bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent Advances Using Immunomodulators for Inflammatory Bowel Disease
Authors: Nielsen Ole Haagen , Bjerrum Jacob Tveiten , Herfarth Hans , Rogler Gerhard 
Published: March 2013

AbstractUse of the immunomodulators thiopurines and methotrexate (MTX) in the treatment of inflammatory bowel disease (IBD), i.e., Crohn's disease and ulcerative colitis (UC), is considered to be good clinical practice. However, despite being administered to a considerable number of IBD patients over the years, questions remain about the most rational treatment regimens of azathioprine (AZA), 6‐mercaptopurine (6‐MP), and MTX, and results from a range of recent studies necessitate increased attention to how to optimize the use of these immunomodulators. First and foremost, it is of utmost importance to define the subgroup of IBD patients in need of immunomodulators, including those in need of combination therapy with biologic agents, especially because some side effects may be rather severe. Second, colorectal cancer is observed more often in IBD patients than in the background population. However, a recent nationwide Dutch study pointed to a preventive effect of thiopurines. Finally, the need for an appropriate approach to the discontinuation of immunomodulators is emphasized. Since controversy continues regarding the most appropriate use of immunomodulators, this paper is focusing on pharmacokinetics, pharmacogenetics, and therapeutic blood testing, as well as the occurrence of adverse events, when using AZA, 6‐MP, and MTX in an attempt to determine a more up‐to‐date and rational treatment regimen in IBD.
Xylitol fermentation using hemicellulose hydrolysate prepared by acid pre‐impregnated steam explosion of corncob
Authors: Wang Le , Fan Xiaoguang , Tang Pingwah , Yuan Qipeng 
Published: March 2013

AbstractBACKGROUNDSteam explosion is widely used on a variety of plant biomass for the hydrolysis of hemicellulose. However, hydrolysis by steam explosion suffers from low xylose yield, long hydrolysis time and high energy consumption, which impede the xylitol fermentation step. This study used a dilute sulfuric acid pre‐impregnation prior to the steam explosion to prepare corncob hemicellulose hydrolysate which offers high xylose yield for xylitol fermentation by Candida tropicalis.RESULTSAfter pre‐impregnation with 0.3% (wt) dilute sulfuric acid at a liquid to corncob ratio of 3 for 6 h, corncobs were steamed at 200 °C for 5 min to obtain a maximum xylose yield of 23.5% in the hydrolysate. The hydrolysate was detoxified by concentrating with vacuum evaporation followed by adsorption using activated carbon. The detoxified hydrolysate was then used for xylitol fermentation. Maximum xylitol yield of 75.1%, volumetric productivity of 2.01 g L‐1 h and biomass of 20.9 g L‐1 were obtained from the detoxified hydrolysate.CONCLUSIONFindings suggested that this acid pre‐impregnated steam explosion strategy provides a highly effective way to prepare hemicellulose hydrolysate with high xylose yield, and could be potentially applied to industrial xylitol fermentation. © 2013 Society of Chemical Industry
Effects of anthropogenic intermixing on the genetic structure of Dybowski's frog populations in northeast China
Authors: Zhang Ming , Wang Weisheng , Xu Yanchun , Jia Xueyuan , Zheng Xin , Ma Jianzhang 
Published: March 2013

AbstractThe Dybowski's frog (Rana dybowskii) is mainly distributed in northeast China and the Russian Far East. Its dried oviduct, or frog oil, has been used in traditional Chinese medicine for thousands of years. Frogs from different geographic regions exhibit variations in their body mass and oil productivity. As a result, farmers usually import high quality breeding stock from different areas to increase oviduct productivity. This practice could alter the genetic structure of the frog populations. We used 10 microsatellite loci to investigate the level of genetic variation for 10 frog populations in the context of human‐mediated disturbance. The study populations comprised the following: the Hebei, Tieli, and Jiamusi populations from the Lesser Khingan Mountains; the Mudanjiang, Jilin, Jiaohe, and Huadian populations from the north central Changbai Mountains; and the Tonghua, Benxi, and Xiuyan populations from the southern Changbai Mountains. Our results showed that the 3 Lesser Khingan Mountain populations exhibited highly significant differentiation values (FST = 0.047–0.071, P < 0.001). In addition, the Tonghua population differentiated significantly from the other 6 populations of the Changbai Mountains (P < 0.001). The genetic differentiation coefficient (FST) and gene flow (Nem) estimates showed that the Benxi and Jiaohe populations had a high degree of genetic similarity despite being geographically separated by mountains and river systems. We obtained similar results for the Xiuyan and Tieli populations. Furthermore, the degree of gene flow between the Jiamusi and the north central Changbai Mountain populations was greater than that observed between the Jiamusi and the other Lesser Khingan Mountain populations. These results therefore suggest that the Benxi, Xiuyan, and Jiamusi populations have undergone substantial intermixing because of human‐mediated relocation. Economic demands make completely stopping the geographical relocation of Dybowski's frog in northeast China virtually impossible. Consequently, effective management strategies are now a high priority to ensure that conservationists and local economies can work together to guarantee the long‐term survival of this species. © 2013 The Wildlife Society.
Harvest mortality in North American mallards: A reply to Sedinger and Herzog
Authors: Pöysä Hannu , Dessborn Lisa , Elmberg Johan , Gunnarsson Gunnar , Nummi Petri , Sjöberg Kjell , Suhonen Sari , Söderquist Pär 
Published: March 2013

