bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influencing models to improve their predictions of standard samples
Authors: DiFoggio Rocco 
Published: August 2007

AbstractThis paper generalizes the Lagrange multiplier solution for a regression subject to inhomogeneous (d ≠ 0) linear equality constraints, Vb′= d, to the case where these constraints are only partially satisfied. It extends the work of an earlier paper that generalized the Lagrange multiplier solution for a regression subject to homogeneous (d = 0) linear equality constraints, Vb′ = 0. With this method, we can insure that our chemometric models predict known standard samples more accurately by making such samples more influential. For example, we can include samples from a particular locale in a calibration set as sample ‘standards’ to create a ‘tuned’ model, b′ from a generic model, b, that is based on samples from a wider geographical area. We introduce new ways to adjustably control a sample's influence and show why they are preferable to simply including that sample multiple times. One new way is to use simultaneous counterbalanced sample‐pair distortion of both X and Y blocks. Another is to generalize the Lagrange multiplier solution that allows the constraints Vb′ = d to be only partially satisfied, which is important when the constraints interfere so that a perfect fit to one standard sample prevents a perfect fit to another standard sample. Some advantages of these new methods are that they cause no frequency filtering of the X‐block, which might remove information, and they allow the user to minimize the standard error of prediction by optimizing influence. Copyright © 2007 John Wiley & Sons, Ltd.
Small sample and selection bias effects in calibration under latent factor regression models
Authors: Sundberg Rolf 
Published: August 2007

AbstractWe study bias of predictors when a multivariate calibration procedure has been applied to relate a scalary(concentration of an analyte, say) to a vector x (spectral intensities, say). The model for data is assumed to be of latent factor regression type, with multiple regression models and errors‐in‐variables models as special cases. The calibration procedures explicitly studied are OLSR, PLSR and PCR. Often a practical device to increase precision in the calibration is to selectymore or less systematically, in order to achieve increased variation (overdispersion). However, this leads to biased coefficients in the predictor, possible to see when observed ityis regressed on predicted ŷ (x) for a separate validation set. Another bias effect is a sample size effect, increasing with reduced calibration sample size and with increasing dimension of x (absent when x is univariate). Formulae are given for these bias effects, both separately and in combination, and the formulae are illustrated and compared with simulation results. As a qualitative example, PLSR and PCR are less sensitive than OLSR to small samples, but equally sensitive to selection. Copyright © 2007 John Wiley & Sons, Ltd.
Structural, Kinetic, and Theoretical Studies on Models of the Zinc‐Containing Phosphodiesterase Active Center: Medium‐Dependent Reaction Mechanisms
Authors: Selmeczi Katalin , Michel Carine , Milet Anne , Gautier‐Luneau Isabelle , Philouze Christian , Pierre Jean‐Louis , Schnieders David , Rompel Annette , Belle Catherine 
Published: August 2007

AbstractDinuclear zinc(II) complexes [Zn2(bpmp)(μ‐OH)](ClO4)2 (1) and [Zn2(bpmp)(H2O)2](ClO4)3 (2) (H‐BPMP=2,6‐bis[bis(2‐pyridylmethyl)aminomethyl]‐4‐methylphenol) have been synthesized, structurally characterized, and pH‐driven changes in metal coordination observed. The transesterification reaction of 2‐hydroxypropyl p‐nitrophenyl phosphate (HPNP) in the presence of the two complexes was studied both in a water/DMSO (70:30) mixture and in DMSO. Complex 2 was not reactive whereas for 1 considerable rate enhancement of the spontaneous hydrolysis reaction was observed. A detailed mechanistic investigation by kinetic studies, spectroscopic measurements (1H, 31P NMR spectroscopy), and ESI‐MS analysis in conjunction with ab initio calculations was performed on 1. Based on these results, two medium‐dependent mechanisms are presented and an unusual bridging phosphate intermediate is proposed for the process in DMSO.
Transsialidase from Trypanosoma cruzi for Regio‐ and Stereoselective Synthesis of N‐Acyl‐Modified Sialylated Oligosaccharides and Measurement of Transfer Rates
Authors: Schroven Andreas , Meinke Sebastian , Ziegelmüller Patrick , Thiem Joachim 
Published: August 2007

