Publications by authors named "Austin Cheng"

Drug solubility is an important parameter in the drug development process, yet it is often tedious and challenging to measure, especially for expensive drugs or those available in small quantities. To alleviate these challenges, machine learning (ML) has been applied to predict drug solubility as an alternative approach. However, the majority of existing ML research has focused on the predictions of aqueous solubility and/or solubility at specific temperatures, which restricts the model applicability in pharmaceutical development.

View Article and Find Full Text PDF

Machine learning has been pervasively touching many fields of science. Chemistry and materials science are no exception. While machine learning has been making a great impact, it is still not reaching its full potential or maturity.

View Article and Find Full Text PDF

Artificial intelligence-guided closed-loop experimentation has emerged as a promising method for optimization of objective functions, but the substantial potential of this traditionally black-box approach to uncovering new chemical knowledge has remained largely untapped. Here we report the integration of closed-loop experiments with physics-based feature selection and supervised learning, denoted as closed-loop transfer (CLT), to yield chemical insights in parallel with optimization of objective functions. CLT was used to examine the factors dictating the photostability in solution of light-harvesting donor-acceptor molecules used in a variety of organic electronics applications, and showed fundamental insights including the importance of high-energy regions of the triplet state manifold.

View Article and Find Full Text PDF
Article Synopsis
  • Structure determination is crucial for identifying unknown organic molecules found in various contexts, and rotational spectroscopy provides essential 3D information through moments of inertia.
  • Kraitchman analysis helps in finding isotopic substitution coordinates of atoms, but the lack of signed coordinates complicates accurate structure identification.
  • The new generative diffusion model called Kreed can accurately predict a molecule's full 3D structure from limited data, achieving high accuracy in structure predictions, especially with complete substitution coordinates.
View Article and Find Full Text PDF

Introduction: Patients with HIV infection have increased risk of atrial fibrillation, but the pathophysiologic mechanisms and the utility of catheter ablation in this population are not well-studied. We aimed to characterize outcomes of atrial fibrillation ablation and left atrial substrate in patients with HIV.

Methods: The study was a retrospective propensity score-matched analysis of patients with and without HIV undergoing atrial fibrillation ablation.

View Article and Find Full Text PDF

We have measured Coulomb drag between an individual single-walled carbon nanotube (SWNT) as a one-dimensional (1D) conductor and the two-dimensional (2D) conductor monolayer graphene, separated by a few-atom-thick boron nitride layer. The graphene carrier density is tuned across the charge neutrality point (CNP) by a gate, while the SWNT remains degenerate. At high temperatures, the drag resistance changes sign across the CNP, as expected for momentum transfer from drive to drag layer, and exhibits layer exchange Onsager reciprocity.

View Article and Find Full Text PDF
Article Synopsis
  • Atrial fibrillation ablation success depends on catheter stability, which can be enhanced by rapid cardiac pacing and high-frequency jet ventilation (HFJV).
  • In a study with 40 patients, the combination of rapid pacing and HFJV significantly reduced variability in contact force during ablation compared to pacing or HFJV alone.
  • The findings indicate that using both techniques together leads to better catheter stability, potentially improving the outcomes of atrial fibrillation ablation procedures.
View Article and Find Full Text PDF

Relativistic massless charged particles in a two-dimensional conductor can be guided by a one-dimensional electrostatic potential, in an analogous manner to light guided by an optical fiber. We use a carbon nanotube to generate such a guiding potential in graphene and create a single mode electronic waveguide. The nanotube and graphene are separated by a few nanometers and can be controlled and measured independently.

View Article and Find Full Text PDF
Article Synopsis
  • * Data was collected before and after implementing the time-out in a lab, showing a 21% reduction in radiation exposure levels for patients and healthcare professionals.
  • * The findings support adopting radiation safety time-outs in electrophysiology and other fluoroscopy-dependent medical practices to enhance safety and minimize radiation risks.
View Article and Find Full Text PDF
Article Synopsis
  • - The study aimed to explore how pacing-induced heart rate changes affect catheter-tissue contact and impedance reduction during radiofrequency ablation procedures for atrial fibrillation (AF) in patients.
  • - Results indicated that pacing significantly decreased the variability of catheter-tissue contact and led to a 30% greater reduction in tissue impedance, suggesting more effective ablation.
  • - The findings suggest that manipulating heart rate can improve catheter performance and lesion quality, offering a new strategy for optimizing AF ablation outcomes.
View Article and Find Full Text PDF

The use of bone marrow-derived mesenchymal stromal cells (BMSC) in the treatment of alloimmune and autoimmune conditions has generated much interest, yet an understanding of the therapeutic mechanism remains elusive. We therefore explored immune modulation by a clinical-grade BMSC product in a model of human-into-mouse xenogeneic graft-versus-host disease (x-GVHD) mediated by human CD4(+) Th1 cells. BMSC reversed established, lethal x-GVHD through marked inhibition of Th1 cell effector function.

View Article and Find Full Text PDF