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11.
Enzymatic Oxygen Microsensor Based on Bilirubin Oxidase Applied to Microbial Fuel Cells Analysis 下载免费PDF全文
Matteo Grattieri Sofia Babanova Carlo Santoro Edoardo Guerrini Stefano PM Trasatti Pierangela Cristiani Massimiliano Bestetti Plamen Atanassov 《Electroanalysis》2015,27(2):327-335
A selective oxygen biosensor based on bilirubin oxidase (BOx) was developed. The sensor was used for determining oxygen profiles in a membraneless, single‐chamber microbial fuel cell (SCMFC), fed with raw wastewater. The linear response of the sensor was optimized by a diffusion layer of silica gel. A computer‐controlled stage was used to obtain accurate and precise measurements. Oxygen concentration in biofilms covering electrodes was measured, showing 3 mg L?1 of O2 in the bulk solution, decreasing to 0 mg L?1 in the cathodic biofilm. The MFC generated power in the range of 0–0.08 mW, associated to the oxygen content. 相似文献
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Dr. Alexander Scholte Christoph Hübner Dr. Dieter Ströhl Olaf Scheufler Dr. Steffen Czich Julia M. Börke Dr. Gerhard Hildebrand Prof. Dr. Klaus Liefeith 《ChemistryOpen》2021,10(9):889-895
Due to their special chemical structure, tetraether lipids (TEL) represent essential elements of archaeal membranes, providing these organisms with extraordinary properties. Here we describe the characterization of a newly isolated structural element of the main lipids. The TEL fragment GDNT-β-Glu was isolated from Sulfolobus metallicus and characterized in terms of its chemical structure by NMR- and MS-investigations. The obtained data are dissimilar to analogically derived established structures – in essence, the binding relationships in the polar head group are re-determined and verified. With this work, we provide an important contribution to the structure elucidation of intact TEL also contained in other Sulfolobus strains such as Solfulobus acidocaldarius and Sulfolobus solfataricus. 相似文献
13.
Th. G. Scholte 《Journal of Polymer Science.Polymer Physics》1968,6(1):91-109
From the sedimentation-diffusion equilibria of some polymer solutions the average molecular weights M?n, M?w, M?z, and M?z+1 have been determined in different ways. In particular, the applicability of Fujita's method, which utilizes concentration gradient values at the midpoint of the solution column at a number of rotor speeds, was examined. It appears that if the gradients at some other places in the column are also used, a smaller range of rotor speeds suffices. This method is generally applicable for determining the average molecular weights specified above. 相似文献
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Effects of directed architecture in epoxy functionalized prepolymers for photocurable thin films 下载免费PDF全文
Jon P. Scholte Soon Ki Kim Christopher L. Lester C. Allan Guymon 《Journal of polymer science. Part A, Polymer chemistry》2017,55(1):144-154
Cationic photopolymerization has become increasingly important in thin‐film applications for advantages including no oxygen inhibition and rapid polymerization rates. Photocurable cationic thin film properties are often modulated by incorporation of oligomeric and prepolymer materials, but little work has directly examined the effect of prepolymer structure and reactive group placement on the thermomechanical properties of the final material. To explore the role of molecular architecture, epoxy functionalized butyl acrylate gradient copolymers were synthesized with reactive groups in end segments or randomly distributed along the prepolymer chain. Polymerized end functionalized formulations exhibit moduli almost double that of random functionalized oligomer formulations. In addition, inclusion of end functionalized prepolymers decreases creep of resulting thin films by a factor of 10. Furthermore, decreasing the concentration of the cross‐linking diluent in end functionalized prepolymer systems results in amorphous networks with significantly lower mechanical strength. Increasing reactive groups at the ends of prepolymers produces stronger materials without affecting tensile elongation at break. These properties indicate that the structured oligomers facilitate the formation of continuous hard domains with high cross‐link density with inclusions of soft, flexible domains of low cross‐link density. This study demonstrates that the prepolymer architecture governs network formation and ultimate properties. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 144–154 相似文献
16.
