K- and L-band spectroscopy of Be stars

We describe the behaviour of IR hydrogen emission lines of a sample of Be stars and discuss the physical properties of the circumstellar envelopes of Be stars classified in Groups I and II (Mennickent et al. 2009). We find that while Humphreys and Pfund lines of Group I stars form in an optically thick envelope/disk, Group II stars show Pfund lines that form in an optically thick medium and Humphreys lines originating in optically thinner regions. The transition between Groups I and II could be understood in terms of the evolution of the circumstellar disk of the star and might bring clues on the mechanism originating the Be phenomeno

Sistemas transportadores de fármacos basados en el polímero poly(e- caprolactona) para el tratamiento del cáncer

Chemotherapy agents have little or no specificity over cancer cells, resulting in low therapeutic concentrations at the tumor site (a consequence of a broad systemic distribution), and severe side effects. With the aim of avoiding cancer therapy failure, several approaches such as design of new anticancer drugs, chemical engineering of conventional drugs and development of drug delivery systems have been proposed. The objective is to enhance drug localization at the tumor region (by controlling its biodistribution profile) and, therefore, to increase the anti-tumor efficacy (even in multi-drug resistant tumors), while reducing systemic side effects. One of the most promising approaches to the problem is the development of drug nanocarriers based on the polymer poly(e-caprolactone). In this review we will focus our attention on these polymeric colloids, particularly on the most significant characteristics and formulation procedures, and on their use as nanoplatforms for the delivery of chemotherapy agents to the tumor site. Furthermore, the most recent in vitro and in vivo investigations on the subject are extensively reviewed

K- and L- band spectroscopy of Be stars

We describe the behaviour of IR hydrogen emission lines of a sample of Be stars and discuss the physical properties of the circumstellar envelopes of Be stars classified in Groups I and II (Mennickent et al. 2009). We find that while Humphreys and Pfund lines of Group I stars form in an optically thick envelope/disk, Group II stars show Pfund lines that form in an optically thick medium and Humphreys lines originating in optically thinner regions. The transition between Groups I and II could be understood in terms of the evolution of the circumstellar disk of the star and might bring clues on the mechanism originating the Be phenomenon.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

Enzyme-Catalyzed Polymerization of Kraft Lignin from Eucalyptus globulus: Comparison of Bacterial and Fungal Laccases Efficacy

Kraft lignin, a side-stream from the pulp and paper industry, can be modified by laccases for the synthesis of high added-value products. This work aims to study different laccase sources, including a bacterial laccase from Streptomyces ipomoeae (SiLA) and a fungal laccase from Myceliophthora thermophila (MtL), for kraft lignin polymerization. To study the influence of some variables in these processes, a central composite design (CCD) with two continuous variables (enzyme concentration and reaction time) and three levels for each variable was used. The prediction of the behavior of the output variables (phenolic content and molecular weight of lignins) were modelled by means of response surface methodology (RSM). Moreover, characterization of lignins was performed by Fourier-transform infrared (FTIR) spectroscopy and different nuclear magnetic resonance (NMR) spectroscopy techniques. In addition, antioxidant activity was also analyzed. Results showed that lignin polymerization (referring to polymerization as lower phenolic content and higher molecular weight) occurred by the action of both laccases. The enzyme concentration was the most influential variable in the lignin polymerization reaction within the range studied for SiLA laccase, while the most influential variable for MtL laccase was the reaction time. FTIR and NMR characterization analysis corroborated lignin polymerization results obtained from the RSM.This research was funded by Comunidad de Madrid via Project SUSTEC-CM S2018/EMT-4348; MICINN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” via Project RTI2018-096080-B-C22; and MICINN via Project TED2021-132122B-C21

Review of the “state of the art” and possibilities of the most significant approaches to the specific delivery of chemotherapy agents to tumor cells

Los principales problemas de la quimioterapia proceden esencialmente de la relativa falta de especificidad derivada de la extensa biodistribución de los agentes antitumorales y de los efectos secundarios generados por la acción inespecífica de éstos en tejidos y órganos sanos. La necesidad de encontrar tratamientos eficaces contra el cáncer ha hecho que se incrementen las líneas de investigación en esta materia. Una de las aproximaciones más prometedoras en este sentido es el desarrollo de sistemas coloidales biodegradables para el transporte de fármacos antitumorales. Gracias a éstos, se logra acumular específicamente la cantidad de fármaco administrada en el lugar de acción, logrando así un aumento significativo de la eficacia clínica, junto con una minimización de las reacciones adversas asociadas. En este trabajo, pretendemos analizar el estado actual en el diseño de coloides como transportadores de fármacos antitumorales, junto con la aplicación de las novedosas estrategias de transporte pasivo y activo de fármacos.The main problems related to chemotherapy mainly come from a relative lack of selectivity, that is associated to the extensive biodistribution of antitumor molecules, and to the severe side effects generated by the unspecific drug action on healthy tissues and organs. The need of finding out efficient treatments against cancer has led to an enhancement in the number of research lines in the field. In this way, one of the most promising approaches is the development of biodegradable colloids for the delivery of antitumor drugs. Thanks to them, it is possible to specifically concentrate the drug into the site of action. Therefore, a significant improvement of the chemotherapy effect is obtained along with a minimization of the related adverse side effects. In this review, we analyze the current “state of the art” in the development of colloidal systems for the efficient delivery of anticancer drugs. The possibilities of novel drug delivery strategies based on passive and active targeting mechanisms are also discussed

