1,166 research outputs found

    Ocorrência de eflorescências sulfatadas na mina de São Domingos

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    The intense exploration of sulphide ore deposit in São Domingos mine, produced considerable amount of sulphide material that when are exposed to weathering generates acid mine drainage (AMD). The main goal of this paper is to study a specific occurrence regarding composition and morphology of the salts that arise at the end of the dry season. Soluble salts appear at the banks of the drainage channels and over the waste materials, exhibiting different colours and aspects. The obtained results showed by X-Ray diffraction and scanning electronic microscopy, that the mineralogy of salt efflorescences is dominated by sulphates, displaying different occurrence modes. Melanterite and copiapite are the main iron sulphates while minerals from the series of pickeringite-halotrichite dominate the aluminium sulphates. In addition, dehydration and dissolution laboratory experiments were carried out in order to simulate the transformations suffered by soluble salts and evaluate the environmental effect in aquatic system.Patrícia Gomes wishes to acknowledge FCT (Science and Technology Foundation, Portugal) by the research fellowship under the POCH (Programa Operacional Capital Humano) supported by the European Social Fund and National Funds of MCTES with reference SFRH/BD/108887/2015. This work was co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690 and national funds provided by FCT (Science and Technology Foundation, Portugal)

    How latanoprost changed glaucoma management

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    Glaucoma is currently considered one of the leading causes of severe visual impairment and blindness worldwide. Topical medical therapy represents the treatment of choice for many glaucoma patients. Introduction of latanoprost, 25 years ago, with an entirely new mechanism of action from that of the antiglaucoma drugs used up to that time was a very important milestone. Since then, due mainly to their efficacy, limited systemic side effects and once daily dosing, prostaglandin analogues (PGAs) have become as the first-choice treatment for primary open-angle glaucoma. PGAs are in general terms well tolerated, although they are associated with several mild to moderate ocular and periocular adverse events. Among them, conjunctival hyperemia, eyelash changes, eyelid pigmentation, iris pigmentation and hypertrichosis around the eyes are the most prevalent. The objective of this paper is to review the role of PGAs in the treatment of glaucoma over the 25 years since the launch of Latanoprost and their impact on clinical practice outcomes

    Anti-proliferative effects of compounds derived from glucopyranuronamide

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    Chemotherapy is a major cancer treatment option. The synthesis of new compounds with better anti-proliferative properties and higher specificity is a current challenge in drug discovery today. Our goal with this work was to develop compounds derived from D-glucuronic acid and to evaluate their anti-proliferative properties. We have synthetized a library of hydroxyamide derivatives of D-glucuronic acid using amines and aminoalcohols. The synthesis of these compounds were based on the work of El-Nezhawy's group, who have designed some novel D-glucuronic acid acetylated and deacetylated derivatives, which showed interesting results with breast cancer cell lines. Anti-proliferative activity of the newly synthesized compounds was examined against human breast adenocarcinoma (MCF-7) and human colon carcinoma (MDST8) cell lines. Cell growth and viability was analysed by the Cell Counting Kit-8 method. The chemotherapeutic agent 5-fluoroacil was used as a positive control, allowing one to estimate the maximal anti-proliferative action expected in both carcinoma cell lines. All the compounds were studied in the 10-9-10-5M range. The compound N-(ethanol)-α/β D-glucopyranuronamide presented the best anti-proliferative potential with an IC50 (concentration of the compound causing 50% decrease in net cell growth) of 1.4x10-7M in MCF-7 cells. The 1-pheny-l-2-hydroxy-ethane-2-yl and the 1-propanol derivatives evoked weak anti-proliferative effects in MCF-7, with slight growth inhibition of 37% and 35%, respectively, for the highest concentration used (10-5M). On the contrary, the MDST-8 cell growth was not affected by these compounds. On the contrary, the 1-hydroxy-2-isopropyl-ethane-2-yl and 3-phenyl-1-hydroxy-propane-2-yl derivatives, exhibited weak anti-proliferative effects (22% and 40%, respectively) at 10-5M, in the MDST8 cell line, without affecting MCF-7 cell growth. None of the compounds exihibited toxic effects, at least up to 72h exposure, in the concentration range studied. These results show that the ethyl substituent was the most effective N-substituent for glucopyranuronamide for anti-proliferative actions in MCF-7 cell line, whilst in the case of the MDST8 cells, 3-phenyl-1-hydroxy-propane-2-yl was the most effective N-substituent. Moreover, all the glucopyranonamide compounds studied presented selective anti-proliferative effects for the different carcinoma cell lines used

