176 research outputs found

    Nanostructured Colloids in Food Science

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    Nanostructured colloids are materials with at least one dimension in the nanometer range (<100 nm). Such materials find multiple and exciting applications in various areas of food science, and can lead to development of new and innovative food products and ingredients. Nanostructured colloids can be naturally present in food or they can be synthetically manufactured and added during different stages of food production and packaging. The building blocks of nanostructures in food consist of organic molecules (proteins, lipids, saccharides), inorganics (metal and metal oxides, carbon-based materials, clays) and combined organic and inorganic compounds. Some examples of nanostructured colloids naturally occurring in food include fat globules in homogenized milk, casein micelles, β-lactoglobulin fibers in milk. Synthetically manufactured colloids (artificial and engineered) include nanoemulsions, nanomicelles, nanocapsules, nanofoams, nanoliposomes, nanogels, nanofibers, metal and metal oxide nanoparticles. Synthetically manufactured nanostructures are normally added in food to enhance solubility, improve bioavailability, protect the biologically active compounds from degradation, increase the shelf life, color, flavor, and add nutritional value. Exciting fields of applications of nanostructured colloids in food science comprise: functional food ingredients, food additives, food supplements, food packaging and nanosensors

    Activismo cívico digital en Rumanía: La comunidad de Facebook en las protestas on-line contra Chevron

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    Este artículo presenta los resultados del análisis cuantitativo de las auto-representaciones de dos comunidades rumanas en Facebook durante las protestas on-line y off-line en contra del «fracking» en Rumanía. En 2013 los rumanos comenzaron a protestar contra las explotaciones de gas del gigante energético norteamericano Chevron en la aldea de Pungești. Este movimiento de resistencia pasó, en poco más de un mes, de ser una herramienta de movilización rural a una de alcance nacional cuyo objetivo era ayudar a los campesinos afectados por las explotaciones de gas planificadas por Chevron. Dado que el óptimo grado de implicación on-line para pasar a una participación off-line depende mucho de las prácticas informativas, consideramos que un análisis de textos publicados en Facebook reflejará si estos son compatibles y relevantes para los manifestantes. Nuestra premisa teórica está basada en la teoría del encuadre en movimientos sociales e informa nuestro análisis de contenido comparativo de los textos de dos comunidades rumanas de Facebook desde octubre de 2013 hasta febrero de 2014. En el trabajo se identifican las estrategias de encuadre verbal y visual, y los marcos de acción colectiva utilizados para formar la identidad de estas comunidades online. Los resultados obtenidos muestran el predominio de «la lucha por la tierra» como principal marco de acción colectiva, seguido del «conflicto» y la «solidaridad», e indican la preeminencia de fotos y archivos de vídeo como recursos de encuadre de relevancia cultural y como pruebas del activismo fuera de Internet en contra del «fracking» en RumaníaThis article presents the results of a quantitative analysis of two Romanian Facebook communities’ self-presentations during the online and offline anti-fracking protests in Romania. In 2013 Romanians started to protest against the gas exploration of the US giant Chevron in the village of Pungești. The online and offline Pungești Resistance Movement turned within one month from a rural to a national mobilization tool meant to help the Romanian peasants affected by the proposed shale gas exploration operations of Chevron. Since the online engagement desired to finally turn into an offline participation is highly dependent on the informing practice, we consider that a framing analysis of the Facebook posts will reflect whether they are culturally compatible and relevant for the protesters. Using the framing theory in social movements as our theoretical background, we provided a comparative content analysis of two Romanian Facebook communities’ postings (October, 2013 - February, 2014). We focused on identifying the verbal and visual framing devices and the main collective action frames used for the shaping of the online communities’ collective identity. The findings revealed a dominance of «land struggle» as a collective action frame followed by «conflict» and «solidarity» and a salience of photos and video files used as framing devices of cultural relevance for Romanian protesters and of evidence of offline anti-fracking activism in Romani

