1,344 research outputs found
Estudo comparativo das castas tintas nobres do Dão: Touriga Nacional, Jaen, Tinta Roriz e Alfrocheiro
Dissertação de Mestrado em Qualidade e Tecnologia AlimentarOs vinhos DOC (Denominação de Origem Controlada)Dão, são reconhecidos pelos consumidores e pela crítica, como vinhos de excelência, fruto da sua tipicidade e qualidade invulgares. Sendo as castas nobres do Dão a Touriga Nacional, o Jaen, a Tinta Roriz e o Alfrocheiro considerámos pertinente o estudo das características sensoriais e físico-químicas de vinhos monocasta produzidos a partir das referidas castas da Região Demarcada do Dão (RDD). Para prossecução desse objectivo dividiu-se o presente trabalho em duas partes distintas. Numa primeira parte foi realizado um levantamento dos dados documentados existentes referentes à região, nomeadamente sobre os vestígios históricos da produção de vinho na RDD; referindo-se ainda em detalhe a criação da Região Demarcada do Dão (origens, regulamentação, demarcação), é feita de igual modo uma caracterização do seu património vitícola, a evolução, regulamentação e caracterização das castas aptas à produção de 'Dão Nobre', bem como os principais estudos encontrados sobre a caracterização dos vinhos produzidos na Região Demarcada do Dão entre 1953 a 2012. A segunda parte da dissertação é constituída pelo trabalho experimental, nela se caracteriza o material em estudo (vinhos tintos mono-castas colheita de 2010 Touriga Nacional, Jaen, Tinta Roriz e Alfrocheiro Preto), referem-se as metodologias utilizadas na análise sensorial e físico-química, os resultados obtidos e as principais conclusões. Para os parâmetros sensoriais e físico-químicos avaliados os resultados obtidos evidenciaram uma clara inferioridade dos vinhos produzidos a partir da casta Alfrocheiro. Relativamente aos vinhos de Jaen e Tinta Roriz apresentam características muito semelhantes entre si e não mostraraam, para a maior parte dos parâmetros avaliados, diferenças estatísticamente significativas quando comparados com os Touriga Nacional. Foram os vinhos produzidos a partir da Touriga Nacional os que se destacaram em todas as análises efetuadas. Os resultados obtidos quer ao nível da prova sensorial quer nas análises físico-químicas permitem-nos afirmar que a Touriga Nacional, o Jaen e a Tinta Roriz são castas bem adaptadas a condições edafo-climáticas da RDD, com capacidade de ao nível mono-varietal originar vinhos de qualidade e levantam alguma discussão sobre a denominação nobre para a casta Alfrocheiro.ABSTRACT:The wines DOC (Denomination of Controlled Origin) Dão have been recognized by consumers and critics as excellent wines. This results of their unusual characteristics and quality. The species Touriga Nacional, Jaen, Tinta Roriz and Alfrocheiro are the noble varieties demarcated region of Dão (RDD). Thus we considered relevant the study of sensory characteristics and physicochemical properties of single variety wines produced from the grapes of those noble species. In order to achieve that purpose we divided the present work into two distinct parts. In the first part we review the historical traces of wine production in RDD. We detailed the creation of the demarcated region of Dão (origins, regulation, demarcation), as well as the description vineyard tradition, evolution, regulation. We also detailed the different vineard varieties suitable for the production of "Dão Nobre", as well as the major studies found on the characterization of wines produced in the RDD between the end of the XX century and the beginning of the XXI century. The second part of the present work describe the experimental work. A presentation of the material and methods used, the obtained results and the discussion of those results. Finally the conclusion and the major findings of the work. For the physical chemical and sensory parameters evaluated results showed a clear inferiority of the wines produced from the grape variety Alfrocheiro. The wines Jaen and Tinta Roriz have very similar characteristics and do not shown statiscally significant differences, when compared with Touriga Nacional. The wines produced from Touriga Nacional have excelled in every analysis. The obtained results in sensorial and in the physicochemical analyzes allow to affirm that the Touriga Nacional, Jaen and Tinta Roriz are vineyards well adapted to soil and climate conditions of the RDD and with ability to produce excellent 'noble' mono-varietal wine. The inclusion of the Alfrocheiro as noble variety deserves further discussion
Avaliação fitoquímica e actividade antioxidante de compostos fenólicos presentes em 'Valerianella Locusta'
