bluuebunny/crossref_metadata_2025 huggingface dataset:
Doerte Bischoff / Martina Wagner-Egelhaaf (Hgg.), Weibliche Rede – Rhetorik der Weiblichkeit. Studien zum Verhältnis von Rhetorik und Geschlechterdifferenz. 2003
Authors: Tabah Mireille
Published: January 2008

Der sehr dichte und höchst aufschlußreiche Sammelband dokumentiert die Beiträge zu einer Tagung, die im Rahmen des seit 1997 von Martina Wagner-Egelhaaf geleiteten gleichnamigen Forschungsprojekts im Juli 2001 an der Universität Münster veranstaltet wurde. In 16 Aufsätzen, die in vier Sektionen unterteilt sind, wird die im Titel angedeutete doppelte Thematik an Beispielen aus Literatur, Philosophie und Religion, Mythologie und Film, Recht und Politik sowie aus verschiedenen Epochen von der griechischen Antike bis zur Gegenwart auf überzeugende Weise erörtert. Unter der Überschrift „Weibliche Rede“ wird „die Geschichte der weiblichen Wortergreifung“ (S. 36) untersucht: Wann, wo, wie und unter welchen Bedingungen haben Frauen trotz aller sozio-kulturellen Vorurteile, die ihnen Redegewandtheit absprechen, ihre Stimme erhoben? Die Frage nach der „Rhetorik der Weiblichkeit“ richtet den Blick auf die Rhetorizität der traditionellen Vorstellungen von Weiblichkeit. Untersucht wird, inwiefern die Rhetorik als männlich geprägte Disziplin zur Konstruktion von Weiblichkeit im kulturellen Diskurs beigetragen hat. Rhetorik wird dabei nicht nur als Lehre und Kunst der wirkungsvollen Rede verstanden, sondern sie wird als Bestandteil der diskursiven Produktion und Ontologisierung von Weiblichkeitsentwürfen, die Frauen in der Gesellschaft und der Kultur marginalisieren, neu perspektiviert. Das Innovative besteht gerade in der Zusammenführung von Rhetorik, Diskursanalyse und Gender Studies.
Matthias Schöning, Ironieverzicht. Friedrich Schlegels theoretische Konzepte zwischen ‚Athenäum‘ und ‚Philosophie des Lebens‘. 2002
Authors: Naschert Guido
Published: January 2008

Die Dissertation Matthias Schönings, die 2001 dem Fachbereich Literaturwissenschaft der Universität Konstanz vorgelegt wurde, unterscheidet sich in ihrer systemtheoretisch geschulten Analyse der Schlegelschen Theorieentwicklung von den inzwischen zahlreichen Studien, die dem Frühromantiker in den letzten Jahren gewidmet worden sind. Sie geht dabei von Voraussetzungen eines Modells literarischer Kommunikation aus, welches die Ausdifferenzierung und Autonomie des Sozialsystems Literatur am Ende des 18. Jahrhunderts ansetzt. Greifbar wird diese unter anderem an kommunikativen Phänomenen wie der Neufunktionalisierung rhetorischer Ironie. Die Schriften Friedrich Schlegels bilden hier ein einschlägiges Textkorpus.
Tilman Fischer, Reiseziel England. Ein Beitrag zur Poetik der Reisebeschreibung und zur Topik der Moderne (1830–1870). 2004
Authors: Maurer Michael
Published: January 2008

Der gewichtige Band vereinigt zwei Werke: eine literaturwissenschaftliche Abhandlung zur Poetik des Reiseberichts und eine kulturwissenschaftliche Abhandlung zum Englandbild des 19. Jahrhunderts. Die Quellengrundlage (im engeren Sinne) bilden etwa 80 Reiseberichte deutscher Englandreisender aus den vier Jahrzehnten der Mitte des 19. Jahrhunderts. Überflüssig zu erwähnen, daß es einen inneren Zusammenhang beider Abhandlungen gibt: Die Poetik des Reiseberichts wird abgeleitet aus der Analyse genau jener Quellen, welche zugleich hinsichtlich einer „Topik der Moderne“ zum Sprechen gebracht werden. Erstaunlicherweise betont der Autor immer wieder die hohe Konstanz beziehungsweise Entwicklungslosigkeit seines Quellencorpus: Trotz 1848 sieht er in den fokussierten Jahrzehnten keine Zäsur, keinen Fortschritt, keine allgemeine Entwicklungstendenz. Das Medium des Reiseberichts war offenkundig 1830 schon genauso ausgebildet, wie es sich die zahlreichen, zumeist zum Bildungsbürgertum zu rechnenden Autoren aneigneten. Fischer sieht Reiseberichte stark als „Medium der Wissenspräsentation“, im übrigen als „Mischform“, die geeignet war, Texte und Fragmente, Dokumente und Tabellen, Lyrisches und Aphoristisches aufzunehmen. Die eigentliche „Poetik“ dieser Gattung ist insofern mit einer Poetik der Lyrik oder des Dramas kaum zu vergleichen.
Heinz Hiebler, Hugo von Hofmannsthal und die Medienkultur der Moderne. 2003
Authors: Schanze Helmut
Published: January 2008

