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排序方式: 共有451条查询结果,搜索用时 15 毫秒
111.
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Maurizio Grasselli Hana Petzeltová Giulio Schimperna 《Journal of Differential Equations》2007,239(1):38-60
We consider a differential model describing nonisothermal fast phase separation processes taking place in a three-dimensional bounded domain. This model consists of a viscous Cahn-Hilliard equation characterized by the presence of an inertial term χtt, χ being the order parameter, which is linearly coupled with an evolution equation for the (relative) temperature ?. The latter can be of hyperbolic type if the Cattaneo-Maxwell heat conduction law is assumed. The state variables and the chemical potential are subject to the homogeneous Neumann boundary conditions. We first provide conditions which ensure the well-posedness of the initial and boundary value problem. Then, we prove that the corresponding dynamical system is dissipative and possesses a global attractor. Moreover, assuming that the nonlinear potential is real analytic, we establish that each trajectory converges to a single steady state by using a suitable version of the ?ojasiewicz-Simon inequality. We also obtain an estimate of the decay rate to equilibrium. 相似文献
113.
A new microflow system was designed and developed for electrochemical measurements. The electrochemical electrodes prepared using thick film technology were used in this arrangement. Results of various measurements such as simple amperometric measurement on the example of H2O2 detection, measurement with glucose oxidase (GOx) biosensor, soluble enzyme activity measurement etc. carried out using this system are reported. It was observed that the sensitivity and reproducibility of the electrochemical measurements is improved significantly. The new device performance was proved on H2O2 detection, activity of GOx measurement and heavy metals detection (measured concentration range: H2O2 10?9 to 10?1 M, glucose 10?6 to 10?2 M, activity of GOx 10?1 to 102 IU, heavy metals (Cu, Pb) 10?4 to 10?3 M). The microflow insert greatly reduces the overall size of the electrolyte vessel and measurements with sample quantity as low as 2 mL can be accomplished. 相似文献
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Vráblíková H Barták M Wonisch A 《Journal of photochemistry and photobiology. B, Biology》2005,79(1):35-41
Hydrated thalli of two lichen species--Umbilicaria antarctica and Lasallia pustulata--were exposed to high light (1800 micromol m-2s-1) for 30 min. High light exposure led to a decrease of total glutathione in both species, while de-epoxidation state of xanthophyll cycle pigments and non-photochemical quenching increased. In the subsequent recovery, the values of de-epoxidation state of xanthophyll cycle pigments decreased towards initial values. Glutathione (GSH) was resynthetised slowly. In conclusion, zeaxanthin-related protection is probably more involved than GSH-related protection in short-term response to high light stress in U. antarctica and L. pustulata. Faster recovery from photoinhibition in L. pustulata than U. antarctica is mainly due to faster conversion of zeaxanthin to violaxanthin and larger GSH pool of former species. 相似文献
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Hana Sklenov Marek Beran Lucie Novosvtsk Daniela mejkalov Petr Solich 《Molecules (Basel, Switzerland)》2021,26(18)
A fully automated sequential injection system was tested in terms of its application in liberation testing, and capabilities and limitations were discussed for clotrimazole liberation from three semisolid formulations. An evaluation based on kinetic profiles obtained in short and longer sampling intervals and steady-state flux values were applied as traditional methods. The obtained clotrimazole liberation profile was faster in the case of Delcore and slower for Clotrimazol AL and Canesten cream commercial formulations. The steady-state flux values for the tested formulations were 52 µg cm−2 h−1 for Canesten, 35 µg cm−2 h−1 for Clotrimazol AL, and 7.2 µg cm−2 h−1 for Delcore measured in 4 min sampling intervals. A simplified approach for the evaluation of the initial rate based on the gradient between the second and third sampling points was used for the first time and was found to correspond well with the results of the conventional methods. A comparison based on the ratio of the steady-state flux and the initial rate values for Canesten and Clotrimazol AL proved the similarity of the obtained results. The proposed alternative was successfully implemented for the comparison of short-term kinetic profiles. Consequently, a faster and simpler approach for dissolution/liberation testing can be used. 相似文献
118.
Dr. Hana Kostrhunova Dr. Juraj Zajac Dr. Lenka Markova Prof. Viktor Brabec Prof. Jana Kasparkova 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(47):21343-21348
HER2-positive breast cancer is an aggressive subtype that typically responds poorly to standard chemotherapy. To design an anticancer drug selective for HER2-expressing breast cancer, a PtIV prodrug with axial oleate and cinnamate ligands was synthesized. We demonstrate its superior antiproliferative activity in monolayer and 3D spheroid models; the antiproliferative efficiency increases gradually with increasing expression of HER2. The results also suggest that the released PtII compound inhibits the proliferation of cancer cells by a DNA-damage-mediated mechanism. Simultaneously, the released oleic and cinnamic acid can effectively inhibit HER2 expression. To our knowledge, this is the first platinum-based complex inhibiting HER2 expression that does not contain protein or peptide. Moreover, this PtIV prodrug is capable of overcoming the resistance of cancer stem cells (CSCs), inducing death in both CSCs and differentiated cancer cells. Thus, the results substantiate our design strategy and demonstrate the potential of this approach for the development of new, therapeutically relevant compounds. 相似文献
119.
Hyun Kyoo Park Hana Rah Dong Jun Kang Uong Chun Sun-Geon Kim 《Journal of Sol-Gel Science and Technology》2013,67(3):464-472
Nanostructures of single crystallites of spinel LiMn2O4 (LMO) were prepared by the simple pyrolysis of aqueous solution of LiNO3 and Mn(NO3)2 in a confined space such as either droplets or mesopores. When the mixed nitrate solution was spray pyrolyzed at temperatures below 700 °C, 1-μm LMO spheres were obtained consisting of ~20-nm single crystallites randomly packed. Such LMO phase, once obtained, would sustain for further heat-treatment. Next, new spraying solution was prepared by adding the precursor for mesoporous silica (MPS) to the nitrates solution. By spray pyrolyzing such solution, LMO was impregnated inside pores of the MPS being structured. The silica could be removed by subsequent NaOH treatment to leave spherical LMO mesophase. The nitrates was also able to soak into the existing MPS having cylindrical pores and form short isolated LMO chains in the mesopores by the subsequent heating. After the same NaOH treatment, the LMO phase turned into bundles of very ‘long’, and often straight, chains, consisting of 8-nm LMO nanoparticles. This will be elucidated through further study. 相似文献
120.