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101.
Eric A. Decker Jean Alamed Inar A. Castro 《Journal of the American Oil Chemists' Society》2010,87(7):771-780
Minor components (polar components) and the degree of unsaturation of the fatty acids are the main factors responsible for
the oxidative stability of bulk oils and emulsions. The isolated effects of these two factors and their interaction were evaluated
in oil–in-water emulsions stored at 32 °C. Samples of coconut, olive, soybean, linseed and fish oils, both full and stripped
of their polar components, were used to prepare the emulsions (1% w/w). The maximum concentration of hydroperoxide (LOOHmax) and the rate of formation of hydroperoxides (μmol L−1 h−1) were used to measure the primary products. Hexanal, propanal and malondialdehyde were used to determine the secondary products
of the oxidized emulsions containing polyunsaturated fatty acids. LOOHmax varied from 0.16 to 12.75 mmol/kg among the samples. The interaction between the polar components and the degree of unsaturation
of the fatty acids was significant (p < 0.001) when the hydroperoxides were evaluated. In general, the degree of unsaturation (β1) and the absence of polar components (β2), respectively, represented 30 and 20% of the contribution to increase the mean oxidation, with the interaction (β12) contribution being more sensitive to the rate of formation of hydroperoxides (16%) than to the LOOHmax (5%). The significance of this interaction suggests that both strategies present synergism and should be applied to improve
the oxidative stability of food emulsions. 相似文献
102.
L.E. Murr E. Martinez X.M. Pan S.M. Gaytan J.A. Castro C.A. Terrazas F. Medina R.B. Wicker D.H. Abbott 《Acta Materialia》2013,61(11):4289-4296
Rene 142, a commercial, columnar grained, gas turbine airfoil Ni-based superalloy, has been fabricated from a pre-alloyed, atomized powder by additive manufacturing using electron beam melting. Monolithic components having [0 0 1] oriented, columnar grain structures exhibited a creep-optimized 59% volume fraction of cuboidal, coherent, γ′-phase precipitates averaging 275 nm on the side, and with γ/γ′ channel widths ranging from 25 to 75 nm. Transmission electron microscopy, utilizing bright and dark field imaging of optimally oriented γ/γ′ interfaces showed prominent misfit coherency strains as δ-fringe patterns. Corresponding hardness measurements also indicated the possibility of creep strength comparable with the commercial alloy. The notable feature of this study was the monolithic development of desirable superalloy properties without conventional, multi-step heat treatments. 相似文献
103.
The corrosion behaviour of electrodeposited Zn, Zn-Co, Zn-Fe and Zn-Ni coatings without and with Chromate films was studied in alkaline solutions and mortar probes. DC polarization measurements were used for electrochemical characterization of the investigated samples, while AES XPS techniques were applied for the Chromate film analysis. The stability of the anodically formed oxide films on unchromated coatings appeared to be dependent on their composition. The oxide layer stability in Cl free NaOH solution was higher for Zn-Ni and Zn-Co alloys, while introduction of Cl ions caused lowering of stability especially for Zn-Ni coating. The detected corrosion current values implied that unchromated Zn alloys did not possess higher corrosion resistance in alkaline media containing Cl ions. Meanwhile, chromated Zn-Co coatings exhibited the beneficial effect of alloying for corrosion in alkaline solutions and concrete. A higher concentration of Cr(Vl) compounds in the passive Chromate layer of the alloyed sample may be the reason for its superior corrosion resistance. 相似文献
104.