    Raman Mapping: Emerging Applications

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    Raman mapping is a noninvasive, label‐free technique with high chemical specificity and high potential to become a leading method in biological and biomedical applications. As opposed to Raman spectroscopy, which provides discrete chemical information at distinct positions within the sample, Raman mapping provides chemical information coupled with spatial information. The laser spot scans the investigated sample area with a preset step size and acquires Raman spectra pixel by pixel. The Raman spectra are then discriminated from each other by chemometric analysis, and the end result is a false color map, an image of the sample that contains highly precise structural and chemical information. Raman imaging has been successfully used for label‐free investigations at cellular and subcellular level. Cell compartments, cell responses to drugs and different stages of the cell cycle from the stem cell to the completely differentiated cell were successfully distinguished. This technique is also able to differentiate between healthy and cancer cells, indicating great potential for replacing conventional cancer detection tools with Raman detection in the future

    The impact of public education spending on economic growth in Central and Eastern Europe. An ARDL approach with structural break

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    The former communist states experienced a period of turbulence in the transition to the market economy and then the accession to the EU, turbulences that also influenced the education sector. This article aims to analyze the impact of public spending on education on economic growth in 11 former communist Eastern European states, current EU members. The methodology used is ARDL with structural break. The results are consistent with those previously obtained The public education expenditure-economic growth relationship is mixed on long term; for five countries, there is no such thing; for six countries, there is one on a long term. On a short term, also, mixed results manifest for four countries are positive, and for two negative

    Treatment of Acute Diarrhoea: Past and Now

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    Context: Since ancient times diarrhoea has been a highly fatal disease and even today diarrhoea, the topic of this review, is a problem affecting millions of people around the world despite the efforts of governments and professionals from the medical area. Worldwide the most common cause of children’s death is diarrhoea. Evidence Acquisition: Diarrhoea disorders generally appear with watery stools, sometimes mixed with blood, accompanied by abdominal pain, vomiting and fever. The symptoms depend on the content and distribution of body fluid, daily water requirements and physiological water loss in connection with age through sweating, urination and breathing, the degree of fluid and electrolyte loss in the liquid stool. Results: Several effective interventions have been introduced as part of diarrhoea management in the last two decades such as oral rehydration solution, zinc supplementation, vitamin A supplementation and oral administration of antibiotics and vaccines. To reduce the mortality rate, control of safe drinking water, good sanitation and vaccination against typhoid and cholera are recommended, especially in high-risk populations. Probiotics have been proposed, after more than a half of century, as additional therapy in the treatment of acute diarrhoea. Several probiotic strains showed benefit in meta-analyses of randomised controlled trials. Conclusions: Due to the high level of evidence available, the term “oral bacteriotherapy”, used for decades in the prevention and therapy of gastroenteritis in the growing age and adults, has expanded, but probiotics are acquiring significant scientific value based on the results from human trials. The future of probiotics depends on further explanation/elucidation of basic mechanisms, allowing scientists and physicians to maximize their health benefits

    L'état de la démocratie en Roumanie: difficultés nationales, solutions européennes

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    Twenty years since the beginning of the democratization process and four years since the accession to the European Union, the debates taking place in the Romanian public space are dominated by the rhetoric of the crisis. Based on the frame analysis, this article analyses the discourses of the main Romanian political parties, held during the 2009 European election's campaign, in order to examine the links between the images of Europe and the perceptions of the state of the Romanian democracy. The paper argues that for the Romanian political elite the European Union is a structure of economic, normative and identity opportunity. This image of Europe is shaped by their perceptions on the functioning of the Romanian democracy

