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91.
Clinical score (A) and viral shedding (B) in goats vaginally infected with CpHV-1 and treated with fig latex (goats A, B, C). Goat D was left untreated.  相似文献   
92.
In this article, we study the approximation of common zeros of non-self inverse strongly monotone operators defined on a closed convex subset C of a Hilbert space H. For a non-self family of operators, we introduce an iterative algorithm without relying on projections. Approximation of common fixed points for finite families of non-self strict pseudo-contractions in the sense of Browder-Petryshyn is also obtained. The novelty of our algorithm is that the coefficients are not given a priori and no assumptions are made on them, but they are constructed step by step in a natural way.  相似文献   
93.
We propose a new formulation of the Karush–Kunt–Tucker conditions of a particular class of quasi-variational inequalities. In order to reformulate the problem we use the Fisher–Burmeister complementarity function and canonical duality theory. We establish the conditions for a critical point of the new formulation to be a solution of the original quasi-variational inequality showing the potentiality of such approach in solving this class of problems. We test the obtained theoretical results with a simple heuristic that is demonstrated on several problems coming from the academy and various engineering applications.  相似文献   
94.
Four‐membered ring thiosulfonium ions may be obtained quantitatively and under mild conditions by anionotropic rearrangement of C‐(tert‐butyl)‐substituted thiiranium ion precursors. Thus, t‐4‐(tert‐butyl)‐r‐1,2,2,c‐3‐tetramethylthietanium tetrafluoroborate or hexachloroantimonate ( 2a or 2b , resp.) were formed from thiiranium ion 1 . The thietanium salts 2a and 2b were characterized by X‐ray crystal‐structure analysis. Their cation geometry was also optimized by ab initio calculations at the RHF/6‐31G*//RHF/6‐31G* level, as were those of its stereoisomer 3 and of the unsubstituted S‐methylthietanium ion 5 . Comparison of 2 , 3 , and 5 with 4 – the only other thietanium ion studied by XRD, where the C‐atoms of the thioniacyclobutane ring are part of a trinorbornane skeleton – indicates that, in these systems, relief from substituent overcrowding is easily achieved by a folding of the four‐membered ring along the line connecting the two opposite C‐atoms. The corresponding ring‐deformation normal mode has a calculated frequency as low as 109 cm−1 in ion 5 , to be compared with a frequency of 138 cm−1 in methylcyclobutane. For thietanium ion 2 , the frequencies of the two normal modes involving such ring deformation have calculated values of 61 and 85 cm−1.  相似文献   
95.
In this paper, we report on the physicochemical characterization of hydrogels recently obtained by crosslinking poly (vinylalcohol), PVA, with telechelic PVA (telPVA, bearing terminal aldehydic groups) via acetalization in aqueous solution. These gels were studied by equilibrium swelling, compression modulus measurements, and proton relaxometry experiments. Swelling and compression modulus data allow to estimate the average molecular weight of PVA chain between crosslinks, the average mesh size of the networks, and the polymer–solvent interaction parameter χ1. The average mesh size of PVA‐telPVA compares well with domain dimensions of diffusionally confined water as detected by NMR relaxometry. Proton relaxometry also showed different network domains in which water is compartmentalized, indicating a complex heterogeneity. The study of the temperature behavior of the nuclear spin–spin relaxation times of the confined water was also considered. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1225–1233, 1999  相似文献   
96.
Herein, we show that acyclic amides that have recently enabled a series of elusive transition‐metal‐catalyzed N?C activation/cross‐coupling reactions are highly twisted around the N?C(O) axis by a new destabilization mechanism of the amide bond. A unique effect of the N‐glutarimide substituent, leading to uniformly high twist (ca. 90°) irrespective of the steric effect at the carbon side of the amide bond has been found. This represents the first example of a twisted amide that does not bear significant steric hindrance at the α‐carbon atom. The 15N NMR data show linear correlations between electron density at nitrogen and amide bond twist. This study strongly supports the concept of amide bond ground‐state twist as a blueprint for activation of amides toward N?C bond cleavage. The new mechanism offers considerable opportunities for organic synthesis and biological processes involving non‐planar amide bonds.  相似文献   
97.
