Protic Ionic Liquid as Reagent, Catalyst, and Solvent: 1-Methylimidazolium Thiocyanate

We propose a new concept of the triple role of protic ionic liquids with nucleophilic anions: a) a regenerable solvent, b) a Brønsted acid inducing diverse transformations via general acid catalysis, and c) a source of a nucleophile. The efficiency of this strategy was demonstrated using thiocyanate-based protic ionic liquids for the ring-opening of donor-acceptor cyclopropanes. A wide variety of activated cyclopropanes were found to react with 1-methylimidazolium thiocyanate under mild metal-free conditions via unusual nitrogen attack of the ambident thiocyanate ion on the electrophilic center of the three-membered ring affording pyrrolidine-2-thiones bearing donor and acceptor substituents at the C(5) and C(3) atoms, respectively, in a single time-efficient step. The ability of 1-methylimidazolium thiocyanate to serve as a triplex reagent was exemplarily illustrated by (4+2)-annulation with 1-acyl-2-(2-hydroxyphenyl)cyclopropane, epoxide ring-opening and other organic transformations

La construcción democrática del orden deseado : Notas sobre la lectura latinoamericana de Hannah Arendt en los escritos tempranos de Norbert Lechner (1969-1984)

En estas notas, que forman parte de un proyecto más amplio, revisaremos un conjunto de trabajos que marcaron hitos significativos en el debate intelectual y académico sobre las transiciones a la democracia en América Latina y Argentina entre finales de los años setenta y principios de los años ochenta. Lo haremos prestando atención a las articulaciones entre las dimensiones discursivas, institucionales y socio-profesionales de la producción del conocimiento social (Wallerstein, 1999). Partimos de una premisa reconocida según la cual la discusión durante este período presenta una serie de rasgos novedosos -en relación con cada una de dichas dimensiones- estrechamente imbricados: la renovación del debate en torno a la política y la democracia en el marco de una creciente "latinoamericanización" e "internacionalización" de las ciencias sociales (los temas comunes a la región comienzan a ser discutidos en espacios de intercambio con especialistas locales y externos); la progresiva "autonomización" de la producción académica en relación con la política militante o las organizaciones partidarias; y finalmente, una paulatina "profesionalización" de la investigación en el marco de redes, centros especializados y circuitos de financiamiento y legitimación que responden a cánones de calidad internacional. En este contexto destacamos la sugerente lectura de Hannah Arendt que Norbert Lechner introduce en el debate latinoamericano en torno a la democratización.Facultad de Humanidades y Ciencias de la Educació

La construcción democrática del orden deseado : Notas sobre la lectura latinoamericana de Hannah Arendt en los escritos tempranos de Norbert Lechner (1969-1984)

En estas notas, que forman parte de un proyecto más amplio, revisaremos un conjunto de trabajos que marcaron hitos significativos en el debate intelectual y académico sobre las transiciones a la democracia en América Latina y Argentina entre finales de los años setenta y principios de los años ochenta. Lo haremos prestando atención a las articulaciones entre las dimensiones discursivas, institucionales y socio-profesionales de la producción del conocimiento social (Wallerstein, 1999). Partimos de una premisa reconocida según la cual la discusión durante este período presenta una serie de rasgos novedosos -en relación con cada una de dichas dimensiones- estrechamente imbricados: la renovación del debate en torno a la política y la democracia en el marco de una creciente "latinoamericanización" e "internacionalización" de las ciencias sociales (los temas comunes a la región comienzan a ser discutidos en espacios de intercambio con especialistas locales y externos); la progresiva "autonomización" de la producción académica en relación con la política militante o las organizaciones partidarias; y finalmente, una paulatina "profesionalización" de la investigación en el marco de redes, centros especializados y circuitos de financiamiento y legitimación que responden a cánones de calidad internacional. En este contexto destacamos la sugerente lectura de Hannah Arendt que Norbert Lechner introduce en el debate latinoamericano en torno a la democratización.Facultad de Humanidades y Ciencias de la Educació

CD69 is a TGF-β/1α,25-dihydroxyvitamin D3 target gene in monocytes

CD69 is a transmembrane lectin that can be expressed on most hematopoietic cells. In monocytes, it has been functionally linked to the 5-lipoxygenase pathway in which the leukotrienes, a class of highly potent inflammatory mediators, are produced. However, regarding CD69 gene expression and its regulatory mechanisms in monocytes, only scarce data are available. Here, we report that CD69 mRNA expression, analogous to that of 5-lipoxygenase, is induced by the physiologic stimuli transforming growth factor-β (TGF-β) and 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) in monocytic cells. Comparison with T- and B-cell lines showed that the effect was specific for monocytes. CD69 expression levels were increased in a concentration-dependent manner, and kinetic analysis revealed a rapid onset of mRNA expression, indicating that CD69 is a primary TGF-β/1α,25(OH)2D3 target gene. PCR analysis of different regions of the CD69 mRNA revealed that de novo transcription was initiated and proximal and distal parts were induced concomitantly. In common with 5-lipoxygenase, no activation of 0.7 kb or ~2.3 kb promoter fragments by TGF-β and 1α,25(OH)2D3 could be observed in transient reporter assays for CD69. Analysis of mRNA stability using a transcription inhibitor and a 3′UTR reporter construct showed that TGF-β and 1α,25(OH)2D3 do not influence CD69 mRNA stability. Functional knockdown of Smad3 clearly demonstrated that upregulation of CD69 mRNA, in contrast to 5-LO, depends on Smad3. Comparative studies with different inhibitors for mitogen activated protein kinases (MAPKs) revealed that MAPK signalling is involved in CD69 gene regulation, whereas 5-lipoxygenase gene expression was only partly affected. Mechanistically, we found evidence that CD69 gene upregulation depends on TAK1-mediated p38 activation. In summary, our data indicate that CD69 gene expression, conforming with 5-lipoxygenase, is regulated monocyte-specifically by the physiologic stimuli TGF-β and 1α,25(OH)2D3 on mRNA level, although different mechanisms account for the upregulation of each gene