AbstractRecombinant transsialidase from Trypanosoma cruzi (TcTS) was used for the sialylation with natural and non‐natural derivatives of neuraminic acid. Neu5Ac‐α(2→3)‐Gal‐β(1→6)‐Glc‐αOMe was prepared in 80 % yield. Correspondingly, the modified trisaccharide derivatives Neu5Prop‐α(2→3)‐Gal‐β(1→6)‐Glc‐αOMe (32 %) and Neu5Gc‐α(2→3)‐Gal‐β(1→6)‐Glc‐αOMe (Prop=propanoyl, Gc=glycolyl) were obtained in 60 % yield, respectively.
Extracardiac Medical and Neuromuscular Implications in Restrictive Cardiomyopathy
Authors: Stöllberger Claudia , Finsterer Josef 
Published: August 2007

AbstractRestrictive cardiomyopathy (RCMP) is characterized by restrictive filling and reduced diastolic volume of either or both ventricles with normal or near‐normal systolic function and wall thickness. It may occur idiopathically or as a cardiac manifestation of systemic diseases such as scleroderma, amyloidosis, Churg‐Strauss syndrome, cystinosis, sarcoidosis, lymphoma, Gaucher's disease, hemochromatosis, Fabry's disease, pseudoxanthoma elasticum, hypereosinophilic syndrome, carcinoid, Noonan's syndrome, reactive arthritis, or Werner's syndrome and various neuromuscular disorders. Whereas in idiopathic RCMP the therapeutic options are only treatment of cardiac congestion, in cases with an underlying disorder, a causal therapy may be available. Patients with RCMP should be investigated as soon as the cardiac diagnosis is established for extracardiac diseases to detect a possibly treatable cause of RCMP before the disease becomes intractable. These investigations include a diligent clinical history and examination, blood tests, and ophthalmologic, otologic, dermatologic, gastroenterologic, nephrologic, hematologic, and neurologic examinations. If extracardiac examinations do not reveal a plausible cause for RCMP, endomyocardial biopsy is indicated. Copyright © 2007 Royal Meteorological Society
Inflammatory Biomarkers are not Predictive of Intermediate‐term Risk of Ventricular Tachyarrhythmias in Stable CHF Patients
Authors: Konstantino Yuval , Kusniec Jairo , Reshef Tamar , David‐Zadeh Ofer , Mazur Alexander , Strasberg Boris , Battler Alexander , Haim Moti 
Published: August 2007

AbstractBackground:Elevated levels of inflammatory biomarkers and brain natriuretic peptide (BNP) are associated with increased mortality in patients with heart failure (HF).Hypothesis:The aim of the current study was to assess the correlation between circulating biomarkers and ventricular tachyarrhythmias among patients with HF.Methods:Blood samples from 50 stable ambulatory HF patients with moderate to severe systolic left ventricular (LV) dysfunction and an implantable cardioverter defibrillator (ICD) were analyzed for interleukin 6 (IL‐6), tumor necrosis factor‐alpha (TNF‐α), high‐sensitivity C‐reactive protein (hsCRP) and BNP. Thereafter, the patients were followed for a mean period of 152 ± 44 days, during which ventricular tachyarrhythmias were recorded by the ICDs.Results:Follow‐up data were obtained from 47 patients. Of them, 45 (96%) had ischemic cardiomyopathy, 38 (81%) had New York Heart Association class I–II, 43 (91%) were males, and the mean age was 68.6 ± 11.1 years. During follow‐up, 5 patients (11%) had nonsustained ventricular tachycardia (NSVT), 6 patients (13%) had sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) and 36 patients (76%) had no events. The circulating biomarkers' levels upon enrollment were not significantly different between patients who subsequently had NSVT or VT/VF and patients who were free of events.Conclusions:No correlation was found between plasma levels of IL‐6, TNF‐α, hsCRP and BNP and ventricular arrhythmic events among stable HF patients during an intermediate term follow‐up of 5.1 months. Further studies are still required to assess the association between these biomarkers and long‐term risk of ventricular tachyarrhythmia. Copyright © 2007 Wiley Periodicals, Inc.
Normalization of Abnormal T‐waves During Stress Testing does not Identify Patients with Reversible Perfusion Defects
Authors: Loeb Henry S. , Friedman Nicholas C. 
Published: August 2007

