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951.
Adrin Leons Valentina Salaris Alicia Mujica-Garcia Marina P. Arrieta Daniel Lopez Marcela Lieblich Jos Maria Kenny Laura Peponi 《Molecules (Basel, Switzerland)》2021,26(16)
In this work, different poly (lactic acid) (PLA)-based nanocomposite electrospun fibers, reinforced with both organic and inorganic nanoparticles, were obtained. As organic fibers, cellulose nanocrystals, CNC, both neat and functionalized by “grafting from” reaction, chitosan and graphene were used; meanwhile, hydroxyapatite and silver nanoparticles were used as inorganic fibers. All of the nanoparticles were added at 1 wt% with respect to the PLA matrix in order to be able to compare their effect. The main aim of this work was to study the morphological, thermal and mechanical properties of the different systems, looking for differences between the effects of the addition of organic or inorganic nanoparticles. No differences were found in either the glass transition temperature or the melting temperature between the different electrospun systems. However, systems reinforced with both neat and functionalized CNC exhibited an enhanced degree of crystallinity of the electrospun fibers, by up to 12.3%. From a mechanical point of view, both organic and inorganic nanoparticles exhibited a decreased elastic modulus and tensile strength in comparison to neat electrospun PLA fibers, improving their elongation at break. Furthermore, all of the organic and inorganic reinforced systems disintegrated under composting conditions after 35 days. 相似文献
952.
Silvia Radrezza Gilda Aiello Giovanna Baron Giancarlo Aldini Marina Carini Alfonsina DAmato 《Molecules (Basel, Switzerland)》2021,26(16)
Hyaluronic acid (HA) is a glycosaminoglycan very common in commercial products from pharmaceuticals to cosmetics due to its widespread distribution in humans and its diversified physico-chemical proprieties. Despite its extended use and preliminary evidence showing even also opposite activities to the native form, the precise cellular effects of HA at low-molecular-weight (LWM-HA) are currently unclear. The ‘omics sciences currently in development offer a new and combined perspective on the cellular and organismal environment. This work aims to integrate lipidomics analyses to our previous quantitative proteomics one for a multi-omics vision of intra- and extra-cellular impact of different concentrations (0.125, 0.25, and 0.50%) of LMW-HA (20–50 kDa) on normal human dermal fibroblasts by LC-high resolution mass spectrometry (LC-HRMS). Untargeted lipidomics allowed us to identify 903 unique lipids mostly represented by triacylglycerols, ceramides, and phosphatidylcholines. According to proteomics analyses, LMW-HA 0.50% was the most effective concentration also in the lipidome rearrangement especially stimulating the synthesis of ceramides involved in skin hydration and reparation, cell signaling, and energy balance. Finally, integrative analyses showed 25 nodes covering several intra- and extra-cellular functions. The more complete comprehension of intra- and extra-cellular effects of LMW-HA here pointed out will be useful to further exploit its features and improve current formulations even though further studies on lipids biosynthesis and degradation are necessary. 相似文献
953.
Elena Yu. Schmidt Dr. Boris A. Trofimov Prof. Dr. Al'bina I. Mikhaleva Prof. Dr. Nadezhda V. Zorina Dr. Nadezhda I. Protzuk Dr. Konstantin B. Petrushenko Dr. Igor A. Ushakov Dr Marina Yu. Dvorko Rachel Méallet‐Renault Prof. Dr. Gilles Clavier Dr. Thanh Truc Vu Ha Thanh Thao Tran Robert B. Pansu Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(23):5823-5830
The light fantastic : Two new 2‐(benzo[b]thiophene‐3‐yl)pyrroles have been synthesized, and are shown to exhibit optical properties that are promising for optoelectronic materials and devices such as highly efficient fluorescent sensors (see scheme). In addition a new BODIPY fluorophore, derived from 2‐(benzo[b]thiophene‐3‐yl)pyrrole, was also isolated and shows good spectroscopic properties in solution which are fully preserved in the solid state.
954.
Bartlomiej Sojka Daria Kociołek Mateusz Banski Tatiana Borisova Natalia Pozdnyakova Artem Pastukhov Arsenii Borysov Marina Dudarenko Artur Podhorodecki 《Journal of nanoparticle research》2017,19(8):275
Specific rare earth doped nanocrystals (NCs), a recent class of nanoparticles with fluorescent features, have great bioanalytical potential. Neuroactive properties of NaYF4 nanocrystals doped with Eu3+ were assessed based on the analysis of their effects on glutamate- and γ-aminobutyric acid (GABA) transport process in nerve terminals isolated from rat brain (synaptosomes). Two types of hydrophilic NCs were examined in this work: (i) coated by polyethylene glycol (PEG) and (ii) with OH groups at the surface. It was found that NaYF4:Eu3+-PEG and NaYF4:Eu3+-OH within the concentration range of 0.5–3.5 and 0.5–1.5 mg/ml, respectively, did not influence Na+-dependent transporter-dependent l-[14C]glutamate and [3H]GABA uptake and the ambient level of the neurotransmitters in the synaptosomes. An increase in NaYF4:Eu3+-PEG and NaYF4:Eu3+-OH concentrations up to 7.5 and 3.5 mg/ml, respectively, led to the (1) attenuation of the initial velocity of uptake of l-[14C]glutamate and [3H]GABA and (2) elevation of ambient neurotransmitters in the suspension of nerve terminals. In the mentioned concentrations, nanocrystals did not influence acidification of synaptic vesicles that was shown with pH-sensitive fluorescent dye acridine orange, however, decreased the potential of the plasma membrane of synaptosomes. In comparison with other nanoparticles studied with similar methodological approach, NCs start to exhibit their effects on neurotransmitter transport at concentrations several times higher than those shown for carbon dots, detonation nanodiamonds and an iron storage protein ferritin, whose activity can be registered at 0.08, 0.5 and 0.08 mg/ml, respectively. Therefore, NCs can be considered lesser neurotoxic as compared to above nanoparticles. 相似文献
955.
