Littérature scientifique sur le sujet « Hydrophilic solute »

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Articles de revues sur le sujet "Hydrophilic solute"

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Monroe, Jacob I., Sally Jiao, R. Justin Davis, Dennis Robinson Brown, Lynn E. Katz et M. Scott Shell. « Affinity of small-molecule solutes to hydrophobic, hydrophilic, and chemically patterned interfaces in aqueous solution ». Proceedings of the National Academy of Sciences 118, no 1 (28 décembre 2020) : e2020205118. http://dx.doi.org/10.1073/pnas.2020205118.

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Performance of membranes for water purification is highly influenced by the interactions of solvated species with membrane surfaces, including surface adsorption of solutes upon fouling. Current efforts toward fouling-resistant membranes often pursue surface hydrophilization, frequently motivated by macroscopic measures of hydrophilicity, because hydrophobicity is thought to increase solute–surface affinity. While this heuristic has driven diverse membrane functionalization strategies, here we build on advances in the theory of hydrophobicity to critically examine the relevance of macroscopic characterizations of solute–surface affinity. Specifically, we use molecular simulations to quantify the affinities to model hydroxyl- and methyl-functionalized surfaces of small, chemically diverse, charge-neutral solutes represented in produced water. We show that surface affinities correlate poorly with two conventional measures of solute hydrophobicity, gas-phase water solubility and oil–water partitioning. Moreover, we find that all solutes show attraction to the hydrophobic surface and most to the hydrophilic one, in contrast to macroscopically based hydrophobicity heuristics. We explain these results by decomposing affinities into direct solute interaction energies (which dominate on hydroxyl surfaces) and water restructuring penalties (which dominate on methyl surfaces). Finally, we use an inverse design algorithm to show how heterogeneous surfaces, with multiple functional groups, can be patterned to manipulate solute affinity and selectivity. These findings, importantly based on a range of solute and surface chemistries, illustrate that conventional macroscopic hydrophobicity metrics can fail to predict solute–surface affinity, and that molecular-scale surface chemical patterning significantly influences affinity—suggesting design opportunities for water purification membranes and other engineered interfaces involving aqueous solute–surface interactions.
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Berg, M. M., K. J. Kim, R. L. Lubman et E. D. Crandall. « Hydrophilic solute transport across rat alveolar epithelium ». Journal of Applied Physiology 66, no 5 (1 mai 1989) : 2320–27. http://dx.doi.org/10.1152/jappl.1989.66.5.2320.

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Diffusional fluxes of a series of hydrophilic nonelectrolytes (molecular radii ranging from 0.15 to 0.57 nm) were measured across the alveolocapillary barrier in the isolated perfused fluid-filled rat lung. Radiolabeled solutes were lavaged into the distal air spaces of isolated Ringer-perfused lungs, and apparent permeability-surface area products were calculated from the rates of isotope appearance in the recirculating perfusate. These data were used to estimate theoretical equivalent pore radii in the alveolar epithelium, with the assumption of diffusive flow through water-filled cylindrical pores. The alveolar epithelium is best characterized by two pore populations, with small pores (radius 0.5 nm) occupying 98.7% of total pore area and larger pores (radius 3.4 nm) occupying 1.3% of total pore area. Net water flow out of the alveolar space was measured by including an impermeant solute (dextran) in the lavage fluid and measuring its concentration in the alveolar space as a function of time. Under control conditions, net water flow averaged 167 nl/s. When 24 microM terbutaline was added to the perfusate, net water flow increased significantly to 350 nl/s (P less than 0.001). Terbutaline had no effect on the fluxes of either glycerol (which traverses the small pore pathway) or sucrose (which traverses the large pore pathway). These findings indicate that the intact mammalian alveolar epithelium is complex and highly resistant to the flow of solutes and water.
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Pandit, Bijan, Abhijit Sarkar et Biswajit Sinha. « Solution thermodynamics of sodium pyruvate in aqueous glycine solutions at T 298.15-313.15 K ». Journal of the Serbian Chemical Society 81, no 11 (2016) : 1283–94. http://dx.doi.org/10.2298/jsc151031034p.

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In this study we investigated the effects of sodium pyruvate on the solution thermodynamics of glycine in terms of the solute-solute and solute-solvent interactions in aqueous solutions. Measured density and viscosity were used to derive apparent molar volumes (?V), standard partial molar volumes (?V0) and viscosity B-coefficients at 298.15, 303.15 K, 308.15, and 318.15 K under ambient pressure. The interactions are further discussed in terms of ion-dipolar, hydrophobic- hydrophobic, hydrophilic-hydrophobic group interactions. The activation parameters of viscous flow were also discussed in terms of transition state theory. The overall results indicated that ion-hydrophilic and hydrophilic-hydrophilic group interactions are predominant in the ternary solutions.
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Sarkar, Abhijit, et Biswajit Sinha. « Solution thermodynamics of aqueous nicotinic acid solutions in presence of tetrabutylammonium hydrogen sulphate ». Journal of the Serbian Chemical Society 78, no 8 (2013) : 1225–40. http://dx.doi.org/10.2298/jsc111212027s.

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In this study we investigated the effects of tetrabutylammonium hydrogen sulphate (Bu4NHSO4) on the solute-solute and solute-solvent interactions in the aqueous solutions of nicotinic acid in terms of apparent molar volumes (?V), standard partial molar volumes (?V0) and viscosity B-coefficients at 298.15, 308.15, and 318.15 K under ambient pressure. These interactions are further discussed in terms of ion-dipolar, hydrophobic- hydrophobic, hydrophilic-hydrophobic group interactions. The activation parameters of viscous flow for Bu4NHSO4 in the aqueous solutions of nicotinic acid were discussed in terms of transition state theory. The overall results indicated that ion-hydrophilic and hydrophilic-hydrophilic group interactions are predominant in the aqueous solutions of nicotinic acid and Bu4NHSO4 has a dehydration effect on the hydrated nicotinic acid.
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Kim, Yong Ho, Kwang-Jin Kim, David Z. D’Argenio et Edward D. Crandall. « Characteristics of Passive Solute Transport across Primary Rat Alveolar Epithelial Cell Monolayers ». Membranes 11, no 5 (30 avril 2021) : 331. http://dx.doi.org/10.3390/membranes11050331.

