bluuebunny/crossref_metadata_2025_split huggingface dataset:
Association of β‐Blocker Dose with Serum Procollagen Concentrations and Cardiac Response to Spironolactone in Patients with Heart Failure
Authors: Cavallari Larisa H. , Momary Kathryn M. , Groo Vicki L. , Viana Marlos A. G. , Camp Joseph R. , Stamos Thomas D. 
Published: June 2007

Study Objective. To determine whether β‐blocker dose influences cardiac collagen turnover and the effects of spironolactone on cardiac collagen turnover in patients with heart failure.Design. Prospective clinical study.Setting. Two heart failure centers.Patients. Eighty‐eight spironolactone‐naïve patients with heart failure who were taking β‐blockers.Intervention. In a subset of 29 patients, spironolactone was started at 12.5 mg/day with the dosage titrated to 25 mg/day if tolerated.Measurements and Main Results. Venous blood samples were collected from each patient. Serum procollagen type I and type III aminoterminal peptides (PINP and PIIINP) were determined by radioimmunoassay and compared between the 25 patients receiving low doses (< 50% of recommended target dose) and the 63 patients receiving high doses (≥ 50% of recommended target dose) of β‐blockers. Patients receiving low‐dose β‐blockers had higher mean ± SD PIIINP concentrations (6.6 ± 3.5 vs 4.9 ± 2.6 μg/L, p=0.03) and tended to have higher PINP concentrations (74.0 ± 44.1 vs 57.1 ± 28.6 μg/L, p=0.10) compared with those receiving high doses. A repeat blood sample was collected from the 29 patients who received spironolactone after 6 months of therapy. Changes in procollagen peptides also were compared in this subset between low‐dose (9 patients) and high‐dose (20 patients) β‐blocker groups. Low β‐blocker doses were associated with greater reductions in concentrations of PINP (median [intraquartile range] −14.3 μg/L [‐9.8 to −19.3 μg/L] vs −2.5 μg/L [5.9 to −9.8 μg/L], p=0.02) and PIIINP (‐1.4 μg/L [‐0.9 to −2.4 μg/L] vs 0.1 μg/L [0.9 to −1.3 μg/L], p=0.045) with spironolactone therapy than high β‐blocker doses. In addition, 100% of the patients in this subset taking low‐dose β‐blockers versus only 35% taking higher doses had reductions in both markers of cardiac fibrosis.Conclusion. Spironolactone may benefit patients with heart failure who cannot tolerate upward titration of β‐blocker dosages, at least in terms of its effects on cardiac remodeling.
Peginterferon alfa‐2a versus Peginterferon alfa‐2b as Initial Treatment of Hepatitis C Virus Infection: A Cost‐Utility Analysis from the Perspective of the Veterans Affairs Health Care System
Authors: Yeh Wei‐Shi , Armstrong Edward P. , Skrepnek Grant H. , Malone Daniel C. 
Published: June 2007

Study Objective. To assess the cost‐utility of peginterferon alfa‐2a plus ribavirin, peginterferon alfa‐2b plus ribavirin, and no therapy for treatment‐naïve patients with chronic hepatitis C virus (HCV) infection from the perspective of the Veterans Affairs (VA) health care system by using patient‐reported utility scores.Design. Cost‐utility analysis using a Markov model.Setting. Veterans Affairs health care system.Data Source. Data for the model were obtained from clinical trials and published literature. Data from the VA health care system were used to define the patient cohorts.Measurements and Main Results. A Markov model incorporating transition probabilities between disease health states that depend only on the current health state was developed to simulate the progression of HCV disease. The patient cohorts were a 45‐year‐old male cohort and a 55‐year‐old male cohort, each with liver fibrosis but no cirrhosis. The lifetime expected costs, quality‐adjusted life‐years (QALYs) gained, and incremental net monetary benefit (INMB) with HCV treatments were determined for each cohort by genotype (genotype 1, and genotypes 2 and 3). Both peginterferon regimens were significantly more cost‐effective than no treatment, although no significant differences in costs or QALYs were noted between peginterferon regimens. For the 45‐year‐old cohort with a genotype 1 infection, the INMB was $128,583 (95% confidence interval [CI] $79,279–$177,308) and $128,025 (95% CI $80,425–$173,448) versus no treatment for peginterferon alfa‐2a plus ribavirin and peginterferon alfa‐2b plus ribavirin, respectively. Treatment with either peginterferon regimen produced significantly lower lifetime HCV‐related medical costs for genotype 2 or 3 infections, but not genotype 1.Conclusions. Peginterferon alfa‐2a plus ribavirin and peginterferon alfa‐2b plus ribavirin were found to be cost‐effective treatments for patients with HCV infections, particularly with genotypes 2 and 3. However, no significant differences in costs or efficacy were observed between these peginterferon treatment regimens.
Absence of an Interaction Between Tigecycline and Digoxin in Healthy Men
Authors: Zimmerman James J. , Harper Dawn M. , Matschke Kyle , Speth John L. , Raible Donald G. , Fruncillo Richard J. 
Published: June 2007