Die Frage nach dem berühmten „und“ in einem Titel darf auch hier gestellt werden. Zwar stehen Hugo von Hofmannsthal, sein Mediengebrauch und seine Theorien zu verschiedenen Medien, so des Kinos, im Mittelpunkt der Untersuchung; quantitativ überwiegend ist jedoch die Frage nach einer „Medienkultur den Moderne“. Der Verfasser legt nicht nur eine kompendiöse Darstellung der Mediengeschichte der Zeit Hugo von Hofmannsthals vor, er greift vielmehr weit in deren Vorgeschichte zurück und entwirft so eine umfassende Medienkulturgeschichte. Gleichwohl kommen dabei Hugo von Hofmannsthal und seine Medien nicht zu kurz. Dies ist in der Tat einerseits der besonderen medialen Konstellation des Medienumbruchs um 1900 geschuldet, die als Paradigma für eine Mediengeschichte gelten kann. Das Monopol der ‚alten Medien‘, Buch, Theater wird durchbrochen, es beginnt das Zeitalter der ‚Audiovisionen‘. Zentral aber sind auch die Beiträge Hofmannsthals zur Theorie und Praxis dieses Umbruchs. Zu erinnern ist hier vor allem an die Essays Ein Brief und Der Ersatz für die Träume, nicht zuletzt an das Konzept der Salzburger Festspiele im Sinne einer Konstruktion des kulturellen Ereignisses als Alternative im Zeitalter der Audiovisionen, dem es zugleich verpflichtet bleibt.
Jacques Le Rider, Arthur Schnitzler ou la Belle Époque viennoise. 2003 – Dagmar C. G. Lorenz (Hg.), A Companion to the Works of Arthur Schnitzler. 2003
Authors: Beniston Judith
Published: January 2008

The two volumes under review – one a single-author monograph, the other a collection of essays in Camden House's prestigious Companion series – both endeavour to make the work of Arthur Schnitzler accessible to audiences outside the German-speaking world.
Christine Meyer, Canetti lecteur de Stendhal. Construction d'une écriture autobiographique. 2004
Authors: Perrig Severin
Published: January 2008

Autobiographisches Schreiben gilt als eine der Hauptformen zur Identitätskonstruktion, deren literarische Gestaltung eine ihr eigene Struktur der Wahrheit kreiert. Speziell der Versuch, der eigenen Lebensgeschichte mittels erinnernder Erzählung gesellschaftliche Relevanz im historischen Kontext zu verleihen, stellt jeweils ein kühnes Unterfangen dar. Nur allzu bewußt versichert sich dieser Schreibprozeß im Rückgriff auf bestehende biographische Vorlagen und Muster. Das gilt insbesondere für begeisterte Leser von Biographien, wie etwa Elias Canetti (1905–1994) einer gewesen ist. Entsprechend läßt sich auch seine Aufzeichnung von 1982 verstehen: „In allen Autobiographien die Spuren fremder Lebensgeschichten suchen.“
Entwicklung eines Einklemmschutzes für die elektrische Autositzverstellung (Development of a Operating Safety Feature for Electric Car Seat Adjusting Systems)
Authors: Reif Konrad , Gruber Martin , Rösch Jochen , Brokate Martin
Published: January 2008

Im vorliegenden Beitrag wird eine Einklemmerkennung für die elektrische Sitzverstellung vorgestellt, die nur auf Drehzahlsignalen der Verstellmotoren basiert. Dabei werden die Merkmale, die mit dem Einklemmfall einhergehen, mit Hilfe der Wavelet-Transformation des Drehzahlsignals charakterisiert. Die Abbildung der Symptome, also die Entscheidung aufgrund der Merkmale, ob ein Einklemmfall vorliegt oder nicht, wird mit einem neuronalen Netz vollzogen.
Flachheitsbasierte Steuerung und Regelung für parabolische Systeme mit verteilten Parametern und gleichverteiltem Eingriff (Flatness-based Feedforward and Feedback Control for Parabolic Distributed Parameter Systems with Uniformly Distributed Control)
Authors: Kharitonov Alexander , Sawodny Oliver
Published: January 2008

Für lineare parabolische Systeme mit verteilten Parametern und gleichverteiltem Eingriff wird ein flachheitsbasiertes Verfahren für den Steuerungs- und Regelungsentwurf vorgeschlagen. Als Ausgangspunkt wird die inhomogene Wärmeleitungsgleichung betrachtet. Die Flachheit, die Wahl eines flachen Ausganges und die Approximation der Strecke mit Potenzreihen werden diskutiert. Die Steuerungs- und Regelungsstrategie basiert auf der inversen Systembeschreibung und der Entkopplung der Ausgangsgröße vom Randeingriff. Das Verfahren wird am Beispiel der Automatisierung eines Glasvorherdes demonstriert.
Expression of membrane progesterone receptors on human T lymphocytes and Jurkat cells and activation of G-proteins by progesterone
Authors: Dosiou C , Hamilton A E , Pang Y , Overgaard M T , Tulac S , Dong J , Thomas P , Giudice L C
Published: January 2008

