466 research outputs found

    Subcutaneous adipose tissue classification

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    The developments in the technologies based on the use of autologous adipose tissue attracted attention to minor depots as possible sampling areas. Some of those depots have never been studied in detail. The present study was performed on subcutaneous adipose depots sampled in different areas with the aim of explaining their morphology, particularly as far as regards stem niches. The results demonstrated that three different types of white adipose tissue (WAT) can be differentiated on the basis of structural and ultrastructural features: deposit WAT (dWAT), structural WAT (sWAT) and fibrous WAT (fWAT). dWAT can be found essentially in large fatty depots in the abdominal area (periumbilical). In the dWAT, cells are tightly packed and linked by a weak net of isolated collagen fibers. Collagenic components are very poor, cells are large and few blood vessels are present. The deep portion appears more fibrous then the superficial one. The microcirculation is formed by thin walled capillaries with rare stem niches. Reinforcement pericyte elements are rarely evident. The sWAT is more stromal; it is located in some areas in the limbs and in the hips. The stroma is fairly well represented, with a good vascularity and adequate staminality. Cells are wrapped by a basket of collagen fibers. The fatty depots of the knees and of the trochanteric areas have quite loose meshes. The fWAT has a noteworthy fibrous component and can be found in areas where a severe mechanic stress occurs. Adipocytes have an individual thick fibrous shell. In conclusion, the present study demonstrates evident differences among subcutaneous WAT deposits, thus suggesting that in regenerative procedures based on autologous adipose tissues the sampling area should not be randomly chosen, but it should be oriented by evidence based evaluations. The structural peculiarities of the sWAT, and particularly of its microcirculation, suggest that it could represent a privileged source for regenerative procedures based on autologous adipose tissues

    Nitrogen fertilization associated with cold storage and its impacts on the maintenance of peach quality.

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    Nitrogen, which is considered the most important nutrient for peach trees, may interfere in both quantitative production characteristics and quality of fruits. This study aimed at evaluating the effect of the combination of doses of N fertilization and different periods of cold storage on physico-chemical and phytochemical characteristics of peaches in post-harvest. The experiment had a randomized complete block design in a 4x3 factorial scheme, i. e., four doses of fertilization (0, 60, 120 and 180 Kg N ha-1) and three periods of storage (on the harvest day, on both the 15th and the 30th storage days at 1±1ºC, each followed by a day of simulated commercialization at 20±1ºC). The following aspects were evaluated in fruits yielded by peach trees of the genotype Cascata 1067: fruit color, soluble solid content, titratable acidity, pulp firmness, mass loss, total phenolic compounds and antioxidant activity. Different periods of cold storage and doses of N fertilization were found to affect epidermis luminosity, pulp firmness and titratable acidity of fruits. Peaches may be stored at low temperatures for 15+1 days. After that, loss of fruit firmness increases. N fertilization affects neither the soluble solid content nor the epidermis color of peaches, but both parameters are influenced by storage. Values of phenolic compounds and antioxidant activity decrease when there is N increment in the soil and when longer storage is carried out. Results suggest that peach composition may be affected by cultural practices, such as N fertilization, in harvest and after storage

    The trochanteric fat pad

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    Technological developments based on the use of autologous white adipose tissue (WAT) attracted attention to minor fat depots as possible sources of adipose tissue. In plastic surgery, the trochanteric fatty pad is one of the most used WAT depots for its location and organoleptic characteristics that make it particularly suitable for reconstructive procedures. Despite its wide use in clinic, the structure of this depot has never been studied in detail and it is not known if structural differences exist among trochanteric fat and other subcutaneous WAT depots. The present study was performed on trochanteric fat pad with the aim to clarify the morphology of its adipocytes, stroma and microcirculation, with particular reference to the stem niches. Histological and ultrastructural studies showed that the main peculiar feature of the trochanteric fat concerns its stromal component, which appears less dense than in the other subcutaneous WATs studied. The intra-parenchymal collagen stroma is poor and the extracellular compartment shows large spaces, filled with electron-light material, in which isolated collagen bundles are present. The adipocytes are wrapped in weak and easily detachable collagen baskets. These connective sheaths are very thin compared to the sheaths in other subcutaneous WAT depots. The capillaries are covered by large, long and thin elements surrounded by an external lamina; these perivascular cells are poor in organelles and mainly contain poly-ribosomes. In conclusion, when compared to other WAT deposits, the trochanteric fatty pad shows structural peculiarities in its stroma and microcirculation suggesting a high regenerative potential. Resistance, dissociability, microvascular weft and high regenerative potential make the trochanteric fatty pad a privileged source for harvesting in autologous WAT-based regenerative procedures

    Dark chocolate modulates platelet function with a mechanism mediated by flavan-3-ol metabolites

