Micrometer-thick and porous nanocomposite coating for electrochemical sensors with exceptional antifouling and electroconducting properties

Development of coating technologies for electrochemical sensors that consistently exhibit antifouling activities in diverse and complex biological environments over extended time is vital for effective medical devices and diagnostics. Here, we describe a micrometer-thick, porous nanocomposite coating with both antifouling and electroconducting properties that enhances the sensitivity of electrochemical sensors. Nozzle printing of oil-in-water emulsion is used to create a 1 micrometer thick coating composed of cross-linked albumin with interconnected pores and gold nanowires. The layer resists biofouling and maintains rapid electron transfer kinetics for over one month when exposed directly to complex biological fluids, including serum and nasopharyngeal secretions. Compared to a thinner (nanometer thick) antifouling coating made with drop casting or a spin coating of the same thickness, the thick porous nanocomposite sensor exhibits sensitivities that are enhanced by 3.75- to 17-fold when three different target biomolecules are tested. As a result, emulsion-coated, multiplexed electrochemical sensors can carry out simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid, antigen, and host antibody in clinical specimens with high sensitivity and specificity. This thick porous emulsion coating technology holds promise in addressing hurdles currently restricting the application of electrochemical sensors for point-of-care diagnostics, implantable devices, and other healthcare monitoring systems.

The Role of the Bile Microbiome in Common Bile Duct Stone Development

INTRODUCTION

Common bile duct (CBD) stones are a health concern for 10-20% of individuals with symptomatic gallstones, leading to health complications and placing a burden on healthcare systems. This study was initiated to investigate the changes in microbiome compositions and the metabolic signature associated with CBD stones. The research approach integrated taxonomic and functional data with metabolomics data, complemented by in vivo experiments.

METHODS

In a single tertiary healthcare institution, a total of 25 patients were enrolled who had undergone endoscopic retrograde cholangiopancreatography (ERCP) between February 2019 and January 2021. We harvested DNA from bile samples acquired from these individuals. The amplification of the bacterial 16S rRNA gene V3-V4 region was conducted through polymerase chain reaction (PCR), followed by sequencing. We utilized QIIME2 for a comprehensive data analysis. Furthermore, we performed a metabolomic analysis of the bile samples using nuclear magnetic resonance (NMR) spectroscopy. For the assessment of functional gene enrichment, we employed MetaboAnalyst 5.0. Lastly, we executed in vivo experiments on C57BL/6 mice and undertook histological examinations of tissue samples.

RESULTS

Out of the 25 study subjects, 17 underwent ERCP due to CBD stones (the CBD stone group), while the remaining 8 had the procedure for different reasons (the non-CBD stone group). An alpha diversity analysis showed a significantly greater microbial diversity in the bile samples of the non-CBD stone group (p < 0.01), and a beta diversity analysis confirmed the greater microbial compositional abundance in the gut microbiomes in this group (p = 0.01). A taxonomic analysis revealed that the abundances of Enterococcaceae and Enterococcus were higher in the bile microbiomes of the CBD stone group. A metabolic profile analysis showed that the acetate, formate, and asparagine levels were higher in the CBD stone group. A pathway enrichment analysis showed the metabolic pathways (Arginine and Proline Metabolism, Aspartate Metabolism, Glycine, and Serine Metabolism, and Ammonia Recycling pathways) that were associated with these differences. Preclinical experiments demonstrated systemic inflammation and extracellular trap formation in the CBD stone group.

CONCLUSIONS

Our study highlights the importance of biliary dysbiosis and bile metabolites, specifically acetate and formate, in CBD stone development and progression. These findings have implications for the development of diagnostic and therapeutic strategies using microbiomes for CBD stones.

Conversion of Charge Carrier Polarity in MoTe2 Field Effect Transistor via Laser Doping

A two-dimensional (2D) atomic crystalline transition metal dichalcogenides has shown immense features, aiming for future nanoelectronic devices comparable to conventional silicon (Si). 2D molybdenum ditelluride (MoTe₂) has a small bandgap, appears close to that of Si, and is more favorable than other typical 2D semiconductors. In this study, we demonstrate laser-induced p-type doping in a selective region of n-type semiconducting MoTe₂ field effect transistors (FET) with an advance in using the hexagonal boron nitride as passivation layer from protecting the structure phase change from laser doping. A single nanoflake MoTe₂-based FET, exhibiting initial n-type and converting to p-type in clear four-step doping, changing charge transport behavior in a selective surface region by laser doping. The device shows high electron mobility of about 23.4 cm²V^-1s^-1 in an intrinsic n-type channel and hole mobility of about 0.61 cm²V^-1s^-1 with a high on/off ratio. The device was measured in the range of temperature 77-300 K to observe the consistency of the MoTe₂-based FET in intrinsic and laser-dopped region. In addition, we measured the device as a complementary metal-oxide-semiconductor (CMOS) inverter by switching the charge-carrier polarity of the MoTe₂ FET. This fabrication process of selective laser doping can potentially be used for larger-scale MoTe₂ CMOS circuit applications.

Two new species of the genus Stericta Lederer (Lepidoptera, Pyralidae, Epipaschiinae) from Laos and Cambodia

Two new species, Stericta jaeshini Kim & Bae, sp. nov. and S. atroaurantiaca Kim & Bae, sp. nov. are described from Southeast Asia. About 50 species of the genus Stericta have been recorded from Southeast Asia, but it has not been recorded to occur in Laos and Cambodia previously. We record the presence of this genus in these two countries for the first time in this study. Illustrations of adults and genitalia of examined species are provided. v.