A fixed topology of stages and/or a fixed branching scheme are common assumptions for applications and numerical solution of scenario based multistage stochastic programs. Using contamination technique to test this structure, we extend the results of Dupačová (Contamination for multistage stochastic programs. In: Hušková M, Janžura M (eds) Prague stochastics. Matfyzpress, Praha, pp 91–101, 2006a) to stochastic programs with multistage polyhedral risk objectives. The ideas are exemplified by bond portfolio management problems and complemented by illustrative numerical results.  相似文献   
98.
Fragments of human ascending aorta harvested during heart surgery were cryofractured and observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Elastic fibers appear as irregular, undulated laminae of variable size and shape. Their surface shows an evident fibrous texture suggestive of a criss-crossed, delicate filamentous scaffold and is marked by a number of features such as ridges, holes and protruding ribs. At higher magnification, both SEM and AFM show the surface composed of a finely granular material, with a bead size of approximately 20 nm. However, the thickness of the metal coating in one case, and the tip convolution effect on the other, may equally result in an artifactual enlargement of the structures, so that the beads may be significantly smaller. The surfaces created by the fracture always appear smooth and compact and with this technique do not reveal significant detail. The collagen component is mostly represented by small, uniform fibrils gathered in flexuous bundles and following a wavy course not unlike that of the elastic laminae. An orthogonal lattice of small proteoglycans is readily evident even without a specific treatment. Occasionally, the fibrils appear encrusted or engulfed in a grainy matrix reminiscent of the elastic fiber surface. Fluid Tapping-Mode Atomic Force Microscopy simultaneously reveals the surface-bound proteoglycans and the inner architecture of the fibrils, composed of smaller subunits following a spiral course with a winding angle of approximately 17 degrees.  相似文献   
99.
The cytoarchitecture of the female gonad of the scutariellid Troglocaridicola sp. has been investigated by means of electron microscopy and cytochemical techniques. It consists of a single germarium and two rows of vitelline follicles, both enveloped by an outer extracellular lamina (EL) and an inner cellular tunica constituted by accessory cells. Some ultrastructural features which differ from the basic pattern of all the other Rhabdocoela studied so far have been found. In the germarium the following are observed: (a) The presence in the oocytes of peripheral translucent vesicles containing glycoproteins, which differ in diameter and substructure from the peripheral egg granules observed in all the other neoophoran Platyhelminthes. These vesicles can be considered an autapomorphic feature of the taxon Troglocaridicola; (b) The presence of proteinaceous acorn-shaped granules which remain scattered in the ooplasm throughout oogenesis and can be interpreted as residual yolk. This situation is shared with some Proseriata and Tricladida; (c) The precence of accessory cell processes between growing and mature oocytes, as is typical of some Proseriata and Tricladida. In the vitellarium, the presence of polyphenolic shell globules whose substructure does not correspond either to the multigranular pattern prevailing in representatives of Eulecithophora (Prolecithophora+Rhabdocoela) or to the homogeneous pattern found in Lecithoepitheliata. They have a meandering/concentric pattern of the content similar to that described in some Proseriata and Tricladida. On the basis of the ultrastructural characteristics of the female gonad described above, the position of Troglocaridicola in the taxon Rhabdocoela is discussed.  相似文献   
100.
Films of a few layers in thickness of reduced graphite oxide (RGO) sheets functionalized by the zwitterionic surfactant N‐dodecyl‐N,N‐dimethyl‐3‐ammonio‐1‐propanesulfonate (DDPS) are obtained by using the Langmuir–Blodgett method. The quality of the RGO sheets is checked by analyzing the degrees of reduction and defect repair by means of X‐ray photoelectron spectroscopy, atomic force microscopy (AFM), field‐emission scanning electron microscopy (SEM), micro‐Raman spectroscopy, and electrical conductivity measurements. A modified Hummers method is used to obtain highly oxidized graphite oxide (GO) together with a centrifugation‐based method to improve the quality of GO. The GO samples are reduced by hydrazine or vitamin C. Functionalization of RGO with the zwitterionic surfactant improves the degrees of reduction and defect repair of the two reducing agents and significantly increases the electrical conductivity of paperlike films compared with those prepared from unfunctionalized RGO.  相似文献   
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