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951.
Renfrow MB Mackay CL Chalmers MJ Julian BA Mestecky J Kilian M Poulsen K Emmett MR Marshall AG Novak J 《Analytical and bioanalytical chemistry》2007,389(5):1397-1407
IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis. In IgAN, IgA1 molecules with incompletely galactosylated
O-linked glycans in the hinge region (HR) are present in mesangial immunodeposits and in circulating immune complexes. It is
not known whether the galactose deficiency in IgA1 proteins occurs randomly or preferentially at specific sites. We have previously
demonstrated the first direct localization of multiple O-glycosylation sites on a single IgA1 myeloma protein by use of activated ion-electron capture dissociation (AI-ECD) Fourier
transform ion cyclotron resonance (FT-ICR) tandem mass spectrometry. Here, we report the analysis of IgA1 O-glycan heterogeneity by use of FT-ICR MS and liquid chromatography FT-ICR MS to obtain unbiased accurate mass profiles of
IgA1 HR glycopeptides from three different IgA1 myeloma proteins. Additionally, we report the first AI-ECD fragmentation on
an individual IgA1 O-glycopeptide from an IgA1 HR preparation that is reproducible for each IgA1 myeloma protein. These results suggest that future
analysis of IgA1 HR from IgAN patients and normal healthy controls should be feasible. 相似文献
952.
We construct a continuous transition density of the semigroup generated by for and b in the Kato class on . For small time the transition density is comparable with that of the fractional Laplacian.
Partially supported by KBN and MEN. 相似文献
953.
Comparative XPS analysis of passive layers composition formed on AISI 304 L SS after standard and high‐current density electropolishing 下载免费PDF全文
Krzysztof Rokosz Frank Simon Tadeusz Hryniewicz Sławomir Rzadkiewicz 《Surface and interface analysis : SIA》2015,47(1):87-92
In the paper, there are described chemical compositions of passive surface layers formed on AISI 304 L (EN 1.4307) stainless steel after standard (EP50; i = 50 A/dm2) and high‐current density (EP1000; i = 1000 A/dm2) electropolishing. For the studies, a mixture of orthophosphoric and sulfuric acid electrolyte in proportion 1:4 was used. The survey and high‐resolution spectra of Cr 2p, Fe 2p, S 2p, P 2p, Ni 2p and C 1s are presented. On the basis of the obtained results it was noted that the chromium‐to‐iron ratio (Cr/Fe) after EP50 was about 3.5 times higher than that after EP1000 treatment. The phosphorus‐to‐sulfur ratios after EP50 and EP1000 electropolishing were 0.13 and 0.3, respectively, and nickel to the sum of chromium and iron coefficient (Ni/Cr + Fe) for both electrochemical polishing was equal to 0.04. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
954.
Dr. Alexander Hermann Dr. Felipe Fantuzzi Dr. Merle Arrowsmith Theresa Zorn Dr. Ivo Krummenacher Benedikt Ritschel Dr. Krzysztof Radacki Prof. Dr. Bernd Engels Prof. Dr. Holger Braunschweig 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(36):15847-15855
The reductive coupling of an N-heterocyclic carbene (NHC) stabilized (dibromo)vinylborane yields a 1,2-divinyldiborene, which, although isoelectronic to a 1,3,5-triene, displays no extended π conjugation because of twisting of the C2B2C2 chain. While this divinyldiborene coordinates to copper(I) and platinum(0) in an η2-B2 and η4-C2B2 fashion, respectively, it undergoes a complex rearrangement to an η4-1,3-diborete upon complexation with nickel(0). 相似文献
955.
Dr. Javier A. Romero Ewa K. Nawrocka Dr. Alexandra Shchukina Dr. Francisco J. Blanco Dr. Tammo Diercks Assist. Prof. Krzysztof Kazimierczuk 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23702-23705
NMR spectroscopy offers unique benefits for ligand binding studies on isotopically labelled target proteins. These benefits include atomic resolution, direct distinction of binding sites and modes, a lowest detectable affinity limit, and function independent setup. Yet, retracing protein signal assignments from apo to holo states to derive exact dissociation constants and chemical shift perturbation amplitudes (for ligand docking and structure-based optimization) requires lengthy titration series of 2D heteronuclear correlation spectra at variable ligand concentration that may exceed the protein's lifetime and available spectrometer time. We present a novel method to overcome this critical limitation, based on non-stationary complementary non-uniform sampling (NOSCO NUS) combined with a robust particle swarm optimization algorithm. We illustrate its potential in two challenging studies with very distinct protein sizes and binding affinities, showing that NOSCO NUS can reduce measurement times by an order of magnitude to make such highly informative NMR titration studies more broadly feasible. 相似文献
956.
