375 research outputs found

    Productionof poly(L-CO-D,L LacticAcid) porous fibers by electrospinning

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    The production of porous scaffolds has been widely investigated by the scientific community due to its suitability for tissue engineering. Among techniques that allow the fabrication of porous materials, electrospinning is appealing for being robust and versatile. This research investigated the pore formation in poly (L-co-D,L lactic acid) fibers obtained by conventional electrospinning and the influence of chloroform as a single solvent on fiber morphology. Random and highly porous fibers with a mean diameter of 2.373 ± 0.564 µm were collected. Chloroform affects the fiber morphology, mainly for its fast evaporation and low density of charges. The solvent on the surface evaporates quickly, and the low stretch of the jet does not help the polymer to reorganize over the length of the fiber, forming pores. In conclusion, the low dielectric constant and boiling point of chloroform induce pores formation along the PLDLA fibers.

    PRODUCTION OF MONOGLYCERIDES AND DIGLYCERIDES THROUGH LIPASE-CATALYZED GLYCEROLYSIS AND MOLECULAR DISTILLATION.

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    PRODUCTION OF MONOGLYCERIDES AND DIGLYCERIDES THROUGH LIPASE-CATALYZED GLYCEROLYSIS AND MOLECULAR DISTILLATION. Monoacilglycerides and diacilglycerides are produced through lipase-catalyzed glycerolysis of soybean oil using Candida antarctica B in a solvent-free system. The reaction was carried Out at a glycerol to triacylglycerol molar ratio of 8:1 with 2% of lipase. Acylglycerides, free fatty acids (FFA) and glycerol produced were separated employing the molecular distillation process. Starting from a product of enzymatic reaction 25.06% of triacylglycerols, 46.63% of diacylglycerides. 21.72% of monoacylglycerides, 5.38% of FFA and 1.21% of glycerol and after consecutively distillations. monoacylglycerides with 80% of purity was obtained and also oil with 54% of diacylglycerides to be used in human dietary.3261539154

    Development of a robust algorithm to compute reactive azeotropes

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    In this paper, a novel approach for establishing the route for process intensification through the application of two developed softwares to characterize reactive mixtures is presented. A robust algorithm was developed to build up reactive phase diagrams and to predict the existence and the location of reactive azeotropes. The proposed algorithm does not depend on initial estimates and is able to compute all reactive azeotropes present in the mixture. It also allows verifying if there are no azeotropes, which are the major troubles in this kind of programming. An additional software was developed in order to calculate reactive residue curve maps. Results obtained with the developed program were compared with-the. published in the literature for several mixtures, showing the efficiency and robustness of the developed softwares.23339540

    Clinicopathological features as prognostic predictors of poor outcome in papillary thyroid carcinoma

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    Papillary thyroid cancer (PTC) has an indolent nature and usually excellent prognosis. Some PTC clinicopathological features may contribute to the development of aggressive metastatic disease. In this work, we want to evaluate PTC clinicopathological features that are presurgical prognostic predictors of patients’ outcomes and find which indicators are more adequate for tailoring surgical procedures and follow-up. We studied a series of 241 PTC patients submitted to surgery. All patients’ files and histological tumor samples were reviewed. The 8th edition AJCC/UICC (American Joint Committee on Cancer/Union for International Cancer) Controlstaging system and the 2015 American Thyroid Association risk stratification system were used. Total thyroidectomy was performed in 228 patients, lymphadenectomy in 28 patients. Gross extrathyroidal extension (ETE) was present in 10 patients and 31 tumor resection margins were incomplete. Cervical lymph node metastases (LNMs) were present in 34 patients and distant metastases at diagnosis in four patients. In multivariate analysis, male gender (OR = 15.4, p = 0.015), venous invasion (OR = 16.7, p = 0.022), and lateral compartment LNM (OR = 26.7, p = 0.004) were predictors of mortality; psammoma bodies (PBs) (OR = 4.5, p = 0.008), lymph vessel invasion (OR = 6.9, p < 0.001), and gross ETE (OR = 16.1, p = 0.001) were predictors of structural disease status; male gender (OR = 2.9, p = 0.011), lymph vessel invasion (OR = 2.8, p = 0.006), and incomplete resection margins (OR = 4.6, p < 0.001) were predictors of recurrent/persistent disease. Our study supports that the factors helping to tailor patient’s surgery are male gender, presence of PBs, gross ETE, and lateral compartment LNM. Together with pathological factors, lymph vessel invasion, venous invasion, necrosis, and incomplete surgical resection, should be taken into consideration regarding treatment and follow-up of patients.This study was supported by FCT, the Portuguese Foundation for Science and Technology through a PhD grant to E.T. SFRH/BD/143458/2019. This work was financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020. Additional funding by the European Regional Development Fund (ERDF) through the Operational Programme for Competitiveness and Internationalization— COMPETE2020, and Portuguese national funds via FCT, under project POCI-01-0145-FEDER-016390: CANCEL STEM and from the FCT under the project POCI-01-0145-FEDER-031438: The other faces of telomerase: Looking beyond tumor immortalization (PDTC/MED_ONC/31438/2017). Additional funding through the Sociedade Portuguesa de Endocrinologia, Diabetes e Metabolismo-BOLSA SPEDM PARA PROJECTO DE INVESTIGAÇÃO-2017

    Limits on WWZ and WW\gamma couplings from p\bar{p}\to e\nu jj X events at \sqrt{s} = 1.8 TeV

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    We present limits on anomalous WWZ and WW-gamma couplings from a search for WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p -> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron Collider during the 1992-1995 run. The data sample corresponds to an integrated luminosity of 96.0+-5.1 pb^(-1). Assuming identical WWZ and WW-gamma coupling parameters, the 95% CL limits on the CP-conserving couplings are -0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also presented.Comment: 11 pages, 2 figures, 2 table
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