124 research outputs found
Enhanced photocatalytic hydrogen generation using carbazole-based sensitizers
No full textPhenothiazine-, phenoxazine- and carbazole-based dyes have been synthesized and used as photosensitizers in Pt/TiO2 films for photocatalytic hydrogen generation. Compared to commonly used phenothiazine dyes, planar and sulphur-free carbazole derivatives showed different molecular and supramolecular features which in turn yielded greatly enhanced (one order of magnitude) H2 production performances
Assessing Endangered Felid Puma concolor Sperm Fertility by In Vitro Fertilization with Domestic Cat Oocytes
No full textThe Puma concolor population has been decreasing during the last 30 years. Semen cryopreservation of this species has been accomplished successfully and offers the possibility of preserving endangered species. We previously showed that fertilizing capability of wild felid spermatozoa can be evaluated using intracytoplasmic sperm injection (ICSI) with in vitro-matured domestic cat oocytes (Moro et al. 2014 Reprod. Domest. Anim. 49, 693-700). Due to the lack of homologous oocytes, we evaluated the capability of the Puma concolor sperm to induce domestic cat oocyte fertilization and subsequent pre-implantation embryo development. In the present study, cryopreserved sperm obtained by electroejaculation from five different males were used for IVF of in vitro-matured (IVM) domestic cat oocytes. Straws were thawed by exposing them to air for 10 s and then immersing in a 37°C water bath for 30 s. The contents of the straws were poured into a sterile 1.5-mL microtube pre-warmed to 37°C. The sperm suspension was diluted (1:3 v/v) by the slow (drop-by-drop) addition of a modified Tyrode’s solution. For IVF, IVM oocytes (n = 370) were co-incubated with 0.5 × 105 motile spermatozoa mL−1 in an atmosphere of 21% O2 in air at 38.5°C for 18 to 20 h. Presumptive zygotes were cultured in vitro in 50-μL drops of modified Tyrode’s medium on 6.5% CO2 in air at 38.5°C. Cleavage was determined at 48 h post-fertilization, and 5% FBS was added at Day 5 of in vitro culture. Blastocyst stage was evaluated at Day 8. Results (mean ± SEM) showed a high cleavage rate (179/370, 49.0 ± 4.0%), and a high development to morula stage (137/370, 34.4 ± 7.2%), and to blastocyst stage (94/370, 23.4 ± 4.7%) for all males. These results indicated that Puma concolor spermatozoa can induce domestic cat oocyte activation and development to blastocyst stage in similar rates to domestic cat homologous IVF: IVM oocytes (n = 291), cleavage rate (199/291, 67.1 ± 6.1%), development to morula stage (144/291, 47.8 ± 4.9%), and to blastocyst stage (86/291, 30.1 ± 1.6%). In conclusion, we demonstrated that domestic cat oocyte can be used to evaluated cryopreserve sperm samples from another felid species.Fil: Duque Rodriguez, Matteo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; ArgentinaFil: Sestelo, A.. Ecoparque Interactivo de Buenos Aires; ArgentinaFil: Salamone, Daniel Felipe. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; Argentin
An Integrated Theoretical/Experimental Study of Quinolinic-Isoquinolinic Derivatives Acting as Reversible Electrochromes
No full textA series of compounds, featuring an ethenylic bridge and quinoline and isoquinoline end capping units possessing systematically varied substitution patterns, were prepared as molecular materials for electrochromic applications. The different structures were optimized in order to maximize the electrochromic contrast in the visible region, mostly by achieving a completely UV-absorbing oxidized state. Density functional theory (DFT) calculations are exploited in order to rationalize the correlation between the molecular structure, the functional groups' electronic properties, and the electrochemical behavior. It is shown that the molecular planarity (i.e. ring/ring pi conjugation) plays a major role in defining the mechanism of the electrochemical charge transfer reaction, while the substituent's nature has an influence on the LUMO energy. Among the compounds here studied, the (E)-10-methyl-9-(2-(2-methylisoquinolinium1- yl)-vinyl)-1,2,3,4-tetrahydroacri-dinium trifluoromethanesulfonate derivative shows the most interesting properties as an electrochromophore
