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61.
Mathew J. Jones Dr. Alice Dawson Prof. Tim G. Hales Prof. William N. Hunter 《Chembiochem : a European journal of chemical biology》2020,21(10):1526-1533
Bicuculline, a valued chemical tool in neurosciences research, is a competitive antagonist of specific GABAA receptors and affects other pentameric ligand-gated ion channels including the glycine, nicotinic acetylcholine and 5-hydroxytryptamine type 3 receptors. We used a fluorescence-quenching assay and isothermal titration calorimetry to record low-micromolar dissociation constants for N-methylbicuculline interacting with acetylcholine-binding protein and an engineered version called glycine-binding protein (GBP), which provides a surrogate for the heteromeric interface of the extracellular domain of the glycine receptor (GlyR). The 2.4 Å resolution crystal structure of the GBP:N-methylbicuculline complex, sequence and structural alignments reveal similarities and differences between GlyR and the GABAA receptor–bicuculline interactions. N-methylbicuculline displays a similar conformation in different structures, but adopts distinct orientations enforced by interactions and steric blocks with key residues and plasticity in the binding sites. These features explain the promiscuous activity of bicuculline against the principal inhibitory pentameric ligand-gated ion channels in the CNS. 相似文献
62.
Veronika Stahl Yuan Shi Werner Kraft Tim Lanz Peter Vetter Raouf Jemmali Fiona Kessel Dietmar Koch 《International Journal of Applied Ceramic Technology》2020,17(5):2040-2050
Thanks to their high energy density and thermal conductivity, metallic Phase Change Materials (mPCM) have shown great potential to improve the performance of thermal energy storage systems. However, the commercial application of mPCM is still limited due to their corrosion behavior with conventional container materials. This work first addresses on a fundamental level, whether carbon-based composite-ceramics are suitable for corrosion critical components in a thermal storage system. The compatibility between the mPCM AlSi12 and the Liquid Silicon Infiltration (LSI)-based carbon fiber reinforced silicon carbide (C/C-SiC) composite is then investigated via contact angle measurements, microstructure analysis, and mechanical testing after exposure. The results reveal that the C/C-SiC composite maintains its mechanical properties and microstructure after exposure in the strongly corrosive mPCM. Based on these results, efforts were made to design and manufacture a container out of C/C-SiC for the housing of mPCM in vehicle application. The stability of the component filled with mPCM was proven nondestructively via computer tomography (CT). Successful thermal input- and output as well as thermal storage ability were demonstrated using a system calorimeter under conditions similar to the application. The investigated C/C-SiC composite has significant application potential as a structural material for thermal energy storage systems with mPCM. 相似文献
63.
Zhiyuan Jiang Peng Liu Qihui Chen Hung-Jue Sue Tim Bremner Lorenzo P. DiSano 《应用聚合物科学杂志》2020,137(33):48966
Interest in developing high-performance blends for niche applications has grown significantly in efforts to meet ever-increasing harsh environment demands. In this work, four model poly(aryl-ether-ketone)/polybenzimidazole (PAEK/PBI) blends were chosen to study the influence of premixing methods, processing, and matrix polymers, on their mechanical properties. Among the model poly(ether ether ketone) (PEEK) and PBI blends, mechanical properties are greatly enhanced by melt premixing. The molding process mainly affects the matrix crystallinity, which in turn greatly influences fracture toughness of the blend. Poly(ether ketone ketone) (PEKK) and PBI blend exhibits a slightly lower tensile strength and fracture toughness than PEEK/PBI due to the differences in inherent properties of PEEK and PEKK matrices and their interfacial interaction with PBI. The processing−structure–property relationship of PAEK/PBI blends is established to help guide optimal design of high-performance polymer blends for structural applications. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48966. 相似文献
64.
