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1.
Dr. Vlastimil Jirasko Dr. Nils-Alexander Lakomek Dr. Susanne Penzel Dr. Marie-Laure Fogeron Prof. Dr. Ralf Bartenschlager Prof. Dr. Beat H. Meier Dr. Anja Böckmann 《Chembiochem : a European journal of chemical biology》2020,21(10):1453-1460
Proton-detected 100 kHz magic-angle-spinning (MAS) solid-state NMR is an emerging analysis method for proteins with only hundreds of microgram quantities, and thus allows structural investigation of eukaryotic membrane proteins. This is the case for the cell-free synthesized hepatitis C virus (HCV) nonstructural membrane protein 4B (NS4B). We demonstrate NS4B sample optimization using fast reconstitution schemes that enable lipid-environment screening directly by NMR. 2D spectra and relaxation properties guide the choice of the best sample preparation to record 2D 1H-detected 1H,15N and 3D 1H,13C,15N correlation experiments with linewidths and sensitivity suitable to initiate sequential assignments. Amino-acid-selectively labeled NS4B can be readily obtained using cell-free synthesis, opening the door to combinatorial labeling approaches which should enable structural studies. 相似文献
2.
Inertial sensors such as gyroscopes and accelerometers are normally considered as the most important sensors in a navigation system. Especially in the underwater or under-ice applications, the accuracy of the entire navigation system has to mainly rely on the precision of the inertial sensors due to inapplicability of global positioning systems. For MEMS-based inertial sensors, fabrication variation and environmental disturbance are among the major error sources. To address these challenges, in this paper we propose an optimization methodology by using parametric analysis on a reference design for improving sensor reliability and resolution. Apart from studying the resolution improvement by deploying an alternative sensing scheme, the effects of changing location, shape, and size of critical cantilevers have been thoroughly explored. By using this method, we have derived an improved mechanical structure for tuning-fork gyroscopes. Our numerical analyses show that the bandwidth of the proposed structure, which is the most important stability measure in the vibratory gyroscopes with slightly mismatched resonant frequencies, is over 1.7 times more immune to fabrication imperfection than the other structural alternatives. The drive and sense resonant amplitude robustness against fabrication imperfection is also improved in the proposed structure. In addition, this structure is able to provide at least 2.3 times larger sense-mode capacitance response to external rotation compared to the previously published designs. More important, it is observed that there is always non-negligible room for improving performance of gyroscopes if our proposed structural optimization methodology is integrated into the conventional MEMS-based inertial sensor design flow. 相似文献
3.
Vidya Kishore Christine Ajinjeru Ahmed A. Hassen John Lindahl Vlastimil Kunc Chad Duty 《Polymer Engineering and Science》2020,60(5):1066-1075
To develop new materials for extrusion additive manufacturing (AM) systems, a fundamental understanding of rheological properties is essential to correlate the effect of processing on material structure and its properties. In this work, the rheological properties of five different grades of neat and carbon fiber (CF)-reinforced poly(ether ketone ketone) are reported. Rheological properties are essential to understand the effect of reinforcing fibers and AM process parameters such as time, temperature, environment, and shear rate on flow behavior during processing. Small-amplitude oscillatory shear tests and steady shear tests indicated neat grades to exhibit less increase in viscosity over time when processed in air than the CF-filled grades. The filled grades showed greater shear thinning and lower sensitivity to temperature. Overall, this rheological analysis provides a broad framework for determining appropriate processing conditions for extrusion deposition AM of such high-temperature polymer systems. 相似文献
4.
This investigation deals with the analysis of intergranular acicular precipitations by X-ray diffraction techniques and SEM. Results obtained during analysing acicular precipitate in 18/10Ti steel, isothermally annealed at 750–850 °C, can be summarised as follows: Intergranular needles are constituted by a complex phosphide of M2P type whose chemical composition can be written as (Ti,Cr,Fe,Ni)2P. Crystal growth direction of intergranular acicular M2P particles in austenite is 〈 100 〉γ. The following orientation relationship was determined between the complex phosphide of M2P type and austenite: . Corrosion testing in boiling 65% HNO3 revealed that there was a relationship between the occurrence of acicular precipitate and a reduction in corrosion rate to a level below 0.5 g m?2h?1. 相似文献
5.
