bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transition metals compounds: Outstanding challenges for multiconfigurational methods
Authors: Pierloot K. 
Published: March 2011

AbstractThe present contribution provides a “perspective” on the work on transition metal (TM) bonding and spectroscopy by Björn O. Roos, performed by means of the CASPT2 method in the period 1992–2010. After giving a short overview of important nondynamic correlation effects appearing in TM atoms and molecules, ample attention is given to the work on the Cr2 molecule and to Björn's fascination for multiple bonds in inorganic molecules containing TM. A short description is also given of his contributions to bioinorganic chemistry, with emphasis on the blue copper proteins. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 111:3291–3301, 2011
Siroheme‐containing sulfite reductase: A density functional investigation of the mechanism
Authors: Silaghi‐Dumitrescu Radu , Makarov Sergei V. 
Published: March 2011

AbstractSiroheme‐containing sulfite reductases (SiR) catalyze the six‐electron reduction of sulfite to sulfide via a mechanism involving sulfite binding at the heme iron. The exact sequence in which the required electrons and protons are delivered to the heme‐bound sulfite has received little attention to date. Here, a detailed account is given of these steps, based on density functional theory, thus providing data for the first attempt to draw a detailed picture of sulfite reduction in SiR by theoretical methods. Parallels are shown with reduction of other small molecules at heme centers: dioxygen (including generation of sulfide high‐valent iron centers akin to hemoproteins Compounds I and II), nitrite (including linkage isomerism akin to the nitro/nitrito known for nitrite reducing proteins), or nitric oxide. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
An adaptive confirmatory trial with interim treatment selection: Practical experiences and unbalanced randomization
Authors: Heritier Stephane , Lô Serigne N. , Morgan Caroline C. 
Published: March 2011

AbstractThis article has been motivated by an ongoing international adaptive confirmatory trial. At the interim analysis of this two‐stage trial, none, one or two active treatment regimens are selected for further study in the second stage. A combination test approach is used in this practical setting with an extension of the theory to unbalanced randomization. We show that a combination test with suitable weights can still preserve the overall Type I error rate provided that the test statistic is chosen appropriately and the unpooledZ‐test for proportions is not used. The accuracy of stagewisep‐values is also discussed in a more general framework. Monte Carlo simulations confirm the validity of the approach retained and evaluate the necessary sample size. Additional issues addressed during the design of the trial are also examined such as multiplicity due to testing hypotheses on key secondary endpoints, a non‐inferiority comparison to an active treatment and covariate adjusted analyses for various types of outcome. Copyright © 2011 John Wiley & Sons, Ltd.
Bias in causal estimates from Mendelian randomization studies with weak instruments
Authors: Burgess Stephen , Thompson Simon G. 
Published: March 2011

AbstractMendelian randomization studies using genetic instrumental variables (IVs) are now being commonly used to estimate the causal association of a phenotype on an outcome. Even when the necessary underlying assumptions are valid, estimates from analyses using IVs are biased in finite samples. The source and nature of this bias appear poorly understood in the epidemiological field. We explain why the bias is in the direction of the confounded observational association, with magnitude relating to the statistical strength of association between the instrument and phenotype. We comment on the size of the bias, from simulated data, showing that when multiple instruments are used, although the variance of the IV estimator decreases, the bias increases. We discuss ways to analyse Mendelian randomization studies to alleviate the problem of weak instrument bias. Copyright © 2011 John Wiley & Sons, Ltd.
Combining multiple continuous tests for the diagnosis of kidney impairment in the absence of a gold standard
Authors: Yu Binbing , Zhou Chuan , Bandinelli Stefania 
Published: March 2011

AbstractReceiver operating characteristic (ROC) curves are commonly used to summarize the classification accuracy of diagnostic tests. It is not uncommon in medical practice that multiple diagnostic tests are routinely performed or multiple disease markers are available for the same individuals. When the true disease status is verified by a gold standard (GS) test, a variety of methods have been proposed to combine such potential correlated tests to increase the accuracy of disease diagnosis. In this article, we propose a method of combining multiple diagnostic tests in the absence of a GS. We assume that the test values and their classification accuracies are dependent on covariates. Simulation studies are performed to examine the performance of the combination method. The proposed method is applied to data from a population‐based aging study to compare the accuracy of three screening tests for kidney function and to estimate the prevalence of moderate kidney impairment. Copyright © 2011 John Wiley & Sons, Ltd.
Reducing false alarms in syndromic surveillance
Authors: Peter William , Najmi Amir H. , Burkom Howard S. 
Published: March 2011