AbstractObjective:To determine if T‐wave normalization during exercise or dobutamine stress testing identified patients with myocardial ischemia as indicated by reversible perfusion defects.Methods:Exercise or dobutamine stress tests with perfusion scintigraphy were performed in 1,173 patients with abnormal T‐waves on their baseline electrocardiograms. The results of perfusion scintigraphy were compared in patients with and without stress‐induced T‐wave normalization.Results:Only 33 of 270 patients with reversible perfusion defects (12.2%) had T‐wave normalization during stress while 76.4% of 140 patients who had T‐wave normalization during stress did not have a reversible perfusion defect. Results were similar for patients who did or did not reach 85% of their maximal predicted heart rate, for patients with and without Q‐wave infarction on the baseline EKG and for patients who did or did not have ischemic ST‐segment depression during stress.Conclusions:T‐wave normalization during stress testing has low sensitivity and poor positive predictive value for stress‐induced reversible myocardial ischemia. Copyright © 2007 Wiley Periodicals, Inc.
Severity of Coronary Artery Disease in Obese Patients Undergoing Coronary Angiography: “Obesity Paradox” Revisited
Authors: Niraj Ashutosh , Pradahan Jyotiranjan , Fakhry Hesham , Veeranna Vikas , Afonso Luis 
Published: August 2007

AbstractBackground:Recent studies have highlighted the existence of an ‘obesity paradox’ in patients undergoing coronary angiography, i.e., a high body mass Index (BMI) is associated with less severe coronary lesions. We sought to confirm the existence of this phenomenon in the US patient population.Methods:Study subjects included 770 consecutive patients (470 men, 428 African‐Americans, 212 Caucasians) referred for coronary angiography to a tertiary care center. Duke myocardial jeopardy score, a prognostication tool predictive of 1‐year mortality in coronary artery disease (CAD) patients, was assigned to angiographic data. Patients were classified according to their BMI (kg/m2) as normal (21–24), overweight (25–29), obesity class I (30–34), class II (35–39) and class III (40 or above).Results:Patients in the increasing obesity class had a higher prevalence of diabetes, hypertension and dyslipidemia and were more likely to be women. A negative correlation was observed between BMI and age (R = − 0.15 p < 0.001) as well as between BMI and Duke Jeopardy score (r = − 0.07, p < 0.05) indicating that patients with higher BMI were referred for coronary angiography at a younger age, and had a lower coronary artery disease (CAD) burden. BMI was not an independent predictor of coronary lesion severity on multivariate stepwise linear regression analysis.Conclusion:Obese patients are referred for coronary angiography at an earlier age and have a lower CAD burden lending further credence to the existence of an apparent “obesity paradox”. However, obesity per se, after adjustment for comorbidities, is not an independent predictor of severity of coronary artery disease. Copyright © 2007 Wiley Periodicals, Inc.
Octa‐O‐bis‐(R,R)‐Tartarate Ditellurane (SAS)—a Novel Bioactive Organotellurium(IV) Compound: Synthesis, Characterization, and Protease Inhibitory Activity
Authors: Yosef Sigal , Brodsky Miri , Sredni Benjamin , Albeck Amnon , Albeck Michael 
Published: August 2007

AbstractOcta‐O‐bis‐(R,R)‐Tartarate Ditellurane (SAS) is a new TeIV compound, comprised of two tellurium atoms, each liganded by four oxygen atoms from two carboxylates and two alkoxides of two tartaric acids. Unlike many other TeIV compounds, SAS was highly stable in aqueous solution. It interacted with thiols to form an unstable Te(SR)4 product. The product of the interaction of SAS with cysteine was isolated and characterized by mass spectroscopy and elemental analysis. SAS selectively inactivated cysteine proteases, but it did not inactivate other families of proteolytic enzymes. It displayed selectivity towards the cysteine protease cathepsin B, a human enzyme of pharmaceutical interest, with a second order rate constant ki/Ki=5900 M−1 s−1.
Contra‐thermodynamic Behavior in Intermolecular Hydrogen Transfer of Alkylperoxy Radicals
Authors: Pfaendtner Jim , Broadbelt Linda J. 
Published: August 2007

AbstractQuantum chemical investigation of bimolecular hydrogen transfer involving alkylperoxy radicals, a key reaction family in the free‐radical oxidation of hydrocarbons, was performed to establish structure–reactivity relationships. Eight different reactions were investigated featuring four different alkane substrates (methane, ethane, propane and isobutane) and two different alkylperoxy radicals (methylperoxy and iso‐propylperoxy). Including forward and reverse pairs, sixteen different activation energies and enthalpies of reaction were used to formulate structure–reactivity relationships to describe this chemistry. We observed that the enthalpy of formation of loosely bound intermediate states has a strong inverse correlation with the overall heat of reaction and that this results in unique contra‐thermodynamic behavior such that more exothermic reactions have higher activation barriers. A new structure–reactivity relationship was proposed that fits the calculated data extremely well: EA=Eo+αΔHrxn where α=−0.10 for ΔHrxn<0, and α=1.10 for ΔHrxn>0 and Eo=3.05 kcal mol−1.
57Fe Mössbauer Spectroscopy and Electron Microscopy Study of Metal Extraction from CuFe2O4 Electrodes in Lithium Cells
Authors: Bomio Mauricio , Lavela Pedro , Tirado José Luis 
Published: August 2007