Kamil Musilek Dr. Ondrej Holas Jan Misik Miroslav Pohanka Dr. Ladislav Novotny Vlastimil Dohnal Dr. Veronika Opletalova Kamil Kuca Dr. 《ChemMedChem》2010,5(2):247-254
Acetylcholinesterase (AChE) reactivators are crucial antidotes to organophosphate intoxication. A new series of 26 monooxime‐monocarbamoyl xylene‐linked bispyridinium compounds was prepared and tested in vitro, along with known reactivators (pralidoxime, HI‐6, obidoxime, trimedoxime, methoxime, K107, K108 and K203), on a model of tabun‐ and paraoxon‐, methylparaoxon‐ and DFP‐inhibited human erythrocyte AChE. Although their ability to reactivate tabun‐inhibited AChE did not exceed that of the previously known compounds, some newly prepared compounds showed promising reactivation of pesticide‐inhibited AChE. The acute toxicity of the novel compounds was also determined. Docking studies using tabun‐inhibited AChE were performed for three compounds of interest. The structure–activity relationship (SAR) study confirmed the apparent influence of the xylene linkage and carbamoyl moiety on the reactivation ability and toxicity of the agents. 相似文献
6.
In theory, the combination of inorganic materials and polymers may provide a synergistic performance for mixed‐matrix membranes (MMMs); however, the filler dispersion into the MMMs is a crucial technical parameter for obtaining compelling MMMs. The effect of the filler distribution on the gas separation performance of the MMMs based on Matrimid®‐PEG 200 and ZIF‐8 nanoparticles is demonstrated. The MMMs were prepared by two different membrane preparation procedures, namely, the traditional method and non‐dried metal‐organic framework (MOF) method. In CO2/CH4 binary mixtures, the MMMs were tested under fixed conditions and characterized by various methods. Finally, regardless of the MMM preparation procedure, the incorporation of 30 wt % ZIF‐8 nanoparticles allowed to increase the CO2 permeability in MMMs. The ZIF‐8 dispersion influenced significantly the separation factor. 相似文献
7.
8.
Michal Košťál František Cvachovec Bohumil Ošmera Wolfgang Hansen Vlastimil Juříček 《Annals of Nuclear Energy》2010
The present paper deals with measured as well as calculated energy spectra of neutron and photon beams from the AKR-2 experimental reactor after having passed through Fe layers and Fe/H2O combined layers. The experiment results are compared with calculations presented in various nuclear data libraries, such as, ENDF/B VI.2., ENDF/B VII., BROND 3, JENDL 3.3 and JEFF 3.1. Two models were used to calculate the neutron transport. The first takes into account the atomic structure of the material, whereas the other neglects the effect of inter-atomic bonds assuming the atomic nucleus behaviour to follow the free gas model. 相似文献
9.
Miroslav Chomat Daniela Berkova Vlastimil Matejec Ivan Kasik Gabriela Kuncova 《Sensors and actuators. B, Chemical》2003,90(1-3):151-156
This paper deals with the effect of hydrodynamic conditions on the detection of toluene dissolved in water by means of fibers with a truncated parabolic inverted-graded index (IGI) profile. The detection is based on refractive-index changes of a detection layer of polydimethylsiloxane (PDMS) applied on the fiber which are induced by penetration of toluene into the layer. The dependence of the response of the sensing fiber placed in a flow cell on the flow velocity of the detected aqueous solution of toluene has been investigated. The sensing fiber was successively exposed to flows of distilled water and aqueous solutions of toluene. The fiber responses were measured for three chosen concentrations of the toluene solutions and for five flow velocities of the solutions. From these results the dependence of the relative decrease of the output signal on the flow velocity was determined. It has been found that the magnitude of output signal changes is approximately proportional to the solution concentration and the rate of the signal changes in the tested concentration range depends approximately linearly on the solution flow velocity. 相似文献
10.