bluuebunny/crossref_metadata_2025_split huggingface dataset:
Delayed gadolinium‐enhanced magnetic resonance imaging of the meniscus: An index of meniscal tissue degeneration?
Authors: Krishnan Nitya , Shetty Sanjay K. , Williams Ashley , Mikulis Brandon , McKenzie Charles , Burstein Deborah 
Published: April 2007

AbstractObjectiveMuch attention has been focused recently on the need for a better understanding of the mechanisms and natural progression of knee osteoarthritis (OA), particularly in its early stages. One technique that has been used to investigate early OA is delayed gadolinium‐enhanced magnetic resonance imaging of cartilage (dGEMRIC), where T1(Gd) (T1 value after penetration of the MRI contrast agent gadopentate dimeglumine [Gd‐DTPA2−]) is used as an index of the molecular status of articular cartilage. The goal of this study was to explore T1(Gd) in the meniscus and its relationship with articular cartilage T1(Gd) in knee dGEMRIC image data sets.MethodsT1(Gd) maps of the meniscus and articular cartilage were made from knee dGEMRIC images obtained from prior studies of dGEMRIC of the knee in 21 asymptomatic subjects and 9 patients with self‐reported OA.ResultsT1(Gd) of the meniscus covered a range of values (247–515 msec) and patterns (homogeneous and focal variations). In addition, T1(Gd) of the meniscus correlated with that of articular cartilage (R = 0.38, P = 0.037; R = 0.57, P = 0.001 for correlations of the medial posterior meniscus with the medial femoral and tibial cartilage, respectively; T1[Gd] of the anterior meniscus and lateral compartments also correlated, with R > 0.38 and P < 0.037), potentially demonstrating parallel degradative processes in the knee.ConclusionWhile the biophysical basis for the T1(Gd) results relative to meniscus molecular structure needs investigation, these findings introduce a potential means of examining the time course of meniscal tissue change in the development and progression of arthritis.
Strong combined gene–environment effects in anti–cyclic citrullinated peptide–positive rheumatoid arthritis: A nationwide case–control study in Denmark
Authors: Pedersen Merete , Jacobsen Søren , Garred Peter , Madsen Hans O. , Klarlund Mette , Svejgaard Arne , Pedersen Bo V. , Wohlfahrt Jan , Frisch Morten 
Published: April 2007

AbstractObjectiveTo study the role of shared epitope (SE) susceptibility genes, alone and in combination with tobacco smoking and other environmental risk factors, for risk of subtypes of rheumatoid arthritis (RA) defined by the presence or absence of serum antibodies against cyclic citrullinated peptides (CCPs).MethodsTo address these issues, a nationwide case–control study was conducted in Denmark during 2002–2004, comprising incident cases of RA or patients with recently diagnosed RA (309 seropositive and 136 seronegative for IgG antibodies against CCP) and 533 sex‐ and age‐matched population controls. Associations were evaluated by logistic regression analyses, in which odds ratios (ORs) served as measures of relative risk.ResultsCompared with individuals without SE susceptibility genes, SE homozygotes had an elevated risk of anti‐CCP–positive RA (OR 17.8, 95% confidence interval [95% CI] 10.8–29.4) but not anti‐CCP–negative RA (OR 1.07, 95% CI 0.53–2.18). Strong combined gene–environment effects were observed, with markedly increased risks of anti‐CCP–positive RA in SE homozygotes who were heavy smokers (OR 52.6, 95% CI 18.0–154), heavy coffee drinkers (OR 53.3, 95% CI 15.5–183), or oral contraceptive users (OR 44.6, 95% CI 15.2–131) compared with SE noncarriers who were not exposed to these environmental risk factors.ConclusionPersons who are homozygous for SE susceptibility genes, notably those who are also exposed to environmental risk factors, have a markedly and selectively increased risk of anti‐CCP–positive RA. A distinction between anti‐CCP–positive RA and anti‐CCP–negative RA seems warranted, because these RA subtypes most likely represent etiologically distinct disease entities.
Differential tissue targeting of autoimmunity manifestations by Autoantigen‐Associated Y RNAs
Authors: Greidinger Eric L. , Zang YunJuan , Martinez Laisel , Jaimes Kimberly , Nassiri Mehdi , Bejarano Pablo , Barber Glen N. , Hoffman Robert W. 
Published: April 2007

