Characteristics of Aqueous Chemical Species Generation in Plasma-Facing Liquid Systems Using Helium Jet Plasma.

Plasma-facing liquids (PFLs) facilitate the storage of reactive O and N species (RONS), including H2O2 and NO2 -, which remain in the PFL after plasma treatment, and they can continuously influence the target immersed in the liquid. However, their behaviors and levels of generation and extinction depend strongly on the plasma characteristics and liquid condition. Therefore, understanding the effects of the liquid type on the plasma discharge characteristics and the RONS generated via plasma discharge is necessary. We compared the RONS generation and storage trends of deionized H2O and a high-conductivity PFL, RPMI 1640, which is a well-known cell culture medium commonly used to culture mammalian cells. RPMI 1640 acted as an electrode and enhanced the plasma discharge power by supplying abundant radicals and RONS. The production of gaseous hydroxyl radicals and NO markedly increased, which facilitated H2O2 and NO2 - production in the PFL for the first 200 s, and then the increase in the RONS concentration stagnated. With respect to storage, as the components within RMPI 1640 exhibited high reaction constants for their reactions with H2O2, H2O2 elimination was completed in <30 min. Unlike H2O2, the concentration of NO2 - in the PFL was unchanged.

Observation of Josephson harmonics in tunnel junctions.

Approaches to developing large-scale superconducting quantum processors must cope with the numerous microscopic degrees of freedom that are ubiquitous in solid-state devices. State-of-the-art superconducting qubits employ aluminium oxide (AlOx) tunnel Josephson junctions as the sources of nonlinearity necessary to perform quantum operations. Analyses of these junctions typically assume an idealized, purely sinusoidal current-phase relation. However, this relation is expected to hold only in the limit of vanishingly low-transparency channels in the AlOx barrier. Here we show that the standard current-phase relation fails to accurately describe the energy spectra of transmon artificial atoms across various samples and laboratories. Instead, a mesoscopic model of tunnelling through an inhomogeneous AlOx barrier predicts percent-level contributions from higher Josephson harmonics. By including these in the transmon Hamiltonian, we obtain orders of magnitude better agreement between the computed and measured energy spectra. The presence and impact of Josephson harmonics has important implications for developing AlOx-based quantum technologies including quantum computers and parametric amplifiers. As an example, we show that engineered Josephson harmonics can reduce the charge dispersion and associated errors in transmon qubits by an order of magnitude while preserving their anharmonicity.

Growth and Electrical Characterization of Hybrid Core/Shell InAs/CdSe Nanowires.

Core-only InAs nanowires (NWs) remain of continuing interest for application in modern optical and electrical devices. In this paper, we utilize the II-VI semiconductor CdSe as a shell for III-V InAs NWs to protect the electron transport channel in the InAs core from surface effects. This unique material configuration offers both a small lattice mismatch between InAs and CdSe and a pronounced electronic confinement in the core with type-I band alignment at the interface between both materials. Under optimized growth conditions, a smooth interface between the core and shell is obtained. Atom probe tomography (APT) measurements confirm substantial diffusion of In into the shell, forming a remote n-type doping of CdSe. Moreover, field-effect transistors (FETs) are fabricated, and the electron transport characteristics in these devices is investigated. Finally, band structure simulations are performed and confirm the presence of an electron transport channel in the InAs core that, at higher gate voltages, extends into the CdSe shell region. These results provide a promising basis toward the application of hybrid III-V/II-VI core/shell nanowires in modern electronics.

Plasma-Activated Media Produced by a Microwave-Excited Atmospheric Pressure Plasma Jet Is Effective against Cisplatin-Resistant Human Bladder Cancer Cells In Vitro.

