排序方式: 共有89条查询结果,搜索用时 15 毫秒
41.
Kateryna D. Volkova Vladyslava B. Kovalska Mykhaylo Yu. Losytskyy Gertjan Veldhuis G. M. J. Segers-Nolten Olexiy I. Tolmachev Vinod Subramaniam Sergiy M. Yarmoluk 《Journal of fluorescence》2010,20(6):1267-1274
A key feature of Parkinson’s disease is the formation and accumulation of amyloid fibrils of the natively unfolded protein
α-synuclein (ASN) inside neurons. Recently we have proposed novel sensitive monomethinecyanine dye T-284 as fluorescent probe
for quantitative detection of ASN amyloid fibrils. In this study the T-284 dye complex with ASN fibril was characterized by
means of fluorescence anisotropy, atomic force microscopy and time-resolved fluorescence techniques to give further insights
into the mode of dye interaction with amyloid fibrils. The fluorescence anisotropy of T-284 was shown to noticeably increase
upon addition of aggregated proteins indicating on stable dye/amyloid fibril complex formation. AFM imaging of fibrillar wild-type
ASN revealed differences in heights between ASN fibrils alone and in presence of the T-284 dye (6.37 ± 1.0 nm and 8.0 ± 1.1 nm
respectively), that is believed to be caused by embedding of T-284 dye molecules in the “binding channel” running along the
fibril. Fluorescence decay analysis of the T-284 in complexes with fibrillar ASN variants revealed the fluorescence lifetime
values for T-284/fibril complexes to be an order of magnitude higher as compared to the free dye. Also, the fluorescence decay
of free T-284 was bi-exponential, while dye bound to protein yields tri-exponential decay. We suppose that in complexes with
fibrillar ASN variants T-284 dye might exist in different “populations” due to interaction with fibrils in different conformers
and ways. The exact binding mode of T-284 with ASN fibrils needs further studies. Studied parameters of dye/amyloid fibril
complexes are important for the characterization and screening of newly-developed amyloid-sensitive dyes. 相似文献
42.
On the infinite semigroup of matrix units
there exists no semigroup compact [countably compact] topology.
Any continuous homomorphism from the infinite topological
semigroup of matrix units into a compact topological semigroup is
annihilating. The semigroup of matrix units is algebraically
h-closed in the class of topological inverse semigroups. Some
H-closed minimal semigroup topologies on the infinite semigroup
of matrix units are considered. 相似文献
43.
Tetyana A. Shantalii Iryna L. Karpova Kateryna S. Dragan Eleonora G. Privalko Vitaly M. Karaman Valery P. Privalko 《先进技术聚合物》2005,16(5):400-404
Poly(amide imide) (PAI) nanocomposites prepared by the in situ generation of crosslinked organosilicon nanophase (ON) through the sol‐gel process were characterized by wide‐angle and small‐angle X‐ray diffraction, thermogravimetric analysis, dynamic mechanical analysis and kinetics of water uptake. It was concluded that the polymer nanocomposite (PNC) were likely to possess a complex morphology on the nanoscale characterized by co‐existence of two mixed nanophases of different compositions. At low methyl triethoxysilane (MTS) contents the fractal‐like organization of paracrystalline nano‐domains of PAI chain fragments is destroyed by the randomly distributed ON particles, whereas on the increase of MTS content the spatial correlations between ON particles become stronger, giving rise to their own fractal‐like structure. The higher values of small‐angle X‐ray scattering (SAXS) invariant, apparent water diffusivity and limiting water uptake for the PNC compared to the pristine PAI were assumed to reflect the loose inner structures of PAI‐rich and ON‐rich nanophases, respectively. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
44.
Igor Levchenko Shuyan Xu Oleg Baranov Olha Bazaka Elena P. Ivanova Kateryna Bazaka 《Molecules (Basel, Switzerland)》2021,26(13)
Plasma-enhanced synthesis and modification of polymers is a field that continues to expand and become increasingly more sophisticated. The highly reactive processing environments afforded by the inherently dynamic nature of plasma media are often superior to ambient or thermal environments, offering substantial advantages over other processing methods. The fluxes of energy and matter toward the surface enable rapid and efficient processing, whereas the charged nature of plasma-generated particles provides a means for their control. The range of materials that can be treated by plasmas is incredibly broad, spanning pure polymers, polymer-metal, polymer-wood, polymer-nanocarbon composites, and others. In this review, we briefly outline some of the recent examples of the state-of-the-art in the plasma-based polymer treatment and functionalization techniques. 相似文献
45.