AbstractObjectiveTo assess the Y RNAs, a family of homologous RNAs that bind to the Ro autoantigen, for the ability to contribute to autoimmune disease by activating RNA‐responsive Toll‐like receptors (TLRs).MethodsUsing cell lines expressing or stably transfected with TLR‐3, TLR‐7, or TLR‐8, we determined the patterns of RNA‐specific TLR activation by in vitro transcripts of all of the known murine and human Y RNAs. Next, 8–10‐week‐old female mice were exposed to a single 50‐μg subcutaneous injection of mouse Y1 or mouse Y3 RNA, and the effects were observed.ResultsY RNA family members differed in their TLR reactivities. Both human and mouse Y3 RNAs, but not other human or mouse Y RNAs, prominently induced TLR‐3 activation. Although most human and mouse Y RNAs activated TLR‐7 efficiently, mouse Y3 RNA and human Y5 RNA did not. Single subcutaneous injections of mice with either mouse Y1 RNA or mouse Y3 RNA induced or inhibited lymphoid infiltrates in different target organs based on the Y RNA and TLR status of the mouse used. Mouse Y1 RNA induced kidney lesions in TLR‐3–intact mice but not in TLR‐3–knockout mice. In contrast, mouse Y3 RNA treatment was associated with nephritis in TLR‐3–knockout mice but not in TLR‐3–intact mice. Sialoadenitis developed in untreated TLR‐3−/− mice and in TLR‐3−/− mice treated with mouse Y3 RNA, but sialoadenitis was not present in TLR‐3−/− mice treated with mouse Y1 RNA.ConclusionY RNAs can induce innate immune responses and influence clinical manifestations of autoimmunity, suggesting that they are relevant to syndromes of anti‐Ro autoimmunity. Distinct patterns of tissue targeting can be seen after exposure to different Y RNAs, in a pattern that correlates with the innate immune signals they induce. Thus, the balance of innate immune signals induced by exposure to endogenous Y RNAs may help determine the nature of the clinical syndrome in anti‐Ro autoimmunity.
The antiinflammatory mechanism of methotrexate depends on extracellular conversion of adenine nucleotides to adenosine by ecto‐5′‐nucleotidase: Findings in a study of ecto‐5′‐nucleotidase gene–deficient mice
Authors: Montesinos M. Carmen , Takedachi Masahide , Thompson Linda F. , Wilder Tuere F. , Fernández Patricia , Cronstein Bruce N. 
Published: April 2007

AbstractObjectiveEvidence from in vitro, in vivo, and clinical studies indicates that adenosine mediates, at least in part, the antiinflammatory effects of methotrexate (MTX), although the biochemical events involved have not been fully elucidated. This study was undertaken to investigate whether MTX exerts antiinflammatory effects in mice that lack ecto‐5′‐nucleotidase (ecto‐5′‐NT) (CD73) and are unable to convert AMP to adenosine extracellularly, in order to determine whether adenosine is generated intracellularly and transported into the extracellular space or is generated from the extracellular dephosphorylation of AMP to adenosine.MethodsMale CD73 gene–deficient mice and age‐matched wild‐type mice received intraperitoneal injections of saline or MTX (1 mg/kg/week) for 5 weeks. Air pouches were induced on the back by subcutaneous injection of air; 6 days later, inflammation was induced by injection of carrageenan.ResultsFewer leukocytes, but higher levels of tumor necrosis factor α (TNFα), accumulated in the air pouches of vehicle‐treated CD73‐deficient mice compared with those of wild‐type mice. As expected, MTX treatment reduced the number of leukocytes and TNFα levels in the exudates and increased exudate adenosine concentrations in wild‐type mice. In contrast, MTX did not reduce exudate leukocyte counts or TNFα levels or increase exudate adenosine levels in CD73‐deficient mice.ConclusionThese results demonstrate that the antiinflammatory actions of MTX are mediated, at least in part, by increased release of adenine nucleotides that are hydrolyzed extracellularly to adenosine via an ecto‐5′‐NT–dependent pathway.
What do we know about the h index?
Authors: Bornmann Lutz , Daniel Hans‐Dieter 
Published: April 2007

