bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tissue culture of rubber: past, present and future prospects
Authors: Nayanakantha NMC , Seneviratne P 
Published: June 2009

In rubber, the current propagation method of grafting on to unselected seedlings, maintains intraclonal heterogeneity for vigour and productivity and hence a great improvement may be expected by using micropropagation in vitro. Micropropagation with nodal and shoot tip explants derived from seedlings are possible as with mature clonal explants. The major problem in using clonal material from mature trees of Hevea is the failure to produce an adequate tap root system necessary for tree stability, and the poor response to culture conditions. The latter problem has been over come to a significant level by in vitro micrografting. Recently, there has been an increasing interest in the induction of somatic embryogenesis in Hevea using different explants, media compositions and conditions, especially for use in genetic transformation studies. Successful somatic embryo formation and plant regeneration have been reported by a few researchers in different countries using limited genotypes of Hevea. Attempts to induce somatic embryos from high yielding Sri Lankan clones have not been successful until the late 1990s. The frequency of somatic embryo induction was found to be very low and non-synchronous, its germination remained very difficult and thus Hevea embryogenic system needed further investigation. There is no large scale commercial application of tissue culture techniques for mass propagation of clonal Hevea as yet, either by microcuttings or by somatic embryogenesis. However, there is sufficient progress at research level to suggest that tissue culture of Hevea can and should be further developed. Key words: Hevea brasiliensis, micropropagation, microcuttings, somatic embryogenesis doi: 10.4038/cjsbs.v36i2.486 Cey. J. Sci. (Bio. Sci.) 36 (2): 116-125, 2007
Supercritical‐Fluid‐Assisted One‐Pot Synthesis of Biocompatible Core(γ‐Fe2O3)/Shell(SiO2) Nanoparticles as High Relaxivity T2‐Contrast Agents for Magnetic Resonance Imaging
Authors: Taboada Elena , Solanas Raul , Rodríguez Elisenda , Weissleder Ralph , Roig Anna 
Published: June 2009

AbstractMonodisperse iron oxide/microporous silica core/shell composite nanoparticles, core(γ‐Fe2O3)/shell(SiO2), with a diameter of approximately 100 nm and a high magnetization are synthesized by combining sol–gel chemistry and supercritical fluid technology. This one‐step processing method, which is easily scalable, allows quick fabrication of materials with controlled properties and in high yield. The particles have a specific magnetic moment (per kg of iron) comparable to that of the bulk maghemite and show superparamagnetic behavior at room temperature. The nanocomposites are proven to be useful as T2 MRI imaging agent. They also have potential to be used in NMR proximity sensing, theranostic drug delivery, and bioseparation.
Die biosynthetische Grundlage der Polyketid‐Vielfalt
Authors: Hertweck Christian 
Published: June 2009

AbstractMolekulares Lego: Polyketide bilden eine äußerst vielfältige Gruppe von Naturstoffen mit faszinierenden Kohlenstoffgerüsten (siehe Beispiele), die aus einfachen Acyl‐Bausteinen synthetisiert werden. Das Zusammenspiel von Chemie, Biochemie und Genetik lieferte wichtige Einblicke in die Programmierung des Polyketid‐Aufbaus und die beteiligten, komplexen Enzymsysteme. Dieser Aufsatz behandelt aktuelle Entwicklungen auf diesem Forschungsgebiet.magnified imagePolyketide bilden eine der größten Naturstoffklassen. Viele dieser Verbindungen – oder Derivate davon – sind wichtige Therapeutika, aber viele sind auch berüchtigte, Lebensmittel verderbende Toxine oder Virulenzfaktoren. Besonders bemerkenswert ist, dass sich die Verbindungen dieser heterogenen Gruppe, zu denen Polyether, Polyene, Polyphenole, Makrolide und Endiine gehören, hauptsächlich von einem der einfachsten natürlichen Bausteine ableiten: Essigsäure. Chemische, genetische und biochemische Untersuchungen haben Aufschluss über die Biosyntheseprogramme gegeben, die zur enormen Strukturvielfalt von Polyketiden führen. Dieser Aufsatz behandelt kürzlich aufgeklärte Biosynthesemechanismen, nach denen höchst unterschiedliche und komplexe Moleküle synthetisiert werden.
Quantitative Assessment of Nanoparticle Single Crystallinity: Palladium‐Catalyzed Splitting of Polycrystalline Metal Oxide Nanoparticles
Authors: Kim Hyunjin , Lee Myounghoon , Kim Youngki , Huh Jiyoung , Kim Heonjo , Kim Minsik , Kim Taekhoon , Phan Vu Ngoc , Lee Young‐Boo , Yi Gi‐Ra , Haam Seungjoo , Lee Kwangyeol 
Published: June 2009