Dissertação de Mestrado em Qualidade e Tecnologia AlimentarNos últimos anos, o consumo de frutas e vegetais tem sido recomendado pela Organização Mundial de Saúde (OMS), numa perspectiva de prevenção de diversas patologias, tais como o cancro, a osteoporose e doenças cardiometabólicas e degenerativas. Os benefícios destes alimentos para a saúde humana estão associados à presença de compostos com actividade antioxidante capazes de minimizar alterações celulares induzidas por espécies reactivas de oxigénio e azoto. O presente trabalho tem como principais objectivos determinar o teor total de polifenóis e consequentemente a capacidade antioxidante dos brócolos e canónigos, avaliando paralelamente a influência das condições de extracção através de variadas técnicas espectrofotométricas; e ainda caracterizar a composição fenólica dos canónigos após separação por cromatografia líquida (HPLC-DAD-ESI/MS/MS). Os resultados mostram que os canónigos possuem um teor de polifenóis totais cerca de 3 vezes superior em relação aos bróculos, bem como 4 a 22 vezes maior capacidade antioxidante. O solvente mais eficaz na extracção dos polifenóis em ambos os vegetais foi o metanol. Foram identificados cinco compostos fenólicos, onde se destaca o ácido clorogénico como principal constituinte da matriz dos canónigos, com 168+-9 mg ACG/100 g peso fresco(PF).ABSTRACT: In last years the consumption of fruits and vegetables has been recommended by world health organization (WHO) trying to prevent several diseases such as, cancer, osteoporosis, cardiomethabolic and degenerative diseades. The benefits of these foods for human health are associated with the presence of compounds with antioxidant activity capable of minimizing cellular changes induced by reactive oxygen species and nitrogen. The present work's main objectives were the total content of plyphenols determination and consequently the antioxidant capacity of broccoli and lamb's lettuce, evaluating the influence of the extraction conditions by spectrophotometric techniques; and characterize the phenolic composition of lamb's lettuce after separation by liquid chromatography (HPLC-DAD-ESI/MS/MS). The results indicate that lamb's lettuce contains about 3-fold higher amount of total polyphenols compared to broccoli, as well as higher antioxidant activity, up to 22-fold. The most efficient solvent extraction of polyphenols in both plants was methanol. A total of five compounds were identified and the main phenolic compound found was chlorogenic acid with a content of 168+-9 mg CGA/100 g fresh weight (FW)
Exact exchange-correlation potential of a ionic Hubbard model with a free surface
We use Lanczos exact diagonalization to compute the exact
exchange-correlation (xc) potential of a Hubbard chain with large binding
energy ("the bulk") followed by a chain with zero binding energy ("the
vacuum"). Several results of density functional theory in the continuum
(sometimes controversial) are verified in the lattice. In particular we show
explicitly that the fundamental gap is given by the gap in the Kohn-Sham
spectrum plus a contribution due to the jump of the xc-potential when a
particle is added. The presence of a staggered potential and a nearest-neighbor
interaction V allows to simulate a ionic solid. We show that in the ionic
regime in the small hopping amplitude limit the xc-contribution to the gap
equals V, while in the Mott regime it is determined by the Hubbard U
interaction. In addition we show that correlations generates a new potential
barrier at the surface
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Comparison of 5-year progression of retinitis pigmentosa involving the posterior pole among siblings by means of SD-OCT: a retrospective study
The blockchain technology promises to transform finance, money and evengovernments. However, analyses of blockchain applicability and robustness typicallyfocus on isolated systems whose actors contribute mainly by running the consensusalgorithm. Here, we highlight the importance of considering trustless platformswithin the broader ecosystem that includes social and communication networks. Asan example, we analyse the flash-crash observed on 21st June 2017 in the Ethereumplatform and show that a major phenomenon of social coordination led to acatastrophic cascade of events across several interconnected systems. We proposethe concept of “emergent centralisation” to describe situations where a single systembecomes critically important for the functioning of the whole ecosystem, and arguethat such situations are likely to become more and more frequent in interconnectedsocio-technical systems. We anticipate that the systemic approach we propose willhave implications for future assessments of trustless systems and call for the attentionof policy-makers on the fragility of our interconnected and rapidly changing world
Higiene do sono: cartilha
UFRA - Campus BelémNós, psicólogos da assistência estudantil, criamos este material para abordarmos sobre a higiene do sono. O que é, como realizar, quais os benefícios do sono e os problemas que a insônia pode causar. Além de algumas dicas para higienizar seu sono. Quando falamos sobre o sono, uma das primeiras coisas associadas é o descanso e esse pensamento não está de todo errado, parte da finalidade do sono é o descanso, mas
engana-se quem pensa que a atividade cerebral seja apenas de repouso, muito da atividade elétrica do cérebro é similar em complexidade a de quando estamos em estado de vigília (BRANDÃO, 2019), isso
