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51.
Adam Wincukiewicz Ewelina Wierzyska Aliaksei Bohdan Mateusz Tokarczyk Krzysztof P. Korona Magdalena Skompska Maria Kamiska 《Molecules (Basel, Switzerland)》2022,27(22)
High-quality perovskite film with large grains and therefore reduced grain boundaries plays a significant role in improving the power conversion efficiency (PCE) and ensuring good long-term stability of the perovskite solar cells. In this work, we found that adding camphorsulfonic acid (CSA), a Lewis base, to the perovskite solution results in the crystallization of larger perovskite grains. By varying the concentration of CSA, we found that the optimal concentration of the additive is 1 mg/mL, which leads to an 20% increase in PCE of the cells compared to the reference CSA-free cell. Interestingly, we observed that the PCE of cells with an excess of CSA was initially poor, but may increase significantly over time, possibly due to CSA migration to the hole-transporting layer, leading to an improvement in its conductivity. 相似文献
52.
Yevheniia Husak Joanna Michalska Oleksandr Oleshko Viktoriia Korniienko Karlis Grundsteins Bohdan Dryhval Sahin Altundal Oleg Mishchenko Roman Viter Maksym Pogorielov Wojciech Simka 《Molecules (Basel, Switzerland)》2021,26(7)
The biodegradable metals, including magnesium (Mg), are a convenient alternative to permanent metals but fast uncontrolled corrosion limited wide clinical application. Formation of a barrier coating on Mg alloys could be a successful strategy for the production of a stable external layer that prevents fast corrosion. Our research was aimed to develop an Mg stable oxide coating using plasma electrolytic oxidation (PEO) in silicate-based solutions. 99.9% pure Mg alloy was anodized in electrolytes contained mixtures of sodium silicate and sodium fluoride, calcium hydroxide and sodium hydroxide. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), contact angle (CA), Photoluminescence analysis and immersion tests were performed to assess structural and long-term corrosion properties of the new coating. Biocompatibility and antibacterial potential of the new coating were evaluated using U2OS cell culture and the gram-positive Staphylococcus aureus (S. aureus, strain B 918). PEO provided the formation of a porous oxide layer with relatively high roughness. It was shown that Ca(OH)2 was a crucial compound for oxidation and surface modification of Mg implants, treated with the PEO method. The addition of Ca2+ ions resulted in more intense oxidation of the Mg surface and growth of the oxide layer with a higher active surface area. Cell culture experiments demonstrated appropriate cell adhesion to all investigated coatings with a significantly better proliferation rate for the samples treated in Ca(OH)2-containing electrolyte. In contrast, NaOH-based electrolyte provided more relevant antibacterial effects but did not support cell proliferation. In conclusion, it should be noted that PEO of Mg alloy in silicate baths containing Ca(OH)2 provided the formation of stable biocompatible oxide coatings that could be used in the development of commercial degradable implants. 相似文献
53.
Dr. Bohdan Andreiuk Dr. Ilya O. Aparin Dr. Andreas Reisch Dr. Andrey S. Klymchenko 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(50):12877-12883
Bulky hydrophobic counterions (weakly coordinating anions) can insulate ionic dyes against aggregation-caused quenching (ACQ) and enable preparation of highly fluorescent dye-loaded nanoparticles (NPs) for bioimaging, biosensing and light harvesting. Here, we introduce a family of hydrophobic anions based on fluorinated C-acyl barbiturates with delocalized negative charge and bulky non-polar groups. Similarly to fluorinated tetraphenylborates, these barbiturates prevent ACQ of cationic dye alkyl rhodamine B inside polymer NPs made of biodegradable poly(lactic-co-glycolic acid) (PLGA). Their efficiency to prevent ACQ increases for analogues with higher acidity and bulkiness. Their structure controls dye-dye communication, yielding bright NPs with on/off switching or stable emission. They enhance dye encapsulation inside NPs, allowing intracellular imaging without dye leakage. Compared to fluorinated tetraphenylborates known as cytotoxic transmembrane ion transporters, the barbiturates display a significantly lower cytotoxicity. These chemically available and versatile barbiturate derivatives are promising counterion scaffolds for preparation of bright non-toxic fluorescent nanomaterials. 相似文献
54.
Peng Xu Da Zhao Florian Berger Aboubakr Hamad Jens Rickmeier Roland Petzold Mykhailo Kondratiuk Kostiantyn Bohdan Tobias Ritter 《Angewandte Chemie (International ed. in English)》2020,59(5):1956-1960
Site‐selective functionalization of C?H bonds in small complex molecules is a long‐standing challenge in organic chemistry. Herein, we report a broadly applicable and site‐selective aromatic C?H dibenzothiophenylation reaction. The conceptual advantage of this transformation is further demonstrated through the two‐step C?H [18F]fluorination of a series of marketed small‐molecule drugs. 相似文献
55.
The intramolecular [4+2] cycloadditions of dienynes was investigated using cobalt-based catalysts. Substrates without substitution on alkyne moiety were found to react under thermal activation. The use of a cobalt salt as catalyst made reactions cleaner by limiting the formation of byproducts. Cycloadditions with dienynes possessing a substituent on the alkyne pattern occurred only in presence of a cobalt catalyst which displayed a moderate to good activity depending on the substrate patterns. 相似文献
56.
Urszula E. Wawrzyniak Mateusz Woźny Jarosław Kowalski Sławomir Domagała Elwira Maicka Renata Bilewicz Prof. Krzysztof Woźniak Prof. Bohdan Korybut‐Daszkiewicz Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(1):149-157
New dithiolated derivatives of neutral CuII and NiII tetraazamacrocyclic complexes have been synthesized and characterized by spectroscopic and diffractional methods. These rod‐shaped molecules were assembled in monocomponent and mixed monolayers on gold electrodes. In the mixed monolayers, the active molecules were embedded in a hexanethiol matrix. The dithiolated complexes are oriented perpendicularly to the electrode, and reveal faster kinetics of electron transfer than those assembled in a single‐component monolayer. They appear as protrusions, which are easily addressed by using the STM method. In the presence of a suitable electron acceptor in the solution, the donor properties of the anchored Cu complex were weakened, which revealed donor–acceptor interactions with the monolayer. The peak position in the voltammogram indicates a stronger interaction of the solution‐based acceptor with the reduced CuII form than with the CuIII complex. This suggests the possibility of switching the association on or off by applying an appropriate potential. 相似文献
57.
Bohdan Mroziewicz Emil Kowalczyk Lech Dobrzanski Jacek Ratajczak Stainslaw J. Lewandowski 《Optical and Quantum Electronics》2007,39(7):585-595
Performance of external cavity diode lasers with silicon gratings produced by E-beam writing and subsequent reactive ion etching
is described. Optical amplifiers used in the experiments were based on single quantum well heterostructures grown by molecular
beam epitaxy. The lasers were set up in the Littrow configuration and have been designed to allow for wavelength tuning in
the range centred at 960 nm. 相似文献
58.
Bohdan Maslowski 《Applications of Mathematics》1998,43(5):399-399
59.
A Random Continuous Model for Two Interacting Populations 总被引:1,自引:0,他引:1
A system of two interacting populations is considered where each population density follow a stochastic partial differential
equation. The stability behaviour of both populations is studied.
Accepted 29 August 2001. Online publication 21 December 2001. 相似文献
60.
We consider a controlled stochastic semilinear evolution equation with the drift depending on the unknown parameter. We show that the maximum likelihood estimator is strongly consistent for a class of bounded predictable controls. 相似文献