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Primary rat alveolar epithelial cell monolayers (RAECM) were grown without (type I cell-like phenotype, RAECM-I) or with (type II cell-like phenotype, RAECM-II) keratinocyte growth factor to assess passive transport of 11 hydrophilic solutes. We estimated apparent permeability (Papp) in the absence/presence of calcium chelator EGTA to determine the effects of perturbing tight junctions on “equivalent” pores. Papp across RAECM-I and -II in the absence of EGTA are similar and decrease as solute size increases. We modeled Papp of the hydrophilic solutes across RAECM-I/-II as taking place via heterogeneous populations of equivalent pores comprised of small (0.41/0.32 nm radius) and large (9.88/11.56 nm radius) pores, respectively. Total equivalent pore area is dominated by small equivalent pores (99.92–99.97%). The number of small and large equivalent pores in RAECM-I was 8.55 and 1.29 times greater, respectively, than those in RAECM-II. With EGTA, the large pore radius in RAECM-I/-II increased by 1.58/4.34 times and the small equivalent pore radius increased by 1.84/1.90 times, respectively. These results indicate that passive diffusion of hydrophilic solutes across an alveolar epithelium occurs via small and large equivalent pores, reflecting interactions of transmembrane proteins expressed in intercellular tight junctions of alveolar epithelial cells.
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Stulc, J., et B. Stulcova. « Asymmetrical transfer of inert hydrophilic solutes across rat placenta ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 265, no 3 (1 septembre 1993) : R670—R675. http://dx.doi.org/10.1152/ajpregu.1993.265.3.r670.

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Transfer of [14C]mannitol, 51Cr-labeled EDTA, and [14C]-inulin from mother to fetus and from fetus to mother was measured in rats under pentobarbital anesthesia. The clearance of the three substances from the mother to fetus (Kmf) was 2.69 +/- 0.38, 1.93 +/- 0.73, and 0.47 +/- 0.14 microliter/min (means +/- SE), respectively, and the clearance from fetus to mother (Kfm) was 5.97, 6.66, and 4.95 microliters/min, respectively (the SE could not be estimated). Kfm appears to be consistently higher than Kmf by an almost constant value of approximately 4 microliters/min. To explain this a hypothesis was proposed according to which volume flow circulates across the placenta. Solute-free water is driven transcellularly across the placental barrier from the maternal to the fetal side by a difference of osmotic pressure created by active transport of some solutes (mainly Na+) to the fetus. Water together with all solutes dissolved returns from fetus to mother by filtration through wide extracellular channels in the placenta down a hydrostatic pressure gradient.
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Brown, Daniel, You Han Bae et Sung Wan Kim. « Hydrophilic Solute Release from a Hydrophobic Elastic Matrix ». Macromolecules 27, no 18 (août 1994) : 4952–59. http://dx.doi.org/10.1021/ma00096a016.

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Xu, Yang, Yingying Zhu, Zhen Chen, Jinyuan Zhu et Geng Chen. « A Comprehensive Review on Forward Osmosis Water Treatment : Recent Advances and Prospects of Membranes and Draw Solutes ». International Journal of Environmental Research and Public Health 19, no 13 (5 juillet 2022) : 8215. http://dx.doi.org/10.3390/ijerph19138215.

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Forward osmosis (FO) is an evolving membrane separation technology for water treatment and reclamation. However, FO water treatment technology is limited by factors such as concentration polarization, membrane fouling, and reverse solute flux. Therefore, it is of a great importance to prepare an efficient high-density porous membrane and to select an appropriate draw solute to reduce concentration polarization, membrane fouling, and reverse solute flux. This review aims to present a thorough evaluation of the advancement of different draw solutes and membranes with their effects on FO performance. NaCl is still widely used in a large number of studies, and several general draw solutes, such as organic-based and inorganic-based, are selected based on their osmotic pressure and water solubility. The selection criteria for reusable solutes, such as heat-recovered gaseous draw, magnetic field-recovered MNPs, and electrically or thermally-responsive hydrogel are primarily based on their industrial efficiency and energy requirements. CA membranes are resistant to chlorine degradation and are hydrophilic, while TFC/TFN exhibit a high inhibition of bio-adhesion and hydrolysis. AQPs are emerging membranes, due to proteins with complete retention capacity. Moreover, the development of the hybrid system combining FO with other energy or water treatment technologies is crucial to the sustainability of FO.
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Briskin, Donald P. « Membranes and Transport Systems in Plants : An Overview ». Weed Science 42, no 2 (juin 1994) : 255–62. http://dx.doi.org/10.1017/s0043174500080371.

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Membranes define the outer boundary of the living protoplast and the internal compartmentation of plant cells. From a structural point of view, membranes consist of a lipid bilayer and proteins essential for functions such as solute transport, signal transduction, and numerous metabolic reactions. While membranes can represent a significant barrier to the free movement of many solutes, those with sufficient lipid solubility may move across membranes by dissolving into the lipid bilayer. However, selective membrane transport is generally observed for hydrophilic solutes such as mineral nutrients and cell metabolites. Such selective transport requires an input of metabolic energy, and in plants this occurs via the production of proton electrochemical gradients across the membrane by substrate- (ex. ATP, PPi) driven proton pumps. Selective solute transport is then mediated by membrane-associated secondary transport systems which utilize the proton electrochemical gradient to drive the transport process. This review of membrane structure and transport system function provides a background for a further examination of herbicide interactions with plant membranes.
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MASON, G. R., A. M. PETERS, E. BAGDADES, M. J. MYERS, D. SNOOK et J. M. B. HUGHES. « Evaluation of pulmonary alveolar epithelial integrity by the detection of restriction to diffusion of hydrophilic solutes of different molecular sizes ». Clinical Science 100, no 3 (25 janvier 2001) : 231–36. http://dx.doi.org/10.1042/cs1000231.

