Torque teno viral load reflects immunosuppression in paediatric kidney-transplanted patients—a pilot study

Background Chronic deterioration of kidney graft function is related to inadequate immunosuppression (IS). A novel tool to assess the individual net state of IS in transplanted patients might be the monitoring of Torque teno virus (TTV) viral load. TTV is a non-pathogen virus detectable in almost all individuals. TTV level in the peripheral blood has been linked to the immune-competence of its host and should thus reflect IS after solid organ transplantation. Methods TTV plasma load was quantified monthly by RT-PCR for a period of 1 year in 45 kidney-transplanted children. Post-transplant time was at least 3 months. The relation of the virus DNA levels to IS and transplant-specific clinical and laboratory parameters was analysed longitudinally. Results TTV DNA was detectable in 94.5% of the plasma samples. There was a significant association with the post-transplant follow-up time as well as with the type of IS regimen, with lower virus loads in patients after longer post-transplant time and mTOR inhibitor–based IS. Furthermore, a significant positive correlation with the dose of prednisolone and mycophenolate mofetil was found. Conclusions TTV levels show an association/correlation with the strength of IS. Further studies are needed in order to evaluate TTV measurement as a tool for IS monitoring for hard clinical outcomes such as presence of donor-specific antibodies, rejections or infections—common consequences of insufficient or too intense IS.

Comparison and Design of Resonant Network Considering the Characteristics of a Plasma Generator

This paper presents a theoretical analysis and experimental study on the resonant network of the power conditioning system (PCS) for a plasma generator. In order to consider the characteristics of the plasma load, the resonant network of the DC-AC inverter is designed and analyzed. Specifically, the design of an LCL resonant network and an LCCL resonant network, which can satisfy the output current specification in consideration of plasma characteristics, is explained in detail. Moreover, the inverter current and phase angle between the inverter voltage and current is derived for evaluating inverter performance. Based on these analysis results, the DC-AC inverter can be designed for a plasma generator considering plasma load characteristics. The theoretical analysis of both networks is validated through the simulation and experimental results.

Pulse-Current Sources for Plasma Accelerators

The pulse source for plasma-accelerators supply operates under the conditions of nonlinear growth of load inductance, which complicates the matching of the source and the load. This article presents experimental studies of the use of both traditional pulse-energy sources based on capacitive storage and alternative ones based on explosive magnetic generators (EMG). It is shown that the EMG with the special device of the current-pulse formation more effectively matches with such a plasma load as the pulse plasma-accelerator (PPA). This device allows a wide range to manage the current-pulse formation in a variable load and, consequently, to optimize the operation of the power source for the specific plasma load. A mathematical model describing the principle of operation of this device in EMG on inductive load was developed. The key adjustable parameters are the current into the load, the residual inductance of the EMG, and the sample time of the specified inductance and the final current in the load. The device was successfully tested in experiments with the operation on both one and two accelerators connected in parallel. In the experiments, the optimal mode of device operation was found in which the total energy inputted to a pair of accelerators in one pulse reached 0.55 MJ, and the maximum current reached about 3.5 MA. A comparison with the results of experiments performed with capacitive sources of the same level of stored energy is given. The experiments confirmed not only the principal possibility of using EMG with a special device of current-pulse formation for operation with plasma loads in the MJ energy range but also showed the advantages of its application with specific types of plasma load.