bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vitro Analysis of Mouse Mesencephalic Neural Crest Development
Authors: Ito Kazuo , Fujita Kyohei 
Published: July 2011

AbstractThe neural crest is a unique structure in vertebrates. Neural crest cells play important roles in the formation of organs that characterize the vertebrate body plan. In this unit, we describe a primary culture method for mouse mesencephalic neural crest cells. The neural crest cells cultured by this method actively proliferate and differentiate into various cell types that originate from cranial neural crest cells, such as chondrocytes, neurons, and glia. Therefore, this primary culture method is useful for analyzing the development of mouse mesencephalic neural crest cells. Curr. Protoc. Neurosci. 56:3.23.1‐3.23.8. © 2011 by John Wiley & Sons, Inc.
Quantitation of DNA and RNA with Absorption and Fluorescence Spectroscopy
Authors: Gallagher Sean R. 
Published: July 2011

AbstractQuantitation of nucleic acids is a fundamental tool in molecular biology that requires accuracy, reliability, and the use of increasingly smaller sample volumes. This unit describes the traditional absorbance measurement at 260 nm and three more sensitive fluorescence techniques employing Hoechst 33258, ethidium bromide, and PicoGreen. The range of the assays covers 25 pg/ml to 50 µg/ml. Absorbance at 260 nm has an effective range from 1 to 50 µg/ml; Hoechst 33258 from 0.01 to 15 µg/ml; ethidium bromide from 0.1 to 10 µg/ml; and PicoGreen from 25 to 1000 pg/ml.Curr. Protoc. Neurosci. 56:A.1K.1‐A.1K.14. © 2011 by John Wiley & Sons, Inc.
Recombineering‐Based Procedure for Creating BAC Transgene Constructs for Animals and Cell Lines
Authors: Hollenback Steven M. , Lyman Suzanne , Cheng JrGang 
Published: July 2011

AbstractThe use of BAC/P1 as a vector for the generation of a transgene has gained popularity after the genomic annotation of many organisms was completed (often based on the respective BAC library). Large‐scale generation of BAC transgenic mice has proven that BAC transgene approaches have less integration position effects and dosage artifacts when compared with traditional transgenic approaches. Also, a BAC can achieve the same tissue‐specific expression as a knock‐in of the same gene with less effort and shorter time of establishment. The λ‐RED recombinogenic system has been used to manipulate DNA constructs with site‐directed mutagenesis, truncation, and tagging with an epitope tag or as a fusion protein by homologous recombination, as well as used here to modify many BACs with various transgenes. The recombineering plasmid, pKD46, is used to fabricate BAC transgenic constructs that can be used in generating transgenic organisms as well as used in mammalian cell culture. Curr. Protoc. Mol. Biol. 95:23.14.1‐23.14.28. © 2011 by John Wiley & Sons, Inc.
Setting Up and Running an Advanced Light Microscopy and Imaging Facility
Authors: Sánchez Carlos , Muñoz Ma Ángeles , Villalba Maite , Labrador Verónica , Díez‐Guerra F. Javier 
Published: July 2011

AbstractDuring the last twenty years, interest in light microscopy and imaging techniques has grown in various fields, such as molecular and cellular biology, developmental biology, and neurobiology. In addition, the number of scientific articles and journals using these techniques is rapidly increasing. Nowadays, most research institutions require sophisticated microscopy systems to cover their investigation demands. In general, such instruments are too expensive and complex to be purchased and managed by a single laboratory or research group, so they have to be shared with other groups and supervised by specialized personnel. This is the reason why microscopy and imaging facilities are becoming so important at research institutions nowadays. In this unit, we have gathered and presented a number of issues and considerations from our own experience that we hope will be helpful when planning or setting up a new facility. Curr. Protoc. Cytom. 57:12.22.1‐12.22.21. © 2011 by John Wiley & Sons, Inc.
Photoactivation and Imaging of Optical Highlighter Fluorescent Proteins
Authors: Patterson George H. 
Published: July 2011