Cuny J Sykina K Fontaine B Le Pollès L Pickard CJ Gautier R 《Physical chemistry chemical physics : PCCP》2011,13(43):19471-19479
Solid-state (95)Mo nuclear magnetic resonance (NMR) properties of molybdenum hexacarbonyl have been computed using density functional theory (DFT) based methods. Both quadrupolar coupling and chemical shift parameters were evaluated and compared with parameters of high precision determined using single-crystal (95)Mo NMR experiments. Within a molecular approach, the effects of major computational parameters, i.e. basis set, exchange-correlation functional, treatment of relativity, have been evaluated. Except for the isotropic parameter of both chemical shift and chemical shielding, computed NMR parameters are more sensitive to geometrical variations than computational details. Relativistic effects do not play a crucial part in the calculations of such parameters for the 4d transition metal, in particular isotropic chemical shift. Periodic DFT calculations were tackled to measure the influence of neighbouring molecules on the crystal structure. These effects have to be taken into account to compute accurate solid-state (95)Mo NMR parameters even for such an inorganic molecular compound. 相似文献
46.
47.
Voitko KV Whitby RL Gun'ko VM Bakalinska OM Kartel MT Laszlo K Cundy AB Mikhalovsky SV 《Journal of colloid and interface science》2011,363(1):129-136
Stable film-forming nanocomposite particles with diameters ranging from 120 to 300 nm, based on polybutylmethacrylate (PBMA) and cellulose whiskers in water dispersions, were successfully synthesized in one step through mini-emulsion polymerization. The nanocomposite dispersion with a solid content of 25 wt.% and up to 5 wt.% of nanofiller loading was prepared by in situ polymerization, in the presence of the whiskers using dodecylpyridinium chloride (DPC), as a cationic surfactant, and 2,2-azobis(isobutyronitrile) (AIBN), as initiator. The electrostatic interaction between the positively charged droplets and negatively charged whiskers ensured the anchoring of the nanofiller around the polymer particles. The ensuing dispersions were characterized by Dynamic Light Scattering (DLS), ζ-Potential Measurements, and Field-Emission Scanning Electron Microscopy (FE-SEM). After the film formation process, the nanocomposite film exhibits a high transparency, denoting the good dispersion of the whiskers throughout the matrix. 相似文献
48.
Kateryna Marynets 《Monatshefte für Mathematik》2020,191(4):749-759
Using the method of sub- and supersolutions for semilinear elliptic equations, in combination with the stereographic projection, we show that Stuart-type vortices can model the steady flow of the Antarctic Circumpolar Current. 相似文献
49.
Kateryna Fominova Taras Diachuk Dmitry Granat Taras Savchuk Vladyslav Vilchynskyi Oleksiy Svitlychnyi Vladyslav Meliantsev Igor Kovalchuk Eduard Litskan Vadym
V. Levterov Valentyn R. Badlo Ruslan I. Vaskevych Alla I. Vaskevych Andrii V. Bolbut Volodymyr V. Semeno Rustam Iminov Kostiantyn Shvydenko Anastasiia S. Kuznetsova Yurii V. Dmytriv Daniil Vysochyn Vasyl Ripenko Andrei A. Tolmachev Olexandra Pavlova Halyna Kuznietsova Iryna Pishel Petro Borysko Pavel K. Mykhailiuk 《Chemical science》2021,12(34):11294
A general approach to a new generation of spirocyclic molecules – oxa-spirocycles – was developed. The key synthetic step was iodocyclization. More than 150 oxa-spirocyclic compounds were prepared. Incorporation of an oxygen atom into the spirocyclic unit dramatically improved water solubility (by up to 40 times) and lowered lipophilicity. More potent oxa-spirocyclic analogues of antihypertensive drug terazosin were synthesized and studied in vivo.A general practical approach to a new generation of spirocyclic molecules – oxa-spirocycles – is developed. 相似文献
50.
Alkylated Aromatic Thioethers with Aggregation‐Induced Emission Properties—Assembly and Photophysics
Steffen Riebe Marco Saccone Jacqueline Stelzer Andrea Sowa Christoph Wlper Kateryna Soloviova Cristian A. Strassert Michael Giese Jens Voskuhl 《化学:亚洲杂志》2019,14(6):814-820
In this contribution, we present the synthesis and self‐assembly of alkylated thioethers with interesting photophysical properties. To this end, the emission, absorption and excitation spectra in organic solvents and as aggregates in water were measured as well as the corresponding photoluminescence quantum yields and lifetimes. The aggregates in aqueous media were visualized and measured using transmission electron microscopy. Besides that, crystal structures of selected compounds allowed a detailed discussion of the structure–property relationship. Furthermore, the mesomorphic behavior was investigated using polarized optical microscopy (POM) as well as differential scanning calorimetry (DSC). 相似文献