bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐Throughput Heterogeneous Catalytic Science
Authors: Hendershot Reed J. , Snively Christopher M. , Lauterbach Jochen 
Published: November 2004

AbstractHigh‐throughput experimentation in heterogeneous catalysis has recently experienced nearly exponential growth. Initial qualitative screening has evolved into quantitative high‐throughput experimentation, characterization, and analysis. This allows high‐throughput catalysis now to rise above simple screening to the level of fundamental understanding of reaction mechanisms, which will lead on a faster path to the Holy Grail of catalysis: rational catalyst design.
Palladium‐Catalyzed Asymmetric Allylic Alkylation of Ketone Enolates
Authors: Trost Barry M. , Schroeder Gretchen M. 
Published: November 2004

AbstractPalladium‐catalyzed asymmetric allylic alkylation of nonstabilized ketone enolates to generate quaternary centers has been achieved in excellent yield and enantioselectivity. Optimized conditions consist of performing the reaction in the presence of two equivalents of LDA as base, one equivalent of trimethytin chloride as a Lewis acid, 1,2‐dimethoxyethane as the solvent, and a catalytic amount of a chiral palladium complex formed from π‐allyl palladium chloride dimer 3 and cyclohexyldiamine derived chiral ligand 4. Linearly substituted, acyclic 1,3‐dialkyl substituted, and unsubstituted allylic carbonates function well as electrophiles. A variety of α‐tetralones, cyclohexanones, and cyclopentanones can be employed as nucleophiles. The absolute configuration generated is consistent with the current model in which steric factors control stereofacial differentiation. The quaternary substituted products available by this method are versatile substrates for further elaboration.
Multiple Refocusing in NMR Spectroscopy: Compensation of Pulse Imperfections by Scalar Couplings
Authors: Dittmer Jens , Bodenhausen Geoffrey 
Published: November 2004

AbstractWhen applying multiple refocusing pulses to characterize the cross‐correlated relaxation of heteronuclear multiple quantum coherence 2NxHx in biomolecules, the unavoidable effects of pulse imperfections are compensated by the scalar couplings between nitrogen atoms and protons. The experiment, which is useful as a tool for studying slow internal dynamics of biomolecules, greatly benefits from this compensation. The underlying effect is a manifestation of an interchange between three noncommuting components of the density operator. One perturbing Hamiltonian is counteracted by another, which leads to a nearly complete suppression of the perturbation. The effect proves to be an example of a hitherto unknown phenomenon in NMR spectroscopy.
Molecular Complexes of Organometallic Molecules with Noble Gases: The Rotational Spectrum of Dimethylsilane–Argon
Authors: Ottaviani Paolo , Melandri Sonia , Caminati Walther , Banser Deike , Schnell Melanie , Grabow Jens‐Uwe 
Published: November 2004

AbstractThe rotational spectrum of the molecular complex dimethylsilane–argon was investigated by free‐jet absorption millimeter‐wave and molecular‐beam Fourier transform spectroscopy. The absolute energy minimum corresponds to a conformation in which the argon atom lies in the plane of symmetry of dimethylsilane, perpendicular to the CSiC plane. The distance of Ar from the center of mass of dimethylsilane is 3.90 Å, and the Ar atom is tilted 14° away from the Si atom. The zero‐point dissociation energy was estimated from the centrifugal distortion constant DJ to be 2.2 kJ mol−1. Small splitting, due to tunneling of the Ar atom and internal rotation of the two methyl groups, was observed, measured, and used to determine the potential energy surface for these motions.
Intramolecular Charge Transfer in Pyrromethene Laser Dyes: Photophysical Behaviour of PM650
Authors: López Arbeloa F. , Bañuelos Prieto J. , Martínez Martínez V. , Arbeloa López T. , López Arbeloa I. 
Published: November 2004

