1,460 research outputs found

    Efficacy of different antifouling treatments for seawater cooling systems

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    In an industrial seawater cooling system, the effects of three different antifouling treatments, viz. sodium hypochlorite (NaClO), aliphatic amines (Mexel1432) and UV radiation, on the characteristics of the fouling formed were evaluated. For this study a portable pilot plant, as a side-stream monitoring system and seawater cooling system, was employed. The pilot plant simulated a power plant steam condenser, having four titanium tubes under different treatment patterns, where fouling progression could be monitored. The nature of the fouling obtained was chiefly inorganic, showing a clear dependence on the antifouling treatment employed. After 72 days the tubes under treatment showed a reduction in the heat transfer resistance (R) of around 70% for NaClO, 48% for aliphatic amines and 55% for UV, with respect to the untreated tube. The use of a logistic model was very useful for predicting the fouling progression and the maximum asymptotic value of the increment in the heat transfer resistance (DRmax). The apparent thermal conductivity (l) of the fouling layer showed a direct relationship with the percentage of organic matter in the collected fouling. The characteristics and mode of action of the different treatments used led to fouling with diverse physicochemical properties

    The action of obestatin in skeletal muscle repair: stem cell expansion, muscle growth, and microenvironment remodeling

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    The development of therapeutic strategies for skeletal muscle diseases, such as physical injuries and myopathies, depends on the knowledge of regulatory signals that control the myogenic process. The obestatin/GPR39 system operates as an autocrine signal in the regulation of skeletal myogenesis. Using a mouse model of skeletal muscle regeneration after injury and several cellular strategies, we explored the potential use of obestatin as a therapeutic agent for the treatment of trauma-induced muscle injuries. Our results evidenced that the overexpression of the preproghrelin, and thus obestatin, and GPR39 in skeletal muscle increased regeneration after muscle injury. More importantly, the intramuscular injection of obestatin significantly enhanced muscle regeneration by simulating satellite stem cell expansion as well as myofiber hypertrophy through a kinase hierarchy. Added to the myogenic action, the obestatin administration resulted in an increased expression of VEGF/VEGFR2 and the consequent microvascularization, with no effect on collagen deposition in skeletal muscle. Furthermore, the potential inhibition of myostatin during obestatin treatment might contribute to its myogenic action improving muscle growth and regeneration. Taken together, our data demonstrate successful improvement of muscle regeneration, indicating obestatin is a potential therapeutic agent for skeletal muscle injury and would benefit other myopathies related to muscle regeneration

    Boyeria Irene (Fonscolombe, 1838) y Cordulegaster Boltonii (Donovan, 1807) (Odonata): Dos estrategias en cuanto a sustratos de emergencia de larvas en un mismo hábitat.

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    Se presentan datos sobre emergencia de Cordulegaster boltonii y Boyeria irene en un río de montaña del centro de España (altitud 1200 m s.n.m.) donde coexisten ambas especies, basados en la recogida semanal de exuvias. Boyeria irene comenzó a emerger 28 días más tarde que C. boltonii. Los sustratos usados por las larvas de ambas especies para emerger se solaparon ampliamente, aunque C. boltonii utilizó significativamente más árboles. Con respecto a otras zonas geográficas, las dos especies han modificado su estrategia, retrasando el inicio del periodo de emergencia. Se discute la importancia de las condiciones ambientales (sobre todo temperatura) en este hecho

    Comparative effect of simulated solar light, UV, UV/H202 and photo-Fenton treatment (UV Vis/H2O2/Fe-2+,Fe-3+) in the Escherichia colt inactivation in artificial seawater

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    Innovative disinfection technologies are being studied for seawater, seeking a viable alternative to chlorination. This study proposes the use of H2O2/UV254 and photo-Fenton as disinfection treatment in seawater. The irradiations were carried out using a sunlight simulator (Suntest) and a cylindrical UV reactor. The efficiency of the treatment was compared for Milli-Q water, Leman Lake water and artificial seawater. The presence of bicarbonates and organic matter was investigated in order to evaluate possible effects on the photo-Fenton disinfection treatment. The photo-Fenton treatment, employing 1 mg L-1 Fe2+ and 10 mg L-1 of H2O2, led to the fastest bacterial inactivation kinetics. Using H2O2/UV254 high disinfection rates were obtained similar to those obtained with photo-Fenton under UV254 light. In Milli-Q water, the rate of inactivation for Escherichia coli was higher than in Leman Lake water and seawater due to the lack of inorganic ions affecting negatively bacteria inactivation. The presence of bicarbonate showed scavenging of the OH center dot radicals generated in the treatment of photo-Fenton and H2O2/UV254. Despite the negative effect of inorganic ions, especially HCOi, the disinfection treatments with AOPs in lake water and seawater improved significantly the disinfection compared to light alone (simulated sunlight and UV254). In the treatment of photo-Fenton with simulated sunlight, dissolved organic matter had a beneficial effect by increasing the rate of inactivation. This is associated with the formation of Fe3 -organo photosensitive complexes leading to the formation of ROS able to inactivate bacteria. This effect was not observed in the photoFenton with UV254 . Growth of E. coli surviving in seawater was observed 24 and 48 h after treatment with UV light. However, growth of surviving bacteria was not detected after photo-Fenton with UV254 and H2O2/UV254 treatments. This study suggests H2O2/UV254 and photo-Fenton treatments for the disinfection of seawater, in spite its high concentration of salts. (C) 2013 Elsevier Ltd. All rights reserved

