1,721,066 research outputs found
Chemical characterization of nutraceutical components in vegetable products
No full textRecent interest in reducing the environmental impact of agricultural and agro-industrial waste is leading to the development of innovative natural products with added healthy qualities, such as novel foods, nutraceuticals, cosmetics and biocides, containing bioactive compounds recovered from what is today considered waste. Presently, agricultural and agro-industrial residues have marginal use and they are often disposed in the fields or used as a source of energy with low enthalpy processes.
In this framework, the main target of the thesis focused to maximize the recovery of bioactive molecules (i.e. polyphenols, glycoalkaloids, terpenoids, glucosinolates and secoiridoids), from side streams of agriculture and agro-industrial activities, in the perspective to produce bioactive compounds. Thus, the thesis aimed to study specific, sustainable and cost-effective methodologies to obtain phytocomplexes for food, feed, pharmaceutical, nutraceutical and cosmetic industries, applying the concept of a whole-by-products biorefinery.
Different vegetables, the cultivation and the industrial processing of which produce a considerable amount of by-products (i.e. green tomatoes, potato leaves and vegetable belonging to the Brassicaceae family), were studied, particularly in terms of their secondary metabolite profiles.
Lab-scale procedures for extraction of bioactive complexes have been defined and validated, in agreement with the main principles of the “green analytical chemistry”, taking advantages from non-conventional extraction methodologies (i.e. ultrasound-assisted extraction), able to overcome the limits of the solid/liquid and liquid/liquid conventional techniques, among which longer extraction time, need of huge amount of solvents, low selectivity, thermal decomposition of thermolabile compounds.
Since one of the main problems of secondary metabolite intake for health-promoting purposes is related to their low bioavailability, another part of this thesis is dedicated to the application of liposomes as nutraceutical delivery systems of tyrosol, hydroxytyrosol and oleuropein, which are among the major phenolic compounds in the olive tree. A high number of by-products and residues derived from both olive tree cultivation and olive processing industry are obtained yearly (e.g. olive leaves and pomace) and they are promising sources of these bioactive compounds.
The limitation of the use of secondary metabolites in nutraceutical and cosmetic industry is due to several factors, i.e. non-standardization, high effective dose and lacking sound scientific data for efficacy and safety. Moreover, little knowledge is available about their mechanism of action.
Nuclear magnetic resonance spectroscopy is a straightforward technique for studying molecular dynamics and in this thesis a study related to highlight the behavior of capsaicin in solution is presented in order to acquire information about its mechanism of action and potential pharmacological effects.
Cereal grains, legumes and their food derived products have gained more and more popularity in contributing to healthy eating behaviors. In fact, they contain a wide range of phytochemicals (e.g. carotenoids, phenolic acids) and other minor components associated with protection against many chronic diseases. Therefore, another part of this thesis was dedicated to the characterization of phytochemical profile in different types of flour obtained from whole cereals and legumes. The data obtained were also discussed considering the different processing techniques used in the pre-treatments of cereals and legumes to enhance their breadmaking characteristics.
The results obtained in the present work provide an overview on the recovery, the applications and thus the potential use of nutraceuticals for human health
Fundamentación del uso de software libre en la universidad pública. Enseñando matemática con herramientas alternativas
No full textEn el presente trabajo se caracterizará al Software Libre, sus ventajas técnicas, morales y pedagógicas por sobre sus contrapartes privativas. Es mi convicción que la Universidad pública debe enseñar métodos de trabajo y no a utilizar una herramienta en particular; principalmente porque los programas de mayor difusión en el ámbito académico no permiten su distribución ni el estudio de su funcionamiento interno. Se presentarán los principales reemplazos a MATLAB y Maple (SAGE, Python+NumPy y Maxima) y se dará una introducción a estos con ejemplos reales.Fil: Pardini, A.. UID IMApEC; Universidad Nacional de La Plata, Departamento de Fisicomatemática
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Intermittent opening and flow of a mitral valve prosthesis caused by acute and chronic thrombosis
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