Comparative studies on vertical-channel charge-trap memory thin-film transistors using In-Ga-Zn-O active channels deposited by sputtering and atomic layer depositions.

Vertical-channel charge-trap memory thin film-transistors (V-CTM TFTs) using oxide semiconductors were fabricated and characterized, in which In-Ga-Zn-O (IGZO) channels were prepared by sputtering and atomic-layer deposition (ALD) methods to elucidate the effects of deposition process. The vertical-channel gate stack of the fabricated device was verified to be well implemented on the vertical sidewall of the spacer patterns due to excellent step-coverage and self-limiting mechanisms of ALD process. The V-CTM TFTs using ALD-IGZO channel exhibited a wide memory window (MW) of 15.0 V at a VGS sweep of ±20 V and a large memory margin of 1.6 × 102 at a program pulse duration as short as 5 ms. The programmed memory margin higher than 105 did not experience any degradation with time evolution for 104 s. The mechanical durability was also evaluated after the delamination process of polyimide (PI) film. There were no marked variations in charge-trap-assisted MW even at a curvature radius of 1 mm and programmed memory margin even after repeated program operations of 104 cycles. The introduction of ALD process for the formation of IGZO active channel was suggested as a main process parameter to ensure the excellent memory device characteristics of the V-CTM TFTs.

Stereoselective Synthesis of Highly Functionalized 5- and 6-Membered Aminocyclitols Starting with a Readily Available 2-Azetidinone.

Stereoselective transformations of 4-vinyl-2-azetidinone derivative 4 into a variety of highly functionalized 6- and 5-membered carbocyclic compounds 7 and 9 were carried out using sequences involving sequential C1-N bond cleavage and Ru-catalyzed ring-closing metathesis. The derived carbocycles were further transformed into polyhydroxylated 6- and 5-membered aminocyclitols.

DBU-Promoted Dynamic Kinetic Resolution in Rh-Catalyzed Asymmetric Transfer Hydrogenation of 5-Alkyl Cyclic Sulfamidate Imines: Stereoselective Synthesis of Functionalized 1,2-Amino Alcohols.

Dynamic kinetic resolution (DKR)-driven asymmetric transfer hydrogenation of 5-alkyl cyclic sulfamidate imine produces the corresponding sulfamidate with excellent levels of diastereo- and enantioselectivity by employing a HCO2H/DBU mixture as the hydrogen source in the presence of the Noyori-type chiral Rh-catalyst at room temperature for 1 h. In this process, DKR was induced by DBU-promoted rapid racemization of the substrate. Stereoselective transformations of the resulting cyclic sulfamidates to functionalized enantiomerically enriched 1,2-amino alcohol and chiral amine substances are also described.

A low-fluence 1064-nm Q-switched neodymium-doped yttrium aluminium garnet laser for the treatment of café-au-lait macules.

BACKGROUND: Café-au-lait macules (CALMs) are a common pigmentary disorder. Although a variety of laser modalities have been used to treat CALMs, their efficacies vary and dyspigmentation may develop. OBJECTIVE: We evaluated the clinical efficacy and safety of a low-fluence 1064-nm Q-switched neodymium-doped yttrium aluminium garnet (Nd:YAG) laser for the treatment of CALMs. METHODS: In a preliminary investigation, 6 patients underwent a split-lesion comparative study with 532- and 1064-nm Q-switched Nd:YAG laser treatment. In total, 32 patients with 39 CALMs were enrolled in a subsequent prospective trial to evaluate the treatment with a low-fluence 1064-nm Q-switched Nd:YAG laser. RESULTS: In the preliminary study, the 1064-nm treatment group had a more favorable response and a shorter recovery time. In a subsequent prospective trial of a 1064-nm laser, 74.4% of the lesions showed a clinical response with clearance of ≥50.0%. The treatment regimen was well tolerated; 15.4% of patients experienced adverse events. LIMITATIONS: The study participants were followed for 6 months, and there were no relevant treatment controls in the prospective trial group. CONCLUSION: Low-fluence 1064-nm Q-switched Nd:YAG laser therapy afforded good clinical improvement for treating CALMs.

Inhibitory role of Id1 on TGF-ß-induced collagen expression in human dermal fibroblasts.

