A convenient synthesis of 2,2',6,6'-Tetramethyl-4,4'-bipyridine and its oxidation to 2,2',6,6'-Tetracarboxy-4,4'-bipyridine

No abstract availabl

Expression of T-Cell Receptor β-Chain mRNA and Protein in γ/δ T-Cells from Euthymic and Athymic Rats: Implications for T-Cell Lineage Divergence

The relationship between α/β and γ/δ T-cell lineages was studied in rats using RT-PCR analysis of TCRβ transcripts in γ/δ T-cell hybridomas and an intracellular staining technique to detect TCRβ protein in primary γ/δ T-cells. We report the presence of functional TCRβ transcripts in 2/9 γ/δ T-cell hybridomas. About 15 % of peripheral γ/δ T-cells and thymocytes also express TCRβ protein, giving a minimum estimate for successful Tcrb rearrangement based on ex vivo single cell analysis. In athymic rats, γ/δ T-cells expressing intracellular β protein are present but at a lower frequency than in euthymic controls, suggesting that in the thymus, more γ/δ T-cell precursors pass through a stage where functional β rearrangement has occurred than in extrathymic sites. Analysis of TCR expression in purified transitory immature CD4-8+ (iCD8SP) thymocytes and their spontaneously developing CD4+8+ (DP) progeny showed that TCRγ mRNA is expressed in iCD8SP cells but not in their immediate DP progeny that reinitiate RAG-1 transcription and commence α/βTCR expression. We conclude that rat γ/δ T cells can separate from the α/β lineage after TCRβ expression, but not after entry into the DP compartment

Darstellung und Charakterisierung neuartiger C-Arylcalix(4)resorcinarene

In der vorliegenden Arbeit wird die Darstellung und Charakterisierung von aromatisch substituierten Calix(4)resorcinarenen behandelt. Im zweiten Kapitel werden die Grundlagen und Besonderheiten bei Calix(4)resorcinarenen angesprochen. Ein Überblick über die wichtigsten Verbindungen dieser Gruppe von Makrocyclen wird gegeben. Im Kapitel 3 werden wesentliche Methoden zur vollständigen O-Alkylierung bei Calix(4)resorcinaren genannt. Außerdem werden Methoden zur partiellen O-Alkylierung von C-Arylcalix(4)resorcinarenen vorgestellt. Das Kapitel 4 stellt die Methoden zur Strukturaufklärung mittels 2D-NMR-Spektroskopie bei diesen Verbindungen vor. Möglichkeiten zur Unterscheidung des rccc-Isomer vom rctt-Isomer werden beschrieben. Das Kapitel 5 zeigt wesentliche Ergebnisse der semiempirischen Rechnungen zu C-Arylcalix(4)resorcinarenen und ihrer Acetate. Am Beispiel einer Verbindung werden Energiewerte aller Isomere und Konformere verglichen. Eine Deutung der ROESY-Spektren von Standpunkt der Quantenchemie aus wird gegeben. Im Ergebnis aller gewonnener Daten werden Aussagen zum wahrscheinlich ablaufenden Mechanismus gemacht. Der Vorgeschlagene Mechanismus geht von dimeren Verbindungen aus und berücksichtigt die Stereochemie der erhaltenen Produkte.In this work the preparation and characterisation of aromatic substituted Calix(4)resorcinarens are shown. In the second chapter the basis's and the peculiarity's of the Calix(4)resorcinarens are given. A summary of the most important compounds of this class is shown. In chapter 3 preparation methods for the complete O-alcylation of Calix(4)resorcinarens are given. Methods for the particular O-alcylation of C-Arylcalix(4)resorcinarens are introduced. Chapter 4 presents the methods for the characterisation of this class of compounds with 2D-NMR-spectroscopy. Methods for the distinction of the rccc-isomer from the rctt-isomer are described. The chapter 5 shows important results of the semiempirical calculations with C-Arylcalix(4)resorcinarens and their acetates. The energy values of all isomers and conformers of one compound are compared. A interpretation of the ROESY-spectras with quantum chemical methods is given. As a result of this work a new mechanism is proposed

Teilhabe und Bildung im Lichte der Bildungstheorie Heinz-Joachim Heydorns. Ein Statement

Die Autorin versucht den Begriff der Teilhabe, wie er in der aktuellen Debatte um Bildungsgerechtigkeit verwendet wird, mit dem begrifflichen Instrumentarium von Heinz-Joachim Heydorn zu prüfen. (DIPF/Orig.

