SINTESIS POLIANILINA PADA MATRIKS SELULOSA SEBAGAI ELEKTROLIT PADAT PADA MODEL BATERAI SEDERHANA

Sintesis polimer konduktif polianilina pada matriks selulosa menghasilkan komposit polianilina-selulosa (PANI-selulosa) sebagai elektrolit padat telah dilakukan. Selulosa yang digunakan berasal dari hasil isolasi tandan kosong kelapa sawit melalui proses pulping dan bleaching. Komposit PANI-selulosa disintesis dengan melakukan variasi terhadap jumlah anilina, yaitu 2 g dan 4 g. Komposit PANI-selulosa dibuat dengan penambahan dopan HCl 1 M dan inisiator (NH4)2S2O8 dengan perbandingan (NH4)2S2O8 terhadap anilina yaitu 3:4. Karakterisasi komposit PANI-selulosa dilakukan menggunakan metode X-Ray Diffraction (XRD) dan Scanning Electron Microscope (SEM). Hasil XRD menunjukkan adanya daerah kristal polianilina yang bersifat semikristalin dan daerah amorf selulosa pada nilai 2θ = 14,87o; 19,98o; dan 25,46o serta diketahui ukuran kristal polianilina sebesar 8,22 nm berdasarkan persamaan Scherrer. Hasil SEM menunjukkan citra polianilina nanokristal berbentuk granular yang terdispersi ke serat selulosa. Komposit PANI-selulosa kemudian diaplikasikan sebagai elektrolit padat pada model baterai sederhana. Komposit PANI-selulosa dengan massa anilina 2 g dan 4 g berturut-turut menghasilkan nilai konduktivitas 0,1259-0,1422 S/cm dan 0,2342-0,3644 S/cm. Pengujian baterai dengan elektrolit padat PANI-selulosa untuk massa anilina 2 g menghasilkan tegangan 0,875-0,876 V dan arus 9,5-10,5 mA. Sedangkan untuk baterai dengan massa anilina 4 g memperoleh tegangan 1,014-1,016 V dan arus 10,5-11,0 mA.   Kata Kunci : Komposit, polianilina (PANI), selulosa, elektrolit pada

El Parto Planificado en Domicilio (PPD) como práctica de cuidadanía: relevamiento cuali-cuantitativo de experiencias en Argentina (2000-2018)

O presente texto discute, a partir de uma perspectiva quali-quantitativa, o modelo de PPD (Parto Planificado em Domicílio) como prática de cuidadanía na Argentina, apresentando-o como um modelo social, político e jurídico passível de ser construído a partir de práticas de cuidado, nesse caso, aquelas relativas aos processos reprodutivos femininos. A análise quantitativa se baseia em um relevamento sobre nascimentos realizados na modalidade PPD na Argentina entre os anos 2000 e 2018. A análise qualitativa se sustenta com o trabajo interpretativo das narrativas de duas mulheres, também co-autoras deste texto, observando as particularidades de seus partos e a construção de suas subjetividades no marco desses processos. Em primeiro lugar, destaca-se que nos casos de PPD estudados predomina a construção vincular de uma lógica de “cuidados”, sendo pouco significativo o índice registrado de práticas de violência obstétrica. Em segundo lugar, indagamos nas limitações e potencialidades do modelo PPD no contexto de uma cuidadania inclusiva, colocando a necessidade de instrumentalizar alternativas para estabelecer um diálogo assíduo com o modelo hospitalar, médico hegemônico e oficial. Finalmente, argumentamos que o PPD sob estudo se apresenta como uma alternativa desejável, segura e significativa desde a perspectiva das mulheres que o têm escolhido

Polifenoles y actividad antioxidante en Equisetum giganteum L. (Equisetaceae)