Raquel Cano Jos L. Prez Liss Angarita Dvila ngel Ortega Yosselin Gmez Nereida Josefina Valero-Cedeo Heliana Parra Alexander Manzano Teresa Isabel Vliz Castro María P. Díaz Albornoz Gabriel Cano Joselyn Rojas-Quintero Maricarmen Chacín Valmore Bermúdez 《International journal of molecular sciences》2021,22(9)
Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver disorder, affecting around 25% of the population worldwide. It is a complex disease spectrum, closely linked with other conditions such as obesity, insulin resistance, type 2 diabetes mellitus, and metabolic syndrome, which may increase liver-related mortality. In light of this, numerous efforts have been carried out in recent years in order to clarify its pathogenesis and create new prevention strategies. Currently, the essential role of environmental pollutants in NAFLD development is recognized. Particularly, endocrine-disrupting chemicals (EDCs) have a notable influence. EDCs can be classified as natural (phytoestrogens, genistein, and coumestrol) or synthetic, and the latter ones can be further subdivided into industrial (dioxins, polychlorinated biphenyls, and alkylphenols), agricultural (pesticides, insecticides, herbicides, and fungicides), residential (phthalates, polybrominated biphenyls, and bisphenol A), and pharmaceutical (parabens). Several experimental models have proposed a mechanism involving this group of substances with the disruption of hepatic metabolism, which promotes NAFLD. These include an imbalance between lipid influx/efflux in the liver, mitochondrial dysfunction, liver inflammation, and epigenetic reprogramming. It can be concluded that exposure to EDCs might play a crucial role in NAFLD initiation and evolution. However, further investigations supporting these effects in humans are required. 相似文献
105.
Ricardo I. Castro Ana Gonzlez-Feliu Marcelo Muoz-Vera Felipe Valenzuela-Riffo Carolina Parra-Palma Luis Morales-Quintana 《International journal of molecular sciences》2021,22(12)
The role of auxin in the fruit-ripening process during the early developmental stages of commercial strawberry fruits (Fragaria x ananassa) has been previously described, with auxin production occurring in achenes and moving to the receptacle. Additionally, fruit softening is a consequence of the depolymerization and solubilization of cell wall components produced by the action of a group of proteins and enzymes. The aim of this study was to compare the effect of exogenous auxin treatment on the physiological properties of the cell wall-associated polysaccharide contents of strawberry fruits. We combined thermogravimetric (TG) analysis with analyses of the mRNA abundance, enzymatic activity, and physiological characteristics related to the cell wall. The samples did not show a change in fruit firmness at 48 h post-treatment; by contrast, we showed changes in the cell wall stability based on TG and differential thermogravimetric (DTG) analysis curves. Less degradation of the cell wall polymers was observed after auxin treatment at 48 h post-treatment. The results of our study indicate that auxin treatment delays the cell wall disassembly process in strawberries. 相似文献
106.
Wright Kathleen M.; Cabrera Oscar A.; Bliese Paul D.; Adler Amy B.; Hoge Charles W.; Castro Carl A. 《Canadian Metallurgical Quarterly》2009,6(2):108
The present study examined the effects of leadership and unit cohesion on mental health stigma and perceived barriers to care. A sample of 680 soldiers from combat support units were surveyed 3 months after their return from combat operations in Iraq. The survey included scales on psychological symptoms and perceptions of leader behaviors and unit cohesion, as well as items assessing stigma and barriers to care. The sample was used to test the independent and interactive effects of leadership and unit cohesion on soldiers’ perceptions of stigma and barriers to care. Analyses yielded significant interaction effects between leadership and cohesion in predicting stigma and barriers to care, while controlling for the effects of mental health symptoms. Soldiers who rated their leaders more highly and who reported higher unit cohesion also reported lower scores on both stigma and perceived barriers to care. Thus, positive leadership and unit cohesion can reduce perceptions of stigma and barriers to care, even after accounting for the relationship between mental health symptoms and these outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
107.
