidized systems, indicates that external diffusion is not the controlling step in this process. It was also found that the presence of inert materials caused the drying material to reach its final internal temperature more rapidly. The internal temperature of the drying material, also increased with increasing diameter and thermal conductivity of the inert materials.
Generalized‐α methods for seismic structural testing
Authors: Bonelli A. , Bursi O. S. 
Published: June 2004

AbstractThis paper presents novel predictor–corrector time‐integration algorithms based on the Generalized‐α method to perform pseudo‐dynamic tests with substructuring. The implicit Generalized‐α algorithm was implemented in a predictor–one corrector form giving rise to the implicit IPC–ρ∞ method, able to avoid expensive iterative corrections in view of high‐speed applications. Moreover, the scheme embodies a secant stiffness formula that can closely approximate the actual stiffness of a structure. Also an explicit algorithm endowed with user‐controlled dissipation properties, the EPC–ρb method, was implemented. The resulting schemes were tested experimentally both on a two‐ and on a six‐degrees‐of‐freedom system, using substructuring. The tests indicated that the numerical strategies enhance the fidelity of the pseudo‐dynamic test results even in an environment characterized by considerable experimental errors. Moreover, the schemes were tested numerically on severe non‐linear substructured multiple‐degrees‐of‐freedom systems reproduced with the Bouc–Wen model, showing the reliability of the seismic tests under these conditions. Copyright © 2004 John Wiley & Sons, Ltd.
Three‐dimensional models of reservoir sediment and effects on the seismic response of arch dams
Authors: Maeso O. , Aznárez J. J. , Domínguez J. 
Published: June 2004

AbstractThe important effects of bottom sediments on the seismic response of arch dams are studied in this paper. To do so, a three‐dimensional boundary element model is used. It includes the water reservoir as a compressible fluid, the dam and unbounded foundation rock as viscoelastic solids, and the bottom sediment as a two‐phase poroelastic domain with dynamic behaviour described by Biot's equations. Dynamic interaction among all those regions, local topography and travelling wave effects are taken into account. The results obtained show the important influence of sediment compressibility and permeability on the seismic response. The former is associated with a general change of the system response whereas the permeability has a significant influence on damping at resonance peaks. The analysis is carried out in the frequency domain considering time harmonic excitation due to P and S plane waves. The time‐domain results obtained by using the Fourier transform for a given earthquake accelerogram are also shown. The possibility of using simplified models to represent the bottom sediment effects is discussed in the paper. Two alternative models for porous sediment are tested. Simplified models are shown to be able to reproduce the effects of porous sediments except for very high permeability values. Copyright © 2004 John Wiley & Sons, Ltd.
Pseudo‐dynamic testing of bridges using non‐linear substructuring
Authors: Pinto A. V. , Pegon P. , Magonette G. , Tsionis G. 
Published: June 2004

AbstractPseudo‐dynamic tests on a large‐scale model of an existing six‐pier bridge were performed at the ELSA laboratory using the substructuring technique. Two physical pier models were constructed and tested in the laboratory, while the deck, the abutments and the remaining four piers were numerically modeled on‐line. These tests on a large‐scale model of an existing bridge are the first to have been performed considering non‐linear behavior for the modeled substructure. Asynchronous input motion, generated for the specific bridge site, was used for the abutments and the pier bases. Three earthquake tests with increasing intensities were carried out, aimed at the assessment of the seismic vulnerability of a typical European motorway bridge designed prior to the modern generation of seismic codes. The experimental results confirm the poor seismic behavior of the bridge, evidenced by irregular distribution of damage, limited deformation capacity, tension shift effects and undesirable failure locations. Copyright © 2004 John Wiley & Sons, Ltd.
Semi‐empirical model for site effects on acceleration time histories at soft‐soil sites. Part 1: formulation and development
Authors: Bárcena Armando , Esteva Luis 
Published: June 2004

AbstractA criterion is developed for the simulation of realistic artificial ground motion histories at soft‐soil sites, corresponding to a detailed ground motion record at a reference firm‐ground site. A complex transfer function is defined as the Fourier transform of the ground acceleration time history at the soft‐soil site divided by the Fourier transform of the acceleration record at the firm‐ground site. Working with both the real and the imaginary components of the transfer function, and not only with its modulus, serves to keep the statistical information about the wave phases (and, therefore, about the time variation of amplitudes and frequencies) in the algorithm used to generate the artificial records. Samples of these transfer functions, associated with a given pair of soft‐soil and firm‐ground sites, are empirically determined from the corresponding pairs of simultaneous records. Each function included in a sample is represented as the superposition of the transfer functions of the responses of a number of oscillators. This formulation is intended to account for the contributions of trains of waves following different patterns in the vicinity of both sites. The properties of the oscillators play the role of parameters of the transfer functions. They vary from one seismic event to another. Part of the variation is systematic, and can be explained in terms of the influence of ground motion intensity on the effective values of stiffness and damping of the artificial oscillators. Another part has random nature; it reflects the random characteristics of the wave propagation patterns associated with the different events. The semi‐empirical model proposed recognizes both types of variation. The influence of intensity is estimated by means of a conventional one‐dimensional shear wave propagation model. This model is used to derive an intensity‐dependent modification of the values of the empirically determined model parameters in those cases when the firm‐ground earthquake intensity used to determine these parameters differs from that corresponding to the seismic event for which the simulated records are to be obtained. Copyright © 2004 John Wiley & Sons, Ltd.
Delirium in elderly hospitalised patients: protective effects of chronic rivastigmine usage
Authors: Dautzenberg Paul L. J. , Mulder Leonie J. , Olde Rikkert Marcel G. M. , Wouters Cees J. , Loonen Anton J. M. 
Published: June 2004