    DNA methylation screening after roux-en Y gastric bypass reveals the epigenetic signature stems from genes related to the surgery per se

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    [Abstract] Background/objectives: Obesity has been associated with gene methylation regulation. Recent studies have shown that epigenetic signature plays a role in metabolic homeostasis after Roux-en Y gastric bypass (RYGB). To conduct a genome-wide epigenetic analysis in peripheral blood to investigate whether epigenetic changes following RYGB stem from weight loss or the surgical procedure per se. Subjects/methods: By means of the Infinium Human Methylation 450 BeadChip array, global methylation was analyzed in blood of 24 severely obese women before and 6 months after RYGB and in 24 normal-weight women (controls). Results: In blood cells, nine DMCpG sites showed low methylation levels before surgery, methylation levels increased after RYGB and neared the levels measured in the controls. Additionally, 44 CpG sites associated with the Wnt and p53 signaling pathways were always differently methylated in the severely obese patients as compared to the controls and were not influenced by RYGB. Finally, 1638 CpG sites related to inflammation, angiogenesis, and apoptosis presented distinct methylation in the post-surgery patients as compared to the controls. Conclusion: Bariatric surgery per se acts on CpGs related to inflammation, angiogenesis, and endothelin-signaling. However, the gene cluster associated with obesity remains unchanged, suggesting that weight loss 6 months after RYGB surgery cannot promote this effect.This study’s data collection, DNA and statistical analysis was supported by São Paulo Research Foundation (FAPESP) (grants #2017/07220–7, #2016/05638–1 and #2015/18669–0). Also, statistical and bioinformatics analysis was supported by “Centro de Investigacion Biomedica En Red” (CIBERobn) and grants (PI17/01287) from the “Instituto de Salud Carlos III” (ISCIII), Spain, co-financed by the European Regional Development Fund (FEDER), MINECO grants MTM2014–52876-R and MTM2017–82724-R, and by the Xunta de Galicia (Grupos de Referencia Competitiva ED431C-2016-015 and Centro Singular de Investigación de Galicia ED431G/01), all of them through the ERDF. A Diaz-Lagares is funded by a research contract “Juan Rodés” (JR17/00016) and Ana B Crujeiras is funded by a research contract “Miguel Servet” (CP17/00088) from the ISCIII, co-financed by the European Regional Development Fund (FEDER)Brasil. Fundação de Amparo à Pesquisa do Estado de São Paulo; #2017/07220–7Brasil. Fundação de Amparo à Pesquisa do Estado de São Paulo; #2016/05638–1Brasil. Fundação de Amparo à Pesquisa do Estado de São Paulo; #2015/18669–0Xunta de Galicia; ED431C-2016-015Xunta de Galicia; ED431G/0

    International Multicenter Validation Study of the SAGIT® Instrument in Acromegaly.

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    Abstract Context The SAGIT® instrument (SAGIT) has been developed to enable accurate characterization of acromegaly disease activity. Objective We evaluated the ability of SAGIT to discriminate acromegaly disease control status. Methods This multicenter, noninterventional, prospective and retrospective, longitudinal study, conducted at academic and private clinical practice sites, included patients aged ≥ 18 years with a diagnosis of controlled (n = 109) or non-controlled (n = 105) acromegaly, assessed by clinical global evaluation of disease control (CGE-DC) questionnaire, investigator therapeutic decision, and international guidelines. Control status was not determined at baseline for 13 patients. Since 9 patients were enrolled retrospectively, all presented analyses are based on the prospective population (N = 227). Patients were assessed over a 2-year follow-up period. Classification and regression tree (CART) analyses were performed to investigate how SAGIT components at baseline (signs/symptoms [S], associated comorbidities [A], growth hormone levels [G], insulin-like growth factor 1 levels [I], tumor features [T]) discriminate between controlled and non-controlled acromegaly. Results Baseline mean subscores S, G, I, and T were significantly lower in patients with CGE-DC controlled vs CGE-DC non-controlled acromegaly. SAGIT components I and G for CGE-DC and S, A, G, I, and T for the clinician's therapeutic decision were retained by CART analyses. For international guidelines, only SAGIT component I was retained. The risk for undergoing ≥ 1 treatment change during the study was 3.44 times greater for CGE-DC non-controlled acromegaly relative to CGE-DC controlled acromegaly. Conclusion The SAGIT instrument is a valid and sensitive tool to comprehensively and accurately assess acromegaly severity
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