Inhibitor of DNA binding 1 (Id1) is a basic helix-loop-helix (bHLH) protein that has a variety of functional roles in cellular events including differentiation, cell cycle and cancer development. In addition, it has been demonstrated that Id1 is related with TGF-ß and Smad signaling in various biological conditions. In this study, we investigated the effect of Id1 on TGF-ß-induced collagen expression in human dermal fibroblasts. When Id1-b isoform was overexpressed, TGF-ß-induced collagen expression was markedly inhibited. Consistent with this result, Id1-b significantly inhibited TGF-ß-induced collagen gel contraction. In addition, Id1-b inhibited TGF-ß-induced phosphorylation of Smad2 and Smad3. Finally, immunohistochemistry showed that Id1 expression was decreased in fibrotic skin diseases while TGF-ß signaling was increased. Together, these results suggest that Id1 is an inhibitory regulator on TGF-ß-induced collagen expression in dermal fibroblasts.

Regional difference in sebum production by androgen susceptibility in human facial skin.

Androgens are important hormones that influence sebum production from the sebaceous glands. Human facial skin can be categorized as T- and U-zones, which are areas with high and low levels of sebum secretion, respectively. This study was performed to investigate whether there are topographical differences in androgen receptor (AR) expression related to regional variations in facial sebum secretion. The results of in vivo analysis indicated a statistically significant increase in AR expression in the sebaceous gland T-zones compared with the U-zones. In vitro experiments using human primary sebocytes also yielded similar results, with higher levels of AR protein and mRNA expression in T-zones. The results of this study suggested that differences in androgen susceptibility may be an important factor influencing regional differences in sebum production in human facial skin.

Toenail onychomycosis treated with a fractional carbon-dioxide laser and topical antifungal cream.

BACKGROUND: Traditional pharmacotherapy for onychomycosis has low to moderate efficacy and may be associated with adverse reactions and medication interactions limiting its use in many patients. OBJECTIVE: We evaluated the clinical efficacy and safety of a fractional carbon-dioxide laser with topical antifungal therapy in the treatment of onychomycosis. METHODS: In all, 24 patients were treated with fractional carbon-dioxide laser therapy and a topical antifungal cream. The laser treatment consisted of 3 sessions at 4-week intervals. Efficacy was assessed based on the response rate from standardized photographs, a microscopic examination of subungual debris, and subjective evaluations. RESULTS: Among the patients, 92% showed a clinical response and 50% showed a complete response with a negative microscopic result. The factors that influenced a successful outcome were the type of onychomycosis and the thickness of the nail plate before treatment. The treatment regimen was well tolerated and there was no recurrence 3 months after the last treatment episode. LIMITATIONS: The study followed up only 24 patients and there were no relevant treatment controls. CONCLUSIONS: Fractional carbon-dioxide laser therapy, combined with a topical antifungal agent, was effective in the treatment of onychomycosis. It should be considered an alternative therapeutic option in patients for whom systemic antifungal agents are contraindicated.

Tailoring Macro/Meso/Microporous Structures of Cellophane Noodle-Derived Activated Carbon for Electric Double-Layer Capacitors.

To address the bottleneck associated with the slow ion transport kinetics observed in the porosity of activated carbons (ACs), hierarchically structured pore sizes were introduced on ACs used for electric double-layer capacitors (EDLCs) to promote ion transport kinetics under fast-rate charge-discharge conditions. In this study, we synthesized cellophane noodle-derived activated carbon (CNAC) with tailored porous structures, including the pore volume fraction of macro/meso/micropores and the specific surface area. The porous structures were effectively modulated by adjusting the KOH concentration during chemical activation. In addition, optimized KOH activation in CNAC modulated the chemical bonding ratios of C=O, pyrrolic-N, and graphitic-N. Given the hierarchically designed porous structure and chemical bonding states, the CNAC fabricated with optimized KOH activation exhibited a superior ultrafast rate capability in EDLCs (132.0 F/g at 10 A/g).

Enhancing LOD determination in gas chromatography: Validating the Hubaux-Vos method for gas concentration measurement.