AbstractSedinger and Herzog (2012) evaluated the evidence for the impact harvest mortality may have on North American duck populations. While doing that, they questioned our review (Pöysä et al. 2004) and conclusion that harvest mortality in North American mallards (Anas platyrhynchos) may have shifted from compensatory to additive over the period from the 1960s to the 1980s. In this reply, we correct Sedinger and Herzog's misrepresentations of our 2004 paper and argue that our interpretations of the results published at that time have not been invalidated. © 2013 The Wildlife Society.
Kinetic Modeling from Early Product Development to Polymerization Process Optimization
Authors: Tracht Ursula , Richter Frank U. 
Published: March 2013

AbstractSummary: This contribution illustrates how kinetic modeling supports early product development stages under industrial constraints also for smaller scale products. Diisocyanate oligomerization is selected as an example. Data for model parameterization and validation are acquired in kinetic experiments with on‐line IR monitoring. Based on these measured data and a proposed reaction scheme for the cyclo‐oligomerization of diisocyanates with equal reactivity of both isocyanate groups, two kinetic models differing in level of detail are developed. All experimental trends are described correctly with these kinetic models. A functional group based model is used for parameterization and prediction of conversion profiles. This model version is also applied for assessing working hypotheses on the details of the catalytic cycle and for developing strategies for catalyst and process optimization. A second model takes into account full molecular weight distribution and thus enables prediction of individual oligomer concentrations. Fast assessment of process alternatives is possible with both models.
Comprehensive Characterization of Chain End Groups of Vinylidene Fluoride Based Polymers
Authors: Albano Margherita , Barchiesi Emma , Biancardi Roberto , Dossi Marco , Geniram Giuliana , Vaccarono Paola 
Published: March 2013

AbstractSummary: In this work an investigation of the chain end groups produced in the free radical copolymerization of vinilydene fluoride (VDF) and hexafluoropropylene (HFP) is performed. Type and amount of chain end groups are evaluated by a meticulous analytical characterization of VDF/HFP copolymer. At first pulsed gradient spin‐echo nuclear magnetic resonance (spin‐echo NMR) is used to identify all the chain end groups also at very low concentration (equal to 0.1 mmol · Kg−1). The instrument sensitivity is increased of an order of magnitude in comparison with the traditional NMR. Moreover potentiometric titration and ion chromatography (IC) are also used to study the chain end groups and, as a consequence, the nature and the amount of the acidity showed by the polymer chains. In details two intensity of acidity are detected by potentiometric titration, namely strong and weak. The strong acidity is associated to the presence of residual surfactant and can be removed washing the polymer, while the weak acidity is due to free molecules of fluoride acid (HF). The standard ion chromatography facility is properly modified to quantify the fluoride in the polymer matrix without any pre extraction in water. Thanks to this the HF concentration in the polymer is evaluated with high accuracy. A detailed kinetic scheme for the VDF/HFP polymerization is also proposed taking into account all the findings obtained studying the chain end groups.
The Effect of Polymer Microstructure and Thermal Post‐Treatment on Latex‐Based Pressure Sensitive Adhesive Performance
Authors: Dubé Marc A. , Qie Lili 
Published: March 2013

