A promising route to the fabrication of biomimetic coatings for artificial implants is the deposition of org./inorg. composite materials consisting of polyelectrolyte multilayers alternating with layers of "in situ" grown calcium phosphate crystals. To facilitate understanding of the underlying mechanisms, in this paper we discuss the influence of polyelectrolytes (PEs), polystyrene sulfonate (PSS), poly-L-lysine (PLL), and poly-L-glutamic acid (PGA) on the formation and properties of amorphous calcium phosphate (ACP) and on the nucleation and growth morphol. of the cryst. phase. PH vs. time curves revealed three distinct pptn. events, i.e., (I) pptn. of ACP, (II) secondary pptn. of a cryst. phase upon the amorphous precursor, and (III) soln.-mediated phase transformation and crystal growth. Finally, cryst. mixts. with low Ca/P molar ratios (1.39), consisting of octacalcium phosphate crystals and small amts. of apatite, were obtained. From the pH vs. time curves, the induction time, ti, preceding crystal nucleation was detd. All PEs at low concns. induced and at high concns. inhibited nucleation. The efficiency of induction increased in the order: LMw PGA equiv. HMw PGA \textless LMw PLL \textless HMw PLL \textless PSS, while the inhibition efficiency increased as LMw PLL equiv. HMw PLL \textless PSS \textless LMw PGA \textless HMw PGA. ACP particles formed in the presence of PE were smaller and less aggregated and had a higher surface charge than in the controls. All investigated PEs also inhibited growth of the cryst. phase in a nonspecific way. [on SciFinder(R)]
We consider a simple dynamic "collective reputation" model of a market for an experience good into'' which we introduce imperfect quality inspections. In each period two markets operate: a prime market'' for sellers with a good reputation, and a regular market for all other sellers. In every period, the quality of produced goods is inspected, and producers who have been found to produce low quality goods are barred from selling in the prime market in the next period. We demonstrate that the average quality of the good in both markets may decrease as inspection technology improves. A few applications of the model are discussed.
Polystyrene scaffolds were grafted with model functionalities featuring strongly interacting hydrogen bonding and aromatic stacking elements. Both glass transition temperatures and degree of microphase separation in functionalized block copolymers depend on the nature of the functionality and in particular on the strength of intermolecular interactions. The polymers under study were amorphous; it was found, however, that domain periodicities of functionalized diblock copolymers in the microphase-separated state are extremely sensitive to local interactions between functionalities and can express even subtle differences in interaction strength. The results emphasize the ability to fine-tune polymer microstructure and thermomechanical behavior using supramolecular chemistry.
Inflammatory processes in the central nervous system (CNS) are considered neurotoxic, although recent studies suggest that they also can be beneficial and confer neuroprotection (neuroprotective autoimmunity). Cells from the immune system have been detected in CNS injury and found to produce and secrete a variety of neurotrophins such as NGF, BDNF, NT-3 and NT-4/5, and to express (similarly to neuronal cells), members of the tyrosine kinase (Trk) receptor family such as TrkA, TrkB and TrkC. Indeed, autocrine and paracrine interactions are observed at the site of CNS injury, resulting in a variety of homologic-heterologic modulations of immune and neuronal cell function. The end result of the inflammatory process, neurotoxicity and/or neuroprotection, is a function of the fine balance between the two cellular systems, i.e., of the complex signaling relationships between anti-inflammatory neuroprotective factors (neurotrophins and other chemical mediators) and proinflammatory neurotoxic factors (TNF, free radicals, certain cytokines, etc.). Autoimmune neuroprotection is a novel therapeutic approach aimed at shifting the balance between the immune and neuronal cells towards survival pathways in a variety of CNS injuries. This review focuses on data supporting this concept and its future therapeutical implications for optic nerve injury and multiple sclerosis.
The essay examines some of the fascinating ways in which islands have inspired writers, and especially poets, into acts of symbolization in which an island provides the pretext for a variety of compulsive themes that range from the love or fear of solitude, isolation, and the need to escape to or from an island. The recurrent figures of this allegorical mode include Crusoe, Caliban, Odysseus, and The Man Who Loved Islands.
January 2004: Professor of English and author of The Long Poems of Wallace Stevens: An Interpretative Study (CUP, 1985); eo-editor of Complicities: Connections and Divisions-Literatures and Cultures of the Asia-Pacific Region (Peter Lang, 2003) and Institutions in Cultures: Theory and Practice (Rodopi, 1996); Guest Editor of The European Legacy 7.6 (December 2002). “Benjamin and Bakhtin: The Possibility of Conversation.” Journal of Narrative Theory 33.1 (Winter 2003): 12-32. Author of numerous articles, including “Adorno and the Postcolonial,” New Formations 47(Summer 2002): 133-43; “Walter Benjamin's Arcades Project and the Postcolonial City,” Diacritics 40.4 (Winter 2000): 3-14.
The thesis of the paper is that Jews are represented in the poetry as the mimetic Other for identification, sponsoring fidelity to faith, the excluded Other allowing consolidation of faith, and the symbolic Other providing a discourse of history as theophany; in representation of the Jewish Other, the Anglo-Saxon textual community furthers the project of nation formation.
January 2004: Born in Brooklyn, New York, Professor Thormann teaches at College of Marin, Kentfield, California. Author of articles on the Anglo-Saxon Chronicle Poems, Old English poetry, Chaucer, Shakespeare, and modern literature, most recently: "The Representation of the Shoah in Maus: History as Psychology," Res Publica 8/2 (2002): 123-139; and "The Ethical Subject of The God of Small Things," Journal for the Psychoanalysis of Culture and Society 8/2, (Fall 2003): 299-307. Coeditor of The Seminar of Moustafa Safouan (New York: Other Press, 2002). Current research: The Aesthetics of Old English poetry.
Nirgends stellt sich das Problem der "Identität" schärfer und belasteter als bei der jüdischen. Alles kommt ja darauf an, ob sie sich einer historischen, politischen und sozialen Zuschreibung oder einem Prozess der Selbstfindung und Selbstidentifizierung verdankt. Deutsche Juden waren sich seit ihrer sog. "Emanzipation" immer schmerzlich bewusst, dass es sich in ihrem Fall eher um eine "Assimilation im Akkusativ" als eine "im Dativ" handelte, und noch heute ist die Rede vom "Jüdischen" zumeist tief von den "Definitionen" der Nazis kontaminiert. Auch für gegenwärtige Juden gestaltet sich ihre jüdische Identität sehr unterschiedlich. Seit der Aufklärung wird sie nicht mehr ausschließlich über die Treue zur Tora und zu den göttlichen Geboten bestimmt. Moderne Juden gehören vielmehr zahlreichen (lokalen, beruflichen, kulturellen, politischen, freizeitlichen) Gemeinschaften an, die sich nicht zwangsläufig entsprechen. Auf der anderen Seite geht es seit der Gründung des Staates Israels aber auch um eine politische Selbstidentifikation, die sich ihrerseits über Einschluss- und Ausschlussverfahren regelt. Die Kriterien dafür sind, wie man weiß, kontrovers - uns so können wir Paul Mendes-Flohr für seine engagierte, klare, aber auch nachdenkliche historische und politische Orientierung nicht dankbar genug sein.