Gut Microbial Profile Changes in Patients with Gallbladder Stones after UDCA/CDCA Treatment

Background: Ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) are used to treat patients with asymptomatic or mildly symptomatic gallstone disease. This study was conducted to evaluate the efficacy of gallbladder (GB) stone dissolution by UDCA/CDCA and the impact of treatment on gut microbial profiles. Methods: Fifteen treatment-naive patients with GB stones were initially included, but two dropped out during the treatment period. UDCA/CDCA was administered for 6 months. Abdominal ultrasonography was performed to evaluate response to treatment. In addition, fecal samples were collected before and after treatment for gut microbiome profiling. Then, 16S ribosomal RNA gene sequencing was carried out on fecal samples obtained before and after treatment, and results were compared with those of forty healthy controls. Results: Eight (62%) of the thirteen evaluable patients treated with UDCA/CDCA responded to treatment (four achieved complete GB stone resolution and four partial dissolution). Taxonomic compositions of fecal samples at the phylum level showed a significantly lower relative abundance of the Proteobacteria phylum in the pre-UDCA/CDCA group than in the healthy control group (p = 0.024). At the genus level, the relative abundances of five bacteria (Faecalibacterium, Roseburia, Lachnospira, Streptococcus, and Alistipes) differed in the control and pre-UDCA/CDCA group. Interestingly, the abundance of Roseburia was restored after 6 months of UDCA/CDCA treatment. Conclusion: Gut microbial dysbiosis was observed in GB stone patients and partially reversed by UDCA/CDCA treatment, which also effectively dissolved GB stones.

Nonpatterned Soft Piezoresistive Films with Filamentous Conduction Paths for Mimicking Multiple-Resolution Receptors of Human Skin

Soft pressure sensors play key roles as input devices of electronic skin (E-skin) to imitate real human skin. For efficient data acquisition according to stimulus types such as detailed pressure images or macroscopic strength of stimuli, soft pressure sensors can have variable spatial resolution, just like the uneven spatial distribution of pressure-sensing receptors on the human body. However, previous methods on soft pressure sensors cannot achieve such tunability of spatial resolution because their sensor materials and read-out electrodes need to be elaborately patterned for a specific sensor density. Here, we report a universal soft pressure-sensitive platform based on anisotropically self-assembled ferromagnetic particles embedded in elastomer matrices whose spatial resolution can be facilely tuned. Various spatial densities of pressure-sensing receptors of human body parts can be implemented by simply sandwiching the film between soft electrodes with different pitches. Since the anisotropically aligned nickel particles form independent filamentous conductive paths, the pressure sensors show spatial sensing ability without crosstalk, whose spatial resolution up to 100 dpi can be achieved from a single platform. The sensor array shows a wide dynamic range capable of detecting various pressure levels, such as liquid drops (∼30 Pa) and plantar (∼300 kPa) pressures. Our universal soft pressure-sensing platform would be a key enabling technology for actually imitating the receptor systems of human skin in robot and biomedical applications.

Comparative analysis of human and bovine thyroglobulin structures

In biology, evolutionary conserved protein sequences show homologous physiological phenotypes in their structures and functions. If the protein has a vital function, its sequence is usually conserved across the species. However, in highly conserved protein there still remains small differences across the species. Upon protein–protein interaction (PPI), it is observed that the conserved proteins can have different binding partners that are considered to be caused by the small sequence variations in a specific domain. Thyroglobulin (TG) is the most commonly found protein in the thyroid gland of vertebrates and serves as the precursor of the thyroid hormones, tetraiodothyronine and triiodothyronine that are critical for growth, development and metabolism in vertebrates. In this study, we comparatively analyzed the sequences and structures of the highly conserved regions of TG from two different species in relation to their PPIs. In order to do so, we employed SIM for sequence alignment, STRING for PPI analysis and cryo-electron microscopy for 3D structural analysis. Our Cryo-EM model for TG of Bos taurus determined at 7.1 Å resolution fitted well with the previously published Cryo-EM model for Homo sapiens TG. By demonstrating overall structural homology between TGs from different species, we address that local amino acid sequence variation is sufficient to alter PPIs specific for the organism. We predict that our result will contribute to a deeper understanding in the evolutionary pattern applicable to many other proteins.

Potential toxicity of inorganic ions in particulate matter: Ion permeation in lung and disruption of cell metabolism

Exposure to ambient particulate matter (PM) is associated with adverse health effects. Yet, due to the complexity of its chemical composition, the molecular effects of PM exposure and the mechanism of PM-mediated toxicity remain largely unknown. Here, we show that water-soluble inorganics such as nitrate and sulfate ions, rather than PM itself, rapidly penetrate the lung surfactant barrier to the alveolar region and perturb gene expression in the lungs. Through high-throughput sequencing of lung adenocarcinoma cells, we find that exposure to nitrate and sulfate ions activates the cholesterol biosynthetic metabolism and induces the expression of genes related to tumorigenesis. Transcriptome analysis of mouse lungs exposed to nitrate/sulfate aerosols reveals interferon gamma-associated immune response. Interestingly, we find that exposure to a nitrate/sulfate mixture leads to a unique gene expression pattern that is not observed when nitrate or sulfate is treated alone. Our work suggests that the water-soluble ions are a potential source of PM-mediated toxicity and provides a roadmap to unveil the molecular mechanism of health hazards from PM exposure.

Rapid meniscus-guided printing of stable semi-solid-state liquid metal microgranular-particle for soft electronics

Liquid metal is being regarded as a promising material for soft electronics owing to its distinct combination of high electrical conductivity comparable to that of metals and exceptional deformability derived from its liquid state. However, the applicability of liquid metal is still limited due to the difficulty in simultaneously achieving its mechanical stability and initial conductivity. Furthermore, reliable and rapid patterning of stable liquid metal directly on various soft substrates at high-resolution remains a formidable challenge. In this work, meniscus-guided printing of ink containing polyelectrolyte-attached liquid metal microgranular-particle in an aqueous solvent to generate semi-solid-state liquid metal is presented. Liquid metal microgranular-particle printed in the evaporative regime is mechanically stable, initially conductive, and patternable down to 50 μm on various substrates. Demonstrations of the ultrastretchable (~500% strain) electrical circuit, customized e-skin, and zero-waste ECG sensor validate the simplicity, versatility, and reliability of this manufacturing strategy, enabling broad utility in the development of advanced soft electronics.

In this article, meniscus-guided printing of polyelectrolyte-attached liquid metal particles to simultaneously achieve mechanical stability and initial electrical conductivity at high resolution is introduced.