Study Objective. To evaluate a potential interaction between tigecycline and digoxin using pharmacokinetic and pharmacodynamic assessments.Design. Open‐label, three‐period, one‐sequence crossover study.Setting. Hospital‐affiliated, inpatient clinical pharmacology unit.Subjects. Twenty healthy men.Intervention. Tigecycline 100 mg was administered intravenously as a single dose on day 1 (period 1). Digoxin was administered as a 0.5‐mg oral loading dose on day 7, followed by 0.25 mg/day on days 8–14 (period 2). Digoxin 0.25 mg/day was continued on days 15–19; in addition, on day 15, a loading dose of tigecycline 100 mg was administered intravenously, followed by 50 mg every 12 hours starting on the evening of day 15 through the morning of day 19 (period 3).Measurements and Main Results. Pharmacokinetic assessments were performed on days 1 and 19 for tigecycline and on days 14 and 19 for digoxin. Electrocardiographic parameters were measured at baseline and on days 1, 14, and 19 to assess digoxin pharmacodynamics. Serum tigecycline concentrations were determined by liquid chromatography with tandem mass spectrometry detection, and plasma and urine digoxin concentrations were determined by radioimmunoassay. Tigecycline area under the concentration‐time curve (AUC), AUC from 0–12 hours (AUC0–12), weight‐normalized clearance, and mean resistance time were not affected by concomitant multiple‐dose digoxin administration, but tigecycline half‐life was decreased during period 1, apparently due to fewer detectable terminal concentrations in some subjects. Digoxin steady‐state AUC0–24, weight‐normalized oral dose clearance, cumulative amount of drug excreted in urine over 24 hours, renal clearance, and QTc (change from baseline) were not affected by multiple‐dose tigecycline administration.Conclusion. No significant effects of tigecycline on digoxin pharmacokinetics and pharmacodynamics were noted, but a small effect of digoxin on tigecycline pharmacokinetics cannot be ruled out due to design issues with period 1 of the study.
Assessment of ground improvement work using radioisotope cone penetrometers
Authors: Shrivastava A. K. 
Published: June 2007

The effectiveness of radioisotope cone penetrometers (RIcones) under various soil conditions is now well established. This paper briefly describes the design of RI-cones, and the advantages associated with their use. Two case histories are presented in which these cone penetrometers were utilised to investigate their effectiveness in ground improvement works. Both case histories involve land reclamation work. In one, reclamation was effected by hydraulically placing the fly ash obtained from a nearby coal-fired power plant, and in the other, the reclamation of land from sea was effected by pluviating sand by a conveyor belt system. It has been shown that RI-cones can detect any small changes in the density profile, which can result in large savings in a project involving millions of cubic metres of sand. L'efficacité des pénétrateurs cônes radio-isotopes (cônes RI) est désormais bien établie, et ce dans des conditions de sol variées. Cet article décrit brièvement la conception des cônes RI et les avantages associés à leur utilisation. Il présente deux études de cas dans lesquelles ces pénétromètres cônes ont é té utilisés pour évaluer leur efficacité dans des travaux d'amélioration de terrain. Ces deux é tudes comportaient des travaux de réhabilitation de terrain. Dans le premier scénario, la réhabilitation est réalisée par la déposition hydraulique de cendres volantes issues d'une centrale électrique au charbon à proximité. Dans le second, elle est effectuée par pluviation de sable par un système de courroie transporteuse. Il est ici démontré que les cônes RI peuvent détecter même de faibles changements dans le profil de densité, ce qui peut permettre de réaliser d'importantes économies dans un projet impliquant des millions de mètres cubes de sable.
Mitigation of liquefaction hazard by dynamic compaction
Authors: Majdi A. , Soltani A. Sharifi , Litkouhi S. 
Published: June 2007