AbstractBlick in die Kristallkugel: Ein einfaches Pd‐katalysiertes Ätzverfahren macht die polykristalline Beschaffenheit von Fe3O4‐ (siehe Bild), Fe2O3‐, MnFe2O4‐, CoFe2O4‐ und MnO‐Nanopartikelsystemen sichtbar. Die Messmethode beruht auf dem schnellen Ätzvorgang an den Domänengrenzen in di‐ oder polykristallinen Nanokristallen und ermöglicht eine quantitative Bestimmung der Polykristallinität.magnified image
White Luminescence from Multiple‐Dye‐Doped Electrospun DNA Nanofibers by Fluorescence Resonance Energy Transfer
Authors: Ner Yogesh , Grote James G. , Stuart Jeffrey A. , Sotzing Gregory A. 
Published: June 2009

AbstractRichtig weiß: Durch Elektrospinnen von DNA‐Komplexen lassen sich Nanofasern mit hochgeordneter Morphologie herstellen, die als Matrix für homogen verteilte Chromophore dienen. Die Emissionsfarbe kann über die Wahl des Donor‐Akzeptor‐Paars und das Dotierungsverhältnis eingestellt werden. Die Emission von reinem weißem Licht durch die Nanofasern wird präsentiert (siehe Bild).magnified image
Cycloadditions in the Total Synthesis of Sporolide B
Authors: Li Pengfei , Menche Dirk 
Published: June 2009

AbstractClosing rings: A recent total synthesis of sporolide B by the Nicolaou group is highlighted by two advantageous cycloadditions. Firstly, a regioselective [2+2+2] cycloaddition of highly elaborate substrates assembles the halogenated aromatic ring and subsequently an ortho‐quinone [4+2] cyclization closes stereoselectively the dioxane‐containing macrocycle. These approaches should be considered in complex target syntheses.magnified image
Mechanical properties and flammability of polycarbonate alloys containing nanosize additives
Authors: Zhang Zhiyi , Liu Yaqing , Zhao Guizhe 
Published: June 2009

AbstractDifferent organic–inorganic composite particles [montmorillonite/poly(butyl acrylate) (PBA)/poly(methyl methacrylate) (PMMA), SiO2/PBA/PMMA, and CaCO3/PBA/PMMA] were synthesized by emulsion polymerization. Furthermore, polycarbonate (PC) alloys were prepared via the doping of these composite particles into PC with a twin‐screw extruder. The structure, mechanical properties, and flammability of the PC alloys were studied in detail. Although the tensile modulus of PC decreased a little, the flexibility and impact resistance were improved by the addition of these composite particles. This result was attributed to the fact that the composite particles were well dispersed in the PC matrix, with a cocontinuous phase formed between the particles and PC. In addition, the combustion behavior of the PC alloys, compared with that of the pure PC, resulted from a ceramic‐like char that formed on the surface of the PC alloys during burning. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of interactions between poly(vinyl alcohol) and urea on the water solubility of poly(vinyl alcohol)
Authors: Lei Chuntang , Wang Qi , Li Li 
Published: June 2009

AbstractPoly(vinyl alcohol) (PVA) is an important water‐soluble polymer. Its many applications (e.g., textile sizing, dispersants, and adhesives) greatly depend on its water solubility and particularly on its dissolution rate in water. In this study, urea, combined with methanol, was adopted to improve the water solubility of PVA. The structures, properties, and dissolving mechanism of the modified PVA were studied with Fourier transform infrared spectroscopy, NMR, laser light scattering, differential scanning calorimetry, and wide‐angle X‐ray diffraction. The results showed that through specific chemical reactions between PVA and urea in methanol, isocyanate and methyl carbamate groups were generated on the lateral chains of PVA. These large side groups could effectively expand PVA macromolecular chains and hence increase their intermolecular distance, weaken the intramolecular and intermolecular hydrogen bonds of PVA, change the aggregation structure of PVA, and decrease its lattice energy and crystallinity. In addition, the isocyanate groups on the PVA macromolecular chains strongly interacted with water. All these effects benefited the water solubility of PVA. Therefore, the dissolution rate of the modified PVA increased by 50% versus that of the neat PVA, and the quality of the modified PVA aqueous solution was improved quite a bit. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Film blowing of silane‐modified polyethylene
Authors: Dintcheva Nadka Tzankova 
Published: June 2009

