Observations of Microphysical Properties of Wintertime Low-altitude Clouds over the Southern Ocean

The Southern Ocean covers 15% of the earth’s surface and has ~87% of the clouds with frequent drizzle. These clouds influence the Earth energy budget a lot but not well presented in the global climate model and other climate related systems. Employing aircraft observations, this thesis studied the cloud microphysical properties which mean the cloud droplet numbers and their sizes which are used as input data to the climate models. The observations were made by 20 flights for 3 years (2013-2015) over the ocean of Tasmania. The result are also compared to the atmospheric satellite observations to evaluate their reliability

Increased incidence of teicoplanin-non-susceptible Staphylococcus epidermidis strains: a 6-year retrospective study

Abstract Glycopeptide antibiotics (vancomycin and teicoplanin) are usually used for the treatment of Staphylococcus epidermidis infections owing to their increased oxacillin resistance. However, S. epidermidis strains with decreased susceptibility to teicoplanin have become increasingly incident in recent years. We aimed to identify the characteristics of teicoplanin-non-susceptible (Teico-NS) S. epidermidis isolated at our hospital and analyze its relationship with teicoplanin usage. We retrospectively evaluated 328 S. epidermidis strains isolated from clinical isolates between January 2016 and December 2021. All strains were susceptible to vancomycin (minimal inhibitory concentration (MIC) ≤ 4 mg/L). The annual incidence for S. epidermidis strains with an elevated teicoplanin MIC of 8 mg/L ranged from 22.2 to 28.9%. In addition, in 2021, the number of S. epidermidis strains with teicoplanin MIC ≥ 16 mg/L rapidly increased (n = 13, 32.5%). Furthermore, teicoplanin use increased annually until 2019; however, in 2020, it decreased abruptly due to the COVID 19 pandemic. Thus, we could not confirm the existence of a clear correlation between teicoplanin usage and increased incidence of S. epidermidis with reduced teicoplanin-susceptibility. We showed the increased incidence of Teico-NS S. epidermidis in recent years. Further studies are needed to identify the mechanisms and risk factors for teicoplanin-resistance in S. epidermidis

Trantenna: Monolithic Transistor-Antenna Device for Real-Time THz Imaging System

We report a circular-shape monolithic transistor-antenna (trantenna) for high-performance plasmonic terahertz (THz) detector. By designing an asymmetric transistor on a ring-type metal-gate structure, more enhanced (45 times) channel charge asymmetry has been obtained in comparison with a bar-type asymmetric transistor of our previous work. In addition, by exploiting ring-type transistor itself as a monolithic circular patch antenna, which is designed for a 0.12-THz resonance frequency, we demonstrated the highly-enhanced responsivity (Rv) > 1 kV/W (x 5) and reduced noise-equivalent power (NEP) < 10 pW/Hz0.5 (x 1/10)

Gradient Lithium Metal Infusion in Ag-Decorated Carbon Fibers for High-Capacity Lithium Metal Battery Anodes

Lithium (Li) metal is a promising anode material for high-energy-density Li batteries due to its high specific capacity. However, the uneven deposition of Li metal causes significant volume expansion and safety concerns. Here, we investigate the impact of a gradient-infused Li-metal anode using silver (Ag)-decorated carbonized cellulose fibers (Ag@CC) as a three-dimensional (3D) current collector. The loading level of the gradient-infused Li-metal anode is controlled by the thermal infusion time of molten Li. In particular, a 5 s infusion time in the Ag@CC current collector creates an appropriate space with a lithiophilic surface, resulting in improved cycling stability and a reduced volume expansion rate. Moreover, integrating a 5 s Ag@CC anode with a high-capacity cathode demonstrates superior electrochemical performance with minimal volume expansion. This suggests that a gradient-infused Li-metal anode using Ag@CC as a 3D current collector represents a novel design strategy for Li-metal-based high-capacity Li-ion batteries

Elevated neutrophil to lymphocyte ratio and ischemic stroke risk in generally healthy adults.

