Search results for "Polyp"
showing 10 items of 1415 documents
Simultaneous application of vacuum and sweep gas in a polypropylene membrane contactor for the recovery of dissolved methane from water
2021
Abstract Vacuum and nitrogen as sweep gas were used simultaneously (combination mode) to generate the driving force in a microporous polypropylene membrane contactor for the recovery of dissolved methane from water. Experiments were carried out under different liquid flow-rates (5.0–28.0 L h−1), N2 flow-rates (0.5–1.5 L h−1) and vacuum pressures (0–480 mbar). The maximum removal efficiency of methane was >90% at moderate values of gas-to-liquid ratios (G/L) and vacuum of 0.2 and ≤ 200 mbar, respectively. Removal efficiencies obtained in combination mode were usually higher than when using vacuum or sweep gas, separately. To achieve a methane content >35% in the recovered gas, G/L values low…
Compatibilization of blends of polyethylene with a semirigid liquid crystalline polymer by PE-g-LCP copolymers
1997
The blends of thermoplastics with liquid crystalline polymers show, in general, poor properties because of the lack of adherence between the two phases. The use of ad hoc synthesized copolymers containing the monomer units of the two polymers has been recently considered by some of us for blend compatibilization, and the results appear promising. In this work, new PE-g-LCP copolymers, prepared either by the synthesis of the LCP in the presence of a functionalized PE, or by reactive blending of the latter polymer with preformed LCP, have been employed as compatibilizing additives for blends of PE with a semirigid LCP. The morphology and the rheological and mechanical properties of the ternar…
Phytochemicals as inhibitors of NF-κB for treatment of Alzheimer's disease.
2017
Alzheimer's disease (AD) is the most prevalent form of dementia. The exact pathophysiology of this disease remains incompletely understood and safe and effective therapies are required. AD is highly correlated with neuroinflammation and oxidative stress in brain causing neuronal loss. Nuclear factor of activated B-cells (NF-κB) is involved in physiological inflammatory processes and thus representing a promising target for inflammation-based AD therapy. Phytochemicals are able to interfere with the NF-κB pathway. They inhibit the phosphorylation or the ubiquitination of signaling molecules, and thus, inhibit the degradation of IκB. The translocation of NF-κB to the nucleus and subsequent tr…
The potential of the Sorb (Sorbus domestica L.) as a minor fruit species in the Mediterranean areas: description and quality traits of underutilized …
2017
Biodiversity linked to fruit cultivation plays a key role in terms of the availability of quality products and nutraceutical compounds for the food industry. Thus underutilized species such as Sorbus domestica L. can be an important resource. The aim of this study was to evaluate 31 local accessions from different growing areas on the Island of Sicily and characterize the fruits according to the biometric-carpological features that constitute their quality in order to understand the potential that this species may have not only regarding the recovery and preservation of genetic resources in the Mediterranean area but also the nutraceutical compounds it offers. The results from this prelimin…
Diastereoselective Synthesis of Dialkylated Bis(phosphino)ferrocenes: Their Use in Promoting Silver-Mediated Nucleophilic Fluorination of Chloroquino…
2017
International audience; The diastereoselective synthesis of dialkylated ferrocenyl bis(phosphane)s bearing aryl, alkyl, and hetero- or polycyclic substituents on the phosphino groups is reported, together with their characterization in the solid state by X-ray structure analysis and in solution by multinuclear NMR spectroscopy. Introduction of various alkyl groups on the ferrocene backbone, namely, tert-butyl, isopropyl, and trimethylsilyl, has a significant influence on the stereoselectivity of the ensuing lithiation/phosphination reactions. Only the introduction of the tert-butyl groups ensures both a high yield and perfect diastereoselectivity, which leads to the exclusive formation of t…
Direct arylation of heteroaromatic compounds with congested, functionalised aryl bromides at low palladium/triphosphane catalyst loading.
2011
International audience; A new ferrocenyl triphosphane ligand associated to palladium was found to be an efficient catalyst for the direct coupling of highly congested, functionalised aryl bromides with a variety of heteroarenes. These coupling reactions can generally be performed by using a low-loading (0.1-0.5 mol%) of the catalyst. The present protocol tolerates important and useful functional groups, which allows for further elaboration into more sophisticated heterocyclic molecules. The straightforward arylation of heteroaromatic compounds with congested ortho-substituted aryl bromides may permit further convergent syntheses of diverse ligands, biologically active molecules and molecula…
Methods of the investigation of bee pollen and bee bread
2017
The main purpose of this publication was to evaluate which types of studies are used with the purpose of the estimation of nutritional value of bee pollen and bee bread. Bee pollen and bee bread are important bee-products that contains large amounts of nutritional and essential active biological compounds. Among different bioactive compounds with antioxidant properties which could be found in bee pollen and bread are polyphenolic substances, flavonoids, unsaturated acids and carotenoids. Bee pollen and bee bread are investigated by plenty of scientists for different quality indexes over two last decades. However, the composition of bee pollen and bee bread are not yet standardized nor defin…
Sarraute's plays : poplyphony and enunciation
2014
The corpus is formed of six plays of Nathalie Sarraute; it hides a duplication of enunciation types in the characters’ dialogue. This duplication is latent due to personal pronouns and verb tenses’ neutralization. The transition from an enunciation layer to another is not marked at all or not traditionally marked. Therefore, deciphering will be more complicated to any reader, listener or spectator. These works of art are also highly polyphonic in terms of enunciation as in semantics, as several voices are intertwined and as the characters resort to authorities of point of view. Thus, readers, listeners and spectators should identify enunciation sources and “other” authorities of point of vi…
Current and New Insights in the Sustainable and Green Recovery of Nutritionally Valuable Compounds from Stevia rebaudiana Bertoni.
2015
International audience; The South American plant Stevia rebaudiana Bertoni is a great source of noncaloric sweeteners (steviol glycosides), mainly concentrated in its leaves, but also has important antioxidant compounds (vitamin C, polyphenols, chlorophylls, and carotenoids) and other important macro- and micronutrients such as folic acid and all of the essential amino acids except tryptophan. Traditionally, conventional methods have been used to recover nutritionally valuable compounds from plant food matrices. However, nowadays, the need for obtaining greener, sustainable, and viable processes has led both food industries and food scientists to develop new processes in full correspondence…
Synthesis of PP-LCP graft copolymers and their compatibilizing activity for PP/LCP blends
1998
The aim of this work was the synthesis of new graft copolymers consisting of polypropylene (PP) backbones and liquid crystalline polymer (LCP) branches, to be used as compatibilizing agents for PP/LCP blends. The PP-g-LCP copolymers have been prepared by polycondensation of the monomers of a semiflexible liquid crystalline polyester (SBH 1 : 1 : 2), that is, sebacic acid (S), 4,4′-dihydroxybiphenyl (B), and 4-hydroxybenzoic acid (H) in the mole ratio of 1 : 1 : 2, carried out in the presence of appropriate amounts of a commercial acrylic-acid-functionalized polypropylene (PPAA). The polycondensation products, referred to as COPP50 and COPP70, having a calculated PPAA concentration of 50 and…