Although there is significant evidence for progesterone's role as an immunomodulator, nuclear progesterone receptors have not been consistently identified in immune cells. Recently, three new putative membrane progesterone receptors (mPRs), mPRα, mPRβ, and mPRγ have been described. The objective of this study was to examine whether mPRs are expressed in peripheral blood leukocytes (PBLs) in women of reproductive age, and to further characterize them in T lymphocytes and immortalized T cells (Jurkat cells). Transcripts for mPRα and mPRβ but not mPRγ, were detected by RT-PCR in PBLs, T lymphocytes, and Jurkat cells. Western blot analysis showed the presence of the mPRα and mPRβ proteins on cell membranes of T lymphocytes and Jurkat cells. Expression of the mPRα mRNA was upregulated in the luteal phase of the menstrual cycle in cluster of differentiation (CD)8+, but not in CD4+, T lymphocytes. Radioreceptor assays revealed specific [3H]progesterone binding to T- and Jurkat cell membranes (Kd 4.25 nM) characteristic of steroid membrane receptors. Progesterone activated an inhibitory G-protein (Gi), suggesting that mPRs are coupled to Gi in Jurkat cells. These results suggest a potential novel mechanism for progesterone's immunoregulatory function through activation of mPRs.
A sexually dimorphic distribution pattern of the novel estrogen receptor G-protein-coupled receptor 30 in some brain areas of the hamster
Authors: Canonaco Marcello , Giusi Giuseppina , Madeo Antonio , Facciolo Rosa Maria , Lappano Rosamaria , Canonaco Alessia , Maggiolini Marcello
Published: January 2008

The isolation of the G-protein-coupled receptor 30 (GPR30), an orphan membrane receptor unrelated to nuclear estrogen receptors (ERs), has become a key factor towards the unraveling of rapid estrogen action. This membrane receptor together with cellular signaling intermediaries, i.e., extracellular signal-dependent kinases 1 and 2, may promote neuronal proliferation and differentiation activities. In the present study, an evident gene expression pattern of GPR30 characterized postnatal 7 (young) and 60 (adult) days of age hamsters as shown by its heterogeneous mRNA distribution in hypothalamic, amygdalar and cerebellar areas of both sexes. In particular, most of the brain areas considered in the adult hamster plus only the amygdala and cerebellum of young animals behaved in a sexually dimorphic fashion. This similar pattern was also detected for the ERα and β, as shown by the latter receptor prevailing in young and adult females, while the former predominated in young females. Even for the two kinases, a sexually dimorphic distribution was featured above all for young hamsters. Overall, the findings of the present study established a distinct expression pattern of the novel ER (GPR30) that may operate differently in some brain areas of the hamster and this may provide interesting insights regarding its probable neuroprotective role during the execution of some hibernating states, which are typical of our rodent model.
Inability to process and store proinsulin in transdifferentiated pancreatic acinar cells lacking the regulated secretory pathway
Authors: Alidibbiat A , Marriott C E , Scougall K T , Campbell S C , Huang G C , Macfarlane W M , Shaw J A M
Published: January 2008

Generation of new β-cells from the adult pancreas or the embryonic stem cells is being pursued by research groups worldwide. Success will be dependent on confirmation of true β-cell phenotype evidenced by capacity to process and store proinsulin. The aim of these studies was to robustly determine endocrine characteristics of the AR42J rat pancreatic acinar cell line before and after in vitro transdifferentiation. β-cell phenotypic marker expression was characterised by RT-PCR, immunostaining, western blotting, ELISA and in human preproinsulin transgene over-expression studies in wild-type AR42J cells and after culture on Matrigel basement membrane matrix with and without growth/differentiation factor supplementation. Pancreatic duodenal homeobox 1 (PDX1), forkhead box transcription factor a2 (Foxa2), glucokinase, pancreatic polypeptide and low-level insulin gene transcription in wild-type AR42J cells were confirmed by RT-PCR. Culture on Matrigel-coated plates and supplementation of medium with glucagon-like peptide 1 induced expression of the β-cell Glut 2 with maintained expression of insulin and PDX1. Increased biosynthesis and secretion of proinsulin were confirmed by immunocytochemical staining and sensitive ELISA. Absence of the regulated secretory pathway was demonstrated by undetectable prohormone convertase expression. In addition, inability to process and store endogenous proinsulin or human proinsulin translated from a constitutively over-expressed preproinsulin transgene was confirmed. The importance of robust phenotypic characterisation at the protein level in attempted β-cell transdifferentiation studies has been confirmed. Rodent and human sensitive/specific differential proinsulin/insulin ELISA in combination with human preproinsulin over-expression enables detailed elucidatation of core endocrine functions of proinsulin processing and storage in putative new β-cells.
Preparation and in vitro characterization of gellan based floating beads of acetohydroxamic acid for eradication of H. pylori
Authors: Rajinikanth Parauvathanahalli , mishra Brahmeshwar
Published: January 2008

Preparation andin vitrocharacterization of gellan based floating beads of acetohydroxamic acid for eradication ofH. pylori

Gellan based floating beads of acetohydroxamic acid (AHA) were prepared by the ionotropic gellation method to achieve controlled and sustained drug release for treatment ofHelicobacter pyloriinfection. The prepared beads were evaluated for diameter, surface morphology and encapsulation efficiency. Formulation parameters like concentrations of gellan, chitosan, calcium carbonate and the drug influenced thein vitrodrug release characteristics of beads. Drug and polymer interaction studies were carried out using differential scanning calorimetry. Chitosan coating increased encapsulation efficiency of the beads and reduced the initial burst release of the drug from the beads. Kinetic treatment of the drug release data revealed a matrix diffusion mechanism. Prepared floating beads showed good antimicrobial activity (in vitro H. pyloriculture) as potent urease inhibitors. In conclusion, an oral dosage form of floating gellan beads containing AHA may form a useful stomach site specific drug delivery system for the treatment ofH. pyloriinfection.
New co-polymer zwitterionic matrices for sustained release of verapamil hydrochloride
Authors: Kostova Bistra , Rachev Dimitar
Published: January 2008