Novel protese from marine organisms with potential interest in restoration procedures
No full textIn the last decades molecular biology allowed the development of innovative protocols in the field of conservation/restoration of cultural assets. In this work we presents novel hydrolyses isolated from marine invertebrate organisms, whose protease activity was previously tested in laboratory by zymography on polyacrilamide gel (in presence of 0.1 of gelatin)
Very interesting these enzymes are activated/work in a range of temperatures between 4 ° C and 37 ° C. In this study two sets of proteases were applied, to bio-clean works of art surfaces, at the environments temperature (19° to 25.5° C). Before remove, the water-soluble components of the layers have been analyzed by high-pressure size molecular exclusion chromatography (SEC-HPLC, BioSuite 250 to 10 μm SEC 7.5 x 300 mm Waters), followed by electrophoresis on acrylamide gel (SDS-PAGE 15%) and silver staining of the bands. The results reveal the presence of protein molecules in concentrations between 24 and 110 μg/m, and molecular weight between 20-35 kDa and 60-90 kDa. The enzymatic cleaning showed skillful results, without providing the heating of the enzyme solution or of the surface on which they were applied. The particular feature makes these protease more appropriate then the other, which usually are activated at temperatures >37 ° C.
Our hypothesis is that these enzymes will implement the efficiency of enzymatic cleaning protocols, according to the conservative restoration procedures
Nuevas estrategias heteroespecíficas en la reproducción asistida felina
No full textThe development of assisted reproductive technologies (ART) in species of the Felidae family has been proposed to guarantee the genetic viability of species that are on the verge of extinction. Sperm cryopreservation research and IVF have been studied in several Felidae species, but the lack of viable homologous oocytes makes it difficult to assess the fertile capacity of sperm after cryopreservation. We propose in chapter 2 to evaluate the ability of cryopreserved sperm from Puma concolor (Pc), Leopardus geoffroyi (Lg) and Panthera onca (Po) to induce fertilization of domestic cat oocytes and subsequent embryonic development prior to implantation. In addition, embryo quality was analyzed based on the number of total cells, the expression of pluripotent (Oct4) and early differentiation (Cdx2) genes, DNA fragmentation and the distribution of the OCT4 protein. After ovariectomy, domestic cat (Felis catus, Fc) oocyte cumulus complexes were matured in vitro in 5% CO2 in humidified air at 38.5°C for 22 h and cryopreserved Pc, Lg, and Po spermatozoa were used for heterologous IVF. The straws were thawed by exposing them to air for 10 s and then immersing them in a 37°C water bath for 30 s. The content of the straws was poured into a sterile 1.5 ml microtube preheated to 37°C. The sperm suspension was diluted (1:3 v/v) by slow enhancement (dropwise) of modified Tyrode's solution. For IVF, in vitro matured oocytes were co-incubated with 2×105 366 motile spermatozoa/mL under 5% CO2 at 38.5°C for 18-20 h. After gamete incubation, putative zygotes were cultured in vitro in 50 µl drops of modified Tyrode's medium in 5% CO2, 5% O2, 90% N2. Cleavage was prolonged 48 h after fertilization and the blastocyst stage was evaluated on day 7. The blastocyst rate was found to be higher using Lg sperm compared to the others. No differences were found in the expression of the pluripotent gene; however, the hPc and hLg hybrids show a higher expression of Cdx2 compared to the Fc embryos. No differences were found between the hPo and Fc hybrids in relation to the expression of the Cdx2 gene. Additionally, hPc blastocysts show less apoptosis and positive cells with OCT4 protein than domestic cat and hLg blastocysts. Hybridization in felines is known, however, no report on the characterization