Porphyrin-silica gel hybrids as effective and selective copper(II) adsorbents from industrial wastewater

Porphyrins are an important class of ligands with a tremendous ability to capture metal ions closely related to the rich coordination chemistry of porphyrins. Herein we use this characteristic to develop silica gel grafted derivatives for water remediation applications. Therefore, two porphyrin derivatives, one with three and the other with four mercaptopyridyl units were grafted on silica gel functionalized with 3-aminopropyltriethoxysilane. The new adsorbents Si3PyS and Si4PyS were characterized using a suitable set of techniques confirming the covalent attachment of the porphyrins to the silica surface. Additionally, microscopy and N2 adsorption analysis confirmed the structural integrity and preservation of the mesoporous structure of Si during surface modification. The results show that both hybrid materials exhibit good chemical and thermal stability and an outstanding Cu2+ removal capability, with a chemical adsorption capacity of 176.32 mg g–1 and 184.16 mg g–1, respectively. These materials have also been used in real water and industrial wastewater samples with minimal interference in their adsorption capabilities. Density Functional Theory calculations were performed to confirm the good performance of the hybrid materials Si3PyS and Si4PyS towards metal ions. The functionalization of silica surface with porphyrin-based ligands bearing additional binding motifs drastically improves the adsorption capability of the new hybrids towards metal ions. The presence of pyridyl units brings a meaningful advantage, since both porphyrin core and appended pyridyl groups are able of binding Cu2+ ions with high affinity, contributing to the enhancement of the chelating features of the adsorbents prepared when compared with other ligands supported in silica-based materials.publishe

Formal Firewall Conformance Testing: An Application of Test and Proof Techniques

Firewalls are an important means to secure critical ICT infrastructures. As configurable off-the-shelf prod\-ucts, the effectiveness of a firewall crucially depends on both the correctness of the implementation itself as well as the correct configuration. While testing the implementation can be done once by the manufacturer, the configuration needs to be tested for each application individually. This is particularly challenging as the configuration, implementing a firewall policy, is inherently complex, hard to understand, administrated by different stakeholders and thus difficult to validate. This paper presents a formal model of both stateless and stateful firewalls (packet filters), including NAT, to which a specification-based conformance test case gen\-eration approach is applied. Furthermore, a verified optimisation technique for this approach is presented: starting from a formal model for stateless firewalls, a collection of semantics-preserving policy transformation rules and an algorithm that optimizes the specification with respect of the number of test cases required for path coverage of the model are derived. We extend an existing approach that integrates verification and testing, that is, tests and proofs to support conformance testing of network policies. The presented approach is supported by a test framework that allows to test actual firewalls using the test cases generated on the basis of the formal model. Finally, a report on several larger case studies is presented

Febre Amarela: revisão e situação epidemiológica atual no Brasil

Desde Janeiro de 2017, foram reportados 1563 casos suspeitos de Febre Amarela, sendo confirmados 629 casos, dos quais foram confirmadas 232 mortes devido a doença. A Febre Amarela é uma doença febril hemorrágica, sendo endêmica de regiões tropicais da África e América do Sul. Nos dias atuais, tem apresentado aumento significativo em sua incidência no Brasil, com repercussões e impactos importantes na saúde pública do país. Neste artigo são descritas as causas de Febre Amarela, bem como sua epidemiologia, progressão, os métodos diagnósticos, tratamento e prevenção da doença, de forma a promover atualização epidemiológica e direcionar futuras pesquisas na área. Método: Foram utilizados dados do Pubmed, SciELO, Medline e de fontes governamentais, referentes a Febre Amarela, que datam de 2002 à 2018. Na coleta do dados foram utilizados os seguintes descritores: Febre Amarela, Aedes, Arbovírus, Flavivirus.Since January 2017, there have been at least 1563 suspected cases of Yellow Fever, 629 confirmed cases and 232 confirmed deaths. Yellow fever is a viral hemorrhagic disease endemic to the tropical parts of Africa and South America. At the present time, it has presented a significant increase in its incidence in Brazil, with important repercussions and impacts on the public health. This review paper outlines the causes of yellow fever, as well as the disease epidemiology, progression, diagnosis, treatment and prevention. We conclude by reporting on the current epidemic in Brazil and future directions for research. Method: Data from Pubmed, SciELO, Medline and government sources concerning Yellow Fever were used, dating from 2002 to 2018. In the collection of the data the following descriptors were used: Yellow-fever, Aedes, Arbovirus and Flavivirus

