Abstract A cationic liposomal gene delivery system comprising DOTAP, DOPE, and cholesterol was prepared and optimized. The results showed that the liposome/DNA (LP/DNA) system had spherical morphology, with a particle size of around 150 nm and zeta potential of approximately 30 mV. Cytotoxicity experiments showed that cells treated with all of the liposome carriers- with the exception of LP1-had more than 80% viability even at a weight ratio of 30. The in vitro transfection efficiency was measured using a Promega™ Luciferase Assay System. Of the tested lipoplexes, LP2/DNA showed the highest cell transfection efficiency (at a weight ratio of 10)-which was similar to or slightly lower than that of Lipofectamine® 2000 in HeLa, A549, and SPC-A1 cell lines. After freeze-drying, the cell transfection efficiency decreased slightly (P>0.05). The cell uptake mechanism study showed that LP/DNA lipoplexes mainly entered cells via clathrin-mediated and caveolin-mediated endocytic pathways. The results confirmed that LP2 has potential for use as an effective gene carrier, and provides experimental evidence to support its further development as a safe and effective gene delivery system.

The hot deformation behaviours of Ti-6Al-4V-0.1Ru alloy were investigated by isothermal hot compression tests in the temperature range of 1023-1423 K and strain rate range of 0.01-10 s-1. The β transus was determined to be 1198 K by continuous heating method. The values of deformation activation energy Q at the strain of 0.3 were calculated to be 630.01 kJ/mol in dual-phase field and 331.75 kJ/mol in β-phase field. Moreover, the processing maps at the strain of 0.2, 0.4, 0.6 and 0.8 were developed based on dynamic materials model (DMM). To deeply understand the microstructure evolution mechanism during hot deformation processes and to verify the processing maps, the microstructures at different deformation conditions were observed. The stable microstructures (i.e. globularization, dynamic recovery (DRV) and β dynamic recrystallization (β-DRX)) and instable microstructures (i.e. lamellae kinking and flow localization) were obtained. To make it useful in the design of industrial hot working schedules for this material, a microstructural mechanism map was constructed on the basis of processing maps and microstructure observation. Deformation conditions in the vicinity of 1150 K & 0.01 s-1 where globularization occurs and in the vicinity of 1323 K & 0.01 s-1 where β-DRX occurs are recommended.

Este estudo empregou pontos de controle de GPS em regiões-teste com altitudes ortométricas de primeira ordem previamente conhecidas, para a obtenção de pontos de coordenadas planas e altitudes elipsoidais, com a utilização do método cinemático em tempo real (RTK). Este estudo aplicou o ajuste de superfície de primeira ordem, ajuste de superfície de segunda ordem, método da retropropagação para redes neurais e "support vector machine" por mínimos quadrados (LS-SVM). Integridade e localização de dados foram examinados, e a certa quantidade e distribuição de pontos de referência modificados para obtenção da solução ideal. O estudo contou também com o LS-SVM e com o modelo de altitude geoidal local que foi estabelecido usando 3 funções de Kernel para análises e pesquisas. Os resultados indicam que a precisão total dos valores calculados das ondulações geóidais geométricas locais usando a rede neural artificial e o polinômio de terceira-ordem da função de Kernel foram ideais com o valor quadrático médio de aproximadamente ± 1.5 cm. O resultado mostrou que o SVM oferece o método rápido e prático para obtenção de altitudes ortométricas e provê a pesquisa acadêmica de referência para modelos geoidais locais.

In this study, test-region global positioning system (GPS) control points exhibiting known first-order orthometric heights were employed to obtain the points of plane coordinates and ellipsoidal heights by using the real-time GPS kinematic measurement method. Plane-fitting, second-order curve-surface fitting, back-propagation (BP) neural networks, and least-squares support vector machine (LS-SVM) calculation methods were employed. The study includes a discussion on data integrity and localization, changing reference-point quantities and distributions to obtain an optimal solution. Furthermore, the LS-SVM was combined with local geoidal-undulation models that were established by researching and analyzing3 kernel functions. The results indicated that the overall precision of the local geometric geoidal-undulation values calculated using the radial basis function (RBF) and third-order polynomial kernel function was optimal and the root mean square error (RMSE) was approximately ± 1.5 cm. These findings demonstrated that the LS-SVM provides a rapid and practical method for determining orthometric heights and should serve as a valuable academic reference regarding local geoid models.