AbstractThe grafting of vinyltriethoxysilane (VTES) onto polyethylene (PE) with the help of small amounts of peroxides was investigated to film‐blow these modified materials. The degree of crosslinking was kept very low to achieve good melt processability and improved mechanical properties. The possibility of obtaining modified PE films with improved properties and regularly distributed crosslinking with a single processing step demonstrates the uniqueness of this study. The additive concentration was established through preliminary studies; with a batch mixer, it was possible to process the modified PE in the film‐blowing operation. Water treatment of the modified films after film blowing allowed for improved properties without the processability being affected. The modification of PE was followed with mechanical, rheological, and extraction tests and with calorimetric analyses. The variations of the main mechanical properties of the films were very important from an application point of view. The elastic modulus and tear strength of the films for both extrusion directions (machine and transverse) increased with the VTES concentration increasing and even more with the addition of a small quantity of a peroxide. Some reductions of the tensile strength and elongation at break were observed, but these reductions were not considerable. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Films from oat spelt arabinoxylan plasticized with glycerol and sorbitol
Authors: Mikkonen Kirsi S. , Heikkinen Susanna , Soovre Annemai , Peura Marko , Serimaa Ritva , Talja Riku A. , Helén Harry , Hyvönen Lea , Tenkanen Maija 
Published: June 2009

AbstractThe development of packaging films based on renewable materials is an important and active area of research today. This is the first extensive study focusing on film‐forming properties of an agrobiomass byproduct, namely, oat spelt arabinoxylan. A plasticizer was needed for cohesive film formation, and glycerol and sorbitol were compared. The tensile properties of the films varied with the type and amount of the polyol. With a 10% (w/w) plasticizer content, the films containing glycerol had higher tensile strength than the films containing sorbitol, but with a 40% plasticizer content, the result was the opposite. Sorbitol‐plasticized films retained their tensile properties better than films with glycerol during 5 months of storage. The films were semicrystalline with similar crystallinity indices of 0.20–0.26. The largest crystallites (9.5 nm) were observed in the film with 40% glycerol. The softening of films with 40% (w/w) glycerol started at a significantly lower relative humidity (RH) than that of the corresponding sorbitol‐containing films. The films with sorbitol also had lower water vapor permeability (WVP) than the films with glycerol. The films plasticized with 10% (w/w) sorbitol had a WVP value of 1.1 g mm/(m2·d·kPa) at the RH gradient of 0/54%. The oxygen permeability of films containing 10% (w/w) glycerol or sorbitol was similar: 3 cm3·μm/(m2·d·kPa) at 50–75% RH. A higher plasticizer content resulted in more permeable films. Permeation of sunflower oil through the films was not detected. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis of poly(methyl methacrylate‐g‐glycidyl azide) graft copolymers using N, N‐dithiocarbamate‐mediated iniferters
Authors: Al‐Kaabi Khalifa , Van Reenen Albert J. 
Published: June 2009

AbstractA glycidyl azide polymer with pendent N, N‐diethyl dithiocarbamate groups (GAP‐DDC) was prepared by the reaction of poly(epichlorohydrin) (PECH) with pendent N, N‐diethyl dithiocarbamate groups (PECH‐DDC) and sodium azide (NaN3) in dimethylformamide (DMF). It was then used as a macro‐photoinitiator for the graft polymerization of methyl methacrylate (MMA). Photopolymerization was carried out in a photochemical reactor at a wavelength greater than 300 nm. Conversion was determined gravimetrically and first‐order time conversion plot for the polymerization system showed linear increase with the polymerization time indicating that polymerization proceed in controlled fashion. The molecular weight distribution (Mw/Mn) was in the range of 1.4–1.6 during polymerization. The formation of poly(methyl methacrylate‐g‐glycidyl azide) (PMMA‐g‐GAP) graft copolymer was characterized by gel permeation chromatography, FT‐IR spectroscopy, Thermogravimetric analysis, and differential scanning calorimetry. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of grafted copolymers of aromatic polyimides and ε‐caprolactam
Authors: Volkova Tat'yana V. , Vygodskii Yakov S. , Zabegaeva Olesya N. , Zubavichus Yan V. , Il'ina Marina N. , Krasnov Alexander P. , Afonicheva Ol'ga V. , Lozinskaya Elena I. , Garbuzova Irina A. , Shaplov Alexander S. 
Published: June 2009

