53 research outputs found
Cell membrane damage induced by phenolic acids on wine lactic acid bacteria
The aim of this work was to investigate the effect of phenolic acids on cell membrane permeability of
lactic acid bacteria from wine. Several phenolic acids were tested for their effects on the cell membrane of
Oenococcus oeni and Lactobacillus hilgardii by measuring potassium and phosphate efflux, proton influx and
by assessing culture viability employing a fluorescence technique based on membrane integrity. The
experimental results indicate that hydroxycinnamic acids (p-coumaric, caffeic and ferulic acids) induce
greater ion leakages and higher proton influx than hydroxybenzoic acids (p-hydroxibenzoic, protocatechuic,
gallic, vanillic, and syringic acids). Among the hydroxycinnamic acids, p-coumaric acid showed the strongest
effect. Moreover, the exposure of cells to phenolic acids caused a significant decrease in cell culture viability,
as measured by the fluorescence assay, in both tested strains. The results agree with previous results
obtained in growth experiments with the same strains. Generally, phenolic acids increased the cell
membrane permeability in lactic acid bacteria from wine. The different effects of phenolic acids on
membrane permeability could be related to differences in their structure and lipophilic character
Surveillance for pancreatic cancer in high-risk individuals
Background: Surveillance of individuals at high risk of pancreatic ductal adenocarcinoma (PDAC) and its
precursors might lead to better outcomes. The aim of this study was to determine the prevalence
and outcomes of PDAC and high-risk neoplastic precursor lesions among such patients participating
in surveillance programmes.
Methods: A multicentre study was conducted through the International CAncer of the Pancreas Screening (CAPS) Consortium Registry to identify high-risk individuals who had undergone pancreatic resection or progressed to advanced PDAC while under surveillance. High-risk neoplastic precursor lesions
were defined as: pancreatic intraepithelial neoplasia (PanIN) 3, intraductal papillary mucinous neoplasia
(IPMN) with high-grade dysplasia, and pancreatic neuroendocrine tumours at least 2 cm in diameter.
Results: Of 76 high-risk individuals identified in 11 surveillance programmes, 71 had undergone surgery
and five had been diagnosed with inoperable PDAC. Of the 71 patients who underwent resection, 32
(45 per cent) had PDAC or a high-risk precursor (19 PDAC, 4 main-duct IPMN, 4 branch-duct IPMN,
5 PanIN-3); the other 39 patients had lesions thought to be associated with a lower risk of neoplastic
progression. Age at least 65 years, female sex, carriage of a gene mutation and location of a lesion in the
head/uncinate region were associated with high-risk precursor lesions or PDAC. The survival of high-risk
individuals with low-risk neoplastic lesions did not differ from that in those with high-risk precursor
lesions. Survival was worse among patients with PDAC. There was no surgery-related mortality.
Conclusion: A high proportion of high-risk individuals who had surgical resection for screening- or
surveillance-detected pancreatic lesions had a high-risk neoplastic precursor lesion or PDAC
Correction: Ocádiz Flores et al. Thermodynamic Description of the ACl-ThCl4 (A = Li, Na, K) Systems
Corrected excess Gibbs energies of the liquid solutions in the ACl-ThCl4 (A = Li, Na, K), as well as revised standard enthalpies of formation and standard entropies of the intermediate phases occurring in the binary systems, are presented. The phase diagrams are reproduced to a similar level of accuracy as in the original publication, and the trends in thermodynamic stability of the liquid solutions are maintained. That is, the main conclusions of the paper are not affected. The original publication has also been update
Thermodynamic Description of the ACl-ThCl4 (A = Li, Na, K) Systems
The ACl-ThCl4 (A = Li, Na, K) systems could be of relevance to the nuclear industry in the near future. A thermodynamic investigation of the three binary systems is presented herein. The excess Gibbs energy of the liquid solutions is described using the quasi-chemical formalism in the quadruplet approximation. The phase diagram optimisations are based on the experimental data available in the literature. The thermodynamic stability of the liquid solutions increases in the orderLi ă Na ă K, in agreement with idealised interactions and structural model
Using the Quasi-chemical formalism beyond the phase Diagram: Density and viscosity models for molten salt fuel systems
CALPHAD models to compute the density and viscosity of four keystone systems related to Molten Salt Reactor (MSR) technology have been optimized: NaCl-UCl3, LiF-ThF4, LiF-UF4, and LiF-ThF4-UF4. Revised thermodynamic assessments of all four systems, using the modified quasichemical formalism in the quadruplet approximation for the description of the liquid solutions, are reported. In the case of NaCl-UCl3, phase diagram and mixing enthalpy data available in the literature are taken into account. For the fluoride systems, recently published data on some solid phases are taken into account, while retaining the most recently published descriptions of the liquid solutions. The densities of the liquid solutions are modelled using pressure-dependent terms of the excess Gibbs energy, while the viscosities are then modelled using an Eyring equation. Both state functions are related to the thermodynamic assessments through the quadruplet distributions.RST/Reactor Physics and Nuclear Material
A promising fuel for fast neutron spectrum Molten Salt Reactor: NaCl-ThCl<sub>4</sub>-PuCl<sub>3</sub>
Chloride salts are considered a good alternative to fluoride salts as fuel carrier in the Molten Salt Fast Reactor concepts. The NaCl–ThCl4–PuCl3 fuel salt solution seems very promising, with low melting temperature eutectic compositions, and the potential to be used in a breeder and burner type of reactor design. This work focuses on the first thermodynamic modeling assessment of the ThCl4–PuCl3 binary system and the NaCl–ThCl4–PuCl3 ternary system, using the CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) method and the quasichemical formalism in the quadruplet approximation. The investigated system shows potential for a high flexibility with respect to composition at operating temperatures, which can be beneficial to accommodate the requirements on other essential fuel properties (e.g. neutronic and thermo-hydraulic).RST/Reactor Physics and Nuclear Material
Thermodynamic Description of the ACl-ThCl4 (A = Li, Na, K) Systems
The ACl-ThCl4 (A = Li, Na, K) systems could be of relevance to the nuclear industry in the near future. A thermodynamic investigation of the three binary systems is presented herein. The excess Gibbs energy of the liquid solutions is described using the quasi-chemical formalism in the quadruplet approximation. The phase diagram optimisations are based on the experimental data available in the literature. The thermodynamic stability of the liquid solutions increases in the orderLi ă Na ă K, in agreement with idealised interactions and structural modelsRST/Reactor Physics and Nuclear Material
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