Publications by authors named "Hoyoung Hwang"

Article Synopsis
  • - The use of lithium-ion batteries has surged, resulting in a growing number of spent batteries that pose significant environmental hazards due to abandoned cathode materials.
  • - Research reveals that a specific microorganism enhances the breakdown of spent LiNiCoMnO (NCM622) cathodes, leading to about 59% dissolution of pristine and 78% of spent material under low-oxygen conditions.
  • - The study indicates that microbial respiration not only affects the dissolution of harmful metals like Li, Ni, Co, and Mn but also suggests a potential method for sustainable recovery of valuable materials from discarded batteries through bioleaching.
View Article and Find Full Text PDF

The oxidation of dissolved Mn(aq) plays a critical role in driving manganese cycles and regulating the fate of essential elements and contaminants in environmental systems. Based on sluggish oxidation rate, abiotic processes have been considered less effective oxidation pathway for manganese oxidation in environmental systems. Interestingly, a recent study (Jung et al.

View Article and Find Full Text PDF

Background: Non-vitamin K direct oral anticoagulant (DOAC) is effective for prevention of embolic events in nonvalvular atrial fibrillation (AF) patients. However, the effectiveness and safety of DOAC in AF patients who have bioprosthetic heart valve (BPHV) is largely unknown.

Methods: We retrospectively identified patients with AF and BPHV, using the diagnostic code and medical device and surgery information from the Korean National Health Insurance Service database, between 2013 and 2018.

View Article and Find Full Text PDF

Background: This study was conducted to evaluate the efficacy of simple suture reduction of the ascending aorta (SRA) performed with aortic valve replacement (AVR) in patients with borderline ascending aortic dilatation (45-50 mm).

Methods: Ninety-eight patients (ascending aortic diameter 47.7±3.

View Article and Find Full Text PDF

Background:  Numerous studies have demonstrated a negative impact of prosthesis-patient mismatch (PPM) on long-term clinical outcomes after aortic valve replacement. However, the impact of PPM after mitral valve replacement (MVR) on clinical outcomes is still controversial. This study was conducted to evaluate the impact of PPM on early and long-term survival after MVR.

View Article and Find Full Text PDF

Purpose To explore the prognostic value of cardiac magnetic resonance (MR) imaging in predicting postoperative cardiac death in patients with severe functional tricuspid regurgitation (TR). Materials and Methods This study was approved by the institutional review board, and written informed consent was obtained from all patients. Prospectively collected data included cardiac MR images, New York Heart Association (NYHA) functional class, a comprehensive laboratory test, and clinical events over the follow-up period in 75 consecutive patients (61 women and 14 men; mean age ± standard deviation, 59 years ± 9) undergoing corrective surgery for severe functional TR.

View Article and Find Full Text PDF

Background: Although atrial fibrillation (AF) and decreased exercise capacity are common in chronic mitral regurgitation patients, the relationship between rhythm status and exercise capacity after corrective surgery is largely unknown.

Methods: Seventy-one patients undergoing repair or replacement of mitral valve for chronic severe mitral regurgitation were examined with preoperative and 6 months' postoperative cardiopulmonary exercise test and two-dimensional echocardiography. Patients were divided into three groups according to preoperative versus postoperative rhythm (sinus/sinus, SS [n=42]; AF/sinus, AS [n=17]; AF/AF, AA group [n=12]).

View Article and Find Full Text PDF

Hydrophobically modified glycol chitosan (HGC) nanoparticles, a new nano-sized drug carrier, were prepared by introducing a hydrophobic molecule, cholanic acid, to water soluble glycol chitosan. The HGC nanoparticles were easily loaded with the anticancer drug docetaxel (DTX) using a dialysis method, and the resulting docetaxel-loaded HGC (DTX-HGC) nanoparticles formed spontaneously self-assembled aggregates with a mean diameter of 350 nm in aqueous condition. The DTX-HGC nanoparticles were well dispersed and stable for 2 weeks under physiological conditions (pH 7.

View Article and Find Full Text PDF