The limit of detection (LOD) is a crucial measure in analytical methods, representing the smallest amount of a substance that can be distinguished from background noise. In the realm of gas chromatography (GC), however, determining LOD can be quite subjective, leading to significant variability among researchers. In this study, we validate the Hubaux-Vos method, an International Standards Organization(ISO)-approved approach for determining LOD in gas concentration measurements, using a GC equipped with a discharge ionization detector (DID) and a dynamic dilution system. We employ a gas mixture certified reference material (CRM) of CO, CH4, and CO2 at various concentrations to generate calibration curves for each gas. Subsequently, we estimate the LODs for each gas using the Hubaux-Vos method. Surprisingly, our findings indicate a notable difference between the LODs calculated using the Hubaux-Vos method and those confirmed through experiments. This highlights the importance of critically examining the theoretical foundations of LOD determination. We strongly recommend researchers to scrutinize the principles guiding LOD determination. The method proposed in this study offers an effective way to rigorously validate theoretical approaches for estimating LODs in gas concentration measurements using GC.

High air flow-rate electrostatic sampler for the rapid monitoring of airborne coronavirus and influenza viruses.

Capturing virus aerosols in a small volume of liquid is essential when monitoring airborne viruses. As such, aerosol-to-hydrosol enrichment is required to produce a detectable viral sample for real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. To meet this requirement, the efficient and non-destructive collection of airborne virus particles is needed, while the incoming air flow rate should be sufficiently high to quickly collect a large number of virus particles. To achieve this, we introduced a high air flow-rate electrostatic sampler (HAFES) that collected virus aerosols (human coronavirus 229E, influenza A virus subtypes H1N1 and H3N2, and bacteriophage MS2) in a continuously flowing liquid. Viral collection efficiency was evaluated using aerosol particle counts, while viral recovery rates were assessed using real-time qRT-PCR and plaque assays. An air sampling period of 20 min was sufficient to produce a sample suitable for use in real-time qRT-PCR in a viral epidemic scenario.

Increased survivability of coronavirus and H1N1 influenza virus under electrostatic aerosol-to-hydrosol sampling.

Airborne virus susceptibility is an underlying cause of severe respiratory diseases, raising pandemic alerts worldwide. Following the first reports of the novel severe acute respiratory syndrome coronavirus-2 in 2019 and its rapid spread worldwide and the outbreak of a new highly variable strain of influenza A virus (H1N1) in 2009, developing quick, accurate monitoring and diagnostic approaches for emerging infections is considered critical. Efficient air sampling of coronaviruses and the H1N1 virus allows swift, real-time identification, triggering early adjuvant interventions. Electrostatic precipitation is an efficient method for sampling bio-aerosols as hydrosols; however, sampling conditions critically impact this method. Corona discharge ionizes surrounding air, generating reactive oxygen species (ROS), which may impair virus structural components, leading to RNA and/or protein damage and preventing virus detection. Herein, ascorbic acid (AA) dissolved in phosphate-buffered saline (PBS) was used as the sampling solution of an electrostatic sampler to counteract virus particle impairment, increasing virus survivability throughout sampling. The findings of this study indicate that the use of PBS+AA is effective in reducing the ROS damage of viral RNA by 95%, viral protein by 45% and virus yield by 60%.

Reusable surface amplified nanobiosensor for the sub PFU/mL level detection of airborne virus.

We developed a reusable surface-amplified nanobiosensor for monitoring airborne viruses with a sub-PFU/mL level detection limit. Here, sandwich structures consisted of magnetic particles functionalized with antibodies, target viruses, and alkaline phosphatases (ALPs) were formed, and they were magnetically concentrated on Ni patterns near an electrochemical sensor transducer. Then, the electrical signals from electrochemical markers generated by ALPs were measured with the sensor transducer, enabling highly-sensitive virus detection. The sandwich structures in the used sensor chip could be removed by applying an external magnetic field, and we could reuse the sensor transducer chip. As a proof of concepts, the repeated detection of airborne influenza virus using a single sensor chip was demonstrated with a detection limit down to a sub-PFU/mL level. Using a single reusable sensor transducer chip, the hemagglutinin (HA) of influenza A (H1N1) virus with different concentrations were measured down to 10 aM level. Importantly, our sensor chip exhibited reliable sensing signals even after more than 18 times of the repeated HA sensing measurements. Furthermore, airborne influenza viruses collected from the air could be measured down to 0.01 PFU/mL level. Interestingly, the detailed quantitative analysis of the measurement results revealed the degradation of HA proteins on the viruses after the air exposure. Considering the ultrasensitivity and reusability of our sensors, it can provide a powerful tool to help preventing epidemics by airborne pathogens in the future.

Prevention of damage caused by corona discharge-generated reactive oxygen species under electrostatic aerosol-to-hydrosol sampling.

