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41.
Inhalational anesthetics was previously reported to suppress glioma cell malignancy but underlying mechanisms remain unclear. The present study aims to investigate the effects of sevoflurane and desflurane on glioma cell malignancy changes via microRNA (miRNA) modulation. The cultured H4 cells were exposed to 3.6% sevoflurane or 10.3% desflurane for 2 h. The miR-138, -210 and -335 expression were determined with qRT-PCR. Cell proliferation and migration were assessed with wound healing assay, Ki67 staining and cell count kit 8 (CCK8) assay with/without miR-138/-210/-335 inhibitor transfections. The miRNA downstream proteins, hypoxia inducible factor-1α (HIF-1α) and matrix metalloproteinase 9 (MMP9), were also determined with immunofluorescent staining. Sevoflurane and desflurane exposure to glioma cells inhibited their proliferation and migration. Sevoflurane exposure increased miR-210 expression whereas desflurane exposure upregulated both miR-138 and miR-335 expressions. The administration of inhibitor of miR-138, -210 or -335 inhibited the suppressing effects of sevoflurane or desflurane on cell proliferation and migration, in line with the HIF-1α and MMP9 expression changes. These data indicated that inhalational anesthetics, sevoflurane and desflurane, inhibited glioma cell malignancy via miRNAs upregulation and their downstream effectors, HIF-1α and MMP9, downregulation. The implication of the current study warrants further study.  相似文献   
42.
This paper presents original research results of automatic polishing on curved surfaces of aluminium alloy moulds at constant pressure. The automatic polishing of aluminium alloy material is achieved. A parameter S is defined, which can express the comprehensive influential factors in the automatic polishing process and give a relationship among the polishing quality and the various machining variables. Based on this, a new method for comprehensive control of polishing quality is suggested.  相似文献   
43.
Humidity Sensor Characteristics of Woodceramics   总被引:9,自引:0,他引:9  
The humidity sensor characteristics of Woodceramics were investigated. The Woodceramics used in this experiment were prepared at 650–900°C. The size of specimens selected was 1 × 1 × 10 mm . One was used as-cut and the other was polished. Above 700°C, the resistance of the specimen was below 50 and the decrease of resistance with increasing relative humidity was small. The specimen prepared at 650°C had a resistance of about 1 k. The resistance of as-cut specimens decreased with increase in relative humidity, but that of the polished specimen did not change significantly. The difference between as-cut and polished samples was explained by the differences in surface micro-structure.  相似文献   
44.
Upon the application of amperometric biosensor to the biological fluid, ascorbic acid interferes the amperometric determination of analytes, because the oxidative potential of ascorbic acid is lower than that of electro active substances such as H2O2 produced by the enzymatic reaction. In this study we propose a method to block ascorbic acid based on the electrostatic interaction with self-assembled monolayer (SAM) and its application of the surface modified electrode to biosensor. In order to form SAM on the gold electrode with carboxyl group, 7-carboxy-heptanethiol (7-CHT) was used. The 7-CHT modified electrode did not show anodic response to ascorbic acid, but oxidized phenanthroline cobalt complex [Co(phen)32+], which can be used as a mediator of biosensor. Thus, the 7CHT-modified electrode was applied to biosensor mediated with Co(phen)32+. Fructose dehydrogenase (FDH) was immobilized to the 7-CHT modified electrode. Fructose was determined selectively with the FDH/7-CHT modified electrode at the range of 0.2-2 mM.  相似文献   
45.
Bi0.5Na0.5TiO3 (BNT) and 0.94Bi0.5Na0.5TiO3·0.06BaTiO3 (BNT–BT) bulk ceramics with extensive 〈100〉 texture were prepared by the reactive-templated grain growth method, using platelike Bi4Ti3O12 (BIT) particles as templates for BNT. Calcined compacts were composed of matrix grains with random orientation and 〈100〉-oriented grains transformed from aligned BIT particles, and the texture developed by the growth of oriented grains during sintering. Ceramics with extensive texture were obtained by using the starting mixture containing the maximum concentration of platelike BIT to form the maximum volume fraction of oriented grains.  相似文献   
46.
47.
To model the molten globule structure of -lactalbumin, moleculardynamics (MD) simulations were carried out for the protein inexplicit water at high temperature. In these simulations, long-rangeCoulomb interactions were evaluated explicitly with an originalmethod (particle–particle and particle–cell: PPPC)to avoid artifacts caused by the cut-off. The MD simulationswere started from two initial conditions to verify that similarresults would be obtained. From the last 150 ps trajectoriesof the two MD simulations, two partially unfolded average structureswere obtained. These structures had the following common structuralfeatures which are characteristic of the molten globule state.The radii of gyration for these conformations were 7.4 and 9.6%larger than that of the native state. These values were almostthe same as the experimental value (9.6%) observed recentlyby small-angle X-ray scattering (Kataoka,M., Kuwajima,K., Tokunaga,F.and Goto,Y., 1997, Protein Sci., 6, 422–430). Furthermore,aromatic residues of clusters I and II in these structures werefar apart from each other except for Try103–Trp104. Thisresult is in good agreement with NMR experimental results forthe acid-denatured molten globule state (Alexandrescu et al.,1992, 1993); that is, NOE signals between the aromatic residueswere not observed, except for that of Try103–Trp104 inthe molten globule state. Other structural features of thesemodels for the molten globule state are discussed with referenceto native state structures.  相似文献   
48.
The room-temperature elastic constants of ErVO4 were considerably smaller than those of isostructural silicate and phosphate analogs. The generally "less-rigid" crystalline lattice and weaker metal-oxygen bond-strength in the RVO4 (R = rare earth elements) phases indicates that these materials are of interest for potential applications as an interphase component in toughened oxide ceramic composites.  相似文献   
49.
Salvia leucophylla, a shrub observed in coastal south California, produces several volatile monoterpenoids (camphor, 1,8-cineole, -pinene, -pinene, and camphene) that potentially act as allelochemicals. The effects of these were examined using Brassica campestris as the test plant. Camphor, 1,8-cineole, and -pinene inhibited germination of B. campestris seeds at high concentrations, whereas -pinene and camphene did not. Root growth was inhibited by all five monoterpenoids in a dose-dependent manner, but hypocotyl growth was largely unaffected. The monoterpenoids did not alter the sizes of matured cells in either hypocotyls or roots, indicating that cell expansion is relatively insensitive to these compounds. They did not decrease the mitotic index in the shoot apical region, but specifically lowered mitotic index in the root apical meristem. Moreover, morphological and biochemical analyses on the incorporation of 5-bromo-2-deoxyuridine into DNA demonstrated that the monoterpenoids inhibit both cell-nuclear and organelle DNA synthesis in the root apical meristem. These results suggest that the monoterpenoids produced by S. leucophylla could interfere with the growth of other plants in its vicinity through inhibition of cell proliferation in the root apical meristem.  相似文献   
50.
The pre-treatment of a silica-supported gallium oxide catalyst with H2 at 823 K increased the yield of aromatics and the selectivity to aromatics in the dehydrogenation of propane over the catalyst at 823 K. Gallium oxide in the catalyst was partially reduced with H2 at 823 K. NH3 desorption and DRIFTS studies on the gallium oxide catalyst suggest that the dehydrogenation of propane over a silica-supported gallium oxide catalyst would proceed in the following way: (1) the dehydrogenation of propane to produce propene would occur on Ga sites including Gaδ+–H sites and (2) the aromatization of propene to aromatics on Ga–O–H acid sites.  相似文献   
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