AbstractAbsorption and fluorescence (steady‐state and time‐correlated) techniques are used to study the photophysical characteristics of the pyrromethene 650 (PM650) dye. The presence of the cyano group at the 8 position considerably shifts the absorption and fluorescence bands to lower energies with respect to other related pyrromethene dyes; this is attributed to the strong electron‐acceptor character of the cyano group, as is theoretically confirmed by quantum mechanical methods. The fluorescence properties of PM650 are intensively solvent‐dependent. The fluorescence band is shifted to lower energies in polar/protic solutions, and the evolution of the corresponding wavelength with the solvent is analysed by a multicomponent linear regression. The fluorescence quantum yield and the lifetime strongly decrease in polar/protic solvents, which can be ascribed to an extra nonradiative deactivation, via an intramolecular charge‐transfer state (ICT state), favoured in polar media.
Torsional Barriers in Aromatic Molecular Clusters as Probe of the Electronic Properties of the Chromophore
Authors: Jacoby Christoph , Schmitt Michael 
Published: November 2004

AbstractWe present a computer program that is capable of fitting n‐fold torsional barriers Vn (n=2–6) and torsional constants F simultaneously to high‐ and low‐resolution spectroscopic data of different isotopomeric internal rotors. The program has been utilized to fit independently barriers and torsional constants for both electronic states of several aromatic clusters. The constant F of the ammonia moiety in the phenol–ammonia cluster is shown to decrease upon electronic excitation, thus imaging the formation of a hydrogen‐bonded complex between the phenoxy radical and the NH4 radical in the excited state. In contrast, for the naphthol–ammonia 1:1 clusters no change of F of ammonia could be found. For phenol–methanol cluster we found a decrease of F upon excitation which points to a stronger hydrogen bond between phenol and methanol in the excited state. A strong reduction of the torsional barrier upon excitation points to the formation of a methoxonium radical in a similar photoreaction as in phenol–ammonia cluster. For the phenol–water system we postulate the same mechanism, a photoreaction, which leads to a translocated hydrogen atom in the S1 state what can be deduced from the change of the torsional constant upon electronic excitation.
Infrared Absorption Features of Gaseous Isopropyl Carbocations
Authors: Chiavarino Barbara , Crestoni Maria E. , Fornarini Simonetta , Lemaire Joel , Mac Aleese Luke , Maître Philippe 
Published: November 2004

AbstractC3H7+ ions were formed in the cell of a Fourier transform ion cyclotron resonance mass spectrometer and assayed by their multiphoton dissociation (MPD) behavior, triggered by the absorption of tunable IR radiation from a free‐electron laser source providing a high fluence. The derived experimental IRMPD spectrum, which reflects the active vibrational modes of the ion, was compared with the IR spectra calculated for the optimized structures of the most‐stable species on the C3H7+ potential energy surface, namely, a chiral iC3H7+ ion of C2 symmetry and an asymmetric corner‐protonated cyclopropane, cC3H7+. The significant features in the IRMPD spectra of both the unlabeled and the perdeuterated ions obtained by ionization and fragmentation of isobutane or 2‐chloro[D7]propane confirm the presence of the isopropyl cation, the ground‐state isomer, whose IR spectroscopic features can thus be comparatively checked in the gas phase and in condensed superacid media. Details of the IRMPD features are suggested to result from the nearly barrierless interconversion of the two C2 enantiomers.
Identifying interacting SNPs using Monte Carlo logic regression
Authors: Kooperberg Charles , Ruczinski Ingo 
Published: November 2004

AbstractInteractions are frequently at the center of interest in single‐nucleotide polymorphism (SNP) association studies. When interacting SNPs are in the same gene or in genes that are close in sequence, such interactions may suggest which haplotypes are associated with a disease. Interactions between unrelated SNPs may suggest genetic pathways. Unfortunately, data sets are often still too small to definitively determine whether interactions between SNPs occur. Also, competing sets of interactions could often be of equal interest. Here we propose Monte Carlo logic regression, an exploratory tool that combines Markov chain Monte Carlo and logic regression, an adaptive regression methodology that attempts to construct predictors as Boolean combinations of binary covariates such as SNPs. The goal of Monte Carlo logic regression is to generate a collection of (interactions of) SNPs that may be associated with a disease outcome, and that warrant further investigation. As such, the models that are fitted in the Markov chain are not combined into a single model, as is often done in Bayesian model averaging procedures. Instead, the most frequently occurring patterns in these models are tabulated. The method is applied to a study of heart disease with 779 participants and 89 SNPs. A simulation study is carried out to investigate the performance of the Monte Carlo logic regression approach. Genet. Epidemiol. 28:157–170, 2005. © 2004 Wiley‐Liss, Inc.
Efficacy and tolerability of venlafaxine in geriatric outpatients with major depression: a double‐blind, randomised 6‐month comparative trial with citalopram
Authors: Allard Per , Gram Lars , Timdahl Kristina , Behnke Kirsten , Hanson Martin , Søgaard Jesper 
Published: November 2004

