High-Performance Ferroelectric Thin Film Transistors with Large Memory Window Using Epitaxial Yttrium-Doped Hafnium Zirconium Gate Oxide

Preventing ferroelectric materials from losing their ferroelectricity over a low thickness of several nanometers is crucial in developing multifunctional nanoelectronics. Epitaxially grown 5 at. % yttrium-doped Hf0.5Zr0.5O2 (YHZO) thin films exhibit an atomically smooth surface, an ability to maintain ferroelectricity even at a thickness of 10 nm, and excellent insulating properties, making them suitable for use as gate oxides in ferroelectric thin film transistors (FeTFTs). Through the epitaxial growth of a YHZO/La0.67Sr0.33MnO3 (LSMO)/SrTiO3 (STO) heterostructure, YHZO effectively retains its ferroelectricity and orthorhombic single phase, leading to enhancing electron mobility (∼19.74 cm2 V-1 s-1) and memory window (3.7 V) in the amorphous InGaZnO4 (a-IGZO)/YHZO/LSMO/STO FeTFTs. These FeTFTs demonstrate a consistent memory function with remarkable endurance (∼106 cycles) and retention (∼104 s). Furthermore, they sustain a constant memory window even under ±6 V bias stress for 104 s and exhibit excellent stability even under ±6 V/1 ms pulse cycling for 107 cycles. For comparison, a transistor with the same structure was fabricated using epitaxial nonferroelectric LaAlO3 (LAO) and epitaxial undoped Hf0.5Zr0.5O2 (HZO) as alternatives to YHZO. This study presents a novel approach to exploit the potential of YHZO in FeTFTs, contributing to the development of next-generation logic-in-memory.

Safety evaluation of vitamin K2 (menaquinone-7) via toxicological tests

This study aims to evaluate the safety of MK-7 produced by fermentation process using a Bacillus subtilis var. natto strain for human ingestion via acute oral toxicity, repeated dose 90-day oral toxicity, 28-day recovery test, and genotoxicity tests. The acute oral toxicity test results indicated that all subjects survived at the dose of 5000 mg/kg with no toxic effects. For the repeated dose 90-day oral toxicity test, MK-7 was administered to rats at 500, 1500, and 4500 mg/kg for 90 d. No abnormal findings were detected in clinical observations or in clinical pathological and histopathological examinations. The no-observed-adverse-effect level(NOAEL) was determined to be 4500 mg/kg/d, the maximum dose tested. For the evaluation of genotoxicity, reverse mutation, chromosomal aberration, and micronucleus tests were performed. In the reversion mutation test, vitamin K2 did not induce reversion in bacterial strains, and no chromosomal abnormality was observed in the chromosomal abnormality test using Chinese hamster lung cells. In the micronucleus test, micronuclei were not induced using ICR mouse bone marrow cells. All the toxicity test results suggest that vitamin K2 produced by fermentation processes using Bacillus subtilis var. natto induced no toxicological changes under the experimental conditions.

Decellularized matrix bioink with gelatin methacrylate for simultaneous improvements in printability and biofunctionality

Gelatin methacrylate (GelMA) bioink has been widely used in bioprinting because it is a printable and biocompatible biomaterial. However, it is difficult to print GelMA bioink without any temperature control because it has a thermally-sensitive rheological property. Therefore, in this study, we developed a temperature-controlled printing system in real time without affecting the viability of the cells encapsulated in the bioink. In addition, a skin-derived decellularized extracellular matrix (SdECM) was printed with GelMA to better mimic the native tissue environment compared with solely using GelMA bioink with the enhancement of structural stability. The temperature setting accuracy was calculated to be 98.58 ± 1.8 % for the module and 99.48 ± 1.33 % for the plate from 5 °C to 37 °C. The group of the temperature of the module at 10 °C and the plate at 20 °C have 93.84 % cell viability with the printable range in the printability window. In particular, the cell viability and proliferation were increased in the encapsulated fibroblasts in the GelMA/SdECM bioink, relative to the GelMA bioink, with a morphology that significantly spread for seven days. The gene expression and growth factors related to skin tissue regeneration were relatively upregulated with SdECM components. In the bioprinting process, the rheological properties of the GelMA/SdECM bioink were successfully adjusted in real time to increase printability, and the native skin tissue mimicked components providing tissue-specific biofunctions to the encapsulated cells. The developed bioprinting strategies and bioinks could support future studies related to the skin tissue reconstruction, regeneration, and other medical applications using the bioprinting process.

Strain Engineering in Perovskites: Mutual Insight on Oxides and Halides

Perovskite materials have garnered significant attention over the past decades due to their applications, not only in electronic materials, such as dielectrics, piezoelectrics, ferroelectrics, and superconductors but also in optoelectronic devices like solar cells and light emitting diodes. This interest arises from their versatile combinations and physiochemical tunability. While strain engineering is a recognized powerful tool for tailoring material properties, its collaborative impact on both oxides and halides remains understudied. Herein, strain engineering in perovskites for energy conversion devices, providing mutual insight into both oxides and halides is discussed. The various experimental methods are presented for applying strain by using thermal mismatch, lattice mismatch, defects, doping, light illumination, and flexible substrates. In addition, the main factors that are influenced by strain, categorized as structure (e.g., symmetry breaking, octahedral distortion), bandgap, chemical reactivity, and defect formation energy are described. After that, recent progress in strain engineering for perovskite oxides and halides for energy conversion devices is introduced. Promising methods for enhancing the performance of energy conversion devices using perovskites through strain engineering are suggested.

MAPbBr3 Halide Perovskite-Based Resistive Random-Access Memories Using Electron Transport Layers for Long Endurance Cycles and Retention Time

Recent studies have focused on exploring the potential of resistive random-access memory (ReRAM) utilizing halide perovskites as novel data storage devices. This interest stems from its notable attributes, including a high ON/OFF ratio, low operating voltages, and exceptional mechanical properties. Nevertheless, there have been reports indicating that memory systems utilizing halide perovskites encounter certain obstacles pertaining to their stability and dependability, mostly assessed through endurance and retention time. Moreover, the presence of these problems can potentially restrict their practical applicability. This study explores a resistive switching memory device utilizing MAPbBr3 perovskite, which demonstrates bipolar switching characteristics. The device fabrication procedure involves a low-temperature, all-solution process. For the purpose of enhancing the device's reliability, the utilization of TPBI(2,2',2″-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) as an electron transfer material on the MAPbBr3 switching layer was implemented for the first time. The formation and rupture of Ag filaments in the MAPbBr3 perovskite switching layer are attributed to reduction-oxidation reactions. The TPBI is involved in the regulation of filaments during the SET and RESET processes. Hence, it can be shown that the MAPbBr3 device incorporating TPBI exhibited about 1000 endurance cycles when subjected to continuous voltage pulses. Moreover, the device consistently maintained ON/OFF ratios above 107. In contrast, the original MAPbBr3 device without TPBI demonstrated a significantly lower endurance with only 90 cycles observed. In addition, the MAPbBr3 device integrated with TPBI exhibited a retention time exceeding 3 × 103 s. The findings of this research provide compelling evidence to support the notion that electron transfer materials have promise for the development of halide perovskite memory systems owing to their favorable attributes of dependability and stability.

