Characterization of the Lipid Fraction in Lamb Meat: Comparison of Different Lipid Extraction Methods

The aim of this study was to evaluate the performance of four different extraction methods commonly used to quantify the intramuscular lipid content in meat: the Association of Analytical Chemists (AOAC) method (reference method) and methods based on the use of a solvent mixture with different polarities, such as chloroform–methanol described by Folch et al. (J Biol Chem 226:497, 1957) and Christie (1989) or hexane–isopropanol described by Hara and Radin (Anal Biochem 90:420, 1978). The following parameters were taken into account: lipid content; relative proportions of neutral and polar lipids; fatty acid composition of total, neutral, and polar lipid fractions; and phospholipid composition. The use of a combination of solvents with different polarities (Hara–Radin, Folch, and modified Folch methods) was more effective in extracting intramuscular lipids than the use of a single solvent (AOAC, reference method). The Hara–Radin method provided a cleaner lipid extract with a significantly higher content of total fatty acids than that obtained with the Folch and modified Folch methods. The lower polarity of the hexane–isopropanol mixture allowed us to obtain an extract richer in neutral lipids (triglycerides and diglycerides) and thus in saturated and monounsaturated fatty acids. The percentage distribution of individual fatty acids in the neutral lipid fraction was generally not affected by the extraction method adopted, while lipid obtained with both the Hara–Radin and Folch methods had a polar fraction with a higher percentage of polyunsaturated fatty acids. The use of the Hara–Radin method provided a polar fraction with less nonlipid material and lower phospholipid degradation.     

Core/Shell Semiconductor Nanocrystals

Colloidal core/shell nanocrystals contain at least two semiconductor materials in an onionlike structure. The possibility to tune the basic optical properties of the core nanocrystals, for example, their fluorescence wavelength, quantum yield, and lifetime, by growing an epitaxial‐type shell of another semiconductor has fueled significant progress on the chemical synthesis of these systems. In such core/shell nanocrystals, the shell provides a physical barrier between the optically active core and the surrounding medium, thus making the nanocrystals less sensitive to environmental changes, surface chemistry, and photo‐oxidation. The shell further provides an efficient passivation of the surface trap states, giving rise to a strongly enhanced fluorescence quantum yield. This effect is a fundamental prerequisite for the use of nanocrystals in applications such as biological labeling and light‐emitting devices, which rely on their emission properties. Focusing on recent advances, this Review discusses the fundamental properties and synthesis methods of core/shell and core/multiple shell structures of II–VI, IV–VI, and III–V semiconductors.

     

In Vitro and In Vivo Modeling of Normal and Leukemic Bone Marrow Niches: Cellular Senescence Contribution to Leukemia Induction and Progression

Cellular senescence is recognized as a dynamic process in which cells evolve and adapt in a context dependent manner; consequently, senescent cells can exert both beneficial and deleterious effects on their surroundings. Specifically, senescent mesenchymal stromal cells (MSC) in the bone marrow (BM) have been linked to the generation of a supporting microenvironment that enhances malignant cell survival. However, the study of MSC’s senescence role in leukemia development has been straitened not only by the availability of suitable models that faithfully reflect the structural complexity and biological diversity of the events triggered in the BM, but also by the lack of a universal, standardized method to measure senescence. Despite these constraints, two- and three dimensional in vitro models have been continuously improved in terms of cell culture techniques, support materials and analysis methods; in addition, research on animal models tends to focus on the development of techniques that allow tracking leukemic and senescent cells in the living organism, as well as to modify the available mice strains to generate individuals that mimic human BM characteristics. Here, we present the main advances in leukemic niche modeling, discussing advantages and limitations of the different systems, focusing on the contribution of senescent MSC to leukemia progression.     

Effect of the spray drying conditions on the physicochemical and structural characteristics and the stability of chia oil microparticles

Chia oil has a high content of linolenic and linoleic acids, which are essential for the human body. However, their high degree of unsaturation (double bonds) makes the oil very susceptible to oxidation. In this context, the use of spray drying can be useful strategy to minimize the oxidation of this oil. Thus, the aim was to assess the effects of inlet temperature and feed rate conditions involved in the spray drying process on the physicochemical and morphological characteristics, and stability of the chia oil microparticles with maltodextrin and GA. The microparticles were obtained with a yield of 50%, encapsulation efficiency greater than 87%, low-moisture content, and mean particle sizes ranging from 3.01 to 4.11 μm. The thermal evaluation and storage evidenced an increase in stability. The ¹H HR-MAS NMR technique showed that the microparticles maintained the characteristic fatty acid profile of chia oil and seeds. Results indicate that the microencapsulation methodology was suitable for preparing microparticles containing chia oil.     

