Generation of human induced pluripotent stem cells by simple transient transfection of plasmid DNA encoding reprogramming factors

<p>Abstract</p> <p>Background</p> <p>The use of lentiviruses to reprogram human somatic cells into induced pluripotent stem (iPS) cells could limit their therapeutic usefulness due to the integration of viral DNA sequences into the genome of the recipient cell. Recent work has demonstrated that human iPS cells can be generated using episomal plasmids, excisable transposons, adeno or sendai viruses, mRNA, or recombinant proteins. While these approaches offer an advance, the protocols have some drawbacks. Commonly the procedures require either subcloning to identify human iPS cells that are free of exogenous DNA, a knowledge of virology and safe handling procedures, or a detailed understanding of protein biochemistry.</p> <p>Results</p> <p>Here we report a simple approach that facilitates the reprogramming of human somatic cells using standard techniques to transfect expression plasmids that encode OCT4, NANOG, SOX2, and LIN28 without the need for episomal stability or selection. The resulting human iPS cells are free of DNA integration, express pluripotent markers, and form teratomas in immunodeficient animals. These iPS cells were also able to undergo directed differentiation into hepatocyte-like and cardiac myocyte-like cells in culture.</p> <p>Conclusions</p> <p>Simple transient transfection of plasmid DNA encoding reprogramming factors is sufficient to generate human iPS cells from primary fibroblasts that are free of exogenous DNA integrations. This approach is highly accessible and could expand the use of iPS cells in the study of human disease and development.</p

InMotion hybrid racecar : F1 performance with LeMans endurance

Purpose : – The purpose of this paper is to demonstrate that using advanced powertrain technologies can help outperform the state of the art in F1 and LeMans motor racing. By a careful choice and sizing of powertrain components coupled with an optimal energy management strategy, the conflicting requirements of high-performance and high-energy savings can be achieved. Design/methodology/approach : – Five main steps were performed. First, definition of requirements: basic performance requirements were defined based on research on the capabilities of Formula 1 race cars. Second, drive cycle generation: a drive cycle was created using these performance requirements as well as other necessary inputs such as the track layout of Circuit de la Sarthe, the drag coefficient, the tire specifications, and the mass of the vehicle. Third, selection of technology: the drive cycle was used to model the power requirements from the powertrain components of the series-hybrid topology. Fourth, lap time sensitivity analysis: the impact of certain design decisions on lap time was determined by the lap time sensitivity analysis. Fifth, modeling and optimization: the design involved building the optimal energy management strategy and comparing the performance of different powertrain component sizings. Findings : – Five different powertrain configurations were presented, and several tradeoffs between lap time and different parameters were discussed. The results showed that the fastest achievable lap time using the proposed configurations was 3¿min 9¿s. It was concluded that several car and component parameters have to be improved to decrease this lap time to the required 2¿min 45¿s, which is required to outperform F1 on LeMans. Originality/value : – This research shows the capabilities of advanced hybrid powertrain components and energy management strategies in motorsports, both in terms of performance and energy savings. The important factors affecting the performance of such a hybrid race car have been highlighted

InMotion hybrid racecar: F1 performance with LeMans endurance

This paper presents the design of a hybrid electric powertrain for the InMotion IM01 race car. InMotion is a multidisciplinary project group of experienced master students, PhD students, and professors. The authors of this paper were involved in the project to develop a suitable powertrain architecture for use in the IM01 series hybrid race car. The most important requirements were to achieve a lap time of below 2 min 45 s on the Circuit de la Sarthe, and to have a durability, efficiency, cornering speed, and acceleration that exceeds Formula 1 race cars. Data provided from InMotion included design restrictions, a simplified drive cycle, and technical data of some components. This data was analyzed and the required powertrain component sizes were determined. A detailed drive cycle calculation and sensitivity analysis were introduced to find the variables that significantly influence the lap time. The powertrain was modeled using the backwards modeling approach. Finally, five different powertrain configurations were presented, and several tradeoffs between lap time and different parameters were discussed. The results showed that the fastest achievable lap time using the proposed configurations was 3 min 9 s. It was concluded that several car and component parameters have to be improved to decrease this lap time to the required 2 min 45 s. Recommendations for future work to achieve this were addressed

InMotion: Hybrid race car, beating F1 at LeMans

This paper presents the design of a hybrid electric powertrain for the InMotion IM01 race car. InMotion is a multidisciplinary project group of experienced master students, PhD students, and professors from Eindhoven University of Technology (TU/e). The authors of this paper were involved in the project to develop a suitable powertrain architecture for use in the IM01 series hybrid race car. The most important requirements were to achieve a lap time of below 2 min 45 s on the Circuit de la Sarthe, and to have a durability, efficiency, cornering speed, and acceleration that exceeds Formula 1 race cars. Data provided from InMotion included design restrictions, a simplified drive cycle, and technical data of some components. This data was analyzed and the required powertrain component sizes were determined. A detailed drive cycle calculation and sensitivity analysis were introduced to find the variables that significantly influence the lap time. The powertrain was modeled using the backwards approach and an energy management strategy was designed with the objective of minimizing fuel consumption. Finally, five different powertrain configurations were presented, and several tradeoffs between lap time and different parameters were discussed. The results showed that the fastest achievable lap time using the proposed configurations was 3 min 9 s. It was concluded that several car and component parameters have to be improved to decrease this lap time to the required 2 min 45 s. Recommendations for future work to achieve this were addressed