AbstractObjectivesTo investigate the efficacy of the chronic usage of the cholinesterase inhibitor rivastigmine in patients with dementia in the prevention of delirium in case of hospitalisation.DesignRetrospective cohort study.SettingNon‐geriatric wards of an 1120 bed general teaching hospital in s‐Hertogenbosch, The Netherlands.ParticipantsOf a group of 366 hospitalised patients, treated by the geriatric consultation team from January 2002 until June 2003, the patients who used rivastigmine chronically were compared with a randomly selected subgroup of all patients not treated with rivastigmine.MeasurementsThe occurrence and duration of a delirium, co‐morbidity, use of medication, length of hospitalisation and psychosocial data were collected from the medical charts of the geriatric consultation team.Results11 patients (3%) were chronic rivastigmine users. A control group of 29 subjects was randomly selected from the non‐rivastigmine users of the patient population. In the group that used rivastigmine five patients (45.5%) developed a delirium, compared with 8 (88.9%) in the control group (p < 0.05).ConclusionsChronic rivastigmine use may contribute to the prevention of a delirium in a high‐risk group of elderly hospitalised patients suffering from dementia. Copyright © 2004 John Wiley & Sons, Ltd.
Competence to consent to treatment of geriatric patients: judgements of physicians, family members and the vignette method
Authors: Vellinga A. , Smit J. H. , van Leeuwen E. , van Tilburg W. , Jonker C. 
Published: June 2004

AbstractObjectiveIn absence of a gold standard of methods to assess competence, three judgements of competency of geriatric patients are evaluated: the judgements of a physician, the judgement of a family member, and the judgement of an instrument.MethodsCompetence of 80 geriatric patients was judged both by a physician and a family member. Decision making capacity was assessed with a vignette. A vignette describes a treatment choice, after which the following abilities are evaluated: evidencing a choice, understanding, reasoning and appreciating a situation. Cognitive functioning was measured with the Mini‐Mental State Examination.ResultsMost of the geriatric patients were judged competent by all three methods. Disagreement between the three judgements was found for 25 patients. Agreement about incompetence was only reached for one patient. Physicians appeared to be most lenient in their incompetency judgement: only three patients were judged incompetent. These patients scored significantly lower than competent patients on cognitive functioning, the decisional ability of understanding, and the total vignette score. Family members appeared to be most stringent in their judgement: they considered 22 patients incompetent. Incompetent patients scored significantly lower than competent patients on cognitive functioning, reasoning and the total vignette score.ConclusionsThe disagreement between the judgements suggests a difference in factors given emphasis by the three methods. The finding that both the judgement of physicians and family members are associated with the assessment of the vignette, suggests that the vignette method has more than a legal theoretical base and is associated with daily life experience and knowledge as well. Physicians can be helped to assess competence by the vignette method to evaluate decisional abilities and by family members who can provide more information about patients' values. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of combined support for people with dementia and carers versus regular day care on behaviour and mood of persons with dementia: results from a multi‐centre implementation study
Authors: Dröes Rose‐Marie , Meiland Franka , Schmitz Mirjam , van Tilburg Willem 
Published: June 2004

AbstractBackgroundA previous study in Amsterdam showed that combined family support in the Meeting Centres Support Programme, in which dementia patients and their carers are both supported by one professional staff member, is more effective in influencing behaviour problems and mood of dementia patients living in the community than non‐integrated support, such as day care only.ObjectiveA multi‐centre implementation study tests if similar effects are achieved in other regions of The Netherlands.MethodsA pretest–posttest control group design was applied. 112 dementia patients who visited psychogeriatric day care in eight community centres across the country and in three nursing homes, and their carers participated in the study. The patients in the experimental group (n = 89) received support from the Meeting Centres Support Programme together with their carers, while the control group (n = 23) received day care only. Behaviour problems (agressive behaviour, inactivity, non‐social behaviour) and mood (dissatisfaction, depressive behaviour) were assessed using standardized observation scales. Quality of life was assessed by interviewing the patients.ResultsAfter 7 months the Meeting Centres Support Programme, compared to regular day care, showed a moderately positive effect on the degree of total behaviour problems (effect size = 0.52), especially on inactivity (effect size = 0.37) and non‐social behaviour (effect size = 0.60), a large effect on depressive behaviour (effect size = 0.92) and a moderate effect on self‐esteem (effect size = 0.43).ConclusionsThe Meeting Centres Support Programme proves to be more effective than regular day care in influencing behaviour problems, especially inactivity and non‐social behaviour, and depressed mood. Participation in the programme also seems to have a positive effect on self‐esteem, an important aspect of quality of life. These findings surpass the results of the Amsterdam study and confirm the surplus value of the combined family support in the Meeting Centres Support Programme as compared to regular day care for people with mild to severe dementia. Copyright © 2004 John Wiley & Sons, Ltd.
Scoring clock tests for dementia screening: a comparison of two scoring methods
Authors: van der Burg Marjoke , Bouwen Anne , Stessens Johan , Ylieff Michel , Fontaine Ovide , de Lepeleire Jan , Buntinx Frank 
Published: June 2004

