A fatal case report of invasive pulmonary aspergillosis and mucormycosis coinfection in an immunocompetent patient with coronavirus disease 2019 in Korea

Systemic glucocorticoid treatment is highly recommended in critically ill coronavirus disease 2019 (COVID-19) patients. However, secondary fungal infections are of concern in such patients. Here, we describe the first case of COVID-19-associated invasive pulmonary aspergillosis (CAPA) and COVID-19-associated mucormycosis (CAM) coinfection in a COVID-19 positive immunocompetent patient in Korea. A 69-year-old man was admitted to our hospital with COVID-19 pneumonia. He had no underlying comorbidities and was not taking medications. He received remdesivir, dexamethasone, and antibiotic therapy under mechanical ventilation. Although his condition improved temporarily, multiple cavities were observed on chest computed tomography, and Aspergillus fumigatus was cultured from tracheal aspiration culture. He was diagnosed with probable CAPA and received voriconazole therapy. However, his condition was not significantly improved despite having received voriconazole therapy for 4 weeks. After release from COVID-19 quarantine, he underwent bronchoscopy examination and was then finally diagnosed with CAPA and CAM coinfection on bronchoscopic biopsy. Antifungal treatment was changed to liposomal amphotericin B. However, his progress deteriorated, and he died 4 months after admission. This case highlights that clinical suspicion and active checkups are required to diagnose secondary fungal infections in immunocompetent COVID-19 patients who receive concurrent glucocorticoid therapy

Hypoxemia and Arrhythmia during Daily Activities and Six-minute Walk Test in Fibrotic Interstitial Lung Diseases

We performed 24-hr monitoring of pulse oximetric saturation (SpO2) with ECG and six-minute walk test (6MWT) in 19 patients with fibrotic interstitial lung diseases (ILD) to investigate; 1) The frequency and severity of hypoxemia and dysrhythmia during daily activities and 6MWT, 2) safety of 6MWT, and 3) the parameters of 6MWT which can replace 24-hr continuous monitoring of SpO2 to predict hypoxemia during daily activities. All patients experienced waking hour hypoxemia, and eight of nineteen patients spent > 10% of waking hours in hypoxemic state. Most patients experienced frequent arrhythmia, mostly atrial premature contractions (APCs) and ventricular premature contractions (VPCs). There were significant correlation between the variables of 6MWT and hypoxemia during daily activities. All of the patients who desaturated below 80% before 300 meters spent more than 10% of waking hour in hypoxemia (P = 0.018). In contrast to waking hour hypoxemia, SpO2 did not drop significantly during sleep except in the patients whose daytime resting SpO2 was already low. In conclusion, patients with fibrotic ILD showed significant period of hypoxemia during daily activities and frequent VPCs and APCs. Six-minute walk test is a useful surrogate marker of waking hour hypoxemia and seems to be safe without continuous monitoring of SpO2

Self-organized growth and self-assembly of nanostructures on 2D materials

Two-dimensional (2D) composite materials have gained much interest, and their synthesis and characterization have been intensively investigated to fully exploit the new functionalities and realize their potential applications. Among the various approaches to prepare heterostructures based on 2D materials, the process of self-organization between different materials is widely employed to obtain a wide range of ordered heterostructures. In this review article, we introduce notable achievements in the domain of self-organized growth of nanostructures on 2D materials. Various examples and synthetic approaches for the self-organized growth of organic molecules, inorganic nanomaterials, and 2D materials, which result in the formation of different types of heterostructures, have been discussed. We especially focus on the self-aligned growth of nanostructures on 2D materials, governed by the van der Waals interaction between the grown nanostructures and 2D substrates. The assembly of various nanostructures on the 2D moiré periodic potential is also highlighted. Finally, we remark the representative applications of the self-organized growth behaviors such as advanced nanofabrication and the mapping of crystal domains of 2D materials

Tailoring Two-Dimensional Matter Using Strong Light???Matter Interactions

The shaping of matter into desired nanometric structures with on-demand functionalities can enhance the miniaturization of devices in nanotechnology. Herein, strong light???matter interaction was used as an optical lithographic tool to tailor two-dimensional (2D) matter into nanoscale architectures. We transformed 2D black phosphorus (BP) into ultrafine, well-defined, beyond-diffraction-limit nanostructures of ten times smaller size and a hundred times smaller spacing than the incident, femtosecond-pulsed light wavelength. Consequently, nanoribbons and nanocubes/cuboids scaling tens of nanometers were formed by the structured ablation along the extremely confined periodic light fields originating from modulation instability, the tailoring process of which was visualized in real time via light-coupled in situ transmission electron microscopy. The current findings on the controllable nanoscale shaping of BP will enable exotic physical phenomena and further advance the optical lithographic techniques for 2D materials

Precise Identification of Graphene???s Crystal Structures by Removable Nanowire Epitaxy

Monitoring crystallographic orientations of graphene is important for the reliable generation of graphene-based nanostructures such as van der Waals heterostructures and graphene nanoribbons because their physical properties are dependent on crystal structures. However, facile and precise identification of graphene???s crystallographic orientations is still challenging because the majority of current tools rely on complex atomic-scale imaging. Here, we present an identification method for the crystal orientations and grain boundaries of graphene using the directional alignment between epitaxially grown AuCN nanowires and the underlying graphene. Because the nanowires are visible in scanning electron microscopy, crystal orientations of graphene can be inspected with simple procedures. Kernel density estimation that we used in analyzing the nanowire directions enables precise measurement of graphene???s crystal orientations. We also confirm that the imaged nanowires can be simply removed without degrading graphene???s quality, thus showing that the present method can be practically used for measuring graphene???s crystal structures.clos