New co-polymer zwitterionic matrices for sustained release of verapamil hydrochloride

Stable co-polymer [vinyl acetate-co-3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate, p(VA-co-DMAPS)] latex of different compositions has been synthesized for the first time by emulsifier-free emulsion copolymerization. The unusual >>overshooting<< behavior of the co-polymer tablets has been explained by the formation of specific clusters from the opposite oriented dipoles-zwitterionic species. The change of their concentration with the DMAPS unit fraction (mDMAPS), pH and ionic strength has been considered responsible for the differences observed in the swelling kinetics. The results obtained prove that mDMAPSand ionic strength could be used to control the swelling degree of the p(VA-co-DMAPS) matrices and their sustained drug delivery. In this way, p(VA-co-DMAPS) matrices could be effectively used to control the sustained release of drugs with basic properties like verapamil hydrochloride from model tablets.
Israel's wall and the logic of encystation
Authors: Bowman Glenn
Published: January 2008

It seems vital, in the face of escalating Israeli expansionism in the Palestinian Territories and obstructionism in the "Peace Process," to theorize the cultural foundations of a process of containment and dispossession of Palestinians that can no longer convincingly be seen as mere strategy. Symptomatic of the Israeli state program is the "wall" (a.k.a., "the Security Fence" or the "Apartheid Wall") and its radical encroachment into territory designated as the grounds of a future Palestinian state. The following essay attempts an anthropological analysis of the concept of "border" in contemporary Israeli thought and practice, and, in so doing, assesses the impact of a limitless sovereignty on both an encompassed minority population and on international relations more generally.
Hydroaminomethylation of n‐Alkenes in a Biphasic Ionic Liquid System
Authors: Hamers Bart , Bäuerlein Patrick S. , Müller Christian , Vogt Dieter
Published: January 2008

Hydroaminomethylation reactions were performed successfully in an imidazolium‐based ionic liquid using a rhodium/sulfoxantphos system by reacting piperidine with different n‐alkenes, affording yields higher than 95 % of the resulting amine with turnover frequencies of up to 16,000 h−1, along with high regioselectivity for the linear amines with l/b ratios up to 78. Additionally, facile quantitative catalyst recovery was accomplished and recycling of the catalyst and product separation was achieved by a fast phase separation after the reaction. The product distribution was monitored over time at different temperatures both in an organic solvent and in the ionic liquid in order to investigate and compare the course of the formation of (side) products and intermediates in these reactions. Furthermore, it was shown that the nature of the rhodium precatalyst has a profound effect on the activity and selectivity. Protic organic solvents and ionic liquids containing a CH acidic bond in the imidazolium part have a beneficial effect on the hydrogenation activity of the catalyst systems.
Heterogeneous Catalysis for Fine Chemicals in Dense Phase Carbon Dioxide
Authors: Ciriminna Rosaria , Carraro Massimo L. , Campestrini Sandro , Pagliaro Mario
Published: January 2008

An increasing number of fine chemicals is being produced using heterogeneously catalysed reactions in supercritical carbon dioxide with significant improvements in terms of process selectivity and purity of the products thereby obtained. A selection of examples and of recent findings shows the large potential of this technology for the synthetic chemistry of the future.
Highly Diastereo‐ and Enantioselective Catalytic Domino Thia‐Michael/Aldol Reactions: Synthesis of Benzothiopyrans with Three Contiguous Stereocenters
Authors: Zhao Gui‐Ling , Vesely Jan , Rios Ramon , Ibrahem Ismail , Sundén Henrik , Córdova Armando
Published: January 2008

Highly enantioselective organocatalytic domino thia‐Michael/aldol reactions between 2‐mercaptoacetophenone and α,β‐unsaturated aldehydes are presented. The reactions proceed with excellent chemo‐, diastereo‐ and enantioselectivity to give the corresponding benzothiopyran derivatives in high yields with up to >15:1 dr and 96 to >99 % ee.
Moving finite elements method applied to dynamic population balance equations
Authors: Duarte Belmiro P. M. , Baptista Cristina M. S. G.
Published: January 2008

A moving finite elements scheme is developed and used for solving 1‐D dynamic population balance equations (PBE). The method stands on the weighted finite‐elements based approach, and the local solutions are represented by cubic Hermite polynomials. The weighting function is the gradient of residuals with respect to time derivatives of the solution at the nodes and nodal velocities. The general PBE considered includes nucleation, growth, aggregation and breakage terms. The accuracy of the moving finite elements method (MFEM) is evaluated by comparing the results to the analytical solution in problems involving combinations of the first three phenomena considered. The formulation addressed was successful when used for solving a two‐ phase system representing a semibatch precipitation reactor. The MFEM enables one to achieve accurate results at reasonable CPU times, thus, showing to be adequate for these kind of problems. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Passage of a bubble through a liquid–liquid interface
Authors: Dietrich N. , Poncin S. , Pheulpin S. , Li Huai Z.
Published: January 2008

