The aurophilic interaction is examined in three model systems Au2((3)Σg(+)), (AuH)2, and (HAuPH3)2 which contain interactions of pairs of the Au centers in the oxidation state (I). Several methods are employed ranging from wave function theory-based (WFT) approaches to symmetry-adapted perturbation theory (SAPT) and range-separated hybrid (RSH) density functional theory (DFT) methods. The most promising and accurate approach consists of a combination of the DFT and WFT approaches in the RSH framework. In this combination the short-range DFT handles the slow convergence of the correlation cusp, whereas the long-range WFT is best suited for the long-range correlation. Of the three tested RSH DFT methods, the one which uses a short-range exchange functional based on the Ernzerhof-Perdew exchange hole model with a range-separation parameter of 0.4 bohr(-1) seems to be the best candidate for treatment of gold. In combination with the long-range coupled cluster singles, doubles, and noniterative triples [CCSD(T)] treatment it places the strength of aurophilic bonding in (HAuPH3)2 at 5.7 kcal/mol at R = 3.09 Å. This value is somewhat larger than our best purely WFT result based on CCSD(T), 4.95 kcal/mol (R = 3.1 Å), and considerably smaller than the Hartree-Fock+dispersion value of 7.4 kcal/mol (R = 2.9 Å). The 5.7 kcal/mol estimate fits reasonably well within the prediction of the empirical relationship proposed by Schwerdtfeger et al. (J. Am. Chem. Soc.1998, 120, 6587). A direct computation of dispersion energy, including exchange corrections, results in values of ca. -9 kcal/mol for Au2((3)Σg(+)) and (AuH)2 and -13 kcal/mol for (HAuPH3)2 at the distance of a typical aurophilic bond, R = 3.0 Å.

Background SARS-CoV-2 is a novel viral illness originating out of Wuhan China in late 2019. This global pandemic has infected nearly 3 million people and accounted for 200 000 deaths worldwide, with those numbers still climbing. Case summary We present a 54-year-old patient who developed respiratory failure requiring endotracheal intubation from her infection with SARS-CoV-2. This patient was subsequently found to have a right ventricular thrombus and bilateral pulmonary emboli, likely contributing to her respiratory status. On the 14th day of hospitalization, the patient was successfully extubated, and 5 days later was discharged to the rehabilitation unit. Discussion SARS-CoV-2 presents primarily with pulmonary symptoms; however, many patients, particularly those who are severely ill, exhibit adverse events related to hypercoagulability. The exact mechanism explaining this hypercoagulable state has yet to be elucidated, but these thrombotic events have been linked to the increased inflammation caused by SARS-CoV-2. This novel viral illness is still largely misunderstood, but the hypercoagulable state, seen in severely ill patients, appears to play a major role in disease progression and prognosis.

Background Aortocoronary arteriovenous fistula (ACAVF) due to iatrogenic bypass grafting to a cardiac vein is an exceedingly rare complication resulting from coronary artery bypass grafting (CABG) surgery. If not identified in a timely fashion, ACAVF has known significant clinical consequences related to left to right shunting and possible residual myocardial ischemia. Case presentation An 82-year-old male with a history of CABG, presented with dyspnea. Over the span of 2 years following CABG, the patient experienced progressive exertional dyspnea and peripheral edema. The patient was found to have a new cardiomyopathy with a severely reduced ejection fraction at 30–35%. The patient underwent diagnostic left heart catheterization, and an ACAVF was discovered between a saphenous vein graft and the coronary sinus. The patient underwent successful percutaneous coiling of the ACAVF with no residual flow. Follow-up echocardiography at 3 months revealed restoration of left ventricular systolic function to 50% and significant improvement in heart failure symptoms. Conclusions ACAVF is an exceedingly rare iatrogenic complication of CABG that may result in residual ischemia from the non-grafted myocardial territory and other sequelae relating to left to right shunting and a high-output state. Management for this pathology includes but is not limited to the use of percutaneous coiling, implantation of covered stents, graft removal and regrafting, and ligation.

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