AbstractBackgroundThe objectives of the study were to compare efficacy and tolerability of venlafaxine ER 75–150 mg/day with that of citalopram 10–20 mg/day in elderly patients with major depression according to DSM‐IV criteria.MethodsA randomised, double‐blind, parallel group 6‐month study. Efficacy was assessed by MADRS, CGI Global Improvement, CGI Severity of Illness and GDS‐20 scores and safety by physical examinations, vital signs, adverse events and UKU side effect rating. Plasma levels of venlafaxine, its major metabolite O‐desmethylvenlafaxine and citalopram were followed.ResultsOne hundred and fifty‐one male and female patients (64–89 years) were enrolled and 118 patients completed the study. Comparable improvements in MADRS, CGI Severity of Illness, CGI Global Improvement and GDS‐20 were observed during venlafaxine and citalopram treatment. The MADRS remission rate was 19% for venlafaxine and 23% for citalopram. Side effects were common during both treatments but differed in tremor being more common during citalopram and nausea/vomiting during venlafaxine treatment. There were no clinically significant changes in blood pressure or body weight.ConclusionThe observed benefits of venlafaxine treatment in elderly patients with major depression were similar to those observed in younger adults as were reported adverse events and side effects. Treatment with venlafaxine ER was well tolerated and induced beneficial effects of similar magnitude as those of citalopram. Copyright © 2004 John Wiley & Sons, Ltd.
Neuropsychological performance in early and late onset Alzheimer's disease: comparisons in a memory clinic population
Authors: Suribhatla Srinivas , Baillon Sarah , Dennis Michael , Marudkar Mangesh , Muhammad Saquib , Munro Dena , Spreadbury Christine , Lindesay James 
Published: November 2004

AbstractObjectivesTo compare the neuropsychological performance associated with early and late onset Alzheimer's disease (AD), in order to identify differences and compare these with previous reports.MethodsPatients attending a memory clinic were given a detailed multi‐disciplinary diagnostic assessment, including a battery of neuropsychological tests. From those meeting ICD‐10 criteria for Alzheimer's disease (AD), an early‐onset (EO) group (n = 40) and a late‐onset (LO) group (n = 90) were identified, and their performances compared. Patients with mixed dementia and co‐morbid depression were excluded.ResultsAfter adjustment, the EO and LO groups performed at a comparable level on the majority of the neuropsychological tests. The LO group performed better on the WAIS digit span test, AMIPB Complex Design and the written picture description, and the EO group performed better on the WAIS similarities test and the Boston naming test.ConclusionsThese findings suggest that, after adjusting for overall dementia severity and pre‐morbid IQ, there is greater fronto‐parietal/right hemisphere involvement in early‐onset AD, and greater temporal/left hemisphere involvement in late‐onset AD. This may be due to different genetic risk profiles for AD at different ages. Copyright © 2004 John Wiley & Sons, Ltd.
Symptoms of depression and anxiety (MHI) following acute medical/surgical hospitalization and post‐discharge psychiatric diagnoses (DSM) in 839 geriatric US veterans
Authors: Gerson Sylvia , Mistry Ritesh , Bastani Roshan , Blow Fred , Gould Robert , Llorente Maria , Maxwell Annette , Moye Jennifer , Olsen Edwin , Rohrbaugh Robert , Rosansky Joel , Van Stone William , Jarvik Lissy 
Published: November 2004

