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Rational design of plasmonic colloidal assemblies via bottom-up synthesis is challenging but would show unprecedented optical properties that strongly relate to the assembly's shape and spatial arrangement. Herein, the synthesis of plasmonic cyclic Au nanosphere hexamers (PCHs) is reported, wherein six Au nanospheres (Au NSs) are connected via thin metal ligaments. By tuning Au reduction, six dangling Au NSs are interconnected with a core hexagon nanoplate (NPL). Then, Pt atoms are selectively deposited on the edges of the spheres. After etching of the core, necklace-like nanostructures of Pt framework are obtained. Deposition of Au is followed, leading to PCHs in high yield (≈90%). Notably, PCHs exhibit the combinatorial plasmonic characteristics of individual Au NSs and the in-plane coupling of the six linked Au NSs. They yield highly uniform, reproducible, and polarization-independent single-particle surface-enhanced Raman scattering signals, which are attributed to the 2-dimensional isotropic alignment of the Au NSs. Those are applied to a SERS-based immunoassay as quantitative and qualitative single particle SERS nanoprobes. This assay shows a low limit-of-detection, down to 100 pm, which is orders of magnitude lower than those based on Au NSs, and one order of magnitude lower than an assay using analogous particles of smooth Au nanorings.

Ammonia has emerged as an attractive liquid fuel for hydrogen production owing to its facile transportation, high capacity of hydrogen storage, and ecofriendly environmental products (N2 and H2). Moreover, the electrolysis of ammonia to produce nitrogen and hydrogen only requires an external voltage of 0.06 V theoretically, which is much lower than the energy needed for water electrolysis (1.23 V). In this study, we propose a well-established procedure using in operando gas chromatography that enables us to reliably compare and evaluate the new catalyst for ammonia oxidation. With the protocol, we could distinguish in detail the competitive oxidation reaction between the ammonia oxidation and oxygen evolution reactions with real-time monitoring. Using a flower-like electrodeposited Pt catalyst, we have efficiently produced hydrogen with less power consumption of 734 LH2 kW h−1, which is significantly lower than that of the water-splitting process (242 LH2 kW h−1). The use of this rigorous protocol should help to evaluate the practical performances for ammonia oxidation, thus enabling the field to focus on viable pathways towards the practical electrochemical oxidation of ammonia to hydrogen.

Wind power is attracting more attention as an alternative energy in accordance with efforts to reduce carbon emissions, but its stable operation is difficult due to the intermittency of wind. Since the 1990s, many previous studies have suggested forecasting models focusing on accuracy and speed using numerical weather prediction models, statistical approaches, and hybrid techniques. However, although their verification methods and periods are different, most showed high errors of about 15% or more. In this study, we developed and validated a hybrid forecasting model using the mesoscale model Weather Research and Forecasting (WRF) and artificial neural network (ANN) for a wind farm located in Yeongyang-gun, Gyeongsangbuk-do, South Korea, a complex mountainous terrain (36°36ʹ49ʺN, 129°13ʹ21ʺE). In order to simulate more accurate wind at hub-height of wind turbine (i.e., 80 m), roughness sublayer parameterization (Yonsei surface layer scheme; YSL) is used and daily spatio-temporal high resolution wind forecasts are performed for one year in 2020. The simulated wind speed and actual wind power generation at that time are used as training data set for ANN to construct a hybrid forecast model, and it is validated for January and February 2021. Our analysis shows that improved parameterization in the roughness sublayer can significantly contribute to wind power forecasting through more accurate wind speed forecasting.

Recent advances in nucleic acids engineering introduced several RNA-based regulatory components for synthetic gene circuits, expanding the toolsets to engineer organisms. In this work, we designed genetic circuits implementing an RNA aptamer previously described to have the capability of binding to the T7 RNA polymerase and inhibiting its activity in vitro. Using in vitro transcription assays, we first demonstrated the utility of the RNA aptamer in combination with programmable synthetic transcription networks. As a step to quickly assess the feasibility of aptamer functions in vivo, a cell-free expression system was used as a breadboard to emulate the in vivo conditions of E. coli. We tested the aptamer and its three sequence variants in the cell-free expression system, verifying the aptamer functionality in the cell-free testbed. In vivo expression of aptamer and its variants demonstrated control over GFP expression driven by T7 RNA polymerase with different response curves, indicating its ability to serve as building blocks for both logic circuits and transcriptional cascades. This work elucidates the potential of RNA-based regulators for cell programming with improved controllability leveraging the fast production and degradation time scales of RNA molecules.