Media exposed to atmospheric pressure plasma (APP) produce reactive oxygen and nitrogen species (RONS), with hydrogen peroxide (H2O2), nitrite (NO2-), and nitrate (NO3-) being among the most detected species due to their relatively long lifetime. In this study, a standardized microwave-excited (ME) APP jet (APPJ) source was employed to produce gaseous RONS to treat liquid samples. The source was a commercially available plasma jet, which generated argon plasma utilizing a coaxial transmission line resonator at the operating frequency of 2.45 GHz. An ultraviolet-visible spectrophotometer was used to measure the concentrations of H2O2 and NO3- in plasma-activated media (PAM). Three different types of media (deionized water, Hank's balanced salt solution, and cell culture solution Dulbecco's modified eagles medium [DMEM]) were utilized as liquid samples. Among these media, the plasma-treated DMEM was observed to have the highest levels of H2O2 and NO3-. Subsequently, the feasibility of using argon ME-APPJ-activated DMEM (PAM) as an adjuvant to enhance the therapeutic effects of cisplatin on human bladder cancer cells (T-24) was investigated. Various cancer cell lines, including T-24 cells, treated with PAM were observed in vitro for changes in cell viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. A viability reduction was detected in the various cancer cells after incubation in PAM. Furthermore, the study's results revealed that PAM was effective against cisplatin-resistant T-24 cells in vitro. In addition, a possible connection between HER expression and cell viability was sketched.

Phase-Selective Epitaxy of Trigonal and Orthorhombic Bismuth Thin Films on Si (111).

Over the past three decades, the growth of Bi thin films has been extensively explored due to their potential applications in various fields such as thermoelectrics, ferroelectrics, and recently for topological and neuromorphic applications, too. Despite significant research efforts in these areas, achieving reliable and controllable growth of high-quality Bi thin-film allotropes has remained a challenge. Previous studies have reported the growth of trigonal and orthorhombic phases on various substrates yielding low-quality epilayers characterized by surface morphology. In this study, we present a systematic growth investigation, enabling the high-quality growth of Bi epilayers on Bi-terminated Si (111) 1 × 1 surfaces using molecular beam epitaxy. Our work yields a phase map that demonstrates the realization of trigonal, orthorhombic, and pseudocubic thin-film allotropes of Bi. In-depth characterization through X-ray diffraction (XRD) techniques and scanning transmission electron microscopy (STEM) analysis provides a comprehensive understanding of phase segregation, phase stability, phase transformation, and phase-dependent thickness limitations in various Bi thin-film allotropes. Our study provides recipes for the realization of high-quality Bi thin films with desired phases, offering opportunities for the scalable refinement of Bi into quantum and neuromorphic devices and for revisiting technological proposals for this versatile material platform from the past 30 years.

Isothermal Heteroepitaxy of Ge1-x Sn x Structures for Electronic and Photonic Applications.

Epitaxy of semiconductor-based quantum well structures is a challenging task since it requires precise control of the deposition at the submonolayer scale. In the case of Ge1-x Sn x alloys, the growth is particularly demanding since the lattice strain and the process temperature greatly impact the composition of the epitaxial layers. In this paper, the realization of high-quality pseudomorphic Ge1-x Sn x layers with Sn content ranging from 6 at. % up to 15 at. % using isothermal processes in an industry-compatible reduced-pressure chemical vapor deposition reactor is presented. The epitaxy of Ge1-x Sn x layers has been optimized for a standard process offering a high Sn concentration at a large process window. By varying the N2 carrier gas flow, isothermal heterostructure designs suitable for quantum transport and spintronic devices are obtained.

Structural and Functional Changes in Soybean Protein via Remote Plasma Treatments.

To the best of our knowledge, few studies have utilized cold plasma to improve soybean protein extraction yield and the functional properties of soybean protein. In this study, we aimed to assess the benefits of remote plasma treatments on soybean with respect to the utilization of soybean protein. This study involved two different sample forms (whole and crushed beans), two different plasma chemistry modes (ozone and nitrogen oxides [NOx = NO + NO2]), and a novel pressure-swing reactor. Crushed soybeans were significantly affected by NOx-mode plasma treatment. Crushed soybeans treated with NOx-mode plasma had the best outcomes, wherein the protein extraction yield increased from 31.64% in the control to 37.90% after plasma treatment. The water binding capacity (205.50%) and oil absorption capacity (267.67%) of plasma-treated soybeans increased to 190.88% and 246.23 % of the control, respectively. The emulsifying activity and emulsion stability slightly increased compared to those of the control. The secondary structure and surface hydrophobicity were altered. The remote plasma treatment of crushed soybeans increased soybean protein extraction yield compared to plasma-treated whole beans as well as untreated beans and altered the structural and physicochemical properties of soybean proteins.

