Littérature scientifique sur le sujet « Complex natural substances »
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Articles de revues sur le sujet "Complex natural substances"
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Api, A. M., D. Belsito, D. Botelho, M. Bruze, G. A. Burton, J. Buschmann, M. A. Cancellieri et al. « The RIFM approach to evaluating Natural Complex Substances (NCS) ». Food and Chemical Toxicology 159 (janvier 2022) : 112715. http://dx.doi.org/10.1016/j.fct.2021.112715.
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Н.Ю., Чеснокова, Приходько Ю.В., Левочкина Л.В., Кузнецова А.А. et Фадеева М.Е. « НАТУРАЛЬНЫЙ КОНЦЕНТРИРОВАННЫЙ КРАСИТЕЛЬ, СОДЕРЖАЩИЙ КОМПЛЕКС АНТОЦИАНОВЫХ ПИГМЕНТОВ И ПЕКТИНОВЫХ ВЕЩЕСТВ ». Bulletin of KSAU, no 12 (18 décembre 2019) : 160–68. http://dx.doi.org/10.36718/1819-4036-2019-12-160-168.
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Изучено влияние температуры и ультразвука на интенсивность извлечения антоцианового пигмента и пектиновых веществ. Показано, что спектры, описывающие интенсивность извлечения антоцианового пигмента черной смородины, имеют два максимума поглощения при длинах волн 510 и 280 нм. Установлено соответствие максимумов поглощения антоцианового пигмента длине волны 510 нм и пектиновых веществ, ассоциированных с полифенолами, длине волны 280 нм. Показано, что наиболее полно экстрагирование антоцианового пигмента и пектиновых веществ происходит при температуре 65 °С в течение 30 мин. Увеличение температуры экстрагирования до 90 °С приводит к снижению интенсивности извлечения биологически активных веществ. Использование ультразвука по-разному влияет на интенсивность извлечения антоцианового пигмента и пектина, выделенных из ягодного сырья. Использование ультразвука для экстрагирования антоцианового пигмента увеличивает интенсивность его выделения. При ультразвуковой экстракции в течение 30 мин содержание антоцианового пигмента в растворе увеличивается на 50 %. Максимальное извлечение антоцианового пигмента наблюдается при ультразвуковой экстракции в течение 60 мин. Степень извлечения антоцианового пигмента повышается в 2,5 раза. Напротив, использование ультразвука для выделения пектиновых веществ приводит к уменьшению их количества в растворе. Полученный методом концентрирования краситель, содержащий антоциановый пигмент и пектиновые вещества, имеет темно-красный цвет и ярко выраженный запах черной смородины, густую сиропообразную консистенцию, содержит в своем составе 4,83 мг/мл антоцианового пигмента, обладает полной растворимостью.
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Špinarová, Š., et K. Petříková. « Variability of the content and quality of some active substances within Achillea millefolium complex ». Horticultural Science 30, No. 1 (25 novembre 2011) : 7–13. http://dx.doi.org/10.17221/3811-hortsci.
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The present paper compares the production of active substances in different subspecies of Achillea millefolium complex growing in the Czech Republic. Representatives of 7 subspecies of A. millefolium complex (A. setacea Waldst. et Kit., A. asplenifolia Vent., A. pratensis Saukel et Langer, A. collina Rchb., A. styriaca Saukel et Langer subsp. bohemica, A. millefolium subsp. millefolium, A. pannonica Scheele) and several natural hybrids of Achillea L. were collected from 75 natural habitats in different parts of the Czech Republic. Plants were cultivated to investigate plant growth and contents of some effective compounds during 1997–1999. Development of plants was divided into 7 typical phenological phases. From the point of view of active substance production, the stage of early flowering was found as the most suitable phase for Achillea (yarrow) harvest. Air-dried powdered flowering heads were analysed for essential oil, tannin and flavonoid content. The essential oil content was obtained by hydro-distillation; the composition of essential oil was analysed by means of gas-liquid chromatography. The total essential oil content of the examined yarrow species ranged between 0.05% and 0.88% of dry matter; ecotypes of A. collina and some of its hybrids showed the best results with the highest content of deep blue essential oil. Content of tannins was determined according to PhBs IV; flavonoids were expressed as an apigenin content by an internal method of pharmaceutical company IVAX ČR, a. s., Opava. The total flavonoid content was in the range of 1.37–3.97%; the content of tannins ranged from 0.02 to 0.64%. The highest content of flavonoids was determined in the sample of A. styriaca subsp. bohemica (3.97%); the highest content of tannins was found in an A. asplenifolia sample (0.64%).
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Kochetov, Andrei, Valentin Minakov, Elena Fisunova, Tatyana Lavrenova et Luybov Filonenko. « Acoustic synthesis of feed proteins under conditions of a complex ultrasonic field ». E3S Web of Conferences 273 (2021) : 13004. http://dx.doi.org/10.1051/e3sconf/202127313004.
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Liquid waste of food industry enterprises contains various valuable organic substances of natural origin, which can be rationally used to obtain feed proteins. The problem of using valuable substances from food waste solves the problem of using biotechnological methods in order to use methods of accumulating biomass, enzymes, vitamins, etc. The biomass of unicellular microorganisms formed in the process of cultivation can be a raw material for obtaining feed additives and other biologically active substances.
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Warren, Richard M. « Synthesizing complex sensations from simple components ». Behavioral and Brain Sciences 31, no 1 (février 2008) : 90–91. http://dx.doi.org/10.1017/s0140525x0800352x.
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AbstractThe target article suggests that taste is not based on the traditional four basic tastes, but rather is a continuum subserved by cross-fiber integration. This commentary describes evidence indicating that the traditional concept is valid, and that with suitable precautions, it is possible to match natural substances using mixtures representing fundamental tastes.
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Adekenov, S. M., А. N. Zhabayeva et G. М. Baisarov. « Water-Soluble Substances of Arglabin ». Eurasian Chemico-Technological Journal 22, no 3 (30 septembre 2020) : 205. http://dx.doi.org/10.18321/ectj971.
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The article discusses the results of a study of the water solubility of natural sesquiterpene lactone arglabin, in particular, its ability to complex formation with complexing agents polyvinylpyrrolidone, the disodium salt of glycyrrhizic acid, magnesium carbonate. Mechanocomposites with polyvinylpyrrolidone and disodium salt of glycyrrhizic acid, which have increased water solubility, were obtained by the method of mechanochemical treatment of arglabin native. At the same time, the best result of dissolution in water is achieved by a two-hour treatment with polyvinylpyrrolidone and with disodium salt of glycyrrhizic acid. The water solubility of complex compounds of arglabin with polyvinylpyrrolidone increases by 4.61 times, and with disodium salt of glycyrrhizic acid by 4.42 times.
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Babina, Liudmila V., et Ksenia E. Lukina. « English deadjectival nouns as models of knowledge representation about the world ». Current Issues in Philology and Pedagogical Linguistics, no 2(2021) (25 juin 2021) : 176–85. http://dx.doi.org/10.29025/2079-6021-2021-2-176-185.
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From the position of a cognitive approach the authors consider English deadjectival nouns, what involves identifying and describing knowledge domains represented by these language units in English language culture. The study is carried out on the material of deadjectival nouns, which are fixed in English dictionaries and selected by a continuous sampling method. A set of methods is used, the main of which are methods of conceptual-definitional and cognitive-matrix analysis. As a result of the study, it is revealed that English deadjectival nouns represent the structure of knowledge of an integrative nature, including the concepts of HUMAN BEING, ARTEFACT, NATURAL OBJECT, SUBSTANCE, and STATE. This knowledge structure is presented as a general cognitive matrix, the components of which are the above concepts. In turn, the matrix components can also be complex and include a variety of knowledge. It is determined that deadjectival nouns presenting the HUMAN BEING concept convey ideas about human physical parameters, psychological features and social status, as well as about human diseases. Deadjectival nouns representing the concept of ARTEFACT name human signs and sign systems, products of human speech, household and personal items, objects of labor activity, vehicles and buildings. Deadjectival nouns representing the NATURAL OBJECT concept convey ideas about natural landscape objects, about the plant and animal world. Deadjectival nouns representing the SUBSTANCE concept reflect ideas about drugs/substances, cleaning products, cosmetics, and technical substances, organic or natural substances. The STATE concept is represented by deadjectival nouns that convey knowledge about the state of a person, object, and phenomenon, about their being in a certain state.