AbstractJorge Hirsch (2005a, 2005b) recently proposed the h index to quantify the research output of individual scientists. The new index has attracted a lot of attention in the scientific community. The claim that the h index in a single number provides a good representation of the scientific lifetime achievement of a scientist as well as the (supposed) simple calculation of the h index using common literature databases lead to the danger of improper use of the index. We describe the advantages and disadvantages of the h index and summarize the studies on the convergent validity of this index. We also introduce corrections and complements as well as single‐number alternatives to the h index.
Die Michaeliskirche in Hildesheim – Erhaltung des Weltkulturerbes
Authors: Eilhardt‐Braune Eva‐Maria , Götz Jürgen , Steffens Klaus 
Published: April 2007

AbstractDie Kirche des ehemaligen Benediktinerklosters St. Michael in Hildesheim gilt als herausragendes Bauwerk der ottonischen Baukunst und wurde 1985 in die Liste der UNESCO zum Schutz des Kultur‐ und Naturerbes der Welt eingetragen.Das Gotteshaus, das Bischof Bernward (993–1022) errichten ließ und dessen Grundstein mit dem Jahr 1010 datiert ist und im Jahre 1022 – kurz vor seinem Tod – von ihm eingeweiht wurde, hat eine bewegte bauliche Vergangenheit.Baugrundprobleme mit der Folge von Teil einstürzen sowie mangelnde Bauunterhaltung über Jahrhunderte erfordern derzeit eine grundlegende Anamnese, Bewertung des Ist‐Zustands und die Planung einer nachhaltigen Sanierung dieser bedeutenden romanischen Kirche.
Zur Traglastermittlung von Druckstäben im Holzbau
Authors: Möller Gunnar 
Published: April 2007

AbstractBei der Bemessung von druckbeanspruchten Bauteilen im Holzbau ist die Zunahme der Beanspruchungen infolge der sich einstellenden Verformungen zu berücksichtigen. Die Zusatzbeanspruchungen aus dem nichtlinearen Anwachsen der Verformungen müssen rechnerisch immer dann berücksichtigt werden, wenn sich die Schnittgrößen infolge des geometrischen nichtlinearen Tragverhaltens (Theorie II. Ordnung) um mehr als 10% vergrößern. Zur Erfassung der Zusatzbeanspruchungen nach Theorie II. Ordnung sieht die DIN 1052 [1] zwei Verfahren vor. Der Nachweis kann mit einer Ermittlung der Schnittgrößen am unverformten System mit einer anschließenden Bemessung nach dem Ersatzstabverfahren erfolgen.Alternativ zum Nachweis nach dem Ersatzstabverfahren können die Schnittgrößen nach Theorie II. Ordnung ermittelt und anschließend eine Bemessung des Querschnitts für Biegung mit Druck durchgeführt werden.In diesem Beitrag werden die Unterschiede der beiden alternativen Nachweise aufgezeigt, und es wird eine Vorgehensweise vorgeschlagen, bei der beide Verfahren unter Berücksichtigung des Modifikationsbeiwertes für einfache Fälle gleiche Traglasten ergeben.
Platten aus Stahlbeton unter zweiaxialer Biegebeanspruchung
Authors: Keuser Manfred , Rüdiger Lars , Hallermann Norman 
Published: April 2007

