Complete encapsulation of sulfur through interfacial energy control of sulfur solutions for high-performance Li-S batteries.

Complete encapsulation of high-content sulfur in porous carbon is crucial for high performance Li-S batteries. To this end, unlike conventional approaches to control the pore of carbon hosts, we demonstrate controlling the interfacial energy of the solution in the process of penetrating the sulfur-dissolved solution. We unveil, experimentally and theoretically, that the interfacial energy with the carbon surface of the sulfur solution is the key to driving complete encapsulation of sulfur. In the infiltration of sulfur solutions with N-methyl-2-pyrrolidone, we achieve complete encapsulation of sulfur, even up to 85 wt %. The sulfur fully encapsulated cathode achieves markedly high volumetric capacity and stable cycle operation in its Li-S battery applications. We achieve a volumetric capacity of 855 mAh/cm3 at 0.2C and a capacity reduction of 0.071% per cycle up to 300 cycles at 1C.

Detection of amphotericin B resistance in Candida haemulonii and closely related species by use of the Etest, Vitek-2 yeast susceptibility system, and CLSI and EUCAST broth microdilution methods.

The emerging fungal pathogens Candida haemulonii and Candida pseudohaemulonii often show high-level resistance to amphotericin B (AMB). We compared the utilities of five antifungal susceptibility testing methods, i.e., the Etest using Mueller-Hinton agar supplemented with glucose and methylene blue (Etest-MH), the Etest using RPMI agar supplemented with glucose (Etest-RPG), the Vitek-2 yeast susceptibility system, and the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution methods, for the detection of AMB-resistant isolates of C. haemulonii and closely related species. Thirty-eight clinical isolates (8 C. haemulonii, 10 C. pseudohaemulonii, and 20 Candida auris isolates) were analyzed. Of the 18 C. haemulonii and C. pseudohaemulonii isolates, 18, 15, 18, 10, and 9 exhibited AMB MICs of >1 µg/ml by the Etest-MH, Etest-RPG, Vitek-2, CLSI, and EUCAST methods, respectively. All 20 C. auris isolates showed AMB MICs of ≤1 µg/ml by all five methods. Of the methods, the Etest-MH generated the broadest distribution of AMB MICs for all 38 isolates and showed the best discrimination between the C. haemulonii and C. pseudohaemulonii isolates (4 to 32 µg/ml) and those of C. auris (0.125 to 0.5 µg/ml). Taking the Etest-MH as the reference method, the essential agreements (within two dilutions) for the Etest-RPG, Vitek-2, CLSI, and EUCAST methods were 84, 92, 55, and 55%, respectively; the categorical agreements were 92, 92, 79, and 76%, respectively. This study provides the first data on the efficacy of the Etest-MH and its excellent agreement with Vitek-2 for discriminating AMB-resistant from AMB-susceptible isolates of these Candida species.

Antifungal susceptibility to amphotericin B, fluconazole, voriconazole, and flucytosine in Candida bloodstream isolates from 15 tertiary hospitals in Korea.

The in vitro antifungal susceptibility of 636 Candida bloodstream isolates collected from 15 tertiary hospitals in Korea was determined using the Vitek-2 yeast susceptibility system (bioMérieux, France). Overall susceptibility rates were 98.1%, 95.9%, 99.1%, and 97.3% for amphotericin B, fluconazole, voriconazole, and flucytosine, respectively. The results show that the rates of resistance to 4 antifungal drugs remain low among Candida bloodstream isolates in Korea.