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Landina, L. N. « Standardization of Dry Extract of Pumpkin Pulp Juice, Which Has a Hypolipidemic Effect on the Content of Β-Carotene ». Medicina 9, no 1 (2021) : 79–92. http://dx.doi.org/10.29234/2308-9113-2021-9-1-79-92.
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The objective is to standardize the content of β-carotene – one of the principal active substances with sufficient hypolipidemic activity in the resultant original product. Search for natural biologically active substances having a hypolipidemic effect is one of the topical questions in modern pharmacy. Most of the research is carried out by means of isolating individual substances from the plant object. We propose to study a native phytocomplex obtained from pumpkin pulp – a dry extract of pumpkin pulp juice. The following materials and methods were used: laboratory-obtained dry extract of pumpkin pulp juice and methods used to determine the qualitative and quantitative content of β-carotene in an individual substance. It was possible to adapt the methods applied to the analysis of an individual substance in relation to the resulting phytocomplex containing both lipophilic and hydrophilic fractions. The rapid method of quantitative determination of β-carotene described in the scientific literature was corrected. An effective alternative method for spectrophotometric determination of β-carotene in the phytocomplex has been developed. Phytocomplexes standardized for the main active substances can be used to obtain effective drugs and biologically active additives with minimal side effects. In addition, the expansion of the search for alternative natural objects containing complexes haaving a hypolipidemic effect is currently relevant. Based on the literature data, in the future it is planned to conduct a pharmacological study to establish the anti-inflammatory effect of the resulting complex on the state of the vascular wall.
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Bondareva, Lydia, et Nadezhda Kudryasheva. « Direct and Indirect Detoxification Effects of Humic Substances ». Agronomy 11, no 2 (20 janvier 2021) : 198. http://dx.doi.org/10.3390/agronomy11020198.
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The review summarizes studies on the detoxification effects of water-soluble humic substances (HS), which are products of the natural transformation of organic substances in soils and bottom sediments that serve as natural detoxifying agents in water solutions. The detoxifying effects of HS on microorganisms are quite complex: HS neutralize free pollutants (indirect bioeffects) and also stimulate the protective response of organisms (direct bioeffects). Prospects and potential problems of bioluminescent bacteria-based assay to monitor toxicity of solutions in the presence of HS are discussed. The main criterion for the bioassay application is versatility and ease of use. The detoxification efficiency of HS in different pollutant solutions was evaluated, and the detoxification mechanisms are discussed. Particular attention was paid to the direct and complex direct + indirect effects of HS. The review focuses on the protective function of HS in solutions of radionuclides and salts of stable metals, with special consideration of the antioxidant properties of HS.
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Napiórkowska, Alicja, et Marcin Kurek. « Coacervation as a Novel Method of Microencapsulation of Essential Oils—A Review ». Molecules 27, no 16 (12 août 2022) : 5142. http://dx.doi.org/10.3390/molecules27165142.
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These days, consumers are increasingly “nutritionally aware”. The trend of “clean label” is gaining momentum. Synthetic additives and preservatives, as well as natural ones, bearing the E symbol are more often perceived negatively. For this reason, substances of natural origin are sought tfor replacing them. Essential oils can be such substances. However, the wider use of essential oils in the food industry is severely limited. This is because these substances are highly sensitive to light, oxygen, and temperature. This creates problems with their processing and storage. In addition, they have a strong smell and taste, which makes them unacceptable when added to the product. The solution to this situation seems to be microencapsulation through complex coacervation. To reduce the loss of essential oils and the undesirable chemical changes that may occur during their spray drying—the most commonly used method—complex coacervation seems to be an interesting alternative. This article collects information on the limitations of the use of essential oils in food and proposes a solution through complex coacervation with plant proteins and chia mucilage.
Thèses sur le sujet "Complex natural substances"
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Bouges, Hélène. « Modifications enzymatiques de la composition de mélanges naturels complexes utilisés en parfumerie ». Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4024.
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Dans le domaine de la chimie des parfums, l’optimisation des propriétés biologiques et sensorielles de substances naturelles complexes, via la biocatalyse, présente un fort intérêt. Dans un contexte de chimie durable, ces travaux de recherche sont dédiés aux développements de modifications enzymatiques de composés purs, d’extraits et d’huiles essentielles de l’industrie des arômes et parfums. Une étude bibliographique a ainsi été consacrée à la composition des matières premières naturelles, leurs propriétés et les principales voies de biosynthèse des composés présents dans les substances naturelles complexes, ainsi que quelques éléments de réglementation. Dans un premier volet, selon un procédé de chimie durable, le but a été de rendre des produits naturels plus sains tout en conservant leurs propriétés et leur « naturalité ». La détoxification en atranol et en chloroatranol de l’extrait de mousse de chêne a été effectué menant à des absolues de mousse de chêne modifiées par biocatalyse conservant leur qualité odorante. Dans le cadre d’un projet collaboratif public-privé, des protocoles de suivis de transformations biocatalytiques ont été établis et mis en œuvre. Dans un troisième volet, des méthodologies de chimie durable ont été mises à profit afin de proposer de nouveaux ingrédients grâce à l’utilisation de procédés biotechnologiques procédant selon le principe d’économie circulaire. Le caractère naturel a été conservé et la méthode a permis de réaliser des transformations fines et ciblées pour développer des facettes olfactives intéressantesIn the field of flavor and fragrance industry, the optimization of natural flavoring essential oils and extracts’ properties by biocatalysis is really interesting. In a context of sustainable chemistry, this research project is dedicated to the development of pure compounds, extracts and essential oils by enzymatic modifications. In this way, a bibliographic study has been carried out on the composition of the natural raw materials, their properties and the main biosynthetic pathways of the compounds present in the natural complex substances and some regulation elements. In the first place, according to a process of sustainable chemistry, the goal is to make healthier natural products while keeping their properties and their "naturalness". The detoxification in atranol and chloroatranol of the oak moss extract was carried out with the oak moss absolute by biocatalysis preserving their olfactory quality. Through an academic /industrial collaboration, protocols for monitoring biocatalytic transformations were established and implemented. In a third part, sustainable chemistry methodologies were used to propose new ingredients through the use of biotechnological processes based on the circular economy principle. The natural character has been preserved and the method allowed targeted transformations to develop interesting olfactory facets
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Spinozzi, Silvia <1987>. « New analytical LC-mass spectrometry methodologies for the quali-quantitative determination of natural substances and drugs in complex matrices ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6997/1/Silvia_Spinozzi_Tesi.pdf.
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This thesis reports an integrated analytical and physicochemical approach for the study of natural substances and new drugs based on mass spectrometry techniques combined with liquid chromatography.
In particular, Chapter 1 concerns the study of Berberine a natural substance with pharmacological activity for the treatment of hepatobiliary and intestinal diseases. The first part focused on the relationships between physicochemical properties, pharmacokinetics and metabolism of Berberine and its metabolites. For this purpose a sensitive HPLC-ES-MS/MS method have been developed, validated and used to determine these compounds during their physicochemical properties studies and plasma levels of berberine and its metabolites including berberrubine(M1), demethylenberberine(M3), and jatrorrhizine(M4) in humans. Data show that M1, could have an efficient intestinal absorption by passive diffusion due to a keto-enol tautomerism confirmed by NMR studies and its higher plasma concentration. In the second part of Chapter 1, a comparison between M1 and BBR in vivo biodistribution in rat has been studied.