AbstractStahlbetonflächentragwerke erfahren i. d. R. zweiaxiale Beanspruchungszustände, beispielsweise in Hohlkästen im Brückenbau, bei zweiachsig gespannten Deckenplatten oder auch im Bereich der Lasteinleitung über und unter Stützen. Die Bemessung solcher Bereiche erfolgt derzeit mit Hilfe vereinfachender Annahmen, die auf der sicheren Seite liegend nicht immer zur wirtschaftlichsten Lösung führen. Durch die Superposition einzelner Lastfälle oder die Aufaddierung der daraus ermittelten Bewehrungsmengen kann es zu einer Überbemessung von Bauteilen kommen. Interaktionen, wie z. B. die Auswirkungen von Änderungen der Bauteilsteifigkeiten, werden gar nicht oder nicht vollständig berücksichtigt. Inhomogenitäten im Material, insbesondere der Einfluss der Bewehrung, sind eine wesentliche Ursache für nichtlineares Materialverhalten, das i. d. R. zu Schnittgrößenumlagerungen führt. Im Rahmen eines Forschungsprojektes am Institut für Konstruktiven Ingenieurbau der Universität der Bundeswehr München wurden aufbauend auf Untersuchungen an Stahlbetonscheiben Versuche an Stahlbetonplatten mit variabler Bewehrungsrichtung und verschiedenen Biegemomentenverhältnissen durchgeführt. Die daraus gewonnenen Versuchsergebnisse sollen als Grundlage zur Entwicklung eines Ingenieurmodells zur vereinfachten Beschreibung der Zusammenhänge dienen.
Zum statischen System von Kellerwänden aus unbewehrtem Beton unter Erddruck
Authors: Hegger Josef , Niewels Jörg , Dreßen Tobias , Will Norbert 
Published: April 2007

AbstractDie üblichen Baustoffe für Kellerwände im Wohnungsbau sind Mauerwerk oder bewehrter Beton. Beide Bauarten sind zeit‐ und kostenintensiver als eine Ausführung der Kelleraußenwände in unbewehrtem Beton. Der Hauptgrund für die allgemeine Zurückhaltung gegenüber Wänden aus unbewehrtem Beton ist die erforderliche Wanddicke. So ergeben sich nach DIN 1045‐1 z. T. deutlich größere Wanddicken als bei einer Bemessung für Mauerwerk nach DIN 1053. Nachfolgend werden, neben den Gründen für die bisher ungünstigere Bemessung, über die Regelungen von DIN 1045‐1 hinausgehende Systemannahmen erläutert, die deutlich geringere Wanddicken für durch Erddruck beanspruchte unbewehrte Kelleraußenwände durch Ausnutzung ihrer Verformungsfähigkeit ergeben.
Anpassung des Verkehrslastmodells des DIN FB 101 für kommunale Brücken
Authors: Novák Balthasar , Brosge Sven , Barthel Klaus , Pfisterer Werner 
Published: April 2007

AbstractFür den Verantwortungsbereich des BMVBS ist das kürzlich eingeführte Lastmodell LM1 für die Verkehrslasten auf Brücken ohne weitere Reduktionen für alle neuen Brückenbauwerke anzusetzen. Dies führt jedoch leider gerade im Bereich der Kommunen zu teilweise konservativen Ergebnissen, da die geometrischen Abmessungen von kommunalen Brücken deutlich von den “üblichen” Abmessungen von Autobahnen und Bundesstraßen abweichen können und die Belastung aus dem LM1 durch den realen Verkehr nicht erzeugt werden kann. Es werden Vorschläge präsentiert, wie bei bestimmten geometrischen Randbedingungen und abhängig vom statischen System eine weitere Abminderung des LM1 möglich ist, ohne das Sicherheitsniveau zu verlassen. Die Arbeit entstand in enger Zusammenarbeit mit den Städten Frankfurt/Main, Leipzig und Stuttgart.
Zuschrift zu Kaldenhoff, M.; Schütte, J.; Hauser, A.: Anwendungserfahrungen mit der neuen DIN 1055 Teil 6 bei der Sanierung zweier Rohmehlsilos
Authors: Lippold Dieter 
Published: April 2007