of hybrid preimplantation embryos in vitro has yet been published, and it could be a powerful tool to generate knowledge about sperm inheritance in early embryonic development. Heterospecific embryo transfer of an endangered species has been carried out using recipients of related domestic females. The aggregation of an embryo of an endangered species with a tetraploid embryo of the species to be transferred could improve pregnancy development to term. The main objective of Chapter 3 was to analyze embryo aggregation in a domestic cat model using hybrid embryos. For this purpose, we compared the in vitro development of synchronous (Sync) or asynchronous (Async) and asynchronous with tetraploid (Async4n) aggregation of domestic cat IVF embryos. In addition, the quality of the aggregated blastocyst was analyzed by evaluating the total number of cells, the location of cells by mitotracker staining, the expression of the Oct4, Nanog, Sox2, Cdx2 genes, the number of OCT4+ nuclei, and the presence of DNA fragmentation. In addition, developmental rates of Async4n aggregation of domestic cats with hybrid embryos of Leopardus geoffroyi (hLg) were evaluated. Asynchronous aggregation increased the number of blastocyst cells and the number of OCT4+ nuclei compared to nonaggregated diploid (2n) and tetraploid (4n) embryos. Furthermore, blastocysts produced by Async4n aggregation showed reduced rates of DNA fragmentation. No differences were found in the expression of pluripotent genes, except for the expression of Cdx2, which was higher in 4n and aggregated embryos compared to the control group. Interestingly, hybrid embryos derived from Async4n aggregation with domestic cat embryos have similar rates of development to blastocyst compared with the control. Taken together, the results support the use of two-cell fused embryos to generate tetraploid blastomeres and demonstrate that Async4n aggregation generates good quality embryosFil: Duque Rodríguez, Matteo. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Buenos Aires, ArgentinaEl desarrollo de tecnologías de reproducción asistida (TRA) en especies de la familia Felidae se ha propuesto para garantizar la viabilidad genética de especies que se encuentran al borde de la extinción. La investigación de la criopreservación de espermatozoides y la FIV se han estudiado en varias especies de Félidos, pero la falta de ovocitos homólogos viables dificulta la evaluación de la capacidad de fertilidad de los espermatozoides después de la criopreservación. Proponemos en el capítulo 2 evaluar la capacidad de los espermatozoides criopreservados de Puma concolor (Pc), Leopardus geoffroyi (Lg) y Panthera onca (Po) para inducir la fecundación de ovocitos de gatos domésticos y el posterior desarrollo embrionario previo a la implantación. Además, se analizó la calidad embrionaria a partir del número de células totales, la expresión de genes pluripotentes (Oct4) y de diferenciación temprana (Cdx2), la fragmentación del ADN y la distribución de la proteína OCT4. Después de la ovariectomía, los complejos cumulus ovocito de gato doméstico (Felis catus, Fc) se maduraron in vitro en 5% de CO2 en aire humidificado a 38.5°C durante 22 h y se usaron espermatozoides criopreservados de Pc, Lg y Po para la FIV heteróloga. Las pajuelas se descongelaron exponiéndolas al aire durante 10 s y luego sumergiéndolas en un baño de agua a 37°C durante 30 s. El contenido de las pajuelas se vertió en un microtubo estéril de 1,5 ml precalentado a 37°C. La suspensión de esperma se diluyó (1:3 v/v) mediante la adición lenta (gota a gota) de una solución de Tyrode modificada. Para la FIV, los ovocitos madurados\nin vitro se incubaron juntamente con 2×105 espermatozoides móviles/mL bajo 5% de CO2 a 38.5°C durante 18-20 h. Después de la incubación de los gametos, los supuestos cigotos se cultivaron in vitro en gotas de 50 µl de medio Tyrode modificado en 5% de CO2, 5% de O2, 90% de N2. El clivaje se determinó 48 h después de la fertilización y el estadio de blastocisto se evaluó el día 7. Se encontró que la tasa de blastocistos fue más alta