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11.
Optics and Spectroscopy - The efficacy of antitumor efficacy and apoptosis induction in A498 human renal cell carcinoma observed when applying extracts of cruciferous herbal material...  相似文献   
12.
This paper shows how the theory of Dirichlet forms can be used to deliver proofs of optimal scaling results for Markov chain Monte Carlo algorithms (specifically, Metropolis–Hastings random walk samplers) under regularity conditions which are substantially weaker than those required by the original approach (based on the use of infinitesimal generators). The Dirichlet form methods have the added advantage of providing an explicit construction of the underlying infinite-dimensional context. In particular, this enables us directly to establish weak convergence to the relevant infinite-dimensional distributions.  相似文献   
13.
Enantioenriched bicyclo[4.1.0]hept-2-enes were synthesized by Ir(I)-catalyzed carbocyclization of 1,6-enynes. No chiral ligands were used, CO and PPh(3) were the only ligands bound to iridium. Instead, the stereochemical information was localized on the counterion of the catalyst, generated in situ by reaction of Vaska's complex (trans-[IrCl(CO)(PPh(3))(2)]) with a chiral silver phosphate. Enantiomeric excesses up to 93% were obtained when this catalytic mixture was used. (31)P NMR and IR spectroscopy suggest that formation of the trans- [Ir(CO)(PPh(3))(2)](+) moiety occurs by chlorine abstraction. Moreover, density functional theory calculations support a 6-endo-dig cyclization promoted by this cationic moiety. The chiral phosphate anion (O-P*) controls the enantioselectivity through formation of a loose ion pair with the metal center and establishes a C-H···O-P* hydrogen bond with the substrate. This is a rare example of asymmetric counterion-directed transition-metal catalysis and represents the first application of such a strategy to a C-C bond-forming reaction.  相似文献   
14.
Optics and Spectroscopy - A method for generation of droplet quasi-Bessel beams using a conical lens with a rounded tip is demonstrated. The study of the longitudinal distribution of the intensity...  相似文献   
15.
We study the cycle structure of words in several random permutations. We assume that the permutations are independent and that their distribution is conjugation invariant, with a good control on their short cycles. If, after successive cyclic simplifications, the word w $$ w $$ still contains at least two different letters, then we get a universal limiting joint law for short cycles for the word in these permutations. These results can be seen as an extension of our previous work (Kammoun and Maïda. Electron. Commun. Probab. 2020;25:1-14.) from the product of permutations to any non-trivial word in the permutations and also as an extension of the results of Nica (Random Struct. Algorithms1994;5:703-730.) from uniform permutations to general conjugation invariant random permutations. In particular, we get optimal assumptions in the case of the commutator of two such random permutations.  相似文献   
16.
17.
Pore opening of KcsA channel is studied using targeted molecular dynamics simulations. Conformational changes of the protein are determined, starting from the crystallized refined 2.0 A structure (pdb 1K4C) determined in x-ray experiments and arriving to the open-state structure constructed on the basis of electron paramagnetic resonance spectroscopic data (pdb 1JQ1). Our results corroborate the essential role played by the terminal residues located on the transmembrane helices M2 which were not taken into account at that time. The aperture mechanism of the channel appears to be ziplike. A small constraint (approximately equal to 5 x 10(-2) kcal mol(-1) A(-2) per C(alpha)) applied to the terminal residues located on the intracellular side is sufficient to initialize the pore opening at the innermost part of the gate, but additional constraint must be applied to definitely complete the pore aperture. The open structure is proved to be a metastable state since releasing the constraint leads to another relaxed open conformation which seems to reach stability.  相似文献   
18.
A subset K of a group G is said to be twisted if 1 ∈ K and the element xy ?1 x lies in K for any x, yK. We study finite involution-free twisted subsets that are not subgroups but all of whose proper twisted subsets are subgroups. We also study the groups generated by such twisted subsets.  相似文献   
19.
Talagrand’s inequalities provide a link between two fundamentals concepts of probability: transportation and entropy. The study of the counterpart of these inequalities in the context of free probability has been initiated by Biane and Voiculescu and later extended by Hiai, Petz and Ueda for convex potentials. In this work, we prove a free analogue of a result of Bobkov and Götze in the classical setting, thus providing free transport-entropy inequalities for a very natural class of measures appearing in random matrix theory. These inequalities are weaker than the ones of Hiai, Petz and Ueda but still hold beyond the convex case. We then use this result to get a concentration estimate for $\beta $ -ensembles under mild assumptions on the potential.  相似文献   
20.
The phosphorylated form of histone H2AX, γH2AX, is a component of the DNA repair system. Most studies have focused on the role of γH2AX during cell transformation and human cancer, but little is known about its role in keratinocytes and the skin during UV irradiation. We analyzed the response to UV irradiation focusing on the phosphorylation of histone H2AX both in vitro, in keratinocyte cultures and in artificial epidermis, and then in vivo, in human skin. Acute UVB irradiation of human keratinocytes increased the phosphorylation of H2AX in a dose-dependent manner; two types of γH2AX response were observed either in vitro or in vivo. After a low nonapoptotic UVB irradiation, cells contained phosphorylated H2AX and arrested their cell cycle to repair the DNA damages. For a stronger and proapoptotic UVB irradiation, keratinocytes dramatically increased the phosphorylation of H2AX and committed apoptosis. Our results indicate that γH2AX constitutes a highly sensitive marker relevant for studying subapoptotic doses as well as proapoptotic doses of UVB in human skin.  相似文献   
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