Search results for "SEP"
showing 10 items of 2642 documents
Ladinian carbonates of the Cabo Cope Unit (Betic Cordillera, SE Spain): a tethys-maláguide palaeogeographic gateway.
2003
7 pages, 4 figures.
A Newly-Detected Reductase fromRauvolfiaCloses a Gap in the Biosynthesis of the Antiarrhythmic Alkaloid Ajmaline
2002
A new enzyme, 1,2-dihydrovomilenine reductase (E.C. 1.3.1), has been detected in Rauvolfia cell suspension cultures. The enzyme specifically converts 2beta( R)-1,2-dihydrovomilenine through an NADPH-dependent reaction into 17-O-acetylnorajmaline, a close biosynthetic precursor of the antiarrhythmic alkaloid ajmaline from Rauvolfia. A five-step purification procedure using SOURCE 30Q chromatography, hydroxyapatite chromatography, 2',5'-ADP Sepharose 4B affinity chromatography and ion exchange chromatography on DEAE Sepharose and Mono Q delivered an approximately 200-fold enriched enzyme in a yield of approximately 6%. SDS-PAGE showed an M r for the enzyme of approximately 48 kDa. Optimum pH …
Influence of Geographical Location of Spirulina (Arthrospira platensis) on the Recovery of Bioactive Compounds Assisted by Pulsed Electric Fields
2022
Spirulina (Arthrospira platensis) has been consumed by humans since ancient times. It is rich in high added-value compounds such as chlorophylls, carotenoids and polyphenols. Pulsed electric fields (PEF) is an innovative non-thermal technique that improves the extraction of bioactive compounds from diverse sources. PEF pre-treatment (3 kV/cm, 100 kJ/kg) combined with supplementary extraction with binary solvents at different times was evaluated to obtain the optimal conditions for extraction. In addition, the results obtained were compared with conventional treatment (without PEF pre-treatment and constant shaking) and different strains of Spirulina from diverse geographical locations. The …
Structural and electrochemical investigation on re-cast Nafion membranes for polymer electrolyte fuel cells (PEFCs) application
2006
Abstract Starting from a 5 wt% ion power Nafion® solution and dissolving the dry residue in a suitable solvent (10 wt% solution in dimethylacetammide), re-cast Nafion films were developed for polymer electrolyte fuel cells (PEFCs) application. The used Doctor-Blade casting technique allowed to prepare scaled-up membranes comparable to the commercial Nafion ones with good mechanical resistance, thickness homogeneity and an excellent reproducibility. The differences between the re-cast membrane nanostructure and that of the commercial Nafion were investigated by synchrotron small-angle X-ray scattering. The obtained re-cast membrane shows at ambient conditions a semi-crystalline structure wit…
Automated multi-dimensional liquid chromatography
2004
A comprehensive on-line sample clean-up with an integrated two-dimensional HPLC system was developed for the analysis of natural peptides. Samples comprised of endogenous peptides with molecular weights up to 20 kDa were generated from human hemofiltrate (HF) obtained from patients with chronic renal failure. The (poly-)peptides were separated using novel silica-based restricted access materials with strong cation-exchange functionalities (SCX-RAM). The size-selective sample fractionation step is followed by cation-exchange chromatography as the first dimension. The subsequent second dimension of separation is based on hydrophobic interaction using four parallel short reversed-phase (RP) co…
1998. Primarias en España. Se inicia la era posfelipista. Almunia versus Borrell. 24 de abril de 1998
2015
Primarias en España. Se inicia la era posfelipista. Almunia versus borrell. 24 de abril de 1998. Felipe González: “…no seré candidato a la Secretaría General”. Las elecciones primarias socialistas en el País Vasco. Nicolás Redondo Terreros/Rosa Díez. 14 de marzo de 1998. Almunia opta por las primarias. Almunia versus Borrell. 24 de abril 1998. Borrell se lanza a la piscina. El proceso. Cómo se organizaron las primeras elecciones primarias. La campaña electoral Almunia/Borrell. Sondeos sobre intención de voto Almunia/ Borrell. Contra pronóstico, Borrell gana las primarias. Los partidos opinan sobre los resultados de las primarias. Valoración en el PSOE. Primarias en el PSOE, una experiencia …
Pittura del XIX e del XX secolo nel segno del collezionismo siciliano
2020
Il volume offre una ricognizione sul collezionismo in Sicilia e prende in esame, per la prima volta nella sua interezza, una collezione privata proponendo la riscoperta di opere di autori rappresentativi della cultura figurativa italiana del XIX e del XX secolo, tra cui Michele Catti, Ettore De Maria Bergler, Onofrio Tomaselli, Pippo Rizzo, Alfonso Amorelli e Pina Calì. La collezione privilegia la pittura dell’isola ma include anche il pittore non siciliano Giuseppe Amisani e la coppia di bronzi di Antonio Ugo e trova nelle opere "Costumi" di Salvatore Lo Forte del 1839 e "Sogno del carabiniere" di Pippo Rizzo degli anni ’50 i propri limiti cronologici. Questa raccolta privata, per lo più i…
Capsaicin differentially modulates voltage-activated calcium channel currents in dorsal root ganglion neurones of rats
2005
It is discussed whether capsaicin, an agonist of the pain mediating TRPV1 receptor, decreases or increases voltage-activated calcium channel (VACC) currents (ICa(V)). ICa(V) were isolated in cultured dorsal root ganglion (DRG) neurones of rats using the whole cell patch clamp method and Ba 2+ as charge carrier. In large diameter neurones (>35Am), a concentration of 50AM was needed to reduce ICa(V) (activated by depolarizations to 0 mV) by 80%, while in small diameter neurones (30Am), the IC50 was 0.36 AM. This effect was concentration dependent with a threshold below 0.025 AM and maximal blockade (>80%) at 5AM. The current–voltage relation was shifted to the hyperpolarized direction with an…
Contesti, sistemi e centralità diffusa
2014
Palermo è una città difficile da capire per le tante contraddizioni che la caratterizzano, per l’ossimoro che racchiude in sé, per le eterne, dicotomiche contrapposizioni delle diverse città comprese forzatamente in un unico corpo multiforme; quella misera e luttuosa dei suoi spazi più interni e interstiziali; quella che si sforza di manifestare la sua fragile bellezza attraverso testimonianze memorabili di una storia unica; quella laico-borghese i cui vaneggiamenti progressisti e riformatori ottocenteschi si sono infranti contro l’irriducibile eterna aspirazione urbana ad una voluttuosa immobilità storica; quella non scettica e indifferente nei confronti della modernità (di tutte le modern…
Palermo tra innesti e piante originarie
2019
Se vi è qualcosa di profondamente e visceralmente connaturato alla stessa dimensione esistenziale della città di Palermo, sin dalle sue molteplici e stratificate origini fenicio-puniche, questo è certamente il concetto di “innesto”. Ed in analogia con l’innesto agrario, cioè con la pratica del far concrescere in una pianta esistente una parte di un altro vegetale, al fine di rafforzare il primo soggetto ma modificandolo verso un genere diverso da quello iniziale, l’intera storia millenaria della città potrà essere riguardata come il frutto di continue, cicliche introduzioni di modelli architettonici e urbani esogeni, declinati rispetto alle contingenze culturali autoctone dei diversi esempi…