Alan Rigter Jan Priem Drophatie Timmers-Parohi Jan PM Langeveld Fred G van Zijderveld Alex Bossers 《BMC biochemistry》2009,10(1):29-16
Background
Molecular mechanisms underlying prion agent replication, converting host-encoded cellular prion protein (PrPC) into the scrapie associated isoform (PrPSc), are poorly understood. Selective self-interaction between PrP molecules forms a basis underlying the observed differences of the PrPC into PrPSc conversion process (agent replication). The importance of previously peptide-scanning mapped ovine PrP self-interaction domains on this conversion was investigated by studying the ability of six of these ovine PrP based peptides to modulate two processes; PrP self-interaction and conversion. 相似文献17.
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J P Boegheim H Scholte T M Dubbelman E Beems A K Raap J van Steveninck 《Journal of photochemistry and photobiology. B, Biology》1987,1(1):61-73
Photodynamic treatment of murine L929 fibroblasts with hematoporphyrin-derivative resulted in the inactivation of cytosolic, mitochondrial and lysosomal enzymes and in a decrease in cellular adenosine triphosphate and reduced glutathione concentrations. Comparison of these results with those of previous studies revealed that transmembrane transport systems and DNA repair enzymes are inactivated after much shorter illumination periods than are intracellular enzymes. Although the pattern of photodynamic damage altered by varying the protocol of preincubation with hematoporphyrin-derivative and washing, it appeared that under all experimental conditions the plasma membrane was much more sensitive to photodynamic damage than were the intracellular enzymes. Lysosomal membrane disruption with subsequent detrimental release of lysosomal enzymes has been implicated previously in certain forms of porphyrin-induced photodynamic cell destruction. Cytochemical studies on enzyme localization virtually exclude such a mechanism in hematoporphyrin-derivative-induced cell inactivation in L929 fibroblasts. 相似文献
19.
Th. G. Scholte 《Journal of Polymer Science.Polymer Physics》1970,8(6):841-868
Sedimentation equilibrium in the ultracentrifuge means that there is such a distribution of molecular species throughout the cell, that the centrifugal forces are balanced by differences in the activities. This provides a method for determination of the activities and the chemical potentials in polymer solutions which, in principle, is very simple and reliable. A complication is caused by polydispersity of the dissolved polymer. If one assumes that the interaction parameter depends on concentration and temperature, but not on molecular weight, it is possible to determine the chemical potential of polymer and solvent from the ultracentrifugal data. Experiments have been carried out on the systems polystyrene–toluene and polystyrene–cyclohexane at different temperatures and in the concentration range 0–80 wt-%. The results are expressed in the data for the chemical potential of the solvent, the number average chemical potential of the polymer and the interaction parameter χ. 相似文献
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Gy. Faigel L. Gránásy T. Kemény A. Lovas I. Vincze W. Hoving P. H. L. O. Scholte F. Van der Woude R. Hauert P. Oelhafen H. -J. Güntherodt 《Hyperfine Interactions》1986,27(1-4):381-384
57Fe Mössbauer and photoemission measurements were performed on meltquenched amorphous Fe(Zr, B) and (Fe, Ni)B alloys. The atomic and electronic structure of Fe90Zr10 and Fe88B12 glasses were found to be different. Half of the Zr content could be replaced by B in the Fe90Zr10 glass without changing its structure. Mossbauer investigation of the amorphous (Fe1?xNix)100?yBy (0<=x<=0.80, 12<=y<=40) system indicates preferential arrangement of Fe and Ni atoms on the transition metal sites. According to the present XPS measurements there is a remarkable shift of 0.5 eV to higher binding energies of the B ls core level energy in the Ni rich glasses compared to Fe88B12 corresponding to a stronger binding between the Ni and the B atoms than that of Fe and B. 相似文献