3,156 research outputs found

    The data envelopment analysis to determine efficiency of Latin American countries for greenhouse gases control in electric power generation

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    The objective of this research is to determine the efficiency of Latin American countries for the control of greenhouse gas (GHG) emissions due to the generation of electrical energy using the Data Envelopment Analysis. A positivist epistemic position is assumed, and a methodology of evaluative character is used, comprising five (5) phases. The results show that the countries that are located on the efficient frontier have common police like the increase in the share of renewable energies, and diversification of the energy matrix, which means a better control of GHG emissions. It is possible to determine the efficiency of the public policies established by the countries of Latin America for the control of GHG emissions. In conclusion, the countries that are located on the efficient frontier are those that generate electricity with predominantly renewable sources or, at least, use natural gas as a fuel in greater proportion

    Coupling of mass transfer and reactive transport for nonlinear reactions in heterogeneous media

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    Fast chemical reactions are driven by mixing‐induced chemical disequilibrium. Mixing is poorly represented by the advection‐dispersion equation. Instead, effective dynamics models, such as multirate mass transfer (MRMT), have been successful in reproducing observed field‐scale transport, notably, breakthrough curves (BTCs) of conservative solutes. The objective of this work is to test whether such effective models, derived from conservative transport observations, can be used to describe effective multicomponent reactive transport in heterogeneous media. We use a localized formulation of the MRMT model that allows us to solve general reactive transport problems. We test this formulation on a simple three‐species mineral precipitation problem at equilibrium. We first simulate the spatial and temporal distribution of mineral precipitation rates in synthetic hydraulically heterogeneous aquifers. We then compare these reaction rates to those corresponding to an equivalent (i.e., same conservative BTC) homogenized medium with transport characterized by a nonlocal in time equation involving a memory function. We find an excellent agreement between the two models in terms of cumulative precipitated mass for a broad range of generally stationary heterogeneity structures. These results indicate that mass transfer models can be considered to represent quite accurately the large‐scale effective dynamics of mixing controlled reactive transport at least for the cases tested here, where individual transport paths sample the full range of heterogeneities represented by the BTC

    Greenhouse gases emissions and electric power generation in Latin American countries in the period 2006–2013

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    The objective of this study is to classify the group of countries that contributes to the emissions of GHG gases in relation to their electric power generation. The data used for this classification are those reported by OLADE during the period from 2006 to 2013. The results show that they were organized in four (4) clusters, dividing them into efficient and inefficient levels. In the highest efficient level is Brazil, while in the lowest efficient level are Colombia, Costa Rica, El Salvador, Panama, Paraguay, Peru, Uruguay, and Venezuela. Argentina and Mexico are in the highest inefficient level, while the rest of the Latin American countries are in the lowest inefficient level. The countries located at the efficient and inefficient levels were labeled as most emitting countries and least emitting countries

    pH-responsive phthalate cashew gum nanoparticles for improving drugs delivery and anti-Trypanosoma cruzi efficacy

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    Funding Information: The authors acknowledge Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco ( FACEPE ) for a scholarship. This study was supported by funding from the Spanish Group CTS-946 and project P18-RT-3786 . Publisher Copyright: © 2023 Elsevier B.V.Nanotechnology is a crucial technology in recent years has resulted in new and creative applications of nanomedicine. Polymeric nanoparticles have increasing demands in pharmaceutical applications and require high reproducibility, homogeneity, and control over their properties. Work explores the use of cashew phthalate gum (PCG) as a particle-forming polymer. PCG exhibited a pH-sensitive behavior due to the of acid groups on its chains, and control drug release. We report the development of nanoparticles carrying benznidazole. Formulations were characterized by DLS, encapsulation efficiency, drug loading, FTIR, pH-responsive behavior, release, and in vitro kinetics. Interaction between polymer and drug was an evaluated by molecular dynamics. Morphology was observed by SEM, and in vitro cytotoxicity by MTT assay. Trypanocidal effect for epimastigote and trypomastigote forms was also evaluated. NPs responded to the slightly basic pH, triggering the release of BNZ. In acidic medium, they presented small size, spherical shape, and good stability. It was indicated NP with enhanced biological activity, reduced cytotoxicity, high anti T. cruzi performance, and pH-sensitive release. This work investigated properties related to the development and enhancement of nanoparticles. PCG has specific physicochemical properties that make it a promising alternative to drug delivery, however, there are still challenges to be overcome.publishersversionpublishe

    Protective efficacy in a hamster model of a multivalent vaccine for human visceral leishmaniasis (Mulevaclin) consisting of the kmp11, leish-f3+, and ljl143 antigens in virosomes, plus gla-se adjuvant