    N-Doped graphene as a metal-free catalyst for glucose oxidation to succinic acid

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    [EN] N-Containing graphenes obtained either by simultaneous amination and reduction of graphene oxide or by pyrolysis of chitosan under an inert atmosphere have been found to act as catalysts for the selective wet oxidation of glucose to succinic acid. Selectivity values over 60% at complete glucose conversion have been achieved by performing the reaction at 160 degrees C and 18 atm O-2 pressure for 20 h. This activity has been attributed to graphenic-type N atoms on graphene. The active N-containing graphene catalysts were used four times without observing a decrease in conversion and selectivity of the process. A mechanism having tartaric and fumaric acids as key intermediates is proposed.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa, Grapas and CTQ2015-69153-CO2-R1) and Generalitat Valenciana (Prometeo 2013-014) is gratefully acknowledged. Prof. Simona M. Coman kindly acknowledges UEFISCDI for financial support (project PN-II-PT-PCCA-2013-4-1090, Nr. 44/2014). Cristina Bucur acknowledges Core Programme, Project PN-480103/2016.Rizescu, C.; Podolean, I.; Albero-Sancho, J.; Parvulescu, VI.; Coman, SM.; Bucur, C.; Puche Panadero, M.... (2017). N-Doped graphene as a metal-free catalyst for glucose oxidation to succinic acid. Green Chemistry. 19(8):1999-2005. https://doi.org/10.1039/C7GC00473GS19992005198Alonso, D. M., Wettstein, S. G., & Dumesic, J. A. (2012). Bimetallic catalysts for upgrading of biomass to fuels and chemicals. Chemical Society Reviews, 41(24), 8075. doi:10.1039/c2cs35188aCherubini, F. (2010). The biorefinery concept: Using biomass instead of oil for producing energy and chemicals. Energy Conversion and Management, 51(7), 1412-1421. doi:10.1016/j.enconman.2010.01.015Christensen, C. H., Rass-Hansen, J., Marsden, C. C., Taarning, E., & Egeblad, K. (2008). The Renewable Chemicals Industry. ChemSusChem, 1(4), 283-289. doi:10.1002/cssc.200700168Lange, J.-P. (2007). Lignocellulose conversion: an introduction to chemistry, process and economics. Biofuels, Bioproducts and Biorefining, 1(1), 39-48. doi:10.1002/bbb.7Corma, A., Iborra, S., & Velty, A. (2007). Chemical Routes for the Transformation of Biomass into Chemicals. Chemical Reviews, 107(6), 2411-2502. doi:10.1021/cr050989dCliment, M. J., Corma, A., & Iborra, S. (2011). Converting carbohydrates to bulk chemicals and fine chemicals over heterogeneous catalysts. Green Chemistry, 13(3), 520. doi:10.1039/c0gc00639dBjerre, A. B., Olesen, A. B., Fernqvist, T., Plöger, A., & Schmidt, A. S. (2000). Pretreatment of wheat straw using combined wet oxidation and alkaline hydrolysis resulting in convertible cellulose and hemicellulose. Biotechnology and Bioengineering, 49(5), 568-577. doi:10.1002/(sici)1097-0290(19960305)49:53.0.co;2-6Klinke, H. B., Ahring, B. K., Schmidt, A. S., & Thomsen, A. B. (2002). Characterization of degradation products from alkaline wet oxidation of wheat straw. Bioresource Technology, 82(1), 15-26. doi:10.1016/s0960-8524(01)00152-3Schmidt, A. S., & Thomsen, A. B. (1998). Optimization of wet oxidation pretreatment of wheat straw. Bioresource Technology, 64(2), 139-151. doi:10.1016/s0960-8524(97)00164-8Gogate, P. R., & Pandit, A. B. (2004). A review of imperative technologies for wastewater treatment I: oxidation technologies at ambient conditions. Advances in Environmental Research, 8(3-4), 