AbstractAnionic polymerization of ε‐caprolactam was performed in the presence of only 5 wt % of aromatic polyimides having five‐ and six‐membered imide cycles and bearing hexafluoroisopropylidene, ether, fluorene, siloxane, phthalide, or SO3H groups, both in the polymer backbone and as side moieties. The synthesized new copolymers were fully characterized by IR spectroscopy, thermomechanical analysis, dilatometry, and X‐ray diffraction. Tough and frictional properties of the obtained copolymers were estimated as well. It was found that on the selection of polyimide activator it is possible to gain the desirable control over the polymer properties, namely the gel‐fraction content, phase composition, compression modulus, notched Izod impact strength, temperature of frictional contact, friction coefficient, etc. These investigations will facilitate the choice of the optimum macromolecular activator for the modification of both the synthetic method and the properties of the commercial polycaproamide. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and properties of superabsorbent hydrogels based on guar gum and succinic anhydride
Authors: Fujioka Rumiko , Tanaka Yukari , Yoshimura Toshio 
Published: June 2009

AbstractSynthesis of novel superabsorbent hydrogels has been investigated with the reaction of guar gum and succinic anhydride (SA), using of 4‐dimethylaminopyridine as esterification promoter and water or dimethylsulfoxide (DMSO) as reaction solvent, followed by NaOH neutralization. Hydrogels prepared in water exhibited somewhat higher water absorbency than those prepared in DMSO; its maximum water absorbency in pure water and aqueous 0.9% NaCl solution was ca. 200 g/g and 80 g/g, respectively. These values were considerably higher than those of hydrogels obtained from starch in a similar way. The products in this study biologically degraded up to 70–80% after 10 days in activated sludge, which shows their excellent biodegradability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
π‐Conjugation Enlargement Toward the Creation of Multi‐Porphyrinic Systems with Large Two‐Photon Absorption Properties
Authors: Aratani Naoki , Kim Dongho , Osuka Atsuhiro 
Published: June 2009

AbstractRecent progress in the synthesis of covalently linked porphyrin arrays with large two‐Photon absorption (TPA) cross‐section values has been reviewed with a particular focus on the relation of TPA properties with molecular structures. Covalently linked porphyrin arrays continue to be important and useful for the creation of functional materials owing to their chemical robustness, fine‐tuning, and easy manipulation. More importantly, the porphyrin electronic systems are quite susceptible to periphery conjugative perturbations, hence allowing facile fabrications to extensively delocalized systems. This property has been used for exploration of porphyrin‐based molecular systems with large TPA values, demonstrating a general trend that enhancement in electronic interactions leads to large TPA cross‐section values. As a representative example, the porphyrin tapes exhibit larger TPA values owing to the fully delocalized nature of the π‐electrons. This Focus Review will help understand the structural requirements of porphyrin arrays with large TPA values, which will be useful for future applications in optical communication in the IR region.
Qualitätsprüfung für Energieausweis‐Software
Authors: Fehlauer Klaus , Winkler Heiko , Brätz Marcel 
Published: June 2009

AbstractNach der Einführung der Energieeinsparverordnung 2007 (EnEV 2007) beauftragte das Bundesamt für Bauwesen und Raumordnung (BBR) ein Forschungsprojekt, um die am Markt verfügbare Software zur EnEV 2007 einer Qualitätsprüfung zu unterziehen. Der Zweck des Projektes war die Prüfung hinsichtlich einer korrekten Nachweisführung und Energiepassausstellung sowie die Erarbeitung von Methoden zur Qualitätsprüfung und ‐sicherung mit dem Ziel, Transparenz bei den am Markt vorhandenen Softwarelösungen zu schaffen. Darüber hinaus sollte durch die Bereitstellung von Testmodulen die Möglichkeit geschaffen werden, vorhandene Softwareprodukte durch das Aufdecken von Mängeln stetig weiter zu entwickeln, um so die Qualität der Produkte auf hohem Niveau dauerhaft zu sichern. Es wurden 15 Softwareprogramme für Nichtwohngebäude und 13 Programme für Wohngebäude für die Bedarfsberechnung nach DIN 4108‐6 und DIN V 4701‐10 und für Verbrauchsausweiserstellung untersucht. Im Rahmen dieser Veröffentlichung wurden schwerpunktmäßig die Ergebnisse für die Bedarfsberechnungen auf Basis von DIN V 18599 für den Nichtwohngebäudebereich vorgestellt.Quality tests for Energy Passport software.Shortly after the introduction of the 2007 Building Energy Conservation Ordinance (EnEV 2007), the German Institute for Applied Information Technology in Construction (IAIB) was commissioned by the German Federal Office for Building and Regional Planning (BBR) to carry out quality tests for the EnEV 2007 software available on the market. The specified project aims were to check calculation and Energy Passport issuing procedures and the development of quality assurance methods with the aim of creating transparency regarding the software solutions available on the market. 15 software programs for office buildings and 13 software programs for residential buildings were examined with regard to the determination of energy demand according to DIN V 18599 and with regard to energy consumption.
“Race salience” in juror decision‐making: misconceptions, clarifications, and unanswered questions
Authors: Sommers Samuel R. , Ellsworth Phoebe C. 
Published: June 2009