Enhanced Performance of WS2 Field-Effect Transistor through Mono and Bilayer h-BN Tunneling Contacts

Transition metal dichalcogenides (TMDs) are of great interest owing to their unique properties. However, TMD materials face two major challenges that limit their practical applications: contact resistance and surface contamination. Herein, a strategy to overcome these problems by inserting a monolayer of hexagonal boron nitride (h-BN) at the chromium (Cr) and tungsten disulfide (WS₂ ) interface is introduced. Electrical behaviors of direct metal-semiconductor (MS) and metal-insulator-semiconductor (MIS) contacts with mono- and bilayer h-BN in a four-layer WS₂ field-effect transistor (FET) are evaluated under vacuum from 77 to 300 K. The performance of the MIS contacts differs based on the metal work function when using Cr and indium (In). The contact resistance is significantly reduced by approximately ten times with MIS contacts compared with that for MS contacts. An electron mobility up to ≈115 cm²  V^-1  s^-1 at 300 K is achieved with the insertion of monolayer h-BN, which is approximately ten times higher than that with MS contacts. The mobility and contact resistance enhancement are attributed to Schottky barrier reduction when h-BN is introduced between Cr and WS₂ . The dependence of the tunneling mechanisms on the h-BN thickness is investigated by extracting the tunneling barrier parameters.

Large-Area Synthesis of Ultrathin, Flexible, and Transparent Conductive Metal-Organic Framework Thin Films via a Microfluidic-Based Solution Shearing Process

Iminosemiquinone-linker-based conductive metal-organic frameworks (c-MOFs) have attracted much attention as next-generation electronic materials due to their high electrical conductivity combined with high porosity. However, the utility of such c-MOFs in high-performance devices has been limited to date by the lack of high-quality MOF thin-film processing. Herein, a technique known as the microfluidic-assisted solution shearing combined with post-synthetic rapid crystallization (MASS-PRC) process is introduced to generate a high-quality, flexible, and transparent thin-film of Ni₃ (hexaiminotriphenylene)₂ (Ni₃ (HITP)₂ ) uniformly over a large-area in a high-throughput manner with thickness controllability down to tens of nanometers. The MASS-PRC process utilizes: 1) a micromixer-embedded blade to simultaneously mix and continuously supply the metal-ligand solution toward the drying front during solution shearing to generate an amorphous thin-film, followed by: 2) immersion in amine solution for rapid directional crystal growth. The as-synthesized c-MOF film has transparency of up to 88.8% and conductivity as high as 37.1 S cm^-1 . The high uniformity in conductivity is confirmed over a 3500 mm² area with an arithmetic mean roughness (R_a ) of 4.78 nm. The flexible thin-film demonstrates the highest level of transparency for Ni₃ (HITP)₂ and the highest hydrogen sulfide (H₂ S) sensing performance (2,085% at 5 ppm) among c-MOFs-based H₂ S sensors, enabling wearable gas-sensing applications.

The Chlamydomonas bZIP transcription factor BLZ8 confers oxidative stress tolerance by inducing the carbon-concentrating mechanism

Photosynthetic organisms are exposed to various environmental sources of oxidative stress. Land plants have diverse mechanisms to withstand oxidative stress, but how microalgae do so remains unclear. Here, we characterized the Chlamydomonas reinhardtii basic leucine zipper (bZIP) transcription factor BLZ8, which is highly induced by oxidative stress. Oxidative stress tolerance increased with increasing BLZ8 expression levels. BLZ8 regulated the expression of genes likely involved in the carbon-concentrating mechanism (CCM): HIGH-LIGHT ACTIVATED 3 (HLA3), CARBONIC ANHYDRASE 7 (CAH7), and CARBONIC ANHYDRASE 8 (CAH8). BLZ8 expression increased the photosynthetic affinity for inorganic carbon under alkaline stress conditions, suggesting that BLZ8 induces the CCM. BLZ8 expression also increased the photosynthetic linear electron transfer rate, reducing the excitation pressure of the photosynthetic electron transport chain and in turn suppressing reactive oxygen species (ROS) production under oxidative stress conditions. A carbonic anhydrase inhibitor, ethoxzolamide, abolished the enhanced tolerance to alkaline stress conferred by BLZ8 overexpression. BLZ8 directly regulated the expression of the three target genes and required bZIP2 as a dimerization partner in activating CAH8 and HLA3. Our results suggest that a CCM-mediated increase in the CO2 supply for photosynthesis is critical to minimize oxidative damage in microalgae, since slow gas diffusion in aqueous environments limits CO2 availability for photosynthesis, which can trigger ROS formation.

Electronic Skin Based on a Cellulose/Carbon Nanotube Fiber Network for Large-Area 3D Touch and Real-Time 3D Surface Scanning

Electronic skin (E-skin) based on tactile sensors has great significance in next-generation electronics such as biomedical application and artificial intelligence that requires interaction with humans. To mimic the properties of human skin, high flexibility, excellent sensing capability, and sufficient spatial resolution through high-level sensor integration are required. Here, we report a highly sensitive pressure sensor matrix based on a piezoresistive cellulose/single-walled carbon nanotube-entangled fiber network, which forms its own porous structure enabling a superior pressure sensor with a high sensitivity (9.097 kPa-1), a fast response speed (<2 ms), and orders of magnitude detection range with a detection limit of 1 Pa. Furthermore, the remarkable device expandability based on the ease of patterning and scalability allows easy implementation of a large-area pressure sensor matrix which has 2304 (48 × 48) pixels. Combined with a real-time pressure distribution monitoring system, a flexible 3D touch sensor that simultaneously displays plane coordinates and pressure information and a scanning device that detects the morphology of the soft body 3D surface are successfully demonstrated.

Microscopic studies on severing properties of actin-binding protein: its potential use in therapeutic treatment of actin-rich inclusions

Actin is an important unit of the cytoskeletal system, involved in many cellular processes including cell motility, signaling, and intracellular trafficking. Various studies have been undertaken to understand the regulatory mechanisms pertaining actin functions, especially the ones controlled by actin-binding proteins. However, not much has been explored about the molecular aspects of these proteins implicated in various diseases. In this study, we aimed to demonstrate the molecular properties of gelsolin, an actin-severing protein on the disassembly of the aggregation of actin-rich intracellular inclusions, Hirano body. We observed a decreasing tendency of actin aggregation by co-sedimentation assay and transmission electron microscopy in the presence of gelsolin. Therefore, we provide suggestive evidence for the use of actin-severing protein in novel therapeutic strategies for neurodegenerative conditions.