3D biofabrication of diseased human skin models in vitro

Human skin is an organ located in the outermost part of the body; thus, it frequently exhibits visible signs of physiological health. Ethical concerns and genetic differences in conventional animal studies have increased the need for alternative in vitro platforms that mimic the structural and functional hallmarks of natural skin. Despite significant advances in in vitro skin modeling over the past few decades, different reproducible biofabrication strategies are required to reproduce the pathological features of diseased human skin compared to those used for healthy-skin models. To explain human skin modeling with pathological hallmarks, we first summarize the structural and functional characteristics of healthy human skin. We then provide an extensive overview of how to recreate diseased human skin models in vitro, including models for wounded, diabetic, skin-cancer, atopic, and other pathological skin types. We conclude with an outlook on diseased-skin modeling and its technical perspective for the further development of skin engineering.

Deeper mechanistic insights into epitaxial nickelate electrocatalysts for the oxygen evolution reaction

Mass production of green hydrogen via water electrolysis requires advancements in the performance of electrocatalysts, especially for the oxygen evolution reaction. In this feature article, we highlight how epitaxial nickelates act as model systems to identify atomic-level composition-structure-property-activity relationships, capture dynamic changes under operating conditions, and reveal reaction and failure mechanisms. These insights guide advanced electrocatalyst design with tailored functionality and superior performance. We conclude with an outlook for future developments via operando characterization and multilayer electrocatalyst design.

Drastic Gas Sensing Selectivity in 2-Dimensional MoS2 Nanoflakes by Noble Metal Decoration

Noble metal nanoparticle decoration is a representative strategy to enhance selectivity for fabricating chemical sensor arrays based on the 2-dimensional (2D) semiconductor material, represented by molybdenum disulfide (MoS₂). However, the mechanism of selectivity tuning by noble metal decoration on 2D materials has not been fully elucidated. Here, we successfully decorated noble metal nanoparticles on MoS₂ flakes by the solution process without using reducing agents. The MoS₂ flakes showed drastic selectivity changes after surface decoration and distinguished ammonia, hydrogen, and ethanol gases clearly, which were not observed in general 3D metal oxide nanostructures. The role of noble metal nanoparticle decoration on the selectivity change is investigated by first-principles density functional theory (DFT) calculations. While the H₂ sensitivity shows a similar tendency with the calculated binding energy, that of NH₃ is strongly related to the binding site deactivation due to preferred noble metal particle decoration at the MoS₂ edge. This finding is a specific phenomenon which originates from the distinguished structure of the 2D material, with highly active edge sites. We believe that our study will provide the fundamental comprehension for the strategy to devise the highly efficient sensor array based on 2D materials.

Correlation between oxygen evolution reaction activity and surface compositional evolution in epitaxial La0.5Sr0.5Ni1-xFexO3-δ thin films

Water electrolysis can use renewable electricity to produce green hydrogen, a portable fuel and sustainable chemical precursor. Improving electrolyzer efficiency hinges on the activity of the oxygen evolution reaction (OER) catalyst. Earth-abundant, ABO₃-type perovskite oxides offer great compositional, structural, and electronic tunability, with previous studies showing compositional substitution can increase the OER activity drastically. However, the relationship between the tailored bulk composition and that of the surface, where OER occurs, remains unclear. Here, we study the effects of electrochemical cycling on the OER activity of La_0.5Sr_0.5Ni_1-xFe_xO_3-δ (x = 0-0.5) epitaxial films grown by oxide molecular beam epitaxy as a model Sr-containing perovskite oxide. Electrochemical testing and surface-sensitive spectroscopic analyses show Ni segregation, which is affected by electrochemical history, along with surface amorphization, coupled with changes in OER activity. Our findings highlight the importance of surface composition and electrochemical cycling conditions in understanding OER performance, suggesting common motifs of the active surface with high surface area systems.

Surface-Tailored Medium Entropy Alloys as Radically Low Overpotential Oxygen Evolution Electrocatalysts

Numerous studies have explored new materials for electrocatalysts, but it is difficult to discover materials that surpass the catalytic activity of current commercially available noble metal electrocatalysts. In contrast to conventional transition metal alloys, high-entropy alloys (HEAs) have immense potential to maximize their catalytic properties because of their high stability and compositional diversity as oxygen evolution reactions (OERs). This work presents medium-entropy alloys (MEAs) as OER electrocatalysts to simultaneously satisfy the requirement of high catalytic activity and long-term stability. The surface of MEA electrocatalyst is tailored to suit the OER via anodizing and cyclic voltammetry activation methods. Optimized electrical properties and hydrophilicity of the surface enable an extremely low overpotential of 187 mV for achieving the current density of 10 mA cm^-2 alkaline media. Furthermore, a combined photovoltaic-electrochemical system with MEA electrocatalyst and a perovskite/Si tandem solar cell exhibits a solar-to-hydrogen conversion efficiency of 20.6% for an unassisted hydrogen generation system. These results present a new pathway for designing sustainable high efficiency water splitting cells.

Controlled Band Offsets in Ultrathin Hematite for Enhancing the Photoelectrochemical Water Splitting Performance of Heterostructured Photoanodes

Formation of type II heterojunctions is a promising strategy to enhance the photoelectrochemical performance of water-splitting photoanodes, which has been tremendously studied. However, there have been few studies focusing on the formation of type II heterojunctions depending on the thickness of the overlayer. Here, enhanced photoelectrochemical activities of a Fe₂O₃ film deposited-BiVO₄/WO₃ heterostructure with different thicknesses of the Fe₂O₃ layer have been investigated. The Fe₂O₃ (10 nm)/BiVO₄/WO₃ heterojunction photoanode shows a much higher photocurrent density compared to the Fe₂O₃ (100 nm)/BiVO₄/WO₃ photoanode. The Fe₂O₃ (10 nm)/BiVO₄/WO₃ trilayer heterojunction anodes have sequential type II junctions, while a thick Fe₂O₃ overlayer forms an inverse type II junction between Fe₂O₃ and BiVO₄. Furthermore, the incident-photon-to-current efficiency measured under back-illumination is higher than those measured under front-illumination, demonstrating the importance of the illumination sequence for light absorption and charge transfer and transport. This study shows that the thickness of the oxide overlayer influences the energy band alignment and can be a strategy to improve solar water splitting performance. Based on our findings, we propose a photoanode design strategy for efficient photoelectrochemical water splitting.

Suicide associated with COVID-19 infection: an immunological point of view

OBJECTIVE

Coronavirus disease 2019 (COVID-19) is a pandemic and leading cause of death. Beyond the deaths directly caused by the virus and the suicides related to the psychological response to the dramatic changes as socioeconomic related to the pandemic, there might also be suicides related to the inflammatory responses of the infection. Infection induces inflammation as a cytokine storm, and there is an increasing number of studies that report a relationship between infection and suicide.