Differential Sensitivity of Melanoma Cells and Their Non-Cancerous Counterpart to Cold Atmospheric Plasma-Induced Reactive Oxygen and Nitrogen Species.

Despite continuous progress in therapy, melanoma is one of the most aggressive and malignant human tumors, often relapsing and metastasizing to almost all organs. Cold atmospheric plasma (CAP) is a novel anticancer tool that utilizes abundant reactive oxygen and nitrogen species (RONS) being deposited on the target cells and tissues. CAP-induced differential effects between non-cancerous and cancer cells were comparatively examined. Melanoma and non-cancerous skin fibroblast cells (counterparts; both cell types were isolated from the same patient) were used for plasma-cell interactions. The production of intracellular RONS, such as nitric oxide (NO), hydroxyl radical (•OH), and hydrogen peroxide (H2O2), increased remarkably only in melanoma cancer cells. It was observed that cancer cells morphed from spread to round cell shapes after plasma exposure, suggesting that they were more affected than non-cancerous cells in the same plasma condition. Immediately after both cell types were treated with plasma, there were no differences in the amount of extracellular H2O2 production, while Hanks' balanced salt solution-containing cancer cells had lower concentrations of H2O2 than that of non-cancerous cells at 1 h after treatment. The melanoma cells seemed to respond to CAP treatment with a greater rise in RONS and a higher consumption rate of H2O2 than homologous non-cancerous cells. These results suggest that differential sensitivities of non-cancerous skin and melanoma cells to CAP-induced RONS can enable the applicability of CAP in anticancer therapy.

Effect of Atmospheric-Pressure Plasma on Functional Compounds and Physiological Activities in Peanut Shells.

Peanut (Arachis hypogaea L.) shell, an abundant by-product of peanut production, contains a complex combination of organic compounds, including flavonoids. Changes in the total phenolic content, flavonoid content, antioxidant capacities, and skin aging-related enzyme (tyrosinase, elastase, and collagenase)-inhibitory activities of peanut shell were investigated after treatment in pressure swing reactors under controlled gas conditions using surface dielectric barrier discharge with different plasma (NOx and O3) and temperature (25 and 150 °C) treatments. Plasma treatment under ozone-rich conditions at 150 °C significantly affected the total phenolic (270.70 mg gallic acid equivalent (GAE)/g) and flavonoid (120.02 mg catechin equivalent (CE)/g) contents of peanut shell compared with the control (253.94 and 117.74 mg CE/g, respectively) (p < 0.05). In addition, with the same treatment, an increase in functional compound content clearly enhanced the antioxidant activities of components in peanut shell extracts. However, the NOx-rich treatment was significantly less effective than the O3 treatment (p < 0.05) in terms of the total phenolic content, flavonoid content, and antioxidant activities. Similarly, peanut shells treated in the reactor under O3-rich plasma conditions at 150 ℃ had higher tyrosinase, elastase, and collagenase inhibition rates (55.72%, 85.69%, and 86.43%, respectively) compared to the control (35.81%, 80.78%, and 83.53%, respectively). Our findings revealed that a reactor operated with O3-rich plasma-activated gas at 150 °C was better-suited for producing functional industrial materials from the by-products of peanuts.

Plasma activated medium prepared by a bipolar microsecond-pulsed atmospheric pressure plasma jet array induces mitochondria-mediated apoptosis in human cervical cancer cells.

