Recurrent hepatitis C after orthotopic liver transplantation (OLT) is universal and can lead to graft failure and, consequently, reduced survival. Hepatitis C treatment can be used to prevent these detrimental outcomes. The aim of this study was to describe rates of hepatitis C recurrence and sustained virological response (SVR) to interferon-based treatment after OLT and its relationship to survival and progression of liver disease through retrospective analysis of medical records of 127 patients who underwent OLT due to cirrhosis or hepatocellular carcinoma secondary to chronic hepatitis C between January 2002 and December 2013. Fifty-six patients were diagnosed with recurrent disease, 42 started interferon-based therapy and 37 completed treatment. Demographic, treatment- and outcome-related variables were compared between SVR and non-responders (non-SVR). There was an overall 54.1% SVR rate with interferon-based therapies. SVR was associated with longer follow-up after treatment (median 66.5 vs 37 months for non-SVR, P=0.03) and after OLT (median 105 vs 72 months, P=0.074), and lower rates of disease progression (15 vs 64.7%, P=0.0028) and death (5 vs 35.3%, P=0.033). Regardless of the result of therapy (SVR or non-SVR), there was a significant difference between treated and untreated patients regarding the occurrence of death (P<0.001) and months of survival (P<0.001). Even with suboptimal interferon-based therapies (compared to the new direct-acting antivirals) there is a 54.1% SVR rate to treatment. SVR is associated with improved survival and reduced risks of clinical decompensation, loss of the liver graft and death.

Baccharis ulicina is a weed widely distributed in pastures of the semiarid zone of Argentina. With the aim of evaluate potential allelopathic effects, aqueous extracts of B. ulicina (leaf, stem, root and whole plant) at two concentrations (50 and 150 g tissue/L water) were used on germination and initial growth of Avena sativa, Lolium perenne and Raphanus sativus. For each species, 100 seeds were watered and maintained at 25°C at darkness. Seed germination and length of coleoptile / hypocotyl (C/H) and radicle (R) was measured. Then, germination percentage, germination rate coefficient, germination vigor, inhibition of germination, inhibition of radicle length and coleoptile / hypocotyl length, radicle vigor index and the coleoptile / hypocotyl vigor index were calculated. High concentration extracts reduced germination an average of 65%, in addition, they produced a length inhibition of 58.8% (C/H) and 93.3% (R) to A. sativa; 71.5% (C/H) and 87.9% (R) to L. perenne, and 93.8% (C/H) and 94.5% (R) to R. sativus. There was an evident phytotoxic effect of B. ulicina on evaluated species, indicating that allelopathy would be an ecological strategy of the species.

Baccharis ulicina es una maleza ampliamente distribuida en los pastizales de la zona semiárida argentina. A fin de evaluar sus posibles efectos alelopáticos, se utilizaron extractos acuosos de B. ulicina (hoja, tallo, raíz y planta entera) a dos concentraciones (50 y 150 g tejido/L agua) sobre la germinación y crecimiento inicial de Avena sativa, Lolium perenne y Raphanus sativus. Para cada especie se regaron 100 semillas y se mantuvieron a 25°C y oscuridad. Se registraron la germinación de las semillas y la longitud de coleóptilo / hipocótile (C/H) y radícula (R). Con los datos obtenidos se determinó: porcentaje de germinación, coeficiente de velocidad de germinación, vigor de la germinación, inhibición de la germinación, inhibición de la longitud de la radícula y del coleóptilo / hipocótile e índice de vigor de radícula y de coleóptilo / hipocótile. Los extractos con alta concentración redujeron la germinación en promedio 65% mientras que inhibieron la longitud en 58,8% (C/H) y 93,3% (R) para A. sativa; 71,5% (C/H) y 87,9% (R) para L. perenne, y 93,8% (C/H) y 94,5% (R) para R. sativus. Se registró un evidente efecto fitotóxico de B. ulicina sobre las especies evaluadas, indicando que la alelopatía sería una estrategia ecológica de la especie.

In this paper, we report on the synthesis of gold and silver nanoparticles in situ functionalized with a phenylene ethynylene polymer sequenced with a -C(O)S-(CH2)2S-(CH2)2S-C(O)- moiety. The synthesis has been carried out by chemical colloidal methods and for silver, also by laser ablation. All particles were characterized by TEM, ¹H NMR, UV-Vis and fluorescence spectroscopy. The gold nanoparticles are smaller and with a narrower size distribution than silver nanoparticles, for which agglomeration is observed with a higher degree for the laser obtained samples. Due to the problem of agglomeration, the films of silver nanoparticles are not homogeneous and thus only gold nanoparticles films were analyzed. The functionalization of the gold nanoparticles improves the morphological and electrical properties of the films showing a lower roughness and higher electrical conductivity with respect to those of the polymer.

En este trabajo se reporta la síntesis de nanopartículas de oro y plata funcionalizadas in situ con un polí(fenilenetinileno) fluorescente y portador de la secuencia flexible -C(O)S-(CH2)2S-(CH2)2S-C(O)-. La síntesis se llevó a cabo por métodos de química coloidal y para la plata también por ablación láser. Todas las partículas se caracterizaron por Microscopía Electrónica de Transmisión (MET), RMN de ¹H, espectroscopia UV-Vis y fluorescencia. Se determinó que las partículas de oro son más pequeñas y aisladas mientras que las de plata presentan aglomeración y de forma más marcada para las que se obtuvieron por ablación láser. Debido a la aglomeración, las partículas de plata no permitieron formar películas homogéneas por lo que estas se elaboraron solamente para las nanopartículas de oro. La funcionalización de nanoparticulas de oro mejora las propiedades morfológicas y eléctricas obteniendo películas con menor rugosidad y mayor conductividad eléctrica con respecto a las del polímero.

We present a technique to prove invariants of model-based specifications in a fragment of set theory. Proof obligations containing set theory constructs are translated to first-order logic with equality augmented with (an extension of) the theory of arrays with extensionality. The idea underlying the translation is that sets are represented by their characteristic function which, in turn, is encoded by an array of Booleans indexed on the elements of the set. A theorem proving procedure automating the verification of the proof obligations obtained by the translation is described. Furthermore, we discuss how a sub-formula can be extracted from a failed proof attempt and used by a model finder to build a counter-example. To be concrete, we use a B specification of a simple process scheduler on which we illustrate our technique.