AbstractObjectiveWe addressed the relatively unexplored use of screening scores measuring symptoms of depression and/or anxiety to aid in identifying patients at increased risk for post‐discharge DSM‐IV Axis I diagnoses. We were unable to find such studies in the literature.MethodElderly veterans without recent psychiatric diagnoses were screened for depression and anxiety symptoms upon admission to acute medical/surgical units using the Mental Health Inventory (MHI). Following discharge, those who had exceeded cut‐off scores and had been randomized to UPBEAT Care (Unified Psychogeriatric Biopsychosocial Evaluation and Treatment, a clinical demonstration project) were evaluated for DSM diagnoses. We report on 839 patients, mostly male (96.3%; mean age 69.6 ± 6.7 years), comparing three groups, i.e. those meeting screening criteria for symptoms of (i) depression only; (ii) anxiety only; and (iii) both depression and anxiety.ResultsDespite absence of recent psychiatric history, 58.6% of the 839 patients received a DSM diagnosis post‐discharge (21.8% adjustment; 15.4% anxiety; 7.5% mood; and 14.0% other disorders). Patients meeting screening criteria for both depression and anxiety symptoms received a DSM diagnosis more frequently than those meeting criteria for anxiety symptoms only (61.9% vs 49.0%, p = 0.017), but did not differ significantly from those meeting criteria for depressive symptoms only (61.9% vs 56.8%, p = 0.174). Although exceeding the MHI screening cut‐off scores for depression, anxiety, or both helped to identify patients with a post‐discharge DSM diagnosis, the actual MHI screening scores failed to do so.ConclusionScreening hospitalized medical/surgical patients for symptoms of depression, anxiety, and particularly for the combination thereof, may help identify those with increased risk of subsequent DSM diagnoses, including adjustment disorder. Copyright © 2004 John Wiley & Sons, Ltd.
Prevalence of major and minor depression in elderly persons with mild cognitive impairment—MADRS factor analysis
Authors: Gabryelewicz T. , Styczynska M. , Pfeffer A. , Wasiak B. , Barczak A. , Luczywek E. , Androsiuk W. , Barcikowska M. 
Published: November 2004

AbstractObjectiveThe aim of the study was to detect the prevalence of depressive syndromes and symptoms in the sample of elderly persons with Mild Cognitive Impairment (MCI), and to analyse Montgomery‐Asberg Depression Rating (MADRS) item scores.MethodThe subjects of the study were 102 consecutive out‐patients with MCI. All subjects were assessed by an experienced psychiatrist and MADRS was applied. Major and minor depressive episodes were defined according to DSM‐IV criteria. Factor analysis was used to analyse baseline MADRS item scores.ResultsThree patient groups emerged according to the depressive symptoms distribution and severity scores basis: those with major depression constituted 19.6% (n = 20), with minor depression 26.5% (n = 27), and with very few depressive symptoms 53.9% (n = 55). Three interpretable MADRS factors were identified, using the factor analysis with Varimax rotation: the first consisting of apparent and reported sadness, inability to feel, pessimistic thoughts, the second consisting of inner tension, reduced sleep, reduced appetite, suicidal thoughts, and the third with concentration difficulties and lassitude.ConclusionsIt was concluded that both major and minor depression is common in MCI. Three MADRS factors were identified and labelled as anhedonia‐pessimism, anxiety‐vegetative, and cognitive‐inhibition. Copyright © 2004 John Wiley & Sons, Ltd.
Adaptation of the ACE for a Malayalam speaking population in southern India
Authors: Mathuranath P. S. , Hodges John R. , Mathew Robert , Cherian P. Joseph , George Annamma , Bak Thomas H. 
Published: November 2004