Tomo lo que encuentro : 19 versiones de Virus

“No hay que juzgar a un producto argentino por lo que le falta con respecto a uno americano o europeo... La crítica suele ser más permisiva con las producciones extranjeras que con las locales... No quiero que tengamos una fama tan grande que nos impida la libertad de seguir haciendo lo que querramos”. Tres conceptos de Federico Moura en el último reportaje radial que le hice (y que se le hizo), que bastarían para mostrar a alguien atento a lo que pasaba y que tenía las palabras para dar cuenta de ese registro. Esto está presente en toda la obra de Virus. Una producción que siempre fue creciendo en calidad, en forma y contenido. Este CD es el mejor testimonio de su vigencia. Que tantos solistas y grupos platenses, talentosos y apasionados, hayan tenido deseos de hacer su versión de temas de Virus, es el reconocimiento más pleno de una obra genuina, que despierta amor y respeto. Y claro que Federico está. Si no cómo sabríamos que falta. Tom Lupo Contenido: 1 - Sergio Pángaro: "Tomo lo que encuentro" 2 - Míster América: "Dame una señal" 3 - Ex: "El banquete" 4 - Cine Continuado: "Wadu-wadu" 5 - Ahora: "Sin disfraz" 6 - Las Canoplas: "En mi garage" 7 - Federico Kempff: "Desesperado secuencia uno" 8 - Alfredo Calvelo: "Loco coco" 9 - Traviatabosnialafortina: "Juegos postergados" 10 - Estelares: "Pronta entrega" 11 - Falso Primer Ministro: "Danza narcótica" 12 - NerdKids: "Me puedo programar" 13 - Plupart: "Se sarpo" 14 - Francisco Bochatón: "Imágenes paganas" 15 - El César: "El 146" 16 - Los Hermanitos Kaiser y su Increíble Organito que Toca Solo: "Juegos incompletos" 17 - La Secta: "Mirada speed" 18 - Norma: "Densa realidad" 19 - Juan Pablo Bochatón: "Tomo lo que encuentro"Radio Universidad Nacional de La Plat

Stability of highly supersaturated vanadium electrolyte solution and characterization of precipitated phases for Vanadium Redox Flow Battery

The vanadium redox flow battery (VRFB) has been receiving great attention in recent years as one of the most viable energy storage technologies for large-scale applications. However, higher concentrations of vanadium species are required in the H2O-H2SO4 electrolyte in order to improve the VRFB energy density. This might lead to unwanted precipitation of vanadium compounds, whose nature has not been accurately characterized yet. For this purpose, this study reports the preparation of V(II), V(III), V(IV) and V(V) supersaturated solutions in a 5 M H2SO4-H2O electrolyte by an electrolytic method, from the only vanadium sulfate compound commercially available (VOSO4). The precipitates obtained by ageing of the stirred solutions are representative of the solids that may form in a VRFB operated with such supersaturated solutions. The solid phases are identified using thermogravimetric analysis, X-ray diffraction and SEM. We report that dissolved V(II), V(III) and V(IV) species precipitate as crystals of VSO4, V2(SO4)3 and VOSO4 hydrates and not in their anhydrous form; conversely V(V) precipitates as an amorphous V2O5 oxide partially hydrated. The measured hydration degrees (respectively 1.5, 9, 3 and 0.26 mol of H2O per mol of compound) might significantly affect the overall engineering of VRFB operating with high vanadium concentrations

Metabolic reprogramming of oncogene-addicted cancer cells to OXPHOS as a mechanism of drug resistance