In Chapter 2 a new HPLC-ES-MS/MS method for the simultaneous determination and quantification of glucosinolates, as glucoraphanin, glucoerucin and sinigrin, and isothiocyanates, as sulforaphane and erucin, has developed and validated. This method has been used for the analysis of functional foods enriched with vegetable extracts.
Chapter 3 focused on a physicochemical study of the interaction between the bile acid sequestrants used in the treatment of hypercholesterolemia including colesevelam and cholestyramine with obeticolic acid (OCA), potent agonist of nuclear receptor farnesoid X (FXR). In particular, a new experimental model for the determination of equilibrium binding isotherm was developed.
Chapter 4 focused on methodological aspects of new hard ionization coupled with liquid chromatography (Direct-EI-UHPLC-MS) not yet commercially available and potentially useful for qualitative analysis and for “transparent” molecules to soft ionization techniques. This method was applied to the analysis of several steroid derivatives.
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Spinozzi, Silvia <1987>. « New analytical LC-mass spectrometry methodologies for the quali-quantitative determination of natural substances and drugs in complex matrices ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/6997/.
Texte intégralRésumé :
This thesis reports an integrated analytical and physicochemical approach for the study of natural substances and new drugs based on mass spectrometry techniques combined with liquid chromatography.
In particular, Chapter 1 concerns the study of Berberine a natural substance with pharmacological activity for the treatment of hepatobiliary and intestinal diseases. The first part focused on the relationships between physicochemical properties, pharmacokinetics and metabolism of Berberine and its metabolites. For this purpose a sensitive HPLC-ES-MS/MS method have been developed, validated and used to determine these compounds during their physicochemical properties studies and plasma levels of berberine and its metabolites including berberrubine(M1), demethylenberberine(M3), and jatrorrhizine(M4) in humans. Data show that M1, could have an efficient intestinal absorption by passive diffusion due to a keto-enol tautomerism confirmed by NMR studies and its higher plasma concentration. In the second part of Chapter 1, a comparison between M1 and BBR in vivo biodistribution in rat has been studied.
In Chapter 2 a new HPLC-ES-MS/MS method for the simultaneous determination and quantification of glucosinolates, as glucoraphanin, glucoerucin and sinigrin, and isothiocyanates, as sulforaphane and erucin, has developed and validated. This method has been used for the analysis of functional foods enriched with vegetable extracts.
Chapter 3 focused on a physicochemical study of the interaction between the bile acid sequestrants used in the treatment of hypercholesterolemia including colesevelam and cholestyramine with obeticolic acid (OCA), potent agonist of nuclear receptor farnesoid X (FXR). In particular, a new experimental model for the determination of equilibrium binding isotherm was developed.
Chapter 4 focused on methodological aspects of new hard ionization coupled with liquid chromatography (Direct-EI-UHPLC-MS) not yet commercially available and potentially useful for qualitative analysis and for “transparent” molecules to soft ionization techniques. This method was applied to the analysis of several steroid derivatives.
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Gilles, Laure. « Découverte et synthèse chimique d'odorants par des technologies innovantes ». Electronic Thesis or Diss., Université Côte d'Azur, 2022. http://www.theses.fr/2022COAZ4100.
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Les contraintes réglementaires des autorités nationales et internationales et les exigences des consommateurs de plus en plus importantes, ainsi que la quête de nouvelles compositions originales, incitent l'industrie de la parfumerie à être constamment à la recherche de nouvelles molécules organoleptiques sûres, durables et innovantes. À cet égard, grâce à la grande diversité du règne végétal, les substances naturelles complexes (SNC), sont une source riche d'ingrédients. Elles sont également une source d'inspiration pour les chimistes, qui peuvent utiliser la synthèse pour avoir un accès contrôlé à des composés d'intérêt (chiralité, quantité suffisante et qualité constante) mais aussi pour préparer des molécules analogues, pouvant générer une amélioration des propriétés olfactives (note et puissance olfactive).Dans ce manuscrit, l'utilisation de la GC-O, complétée par la GC-MS pour l'analyse approfondie du distillat d'une concrète de la plante Ocimum gratissimum est présentée. Cette étude a permis de réaliser la composition chimique de cette extrait, l'identification du chémotype (E)-cinnamate de méthyle, l'évaluation olfactive par un maître-parfumeur ainsi que l'identification des composés odorants importants. Ce manuscrit expose également les stratégies de synthèses asymétriques et multi-étapes investiguées, dans l'objectif d'atteindre les différents énantiomères du vetispira-2(11),6-dien-14-al. En effet, il s'agit d'un composé important de l'huile essentielle d'agarwood, décrit comme ayant une odeur typique du bois d'agar et dont aucune synthèse n'a été publiée à ce jour. Enfin, la mise au point d'une méthodologie d'acétalisation de composés α,β-insaturés, catalysée par FeCl3 est détaillée. Une série de 24 analogues hétérocyliques spiraniques a ainsi été synthétisée et ces composés seront soumis à un maître parfumeur afin d'évaluer leurs notes et pertinence olfactivesThe perfumery industry in under constant pressure from national and international regulatory bodies as well and the demands of consumers to produce novel and safe organoleptic molecules via methods which are both durable and innovative. This constant drive for innovation pushes researchers towards diverse domains of the plant kingdom which contains numerous complex natural substances (CNS). At present these natural products are a source of ingredients, however, they are equally a source of inspiration for the chemist who may identify structures of interest to be synthesised with a high degree of control (chirality, quantity, quality, consistency), as well as structural analogues to provide an improvement of the olfactory properties (notes, intensity).This manuscript presents an extended analysis of the distillate of a concrete of the plant Ocimum gratissimum via GC-O complemented with GC-MS analysis. This study has also enlighted the chemical composition of the extract, characterisation of the poorly described (E)-methyl cinnamate chemotype, olfactory evaluation by a master perfumer and the identification of the principal olfactive compounds. This work simultaneously explores multistep asymmetric synthetic strategies in the aim of obtaining the different enantiomers of vetispira-2(11),6-dien-14-al. This compound is known to be an important component of agar wood essential oil and largely responsible for its particular odour. Currently no syntheses of this compound have been published. An FeCl3 catalysed acetylation of α,β-unsaturated compounds was optimised and applied to the synthesis of 24 different heterocyclic spirocycles, which are to be submitted to a master perfumer for the evaluation of their notes and olfactory interest
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Richieu, Antoine. « Synthèse totale de la vescaline, substance naturelle bioactive de la famille des ellagitannins C-arylglucosidiques ». Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0937/document.