Zheng Zhou Zheng Wei Yuki Tokimaru Shingo Ito Kyoko Nozaki Marina A. Petrukhina 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(35):12235-12239
Mono‐ and dianions of 2‐tert‐butyl‐3a2‐azapentabenzo[bc,ef,hi,kl,no]corannulene ( 1 a ) were synthesized by chemical reduction with sodium and cesium metals, and crystallized as the corresponding salts in the presence of 18‐crown‐6 ether. X‐ray diffraction analysis of the sodium salt, [{Na+(18‐crown‐6)(THF)2}3{Na+(18‐crown‐6)(THF)}( 1 a 2?)2], revealed the presence of a naked dianion. In contrast, controlled reaction of 1 a with Cs allowed the isolation of singly and doubly reduced forms of 1 a , both forming π‐complexes with cesium ions in the solid state. In [{Cs+(18‐crown‐6)}( 1 a ?)]?THF, asymmetric binding of the Cs+ ion to the concave surface of 1 a ? is observed, whereas in [{Cs+(18‐crown‐6)}2( 1 a 2?)], two Cs+ ions bind to both the concave and convex surfaces of the dianion. The present study provides the first successful isolation and characterization of the reduced products of heteroatom‐containing buckybowl molecules. 相似文献
956.
957.
Marina A. Katkova Alexey N. Konev Irina I. Pestova Mikhail N. Bochkarev 《Applied Surface Science》2008,254(8):2216-2219
Influence of thin chalcogen X (S, Se, Te) interlayer between anode (indium-tin oxide, ITO) and a layer of N,N′-bis(3-methylphenyl)-N,N′-diphenylbenzidine (TPD) used as a hole-transport layer (HTL) on the operating characteristics of organic light-emitting diodes (OLEDs) of composition ITO/X/TPD/Alq3/Yb (Alq3 - aluminum 8-quinolinolate) has been investigated. It was found that the sulphur layer decreases operating voltage and enhances operating stability of a device while the selenium or tellurium interlayers impair these characteristics. 相似文献
958.
Application of the differential method (also called the C method) to plane-wave diffraction by a perfectly conducting, sinusoidally corrugated metallic grating coated with a linear, homogeneous, isotropic, lossless dielectric-magnetic material shows that coating materials with negative index of refraction may deliver enhanced maximum nonspecular reflection efficiencies in comparison to coating materials with positive index of refraction. 相似文献
959.
An optimized 3D inversion recovery prepared fast spoiled gradient recalled sequence (IR FSPGR) on a 3-T scanner for carotid plaque imaging is described. It offers clear blood and fat signal suppression at the carotid artery bifurcation and highlights the regions of carotid plaque affected by hemorrhage at 3 T with high contrast and contrast-to-noise ratio compared with other sequences. It can potentially be used to replace the more traditional noncontrast T1-weighted 2D black-blood imaging for hemorrhage detection and offers additional benefits of high-resolution 3D volumetric visualization. 相似文献
960.
Kristi Leonard Marina Nelen Madhavi Raghu Michael R. Detty 《Journal of heterocyclic chemistry》1999,36(3):707-717
Enol ethers 9 are formed as a mixture of E- and Z-isomers from the addition of ethanol to 1,4-pentadiyn-3-ones 2 in sodium ethoxide/ethanol. The enol ethers react with disodium chalcogenides to give the corresponding 2,6-disubstituted chalcogenopyranones 1 bearing alkyl, aryl, or heteroaryl substituents in high yield as the only heterocyclic product of reaction. Diynones 2 react with disodium chalcogenides to give mixtures of products in which the chalcogenopyranones 1 are minor components and the dihydrochalcogenophenes 3 are the major products. The addition of hydrogen sulfide to diynone 2b in ethanol gives a product mixture nearly identical to that observed for the addition of disodium sulfide in sodium ethoxide in ethanol to 2b . Intermediates for the addition of hydrogen chalcogenides and disodium chalcogenides to both 2 and 9 are described, which lead to the heterocyclic products. 相似文献