AbstractAlgorithms for identifying public health threats or disease outbreaks are vulnerable to false alarms arising from sudden shifts in health‐care utilization or data participation. This paper describes a method of reducing false alerts in automated public health surveillance algorithms, and in particular, automated syndromic surveillance algorithms, that rely on health‐care utilization data. The technique is based on monitoring syndromic counts with reference to a suitable background, or reference, series of counts. The suitability of the background time series in decreasing the false‐alarm rate will be shown to be related mathematically to the so‐called mutual information that exists between the random variables representing the syndromic and background time series of counts. The method can be understood as a noise cancellation filter technique in which one noisy (reference) channel is used to cancel the background noise of the monitored (measured) channel. The issues discussed here may also be relevant to the appropriate use of rates in epidemiology and biostatistics. Copyright © 2011 John Wiley & Sons, Ltd.
How a new stratified adaptive phase II design could improve targeting population
Authors: Tournoux‐Facon, Caroline , De Rycke Yann , Tubert‐Bitter Pascale 
Published: March 2011

AbstractPhase II clinical trials in oncology are used for initial evaluation of the therapeutic efficacy of a new treatment regimen. Simon's two‐stage or Fleming designs are commonly used for such trials. Treatment effect dilution may be observed because of heterogeneity of the population leading to negative conclusion on the whole population and termination of drug development while patients with particular characteristics may have benefit. Several authors have proposed alternative strategies based on Simon's design, including stratification on the patients' characteristics. In this paper, the authors develop a new stratified phase II design, allowing early stop of the trial for efficacy as it is an extension of Fleming's design. An example based on real data is given and the results from exact binomial calculations are developed to explore several assumptions on response rates, prevalence of each population and errors. Copyright © 2011 John Wiley & Sons, Ltd.
A Bayesian response‐adaptive covariate‐balanced randomization design with application to a leukemia clinical trial
Authors: Yuan Ying , Huang Xuelin , Liu Suyu 
Published: March 2011

AbstractWe propose a Bayesian response‐adaptive covariate‐balanced (RC) randomization design for multiple‐arm comparative clinical trials. The goal of the design is to skew the allocation probability to more efficacious treatment arms, while also balancing the distribution of the covariates across the arms. In particular, we first propose a new covariate‐adaptive randomization (CA) method based on a prognostic score that naturally accommodates continuous and categorical prognostic factors and automatically assigns imbalance weights to covariates according to their importance in response prediction. We then incorporate this CA design into a group sequential response‐adaptive randomization (RA) scheme. The resulting RC randomization design combines the advantages of both CA and RA randomizations and meets the design goal. We illustrate the proposed design through its application to a phase II leukemia clinical trial, and evaluate its operating characteristics through simulation studies. Copyright © 2011 John Wiley & Sons, Ltd.
Die Sondertragwerke der “Mansueto Library” in Chicago – vom Entwurf zum Bau
Authors: Sobek Werner , Blandini Lucio , Krtscha Annette 
Published: March 2011

