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排序方式: 共有276条查询结果,搜索用时 15 毫秒
101.
Bartlomiej?Sojka Aurelia?Liskova Miroslava?Kuricova Mateusz?Banski Jan?Misiewicz Maria?Dusinska Mira?Horvathova Silvia?Ilavska Michaela?Szabova Eva?Rollerova Artur?PodhorodeckiEmail author Jana?TulinskaEmail author 《Journal of nanoparticle research》2017,19(2):68
Sodium fluoride-based β-NaLnF4 nanoparticles (NPs) doped with lanthanide ions are promising materials for application as luminescent markers in bio-imaging. In this work, the effect of NPs doped with yttrium (Y), gadolinium (Gd), europium (Eu), thulium (Tm), ytterbium (Yb) and terbium (Tb) ions on phagocytic activity of monocytes and granulocytes and the respiratory burst was examined. The surface functionalization of <10-nm NPs was performed according to our variation of patent pending ligand exchange method that resulted in meso-2,3-dimercaptosuccinic acid (DMSA) molecules on their surface. Y-core-based NCs were doped with Eu ions, which enabled them to be excited with UV light wavelengths. Cultures of human peripheral blood (n = 8) were in vitro treated with five different concentrations of eight NPs for 24 h. In summary, neither type of nanoparticles is found toxic with respect to conducted test; however, some cause toxic effects (they have statistically significant deviations compared to reference) in some selected doses tested. Both core types of NPs (Y-core and Gd-core) impaired the phagocytic activity of monocytes the strongest, having minimal or none whatsoever influence on granulocytes and respiratory burst of phagocytic cells. The lowest toxicity was observed in Gd-core, Yb, Tm dopants and near-infrared nanoparticles. Clear dose-dependent effect of NPs on phagocytic activity of leukocytes and respiratory burst of cells was observed for limited number of samples. 相似文献
102.
Mateusz Szczepaczyk Dorota A. Rzechonek Adam Dobrowolski Aleksandra M. Miroczuk 《Molecules (Basel, Switzerland)》2021,26(24)
The unconventional yeast Yarrowia lipolytica is used to produce erythritol from glycerol. In this study, the role of the erythrose reductase (ER) homolog YALI0B07117g in erythritol synthesis was analyzed. The deletion of the gene resulted in an increased production of mannitol (308%) and arabitol (204%) before the utilization of these polyols began. The strain overexpressing the YALI0B07117g gene was used to increase the erythritol yield from glycerol as a sole carbon source in batch cultures, resulting in a yield of 0.4 g/g. The specific consumption rate (qs) increased from 5.83 g/g/L for the WT strain to 8.49 g/g/L for the modified strain and the productivity of erythritol increased from 0.28 g/(L h) for the A101 strain to 0.41 g/(L h) for the modified strain. The application of the research may prove positive for shortening the cultivation time due to the increased rate of consumption of the substrate combined with the increased parameters of erythritol synthesis. 相似文献
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Zajdel P Bojarski AJ Bugno R Jurczyk S Kołaczkowski M Nowak M Subra G Martinez J Pawłowski M 《Biomedical chromatography : BMC》2004,18(8):542-549
Six extended analogues of the recently described peptides (LDVL, ADVL) were designed and synthesized on a solid support, and then impregnated on TLC stationary phases. The impact of the impregnated peptide sequence modifications on the chromatographic retard, Delta R(f) (difference in the migration of tested compound on control and impregnated plates), of 42 arylpiperazine 5-HT(1A) receptor ligands was studied. None of the new models tested made a better prediction of 5-HT(1A) affinity than that utilizing ADVL tetrapeptide. Further validation of the ADVL model on a set of 22 structurally differentiated 2-methoxy-phenylpiperazine derivatives confirmed its effectiveness in the affinity discrimination of a coherent group of 5-HT(1A) receptor ligands. 相似文献
106.
Fraser-Reid B Lopez JC Radhakrishnan KV Mach M Schlueter U Gomez AM Uriel C 《Journal of the American Chemical Society》2002,124(13):3198-3199
Glycosidation of several vicinal diols reveals that exquisite regioselectivity can be achieved by using 2-O-benzoyl n-pentenyl glycoside donors and/or their cyclic 1,2-ortho ester counterparts. The regioselective preferences for both are the same, although ratios and yields may differ. In stark contrast, glycosidation of the diols with the corresponding 2-O-benzylated donors gives poor, if any, regioselectivity. 相似文献
107.
