Banking of AT-MSC and its Influence on Their Application to Clinical Procedures

Processing of MSCs to obtain a therapeutic product consists of two main steps: 1) the in vitro expansion of the cells until an appropriate number of them is obtained, and 2) freezing and storage of the expanded cells. The last step is critical and must be optimized so that after thawing the cells retain all their physiological properties including the secretory function. In this paper, we evaluated physiological parameters of AT-MSC’s after a full cycle of their processing, particularly freezing and storing at the liquid nitrogen vapor temperature. Based on the recovered proliferative and secretory capacities of the thawed cells, we have designed the optimal technique for processing of MSCs for clinical applications. In our work, we tried to select the best DMSO-based cryoprotectant mixture on the base of post thawing fully retain their properties. We have demonstrated the effectiveness of the use of DMSO in various configurations of the constituent cryoprotective fluids. We have also shown that AT-MSCs that show control levels in most standard tests (viability, shape, culture behaviour, and proliferative properties) after thawing, may show transient variations in some important physiological properties, such as the level of secreted growth factors. Obtained results let us to indicate how to optimize the AT-MSC preparation process for clinical applications. We suggest that before their clinical application the cells should be cultured for at least one passage to recover their physiological stability and thus assure their optimal therapeutic potential.

Dimension Effect of Sapphire Substrate in Current-Switching Device Based on Vanadium Dioxide Thin Film Controlled by Photothermal Effect

The switching characteristics of a vanadium dioxide (VO2) thin-film device, in which the current flowing through the device can be switched through the photothermal effect using focused laser pulses, were investigated according to the dimensions of the sapphire substrate on which the VO2 thin film was deposited through simulation using COMSOL Multiphysics. The physical properties of the VO2 device, modeled for the simulation, were determined according to the structural and electrical properties and photothermally controlled current-switching characteristics of fabricated VO2 devices. For a variety of substrate dimensions of the modeled VO2 device, we explored transient variations in the temperature of some specific regions and the device current switched by laser irradiation. The investigation results revealed that the stability of the bidirectional current-switching operation triggered on and off by laser illumination tends to increase as the area of the substrate increases with its thickness fixed. However, above a certain substrate area, the rate of improvement in the switching stability decreases rapidly and approaches zero.

Atmosphere response to pre-earthquake processes revealed by satellite and ground observations. Case study for few strong earthquakes in Xinjiang, China (2008-2014)

We are presenting the latest results of multi-sensor observations of short-term pre-earthquake phenomena preceding significant earthquakes. We study satellite thermal infrared radiation (OLR) anomalous signals in association with three major earthquakes, which occurred in Xinjiang province, China at different periods M7.3 of 02.12.2014; M6.2 of 08.12.2012; and M7.2 of 03.20.2008. We systematically apply multi-sensor satellite thermal data and ground temperature /humidity and estimates of the atmospheric chemical potential (ACP) parameter. Data analyses include NOAA NPOESS, the Chinese geostationary satellite FY-2D, and in-situ hourly NOAA data from the Hotan weather station. In all three cases, we detected atmospheric satellite OLR anomalies developed near the epicenter area and ACP increases (significant change for 2008 and 2014, weak for 2012) over the major Altyn Tagh fault lines within 10-20 days before the earthquake event. These findings demonstrate the occurrence and reoccurrence of transient variations of these parameters, implying their connection with the earthquake preparation process.

Massive, continuous and non-invasive surface measurement of degree of saturation by shortwave infrared images

Short wave infrared (SWIR) images provide an accurate procedure to measure the degree of saturation (Sr) of soils. Changes in Sr result in reflectance changes which were recorded by a special digital camera optimized for a particular range of wavelengths which provide the maximum resolution of the method. The paper describes the developed methodology, which relies on sample-determined calibration of soil reflectance for a few values of Sr covering the dry-fully saturated range of moistures. The accuracy of the method was checked by comparing equilibrated profiles of SWIR- determined Sr with other procedures (sensor readings and water retention information). It was found that the SWIR-based method correlates well with the degree of saturation of the soil but not with its water content, which may change, for a given Sr, when the soil deforms volumetrically. The transient variations of Sr are also well captured by the method. The recorded evolution of two-dimensional Sr maps of an initially unsaturated soil column was satisfactorily compared with the results of a numerical model.

Enhanced decoupled current control with voltage compensation for modular multilevel converter (MMC) based STATCOM

<p>This paper presents the application of modular multilevel converter (MMC) as a static compensator (STATCOM) for reactive current control. The current control is mostly achieved using proportional controller, proportional-integral (PI) controller, and hysteresis controller among others. PI controllers have the advantage of low harmonics and small variations. However, due to the PI controller’s dependency on the system parameters and also due to the variations within the MMC during capacitors voltage control, variation in the MMC performance during the STATCOM non-ideal operations occur. To mitigate this, an improved performance of MMC will be presented using vector-based compensation concept. The proposed control will be introduced to depress the effect of the dynamics of the MMC based STATCOM non-ideal variations considering the impact of the voltage disturbance. This will be achieved by the introduction of voltage variables to subtract the transient variations from PI controllers’ outputs at the grid-interface; thus, improving the performance.</p>