MATERIALS AND METHODS

We searched the World Health Organization status report and the PubMed database for keywords (COVID-19, suicide, infection, inflammation, cytokines), and reviewed five cytokine pathways between suicide and inflammation using two meta-analyses and two observational studies starting from November 31, 2020, focusing on the relationship between suicide and inflammation by infection. First, we discussed existing evidence explaining the relationship between suicidal behaviors and inflammation. Second, we summarized the inflammatory features found in COVID-19 patients. Finally, we highlight the potential for these factors to affect the risk of suicide in COVID-19 patients.

RESULTS

Patients infected with COVID-19 have high amounts of IL-1β, IFN-γ, IP10, and MCP1, which may lead to Th1 cell response activation. Also, Th2 cytokines (e.g., IL-4 and IL-10) were increased in COVID-19 infection. In COVID-19 patients, neurological conditions, like headache, dizziness, ataxia, seizures, and others have been observed.

CONCLUSIONS

COVID-19 pandemic can serve as a significant environmental factor contributing directly to increased suicide risk; the role of inflammation by an infection should not be overlooked.

Enhancing photoelectrochemical water splitting with plasmonic Au nanoparticles

The water-based renewable chemical energy cycle has attracted interest due to its role in replacing existing non-renewable resources and alleviating environmental issues. Utilizing the semi-infinite solar energy source is the most appropriate way to sustain such a water-based energy cycle by producing and feeding hydrogen and oxygen. For production, an efficient photoelectrode is required to effectively perform the photoelectrochemical water splitting reaction. For this purpose, appropriately engineered nanostructures can be introduced into the photoelectrode to enhance light-matter interactions for efficient generation and transport of charges and activation of surface chemical reactions. Plasmon enhanced photoelectrochemical water splitting, whose performance can potentially exceed classical efficiency limits, is of great importance in this respect. Plasmonic gold nanoparticles are widely accepted nanomaterials for such applications because they possess high chemical stability, efficiently absorb visible light unlike many inorganic oxides, and enhance light-matter interactions with localized plasmon relaxation processes. However, our understanding of the physical phenomena behind these particles is still not complete. This review paper focuses on understanding the interfacial phenomena between gold nanoparticles and semiconductors and provides a summary and perspective of recent studies on plasmon enhanced photoelectrochemical water splitting using gold nanoparticles.

Enhanced Oxygen Evolution Electrocatalysis in Strained A-Site Cation Deficient LaNiO3 Perovskite Thin Films

As the BO₆ octahedral structure in perovskite oxide is strongly linked with electronic behavior, it is actively studied for various fields such as metal-insulator transition, superconductivity, and so on. However, the research about the relationship between water-splitting activity and BO₆ structure is largely lacking. Here, we report the oxygen evolution reaction (OER) of LaNiO₃ (LNO) by changing the NiO₆ structure using compositional change and strain. The 5 atom % La deficiency in LNO resulted in an increase of the Ni-O-Ni bond angle and an expansion of bandwidth, enhancing the charge transfer ability. In-plane compressive strain derives the higher d_z² orbital occupancy, leading to suitable metal-oxygen bond strength for OER. Because of the synergistic effect of A-site deficiency and compressive strain, the overpotential (η) of compressively strained L_0.95NO film is reduced to 130 mV at j = 30 μA/cm² compared with nonstrained LNO (η = 280 mV), indicating a significant enhancement in OER.

Lead-Free Dual-Phase Halide Perovskites for Preconditioned Conducting-Bridge Memory

Organometallic and all-inorganic halide perovskites (HPs) have recently emerged as promising candidate materials for resistive switching (RS) nonvolatile memory due to their current-voltage hysteresis caused by fast ion migration. Lead-free and all-inorganic HPs have been researched for non-toxic and environmentally friendly RS memory devices. However, only HP-based devices with electrochemically active top electrode (TE) exhibit ultra-low operating voltages and high on/off ratio RS properties. The active TE easily reacts to halide ions in HP films, and the devices have a low device durability. Herein, RS memory devices based on an air-stable lead-free all-inorganic dual-phase HP (AgBi₂ I₇ -Cs₃ Bi₂ I₉ ) are successfully fabricated with inert metal electrodes. The devices with Au TE show filamentary RS behavior by conducting-bridge involving Ag cations in HPs with ultra-low operating voltages (<0.15 V), high on/off ratio (>10⁷ ), multilevel data storage, and long retention times (>5 × 10⁴ s). The use of a closed-loop pulse switching method improves reversible RS properties up to 10³ cycles with high on/off ratio above 10⁶ . With an extremely small bending radius of 1 mm, the devices are operable with reasonable RS characteristics. This work provides a promising material strategy for lead-free all-inorganic HP-based nonvolatile memory devices for practical applications.

Electrochemical activity of Samarium on starch-derived porous carbon: rechargeable Li- and Al-ion batteries

Rechargeable metal-ion batteries are considered promising electric storage systems to meet the emerging demand from electric vehicles, electronics, and electric grids. Thus far, secondary Li-ion batteries (LIBs) have seen great advances in terms of both their energy and their power density. However, safety issues remain a challenge. Therefore, rechargeable Al-ion batteries (AIBs) with a highly reliable safety advantage and active electrochemical performances have gathered intensive attention. However, the common issue for these two metal-ion batteries is the lack of cathode materials. Many advanced electrode materials reported provide greatly enhanced electrochemical properties. However, their inherent disadvantages-such as complicated fabrication procedures, restricted manufacturing parameters, and the requirement of expensive instruments-limits their potential for further applications. In this work, we demonstrate the high electrochemical activity of the lanthanide element, Sm, towards storing charges when used in both LIBs and AIBs. Lanthanide elements are often overlooked; however, they generally have attractive electrochemical properties owing to their unpaired electrons. We employed starch as both a low-cost carbon source and as a three-dimensional support for Sm metal nanoparticles. The composite product is fabricated using a one-pot wet-chemical method, followed by a simultaneous carbonization process. As a result, highly improved electrochemical properties are obtained when it is used as a cathode material for both LIBs and AIBs when compared to bare starch-derived C. Our results may introduce a new avenue toward the design of high-performance electrode materials for LIBs and AIBs.

Two-Dimensional NbS2 Gas Sensors for Selective and Reversible NO2 Detection at Room Temperature

Transition metal dichalcogenides (TMDs) have attracted enormous attention in diverse research fields. Especially, gas sensors are considered in a promising application exploiting TMDs. However, the studies are confined to only major TMDs such as MoS₂ and WS₂. Particularly, the chemoresistive sensing properties of two-dimensional (2D) NbS₂ have never been explored. For the first time, we report room temperature NO₂ sensing characteristics of 2D NbS₂ nanosheets and the sensing mechanisms using first-principles calculations based on density functional theory. The results demonstrate that the NbS₂ edges possessing different configurations depending on synthetic conditions differ in the sensing ability of the TMD nanosheets. This study not only broadens the potential of 2D NbS₂ for gas sensing applications, but also presents the important role of edge configuration of TMDs depending on synthetic conditions for further studies.