In this Letter, a rational and stepwise method for the solution-phase synthesis of asymmetric Au split nanorings by adopting Au nanoprisms as a template has been demonstrated. The selective chemical etching of Au nanoprism tips activated the surface reactivity of edges and led to the selective deposition of Pt at the periphery of Au nanoplates. By controlling the total amount of Pt on the edges, different degrees of split Au@Pt nanorings were obtained; the subsequent Au coating around the Au@Pt scaffold eventually resulted in asymmetric Au hexagonal split nanorings. Their surface plasmonic features as a function of split degrees were investigated, including straight nanorods, bent nanorods, split nanorings, and full nanorings. The electrical field focusing using single-particle surface-enhanced Raman spectroscopy was evaluated under different polarization angles of the incident light for two different structures with the point gap and line gap between two arms.

Silver double nanorings with circular intra-nanogaps between two nanorings of different diameters were synthesized without a linker molecule to confine an incident electromagnetic field in a single entity. We used on-demand, rational, and systematic multi-stepwise reactions consisting of (1) selective etching of gold, (2) rim-on deposition of platinum, (3) eccentric growth of gold, and (4) concentric growth of silver. The resulting silver double nanorings exhibited a high degree of homogeneity in both shape and size, with strongly coupled circular hot zones (or "hot halos", referring to the circular intra-nanogaps capable of focusing the near electromagnetic field) resulting from strong surface plasmon coupling between the inner and outer nanorings. Remarkably, these silver double nanorings exhibited strong, stable, and reproducible single-particle surface-enhanced Raman scattering signals without blinking. The signals appeared independently of polarization directions, which is a unique feature of a circular hot halo. The estimated enhancement factor was between 2 × 108 and 7 × 108. The measured limit of detection was 10-7 M in bulk concentration, and the signal appeared 570 s after sample exposure.

Herein, plasmonic metal tripod nanoframes with three-fold symmetry were synthesized in a high yield (∼83%), and their electric field distribution and single-particle surface-enhanced Raman scattering (SERS) were studied. We realized such complex frame morphology by synthesizing analogous tripod nanoframes through multiple transformations. The precise control of the Au growth pattern led to uniform tripod nanoframes embedded with circle or line-shaped hot spots. The linear-shaped nanogaps ("Y"-shaped hot-zone) of the frame structures can strongly and efficiently confine the electric field, allowing for strong SERS signals. Coupled with a high synthetic yield of the targeted frame structure, strong and uniform SERS signals were obtained inside the nanoframe gaps. Remarkably, quite reproducible SERS signals were obtained with these structures-the SERS enhancement factors with an average value of 7.9 × 10

Developing a cost-effective, scalable, and efficient electrocatalyst for the hydrogen evolution reaction (HER) is the heart of producing pure hydrogen in practical applications. In this work, a unique approach to allow ruthenium (Ru) nanoparticles on carboxyl-functionalized porous sphere carbon (CF-Ru@PSC) for an aqueous Zn–CO2 system is reported. The CF-Ru@PSC catalyst was produced by inducing additional junction sites between metallic Ru and the carbon substrate for enhanced HER properties under a CO2 saturated condition. The strongly bonded Ru–C caused electron transfer from the bottom side of the metallic Ru to the PSC substrate, leading to efficient hydrogen adsorption energy of the surface. The DFT calculations and XAFS investigation suggested that the reconstructed electronic configuration from the Ru–C linkage acted as an efficient active site for HER. The CF-Ru@PSC electrocatalyst presented a high turnover frequency of 2.70H2 s−1 at an overpotential of 0.20 V in the CO2-saturated condition and high Faraday efficiency (98.2%) over 1000 min in the aqueous Zn–CO2 system.

The development of a stepwise synthetic strategy for Au ring-in-a-triangle nanoframes with a high degree of structural solidity is essential to the advancement of highly amplified near-field focusing. This strategy leads to the formation of an inscribed nanoring in a triangular metal frame with stability to withstand elevated temperatures and an oxidizing environment, which is critical for successful single-particle surface-enhanced Raman scattering (SERS). The existence of inscribed nanorings plays an important role in enhancing the so-called "lightning rod effect," whereby the electromagnetic near-field enhancement occurs on the highly curved curvature of a metallic interface. We evaluated the corresponding single-particle SERS as a function of the thickness of the rims and then constructed two-dimensional (2D) bulk SERS substrates, wherein an ensemble of hotspots exists. The synergic contribution from both inter- and intrahotspots allowed the outstanding linearity of the calibration curve and the lowest limit of detection, ∼10