Almeida G Figueiredo A Rôla M Barros RM Gibbs P Hogg T Teixeira P 《Journal of food protection》2007,70(7):1710-1716
Seventy raw milk cheeses made in different regions of Portugal, both hard and soft varieties, made with cow's, ewe's, or goat's milk or combinations of these, were sampled within their quoted shelf lives for microbiological safety. On the basis of the presence or numbers of Escherichia coli, E. coli O157, Staphylococcus aureus, Salmonella, and Listeria monocytogenes, cheeses were categorized as satisfactory, acceptable, unsatisfactory, or unacceptable and potentially hazardous. Twenty-two of the 70 cheeses were classified as satisfactory or acceptable. Thirty-seven of the cheeses were considered unsatisfactory because of the presence of E. coli, S. aureus, or both, while 11 of the cheeses were graded as unacceptable and potentially hazardous because of the presence of excessive numbers of S. aureus, E. coli, or L. monocytogenes and the presence of Salmonella in three of these. All cheeses graded as unacceptable and potentially hazardous were soft or semisoft cheeses made with ewe's and goat's milk, with the exception of two hard cheeses made with cow's milk. E. coli O157 was not detected in any of the cheeses. According to the present results, it seems that the presence or counts of pathogenic or indicator organisms in raw milk cheeses cannot be related to the processing conditions, milk type, or region of production. 相似文献
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66.
This paper focuses on the problem of extreme wind gust and direction change recognition (EG&DR) and control (EEC). An extreme wind gust with direction change can lead to large loads on the turbine (causing fatigue) and unnecessary turbine shutdowns by the supervisory system caused by rotor overspeed. The proposed EG&DR algorithm is based on a non‐linear observer (extended Kalman filter) that estimates the oblique wind inflow angle and the blade effective wind speed signals, which are then used by a detection algorithm (cumulative sum test) to recognize extreme events. The non‐linear observer requires that blade root bending moments measurements (in‐plane and out‐of‐plane) are available. Once an extreme event is detected, an EEC algorithm is activated that: (i) tries to prevent the rotor speed from exceeding the overspeed limit by fast collective blade pitching; and (ii) reduces 1p blade loads by means of individual pitch control algorithm, designed in an ?∞ optimal control setting. The method is demonstrated on a complex non‐linear test turbine model. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
67.
Alexandra A. Suvorova Tim Nunney Alexander V. Suvorov 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(8-9):1294-1298
The chemical variation and depth profile of silicon carbide implanted with nitrogen and overgrown with epitaxial layer has been studied using X-ray photoelectron spectroscopy (XPS). The results of this study have been supplemented by transmission electron microscopy (TEM) imaging and electron energy loss-spectroscopy (EELS) in an attempt to correlate the chemical and structural information. Our results indicate that the nitrogen implantation into silicon carbide results in the formation of the Si–C–N layer. XPS revealed significant change in the bonding structure and chemical states in the implanted region. XPS results can be interpreted in terms of the silicon nitride and silicon carbonitride nanocrystals formation in the implanted region which is supported by the electron microscopy and spectroscopy results. 相似文献
68.
69.
Araceli Diez-Fraile Joke De Ceulaer Charlotte Derpoorter Christophe Spaas Tom De Backer Philippe Lamoral Johan Abeloos Tim Lammens 《International journal of molecular sciences》2022,23(5)
The 5-year relative survival for patients with head and neck cancer, the seventh most common form of cancer worldwide, was reported as 67% in developed countries in the second decade of the new millennium. Although surgery, radiotherapy, chemotherapy, or combined treatment often elicits an initial satisfactory response, relapses are frequently observed within two years. Current surveillance methods, including clinical exams and imaging evaluations, have not unambiguously demonstrated a survival benefit, most probably due to a lack of sensitivity in detecting very early recurrence. Recently, liquid biopsy monitoring of the molecular fingerprint of head and neck squamous cell carcinoma has been proposed and investigated as a strategy for longitudinal patient care. These innovative methods offer rapid, safe, and highly informative genetic analysis that can identify small tumors not yet visible by advanced imaging techniques, thus potentially shortening the time to treatment and improving survival outcomes. In this review, we provide insights into the available evidence that the molecular tumor fingerprint can be used in the surveillance of head and neck squamous cell carcinoma. Challenges to overcome, prior to clinical implementation, are also discussed. 相似文献
70.