AuCN Nanowire Epitaxy on Graphene for Hybrid Phototransistor

The van der Waals epitaxy of functional materials provides an interesting and efficient way to manipulate the electrical properties of various hybrid two dimensional (2D) systems. We study the controlled epitaxial assembly of semiconducting one-dimensional (1D) atomic chains, AuCN, on graphene and investigate the electrical properties of 1D/2D van der Waals heterostructures. AuCN nanowire assembly is tuned by different growth conditions, although the epitaxial alignment between AuCN chains and graphene remains unchanged. Semiconducting AuCN chains endow the 1D/2D hybrid system with a strong responsivity to photons with an energy above 2.7 eV, which is consistent with the bandgap of AuCN. A large UV response (responsivity ???104 A/W) was observed under illumination using 3.1 eV (400 nm) photons. Such optical and electrical responses are changed by tuning the morphology of AuCN nanowires. Our study clearly demonstrates that 1D chain-structured semiconductors can play a crucial role as a component in multifunctional van der Waals heterostructures

Dramatic Reduction of Contact Resistance via Ultrathin LiF in Two-Dimensional MoS2 Field Effect Transistors

Molybdenum disulfide (MoS2) has been regarded as one of the most important n-type two-dimensional (2D) transition metal dichalcogenide semiconductors for nanoscale electron devices. Relatively high contact resistance (RC) remains as an issue in the 2D-devices yet to be resolved. Reliable technique is very compelling to practically produce low RC values in device electronics, although scientific approaches have been made to obtain a record-low RC. To resolve this practical issue, we here use thermal-evaporated ultrathin LiF between channel and source/drain metal to fabricate 2D-like MoS2 field effect transistors (FETs) with minimum RC. Under 4-bar FET method, RC less than similar to 600 Omega.mu m is achieved from the LiF/Au contact MoS2 FET. Our normal 2-bar FET with LiF thus shows the same mobility as that of 4-bar FET that should have no RC in principle. On the basis of these results, ultrathin LiF is also applied for transparent conducting oxide contact, successfully enabling transparent MoS2 FETs.11Nsciescopu

System Development for Diffusion Bonding of Multiple Unit Tubes to Produce Long Tubular Tungsten Heavy Alloys

A diffusion bonding system to fabricate long tubular parts by joining of two- or more-unit tubes made of tungsten heavy alloys (THAs) is proposed and characterized in this study. The difficulty of powder processing of THA originates from the weak strength of the green compact and the high weight of the THA powders. The long tubular green compact is difficult to handle due to its weak structural integrity. Furthermore, gravity-induced slumping during liquid phase sintering induces dimensional distortion and degrades the mechanical performances. As a clue for solving these problems, the unit tubes are fabricated. However, the mass of green compacts for unit tubes is not sufficiently great as to cause problematic slumping; tubular unit tubes can be obtained without significant difficulty. Fabricated unit tubes are stacked in a furnace chamber and diffusion-bonded to produce a long tubular part having bond strength substantially equal to that of a monolithic tube. The proposed diffusion bonding system was well characterized and successfully applied to the industrial production line. The feasibility was also confirmed by investigating the bond quality, which can be assessed by metallographic microstructure and mechanical property

The Effectiveness of the Use of Regdanvimab (CT-P59) in Addition to Remdesivir in Patients with Severe COVID-19: A Single Center Retrospective Study

Introduction: Coronavirus disease 2019 (COVID-19) still has a high mortality rate when it is severe. Regdanvimab (CT-P59), a neutralizing monoclonal antibody that has been proven effective against mild to moderate COVID-19, may be effective against severe COVID-19. This study was conducted to determine the effectiveness of the combined use of remdesivir and regdanvimab in patients with severe COVID-19. Methods: From March to early May 2021, 124 patients with severe COVID-19 were admitted to Ulsan University Hospital (Ulsan, Korea) and received oxygen therapy and remdesivir. Among them, 25 were also administered regdanvimab before remdesivir. We retrospectively compared the clinical outcomes between the remdesivir alone group [n = 99 (79.8%)] and the regdanvimab/remdesivir group [n = 25 (20.2%)]. Results: The oxygen-free days on day 28 (primary outcome) were significantly higher in the regdanvimab/remdesivir group [mean ± SD: 19.36 ± 7.87 vs. 22.72 ± 3.66, p = 0.003]. The oxygen-free days was also independently associated with use of regdanvimab in the multivariate analysis, after adjusting for initial pulse oximetric saturation (SpO2)/fraction of inspired oxygen (FiO2) ratio (severity index). Further, in the regdanvimab/remdesivir group, the lowest SpO2/FiO2 ratio during treatment was significantly higher (mean ± SD: 237.05 ± 89.68 vs. 295.63 ± 72.74, p = 0.003), and the Kaplan-Meier estimates of oxygen supplementation days in surviving patients (on day 28) were significantly shorter [mean ± SD: 8.24 ± 7.43 vs. 5.28 ± 3.66, p = 0.024]. Conclusions: In patients with severe COVID-19, clinical outcomes can be improved by administering regdanvimab, in addition to remdesivir