Search results for "BES"
showing 10 items of 3692 documents
Enhancing the mechanical performance of polymer based nanocomposites by plasma-modification of nanoparticles
2012
Abstract The possibility of enhancing the mechanical performance of two different polymer-based nanocomposites using polyamide 6 (PA6) and poly[ethylene-co-(vinyl acetate)] (EVA) as matrices was investigated. The nanofillers used were, respectively, either carbon nanotubes (CNTs) or an organically modified montmorillonite (Cloisite 15A), both previously modified by plasma treatment to introduce polar moieties. The nanofillers were fully characterized by Raman spectroscopy, XPS, FT-IR and XRD, demonstrating their effective modification with oxygenated groups. The nanocomposites were prepared by melt processing in order to obtain films and fibres. The mechanical tests carried out on the nanoc…
Halloysite nanotubes as polyolefin fillers
2015
Artykuł stanowi przegląd najnowszej literatury dotyczącej nanokompozytów poliolefinowych napełnianych nanorurkami haloizytowymi (HNT). Omówiono wpływ dodatku HNT na osnowę poliolefinową, ze szczególnym uwzględnieniem morfologii oraz właściwości mechanicznych nanokompozytów poliolefina/HNT. Modyfikowane HNT wykazywały wysoki stopień rozproszenia w osnowie poliolefinowej, dzięki czemu powodowały poprawę właściwości mechanicznych poliolefinowych nanokompozytów napełnianych nanorurkami haloizytowymi. Połączenie korzystnych właściwości poliolefin, ekonomicznych metod ich przetwórstwa oraz unikatowych w³aoeciwooeci HNT pozwoli na szersze rozpowszechnienie nanokompozytów wytworzonych z ich udziałe…
Biocompatible Poly(N-isopropylacrylamide)-halloysite Nanotubes for Thermoresponsive Curcumin Release
2015
The grafting of poly(N-isopropylacrylamide) (PNIPAAM) onto the halloysite external surface is proposed in order to obtain a novel thermoresponsive drug carrier for curcumin delivery. The new nanomaterial is characterized by means of FT-IR spectroscopy, thermogravimetric analysis, and SEM investigations. A high density of polymer chain was achieved at the nanoparticle surface. The PNIPAAM dehydration phenomenon was observed in water above 32 °C that is nearly coincident with the lower critical solution temperature for the polymer. The colloidal stability as well as the wettability of the obtained nanomaterial may be triggered by temperature stimuli. In vitro tests simulating the gastro-intes…
Guest-Induced Folding and Self-Assembly of Conformationally Adaptive Macrocycles into Nanosheets and Nanotubes
2017
A conformationally adaptive macrocycle is presented, namely zorb[4]arene, which exists in multiple conformations in the uncomplexed state. The binding cavity of zorb[4]arene is concealed, either due to a collapsed conformation or by self-inclusion. The zorb[4]arene with long alkyl chains manifests itself with surprisingly low melting point and thus exist as an oil at room temperature. Binding of a guest molecule induces the folding and conformational rigidity of zorb[4]arene and leads to well-defined three-dimensional structures, which can further self-assemble into nanosheets or nanotubes upon solvent evaporation, depending on guest molecules and the conformations they can induce.