Equisetum giganteum L. (Equisetaceae) es una especie nativa de Sudamérica y América Central, que es empleada en la medicina tradicional como diurético y en el tratamiento de diversas patologías. El objetivo de este trabajo fue estudiar el perfil de polifenoles y la actividad antioxidante de extractos obtenidos de las ramas laterales (tallos finos), tallos entrenudos y tallos basales. Se detectaron diferencias cuali-cuantitativas, con mayor contenido de fenoles, taninos, taninos condensados, flavonoides y ácidos hidroxicinámicos en las ramas laterales. Las proantocianidinas propelargonidina y procianidina sólo se detectaron en las ramas laterales. En estos extractos se detectó la mayor actividad antioxidante. Debido a la alta concentración y composición química, los tallos laterales podrían ser empleados como fuente de compuestos con actividad antioxidante

Hypofractionation as a solution to radiotherapy access in latin america: expert perspective

Background: Limited radiation therapy resources have resulted in an interest in developing time and cost-saving innovations to expand access to cancer treatment, in Latin America. Therefore, hypofractionated radiotherapy (HRT) is a possible solution, as this modality delivers radiation over a shorter period of time. Materials and methods: A selected panel of Latin American (LA) experts in fields related to HRT were provided with a series of relevant questions to address, prior to the multi-day conference. Within this meeting, each narrative was discussed and edited, through numerous rounds of discussion, until agreement was achieved. Results: The challenges identified in increasing the adoption of HRT in LA include a lack of national and regional clinical practice guidelines and cancer registries; a lack of qualified human resources and personnel education; high up-front costs of equipment; disparate resource distribution and scarce HRT research. An analysis for these overarching challenges was developed and answered with recommendations. Conclusion: Extending the adoption of HRT in LA can provide a path forward to increase access to radiotherapy and overcome the shortage of equipment. HRT has the potential to improve population health outcomes and patient centered care, while offering comparable local control, toxicity, palliation, and late effects for multiple indications, when compared to conventional RT. Concerted efforts from all involved stakeholders are needed to overcome the barriers in adopting this strategy in LA countries. The recommendations presented in this article can serve as a plan of action for HRT adoption in other countries in a similar situation

Comprehensive and quantitative analysis of G1 cyclins. A tool for studying the cell cycle.

In eukaryotes, the cell cycle is driven by the actions of several cyclin dependent kinases (CDKs) and an array of regulatory proteins called cyclins, due to the cyclical expression patterns of the latter. In yeast, the accepted pattern of cyclin waves is based on qualitative studies performed by different laboratories using different strain backgrounds, different growing conditions and media, and different kinds of genetic manipulation. Additionally, only the subset of cyclins regulating Cdc28 was included, while the Pho85 cyclins were excluded. We describe a comprehensive, quantitative and accurate blueprint of G1 cyclins in the yeast Saccharomyces cerevisiae that, in addition to validating previous conclusions, yields new findings and establishes an accurate G1 cyclin blueprint. For the purposes of this research, we produced a collection of strains with all G1 cyclins identically tagged using the same and most respectful procedure possible. We report the contribution of each G1 cyclin for a broad array of growing and stress conditions, describe an unknown role for Pcl2 in heat-stress conditions and demonstrate the importance of maintaining the 3'UTR sequence of cyclins untouched during the tagging process

Contenido de polifenoles en Ligaria cuneifolia y su relación con la capacidad antioxidante

Ligaria cuneifolia (R et P.) Tiegh. (Loranthaceae) es una especie hemiparásita conocida vulgarmente con el nombre de “muérdago criollo”, “liga” o “liguilla”. Esta especie es utilizada popularmente como agente hipotensor y, debido a su similitud morfológica, constituye el sustituto natural del muérdago europeo (Viscum álbum L. –Viscaceae–). L. cuneifolia, al igual que las otras especies de la familia Loranthaceae, son ricas en flavonoides, especialmente flavonoles, compuestos que podrían ser determinantes de su acción biológica. El objetivo de este trabajo consiste en valorar el contenido de polifenoles en diferentes extractos y evaluar la relación de estos compuestos con la actividad antioxidante. Para ello, se procede a la cuantificación de fenoles totales, de ácidos hidroxicinámicos, flavonoides totales y de taninos condensados en las fracciones acetato de etilo, butanólica y acuosa. En estas mismas fracciones se realiza también la determinación de actividad antioxidante total hidrosoluble mediante el método de ABTS y la capacidad antioxidante total liposoluble mediante el método de DPPH. Los resultados obtenidos permiten suponer que, si bien la fracción butanólica presenta mayor capacidad antioxidante mediante el método de DPPH, asociado a un mayor contenido de taninos condensados de alto peso molecular, la fracción acetato de etilo presenta mayor contenido de polifenoles, que implica un significativo poder antioxidante liposoluble y mayor capacidad antioxidante mediante el método de ABTS

