Search results for "Gate"
showing 10 items of 1811 documents
Dipeptides of S-Substituted Dehydrocysteine as Artzyme Building Blocks: Synthesis, Complexing Abilities and Antiproliferative Properties †
2021
Background: Dehydropeptides are analogs of peptides containing at least one conjugate double bond between α,β-carbon atoms. Its presence provides unique structural properties and reaction centre for chemical modification. In this study, the series of new class of dipeptides containing S-substituted dehydrocysteine with variety of heterocyclic moieties was prepared. The compounds were designed as the building blocks for the construction of artificial metalloenzymes (artzymes). Therefore, the complexing properties of representative compounds were also evaluated. Furthermore, the acknowledged biological activity of natural dehydropeptides was the reason to extend the study for antiproliferativ…
Molecular dynamics of electrosprayed water nanodroplets containing sodium bis(2-ethylhexyl)sulfosuccinate
2013
The behavior of aqueous solutions of sodium bis(2-ethylhexyl)sulfosuccinate (AOTNa) subject to electrospray ionization (ESI) has been investigated by molecular dynamics (MD) simulations at three temperatures (350, 500 and 800 K). We consider several types of water nanodroplets containing AOTNa molecules and composed of a fixed number of water molecules (1000), N(AOT)(0) AOT(-) anions (N(AOT)(0) = 0, 5, 10) and N(Na)(0) sodium ions (N(Na)(0) = 0, 5, 10, 15, 20): in a short time scale (less than 1 ns), the AOTNa molecules, initially forming direct micelles in the interior of the water nanodroplets, are observed in all cases to diffuse nearby the nanodroplet surface, so that the hydrophilic …
Nonlinear optical properties of diaromatic stilbene, butadiene and thiophene derivatives
2021
Series of highly polar stilbene (1a–e), diphenylbutadiene (2a–c) and phenylethenylthiophene (3a–c) derivatives were prepared via Horner–Wadsworth–Emmons method with a view to produce new and efficient materials for second harmonic generation (SHG) in the solid-state. The single-crystal X-ray structures of compounds 1–3 reveal extensive polymorphism and a peculiar photodimerization of the 2-chloro-3,4-dimethoxy-4′-nitrostilbene derivative 1a to afford two polymorphs of tetra-aryl cyclobutane 4. The stilbene congeners 2-chloro-3,4-dimethoxy-4′-nitrostilbene (1a·non-centro), 5-bromo-2-hydroxy-3-nitro-4′-nitrostilbene (1b) and 4-dimethylamino-4′-nitrostilbene (1e), as well as 4′-fluoro-4′′-nitr…
La soglia e i custodi delle arti. The Pale and Gatekeepers of the Arts
2016
For this year’s issue Venezia Arti is set to examine the idea of threshold in the arts, primarily meaning the limit or boundary that separates art from what is not considered as such. The definition embraces every possible kind of frontier between the art world and that, which is alien to it, hence observing the arts from the perspective of Pierre Bourdieu’s field of forces, where interdependencies and positions among numerous actors legitimize artistic production. The focus thus shifts to the edge of the art world and to those who are identified as gatekeepers and possibly modify the barriers of a specific artistic discipline. Hereafter all subjects and groups who hold an institutional rol…
Le soglie e i custodi delle arti. Una nota introduttiva
2016
Introduction to the special issue devoted to philosophy and art theory of the art system.
Memory degradation induced by attention in recurrent neural architectures
2022
This paper studies the memory mechanisms in recurrent neural architectures when attention models are included. Pure-attention models like Transformers are more and more popular as they tend to outperform models with recurrent connections in many different tasks. Our conjecture is that attention prevents the recurrent connections from transferring information properly between consecutive next steps. This conjecture is empirically tested using five different models, namely, a model without attention, a standard Loung attention model, a standard Bahdanau attention model, and our proposal to add attention to the inputs in order to fill the gap between recurrent and parallel architectures (for b…
Sigma-1 Receptor Activation Induces Autophagy and Increases Proteostasis Capacity In Vitro and In Vivo
2019
Dysfunction of autophagy and disturbed protein homeostasis are linked to the pathogenesis of human neurodegenerative diseases and the modulation of autophagy as the protein clearance process has become one key pharmacological target. Due to the role of sigma-1 receptors (Sig-1R) in learning and memory, and the described pleiotropic neuroprotective effects in various experimental paradigms, Sig-1R activation is recognized as one potential approach for prevention and therapy of neurodegeneration and, interestingly, in amyotrophic lateral sclerosis associated with mutated Sig-1R, autophagy is disturbed. Here we analyzed the effects of tetrahydro-N,N-dimethyl-2,2-diphenyl-3-furanmethanamine hyd…
Refined Analysis of a Cross-Sectional Doping Survey Among Recreational Triathletes: Support for the Nutritional Supplement Gateway Hypothesis
2020
Introduction: The current literature provides no consensus that nutritional supplements (NS) may provide a gateway to doping. In particular, studies in recreational athletes are lacking. Within a previous cross-sectional empirical study, our group provided first evidence that the use of NS may provide a gateway for the use of doping substances in recreational triathletes. For the present paper, we refine the analysis of the triathletes’ survey in order to provide evidence for a NS gateway hypothesis in recreational athletes. Methods: A self-report, paper-and-pencil questionnaire was distributed to a sample of 2,997 competitive ironman and half-ironman (n = 1,076; 36.1%) triathletes. The ran…
Purification by affinity chromatography of H1 RNA-Binding Proteins from rat brain
2003
Post-transcriptional regulation of mRNA metabolism is involved in processes as different as cell fate specification in development and cell response to a large variety of environmental cues. Regulation of all steps of RNA metabolism depends on RNA-binding proteins (RBPs). By using a T1 RNase protection assay, we previously identified three H1° RNA-binding factors (p40, p70 and p110), highly expressed in the rat brain. Here we report enrichment of these factors from brain extracts, obtained by affinity chromatography of biotinylated H1° RNA-protein complexes on streptavidin-conjugated paramagnetic particles. The purified proteins maintain RNA-binding ability and preference for histone messag…
Metallomacrocycles with metalmetal bonds: synthesis, characterization and electrochemistry of [(P)SnRe(CO)5]BF4 and [{(P)Sn}2Re(CO)4]BF4 derivatives…
1996
Abstract The synthesis and characterization of bimetallic and trimetallic porphyrins of the type [(P)SnRe(CO) 5 ]BF 4 and [{(P)Sn} 2 Re(CO) 4 ]BF 4 are reported where P is the dianion of tetra- p -tolyporphyrin (TpTP) or tetra- m -tolyporphyrin (TmTP). These metal-metal bonded complexes were synthesized by reaction of Re 2 (CO) 10 with the corresponding (P)SnCl 2 derivatives in 1,2-dichlorobenzene followed by a reaction with NaBF 4 or TBABF 4 in toluene to give the BF − 4 salt. Each compound was characterized by a variety of spectroscopic and electrochemical techniques while the structures were assigned on the basis of FAB mass spectral data and by comparison of their physicochemical proper…