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The rate of transfer of a hydrophilic solute from the alveoli to pulmonary blood following inhalation as an aerosol depends on the molecular size of the solute and the permeability of the alveolar epithelium. The value of this measurement for assessing damage to the epithelium in lung disease is compromised by cigarette smoking, which accelerates clearance by unknown mechanisms. The rates of clearance of 99mTc-labelled diethylenetriaminepenta-acetic acid (DTPA) (molecular mass 492 Da) and 113mIn-labelled biotinylated DTPA (B-DTPA) (molecular mass 1215 Da) were monitored simultaneously by dynamic γ-radiation camera imaging following simultaneous inhalation, and compared between eight normal non-smoking subjects and nine habitual cigarette smokers. The clearance rates of DTPA were 0.95 (S.D. 0.39)%/min in non-smokers and 4.13 (1.06) %/min in smokers. These were about twice the clearance rates of B-DTPA, which in the corresponding groups were 0.41 (0.26) and 2.12 (0.72)%/min respectively. The ratio of the B-DTPA/DTPA clearance rates was, in all subjects, less than the ratio (0.74) of the cube roots of the molecular masses of the solutes, assumed to correspond to the ratio of their free diffusion coefficients in water, and was not significantly different between smokers and non-smokers. As alveolar permeability increased, the ratio of clearance rates in the entire population showed a significant trend to increase in a non-linear fashion towards the value corresponding to the ratio of the free diffusion coefficients. We conclude that the diffusion of at least the larger of these two solutes through the pulmonary alveolar epithelium is restricted (i.e. associated with a reflection coefficient greater than zero). Cigarette smoking, however, does not appear to cause a loss of this restriction, and may increase solute clearance by other mechanisms, such as reducing fluid volume within the alveolus, thereby raising the local radiotracer concentration, or increasing the number of pores available for solute exchange without affecting pore size. Conversely, if restriction was lost in lung disease, the ratio of the clearance rates of two solutes of dissimilar sizes could be used to detect disease in smokers as well as non-smokers.
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Thèses sur le sujet "Hydrophilic solute"

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Baines, Fiona Louise. « Water-soluble hydrophilic-hydrophobic block copolymers ». Thesis, University of Sussex, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283139.

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Plummer, Ronda. « Living polymerization of novel hydrophilic polymers / ». [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19201.pdf.

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Soulas, Dimitrios N., et Kyriaki G. Papadokostaki. « Experimental investigation of the release mechanism of hydrophilic solutes from hydrophobic matrices ». Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-188878.

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Soulas, Dimitrios N., et Kyriaki G. Papadokostaki. « Experimental investigation of the release mechanism of hydrophilic solutes from hydrophobic matrices ». Diffusion fundamentals 11 (2009) 9, S. 1-2, 2009. https://ul.qucosa.de/id/qucosa%3A13929.

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Boudendouna, Abdel Hakim. « Méthodologie de la formulation d’une forme orale solide à libération prolongée ». Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0052/document.

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L'objectif de ce travail a été l'utilisation d'une méthodologie de formulation des formes à libération prolongée. Le choix de «matrices hydrophiles» a été fait en raison de l'intérêt et de l'importance des travaux qui lui sont consacrés, mais surtout en raison de la possibilité d'utilisation de la technologie simple de fabrication des comprimés par compression directe.Le principe actif choisi est le diclofenac de sodium, un anti-inflammatoire largement utilisé dont la molécule est tombée dans le domaine public. Utilisé à raison de 100 mg par comprimé. La première partie bibliographique résume l'intérêt des formes à libération prolongée, décrit les différentes formes galéniques existantes pour la voie orale et fait le point sur les formules et les propriétés des agents matriciels hydrophiles parmi les plus utilisés, notamment les éthers de celluloses, hydroxypropymethylcellulose (METOLOSES®) (1). Dans la partie expérimentale, nous avons réalisé les différentes étapes nécessaires au développement d'une forme à libération prolongée qui correspondant aux étapes classiques de pré-formulation, formulation et optimisation. Dans une première étape d'essais préliminaires nous avons étudiés le comportement d'un point de vue pharmacotechnique des matières premières utilisés seuls et en mélange. Ce qui a permis de faire des orientations en ce qui concerne les différents types de METOLOSES, la nature du diluant, et leurs concentrations. Dans une deuxième étape, nous avons réalisé un premier plan d'expériences de criblage des facteurs, qui permet de déterminer le poids de chacun et leurs éventuelles interactions. Ce qui nous a permis de conclure sur l'effet des différents facteurs en formulation. Dans une troisième étape, nous avons réalisé un deuxième plan d'expériences d'optimisation de la formulation en utilisant un plan composite centré constitué de 9 expériences ce qui a permis de sélectionner une zone de formules optimales. Enfin, la réalisation d'une formule optimale nous a permis de confirmer les résultats obtenus dans les travaux de développement et dont l'objectif été une libération sur 12 heures
The objective of this work was the use of a formulation methodology of prolonged release dosage forms. The choice of “hydrophilic matrices” was done because of the interest and the numbered works which is devoted to it, but also for the use of a simple manufacture technology by direct compression. The selected active pharmaceutical ingredient is one of the most largely used nonsteroidial anti-inflammatory drug, the sodium diclofenac which is out of patent and used at 100 Mg per tablet. The first bibliographical part summarizes the interest of the prolonged release dosage forms, described the existing oral dosage forms and gives a progress report on the formulas and the properties of hydrophilic matrices agents among most used, in particular the cellulose ethers, hydroxypropymethylcellulose (METOLOSES®) (1). In the experimental part, we carried out the various steps necessary to the development of a prolonged release dosage form which correspond to the traditional steps of pre-formulation, formulation and optimization. In a first step of pharmaceutics preliminary tests we studied the behavior of raw materials used alone and in mixture. What made orientations with regard to the various types of METOLOSES, the nature of diluents, and their concentrations. In a second step, we carried out a first screening factors experimental design, which enabled us to conclude on the effect of the various factors in formulation. In a third step, we carried out a second optimization experimental design using a centered composite plan consisted of 9 experiments which lead us to define a space design of optimal formulas. Lastly, the manufacture of a formula from the design space enabled us to confirm the results to development work and for which the objective was a sustained release over 12 hours
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Böhm, Fabian [Verfasser], Martina [Gutachter] Havenith et Christian [Gutachter] Herrmann. « Terahertz spectroscopy of hydrophilic and hydrophobic solutes in aqueous solution / Fabian Böhm ; Gutachter : Martina Havenith, Christian Herrmann ». Bochum : Ruhr-Universität Bochum, 2017. http://d-nb.info/1144614686/34.