AbstractZuschrift zu Beton‐und Stahlbetonbau 102 (2007), Heft 2, S. 107–113, Erwiderung der Autoren
Remarks upon Empirical Regression Belt
Authors: Schmerling S. , Peil J. 
Published: April 2007

AbstractIn the presented paper the method of the empirical regression belt is demonstrated. An empirical regression curve r(x), which is determined by the realizations (measured points) (x1, y1), i = 1,…., n of a continuous two‐dimensional random variable (X, Y), is enclosed by a belt, the local width of which varies dependent on local frequency and variance of the measured points. This empirical regression belt yields certain information for evaluating the empirical regression curve, providing a useful basis for the biomathematical forming of a model. By giving three examples derived from morphometrics the authors discuss important qualities of the empirical regression belt.
Relative Efficiency of Estimators of the Mean of a Normal Distribution when Coefficient of Variation is Known
Authors: Sen A. R. 
Published: April 2007

AbstractA biased but simple and consistent estimator of the parameter ϑ has been obtained for the normal distribution N(ϑ, aϑ2), ϑ>0 where a is a known constant. It is shown that the estimator is more efficient than the sample mean or any suitably chosen constant multiple of the sample standard deviation. It is also proved to be more efficient than the mimumum variance unbiased estimator among a typical class of unbiased estimators derived by RASUL KHAN (1968).
Some Theorems Concerning Characterization of the WEIBULL Distribution
Authors: Janardan K. G. , Taneja V. S. 
Published: April 2007

AbstractThis paper presents a number of characterizations of the WEIBULL distribution. Some of these results are generalizations of the corresponding results for the exponential distribution. Some characterizing properties lead to a functional equation f(x) · f(y) = f((xc+yc)i/c) which is analogous to the CAUCHY functional equation. While the first two characterizations assume somewhat less accessible information concerning the probability distribution, the third and fourth require more readily available information regarding the expected values.
In vitro scavenging activity for reactive oxygen species by N‐substituted indole‐2‐carboxylic acid esters
Authors: Kruk Irena , Aboul‐Enein Hassan Y. , Michalska Teresa , Lichszteld Krzysztof , Kubasik‐Kladna Katarzyna , Ölgen Sureyya 
Published: April 2007

AbstractThe hydroxyl radical (HO•)‐ and superoxide anion radical (O)‐scavenging activity, as well as the singlet oxygen (1O2)‐quenching property of N‐substituted indole‐2‐carboxylic acid esters (INDs) were investigated by deoxyribose degradation assay, a chemiluminescence method and the electron spin resonance (ESR) spin‐trapping technique. This novel group of compounds was developed as a search for cyclooxygenase‐2 (COX‐2)‐selective enzyme inhibitors. The results obtained demonstrated that of the 16 compounds examined, five inhibited light emission from the superoxide anion radical (O)–DMSO system by at least 60% at a concentration of 1 mmol/L, nine prevented the degradation of deoxyribose induced by the Fenton reaction system (range 3–78%) or scavenged hydroxyl radicals (HO•) directly (range 8–93%) and 14 showed the 1O2‐quenching effect (range 10–74%). These results indicate that majority of the indole esters tested possess the ability to scavenge O−2 and HO radicals and to quench 1O2 directly, and consequently may be considered effective antioxidative agents. Copyright © 2007 John Wiley & Sons, Ltd.
Plasmid adsorption to anion‐exchange matrices: Comments on plasmid recovery
Authors: Tiainen Peter , Galaev Igor , Larsson Per‐Olof 
Published: April 2007