Macrocell corrosion of steel in concrete: Characterization of anodic behavior in relation to the chloride content

This study presents the determination of electrochemical properties of active steel in mortar, based on inverse numerical modeling that focuses on their dependency on chloride content. An experimental campaign, consisting of galvanic coupling tests between anode samples contaminated with different chloride concentrations and cathode samples without chlorides, was carried out. Cathode polarization tests allowed for directly determining passive steel electrochemical parameters. Anode polarization tests coupled with a numerical optimization were then performed for quantifying active steel parameters and focusing on chloride's effect on the iron anodic Tafel coefficient. Furthermore, the steel electrochemical properties were successfully used as input parameters to model the galvanic experiments.     

Vascular Inflammation and Dysfunction in Lupus-Prone Mice-IL-6 as Mediator of Disease Initiation

Background: Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease and patients are under an increased risk for cardiovascular (CV) events and mortality. The increased CV risk for patients with SLE seems to be caused by a premature and accelerated atherosclerosis, attributable to lupus-specific risk factors (i.e., increased systemic inflammation, altered immune status), apart from traditional CV risk factors. To date, there is no established experimental model to explore the pathogenesis of this increased CV risk in SLE patients. Methods: Here we investigated whether MRL-Fas^lpr mice, which develop an SLE-like phenotype, may serve as a model to study lupus-mediated vascular disease. Therefore, MRL-Fas^lpr, MRL-++, and previously generated Il6^−/− MRL-Fas^lpr mice were used to evaluate vascular changes and possible mechanisms of vascular dysfunction and damage. Results: Contrary to MRL-++ control mice, lupus-prone MRL-Faslpr mice exhibited a pronounced vascular and perivascular leukocytic infiltration in various organs; expression of pro-inflammatory cytokines in the aorta and kidney was augmented; and intima-media thickness of the aorta was increased. IL-6 deficiency reversed these changes and restored aortic relaxation. Conclusion: Our findings demonstrate that the MRL-Fas^lpr mouse model is an excellent tool to investigate vascular damage in SLE mice. Moreover, IL-6 promotes vascular inflammation and damage and could potentially be a therapeutic target for the treatment of accelerated arteriosclerosis in SLE.     

Integrating adaptation rules for people with special needs in model-based UI development process

The adaptation of user interfaces for people with special needs is a promising approach in order to enable their access to digital services. Model-based user interfaces provide a useful approach for this purpose since they allow tailoring final user interfaces with a high degree of flexibility. This paper describes a system called Adaptation Integration System aimed at providing Cameleon Reference Framework model-based tools with a mechanism to integrate adaptation rules in the development process. Thus, more accessible user-tailored interfaces can be automatically generated. The services provided by the system can be applied at both design time and runtime. At design time, a user interface can be tailored at any abstraction level in the development process. At runtime, changes in the context of use trigger the adaptation process. Adaptation rules are stored in a repository tagged with meta-information useful for the adaptation process, such as the granularity of the adaptations and the abstraction level. As case studies, two applications have been developed using the services provided by the system. One of them exploits the benefits at design time, whereas the other application is devoted to describe the adaptation process at runtime. The results obtained in these two scenarios demonstrate the viability and potential of the adaption integration system since even inexperienced designers may efficiently produce accessible user interfaces.     

Accessible Ubiquitous Services for Supporting Daily Activities: A Case Study with Young Adults with Intellectual Disabilities

ABSTRACT

Ubiquitous environments have considerable potential to provide services supporting daily activities (using public transportation to and from workplace, using ATM machines, selecting and purchasing goods in ticketing or vending machines, etc.) in order to assist people with disabilities. Nevertheless, the ubiquitous service providers generally supply generic user interfaces which are not usually accessible for all potential end users. In this article, a case study to verify the adequacy of the user interfaces automatically generated by the Egoki system for two supporting ubiquitous services adapted to young adults with moderate intellectual disabilities was presented. The task completion times and the level of assistance required by participants when using the interfaces were analyzed. Participants were able to access services through a tablet and successfully complete the tasks, regardless of their level of expertise and familiarity with the service. Moreover, results indicate that their performance and confidence improved with practice, as they required fewer direct verbal and pointer cues to accomplish tasks. By applying observational methods during the experimental sessions, several potential improvements for the automated interface generation process were also detected.     

Automatic device-tailored evaluation of mobile web guidelines

Mobile web guidelines aim at providing developers with guidance to develop web content suitable for mobile devices. Automatic guideline review tools help evaluating conformance with respect to these guidelines in a systematic way. Yet, a number of mobile web guidelines refer to specific device features such as screen size, support for particular picture formats or support for pointing device. Since mobile devices are very diverse, in order to address the greater number of devices, guidelines adopt a device profile that may be considered as the common denominator device which is able to provide a satisfactory experience. While this approach is useful to define guidelines and make them more understandable, it introduces critical inaccuracies that make tool effectiveness decrease. This paper presents an application that considers specific device features in the evaluation process to produce device-tailored reports. As a result, higher rates of evaluation tool completeness, correctness and specificity are obtained.