AbstractObjectiveTo adapt the Addenbrooke's Cognitive Examination (ACE) as a dementia‐screening tool in a community in south India. To establish that items in the adapted version are equivalent to that in the original.MethodsThe ACE was adapted into the local language, Malayalam (m‐ACE), following cultural/linguistic modifications. To establish equivalence, qualitative comparisons were made (on the distribution of scores, percentage scoring at ceiling, and relative difficulty across items) between a UK sample receiving the ACE (n = 50; mean age = 67.9 ± 7.4; education ≥ 9, mean = 10.9 ± 2.5) and a community‐based educationally‐stratified Indian sample receiving the m‐ACE: ‘India ≥ 9’ (n = 50; mean age = 67.8 ± 5.2; education ≥ 9, mean = 13.9 ± 2.7) and ‘India ≤ 8’ (n = 50; mean age = 67.1 ± 5.3; education ≤ 8, mean = 3.1 ± 2.0).ResultsMost ACE items were retained. The score distribution (mean ± 1SD), percentage at ceiling, and relative difficulties across items is comparable between the UK and the educationally equivalent India ≥ 9 groups. Language, Naming, Attention and Orientation are relatively easy (≥ 80% at ceiling) and Recall and Verbal fluency are relatively difficult (≤ 22% at ceiling). Although the percentage at ceiling were lower for the India ≤ 8 group, the order of relative difficulty was similar and the percentage scoring at floor was ≤ 10% on all except visuospatial item.ConclusionsThe m‐ACE provides a culture‐fair Malayalam adaptation of the ACE with component items of equivalent difficulty. Copyright © 2004 John Wiley & Sons, Ltd.
Flow and heat transfer of natural convection around an upward‐facing horizontal plate with a vertical plate at the edge
Authors: Kimura Fumiyoshi , Ishihara Suguru , Kitamura Kenzo 
Published: November 2004

AbstractNatural convective flows around an upward‐facing horizontal heated plate with a vertical plate at the edge were investigated experimentally. Of particular concern were the influences of the vertical plate on the fluid flow and the heat transfer of the horizontal plate. The flow and temperature fields adjacent to the horizontal plate were visualized with dye and a liquid‐crystal thermometry. The results show that the vertical plate obstructs the flow from the top of the vertical plate, while the flow from the open edge of the horizontal plate covers the whole horizontal surface when the height of the vertical plate exceed H/W = 0.14 for adiabatic vertical plate and H/W = 0.1 for the heated vertical plate. The local heat‐transfer‐coefficients of the horizontal plate were also measured. It was found that the vertical adiabatic plates deteriorate the heat transfer, while the heated vertical plates enhance the heat transfer from the horizontal plates. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(8): 527–539, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20033
Preterm behavior, maternal adjustment, and competencies in the newborn period: What influence do they have at 12 months postnatal age?
Authors: Veddovi M. , Gibson F. , Kenny D.T. , Bowen J. , Starte D. 
Published: November 2004

AbstractThis article examines whether preterm newborns' behavior and their mother's adjustment to the premature birth and infant hospitalization have an influence on subsequent infant development and behavior, maternal adjustment, and mother–infant relationship. The behavioral competencies of 42 well, singleton preterm infants (mean gestational age=31 weeks) were assessed, as were their mothers' adjustment (depression and coping) and competencies (knowledge of child development). At 12 months of postnatal age, child competencies (development and behavior) were assessed, together with maternal adjustment (parenting stress and depression). Mother–infant interaction also was observed. Regression analyses indicated that in the newborn period, maternal positive reappraisal and a planful coping style, more knowledge of child development, and previous experience with baby‐sitting were associated with better infant development (p=.002), maternal adjustment (p=.012), and mother–child relationship (p=.002) at 12 months. Newborn infant muscle‐tone maturity was predictive of better motor quality at 12 months (p=.011), and being a firstborn infant who was more sleepy and drowsy was associated with subsequent higher maternal parenting stress (p=.007). Social and educational support groups combined with an approach that assists mothers to develop problem‐solving coping styles may have a beneficial influence on infant development.
Impact of fathers' alcoholism and associated risk factors on parent–infant attachment stability from 12 to 18 months
Authors: Edwards Ellen P. , Eiden Rina D. , Leonard Kenneth E. 
Published: November 2004

AbstractThis study examined short‐term attachment stability and sought to identify predictors of stability and change within a sample characterized by fathers' alcoholism. Results suggest moderate stability of attachment classifications (60% for mothers, 53% for fathers) from 12 to 18 months. Higher paternal and maternal alcohol symptoms, maternal depression, and maternal antisocial behavior were found in families with stable insecure mother–infant attachment compared to those who were stable secure. Mother–infant stable insecurity was associated with higher levels of maternal negative affect expression during play. Father–infant stable insecurity was associated with lower levels of paternal positive affect expression and decreased sensitivity during play. Stable insecure children also had higher levels of negative affect during parent–infant interactions and higher negative emotionality during other episodes compared to stable secure children. Results indicate that infants who were insecure at both time points had the highest constellation of family risk characteristics.