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1.
Numerous biological processes are connected with the efficient electron transfer reactions in proteins and peptides. In this review, we discuss briefly the relevance and current challenges associated with the voltammetric analysis of peptides and proteins with and without a metal redox center. Special attention is paid to the integration of electrochemical methods with new nanomaterials which offers amplification of multiplexing capabilities for simultaneous and very sensitive examination of various proteins. After critically discussing the most interesting approaches in the proteins/peptides voltammetric analysis reported so far, for the single or multiplexed examination of such biomolecules with demonstrated applicability in the real-sample analysis, existing challenges still need to be addressed and future directions in this field will be pointed out. 相似文献
2.
Mohammad Azam Saud I. Al-Resayes Agata Trzesowska-Kruszynska Rafal Kruszynski S.F. Adil N.K. Lokanath 《Journal of Saudi Chemical Society》2019,23(5):636-641
A new derivative of dioxouranium(VI) salen complex, [UO2(L)(pyridine)], where [L = N,N′-Bis(2-hydroxybenzylidene)-2,2-dimethyl-1,3-propanediamine] is synthesized and characterized by elemental analysis (C, H, N), FT-IR, ESI-MS spectrometry, UV/Vis, fluorescence, 1H and 13C NMR spectroscopy and thermal gravimetric (TG) study. Furthermore, the single crystal X-ray diffraction measurements of the complex were carried out at 100 and 273 K. The crystal structure measurements revealed that the complex has distorted pentagonal bipyramidal geometry with uranium atom located at the centre and bonded to two phenoxy oxygen and two azomethine nitrogen in tetradenate fashion and one nitrogen from pyridine making it seven coordinated. In addition, the photoluminescence property of the complex was also recorded. 相似文献
3.
4.
The famous 1960's construction of Golod and Shafarevich yields infinite dimensional nil, but not nilpotent, algebras. However, these algebras have exponential growth. Here, we construct an infinite dimensional nil, but not locally nilpotent, algebra which has polynomially bounded growth.
5.
Piotr Ziba Agnieszka Skara Emilia Berna Agata Krakowska Katarzyna Sukowska-Ziaja Edward Kunicki Magorzata Suchanek Boena Muszyska 《Molecules (Basel, Switzerland)》2021,26(11)
The use of substrates supplemented with minerals is a promising strategy for increasing the nutraceutical value of Pleurotus spp. The current research was performed to analyze the effect of substrate supplementation with magnesium (Mg) salts on the Mg content, biomass, and chemical composition of pink oyster mushroom (Pleurotus djamor) fruiting bodies. Before inoculation, substrate was supplemented with MgCl2 × 6 H2O and MgSO4, both salts were applied at three concentrations: 210, 420, and 4200 mg of Mg per 2 kg of substrate. The harvest period included three flushes. Substrate supplementation with 4200 mg of Mg caused the most significant decrease in mushroom productivity, of about 28% for both Mg salts. The dry matter content in fruiting bodies was significantly lower in the treatment in which 210 mg of Mg was applied as MgSO4 in comparison to the control. Supplementation effectively increased the Mg content in fruiting bodies of P. djamor by 19–85% depending on the treatment, and significantly affected the level of remaining bioelements and anions. One hundred grams of pink oyster fruiting bodies, supplemented with Mg salts, provides more than 20% of the Mg dietary value recommended by the Food and Drug Administration (FDA); thus, supplementation can be an effective technique for producing mushrooms that are rich in dietary Mg. Although P. djamor grown in supplemented substrate showed lower productivity, this was evident only in the fresh weight because the differences in dry weight were negligible. Mg supplementation increased the antioxidant activity of the fruiting bodies, phenolic compounds, and some amino acids, including L-tryptophan, and vitamins (thiamine and l-ascorbic acid). 相似文献
6.
Conducting polymer (CP) films, used as ion-sensing membranes under open circuit potentiometric conditions, are usually characterised with rather high detection limit, in the range of 10−4-10−5 mol dm−3. This effect is unfavourable, not only from the point of view of CP applications in potentiometry as ion sensitive membranes, but also when these materials are used as ion-to-electron transducers (solid contacts) for ion-selective electrodes. The theoretical considerations presented underline the crucial role of spontaneous processes of polymer charging/discharging—the source of observed high detection limit of sensors comprising CP layer under zero current conditions. Although the mechanism of occurring process is different from that observed for plastic, solvent polymeric based ion-selective electrodes, the ultimate result—alteration of activity of electrolyte at the membrane/solution interface leading to elevation of the detection limit—is the same.The method of estimation of parameters characterising spontaneous charge transfer processes is presented. The values obtained can be used to calculate the resulting polymer/solution interface activity of electrolyte ions, thus the detection limit of CP membrane can be theoretically predicted.A method of lowering of the detection limit of conducting polymer membranes, applying galvanostatic polarisation to compensate the spontaneous process of polymer charging/discharging, is presented.The experimental results obtained for poly(pyrrole), poly(N-methylpyrrole) and poly(3,4-ethylenedioxythiophene) are in good accordance with predictions of the presented model. 相似文献
7.
Wagner-Czauderna Elżbieta Boroń-Cegiełkowska Agata Orłowska Elżbieta Kalinowski Marek K. 《Transition Metal Chemistry》2004,29(1):61-65
The visible absorption spectra of CoCl2 in binary mixtures of acetone, dmf, dma and dmso with H2O show the existence of configuration equilibria between tetrahedral (T) and octahedral (O) species. Linear correlations between the values of log K (K = [O]/[T]) and the mole fraction of H2O,
w, have been observed in all the systems under study; their slopes decrease linearly with an increase of the donor number, DN, of the organic component of the mixture. The formation of octahedral species is enthalpy favoured but entropy disfavoured. It was found that both H and S values change linearly with
w and the slopes of these relationships depend clearly on the DN values. 相似文献
8.
Magdalena Kurdziel Elżbieta Szczepaniec-Cieciak Monika Watorczyk Barbara Dabrowska 《Journal of solution chemistry》2004,33(5):453-464
The solubility of solid 2-methyl-1,3-butadiene (isoprene) in liquid argon at a temperature of 87.3 K and in liquid nitrogen at 77.4 K has been measured by the filtration method. The hydrocarbon contents in solutions were determined using gas chromatography. GC–MS was used to identify impurities in the solute. The experimental value of the mole fraction solubility of solid isoprene in liquid argon at 87.3 K is (1.41 ± 0.27) × 10–6 and (1.56 ± 0.36) × 10–7 in liquid nitrogen at 77.4 K. The Preston–Prausnitz method was used for calculation of the solubilities of solid hydrocarbon in liquid argon in the temperature range 84.0–110.0 K and in liquid nitrogen from 64.0 to 90.0 K. The solvent–solute interaction parameters l
12 were also calculated. At 90.0 K liquid argon is a better solvent for isoprene than is liquid nitrogen. The experimental values of the solubilities of isoprene in liquid argon and nitrogen were compared with results obtained for selected unsaturated and aromatic hydrocarbons. 相似文献
9.
Agata Biaoska Zbigniew Ciunik 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(4):o182-o185
Comparison of the structures of strychninium N‐phthaloyl‐β‐alaninate N‐phthaloyl‐β‐alanine, C21H23N2O2+·C11H8NO4−·C11H9NO4, and brucinium N‐phthaloyl‐β‐alaninate 5.67‐hydrate, C23H27N2O4+·C11H8NO4−·5.67H2O, reveals that, unlike strychninium cations, brucinium cations display a tendency to produce stacking interactions with cocrystallizing guests. 相似文献
10.
Jos Antonio Andrades Manuel Lojo-Lpez Agata Egea-Corbacho Jos María Quiroga 《Molecules (Basel, Switzerland)》2022,27(14)
Different advanced oxidation processes (AOPs) (ultraviolet radiation, hydrogen peroxide photolysis and photo-Fenton) were applied to test the degradation of terbuthylazine in three types of water: (a) ultrapure water, (b) surface water from the Gaditana area (Los Hurones reservoir, Cádiz, Spain) and (c) groundwater from the Tempul spring in Jerez de la Frontera (Cádiz, Spain). The experiments were carried out on a laboratory scale, using two different types of reactors, batch and semi-continuous. In batch reactors, the most efficient process for the experiments carried out with both ultrapure water and underground groundwater was ultraviolet radiation, whereas for surface water from the Gaditana area, the process that obtained the best results was the photolysis of hydrogen peroxide with 2.5 mg L−1 of H2O2. In semi-continuous reactors, the most efficient process was the photolysis of hydrogen peroxide with 2.5 mg L−1 of H2O2 for all the matrices studied. In both types of reactors, terbuthylazine degradation percentages higher than 90% were achieved; the main difference was in the reaction time, which varied from minutes in the batch reactor to seconds in the semi-continuous reactor. In all the applied AOPs, N-terbutyl-6-hydroxy-N′ethyl-1,3,5-triazine-2,4-diamine (TBA-212) was generated as a reaction intermediate. 相似文献