Probiotic microorganisms: 100 years of innovation and efficacy. Modes of action

AbstractArticle StructureFigures and TablesReferences Benefits from probiotic micro-organisms have been recognised for over 100 years, and as being useful in poultry for 50 years. Fuller (1989) redefined probiotics as ‘a live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance’. Benefits derived from this improved intestinal microbial balance could be reflected in performance or prevention of pathogen colonisation. Probiotic micro-organisms use in poultry production has been widely accepted and new opportunities arose from the 2006 EU ban on antimicrobial growth promoters. The majority of microbial products for compound feeds are made up from a relatively small number of micro-organisms that are normally present in the GI tract. They include non-sporulated bacteria, sporulated bacteria, fungi or yeasts; and presented from single to multi-strain products. A review on the proposed modes of action is presented including recent approaches to quorum sensing interference

Microdiálisis cerebral de alta resolución: Estudio del perfil funcional y estructural de las membranas de 100 kDa

La microdiàlisi és una tècnica de neuromonitoratge que permet el mostreig continu del contingut molecular i iònic de l’espai intersticial cerebral. Aquesta tècnica es basa en la implantació d’un catèter en el parènquima cerebral humà de manera mínimament invasiva. Actualment, la microdiàlisi s’ha implantat de manera rutinària en moltes unitats de cures intensives pel neuromonitoratge de pacients amb lesions cerebrals agudes. No obstant, l’estudi in vivo del perfil temporal del proteoma en aquestes lesions i la correcta avaluació de la concentració de les molècules d’interès en el líquid extracel•lular cerebral requereix la determinació prèvia in vitro del percentatge de recuperació relativa de les proteïnes d’estudi.

Perpendicular magnetic anisotropy in chemically disordered FePd-FeV(100) alloy thin films

We find that the use of V(100) buffer layers on MgO(001) substrates for the epitaxy of FePd binary alloys yields to the formation at intermediate and high deposition temperatures of a FePd¿FeV mixed phase due to strong V diffusion accompanied by a loss of layer continuity and strong increase of its mosaic spread. Contrary to what is usually found in this kind of systems, these mixed phase structures exhibit perpendicular magnetic anisotropy (PMA) which is not correlated with the presence of chemical order, almost totally absent in all the fabricated structures, even at deposition temperatures where it is usually obtained with other buffer layers. Thus the observed PMA can be ascribed to the V interdiffusion and the formation of a FeV alloy, being the global sample saturation magnetization also reduced.

Model for the emission of Si+ ions during oxygen bombardment of Si(100) surfaces

The variation in the emission of Si+ ions from ion-beam-induced oxidized silicon surfaces has been studied. The stoichiometry and the electronic structure of the altered layer has been characterized using x-ray photoelectron spectroscopy (XPS). The XPS analysis of the Si 2p core level indicates the strong presence of suboxide chemical states when bombarding at angles of incidence larger than 30 °. Since the surface stoichiometry or degree of oxidation varies with the angle of incidence, the corresponding valence-band structures also differ among each other. A comparison between experimental measurements and theoretically calculated Si and SiO2 valence bands indicates that the valence bands for the altered layers are formed by a combination of those two. Since Si-Si bonds are present in the suboxide molecules, the top of the respective new valence bands are formed by the corresponding 3p-3p Si-like subbands, which extend up to the Si Fermi level. The changes in stoichiometry and electronic structure have been correlated with the emission of Si+ ions from these surfaces. From the results a general model for the Si+ ion emission is proposed combining the resonant tunneling and local-bond-breaking models.

Vortex state and effect of anisotropy in sub-100 nm magnetic nanodots

Magnetic properties of Fe nanodots are simulated using a scaling technique and Monte Carlo method, in good agreement with experimental results. For the 20-nm-thick dots with diameters larger than 60¿nm, the magnetization reversal via vortex state is observed. The role of magnetic interaction between dots in arrays in the reversal process is studied as a function of nanometric center-to-center distance. When this distance is more than twice the dot diameter, the interaction can be neglected and the magnetic properties of the entire array are determined by the magnetic configuration of the individual dots. The effect of crystalline anisotropy on the vortex state is investigated. For arrays of noninteracting dots, the anisotropy strongly affects the vortex nucleation field and coercivity, and only slightly affects the vortex annihilation field

Hepatitis G virus infection in primary Sjögren's syndrome: analysis in a series of 100 patients.