The synthesis of highly complex two-dimensional (2D) metal nanoframes remains a great challenge. Synthetic strategies for preparing 2D metal nanoframes are few, and rational and systematic synthetic pathways to more complicated architectures have not yet been reported. Herein, we demonstrate a stepwise synthetic strategy for complex 2D metal nanoframes with a high degree of intricacy; the strategy leads to a variety of shapes, including rings, triangles, hexagons, and tripods with tailorable single or double frames in a single entity. These nanoframes of high homogeneity could be obtained through selective combination of four different chemical toolkits consisting of selective etching and deposition on certain facets, and concentric and/or eccentric regrowth by controlling the mismatches of lattice constants of metals. The resulting nanoframes were highly homogeneous in size and shape and had van der Waals interactions that maximized rim-to-rim contact, allowing them to uniquely self-assemble into large-area superstructures., The synthesis of anisotropic nanoparticles with structural diversity and complexity in a rational and systematic fashion is rare. Here, the authors demonstrate a rational and stepwise synthetic strategy for nanoplates with a high degree of intricacy, leading to a gallery of shapes such as rings, triangles, hexagons, and tripods, with tailorable single or double frames.

Autophagy, a mechanism that maintains cellular homeostasis, is involved in tumor cell growth and survival in cancer, and autophagy inhibitors have been tested clinical trials for anticancer therapy. To elucidate the clinical and prognostic implications of autophagy in small intestinal adenocarcinoma (SIAC), we assessed the expression of autophagy markers, LC3B and p62, in 171 surgically resected primary SIACs using automated quantitative analysis. Positive LC3B, p62 nuclear (p62Nu), and p62 cytoplasmic (p62Cy) expression was observed in 23 (13.5%), 52 (30.4%), and 43 (25.1%) carcinomas, respectively. LC3B+ expression was correlated with undifferentiated carcinoma (p &lt, 0.001) and high histologic grade (p = 0.029). The combined expression of LC3B and p62Nu (LC3+/p62Nu+) was related to the older age of patients (p = 0.017), undifferentiated carcinoma (p &lt, 0.001), and high grade (p = 0.031). LC3B+ (p = 0.006), p62Cy+ (p = 0.041), or p62Nu+ (p = 0.006) expression were associated with worse survival. In addition, SIAC patients with either LC3B+/p62Nu+ (p = 0.001) or LC3B+/p62Cy+ (p = 0.002) expression had shorter survival times. In multivariate analysis, LC3B expression remained an independent prognostic factor (p = 0.025) for overall survival. In conclusion, autophagy may play a role in the tumorigenesis of SIACs, and LC3B and p62 could be used as prognostic biomarkers and potential therapeutic targets for SIACs.

In this study, the carburization characteristics of cast and cold-rolled CoCrFeMnNi high-entropy alloys (HEAs) with various grain sizes were investigated. All specimens were prepared by vacuum carburization at 940 °C for 8 h. The carburized/diffused layer was mainly composed of face-centered cubic structures and Cr7C3 carbide precipitates. The carburized/diffused layer of the cold-rolled specimen with a fine grain size (~1 μm) was thicker (~400 μm) than that of the carburized cast specimen (~200 μm) with a coarse grain size (~1.1 mm). In all specimens, the carbides were formed primarily through grain boundaries, and their distribution varied with the grain sizes of the specimens. However, the carbide precipitates of the cast specimen were formed primarily at the grain boundaries and were unequally distributed in the specific grains. Owing to the non-uniform formation of carbides in the carburized cast specimen, the areas in the diffused layer exhibited various carbide densities and hardness distributions. Therefore, to improve the carburization efficiency of equiatomic CoCrFeMnNi HEAs, it is necessary to refine the grain sizes.

We report the synthetic methodology for silver nanorings with controlled nanoscale morphology. The morphology of Ag nanorings was kinetically controlled by electrochemical potential tuning of Ag deposition using halide counter-ions, which resulted in concentric PtAu@Ag nanorings (i.e., Ag homogeneously wrapped around the Pt nanorings) and eccentric PtAu@Ag nanorings (i.e., Ag selectively deposited at the inner boundary of the Pt nanorings). The resulting high quality of each Ag nanoring allowed us to systematically investigate their corresponding localized surface plasmon resonance (LSPR) profiles as a function of their geometrical parameters. Additionally, we evaluated the application of the samples as surface-enhanced Raman spectroscopy (SERS) substrates composed of 2D monolayers of varied compositions of Ag and Au nanorings, which showed a different extent of enhancement depending on the adsorption characteristics of the analytes.