Plasma activated medium (PAM) was prepared by a bipolar microsecond-pulsed atmospheric pressure plasma jet (APPJ) array source and was utilized for cancer cell treatment. APPJ array-produced plasma were characterized. APPJ array treatment of three different solutions (deionized water (DW), HBSS (serum-free Hanks' balanced salt solution), and DMEM (Dulbecco's Modified Eagle Medium) + 10% FBS (fetal bovine serum)) were performed to induce the changes in the concentration of reactive oxygen and nitrogen species (RONS) as functions of the operating parameters. Human cervical cancer cells (HeLa) injected with plasma-treated media were investigated for changes in cell viability using MTT assay. It was observed that PAM-induced ROS can regulate the protein expression associated with mitochondria, and PAM causes apoptosis through Cyto C/JNK/p38 signaling on human cervical cancer cells.

Plasma-activated medium induces ferroptosis by depleting FSP1 in human lung cancer cells.

Cold atmospheric plasma (CAP) that generates reactive oxygen species (ROS) has received considerable scientific attentions as a new type of anticancer. In particular, an indirect treatment method of inducing cancer cell death through plasma-activated medium (PAM), rather than direct plasma treatment has been well established. Although various cell death pathways such as apoptosis, necroptosis, and autophagy have been suggested to be involved in PAM-induced cell death, the involvement of ferroptosis, another type of cell death regulated by lipid ROS is largely unknown. This study reports, that PAM promotes cell death via ferroptosis in human lung cancer cells, and PAM increases intracellular and lipid ROS, thereby resulting in mitochondrial dysfunction. The treatment of cells with N-acetylcysteine, an ROS scavenging agent, or ferrostatin-1, a ferroptosis inhibitor, protects cells against PAM-induced cell death. Interestingly, ferroptosis suppressor protein 1 (FSP1) is downregulated upon PAM treatment. Furthermore, the treatment of cells with iFSP1, an inhibitor of FSP1, further enhances PAM-induced ferroptosis. Finally, this study demonstrates that PAM inhibits tumor growth in a xenograft model with an increase in 4-hydroxynoneal and PTGS2, a byproduct of lipid peroxidation, and a decrease in FSP1 expression. This study will provide new insights into the underlying mechanism and therapeutic strategies of PAM-mediated cancer treatment.

Artificial Synapses Based on Ferroelectric Schottky Barrier Field-Effect Transistors for Neuromorphic Applications.

Artificial synapses based on ferroelectric Schottky barrier field-effect transistors (FE-SBFETs) are experimentally demonstrated. The FE-SBFETs employ single-crystalline NiSi2 contacts with an atomically flat interface to Si and Hf0.5Zr0.5O2 ferroelectric layers on silicon-on-insulator substrates. The ferroelectric polarization switching dynamics gradually modulate the NiSi2/Si Schottky barriers and the potential of the channel, thus programming the device conductance with input voltage pulses. The short-term synaptic plasticity is characterized in terms of excitatory/inhibitory post-synaptic current (EPSC) and paired-pulse facilitation/depression. The EPSC amplitude shows a linear response to the amplitude of the pre-synaptic spike. Very low energy/spike consumption as small as ∼2 fJ is achieved, demonstrating high energy efficiency. Long-term potentiation/depression results show very high endurance and very small cycle-to-cycle variations (∼1%) after 105 pulse measurements. Furthermore, spike-timing-dependent plasticity is also emulated using the gate voltage pulse as the pre-synaptic spike and the drain voltage pulse as the post-synaptic spikes. These findings indicate that FE-SBFET synapses have high potential for future neuromorphic computing applications.

Transformation of Arden Syntax's medical logic modules into ArdenML for a business rules management system.

