439 research outputs found
An unusual presentation of an uncommon disease
Extrapulmonary manifestations of sarcoidosis often go undiagnozed. Sarcoidosis should be considered in the differential diagnosis of cases presenting with parotid gland swelling, renal failure, and hypercalcemia. It’s imperative to confirm the diagnosis with a tissue biopsy, as the condition is easily treatable with steroids
Pleiotropic effects of the HMG-CoA reductase inhibitors
The HMG-CoA reductase inhibitors (statins) are used extensively in the treatment of hyperlipidemia. They have also demonstrated a benefit in a variety of other disease processes. These secondary actions are known as pleiotropic effects. Our paper serves as a focused and updated discussion on the pleiotropy of statins and emphasizes the importance of randomized placebo-controlled trials to further elucidate this interesting phenomenon
Catch variability and growth of pink shrimp (Farfantepenaeus paulensis) in two coastal lagoons of uruguay and their relationship with ENSO events
The pink shrimp Farfantepenaeus paulensis (Pérez Farfante, 1967) is distributed along the Atlantic Coast from Bahia (Brazil) to Mar del Plata (Argentina). The larval stages enter the Uruguayan brackish water lagoons during late spring to summer associated with tidal currents of the Brazilian Current. In such environments the growth is accelerated and in early autumn the individuals attain commercial size, supporting important regional artisanal fisheries. The pink shrimp catches from 1988 to 2013 were analyzed and related to phenomena of climate variability in ENSO events and to the growth of the species. The total catch ranges from 0.7 to 162 tons. The variation in catches has a negative relationship with the varied climatic events caused by El Niño. Growth parameters yielding values of L ∞ = 177 mm (total carapace length) and K = 1.48 for the period 2009-2013. These values differ slightly from those calculated for natural populations in southern Brazil, suggesting that the population is the same and thus implying the need for coordinated fisheries management between the two countries.O camarão rosa Farfantepenaeus paulensis (Pérez Farfante, 1967) distribui-se ao longo da costa atlântica do Brasil (Bahia) até a Argentina (Mar del Plata). Os estágios larvais entram na primavera-verão nas lagoas salobras do Uruguai associados com correntes de maré, onde a água dominante é da Corrente do Brasil. Nesses ambientes, o crescimento é acelerado e no início do outono geralmente atinge o tamanho comercial, apoiando importantes pescarias regionais. A captura de camarão foi analisada nas lagoas costeiras uruguaias entre 1988 e 2013 e relacionadas com os fenômenos da variabilidade climática em eventos ENSO e com elementos da dinâmica populacional da espécie. A captura total variou entre 0,7 e 162 ton. A variação das capturas apresentou relação negativa com os eventos de variabilidade climática causados pelo El Niño. Os parâmetros de crescimento analisados originaram valores de L ∞ = 177 mm (comprimento total) e K = 1,48 no período 2009 -2013. Esses valores sãoligeiramente diferentes dos calculados para populações naturais no sul do Brasil, o que sugeriria a existência de uma mesma população, implicando na necessidade de coordenação pesqueira entre os dois países
Fractura de mezclas de policarbonato con acrilonitrilo-butadieno-estireno
Postprint (published version
Multifunctional enzymatically generated hydrogels for chronic wound application
The healing of chronic wounds requires intensive medical intervention at huge healthcare costs. Dressing materials should consider the multifactorial nature of these wounds comprising deleterious proteolytic and oxidative enzymes and high bacterial load. In this work, multifunctional hydrogels for chronic wound application were produced by enzymatic cross- linking of thiolated chitosan and gallic acid. The hydrogels combine several beneficial to wound healing properties, controlling the matrix metalloproteinases (MMPs) and myeloperoxidase (MPO) activities, oxidative stress, and bacterial contamination. In vitro studies revealed above 90% antioxidant activity, and MPO and collagenase inhibition by up to 98 and 23%, respectively. Ex vivo studies with venous leg ulcer exudates confirmed the inhibitory capacity of the dressings against MPO and MMPs. Additionally, the hydrogels reduced the population of the most frequently encountered in nonhealing wounds bacterial strains. The stable at physiological conditions and resistant to lysozyme degradation hydrogels showed high biocompatibility with human skin fibroblastsPeer ReviewedPostprint (author's final draft