γ/δ Cells in Fetal, Neonatal, and Adult Rat Lymphoid Organs

In the present study, we have analyzed the appearance and maturation of γ/δ T cells, recognized with a new mAb V65, in the central and peripheral lymphoid organs of fetal, neonatal, and adult Wistar rats. Cytofluorometrical analysis demonstrated the first V65+ γ/δ T cells in the thymus of 16-17-day embryonic rats, although by immunohistology, they were identified only in 19-day rat embryos in both the cortico-medullary border and thymic medulla. Phenotypically, γ/δ thymocytes from fetal and neonatal thymus expressed CD3, CD2, and CD5, but only 60-80% were CD8+ and approximately 40-50% expressed the α chain (p55) of the IL-2R. In the periphery, the immunohistological study identified for the first time ,γ/δ T cells in the splenic white pulp and the gut of 21-day fetal rats, where they occurred within the epithelium as well as in the lamina propria. After birth, γ/δ lymphocytes appeared in the skin, where they were present as dendritic epidermal T cells in increasing numbers during postnatal life. Whereas these γ/δ T cells formed the predominant T-cell population in the rat skin, γ/δ T cells in peripheral lymphoid organs, BALT, or the gut only represented a minor T-cell population. These results are discussed in comparison to γ/δ T cells of other vertebrate species

19th century German versions of Shakespeare`s Coriolanus

Die Übersetzung der dramatischen Werke William Shakespeares durch August Wilhelm Schlegel und Ludwig Tieck, Dorothea Tieck und Wolf von Baudissin (1797-1831) erlangte in der zweiten Hälfte des 19. Jahrhunderts Klassikerstatus in Deutschland und hat ihn auch heute noch. Zeitgleich und das gesamte 19. Jahrhundert hindurch erschienen noch diverse andere Shakespeare-Übersetzungen, die jedoch spätestens ab Anfang des 20. Jahrhunderts völlig in Vergessenheit gerieten. Die Verbannung aus dem literarischen Kanon wurde und wird von der Übersetzungskritik mit dem Urteil des puren "Übersetzungseklektizismus" in der Folge auf Schlegel-Tieck gerechtfertigt. Das Ziel dieser Arbeit ist es, mittels einer mikrotextuellen und makrotextuellen Analyse, darzulegen, dass das Urteil des Übersetzungseklektizismus und der Vorwurf der mangelnden Innovation in der Shakespeare-Übersetzung des 19. Jahrhunderts nicht gerechtfertigt sind, und aufzuzeigen, welche Mechanismen einerseits zur Kanonisierung des Schlegel-Tieck-Textes führten, und andererseits dazu, dass alle anderen Übersetzungsversuche von der Rezeptionsforschung und der Übersetzungskritik das gesamte 20. Jahrhundert hindurch nicht mehr zur Kenntnis genommen wurden.The translation of the dramatical works of William Shakespeare by the German translators August Wilhelm Schlegel, Ludwig Tieck, Dorothea Tieck and Wolf von Baudissin (1797-1831) became a German classic during the second half of the 19th century - and still is. On the other hand a great number of German Shakespeare-translations, published at the same time and all through the 19th century went more or less unnoticed, at least from the beginning of the 20th century onwards. According to modern critics they are nothing but slightly altered Schlegel-Tieck-versions, that are characterised by a complete lack of innovation and skill. The scope of this work is to show, by way of a microtextual and macrotextual analysis, that the negative notion of the so-called "Übersetzungseklektizismus" is not justified, and to outline the mechanisms, which led to the canonization of the Schlegel-Tieck-version on the one hand and the banishment of all the other 19th-century German versions of Shakespeare from the literary canon on the other hand

Sequential induction of effector function, tissue migration and cell death during polyclonal activation of mouse regulatory T-cells

The ability of CD4+Foxp3+ regulatory T-cells (Treg) to produce interleukin (IL)-10 is important for the limitation of inflammation at environmental interfaces like colon or lung. Under steady state conditions, however, few Tregs produce IL-10 ex vivo. To investigate the origin and fate of IL-10 producing Tregs we used a superagonistic mouse anti-mouse CD28 mAb (CD28SA) for polyclonal in vivo stimulation of Tregs, which not only led to their numeric expansion but also to a dramatic increase in IL-10 production. IL-10 secreting Tregs strongly upregulated surface receptors associated with suppressive function as compared to non-producing Tregs. Furthermore, polyclonally expanding Tregs shifted their migration receptor pattern after activation from a CCR7+CCR52 lymph node-seeking to a CCR72CCR5+ inflammationseeking phenotype, explaining the preferential recruitment of IL-10 producers to sites of ongoing immune responses. Finally, we observed that IL-10 producing Tregs from CD28SA stimulated mice were more apoptosis-prone in vitro than their IL-10 negative counterparts. These findings support a model where prolonged activation of Tregs results in terminal differentiation towards an IL-10 producing effector phenotype associated with a limited lifespan, implicating built-in termination of immunosuppression