3D Printable concentrated liquid metal composite with high thermal conductivity

Heat dissipation materials in which fillers are dispersed in a polymer matrix typically do not exhibit both high thermal conductivity (k) and processability due to a trade-off. In this paper, we fabricate heat dissipation composites which overcome the trade-off using liquid metal (LM). By exceeding the conventional filler limit, ten times higher k is achieved for a 90 vol% LM composite compared with k of 50 vol% LM composite. Further, an even higher k is achieved by introducing h-BN between the LM droplets, and the highest k in this study was 17.1 W m^-1 K^-1. The LM composite is processable at room temperature and used as inks for 3D printing. This combination of high k and processability not only allows heat dissipation materials to be processed on demand under ambient conditions but it also increases the surface area of the LM composite, which enables rapid heat dissipation.

Two new species and a new record of the genus Meganola Dyar, 1898 (Lepidoptera, Nolidae, Nolinae) from Laos

The paper contains the description of two new Meganola Dyar, 1898 species (M. canaliculata Cha Bae, sp. n. and M. phuana Cha Bae, sp. n.) and a new record of M. tetrodon (de Joannis, 1928) from Laos. Color figures of adults and genitalia of the examined species are provided.

Giant Thermoelectric Seebeck Coefficients in Tellurium Quantum Wires Formed Vertically in an Aluminum Oxide Layer by Electrical Breakdown

High efficiency thermoelectric (TE) materials still require high thermopower for energy harvesting applications. A simple elemental metallic semiconductor, tellurium (Te), has been considered critical to realize highly efficient TE conversion due to having a large effective band valley degeneracy. This paper demonstrates a novel approach to directly probe the out-of-plane Seebeck coefficient for one-dimensional Te quantum wires (QWs) formed locally in the aluminum oxide layer by well-controlled electrical breakdown at 300 K. Surprisingly, the out-of-plane Seebeck coefficient for these Te QWs ≈ 0.8 mV/K at 300 K. This thermopower enhancement for Te QWs is due to Te intrinsic nested band structure and enhanced energy filtering at Te/AO interfaces. Theoretical calculations support the enhanced high Seebeck coefficient for elemental Te QWs in the oxide layer. The local-probed observation and detecting methodology used here offers a novel route to designing enhanced thermoelectric materials and devices in the future.

Improved Contact Resistance by a Single Atomic Layer Tunneling Effect in WS2 /MoTe2 Heterostructures

Manipulation of Ohmic contacts in 2D transition metal dichalcogenides for enhancing the transport properties and enabling its application as a practical device has been a long-sought goal. In this study, n-type tungsten disulfide (WS2 ) single atomic layer to improve the Ohmic contacts of the p-type molybdenum ditelluride (MoTe2 ) material is covered. The Ohmic properties, based on the lowering of Schottky barrier height (SBH) owing to the tunneling barrier effect of the WS2 monolayer, are found to be unexpectedly excellent at room temperature and even at 100 K. The improved SBH and contact resistances are 3 meV and 1 MΩ µm, respectively. The reduction in SBH and contact resistance is confirmed with temperature-dependent transport measurements. This study further demonstrates the selective carrier transport across the MoTe2 and WS2 layers by modulating the applied gate voltage. This WS2 /MoTe2 heterostructure exhibits excellent gate control over the currents of both channels (n-type and p-type). The on/off ratios for both the electron and hole channels are calculated as 107 and 106 , respectively, indicating good carrier type modulation by the electric field of the gate electrode. The Ohmic contact resistance using the tunneling of the atomic layer can be applied to heterojunction combinations of various materials.

Synthesis of Retinol-Loaded Lipid Nanocarrier via Vacuum Emulsification to Improve Topical Skin Delivery

Retinol has been widely used as an anti-wrinkle active ingredient in cosmetic fields. However, the oxidation of retinol by air was one of the critical problems for application in the skincare field. In this study, Retinol-loaded lipid nanocarriers were prepared via the vacuum emulsification method to increase the stability of retinol vulnerable to air and optimized encapsulation conditions and to increase the penetration efficiency into skin. Optimizing the components of lipid nanocarriers, gradients of carbon chain C8-22 using various lipid species which made the amorphous structure and enough spaces to load retinol inside the capsules were estimated from the lower enthalpy change and peak shift in DSC analysis. The vacuum-assisted lipid nanocarriers (VLN) could help suppress oxidation, which could have advantages to increase the thermal stability of retinol. The retinol-loaded VLN (VLN-ROL) had narrow size distribution under 0.3 PDI value, under 200 nm scaled particle size, and fully negative surface charge of about -50 mV for the electrostatic repulsion to avoid aggregation phenomenon among the lipid nanoparticles. It maintained 90% or more retinol concentration after 4 weeks of storage at 25, 40 and 50 °C and kept stable. The VLN-ROL-containing cream showed improved penetration efficiency applied to porcine skins compared to the commercial retinol 10S from BASF. The total amount of retinol into the skin of VLN-ROL (0.1% of retinol) was enhanced by about 2.2-fold (2.86 ± 0.23 μg) higher than that in 0.1% of bare retinol (about 1.29 ± 0.09 μg). In addition, applied on a 3D Human skin model, the epidermal thickness and the relative percentage of dermal collagen area effectively increased compared to the control and retinol, respectively. Additionally, the level of secreted IL-1α was lower and epidermal damage was weaker than commercial product A. This retinol-loaded lipid nanocarrier could be a potentially superior material for cosmetics and biomedical research.

Direct Measurement of Contact Angle Change in Capillary Rise

Capillary rise is important in many aspects of physical phenomena from transport in porous media to biotechnology. It is typically described by the Lucas-Washburn-Rideal equation (LWRE), but discrepancy between some experiments and the model still remains elusive. In this paper, we show that the discrepancy is simply from the contact angle change during the capillary rise with no help of any specific models, such as dynamic contact angle (DCA) models. To demonstrate this, we directly measure the contact angle change in the capillary rise for glycerol and carboxymethyl cellulose solutions as examples of Newtonian and non-Newtonian liquids. Unlike previous studies that used DCA models to explain the discrepancy, when the contact angle change is directly applied to the LWRE for all four tested fluids, the model agrees well with experimental data. The estimated contact angle from the capillary rise as a function of time is in good agreement with the directly measured contact angle within a narrow margin of error. To pinpoint the conditions for the discrepancy, we propose a new time scale when contact angle dynamics dominates. The contact angle dynamics that can be obtained from the macroscopic capillary rise may provide useful information for capillary flow in a more complicated geometry such as porous media.