significa que enquanto dormimos muitas coisas acontecem, uma delas é o sonho, mas ela é apenas uma parte, para sermos mais precisos o sono é dividido em sono REM e sono não-REM.We, student assistance psychologists, created this material to address sleep hygiene. What it is, how to do it, what are the benefits of sleep and the problems that insomnia can cause. In addition to some tips to sanitize your sleep. When we talk about sleep, one of the first things associated with it is rest and this thought is not at all wrong, part of the purpose of sleep is rest, but It is wrong to think that brain activity is only at rest, much of the brain's electrical activity is similar in complexity to when we are in a waking state (BRANDÃO, 2019), this
means that while we sleep many things happen, one of them is the dream, but it is only a part, to be more precise sleep is divided into REM sleep and non-REM sleep
Duration of temporary catheter use for hemodialysis: an observational, prospective evaluation of renal units in Brazil
<p>Abstract</p> <p>Background</p> <p>For chronic hemodialysis, the ideal permanent vascular access is the arteriovenous fistula (AVF). Temporary catheters should be reserved for acute dialysis needs. The AVF is associated with lower infection rates, better clinical results, and a higher quality of life and survival when compared to temporary catheters. In Brazil, the proportion of patients with temporary catheters for more than 3 months from the beginning of therapy is used as an evaluation of the quality of renal units. The aim of this study is to evaluate factors associated with the time between the beginning of hemodialysis with temporary catheters and the placement of the first arteriovenous fistula in Brazil.</p> <p>Methods</p> <p>This is an observational, prospective non-concurrent study using national administrative registries of all patients financed by the public health system who began renal replacement therapy (RRT) between 2000 and 2004 in Brazil. Incident patients were eligible who had hemodialysis for the first time. Patients were excluded who: had hemodialysis reportedly started after the date of death (inconsistent database); were younger than 18 years old; had HIV; had no record of the first dialysis unit; and were dialyzed in units with less than twenty patients. To evaluate individual and renal unit factors associated with the event of interest, the frailty model was used (N = 55,589).</p> <p>Results</p> <p>Among the 23,824 patients (42.9%) who underwent fistula placement in the period of the study, 18.2% maintained the temporary catheter for more than three months until the fistula creation. The analysis identified five statistically significant factors associated with longer time until first fistula: higher age (Hazard-risk - HR 0.99, 95% CI 0.99-1.00); having hypertension and cardiovascular diseases (HR 0.94, 95% CI 0.9-0.98) as the cause of chronic renal disease; residing in capitals cities (HR 0.92, 95% CI 0.9-0.95) and certain regions in Brazil - South (HR 0.83, 95% CI 0.8-0.87), Midwest (HR 0.88, 95% CI 0.83-0.94), Northeast (HR 0.91, 95% CI 0.88-0.94), or North (HR 0.88, 95% CI 0.83-0.94) and the type of renal unit (public or private).</p> <p>Conclusion</p> <p>Monitoring the provision of arteriovenous fistulas in renal units could improve the care given to patients with end stage renal disease.</p
Towards the use of a smartphone imaging-based tool for point-of-care detection of asymptomatic low-density malaria parasitaemia
Background: Globally, there are over 200 million cases of malaria annually and over 400,000 deaths. Early and accurate detection of low-density parasitaemia and asymptomatic individuals is key to achieving the World Health Organization (WHO) 2030 sustainable development goals of reducing malaria-related deaths by 90% and eradication in 35 countries. Current rapid diagnostic tests are neither sensitive nor specific enough to detect the low parasite concentrations in the blood of asymptomatic individuals.
Methods: Here, an imaging-based sensing technique, particle diffusometry (PD), is combined with loop mediated isothermal amplification (LAMP) on a smartphone-enabled device to detect low levels of parasitaemia often associated with asymptomatic malaria. After amplification, PD quantifies the Brownian motion of fluorescent nanoparticles in the solution during a 30 s video taken on the phone. The resulting diffusion coefficient is used to detect the presence of Plasmodium DNA amplicons. The coefficients of known negative samples are compared to positive samples using a one-way ANOVA post-hoc Dunnett's test for confirmation of amplification.
Results: As few as 3 parasite/µL of blood was detectable in 45 min without DNA extraction. Plasmodium falciparum parasites were detected from asymptomatic individuals' whole blood samples with 89% sensitivity and 100% specificity when compared to quantitative polymerase chain reaction (qPCR).
Conclusions: PD-LAMP is of value for the detection of low density parasitaemia especially in areas where trained personnel may be scarce. The demonstration of this smartphone biosensor paired with the sensitivity of LAMP provides a proof of concept to achieve widespread asymptomatic malaria testing at the point of care
Playing in the waiting room of an infant outpatient clinic from the perspective of children and their companions
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