Texte intégralRésumé :
Les ellagitannins C-arylglucosidiques sont des composés polyphénoliques issus du métabolisme spécialisé de nombreuses plantes, en particulier celles appartenant à la famille des Fagacées comme le chêne et le châtaignier. La vescaline qui appartient à cette famille de composés exhibe d’intéressantes propriétés biologiques, notamment antivirales et antitumorales. Plus précisément elle inhibe la topoisomérase 2α, une enzyme ciblée par les chimiothérapies utilisées contre le cancer, et possède également une activité contre les filaments d’actine du cytosquelette. La structure particulièrement unique de la vescaline comporte un motif NonaHydroxyTriPhénoyle (NHTP) lié par une liaison C-arylglucosidique à un coeur D-glucose en forme ouverte. La synthèse totale de différents membres de cette classe de polyphénols d’origine végétale, dont celle de la vescaline, constituait l’objectif principal de cette thèse. Les voies d’accès à ces cibles exploitent en partie des méthodes développées précédemment lors de la synthèse totale de l’épipunicacortéine A 5-O-dégalloylée et sont complétées par de nouvelles méthodologies de synthèse. Ainsi, la méthode et le rendement de l’étape de C-arylglucosidation ont été améliorés et des conditions efficaces de couplage terarylique intramoléculaire entre un motif HexaHydroxyDiPhénoyle (HHDP) et une unité galloyle ont été élaborées. En adaptant la stratégie mise au point pour la synthèse totale de la vescaline, trois ellagitannins C-arylglucosidiques supplémentaires ont été préparés : la punicacortéine A, l’épipunicacortéine A et la castalineC-arylglucosidic ellagitannins are polyphenolic compounds biosynthesized through the secondary metabolism of various plants, in particular from the Fagaceae family such as oak and chestnut. Vescalin, which belongs to this class of plant polyphenols, displays interesting biological activities, with antiviral and antitumoral properties. More specifically, it inhibits topoisomerase 2α, a targeted enzyme in chemotherapy used in cancer treatment, and have also an activity against the cytoskeletal filamentous actin. Unique structure of vescalin displays a NonaHydroxyTriPhenoyl moiety (NHTP) linked to an open chain D-glucose with a C-arylglucosidic bond. The total synthesis of vescalin constitutes the main goal of this doctoral work. Synthetic routes employ in part chemical methods previously used for the total synthesis of 5-O-desgalloylepipunicacortein A in addition to new methodologies. Therefore, the C-arylglucosidation method and chemical yield have been improved and an efficient intramolecular terarylic coupling between a HexaHydroxyDiPhenoyl moiety (HHDP) and a galloyl unit has been developed. Taking advantage of the synthetic strategy elaborated for vescalin total synthesis, three additional C-arylglucosidic ellagitannins were obtained: punicacortein A, epipunicacortein A and castalin
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Bastos, de lemos e. silva Siguara. « Chimie et biosynthèse de substances naturelles hautement complexes de la biodiversité méditerranéenne ». Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS214.
Texte intégralRésumé :
Le but de ce travail de doctorat est l’étude chimique et biosynthétique de familles d’alcaloïdes guanidiniques d’origine marine provenant d’éponges de Méditerranée.Le travail est divisé en trois parties successives : 1) l’isolement d’alcaloïdes produits par des éponges marines de l’ordre des Poeciloscerida; 2) l’élucidation de la biosynthèse de la crambescine C1 par des études in vivo d’incorporation de précurseurs marqués au 14C; 3) la synthèse biomimétique de la crambescine A2 448 et de dérivés proches.La famille des alcaloïdes guanidiniques cycliques des crambescines est au coeur de la thèse, ces substances naturelles sont produites par l’éponge incrustante Crambe crambe. Ces alcaloïdes ont été découverts dans les années 1990 et ont suscité beaucoup d’intérêt pour leurs propriétés biologiques et écologiques et leurs synthèses totales. Par contre, leur biosynthèse était encore inconnue à ce jour. La seule synthèse biomimétique disponible était basée sur une hypothèse d’origine polyacétique. Les hypothèses récentes de nos groupes ont permis de mettre en avant une origine mixte: la partie cyclique guanidinique proviendrait d’un pyrrolidinium issu de l’arginine et d’un précurseur “céto-acide” proche des acides gras. Sur la base de cette hypothèse, nous avons mis au point une expérience d’incorporation qui a ensuite inspirée une voie de synthèse biomimétique pour l’accès aux crambescines et dérivés. Les premières conclusions quant à l’origine biosynthétique de ces molécules sont les faits les plus marquants de ce travail. Nous apportons une meilleure compréhension de la biochimie des alcaloïdes guanidiniques marins de structures complexesThis thesis aims at the study of the chemical and biogenetic origin of specialized guanidine-alkaloid metabolites produced by sponges from the Mediterranean Sea.The work is divided into three main parts: 1) isolation of alkaloids produced by sponges of the Poeciloscerida order; 2) biosynthesis of crambescin C1 by in-vivo 14C-feeding experiments with Crambe crambe sponge; 3) biomimetic synthesis of crambescin A2 448 and derivatives. The main focus of the thesis will be the family of cyclic-guanidine alkaloids "crambescins", produced by the red incrusting sponge Crambe crambe.These alkaloids were discovered in the early 90s and despite the large interest on their biological activities, ecological roles, and synthesis, their biosynthesis is still unknown.The only available biomimetic synthesis of crambescins was based on a fully polyketide origin hypothesis. Recently our groups suggested an alternative biosynthetic hypothesis in which the guanidine-core would be originated from a condensation between a guanidinated pyrrolidinium derived from arginine and a beta-keto fatty acid. Based on this hypothesis, we designed a biosynthesis experiment that inspired a biomimetic synthesis route to access the crambescins and derivatives. The insights from these studies are the first experimental conclusions about the biosynthesis of crambescins. Finally, this work leads to a better comprehension of the biochemistry involved in guanidine marine alkaloids of complex structures
Livres sur le sujet "Complex natural substances"
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Office, General Accounting. Nuclear materials : Plutonium processing in the nuclear weapons complex : fact sheet for the Chairman, Environment, Energy, and Natural Resources Subcommittee, Committee on Government Operations, House of Representatives. Washington, D.C : U.S. General Accounting Office, 1992.
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Office, General Accounting. Nuclear materials : Plutonium processing in the nuclear weapons complex : fact sheet for the chairman, Environment, Energy, and Natural Resources Subcommittee, Committee on Government Operations, House of Representatives. [Washington, D.C.] : GAO, 1992.
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Litvin, Feliks, Lyudmila Satina, Ravil' Hatypov, Galina Mikulinskaya, Nikita Pen'kov et Konstantin Neverov. Molecular spectroscopy. Fundamentals of theory and practice. ru : INFRA-M Academic Publishing LLC., 2022. http://dx.doi.org/10.12737/1870280.
Texte intégralRésumé :
The textbook is an introduction to the theory and practice of spectroscopy in the ultraviolet, visible and infrared regions. The presentation of the theoretical foundations is accompanied by a detailed guide on the practical use of spectroscopy for quantitative and qualitative analysis of substances and reactions in simple and complex systems. Attention is paid to modern methods of infrared spectroscopy with Fourier transform (FTIR), intermolecular energy transfer (FRET), linear dichroism of complex objects.
It is intended for a wide range of biologists, chemists, students and postgraduates of natural science specialties.
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Borzyh, Stanislav. Theory of the possible. ru : INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1074108.
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In this book, we are talking about a single principle that permeates every organized entity, regardless of what sphere it belongs to. Everywhere and always, and in accordance with the current circumstances, the process of formation, support and regulation of any complex complexes and ensembles is guided and controlled by the concept of the realizable, which postulates that only what is stable and stable will be realized, and everything else will be discarded as untenable and unbalanced. These patterns and patterns can be traced resolutely at all levels of existence. And the universe, and life, and consciousness, and mind, and culture are arranged and assembled according to these schemes, because it is difficult, if possible, for them to be any other. This paper provides an overview of this type of layout in these areas, as well as the theory of the achievable and accessible itself. Using examples and theoretical considerations, it is shown that the configuration of all reliable and long-lasting structures is approximately the same or very similar, because it obeys a single end-to-end logic of the formation of any similar substances, whatever they touch and wherever they are found. In addition, it is demonstrated that if something in this spirit is objectified in practice, then its nature and properties must be fundamentally the same as what we observe around or extremely close to it. Finally, the view is argued and developed, according to which everything consists of matter, is constituted by it, is reduced only to it, including any non-physical phenomena. It is concluded that all the wealth of the world is subject to the same laws of its construction, and all this construction observes the universal rules of the functioning of complex things, no matter what they are aimed at. For all those interested in philosophy.
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Lobanov, Aleksey. Medical and biological bases of safety. ru : INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/1439619.