The aim of this study is to investigate the bubble passage at a liquid–liquid interface using a high‐speed video camera (950 images per second) and a Particle Image Velocimetry (PIV) system. Experiments were conducted in a square Plexiglas column of 0.1 m. Bubbles were generated through a submerged orifice (D = 1 × 10−3 m). The Newtonian Emkarox (HV45) solution was employed for the heavy phase whereas two different organic liquids of different viscosity (Silicone oil 10 mPa s and 100 mPa s) were used as light phase. Experimental results show the effect of the bubble size and the viscosity of the light phase on the retention time, the length of the column of fluid entrained behind the bubble, the bubble velocity as well as the velocity fields at the liquid–liquid interface. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Heparin‐induced thrombocytopenia in myeloproliferative disorders: A rare or under‐diagnosed complication?
Authors: Spectre Galia , Kalish Yossi , Schliamser Liliana , Varon David
Published: January 2008

Patients with myeloproliferative disorders (MPD) are prone to develop thrombotic complications and thus frequently receive heparin. Surprisingly heparin‐induced thrombocytopenia (HIT) has been rarely reported in MPD and is potentially under‐diagnosed due to the relatively high platelet count. We report three patients with MPD who developed HIT; all presented with a relative fall of platelet counts (although without an absolute thrombocytopenia), thrombosis or skin necrosis and a positive test for HIT antibodies (particle gel immunoassay). Risk factors for developing HIT in our patients were exposure to unfractionated heparin, a recent surgical procedure and female gender. We review the literature on HIT in MPD and discuss the diagnosis of HIT in the absence of an absolute thrombocytopenia. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Optimizing BeLPT criteria for beryllium sensitization
Authors: Middleton D.C. , Fink J. , Kowalski P.J. , Lewin M.D. , Sinks T.
Published: January 2008

Background

The beryllium lymphocyte proliferation test (BeLPT) is used to identify persons sensitized to beryllium. ATSDR convened an expert panel of physicians and scientists in April 2006 to discuss this test and to consider what BeLPT test results actually establish beryllium sensitization. The three criteria proposed by panel members were

one abnormal result,

one abnormal and one borderline result, and

two abnormal results.

Methods

Complete algorithms were developed for each of the three proposed criteria. Using single‐test outcome probabilities developed by Stange et al. [2004. Am J Ind Med 46:453–462], we calculated and compared the sensitivity, specificity, and positive predictive values (PPVs) for each set of criteria.

Results

The overall sensitivity and specificity of the three criteria were similar. When the criteria required confirmation of an abnormal result the PPV was higher—whether the requirement was satisfied by a borderline result, or only by another abnormal result. Confirmation also reduced the likelihood of false positives. The differences between the three criteria decreased as the prevalence of sensitization increased.

Conclusions

A single unconfirmed abnormal is usually insufficient to establish sensitization for an apparently healthy person. When the prevalence of beryllium sensitization in a group is high, however, even a single abnormal BeLPT can be a strong predictor. Am. J. Ind. Med. 51:166–172, 2008. © 2008 Wiley‐Liss, Inc.
Effect of UV and hygrothermal aging on the mechanical performance of polyurethane elastomers
Authors: Aglan H. , Calhoun M. , Allie L.
Published: January 2008

In this study, the effects of environmental aging on the mechanical performance of elastomeric polyurethane (PU) were investigated using two accelerated aging techniques, namely, ultraviolet (UV) and hygrothermal (HT). Samples were prepared and subjected to UV and HT exposure for a period of 5 months and removed and mechanically tested at different time intervals. Differential scanning calorimetry (DSC) was performed. A noticeable change in the chemical structure of the PU after 1 month of UV exposure was found, however, that was not the case after 1 month of HT exposure. The stress and strain to failure, tearing energy, and storage modulus were evaluated at different intervals for both aging techniques. It was found that the UV exposure caused severe degradation of the PU in comparison with the HT. A reduction of more than 98% in the tearing energy was observed for the UV‐exposed samples after 5 months when compared with only a 35% reduction in the tearing energy for the HT‐exposed samples. A similar trend was observed for tear strength and storage modulus. The degradation mechanisms of the PU elastomers have been identified using SEM and correlated with the tearing energy. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Shear‐induced migration of nanoclay during morphology evolution of PBT/PS blend
Authors: Hong Joung Sook , Kim Yong Kyoung , Ahn Kyung Hyun , Lee Seung Jong
Published: January 2008

In this study, we investigated clay migration and its localization in multiphase blend nanocomposite systems during the evolution of blend morphology to elucidate how a hydrodynamic stress and chemical affinity between the polymer and clay induce them. To observe the morphology evolution, a multilayered blend, alternatively superposed poly(butylenes terephthalate) (PBT) and polystyrene (PS)/clay films or PBT/clay and PS films, was subjected to homogeneous shear flow, 1 s−1. Furthermore, the morphology was observed at different shear rates 1 s−1. When the PBT/(PS/clay) multilayered blend is subjected to flow, the clay dispersed in the PS layer first migrates to the interface depending on the amount of applied strain. The clay at the interface causes the average drop size of blend morphology to become smaller and the blend morphology becomes more stable because of the coalescence suppression effect. As more shear is applied, the clay at the interface moves further into more compatible phase, PBT, although the viscosity of PBT is higher than PS. On the contrary, the clay in the PBT layer does not migrate to the PS phase at any shear rate, which means that its chemical affinity is strong enough to prevent shear‐induced migration. The clay increases the viscosity of the PBT phase and results in a different morphology with a droplet, cocontinuous structure. As a result, when the clay is induced to migrate by hydrodynamic stress, it migrates into thermodynamically more stable positions at the interface or in the chemically more compatible phase, depending on the applied strain. Once it is located at a thermodynamically more stable position, it is difficult to push it out only by hydrodynamic stress. The location of clay is significantly affected by the morphology during evolution, which means that the blend morphology can control the droplet form and cocontinuous structure by control of the clay migration kinetics. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Resultant synergism in the shear resistance of acrylic pressure‐sensitive adhesives prepared by emulsion polymerization of n‐butyl acrylate/2‐ethyl hexyl acrylate/acrylic acid
Authors: Moghbeli M. R. , Zamir S. M. , Molaee B.
Published: January 2008