Livelli serici di insulina nel soggetto normale (Obeso e non) e nel diabetico obeso Dopo Carico Intragastrico di Aminoacidi
1968
Gli AA. hanno somministrato in 5 soggetti normali normosomici, in 5 obesi metabolicamente sani e in 5 diabetici obesi un carico intragastrico (mediante sondino) di 9 aminoacidi essenziali (arginina, fenil-alanina, valina, leucina, lisina, metionina, isoleucina, istidina, triptofano) per un totale di g 30 ed hanno valutato la risposta insulo-pancreatica. In tutti i casi di soggetti in esame si e messo in evidenza un significativo aumento dell'insulinemia, determinata con metodo radioimmunologico. Il picco insulinemico e stato di 45 ± 11 µU/ml nei normali normosomici, di 65 ± 6 µU/ml negli obesi e di 52 ± 8 nei diabetici obesi, rispettivamente a 75 mp, a 60 mp e a 105 mp. La caduta insulinemi…
Sugar reduction: Stevia rebaudiana Bertoni as a natural sweetener
2020
Abstract Excessive sugar consumption is associated with the development of numerous health problems, such as obesity and many chronic diseases (e.g., cardiovascular disease, diabetes). Obesity is a rapidly growing public health problem, thus its prevention and treatment are crucial to improve the quality of life. Among others, sugar-sweetened beverage consumption was considered as a key risk factor that contributes to a significant excess of sugar in the diet. The World Health Organization is intensively working on strategies to reduce sugar intake by featuring educational methods and innovative marketing techniques for various communities, media, governments, and industries. Despite many s…
Nanocomposite, an innovative route to large structure and infrastructure protection. A case of study: CNT-doped polyurea
2010
<p>In this work we focus on experimental studies of polymer-nanocomposites intended for passive protection of civil structures. The material consists of a polyurea-matrix enhanced by different quantities of multiwalled carbon nanotubes. Several tensile and cyclic tests are performed to evaluate and characterize the mechanical behaviour of this new material. Furthermore, we subject the material to accelerated thermal aging and study its performance deterioration which is fairly unknown. The results on the unaged specimens are intuitive and indicate that an arbitrary amount of CNTs may result in suboptimal performance. More specifically, 1% in weight of CNTs yields the best mechanical p…
Templating effect of carbon nanoforms on highly cross-linked imidazolium network: Catalytic activity of the resulting hybrids with Pd nanoparticles
2019
Two different carbon nanoforms (CNFs), namely multi-walled carbon nanotubes (MWCNTs) and carbon nanohorns (CNHs), have been chosen as support for the direct polymerization of a bis-vinylimidazolium salt. Transmission electron microscopy analyses revealed a templating effect of the CNFs on the growth of the polymeric network, which perfectly covers their whole surfaces creating a cylindrical or spherical coating for MWCNTs and CNHs, respectively. Subsequently, the CNFs-polyimidazolium have been used as stabilizers for Pd nanoparticles (Pd NPs), and the obtained materials have been characterized by means of analytical and spectroscopic techniques and then employed as easily recoverable and re…
Normal-weight obesity and cardiometabolic risk : A 7-year longitudinal study in girls from prepuberty to early adulthood
2017
Objective: To study whether normal-weight obesity in childhood is associated with increased cardiometabolic risk in early adulthood. Methods: This study assessed data for 236 girls followed from prepuberty to early adulthood. Growth chart data were obtained from birth to 18 years. Body composition was assessed by dual-energy x-ray absorptiometry and cardiometabolic risk by calculating continuous clustered risk score (at ages 11, 14, and 18). The association of body weight status with cardiometabolic risk from childhood to early adulthood was examined. Results: Subjects with normal-weight obesity were virtually indistinguishable from their normal-weight lean peers in terms of relative body w…
Les sépultures de Truchtersheim "Holderacker" (Bas-Rhin) et les pratiques funéraires du Bronze A1 dans le sud de la plaine du Rhin supérieur
2023
Die Freilegung 2019 eines kleinen frühbronzezeitlichen (2030-1900 v. Chr.) Bestattungsensemblesin Truchtersheim „Holderacker“, etwa 12 km nordwestlich von Straßburg, hat uns bewegt uns mit der gesamten für das Elsassverfügbaren Dokumentation der frühbronzezeitlichen Bestattungssitten zu befassen. Dieser bisher kaum dokumentiertechronologische Horizont wurde kürzlich durch eine Reihe von Funden bereichert, die vorwiegend zwischen 2017 und 2019bei präventivarchäologischen Operationen im Vorfeld der Bauarbeiten der Westumgehung von Straßburg entdeckt wurden.Das bescheidene regionale Corpus mit 20 Gräbern erlaubt nur begrenzte Beobachtungen, es weist jedoch doch mehrere für dieFrühbronzezeit ch…