    Acute hemodynamic effect of inhaled iloprost in pulmonary artery hypertension evaluated with echocardiography

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    Doppler echocardiography is useful in the initial evaluation and long-term follow-up of patients with pulmonary artery hypertension. Aerosolised iloprost has been shown to reduce pulmonary pressure immediately after inhalation. We report the echocardiographic findings in a patient with severe pulmonary hypertension, before and after the inhalation of aerosolized iloprost. These findings illustrate the acute influence of iloprost in right and left ventricular hemodynamics and morphology. These findings were reproduced in subsequent echocardiographic evaluations

    One-Pot Synthesis of Polycyclic Nucleosides with Unusual Molecular Skeletons

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    An R hydroxy pyrrolidine tricyclic nucleoside 3 and its spontaneous reaction with acetone is described. In this transformation highly functionalized polycyclic nucleosides with rather unusual molecular skeletons are formed in a complete regio-and stereoselective way. The reaction involves the formation of three new bonds, two of them novel carbon-carbon bonds, in a one-pot way. An enamine-iminium mechanism with participation of carbinolamine, iminium ion, and enamine intermediates is proposed as a plausible explanation for this transformation. The scope of the reaction is briefly studied concluding that the nature of the ketone (R1COR2) is critical for the initial attack of the NH to the carbonyl group.We thank Susana Ruiz for excellent technical assistance. The Spanish MEC/MCINN (project SAF 2006-12713-C02-01) and the Comunidad de Madrid (project BIPEDD-CM S-B10-0214-2006) are also acknowl- edged for financial support. The Spanish Consejo Superior de Investigaciones Cientı´ ficas is also acknowledged for a JAE-Doc contract to M.-C.B.Peer reviewe

    Novel hydroxyamides and amides containing D-glucopyranose or D-fructose units: biological assays in MCF-7 and MDST8 cell lines

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    A novel library of 15 compounds, hydroxyamides and amides containing a β-d-glucopyranose (d-Gluc) or a β-d-fructose (d-Fruc) units was designed and synthesized for antiproliferative assays in breast (MCF-7) and colon (MDST8) cancer cell lines. Twelve of them were hydroxyamides and were successfully synthesized from β-d-glucuronic acid (d-GluA). Six of these hydroxyamides which were acetylated hydroxy-β-d-glucopyranuronamide 2a–2f (1st Family) and the other six were their respective isomers, that is, hydroxy-β-d-fructuronamide 3a–3f (2nd Family), obtained by acid–base catalyzed isomerization. These compounds have the general structure, d-Glucsingle bondCdouble bond; length as m-dashONHsingle bondCHRsingle bond(CH2)nsingle bondOH and d-Frucsingle bondCdouble bond; length as m-dashONHsingle bondCHRsingle bond(CH2)nsingle bondOH, where R = an aromatic, alkyl or a hydrogen substituent, with n = 0 or 1. Eight of these contained a chiral aminoalcohol group. Three compounds were amides containing a d-glucopyranose unit (3rd Family). SAR studies were conducted with these compounds. Antiproliferative studies showed that compound 4a, the bromo-amide containing the β-d-glucopyranose ring, potently inhibits the proliferation of the MDST8 cells. Five compounds (2e, 2f, 3d, 3e, and 3f) were shown to potently selectively inhibit the proliferation of the MCF-7 cells. Compound 4b was the only one showing inhibition in both cell lines. In general, the more active compounds were the amides and hydroxyamides containing the β-d-fructose moiety, and containing an alkyl group or hydrogen. Half-inhibitory concentrations (IC50) of between 0.01 and 10 μM, were observed