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Plumail, Elisabeth. « Mise au point de comprimés matriciels hydrophiles d'un principe actif facilement soluble/ Elisabeth Plumail ». Paris 5, 1991. http://www.theses.fr/1991PA05P052.

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Chirita, Raluca-Ioana. « Développement de nouvelles méthodes séparatives compatibles avec une détection par spectrométrie de masse et par électrochimie pour l'analyse de traces de catécholamines et molécules apparentées ». Thesis, Orléans, 2009. http://www.theses.fr/2009ORLE2043/document.

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Les catécholamines et les indolamines font partie de la famille des neurotransmetteurs. Un déséquilibre dans leur concentration peut être associé à différentes maladies telles les maladies de Parkinson et Alzheimer, la dépression ou la schizophrénie. C’est pourquoi le développement de méthodes de dosage spécifiques et très sensibles du fait de leurs très faibles teneurs dans les fluides biologiques est nécessaire. Dans un premier temps nous avons développé une méthode chromatographique en appariement d’ions (IP-LC) utilisant des colonnes C18 de nouvelle génération (monolithique et « fused core ») et l’acide nonafluoropentanoïque, comme agent d’appariement d’ions volatil. Cette méthode est compatible avec une détection SM en mode d’ionisation positive. Dans un deuxième temps, différents systèmes en mode HILIC ont été évalués. Le choix raisonné de la phase stationnaire offrant la meilleure séparation du mélange de catécholamines a pu être réalisé après avoir testé l’influence sur la séparation des différents groupements fonctionnels disponibles : groupement soit neutre (greffage diol, amide, ou cyano), soit positivement chargé (greffage amino ou triazole) soit négativement chargé (silice vierge avec particules totalement poreuses ou partiellement poreuses « fused core ») ou zwitterionique (greffage sulfobetaïne). La méthode HILIC présente l’avantage d’être compatible aussi bien avec une détection SM en mode d’ionisation positive que négative. Les deux méthodes (IP-LC et HILIC) ont été comparées en termes de résolution, efficacité et limites de détection (LOD), linéarité et répétabilité. Les LODs obtenues sont comprises entre 1 et 100 ng.mL-1. Pour pouvoir doser des teneurs plus faibles, une méthode de pré-concentration de l’échantillon a été développée en associant 2 supports différents (Oasis HLB et PGC). La méthode optimisée SPE-CPL-MS/MS a été enfin appliquée à un extrait de cerveau de mouton
As neurotransmitters, catecholamines play an important role in the control and regulation of numerous brain functions. They are also believed to be implicated in different neurodegenerative disorders. First an ion pairing chromatography method using nonafluoropentanoic acid as volatile ion paring agent was developed on the new generation of C18 columns (monolith and fused core). This method is compatible with MS detection in positive ionization mode. Secondly an HILIC method was optimized using different commercially available HILIC supports, they can be classified as follows: neutral (diol, amide, and cyano bounded), positively charged (amino, triazole bounded), negatively charged (bare silica as wholly porous particles or fused core particles columns) and zwitterionic (sulfobetaine bounded). Our studies lead us to a better understanding of the HILIC retention mechanism and also to the selection of the most appropriated column for catecholamine analysis. Only the HILIC system was compatible with both positive and negative ionization modes. The two chromatographic systems were then compared in terms of resolution, efficiency, detection and quantification limits (LOD/LOQ), calibration linearity and repeatability. The LODs obtained were in the range of 1-100 ng.mL-1. A simple pre-concentration method using Oasis HLB and PGC solid phase extraction cartridges has been optimized in order to enhance the LODs. Finally the optimized SPE-LC-MS/MS method has been applied to the identification of these compounds present in brain extracts
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TAPTUE, ZUBOU GABY BRICE. « Synthesis of Amphiphilic and Hydrophilic Non-PAMAM Dendrimers Nanoparticles for Biomedical Applications and Realization of Water-soluble DDSs of two Triterpenoid Acids ». Doctoral thesis, Università degli studi di Genova, 2019. http://hdl.handle.net/11567/940919.

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Carriers-mediated Drug Delivery emerged as a powerful strategy for the treatment of various pathologies. Many newly developed drugs are rejected by the pharmaceutical industry and will never benefit a patient because of poor bioavailability due to low water solubility and/or cell membrane permeability. Therefore, the development of new delivery technologies could help to overcome this challenge via the increase of specificity due to targeting of drugs to a particular tissue, cell or intracellular compartment, the control over release kinetics, the protection of the active agent or a combination of the above. For years, nanoparticles were proposed as drug carriers, and now are of eminent interest in biomedical applications mainly due to their stability and high drug-loading capabilities as well as permitting an easy control over their physicochemical properties. Among the various nanoparticles successfully tested as delivery tools systems dendrimers represent the most prospective drug delivery systems thanks to their inimitable characteristics including the exact molecular weight, the tree-like structure, poly-fuctionality, the spherical shapes as well as having a low index of polydispersion. The first part of this thesis focuses on the design, preparation and characterization of not cytotoxic amphiphilic polyester-based dendrimers obtained from the 2,2-bis(hydroxymethyl)propanoic acid and functionalized with positive charged amino acids as nanostructures for Drug Delivery applications. While the second part discusses the encapsulation of Ursolic and Oleanolic acids in hydrophilic arginine dendrimers.These acids are two triterpenoids acids from plants kingdom endowed with several pharmacological activities but unfortunately not exploitable because of restrictions such as very poor solubility and consequently low bioavailability.
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Chaparro, Francisco Javier. « Biocompatible Electrospun Vehicles To Enhance the Effectiveness Of Anti-Fertility Strategies And Their Biomimetic Properties As Blood Vessel Scaffolds ». The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1514986344784852.