The tendency to apply soil improvement techniques in comparison with conventional remedial methods has been widely increasing in Iran, especially over the past decade. This is because these techniques are less time-consuming and more cost-effective. The risk of liquefaction at the Caspian Sea Republics Oil Swap (CROS) project site for loose saturated sandy layers down to 13 m was revealed subsequent to completion of the geotechnical investigations. Following a detailed study, dynamic compaction was selected to be the best option, especially for the foundations of the nine oil tanks at the site. To determine the dynamic compaction pattern, including the optimum number of drops, total energy and height of drop, a detailed trial programme was carried out. This included drilling boreholes, cone penetration test and standard penetraiton test performance and trial tamping as well as heave tests. The results were quite satisfactory, and the liquefaction hazard was well mitigated. Because of the lack of time, no ageing effect was investigated. L'approche consistant à appliquer des techniques d'amé-lioration des sols en comparaison avec les méthodes de traitement conventionnelles s'est répandue en Iran, particuliè rement ces dix dernières années. En effet, ces techniques sont plus économiques et permettent de ne pas perdre de temps. Les études géotechniques réalisées sur le site du projet CROS ont permis de révéler le risque de liquéfaction pour les couches sableuses saturées et meubles jusqu'à 13 m de profondeur. Après une é tude détaillèe, il a é té décidé que la compaction dynamique offrait la meilleure solution, en particulier pour les fondations des neufs réservoirs de pétrole sur le site. Un programme d'essais détaillé a été mis en place pour déterminer le profil de compaction dynamique, y compris le nombre optimal de chutes de pilon et l'énergie totale et la hauteur de chute. Il comprenait le creusement de trous de forage, la réalisation de tests de performance CPT et SPT, un damage d'essai et des tests de soulèvement. Les résultats obtenus sont satisfaisants et le risque de liquéfaction a puêtre bien atténué. En raison du manque de temps à disposition, il n'a pas é té possible d'étudier les effets du vieillissement.
Effect of preloading on the cyclic strength of reconstituted sand
Authors: Stamatopoulos C. , Stamatopoulos A. 
Published: June 2007

The effect of preloading on the cyclic soil strength under level ground was investigated by cyclic direct-shear tests where horizontal shear stress oscillated about a zero mean value. Tests on reconstituted samples were performed on two different sands and at varying prestress ratios, densities and vertical stresses. Test results showed a marked increase of the cyclic soil strength with the prestress ratio. The effect is more pronounced for the looser specimens. Arelationship giving the increase of the cyclic strength of sands with the prestress ratio is proposed. This relationship predicted reasonably well the increase in cyclic soil strength measured in previous laboratory studies. The domain of validity of this equation and the manner in which it can be used for ground modification projects under earthquakes are discussed.On étudie ici l'effet du préchargement sur la résistance cyclique du sol en dessous de la surface à niveau au moyen d'essais cycliques de cisaillement direct où la contrainte de cisaillement oscillait autour d'une valeur moyenne nulle. Des tests, réalisés sur des échantillons reconstitués, ont étéeffectués sur deux types de sables et pour des rapports de précontrainte, densités et contraintes verticales variables. Les résultats ainsi obtenus montrent une augmentation significative de la résistance cyclique du sol avec le rapportde précontrainte. Ce phénoméne est encore plus marqué pour les échantillons les plus meubles. Il est proposé uneéquation donnant l'augmentation de la résistance cyclique des sables en fonction du rapport de prélcontrainte. Cetterelation a permis de prédire de maniére relativement satisfaisante l'augmentation de résistance cyclique du solmesurée dans des é tudes de laboratoire précédentes. Ondiscute ici également du domaine de validité de cette équation et de la façon dont elle peut être appliquée auxprojets d'amélioration des sols soumis à des tremblementsde terre.
Settlement of circular foundations on stone-column-reinforced grounds
Authors: Elshazly H. , Hafez D. , Mossaad M. 
Published: June 2007

