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排序方式: 共有642条查询结果,搜索用时 15 毫秒
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Manoel Carneiro Oliveira‐Junior Aldaíza Salomão Monteiro Ernesto César Pinto Leal‐Junior Egberto Munin Rodrigo Aléxis Lazo Osório Wellington Ribeiro Rodolfo Paula Vieira 《Photochemistry and photobiology》2013,89(1):173-178
This study investigated the effects of low‐level laser therapy (LLLT) in the liver function, structure and inflammation in a experimental model of carbon tetrachloride (CCl4)‐induced liver cirrhosis. Wistar rats were divided into Control, LLLT, CCl4 and CCl4+LLLT groups. CCl4 groups received CCl4 (0.4 g kg?1; i.p.), three times a week, for 12 weeks. A 830 nm LLLT was performed with a continuous wave, 35 mW, 2.5 J cm?2 per point, applied to four points of the liver (right and left upper and lower extremities, in the four lobes of the liver) for 2 weeks. Liver structure and inflammation (cirrhotic areas, collagen deposition, inflammation, density of Kupffer and hepatic stellate cells) and function (aspartate aminotransferase, alkaline phosphatase, gamma glutamyltransferase, lactate dehydrogenase, total proteins and globulins) were evaluated. LLLT significantly reduced CCl4‐increased aspartate aminotransferase (P < 0.001), alkaline phosphatase (P < 0.001), gamma‐glutamyl transferase (P < 0.001) and lactate dehydrogenase (P < 0.01) activity, as well as total proteins (P < 0.05) and globulins (P < 0.01). LLLT also reduced the number of cirrhotic areas, the collagen accumulation and the hepatic inflammatory infiltrate. Of note, LLLT reduced CCl4‐increased number of Kupffer cells (P < 0.05) and hepatic stellate cells (P < 0.05). We conclude that LLLT presents beneficial effects on liver function and structure in an experimental model of CCl4‐induced cirrhosis. 相似文献
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Rodolfo Sánchez Angela Braeuning-Demian Jan Glorius Siegbert Hagmann Pierre-Michel Hillenbrand Anton Kalinin Thomas Köhler Yuri A. Litvinov Nikolaos Petridis Shahab Sanjari Uwe Spillmann Thomas Stöhlker 《X射线光谱测定》2020,49(1):33-36
The atomic physics collaboration SPARC is a part of the APPA pillar at the future Facility for Antiproton and Ion Research. It aims at atomic-physics research across virtually the full range of atomic matter. An emphasis of this contribution are the atomic physics experiments addressing the collision dynamics in strong electro-magnetic fields as well as the fundamental interactions between electrons and heavy nuclei at the HESR. Here we give a short overview about the central instruments for SPARC experiments at this storage ring. 相似文献
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In order to advance the knowledge of prototropic tautomerism from the physicochemical point of view, the purine derivative hypoxanthine has been selected and studied. The overall purpose has been to explore thermodynamic aspects of the heterocycle tautomerism under the influence of both its protonation level and the surrounding dielectric constant. A Density Functional Theory study (at the B3LYP/6-31++G** level) was performed, in which the energetic and thermodynamic stabilities, the electric dipole moment values, the tautomeric equilibrium constants and the tautomeric populations were obtained for several hypoxanthine tautomers under systematically modified heterocyclic protonation levels, considering both isolated and ideal aqueous solution states. Among the interesting results obtained are changes in the tautomeric populations for several heterocyclic protonation states and with the increase of the dielectric constant. Several of the predictions made for an aqueous solution show good agreement with recently reported experimental conclusions. Also, the ionizable groups that contribute to the different hypoxanthine ionization steps in the main tautomers have been established. These and other related results are presented and discussed. Finally, the confidence developed in the predicted tautomeric populations in a modeled-ideal aqueous solution allows us to propose that the methodology applied here can be used for the study of prototropic tautomerism in heterocycles belonging to this class, particularly when the experimental work is challenging in both performance and physicochemical data analysis. 相似文献
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Combining high and low probability densities in intensity hybrids , we study some of their properties in double-slit setups. In particular, we connect to earlier results on beam attenuation techniques in neutron interferometry and study the effects of very small transmission factors, or very low counting rates, respectively, at one of the two slits. We use a “superclassical” modeling procedure which we have previously shown to produce predictions identical with those of standard quantum theory. Although in accordance with the latter, we show that there are previously unexpected new effects in intensity hybrids for transmission factors below a?10−4, which can eventually be observed with the aid of weak measurement techniques. We denote these as quantum sweeper effects, which are characterized by the bunching together of low counting rate particles within very narrow spatial domains. We give an explanation of this phenomenology by the circumstance that in reaching down to ever weaker channel intensities, the nonlinear nature of the probability density currents becomes ever more important, a fact which is generally not considered–although implicitly present–in standard quantum mechanics. 相似文献
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Rodolfo Gambini Jorge Pullin Saeed Rastgoo 《General Relativity and Gravitation》2011,43(12):3569-3592
We recently studied gravity coupled to a scalar field in spherical symmetry using loop quantum gravity techniques. Since there
are local degrees of freedom one faces the “problem of dynamics”. We attack it using the “uniform discretization technique”.
We find the quantum state that minimizes the value of the master constraint for the case of weak fields and curvatures. The
state has the form of a direct product of Gaussians for the gravitational variables times a modified Fock state for the scalar
field. In this paper we do three things. First, we verify that the previous state also yields a small value of the master
constraint when one polymerizes the scalar field in addition to the gravitational variables. We then study the propagators
for the polymerized scalar field in flat space-time using the previously considered ground state in the low energy limit.
We discuss the issue of the Lorentz invariance of the whole approach. We note that if one uses real clocks to describe the
system, Lorentz invariance violations are small. We discuss the implications of these results in the light of Hořava’s Gravity at the Lifshitz point and of the argument about potential large Lorentz violations in interacting field theories of Collins et al. 相似文献
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A new method for synthesizing phenolic N-benzylazacyclophanes starting from tyramine is presented here. Computational calculations showed that macrocyclization is favored by the formation of hydrogen bond-based templates; these templates are not affected by including benzyl groups in the nitrogen atom of the tyramine moiety. The results showed that N-benzyl groups with electron-donating substituents have more nucleophilic nitrogen atoms, thereby favoring macrocyclization, while electron-withdrawing groups favor polymerization. 相似文献