501-551. doi:10.1016/s1093-0191(03)00032-7Mishra, V. S., Mahajani, V. V., & Joshi, J. B. (1995). Wet Air Oxidation. Industrial & Engineering Chemistry Research, 34(1), 2-48. doi:10.1021/ie00040a001Zakzeski, J., Bruijnincx, P. C. A., Jongerius, A. L., & Weckhuysen, B. M. (2010). The Catalytic Valorization of Lignin for the Production of Renewable Chemicals. Chemical Reviews, 110(6), 3552-3599. doi:10.1021/cr900354uPodolean, I., Rizescu, C., Bala, C., Rotariu, L., Parvulescu, V. I., Coman, S. M., & Garcia, H. (2016). Unprecedented Catalytic Wet Oxidation of Glucose to Succinic Acid Induced by the Addition ofn-Butylamine to a RuIIICatalyst. ChemSusChem, 9(17), 2307-2311. doi:10.1002/cssc.201600474Huang, C., Li, C., & Shi, G. (2012). Graphene based catalysts. Energy & Environmental Science, 5(10), 8848. doi:10.1039/c2ee22238hNavalon, S., Dhakshinamoorthy, A., Alvaro, M., & Garcia, H. (2014). Carbocatalysis by Graphene-Based Materials. Chemical Reviews, 114(12), 6179-6212. doi:10.1021/cr4007347Su, D. S., Perathoner, S., & Centi, G. (2013). Nanocarbons for the Development of Advanced Catalysts. Chemical Reviews, 113(8), 5782-5816. doi:10.1021/cr300367dDhakshinamoorthy, A., Primo, A., Concepcion, P., Alvaro, M., & Garcia, H. (2013). Doped Graphene as a Metal-Free Carbocatalyst for the Selective Aerobic Oxidation of Benzylic Hydrocarbons, Cyclooctane and Styrene. Chemistry - A European Journal, 19(23), 7547-7554. doi:10.1002/chem.201300653Huang, H., Huang, J., Liu, Y.-M., He, H.-Y., Cao, Y., & Fan, K.-N. (2012). Graphite oxide as an efficient and durable metal-free catalyst for aerobic oxidative coupling of amines to imines. Green Chemistry, 14(4), 930. doi:10.1039/c2gc16681jLi, X.-H., Chen, J.-S., Wang, X., Sun, J., & Antonietti, M. (2011). Metal-Free Activation of Dioxygen by Graphene/g-C3N4Nanocomposites: Functional Dyads for Selective Oxidation of Saturated Hydrocarbons. Journal of the American Chemical Society, 133(21), 8074-8077. doi:10.1021/ja200997aSun, H., Wang, Y., Liu, S., Ge, L., Wang, L., Zhu, Z., & Wang, S. (2013). Facile synthesis of nitrogen doped reduced graphene oxide as a superior metal-free catalyst for oxidation. Chemical Communications, 49(85), 9914. doi:10.1039/c3cc43401jYang, J.-H., Sun, G., Gao, Y., Zhao, H., Tang, P., Tan, J., … Ma, D. (2013). Direct catalytic oxidation of benzene to phenol over metal-free graphene-based catalyst. Energy & Environmental Science, 6(3), 793. doi:10.1039/c3ee23623dRocha, R. P., Gonçalves, A. G., Pastrana-Martínez, L. M., Bordoni, B. C., Soares, O. S. G. P., Órfão, J. J. M., … Pereira, M. F. R. (2015). Nitrogen-doped graphene-based materials for advanced oxidation processes. Catalysis Today, 249, 192-198. doi:10.1016/j.cattod.2014.10.046Wang, Y., Xie, Y., Sun, H., Xiao, J., Cao, H., & Wang, S. (2016). Efficient Catalytic Ozonation over Reduced Graphene Oxide for p-Hydroxylbenzoic Acid (PHBA) Destruction: Active Site and Mechanism. ACS Applied Materials & Interfaces, 8(15), 9710-9720. doi:10.1021/acsami.6b01175Duan, X., Su, C., Zhou, L., Sun, H., Suvorova, A., Odedairo, T., … Wang, S. (2016). Surface controlled generation of reactive radicals from persulfate by carbocatalysis on nanodiamonds. Applied Catalysis B: Environmental, 194, 7-15. doi:10.1016/j.apcatb.2016.04.043Kang, J., Duan, X., Zhou, L., Sun, H., Tadé, M. O., & Wang, S. (2016). Carbocatalytic activation of persulfate for removal of antibiotics in water solutions. Chemical Engineering Journal, 288, 