Most of the available methods of settlement prediction for foundations on stone-column-reinforced grounds assume infinitely extended foundations on infinite grids of columns. Nevertheless, the real performance of a foundation with finite size is believed to differ from that of a corresponding foundation with infinite size. In the current paper, foundations with real sizes in the common engineering range are analysed. To cover various site conditions, both homogeneous and stratified weak soils are considered. In order to obtain reliable results, a well-tested advanced nonlinear finite element code is used in the modelling. Moreover, field load test results are utilised to calibrate the mathematical model. In the simulation, the post-installation in situ stress state is included in order to ensure that the mathematical model is capable of reproducing the field settlement records. It was shown that composite grounds with the same stone replacement ratio under structures with different sizes lead to different settlement improvement degrees. La plupart des méthodes disponibles pour la prédiction du tassement des fondations sur un terrain renforcé par des colonnes de pierre prennent pour hypothèse des fondations étendues à l'infini selon des maillages infinis de colonnes. On pense cependant que les performances réelles d'une fondation de dimension finie diffèrent de celles d une fondation correspondante de dimension infinie. Cet article étudie des fondations de dimensions réelles dans le domaine d ingénierie courant. Afin de couvrir diverses conditions de site, on examine des sols mous stratifiés et homogènes. Pour obtenir des résultats fiables, on applique dans la modélisation un code d analyse linéaire élaboré à éléments finis parfaitement éprouvé. Des résultats d'essais de charge in situ sont également utilisés pour étalonner le modèle mathématique. La simulation intègre l état de contrainte in situ après installation afin de s assurer que le modèle mathématique est capable de reproduire les relevés de tassement sur le terrain. Il a été montré que des sols composites avec le même taux de remplacement de pierre sous des structures de dimensions différentes atteignent des niveaux d'amélioration du tassement différents.
Tire Energy Loss from Obstacle Impact
Authors: Rhyne Timothy B. , Cron Steven M. 
Published: June 2007

Abstract
Tires in actual service conditions operate on rough roads with a random distribution of obstacles. Rolling resistance, however, is typically measured on smooth surfaces. This paper considers the nature of tire energy loss when impacting obstacles. It is demonstrated by a simple example that translational energy can be “lost,” even in purely elastic impacts, by trapping energy in structural vibrations that cannot return the energy to translation during the restitution phase of the impact. Tire simulations and experiments demonstrate that this dynamic energy loss can be very large in tires if the impact times are short. Impact times indicating the potential for large energy loss are found to be in the range of normal highway speeds.
Memories of a 'decision‐map': Recall of a real‐life decision
Authors: Galotti Kathleen M. 
Published: June 2007

AbstractFirst‐year students in college who had participated in a study of college‐decision‐making 8 to 20 months earlier were asked to recall the criteria they had used and the alternatives they had considered in making the decision. They were also asked to describe the criteria they thought, in retrospect, that they ought to have used, and to rate their satisfaction with the decision‐making process and its outcome. Two hundred and seven of the original 322 participants responded to a follow‐up questionnaire through the mail. Participants recalled about half of the criteria they originally reported using, and about two‐thirds of the schools they originally reported considering. Their recall of criteria was affected by their current view of teh criteria they should have used, providing a replication for previous findings. No gender or academic ability effects were found. Somewhat surprisingly, given existing literature, recall was unaffected by emotional responses to the decision, either those reported during the decision‐making process or those reported retrospectively. Overall, the pattern of results suggests that memory is affected by a decision‐maker's current cognitive framework of the decision, specifically, their retrospective view of how they ought to have made the decision. Moreover, memory is far from perfect, even for stimuli that the decision‐maker generated her‐ or himself, and to which presumably, they gave significant amounts of thought.
Measures of feeling‐of‐knowing accuracy: A new look at an old problem
Authors: Schraw Gregory 
Published: June 2007

AbstractTwo ordinal measures of feeling‐of‐knowing performance appropriate for n × n data arrays are reviewed. Goodman and Kruskal's gamma provides a measure of association between recognition performance and feeling‐of‐knowing judgements. The Hamann coefficient provides a measure of agreement accuracy. The relative strengths and weaknesses of each measure are compared at length. A proof is provided, which reveals a lack of one‐to‐one relation between the two and suggests that they may be independent under most circumstances. It is concluded that both measures should be reported together as complementary indices as each captures a different facet of feeling‐of‐knowing performance. Alternative measures for gamma and the Hamann coefficient are considered and a number of recommendations are made for future research.
The overjustification effect: A meta‐analysis
Authors: Tang Shu‐Hua , Hall Vernon C. 
Published: June 2007

AbstractThis article reports the results of a meta‐analysis using 50 experimental studies (256 effect sizes) of the overjustification effect. In general, we found support for the effect across age, dependent measure, and design type in specific situations where it is predicted to occur. Findings are less supportive of the theory for situations where there should be no difference between experimental and control groups (e. g. non‐contingent or unexpected reward). Suggestions for future research are made.
Highly Enantioselective Synthesis of Arylaliphatic Tertiary Alcohols using Mutants of an Esterase from Bacillus subtilis
Authors: Kourist Robert , Bartsch Sebastian , Bornscheuer Uwe T. 
Published: June 2007