The ability to selectively eradicate oncogene-addicted tumors while reducing systemic toxicity has endeared targeted therapies as a treatment strategy. Nevertheless, development of acquired resistance limits the benefits and durability of such a regime. Here we report evidence of enhanced reliance on mitochondrial oxidative phosphorylation (OXPHOS) in oncogene-addicted cancers manifesting acquired resistance to targeted therapies. To that effect, we describe a novel OXPHOS targeting activity of the small molecule compound, OPB-51602 (OPB). Of note, a priori treatment with OPB restored sensitivity to targeted therapies. Furthermore, cancer cells exhibiting stemness markers also showed selective reliance on OXPHOS and enhanced sensitivity to OPB. Importantly, in a subset of patients who developed secondary resistance to EGFR tyrosine kinase inhibitor (TKI), OPB treatment resulted in decrease in metabolic activity and reduction in tumor size. Collectively, we show here a switch to mitochondrial OXPHOS as a key driver of targeted drug resistance in oncogene-addicted cancers. This metabolic vulnerability is exploited by a novel OXPHOS inhibitor, which also shows promise in the clinical setting

New nitroindazole-porphyrin conjugates: synthesis, characterization and antibacterial properties

The synthesis of new porphyrin-indazole hybrids by a Knoevenagel condensation of 2-formyl-5,10,15,20-tetraphenylporphyrin and N-methyl-nitroindazolylacetonitrile derivatives is reported. The target compounds were isolated in moderate to good yields (32-57%) and some of the isolated porphyrin-indazole conjugates showed good performance in the generation of singlet oxygen when irradiated with visible light. Their efficiency as photosensitizers in the photoinactivation of methicillin resistant Staphylococcus aureus-MRSA was evaluated. All derivatives showed to be able to photoinactivate the MRSA bacteria. Compound 3a appears to be the most promising photosensitiser (PS) in the photoinactivation of these bacteria, despite being the least efficient in singlet oxygen generation. The addition of potassium iodide (KI) significantly potentiated the antimicrobial Photodynamic Therapy (aPDT) process mediated by all the analysed porphyrin-indazole conjugates. The combined action of nitroindazole-porphyrins with potassium iodide (KI) action appears to be promising in the photoinactivation of MRSA.publishe

Ichthyofauna Used in Traditional Medicine in Brazil

Fish represent the group of vertebrates with the largest number of species and the largest geographic distribution; they are also used in different ways by modern civilizations. The goal of this study was to compile the current knowledge on the use of ichthyofauna in zootherapeutic practices in Brazil, including ecological and conservational commentary on the species recorded. We recorded a total of 85 species (44 fresh-water species and 41 salt-water species) used for medicinal purposes in Brazil. The three most commonly cited species were Hoplias malabaricus, Hippocampus reidi, and Electrophorus electricus. In terms of conservation status, 65% of species are in the “not evaluated” category, and 14% are in the “insufficient data” category. Three species are in the “vulnerable” category: Atlantoraja cyclophora, Balistes vetula, and Hippocampus erectus. Currently, we cannot avoid considering human pressure on the population dynamics of these species, which is an essential variable for the conservation of the species and the ecosystems in which they live and for the perpetuation of traditional medical practices

Realizing Omega-regular Hyperproperties

We studied the hyperlogic HyperQPTL, which combines the concepts of trace relations and $\omega$-regularity. We showed that HyperQPTL is very expressive, it can express properties like promptness, bounded waiting for a grant, epistemic properties, and, in particular, any $\omega$-regular property. Those properties are not expressible in previously studied hyperlogics like HyperLTL. At the same time, we argued that the expressiveness of HyperQPTL is optimal in a sense that a more expressive logic for $\omega$-regular hyperproperties would have an undecidable model checking problem. We furthermore studied the realizability problem of HyperQPTL. We showed that realizability is decidable for HyperQPTL fragments that contain properties like promptness. But still, in contrast to the satisfiability problem, propositional quantification does make the realizability problem of hyperlogics harder. More specifically, the HyperQPTL fragment of formulas with a universal-existential propositional quantifier alternation followed by a single trace quantifier is undecidable in general, even though the projection of the fragment to HyperLTL has a decidable realizability problem. Lastly, we implemented the bounded synthesis problem for HyperQPTL in the prototype tool BoSy. Using BoSy with HyperQPTL specifications, we have been able to synthesize several resource arbiters. The synthesis problem of non-linear-time hyperlogics is still open. For example, it is not yet known how to synthesize systems from specifications given in branching-time hyperlogics like HyperCTL$^*$.Comment: International Conference on Computer Aided Verification (CAV 2020