Protective effects of fasudil hydrochloride post-conditioning on acute myocardial ischemia/reperfusion injury in rats

Background: In recent years, the alleviation of acute myocardial ischemia and reperfusioninjury (MI/RI) during myocardial reperfusion has presented a significant clinical challenge.This study was performed to investigate the effects of fasudil hydrochloride (FH) postconditioningon MI/RI and the underlying mechanism.Methods: Seventy-two rats were randomly divided into four groups: a Sham group, anischemia/reperfusion (I/R) group, a fasudil hydrochloride (FH) group, and a fasudilhydrochloride+PI3K inhibitor (FH+I) group. Myocardial infarct size, cell apoptotic index(AI), and myocardial tissue expression of Rho-associated coiled-coil containing proteinkinase 1 (ROCK1), Bcl-2, Bcl-2 associated X protein (Bax), caspase-3, Akt and phosphorylatedAkt (P-Akt) were detected.Results: All these parameters, except Akt expression, were higher in the I/R group than in theSham group (p < 0.05). Compared to the I/R group, myocardial infarct size, AI, Bax andcaspase-3 expression were significantly reduced in the FH group (p < 0.05), while Bcl-2expression was increased (p < 0.05). However, the myocardial infarct size and AI of the FH+Igroup were similar to those of the I/R group (p > 0.05). Compared to the FH group, Bcl-2expression was reduced in the FH+I group, while Bax and caspase-3 expression was increased(p < 0.05). Furthermore, P-Akt expression in the FH group was significantly higherthan that of the I/R group (p < 0.05).Conclusions: FH post-conditioning alleviated MI/RI, with narrowing of the infarct size anddecreased apoptosis of ischemic cardiocytes. The mechanism was associated with activation ofthe PI3K-Akt signaling pathway

Unusual Compression Behavior of Columbite TiO2 via First-Principles Calculations

The physical mechanisms behind the reduction of the bulk modulus of a high-pressure cubic TiO2 phase are confirmed by first-principles calculations. An unusual and abrupt change occurs in the dependence of energy on pressure at 43 GPa, indicating a pressure-induced phase transition from columbite TiO2 to a newly-identified modified fluorite TiO2 with a Pca21 symmetry. Oxygen atom displacement in Pca21 TiO2 unexpectedly reduces the bulk modulus by 34% relative to fluorite TiO2. This discovering provides a direct evidence for understanding the compressive properties of such groups of homologous materialsComment: [email protected] or [email protected]

Topolgical Charged Black Holes in Generalized Horava-Lifshitz Gravity

As a candidate of quantum gravity in ultrahigh energy, the $(3+1)$-dimensional Ho\v{r}ava-Lifshitz (HL) gravity with critical exponent $z\ne 1$, indicates anisotropy between time and space at short distance. In the paper, we investigate the most general $z=d$ Ho\v{r}ava-Lifshitz gravity in arbitrary spatial dimension $d$, with a generic dynamical Ricci flow parameter $\lambda$ and a detailed balance violation parameter $\epsilon$. In arbitrary dimensional generalized HL$_{d+1}$ gravity with $z\ge d$ at long distance, we study the topological neutral black hole solutions with general $\lambda$ in $z=d$ HL$_{d+1}$, as well as the topological charged black holes with $\lambda=1$ in $z=d$ HL$_{d+1}$. The HL gravity in the Lagrangian formulation is adopted, while in the Hamiltonian formulation, it reduces to Dirac$-$De Witt's canonical gravity with $\lambda=1$. In particular, the topological charged black holes in $z=5$ HL$_6$, $z=4$ HL$_5$, $z=3,4$ HL$_4$ and $z=2$ HL$_3$ with $\lambda=1$ are solved. Their asymptotical behaviors near the infinite boundary and near the horizon are explored respectively. We also study the behavior of the topological black holes in the $(d+1)$-dimensional HL gravity with $U(1)$ gauge field in the zero temperature limit and finite temperature limit, respectively. Thermodynamics of the topological charged black holes with $\lambda=1$, including temperature, entropy, heat capacity, and free energy are evaluated.Comment: 51 pages, published version. The theoretical framework of z=d HL gravity is set up, and higher curvature terms in spatial dimension become relevant at UV fixed point. Lovelock term, conformal term, new massive term, and Chern-Simons term with different critical exponent z are studie

Ab initio study of the formation of transparent carbon under pressure

A body-centered tetragonal carbon (bct-Carbon) allotrope has been predicted to be a transparent carbon polymorph obtained under pressure. The structural transition pathways from graphite to diamond, M-Carbon, and bct-Carbon are simulated and the lowest activation barrier is found for the graphite-bct transition. Furthermore, bct-Carbon has higher shear strength than diamond due to its perpendicular graphene-like structure. Our results provide a possible explanation for the formation of a transparent carbon allotrope via the cold compression of graphite. We also verify that this allotrope is hard enough to crack diamond.Comment: [email protected] or [email protected]