Microwave-assisted Palladium catalysed C-H acylation with aldehydes. Synthesis and diversification of 3-acylthiophenes

The use of MW allows the efficient palladium(II)-catalysed C-3 acylation of thiophenes with aldehydes via C(sp2)-H activation for the synthesis of (cyclo)alkyl/aryl thienyl ketones (43 examples). Compared to standard thermal conditions, the use of MW reduces the reaction time (15 to 30 min vs. 1 to 3 hours), leading to improved yields of the ketones (up to 92%). Control of positional selectivity is achieved by 2-pyridinyl and 2-pyrimidyl ortho-directing groups at C-2 of the thiophene scaffold. To show the synthetic applicability, selected ketones were subjected to further transformations, including intramolecular reactions to directly embed the directing-group in the core-structure of the new moleculeMinisterio de Ciencia e Innovación (PID2019-104148GB-I00) / Gobierno Vasco (IT1045-16

Performance of upstream interaction region detectors for the FIRST experiment at GSI

The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at GSI has been designed to study carbon fragmentation, measuring 12C double differential cross sections (∂2σ/ ∂θ∂E) for different beam energies between 100 and 1000 MeV/u. The experimental setup integrates newly designed detectors in the, so called, Interaction Region around the graphite target. The Interaction Region upstream detectors are a 250 μm thick scintillator and a drift chamber optimized for a precise measurement of the ions interaction time and position on the target. In this article we review the design of the upstream detectors along with the preliminary results of the data taking performed on August 2011 with 400 MeV/u fully stripped carbon ion beam at GSI. Detectors performances will be reviewed and compared to those obtained during preliminary tests, performed with 500 MeV electrons (at the BTF facility in the INFN Frascati Laboratories) and 80 MeV/u protons and carbon ions (at the INFN LNS Laboratories in Catania)

Primer registro de tetracha sobrina dejean, 1831 y tetracha cribata steinheil, 1875 (coleoptera: cicindelidae) en sincelejo-sucre, colombia

Los cicindélidos ó escarabajos tigre son insectos pertenecientes a la familia Cicindelidae, los cuales se caracterizan por presentar la cabeza en conjunto con los ojos más ancha que el tórax, mandíbulas en forma de hoz, patas cursoras largas y delgadas y tonalidades que varían desde oscuro y opaco hasta patrones coloridos y brillantes (VÍTOLO, 2004). Los cicindélidos están compuestos por cerca de 2.500 especies con una amplia distribución mundial y con un rango altitudinal que van desde el nivel del mar hasta casi los 4.000 m (CASSOLA y PEARSON, 2001). La Región Neotropical es la segunda más rica en el mundo con 537 especies (CASSOLA y PEARSON, 2001); por su parte, Colombia cuenta con 19 géneros y 93 especies siendo uno de los países neotropicales con mayor diversidad de escarabajos tigre (VÍTOLO y PEARSON, 2003). Esta nota present

Micetoma podal por fusarium solani (Mart.) Appel & Wollenweber

Se presenta un caso de micetoma de pie derecho, producido por fusarium solani, en un hombre de 24 años procedente del Chaco. La infección se produjo debido a una lesión con una astilla de quebracho.La determinación del agente causal fue realizada en muestras seriadas (biopsias y secreciones) por el estudio de los gránulos, exámenes directos, coloraciones y caracteres culturales en medio de Agar Sabouraud-glucosa, Agar Sabouraud cloranfenicol, Agar extracto de Malta y Cerebro Corazón.Se considera a fusarium solani y otros especies del género, como raros agentes productores de micetoma, pero las cepas con capacidad de crecer a elevadas temperaturas y las circunstancias apropiadas en hospedador, permiten su adaptación al ambiente tisular y el inicio de esta micosis

Divergent male androgen patterns in two sympatric species of Leptodactylus from subtropical South America

Leptodactylus ocellatus L. is sympatric with L. chaquensis Cei on the banks of the Parana river, yet does not show evident gametogenic discontinuity or cyclical variation of secondary sex characters compared with the striking and well-defined seasonal rhythm found in L. chaquensis. The endocrine mechanisms regulating the seasonal reproductive cycle in the male of both species in their sympatric area have been studied through assessment of plasma androgens, related to the morphological examination of testis. A sudden intense spermatogenic activity was recorded in the testes of L. chaquensis in spring months (September-October), but this ceased in late November, and was followed by a strikingly long summer rest. Conversely, few morphological changes in L. ocellatus were found, since the mating period is more irregular and extensive. The androgen plasma changes paralleled the morphological observations. The plasma androgens behaved differently in the two species, since in L. chaquensis the androgen peak values occurred at the end of the intense spermatogenic activity, accompanied by dramatic increase of testicular weight and spermiation, while in L. ocellatus, the highest androgen plasma levels, occurring in August, seemed to indicate a precocious reproductive activity in this species. These data are discussed, in view of the pivotal role played by androgens in regulating the discontinuous reproductive cycle of L. chaquensis.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Divergent male androgen patterns in two sympatric species of Leptodactylus from subtropical South America

Leptodactylus ocellatus L. is sympatric with L. chaquensis Cei on the banks of the Parana river, yet does not show evident gametogenic discontinuity or cyclical variation of secondary sex characters compared with the striking and well-defined seasonal rhythm found in L. chaquensis. The endocrine mechanisms regulating the seasonal reproductive cycle in the male of both species in their sympatric area have been studied through assessment of plasma androgens, related to the morphological examination of testis. A sudden intense spermatogenic activity was recorded in the testes of L. chaquensis in spring months (September-October), but this ceased in late November, and was followed by a strikingly long summer rest. Conversely, few morphological changes in L. ocellatus were found, since the mating period is more irregular and extensive. The androgen plasma changes paralleled the morphological observations. The plasma androgens behaved differently in the two species, since in L. chaquensis the androgen peak values occurred at the end of the intense spermatogenic activity, accompanied by dramatic increase of testicular weight and spermiation, while in L. ocellatus, the highest androgen plasma levels, occurring in August, seemed to indicate a precocious reproductive activity in this species. These data are discussed, in view of the pivotal role played by androgens in regulating the discontinuous reproductive cycle of L. chaquensis.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Divergent male androgen patterns in two sympatric species of Leptodactylus from subtropical South America

Leptodactylus ocellatus L. is sympatric with L. chaquensis Cei on the banks of the Parana river, yet does not show evident gametogenic discontinuity or cyclical variation of secondary sex characters compared with the striking and well-defined seasonal rhythm found in L. chaquensis. The endocrine mechanisms regulating the seasonal reproductive cycle in the male of both species in their sympatric area have been studied through assessment of plasma androgens, related to the morphological examination of testis. A sudden intense spermatogenic activity was recorded in the testes of L. chaquensis in spring months (September-October), but this ceased in late November, and was followed by a strikingly long summer rest. Conversely, few morphological changes in L. ocellatus were found, since the mating period is more irregular and extensive. The androgen plasma changes paralleled the morphological observations. The plasma androgens behaved differently in the two species, since in L. chaquensis the androgen peak values occurred at the end of the intense spermatogenic activity, accompanied by dramatic increase of testicular weight and spermiation, while in L. ocellatus, the highest androgen plasma levels, occurring in August, seemed to indicate a precocious reproductive activity in this species. These data are discussed, in view of the pivotal role played by androgens in regulating the discontinuous reproductive cycle of L. chaquensis.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse