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191.
192.
Marek Jasiorski Anna Leszkiewicz Stefan Brzeziński Gabriela Bugla-Płoskońska Grażyna Malinowska Beata Borak Iwona Karbownik Agnieszka Baszczuk Wiesław Stręk Włodzimierz Doroszkiewicz 《Journal of Sol-Gel Science and Technology》2009,51(3):330-334
The aim of this study was to investigate antimicrobial activity of textiles doped with silver in different forms. Three types
of textiles were prepared and examined: textiles doped with commercially available Ag nanoparticles, textiles doped with commercial
colloidal silver and textiles doped with silver silica SiO2/Ag spheres. The specimens of silica submicron spheres were synthesized by the sol–gel method as a matrix for biological active
silver. The results of microbiological tests revealed that among three kinds of Ag doped textiles only these doped with SiO2/Ag spheres are bacteriostatically active. During the experiments minimal inhibiting bacteria growth concentration of active
SiO2/Ag spheres added to textiles was determined. 相似文献
193.
Aldona Kostuch Iwona A. Rutkowska Beata Dembinska Anna Wadas Enrico Negro Keti Vezz Vito Di Noto Pawel J. Kulesza 《Molecules (Basel, Switzerland)》2021,26(17)
Platinum is a main catalyst for the electroreduction of oxygen, a reaction of primary importance to the technology of low-temperature fuel cells. Due to the high cost of platinum, there is a need to significantly lower its loadings at interfaces. However, then O2-reduction often proceeds at a less positive potential, and produces higher amounts of undesirable H2O2-intermediate. Hybrid supports, which utilize metal oxides (e.g., CeO2, WO3, Ta2O5, Nb2O5, and ZrO2), stabilize Pt and carbon nanostructures and diminish their corrosion while exhibiting high activity toward the four-electron (most efficient) reduction in oxygen. Porosity of carbon supports facilitates dispersion and stability of Pt nanoparticles. Alternatively, the Pt-based bi- and multi-metallic catalysts, including PtM alloys or M-core/Pt-shell nanostructures, where M stands for certain transition metals (e.g., Au, Co, Cu, Ni, and Fe), can be considered. The catalytic efficiency depends on geometric (decrease in Pt–Pt bond distances) and electronic (increase in d-electron vacancy in Pt) factors, in addition to possible metal–support interactions and interfacial structural changes affecting adsorption and activation of O2-molecules. Despite the stabilization of carbons, doping with heteroatoms, such as sulfur, nitrogen, phosphorus, and boron results in the formation of catalytically active centers. Thus, the useful catalysts are likely to be multi-component and multi-functional. 相似文献
194.
Łukasz Ciura Andrzej Kolek Jarosław Jureńczyk Krzysztof Czuba Agata Jasik Iwona Sankowska Janusz Kaniewski 《Optical and Quantum Electronics》2018,50(1):36
The empirical 1/f noise model for p\(^{+}\)-p-n infrared detector made of type-II InAs/GaSb superlattice material is presented. It is shown that 1/f noise magnitude can be accurately estimated if dark current contributions are determined and noise coefficients are known. It is found that the shunt, the bulk generation–recombination, and the trap-assisted tunneling currents contribute to the total 1/f noise. No 1/f noise connected with the diffusion and the band-to-band tunneling currents is observed. 相似文献
195.
Iwona Gulaczyk 《Journal of Molecular Spectroscopy》2008,249(2):73-77
For the first time a weak fundamental symmetric amino-wagging band, ν6, was assigned in the high-resolution Fourier-transform infrared spectrum of hydrazine. The analysis of the Fermi-type resonance between the ν6 and the third excited torsional state, 3ν7, is presented. A global fitting was carried out taking into account 3392 lines of the ν6 band (for K′ from 0 to 10 and for all symmetry species) and 428 lines of the 3ν7 band (for K′ from 3 to 9 and only for the symmetry species in resonance). For all 3820 rovibrational transitions the overall standard deviation of the fit of 0.019 cm−1 was obtained. The band centers of the symmetric wagging state and the third torsional were determined at 795.137 and 860.138 cm−1, respectively. Individual fits were also carried out for K′ from 3 to 8 for all symmetry species with much improved standard deviations. The effective group-theoretical Hamiltonian for the coupling between inversion and torsion states was used. 相似文献
196.
Dr. Ottavia Bettucci Dr. Jorge Pascual Dr. Silver-Hamill Turren-Cruz Andrea Cabrera-Espinoza Dr. Wakana Matsuda Dr. Sebastian F. Völker Hans Köbler Dr. Iwona Nierengarten Dr. Gianna Reginato Dr. Silvia Collavini Prof. Shu Seki Prof. Jean-François Nierengarten Prof. Antonio Abate Prof. Juan Luis Delgado 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(31):8110-8117
Multi-branched molecules have recently demonstrated interesting behaviour as charge-transporting materials within the fields of perovskite solar cells (PSCs). For this reason, extended triarylamine dendrons have been grafted onto a pillar[5]arene core to generate dendrimer-like compounds, which have been used as hole-transporting materials (HTMs) for PSCs. The performances of the solar cells containing these novel compounds have been extensively investigated. Interestingly, a positive dendritic effect has been evidenced as the hole transporting properties are improved when going from the first to the second-generation compound. The stability of the devices based on the best performing pillar[5]arene material has been also evaluated in a high-throughput ageing setup for 500 h at high temperature. When compared to reference devices prepared from spiro-OMeTAD, the behaviour is similar. An analysis of the economic advantages arising from the use of the pillar[5]arene-based material revealed however that our pillar[5]arene-based material is cheaper than the reference. 相似文献
197.
Cancer is a serious problem in modern medicine, mainly due to the insufficient effectiveness of currently available therapies. There is a particular interest in compounds of natural origin, which can be used in the prophylaxis, as well as in the treatment and support of cancer treatment. One such compound is jasmonic acid (3-oxo-2-(pent-2’-enyl)cyclopentane acetic acid; isolated active form: trans-(-)-(3R,7R)- and cis-(+)-(3R,7S)-jasmonic acid) and its derivatives, which, due to their wide range of biological activities, are also proposed as potential therapeutic agents. Therefore, a review of literature data on the biological activity of jasmonates was prepared, with particular emphasis on the mechanisms of jasmonate action in neoplastic diseases. The anti-tumor activity of jasmonate compounds is based on altered cellular ATP levels; induction of re-differentiation through the action of Mitogen Activated Protein Kinases (MAPKs); the induction of the apoptosis by reactive oxygen species. Jasmonates can be used in anti-cancer therapy in combination with other known drugs, such as cisplatin, paclitaxel or doxorubicin, showing a synergistic effect. The structure–activity relationship of novel jasmonate derivatives with anti-tumor, anti-inflammatory and anti-aging effects is also shown. 相似文献
198.
Dr. Iwona Nierengarten Marc Nothisen Dr. David Sigwalt Thomas Biellmann Dr. Michel Holler Dr. Jean‐Serge Remy Dr. Jean‐François Nierengarten 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(51):17552-17558
Dendritic pillar[5]arene derivatives have been efficiently prepared by grafting dendrons with peripheral Boc‐protected amine subunits onto a preconstructed pillar[5]arene scaffold. Upon cleavage of the Boc‐protected groups, water‐soluble pillar[5]arene derivatives with 20 ( 13 ) and 40 ( 14 ) peripheral ammonium groups have been obtained. The capability of these compounds to form stable nanoparticles with plasmid DNA has been demonstrated by gel electrophoresis, transmission electron microscopy (TEM), and dynamic light scattering (DLS) investigations. Transfection efficiencies of the self‐assembled 13 /pCMV‐Luc and 14 /pCMV‐Luc polyplexes have been evaluated in vitro with HeLa cells. The transfection efficiencies found for both compounds are good, and pillar[5]arenes 13 and 14 show very low toxicity if any. 相似文献
199.
Iwona Szkoda Andrew McDowall Clemens Ritter 《Journal of solid state chemistry》2009,182(10):2806-2814
A new series of non-stoichiometric sulfides Ga1−xGexV4S8−δ (0≤x≤1; δ≤0.23) has been synthesized at high temperatures by heating stoichiometric mixtures of the elements in sealed quartz tubes. The samples have been characterized by powder X-ray diffraction, SQUID magnetometry and electrical transport-property measurements. Structural analysis reveals that a solid solution is formed throughout this composition range, whilst thermogravimetric data reveal sulfur deficiency of up to 2.9% in the quaternary phases. Magnetic measurements suggest that the ferromagnetic behavior of the end-member phase GaV4S8 is retained at x≤0.7; samples in this composition range showing a marked increase in magnetization at low temperatures. By contrast Ga0.25Ge0.75V4S8−δ appears to undergo antiferromagnetic ordering at ca. 15 K. All materials with x≠1 are n-type semiconductors whose resistivity falls by almost six orders of magnitude with decreasing Ga content, whilst the end-member phase GeV4S8−δ is a p-type semiconductor. The results demonstrate that the physical properties are determined principally by the degree of electron filling of narrow-band states arising from intracluster V-V interactions. 相似文献
200.
We propose an incomplete split plot design where levels of one factor (say A) are applied to the wholeplots and levels of the other (say B) to subplots, and where the number of subplots in each wholeplot may be less than the number of levels of factor B.The t levels of factor A are arranged in a completely randomized design. The s levels of factor B are arranged in a connected and proper incomplete block design within each level of factor A, by considering the wholeplots as blocks. 相似文献