399-405. doi:10.1016/j.cej.2015.12.040Sun, H., Kwan, C., Suvorova, A., Ang, H. M., Tadé, M. O., & Wang, S. (2014). Catalytic oxidation of organic pollutants on pristine and surface nitrogen-modified carbon nanotubes with sulfate radicals. Applied Catalysis B: Environmental, 154-155, 134-141. doi:10.1016/j.apcatb.2014.02.012Wang, X., Qin, Y., Zhu, L., & Tang, H. (2015). Nitrogen-Doped Reduced Graphene Oxide as a Bifunctional Material for Removing Bisphenols: Synergistic Effect between Adsorption and Catalysis. Environmental Science & Technology, 49(11), 6855-6864. doi:10.1021/acs.est.5b01059Lai, L., Potts, J. R., Zhan, D., Wang, L., Poh, C. K., Tang, C., … Ruoff, R. S. (2012). Exploration of the active center structure of nitrogen-doped graphene-based catalysts for oxygen reduction reaction. Energy & Environmental Science, 5(7), 7936. doi:10.1039/c2ee21802jLi, X., Wang, H., Robinson, J. T., Sanchez, H., Diankov, G., & Dai, H. (2009). Simultaneous Nitrogen Doping and Reduction of Graphene Oxide. Journal of the American Chemical Society, 131(43), 15939-15944. doi:10.1021/ja907098fLong, D., Li, W., Ling, L., Miyawaki, J., Mochida, I., & Yoon, S.-H. (2010). Preparation of Nitrogen-Doped Graphene Sheets by a Combined Chemical and Hydrothermal Reduction of Graphene Oxide. Langmuir, 26(20), 16096-16102. doi:10.1021/la102425aLavorato, C., Primo, A., Molinari, R., & Garcia, H. (2013). N-Doped Graphene Derived from Biomass as a Visible-Light Photocatalyst for Hydrogen Generation from Water/Methanol Mixtures. Chemistry - A European Journal, 20(1), 187-194. doi:10.1002/chem.201303689Primo, A., Atienzar, P., Sanchez, E., Delgado, J. M., & García, H. (2012). From biomass wastes to large-area, high-quality, N-doped graphene: catalyst-free carbonization of chitosan coatings on arbitrary substrates. Chemical Communications, 48(74), 9254. doi:10.1039/c2cc34978gPrimo, A., Sánchez, E., Delgado, J. M., & García, H. (2014). High-yield production of N-doped graphitic platelets by aqueous exfoliation of pyrolyzed chitosan. Carbon, 68, 777-783. doi:10.1016/j.carbon.2013.11.068Chan, L. H., Hong, K. H., Xiao, D. Q., Lin, T. C., Lai, S. H., Hsieh, W. J., & Shih, H. C. (2004). Resolution of the binding configuration in nitrogen-doped carbon nanotubes. Physical Review B, 70(12). doi:10.1103/physrevb.70.125408Guo, B., Liu, Q., Chen, E., Zhu, H., Fang, L., & Gong, J. R. (2010). Controllable N-Doping of Graphene. Nano Letters, 10(12), 4975-4980. doi:10.1021/nl103079jSun, L., Wang, L., Tian, C., Tan, T., Xie, Y., Shi, K., … Fu, H. (2012). Nitrogen-doped graphene with high nitrogen level via a one-step hydrothermal reaction of graphene oxide with urea for superior capacitive energy storage. RSC Advances, 2(10), 4498. doi:10.1039/c2ra01367cAsedegbega-Nieto, E., Perez-Cadenas, M., Morales, M. V., Bachiller-Baeza, B., Gallegos-Suarez, E., Rodriguez-Ramos, I., & Guerrero-Ruiz, A. (2014). High nitrogen doped graphenes and their applicability as basic catalysts. Diamond and Related Materials, 44, 26-32. doi:10.1016/j.diamond.2014.01.019Jiang, H., Yu, X., Nie, R., Lu, X., Zhou, D., & Xia, Q. (2016). Selective hydrogenation of aromatic carboxylic acids over basic N-doped mesoporous carbon supported palladium catalysts. Applied Catalysis A: General, 520, 73-81. doi:10.1016/j.apcata.2016.04.009Primo, A., Parvulescu, V., & Garcia, H. (2016). Graphenes as Metal-Free Catalysts with Engineered Active Sites. The Journal of Physical Chemistry Letters, 8(1), 264-278. doi:10.1021/acs.jpclett.6b0199
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