Peter B. Weber Raphael Hellwig Tobias Paintner Dr. Marie Lattelais Mateusz Paszkiewicz Pablo Casado Aguilar Peter S. Deimel Dr. Yuanyuan Guo Dr. Yi‐Qi Zhang Dr. Francesco Allegretti Dr. Anthoula C. Papageorgiou Dr. Joachim Reichert Dr. Svetlana Klyatskaya Prof. Dr. Mario Ruben Prof. Dr. Johannes V. Barth Dr. Marie‐Laure Bocquet Dr. Florian Klappenberger 《Angewandte Chemie (International ed. in English)》2016,55(19):5754-5759
Organocobalt complexes represent a versatile tool in organic synthesis as they are important intermediates in Pauson–Khand, Friedel–Crafts, and Nicholas reactions. Herein, a single‐molecule‐level investigation addressing the formation of an organocobalt complex at a solid–vacuum interface is reported. Deposition of 4,4′‐(ethyne‐1,2‐diyl)dibenzonitrile and Co atoms on the Ag(111) surface followed by annealing resulted in genuine complexes in which single Co atoms laterally coordinated to two carbonitrile groups undergo organometallic bonding with the internal alkyne moiety of adjacent molecules. Alternative complexation scenarios involving fragmentation of the precursor were ruled out by complementary X‐ray photoelectron spectroscopy. According to density functional theory analysis, the complexation with the alkyne moiety follows the Dewar–Chatt–Duncanson model for a two‐electron‐donor ligand where an alkyne‐to‐Co donation occurs together with a strong metal‐to‐alkyne back‐donation. 相似文献
108.
Wielopolski M Atienza C Clark T Guldi DM Martín N 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(21):6379-6390
A series of donor-acceptor arrays (exTTF-oPPE-C60) containing pi-conjugated oligo(phenyleneethynylene) wires (oPPE) of different length between pi-extended tetrathiafulvalene (exTTF) as electron donor and fullerene (C60) as electron acceptor has been prepared by following a convergent synthesis. The key reaction in these approaches is the bromo-iodo selectivity of the Hagihara-Sonogashira reaction and the deprotecting of acetylenes with different silyl groups to afford the corresponding donor-acceptor conjugates in moderate yields. The electronic interactions between the three electroactive species were determined by using UV-visible spectroscopy and cyclic voltammetry. Our studies clearly confirm that, although the C60 units are connected to the exTTF donor through pi-conjugated oPPE frameworks, no significant electronic interactions are observed in the ground state. Theoretical calculations predict how a simple exchange from C=C double bonds (i.e., oligo(p-phenylenevinylene) to C triple chemical bond C triple bonds (i.e., oPPE) in the electron donor-acceptor conjugates considerably alters long-range electron transfer. Photoexcitation of exTTF-oPPE-C60 leads to the following features: a transient photoproduct with maxima at 660 and 1000 nm, which are unambiguously attributed to the photolytically generated radical-ion-pair state, [exTTF*+-oPPE-C60*]. Both charge-separation and charge-recombination processes give rise to a molecular-wire behaviour of the oPPE moiety with an attenuation factor (beta) of (0.2+/-0.05) A(-1). 相似文献
109.
Hyeongrae Cho Dirk Henkensmeier Mateusz Brela Artur Michalak Jong Hyun Jang Kwan‐Young Lee 《Journal of Polymer Science.Polymer Physics》2017,55(3):256-265
A methylated polybenzimidazole with an aliphatic chain in the backbone (Me‐PBI‐C10) was synthesized and formed into membranes. Literature suggests that alkyl chains on C2 of imidazolium ions increase their alkaline stability. While this may be true for model compounds or ions attached as a side chain, both our DFT calculations and experimental results show that Me‐PBI‐C10 does not withstand alkaline conditions. To increase the alkaline stability, blend membranes with PBI‐OO were fabricated. A blend membrane with 50% PBI‐OO showed a chloride conductivity of up to 6 mS/cm, indicating that these membranes could find use in non‐alkaline applications like vanadium redox flow batteries (VRFB). The high mechanical stability (tensile strength: 70.25 ± 14.85 MPa, Young modulus: 1.65 ± 0.16 GPa) would be an advantage over currently used Nafion membranes. Finally, three different models were successfully applied to qualitatively predict the water uptake of Me‐PBI‐C10 exchanged with different anions. The results match with experimental data. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 256–265 相似文献
110.