usando espermatozoides de Lg en\ncomparación con los otros grupos. No se encontraron diferencias en la expresión del gen de pluripotencialidad; sin embargo, los híbridos hPc y hLg presentan una mayor expresión de Cdx2 en comparación con los embriones Fc. No se encontraron diferencias entre los híbridos hPo y Fc en relación con la expresión del gen dx2.Adicionalmente, Los blastocistos hPc presentan menor apoptosis y células positivas con la proteína OCT4 que los blastocistos de gato doméstico y de hLg. Se conoce la hibridación en felinos, sin embargo, aún no se ha publicado ningún informe sobre la caracterización de embriones preimplantacionales híbridos in vitro, y podría ser una herramienta poderosa para generar conocimiento sobre la herencia espermática en el desarrollo embrionario temprano. La transferencia de embriones heteroespecíficos de una especie en peligro de extinción se ha llevado a cabo utilizando receptoras de hembras domésticas emparentadas. La agregación de un embrión de una especie en peligro de extinción con un embrión tetraploide de la especie a transferir podría mejorar el desarrollo de la preñez a término. El objetivo principal del capítulo 3 fue analizar la agregación de embriones en un modelo de gato doméstico utilizando embriones híbridos. Para este propósito, comparamos el desarrollo in vitro de agregación sincrónica (Sync) o asincrónica (Async) y asincrónica con tetraploide (Async4n) de embriones de FIV de gato doméstico. Además, la calidad del blastocisto agregado se analizó mediante la evaluación del número total de células, la asignación de células mediante la tinción de mitotrackers, la expresión de los genes Oct4, Nanog, Sox2, Cdx2, el número de núcleos OCT4+ y la presencia de fragmentación del ADN. Además, se evaluaron las tasas de desarrollo de la agregación Async4n de gatos domésticos con embriones híbridos de Leopardus geoffroyi (hLg). La agregación asíncrona aumentó el número de células de blastocisto y el número de núcleos OCT4+ en comparación con los embriones diploides (2n) y tetraploides (4n) no agregados. Además, los blastocistos producidos por la agregación Async4n mostraron tasas reducidas de ADN fragmentado. No se encontraron diferencias en la expresión de los genes pluripotentes, a excepción de la expresión de Cdx2, que fue mayor en los embriones 4n y agregados en comparación con el grupo control. Curiosamente, los embriones híbridos derivados de la agregación Async4n con embriones de gatos domésticos tenían tasas similares de desarrollo hasta blastocisto en comparación con el control. En conjunto, los hallazgos respaldan el uso de embriones fusionados de dos células para generar blastómeros tetraploides y demuestran que la agregación Async4n genera embriones de buena calidadDoctor de la Universidad de Buenos Aires en Ciencias Veterinaria
Removal of old protein layers from surfaces of works of art by new enzymes
No full textThe aim of the present project is to set up bio-cleaning protocols in order to easily remove altered protein
layers (e.g. animal glues) by enzymatic proteins (proteases).
Protein molecules were isolated from marine invertebrate organisms, characterized by size exclusion highpressure
liquid chromatography (Waters: SEC-HPLC, BioSuite 250 to 10μm SEC 7.5 x 300 mm) and their
gelatinase activity analyzed by zymography on polyacrilamide gel. The remarkably proteolytic activity and the
reaction temperature range of these enzymes, 4° to 37°C, made it possible to hypothesize their use in bioremediation
projects. Tests were performed on protein coating found on some polychrome wooden artifacts
exposed to different environmental conditions (temperature, humidity, UV radiation). Particularly, altered
animal glue layers were removed by using these enzymes at“ room temperature” (19-25.5°C) without changing
the temperature of the surface or of the enzyme solution. The results of the applications were satisfying since
the removal of the protein layers was carried out in controlled conditions, conducted at the same temperature
as that of the environments where the objects were exposed/stored.
