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21.
estmír ejka Jan Pláteník Richard Buchal Vilém Guryca Jakub irc Martin Vejraka Jiina Crkovská Taras Ardan Jií Michálek Blanka Brnová Jitka ejková 《Photochemistry and photobiology》2009,85(3):794-800
The aim of the present paper was to examine the irradiation effect of two doses of UVA rays (365 nm) on the rabbit cornea and lens. Corneas of anesthetized adult albino rabbits were irradiated with UVA rays for 5 days (daily dose 1.01 J cm−2 in one group of rabbits and daily dose 2.02 J cm−2 in the second group of animals). The third day after the last irradiation, the rabbits were killed, and their eyes were employed for spectrophotometrical, biochemical and immunohistochemical investigations. Normal eyes served as controls. Absorption spectra of the whole corneal centers were recorded over the UV–VIS (visible) spectral range. Levels of antioxidant and prooxidant enzymes, nitric oxide synthases and nitric oxide (indirectly measured as nitrate concentration) were investigated in the cornea. Malondialdehyde, a byproduct of lipid peroxidation, was examined in the cornea and lens. The results show that the staining for endothelial nitric oxide synthase was more pronounced in corneas irradiated with the higher UVA dose. Otherwise, UVA rays at either dose did not significantly change corneal light absorption properties and did not cause statistically significant metabolic changes in the cornea or lens. In conclusion, UVA rays at the employed doses did not evoke harmful effects in the cornea or lens. 相似文献
22.
Taras Radul 《Applied Categorical Structures》2001,9(5):457-463
We introduce a class of Lawson monads and show that these monads have a functional representation. A characterisation of such a representation for the inclusion hyperspace monad is given. 相似文献
23.
24.
We prove that for each universal algebra ${(A, \mathcal{A})}$ of cardinality ${|A| \geq 2}$ and infinite set X of cardinality ${|X| \geq | \mathcal{A}|}$ , the X-th power ${(A^{X}, \mathcal{A}^{X})}$ of the algebra ${(A, \mathcal{A})}$ contains a free subset ${\mathcal{F} \subset A^{X}}$ of cardinality ${|\mathcal{F}| = 2^{|X|}}$ . This generalizes the classical Fichtenholtz–Kantorovitch–Hausdorff result on the existence of an independent family ${\mathcal{I} \subset \mathcal{P}(X)}$ of cardinality ${|\mathcal{I}| = |\mathcal{P}(X)|}$ in the Boolean algebra ${\mathcal{P}(X)}$ of subsets of an infinite set X. 相似文献
25.
Andrii I Trypolskyi Tetyana M Gurnyk Peter E. Strizhak 《Chemical physics letters》2008,460(4-6):492-494
We present an approach establishing a relation between the activation energy of heterogeneous catalytic processes and the fractal dimension of a catalyst. The approach is verified by experimental study of the CO oxidation on various porous silica and zeolite NaX. The fractal dimension of a catalyst (DF) was calculated from the nitrogen adsorption isotherms. Our results indicate that the activation energy increases with increasing the fractal dimension of a catalyst. We show a good correspondence between theoretical and experimental results. 相似文献
26.
27.
Dynamic structure factors for Na(c)K(1-c) liquid metallic alloys and pure components are studied by molecular dynamics simulations. Large values of Landau-Placzek ratio for four compositions of the liquid alloy are analyzed by wave-number dependent contributions from relaxation and propagating processes within the generalized collective modes method. The origin of the large Landau-Placzek ratio for liquid alloys is discussed. 相似文献
28.
We study algebraic and topological properties of the convolution semigroup of probability measures on a topological groups
and show that a compact Clifford topological semigroup S embeds into the convolution semigroup P(G) over some topological group G if and only if S embeds into the semigroup exp(G)\exp(G) of compact subsets of G if and only if S is an inverse semigroup and has zero-dimensional maximal semilattice. We also show that such a Clifford semigroup S embeds into the functor-semigroup F(G) over a suitable compact topological group G for each weakly normal monadic functor F in the category of compacta such that F(G) contains a G-invariant element (which is an analogue of the Haar measure on G). 相似文献
29.
Taras Radul 《Applied Categorical Structures》2011,19(4):729-739
Let
\mathbbF\mathbb{F} be a monad in the category Comp. We build for each
\mathbbF\mathbb{F}-algebra a convexity in general sense (see van de Vel 1993). We investigate properties of such convexities and apply them to prove that the multiplication map of the order-preserving
functional monad is soft. 相似文献
30.
Tetyana A Mykhaylyk Stephen Collins Chintan Jani Ian W Hamley 《European Polymer Journal》2004,40(8):1715-1721
The ozone etching of thin films of a commercial polystyrene-polyisoprene-polystyrene (PS-PI-PS) triblock copolymer (Vector 4111) was studied using atomic force microscopy (AFM) and ellipsometry. The major phase of the copolymer consists of PI (82 wt.%) and the copolymer forms a cylindrical structure upon annealing. Moderate ozone doses (1.4% wt/wt) were used to etch the copolymer. This revealed two stages of the ozonation: rapid etching of the PI fragments followed by slow compacting of the remaining PS cylinders. Under certain conditions ozone treatment results in the formation of nanosized grooves in a PS matrix which is suitable for lithographic processes. 相似文献