OBJECTIVE To determine the prevalence and clinical significance of hepatitis G virus (HGV) infection in a large cohort of patients with primary Sjögren¿s syndrome (SS). PATIENTS AND METHODS The study included 100 consecutive patients (92 female and eight male), with a mean age of 62 years (range 31¿80) that were prospectively visited in our unit. All patients fulfilled the European Community criteria for SS and underwent a complete history, physical examination, as well as biochemical and immunological evaluation for liver disease. Two hundred volunteer blood donors were also studied. The presence of HGV-RNA was investigated in the serum of all patients and donors. Aditionally, HBsAg and antibodies to hepatitis C virus were determined. RESULTS Four patients (4%) and six volunteer blood donors (3%) presented HGV-RNA sequences in serum. HGV infection was associated with biochemical signs of liver involvement in two (50%) patients. When compared with primary SS patients without HGV infection, no significant differences were found in terms of clinical or immunological features. HCV coinfection occurs in one (25%) of the four patients with HGV infection. CONCLUSION The prevalence of HGV infection in patients with primary SS is low in the geographical area of the study and HCV coinfection is very uncommon. HGV infection alone does not seen to be an important cause of chronic liver injury in the patients with primary SS in this area.

Nanometer-scale oxidation of Si(100) surfaces by tapping mode atomic force microscopy

The nanometer¿scale oxidation of Si(100) surfaces in air is performed with an atomic force microscope working in tapping mode. Applying a positive voltage to the sample with respect to the tip, two kinds of modifications are induced on the sample: grown silicon oxide mounds less than 5 nm high and mounds higher than 10 nm (which are assumed to be gold depositions). The threshold voltage necessary to produce the modification is studied as a function of the average tip¿to¿sample distance.

La mania de les llistes: 100 biblioteques digitals i 'recol·lectors' de llibres electrònics

Selecció personal de 100 projectes de digitalització internacionals i locals actualment en funcionament. La tria s'ha fet seguint l'interès que poden tenir les obres incloses i en altres ocasions pels serveis, les eines i les aplicacions diferents que s'hi proposen. La major part dels recursos tenen com a objectiu oferir una còpia digital de llibres però també s'hi inclouen altres tipologies documentals: publicacions periòdiques, tesis, literatura grisa, fotografies, gravats, enregistraments sonors¿ Hi abunden els projectes fets per les biblioteques nacionals i universitàries, els projectes comercials més representatius i les col·leccions col·laboratives. Una tipologia a destacar és la de les plataformes que pretenen recuperar i difondre una cultura o una llengua. La llista inclou preferentment projectes de biblioteques digitals amb obres de domini públic, les obres de les quals es poden descarregar i imprimir; també hi són inclosos però materials de pagament. L'ordenació de la selecció està presentada alfabèticament.

La manía de las listas: 100 bibliotecas digitales y 'recolectores' de libros electrónicos

Selección personal de 100 proyectos de digitalización internacionales y locales actualmente en funcionamiento. La elección se ha hecho siguiendo el interés que pueden tener las obras incluidas y en otras ocasiones por los servicios, las herramientas y las aplicaciones diferentes que se proponen. La mayor parte de los recursos tienen como objetivo ofrecer una copia digital de libros pero también se incluyen otras tipologías documentales: publicaciones periódicas, tesis, literatura gris, fotografías, grabados, grabaciones sonoras... Abundan los proyectos realizados por las bibliotecas nacionales y universitarias, los proyectos comerciales más representativos y las colecciones colaborativas. Una tipología a destacar es la de las plataformas que pretenden recuperar y difundir una cultura o una lengua. La lista incluye preferentemente proyectos de bibliotecas digitales con obras de dominio público, las obras de las que se pueden descargar e imprimir, también están incluidos pero materiales de pago. La ordenación de la selección está presentada alfabéticamente.

«Conocimientos situados»: reflexión sobre las geografías de la Geografía (Crónica de un viaje al 100 Congreso de la Association of American Geographers)

Dolido por la escasa repercusión y el nulo interés de la geografía (crítica) estadounidense ante los atentados de Al Qaeda en Madrid, el cuaderno de viaje de Margarita del Vez (participante en el 100 Congreso de la Association of American Geographers) reprocha no sólo que el conocimiento geográfico sigue siendo mercantilizado y puesto al servicio del poder, sino que, descontextualizado y desideologizado, a menudo se convierte en una nueva forma de «saber ignorante». Con la deconstrucción formal de la narrativa «científica», el texto pretende ser también una denuncia al hecho de que la institución académica, por guardar las formas, llegue al extremo de dar la espalda a la realidad.