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111.
Maria Clariana Isabel D��az Carmen S��rraga Jose A. Garc��a-Regueiro 《Food Analytical Methods》2011,4(4):465-474
The analysis of eight cholesterol oxidation products: 7α–hydroxycholesterol, 7β–hydroxycholesterol, α–epoxycholesterol, β–epoxycholesterol,
20α–hydroxycholesterol, cholestanetriol, 25–hydroxycholesterol, and 7–ketocholesterol in dry–cured shoulder was carried out.
The extraction of lipids was performed by using the Bligh and Dyer method (1959). Interferences were removed by solid-phase extraction (SPE) in two steps with silica and aminipropylsilica SPE columns.
The separation of the eight cholesterol oxidation products was done by gas chromatography, and the detection was performed
by flame ionization detection (FID) and mass spectrometry (MS). The results obtained from the use of both systems of detection
were compared. The results showed that gas chromatography-mass spectrometry (GC–MS) was the most suitable technique to obtain
reliable quantitative data, and significant differences (p < 0.05) between FID and MS determining 7α–hydroxycholesterol, 20α–hydroxycholesterol, and 25–hydroxycholesterol were observed.
For the determination of cholesterol oxidation products, it was necessary to apply gas chromatography-tandem mass spectrometry
to increase the sensitivity and to avoid interference from other compounds. 相似文献
112.
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
113.
M. Carmen Portillo 《The Science of the total environment》2009,407(3):1114-2222
The conservation of paleolithic paintings such as those in Altamira Cave (Spain) is a primary objective. Recent molecular studies have shown the existence of unknown microbial communities in this cave including anaerobic microorganisms on cave walls. Herein, we analyzed an anaerobic microbial group, the sulfate-reducing bacteria (SRB), from Altamira Cave with potential negative effects on painting conservation. In the present work, the communities of bacteria and SRB were studied through PCR-DGGE analysis. Data suggest that SRB communities represent a significant, highly diverse bacterial group in Altamira Cave. These findings represent a first report on this physiological group on caves with paleolithic paintings and their potential biodegradation consequences. Expanding our knowledge on microbial communities in Altamira Cave is a priority to design appropriate conservation strategies. 相似文献
114.
Elisardo González-Agulla Enrique Otero-Muras Carmen García-Mateo José L. Alba-Castro 《Computer Standards & Interfaces》2009,31(1):186-191
We present a solution for the development of multiplatform and web-oriented Java applications for biometric authentication based on the BioAPI framework. Our proposal is a single Java Native Interface wrapper that is compatible with the BioAPI instantiations of Windows and Linux/Unix operating systems. Following a study of existing wrappers, we extended the open-source Linux/Unix wrapper to include Windows support. In order to show the utility of this multiplatform Java wrapper, we discuss some of its possible uses and present a real-life application. 相似文献
115.
116.
Agustín Caminero Omer Rana Blanca Caminero Carmen Carrión 《Journal of Computer and System Sciences》2011,77(2):262-281
Grid computing generally involves the aggregation of geographically distributed resources in the context of a particular application. As such resources can exist within different administrative domains, requirements on the communication network must also be taken into account when performing meta-scheduling, migration or monitoring of jobs. Similarly, coordinating efficient interaction between different domains should also be considered when performing such meta-scheduling of jobs. A strategy to perform peer-to-peer-inspired meta-scheduling in Grids is presented. This strategy has three main goals: (1) it takes the network characteristics into account when performing meta-scheduling; (2) communication and query referral between domains is considered, so that efficient meta-scheduling can be performed; and (3) the strategy demonstrates scalability, making it suitable for many scientific applications that require resources on a large scale. Simulation results are presented that demonstrate the usefulness of this approach, and it is compared with other proposals from literature. 相似文献
117.