AbstractSummary: Butyl acrylate/acrylic acid/2‐hydroxyl methacrylate (BA/AA/HEMA, weight ratio: 96/2/2) latexes were produced via starved seeded semi‐batch emulsion polymerization. The microstructure of the latex polymers was controlled by varying the amount of chain transfer agent (1‐dodecanethiol). The latexes were characterized for gel content, Mc (molecular weight between two adjacent cross‐linking points), Mw (molecular weight of sol polymers) and Me (molecular weight between entanglements). From these latexes, PSA films were cast, dried, conditioned and then thermally post‐treated at 120 °C to react the carboxyl and hydroxyl groups from the AA and HEMA units. Tack, peel strength and shear strength of the PSA films were then measured. The thermal post‐treatment was shown to be an effective way to improve latex‐based PSA performance. The effectiveness of the post‐treatment was observed to depend on the polymer microstructure (Mc relative to Me relative to Mw) of the untreated latex‐based PSAs and on the gel content.
Coupling Deterministic and Stochastic Simulation to Model the Polymeric Microstructure of LDPE
Authors: Neuhaus Eric , Busch Markus , Gonioukh Andrei , Herrmann Thomas , Lilge Dieter , Mannebach Gerd , Vittorias Iakovos 
Published: March 2013

AbstractSummary:Simulation based process development of new LDPE grades often requires a deep insight into the exact microstructure of individual macromolecules. Therefore, we developed an approach, which combines the advantages of the deterministic (low computational time and high accuracy) and stochastic simulation (individual macromolecules with distinct microstructure). The approach can be used for the modeling of continuously driven autoclave and tubular reactors. First results visualize the random conformation of a distinct macromolecule as well as the resulting contraction factor.
Modeling Free Radical Ethylene Polymerization with Multifunctional Comonomers in Tubular Reactors: Influence on Microstructural LDPE Properties
Authors: Kadel Isabel , Herrmann Thomas , Busch Markus 
Published: March 2013

AbstractSummary: A kinetic model is developed to predict the effect of multi‐functional comonomers in the high‐pressure polymerization of ethylene in industrial tubular reactors. Two different modified acrylate based comonomers were tested in the simulation for their influence on molecular‐weight distribution and branching densities. A comparison of both methods shows their potential to be used in an industrial process.
Cytotoxicity of PMMA‐Based Nanoparticles Synthesized Adopting SDS and Tween 80
Authors: Colombo Claudio , Lupi Monica , Ubezio Paolo , Moscatelli Davide 
Published: March 2013

AbstractSummary: in this work the cytotoxicity of PMMA‐based nanoparticles against mouse mammary cancer cells (4T1) has been investigated. NPs have been synthesized using either monomer starved semi‐batch emulsion polymerization (MSSEP) or standard batch emulsion polymerization (BEP) processes adopting potassium persulfate (KPS) as initiator and two different emulsifiers: sodium dodecyl sulfate (SDS) and Tween 80. The toxicity of NPs produced using SDS has been confirmed in in vitro experiments while it has been found that NPs stabilized with Tween 80 show a good biocompatibility. Moreover, the absence of toxicity of NPs in which the SDS is substituted with Tween 80 adopting ion exchange resins (IER) has been proved. Finally the biocompatibility of the sulfate chain end groups coming from the adopted initiator has been assessed.
Modeling Crosslinking Polymerization in Batch and Continuous Reactors
Authors: Kryven Ivan , Berkenbos Arjen , Melo Priamo , Kim Dong‐Min , Iedema Piet D. 
Published: March 2013

AbstractA new pseudo‐distribution approach is applied to the modeling of crosslinking copolymerization of vinyl and divinyl monomer and compared to Monte Carlo (MC) simulations. With the number of free pending double bonds as the main distribution variable, a rigorous solution of the three leading moments of the molecular size distribution becomes possible. Validation takes place with data of methyl methacrylate with ethylene glycol dimethacrylate. Well within the sol regime perfect agreement is found, but near the gelpoint larger discrepancies do appear. This is probably due to the existence of multiradicals that are not taken into account in the population balance approaches. magnified image
Analysis of an exact algorithm for the vessel speed optimization problem
Authors: Hvattum Lars Magnus , Norstad Inge , Fagerholt Kjetil , Laporte Gilbert 
Published: March 2013

AbstractIncreased fuel costs together with environmental concerns have led shipping companies to consider the optimization of vessel speeds. Given a fixed sequence of port calls, each with a time window, and fuel cost as a convex function of vessel speed, we show that optimal speeds can be found in quadratic time. © 2013 Wiley Periodicals, Inc. NETWORKS, 2013
A mass weighted chemical elastic network model elucidates closed form domain motions in proteins
Authors: Kim Min Hyeok , Seo Sangjae , Jeong Jay Il , Kim Bum Joon , Liu Wing Kam , Lim Byeong Soo , Choi Jae Boong , Kim Moon Ki 
Published: March 2013