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Livres sur le sujet "Hydrophilic solute"

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Hydrophilic polymers : Performance with environmental acceptance. Washington, DC : American Chemical Society, 1996.

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Chapitres de livres sur le sujet "Hydrophilic solute"

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Bütün, V., et S. P. Armes. « Synthesis of Novel Shell Cross-Linked Micelles with Hydrophilic Cores ». Dans Stimuli-Responsive Water Soluble and Amphiphilic Polymers, 115–39. Washington, DC : American Chemical Society, 2000. http://dx.doi.org/10.1021/bk-2001-0780.ch007.

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Fink, M. P. « Alterations in Gastrointestinal Barrier Function in Sepsis : The Effect of Lipopolysaccharide on Mucosal Permeability to Hydrophilic Solutes ». Dans Yearbook of Intensive Care and Emergency Medicine, 248–58. Berlin, Heidelberg : Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-84734-9_24.

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Peppas, Nikolaos A., et Steven R. Lustig. « Solute Diffusion in Hydrophilic Network Structures ». Dans Hydrogels in Medicine and Pharmacy, 57–84. CRC Press, 2019. http://dx.doi.org/10.1201/9780429285097-3.

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« Water with Two Solute Molecules ; Hydrophobic Hydrophilic Phenomena ». Dans Molecular Theory of Water and Aqueous Solutions, 411–563. World Scientific Publishing Company, 2009. http://dx.doi.org/10.1142/9789812837615_0004.

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« HYDROPHILIC SOLUTES IN WATER ». Dans Lecture Notes on Solution Chemistry, 109–16. WORLD SCIENTIFIC, 1995. http://dx.doi.org/10.1142/9789812830975_0011.

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Kasturi, Madhavi. « Development of Liquisolid Compacts : An Approach for Dissolution Enhancement of Poorly Aqueous Soluble Drugs ». Dans Drug Formulation Design [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.108706.

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Solubility plays a key role to achieve desired concentration of drug in systemic circulation and show its pharmacological action. An approach of liquisolid technique, developed by Spireas, was employed for the dissolution enhancement of poorly aqueous soluble drugs. Initially, liquid medication (liquid drug or drug solution or suspension in hydrophilic liquid vehicle) is transformed to free-flowing, non-sticky, compressible powder by the addition of suitable carrier material and coating materials for the development of liquisolid compacts. The postulated mechanism for enhanced solubility was improved wettability of drug and enhanced surface area of molecularly dispersed drug in the liquid environment. Pre- and post-the compression tests were performed for the developed liquisolid compacts to obtain optimized formulation. For the optimized compacts, FTIR and DSC studies were performed for determining drug-excipient compatibility; SEM and PXRD studies were performed to study the solid-state characterization. Furthermore, accelerated stability studies were performed for optimized liquisolid compacts for 6 months according to ICH guidelines and the results were compared with freshly prepared formulations. In conclusion, liquisolid compact formulation was proved to be safe, economic and alternative approach to formulate solid oral dosage forms of poorly aqueous soluble drugs.
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Johnston, Keith P., et C. T. Lee. « Interfacial Phenomena with Carbon Dioxide Soluble Surfactants ». Dans Green Chemistry Using Liquid and Supercritical Carbon Dioxide. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195154832.003.0013.

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A fundamental understanding of colloid and interface science for surfactant design in CO2-based systems is emerging on the basis of studies of interfacial tension and surfactant adsorption (da Rocha et al., 1999) along with complementary studies of colloid structure (Chillura-Martino et al., 1996; Meredith and Johnston, 1999; Wignall, 1999) and stability (Meredith and Johnston, 1999; O’Neill, 1997; Yates et al., 1997). The interfacial tension, γ, between a supercritical fluid (SCF) phase and a hydrophilic or lipophilic liquid or solid, along with surfactant adsorption, play a key role in a variety of processes including nucleation, coalescense and growth of dispersed phases, formation of microemulsions and emulsions (Johnston et al., 1999), particle and fiber formation, atomization, foaming (Goel and Beckman, 1995), wetting, adhesion, lubrication, and the morphology of blends and composites (Watkins et al., 1999). The first generation of research involving surfactants in SCFs addressed water/oil (w/o) microemulsions (Fulton and Smith, 1988; Johnston et al., 1989) and polymer latexes (Everett and Stageman, 1978) in ethane and propane (Bartscherer et al., 1995; Fulton, 1999; McFann and Johnston, 1999). This work provided a foundation for studies in CO2, which has modestly weaker van der Waals forces (polarizability per volume) than ethane. Consequently, polymers with low cohesive energy densities and thus low surface tensions are the most soluble in CO2: for example, fluoroacrylates (DeSimone et al., 1992), fluorocarbons, fluoroethers (Singley et al., 1997), siloxanes, and to a lesser extent propylene oxide. Since CO2 is nonpolar (unlike water) and has weak van der Waals forces (unlike lipophilic phases), it may be considered to be a third type of condensed phase. Surfactants with the above types of “CO2-philic” segments and a “CO2-phobic” segment have been used to form microemulsions (Harrison et al., 1994; Johnston et al., 1996), emulsions (da Rocha et al., 1999; Jacobson et al., 1999a; Lee et al., 1999b), and organic polymer latexes (DeSimone et al., 1994) in CO2. Microemulsion droplets are typically 2–10 nm in diameter, making them optically transparent and thermodynamically stable, whereas kinetically stable emulsion droplets and latexes in the range of 200 nm to 10 mm are opaque and thermodynamically unstable.
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de Jesús, Ernesto, Juan C. Flores et Gustavo F. Silbestri. « Water-soluble transition-metal complexes with hydrophilic N-heterocyclic carbene ligands for aqueous-phase applications ». Dans Advances in Organometallic Chemistry. Elsevier, 2022. http://dx.doi.org/10.1016/bs.adomc.2022.02.002.

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Agrawal, Ranu. « Psyllium : A Source of Dietary Fiber ». Dans Dietary Fibers. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.99372.