Javier S. Castro Bartosz Trzaskowski Pierre A. Deymier Jaim Bucay Ludwik Adamowicz James B. Hoying 《Materials science & engineering. C, Materials for biological applications》2009,29(5):1609-1615
The ability of Taxol (paclitaxel) to bind and stabilize microtubules is the basis for its use as an anti-mitotic drug as well as an additive for in vivo and in vitro studies of microtubules. The low solubility of Taxol in aqueous solutions, however, facilitates the formation of Taxol crystals that can be decorated with fluorescent tubulin. In cells treated with Taxol, these decorated Taxol crystals may be mistaken for self-assembled tubulin asters when observed with a fluorescent microscope. We confirmed via fluorescent and differential interference contrast microscopy that Taxol crystals can be decorated not only with fluorescent tubulin but also with other fluorescent proteins and fluorochromes without perturbing their morphology. We used theoretical calculations to further investigate Taxol-fluorescent agent interactions. Using computational docking studies we identified a new, potential Taxol binding site within the tubulin dimmer, allowing the interaction between crystalline Taxol and tubulin. Our calculations, however, show that fluorescent tubulin binding to Taxol crystals is more favorable via the fluorochromes covalently linked to the tubulin dimmers, rather than via the new Taxol-binding site, what is in accordance with our experimental data. 相似文献
108.
Adler Amy B.; Bliese Paul D.; McGurk Dennis; Hoge Charles W.; Castro Carl Andrew 《Canadian Metallurgical Quarterly》2009,77(5):928
Researchers have found that there is an increase in mental heath problems as a result of military-related traumatic events, and such problems increase in the months following return from combat. Nevertheless, researchers have not assessed the impact of early intervention efforts with this at-risk population. In the present study, the authors compared different early interventions with 2,297 U.S. soldiers following a year-long deployment to Iraq. Platoons were randomly assigned to standard postdeployment stress education, Battlemind debriefing, and small and large group Battlemind training. Results from a 4-month follow-up with 1,060 participants showed those with high levels of combat exposure who received Battlemind debriefing reported fewer posttraumatic stress symptoms, depression symptoms, and sleep problems than those in stress education. Small group Battlemind training participants with high combat exposure reported fewer posttraumatic stress symptoms and sleep problems than stress education participants. Compared to stress education participants, large group Battlemind training participants with high combat exposure reported fewer posttraumatic stress symptoms and lower levels of stigma and, regardless of combat exposure, reported fewer depression symptoms. Findings demonstrate that brief early interventions have the potential to be effective with at-risk occupational groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
109.
Aponte G. Castro J.C. Sanchez V.H. Castro M. Espinosa A. Rosales N. 《Latin America Transactions, IEEE (Revista IEEE America Latina)》2009,7(2):190-195
This paper presents the contamination levels, obtained applying the Equivalent Salt Deposit Density ESDD methodology in nine distribution circuits and five substations, belonging to ELECTRICARIBE S.A. E.S.P., and located in the north area of Barranquilla, the main Colombian Atlantic Ocean port. The paper shows the different study stages such as the sampling places selection and configuration, the ESDD measurement procedures and the results evaluation applying statistical techniques. 相似文献
110.
The ever-increasing robustness and reliability of flow-simulation methods have consolidated CFD as a major tool in virtually
all branches of fluid mechanics. Traditionally, those methods have played a crucial role in the analysis of flow physics.
In more recent years, though, the subject has broadened considerably, with the development of optimization and inverse design
applications. Since then, the search for efficient ways to evaluate flow-sensitivity gradients has received the attention
of numerous researchers. In this scenario, the adjoint method has emerged as, quite possibly, the most powerful tool for the
job, which heightens the need for a clear understanding of its conceptual basis. Yet, some of its underlying aspects are still
subject to debate in the literature, despite all the research that has been carried out on the method. Such is the case with
the adjoint boundary and internal conditions, in particular. The present work aims to shed more light on that topic, with
emphasis on the need for an internal shock condition. By following the path of previous authors, the quasi-1D Euler problem
is used as a vehicle to explore those concepts. The results clearly indicate that the behavior of the adjoint solution through
a shock wave ultimately depends upon the nature of the objective functional. 相似文献