Organoboron Complexes as Thermally Activated Delayed Fluorescence (TADF) Materials for Organic Light-Emitting Diodes (OLEDs): A Computational Study.

We report on organoboron complexes characterized by very small energy gaps (ΔEST) between their singlet and triplet states, which allow for highly efficient harvesting of triplet excitons into singlet states for working as thermally activated delayed fluorescence (TADF) devices. Energy gaps ranging between 0.01 and 0.06 eV with dihedral angles of ca. 90° were registered. The spin-orbit couplings between the lowest excited S1 and T1 states yielded reversed intersystem crossing rate constants (KRISC) of an average of 105 s-1. This setup accomplished radiative decay rates of ca. 106 s-1, indicating highly potent electroluminescent devices, and hence, being suitable for application as organic light-emitting diodes.

A student led computational screening of peptide inhibitors against main protease of SARS-CoV-2.

The main protease of SARS-CoV-2 is a promising drug target due to its functional role as a catalytic dyad in mediating proteolysis during the viral life cycle. In this study, experimentally proven 14 HIV protease peptides were screened against the main protease of SARS-CoV-2. Fourteen middle and high school "student researchers" were trained on relevant computational tools, provided with necessary biological and chemical background and scientific article writing. They performed the primary screening via molecular docking and the best performing complexes were subjected to molecular dynamics simulations. Molecular docking revealed that HIP82 and HIP1079 can bind with the catalytic residues, however after molecular dynamics simulation only HIP1079 retained its interaction with the catalytic sites. The student researchers were also trained to write scientific article and were involved with drafting of the manuscript. This project provided the student researchers an insight into multi-disciplinary research in biology and chemistry, inspired them about practical approaches of computational chemistry in solving a real-world problem like a global pandemic. This project also serves as an example to introduce scientific inquiry, research methodology, critical thinking, scientific writing, and communication for high school students.

Aortic pseudoaneurysm with fistulization into the pulmonary artery: a cause of refractory heart failure after bentall procedure.

We present the case of a patient who developed left-sided congestive heart failure several years after undergoing composite graft surgery for annuloaortic ectasia and aortic regurgitation. Transthoracic echocardiography showed markedly elevated left ventricular filling pressures and severe pulmonary hypertension. However, no underlying pathology or anatomic abnormality to explain the high filling pressures could be identified. On transesophageal echocardiography, a large aortic pseudoaneurysm was demonstrated arising from dehiscence of the distal graft anastomosis to the native aorta. A fistulous communication was noted between the pseudoaneurysm and the right pulmonary artery resulting in a large aortopulmonary shunt. This case illustrates the inherent limitations of transthoracic echocardiography in the detection of complications after composite graft surgery of the aorta.