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    Visceral leishmaniasis (VL) is the most severe clinical form of leishmaniasis, fatal if untreated. Vaccination is the most cost-effective approach to disease control; however, to date, no vaccines against human VL have been made available. This work examines the efficacy of a novel vaccine consisting of the Leishmania membrane protein KMP11, LEISH-F3+ (a recombinant fusion protein, composed of epitopes of the parasite proteins nucleoside hydrolase, sterol-24-c-methyltransferase, and cysteine protease B), and the sand fly salivary protein LJL143, in two dose ratios. The inclusion of the TLR4 agonist GLA-SE as an adjuvant, and the use of virosomes (VS) as a delivery system, are also examined. In a hamster model of VL, the vaccine elicited antigen-specific immune responses prior to infection with Leishmania infantum. Of note, the responses were greater when higher doses of KMP11 and LEISH-F3+ proteins were administered along with the GLA-SE adjuvant and/or when delivered within VS. Remarkably, hamsters immunized with the complete combination (i.e., all antigens in VS + GLA-SE) showed significantly lower parasite burdens in the spleen compared to those in control animals. This protection was underpinned by a more intense, specific humoral response against the KMP11, LEISH-F3+, and LJL143 antigens in vaccinated animals, but a significantly less intense antibody response to the pool of soluble Leishmania antigens (SLA). Overall, these results indicate that this innovative vaccine formulation confers protection against L. infantum infection, supporting the advancement of the vaccine formulation into process development and manufacturing and the conduction of toxicity studies towards future phase I human clinical trialsEuropean Community’s Seventh Framework Programme, grant number 603181 (Clinical Studies on a Multivalent Vaccine for Human Visceral Leishmaniasis [MuLeVaClin]), and by the RD16CIII/0003/0002 and RD16/0027/0008 Red de Investigación Cooperativa de Enfermedades Tropicales, Subprograma RETICS del Plan Estatal de I+D+I 2013–2016, co-funded by ERD

    Copper nanoparticles stabilized with cashew gum: Antimicrobial activity and cytotoxicity against 4T1 mouse mammary tumor cell line

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    Copper nanoparticles stabilized with cashew (CG-CuNPs) were synthesized by reduction reaction using ascorbic acid and sodium borohydride, using the cashew gum (CG) as a natural polymer stabilizer. Dynamic light scattering, atomic force microscopy, Fourier-transform infrared spectroscopy, UV-Vis spectrophotometry, and x-ray diffraction were used to characterize the nanoparticles (CG-CuNPs), and copper was quantified by electrochemical measurement. The UV-vis spectra of the CG-CuNPs confirmed the formation of nanoparticles by appearance of a surface plasmon band at 580 nm after 24 h of reaction. The Fourier-transform infrared spectrum of CG-CuNPs showed the peak at 1704 cm−1 from cashew gum, confirming the presence of the gum in the nanoparticles. The average size of CG-CuNPs by dynamic light scattering and atomic force microscopy was around 10 nm, indicating small, approximately spherical particles. Antimicrobial assays showed that CG-CuNPs had activity against Staphylococcus aureus ATCC 29213 with a minimal inhibitory concentration of 0.64 mM. The cytotoxicity assay on BALB/c murine macrophages showed lower cytotoxic effects for CG-CuNPs than CuSO4·5H2O. Viability cell assays for CG-CuNPs at (0.250 mM) inhibited by 70% the growth of 4T1 LUC (4T1 mouse mammary tumor cell line) and NIH 3T3 cells (murine fibroblast cells) over a 24-h period. Therefore, CG-CuNPs can be used as an antimicrobial agent with lower cytotoxic effects than the CuSO4·5H2O precursor.The author would like to thank at UCM for performingDPV, USP by X-ray diffraction experiment, REQUIMTE/LAQV for FTIR, UnB and UFPI for the cytotoxicityassays, as well as at UFPI for help with DLS, UV-Vis,AFM, and microbiological experiments. This work was supported by Project 400398/2014-1—Desenvolvimento de Nanopartículas Estabilizadas com Goma de Cajueiro para Aplicações Biotecnologicas, financed by CNPq. AlexandraPlácido is grateful to FCT by her grant SFRH/BD/97995/2013, financed by POPH-QREN-Tipologia 4.1-Formação Avançada, subsidized by Fundo Social Europeu and Ministério da Ciência, Tecnologia e Ensino Superior.info:eu-repo/semantics/publishedVersio

    Genomic epidemiology of a national outbreak of post-surgical Mycobacterium abscessus wound infections in Brazil.

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    An epidemic of post-surgical wound infections, caused by a non-tuberculous mycobacterium, has been on-going in Brazil. It has been unclear whether one or multiple lineages are responsible and whether their wide geographical distribution across Brazil is due to spread from a single point source or is the result of human-mediated transmission. 188 isolates, collected from nine Brazilian states, were whole genome sequenced and analysed using phylogenetic and comparative genomic approaches. The isolates from Brazil formed a single clade, which was estimated to have emerged in 2003. We observed temporal and geographic structure within the lineage that enabled us to infer the movement of sub-lineages across Brazil. The genome size of the Brazilian lineage was reduced relative to most strains in the three subspecies of Mycobacterium abscessus and contained a novel plasmid, pMAB02, in addition to the previously described pMAB01 plasmid. One lineage, which emerged just prior to the initial outbreak, is responsible for the epidemic of post-surgical wound infections in Brazil. Phylogenetic analysis indicates that multiple transmission events led to its spread. The presence of a novel plasmid and the reduced genome size suggest that the lineage has undergone adaptation to the surgical niche

    Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits

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    The WWgamma triple gauge boson coupling parameters are studied using p-pbar -> l nu gamma + X (l = e,mu) events at sqrt(s) = 1.96 TeV. The data were collected with the DO detector from an integrated luminosity of 162 pb^{-1} delivered by the Fermilab Tevatron Collider. The cross section times branching fraction for p-pbar -> W(gamma) + X -> l nu gamma + X with E_T^{gamma} > 8 GeV and Delta R_{l gamma} > 0.7 is 14.8 +/- 1.6 (stat) +/- 1.0 (syst) +/- 1.0 (lum) pb. The one-dimensional 95% confidence level limits on anomalous couplings are -0.88 < Delta kappa_{gamma} < 0.96 and -0.20 < lambda_{gamma} < 0.20.Comment: Submitted to Phys. Rev. D Rapid Communication
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