    Students’ perception of campus sustainability in a Brazilian university

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    Over recent decades, higher education institutions (HEIs) have been recognised as ideal leaders in supporting the transition to sustainable societies. Leading by example, they have been embarking upon committing themselves to sustainability by incorporating sustainable development practices (SDP) into their integrated management system. As a major stakeholders group, students play a significant role in moving this agenda forward. This study aims to develop an assessment framework to evaluate the students’ perception of campus sustainability, based on a Brazilian HEI case study. A survey was assembled using five demographic questions, three dichotomous questions, and 43 items resorting to a 1–5 Likert scale and administered to a sample of 207 undergraduate technology students. Through exploratory and confirmatory factor analysis, a reliable scale emerges with 31 items grouped into eight dimensions: Waste; Emissions/Procurement; Energy; Quality of Life in the Workplace (QLW); Fauna and Flora; Institutional Framework; Education/Research; and, Water. The dimensions explain 68.50% of the total model variance. The lowest-evaluated dimension was Emissions/Procurement, with a 2.26 average value, followed by water (2.27) and Energy (2.28); all three of these were below the scale’s midpoint. The best-evaluated dimension was Education/Research, with an average of 3.30. This research provides an insight into HEI students’ sustainability perception and into how the university decision-makers could improve the sustainable practices to increase the students’ engagement.- (undefined

    Composição química e atividade inibidora de acetilcolinesterase de óleos voláteis de Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedeliana O. Berg, Myrtaceae

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    The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesquiterpenes were found in higher amounts, being valerianol the major compound, and this oil presented a strong acetylcholinesterase inhibition.A composição química dos óleos voláteis de duas espécies de Myrtaceae, Myrceugenia myrcioidese Eugenia riedeliana, ambas nativas da Mata Atlântica, foi analisada por CG-EM. A atividade inibidora de acetilcolinesterase foi determinada colorimetricamente para estes óleos. Em M. myrcioides, hidrocarbonetos monoterpênicos representaram a classe majoritária de compostos presentes no óleo volátil, sendo α-pineno o componente mais abundante e a atividade inibidora de acetilcolinesterase foi baixa, enquanto para E. riedelianaos sesquiterpenos foram observados em maiores concentrações, sendo o valerianol o componente majoritário, e este óleo apresentou uma forte atividade inibidora da enzima.BIOTA/FAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    MAPEAMENTO TECNOLÓGICO DA UTILIZAÇÃO DA GLICERINA COPRODUTO DA PRODUÇÃO DO BIODIESEL NA REMEDIAÇÃO DE ÁREAS IMPACTADAS POR ATIVIDADES PETROLÍFERAS

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    Acredita-se que a crescente utilização do biodiesel irá saturar o mercado com o seu principal co-produto, a glicerina. Apesar de já existirem inúmeros destinos para esse rejeito, há a necessidade de incorporar o mesmo em outras técnicas ou processos. Este trabalho tem como objetivo possibilitar uma maior compreensão acerca das tecnologias já existentes referentes à utilização da glicerina, co-produto da produção do biodiesel. O estudo analisará a evolução anual dos depósitos, a inter-relação das patentes com diferentes aplicações que envolvem a glicerina, os países que mais depositaram patentes utilizando a glicerina e o que ainda pode ser desenvolvido através do aproveitamento desse co-produto. Para tanto, realizou-se uma busca por patentes através da base European Patent Office (EPO), usualmente escolhida para varredura de tecnologias. As 1233 patentes encontradas mostraram algumas das aplicações possíveis da glicerina, métodos de obtenção da mesma e como modificar algumas de suas propriedades químicas, através de reações. Apesar da glicerina já ter sido utilizada em processos de biorremediação em áreas contaminadas por poluentes orgânicos, observou-se que ainda não existe nenhuma patente depositada utilizando a glicerina como fluido de lavagem para remediação ex situ de solos
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