AbstractObjectiveTo compare the dementia screening performance of two scoring systems of the clock drawing test.MethodsA sample of 1199 elderly subjects was administered the clock drawing test as part of a study on aging and dementia. The clock drawings were scored using published criteria for the two scoring systems that were compared. Additionally, a selection of 103 drawings was scored by three different raters to evaluate inter‐rater agreement within each of the two methods. For a selection of 473 drawings the final diagnosis on the presence or absence of dementia was known. For these drawings accuracy for the detection of dementia was compared between the two methods.ResultsThe four‐item scoring system (Kappa 0.76; sensitivity 0.97; specificity 0.32; PPV 0.53; NPV 0.93) was found to be a little more reliable and as accurate as the six‐item scoring system (Kappa 0.67; sensitivity 0.96; specificity 0.42; PPV 0.56; NPV 0.94).ConclusionSince both scoring systems showed largely similar results, primary care physicians and other health care providers should be encouraged to use the four‐item scoring checklist as it is easier and requires less time than the more elaborate checklist of the six‐item system. Copyright © 2004 John Wiley & Sons, Ltd.
Association between subcortical vascular disease on CT and neuropathological findings
Authors: Rossi Roberta , Joachim Catherine , Geroldi Cristina , Combrinck Marc , Esiri Margaret M. , Smith A. David , Frisoni Giovanni B. 
Published: June 2004

AbstractBackgroundSmall vessel cerebrovascular disease (svCVD) causes cognitive impairment and predicts poorer outcomes in elderly persons. The demonstration of svCVD by structural imaging such as computed tomography (CT) is central to the clinical diagnosis but its accuracy is uncertain.ObjectiveThe aim of this study was to assess the validity of CT to detect pathologically verified svCVD.MethodsLeukoaraiosis, patchy lesions, and lacunes were assessed separately in different cerebral regions on CT scans of 87 elderly persons with Mini‐Mental State Examination scores between 0 and 30 enrolled in the OPTIMA project. We rated small vessel disease on pathology separately in the white matter and basal ganglia as absent/mild, moderate, and severe. The presence of microinfarcts was also noted.ResultsThe severity of all types of CT lesions was associated with pathological findings. Subjects with absent/mild leukoaraiosis on CT decreased and those with severe leukoaraiosis increased with increasing severity of subcortical small vessel ratings on pathology (31, 18 and 0%; 17, 23 and 50%, respectively; p = 0.028). A similar association was present for patchy lesions (73, 59 and 17%; 7, 18 and 33%, respectively; p = 0.004) and lacune (83, 77 and 50%; 0, 4 and 17%, respectively; p = 0.023). Leukoaraiosis, patchy lesions, and lacunes on CT were associated also with microinfarcts on pathology (p < 0.05).ConclusionThe standardized assessment of svCVD on CT films at the time of the diagnosis correlates with small vessel disease on pathology at death. Copyright © 2004 John Wiley & Sons, Ltd.
Measuring inequality in self‐reported health—discussion of a recently suggested approach using Finnish data
Authors: Lauridsen Jorgen , Christiansen Terkel , Häkkinen Unto 
Published: June 2004

AbstractHealth surveys often include a general question on self‐assessed health (SAH), usually measured on an ordinal scale with three to five response categories, from ‘very poor’ or ‘poor’ to ‘very good’ or ‘excellent’. This paper assesses the scaling of responses on the SAH question. It compares alternative procedures designed to impose cardinality on the ordinal responses. These include OLS, ordered probit and interval regression approaches. The cardinal measures of health are used to compute and decompose concentration indices for income‐related inequality in health. Results are provided using Finnish data on 15D and the SAH questions. Further evidence emerges for the internal validity of a method used in a pioneering study by van Doorslaer and Jones which was based on Canadian data on the McMaster Health Utility Index Mark III (HUI) and SAH. The study validates the conclusions drawn by van Doorslaer and Jones. It confirms that the interval regression approach is superior to OLS and ordered probit regression in assessing health inequality. However, regarding the choice of scaling instrument, it is concluded that the scaling of SAH categories and, consequently, the measured degree of inequality, are sensitive to characteristics of the chosen scaling instrument. Copyright © 2003 John Wiley & Sons, Ltd.