SYNTHESIS OF N,S-CONTAINING COMPOUNDS USING (ISO)THIOCYANIC ACID SURROGATES

This work was supported by the Russian Science Foundation, project # 21-73-10212

Venezuela, April 2002: Coup or Popular Rebellion? The Myth of a United Venezuela

This article assesses the merits of opposing National Assembly reports into the coup against President Chavez of Venezuela in April 2002. Looking at the historical context and the content of the reports, it argues that the two opposing accounts reflect a class division that has always existed in Venezuela but has been officially denied. It concludes that a possible exit from the stalemate could be that the opposition accept the reality of this class division and therefore the Chavez government as a legitimate representative of the popular classes. This, however, is unlikely in the present circumstances

Terrestrial implications for the maritime geoarchaeological resource: A view from the Lower Palaeolithic

Stone tools and faunal remains have been recovered from the English Channel and the North Sea through trawling, dredging for aggregates, channel clearance, and coring. These finds highlight the potential for a maritime Lower Palaeolithic archaeological resource. It is proposed here that any Lower Palaeolithic artefacts, faunal remains, and sediments deposited in the maritime zone during dry, low-stand phases were once (and may still be) contextually similar to their counterparts in the terrestrial Lower Palaeolithic records of north-western Europe. Given these similarities, can interpretive models and analytical frameworks developed for terrestrial archaeology be profitably applied to an assessment of the potential value of any maritime resource? The terrestrial geoarchaeological resource for the Lower Palaeolithic is dominated by artefacts and ecofacts that have been fluvially reworked. The spatio-temporal resolution of these data varies from entire river valleys and marine isotope stages to river channel gravel bar surfaces and decadal timescales, thus supporting a variety of questions and approaches. However, the structure of the terrestrial resource also highlights two fundamental limitations in current maritime knowledge that can restrict the application of terrestrial approaches to any potential maritime resource: (i) how have the repetitive transgressions and regressions of the Middle and Late Pleistocene modified the terrace landforms and sediments associated with the river systems of the English Channel and southern North Sea basins?; and (ii) do the surviving submerged terrace landforms and fluvial sedimentary deposits support robust geochronological models, as is the case with the classical terrestrial terrace sequences? This paper highlights potential approaches to these questions, and concludes that the fluvial palaeogeography, Pleistocene fossils, and potential Lower Palaeolithic artefacts of the maritime geoarchaeological resource can be profitably investigated in future as derived, low-resolution data sets, facilitating questions of colonisation, occupation, demography, and material culture

Lignan Derivatives from Krameria lappacea Roots Inhibit Acute Inflammation in Vivo and Pro-inflammatory Mediators in Vitro

The roots of Krameria lappacea are used traditionally against oropharyngeal inflammation. So far, the astringent and antimicrobial properties of its proanthocyanidin constituents are considered to account for the anti-inflammatory effect. The aim of the present study was to characterize pharmacologically a lipophilic extract of K. lappacea roots and several isolated lignan derivatives (111) in terms of their putative anti-inflammatory activity. The dichloromethane extract (ID50 77 \u3bcg/cm2) as well compounds 111 (ID50 0.310.60 \u3bcmol/cm2) exhibited topical antiedematous properties comparable to those of indomethacin (ID50 0.29 \u3bcmol/cm2) in a mouse ear in vivo model. Two of the most potent compounds, 2-(2-hydroxy-4-methoxyphenyl)-5-(3-hydroxypropyl)benzofuran (5) and (+)-conocarpan (7), were studied regarding their time-dependent edema development and leukocyte infiltration up to 48 h after croton oil-induced dermatitis induction, and they showed activity profiles similar to that of hydrocortisone. In vitro studies of the isolated lignan derivatives demonstrated the inhibition of NFkB, cyclooxygenase-1 and -2, 5-lipoxygenase, and microsomal prostaglandin E2 synthase-1 as well as antioxidant properties, as mechanisms possibly contributing to the observed in vivo effects. The present findings not only support the ethnopharmacological use of K. lappacea roots but also reveal that the isolated lignan derivatives contribute strongly to the anti-inflammatory activity of this herbal drug