Suchergebnisse

The Campo Coy basin contains an important evaporite succession, up to 350 meters thick of gypsum, including two gypsum units: lower and upper gypsum units. These are characterized by fine-grain laminated and selenitic primary gypsums and by nodular-laminated and meganodular secondary gypsums. The geochemical study based on sulfate isotope compositions (δ34S and δ18O) and strontium isotope ratios (87Sr/86Sr) point to the chemical recycling of Triassic marine evaporites. Isotope compositions (δ18O and δD) of the hydration water of gypsum point to continental waters for primary gypsum precipitation. These results are consistent with a shallow lacustrine environment for the Campo Coy gypsum deposit. ; La cuenca de Campo Coy registra una sucesión evaporítica de más de 350 metros de potencia de yeso, dividida en dos unidades de yesos: unidad inferior y unidad superior. Estas unidades están formadas por litofacies de yeso primario laminado y yeso selenítico junto con litofacies de yeso secundario laminado-nodular y meganodular. El estudio geoquímico de la composición isotópica del sulfato (δ34S y δ18O) y de la relación isotópica del estroncio (87Sr/86Sr) muestra valores indicativos del reciclaje de evaporitas marinas triásicas. Los valores isotópicos del agua de hidratación del yeso (δ18O y δD) indican aguas de origen continental para el yeso primario. Estos resultados reflejan un ambiente lacustre somero durante la formación del depósito evaporítico de Campo Coy. ; This study was supported by the projects CGL-2013-42689 and CGL2016-79458 of the Spanish Government.

9 p.-8 fig. ; Experimental conditions that simulate the crowded bacterial cytoplasmic environment have been used to study the assembly of the essential cell division protein FtsZ from Escherichia coli. In solutions containing a suitable concentration of physiological osmolytes, macromolecular crowding promotes the GTP-dependent assembly of FtsZ into dynamic two-dimensional polymers that disassemble upon GTP depletion. Atomic force microscopy reveals that these FtsZ polymers adopt the shape of ribbons that are one subunit thick. When compared with the FtsZ filaments observed in vitro in the absence of crowding, the ribbons show a lag in the GTPase activity and a decrease in the GTPase rate and in the rate of GTP exchange within the polymer. We propose that, in the crowded bacterial cytoplasm under assembly-promoting conditions, the FtsZ filaments tend to align forming dynamic ribbon polymers. In vivo these ribbons would fit into the Z-ring even in the absence of other interactions. Therefore, the presence of mechanisms to prevent the spontaneous assembly of the Z-ring in non-dividing cells must be invoked. ; This work was supported in part by Grants BIO99-0859-C03-03 and BMC2002-04617-C02-01 (to G. R.), BMC2002-04617-C02-02 (to M. Ve ́.), BIO2000-0451-P4-02 (to M. Vi.), and BIO99-0859-C03-02 and BIO2002- 03665 (to J. M. A.), all from the Spanish Ministry of Science and Tech- nology (MCyT), and by the Programa de Grupos Estrate ́gicos of the Madrid Government (to J. M. A. and G. R.). ; Peer reviewed

Carbapenem-resistant Enterobacteriaceae have recently become an important cause of morbidity and mortality due to healthcare-associated infections. Most commonly used diagnostic methods are incompatible with fast and accurate directed therapy. We report here the direct identification of the blaOXA48 gene, which codes for the carbapenemase OXA-48, in lysate samples from Klebsiella pneumoniae. The method is PCR-free and label-free. It is based on the measurement of changes in the stiffness of DNA self-assembled monolayers anchored to microcantilevers that occur as a consequence of the hybridization. The stiffness of the DNA layer is measured through changes of the sensor resonance frequency upon hybridization and at varying relative humidity. ; This work was supported by the Spanish Science Ministry (MINECO) through project MAT2015-66904-R and by European Research Council through NANOFORCELLS project (ERC-StG-2011-278860) and European Union's Horizon 2020 research and innovation program under grant agreement No. 731868-VIRUSCAN. D.R. acknowledges the Ramon y Cajal fellowship supported by Spanish Ministry MINECO. Authors also acknowledge the service from the XSEM Laboratory at IMN and funding from MINECO under project CSIC13-4E-1794 with support from EU (FEDER, FSE). ; Peer reviewed