Ultraflexible and transparent electroluminescent skin for real-time and super-resolution imaging of pressure distribution

The ability to image pressure distribution over complex three-dimensional surfaces would significantly augment the potential applications of electronic skin. However, existing methods show poor spatial and temporal fidelity due to their limited pixel density, low sensitivity, or low conformability. Here, we report an ultraflexible and transparent electroluminescent skin that autonomously displays super-resolution images of pressure distribution in real time. The device comprises a transparent pressure-sensing film with a solution-processable cellulose/nanowire nanohybrid network featuring ultrahigh sensor sensitivity (>5000 kPa-1) and a fast response time (<1 ms), and a quantum dot-based electroluminescent film. The two ultrathin films conform to each contact object and transduce spatial pressure into conductivity distribution in a continuous domain, resulting in super-resolution (>1000 dpi) pressure imaging without the need for pixel structures. Our approach provides a new framework for visualizing accurate stimulus distribution with potential applications in skin prosthesis, robotics, and advanced human-machine interfaces.

Clean Interface Contact Using a ZnO Interlayer for Low-Contact-Resistance MoS2 Transistors

Two-dimensional transition metal dichalcogenides (TMDCs) have emerged as promising materials for next-generation electronics due to their excellent semiconducting properties. However, high contact resistance at the metal-TMDC interface plagues the realization of high-performance devices. Here, an effective metal-interlayer-semiconductor (MIS) contact is demonstrated, wherein an ultrathin ZnO interlayer is inserted between the metal electrode and MoS₂, providing damage-free and clean interfaces at electrical contacts. Using TEM imaging, we show that the contact interfaces were atomically clean without any apparent damages. Compared to conventional Ti/MoS₂ contacts, the MoS₂ devices with a Ti/ZnO/MoS₂ contact exhibit a very low contact resistance of 0.9 kΩ μm. These improvements are attributed to the following mechanisms: (a) Fermi-level depinning at the metal/MoS₂ interface by reducing interface disorder and (b) presence of interface dipole at the metal/ZnO interface, consequently reducing the Schottky barrier and contact resistance. Further, the contact resistivity of a Ti/ZnO/MoS₂ contact is insensitive to the variation of ZnO thickness, which facilitates large-scale production. Our work not only elucidates the underlying mechanisms for the operation of the MIS contact but also provides a simple and damage-free strategy for conventional aggressive metal deposition that is potentially useful for the realization of large-scale 2D electronics with low-resistance contacts.

Structural and kinetic insights into flavin-containing monooxygenase and calponin-homology domains in human MICAL3

MICAL is an oxidoreductase that participates in cytoskeleton reorganization via actin disassembly in the presence of NADPH. Although three MICALs (MICAL1, MICAL2 and MICAL3) have been identified in mammals, only the structure of mouse MICAL1 has been reported. Here, the first crystal structure of human MICAL3, which contains the flavin-containing monooxygenase (FMO) and calponin-homology (CH) domains, is reported. MICAL3 has an FAD/NADP-binding Rossmann-fold domain for mono-oxygenase activity like MICAL1. The FMO and CH domains of both MICAL3 and MICAL1 are highly similar in structure, but superimposition of the two structures shows a different relative position of the CH domain in the asymmetric unit. Based on kinetic analyses, the catalytic efficiency of MICAL3 dramatically increased on adding F-actin only when the CH domain was available. However, this did not occur when two residues, Glu213 and Arg530, were mutated in the FMO and CH domains, respectively. Overall, MICAL3 is structurally highly similar to MICAL1, which suggests that they may adopt the same catalytic mechanism, but the difference in the relative position of the CH domain produces a difference in F-actin substrate specificity.

Structural insights into stressosome assembly

The stressosome transduces environmental stress signals to SigB to upregulate SigB-dependent transcription, which is required for bacterial viability. The stressosome core is composed of RsbS and at least one of the RsbR paralogs. A previous cryo-electron microscopy (cryo-EM) structure of the RsbRA-RsbS complex determined under a D2 symmetry restraint showed that the stressosome core forms a pseudo-icosahedron consisting of 60 STAS domains of RsbRA and RsbS. However, it is still unclear how RsbS and one of the RsbR paralogs assemble into the stressosome. Here, an assembly model of the stressosome is presented based on the crystal structure of the RsbS icosahedron and cryo-EM structures of the RsbRA-RsbS complex determined under diverse symmetry restraints (nonsymmetric C1, dihedral D2 and icosahedral I envelopes). 60 monomers of the crystal structure of RsbS fitted well into the I-restrained cryo-EM structure determined at 4.1 Å resolution, even though the STAS domains in the I envelope were averaged. This indicates that RsbS and RsbRA share a highly conserved STAS fold. 22 protrusions observed in the C1 envelope, corresponding to dimers of the RsbRA N-domain, allowed the STAS domains of RsbRA and RsbS to be distinguished in the stressosome core. Based on these, the model of the stressosome core was reconstructed. The mutation of RsbRA residues at the binding interface in the model (R189A/Q191A) significantly reduced the interaction between RsbRA and RsbS. These results suggest that nonconserved residues in the conserved STAS folds between RsbS and RsbR paralogs determine stressosome assembly.