Human exposure to airborne pathogens is a major cause of health concerns; therefore, it is imperative to monitor, sample, and detect airborne bio-particles. Among various bio-aerosol sampling methods, electrostatic precipitation (EP) is an efficient technique for capturing bio-aerosols as hydrosols due to a lower pressure drop and less damage to sensitive bio-particles. Corona discharge is the main EP mechanism; however, this inevitably generates reactive oxygen species (ROS), which can be transported and dissolved in the sampling liquid. ROS can modify cellular component structures and damage DNA. Additionally, during the sampling process, the liquid flow rate and sampling liquid type can highly affect sampling efficiency. Here, different liquid types and flow rates are examined and ascorbic acid (AA), known as vitamin C, is added to prevent bio-particle damage. However, a high AA concentration can cause oxidative damage. Therefore, the optimal AA concentration should be chosen to obtain the greatest protective effect.

An integrated system of air sampling and simultaneous enrichment for rapid biosensing of airborne coronavirus and influenza virus.

Point-of-care risk assessment (PCRA) for airborne viruses requires a system that can enrich low-concentration airborne viruses dispersed in field environments into a small volume of liquid. In this study, airborne virus particles were collected to a degree above the limit of detection (LOD) for a real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). This study employed an electrostatic air sampler to capture aerosolized test viruses (human coronavirus 229E (HCoV-229E), influenza A virus subtype H1N1 (A/H1N1), and influenza A virus subtype H3N2 (A/H3N2)) in a continuously flowing liquid (aerosol-to-hydrosol (ATH) enrichment) and a concanavalin A (ConA)-coated magnetic particles (CMPs)-installed fluidic channel for simultaneous hydrosol-to-hydrosol (HTH) enrichment. The air sampler's ATH enrichment capacity (EC) was evaluated using the aerosol counting method. In contrast, the HTH EC for the ATH-collected sample was evaluated using transmission-electron-microscopy (TEM)-based image analysis and real-time qRT-PCR assay. For example, the ATH EC for HCoV-229E was up to 67,000, resulting in a viral concentration of 0.08 PFU/mL (in a liquid sample) for a viral epidemic scenario of 1.2 PFU/m3 (in air). The real-time qRT-PCR assay result for this liquid sample was "non-detectable" however, subsequent HTH enrichment for 10 min caused the "non-detectable" sample to become "detectable" (cycle threshold (CT) value of 33.8 ± 0.06).

Aerosol-to-Hydrosol Sampling and Simultaneous Enrichment of Airborne Bacteria For Rapid Biosensing.

Rapid monitoring of biological particulate matter (Bio-PM, bioaerosols) requires an enrichment technique for concentrating the Bio-PM dispersed in the air into a small volume of liquid. In this study, an electrostatic air sampler is employed to capture aerosolized test bacteria in a carrier liquid (aerosol-to-hydrosol (ATH) enrichment). Simultaneously, the captured bacteria are carried into a fluid channel for hydrosol-to-hydrosol (HTH) enrichment with Concanavalin A coated magnetic particles (CMPs). The ATH enrichment capacity of the air sampler was evaluated with an aerosol particle counter for the following test bacteria: Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Acinetobacter baumannii. Then, the HTH enrichment capacity for the ATH-collected sample was evaluated using the colony-counting method, scanning electron microscopy based image analysis, fluorescence microscopy, electrical current measurements, and real-time quantitative polymerase chain reaction (qPCR). The ATH and HTH enrichment capacities for the given operation conditions were up to 80 000 and 14.9, respectively, resulting in a total enrichment capacity of up to 1.192 × 106. Given that air-to-liquid enrichment required to prepare detectable bacterial samples for real-time qPCR in field environments is of the order of at least 106, our method can be used to prepare a detectable sample from low-concentration airborne bacteria in the field and significantly reduce the time required for Bio-PM monitoring because of its enrichment capacity.

In situ lysis droplet supply to efficiently extract ATP from dust particles for near-real-time bioaerosol monitoring.

