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91.
Johansson SM Arnberg N Elofsson M Wadell G Kihlberg J 《Chembiochem : a European journal of chemical biology》2005,6(2):358-364
Adenoviruses of serotypes 8, 19 and 37 are the major cause of the severe eye infection EKC (epidemic keratoconjunctivitis). In general, all adenoviruses interact with their cellular receptors through the fibre proteins, which extend from the virus particle. Recently, adenovirus type 37 (Ad37) was found to bind and infect human corneal cells through attachment to carbohydrate structures that carry terminal alpha-(2-3)-linked sialic acids. Herein we present a synthetic route to a 3'-sialyllactose derivative and corresponding multivalent HSA conjugates with varying orders of valency. The potential of these compounds as inhibitors of EKC-causing adenovirus of serotype Ad37, was studied with both a binding assay and an infectivity assay. The results revealed that these compounds effectively prevent Ad37 from binding to and infecting human corneal epithelial (HCE) cells. Moreover, the inhibition is significantly increased with higher orders of multivalency. 相似文献
92.
A cryostat is described whose construction makes optical and X-ray examination of crysotals possible within the temperature range 70–500 K. The cryostat is equipped with two quartz glass windows, one metallized mylar window, and a sorption pump which allows an integral vacuum of the order of 10?3 Pa to be maintained during measurements. A handle allows specimens to be turned by 180° so that an optimum position is obtained in relation to the window. 相似文献
93.
Jan-Fredrik Jansson 《应用聚合物科学杂志》1973,17(10):2965-2975
In order to evolve the methods of mechanical spectroscopy and find new methods of studying the rise of nonlinear viscoelasticity, periodic square and triangular stress functions have been used. A “new” viscoelastic function is defined, log J2 = g{log J1}, where J1 and J2 are the compliances at the time (ζ/2 + 2nζ)n→∞ for an odd, periodic, square function and an even, periodic, triangular function, respectively, with periods of 2ζ. The function shows characteristic shapes for viscoelastic spring and dashpot models. The interrelations between the complex compliance and J1 and J2 are developed; and since the sum of J1 and J2 at the time ζ/2 agrees very well with the creep compliance at the same time, J1 and J2 can be used as an interrelation between complex compliance and creep compliance. Special equipment for measuring the compliances J1 nd J2 is described. 相似文献
94.
The weight increase curves of pure iron specimens cold-worked by abrasion with SiC and 7- diamond paste have been registered as a function of pressure and temperature. The oxidation rate increases with temperature and pressure when the pressure is raised from 0.02 to 0.2 bar. When the pressure is further increased to 1.02 bar at 500 and 625°C the oxidation rate decreases. This decrease is attributed to an orientation of the oxide grains in the -Fe2O3 surface. 相似文献
95.
Further studies on the epoxidation of propylene via electrogenerated hypobromite in a trickle bed have been carried out with the aim of increasing the space-time yield. Factors which have been studied in more detail include electrode material, applied voltage, sense of polarity, cell packing arrangements, electrolyte flow rate and sodium bromide concentration. By suitable choice of conditions a significant increase in space-time yield can be obtained, up to a limit set by the depletion of propylene, without a large increase in energy consumption. 相似文献
96.
Comparison of the phase transfer oxidation of benzyl alcohol in a pump cell and stirred-tank reactor
The oxidation of benzyl alcohol by electrogenerated hypobromite in a two-phase emulsion has been studied using a quaternary ammonium salt as a phase transfer agent. The performances of a stirred-tank batch reactor and a bipolar electrochemical pump cell have been compared and the differences found are discussed in terms of the different mixing/transport/reaction regimes of the two cells. Benzaldehyde can be produced at a rate of 0.2 mol h–1 dm–2 of electrode area for 4.20 kWh kg–1. 相似文献
97.
Berger Harold Kraska I. R. Niklas Wilfrid F. Schmidt Adolph 《IEEE transactions on nuclear science》1966,13(2):79-83
An image intensifier tube of the vacuum tube type, sensitive to thermal neutrons has been developed and tested. The tube provides a bright visible output signal for an incoming thermal neutron image. Sensitivity, resolution, speed, contrast and relative response to radiation other than thermal neutrons all appear to be adequate for application to neutron imaging studies employing either reactor or non-reactor thermal neutron sources. The above characteristics, and applications of the system, are discussed. 相似文献
98.
Ondrej L. Krivanek Niklas Dellby Matthew F. Murfitt Matthew F. Chisholm Timothy J. Pennycook Kazutomo Suenaga Valeria Nicolosi 《Ultramicroscopy》2010
Aberration correction of the scanning transmission electron microscope (STEM) has made it possible to reach probe sizes close to 1 Å at 60 keV, an operating energy that avoids direct knock-on damage in materials consisting of light atoms such as B, C, N and O. Although greatly reduced, some radiation damage is still present at this energy, and this limits the maximum usable electron dose. Elemental analysis by electron energy loss spectroscopy (EELS) is then usefully supplemented by annular dark field (ADF) imaging, for which the signal is larger. Because of its strong Z dependence, ADF allows the chemical identification of individual atoms, both heavy and light, and it can also record the atomic motion of individual heavy atoms in considerable detail. We illustrate these points by ADF images and EELS of nanotubes containing nanopods filled with single atoms of Er, and by ADF images of graphene with impurity atoms. 相似文献
99.
The estimation of signal covariance matrices is a crucial part of many signal processing algorithms. In some applications, the structure of the problem suggests that the underlying, true covariance matrix is the Kronecker product of two valid covariance matrices. Examples of such problems are channel modeling for multiple-input multiple-output (MIMO) communications and signal modeling of EEG data. In applications, it may also be that the Kronecker factors in turn can be assumed to possess additional, linear structure. The maximum-likelihood (ML) method for the associated estimation problem has been proposed previously. It is asymptotically efficient but has the drawback of requiring an iterative search for the maximum of the likelihood function. Two methods that are fast and noniterative are proposed in this paper. Both methods are shown to be asymptotically efficient. The first method is a noniterative variant of a well-known alternating maximization technique for the likelihood function. It performs on par with ML in simulations but has the drawback of not allowing for extra structure in addition to the Kronecker structure. The second method is based on covariance matching principles and does not suffer from this drawback. However, while the large sample performance is the same, it performs somewhat worse than the first estimator in small samples. In addition, the Cramer-Rao lower bound for the problem is derived in a compact form. The problem of estimating the Kronecker factors and the problem of detecting if the Kronecker structure is a good model for the covariance matrix of a set of samples are related. Therefore, the problem of detecting the dimensions of the Kronecker factors based on the minimum values of the criterion functions corresponding to the two proposed estimation methods is also treated in this work. 相似文献
100.
Journal of Mathematical Imaging and Vision - The ability to handle large scale variations is crucial for many real-world visual tasks. A straightforward approach for handling scale in a deep... 相似文献