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101.
Adrian?F?Lozada Antti?A?Aarnisalo Kaj?Karlstedt Holger?Stark Pertti?PanulaEmail author 《BMC neuroscience》2004,5(1):32
Background
In rat, deafferentation of one labyrinth (unilateral labyrinthectomy) results in a characteristic syndrome of ocular and motor postural disorders (e.g., barrel rotation, circling behavior, and spontaneous nystagmus). Behavioral recovery (e.g., diminished symptoms), encompassing 1 week after unilateral labyrinthectomy, has been termed vestibular compensation. Evidence suggesting that the histamine H3 receptor plays a key role in vestibular compensation comes from studies indicating that betahistine, a histamine-like drug that acts as both a partial histamine H1 receptor agonist and an H3 receptor antagonist, can accelerate the process of vestibular compensation. 相似文献102.
Kaj M⇘rtensson 《Applied biochemistry and biotechnology》1982,7(1-2):11-18
A short review of different types of enzyme reactors and factors of influence on the reactor choice is given. The background of their kinetic differences is discussed. The conversion of starch to maltose by use of an immobilized two-enzyme system has been chosen as a case study. 相似文献
103.
104.
Corzana F Motawia MS Hervé du Penhoat C van den Berg F Blennow A Perez S Engelsen SB 《Journal of the American Chemical Society》2004,126(40):13144-13155
The hydration behavior of a model compound for the amylopectin branch point, methyl 6'-alpha-maltosyl-alpha-maltotrioside, was investigated by combining molecular dynamics simulations in explicit water, 500 MHz NMR spectroscopy, including pulsed field gradient diffusion measurements, and exploratory multivariate data analysis. In comparison with results on a tetrasaccharide analogue, the study reveals that the conformational diversity of the three-bond alpha-(1-->6) linkage becomes quite limited in aqueous solution upon the addition of a fifth glucose residue that elongates the alpha-(1-->6) branch. This investigation reveals two plausible starch branch point structures, one that permits the formation of double helices and one that is adapted for interconnection of double helices. The apparent rigidity of the former is explained by the presence of water pockets/bridges in the vicinity of the branch point that lock the pentasaccharide structure into one conformational family that is able to accommodate the creation of the double-helical amylopectin structure. 相似文献
105.
This study presents a novel, fast and easy method to isolate starch branching enzyme I (EC 2.4.1.18, SBE-I) from potato (Solanum tuberosum L. cv. ‘Dianella') by γ-cyclodextrin (γ-CD) affinity chromatography of the supernatant obtained after polyethylene glycol 6000 precipitation of the crude homogenate. SBE-I was specifically eluted by competition with free γ-CD. The resulting protein fraction was homogeneous, as analysed by sodium dodecyl sulphate–polyacrylamide gel electrophoresis and contained no contaminating hydrolytic activities, as monitored by activity staining using zymograms and specific assays for - and β-amylase. The overall purification was 296-fold and the yield was 38%. 相似文献
106.
The role of stabilizing agents in the interaction between styrene/butadiene latex and calcium carbonate particles has been studied using isothermal titration calorimetry (ITC) and an electrokinetic sonic amplitude (ESA) technique. It is demonstrated that the polyacrylate sodium salt (dispersing agent, referred to as NaPA) used as stabilizing agent for the calcium carbonate suspensions principally affects the interfacial properties of the calcite surface. An electrostatic barrier is created and this decreases the attractive interactions between the latex and the negatively charged mineral surface. The total enthalpy change observed when an emulsion of styrene/butadiene particles substantially free from surfactant was added to the dispersed calcium carbonate could be described via a relatively complex path. The process included (i) an exothermic response from the association of the latex particles (adsorption process) with the dispersed calcium carbonate surface and (ii) an endothermic bulk phase effect due to the adsorption on the latex particles of dissolved species originating from the calcium carbonate. Stabilization of the latex particles with sodium dodecyl benzene sulfonate (SDBS) or a non-ionic fatty alcohol ethoxylate surfactant did not significantly change the enthalpy of interaction. It was further demonstrated that SDBS had a very weak affinity for the dispersed calcium carbonate particles and that dissolution of species, such as calcium ions, from the calcium carbonate surface, allows further adsorption of SDBS onto the latex particles. 相似文献
107.
Kaj Heydorn 《Accreditation and quality assurance》2008,13(12):723-724
The distribution of mutually consistent results from interlaboratory comparisons is expected to be leptokurtic, and readers
are warned against accepting conclusions based on simulations assuming normality.
Papers published in this section do not necessarily reflect the opinion of the Editors, the Editorial Board and the Publisher 相似文献
108.
Kaj Heydorn 《Accreditation and quality assurance》2008,13(4-5):217-222
The novel proposed definition of measurement result in the international metrology vocabulary requires a revision of standards and guidelines for proficiency testing (PT), and
a new approach to processing proficiency data is needed to test the ability of laboratories to present not only unbiased quantity
values, but reliable estimates of their uncertainty. Hence, an accepted reference value with the smallest possible uncertainty
is needed to ascertain the proficiency of laboratories reporting results with lower than average uncertainty. A strategy based
on the T-statistic is proposed leading to an accepted reference value that fully reflects the uncertainties reported by participants
in a PT scheme and permits calculation of E
n
numbers to distinguish whether or not measurement results are consistent with the accepted definition of the measurand. The strategy
is applied to PT data from a recent international laboratory intercomparison of uranium isotopic ratios. 相似文献
109.
John L. Lewis Kaj Nyströ m 《Proceedings of the American Mathematical Society》2008,136(4):1311-1323
We prove the boundary Harnack inequality for positive infinity harmonic functions vanishing on a portion of the boundary of a bounded domain under the assumption that is a quasicircle.
110.
1 , the smallest eigenvalue of a symmetric, positive definite matrix, and is solved by Newton iteration with line search. The
paper describes the algorithm and its implementation including estimation of λ1, how to get a good starting point for the iteration, and up- and downdating of Cholesky factorization. Results of extensive
testing and comparison with other methods for constrained QP are given.
Received May 1, 1997 / Revised version received March 17, 1998 Published online November 24, 1998 相似文献