298 research outputs found

    Spatial-temporal variation in Greenland shark (Somniosus microcephalus) bycatch in the NAFO Regulatory Area

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    Spatial and temporal variation in Greenland shark (Somniosus microcephalus) bycatch occurrence was investigated using At-Sea Fisheries Observer data and MaxEnt, a maximum entropy species distribution model. Within the Northwest Atlantic Fisheries Organization Regulatory Area (NRA), the Flemish Pass, the slopes of the Flemish cap, and the shelf edge of Divisions 3NO contained areas of suitable habitat where Greenland shark bycatch is expected to occur. However, it should be noted that there are major areas of Greenland shark bycatch outside the NRA, in the Canadian and Greenland Exclusive Economic Zones (EEZ).En prens

    Adipates as new phase change material: seeking for a low temperature energy storage system

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    The recent and endless increasing need for energy is requiring imperative and efficient solutions. Renewable energies are an effective solution, but they are also intermittent, which often leads to a gap between the availability of energy and its demand. Therefore, energy storage becomes crucial for improving the efficiency by reducing the mismatch between demand and supply thus offering better management capabilities. The use of phase change materials (PCMs) became an attractive technology, especially for active cooling systems. In particular, eutectic systems can be designed for each application, allowing significant energy savings, which is very relevant in what concerns economic and environmental sustainability [1]. Equilibrium studies and their phase diagrams are crucial to characterize the behavior of these systems, particularly for new PCMs [2]. This work aims the characterization of a selected type of binary system composed by di-n-alkyl adipates that can be used for energy storage at low temperatures, starting by the construction of solid-liquid phase diagram based on Differential Scanning Calorimetry (DSC) and Raman Spectroscopy results. The studied system is a binary mixture of diethyl and dibutyl adipates and reveals to behave as a eutectic system at low temperatures, possessing also polymorphism, therefore presenting a relatively complex phase diagram. The eutectic point was found around -33ºC and the polymorphism transition, being characteristic of the dibutyl adipate, occurs at around -36ºC for the overall phase diagram. Raman spectroscopy was fundamental concerning the construction of the phase diagram, enabling to identify the different solid and liquid phases of the system. This work provides new phase equilibrium data, which, to the knowledge of the authors, are the first in the literature, concerning these compounds. The studied binary system has promising characteristics for low temperature energy storage. It is also demonstrated how solid-liquid-phase equilibrium studies are the key to select the most appropriate phase change material for a specific thermal energy storage (TES) application.N/

    Di-Alkyl adipates as new phase change material for low temperature energy storage

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    This work is a contribution to the thermal characterization of a selected binary system of two di-n-alkyl adipates that can be used as phase change material for thermal energy storage at low temperatures. The construction of the solid–liquid phase diagram using differential scanning calorimetry (DSC), complemented with Raman Spectroscopy studies for the system composed by diethyl and dibutyl adipates is presented. The solidus and liquidus equilibrium temperatures were determined by DSC for the pure components and 30 binary mixtures at selected molar compositions were used to construct the corresponding solid–liquid phase diagram. The binary system of diethyl and dibutyl adipates presents eutectic behaviour at low temperatures. The eutectic temperature was found at 240.46 K, and the eutectic composition was determined to occur at the molar fraction xdibutyl = 0.46. Additionally, the system shows a polymorphic transition, characteristic of dibutyl adipate, occurring at ca. 238 K, confirmed by optical microscopy. To the best of our knowledge, no reference to the phase diagram of the present system could be found in the literature. Raman spectroscopy was essential to complement the construction of the phase equilibrium diagram, enabling the identification of the solid and liquid phases of the system. Finally, the liquidus curve of the phase diagram was also successfully predicted using a suitable fitting equation, being the root mean square deviation of the data from the correlation equal to 0.54 K. In addition, this fitting operation enabled a correct prediction of the eutectic composition of the system.info:eu-repo/semantics/publishedVersio

    Solid-liquid phase equilibrium: alkane systems for low temperature energy storage