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The textbook considers the subject and tasks of the discipline, highlights the medical and biological foundations of ensuring human security in the conditions of natural, man-made and biological-social emergencies, as well as when using modern weapons of destruction by a probable enemy.
Briefly, but quite informative, the structure of the human body and the basics of its functioning are described. The specificity and mechanism of the toxic effect of harmful substances on a person, the energy effect and the combined effect of the main damaging factors of the sources of emergency situations of peacetime and wartime are shown. The article highlights the medical and biological aspects of ensuring the safe life of people in adverse environmental conditions, including in regions with hot and cold climates (the Arctic). The methods of forecasting and assessing the medical situation in emergency zones and lesions are presented.
The means and methods of medical and biological protection and first aid to the affected are shown. The main tasks and organizational structure of formations and institutions of the medical rescue service of the GO, the All-Russian Service of Disaster Medicine and medical formations of the EMERCOM of Russia are considered. Organizational issues of medical and biological protection in emergency situations are highlighted. The features of the organization of medical support for those affected by terrorist attacks are considered.
It is intended for students and cadets of educational institutions of higher education studying under the bachelor's degree program in the following areas of training: "Technosphere security", "Infocommunication technologies and communication systems", "Information systems and technologies", "State and municipal management", "Economics", "Mechatronics and robotics", "Operation of transport and technological machines and complexes", "Informatics and computer engineering", "Air Navigation", "System analysis and management". It can also be useful for researchers and a wide range of specialists engaged in practical work on planning and organizing medical and biological protection of the population.
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Brown, Deborah J., et Calvin G. Normore. Descartes and the Ontology of Everyday Life. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198836810.001.0001.
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Far from being the founder of an austere reductionism, Descartes is committed to a rich, multilayered, and complex metaphysics. This book begins by locating Descartes’s work against the ancient and medieval background to which he is reacting. It proceeds to argue that his theory of distinctions requires what he explicitly endorses―that in addition to minds and modes, there are material substances of every size. These substances when appropriately configured form automata, self-sustaining, functionally integrated systems of which animals and human bodies are important sub-classes. Descartes’ conception of function, which is crucial to his characterization of these uniquely organized collections of matter, is shown to be compatible with his rejection of final causes in natural science, and gives him resources to account for composite beings which are not themselves substances. It is argued that besides automata, these composites include individual human beings, which are unions of minds and bodies individuated by minds. The unique modes which characterize the union, in particular, its passions, set the foundation for a social ontology that includes genuine social entities such as families and nation states. Societies are forged by individuals in acts of willing to join in union with others that Descartes takes to be of the essence of love. The result is a picture of Descartes very different from the myths that have come to surround him.
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Schmidgen, Henning. Horn, or The Counterside of Media. Traduit par Nils F. Schott. Duke University Press, 2022. http://dx.doi.org/10.1215/9781478022343.
Texte intégralRésumé :
We regularly touch and handle media devices. At the same time, media devices such as body scanners, car seat pressure sensors, and smart phones scan and touch us. In Horn, Henning Schmidgen reflects on the bidirectional nature of touch and the ways in which surfaces constitute a site of mediation between interior and exterior. Schmidgen uses the concept of horn—whether manifested as a rhinoceros horn or a musical instrument—to stand for both natural substances and artificial objects as a space of tactility. He enters into creative dialogue with artists, scientists, and philosophers, ranging from Salvador Dalí, William Kentridge, and Rebecca Horn to Sigmund Freud, Walter Benjamin, and Marshall McLuhan, who plumb the complex interplay between tactility and technological and biological surfaces. Whether analyzing how Dalí conceived of images as tactile entities during his “rhinoceros phase” or examining the problem of tactility in Thomas Pynchon’s The Crying of Lot 49, Schmidgen reconfigures understandings of the dynamic phenomena of touch in media.
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Dzhafarov, M., Fedor Vasilevich, Leonid Menchikov, Elena Chernoburova et Igor Zavarzin. CHEMISTRY OF AVERMECTINS AND MILBEMYCINS. LCC MAKS Press, 2021. http://dx.doi.org/10.29003/m2530.978-5-317-06727-4.
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Parasitic diseases are a serious problem for medicine and the agro-industrial complex. The most effective antiparasitic compounds are avermectins, for the discovery of which Satoshi Omura and William Campbell were awarded the 2015 Nobel Prize in Physiology or Medicine. For the first time, the monograph summarizes and analyzes the achievements in the chemistry of avermectins and milbemycins, as well as analyzes the possible directions and patterns of chemical modification of these compounds. In addition, the analysis of data on the relationship «structure-property» allows a more conscious approach to the modification of these compounds in order to increase their biological activity, stability, etc. The monograph is intended for wide range of specialists in the field of chemistry of natural compounds and biologically active substances.
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Anderson, Leslie K., Stuart B. Murray et Walter H. Kaye, dir. Clinical Handbook of Complex and Atypical Eating Disorders. Oxford University Press, 2017. http://dx.doi.org/10.1093/med-psych/9780190630409.001.0001.
Texte intégralRésumé :
The aim of this book is to collate what is known about an array of complicating factors for patients with eating disorders, serving as an accessible introduction to each of the comorbidities and symptom presentations highlighted in the volume. The Handbook of Complex and Atypical Eating Disorders presents the available data about atypical and complex ED, in addition to what is known about treatment approaches. The first section contains chapters on the treatment of eating disorders with various psychiatric comorbidities, including trauma, borderline personality disorder, substance use, suicidality, anxiety disorders, and autism spectrum disorders, which may greatly complicate the application of standard treatment approaches. The second section contains chapters exploring treatment of eating disorders with atypical symptom presentations which (i) are not located as a specific diagnostic category in diagnostic criteria for ED’s, (ii) centrally feature ED pathology, and (iii) have emerging data suggesting the distinct nature of the syndrome, including purging disorder, muscle dysmorphia, night eating syndrome, and anorexia with a history of obesity. The final section has chapters which focus on how to adapt eating disorder treatment for atypical populations typically neglected in controlled treatment trials: LGBT, pediatric, male, ethnically diverse, and older adults.
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Appelbaum, Kenneth L., et Kevin R. Murphy. Attention deficit disorders. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199360574.003.0037.
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The diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) in correctional settings is in itself problematic and quite contentious; treating the disorder more so. Community prevalence studies estimate that 2.5% to 4% of adults in the United States and worldwide meet diagnostic criteria for ADHD. Some research findings suggest that ADHD occurs at far greater prevalence rates among criminal justice populations than in the population at large. The nature of the condition, its assessment, and its management combine to create a perfect storm of potentially vexing challenges for the prison psychiatrist. This chapter reviews those diagnostic and treatment challenges, including the risk of diversion and misuse of controlled substances among inmates. An assessment and treatment model is presented that takes into account and minimizes risk while helping ensure access to care in appropriately selected cases. Some inmates have a compelling need for treatment, potentially including stimulant medications. Neither unbridled use nor complete elimination of stimulants makes good clinical or administrative sense for correctional systems. An approach that relies on current impairment in significant functional areas, meaningful involvement in treatment, and absence of active misuse of substances will allow access to medication for those with verifiable need while lessening the risks associated with prescription of controlled substances in jails and prisons. The issues of differential diagnosis in a population with epidemic substance abuse, the challenges of appropriate management, and an evidence-based treatment model are discussed in this chapter.
Chapitres de livres sur le sujet "Complex natural substances"
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Ruether, Feelly, et Gabriele Sadowski. « Solubility of Complex Natural and Pharmaceutical Substances ». Dans Industrial Scale Natural Products Extraction, 27–54. Weinheim, Germany : Wiley-VCH Verlag GmbH & Co. KGaA, 2011. http://dx.doi.org/10.1002/9783527635122.ch2.
