Self collimation of ultrasound in a 3D sonic crystal

We present the experimental demonstration of self-collimation (subdiffractive propagation) of an ultrasonic beam inside a three-dimensional sonic crystal. The crystal is formed by two crossed steel cylinders structures in a woodpile-like geometry disposed in water. Measurements of the 3D field distribution show that a narrow beam which diffractively spreads in the absence of the sonic crystal is strongly collimated in propagation inside the crystal, demonstrating the 3D self-collimation effect.Comment: 3 figures, submitted to Applied Physics Letter

Effect of methyl jasmonate in gene expression, and in hormonal and phenolic profiles of holm oak embryogenic lines before and after infection with Phytophthora Cinnamomi

The dieback syndrome affecting Quercus ilex and other oak species impels the search for tolerant plant genotypes, as well as methods of plant immunization against such infections. Elicitation treatments can be an effective strategy to activate plant defense response and embryogenic lines represent a promising tool to generate new tolerant genotypes and also to study early markers involved in defense response. The aim of the presented work was to investigate changes in gene expression, and in hormonal and phenolic profiles induced in three holm oak embryogenic lines (ELs) elicited with methyl jasmonate (MeJA) before and after infection with the oomycete Phytophthora cinnamomi, which is the main biotic agent involved in this pathogenic process. The three ELs, derived from three genotypes, showed different basal profiles in all tested parameters, noting that the VA5 naïve genotype from a scape tree was characterized by a basal higher expression in NADPH-dependent cinnamyl alcohol dehydrogenase (CAD) and chalcone synthase (CHS) genes and also by higher caffeic acid content. Our work also identifies changes triggered by MeJA elicitation in holm oak embryogenic lines, such as increases in ABA and JA contents, as well as in levels of most of the determined phenolic compounds, especially in caffeic acid in Q8 and E00 ELs, but not in their biosynthesis genes. Irrespective of the EL, the response to oomycete infection in holm oak elicited plant material was characterized by a further increase in JA. Since JA and phenols have been described as a part of the Q. ilex defense response against P. cinnamomi, we propose that MeJA may act as an induced resistance (IR) stimulus and that in our embryogenic material induced both direct (detected prior to any challenge) and primed (detected after subsequent challenge) defense responses. Copyright © 2022 Morcillo, Sales, Corredoira, Martínez, Segura and Arrillaga

Effect of elicitors on holm oak somatic embryo development and efficacy inducing tolerance to Phytophthora cinnamomi

Holm oak trees (Quercus ilex L.) mortality is increasing worryingly in the Mediterranean area in the last years. To a large degree this mortality is caused by the oomycete Phytophthora spp., which is responsible for forest decline and dieback in evergreen oak forest areas of the southwestern Iberian Peninsula. This study is based on the possibility of applying chemical elicitors or filtered oomycete extracts to holm oak somatic embryos (SE) in order to induce epigenetic memory, priming, that may increase tolerance to the pathogen in future infections. To this end, we first examined the effect of priming treatments on SE development and its oxidative stress state, to avoid elicitors that may cause damage to embryogenic tissues. Both, the sterile oomycete extracts and the chemical elicitor methyl jasmonate (MeJA) did not produce any detrimental effect on SE growth and development, unlike the elicitors benzothiadiazole (BTH) and p-aminobenzoic acid (PABA) that reduced the relative weight gain and resulted in necrotic and deformed SE when were applied at high concentrations (25 µM BTH or 50 µM PABA) in accordance with their high malondialdehyde content. No significant differences among elicitation treatments were found in dual culture bioassays,  although those SEs elicited with 50 µM MeJA increased H2O2 production after challenged against active oomycete indicating the activation of stress response. Since this elicitation treatment did not produce any adverse effect in the embryogenic process we suggest that could be used in further priming experiments to produce holm oak plants adapted to biotic stress

Influencia de agentes Tensioactivos sobre la velocidad de disolución de comprimidos

El presente trabajo ha sido realizado con una Beca del Fondo Lepetit para ayuda y fomento de la investigación médico-farmacéutica. Agradecemos sinceramente dicha concesión merced a la cual ha sido posible su elaboración. Ha sido presentado al I Congreso Nacional de Biofarmacia y Farmacocinética. Barcelona. Mayo 1975.En el presente trabajo se estudia la infiuencia que los agentes tensioactivos ejercen sobre la velocidad de disolución de comprimidos, y por tanto sobre su disponibilidad "in vitro". Para ello se han elaborado siete series de comprimidos de fenilbutazona en los que se han incluido Tween 80 Y Lauril sulfato sódico en diversas etapas de su fabricación. Se han sometido a ensayos de disolución utilizando un dispositivo automático de flujo continuo, y se ha observado un gran aumento de la misma, mayor en el caso del Laurilsulfato sódico, y especialmente cuando el tensioactivo va adicionado al aglutinante. La valoración cuantitativa de fenilbutazona en les comprimidos y en la disolución final permite apreciar la total liberación de la sustancia medicamentosa.In the present work we study the influence of "surfactants" on the dlssolution speed nf tabIets, thus, on its availability "in vitro". We have elaborated seven series of Phenylbutazone tablets with Tween 80 and sodium Lauryl Sulfate added at diff.er,ent steps of its manufactu ringo They were subjeted to dissolution tests using an automatic disposi tive of continuous flux, and a great increase of ,H was observed, greater With Sodlum Lauryl Sulfate and specially when the surfactants was added to the binding agent. The quantitative appraisemeni of Phenybutazone, in the tablets and final dissolution allows to stimate the total release of the drug.Fondo Lepeti