Tailoring of Interfacial Band Offsets by an Atomically Thin Polar Insulating Layer To Enhance the Water-Splitting Performance of Oxide Heterojunction Photoanodes

An important factor in the performance of photoelectrochemical water splitting is the band edge alignment of the photoelectrodes for efficient transport and transfer of photogenerated carriers. Many studies for improving charge transfer ability between the electrode and the electrolyte have been reported, while research to improve charge transfer at the interface of the photoactive semiconductor and the conducting substrate is largely lacking. Here, we demonstrate that the water-splitting performance of an oxide heterostructured photoelectrode can be increased 6-fold by inserting an atomically thin polar LaAlO₃ interlayer compared with that of an oxide heterostructure without an insertion to modify interfacial band offsets. The electrically lowered Schottky barrier is driven by the atomically thin layer, and the charge transfer resistance between the oxides is reduced by up to 2 orders of magnitude upon insertion of LaAlO₃, a wide-gap (5.6 eV) insulator. We show that the critical thickness of the polar layer for enhancing the charge transfer is 3 unit cells. The dipole moment from the polar sheets of LaAlO₃ introduces an internal electric field, which modifies the effective band offsets in the device. This work serves as a proof of concept that photoelectrochemical performance can be improved by manipulating the band offsets of the heterostructure interface, suggesting a new design strategy for heterostructured water-splitting photoelectrodes.

Fabrication of a WS2/p-Si Heterostructure Photocathode Using Direct Hybrid Thermolysis

P-N heterostructures based on transition-metal dichelcongenides (TMDs) and a conventional semiconductor, such as p-Si, have been considered a promising structure for next-generation electronic devices and applications. However, synthesis of high-quality, wafer-scale TMDs, particularly WS₂ on p-Si, is challenging. Herein, we propose an efficient method to directly grow WS₂ crystals on p-Si via a hybrid thermolysis process. The WO₃ is deposited to prepare the p-Si surface for coating of the (NH₄)₂WS₄ precursor and converted to WS₂/p-Si during thermolysis. Moreover, the WS₂/p-Si heterojunction photocathode is fabricated and used in solar hydrogen production. The fabricated n-WS₂/p-Si heterojunction provided an onset potential of +0.022 V at 10 mA/cm² and a benchmark current density of -9.8 ± 1.2 mA/cm² at 0 V. This method reliably and efficiently produced high-quality, wafer-scale WS₂ crystals and overcame the challenges associated with previous approaches. The approach developed in this research demonstrates a magnificent progress in the fabrication of 2D material-based electronic devices.

Influence of MoS₂ Nanosheet Size on Performance of Drilling Mud

Water-based drilling mud (WBM) is a non-Newtonian fluid that has a variety of applications such as in transporting cuttings during drilling, protecting the borehole, and cooling the drill bit. With the development of nano-technology, various nanoparticles have been synthesized and have been added to WBM to improve its performance. Shear thinning is the most important factor in drilling mud and this attribute can be improved when two-dimensional particles are added. MoS₂ nanoparticles, which represent a typical two-dimensional material, are easy to synthesize in large quantities and have a high thermal conductivity and low coefficient of friction. Since the two-dimensional structure, thermal conductivity, and low coefficient of friction of MoS₂ would improve the performance of WBM, we experimented with MoS₂ nanosheets as an additive, under optimal conditions, using various samples each with uniform sizes and thicknesses of nanosheets. A large amount of MoS₂ nanosheets was synthesized, sorted by thickness and diameter, and added to drilling mud. The diameter of MoS₂ was divided into a small diameter group (about 100–400 nm) and a big diameter group (about 300–650 nm), and the thickness was divided into 1–2 nm and 5–10 nm groups. Experimental results showed that when MoS₂ is added to WBM, shear thinning occurs more strongly. In addition, the addition of MoS₂ with a thickness of 1–2 nm and a diameter of 300–650 nm resulted in the highest increase in viscosity and thermal conductivity of WBM. As a result, we experimentally confirmed that MoS₂ can be used as an additive to increase the thermal conductivity and viscosity of WBM and to make shear thinning phenomenon more.

Clinical significance of serum YKL-40 in Behçet disease

BACKGROUND

Serum YKL-40 is an inflammatory biomarker of endothelial dysfunction and may play a role in the inflammatory process of Behçet disease (BD).

OBJECTIVES

Serum YKL-40 levels were evaluated in patients with BD in order to identify associations with other inflammatory cytokines and establish laboratory parameters. Serum YKL-40 levels were also compared with BD clinical features and disease activity.

METHODS

In total, 112 patients with BD and 45 age- and sex-matched healthy volunteers were included. Disease activity was assessed with BD Current Activity Form score and Electronic Medical Record-based Activity Index (EMRAI) score.

RESULTS

Serum YKL-40 levels were significantly higher in patients with BD (median 41·88, range 12·52-171·30 ng mL(-1) ) than in healthy volunteers (median 20·92, range 5·01-64·20 ng mL(-1) ; P < 0·01). The cut-off value for YKL-40 (30·005 ng mL(-1) ) was determined from the receiver operating characteristic curve. EMRAI scores and the proportion of patients in the active phase of BD presenting with two or more major criteria were significantly higher in patients with elevated YKL-40 levels (P = 0·04 and P = 0·04, respectively). A statistically significant elevation in YKL-40 levels was observed in patients with active BD compared with patients with inactive BD (P = 0·05). Serum YKL-40 values were positively correlated with interleukin-6 and EMRAI scores (both P = 0·04), indicating that serum YKL-40 levels are increased in patients with BD and positively correlate with disease activity.

CONCLUSIONS

YKL-40 may play a role in the pathophysiology of BD and provide a useful marker for monitoring patients with BD.

Achieving Antifingerprinting and Antibacterial Effects in Smart-Phone Panel Applications Using ZnO Thin Films without a Protective Layer

When crystalline ZnO films with a thickness of 30 nm and hydrophilic properties were deposited at room temperature onto a glass substrate via radio frequency sputtering, they exhibited antifingerprinting qualities following annealing treatment that was simple and accomplished at low temperature (100 °C). Hydrophobic properties were achieved using as-deposited ZnO films with hydrophilic properties via annealing treatment without the deposition of a protective layer with hydrophobic properties. The annealed 30 nm ZnO films showed a high transmittance (∼91.3%) comparable to that of a glass substrate at a wavelength of 550 nm. The annealed films showed strong antibacterial activity against E. coli and S. aureus bacteria. The ZnO films with a thickness of 30 nm showed predominant mechanical durability with strong antibacterial activity for smart-phone panel applications.