AbstractDie Bibliothek der Universität Chicago wird momentan durch einen Anbau, die sogenannte Mansueto Library, erweitert. Dieser vom Chicagoer Architekten Helmut Jahn entworfene Anbau wird durch eine weitspannende Stahlgitterschale überdacht, die eine natürliche Belichtung des gesamten Innenraums ermöglicht. Der Erweiterungsbau besteht aus einem ebenerdigen Lesesaal und einem unterirdischen Archivraum. Die gesamte Bibliothek soll bis zu 3 Mio. Bücher beherbergen und wird nach der Eröffnung im Jahr 2011 zu den größten “on‐campus”‐Bibliotheken der Welt zählen. Am Standort des Bibliotheksanbaus gelang übrigens im Dezember 1942 die weltweit erste “self‐sustaining” nukleare Kettenreaktion.Die 36,5 m breite und 73 m lange Translationsschale über dem neuen Lesesaal ist mit bedrucktem Isolierglas eingedeckt, das auf einer minimierten Aluminium‐Unterkonstruktion aufliegt, welche ihrerseits über Abstandhalter auf das Primärtragwerk, eine Gitterschale aus Stahlrohren, aufgeständert ist. Die von Helmut Jahn in enger Zusammenarbeit mit Werner Sobek entworfene transparente Gitterschale kontrastiert eindrucksvoll mit der massiven, gänzlich geschlossenen Hülle der bereits bestehenden Universitätsbibliothek. Der Entwurf besticht durch die Klarheit seiner Formensprache und durch seine große Detailqualität (Bild 1).Im Innern des Neubaus befindet sich eine Reihe von Studienräumen, die als Ganzglaskonstruktion konzipiert wurden. Durch den Einsatz von Glas als statisch tragendem Element kann maximale Transparenz erreicht werden. Eine weitere interessante Sonderkonstruktion, die im Rahmen der Bibliothekserweiterung entsteht, ist die 20 m lange, verglaste Brückenkonstruktion, die den Neubau mit dem Bestandsgebäude verbindet. Der Aufsatz gibt einen Überblick über Entwurf und Bau der Gitterschale und der weiteren Sonderkonstruktionen.The special structures for the Mansueto Library in Chicago. From design to construction. The library of the University of Chicago is currently extended by means of a building directly adjacent to the existing library. The extension building called Mansueto Library – designed by Chicago‐based architect Helmut Jahn – is covered by an all but dematerialized glazed steel grid shell spanning over the reading room. The translational shell is 36.5 m wide and 73 m long. It is clad with fritted insulated glass units lying on minimized aluminium extrusions. The building includes further special structures, such as a 20 m long glazed steel bridge; this bridge connects the new library with the existing building. Another interesting special structure is the row of glazed study rooms: the walls of these rooms are fully transparent due to the use of glass as a loadbearing element. The present article gives an overview of the design and construction of the grid shell and the other special structures.
Geometrie und Tragverhalten von doppelt gekrümmten Ganzglasschalen aus kalt verformten Glaslaminaten
Authors: Fildhuth Thiemo , Knippers Jan 
Published: March 2011

AbstractDie Herstellung doppelt gekrümmter Glaselemente mittels Kaltverformens, wie sie auf der glasstec 2010 vorgestellt wurden, ist vielversprechend für die Verwendung für Ganzglas‐Schalenkonstruktionen, deren optische und technische Qualität auf die Ansprüche der Architektur nach hochtransparenten, sanft gekrümmten Formen reagiert.Die Ergebnisse der Untersuchung von Formgebungs‐ und Materialeigenschaften der kaltgekrümmten Scheiben ermöglichten die Erarbeitung und Vorauswahl entsprechender doppelt gekrümmter Schalengeometrien. Charakteristische Grundformen sind dann Parameterstudien und Sensibilitätsanalysen zur Ermittlung des Tragverhaltens abhängig von Fügung, Lagerung und Einteilung unterzogen worden. Antiklastische Geometrien haben sich dabei als besonders interessant herausgestellt.Research on Glass Shell Design from Double Curved, Cold Bent Glass Laminates.The manufacturability of cold bent, double curved laminated glass panels as presented at glasstec 2010 is promising for the application in full glass membrane shells. Their optical and technical quality meets with the demand of smoothly curved, transparent surfaces in architecture.The material and shape properties of cold bent laminates limit the range of adequate double curved shell geometries. Parametric and sensitivity analyses performed on characteristic shell geometries have been used to explore the structural behaviour and performance of joining, supports and element layout. Especially anticlastic geometries are interesting for such shallow shells.
Zum Biegeverhalten von VSG‐Laminaten unter Quer‐ oder Längsbelastung
Authors: Feldmann Markus , Langosch Katharina 
Published: March 2011