AbstractAn elastic network model (ENM), usually Cα coarse‐grained one, has been widely used to study protein dynamics as an alternative to classical molecular dynamics simulation. This simple approach dramatically saves the computational cost, but sometimes fails to describe a feasible conformational change due to unrealistically excessive spring connections. To overcome this limitation, we propose a mass‐weighted chemical elastic network model (MWCENM) in which the total mass of each residue is assumed to be concentrated on the representative alpha carbon atom and various stiffness values are precisely assigned according to the types of chemical interactions. We test MWCENM on several well‐known proteins of which both closed and open conformations are available as well as three α‐helix rich proteins. Their normal mode analysis reveals that MWCENM not only generates more plausible conformational changes, especially for closed forms of proteins, but also preserves protein secondary structures thus distinguishing MWCENM from traditional ENMs. In addition, MWCENM also reduces computational burden by using a more sparse stiffness matrix.
The thresholds for diameter 2 in random Cayley graphs
Authors: Christofides Demetres , Markström Klas 
Published: March 2013

ABSTRACTGiven a group G, the model denotes the probability space of all Cayley graphs of G where each element of the generating set is chosen independently at random with probability p.In this article we show that for any and any family of groups Gk of order nk for which , a graph with high probability has diameter at most 2 if and with high probability has diameter greater than 2 if .We also provide examples of families of graphs which show that both of these results are best possible.Of particular interest is that for some families of groups, the corresponding random Cayley graphs achieve Diameter 2 significantly faster than the Erdős‐Renyi random graphs. © 2014 Wiley Periodicals, Inc. Random Struct. Alg., 45, 218–235, 2014
Neue Technologie für die Hängebrücke über die Saar in Mettlach – Brückenfahrbahn aus Sandwich Plate System (SPS)
Authors: Stihl Thomas , Chassard Carsten , Feldmann Markus , Bild Stefan 
Published: March 2013

AbstractDie 1951 gebaute Hängebrücke über die Saar in Mettlach musste wegen Schäden am Seiltragwerk und an der Verbundfahrbahntafel für Fahrzeuge über 12 t gesperrt werden. Damit die denkmalgeschützte innerstädtische Brücke den vorhandenen Verkehrsverhältnissen wieder gerecht wird, musste die Fahrbahn durch eine wesentlich leichtere Konstruktion ersetzt werden. Durch den Einbau einer Stahlleichtfahrbahn in SPS‐Bauweise ist es möglich, den Verkehr über die Brücke wieder ohne Beschränkungen freizugeben. Der Beitrag beschreibt die Vorteile der neuen Technologie der eingebauten Sandwich Plate‐Fahrbahn im Vergleich zu klassischen Bauweisen. Die Entscheidungsfindung zur Vergabe der Bauleistung sowie Inhalte der Zustimmung im Einzelfall werden aufgezeigt. Der Vorgang und die Besonderheiten beim Einsatz der in Deutschland noch nicht eingeführten Technologie werden dargestellt.Der Weg des von der Baufirma vorgeschlagenen Konzeptes ist ein innovatives Beispiel für aktuelle Entwicklungen im Stahlbau. Das Konzept basiert auf der 2010 im kanadischen Edmonton durchgeführten Fahrbahnsanierung der Dawson Bridge, die 2012 mit dem Nachhaltigkeitspreis der CISC (Canadian Institute of Steel Construction) ausgezeichnet wurde. Für den Einsatz in Mettlach wurde der Entwurf weiterentwickelt, um den Regularien der DIN‐Fachberichte 101 und 103 mit den Ansprüchen an Ermüdung gerecht zu werden.New technology for the suspension bridge near Mettlach, Germany – A Sandwich Plate System made bridge deck. The 1951‐built suspension bridge spanning the river Saar at Mettlach, Germany needed to be closed for vehicles more than 12 t because of defects in the cable structure and damage of the composite bridge deck. So that the preservation listed urban bridge will meet again the existing traffic conditions, the bridge deck had to be replaced and lightened. Through the installation of a light steel roadway in SPS design it is possible to allow the traffic over the bridge without restrictions again. The paper describes the advantages of the new technology built Sandwich Plate bridge deck compared to traditional construction methods. The decision to award the construction works and contents of the individual approval are presented. The procedure and features in the use of this technology not yet introduced in Germany are given.The realization concept proposed by the construction company is an innovative example of current development in steel construction. The concept is based on the 2010 roadway rehabilitation of the Dawson Bridge in Canadian Edmonton which won the Sustainability Award 2012 of CISC. For application in Mettlach additional development was required to meet the regulations of the DIN Fb 101 and 103 in accordance to the standards of fatigue.
Zur Grenztragfähigkeit von Verbunddübeln mit Klothoidenform
Authors: Lorenc Wojciech , Kożuch Maciej , Seidl Günter 
Published: March 2013