AbstractIn two frequently cited articles, Sommers and Ellsworth (2000, 2001) concluded that the influence of a defendant's race on White mock jurors is more pronounced in interracial trials in which race remains a silent background issue than in trials involving racially charged incidents. Referring to this variable more generally as “race salience,” we predicted that any aspect of a trial that leads White mock jurors to be concerned about racial bias should render the race of a defendant less influential. Though subsequent researchers have further explored this idea of “race salience,” they have manipulated it in the same way as in these original studies. As such, the scope of the extant literature on “race salience” and juror bias is narrower than many realize. The present article seeks to clarify this and other misconceptions regarding “race salience” and jury decision‐making, identifying in the process avenues for future research on the biasing influence of defendant race. Copyright © 2009 John Wiley & Sons, Ltd.
Advanced dynamical risk analysis for monitoring anaerobic digestion process
Authors: Hess Jonathan , Bernard Olivier 
Published: June 2009

AbstractMethanogenic fermentation involves a natural ecosystem that can be used for waste water treatment. This anaerobic process can have two locally stable steady‐states and an unstable one making the process hard to handle. The aim of this work is to propose analytical criteria to detect hazardous working modes, namely situations where the system evolves towards the acidification of the plant. We first introduce a commonly used simplified model and recall its main properties. To assess the evolution of the system we study the phase plane and split it into nineteen zones according to some qualitative traits. Then a methodology is introduced to monitor in real‐time the trajectory of the system across these zones and determine its position in the plane. It leads to a dynamical risk index based on the analysis of the transitions from one zone to another, and generates a classification of the zones according to their dangerousness. Finally the proposed strategy is applied to a virtual process based on model ADM1. It is worth noting that the proposed approach do not rely on the value of the parameters and is thus very robust. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Oxidative Folding of Peptides and Proteins. Edited by Johannes Buchner and Luis Moroder.
Authors: Neundorf Ines , Beck‐Sickinger Annette G. 
Published: June 2009

AbstractRSC, Cambridge 2009, xxi+429 pp., hardcover £ 119.95—ISBN 978‐0‐85404‐148‐0
“Valve‐in‐valve” for the treatment of paravalvular leaks following transcatheter aortic valve implantation
Authors: Rodés‐Cabau Josep , Dumont Eric , Doyle Daniel 
Published: June 2009

AbstractTranscatheter aortic valve implantation (TAVI) is commonly associated with some degree of aortic regurgitation (AR) secondary to the presence of paravalvular leaks. We present the case of an 86‐year‐old woman diagnosed with severe aortic stenosis who underwent TAVI with a 23‐mm Edwards‐SAPIEN valve. The procedure complicated with a severe paravalvular leak following TAVI that was unresponsive to balloon postdilation. This complication was successfully managed with the implantation of a second valve of the same diameter within the first one (“valve‐in‐valve”) resulting in trivial residual AR and the absence of significant transvalvular gradient at the end of the procedure. © 2009 Wiley‐Liss, Inc.
Passing sheaths and electrode catheters through inferior vena cava filters: Safer than we think?
Authors: Kanjwal Yousuf , John Jerry M. , Burket Mark W. 
Published: June 2009

AbstractInferior vena cava (IVC) filters are being inserted with increasing frequency for the prevention of pulmonary embolus. Previous case reports have documented the passage of up to three electrode catheters or an individual long sheath through an IVC filter. The current report expands on prior series with regard to the number of devices used. We describe our experience in 10 patients in whom up to five electrode catheters and/or sheaths were placed through an IVC filter using a transfemoral approach under fluoroscopic guidance without routine venography. Devices were successfully introduced and withdrawn in each case without filter dislodgment. Our series illustrates the feasibility and safety of passing multiple electrode catheters and long sheaths through an IVC filter. Evidence is accumulating to suggest that an IVC filter should not be considered an absolute contraindication to performing diagnostic or therapeutic procedures. © 2009 Wiley‐Liss, Inc.