Evidence of the evolved nature of the B[e] star MWC 137

The evolutionary phase of B[e] stars is difficult to establish due to the uncertainties in their fundamental parameters. For instance, possible classifications for the Galactic B[e] star MWC 137 include pre-main-sequence and post-main-sequence phases, with a large range in luminosity. Our goal is to clarify the evolutionary stage of this peculiar object, and to study the CO molecular component of its circumstellar medium. To this purpose, we modeled the CO molecular bands using high-resolution K-band spectra. We find that MWC 137 is surrounded by a detached cool (T = 1900 ± 100 K) and dense (N = (3 ± 1) × 1021 cm-2) ring of CO gas orbiting the star with a rotational velocity, projected to the line of sight, of 84 ± 2 km s-1. We also find that the molecular gas is enriched in the isotope 13C, excluding the classification of the star as a Herbig Be. The observed isotopic abundance ratio (12C/13C = 25 ± 2) derived from our modeling is compatible with a proto-planetary nebula, main-sequence, or supergiant evolutionary phase. However, based on some observable characteristics of MWC 137, we propose that the supergiant scenario seems to be the most plausible. Hence, we suggest that MWC 137 could be in an extremely short-lived phase, evolving from a B[e] supergiant to a blue supergiant with a bipolar ring nebula.Facultad de Ciencias Astronómicas y Geofísica

The sudden appearance of CO emission in LHA 115-S 65

Molecular emission has been detected in several Magellanic Cloud B[e] supergiants. In this Letter, we report on the detection of CO band head emission in the B[e] supergiant LHA 115-S 65, and present a K-band near-infrared spectrum obtained with the Spectrograph for INtegral Field Observation in the Near-Infrared (SINFONI; R = 4500) on the ESO VLT UT4 telescope. The observed molecular band head emission in S65 is quite surprising in the light of a previous non-detection by McGregor, Hyland & McGinn, as well as a high-resolution (R = 50 000) Gemini/Phoenix spectrum of this star taken nine months earlier showing no emission. Based on analysis of the optical spectrum by Kraus, Borges Fernandes & de Aráujo, we suspect that the sudden appearance of molecular emission could be due to density buildup in an outflowing viscous disc, as seen for Be stars. This new discovery, combined with variability in two other similar evolved massive stars, indicates an evolutionary link between B[e] supergiants and luminous blue variables.Facultad de Ciencias Astronómicas y Geofísica

Diversidad genética de cultivares de caña de azúcar determinada por marcadores de ADN y caracteres morfológicos

Un mejor conocimiento de la diversidad genética de la caña de azúcar proveerá información útil sobre el valor de los genotipos para los programas de mejoramiento y contribuirá tanto a hacer un más eficiente uso y conservación de los recursos genéticos, como a asegurar los derechos de propiedad intelectual de los creadores de nuevas variedades. Si bien los descriptores morfológicos constituyen las herramientas más tradicionales para caracterizar a las variedades, pueden presentar variaciones fenotípicas causadas por factores ambientales. Por este motivo los marcadores moleculares son cada vez más importantes en la identificación de genotipos y la estimación de la diversidad, debido a su precisión, abundancia e independencia de factores ambientales. El objetivo de este trabajo fue evaluar genotipos empleados como padres en el Programa de Mejoramiento de la Caña de Azúcar de la Estación Experimental Agroindustrial Obispo Colombres (EEAOC), usando marcadores moleculares (AFLP y SSR) y caracteres morfológicos y comparando los datos obtenidos con dos programas informáticos estadísticos (NTSys e InfoStat). Todos los cultivares se agruparon en un mismo grupo con ambos programas, cuando se emplearon al menos 150 datos. Probablemente debido al intercambio regular de germoplasma, no se observó una clara diferenciación genética entre los genotipos locales y las variedades de los EE. UU., que se agruparon juntos. Aunque los caracteres morfológicos reflejan solamente la semejanza externa, la topología del dendrograma no se modificó cuando se combinaron datos moleculares y morfológicos. Estos resultados sugieren que ambos métodos de caracterización deberían ser utilizados para estimar la diversidad genética y que los marcadores moleculares deberían ser incluidos a un nivel internacional, para proteger las nuevas variedades de caña de azúcar.Better knowledge of sugarcane genetic diversity will provide useful information concerning genotypic value for breeding programs and should help to improve the use and conservation of genetic resources and the protection of sugarcane varieties by intellectual property rights. Morphological descriptors are traditional tools to characterise varieties; however, they vary phenotypically because of environmental effects. Therefore, molecular markers have become increasingly important for identifying genotypes and estimating diversity, as they are accurate, readily available, and are not affected by the environment. The aim of this research was to evaluate genotypes used as parental materials in the Sugarcane Breeding Program of Estación Experimental Agroindustrial Obispo Colombres (EEAOC), Argentina, by using molecular markers (AFLP and SSR) and morphological traits, and by comparing the data obtained with two statistical software programs (NTSys and InfoStat). All cultivars grouped in one main cluster of the dendrogram when using both programs and at least 150 data points. Local Argentine genotypes grouped together with US-varieties and no clear genetic differentiation was found, probably due to regular germplasm exchange. Although morphological traits reflected external resemblance only, the topology of the dendrogram was not modified when combining both molecular and morphological data. These results suggest that both characterisation methods should be used to estimate genetic diversity. Molecular markers should be included internationally for sugarcane variety protection.Fil: Perera, María Francisca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Arias, Marta E.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales E Instituto Miguel Lillo; ArgentinaFil: Costilla, Diego D.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Luque, Catalina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales E Instituto Miguel Lillo; ArgentinaFil: García, María B.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Racedo, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Cuenya, María Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Filippone, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Castagnaro, Atilio Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentin

Mössbauer study of iron gall inks on historical documents

AL designed and coordinated the practical and scientific work, was involved in the evaluation and interpretation of the data and wrote various drafts of the paper. FEW designed and coordinated the practical and scientific work, performed the Mössbauer spectroscopy, evaluated and interpreted the data and wrote the final version of the manuscript. MD carried out the pH measurements of the papers and determined the nature of the papers and gave valuable hints to research on historical documents. TE provided the fragments of the two Spanish documents. JLPP proposed this investigation and gave valuable hints on the documents. All authors read and approved the final manuscript.Iron gall ink was used in the Western world as a permanent writing material already in late Roman times and throughout the Middle Ages, until it became obsolete in the twentieth century. There is much interest in experimental methods to determine the state of the ink and its degradation products on historical documents. Mossbauer spectroscopy with Fe-57 is such a method, and it has the particular advantage to be sensitive to the chemical bonding of iron, but this method has only rarely been applied to historical documents. In this paper we present Mossbauer data for two damaged documents from a Library in Granada and a handwritten German book from the eighteenth century. In addition to the inked parts of the manuscripts, ink-free parts were studied to determine the amount and chemical state of the iron in the papers. These new results are discussed in the context of previously published Mossbauer data. In one of the investigated documents Fe(II)-oxalate, FeC2O4 center dot 2H(2)O, was observed. The assignment of the various Fe3+ sites in the different documents is rather difficult and often there is a superposition of various species. Known forms of iron gallate are definitely not present on the inked papers. The observed ferric species can be remains of Fe3+ polyphenol complexes of the ink, complexes of Fe3+ with degradation products of the cellulose of the paper or gum arabic, or very small iron oxide or hydroxide nanoparticles

Características epidemiológicas y moleculares de <i>Chlamydia psittaci</i> provenientes de 8 casos humanos de psitacosis y de 4 aves relacionadas en la Argentina

In Argentina, the epidemiological and molecular characteristics of Chlamydia psittaci infections are still not sufficiently known. A total of 846 respiratory and 10 ocular samples from patients with suspected human psittacosis were tested for C. psittaci from January 2010 to March 2015. Four samples of birds related to these patients were also studied. Forty-eight samples were positive for C. psittaci by a nested PCR. The molecular characterization of twelve C. psittaci PCR-positive samples received in the National Reference Laboratory INEI-ANLIS “Dr. Carlos G. Malbrán”, Buenos Aires, Argentina was performed. Eight positive samples from humans and four from birds were genotyped by ompA gene sequencing. C. psittaci genotype A was found in all human samples and in the related birds. This report contributes to our increasing knowledge of the epidemiological and molecular characteristics of C. psittaci to conduct effective surveillance of its zoonotic infections.En la Argentina, aún no se conocen suficientemente las características epidemiológicas y moleculares de las infecciones por Chlamydia psittaci. Entre enero del 2010 y marzo del 2015 se estudiaron 846 muestras respiratorias y 10 oculares de pacientes con sospecha de psitacosis para la búsqueda de C. psittaci. También se estudiaron 4 muestras de aves relacionadas con estos pacientes. De ese total, 48 muestras fueron positivas para C. psittaci mediante una reacción en cadena de la polimerasa (PCR) anidada. Posteriormente, se realizó en el INEI-ANLIS «Dr. Carlos G. Malbrán» la caracterización molecular de 12 muestras positivas para C. psittaci, 8 de humanos y 4 de aves, que fueron genotipificadas por secuenciación del gen ompA. C. psittaci genotipo A se encontró en todas esas muestras. Este informe contribuye a mejorar nuestro conocimiento de las características epidemiológicas y moleculares de C. psittaci para lograr una vigilancia efectiva de la zoonosis que produce.Facultad de Ciencias Veterinaria