AbstractActive CuFe2O4 electrode materials for lithium cells are produced by thermal decomposition of a citrate precursor. The precipitation of the metal citrate is carried out by a freeze‐drying procedure. A tetragonally distorted spinel structure is prepared by the decomposition of a citrate precursor. Samples free of impurities are obtained depending on the annealing temperature. The sample heated at 800 °C performed at 470 mAh g−1 after 50 cycles. Electron microscopy is used as the ultimate technique to monitor the morphological changes upon the reversible conversion reaction. Detachment of metallic particles from the starting material, the formation of a polymeric organic film, and the subsequent removal on charging are discussed as determining factors in the electrochemical behaviour of this oxide as an electrode versus lithium. The growth of metallic iron aggregates is inferred from the 57Fe Mössbauer spectra.
Dipole Moment Enhancement in Molecular Crystals from X‐ray Diffraction Data
Authors: Spackman Mark A. , Munshi Parthapratim , Dittrich Birger 
Published: August 2007

AbstractAlthough reliable determination of the molecular dipole moment from experimental charge density analyses on molecular crystals is a challenging undertaking, these values are becoming increasingly common experimental results. We collate all known experimental determinations and use this database to identify broad trends in the dipole moment enhancements implied by these measurements as well as outliers for which enhancements are pronounced. Compelling evidence emerges that molecular dipole moments from X‐ray diffraction data can provide a wealth of information on the change in the molecular charge distribution that results from crystal formation. Most importantly, these experiments are unrivalled in their potential to provide this information in such detail and deserve to be exploited to a much greater extent. The considerable number of experimental determinations now available has enabled us to pinpoint those studies that merit further attention, either because they point unequivocally to a considerable enhancement in the crystal (of 50 % or more), or because the experimental determinations suggest enhancements of 100 % or more—much larger than independent theoretical estimates. In both cases further detailed experimental and theoretical studies are indicated.
Single Dibenzoterrylene Molecules in an Anthracene Crystal: Main Insertion Sites
Authors: Nicolet Aurélien A. L. , Bordat Patrice , Hofmann Clemens , Kol'chenko Mikhail A. , Kozankiewicz Boleslaw , Brown Ross , Orrit Michel 
Published: August 2007

AbstractWe present a spectroscopic study of the properties of the two principal insertion sites (at 785.1 and 794.3 nm) of single dibenzoterrylene molecules in anthracene single crystals at cryogenic temperatures. We measured the temperature dependence of the line width, the orientation of the transition dipole moments, and the Stark effect. We performed molecular dynamics simulations, which show that one dibenzoterrylene molecule preferably replaces three anthracene molecules. From simulated annealing, we derive the molecular conformations in the most stable insertion sites and the orientations of the transition dipole moments. The good agreement between the spectroscopic results and the simulations allows us to propose unambiguous structures for the two principal spectroscopic sites.
Characteristics of Photoexcitations and Interfacial Energy Levels of Regioregular Poly(3‐hexythiophene‐2,5‐diyl) on Gold
Authors: Sohn Youngku , Stuckless John Todd 
Published: August 2007

AbstractWe have studied characteristics of photoexcitations and interfacial electronic structures of regioregular poly(3‐hexlythiophene‐2,5‐diyl) (P3HT) on gold using two‐photon photoemission (2PPE) spectroscopy. The vacuum level threshold is decreased by 1.3 eV from that of bare gold, attributable to interface dipole effects. The 2PPE spectral width narrows as the film thickness increases. We tentatively understand that this is due to destabilization of long‐lived localized polaron, attributed to strong interchain interactions. On the basis of the analysis of the 2PPE distribution as a function of photon energy and laser power, the polaron level is located at 3.1 eV below the vacuum level. Using this value and a polaron level of 1.75 eV above the HOMO, we indirectly estimate an ionization potential of 4.85 eV for P3HT. An increase in two‐photon photoemission yield with increasing photon energy is attributed to an enhanced electron‐hole pair dissociation yield at higher photo‐excitation levels. The decrease in power law slope with increasing film thickness is understood by Langevin recombination kinetics and saturation of photoexcitations
Light Intensity Effects on Photoinduced Charge Separation Parameters in a Molecular Triad Based on an Iridium(III) Bis(terpyridine) Unit
Authors: Flamigni Lucia , Baranoff Etienne , Collin Jean‐Paul , Sauvage Jean‐Pierre , Ventura Barbara 
Published: August 2007