AbstractA major advance in the microscopic study of cells and tissues is the introduction of photoactivatable fluorescent proteins, which can specifically mark proteins of interest within a living cell. Fluorescent proteins are now available that allow a pool of molecules to be “turned on” by photoactivation. This unit discusses technical aspects for the general use of photoactivatable fluorescent proteins and introduces some specific applications in the concluding remarks. Curr. Protoc. Cytom. 57:12.23.1‐12.23.12. © 2011 by John Wiley & Sons, Inc.
Circumpolar adaptation, social change, and the development of autoimmune thyroid disorders among the Yakut (Sakha) of Siberia
Authors: Cepon Tara J. , Snodgrass J. Josh , Leonard William R. , Tarskaia Larissa A. , Klimova Tatiana M. , Fedorova Valentina I. , Baltakhinova Marina E. , Krivoshapkin Vadim G. 
Published: July 2011

AbstractObjectives:Alterations in thyroid function appear to play a central role in adaptation to Arctic environments. Increased thyroid activity in indigenous circumpolar populations is associated with upregulated metabolism, including elevated basal metabolic rate (BMR); however, little is known about the possible health consequences of these climate‐induced changes on thyroid function. The focus of the present study is to determine the prevalence of autoimmune thyroid disorders and their lifestyle and metabolic correlates among a sample of indigenous Yakut adults from northeastern Siberia.Methods:Anthropometric dimensions, health data, and plasma samples were collected among 281 adults (143 women, 138 men; ≥18 years old) from the rural community of Berdygestiakh (62°N, 127°E; pop. 4,900), Sakha Republic (Yakutia), Russia. BMR measurements were available for 96 women and 98 men. Free triiodothyronine (T3), free thyroxine (T4), thyroid stimulating hormone (TSH), and anti‐thyroid peroxidase antibody (TPOAb) levels were determined using enzyme immunoassay.Results:Twenty‐two percent of women and 6% of men had clinically elevated (>30 IU/ml) TPOAb. TPOAb was positively correlated with TSH (P < 0.01), T3 (P < 0.05), and T4 (P < 0.05) in women and showed a positive trend with T4 (P = 0.06) in men. Monthly household income was significantly positively correlated with TPOAb in men (P < 0.01) and showed a trend among women (P = 0.06).Conclusions:Although preliminary, these findings document higher than expected TPOAb levels among Yakut women and suggest possible consequences of increased thyroid activity associated with circumpolar adaptation and social change. Am. J. Hum. Biol. 2011. © 2011 Wiley‐Liss, Inc.
Modeling neolithic dispersal in Central Europe: Demographic implications
Authors: Galeta Patrik , Sládek Vladimír , Sosna Daniel , Bruzek Jaroslav 
Published: July 2011

AbstractOn the basis of new examination of ancient DNA and craniometric analyses, Neolithic dispersal in Central Europe has been recently explained as reflecting colonization or at least a major influx of near eastern farmers. Given the fact that Neolithic dispersal in Central Europe was very rapid and extended into a large area, colonization would have to be associated with high population growth and fertility rates of an expanding Neolithic population. We built three demographic models to test whether the growth and fertility rates of Neolithic farmers were high enough to allow them to colonize Central Europe without admixture with foragers. The principle of the models is based on stochastic population projections. Our results demonstrate that colonization is an unlikely explanation for the Neolithic dispersal in Central Europe, as the majority of fertility and growth rate estimates obtained in all three models are higher than levels expected in the early Neolithic population. On the basis of our models, we derived that colonization would be possible only if (1) more than 37% of women survived to mean age at childbearing, (2) Neolithic expansion in Central Europe lasted more than 150 years, and (3) the population of farmers grew in the entire settled area. These settings, however, represent very favorable demographic conditions that seem unlikely given current archaeological and demographic evidence. Therefore, our results support the view that Neolithic dispersal in Central Europe involved admixture of expanding farmers with local foragers. We estimate that the admixture contribution from foragers may have been between 55% and 72%. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Graphen: Materialien im Flachland (Nobel‐ Aufsatz)
Authors: Novoselov Kostya S. 
Published: July 2011

AbstractGleich der Welt von Abbotts “Flächenland” ist auch die Welt von Graphen eine zweidimensionale. Und ebenso wie “Flächenland” ein “Märchen mit vielerlei Dimensionen” ist, ist auch Graphen viel mehr als nur ein flacher Kristall. Graphen hat eine Vielzahl ungewöhnlicher Eigenschaften, die oftmals einzigartig oder denen von anderen Materialien überlegen sind. In diesem Aufsatz möchte ich erläutern, warum ich (und viele andere) mich davon so sehr habe faszinieren lassen, und den Leser dazu einladen, meine Begeisterung bei der Erforschung dieses Materials mitzuerleben.
Graphene: Materials in the Flatland (Nobel Lecture)
Authors: Novoselov Kostya S. 
Published: July 2011