The bZIP1 Transcription Factor Regulates Lipid Remodeling and Contributes to ER Stress Management in Chlamydomonas reinhardtii

Endoplasmic reticulum (ER) stress is caused by the stress-induced accumulation of unfolded proteins in the ER. Here, we identified proteins and lipids that function downstream of the ER stress sensor INOSITOL-REQUIRING ENZYME1 (CrIRE1) that contributes to ER stress tolerance in Chlamydomonas (Chlamydomonas reinhardtii). Treatment with the ER stress inducer tunicamycin resulted in the splicing of a 32-nucleotide fragment of a basic leucine zipper 1 (bZIP1) transcription factor (CrbZIP1) mRNA by CrIRE1 that, in turn, resulted in the loss of the transmembrane domain in CrbZIP1, and the translocation of CrbZIP1 from the ER to the nucleus. Mutants deficient in CrbZIP1 failed to induce the expression of the unfolded protein response genes and grew poorly under ER stress. Levels of diacylglyceryltrimethylhomoserine (DGTS) and pinolenic acid (18:3Δ5,9,12) increased in the parental strains but decreased in the crbzip1 mutants under ER stress. A yeast one-hybrid assay revealed that CrbZIP1 activated the expression of enzymes catalyzing the biosynthesis of DGTS and pinolenic acid. Moreover, two lines harboring independent mutant alleles of Chlamydomonas desaturase (CrDES) failed to synthesize pinolenic acid and were more sensitive to ER stress than were their parental lines. Together, these results indicate that CrbZIP1 is a critical component of the ER stress response mediated by CrIRE1 in Chlamydomonas that acts via lipid remodeling.

WNK1 kinase is essential for insulin-stimulated GLUT4 trafficking in skeletal muscle

With‐no‐lysine 1 (WNK1) kinase is a substrate of the insulin receptor/Akt pathway. Impaired insulin signaling in skeletal muscle disturbs glucose transporter 4 (GLUT4) translocation associated with the onset of type 2 diabetes (T2D). WNK1 is highly expressed in skeletal muscle. However, it is currently unknown how insulin signaling targeting WNK1 regulates GLUT4 trafficking in skeletal muscle, and whether this regulation is perturbed in T2D. Hereby, we show that insulin phosphorylates WNK1 at its activating site via a phosphatidylinositol 3‐kinase‐dependent mechanism. WNK1 promotes the cell surface abundance of GLUT4 via regulating TBC1D4. Of note, we observed insulin resistance and decreased WNK1 phosphorylation in T2D db/db mice as compared to the control mice. These results provide a new perspective on WNK1 function in the pathogenesis of hyperglycemia in T2D.

High performance self-gating graphene/MoS2 diode enabled by asymmetric contacts

A graphene-MoS₂ (GM) heterostructure based diode is fabricated using asymmetric contacts to MoS₂, as well as an asymmetric top gate (ATG). The GM diode exhibits a rectification ratio of 5 from asymmetric contacts, which is improved to 10⁵ after the incorporation of an ATG. This improvement is attributed to the asymmetric modulation of carrier concentration and effective Schottky barrier height (SBH) by the ATG during forward and reverse bias. This is further confirmed from the temperature dependent measurement, where a difference of 0.22 eV is observed between the effective SBH for forward and reverse bias. Moreover, the rectification ratio also depends on carrier concentration in MoS₂ and can be varied with the change in temperature as well as back gate voltage. Under laser light illumination, the device demonstrates strong opto-electric response with 100 times improvement in the relative photo current, as well as a responsivity of 1.9 A W^-1 and a specific detectivity of 2.4 × 10¹⁰ Jones. These devices can also be implemented using other two dimensional (2D) materials and suggest a promising approach to incorporate diverse 2D materials for future nano-electronics and optoelectronics applications.

Low temperature flow lithography

Flow lithography (FL) is a microfluidic technique distinguished for its ability to produce hydrogel microparticles of various geometrical and chemical designs. While FL is typically performed in room temperature, this paper reports a new technique called low temperature flow lithography that uses low synthesis temperature to increase the degree of polymerization of microparticles without compromising other aspects of flow lithography. We suggest that decreased oxygen diffusivity in low temperature is responsible for the increase in polymerization. Microparticles that exhibit a higher degree of polymerization display a more developed polymer network, ultimately resulting in a more defined morphology, higher incorporation of materials of interest, and improved functional performance. This work demonstrates the increase in the degree of polymerization by examining the temperature effect on both the physical and chemical structures of particles. We show applications of this technique in synthesizing thin microparticles and enhancing microparticle-based detection of microRNA. Low temperature FL offers a simple and easy method of improving the degree of polymerization, which can be implemented in a wide range of FL applications.

Identification and functional study of the endoplasmic reticulum stress sensor IRE1 in Chlamydomonas reinhardtii

In many eukaryotes, endoplasmic reticulum (ER) stress activates the unfolded protein response (UPR) via the transmembrane endoribonuclease IRE1 to maintain ER homeostasis. The ER stress response in microalgae has not been studied in detail. Here, we identified Chlamydomonas reinhardtii IRE1 (CrIRE1) and characterized two independent knock-down alleles of this gene. CrIRE1 is similar to IRE1s identified in budding yeast, plants, and humans, in terms of conserved domains, but differs in having the tandem zinc-finger domain at the C terminus. CrIRE1 was highly induced under ER stress conditions, and the expression of a chimeric protein consisting of the luminal N-terminal region of CrIRE1 fused to the cytosolic C-terminal region of yeast Ire1p rescued the yeast ∆ire1 mutant. Both allelic ire1 knock-down mutants ire1-1 and ire1-2 were much more sensitive than their parental strain CC-4533 to the ER stress inducers tunicamycin, dithiothreitol and brefeldin A. Treatment with a low concentration of tunicamycin resulted in growth arrest and cytolysis in ire1 mutants, but not in CC-4533 cells. Furthermore, in the mutants, ER stress marker gene expression was reduced, and reactive oxygen species (ROS) marker gene expression was increased. The survival of ire1 mutants treated with tunicamycin improved in the presence of the ROS scavenger glutathione, suggesting that ire1 mutants failed to maintain ROS levels under ER stress. Together, these results indicate that CrIRE1 functions as an important component of the ER stress response in Chlamydomonas, and suggest that the ER stress sensor IRE1 is highly conserved during the evolutionary history.

Hemodynamic Adaptations to Regular Exercise in People With Spinal Cord Injury

Objective

To investigate the real-time cardiovascular response to the progressive overload exercise in different levels of spinal cord injury (SCI), and to find out whether regular exercise has effect on these cardiovascular responses.

Methods

The study enrolled 8 able-bodied individuals in the control group plus 15 SCI subjects who were divided into two groups by their neurological level of injury: high-level SCI group (T6 or above) and low-level SCI group (T7 or below). Also, subjects were divided into exercise group and non-exercise group by usual exercise habits. We instructed the subjects to perform exercises using arm ergometer according to the protocol and checked plethysmograph for the real time assessment of blood pressure, heart rate, and cardiac output.