Krzysztof?SzczepaniecEmail author Bart?omiej?DybiecEmail author 《The European Physical Journal B - Condensed Matter and Complex Systems》2013,86(11):468
The classical model revealing stochastic resonance is a motion of an overdamped particle in a double-well fourth order potential when combined action of noise and external periodic driving results in amplifying of weak signals. Resonance behavior can also be observed in non-dynamical systems. The simplest example is a threshold triggered device. It consists of a periodic modulated input and noise. Every time an output crosses the threshold the signal is recorded. Such a digitally filtered signal is sensitive to the noise intensity. There exists the optimal value of the noise intensity resulting in the “most” periodic output. Here, we explore properties of the non-dynamical stochastic resonance in non-equilibrium situations, i.e. when the Gaussian noise is replaced by an α-stable noise. We demonstrate that non-equilibrium α-stable noises, depending on noise parameters, can either weaken or enhance the non-dynamical stochastic resonance. 相似文献
957.
Krzysztof Kempa 《固体物理学:研究快报》2013,7(7):465-468
It is shown, that hot electrons generated in a semiconductor can transfer their excess free energy into an embedded/adjacent plasmonic metallic structure (reservoir), before it is lost irreversibly to phonons in the semiconductor. Since the plasmon–phonon (and plasmon–photon) scattering in the metallic structure could be much slower than the electron–phonon scattering in the semiconductor, free energy of the hot electrons can be this way effectively protected from phonon emission for a significant amount of time. While the cubic point‐dipole crystal is proposed and studied here specifically as the plasmonic reservoir, other plasmonic structures including planar can be employed. It is also shown how the plasmon‐protected energy can by recycled in a novel, 3rd generation solar cell, be employing a planar plasmonic structure that is simultaneously also an electron collector of the cell. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
958.
The significant effect of hydrostatic pressure on the difficult organocatalytic 1,4-conjugate addition of nitroalkanes to prochiral sterically congested β,β-disubstituted enones is demonstrated. This approach allows for the synthesis of γ-nitroketones containing quaternary stereogenic centers with good yields, excellent enantioselectivity, and low loading (1-5 mol %) of simple chiral primary amine catalysts. 相似文献
959.
Gadzała-Kopciuch R Cendrowski K Cesarz A Kiełbasa P Buszewski B 《Analytical and bioanalytical chemistry》2011,401(7):2069-2078
This study presents a selective method of isolation of zearalenone (ZON) and its metabolite, α-zearalenol (α-ZOL), in neoplastically
changed human tissue by accelerated solvent and ultrasonic extractions using a mixture of acetonitrile/water (84/16% v/v) as the extraction solvent. Extraction effectiveness was determined through the selection of parameters (composition of the
solvent mixture, temperature, pressure, number of cycles) with tissue contamination at the level of nanograms per gram. The
produced acetonitrile/water extracts were purified, and analytes were enriched in columns packed with homemade molecularly
imprinted polymers. Purified extracts were determined by liquid chromatography (LC) coupled with different detection systems
(diode array detection - DAD and mass spectrometry - MS) involving the Ascentis RP-Amide as a stationary phase and gradient
elution. The combination of UE-MISPE-LC (ultrasonic extraction - molecularly imprinted solid-phase extraction - liquid chromatography)
produced high (R ≈ 95–98%) and repeatable (RSD < 3%) recovery values for ZON and α-ZOL. 相似文献
960.
Jeong Ae Yoon Dr. Sidi A. Bencherif Dr. Burak Aksak Eun Kyung Kim Prof. Tomasz Kowalewski Prof. Jung Kwon Oh Prof. Krzysztof Matyjaszewski 《化学:亚洲杂志》2011,6(1):128-136
Thermoresponsive hydrogels with efficient water‐release channels were prepared by incorporating star‐shaped macromolecular pore precursors, with degradable disulfide crosslinked cores and hydrophilic poly(ethylene oxide) (PEO) arms, into the gel network. The gel framework exhibiting lower critical solution temperature (LCST) behavior was synthesized by atom transfer radical polymerization (ATRP) of 2‐(2‐methoxyethoxy)ethyl methacrylate and ethylene glycol dimethacrylate. The incorporation of degradable star macromolecules (dSM) was facilitated by growing the gel from ATRP initiator sites contained within their cores. Following the formation of the gel, the dSM cores were degraded, yielding uniform pores lined with hydrophilic PEO chains. The effect of hydrophilic pores on thermoresponsive hydrogel performances was studied by comparing hydrogels containing hydrophilic pores with analogous hydrogels with neutral pores or with pore‐free controls. Dye absorption/release experiments pointed to the suitability of newly synthesized hydrogels as controlled‐release media, for example, for drug delivery. Cell culture experiments confirmed their nontoxicity and biocompatibility (cell viability>98 %). 相似文献