Detection of first- and second-line drug resistance in Mycobacterium tuberculosis clinical isolates by pyrosequencing

Conventional phenotypic drug susceptibility testing (DST) methods for Mycobacterium tuberculosis are laborious and very time-consuming. Early detection of drug-resistant tuberculosis (TB) is essential for prevention and control of TB transmission. We have developed a pyrosequencing method for simultaneous detection of mutations associated with resistance to rifampin, isoniazid, ethambutol, amikacin, kanamycin, capreomycin, and ofloxacin. Seven pyrosequencing assays were optimized for following loci: rpoB, katG, embB, rrs, gyrA, and the promoter regions of inhA and eis. The molecular method was evaluated on a panel of 290 clinical isolates of M. tuberculosis. In comparison to phenotypic DST, the pyrosequencing method demonstrated high specificity (100%) and sensitivity (94.6%) for detection of multidrug-resistant M. tuberculosis as well as high specificity (99.3%) and sensitivity (86.9%) for detection of extensively drug-resistant M. tuberculosis. The short turnaround time combined with multilocus sequencing of several isolates in parallel makes pyrosequencing an attractive method for drug resistance screening in M. tuberculosis.Fil: Engström, Anna. Karolinska Huddinge Hospital. Karolinska Institutet; Suecia. Swedish Institute for Communicable Disease Control; SueciaFil: Morcillo, Nora Susana. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; ArgentinaFil: Imperiale, Belén Rocío. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia de Buenos Aires. Ministerio de Salud. Hospital "Dr. Antonio A. Cetrángolo"; ArgentinaFil: Hoffner, Sven E.. Karolinska Huddinge Hospital. Karolinska Institutet; Suecia. Swedish Institute for Communicable Disease Control; SueciaFil: Juréen, Pontus. Karolinska Huddinge Hospital. Karolinska Institutet; Suecia. Swedish Institute for Communicable Disease Control; Sueci

Contaminantes emergentes: determinación de fármacos antihipertensivos en aguas superficiales

Estudios recientes han mostrado la presencia de un amplio grupo de principios activos farmacológicos en el medioambiente procedentes principalmente de la descarga de estaciones depuradoras de aguas residuales. Entre ellos, son de especial interés aquellos empleados en el tratamiento de enfermedades crónicas, como los fármacos antihipertensivos, no sólo debido a su consumo continuado, sino además a su potente mecanismo de acción, lo que los hace especialmente peligrosos para el medioambiente. En este trabajo se ha optimizado y validado una metodología analítica, basada en la extracción en fase sólida y determinación mediante cromatografía líquida con detector de espectrometría de masas de triple cuadrupolo, para la determinación de los tres fármacos antihipertensivos más consumidos (irbesartán, telmisartán y valsartán) en aguas superficiales. Las recuperaciones obtenidas se situaron entre el 84 y el 101 %. La precisión, medida en unidades de desviación estándar relativa, fue inferior al 10 % y los límites de detección se situaron entre 0.24 y 2.01 ng/L.Recent studies have reported the presence of a broad spectrum of pharmaceutical compounds in several environmental compartments, where they mainly end up due to discharges of effluent wastewater. Among them, pharmaceuticals designed to treat chronic diseases, including hypertensive pharmaceuticals, are of special interest, not only due to its continued consumption, but also for their potent mechanism of action, which makes them especially dangerous for the environment. In this work, an analytical method, based on solid phase extraction and determination by liquid chromatography with triple quadrupole mass spectrometry detector, has been optimized and validated for the determination of three of the most consumed antihypertensive pharmaceuticals (irbesartan, telmisartan and valsartan) on surface water samples. The recoveries obtained were between 84 and 101%. Precision, expressed as relative standard deviation, was < 10%, and limits of detection were between 0.24 and 2.01 ng/L.Ministerio de Economía y Competitividad. Proyecto CGL2013-44402-

Atmospheric corrosion of reference metals in Antarctic sites

This paper presents the results obtained at three Antarctic test sites participating in the >Ibero-American Map of Atmospheric Corrosiveness> (MICAT), a project on atmospheric corrosion carried out during the period 1988-1994 at some 70 sites distributed across 12 countries of the Latin-American region, Spain and Portugal. The three Antarctic sites are located near the coastline. The singular climatic characteristics of Antarctic regions are related with the purity of the air, the absence of rainfall and the formation of ice on the metallic surface during an important part of the exposure time. However, electrochemical activity is possible below ice layers. This situation affects the structure and morphology of corrosion product films and the resulting corrosion rates of metallic surfaces. © 2004 Elsevier B.V. All rights reserved.Peer Reviewe