AbstractThe effect of photon flux on the yield and lifetime of charge separation over the extreme components of a D‐Ir‐A triad, where D is a triphenyl amine electron donor, A is a naphthalene bis(imide) electron acceptor and Ir is an IrIII bis(terpyridine) complex, has been investigated. In usual laboratory conditions, with nanosecond and picosecond laser pulses in the 4–8 mJ range, biphotonic processes take place. Biphotonic products and their evolution can introduce complications in reaction mechanisms and their interpretation but can also drastically reduce the yield and the lifetime of the charge‐separated state. In the present case, after discussion of several possible mechanisms, the process detrimental to charge separation is ascribed to absorption of a photon by the photogenerated charge‐separated state D+‐Ir‐A−.
Metacognitive beliefs and strategies predict worry, obsessive–compulsive symptoms and coping styles: A preliminary prospective study on an Italian non‐clinical sample
Authors: Sica Claudio , Steketee Gail , Ghisi Marta , Chiri Luigi Rocco , Franceschini Sandro 
Published: August 2007

AbstractEighty undergraduate students completed the Italian versions of the Metacognition Questionnaire and Thought Control Questionnaire along with well‐established measures of worry, obsessive–compulsive symptoms and coping styles on two occasions four months apart. A series of hierarchical regression analyses revealed that, after controlling the initial level of both worry and obsessionality, negative beliefs about worry focused on uncontrollability and danger appeared consistently associated with worry and obsessive symptoms at a four‐month distance. In addition, positive beliefs about worry predicted maladaptive coping styles whereas cognitive self‐consciousness and thought strategies aimed at distraction appeared to foster or facilitate adaptive coping styles. Results, implications and limitations are discussed according to Well's metacognitive model of emotional disorders. Copyright © 2007 John Wiley & Sons, Ltd.
Three‐year‐olds' attachment play narratives and their associations with internalizing problems
Authors: Miljkovitch Raphaële , Pierrehumbert Blaise , Halfon Olivier 
Published: August 2007

AbstractRepresentational strategies of emotion regulation during play are believed to protect children against behaviour problems. Yet, before the age of 4, it appears that children rely more on their attachment figure than on representational strategies to assuage distress. The study was aimed at testing whether 3‐year‐olds' narrative features during the Attachment Story Completion Task (ASCT) could predict concurrent internalizing problems assessed by the mothers' and fathers' ratings of the child, using the Child Behaviour Checklist. Regression analyses including gender, IQ, socio‐economic status and ASCT dimensions revealed that representations of supportive caregiving predicted mother‐reported internalizing problems (negative association), whereas positive resolution and attachment strategies (security, deactivation, hyperactivation, disorganization) did not. Results were interpreted with reference to Bowlby's hypotheses regarding the aetiology of depression and anxiety disorders. Copyright © 2007 John Wiley & Sons, Ltd.
Sense of self, adaptation and recovery in patients with psychosis in a forensic NHS setting
Authors: Laithwaite Heather , Gumley Andrew 
Published: August 2007

AbstractQualitative methods have been used to explore users' recovery from psychosis. These studies have highlighted the importance of hope and redefining sense of self as being important aspects of the recovery process. To date there have been no studies that have collaborated with users in high‐security forensic settings to develop an experiential perspective of recovery in psychosis. This study used a social constructionist version of grounded theory to develop an experiential account of recovery in psychosis. Thirteen individuals who had experience of psychosis and were residing in a high‐security setting were interviewed in depth about their experiences of recovery. The interviews were transcribed and analysed using the social constructionist version of grounded theory. Contrasting accounts of recovery were apparent from the way in which participants spoke about their experiences. Some participants gave rich and reflective accounts of their recovery. These participants spoke about the nature of past experiences and the importance of those experiences in contextualizing their problems, and reflected on the implications of this on the tasks of recovery. In contrast, other participants' transcripts tended to be short and unelaborated. Recovery tasks seemed to be segregated from previous experiences and their reflection on their experience of psychosis seemed minimized. However, all participants spoke about the importance of developing relationships with staff and family. The development of relationships influenced how participants redefined themselves. Implications for clinical practice and further research are reviewed. Copyright © 2007 John Wiley & Sons, Ltd.