No abstract

Stable operation of a laser-plasma accelerator near the threshold for electron self-injection in the blowout regime has been demonstrated with 25-60 TW, 30 fs laser pulses focused into a 3-4 millimeter length gas jet. Nearly Gaussian shape and high nanosecond contrast of the focused pulse appear to be critically important for controllable, tunable generation of 250-430 MeV electron bunches with a lowenergy spread, $10 pC charge, a few-mrad divergence and pointing stability, and a vanishingly small low-energy background. The physical nature of the near-threshold behavior is examined using threedimensional particle-in-cell simulations. Simulations indicate that properly locating the nonlinear focus of the laser pulse within the plasma suppresses continuous injection, thus reducing the low-energy tail of the electron beam.

Manifestations of cardiovascular diseases (CVDs) in a patient or a population differ based on inherent biological makeup, lifestyle, and exposure to environmental risk factors. These variables mean that therapeutic interventions may not provide the same benefit to every patient. In the context of CVDs, human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) offer an opportunity to model CVDs in a patient-specific manner. From a pharmacological perspective, iPSC-CM models can serve as go/no-go tests to evaluate drug safety. To develop personalized therapies for early diagnosis and treatment, human-relevant disease models are essential. Hence, to implement and leverage the utility of iPSC-CMs for large-scale treatment or drug discovery, it is critical to (i) carefully evaluate the relevant limitations of iPSC-CM differentiations, (ii) establish quality standards for defining the state of cell maturity, and (iii) employ techniques that allow scalability and throughput with minimal batch-to-batch variability. In this review, we briefly describe progress made with iPSC-CMs in disease modelling and pharmacological testing, as well as current iPSC-CM maturation techniques. Finally, we discuss current platforms for large-scale manufacturing of iPSC-CMs that will enable high-throughput drug screening applications.