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    The incessant and increasing need for energy requires urgent and effective solutions. The supply of renewable energies is mainly intermittent, which often leads to a gap between the availability of energy and its consumption. Therefore, energy storage becomes imperative for increasing the efficiency in the use of the produced energy. Concerning this, the use of phase change materials (PCMs) has taken a very important role, especially for active cooling systems. In particular, eutectic systems can be designed with characteristics that make them suitable for each application, allowing significant energy savings, which is very relevant in what concerns economic and environmental sustainability [1]. This work aims to the characterization of selected systems that can be used for energy storage at low temperatures, starting by the construction of solid-liquid phase diagrams using differential scanning calorimetry (DSC) and Raman Spectroscopy results. Phase diagrams are crucial to characterize the behaviour of these systems and reveals the robustness of the PCM, and for new PCMs, equilibrium studies are essential to achieve the desired melting temperature [2]. This work is focused on binary systems composed by normal alkanes, in particular, the binary mixtures C8-C10 and C10-C12. These systems revealed to behave as eutectic systems at low temperatures, showing a promising applicability for thermal energy storage for low temperature applications. The eutectic points are around -61ºC and -35ºC, respectively. Additionally, a fitting equation for the experimental liquidus lines of the phase equilibrium diagrams is proposed for each system.N/

    Metilfenidato: influência da notificação de receita A (cor amarela) sobre a prática de prescrição por médicos brasileiros

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    Oitocentos e noventa e dois médicos, entre eles neurologistas (463) e psiquiatras (411), responderam a um questionário sobre a prescrição do metilfenidato para o transtorno do déficit de atenção e hiperatividade (TDAH). A maioria dos médicos relatou a ocorrência esporádica de reações adversas não-sérias, tais como dor de cabeça, emagrecimento, inapetência, hiperexcitabilidade, taquicardia, etc; apenas seis médicos, entretanto, relataram casos que poderiam levar à suspeita de dependência, embora nenhum deles satisfizesse os critérios da CID-10 para tal. A grande maioria opinou que a exigência da notificação de receita A (amarela) é inadequada, criando preconceitos em relação à condição dos pacientes e amedrontando seus parentes. Relatam ainda que tal classificação dificulta a prescrição do medicamento, fazendo muitas vezes com que o metilfenidato se torne a segunda opção para o tratamento de TDAH, além de tornar o produto pouco disponível nas farmácias e dificultar o trabalho dos profissionais. Isso faz com que a adesão ao tratamento se torne mais difícil, pois, além dos vários entraves burocráticos para se adquirir o medicamento, há também o medo por parte dos familiares e do próprio paciente de estar tomando tal medicação. Neurologistas e psiquiatras argumentam que o controle do metilfenidato deve existir, mas, em se tratando de um medicamento prescrito por especialistas e de não possuir grande potencial de dependência, o receituário azul já seria suficiente para o controle adequado. A classificação do metilfenidato, juntamente com as anfetaminas e com o princípio ativo da maconha (dronabinol), é uma outra questão levantada, sendo tal fato para grande parte dos profissionais uma total incoerência.Four hundred and sixty three brazilian neurologists and 411 brazilian psychiatrists answered a questionnaire aimed at to obtain information on the prescription of methylphenidate for the treatment of the Attention Deficit and Hyperactivity Disorder. The majority of the doctors reported the erratic occurrence of a few non serious adverse reactions such as headache, weight loss, inapetence, hyperexcitability and tachycardia. On the other hand, only six doctors reported cases that cold raise a suspicion of drug dependence, although none of these six cases satisfied the ICD-10 criteria for dependence. The vast majority of the medical doctors manifested the opinion that the especial prescriptions the "Notifications A" of yellow color, the same used for opiates also, as demanded by the Brazilian Health Authorities, is inadequate as it raises misconceptions in relation to the real patient disease and frightens the parents and relatives. The doctors also claimed the such especial prescription form encumbers the prescription of the medicament making methylphenidate the second choice for the treatment and, for this reason, less available in pharmacies and drugstores. As a consequence the adherence to the treatment is more difficult to attain. The neurologists and psychiatrists agree that a certain control over methylphenidate is necessary, but as it is prescribed mostly by specialists and does not possess an evident abuse potential, the "Prescription Notification B", of blue color, would be enough for efficient control. In fact, according to the doctors, the scheduling in Brazil of methylphenidate in the same list as the amphetamines and dronabinol (the active principle of Cannabis sativa) should be reviewed

    Peginterferon plus ribavirin and sustained virological response rate in HCV-related advanced fibrosis: a real life study