Antioxidant Activity of Flavonoid Rich Fraction of Ligaria cuneifolia (Loranthaceae)

Ligaria cuneifolia (Ruiz & Pav.) Tiegh. (Loranthaceae), the ‘Argentine mistletoe’, is a hemiparasite species largely used in folk medicine. The aim of this study was to evaluate the antioxidant activity using in vitro, ex vivo, and in vivo methods. A screening of phenolics was performed by UV spectroscopy on different fractions. The antioxidant capacity was evaluated in vitro by the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH.) assay on a crude extract (CE), ethyl acetate fraction (EAF), and aqueous fraction (AF). The results suggest that EAF concentrates the antioxidant capacity and was selected for further analysis. Capillary electrophoresis was employed to monitor the individual antioxidant capacity and the potential contributors to this effect. Ex vivo assays showed an efficient inhibition of tert-butyl hydroperoxide-induced rat liver phospholipid oxidation, as well as rat brain autoxidation, and H2O2-induced DNA damage in blood monocytes. In vivo, the topical application of EAF significantly decreased skin chemiluminescence in a mice model.Fil: Dobrecky, Cecilia Beatriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Marchini, Timoteo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Ricco, Rafael Alejandro. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacobótanica; ArgentinaFil: Garcés, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; ArgentinaFil: Gadano, Andrea. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; ArgentinaFil: Carballo, Marta Ana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Fisiopatología y Bioquímica Clínica; ArgentinaFil: Wagner, Marcelo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología. Cátedra de Farmacobótanica; ArgentinaFil: Lucangioli, Silvia Edith. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; ArgentinaFil: Evelson, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentin

Morphology and oxygen incorporation effect on antimicrobial activity of silver thin films

Ag and AgxO thin films were deposited by non-reactive and reactive pulsed DC magnetron sputtering, respectively, with the final propose of functionalizing the SS316L substrate with antibacterial properties. The coatings were characterized chemically, physically and structurally. The coatings nanostructure was assessed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), while the coatings morphology was determined by scanning electron microscopy (SEM). The XRD and XPS analyses suggested that Ag thin film is composed by metallic Ag, which crystallizes in fcc-Ag phase, while the AgxO thin film showed both metallic Ag and Ag-O bonds, which crystalize in fcc-Ag and silver oxide phases. The SEM results revealed that Ag thin film formed a continuous layer, while AgxO layer was composed of islands with hundreds of nanometers surrounded by small nanoparticles with tens of nanometers. The surface wettability and surface tension parameters were determined by contact angle measurements, being found that Ag and AgxO surfaces showed very similar behavior, with all the surfaces showing a hydrophobic character. In order to verify the antibacterial behavior of the coatings, halo inhibition zone tests were realized for Staphylococcus epidermidis and Staphylococcus aureus. Ag coatings did not show antibacterial behavior, contrarily to AgxO coating, which presented antibacterial properties against the studied bacteria. The presence of silver oxide phase along with the development of different morphology were pointed as the main factors in the origin of the antibacterial effect found in AgxO thin film. The present study demonstrated that AgxO coating presented antibacterial behavior and its application in cardiovascular stents is promising.The authors acknowledgments the financial support of FCT-Fundacao para a Ciencia e Tecnologia through grants: SFRH/BD/90321/2012 and SFRH/BD/82472/2011.Also thank support by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project PEST-C/FIS/UI607/2014, and projects ERA-SIINN/0004/2013 and the project Matepro-Optimizing Materials and Processes, ref. NORTE-07-0124-FEDER-000037", co-funded by the "Programa Operacional Regional do Norte" (ON.2-O Novo Norte), under the "Quadro de Referencia Estrategico Nacional" (QREN), through the "Fundo Europeu de Desenvolvimento Regional" (FEDER)