Elevated neutrophil to lymphocyte ratio (NLR) has been reported as a marker for chronic inflammation, associated with poor prognosis in ischemic stroke patients, but there has been no study that investigated its association with ischemic stroke risk. This study was conducted to investigate elevated NLR as an independent risk factor for ischemic stroke incidence. Our retrospective cohort study included 24,708 generally healthy subjects aged 30-75 who received self-referred health screening at Seoul National University Hospital. Data on ischemic stroke incidence was retrieved from national medical claims registry. Median follow-up time was 5.9 years (interquartile range 4.2 years). Adjusted for major cardiovascular risk factors, compared to subjects with NLR<1.5, subjects with 2.5≤NLR<3.0, 3.0≤NLR<3.5, and NLR≥3.5 had elevated risk for ischemic stroke incidence with aHR (95% CI) of 1.76 (1.09-2.84), 2.21 (1.21-4.04), and 2.96 (1.57-5.58), respectively. NLR showed significant improvement in discrimination for ischemic stroke incidence compared to traditional cardiovascular risk factors (C-index 0.748 vs. 0.739, P = 0.025). There was significant net improvement in reclassification in Framingham risk for ischemic stroke incidence after addition of NLR, with IDI 0.0035 (P<0.0001), and NRI 6.02% (P = 0.0015). This reclassification for ischemic stroke incidence by NLR was markedly pronounced among subjects with atrial fibrillation with CHA2DS2-VASc<2 (NRI 42.41%, P = 0.056). Our study suggests elevated NLR to be an independent risk factor for ischemic stroke incidence in generally healthy adults. Future studies are needed to validate our results and further assess how subjects with elevated NLR should be managed within current guidelines

Highly-Sensitive Plasmonic Nano-Ring Transistor for Monolithic Terahertz Active Antenna

We report a highly-sensitive plasmonic nano-ring transistor for monolithic terahertz (THz) active antenna. By designing an ultimate asymmetric transistor on a metal-gate structure, more enhanced (180 times) channel charge asymmetry has been obtained in comparison with a bar-type asymmetric transistor of our previous work. In addition, by exploiting ring-type transistor itself as a monolithic circular active antenna, which is designed for a 0.12-THz resonance frequency, we experimentally demonstrated the highly-enhanced responsivity (Rv) &gt; 1 kV/W (x 5) and reduced noise-equivalent power (NEP) &lt; 10 pW/Hz0.5 (x 1/10)

In situ observations of wintertime low‐altitude clouds over the Southern Ocean

<div>Cloud droplet concentration (Nd), effective radius (reff) and liquid water content (LWC) measured by a DMT CAPS and an SEA WCM‐2000 of wintertime low‐altitude clouds over the Southern Ocean (SO) are presented for 20 flights taken over 3 years (June–October, 2013–2015). Such clouds have been reported to have the lowest Nd on record (10–40 cm−3) from the Southern Ocean Cloud Experiment (SOCEX I) field campaign in 1993. Of the total 20 357 one‐second records spent in cloud, 38.5% were found to contain ice crystals, primarily in mixed‐phase clouds (36.7%). Ice was observed at some point during 19 of the 20 missions. The droplet spectra and temperature range suggest these clouds were often ideal for the Hallett–Mossop ice multiplication process.</div><div><br></div><div>The average Nd and reff for liquid clouds were 28 (±30) cm−3 and 12.5 (±2.9) µm, which are consistent with those from SOCEX I. Forty‐nine percent of all liquid cloud samples were observed to be drizzling with an average drizzle rate of 0.733 mm h−1. As drizzle samples were commonly in the neighbourhood of mixed‐phase or non‐drizzling clouds, it was rare to observe solid patches of drizzle of greater than 10 s. On average, drizzling clouds had lower Nd and greater reff and LWC than those of non‐drizzling clouds. Distinct observations of non‐drizzling clouds with relatively high Nd (∼89 cm−3), small reff (∼8.5 µm) and low LWC (∼0.173 g kg−1) were noted for two flights. An initial examination of the local environment and synoptic meteorology for these flights failed to identify any particular forcing that may have led to these unique microphysical properties, although these were the only observations of closed mesoscale cellular convection. This research highlights that greater variability exists in the microphysics of wintertime clouds over the SO, when a wider range of synoptic meteorology is investigated.</div