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    Background: Tolerance and response to antiviral HCV treatment is poor in advanced fibrosis. The aim of this study was to assess SVR rate and its predictive factors in HCV advanced fibrosis patients treated in real life with full dose PEG-IFN plus RBV and to evaluate the adverse events related to treatment. Methods: A multicentric, retrospective study was conducted at six university hospitals. METAVIR F3 and F4 HCV monoinfected patients who were treated with PEG-IFN and RBV had their data analyzed. A stepwise logistic regression analysis was performed to identify the variables independently related to SVR. Adverse events were recorded during treatment. Results: 308 patients were included, 75% genotype 1 and 23% genotype 3. METAVIR F3 was present in 39% and F4 in 61% of patients. The median Child Pugh score for F4 patients was 5 (5–9). The global SVR rate was 34%, 11% were relapsers and 55% were nonresponders. SVR rates were similar between patients treated with PEG-IFN alfa 2a or alfa 2b (p = 0.24). SVR rates according to Child–Pugh score were 26% (Child A) and 18% (Child B). The independent factors related to SVR in F4 patients were genotype 3, RVR and fewer Child Pugh score points. Treatment interruption occurred in 31% patients and death occurred in 1.9%, all with liver cirrhosis. Conclusion: Treatment of HCV in patients with advanced fibrosis should not be postponed. However, a very careful evaluation of cirrhotic patients must be performed before treatment is indicated and careful monitoring is required during treatment.Universidade Estadual Paulista (UNESP) Botucatu School of MedicineUniversidade Federal do Rio de JaneiroUniversidade Estadual de CampinasUniversidade Federal de São Paulo (UNIFESP)Pontificia Universidade Catolica de São PauloUNIFESPSciEL

    Actinomycosis of the central nervous system: a rare complication of cervicofacial actinomycosis

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    Central nervous system actinomycosis is a rare but treatable chronic suppurative bacterial infection. The case of a young immunocompetent male with actinomycosis of the CNS is presented. The abscess originated from a primary cervico-facial infection and was located in the left parasellar region. After excision of the mass, that showed Actinomyces colonies, the patient was treated with intravenous Penicillin for 42 days followed by oral administration of the drug for 30 days. After surgery the patient was left with mild sequelae that had improved by the last follow-up, 7 months later. A new CT scan at that time revealed no residual disease or recurrence. The early diagnosis of cerebral actinomycosis relies essentially on a clinical suspicion. Hence it is imperative to be aware of the natural history of this infection and its various modes of presentation.A actinomicose do sistema nervoso central (SNC) é afecção rara, caracterizada pela formação de abscesso único e de evolução crônica. Os autores descrevem o caso de um paciente jovem, imunocompetente, com actinomicose cerebral oriunda de foco primário cervicofacial, submetido a ressecção cirúrgica e antibioticoterapia. Ressalta-se a importância do conhecimento da entidade e de suas principais formas de acometimento, como a base do diagnóstico precoce dessa enfermidade potencialmente curável e de bom prognóstico.Escola Paulista de MedicinaUNIFESP, EPMSciEL

    Tricritical Points in the Sherrington-Kirkpatrick Model in the Presence of Discrete Random Fields

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    The infinite-range-interaction Ising spin glass is considered in the presence of an external random magnetic field following a trimodal (three-peak) distribution. The model is studied through the replica method and phase diagrams are obtained within the replica-symmetry approximation. It is shown that the border of the ferromagnetic phase may present first-order phase transitions, as well as tricritical points at finite temperatures. Analogous to what happens for the Ising ferromagnet under a trimodal random field, it is verified that the first-order phase transitions are directly related to the dilution in the fields (represented by p0p_{0}). The ferromagnetic boundary at zero temperature also exhibits an interesting behavior: for 0<p0<p0∗≈0.308560<p_{0}<p_{0}^{*} \approx 0.30856, a single tricritical point occurs, whereas if p0>p0∗p_{0}>p_{0}^{*} the critical frontier is completely continuous; however, for p0=p0∗p_{0}=p_{0}^{*}, a fourth-order critical point appears. The stability analysis of the replica-symmetric solution is performed and the regions of validity of such a solution are identified; in particular, the Almeida-Thouless line in the plane field versus temperature is shown to depend on the weight p0p_{0}.Comment: 23pages, 7 ps figure
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