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Colombo, Claudio, Giuseppe Palumbo, Ruggero Angelico, Andrea Ceglie et Jizheng He. « Molecular Size Distribution and Shape of Humic Substance and Ferrihydrite Coprecipitated Complexes ». Dans Functions of Natural Organic Matter in Changing Environment, 197–201. Dordrecht : Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-5634-2_35.
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Huntjens, Patrick. « Conceptual Background of Transformative Social-Ecological Innovation ». Dans Towards a Natural Social Contract, 83–120. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-67130-3_4.
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AbstractIn this chapter I survey key theories and concepts that provide substance to the workings of Transformative Social-Ecological Innovation (TSEI). A number of relevant theories and concept have already been mentioned in the previous chapters, such as Social Contract theory (Sect. 10.1007/978-3-030-67130-3_3#Sec1), and in Sects. 10.1007/978-3-030-67130-3_3#Sec8 and 10.1007/978-3-030-67130-3_3#Sec13, including resilience theory and social-ecological systems (Sect. 10.1007/978-3-030-67130-3_3#Sec8), quintuple helix innovation model (Sect. 10.1007/978-3-030-67130-3_3#Sec13), as well as institutional change and the structure-agency debate (Sect. 10.1007/978-3-030-67130-3_3#Sec13), and several economic theories (Sects. 10.1007/978-3-030-67130-3_3#Sec2 and 10.1007/978-3-030-67130-3_3#Sec3). In this chapter I will start with providing a conceptual discussion and definition on Transformative Social-Ecological Innovation (Sect. 4.1), and devote more attention to various theories and approaches that are relevant for TSEI, such as transition studies (Sect. 4.2), institutional design principles for governing the commons (Sect. 4.3), design principles from nature (Sect. 4.4), complex adaptive systems (Sect. 4.5), adaptive, reflexive, and deliberative approaches to governance, management, and planning (Sect. 4.6), social learning, policy learning, and transformational learning (Sect. 4.7), shared value, multiple value creation, and mutual gains approach (Sect. 4.8), effective cooperation (Sect. 4.9), transdisciplinary cooperation, living labs, and citizen science (Sect. 4.10), and the art of co-creation: approaches, principles and pitfalls (Sect. 4.11).
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Roxo, Mariana, et Michael Wink. « The Use of the Nematode Caenorhabditis Elegans to Study Antioxidant and Longevity-Promoting Plant Secondary Metabolites ». Dans New Findings from Natural Substances, 133–63. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815051421122010009.
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Oxidative stress is implicated in the pathophysiology of aging and age.related health conditions, such as cancer, cardiovascular disorders and neurodegenerative diseases; therefore, the supplementation of diet with plant-derived antioxidants is recognized as a potential strategy to delay or even prevent the onset of age-related diseases. Among the model organisms commonly used in the early phases of anti-aging drug discovery, the nematode Caenorhabditis elegans has proven useful for investigating the bioactivity of complex extracts and isolated plant secondary metabolites. In this chapter, we have reviewed recent studies on the antioxidant, longevity-promoting and neuroprotective activities of polyphenol-rich plant extracts in C. elegans, with particular focus on the highly conserved insulin/IGF-1 signaling pathway.
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Raymont, Paul. « Leibniz’s Distinction Between Natural and Artificial Machines ». Dans The Paideia Archive : Twentieth World Congress of Philosophy, 148–52. Philosophy Documentation Center, 1998. http://dx.doi.org/10.5840/wcp20-paideia199811256.
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I maintain that Leibniz's distinction between 'organic machines of nature' and the artificial machine that we produce cannot be adequately understood simply in terms of differing orders of structural complexity. It is not simply that natural machines, having been made by God, are infinitely more complex than the products of our own artifice. Instead, Leibniz's distinction is a thoroughly metaphysical one, having its root in his belief that every natural machine is a corporeal substance, the unity and identity conditions of which derive ultimately from its substantial form. Natural machines are thus true unities, while artificial machines are mere aggregates of substances and are therefore only accidental unities. I briefly explore this connection between Leibniz's distinction between natural and artificial machines and his views about individuality. I conclude on a polemical note, in which it is suggested that these results undermine the currently popular view that Leibniz renounced corporeal substances toward the end of his life.
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Kumar Gautam, Rajneesh, Dimuth Navaratna, Shobha Muthukumaran, Amarendra Singh, Islamuddin et Nandkishor More. « Humic Substances : Its Toxicology, Chemistry and Biology Associated with Soil, Plants and Environment ». Dans Humic Substance [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98518.
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In recent decades, scientists in different disciplines have been increasingly concerned about the fate of natural organic matter, and in particular of humic substances (HS). The term humic substances (HS) incorporates refractory autochthonous and terrestrial organic matter in the soil and aquatic ecosystem, and are one of the key fractions of natural organic matter. These substances are important chelators of trace elements constituting complex class of molecular structures that occur naturally, consisting of aggregation and assembly processes in which biomolecules derived from plant and animal residues are gradually transformed through biotic and abiotic tracts. Since these organic compounds are bound by or linked with soil mineral fractions, they must be physically or chemically separated from the inorganic components by an extraction method before their physico-chemical study. This chapter focuses on the chemo-toxicological, molecular aspects of humic compounds and their derivatives such as humins, fulvic acids, humic acids etc., with their agricultural, biomedical, environmental and biochemical applications. In addition to studying their impact on plant physiology and soil microstructure to expand our understanding about humic compounds.
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Hallinan, Dara. « Testing the GDPR in Relation to Biobanking ». Dans Protecting Genetic Privacy in Biobanking through Data Protection Law, 129–47. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780192896476.003.0007.
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This chapter looks at when the General Data Protection Regulation (GDPR) applies, rationae materiae, to biobanking—only when the law applies to biobanking can it be expected to provide any protection for genetic privacy rights in biobanking at all. The GDPR's applicability criteria are outlined in Article 2; criteria concern both the types of processing activity covered by the GDPR and the mechanics of processing covered by the GDPR. In relation to the mechanics of biobank processing, the situation is complex. The key question which emerges is which types of biobanking substances can qualify as personal data? The concept of personal data can be usefully broken down into two aspects of any processing operation. First, the substance being processed: to qualify as personal data, a substance must be able to fulfil three criteria. A substance must be ‘information’, it must ‘relate to’ a specific person, and that person must be a ‘natural person’. In the biobanking context, health, lifestyle, and biographical information, sequenced genomic data, and individual research results certainly fulfil these criteria. Second, the link between the substance and a specific individual: to qualify as personal data, a substance must relate to an individual who is ‘identified or identifiable’. All biobanking substances processed in either linked or pseudonymised form will certainly qualify as ‘identified or identifiable’.
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Fernando Mahler, Claudio, Nicoly Dal Santo Svierzoski et Cassiano Augusto Rolim Bernardino. « Chemical Characteristics of Humic Substances in Nature ». Dans Humic Substance [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.97414.
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Humic substances are the main constituents of natural organic matter, found in both aquatic and terrestrial environments. Humic substances are a complex, dispersed, and heterogeneous mixture of various organic compounds synthesized from organic matter residues, decomposed by microorganisms. Most scientists indicate that humic substances are as a supramolecular association of small heterogeneous molecules stabilized by weak intermolecular bonds. When these substances are presented in water intended for drinking or industrial use, it can have a significant impact on the treatability of this water and on the success of chemical disinfection processes, due to possible formation of organic compounds harmful to human health. Moreover, the humic substances can be used of several ways such as fertilizer to help in the development of plants, to improve soil erosion and to removal of organic compounds and metals from soils and waters. In addition, humic substances suggest an important role in mitigating areas degraded by the phytoremediation technique. The purpose of chapter is to provide an overview of humic substances and to discuss their concepts, chemical characteristics, ecological effects and technological applications for soils and aquatic systems.