Acrylic emulsion pressure‐sensitive adhesives (PSAs) were synthesized by the copolymerization of n‐butyl acrylate with various levels of 2‐ethyl hexyl acrylate (2EHA) and a small constant amount of acrylic acid. The effect of varying the n‐butyl acrylate/2EHA monomer composition on the kinetic behavior of the polymerization and the characteristics of the copolymers prepared in a batch process were investigated. The results showed that increasing the amount of 2EHA in the monomer caused the polymerization rate and the glass‐transition temperature of the acrylic copolymers to decrease. Increasing the amount of 2EHA caused the gel content of the copolymers to decrease, reaching a minimum at 50 wt %; thereafter, the gel content increased at higher 2EHA levels. For the acrylic emulsion, the peel‐fracture energy of the PSAs decreased as the amount of 2EHA in the monomer was increased up to 50 wt %. At higher 2EHA levels, the peel‐fracture energy was relatively constant. Interestingly, a synergistic effect of increased shear resistance at 25 wt % 2EHA was observed without a significant trade‐off in terms of the peel and tack properties. This behavior was attributed to a good interconnection between the microgels and the free polymer chains inside the contacting particles in the adhesive film. Cooperation between various levels of 2EHA in the copolymer structure simultaneously changed the crosslink molecular weight (Mc) of the microgels and the entanglement molecular weight (Me) of the free chains in the adhesive network morphology. The adhesive performance of the PSAs was found to be correlated with their Mc/Me values as the 2EHA proportion was varied. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Dithioester functionalization of poly(cyclohexene oxide) and its application to obtain block copolymers
Authors: Acosta Ortiz Ricardo , Guerrero Santos Ramiro , Berlanga Duarte Lydia , Perez Alvarez Erik A. , Cabello Romero Judith N. , Garcia Valdez Aida E.
Published: January 2008

A new method of introducing dithioester groups into the polymer chain of poly(cyclohexene oxide) is reported. It includes the use of diaryliodonium salt and an aromatic dithioacid as a redox couple to initiate the cationic polymerization of cyclohexene oxide. It was found that the dithioacid by itself cannot start the polymerization of cationic polymerizable monomers; however, in combination with a diaryliodonium salt, an exothermic reaction was produced, yielding a thiocarbonylthio‐functionalized polyether. Thermal profiles of the redox polymerizations were determined by means of optical pyrometry. A preliminary study showed that when the poly(cyclohexene oxide) functionalized with dithioester groups was introduced into the radical polymerization of styrene, the polystyryl growing radicals reacted with the dithioester‐functionalized polyether to form a block polymer. The amount of polyether actually incorporated into the block copolymer was calculated to be 70% of the initial amount of poly(cyclohexene oxide)/dithiobenzoic acid charged into the reactor. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Crystal morphology and isothermal crystallization kinetics of short carbon fiber/poly(ethylene 2,6‐naphthalate) composites
Authors: Zheng Li‐Juan , Qi Jian‐Gang , Zhang Qing‐Hong , Zhou Wen‐Feng , Liu Dan
Published: January 2008

Isothermal crystallization kinetics, subsequent melting behavior, and the crystal morphology of short carbon fiber and poly(ethylene 2,6‐naphthalate) composites (SCF/PEN) were investigated by using differential scanning calorimetry and polarized optical microscopy. The crystal morphology of the composites isothermally crystallized at Tc = 220°C is predominantly banded spherulites observed under polarizing micrographs, while the pattern of banded spherulites changed from ring to serration as the SCF content added into the PEN. Moreover, nonbanded spherulites formed at Tc = 210°C. The commonly used Avrami equation was used to fit the primary stage of the isothermal crystallization. The Avrami exponents n are evaluated to be 2.6–3.0 for the neat PEN and 3.7–4.0 for SCF/PEN composites, and the SCF acting as nucleation agents in composites accelerates the crystallization rate with decreasing the half‐time of crystallization, and the sample with SCF component of 2% has the fastest crystallization rate. The crystallization activation energy calculated from the Arrhenius formula suggests that the adding SCF component improved the crystallization ability of the PEN matrix greatly, and the sample with of 2% SCF component has the most crystallization ability. Subsequent melting scans of the isothermally crystallized composites exhibited triple melting endotherms, in which the more the component of SCF, the lower temperature of the melting peak, indicating the less perfect crystallites formed in those composites. Furthermore, the melting peaks of the same sample are shifted to higher temperature with increasing Tc, suggesting the more perfect crystallites formed at higher Tc. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and photopolymerization characterization of a novel difunctional photoinitiator
Authors: Xiao Pu , Dai Mingzhi , Nie Jun
Published: January 2008