AbstractMuch like the world described in Abbott’s “Flatland”, graphene is a two‐dimensional object. And, as “Flatland” is “A Romance of Many Dimensions”, graphene is much more than just a flat crystal. It possesses a number of unusual properties which are often unique or superior to those in other materials. In this brief lecture I would like to explain the reason for my (and many other people’s) fascination with this material, and invite the reader to share some of the excitement I’ve experienced while researching it.
Repetitive controller design for optimal performance
Authors: Chen Wentao , Lin Yechun 
Published: July 2011

AbstractIn this paper, a repetitive controller design method is proposed for optimal performance. Firstly, to compensate for phase lag introduced by the low‐pass filter in the scheme, the dead time of the repetitive controller is modified. Secondly, a lead compensator is introduced to the repetitive controller, which not only widens the bandwidth of the low‐pass filter, but also improves system gain at high frequencies. The optimal parameters of the repetitive controller are obtained by solving two optimization problems. A numerical example is provided to illustrate the validity of the proposed method.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Verbesserte Bemessungsrichtlinien für Bewehrte Elastomerlager
Authors: Gerharer Ulrich , Strauss Alfred , Bergmeister Konrad 
Published: July 2011

AbstractDer Aufsatz stellt eine Zusammenfassung der im Rahmen eines FWF‐Projekts (Fonds zur Förderung der wissenschaftlichen Forschung in Österreich) erarbeiteten Verbesserung der Bemessungsrichtlinien für bewehrte Elastomerlager dar. Die Untersuchungen sind eine Reaktion auf die Defizite der derzeitigen Normenlage für statisch und dynamisch beanspruchte Elastomerlager im Bauwesen. Die in den Normen getroffenen Vereinfachungen sowie die Widersprüche zwischen den Normen [1] und [2] werden hinterfragt. Darüber hinaus wird die Diskrepanz zwischen den vereinfachten Bemessungsansätzen und dem komplexen mechanischen Verhalten von Elastomerlagern thematisiert.Advanced Design Guidelines for Fiber Reinforced Elastomeric Bearings. This paper represents the summary of the development of advanced design guidelines for elastomeric bearings acquired in the course of a FWF project. This research is a reaction on the deficits of the current design codes for statically and dynamically loaded elastomeric bearings. Simplifications and contradictions of the design codes [1] and [2] are discussed. Furthermore the discrepancy between the simplified analytical formulations and the complex bearing behavior is described.
Verfahren für Biegeverstärkungen an Stahlbetonbauteilen
Authors: Jesse Frank , Kaplan Felix 
Published: July 2011

AbstractIm Falle nicht ausreichender Tragfähigkeit eines Stahlbetonbauteils liegt die Entscheidung für eine Verstärkung oder einen Ersatz beim Tragwerksplaner. In aller Regel kommen mehrere Möglichkeiten in Betracht, darunter auch verschiedene Verfahren der Ertüchtigung der Zugzone. Der Beitrag stellt den aktuellen Stand der Technik der Verstärkungsverfahren (Spritzbeton, geklebte Carbonfaserkunststoffe und Textilbeton) für Verstärkungen der Zugzone von Biegebauteilen gegenüber, erläutert die charakteristischen Eigenschaften und Anwendungsbereiche und fasst die wesent lichen Kriterien in einer einfach handhabbaren Entscheidungsmatrix zusammen, um den Ingenieur bei der Entscheidungsfindung zu unterstützen.Methods for flexural strengthening of RC members. In case of insufficient capacity of an RC structural member the decision making on strengthening or replacement is up to the design engineer. Generally, several options are taken into consideration, among others also different techniques for tension zone strengthening. This paper gives an overview on state of the art tension zone strengthening techniques with non prestressed reinforcement for bending members. Typical properties and application areas are characterised and essential criterions are summarised in a simple to handle decision matrix to support design engineers decision making process.
Bahrmühlenviadukt — Erhaltung und Ertüchtigung der 15‐Bogen‐Natursteinbrücke an der Strecke Neukieritzsch—Chemnitz
Authors: Hering Elke , Bösche Thomas , Burkhardt Rüdiger 
Published: July 2011

