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Annals of Global Analysis and Geometry - We construct, for $$p>n$$ , a concrete example of a complete non-compact n-dimensional Riemannian manifold of positive sectional curvature which does... 相似文献
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Michel Prudent Giona Sonego Mélanie Abonnenc Jean-Daniel Tissot Niels Lion 《Journal of the American Society for Mass Spectrometry》2014,25(4):651-661
Pathogen reduction technologies (PRT) are photochemical processes that use a combination of photosensitizers and UV-light to inactivate pathogens in platelet concentrates (PCs), a blood-derived product used to prevent hemorrhage. However, different studies have questioned the impact of PRT on platelet function and transfusion efficacy, and several proteomic analyses revealed possible oxidative damages to proteins. The present work focused on the oxidative damages produced by the two main PRT on peptides. Model peptides containing residues prone to oxidation (tyrosine, histidine, tryptophane, and cysteine) were irradiated with a combination of amotosalen/UVA (Intercept process) or riboflavin/UVB (Mirasol-like process). Modifications were identified and quantified by liquid chromatography coupled to tandem mass spectrometry. Cysteine-containing peptides formed disulfide bridges (R-SS-R, ?2 Da; favored following amotosalen/UVA), sulfenic and sulfonic acids (R-SOH, +16 Da, R-SO3H, +48 Da, favored following riboflavin/UVB) upon treatment and the other amino acids exhibited different oxidations revealed by mass shifts from +4 to +34 Da involving different mechanisms; no photoadducts were detected. These amino acids were not equally affected by the PRT and the combination riboflavin/UVB generated more oxidation than amotosalen/UVA. This work identifies the different types and sites of peptide oxidations under the photochemical treatments and demonstrates that the two PRT may behave differently. The potential impact on proteins and platelet functions may thus be PRT-dependent. Fig. a
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Giona Kilcher Lei Wang Nicola Tirelli 《Journal of polymer science. Part A, Polymer chemistry》2008,46(6):2233-2249
Episulfide polymerization offers a number of features that are uncommon in other ring‐opening anionic mechanisms. Besides the negligible sensitivity to water, the most distinctive and novel one is likely to be the role of disulfides, which may act both at the levels of chain transfer and end‐capping, producing polymers that feature both terminal and internal disulfides. In this article, we have qualitatively studied the kinetics of chain transfer and measured the thiolate–disulfide exchange equilibrium constants. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2233–2249, 2008 相似文献
5.
In this paper we study the behavior of solutions of a second-order differential equation. The existence of a zero and its localization allow us to get some compactness results. In particular we obtain a Myers-type theorem even in the presence of an amount of negative curvature. The technique we use also applies to the study of spectral properties of Schr?dinger operators on complete manifolds. 相似文献
6.
Giona Veronelli 《Geometriae Dedicata》2011,155(1):1-20
We study positive solutions u of the Yamabe equation
cm Du-s( x) u+k( x) u\fracm+2m-2=0{c_{m} \Delta u-s\left( x\right) u+k\left( x\right) u^{\frac{m+2}{m-2}}=0}, when k(x) > 0, on manifolds supporting a Sobolev inequality. In particular we get uniform decay estimates at infinity for u which depend on the behaviour at infinity of k, s and the L
Γ-norm of u, for some
G 3 \tfrac2mm-2{\Gamma\geq\tfrac{2m}{m-2}}. The required integral control, in turn, is implied by further geometric conditions. Finally we give an application to conformal
immersions into the sphere. 相似文献
7.
The problem of identifying different two phase flow regimes from experimental time series by employing the method of diffusional
analysis is addressed. This technique, recently applied to the multiphase flow field, is described and compared with other
techniques used to characterize multiphase flow regimes. Diffusional analysis is applied to experimental time-series obtained
from both a γ-densitometer and capacitance probes. The choice of the appropriate experimental signal to be processed is also
discussed. The experimental time series were obtained from a rig with air and light oil. The results obtained confirm the
advantages of the method proposed in identifying the features of different flow regimes. The advantages are particularly evident
when comparing diffusional analysis with the widely applied Rescaled Range technique.
We would like to thank K. Bendiksen and O. J. Nydal of the Institutt for Energyteknikk (IFE), Kjeller, Norway, where one of
the authors (A. P.) performed the experiments. 相似文献
8.
We prove that for every metric on the torus with curvature bounded from below by ?1 in the sense of Alexandrov there exists a hyperbolic cusp with convex boundary such that the induced metric on the boundary is the given metric. The proof is by polyhedral approximation. This was the last open case of a general theorem: every metric with curvature bounded from below on a compact surface is isometric to a convex surface in a 3-dimensional space form. 相似文献
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Meccanica - We present a simple representation of the hydrodynamic Green functions grounded on the free propagation of a vector field without any constraints (such as incompressibility) coupled... 相似文献
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This Article extends the geometric analysis of slow invariant manifolds in explosive kinetics developed by Creta et al. to three-dimensional and higher systems. Invariant manifolds can be characterized by different families of Lyapunov-type numbers, based either on the relative growth of normal to tangential perturbations or on the deformation of m-dimensional volume elements (if the manifold is m-dimensional) and of the complementary (n - m)-elements in the normal orthogonal complement. The latter approach, based on elementary concepts of exterior algebra, is particularly simple because the evolution of the relevant volume elements can be related to suitable local stretching rates, and local analysis can be performed directly from the knowledge of the Jacobian matrix of the vector field. Several examples of bifurcations of the points-at-infinity, which modify the manifold structure, are discussed for 3-D models of exothermic reactions. 相似文献