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Dietary fiber is commonly known as roughage. Fibers are mostly present in vegetables, whole grain, nuts, legumes, and fruits. This is an indigestible part of the food obtained by plants. It includes polysaccharides such as cellulose, hemicellulose, pectic substances, mucilages, gums and lignin as well. Dietary fiber has beneficial physiological effect on health, so it is included in daily diet to decrease occurrence of several diseases. In this sequence, this chapter describes about the dietary fiber, psyllium commonly known as Isabgol which is prepared from the seed of the Plantago ovata Forsk (Psyllium ispaghula). Psyllium is hydrophilic mucilloid, has the capacity to absorb water and increases in volume while absorbing water. Psyllium consists of mixed viscous polysaccharide in which about 35% soluble and 65% insoluble polysaccharides (cellulose, hemicellulose, and lignin) are present. This can be used as gelling, food thickener, emulsifying and stabilizing agents in some food products. Psyllium is a natural biopolymer which has high quantity of hemicelluloses consist of xylan backbone connected with arabinose, galacturonic acid and rhamnose units. Since last many years it is being used as therapeutic agent in several diseases like chronic constipation, inflammation of mucous membrane of GIT tract, duodenal ulcers, piles or diarrohoea etc. It may be source of renewable and biodegradable polymer.
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Alagawany, Mahmoud, Rana Muhammad Bilal, Fiza Batool, Youssef A. Attia, Mohamed E. Abd El-Hack, Sameh A. Abdelnour, Mayada R. Farag, Ayman A. Swelum et Mahmoud Madkour. « Use of Psyllium Husk (Plantago ovata) in Poultry Feeding and Possible Application in Organic Production ». Dans Antibiotic Alternatives in Poultry and Fish Feed, 111–23. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815049015122010011.

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Herbs or medicinal plants have gained significant attention due to their bioactive compounds that could act as antioxidants, anti-inflammatory, antimicrobial, anticancer agents, etc. Psyllium husk (Plantago ovata) is an Indian native herb. The water-loving (hydrophilic) mucilloid and water-soluble fiber derived from Plantago ovata have been used in traditional Indian Ayurvedic medicine as a crucial remedial mediator of constipation. Psyllium is a rich source of fiber and has many other remedial properties, including lowering the level of cholesterol, raising energy, relaxing inflammation, serving as an antidiarrhoeal, antidiabetic, laxative, and also used in hemorrhoid therapy, and as weight loss agent. The blood serum cholesterol-lowering property of the psyllium husk had drawn the researchers' main focus; thus, Psyllium is thought to be a plausible herbal agent helpful in treating hyperlipidemia. In various animal models, cholesterol levels are reduced by binding Psyllium husk with bile acids in the intestinal, thereby lowering its absorption rate. Screening literature has demonstrated that Psyllium husk could be utilized as an antidiarrheal mediator to cope with the diarrheal symptoms associated with poultry farming disorders. Additionally, Psyllium may also benefit various poultry species' production and growth traits. The present chapter explored Psyllium's potential responsibility for coping the hypercholesterolemia and the uses of psyllium husk as a safe feed additive in poultry farming for organic production and lowering cholesterol in meat and for production of functional foods.
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Actes de conférences sur le sujet "Hydrophilic solute"

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Banerjee, Rupak K., Peter M. Bungay, Malisa Sarntinoranont et Srinivas Chippada. « Generalizing the Theory of Microdialysis ». Dans ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-32970.

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The efficiency of sampling or delivering solutes (analytes) by in vivo microdialysis is influenced by the diffusive permeabilities of the probe and the tissue in which the probe is implanted. In tissue, processes removing the analyte from the extracellular space are as important as diffusion in determining permeability. In addition to diffusion, analyte permeation through these media may be augmented or diminished by bulk fluid movement (transmembrane and interstitial convection). Within the perfusate, the dominant process is axial convection. Both diffusive and convective determinants of probe efficiency may be influenced by probe geometry (Figure 1; longitudinal cross-sectional view). The main geometric parameters are the probe membrane length and radii, but inner cannula geometry can also be an appreciable factor. The objective of this study is to generalize the mathematical description of microdialysis. The treatment extends in several ways previous mathematical models (Bungay et al. [1]; Morrison et al. [2]; Morrison et al. [3]; Wallgren et al. [4]). In addition to removing some simplifications and approximations and adding convective transport, the revised theory is applicable to low-molecular-weight lipophilic, as well as hydrophilic solutes. This is achieved by incorporating transcellular solute movement as a pathway paralleling interstitial diffusion. This change accompanies employing the combined intracellular and extracellular volumes, rather than the interstitial volume, as the basis for solute mass balances.
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Han, Kewen, Zhe Zhang, Steven T. Wereley et Je Hoon Oh. « Study of Factors in Coffee-Ring Structure Formation Using PIV Methods ». Dans ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-63231.

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The evaporating liquid droplet with suspended particles on a solid substrate may leave a ring-like structure along the droplet circumference under certain conditions, which is commonly known as the coffee ring phenomenon. This phenomenon has many interesting applications related to microfluidic problem such as self-assembly of colloidal particle, particle and biomolecule separation and concentration and ink-jet printing. Although much work has been done on this topic, not very much work focused on the fluid flow inside a droplet. In order to investigate the inner flow inside of the droplet, water solutions with the fluorescing or non-fluorescing particles as the solute are dropped on surfaces with different hydrophilicity. The whole process are recorded using high dynamic CCD camera system and analyzed using Particle Image Velocimetry (PIV) methods. It is found that in all the droplets that form coffee ring, a central symmetric outward radial flow is observed. The velocity of the flow is zero at the center of the droplet. Along with radius outside, the flow velocity increases. For the same droplet, the flow velocity increases as the evaporation goes on and the velocity reaches its maximum at the end the evaporation. For different droplets, with the higher concentration, smaller droplet size and more hydrophilic surface, the flow velocity is larger. Comparisons between the experimental data and the published convection models show that the flow can be considered as part of the flow caused by the maximum evaporation rate at the pinned wetting line.
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He, Xuefeng, Rong Chen, Xun Zhu et Qiang Liao. « Effect of the Wettability on the IR Laser Photothermally Induced Phase Change in Microchannels ». Dans ASME 2016 Heat Transfer Summer Conference collocated with the ASME 2016 Fluids Engineering Division Summer Meeting and the ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/ht2016-1007.