A high-fat diet (HFD) is a major risk factor for chronic kidney disease. Although HFD promotes renal injury, characterized by increased inflammation and oxidative stress leading to fibrosis, the underlying mechanism remains elusive. Here, we investigated the role and mechanism of protease-activating receptor 2 (PAR2) activation during HFD-induced renal injury in C57/BL6 mice. HFD for 16 weeks resulted in kidney injury, manifested by increased blood levels of blood urea nitrogen, increased levels of oxidative stress with inflammation, and structural changes in the kidney tubules. HFD-fed kidneys showed elevated PAR2 expression level in the tubular epithelial region. To elucidate the role of PAR2, PAR2 knockout mice and their littermates were administered HFD. PAR2 deficient kidneys showed reduced extent of renal injury. PAR2 deficient kidneys showed significantly decreased levels of inflammatory gene expression and macrophage infiltration, followed by reduced accumulation of extracellular matrix proteins. Using NRK52E kidney epithelial cells, we further elucidated the mechanism and role of PAR2 activation during renal injury. Palmitate treatment increased PAR2 expression level in NRK52E cells and scavenging of oxidative stress blocked PAR2 expression. Under palmitate-treated conditions, PAR2 agonist-induced NF-κB activation level was higher with increased chemokine expression level in the cells. These changes were attenuated by the depletion of oxidative stress. Taken together, our results suggest that HFD-induced PAR2 activation is associated with increased levels of renal oxidative stress, inflammatory response, and fibrosis.

We designed complex Au nanorings with intertwined triple rings (ANITs) in a single entity to amplify the efficacy of near-field focusing. Such a complex and unprecedented morphology at the nanoscale was realized through on-demand multistepwise reactions. Triangular nanoprisms were first sculpted into circular nanorings, followed by a series of chemical etching and deposition reactions eventually leading to ANITs wherein thin metal bridges hold the structure together without any linker molecules. In the multistepwise reaction, the well-faceted growth pattern of Au, which induces the growth of two distinctive flat facets in a lateral direction, is important to evolve the morphology from single to multiple nanorings. Although our synthesis proceeds through multiple steps in one batch without purification steps, it shows a remarkably high yield (>∼90%) at the final stage. The obtained high degree of homogeneity (in both shape and size) of the resulting ANITs allowed us to systematically investigate the corresponding localized surface plasmon resonance (LSPR) coupling with varying nanoring arrangements and observe their single-particle surface enhanced Raman scattering (SERS). Surprisingly, individual ANITs exhibited an enormously large enhancement factor (∼109), which confirms their superior near-field focusing relative to other reported nanoparticles.

Atmospheric carbon dioxide (CO2 ) has increased from 278 to 408 parts per million (ppm) over the industrial period and has critically impacted climate change. In response to this crisis, carbon capture, utilization, and storage/sequestration technologies have been studied. So far, however, the economic feasibility of the existing conversion technologies is still inadequate owing to sluggish CO2 conversion. Herein, we report an aqueous zinc- and aluminum-CO2 system that utilizes acidity from spontaneous dissolution of CO2 in aqueous solution to generate electrical energy and hydrogen (H2 ). The system has a positively shifted onset potential of hydrogen evolution reaction (HER) by 0.4 V compared to a typical HER under alkaline conditions and facile HER kinetics with low Tafel slope of 34 mV dec-1 . The Al-CO2 system has a maximum power density of 125 mW cm-2 which is the highest value among CO2 utilization electrochemical system.

Nucleic acid-based regulatory components provide a promising toolbox for constructing synthetic biological circuits due to their design flexibility and seamless integration towards complex systems. In particular, small-transcriptional activating RNA (STAR) and toehold switch as regulators of transcription and translation steps have shown a large library size and a wide dynamic range, meeting the criteria to scale up genetic circuit construction. Still, there are limited attempts to integrate the heterogeneous regulatory components for multilevel regulatory circuits in living cells. In this work, inspired by the design principle of STAR, we designed several switchable transcription terminators starting from natural and synthetic terminators. These switchable terminators could be designed to respond to specific RNA triggers with minimal sequence constraints. When combined with toehold switches, the switchable terminators allow simultaneous control of transcription and translation processes to minimize leakage in Escherichia coli. Further, we demonstrated a set of logic gates implementing 2-input AND circuits and multiplexing capabilities to control two different output proteins. This study shows the potential of novel switchable terminator designs that can be computationally designed and seamlessly integrated with other regulatory components, promising to help scale up the complexity of synthetic gene circuits in living cells.