AbstractIn derzeitiger Bemessungspraxis wird eine Verbundwirkung der Zwischenfolie von VSG nicht angesetzt, sofern diese günstig wirkt. Bei ungünstiger Wirkung des Schubverbunds, beispielsweise bei wechselnder Belastung, kann es jedoch durchaus relevant werden, den Schubmodul der Zwischenschicht anzusetzen. Hierzu ist eine übersichtliche Darstellung des Laminatschlupfund ‐biegeverhaltens von Vorteil. Im Aufsatz werden auf Grundlage der Schlupfdifferentialgleichung für verschiedene Arten von Querlasten und Längsbelastung, jeweils bei freiem Endschlupf in der Verbundfuge, die Verformungs‐ und Spannungszeitfunktionen abhängig von Belastung hergeleitet. Ein kurzer Vergleich mit Versuchen und Numerik schließt sich an.Bending behaviour of laminated safety glass subjected to cross or axial loading. According to recent practise the composite action of interlayers of laminated glass is not being considered in case this effect is favourable. In case the composite action is unfavourable, for example during alternating loads, it can also be relevant to consider the shear bond of the interlayer. Therefore a comprehensive presentation of the slip and bending behaviour of laminated glass will be advantageous. In this paper the derivation of the deflection and stress functions based on the slip differential function are presented. Thereby different kinds of transversal and normal loading with non‐slip restraint at the endings of the glass laminates are treated. Finally a short comparison of the results with experiments and numerical calculations is shown.
Zwei Verfahren zum rechnerischen Nachweis der dynamischen Beanspruchung von Verglasungen durch weichen Stoß
Authors: Schneider Jens , Schula Sebastian , Burmeister Albrecht 
Published: March 2011

AbstractDer Nachweis des weichen Stoßes zur Simulation eines Personenanpralls ist für Fassaden‐ und Dachverglasungen häufig bemessungsrelevant. Der Beitrag stellt hierzu zwei rechnerische Nachweisverfahren vor, die auf den Forschungsergebnissen, den experimentellen und praktischen Erfahrungen der letzten zehn Jahre beruhen. Ein Nachweisverfahren basiert auf transienten Simulationsberechnungen auf Grundlage der Methode der Finiten Elemente; hieraus abgeleitet wurde ein vereinfachtes Verfahren mit statischen Ersatzlasten auf Basis eines Zweimassenschwingers. Beide Verfahren sind geeignet, experimentelle Ergebnisse von Pendelschlagversuchen mit dem Doppelreifen‐Pendelkörper mit sehr guter Übereinstimmung abzubilden. Die in diesem Teil der Veröffentlichung vorgestellten Berechnungsverfahren werden anschließend in Teil 2 angewendet.Two mechanical design concepts for simulating the soft body impact at glazings – Part 1: Numerical, transient Finite Element simulation and simplified concept with equivalent static loads. Glass facades and glass roofs should be designed to resist dynamic human body impact. This article presents two mechanical design concepts based on the experimental and theoretical research from the last decade. One concept uses dynamic, transient Finite Element (FE‐)simulations, the other (simplified) concept uses equivalent static loads derived from a two degree of freedom (2‐DOF‐) model. The agreement between experimental results and the design concepts is very good. The concepts presented here are practically applied in part 2 of this article.
Bemessung von Dreifach‐Isolierglas
Authors: Feldmeier Franz 
Published: March 2011

AbstractDas im Scheibenzwischenraum eingeschlossene Gasvolumen bewirkt eine mechanische Kopplung der Scheiben und verteilt die von außen einwirkenden Lasten auf die Scheiben des Isolierglases. Des Weiteren führt eine Änderung der Temperatur oder eine Änderung des äußeren Luftdruckes zu einer Druckdifferenz zwischen Scheibenzwischenraum und der Umgebung und damit zu einer flächigen Belastung der Einzelscheiben. Der Beitrag gibt eine zusammenfassende Darstellung des Tragverhaltens und der Behandlung der internen Lasten von Mehrscheiben‐Isolierglas.Design of triple insulating glass units. The gas volume inside the cavity of an insulating glass unit (IGU) causes a mechanical coupling of the glasses panes and distributes the external loads to all of the unit. Furthermore, variations of temperature or external air pressure result in a difference of pressure between the enclosed gas volume and the environment and this leads to an uniform load of the single panes. This article gives a summary of the load bearing behavior and the handling of internal loads of IGUs.
engineered transparency – international conference at glasstec
Authors: Krampe Philipp 
Published: March 2011

AbstractErstmalig fand 2010 die internationale Tagung enginereed transparency im Rahmen der glasstec in Düsseldorf statt. 220 Teilnehmer aus 23 Nationen konnten sich am 29. und 30. September 2010 über die neuesten Trends und Entwicklungen im Glasbau und glasverwandten Themen im Bauwesen informieren. Die Veranstaltung wurde von der Technischen Universität Darmstadt und der Technischen Universität Dresden in Kooperation mit der Messe Düsseldorf organisiert und insbesondere durch die Ingenieurkammer‐Bau Nordrhein‐Westfalen unterstützt
A comparative study on different analysis approaches for estimating the axial loads on columns and structural walls at tall buildings
Authors: Kurc Ozgur , Lulec Andac 
Published: March 2011