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In this paper, the IR laser photothermally induced phase change characteristics in the microchannels with different wettabilities were studied using visual experiments. The hydrophobic microchannel was obtained by the hydrophobic nature of the PDMS material while the hydrophilic microchannels were obtained by the inert gas plasma surface treatments. Effects of the contact angle, laser power and spot position were investigated. It is interesting to find the change of the wettability and laser power could alter the phase change behaviors. The hydrophobic microchannel showed the interface advancement at low laser power and the liquid slug formation accompanying with the interface receding at high laser power. For less hydrophilic microchannel, the liquid slug formation accompanying with the interface receding was observed at low laser power while the sole interface receding was observed at high laser power. For more hydrophilic microchannel, the sole interface receding was observed for both low and high laser powers. Besides, it was also found that increasing the distance between the initial interface location and laser spot led to the increased thermal resistance, lowering the evaporation rate and thereby the above-mentioned effect.
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Pien, Michael, Steven Lis, Radha Jalan, Marvin Warshay et Suresh Pahwa. « Advanced Integrated Flow Field (IFF) Design for High Performance Fuel Cell and Electrolyzer ». Dans ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2014 8th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fuelcell2014-6507.

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Higher efficiency operation of PEM fuel cells needs an advanced passive way to remove product water. Water flooding in gas flow channels reduces efficiency and needs to be mitigated by a support of balance of plant design and components which results in parasitic power losses. ElectroChem’s Integrated Flow Field (IFF) design with the integration of hydrophobic and hydrophilic matrix has been proven to solve these challenges with no impact on the performance. The hydrophobic and hydrophilic matrix facilitates two phase (gas and liquid) flow to and away from the interface between the electrode membrane assembly and the flow field. A phase-separation feature of the IFF allowed the fuel cells to operate on a flow rate at its consumption rate. The IFF fuel cell has demonstrated operation at the ideal one stoichiometric ratio with 100% gas utilization and orientation independent. The IFF also served as gas humidifier through the creation of simultaneous distribution of gas and water within the cell. The self-humidification capability keeps the cell operating without the humidity of the input gas. The IFF design also enhanced the performance of water electrolysis which is a reverse process of fuel cell. The IFF supported the passive water feed to the cell and gas separation from the cell.
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Markovic, Maja, Vesna Panic, Julijana Tadic et Rada Pjanovic. « EFFECT OF CROSSLINKER AMOUNT ON HYBRID HYDROGELS SWELLING AND DRUG RELEASE ». Dans 1st INTERNATIONAL Conference on Chemo and BioInformatics. Institute for Information Technologies, University of Kragujevac, 2021. http://dx.doi.org/10.46793/iccbi21.125m.

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Targeted drug delivery is powerful tool which researchers use to achieve safer and more efficient therapy of many diseases, including various types of cancer. Many chemotherapeutics are poorly water- soluble, so their encapsulation and targeted delivery remain quite challenge. Hydrogels based on poly(methacrylic acid) (PMAA) are widely investigated for targeted drug delivery due to their pH sensitivity, non-toxicity and biocompatibility. Still, due to the PMAA highly hydrophilic nature, PMAA can only be used for encapsulation and targeted delivery of water-soluble drugs. Our previous research was directed towards overcoming this limitation: PMAA was modified with amphiphilic protein – casein and poorly-water soluble model drug – caffeine – was encapsulated (PMAC). Present study is focused on investigation how variation of amount of one of the most important hydrogels network parameter such as crosslinker affect PMAC swelling properties and caffeine release. The group of hybrid hydrogels – PMAC – was synthesized with various amount of crosslinker: 0.4mol%, 0.8mol%, 1.6mol% and 3.2mol% with respect to methacrylic acid. Swelling behavior of hybrid hydrogels and caffeine release was investigated in two environments which simulated human stomach and intestines. Obtained results showed that targeted delivery of poorly water-soluble model drug was achieved and that its release can be prolonged up to 24h. Also, kinetic of poorly water-soluble drug release can be easily modified only by changing crosslinker amount. PMAC hybrid hydrogels have huge potential for targeted delivery of poorly water-soluble active substances.
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Marković, Maja. « Controlled release of caffeine from three dimensional networks based on poly(metacrylic acid) and casein - analysis of the effect of caffeine concentration on release process ». Dans 35th International Congress on Process Industry. SMEITS, 2022. http://dx.doi.org/10.24094/ptk.022.019.

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Everyday demands for safer and more efficient therapy for many diseases, especially serious ones such as various types of cancer, put various challenges in front of modern science. One of them lies in the fact that numerous anticancer drugs are poorly-water soluble and therefore their encapsulation and controlled release are quite demanding processes. In the present study, we deepened our research of carrier based on hydrophilic poly(methacrylic acid) modified with amphiphilic casein, in which poorly water-soluble model drug caffeine was encapsulated (PMAC-Caf hydrogels). It was investigated how neutralization degree of methacrylic acid (MAA) and amount of encapsulated caffeine affected swelling behavior of the PMAC-Caf hydrogels and caffeine release. Easy, one pot, simultaneous synthesis of the carrier and the encapsulation of caffeine is presented, obtaining thereby as prepared PMAC-Caf drug delivery system that could respond to the specific demands of the targeted delivery of the poorly water-soluble drug - protecting it in the environment which simulated human stomach and releasing it in the environment which simulated human intestines. Changing the synthesis parameters (neutralization degree of MAA and/or amount of encapsulated caffeine) we achieved controlled release of caffeine, indicating that the number of the required doses of the drug in the treatment and its side effects could be reduced. Results showed that the PMAC-Caf drug delivery systems have huge potential for controlled release of poorly water-soluble drugs.
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Felicia, Suciu, Arcuș Mariana, Roșca Adrian Cosmin, Bucur Laura, Popescu Antoanela et Badea Victoria. « RESEARCH ON THE BOTANICAL AND PHARMACOGNOSTIC PARTICULARITIES OF THE INDIGENOUS SPECIES LYSIMACHIA NUMMULARIA L. » Dans GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b1/v3/20.