A novel difunctional photoinitiator HBP‐TDI‐HBP based on 4‐hydroxybenzophenone (HBP) and toluene‐2,4‐diisocyanate (TDI) was synthesized and characterized by 1H NMR and UV–Vis absorption spectroscopy. The kinetics of photopolymerization was studied by real‐time infrared spectroscopy. It showed that HBP‐TDI‐HBP was a more effective photoinitiator than benzophenone. When this photointiator and amine were used to efficiently initiate polymerization of acrylates and methacrylates, both rate of polymerization and final conversion increased with increase of HBP‐TDI‐HBP concentration, light intensity, and amine concentration. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Time and temperature effect on the linear–nonlinear viscoelastic transition threshold of a polymeric system
Authors: Papanicolaou G. C. , Xepapadaki A. G. , Karagounaki K. , Zaoutsos S. P.
Published: January 2008

In the present study, the transition of a polymeric material from the linear to the nonlinear viscoelastic behavior and the determination of the nonlinearity stress threshold variation with time and temperature are investigated. For this purpose a systematic experimental program consisted of thermal and mechanical characterization of certain polymeric material followed by isothermal creep tests at different stress levels and temperatures was conducted. Through isochronal curves that occurred from creep tests, the nonlinearity threshold dependence on both time and temperature is presented. The reported results provide information that is critical for the design and development of polymer structures and components. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Biological Activity, Structural Features, and Synthetic Studies of (−)‐Ternatin, a Potent Fat‐Accumulation Inhibitor of 3T3‐L1 Adipocytes
Authors: Shimokawa Kenichiro , Mashima Itsuka , Asai Akiko , Ohno Tomohiro , Yamada Kaoru , Kita Masaki , Uemura Daisuke
Published: January 2008

A series of studies, including preliminary screening, isolation, structure determination, synthesis, and biological evaluation, of (−)‐ternatin (1) are described. A highly N‐methylated cyclic heptapeptide isolated from the mushroom Coriolus versicolor, 1 shows an inhibitory effect on fat accumulation by 3T3‐L1 murine adipocytes (EC50=0.02 μg mL−1). Detailed analysis of 1D and 2D NMR spectra, as well as amino acid analysis, suggested four stereoisomers as candidates for 1. For the complete structural elucidation of 1, chemical syntheses were carried out by solid‐phase peptide synthesis. By comparing the spectroscopic data for the natural product with the data for the synthetic stereoisomers, the structure of 1 was confirmed to be cyclo[D‐allo‐Ile1‐L‐(NMe)Ala2‐L‐(NMe)Leu3‐L‐Leu4‐L‐(NMe)Ala5‐D‐(NMe)Ala6‐(2R,3R)‐3‐hydroxy‐Leu7].
Cooperative AND Ion‐Pair Recognition by Heteroditopic Calix[4]diquinone Receptors
Authors: Lankshear Michael D. , Dudley Ian M. , Chan Kar‐Man , Cowley Andrew R. , Santos Sérgio M. , Felix Vitor , Beer Paul D.
Published: January 2008

A new family of heteroditopic calix[4]diquinone receptors capable of the cooperative recognition of ion‐pair species through a contact binding mechanism has been developed. The receptors bind contact ion pairs cooperatively, with an unprecedented AND recognition phenomenon being observed to operate in certain cases, in which receptors display no affinity for either of the individual “free” cation or anion, but bind the cation and anion ion‐pair strongly. X‐ray crystallographic, solution‐state, and computational methods rationalize the observed recognition behavior of the receptors. It is shown that the contact ion‐pair interaction occurs through a π‐stacking‐mediated folding of the receptors such that the anion and cation binding sites are arranged in close proximity, while in the solid state an unusual ion‐mediated receptor dimerization is observed. Molecular dynamics simulations are further used to explain the observed trends in the association constants of different ion‐pair species and the mechanism of interaction.
First Principles Computation of Lattice Energies of Organic Solids: The Benzene Crystal
Authors: Ringer Ashley L. , Sherrill C. David
Published: January 2008