SUMMARYEstimating axial loads on columns and structural walls at tall buildings is a complicated task because time‐dependent deformations of concrete and the way the building is constructed affect the way the gravity loads are carried by them. The accurate computation of axial loads is crucial for determining the size and strengths of columns and structural walls. This study investigates several analysis approaches commonly used during the design of such buildings. Construction sequences, time‐dependent deformations and longitudinal reinforcement were considered, and their influences on results were discussed. A simplified model of an actual 37‐story building was used as a case study. The results indicated that the column and wall axial load might vary up to 45% depending on the type of analysis and effects that were considered. Copyright © 2011 John Wiley & Sons, Ltd.
Thermal buckling of clamped thin rectangular FGM plates resting on Pasternak elastic foundation (Three approximate analytical solutions)
Authors: Kiani Y. , Bagherizadeh E. , Eslami M.R. 
Published: March 2011

AbstractBuckling of rectangular plates made of functionally graded material (FGM) under various types of thermal loading is considered. It is assumed that the plate is in contact with an elastic foundation during deformation. The derivation of equations is based on the classical plate theory. It is assumed that the mechanical and thermal non‐homogeneous properties of FGM plate vary smoothly by distribution of power law across the plate thickness. Using the non‐linear strain‐displacement relations, the equilibrium and stability equations of plates made of FGMs are derived. The boundary conditions for the plate are assumed to be clamped for all edges. The elastic foundation is modelled by two parameters Pasternak model, which is obtained by adding a shear layer to the Winkler model. Three distinct analytical solutions are presented to study the thermal buckling problem of thin FGM plates. These methods may be useful to study the eigenvalue problems for other loading types of FGM plates. Closed‐form solutions are presented and effects of various parameters, such as geometric characteristics and Pasternak elastic coefficients, are presented comprehensively.
Potential Economic Benefit of Cleft Lip and Palate Repair in Sub‐Saharan Africa
Authors: Alkire Blake , Hughes Christopher D. , Nash Katherine , Vincent Jeffrey R. , Meara John G. 
Published: March 2011

AbstractBackgroundAcceptance of basic surgical care as an essential element of any properly functioning health system is growing. To justify investment in surgical interventions, donors require estimates of the economic benefit of treating surgical disease. The present study aimed to establish a methodology for valuing the potential economic benefit of surgical intervention using cleft lip and palate (CLP) in sub‐Saharan Africa (SSA) as a model.MethodsEconomic modeling of cleft lip and cleft palate (CLP) in SSA was performed with retrospective demographic and economic data from 2008. The total number of Disability‐Adjusted Life‐Years (DALYs) secondary to CLP in 2008 was calculated from accepted clefting incidence rates and disability weights taken from the Global Burden of Disease Project. DALYs were then converted to monetary terms ($US), using both a human capital approach and Value of a Statistical Life (VSL) approach.ResultsWith the human capital approach, the potential economic benefit if all incident cases of CLP in SSA in 2008 were repaired at birth ranged from $252 million to $441 million. With VSL, the potential economic benefit of the same CLP repair would range from $5.4 billion to $9.7 billion.ConclusionsCleft lip and cleft palate can have a substantial impact on the economic health of countries in the developing world. Further studies should be directed at quantifying the economic benefit of surgical interventions and quantifying their costs with an economically sound approach.
Retained Surgical Items and Minimally Invasive Surgery
Authors: Gibbs Verna C. 
Published: March 2011

AbstractA retained surgical item is a surgical patient safety problem. Early reports have focused on the epidemiology of retained‐item cases and the identification of patient risk factors for retention. We now know that retention has very little to do with patient characteristics and everything to do with operating room culture. It is a perception that minimally invasive procedures are safer with regard to the risk of retention. Minimally invasive surgery is still an operation where an incision is made and surgical tools are placed inside of patients, so these cases are not immune to the problem of inadvertent retention. Retained surgical items occur because of problems with multi‐stakeholder operating room practices and problems in communication. The prevention of retained surgical items will therefore require practice change, knowledge, and shared information between all perioperative personnel.