132 research outputs found

    HIV knowledge and its correlation with the Undetectable = Untransmittable slogan in Brazil

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    Knowledge about HIV transmission and prevention is a necessary step for adopting preventive behaviors. We assessed HIV knowledge and its correlation with the perceived accuracy of the “Undetectable = Untransmittable” (U=U) slogan in an online sample with 401 adult Brazilians. Overall, 28% of participants showed high HIV knowledge level. The perceived accuracy of the U=U slogan significantly correlated with HIV knowledge. Younger participants, those reporting lower income or lower education, or who had never tested for HIV showed poorer HIV knowledge. Filling gaps of knowledge among specific populations is urgent in order to increase preventive behaviors and decrease HIV stigma

    Synergy of DNA intercalation and catalytic activity of a copper complex towards improved polymerase inhibition and cancer cell cytotoxicity

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    Improving the binding of metal complexes to DNA to boost cancer cell cytotoxicity requires fine tuning of their structural and chemical properties. Copper has been used as a metal center in compounds containing intercalating ligands due to its ability to catalytically generate reactive oxygen species (ROS), such as hydroxyl radicals (OH˙). We envision the synergy of DNA binding and ROS generation in proximity to target DNA as a powerful chemotherapy treatment. Here, we explore the use of [Cu(2CP-Bz-SMe)]2+(2CP-Bz-SMe = 1,3-bis(1,10-phenanthrolin-2-yloxy)-N-(4-(methylthio)benzylidene)propan-2-amine) for this purpose by characterizing its cytotoxicity, DNA binding, and ability to affect DNA replication through the polymerase chain reaction - PCR and nuclease assays. We determined the binding (Kb) and Stern-Volmer constants (KSV) for complex-DNA association of 5.8 ± 0.14 × 104and 1.64 (±0.08), respectively, through absorption titration and competitive fluorescence experiments. These values were superior to those of other Cu-complex intercalators. We hypothesize that the distorted trigonal bipyramidal geometry of [Cu(2CP-Bz-SMe)]2+allows the phenanthroline fragments to be better accommodated into the DNA double helix. Moreover, the aromaticity of these fragments increases the local hydrophobicity thus increasing the affinity for the hydrophobic domains of DNA. Nuclease assays in the presence of common reducing agents ascorbic acid, nicotinamide adenine dinucleotide, and glutathione showed the effective degradation of DNA due to thein situgeneration of OH˙. The [Cu(2CP-Bz-SMe)]2+complex showed cytotoxicity against the following human cancer cells lines A549, MCF-7, MDA-MB-231 and MG-63 with half maximal inhibitory concentration (IC50) values of 4.62 ± 0.48, 5.20 ± 0.76, 5.70 ± 0.42 and 2.88 ± 0.66 μM, respectively. These low values of IC50, which are promising if compared to that of cisplatin, are ascribed to the synergistic effect of ROS generation with the intercalation ability into the DNA minor grooves and blocking DNA replication. This study introduces new principles for synergizing the chemical and structural properties of intercalation compounds for improved drug-DNA interactions targeting cancer.Fil: Romo, Adolfo I. B.. University of Illinois. Urbana - Champaign; Estados Unidos. Universidade Federal do Ceara; BrasilFil: Carepo, Marta P.. Universidade Nova de Lisboa; PortugalFil: Levin, Pedro. Universidad de Santiago de Chile; ChileFil: Nascimento, Otaciro R.. Universidade Federal do São Carlos; BrasilFil: Díaz, Daniel E.. Universidad de Santiago de Chile; ChileFil: Rodriguez Lopez, Joaquin. University of Illinois. Urbana - Champaign; Estados UnidosFil: Leon, Ignacio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Bezerra, Lucas F.. Universidade Federal do Ceara; BrasilFil: Lemus, Luis A.. Universidad de Santiago de Chile; ChileFil: Diógenes, Izaura C. N.. Universidade Federal do Ceara; Brasi

    Differential Regularization of Topologically Massive Yang-Mills Theory and Chern-Simons Theory

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    We apply differential renormalization method to the study of three-dimensional topologically massive Yang-Mills and Chern-Simons theories. The method is especially suitable for such theories as it avoids the need for dimensional continuation of three-dimensional antisymmetric tensor and the Feynman rules for three-dimensional theories in coordinate space are relatively simple. The calculus involved is still lengthy but not as difficult as other existing methods of calculation. We compute one-loop propagators and vertices and derive the one-loop local effective action for topologically massive Yang-Mills theory. We then consider Chern-Simons field theory as the large mass limit of topologically massive Yang-Mills theory and show that this leads to the famous shift in the parameter kk. Some useful formulas for the calculus of differential renormalization of three-dimensional field theories are given in an Appendix.Comment: 25 pages, 4 figures. Several typewritten errors and inappropriate arguments are corrected, especially the correct adresses of authors are give

    Target 2035-update on the quest for a probe for every protein

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    Twenty years after the publication of the first draft of the human genome, our knowledge of the human proteome is still fragmented. The challenge of translating the wealth of new knowledge from genomics into new medicines is that proteins, and not genes, are the primary executers of biological function. Therefore, much of how biology works in health and disease must be understood through the lens of protein function. Accordingly, a subset of human proteins has been at the heart of research interests of scientists over the centuries, and we have accumulated varying degrees of knowledge about approximately 65% of the human proteome. Nevertheless, a large proportion of proteins in the human proteome (∼35%) remains uncharacterized, and less than 5% of the human proteome has been successfully targeted for drug discovery. This highlights the profound disconnect between our abilities to obtain genetic information and subsequent development of effective medicines. Target 2035 is an international federation of biomedical scientists from the public and private sectors, which aims to address this gap by developing and applying new technologies to create by year 2035 chemogenomic libraries, chemical probes, and/or biological probes for the entire human proteome

    Desafíos políticos de los países de inmigración

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    13 págs.-- Publicado en "Confluencia XXI. Revista de Pensamiento Político" (México), nº 3 (Oct-Dic 2008) bajo el título monográfico "Migrantes: ¿Por qué se van? ¿Por qué se quedan?".Las migraciones, una práctica tan antigua como la propia condición humana, se han convertido en un factor estructural de primer orden, en uno de los macrofenómenos más definitorios de nuestra época y en un complejo reto para las sociedades contemporáneas. En prácticamente todos los países del mundo, todo lo que concierne a este complejo fenómeno ocupa un lugar destacado en la agenda política. La gestión, el control y la integración de los movimientos internacionales de personas se presentan como un policy field de creciente y prioritaria relevancia. No se trata, sin embargo, de una cuestión de mera moda: el número de países implicados de manera significativa en las migraciones internacionales ha aumentado considerablemente, hasta el punto de que resulta realmente difícil encontrar algún Estado que no sea bien un país de inmigración, bien un país de emigración o bien ambas cosas a la vez, cuando no al menos un país de tránsito. No ha de extrañar entonces que la mayoría de los gobiernos haya tomado conciencia de la necesidad de ofrecer una respuesta en términos legales e institucionales a un fenómeno de carácter permanente que puede llegar a alterar la estructura demográfica, social, cultural, económica y laboral de un país. Dada la complejidad de la cuestión, y por cuestiones de economía argumentativa, aquí se abordará de manera fundamental desde la perspectiva de los países receptores, que, por lo demás, es también la adoptada en forma habitual por los países europeos que registran mayor inmigración. Sin embargo, el fenómeno migratorio es fundamentalmente transnacional y tiene fehacientes repercusiones en los países de emigración.Peer reviewe
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