Leticia Cubo Dr. Michael Groessl Dr. Paul J. Dyson Prof. Adoración G. Quiroga Dr. Carmen Navarro‐Ranninger Prof. Angela Casini Dr. 《ChemMedChem》2010,5(8):1335-1343
The reactivity of three cytotoxic trans‐PtII complexes bearing aliphatic amine ligands, with transferrin and single‐stranded oligonucleotides as DNA models, was investigated by ESI‐MS and the results obtained are discussed in comparison with cisplatin. Tandem MS studies provided additional information on the preferential Pt binding sites. To determine whether trans‐PtII complexes can migrate from a peptide to an oligonucleotide, transfer experiments were also performed using ESI‐MS, and competitive binding of the trans‐PtII complexes toward a model peptide and different oligonucleotides was also investigated. Significant differences in the reactivity of the trans complexes with respect to cisplatin were observed. In general, adduct formation with the selected peptide is favored for the trans compounds, whereas cisplatin shows a preference for oligonucleotides, especially if adjacent G–G residues are present. The results are discussed in relation to the possible mechanism of action of the trans‐PtII complexes. 相似文献
118.
Charles Cooper Paul Galick Stephen Harris Daniel Pourreau Carmen Rodriguez 《Journal of Coatings Technology》2001,73(992):19-24
Xylene is the traditional diluent solvent for formulating epoxy/amine paints used in protective coatings and linings. Currently,
it is under regulatory pressure because it is on the hazardous air pollutant (HAP) list and it is also a volatile organic
compound (VOC). Ketones and acetate esters are powerful solvents, but their use is limited by their reaction with the amine
curatives before paint application. Tert-butyl acetate (t-BAc) proposed as a VOC-exempt solvent, is a nonreactive, non-HAP
solvent suitable for both the epoxy resin and amine curative sides of a two-component epoxy system. Molecular modeling predicts
very low reactivity of the t-BAc ester functionality with amine nucleophiles as a result of steric hindrance. Long-term aging
studies with amine curatives in t-BAc solutions confirm these theoretical results. Kinetics of the reaction of amines with
t-BAc and its n-butyl acetate isomer support the view that steric hindrance plays a major role in amine solution stability.
Presented at the International Waterborne, High-Solids, and Powder Coatings Symposium, February 21–23, 2001, New Orleans,
LA.
3801 West Chester Pike, Newtown Square, PA 19073. 相似文献
119.
Carmen M. Carney 《Journal of Materials Science》2009,44(20):5673-5681
Oxidation resistance tests were carried out on HfB2-20 vol.% SiC prepared by spark plasma sintering. The dense samples were exposed from 1400 to 2000 °C in an ambient atmosphere
for 1 h. For comparison, the same material was tested using an arc jet to simulate an atmospheric reentry environment. The
oxidation properties of the samples were determined by measuring the weight gain per unit surface area and the thicknesses
of the oxide scale. The oxide scale consists of a SiO2 outer layer, porous HfO2 layers, and an HfB2 layer depleted in SiC. A transition in HfO2 morphology from equixed to columnar and a decrease in SiO2 viscosity between 1800 and 1900 °C accompanied a rapid increase in weight gain and scale thickness. 相似文献
120.
Abdenour Ait-Ouazzou Susana Lorán Abdelhay Arakrak Amin Laglaoui Carmen Rota Antonio Herrera Rafael Pagán Pilar Conchello 《Food research international (Ottawa, Ont.)》2012,45(1):313-319
The present study evaluates the chemical composition and antimicrobial activity of the essential oils (EOs) of Mentha pulegium L., Juniperus phoenicea L. and Cyperus longus L. from Morocco. The composition of these species was analyzed by GC/MS and 84 components were identified. M. pulegium EO showed a great similarity with EOs coming from other regions, as pulegone, the major component, accounted for about 70% of the EO. The EO of J. phoenicea had as main components α-pinene (24.9%), β-phellandrene (24.4%) and α-terpinyl acetate (12.9%). The EO extracted from C. longus was remarkably rich in sesquiterpene hydrocarbons (83.2%), which included β-himachalene (46.6%), α-humulene (16.9%), and γ-himachalene (10.1%). The antimicrobial activity of these EOs has been evaluated against seven bacteria of significant importance for food hygiene. According to the results, M. pulegium showed the best bacteriostatic and bactericidal effect, followed by J. phoenicea and C. longus. So far as we know, this is the first report on the quantitative composition and biological activity of the essential oil from C. longus. The tested EOs showed a variable degree of antimicrobial activity being M. pulegium the most effective one. 相似文献