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Vladimirovna Simakova, Inna, Alexey Alekseevich Vasiliev, Konstantin Vyacheslavovich Korsakov, Lyudmila Alexandrovna Sivokhina, Vladimir Vasilievich Salautin, Lyudmila Yurievna Gulyaeva et Nikita Olegovich Dmitriev. « Role of Humic Substances in Formation of Safety and Quality of Poultry Meat ». Dans Humic Substance [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96595.
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The purpose of this chapter was to study the influence of humic substances on the formation of the safety and quality of poultry meat. The high abilities of the natural and organic complex of humic acids “Reasil®HumicHealth” (produced in Russia, Saratov) to sorb and desorb five mycotoxins of compound feed (aflatoxin B1, ochratoxin, toxin T-2, zearalenone and fuminisin B1) were experimentally established. The hepatoprotective ability of humic acids was observed in experiments on broilers using rapeseed meal containing an increased amount of secondary plant metabolites that could cause liver damage. It was found out that the inclusion of humic acids in the amount of 1 and 1.5 g per 1 kg of feed to the main diet of broiler chickens has a more stable positive effect, both in terms of slaughter indicators (yield of semieviscerated carcasses and carcasses of complete evisceration), and in the production of the most valuable natural semi-finished products (breast, chicken legs) due to the intensive growth of muscle tissue. A clear improvement in the morpho-biochemical and immunological parameters of blood and micromorphometric characteristics of the organs of the immune system of poultry was noted with the use of different concentrations of humic acid salts. The use of the additive at the rate of 1 and 1.5 g per 1 kg of feed does not negatively affect the sensory indicators of finished culinary products.
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Mauli, Marcia M., Adriana M. Meneghetti et Lúcia H. P. Nóbrega. « Terpenes Behavior in Soil ». Dans Terpenoids : Recent Advances in Extraction, Biochemistry and Biotechnology, 169–99. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9781681089645122010010.
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Soil is a complex and dynamic system in constant change due to its natural processes, as well as interaction among physical, chemical and biological characteristics that take part in it. However, the greatest transformation occurred due to the farm business and the adopted management system. Thus, man can manipulate some soil characteristics and make it more suitable for cropping development. Although anthropic action cannot fully control how soil characteristics interact, it is possible to track them. The action of chemical substances should not be disregarded, a product of the secondary metabolism of plants, since they interfere with plant's ability to compete and survive. Such substances can act out as protectors against herbivores and pathogens. They can be attractive or repellent agents in plant-plant competition and plant-microorganism symbiosis. They can also influence the interaction between plant matter and soil organisms. Among these substances, terpenoids are highlighted as the most structurally diverse chemical family in the class of secondary metabolites that are part of natural products. This knowledge allows a better understanding of nutrient decomposition and cycling processes, the influence of environmental factors on production and terpenoid variability in some plants with medicinal and economic importance.
Actes de conférences sur le sujet "Complex natural substances"
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Abdullina, D., K. Valeev et R. Safin. « ENERGY RESOURCE-SAVING PLANT FOR EXTRACTION OF BIOLOGICALLY ACTIVE SUBSTANCES ». Dans Modern machines, equipment and IT solutions for industrial complex : theory and practice. FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov, 2021. http://dx.doi.org/10.34220/mmeitsic2021_175-179.
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As know, all wood material is recycled only half, and the rest of it remains unused. In practice, wood waste is most often plowed or burned, at a time when such wood is a valuable natural raw material that can compensate for the needs of a number of sectors of the economy. In this regard, the problem of recycling waste from the woodworking industry is very relevant today. Wood waste contains a large amount of substances capable of exhibiting biological activity. In particular, such biologically active substances include betulin, which is found in birch bark, which, due to its many advantages, has found wide application in medical, perfumery, cosmetic, food and other industries. For the rational use of wood and wood materials, it is necessary to develop new technologies and equipment for processing wood into products that are in demand for mankind. The paper provides an overview of the processing of birch bark. The relevance and prospects of birch species as a raw material for the chemical industry have been established. An installation for obtaining biologically active substances from wood waste is presented.
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Tomenko, D., E. Aksenov et Lyudmila Novikova. « PHENOLIC COMPOUNDS OF CONIFEROUS TREES ». Dans Modern machines, equipment and IT solutions for industrial complex : theory and practice. FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov, 2021. http://dx.doi.org/10.34220/mmeitsic2021_351-356.
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The paper discusses the classification, structure and properties of natural phenolic compounds found in conifers wood species of Russia. The reasons for the variety of detected phenolic compounds (more than 2000) are considered, including the type and conditions of plant growth, environmental factors, as well as methods for extraction of substances. Coniferous extractives include monomeric, dimeric and polymeric phenolic compounds in bound and free form, and their content differs significantly for various species and parts of a woody plant. Depending on the polarity of the solvent used (water, petroleum ether, dimethyl ether, ethyl acetate, acetone, etc.), the yield, chemical composition and structure of the extracted phenolic compound change. It was shown that bark extracts of Larch and Fir contain the most phenolic acids and extractive substances than Pine, Cedar and Spruce, while the content of polar substances is higher in needles, and non- polar substances in plant shoots. Phenolic compounds are secondary plant metabolites, exhibiting fungicidal, virucidal and strong antioxidant effects, that make them a valuable basis for the creation of drugs.
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Potapova, I. A., E. V. Nielina et N. V. Prokhorova. « Metal storage capacity evaluation of humic and himatomelanic acids hydroxymethyl derivatives obtained from brown coal ». Dans VIII Vserossijskaja konferencija s mezhdunarodnym uchastiem «Mediko-fiziologicheskie problemy jekologii cheloveka». Publishing center of Ulyanovsk State University, 2021. http://dx.doi.org/10.34014/mpphe.2021-165-168.
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Humic substances represent the most extensive and reactive class of natural compounds. A more nature-saving way is to obtain humus substances from solid combustible minerals and waste from their processing. The ability of these compounds to form stable complexes with heavy metals, which increases with their directed chemical modification, has been experimentally confirmed. The effectiveness of the phenol-formaldehyde condensation method for the modification of initial humus substances has been confirmed. The interaction of humic and himatomelanic acids with formaldehyde leads to an increase in sorption activity in comparison with the initial humic acids with respect to heavy metals. This aspect has been studied and confirmed in model experiments with copper ions.
Key words: humic substances, brown coal, humic and himatomelanic acids, directed chemical modification, hydroxymethyl (methyl) derivatives, heavy metals, copper ions, complex formation.
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Buchatskaya, Yu, S. Salah, D. Durce, M. Devillers et R. Steudtner. « How does the complex structure and size of Boom Clay natural dissolved organic matter affect its reactivity towards radionuclides ? » Dans Fifth International Conference of CIS IHSS on Humic Innovative Technologies «Humic substances and living systems». CLUB PRINT ltd., 2019. http://dx.doi.org/10.36291/hit.2019.buchatskaya.023.
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Bryndina, Larisa, et Ol'ga Baklanova. « BIOTECHNOLOGICAL METHODS OF PROCESSING FOREST COMPLEX WASTE ». Dans Modern machines, equipment and IT solutions for industrial complex : theory and practice. FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov, 2021. http://dx.doi.org/10.34220/mmeitsic2021_210-214.
Texte intégralRésumé :
The intensive development of agriculture in the Voronezh Region has led to serious negative changes in the soil condition. There was a decrease in the content of humus and mineral substances. More than 350 thousand hectares of the region’s soils have a low content of humus and, as a result, organic matter (s) available for decomposition. Among the methods of soil restoration, soil improvers are gaining popularity. These are, as a rule, compost, various organic fillers, bio-coal. The latter are considered promising meliorants of natural origin. The processing of waste from the timber industry and sewage sludge into bio-coal is proposed. Its influence on the water permeability of leached chernozem is studied. The positive effect of biochar on the filtration properties of the soil has been established. The filtration rate after applying the biochar increased by 2.5-4 times compared to the control. The maximum water permeability was observed at a biochar concentration of 20 -30% to the soil mass. It is established that the amount of moisture that has passed through the soil depends on the dose of the introduced biochar. The addition of biochar in the amount of 5, 10, 20 and 30% led to a significant increase in the filtration qualities of the soil, compared with the control. The tendency of the ability of biochar to improve the water-physical properties of the soil is revealed.