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    Cocoa is a rich source bioactive compounds, i.e., flavan-3-ols, and its consumption has been associated with several beneficial effects, such as the positive modulation of the hemostasis targeted by the platelet function. However, these phenolic compounds have a very low bioavailability and extensively undergo phase I and II metabolism, with the appearing into the bloodstream of (epi) catechin conjugates and phenyl-g-valerolactones and their conjugates, at different times. The aims of this study were to explore the effect of dark chocolate on platelet function and to investigate the relationship between this interplay and flavan-3-ol derived metabolites. Eighteen healthy male volunteers ingested 50 g of 90% cocoa chocolate within 5 minutes. Blood samples were collected immediately before chocolate ingestion (T0) and 4 hours afterwards (T1). Platelet function analyzer (PFA)-100 closure time was assessed using collagen/adenosine-50-diphosphate (COL/ADP) and collagen/epinephrine (COL/EPI) cartridges. Plasma flavan-3-ol metabolites were identified and quantified by means of liquid chromatography coupled to a triple quadrupole mass spectrometer (UHPLC-ESI-MS/MS). Results evidenced a significant increase of COL/ADP-induced PFA-100 closure time, but not COL/EPI, 4 hours after ingestion of dark chocolate. Total plasma structurally-related (epi)catechin metabolite (SREM) concentration significantly increased at T1, together with 4 out of the 6 detected metabolites. Total phenyl-g-valerolactone concentrations remained unchanged. Spearman correlations evidenced a strong correlation between COL/ADP closure time and SREMs, mainly led by (epi)catechin-sulfate isomers. These data confirm that the potential beneficial effect of dark chocolate on primary hemostasis may be mediated by flavan-3-ol circulating metabolites

    Digital dermoscopic changes during follow-up of de-novo and nevus-associated melanoma: a cohort study

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    Background: Nevus-associated melanoma (NAM) has been regarded as a distinct biological entity from de-novo melanoma (DNM); however, static dermoscopy often fails in differentiating these entities. Digital dermoscopic monitoring allows to identify dynamic changes occurring during follow-up; this may improve diagnostic accuracy and potentially our knowledge on NAM biology. We aimed to define main independent factors associated with NAM diagnosis and those influencing follow-up time in a population of melanomas excised at follow-up. Methods: A cohort of melanomas excised at follow-up was retrospectively and consecutively selected. NAMs and DNMs were compared according to baseline features and main dermoscopic changes occurring during follow-up. Univariate and multivariable logistic and Cox's regression analysis were performed to respectively define factors associated with NAM diagnosis and those influencing the risk for excision. Results: Eighty-six melanomas were enrolled, of which 21 (24.4%) were nevus-associated. During follow-up NAMs mainly underwent atypical network modifications (47.6%), followed by inverse network (28.6%) and dermoscopic island (23.8%) worsening or appearance. DNMs were also mainly characterized by atypical network modifications (47.7%), however, a significant proportion of cases underwent irregular pigmentation/dots/globules or regression changes (29.2%), which were rarely seen among NAMs. Furthermore, both multivariable logistic and Cox's regression analysis demonstrated a significant association between NAM and a longer follow-up. Conclusions: We demonstrated that among melanomas excised at follow-up, different patterns of dermoscopic changes may be found between NAMs and DNMs. This finding, together with the association of NAM with a longer follow-up time, supports the hypothesis of different biological behavior of these two entities

    Nitrogen fertilization and genotypes of peaches in high-density.

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    Entre os fatores que afetam a produtividade dos pessegueiros, está a nutrição adequada das plantas, sendo o nitrogênio (N) um dos nutrientes primordiais para a cultura. Deste modo, o objetivo do presente trabalho foi avaliar o efeito da adubação nitrogenada de manutenção nos teores foliares de macronutrientes, no crescimento das plantas e na produção de diferentes genótipos de pessegueiros cultivados em alta densidade de plantio, buscando-se recomendar a concentração mais adequada. O experimento foi conduzido entre 2016 e 2018, com seleções avançadas de pessegueiros "Cascata 1513" e "Cascata 1067", e com concentrações de adubação nitrogenada (0; 60; 120 e 180 kg ha-1 de N). Avaliaram-se: massa de poda, diâmetro de tronco, número de frutos por planta, massa dos frutos, produção por planta e teor de macronutrientes nas folhas. O incremento das concentrações de N aumenta o teor do N nas folhas. Para as condições deste experimento, a máxima produção por planta foi obtida para a maior dose de 180 kg ha de N

    Raleio mecânico de flores e frutos de diferentes genótipos de pessegueiros.

