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Aufsatz
Single-wall carbon nanotubes-chitosan nanocomposites: Surface wettability, mechanical and thermal properties
(2021-04-14)
Functionalized single-wall carbon nanotubes (f-SWCN) are dispersed in chitosan films by self-assembly of both components in aqueous media. This carbon form is a promising nanofiller to achieve nanocomposites with refined thermal, mechanical and surface features. In this study, we investigated the influence of functionalized single-wall carbon nanotubes concentration on the resulting properties of the nanocomposites structures. Functionalized single-wall carbon nanotubes are dispersed on a molecular scale in the ...
Aufsatz
Mineralization of Phosphorylated Fish Skin Collagen/Mangosteen Scaffolds as Potential Materials for Bone Tissue Regeneration
(2021-05-13)
In this study, a potential hard tissue substitute was mimicked using collagen/mangosteen porous scaffolds. Collagen was extracted from Tilapia fish skin and mangosteen from the waste peel of the respective fruit. Sodium trimetaphosphate was used for the phosphorylation of these scaffolds to improve the nucleation sites for the mineralization process. Phosphate groups were incorporated in the collagen structure as confirmed by their attenuated total reflection Fourier transform infrared (ATR-FTIR) bands. The phosphorylation ...
Aufsatz
Molecular Basis for Ser/Thr Specificity in PKA Signaling
(2020-06-25)
cAMP-dependent protein kinase (PKA) is the major receptor of the second messenger cAMP and a prototype for Ser/Thr-specific protein kinases. Although PKA strongly prefers serine over threonine substrates, little is known about the molecular basis of this substrate specificity. We employ classical enzyme kinetics and a surface plasmon resonance (SPR)-based method to analyze each step of the kinase reaction. In the absence of divalent metal ions and nucleotides, PKA binds serine (PKS) and threonine (PKT) substrates, ...
Aufsatz
Oxidation Reactions of the N-Heterocyclic Stannylenes [𝘰-C₆H₄ (NSi𝑡BuMe₂)]₂Sn and [{Fe(η⁵ -C₅H₄ -NSi𝑡BuMe₂)₂}Sn] with Sulfur, Selenium, and Diphenyl Diselenide
(2020-01-27)
The N‐heterocyclic stannylenes [{Fe(η$^5$‐C$_5$H$_4$‐NSi𝑡 BuMe$_2$)$_2$}Sn] (1 ) and [𝘰‐C$_6$H$_4$(NSi𝑡 BuMe$_2$)]$_2$Sn (2 ) were prepared in one‐pot reactions from SnCl$_2$, LiN(SiMe$_3$)$_2$, and the corresponding diamine, viz. [Fe(η$^5$‐C$_5$H$_4$‐NHSi𝑡 BuMe$_2$)$_2$] and 𝘰‐C$_6$H$_4$(NSiH𝘵 BuMe$_2$)$_2$, respectively. Oxidative addition reactions of 1 and 2 with S$_8$ and Se$_8$, respectively, afforded the corresponding 1,3,2,4‐dithiadistannetanes ((1 S$_2$), (2 S$_2$)), and 1,3,2,4‐diselenadistannetanes ...
Aufsatz
Recent Progress in Synthesis and Application of Nanosized and Hierarchical Mordenite—A Short Review
(2021-02-26)
Zeolites with their unique properties find applications in various fields, including medicine, agronomy, ecology, production of detergents and drying agents, and in a number of industrial processes. Among zeolites, mordenite is particularly widespread because of its high silica/alumina ratio, which allows it to resist exposure to high temperatures and to acidic gases and liquids. Mordenite is commercially available as a natural mineral and as a synthesized material. This zeolite is mostly used in its synthetic form ...
Aufsatz
S-Adenosyl-L-Homocysteine Hydrolase Inhibition by a Synthetic Nicotinamide Cofactor Biomimetic
(2018-03-21)
S-adenosyl-L-homocysteine (SAH) hydrolases (SAHases) are involved in the regulation of methylation reactions in many organisms and are thus crucial for numerous cellular functions. Consequently, their dysregulation is associated with severe health problems. The SAHase-catalyzed reaction is reversible and both directions depend on the redox activity of nicotinamide adenine dinucleotide (NAD+) as a cofactor. Therefore, nicotinamide cofactor biomimetics (NCB) are a promising tool to modulate SAHase activity. In the ...
Aufsatz
Photoinduced supramolecular chirality and spontaneous surface patterning in high-performance azo materials
(2019-06-18)
In this work, two photo-structuring processes, photo induced spontaneous surface structuring (PSSP) and photo induced supramolecular chirality (PSC) are applied to high-performance azo polymers. We demonstrate higher induced optical rotation than described previously in other reports and show that self-organized surface morphologies are not detrimental for the formation of PSC.
Aufsatz
Generation of twisted nanowires with achiral organic amphiphilic copper complexes
(2019-01-14)
Drying under solvent atmosphere (DUSA) was investigated as an experimental technique to generate self-assembled nanowires and needles from solutions of organic molecules under controlled conditions. Experimental observations of twisted nanowires are reported. These twisted nanowires were obtained by drying of solutions of achiral molecules under solvent controlled atmospheres: achiral, amphiphilic copper complexes were dissolved in an achiral solvent and these solutions were dried under controlled conditions. Two ...
Aufsatz
Synthesis, Structure and Cu-Phenylacetylide Coordination of an Unsymmetrically Substituted Bulky dppf-Analog
(2021-12-03)
The donor properties of a set of bulky ferrocene based bisphosphanes (Fe(C₅H₄PMes₂)₂ and (C₅H₄PMes₂)Fe(C₅H₄PᵗBu₂ with Mes= mesityl and ᵗBu=tert-butyl) were probed by exploring the NMR parameters of the corresponding selenophosphoranes amended by cyclovoltammetry. The ligand properties were explored in the complexation of copper phenylacetylide which is relevant as intermediate in the Cu(I) catalyzed CO₂ addition to phenylacetylene. Owing to the poor solubility of the resulting complexes their characterization was ...
Aufsatz
Site-specific interrogation of an ionic chiral fragment during photolysis using an X-ray free-electron laser
(2021-08-12)
Short-wavelength free-electron lasers with their ultrashort pulses at high intensities have originated new approaches for tracking molecular dynamics from the vista of specific sites. X-ray pump X-ray probe schemes even allow to address individual atomic constituents with a ‘trigger’-event that preludes the subsequent molecular dynamics while being able to selectively probe the evolving structure with a time-delayed second X-ray pulse. Here, we use a linearly polarized X-ray photon to trigger the photolysis of a ...