Kinetics of the thermal degradation of poly(Lactic acid) and polyamide bioblends
Poly(lactic acid) (PLA) and biosourced polyamide (PA) bioblends, with a variable PA weight content of 10–50%, were prepared by melt blending in order to overcome the high brittleness of PLA. During processing, the properties of the melt were stabilized and enhanced by the addition of a styrene-acrylic multi-functional-epoxide oligomeric reactive agent (SAmfE). The general analytical equation (GAE) was used to evaluate the kinetic parameters of the thermal degradation of PLA within bioblends. Various empirical and theoretical solid-state mechanisms were tested to find the best kinetic model. In order to study the effect of PA on the PLA matrix, only the first stage of the thermal degradation was taken into consideration in the kinetic analysis (a < 0.4). On the other hand, standardized conversion functions were evaluated. Given that it is not easy to visualize the best accordance between experimental and theoretical values of standardized conversion functions, an index, based on the integral mean error, was evaluated to quantitatively support our findings relative to the best reaction mechanism. It was demonstrated that the most probable mechanism for the thermal degradation of PLA is the random scission of macromolecular chains. Moreover, y(a) master plots, which are independent of activation energy values, were used to confirm that the selected reaction mechanism was the most adequate. Activation energy values were calculated as a function of PA content. Moreover, the onset thermal stability of PLA was also determined.Peer ReviewedPostprint (published version
The characteristics of stress cardiomyopathy in an ethnically heterogeneous population
OBJECTIVES: Stress cardiomyopathy is a cardiac syndrome that is characterized by transient left ventricular systolic dysfunction in the absence of obstructive coronary artery disease. Its epidemiology has been described in homogeneous Asian, Caucasian and Black populations, but its characteristics in heterogeneous populations are poorly understood. Our aim was to assess the characteristics of stress cardiomyopathy in a heterogeneous population that included a large percentage of Hispanics. METHODS: We reviewed 59 consecutive cases of stress cardiomyopathy that were confirmed by coronary angiography and were in agreement with the Mayo Clinic diagnostic criteria. RESULTS: The mean age of the patients was 74 years (range, 39-91 years), and 37 patients were female (62.7%). Twenty-nine patients (49.2%) were Latino/Hispanic, 26 (44%) were Caucasian, 3 (5%) were Asian, and 1 patient (1.7%) was Black. The most common chief symptom was dyspnea, followed by chest pain and an absence of symptoms in 54.2, 28.8, and 18.6% of the patients, respectively. The primary EKG abnormalities consisted of a T wave inversion, an ST segment elevation, and ST segment depression in 69.5%, 25.4%, and 15.3% of the patients, respectively. The stressor event was identified in 90% of the cases. In 32 cases (54%), the stressor event was physical stress or a medical illness, and in 21 cases (35.6%), the stressor event was emotional stress. The in-hospital mortality rate was 8.5%. CONCLUSIONS: In our heterogeneous study population, stress cardiomyopathy presented with a 3:2 female-to-male ratio, and dyspnea was the most common chief complaint. Stress cardiomyopathy exhibited a T wave inversion as the primary EKG abnormality. These findings differ from previous cases that have been reported, and further studies are needed
Effect of the viscosity ratio on the PLA/PA10.10 bioblends morphology and mechanical properties
PLA bio-blends with a predominantly biosourced PA10.10 in the composition range 10-50wt.% were prepared by melt blending in order to overcome the advanced brittleness of PLA. Due to the inherent immiscibility of the blends, 30 wt.% of PA was needed to achieve a brittle-to-ductile transition and a co-continuous morphology was predicted at 58 wt.% of PA. The initial enhancement of the PLA rheological behaviour through the environmentally friendly reactive extrusion process yielded a finer and more homogeneous microstructure and hence enhanced the mechanical properties of the bio-blends at much lower PA contents. The brittle-to-ductile transition could be achieved with only 10 wt.% and co-continuity was observed already at 44 wt.% of PA. Results indicate the significant potential of modifying PLA flow behaviour as a promising green manufacturing method toward expanding PLA-based bio-blends applications.Peer ReviewedPostprint (published version
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