Simultaneous improvement in detection speed and reliability is critical for bioaerosol monitoring. Recent rapid detection strategies exhibit difficulties with misinterpretation due to signal interference from co-existing nonbiological particles, whereas biomolecular and bioluminescent approaches require long process times (>several tens of minutes) to generate readable values despite their better detection reliability. To overcome these shortcomings, we designed a system to achieve rapid reliable field detection of bioaerosols (>104 relative luminescence units [RLU] per cubic meter of air) in <3 min processing time (equivalent to 24 L sampling air volume) by employing a lysis droplet supply for efficient extraction of adenosine triphosphate (ATP) from particulate matter (PM) and a photomultiplier tube detector for signal amplification of ATP bioluminescence. We also suggested the use of the ratio of RLU (m-3) to total PM (µg m-3), or specific bioluminescence (RLU µg-1), as a measure of the biofraction of PM (i.e., potential biohazards). A correlation between RLU and colony forming unit was also obtained from simultaneous aerosol sampling using an agar-inserted sampler.

Continuous and real-time bioaerosol monitoring by combined aerosol-to-hydrosol sampling and ATP bioluminescence assay.

We present a methodology for continuous and real-time bioaerosol monitoring wherein an aerosol-to-hydrosol sampler is integrated with a bioluminescence detector. Laboratory test was conducted by supplying an air flow with entrained test bacteria (Staphylococcus epidermidis) to the inlet of the sampler. High voltage was applied between the discharge electrode and the ground electrode of the sampler to generate air ions by corona discharge. The bacterial aerosols were charged by the air ions and sampled in a flowing liquid containing both a cell lysis buffer and adenosine triphosphate (ATP) bioluminescence reagents. While the liquid was delivered to the bioluminescence detector, sampled bacteria were dissolved by the cell lysis buffer and ATP was extracted. The ATP was reacted with the ATP bioluminescence reagents, causing light to be emitted. When the concentration of bacteria in the aerosols was varied, the ATP bioluminescence signal in relative light units (RLUs) closely tracked the concentration in particles per unit air volume (# cm-3), as measured by an aerosol particle sizer. The total response time required for aerosol sampling and ATP bioluminescence detection increased from 30 s to 2 min for decreasing liquid sampling flow rate from 800 to 200 µLPM, respectively. However, lower concentration of S. epidermidis aerosols was able to be detected with lower liquid sampling flow rate (1 RLU corresponded to 6.5 # cm-3 of S. epidermidis aerosols at 200 µLPM and 25.5 # cm-3 at 800 µLPM). After obtaining all data sets of concentration of S. epidermidis aerosols and concentration of S. epidermidis particles collected in the flowing liquid, it was found that with our bioluminescence detector, 1 RLU corresponded to 1.8 × 105 (±0.2 × 105) # mL-1 of S. epidermidis in liquid. After the lab-test with S. epidermidis, our bioaerosol monitoring device was located in the lobby of a building. Air sampling was conducted continuously for 90 min (air flow rate of 8 LPM, liquid flow rate of 200 µLPM) and the ATP bioluminescence signal of indoor bioaerosols was displayed with time. Air sampling was also carried out using the 6th stage of Andersen impactor in which a nutrient agar plate was used for the impaction plate. The sample was cultured at 37 °C for five days for colony counting. As a result, it was found that the variation of the bioluminescence signal closely followed the variation of indoor bioaerosol concentration in colony forming unit (CFU) and 1 RLU corresponded to 1.66 CFU m-3 of indoor bioaerosols. Our method can be used as a trigger in biological air contamination alarm systems.

EK-2612, a new cyclohexane-1,3-dione possessing selectivity between rice (Oryza sativa) and barnyardgrass (Echinochloa crus-galli).

A newly synthesized experimental compound, EK-2612 is one of the class of cyclohexane-1,3-diones which are commonly known to be grasskillers. A greenhouse study was conducted to evaluate the herbicidal performances of EK-2612 on several grass species in comparison with tralkoxydim, a commercialized cyclohexanedione derivative. Like tralkoxydim, the compound EK-2612 showed excellent control efficacy on most grass weeds tested through foliar application rates between 250 and 63 g AI ha(-1). Unlike tralkoxydim, however, EK-2612 showed a good rice safety, and there was no rice damage observed at the level below 125 g AI ha(-1), while rice injury developed at the same application rates of tralkoxydim. With this rice safety, EK-2612 controlled barnyardgrass effectively up to the two-leaf stage under both submerged and dried paddy conditions. An in vitro ACCase assay indicated that EK-2612 is a strong ACCase inhibitor; however, the dose-response was not substantially different in rice and barnryardgrass, showing I50 values of 0.1 and 0.12 microM, respectively. These results suggest that the compound EK-2612 is targeting plant ACCase, but the whole-plant rice safety is not attributable to a different inhibition of the target site in rice from that in barnyardgrass.