AbstractIn den Jahren 2007 bis 2010 wurden durch die Deutsche Bahn AG anspruchsvolle Instandsetzungs‐ und Ertüchtigungsmaßnahmen am Bahrmühlenviadukt bei Chemnitz ausgeführt. Erläutert werden die zur Qualitätssicherung wichtigen Planungsschritte am Beispiel der denkmalgeschützten Natursteinbogenbrücke. Beschrieben werden die Planungsziele und ausgewählte Ergebnisse der Bestands‐ und Bauwerkszustandsanalyse als wichtige Projektgrundlagen.Das Projekt liefert einen überzeugenden Nachweis für die technische Eignung und Anpassungsfähigkeit von historischen Gewölbebogenbrücken an moderne Nutzungsanforderungen.
Tragsicherheit einer historischen Sandsteinbalustrade
Authors: Curbach Manfred , Hampel Torsten , Scheerer Silke , Liebau Henning 
Published: July 2011

AbstractIn diesem Bericht wird der Belastungstest an einer historischen Sandsteinbalustrade beschrieben. Die Balustrade ist Bestandteil einer Freitreppe, die für die öffentliche Nutzung freigegeben werden soll. Die statische Berechnung war in diesem Fall nicht ausreichend, da die Konstruktion nur in Teilen bekannt war. Mit dem In‐situ‐Test konnte aber experimentell eine ausreichende Sicherheit nachgewiesen werden.Structural safety of a historic sandstone balustrade. In this report the load test on a historic sandstone balustrade is described. The balustrade is part of an outside staircase that should be opened for public use. The static proof in this case was not sufficient because the construction was known only in part. With the experimental in‐situ‐test could be demonstrated adequate security.
Isothermal titration calorimetry study of the polyelectrolyte complexation of xanthan and chitosan samples of different degree of polymerization
Authors: Maurstad Gjertrud , Kitamura Shinichi , Stokke Bjørn T. 
Published: July 2011

AbstractMixing oppositely charged polyelectrolytes in aqueous solutions leads to the spontaneous formation of polyelectrolyte complexes. Here, we characterize the interaction between xanthan of two different chain lengths, a tri‐glucosamine and a chitosan polymer by isothermal titration calorimetry (ITC). Analysis of the experimental thermodynamic data assuming a single set of identical sites indicated both enthalpic and entropic contributions to the overall interaction in the interaction between xanthan and tri‐glucosamine. The relative contribution of entropy compared to enthalpy was found to be largest for the shortest chain length of xanthan. Using a chitosan polymer instead of tri‐glucosamine gave rise to two different stages in the interaction process. A model where the first stage of the ITC curve represent an initial polyelectrolyte complexation stage followed by aggregation on further titration of chitosan to the xanthan is suggested. Ultrastructure images by applying atomic force microscopy at some selected extents of titration are consistent with the two‐stage interpretation of the thermodynamic data. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 1–10, 2012.
Optimization of flowrate for expansion of human embryonic stem cells in perfusion microbioreactors
Authors: Titmarsh Drew , Hidalgo Alejandro , Turner Jennifer , Wolvetang Ernst , Cooper‐White Justin 
Published: July 2011

AbstractMicrofluidic systems create significant opportunities to establish highly controlled microenvironmental conditions for screening pluripotent stem cell fate. However, since cell fate is crucially dependent on this microenvironment, it remains unclear as to whether continual perfusion of culture medium supports pluripotent stem cell maintenance in feeder‐free, chemically defined conditions, and further, whether optimum perfusion conditions exist for subsequent use of human embryonic stem cell (hESCs) in other microfludic systems. To investigate this, we designed microbioreactors based on resistive flow to screen hESCs under a linear range of flowrates. We report that at low rates (conditions where glucose transport is convection‐limited with Péclet number <1), cells are affected by apparent nutrient depletion and waste accumulation, evidenced by reduced cell expansion and altered morphology. At higher rates, cells are spontaneously washed out, and display morphological changes which may be indicative of early‐stage differentiation. However, between these thresholds exists a narrow range of flowrates in which hESCs expand comparably to the equivalent static culture system, with regular morphology and maintenance of the pluripotency marker TG30 in >95% of cells over 7 days. For MEL1 hESCs the optimum flowrate also coincided with the time‐averaged medium exchange rate in static cultures, which may therefore provide a good first estimate of appropriate perfusion rates. Overall, we demonstrate hESCs can be maintained in microbioreactors under continual flow for up to 7 days, a critical outcome for the future development of microbioreactor‐based screening systems and assays for hESC culture. Biotechnol. Bioeng. 2011;108: 2894–2904. © 2011 Crown in the right of Canada.
Optimized Biocatalytically Active Static Emulsions for Organic Synthesis in Nonaqueous Media
Authors: Wu Changzhu , Kraume Matthias , Ansorge‐Schumacher Marion B. 
Published: July 2011