Post calibration of the two-dimensional electron cyclotron emission imaging instrument with electron temperature characteristics of the magnetohydrodynamic instabilities

The electron cyclotron emission imaging (ECEI) instrument is widely used to study the local electron temperature (Te) fluctuations by measuring the ECE intensity IECE ∝ Te in tokamak plasmas. The ECEI measurement is often processed in a normalized fluctuation quantity against the time averaged value due to complication in absolute calibration. In this paper, the ECEI channels are relatively calibrated using the flat Te assumption of the sawtooth crash or the tearing mode island and a proper extrapolation. The 2-D relatively calibrated electron temperature (Te,rel) images are reconstructed and the displacement amplitude of the magnetohydrodynamic modes can be measured for the accurate quantitative growth analysis.

Quasi 3D ECE imaging system for study of MHD instabilities in KSTAR

A second electron cyclotron emission imaging (ECEI) system has been installed on the KSTAR tokamak, toroidally separated by 1/16th of the torus from the first ECEI system. For the first time, the dynamical evolutions of MHD instabilities from the plasma core to the edge have been visualized in quasi-3D for a wide range of the KSTAR operation (B0 = 1.7∼3.5 T). This flexible diagnostic capability has been realized by substantial improvements in large-aperture quasi-optical microwave components including the development of broad-band polarization rotators for imaging of the fundamental ordinary ECE as well as the usual 2nd harmonic extraordinary ECE.

Distal renal tubular acidosis associated with Sjogren syndrome

Renal tubular acidosis is a common cause of normal anion gap metabolic acidosis but these disorders can be easily missed or misdiagnosed. We highlight the approach to assessing renal tubular acidosis by discussing a case study with a temporal data set collected over more than 5 weeks. We highlight the principles and the necessary information required for a diagnosis of classic distal renal tubular acidosis. We also briefly review several aspects of type 1 renal tubular acidosis related to autoimmune disease, drugs and thyroid disorders.

Toroidal mode number estimation of the edge-localized modes using the KSTAR 3-D electron cyclotron emission imaging system

A new and more accurate technique is presented for determining the toroidal mode number n of edge-localized modes (ELMs) using two independent electron cyclotron emission imaging (ECEI) systems in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The technique involves the measurement of the poloidal spacing between adjacent ELM filaments, and of the pitch angle α* of filaments at the plasma outboard midplane. Equilibrium reconstruction verifies that α* is nearly constant and thus well-defined at the midplane edge. Estimates of n obtained using two ECEI systems agree well with n measured by the conventional technique employing an array of Mirnov coils.

Automated registration of optical coherence tomography and dermoscopy in the assessment of sub-clinical spread in basal cell carcinoma

Optical coherence tomography (OCT) has been shown to be of clinical value in imaging basal cell carcinoma (BCC). A novel dual OCT-video imaging system, providing automated registration of OCT and dermoscopy, has been developed to assess the potential of OCT in measuring the degree of sub-clinical spread of BCC. Seventeen patients selected for Mohs micrographic surgery (MMS) for BCC were recruited to the study. The extent of BCC infiltration beyond a segment of the clinically assessed pre-surgical border was evaluated using OCT. Sufficiently accurate (<0.5 mm) registration of OCT and dermoscopy images was achieved in 9 patients. The location of the OCT-assessed BCC border was also compared with that of the final surgical defect. Infiltration of BCC across the clinical border ranged from 0 mm to >2.5 mm. In addition, the OCT border lay between 0.5 mm and 2.0 mm inside the final MMS defect in those cases where this could be assessed. In one case, where the final MMS defect was over 17 mm from the clinical border, OCT showed >2.5 mm infiltration across the clinical border at the FOV limit. These results provide evidence that OCT allows more accurate assessment of sub-clinical spread of BCC than clinical observation alone. Such a capability may have clinical value in reducing the number of surgical stages in MMS for BCC. There may also be a role for OCT in aiding the selection of patients most suitable for MMS.

Serum IgA reactivity against GroEL of Streptococcus sanguinis and human heterogeneous nuclear ribonucleoprotein A2/B1 in patients with Behçet disease

BACKGROUND

Infectious agents, especially Streptococcus sanguinis and herpes simplex virus, have long been postulated as major triggering factors for Behçet disease (BD).

OBJECTIVES

To identify an anti-S. sanguinis antigen reacting with serum IgA antibody in patients with BD.

METHODS

We detected a target protein by proteomics analysis and evaluated serum IgA reactivity of 100 patients with BD against the identified streptococcal target protein and human heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1. Homologous epitope sequences between the streptococcal target protein and human hnRNP A2/B1 were also evaluated.

RESULTS

Four protein bands were detected by immunoprecipitation, and chaperonin GroEL was identified by a proteomics analysis. Reactivity of serum IgA against recombinant S. sanguinis GroEL was detected in 77 of 100 patients with BD (77%) and in 21 of 70 healthy controls (30%). In addition, reactivity of serum IgA against human recombinant hnRNP A2/B1 was seen in 79 of 100 patients with BD (79%) and in eight of 70 healthy controls (11%). Among the eight distinctive epitopes with significant homology between S. sanguinis GroEL and human hnRNP A2/B1, the serum IgA reactivity of patients with BD was markedly higher with epitope 3 (hnRNP A2/B1 peptide 33-46 and GroEL peptide 57-70) and epitope 6 (hnRNP A2/B1 peptide 177-188 and GroEL peptide 347-358).

CONCLUSION

We identified an S. sanguinis GroEL protein as a target of serum anti-S. sanguinis IgA antibody reactivity in patients with BD. In addition, patients with BD exhibited serum IgA reactivity against homologous epitope regions between S. sanguinis GroEL and human hnRNP A2/B1.

RAF kinase inhibitor-independent constitutive activation of Yes-associated protein 1 promotes tumor progression in thyroid cancer

The transcription coactivator Yes-associated protein 1 (YAP1) is regulated by the Hippo tumor suppressor pathway. However, the role of YAP1 in thyroid cancer, which is frequently associated with the BRAF^V600E mutation, remains unknown. This study aimed to investigate the role of YAP1 in thyroid cancer. YAP1 was overexpressed in papillary (PTC) and anaplastic thyroid cancer, and nuclear YAP1 was more frequently detected in BRAF^V600E (+) PTC. In the thyroid cancer cell lines TPC-1 and HTH7, which do not have the BRAF^V600E mutation, YAP1 was cytosolic and inactive at high cell densities. In contrast, YAP1 was retained in the nucleus and its target genes were expressed in the thyroid cancer cells 8505C and K1, which harbor the BRAF^V600E mutation, regardless of cell density. Furthermore, the nuclear activation of YAP1 in 8505C was not inhibited by RAF or MEK inhibitor. In vitro experiments, YAP1 silencing or overexpression affected migratory capacities of 8505C and TPC-1 cells. YAP1 knockdown resulted in marked decrease of tumor volume, invasion and distant metastasis in orthotopic tumor xenograft mouse models using the 8505C thyroid cancer cell line. Taken together, YAP1 is involved in the tumor progression of thyroid cancer and YAP1-mediated effects might not be affected by the currently used RAF kinase inhibitors.