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Burlakovs, Juris, Jovita Pilecka, Inga Grinfelde et Ruta Ozola-Davidane. « Clay minerals and humic substances as landfill closure covering material constituents : first studies ». Dans Research for Rural Development 2020. Latvia University of Life Sciences and Technologies, 2020. http://dx.doi.org/10.22616/rrd.26.2020.032.
Texte intégralRésumé :
Soil and groundwater as the leachate may contaminate surrounding watersheds, thus different pollutants from closed dumps and landfills pose significant risks to human health and ecology. Pollution may lead to soil and water degradation however it might be diminished through sustainable dump site closure projects and processual management. Several decades of clays and clay minerals studies lead to modified clay composites concept that is one of the potential promising solutions for building the landfill covering material and serve as capping biocover layer at the same time. As humic substances are constituents of soil organic matter, pollutants can be sorbed on the surfaces of complex molecules. This kind of humic acid-clay mineral composite materials thus might become as low cost building material component - covering material. Construction of such layer are to be performed as a combination of clay-humic composites and landfill mined fine fraction of waste with small amendment of natural soil. Several hypotheses that are already proven has to be mentioned: a) Clay minerals produce composites with humic substances; 2) Clay-humic complexes reduce through sorption both organic and inorganic pollutants; 3) Low risk of toxic byproducts from landfill mined waste fine fraction can be the problem; 4) Such composites mostly would trap toxic contaminants (e.g., pharmaceuticals) found in reworked fine fraction of waste. The aim of the work is to provide alternative solution for landfill closure by giving theoretical considerations from multidisciplinary knowledge of environmental engineering, chemistry and waste management.
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Mikheeva, L. A., S. A. Shchelkaev et A. V. Mikheeva. « Preparation of copper pectate preparation for use in medical practice ». Dans VIII Vserossijskaja konferencija s mezhdunarodnym uchastiem «Mediko-fiziologicheskie problemy jekologii cheloveka». Publishing center of Ulyanovsk State University, 2021. http://dx.doi.org/10.34014/mpphe.2021-147-150.
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Currently, the processes of complexation of various ligands, including biopolymers with metals, attract the attention of scientists from different countries not only in order to obtain new data on the methods of synthesis and properties of metal complexes, but also in connection with the search for ways to obtain new effective biologically active drugs among them.
Since the life around us is oversaturated with various artificially produced drugs that have a negative effect on the human body, today, more than ever before, the question arises of using natural, environmentally friendly ingredients instead of synthetic ones, for example, such as pectin. The study of the structural parameters and physico-chemical properties of complexes of pectin substances with metals will significantly expand the scope of their practical use.
Key words: metal complexes, pectin, copper pectate, complex formation.
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BŁASIAK, S. « Analysis of Pressure Distribution in Non-Contacting Impulse Gas Face Seals ». Dans Terotechnology XII. Materials Research Forum LLC, 2022. http://dx.doi.org/10.21741/9781644902059-37.
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Abstract. Strict norms regarding the emission of harmful substances into the natural environment impose stringent requirements on engineers designing sealing units, especially when designing new mechanical seals. This especially concerns mechanical non-contacting seals with various surface layer modifications. Complex mathematical models that enable analyzing complex physical phenomena are developed to support the designing works. The presented paper includes specification of the impulse gas face seals mathematical model which takes into consideration the non-linear Reynolds equation. The mathematical model was solved based on the author’s computer program developed in the C++ language, thereby enabling a series of numerical tests and analyses on the phenomena taking place in the radial clearance during the seal’s operation. The paper also includes the final conclusions and a series of features specific for the subject impulse gas face seals.
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Miu, Lucretia, Simona-Maria Paunescu, Maria-Cristina Micu, Iulia-Maria Caniola, Madalina Ignat, Claudiu Sendrea et Elena Badea. « Chemical and physico-mechanical characterizations of leather for restoration ». Dans The 8th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2020. http://dx.doi.org/10.24264/icams-2020.v.7.
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Leather is a complex material mostly consisting of a matrix of collagen, chemically stabilized by various tannins. This matrix, sooner or later undergoes alterations as a consequence of interactions between their structure and environment. A comprehensive study based on multiple chemical and physico-mechanical standard tests regarding leather samples which were artificially aged from 7 to 112 days has been made at 70°C. The behavior in artificial aging of calf leather samples tanned at pilot level with two different vegetal tannins, mimosa and quebracho, were investigated due to its’s similarity to the natural degradation of historical leather samples. Physico-mechanical characteristics of historical leather can be corelated with the high impact of degree of deterioration even though there are no standard regulations. To be able to choose the proper way to achieve compatibility with an appropriate material in the restoration-conservation process, multiple sample characteristic must be known. The condition of historical leather can be assessed by a series of simple visual and physical examinations which determine the flexibility, strength and coherency of the fibers and then correlate these assessments with the condition of leather as determined by various chemical and physical-chemical analyses. Therefore, the following chemical standard tests were made: volatile substances, shrinkage temperature, extractable substances, total soluble substances and the following physico-mechanical tests: tensile strength, elongation at breaking and tear resistance.
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Dimitrov, Emil, Martin Nenov et Toma Shishkov. « SOIL PROPERTIES OF CHROMIC CAMBISOLS FROM THE UPPER THRACIAN LOWLAND IN THE SOUTHERN BULGARIA ». Dans 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/3.1/s13.34.
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The paper deals with soil properties characterized the intrinsic peculiarity of studied Chromic Cambisols from the Upper Thracian Lowland, in the Southern Bulgaria. To fulfill the aim, a systematic survey and sampling have been carried out on the terrain with conventional and organic systems of farming. Soil physical, chemical and physicochemical properties were discussed including the analyzed data for particle size distribution, content and composition of organic substances, cation exchange capacity, soil bulk density, soil particle density and porosity. The organic matter was directly dependent on the local environmental conditions, the result of natural bioactivity. Soil adsorbent was affected by acidification in the surface horizon so there was evidence of initial destructive processes of the soil adsorption complex, despite the relatively high degree of soil saturation with bases. The comparison between conventional and organic farming showed that there was no statistically significant difference in the studied soil indexes, that could be provoked by the farming system applied at the trials.
Rapports d'organisations sur le sujet "Complex natural substances"
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Schutt, Timothy C., et Manoj K. Shukla. Computational Investigation on Interactions Between Some Munitions Compounds and Humic Substances. Engineer Research and Development Center (U.S.), février 2021. http://dx.doi.org/10.21079/11681/39703.
Texte intégralRésumé :
Humic acid substances (HAs) in natural soil and sediment environments effect the retention and degradation of insensitive munitions compounds and legacy high explosives (MCs): DNAN, DNi- NH4+, nMNA, NQ, NTO (neutral and anionic forms), TNT, and RDX.A humic acid model compound has been considered using molecular dynamics, thermodynamic integration, and density functional theory to characterize the munition binding ability, ionization potential, and electron affinity compared to that in the water solution. Humic acids bind most compounds and act as both a sink and source for electrons. Ionization potentials suggest HAs are more susceptible to oxidation than the MCs studied. The electron affinity of HAs are very conformation-dependent and spans the same range as the munition compounds. When HAs and MCs are complexed the HAs tend to radicalize first thus buffering MCs against reductive as well as oxidative attacks.