AbstractLiterature reports biocatalytically active static emulsions (BASE) as promising systems for the preparation of biocatalysts designed for synthetic use in organic media. Their excellent catalytic performance is attributed to the numerous micropools of dissolved enzymes independently dispersed in silicone beads. Here, a systematic study of the structure and morphology of BASE and optimization in terms of bead size distribution and overall catalytic performance is presented. The study relies on beads obtained by using a novel preparation method that enables a considerably improved reproducibility of the particle size and catalytic activity in separate batches. A large interfacial area of 0.023 m2 g−1 material was calculated. The adjustment of bead composition increased the apparent catalytic activity of entrapped lipase A from Candida antarctica (CalA) to 0.71 U gBASE−1, which is almost twofold higher than that previously reported. The specific activity remained in the range of prototype BASE (0.21 U mgprotein−1), which nevertheless is about 53 times higher than that reported for CalA entrapped in a sol–gel.
Cubic and Hexagonal Mesoporous Carbon in the Pores of Anodic Alumina Membranes
Authors: Schuster Jörg , Keilbach Andreas , Köhn Ralf , Döblinger Markus , Dörfler Thilo , Dennenwaldt Teresa , Bein Thomas 
Published: July 2011

AbstractCubic and circular hexagonal mesoporous carbon phases in the confined environment of the pores of anodic alumina membranes (AAM) were obtained by organic–organic self‐assembly of a preformed oligomeric resol precursor and the triblock copolymer templates Pluronic F127 or P123, respectively. Casting and solvent evaporation were followed by self‐assembly and the formation of a condensed wall material by thermopolymerization of the precursor oligomers, thus resulting in mesostructured phenolic resin phases. Subsequent thermal decomposition of the surfactant and carbonization were achieved through thermal treatment at temperatures up to 1000 °C under an inert atmosphere. The resulting hierarchical mesoporous composite materials were characterized by small‐angle X‐ray scattering and nitrogen‐sorption measurements. The structural features were directly imaged in TEM cross‐sections of the composite membranes. For both structures, the AAM pores were completely filled and no shrinkage was observed due to strong adhesion of the carbon‐wall material to the AAM pore walls. As a consequence, the pore size of the mesophase system stays almost constant even after thermal treatment at 1000 °C.
Self‐Assembly of Supramolecular Architectures and Polymers by Orthogonal Metal Complexation and Hydrogen‐Bonding Motifs
Authors: Grimm Felix , Ulm Nadine , Gröhn Franziska , Düring Jasmin , Hirsch Andreas 
Published: July 2011

AbstractA modular construction kit with two orthogonal noncovalent binding sites for self‐assembly of supramolecular architectures is presented. The heteroditopic building blocks contain a terpyridine (tpy) unit for coordination of metal ions and a Hamilton receptor for multiple H‐bonding of cyanuric acid derivatives. The association constants of ligand binding of MII complexes (M=Ru, Zn, Fe, and Pt) with a dendritic end cap were determined to be in the range of 102 and 104 L mol−1 in chloroform. The capabilities for binding of metal ions were investigated by 1H NMR and UV/Vis spectroscopy. The Fe complexes are most appropriate for the generation of discrete and high‐ordered architectures due to their strong tendency to form FeL2 complexes. Superstructures are readily formed in a one‐pot procedure at room temperature. No mutual interactions between the orthogonal binding motifs were observed, and this demonstrates the highly specific nature of each binding process. Decomplexation experiments were carried out to examine the reversibility of Fe–tpy coordination. Substitution of the terminal end cap with a homoditopic bis‐cyanurate linkage leads to formation of an iron‐containing supramolecular strand. Formation of coordination polymers was confirmed by viscosity measurements. The supramolecular polymer strands can be reversibly cleaved by addition of a terminating cyanuric acid building block, and this proves the dynamic nature of this noncovalent polymerization process.