AbstractA number of anion‐exchange adsorbents were constructed, employing nonporous silica fibers, and examined with the aim of describing factors that influence desorption and recovery of plasmid DNA (pDNA). The fibers were provided with ligands via adsorption of the polymeric amines poly(ethyleneimine) or chitosan, or via graft‐polymerization of primary, tertiary, or quaternary amine monomers to vinyl‐silanized fibers. Several adsorbents showed an almost irreversible plasmid binding. It was suggested that important factors affecting the DNA releasing ability are (i) type of amine ligand used (primary amines bind plasmids the strongest), (ii) the structure of the nucleic acid (supercoiled pDNA may bind stronger than linear genomic DNA), (iii) shift of ligand pKa (due to the proximity of highly charged pDNA), and (iv) the solid support itself (steric factors may lead to kinetically stable complexes). The last factor was derived from several comparisons between support‐bound ligand and free soluble ligand. It was thus observed that polyelectrolyte complexes associated with a surface were much more difficult to dissociate than the equivalent soluble complexes.
Influence of microbial growth kinetics on steady state multiplicity and stability of a two‐step nitrification (SHARON) model
Authors: Volcke Eveline I.P. , Sbarciog Mihaela , Loccufier Mia , Vanrolleghem Peter A. , Noldus Erik J.L. 
Published: April 2007

AbstractIn this paper, the influence of microbial growth kinetics on the number and the stability of steady states for a nitrogen removal process is addressed. A two‐step nitrification model is studied, in which the maximum growth rate of ammonium oxidizers is larger than the one of nitrite oxidizers. This model describes the behavior of a SHARON reactor for the treatment of wastewater streams with high ammonium concentrations. Steady states are identified through direct calculation using a canonical state space model representation, for several types of microbial kinetics. The stability of the steady states is assessed and the corresponding phase portraits are analyzed. Practical operation of a SHARON reactor aims at reaching ammonium conversion to nitrite while suppressing further conversion to nitrate. Regions in the input space are identified that result in this desired behavior, with only nitrite formation. It is demonstrated that not only the dilution rate plays a role, as is commonly known, but also the influent ammonium concentration. Besides, the type of microbial (inhibition) kinetics has a nonnegligible influence. While the results indicate that product inhibition does not affect the number of steady states of a (bio)reactor model, it is shown that substrate inhibition clearly yields additional steady states. Particular attention is devoted to the physical interpretation of these phenomena. Biotechnol. Bioeng. 2007;98: 882–893. © 2007 Wiley Periodicals, Inc.
Production of lentiviral vectors by large‐scale transient transfection of suspension cultures and affinity chromatography purification
Authors: Segura María Mercedes , Garnier Alain , Durocher Yves , Coelho Helene , Kamen Amine 
Published: April 2007

AbstractThe use of lentiviral vectors as gene delivery vehicles has become increasingly popular in recent years. The growing interest in these vectors has created a strong demand for large volumes of vector stocks, which entails the need for scaleable vector manufacturing procedures. In this work, we present a simple and robust process for the production of lentiviral vectors using scaleable production and purification methodologies. Lentivirus particles were produced by transient transfection of serum‐free suspension‐growing 293 EBNA‐1 cells with four plasmids encoding the vector components using linear polyethylenimine (PEI) as transfection reagent. This process was successfully scaled‐up from shake flaks to a 3‐L bioreactor from which 1010 IVP were recovered. In addition, an affinity chromatography protocol designed for purification of bioactive oncoretroviral vectors has been adapted in this work for the purification of VSV‐G pseudotyped lentiviral vectors. Using heparin affinity chromatography, lentiviral particles were concentrated and purified directly from the clarified supernatants. During this step, a recovery of 53% of infective lentiviral particles was achieved while removing 94% of the impurities contained in the supernatant. Biotechnol. Bioeng. 2007; 98: 789–799. © 2007 Wiley Periodicals, Inc.