AbstractVerbunddübel sind ein robustes und wirtschaftliches Tragelement zur Einleitung von Schubkräften zwischen Beton in Stahl, dessen Tragverhalten in der letzten Zeit Thema verschiedener Forschungsprojekte ist. Ausgehend vom Stand der Technik werden Untersuchungen zur plastischen Tragfähigkeit des Stahldübels erläutert. Neben Versuchen zur Stahldübeltragfähigkeit werden auch neue numerische Modelle vorgestellt und ein erweiterter Bemessungsansatz bewertet.The ultimate load bearing capacity of composite dowels with clothoid form. Composite dowels are acting as a ductile and economic member to transfer shear forces from concrete to steel. Their load bearing behavior is highlighted in recent research projects. To complete the state‐of‐the‐art investigations in the plastic load bearing behavior of the steel dowel are presented. Beside experimental tests new numerical models of composite dowels will be discussed and a design recommendation will be validated.
Schrägseilbrücke mit Litzenbündelseilen: Elbebrücke Schönebeck – Konstruktion und Ausführung (Teil 1)
Authors: Brand Werner , Puls Joachim , Langer Stephan 
Published: March 2013

AbstractAm 01. 11. 2012 wurde das letzte Stahlsegment des Stromfeldes der neuen Elbebrücke Schönebeck erfolgreich eingehoben. Mit einer Länge von 1128,5 m stellt das Bauwerk im Zuge der Ortsumgehung Schönebeck, B246a, eine der längsten und anspruchsvollsten Brückenbauwerke Sachsen‐Anhalts dar. Kernstück der neuen Elbquerung ist eine einhüftige Schrägseilbrücke mit der Hauptspannweite von 185 m. Der vorliegende Aufsatz behandelt die Konstruktion und Ausführung der Schrägseilbrücke.A cable‐stayed bridge with parallel strand cables: Elbe Bridge Schönebeck (Germany) – construction and execution (part 1). On the first of November was the last steel segment of the main span of the new bridge over the Elbe near Schönebeck successfully lifted. The new bridge has a total length of 1128.50 m and a mainspan of 185 m built as a single tower cable‐stayed Bridge.
Hierarchical approaches for systems modeling in cardiac development
Authors: Gould Russell A. , Aboulmouna Lina M. , Varner Jeffrey D. , Butcher Jonathan T. 
Published: March 2013

AbstractOrdered cardiac morphogenesis and function are essential for all vertebrate life. The heart begins as a simple contractile tube, but quickly grows and morphs into a multichambered pumping organ complete with valves, while maintaining regulation of blood flow and nutrient distribution. Though not identical, cardiac morphogenesis shares many molecular and morphological processes across vertebrate species. Quantitative data across multiple time and length scales have been gathered through decades of reductionist single variable analyses. These range from detailed molecular signaling pathways at the cellular levels to cardiac function at the tissue/organ levels. However, none of these components act in true isolation from others, and each, in turn, exhibits short‐ and long‐range effects in both time and space. With the absence of a gene, entire signaling cascades and genetic profiles may be shifted, resulting in complex feedback mechanisms. Also taking into account local microenvironmental changes throughout development, it is apparent that a systems level approach is an essential resource to accelerate information generation concerning the functional relationships across multiple length scales (molecular data vs physiological function) and structural development. In this review, we discuss relevant in vivo and in vitro experimental approaches, compare different computational frameworks for systems modeling, and the latest information about systems modeling of cardiac development. Finally, we conclude with some important future directions for cardiac systems modeling. WIREs Syst Biol Med 2013, 5:289–305. doi: 10.1002/wsbm.1217This article is categorized under:

Models of Systems Properties and Processes > Cellular Models
Developmental Biology > Developmental Processes in Health and Disease
Biological Mechanisms > Regulatory Biology