INTRODUCTION: Arden Syntax is a Health Level Seven International (HL7) standard language that is used for representing medical knowledge as logic statements. Arden Syntax Markup Language (ArdenML) is a new representation of Arden Syntax based on XML. Compilers are required to execute medical logic modules (MLMs) in the hospital environment. However, ArdenML may also replace the compiler. The purpose of this study is to demonstrate that MLMs, encoded in ArdenML, can be transformed into a commercial rule engine format through an XSLT stylesheet and made executable in a target system. METHODS: The target rule engine selected was Blaze Advisor. We developed an XSLT stylesheet to transform MLMs in ArdenML into Structured Rules Language (SRL) in Blaze Advisor, through a comparison of syntax between the two languages. The stylesheet was then refined recursively, by building and applying rules collected from the billing and coding guidelines of the Korean health insurance service. Two nurse coders collected and verified the rules and two information technology (IT) specialists encoded the MLMs and built the XSLT stylesheet. Finally, the stylesheet was validated by importing the MLMs into Blaze Advisor and applying them to claims data. RESULTS: The language comparison revealed that Blaze Advisor requires the declaration of variables with explicit types. We used both integer and real numbers for numeric types in ArdenML. "IF∼THEN" statements and assignment statements in ArdenML become rules in Blaze Advisor. We designed an XSLT stylesheet to solve this issue. In addition, we maintained the order of rule execution in the transformed rules, and added two small programs to support variable declarations and action statements. A total of 1489 rules were reviewed during this study, of which 324 rules were collected. We removed duplicate rules and encoded 241 unique MLMs in ArdenML, which were successfully transformed into SRL and imported to Blaze Advisor via the XSLT stylesheet. When applied to 73,841 outpatients' insurance claims data, the review result was the same as that of the legacy system. CONCLUSION: We have demonstrated that ArdenML can replace a compiler for transforming MLMs into commercial rule engine format. While the proposed XSLT stylesheet requires refinement for general use, we anticipate that the development of further XSLT stylesheets will support various rule engines.

Fabrication of Phaeodactylum tricornutum extract-loaded gelatin nanofibrous mats exhibiting antimicrobial activity.

Microalgae have recently been recognized as a valuable resource for various applications. Phaeodactylum tricornutum is a diatom that lives in marine water and has an unusually high content of lipids. In this study, we added P. tricornutum into a gelatin dope solution to examine the effect of this diatom using electrospinning. The addition of P. tricornutum extracts increased the conductivity of the dope solution but had little effect on the viscosity. Due to the increased conductivity, the fiber diameter was reduced compared with the neat gelatin nanofiber. The loading of P. tricornutum extracts was confirmed using fluorescence microscopy, and the incorporation of lipids was detected through gas chromatography. The P. tricornutum-loaded nanofiber mat exhibited anti-microbial activity against Escherichia coli and multidrug-resistant Staphylococcus aureus (MRSA). The cell viability test showed that the P. tricornutum-loaded nanofiber has no cytotoxicity. We expect that this antimicrobial P. tricornutum-loaded gelatin nanofiber mat can be applied as a wound dressing.

Stable integration and functional expression of flounder growth hormone gene in transformed microalga, Chlorella ellipsoidea.

Chlorella is an attractive organism for complex recombinant protein production because of its eukaryotic characteristics and low cost for large-scale culture. Protoplasts of C. ellipsoidea were transformed with a vector containing the flounder growth hormone gene (fGH) under the control of the cauliflower mosaic virus 35S promoter, and the phleomycin resistance Sh ble gene under the control of the Chlamydomonas RBCS2 gene promoter. The presence of introduced DNA was first determined by PCR amplification of both the fGH and Sh ble genes from genomic DNA isolated from transformants and fGH protein expression was detected by immunoblot analysis. Over 400 microg of fGH protein expression per one liter culture containing 1 x 10(8) cells/ml was estimated by ELISA. Stable integration of introduced DNA was confirmed by Southern blot analysis of genomic DNA digested with restriction enzymes. The introduced DNA and fGH expression were detected after seven successive transfers in media devoid of phleomycin, but stably remained in the presence of the antibiotic. Flounder fry fed on the transformed Chlorella revealed a 25% growth increase after 30 days of feeding.