Both the sera of patients with Behçet's disease and Streptococcus sanguis stimulate membrane expression of hnRNP A2/B1 in endothelial cells

OBJECTIVES

Heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 has been identified as a target antigen of anti-endothelial cell immunglobulin (Ig)A antibodies in patients with Behçet's disease (BD). The aim was to investigate the effects of the sera from BD patients and Streptococcus sanguis on the subcellular expression of hnRNP A2/B1 in human dermal microvascular endothelial cells (HDMECs).

METHOD

The sera of BD patients and healthy controls (HC) as well as cultured S. sanguis were used to stimulate HDMECs. Subcellular fractions were obtained from stimulated HDMECs and were subjected to immunoblot analyses. The distribution of hnRNP A2/B1 was investigated by immunocytochemistry and direct immunofluorescence study was performed in biopsy specimens of mucosal ulcers from BD patients.

RESULTS

BD patients' sera increased the membrane expression of hnRNP A2/B1 in HDMECs after 12 and 24 h of incubation compared with HDMECs incubated with endothelial cell culture media and HC sera. S. sanguis also increased hnRNP A2/B1 in the cellular membrane. hnRNP A2/B1 mRNA level was also significantly upregulated in HDMECs incubated with BD patients' sera and S. sanguis. Immunocytochemistry demonstrated marked expression of hnRNP A2/B1 in the cytoplasm and cellular membrane of HDMECs incubated with BD patients' sera or S. sanguis. In addition, direct immunofluorescence experiments revealed the co-localization of serum IgA antibodies and monoclonal antibodies (mAbs) against hnRNP A2/B1 in tissue sections from ulcers of BD patients.

CONCLUSIONS

Our data indicate that both the sera of BD patients with active disease and S. sanguis infection are inflammatory stimuli that can induce membranous hnRNP A2/B1 expression in HDMECs.

Appearance and dynamics of helical flux tubes under electron cyclotron resonance heating in the core of KSTAR plasmas

Dual (or sometimes multiple) flux tubes (DFTs) have been observed in the core of sawtoothing KSTAR tokamak plasmas with electron cyclotron resonance heating. The time evolution of the flux tubes visualized by a 2D electron cyclotron emission imaging diagnostic typically consists of four distinctive phases: (1) growth of one flux tube out of multiple small flux tubes during the initial buildup period following a sawtooth crash, resulting in a single dominant flux tube along the m/n=1/1 helical magnetic field lines, (2) sudden rapid growth of another flux tube via a fast heat transfer from the first one, resulting in approximately identical DFTs, (3) coalescence of the two flux tubes into a single m/n=1/1 flux tube resembling the internal kink mode in the normal sawteeth, which is explained by a model of two current-carrying wires confined on a flux surface, and (4) fast localized crash of the merged flux tube similar to the standard sawtooth crash. The dynamics of the DFTs implies that the internal kink mode is not a unique prerequisite to the sawtooth crash, providing a new insight on the control of the sawtooth.

The optimization of ELISA for methamphetamine determination: the effect of immunogen, tracer and antibody purification method on the sensitivity

To obtain more sensitive immunoassay for methamphetamine (MA) determination, the optimum condition of enzyme-linked immunosorbent assay (ELISA) was investigated in regard to immunogens, antibody purification methods and coating tracers. Activated MA, N-(4-aminobutyl)methamphetamine (4-ABMA), was conjugated with bovine serum albumin (BSA) or keyhole limpet hemocyanin (KLH) and used as immunogen. The antibodies were purified by protein G chromatography or various immunoaffinity chromatography-linked MA-protein ligands, such as MA-BSA, MA-KLH or MA-ovalbumin (OVA). Each purified antibody was characterized by means of sensitivity and cross-reactivity using the three MA-protein coating tracers, MA-BSA, MA-KLH and MA-OVA. The best sensitivity of each antibody was acquired with the MA-OVA tracer although the tracer concentration and the antibody titer level at optimum condition were varied. The antibody with high titer level did not always yield good sensitivity. At optimum condition, immunoaffinity chromatography-purified antibodies were better for sensitivity and for specificity than protein G-purified antibodies. The cross-reactivity of the purified antibodies seemed to be affected by immunogen structure and showed somewhat different patterns according to the immunoaffinity ligand utilized. These data show that the antibody purification method as well as choice of coating tracer and immunogen is essential for the sensitivity and specificity of EIA; the optimum condition for assay should be discovered using various methods and combinations.

Behçet's disease in concurrence with psoriasis

BACKGROUND

Behçet's disease (BD) and psoriasis are chronic inflammatory diseases characterized by multisystemic vasculitis and epidermal hyperplasia respectively. Although it has been found that the pathogenesis of BD and psoriasis share common perspectives, reports of patients who have both diseases in concurrence are rare.

OBJECTIVES

To analyse and evaluate the clinical manifestations of BD patients who have psoriasis together.

METHODS

Retrospective evaluation of the medical records of nine BD patients who were also diagnosed with psoriasis at the BD Specialty Clinic of Severance Hospital was carried out. We analysed the characteristics of patients and the clinical activity of both diseases, and also the effect of the treatment of one disease against the other.

RESULTS

Of the nine BD patients who also had psoriasis, male to female ratio was 1 : 2. Two (22.2%) patients had a complete type of BD and seven (77.8%) patients had an incomplete type of BD. For the psoriatic lesions, all nine (100%) patients were diagnosed as psoriasis vulgaris. Five (55.6%) patients had BD as the preceding disease and four (44.4%) patients had psoriasis as the preceding. All five patients who formerly developed BD followed by psoriasis had an active state of BD, but the activity of psoriasis of all nine patients was minimal to average.

CONCLUSION

In this study, we evaluated the clinical manifestations of nine patients who had BD and psoriasis together. Although the exact pathogenesis remains unclear, there might be some influence by each disease to the other between BD and psoriasis.

Transthoracic needle biopsy using a C-arm cone-beam CT system: diagnostic accuracy and safety

OBJECTIVE

The purpose of this study was to evaluate the diagnostic accuracy and safety of performing transthoracic needle biopsy (TNB) under combined fluoroscopy and CT guidance using a C-arm cone-beam CT (CBCT) system.

METHODS

We evaluated the diagnostic accuracy and safety of performing TNB using a C-arm CBCT system. We retrospectively evaluated 99 TNB cases performed in 98 patients using a C-arm CBCT system with an 18-gauge automated cutting needle. We reviewed the diagnostic accuracy according to the size and depth of the lesion, incidence of complications, additional treatment for complications, procedure time, number of needle passes per biopsy and radiation dose.