Results

Six subjects were included in high-level SCI group (3 cervical, 3 thoracic injuries), 9 subjects in low-level SCI group (9 thoracic injuries), and 8 able-bodied individuals in control group. During arm ergometer-graded exercise, mean arterial pressure (MAP) was significantly lower in high-level SCI subjects of non-exercise group, compared with high-level SCI subjects of exercise group. In addition, HR was significantly higher in low-level SCI group compared with control group.

Conclusion

There are significant differences in mean arterial pressure of high-level SCI group according to usual exercise habits. We discovered that even in non-athlete high-level SCI, regular exercise can bring cardiac modulation through blood pressure control.

Cytochrome b5 Reductase 1 Triggers Serial Reactions that Lead to Iron Uptake in Plants

Rhizosphere acidification is essential for iron (Fe) uptake into plant roots. Plasma membrane (PM) H(+)-ATPases play key roles in rhizosphere acidification. However, it is not fully understood how PM H(+)-ATPase activity is regulated to enhance root Fe uptake under Fe-deficient conditions. Here, we present evidence that cytochrome b5 reductase 1 (CBR1) increases the levels of unsaturated fatty acids, which stimulate PM H(+)-ATPase activity and thus lead to rhizosphere acidification. CBR1-overexpressing (CBR1-OX) Arabidopsis thaliana plants had higher levels of unsaturated fatty acids (18:2 and 18:3), higher PM H(+)-ATPase activity, and lower rhizosphere pH than wild-type plants. By contrast, cbr1 loss-of-function mutant plants showed lower levels of unsaturated fatty acids and lower PM H(+)-ATPase activity but higher rhizosphere pH. Reduced PM H(+)-ATPase activity in cbr1 could be restored in vitro by addition of unsaturated fatty acids. Transcript levels of CBR1, fatty acids desaturase2 (FAD2), and fatty acids desaturase3 (FAD3) were increased under Fe-deficient conditions. We propose that CBR1 has a crucial role in increasing the levels of unsaturated fatty acids, which activate the PM H(+)-ATPase and thus reduce rhizosphere pH. This reaction cascade ultimately promotes root Fe uptake.

Qualitative muscle mass index as a predictor of skeletal muscle function deficit in Asian older adults

AIM

The present cross-sectional study was carried out among community-dwelling Koreans to determine the validity of various muscle mass indices and to propose more clinically relevant diagnostic criteria.

METHODS

This study measured the anthropometrics, body composition and physical capability of 415 older Koreans. Skeletal muscle indices were calculated by dividing appendicular lean mass by height or weight. Apart from this, we adjusted appendicular lean mass for body mass index, body surface area or waist-to-height ratio, which we then named the qualitative muscle mass index. Skeletal muscle function deficit was defined as a combination of weakness and slowness.

RESULTS

Qualitative muscle indices were closely associated with physical capabilities. Receiver operating characteristic and logistic analyses showed that qualitative muscle indices had significantly greater discriminatory powers regarding low muscle function than did the height-adjusted index in both men and women, and even showed higher discriminatory potentials than the weight-adjusted index in men (all P < 0.05). The cut-off values of qualitative muscle indices of body mass index-, body surface area-, and waist-to-height ratio-adjusted indices for identifying functional deficits were 0.760, 11.40 and 34.18 for men, and 0.530, 8.91 and 23.07 for women, respectively.

CONCLUSIONS

The present study suggests that qualitative muscle indices are more accurate in predicting low muscle function than are height- and weight-adjusted indices, because they consider anthropometric characteristics as part of the definition. The results might provide new avenues for conceptualizations of sarcopenia accompanied by obesity, and can be used as ethnic-specific reference values of muscle mass indices based on functional outcome in an elderly Korean/Asian population. Geriatr Gerontol Int 2017; 17: 99-107.

Intense Walking Exercise Affects Serum IGF-1 and IGFBP3

Background

Insulin-like growth factor (IGF-1) is associated with chronic diseases such as diabetes, cardiovascular disease, and hypertension, as well as muscle dysfunction. Previous studies of exercise interventions yield controversial results regarding plasma IGF-1, IGFBP3, and IGF-1/IGFBP3 ratio. In this study, we examined whether 100 km walking exercise affects serum levels of IGF-1 and IGFBP3 and IGF-1/IGFBP3 ratio. We also investigated several metabolic-related blood parameters before and after walking.

Methods

Participants were 14 healthy middle aged men (41.0 ± 6.78 years of age). We assessed body composition and measured metabolic-related blood indicators, such as such as lipid profiles, glucose, renal and hepatic metabolic bio-markers before and after a 100 km walking race. Blood samples from all participants were taken before and immediately after the walkathon. We also analyzed serum levels of IGF-1 and IGFBP3, and calculated the IGF-1/IGFBP3 ratio.

Results

After participants completed a 100 km walking race, some of their metabolic profiles were markedly changed. Serum levels of IGF-1 and IGFBP3 were significantly decreased, and therefore the IGF-1/IGFBP3 ratio also decreased before and after 100 km of walking.

Conclusion

Our results indicate that intense walking exercise affects serum levels of IGF-1 and IGFBP3 as well as metabolic bio-markers including high density cholesterol, glucose and triglycerides.

The small molecule fenpropimorph rapidly converts chloroplast membrane lipids to triacylglycerols in Chlamydomonas reinhardtii

Concern about global warming has prompted an intense interest in developing economical methods of producing biofuels. Microalgae provide a promising platform for biofuel production, because they accumulate high levels of lipids, and do not compete with food or feed sources. However, current methods of producing algal oil involve subjecting the microalgae to stress conditions, such as nitrogen deprivation, and are prohibitively expensive. Here, we report that the fungicide fenpropimorph rapidly causes high levels of neutral lipids to accumulate in Chlamydomonas reinhardtii cells. When treated with fenpropimorph (10 μg mL(-1)) for 1 h, Chlamydomonas cells accumulated at least fourfold the amount of triacylglycerols (TAGs) present in the untreated control cells. Furthermore, the quantity of TAGs present after 1 h of fenpropimorph treatment was over twofold higher than that formed after 9 days of nitrogen starvation in medium with no acetate supplement. Biochemical analysis of lipids revealed that the accumulated TAGs were derived mainly from chloroplast polar membrane lipids. Such a conversion of chloroplast polar lipids to TAGs is desirable for biodiesel production, because polar lipids are usually removed during the biodiesel production process. Thus, our data exemplified that a cost and time effective method of producing TAGs is possible using fenpropimorph or similar drugs.