AbstractThe kinetic resolution of a series of acetates of arylaliphatic tertiary alcohols was studied using recombinant esterase variants from Bacillus subtilis (BS2) expressed in E. coli. Highest enantioselectivities (E>100) were achieved in the synthesis of 1,1,1‐trifluoro‐2‐phenylbut‐3‐yn‐2‐ol and three para‐substituted analogues using BS2 mutant G105A. With mutant E188D only two compounds were converted with E>100. For a thiophene analogue or compounds with small variations in the aliphatic chain substantially lower conversions and/or enantioselectivity were observed, which also varied with the BS2 variant used. Thus, small changes in the substrate structure and point mutations in the esterase had a remarkable influence on both activity and enantioselectivity.
Stereo‐Complementary Two‐Step Cascades Using a Two‐Enzyme System Leading to Enantiopure Epoxides
Authors: Seisser Birgit , Lavandera Iván , Faber Kurt , Spelberg Jeffrey H. Lutje , Kroutil Wolfgang 
Published: June 2007

AbstractA novel one‐pot, two‐step, two‐enzyme cascade is described. Pro‐chiral α‐chloro ketones are stereoselectively reduced to the corresponding halohydrins as an intermediate by a biocatalytic hydrogen transfer process. The intermediate is transformed to the corresponding epoxide by a non‐enantioselective halohydrin dehalogenase. Thus, by combining a Prelog‐ or anti‐Prelog alcohol dehydrogenase with a non‐selective halohydrin dehalogenase, enantiopure (R)‐ as well as (S)‐epoxides were obtained.
Enzyme‐Promoted Desymmetrisation of Prochiral Bis(cyanomethyl) Sulfoxide
Authors: Kiełbasiński Piotr , Rachwalski Michał , Mikołajczyk Marian , Szyrej Małgorzata , Wieczorek Michał W. , Wijtmans Roel , Rutjes Floris P. J. T. 
Published: June 2007

AbstractProchiral bis(cyanomethyl) sulfoxide has been successfully transformed into the corresponding optically active mono amide and mono acid with enantiomeric excesses ranging from low (10 %) to very high (up to 99 %) using a broad spectrum of nitrile‐hydrolysing enzymes.
Laccase‐Catalyzed Dimerization of Hydroxystilbenes
Authors: Ponzoni Chiara , Beneventi Elisa , Cramarossa Maria Rita , Raimondi Stefano , Trevisi Giulia , Pagnoni Ugo Maria , Riva Sergio , Forti Luca 
Published: June 2007

AbstractA series of hydroxystilbenes, analogues of the bioactive phytoalexin resveratrol, were synthesized and submitted to the catalytic action of a laccase from Trametes pubescens in a biphasic system made of ethyl acetate and acetate buffer. Oxidation took place at the 4′‐hydroxy (4‐hydroxy) position of the hydroxystilbenic moieties, followed by radical‐radical coupling dimerization reactions. Most of the products were isolated in good yields and fully characterized. Depending on the substrates, three different dimeric products could be identified, the main products usually being 4‐O‐α‐ß‐5 (dihydrofuran‐like) dimers.
Altering the Substrate Specificity and Enantioselectivity of Phenylacetone Monooxygenase by Structure‐Inspired Enzyme Redesign
Authors: Pazmiño Daniel E. Torres , Snajdrova Radka , Rial Daniela V. , Mihovilovic Marko D. , Fraaije Marco W. 
Published: June 2007

AbstractOf all presently available Baeyer–Villiger monooxygenases, phenylacetone monooxygenase (PAMO) is the only representative for which a structure has been determined. While it is an attractive biocatalyst because of its thermostability, it is only active with a limited number of substrates. By means of a comparison of the PAMO structure and a modeled structure of the sequence‐related cyclopentanone monooxygenase, several active‐site residues were selected for a mutagenesis study in order to alter the substrate specificity. The M446G PAMO mutant was found to be active with a number of aromatic ketones, amines and sulfides for which wild‐type PAMO shows no activity. An interesting finding was that the mutant is able to convert indole into indigo blue: a reaction that has never been reported before for a Baeyer–Villiger monooxygenase. In addition to an altered substrate specificity, the enantioselectivity towards several sulfides was dramatically improved. This newly designed Baeyer–Villiger monooxygenase extends the scope of oxidation reactions feasible with these atypical monooxygenases.