RESULTS

The final diagnoses revealed 72 malignant and 27 benign lesions. The overall malignancy sensitivity, malignancy specificity and diagnostic accuracy were 95.8%, 100% and 97.0%, respectively, and those for small pulmonary nodules <20 mm in size were 94.1%, 100% and 96.6%, respectively. There was no significant difference in the correct diagnosis of malignancy according to lesion size (p = 0.634) or depth (p = 0.542). For benign lesions, a specific diagnosis was obtained in 14 cases (51.9%). TNB induced complications in 19 out of 99 procedures (19.2%), including pneumothorax (16.2%), immediate haemoptysis (2.0%) and subcutaneous emphysema (1.0%). Among these, four patients with pneumothorax required chest tube insertion (2.0%) or pig-tail catheter drainage (2.0%). The mean procedure time, number of needle passes and radiation doses were 11.9 ± 4.0 min, 1.2 ± 0.5 times and 170.0 ± 67.2 mGy, respectively.

CONCLUSION

TNB using a C-arm CBCT system provides high diagnostic accuracy with a low complication rate and a short procedure time, particularly for small pulmonary nodules.

Two-dimensional visualization of growth and burst of the edge-localized filaments in KSTAR H-mode plasmas

The filamentary nature and dynamics of edge-localized modes (ELMs) in the KSTAR high-confinement mode plasmas have been visualized in 2D via electron cyclotron emission imaging. The ELM filaments rotating with a net poloidal velocity are observed to evolve in three distinctive stages: initial linear growth, interim quasisteady state, and final crash. The crash is initiated by a narrow fingerlike perturbation growing radially from a poloidally elongated filament. The filament bursts through this finger, leading to fast and collective heat convection from the edge region into the scrape-off layer, i.e., ELM crash.

Brain-derived neurotrophic factor gene polymorphisms and mirtazapine responses in Koreans with major depression

Brain-derived neurotrophic factor (BDNF) is a candidate molecule for influencing the clinical response to antidepressant treatment. The aims of this study were to determine the relationship between the Val66Met polymorphism in the BDNF gene and the response to mirtazapine in 243 Korean subjects with major depressive disorder (MDD). The reduction in the Hamilton Depression score over the 8-week treatment period was not influenced by BDNF V66M genotypes. A marginal effect of genotype on somatic anxiety score was observed at baseline (P = 0.047 in the dominant model). However, genotype-time interaction had no effect on somatic anxiety score after the 8-week a treatment period. Plasma BDNF levels tended to increase during mirtazapine treatment, although without statistical significance (P = 0.055). After 8 weeks of mirtazapine treatment, plasma BDNF levels were higher in Met allele homozygotes (1499.7 ± 370.6 ng/mL) than in Val allele carriers (649.7 ± 158.5 ng/mL, P = 0.049). Our results do not support the hypothesis that the Val66Met promoter polymorphism in the BDNF gene influences the therapeutic response to mirtazapine in Korean MDD patients. However, our data indicate that this polymorphism results in increased plasma BDNF after mirtazapine treatment.

Relatively scaled ECE temperature profiles of KSTAR plasmas

A scheme to obtain relatively scaled profiles of electron cyclotron emission (ECE) temperature directly from uncalibrated raw radiometer data is proposed and has been tested for the 2009 campaign KSTAR plasmas. The proposed method utilizes a position controlled system to move the plasma adiabatically and compares ECE radiometer channels at the same relative radial positions assuming the profile consistency during the adiabatic change. This scaling method is an alternative solution when an absolute calibration is unreliable or too time consuming. The application to the two dimensional ECE imaging data, wherein calibration is extremely difficult, may also prove to be useful.

Development of KSTAR ECE imaging system for measurement of temperature fluctuations and edge density fluctuations

The ECE imaging (ECEI) diagnostic tested on the TEXTOR tokamak revealed the sawtooth reconnection physics in unprecedented detail, including the first observation of high-field-side crash and collective heat transport [H. K. Park, N. C. Luhmann, Jr., A. J. H. Donné et al., Phys. Rev. Lett. 96, 195003 (2006)]. An improved ECEI system capable of visualizing both high- and low-field sides simultaneously with considerably better spatial coverage has been developed for the KSTAR tokamak in order to capture the full picture of core MHD dynamics. Direct 2D imaging of other MHD phenomena such as tearing modes, edge localized modes, and even Alfvén eigenmodes is expected to be feasible. Use of ECE images of the optically thin edge region to recover 2D electron density changes during L/H mode transitions is also envisioned, providing powerful information about the underlying physics. The influence of density fluctuations on optically thin ECE is discussed.

Elastic vesicles as topical/transdermal drug delivery systems

Skin acts a major target as well as a principle barrier for topical/transdermal drug delivery. Despite the many advantages of this system, the major obstacle is the low diffusion rate of drugs across the stratum corneum. Several methods have been assessed to increase the permeation rate of drugs temporarily. One simple and convenient approach is application of drugs in formulation with elastic vesicles or skin enhancers. Elastic vesicles are classified with phospholipid (Transfersomes((R)) and ethosomes) and detergent-based types. Elastic vesicles were more efficient at delivering a low and high molecular weight drug to the skin in terms of quantity and depth. Their effectiveness strongly depends on their physicochemical properties: composition, duration and application volume, and entrapment efficiency and application methods. This review focuses on the effect of elastic liposomes for enhancing the drug penetration and defines the action mechanism of penetration into deeper skin.

Effects of low-intensity ultrasound (LIUS) stimulation on human cartilage explants

OBJECTIVE

To evaluate the effects of low-intensity ultrasound (LIUS) stimulation on the anabolic state of human cartilage from patients with osteoarthritis (OA).

METHODS

Explant cultures of human OA cartilage were stimulated for 10 min every day for 7 consecutive days using continuous-wave sonication at a frequency of 1 MHz with spatial and temporal average intensities of 0 (control), 40, 200, 500, or 700 mW/cm2. The effects of LIUS on cell proliferation were evaluated by 3H-thymidine incorporation. Proteoglycan synthesis was evaluated by the incorporation of 35S-sulfate and by Safaranin O staining. Collagen synthesis was evaluated by 3H-proline incorporation and immunohistochemistry.

RESULTS

At an intensity of 200 mW/cm2, LIUS treatment induced the expression of collagen type II and proteoglycan measured by the incorporation of radioactivity and specific staining of the cartilage explants. However, the expression decreased again at the higher intensities of 500 or 700 mW/cm2. Ultrasound had no stimulatory effect on cell proliferation at any intensity.

CONCLUSION

LIUS has anabolic effects on human cartilage in explant cultures, indicating a potentially important method for the repair of osteoarthritic cartilage.