Eddy covariance (EC) method has been used to measure CO2 fluxes over various ecosystems. Recently, the EC method has been also deployed in urban areas to measure CO2 fluxes. Urban carbon cycle is complex because of the additional anthropogenic processes unlike natural ecosystems but the EC method only measures the net sum of all CO2 sources and sink. This limitation of the EC method hinders us from the underlying processes of the carbon cycle, and it is necessary to partition the net CO2 fluxes into individual contributions for a better understanding of the urban carbon cycle. Here we propose a statistical method to partition CO2 fluxes into individual components by extending the method of Menzer and McFadden (2017).•Statistical method is proposed to partition CO2 fluxes into gross primary production, ecosystem respiration, anthropogenic emissions from a vehicle and building.•This method uses eddy fluxes and footprint-weighted high-resolution land cover data with temporal subsets that a few components can be negligible.•New partitioning method produces reliable individual components of the urban carbon cycle when compared to inventory data and typical biotic responses to environmental conditions., Graphical abstract Image, graphical abstract

Herein, we report the novel strategy for the synthesis of complex 3-dimensional (3D) nanostructures, mimicking the linker molecule-free 3D arrangement of six Au nanospheres at the vertices of octahedrons. We utilized 3D PtAu skeleton for the structural rigidity and deposited Au around the PtAu skeleton in a site-selective manner, allowing us to investigate their surface plasmonic coupling phenomenon and near-field enhancement as a function of sizes of nanospheres, which are directly related to the intrananogap distance and interior volume size. The resulting 3D Au hexamer structures with octahedral arrangement were realized through precise control of the Au growth pattern. The complex 3D Au hexamers were composed of six Au nanospheres connected by thin metal conductive bridges. The standard deviation of the metal conductive bridges and Au nanospheres was within ca. 10%, exhibiting a high degree of homogeneity and precise structural tunability. Interestingly, charge transfer among the six Au nanospheres occurred along the metal conductive bridges leading to surface plasmonic coupling between Au nanospheres. Accordingly, electric near fields were strongly and effectively focused at the vertices, intrananogap regions between Au nanospheres, and interior space, exhibiting well-resolved single-particle surface-enhanced Raman spectroscopy signals of absorbed analytes.

An epidermoid cyst is a benign tumor found anywhere in the body. However, the occurrence of epidermoid cysts in the thymus is extremely rare, with only six cases reported worldwide. The correct diagnosis of thymic epidermoid cysts is often difficult due to the unusual location and nonspecific imaging findings. Herein, we present a case of a thymic epidermoid cyst in a 37-year-old female with clinical information and chest CT findings. Further, we have reviewed previous literature reports describing imaging findings of thymic epidermoid cysts.

Summary Carbon capture, utilization, and sequestration technologies have been extensively studied to utilize carbon dioxide (CO2), a greenhouse gas, as a resource. So far, however, effective technologies have not been proposed owing to the low efficiency conversion rate and high energy requirements. Here, we present a hybrid Na-CO2 cell that can continuously produce electrical energy and hydrogen through efficient CO2 conversion with stable operation for over 1,000 hr from spontaneous CO2 dissolution in aqueous solution. In addition, this system has the advantage of not regenerating CO2 during charging process, unlike aprotic metal-CO2 cells. This system could serve as a novel CO2 utilization technology and high-value-added electrical energy and hydrogen production device., Graphical Abstract, Highlights • Hybrid Na-CO2 cell continuously produces electricity and H2 through CO2 conversion • Hybrid Na-CO2 does not regenerate CO2 during charging, unlike aprotic metal-CO2 cells • Highly stable operation over 1,000 hr was achieved with CO2 utilization, Environmental Chemical Engineering; Environmental Science; Energy Materials

Protonic ceramic fuel cells (PCFCs) are attractive energy conversion systems at intermediate operating temperatures (500–650°C) because of the low activation energy for proton conduction. Despite this advantage, the efficient operation of PCFCs is still limited partly due to the large cathodic polarization resistance. To decrease the large cathodic polarization, the modification of cathode microstructure could be an effective way because the PCFC cathode microstructure requires both sufficient pathways for oxygen supply and water vapor removal, along with a large surface area for electrochemical reactions. Herein, the correlation between the cathode microstructure and the electrochemical performance is investigated based on BaZr0.1Ce0.7Y0.1Yb0.1O3−δ (BZCYYb) electrolyte under the PCFC operating condition at 650°C. Four cells with PrBa0.5Sr0.5Co1.5Fe0.5O5-δ (PBSCF) cathode of different porosity with identical anode/electrolyte configuration were fabricated and tested. Interestingly, the modification of cathode porosity effectively decreases the cathodic polarization resistance from 0.077 to 0.048 Ω cm2 at 650°C, and the corresponding maximum power density of PCFCs is improved from 1.23 to 1.62 W cm− 2. The influence of other microstructural factors such as grain size, specific surface area (per volume), and porosity in the cathode should be studied to fully understand the impacts of microstructure on the cathode performance of PCFC.