Rapid induction of lipid droplets in Chlamydomonas reinhardtii and Chlorella vulgaris by Brefeldin A

Algal lipids are the focus of intensive research because they are potential sources of biodiesel. However, most algae produce neutral lipids only under stress conditions. Here, we report that treatment with Brefeldin A (BFA), a chemical inducer of ER stress, rapidly triggers lipid droplet (LD) formation in two different microalgal species, Chlamydomonas reinhardtii and Chlorella vulgaris. LD staining using Nile red revealed that BFA-treated algal cells exhibited many more fluorescent bodies than control cells. Lipid analyses based on thin layer chromatography and gas chromatography revealed that the additional lipids formed upon BFA treatment were mainly triacylglycerols (TAGs). The increase in TAG accumulation was accompanied by a decrease in the betaine lipid diacylglyceryl N,N,N-trimethylhomoserine (DGTS), a major component of the extraplastidic membrane lipids in Chlamydomonas, suggesting that at least some of the TAGs were assembled from the degradation products of membrane lipids. Interestingly, BFA induced TAG accumulation in the Chlamydomonas cells regardless of the presence or absence of an acetate or nitrogen source in the medium. This effect of BFA in Chlamydomonas cells seems to be due to BFA-induced ER stress, as supported by the induction of three homologs of ER stress marker genes by the drug. Together, these results suggest that ER stress rapidly triggers TAG accumulation in two green microalgae, C. reinhardtii and C. vulgaris. A further investigation of the link between ER stress and TAG synthesis may yield an efficient means of producing biofuel from algae.

Surgical anatomy of the natural ostium of the sphenoid sinus

OBJECTIVES

This study was undertaken to measure the distance and the angle between the anterior part of nasal cavity and the natural ostium of the sphenoid sinus. The anatomical location of the natural ostium according to the direction of surgeon's operating view toward the anterior wall of the sphenoid sinus was also analyzed.

STUDY DESIGN

This study used careful cadaver dissection under a surgical microscope.

METHODS

One hundred sagittally sectioned adult cadaveric heads were used. We measured the distances and angles for identifying the natural ostium of the sphenoid sinus using several reference points such as the limen nasi, the sill, and the posteroinferior end of the superior turbinate. In addition, we tried to identify whether the location of the natural ostium is medial or lateral to the posterior end of the superior turbinate.

RESULTS

The natural ostium of the sphenoid sinus was located at an angle of 35.9 degrees with a distance of 56.5 mm from limen nasi and at an angle of 34.3 degrees with a distance of 62.7 mm from nasal sill. It was located approximately 1 cm above the posteroinferior end of the superior turbinate and at a medial aspect to the posterior end of the superior turbinate in 83% of specimens.

CONCLUSIONS

We speculate that the posteroinferior end of the superior turbinate is the best landmark for identifying the natural ostium of the sphenoid sinus. Furthermore, the natural ostium should ideally be searched from a superior and medial aspect in relation to the posteroinferior end of the superior turbinate.

Surgical anatomy of the nasofrontal duct: anatomical and computed tomographic analysis

OBJECTIVES

Although complete anatomical knowledge of the nasofrontal duct has been of great importance, little is known about it. The aim of this study is to examine the drainage site of the nasofrontal duct and to investigate the anatomical boundaries of the nasofrontal duct according to the drainage site.

STUDY DESIGN

One hundred sagittally divided adult head specimens were analyzed by computed tomography and dissection under the surgical microscope.

METHODS

Computed tomography scans of 50 adult cadaver heads were taken sagittally at 1-mm intervals and coronally at 3-mm intervals to find the nasofrontal duct. One hundred specimens, made up of sagittally divided adult cadaver heads, were dissected under the microscope to study the structure of the nasofrontal duct.

RESULTS

We identified the anterior, posterior, medial, and lateral boundaries of the nasofrontal duct. In the most common type, the superior portion of the uncinate process formed the anterior border and the superior portion of the bulla ethmoidalis formed the posterior border of the nasofrontal duct. The conchal plate formed the medial border and the suprainfundibular plate formed the lateral border of the nasofrontal duct. Other variations are described in detail.

CONCLUSIONS

To widen the nasofrontal communication, removing the upper portion of the ground lamella of the ethmoid bulla, which is the posterior boundary of the nasofrontal duct, with cutting forceps seems to be a safe and easy method.

Surgical anatomy of the anterior ethmoidal canal in ethmoid roof

OBJECTIVES/HYPOTHESIS

This study was undertaken to examine three main relationships. First, the distance and angle from the anterior ethmoidal canal to the limen nasi and the sill were measured. Second, the location of the anterior ethmoidal canal was examined in relation to the lamellas and the skull base. Third, the existence of bony defects in the canal and the course of the canal through the anterior cranial fossa were studied.

STUDY DESIGN

This study employed both sagittal computed tomography and cadaver dissection.

METHODS

Seventy sagittally divided heads from randomly chosen Korean adult cadavers were used. Sagittal computed tomography was performed on all specimens. Then they were meticulously dissected under a surgical microscope.

RESULTS

The mean distance and angle between the limen nasi and the anterior ethmoidal canal were 49.0 mm and 54.5 degrees, respectively. The anterior ethmoidal canal was located between the second and third lamella in 61 of 70 cases. In 60 of 70 cases it was attached to the base of the skull, and in the remaining 10 cases it ran 2 to 3 mm below the skull base. When viewed from the superior side, the course of the anterior ethmoidal canal formed a diagonal line from the lateral to the medial side. Partial bony defects of the anterior ethmoidal canal were observed in eight cases, and complete bony defects in none.

CONCLUSION

This study provides surgeons with a better understanding of the anatomy of the anterior ethmoidal canal.