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"Preliminary pharmacochemical research on Lysimachia nummularia L. was performed by dint of pharmacognostic analysis (macroscopic examination, global chemical analysis, preliminary quantitative determinations).The article includes the analysis of the macroscopic characters of the vegetative organs (root, stem and leaf), as well as of the reproductive organs (flower, fruit, seed) belonging to the spontaneous native species Lysimachia nummularia L. Morphological features were described and discussed. The identification of these aspects was done with the naked eye, but also with the help of a hand magnifier and a binocular magnifier. The results revealed that the external appearance of the plant justifies the species belonging to the genus Lysimachia, family Primulaceae. They are found in the glabrous and creeping appearance of the plant, opposite, almost round leaves, solitary, yellow flowers, axillary with vigorous pedicels, perianth pentamer, actinomorphic, dialisepal and dialipetal, globular capsule fruit. The semi-hydrophilic nature is found in the presence of adventitious roots that develop both from the rhizome and at the nodes of the stem. The preliminary quantitative determinations performed were loss by drying as well as soluble substances of the species Lysimachia nummularia L. Following the global chemical analysis, active principles known in the literature for the antioxidant potential were identified. Following the preliminary quantitative determinations (drying loss, determination of soluble substances) results comparable to those in the literature on the content of volatile substances and soluble substances were obtained."
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Kooshki, Pantea, et Tsz-Ho Kwok. « Review of Natural Fiber Reinforced Elastomer Composites ». Dans ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/detc2018-86042.

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This paper is a review on mechanical characteristics of natural fibers reinforced elastomers (both thermoplastics and thermosets). Increasing environmental concerns and reduction of petroleum resources attracts researchers attention to new green eco-friendly materials. To solve these environmental related issues, cellulosic fibers are used as reinforcement in composite materials. These days natural fibers are at the center of attention as a replacement for synthetic fibers like glass, carbon, and aramid fibers due to their low cost, satisfactory mechanical properties, high specific strength, renewable resources usage and biodegradability. The hydrophilic property of natural fibers decreases their compatibility with the elastomeric matrix during composite fabrication leading to the poor fiber-matrix adhesion. This causes low mechanical properties which is one of the disadvantages of green composites. Many researches have been done modifying fiber surface to enhance interfacial adhesion between filler particles and elastomeric matrix, as well as their dispersion in the matrix, which can significantly affect mechanical properties of the composites. Different chemical and physical treatments are applied to improve fiber/matrix interlocking.
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Usta, Aybala, Muhammad Rahman et Ramazan Asmatulu. « Synthesis, Stability and Selection Study of Oil-in-Water Nanoemulsions Containing Nigella Sativa L. Essential Oil ». Dans ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-72205.

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Targeted drug delivery has a great importance in cancer treatment and is in interest of many scientists worldwide. Targeted drug delivery renders local treatment of cancerous cells possible without affecting healthy cells. Hydrogels are promising materials to be used in targeted drug delivery systems due to their biocompatible nature and injectable behaviors where they can be used to load drugs. However, considering that not all the drugs are water soluble, entrapment of some drugs into hydrogels is not practical in terms of poor drug solubility and burst drug release because of this. At this point, an oil phase can be considered as a drug carrying agent, and entrapment of this oil phase into hydrogel would make it possible for in-situ injection of dissolved drug in oil phase. Oil in water (O/W)-type nanoemulsions were prepared using black seed oil, which is known to cause apoptosis via p-53 dependent mechanism, water and Triton X-100, Span-80 surfactant combinations. Three different oil percentage and three different surfactant percentage were tested, and stability behaviors of nanoemulsions were investigated and compared. Dynamic light scattering analysis and zeta potential measurements were conducted for determination of particles sizes and surface charges of the nanoemulsions. The most stable nanoemulsion along with having smallest diameter and lowest polydispersity index (PDI) was used for further studies. Results indicated that using both hydrophilic and hydrophobic surfactants together increased the stability of nanoemulsions compared to those using either of them.
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Rackov, Sanja, Aleksandra Nešić, Milan Vraneš et Branka Pilić. « DEVELOPMENT OF ELECTROSPUN POLY(VINYLPYRROLIDONE) (PVP) NANOFIBER MATS LOADED BY CALENDULA OFFICINALIS EXTRACT AND COENZYME Q10 ». Dans 1st INTERNATIONAL Conference on Chemo and BioInformatics. Institute for Information Technologies, University of Kragujevac, 2021. http://dx.doi.org/10.46793/iccbi21.169r.

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Electrospun systems can be applied to various areas, particularly in biomedicine for skin treatment. The fabricated nanofibers represent an interconnected three-dimensional network with a high surface area to volume ratio providing structural and morphological similarities with the extracellular matrix. Hence, facilitate the removal of exudates, promote gaseous exchange, conform to the contour of the treated area and in the case of drug-loaded nanofibers resulting in improved bioavailability. Polyvinylpyrrolidone was selected as a polymer carrier due to its biocompatible, hydrophilic nature with good chemical and mechanical properties, approved by the U.S. FDA (Food and Drug Administration) as a safe polymer for biomedical and food applications. Calendula officinalis or Marigold extract is one of the oldest medical plants with numerous proven pharmacological effects including anti-inflammatory, antibacterial/antifungal and wound healing activity related to the components of the flowers such as sesquiterpenes, saponins, triterpenes, flavonoids. Coenzyme Q10 (CoQ10, Ubiquinone) is a naturally occurring oil-soluble antioxidant and anti-inflammatory agent that supports collagen production, mostly popularized as an anti-aging ingredient in skincare products for topical use. Novel Marigold extract and CoQ10–loaded polyvinylpyrrolidone nanofibers intended for skin treatment and wound therapy were developed using the electrospinning technique. The presence of functional groups on the nanofibrous surfaces was confirmed by FTIR analysis, the SEM images show the average size of the obtained nanomats and the thermal properties were investigated via DSC analysis.
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