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    O raleio em pessegueiro tem como objetivo retirar o número excessivo de frutos da planta e eliminar aqueles danificados e/ou doentes, mas sem prejudicar a produtividade do pomar. Na produção de pêssegos, o raleio é realizado de forma manual para retirada dos frutos em excesso, necessitando ser executado em um curto período de tempo e com mão de obra especializada, o que eleva os custos de produção. Nesse sentido, o raleio mecânico pode ser uma alternativa ao raleio manual de frutos. Assim, o objetivo deste trabalho foi avaliar a eficiência do raleio mecânico de flores e frutos de pessegueiros com dois tipos de equipamentos. Foram realizados testes com os equipamentos derriçadeira e Carpa Electro®, mantendo-se o raleio manual como testemunha. No primeiro experimento, foi testado, nos anos de 2016 e 2017, o raleio mecânico de flores em seleções avançadas de pessegueiros. O segundo experimento foi realizado no ano de 2017, em pomar comercial da cultivar Maciel, testando-se os raleios mecânicos de flores e de frutos. Nos dois ensaios avaliou-se: porcentagem de derrubada de flores ou frutos, número de frutos por planta, massa média dos frutos, produção por planta e tempo de execução do raleio. Conforme os resultados, o raleio mecânico com os dois equipamentos pode ser alternativa ao raleio manual de frutos no cultivo de pessegueiros. Os equipamentos testados podem ser utilizados para o raleio mecânico de pessegueiro, pois auxiliam na derrubada de flores e frutos e reduzem o tempo de realização dessa operação.bitstream/item/224624/1/Boletim-339.pd

    Online measurement of fluence and position for protontherapy beams

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    Tumour therapy with proton beams has been used for several decades in many centres with very good results in terms of local control and overall survival. Typical pathologies treated with this technique are located in head and neck, eye, prostate and in general at big depths or close to critical organs. The Experimental Physics Department of the University of Turin and the local Section of INFN, in collaboration with INFN Laboratori Nazionali del Sud Catania and Centre de Protontherapie de Orsay Paris, have developed detector systems that allow the measurement of beam position and fluence, obtained in real time during beam delivery. The centre in Catania (CATANA: Centro di AdroTerapia ed Applicazioni Nucleari Avanzate) has been treating patients with eye pathologies since spring 2002 using a superconducting cyclotron accelerating protons up to 62 MeV. This kind of treatments need high-resolution monitor systems and for this reason we have developed a 256-strip segmented ionisation chamber, each strip being 400 μm wide, with a total sensitive area 13 × 13 cm2. The Centre de Protontherapie de Orsay (CPO) has been operational since 1991 and features a synchrocyclotron used for eye and head and neck tumours with proton beams up to 200 MeV. The monitor system has to work on a large surface and for this purpose we have designed a pixel-segmented ionisation chamber, each pixel being 5×5 mm2, for a total active area of 16 × 16 cm2. The results obtained with two prototypes of the pixel and strip chambers demonstrate that the detectors allow the measurement of fluence and centre of gravity as requested by clinical specifications

    Avaliação de duas técnicas de translocação de serrapilheira sobre as assembleias de aranhas (Arachnida: Araneae) e formigas (Hymenoptera: Formicidae)

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    Due to the current rhythm of ecosystem destruction, the development of new techniques aiming at the conservation of forest remnants and their biota is urgent. Our objective was to compare two techniques of leaf-litter translocation (with and without  withdrawing the pre-extent litter layer), through observations on spider and ant richness and assemblage composition, in order to define the best way to perform translocation. The study was carried out in two Brazilian Atlantic rain forest remnants  (called releaser and receptor fragments) in Salvador, State of Bahia, Brazil. A comparison between the faunas of both fragments was performed before translocation and a significant difference was found both in their richness and composition, which is an essential condition to carry out the experiment. A small scale environmental characterization] was made in order to choose similar units capable of  minimizing the stress on leaf-litter organisms living there. Both for spiders and ants, the species richness increased in units that received leaf-litter and it was higherfor spiders in units where the pre-extent litter had not been removed. For the ants, the two forms of translocation seem to be efficient. Nevertheless, taking into account the two groups of organisms, it is suggested that the translocation must be done maintaining the pre-extent leaf-litter.Key words: conservation, litter, fauna manipulation, spiders, ants.Com o ritmo atual de destruição dos ecossistemas surge a necessidade de se investir em técnicas que visem à conservação dos remanescentes florestais e das suas espécies. Nosso objetivo foi comparar duas técnicas para translocação da serrapilheira (com e sem a retirada da camada de serrapilheira preexistente), observando como varia a riqueza e composição de aranhas e formigas no local da translocação, a fim de definir a melhor forma de realizá-la. O estudo foi realizado em dois remanescentes de Mata Atlântica (fragmento doador e receptor) localizados em Salvador (BA). Antes da translocação foi realizada uma comparação de ambas as faunas, entre os fragmentos, e foi  encontrada diferença significativa tanto na riqueza quanto na composição. Assim pôde-se realizar o experimento. Para tanto, foi realizada a  caracterização ambiental a fim de translocar a serrapilheira para as unidades mais similares na  tentativa de minimizar o estresse dos organismos. A riqueza em espécies tanto de aranhas quanto de  formigas aumentou nas unidades que receberam a serrapilheira, sendo para aranhas mais elevada nas unidades onde não foi retirada a serrapilheira preexistente. Já para as formigas as duas formas parecem eficientes. Contudo, levando em consideração os dois grupos, propõe-se que a translocação deve ser feita mantendo a serrapilheira preexistente.Palavras-chave: conservação, serrapilheira, manipulação da fauna, aranhas, formigas
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