In conclusion, the hypothesis is that these enzymes will improve bio-cleaning efficiency even when used at
low temperature instead of commercially available proteases, which are usually active at ≥ 37°C, thus
respecting the aim of conservative restoration
Novel proteases from marine organisms with potential interest in restoration procedure
No full textIn the last decades, molecular biology allowed the development of innovative protocols in the field of conservation/restoration of cultural assets. In this work new hydrolyses, isolated from marine invertebrate organisms, are applied to remove protein layers form works of art surface. Proteolytic zymography assay evidenced that these enzymes are active in a broad temperature range, between 4 degrees and 37 degrees C. The enzymatic cleaning by these proteases, tested on wooden furniture of the second half of the eighteenth century showed positive results, without needing to heat the enzyme solution or the surface on which they were applied. The present report proposes novel proteases more appropriate than other, which usually are active at temperature >= 37 degrees C, for a controlled removal of protein layers from wooden painted artifacts
Erratum to: HBV and HCV infection in type 2 diabetes mellitus: a survey in three diabetes units in different Italian areas
No full textUnfortunately, in the original online publication, the surname of the co-author “Mario Masarone” was incorrectly published. The co-author name is corrected here in this erratum
Canine IVM With SOF Medium, Insulin-Transferrin-Selenium, and Low O2 Tension Improves Oocyte Meiotic Competence and Decreases Reactive Oxygen Species Levels
No full textAssisted reproductive technologies in canine species are limited due to the low efficiency of in vitro maturation (IVM). Unlike other mammals, bitches ovulate oocytes in the germinal vesicle stage and complete metaphase II (MII) after 48–72 h in the oviductal environment and become fertilizable. For this reason, we compared two different IVM media, synthetic oviductal fluid (SOF) supplemented with 8% bovine serum albumin (BSA) or a mixture of 8% BSA–2.5% fetal bovine serum (FBS) and TCM-199 with 10% FBS. Additionally, we evaluated the effect of supplementation with insulin-transferrin-selenium (ITS) and low O2 tension in oocyte maturation, reactive oxygen species (ROS) levels, membrane integrity, and embryo development following parthenogenetic activation (PA). After 72 h of culture, SOF + BSA, SOF + BSA + FBS, and TCM-199 + FBS show 5, 7, and 4% of MII, respectively, without a statistical difference. However, SOF + BSA produced significantly higher degeneration rates compared to SOF + BSA + FBS (44 and 23%, respectively). Remarkably, supplementation with 1 μl/ml of ITS under high O2 tension demonstrated a beneficial effect by improving maturation rates up to 20% compared to the other groups. Low O2 tension increased maturation rates to 36.5%, although there were no statistical differences compared to high O2 tension in the presence of ITS. Lower ROS levels and higher integrity of the cytoplasmic membrane were found in the presence of ITS despite no differences in maturation rates under low O2 tension groups. Additionally, after PA, 1% development until the eight-cell stage was obtained after activation of in vitro-matured oocytes in the presence of ITS. Taken together, these results indicate that SOF supplemented with 8% BSA and 2.5% FBS is suitable for IVM of canine oocytes and ITS supplementation was beneficial for both high and low O2 tension. Furthermore, the addition of ITS in the cultured system lowers ROS levels and increases membrane integrity in domestic dog oocytes after IVM.Fil: Duque Rodriguez, Matteo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; ArgentinaFil: Cittadini, Camila O.. Universidad de Buenos Aires; ArgentinaFil: Teplitz, Gabriela Maia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Instituto de Investigación y Tecnología en Reproducción Animal; ArgentinaFil: De Stefano, Adrian M.. Universidad de Buenos Aires; ArgentinaFil: Lombardo, Daniel M.. Universidad de Buenos Aires; ArgentinaFil: Salamone, Daniel Felipe. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; Argentin
Činnost římské mincovny na sklonku pontifikátu Urbana VIII. a strojová výroba zlatých, stříbrných a měděných mincí technologií válcování v letech 1634-1644
No full textIn this study the Author sumarised new reseults of his scientific research concernig the rolling of gold, silver and copper coins in the papal Mint of Roma during the years 1634-1644. This study is based on the original research of archival sources (accounts of papal mint) and material sources (historical cois from public and privat collections).Autor ve své studii shrnuje nové poznatky svého základního výzkumu, týkající se strojové výroby (válcování) zlatých, stříbrných a měděných mincí v papežské římské mincovně v průběhu let 1634-1644. Práce je založena na původním výzkumu pramenů archívních (účetní dokumentace papežské mincovny) i hmotných (historické mince z veřejných i soukromých sbírek
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