We provide a first‐principles methodology to obtain converged results for the lattice energy of crystals of small, neutral organic molecules. In particular, we determine the lattice energy of crystalline benzene using an additive system based on the individual interaction energies of benzene dimers. Enthalpy corrections are estimated so that the lattice energy can be directly compared to the experimentally determined sublimation energy. Our best estimate of the sublimation energy is 49.4 kJ mol−1, just over the typical experimentally reported values of 43–47 kJ mol−1. Our results underscore the necessity of using highly correlated electronic structure methods to determine thermodynamic properties within chemical accuracy. The first coordination sphere contributes about 90 % of the total lattice energy, and the second coordination sphere contributes the remaining 10 %. Three‐body interactions are determined to be negligible.
ChemInform Abstract: Low‐Lying Electronic States of M3O9‐ and M3O92‐ (M: Mo, W)
Authors: Li Shenggang , Dixon David A.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Highly Diastereoselective Formation of Ruthenium Complexes for Efficient Catalytic Asymmetric Transfer Hydrogenation.
Authors: Baratta Walter , Chelucci Giorgio , Herdtweck Eberhardt , Magnolia Santo , Siega Katia , Rigo Pierluigi
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Ring Transformations of Heterocyclic Compounds. Part 25. Phenanthrene Aldehyde Imines (III) via Ring Transformation of Pyrylium Salts with Methylenedihydroisoquinolines — A Novel Access to the Phenanthrene Skeleton.
Authors: Zimmermann Thomas , Krautscheid Harald
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A Copper‐Catalyzed Domino Radical Cyclization Route to Benzospiro‐indolizidinepyrrolidinones.
Authors: Stevens Christian V. , Van Meenen Ellen , Masschelein Kurt G. R. , Eeckhout Yves , Hooghe Wim , D'hondt Bart , Nemykin Victor N. , Zhdankin Viktor V.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Stereoselective Total Synthesis of Arenastatin A, a Spongean Cytotoxic Depsipeptide.
Authors: Kotoku Naoyuki , Narumi Fuminori , Kato Tomoya , Yamaguchi Miho , Kobayashi Motomasa
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis and Absolute Configuration of (‐)‐Serantrypinone.
Authors: Hart David J. , Oba Gabriel
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A Novel Nuclear Export Inhibitor JBIR‐02, a New Piericidin Discovered from Streptomyces sp. ML55.
Authors: Shin‐ya Kazuo , et al. et al.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Asymmetric Hydrogenation Through Metal—Ligand Bifunctional Catalysis
Authors: Noyori Ryoji , Ohkuma Takeshi , Sandoval Christian A. , Muniz Kilian
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Preparation, Crystal Structure and Magnetic Behavior of New Double Perovskites Sr2B′UO6 with B′: Mn, Fe, Ni, Zn.
Authors: Pinacca R. M. , Viola M. C. , Pedregosa J. C. , Martinez‐Lope M. J. , Carbonio R. E. , Alonso J. A.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Gold‐Catalyzed 5‐ and 6‐exo‐dig Selective Cyclizations of Alkynyl Silyl Enol Ethers: Efficient Method for [3 + 2] and [4 + 2] Annulations onto α,β‐Enones.
Authors: Lee Kooyeon , Lee Phil Ho
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of Silver Nanostructures with Controlled Shapes and Properties
Authors: Wiley Benjamin , Sun Yugang , Xia Younan
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Chemistry, Biology, and QSAR Studies of Substituted Biaryl Hydroxamates and Mercaptoacetamides as HDAC Inhibitors—Nanomolar‐Potency Inhibitors of Pancreatic Cancer Cell Growth
Authors: Kozikowski Alan P. , Chen Yufeng , Gaysin Arsen M. , Savoy Doris N. , Billadeau Daniel D. , Kim Ki Hwan
Published: January 2008

The histone deacetylases (HDACs) are able to regulate gene expression, and inhibitors of the HDACs (HDACIs) hold promise in the treatment of cancer as well as a variety of neurodegenerative diseases. To investigate the potential for isoform selectivity in the inhibition of HDACs, we prepared a small series of 2,4′‐diaminobiphenyl ligands functionalized at the para‐amino group with an appendage containing either a hydroxamate or a mercaptoacetamide group and coupled to an amino acid residue at the ortho‐amino group. A smaller series of substituted phenylthiazoles was also explored. Some of these newly synthesized ligands show low‐nanomolar potency in HDAC inhibition assays and display micromolar to low‐nanomolar IC50 values in tests against five pancreatic cancer cell lines. The isoform selectivity of these ligands for class I HDACs (HDAC1–3 and 8) and class IIb HDACs (HDAC6 and 10) together with QSAR studies of their correlation with lipophilicity are presented. Of particular interest is the selectivity of the mercaptoacetamides for HDAC6.
Sensitivity of tumor cells to proteasome inhibitors is associated with expression levels and composition of proteasome subunits
Authors: Busse Antonia , Kraus Marianne , Na Il‐Kang , Rietz Anika , Scheibenbogen Carmen , Driessen Christoph , Blau Igor Wolfgang , Thiel Eckhard , Keilholz Ulrich
Published: January 2008

BACKGROUND.

Sensitivity of tumor cells to induction of apoptosis by proteasome inhibitors varies greatly. This study was undertaken to investigate the sensitivity of neoplastic B cells and solid tumor cells to proteasome inhibition with respect to constitutive expression levels of proteasome subunits.

METHODS.

Twelve neoplastic B‐cell lines and 12 solid tumor cell lines were assessed for their expression levels of proteasome subunits by using quantitative reverse transcriptase‐polymerase chain reaction analysis and were assessed for their sensitivity to the proteasome inhibitors PS‐341 and lactacystin by using a flow cytometry assay that detected activated caspases.

RESULTS.

The neoplastic B‐cell lines were categorized into 3 groups representing refractory cell lines, cell lines with moderate sensitivity, and cell lines with high sensitivity. Correlating expression levels of proteasome subunits with sensitivity to proteasome inhibition indicated that refractory B cells exhibited lower expression levels of the standard subunit β2 and of the immunoproteasome subunit LMP2 compared with sensitive B cell lines. Compared with neoplastic B cells solid tumor cells were less sensitive. They expressed the immunoproteasome subunits LMP2, LMP7 and MECL‐1 and the standard subunit β2 clearly below the median of the expression level of the sensitive B cell lines. IFN‐γ pretreatment enhanced sensitivity to PS‐341 in 50% of the tumor cell lines, potentially related to the induction of immunoproteasomes.

CONCLUSIONS.

The results of this study indicated that sensitivity to proteasome inhibition is correlated with expression levels of proteasome subunits, which determine the enzymatic activity of the proteasome. Combining PS‐341 with IFN‐γ may enhance its clinical efficacy. Cancer 2008. © 2008 American Cancer Society.