Evaluation of the Antioxidant Capacity and Preventive Effects of a Topical Emulsion and Its Vehicle Control on the Skin Response to UV Exposure

Supplying topical exogenous antioxidants to the skin may prevent or minimize free radical-induced damaging. This study determines antioxidative capacity of a topical skin care emulsion (an oil-in-water vitamin E-containing formulation) versus its vehicle on human skin that was exposed to ultraviolet radiation (UVR) by utilizing a photochemiluminescence device and biophysical methods. Ten healthy Caucasians (3 male and 7 female; mean age 47 +/- 10 years) were enrolled. In a randomized and double-blind manner, a pH-balanced vitamin E emulsion or its vehicle control was applied onto predesignated forearm prior to UVR exposure. Thirty minutes after application, these test sites were exposed to a UV light to induce the minimal erythema dose. One untreated site served as a blank control. Visual scoring and instrumental measurements were recorded at baseline and at 24 h and 48 h thereafter. At day 3, after completing instrumental measurements, each test site was stripped three times in a consecutive manner with a proprietary adhesive tape disc. These tapes were quantified for antioxidant capacity using a photochemiluminescence device. Vitamin E emulsion and vehicle control significantly (p < 0.05) suppressed visual scores when compared with blank control at day 2 and day 3 after UV exposure. However, vitamin E emulsion showed significantly (p < 0.05) lower visual scores when compared with vehicle control at day 2 and day 3 after UV exposure.Also,vitamin E emulsion and its vehicle control significantly (p < 0.05) diminished skin color measurement (a*) values when compared with blank control at day 2 and day 3 after UV exposure. At day 2 after UV exposure, only vitamin E emulsion significantly (p < 0.05) reduced skin blood flow volume when compared with blank control. Vitamin E emulsion and its vehicle control showed significant (p < 0.05) reduction of blood flow volume when compared with blank control at day 3 after UV exposure. Vitamin E emulsion and its vehicle control proved effective in preventing induction of erythema and reducing inflammatory damage caused by UV exposure. The effect of vitamin E emulsion exceeded that of an 'active control'.

Liposomes and niosomes as topical drug delivery systems

The skin acts as a major target as well as a principle barrier for topical/transdermal (TT) drug delivery. The stratum corneum plays a crucial role in barrier function for TT drug delivery. Despite major research and development efforts in TT systems and the advantages of these routes, low stratum corneum permeability limits the usefulness of topical drug delivery. To overcome this, methods have been assessed to increase permeation. One controversial method is the use of vesicular systems, such as liposomes and niosomes, whose effectiveness depends on their physicochemical properties. This review focuses on the effect of liposomes and niosomes on enhancing drug penetration, and defines the effect of composition, size and type of the vesicular system on TT delivery.

Topical vaccination of DNA antigens: topical delivery of DNA antigens

Topical DNA vaccines have been shown to elicit both broad humoral and cellular immune responses in vivo. The skin is an attractive site for the delivery of DNA antigens for DNA vaccination. However, due to skin's barrier properties, the penetration of DNA and the applications of topical vaccination are limited. To improve permeability, chemical and physical approaches have been examined to decrease stratum corneum barrier properties. Topical vaccination has been achieved using topical application of naked DNA, DNA/liposomes or emulsion complex, liposomal cream, as well as physical methods such as stripping, electroporation, and micromechanical disruption methods. All methods resulted in a significant enhancement in humoral and cellular immune responses over naked DNA alone. To develop more cost-effective and needle-free vaccines, skin-targeted immunizations are required. This review focuses on the chemical and physical methods developed to enhance DNA delivery into skin.

Applications of the pulsatile flow versatile ECLS: in vivo studies

INTRODUCTION

T-PLS (Twin-Pulse Life Support) is the first commercial pulsatile ECLS (Extra Corporeal Life Support) device (1). The dual sac structure of T-PLS can effectively reduce high membrane oxygenator inlet pressure and hemolysis. To verify both the use of T-PLS for ECLS and the advantages of T-PLS, we tested various models.

METHOD AND RESULTS

In the partial CPB (cardio pulmonary bypass) model (swine), T-PLS (N = 6), and Biopump (N = 2), a single pulsatile pump (N = 2), were compared. In the case of single pulsatile flow, during pump systole, pressure increased to 700 - 800 mmHg at the inlet port of the membrane oxygenator. fHb, a hemolysis measurement value, was about 80 mg/dL at 3 hours. On the contrary, because of T-PLS's dual sac system, the pressure of T-PLS had a maximum value of about 250 mmHg and fHb was similar to that of the commercial centrifugal pumps. In the total CPB model (bovine, N = 6), the heart was stopped via cardioplegia (Kcl). T-PLS flow was maintained at 3.0-4.5 L/min. T-PLS functioned like a natural heart, having a pulse pressure of 26-43 mmHg and a pulse rate of 40-60 bpm (beats per minute). In the emergency case model (canine, N = 6), T-PLS was started 10 minutes after cardiac arrest from electronic shock. In spite of cardiac arrest for a period of 40 minutes, the heart was recovered after defibrillation. In the ARDS (Acute Respiratory Distress Syndrome) model (canine, N = 6), minimal ventilator parameters were set: tidal volume 130 ml, respiration rate = bpm, FiO2 = 10%. Three hours after starting T-PLS, PO2 of the carotid artery blood (after 2 hours: 195 +/- 89.4; after 3 hours: 258 +/- 99.3 mmHg) was above half the value of the femoral artery but was within normal range.

CONCLUSION

It is suggested that a portable pulsatile ECLS like T-PLS may be used as a CPB device and as an alternative CPR (cardiopulmonary resuscitation) device in the case of cardiac arrest. Due to the pulsatile flow, oxygenated blood is delivered to the patient without overloading the ARDS patients heart.

Application of the moving-actuator type pump as a ventricular assist device: in vitro and in vivo studies

A moving actuator type pump has been developed as a multifunctional Korean artificial heart (AnyHeart). The pump consists of a moving actuator as an energy converter, right and left sacs, polymer (or mechanical) valves, and a rigid polyurethane housing. The actuator containing a brushless DC motor moves back and forth on an epicyclical gear train to produce a pendular motion, which compresses both sacs alternately. Of its versatile functions of ventricular assist device and total artificial heart use, we have evaluated the system performance as a single or biventricular assist device through in vitro and in vivo experiments. Pump performance and anatomical feasibility were tested using various animals of different sizes. In the case of single ventricular assist device (VAD) use, one of the sacs remained empty and a mini-compliance chamber was attached to either an outflow or inflow port of the unused sac. The in vitro and in vivo studies show acceptable performance and pump behavior. Further extensive study is required to proceed to human application.

A surprisingly mild and versatile method for palladium-catalyzed Suzuki cross-couplings of aryl chlorides in the presence of a triarylphosphine

In the presence of new air-stable triarylphosphine 2, palladium-catalyzed Suzuki reactions of a wide array of aryl chlorides can be accomplished in uniformly good yield, including couplings of very sterically demanding and electronically deactivated substrates; activated aryl chlorides can be coupled at room temperature. In terms of scope and mildness, Pd-2 compares well with other catalyst systems that have been described for Suzuki reactions of aryl chlorides, thereby establishing that triarylphosphines should be regarded as fertile ground for future ligand-design efforts for palladium-catalyzed couplings of aryl chlorides.