Combinatorial Effect of Tricomponent Dual-Rim Nanoring Building Blocks: Label-Free SERS Detection of Biomolecules.

Detecting weakly adsorbing molecules via label-free surface-enhanced Raman scattering (SERS) has presented a significant challenge. To address this issue, we propose a novel approach for creating tricomponent SERS substrates using dual-rim nanorings (DRNs) made of Au, Ag, and CuO, each possessing distinct functionalities. Our method involves depositing different metals on Pt nanoring skeletons to obtain each nanoring with varying surface compositions while maintaining a similar size and shape. Next, the mixture of these nanorings is transferred into a monolayer assembly with homogeneous intermixing on a solid substrate. The surface of the CuO DRNs has dangling bonds (Cu2+) that facilitate the strong adsorption of carboxylates through the formation of chelating bonds, while the combination of Au and Ag DRNs significantly enhances the SERS signal intensity through a strong coupling effect. Notably, the tricomponent assemblies enable the successful SERS-based analysis of biomolecules such as amino acids, proteins, nucleobases, and nucleotides.

Three-Dimensional Au Octahedral Nanoheptamers: Single-Particle and Bulk Near-Field Focusing for Surface-Enhanced Raman Scattering.

Herein, we present a synthetic approach to fabricate Au nanoheptamers composed of six individual Au nanospheres interconnected through thin metal bridges arranged in an octahedral configuration. The resulting structures envelop central Au nanospheres, producing Au nanosphere heptamers with an open architectural arrangement. Importantly, the initial Pt coating of the Au nanospheres is a crucial step for protecting the inner Au nanospheres during multiple reactions. As-synthesized Au nanoheptamers exhibit multiple hot spots formed by nanogaps between nanospheres, resulting in strong electromagnetic near-fields. Additionally, we conducted surface-enhanced Raman-scattering-based detection of a chemical warfare agent simulant in the gas phase and achieved a limit of detection of 100 ppb, which is 3 orders lower than that achieved using Au nanospheres and Au nanohexamers. This pseudocore-shell nanostructure represents a significant advancement in the realm of complex nanoparticle synthesis, moving the field one step closer to sophisticated nanoparticle engineering.

Plasmonic Annular Nanotrenches with 1 nm Nanogaps for Detection of SARS-CoV-2 Using SERS-Based Immunoassay.

This study represents the synthesis of a novel class of nanoparticles denoted as annular Au nanotrenches (AANTs). AANTs are engineered to possess embedded, narrow circular nanogaps with dimensions of approximately 1 nm, facilitating near-field focusing for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via a surface-enhanced Raman scattering (SERS)-based immunoassay. Notably, AANTs exhibited an exceedingly low limit of detection (LOD) of 1 fg/mL for SARS-CoV-2 spike glycoproteins, surpassing the commercially available enzyme-linked immunosorbent assay (ELISA) by 6 orders of magnitude (1 ng/mL from ELISA). To assess the real-world applicability, a study was conducted on 50 clinical samples using an SERS-based immunoassay with AANTs. The results revealed a sensitivity of 96% and a selectivity of 100%, demonstrating the significantly enhanced sensing capabilities of the proposed approach in comparison to ELISA and commercial lateral flow assay kits.

Exploration and genetic analyses of canopy leaf pigmentation changes in soybean (Glycine max L.): unveiling a novel phenotype.

KEY MESSAGE: Pigmentation changes in canopy leaves were first reported, and subsequent genetic analyses identified a major QTL associated with levels of pigmentation changes, suggesting Glyma.06G202300 as a candidate gene. An unexpected reddish-purple pigmentation in upper canopy leaves was discovered during the late reproductive stages in soybean (Glycine max L.) genotypes. Two sensitive genotypes, 'Uram' and PI 96983, exhibited anomalous canopy leaf pigmentation changes (CLPC), while 'Daepung' did not. The objectives of this study were to: (i) characterize the physiological features of pigmented canopy leaves compared with non-pigmented leaves, (ii) evaluate phenotypic variation in a combined recombinant inbred line (RIL) population (N = 169 RILs) under field conditions, and (iii) genetically identify quantitative trait loci (QTL) for CLPC via joint population linkage analysis. Comparison between pigmented and normal leaves revealed different Fv/Fm of photosystem II, hyperspectral reflectance, and cellular properties, suggesting the pigmentation changes occur in response to an undefined abiotic stress. A highly significant QTL was identified on chromosome 6, explaining ~ 62.8% of phenotypic variance. Based on the QTL result, Glyma.06G202300 encoding flavonoid 3'-hydroxylase (F3'H) was identified as a candidate gene. In both Uram and PI 96983, a 1-bp deletion was confirmed in the third exon of Glyma.06G202300 that results in a premature stop codon in both Uram and PI 96983 and a truncated F3'H protein lacking important domains. Additionally, gene expression analyses uncovered significant differences between pigmented and non-pigmented leaves. This is the first report of a novel symptom and an associated major QTL. These results will provide soybean geneticists and breeders with valuable knowledge regarding physiological changes that may affect soybean production. Further studies are required to elucidate the causal environmental stress and the underlying molecular mechanisms.

A Density Functional Theory Analysis of Electrochemical Oxidation of Methane to Alcohol over High-Entropy Oxide (CoCrFeMnNi)3O4 Catalysts.

The direct conversion of methane into alcohol is a promising approach for achieving a low-carbon future, yet it remains a major challenge. In this study, we utilize density functional theory to explore the potential of the (CoCrFeMnNi)3O4 (CCFMNO) high entropy oxide (HEO) for electrochemical oxidation of methane to methanol and ethanol, alongside their competition with CO2 production. Our primary focus in this study is on thermodynamics, enabling a prompt analysis of the catalyst's potential, with the calculation of electrochemical barriers falling beyond our scope. Among all potential active sites within CCFMNO HEO, we identify Co as the most active site for methane activation when using carbonate ions as oxidants. This results in methanol production with a limiting potential of 1.4 VCHE, and ethanol and CO2 productions with a limiting potential of 1.2 VCHE. Additionally, our findings suggest that the occupied p-band center of O* on CCFMNO HEO is a potential descriptor for identifying the most active site within CCFMNO HEO. Overall, our results indicate that CCFMNO HEO holds promise as catalysts for methane oxidation to alcohols, employing carbonate ions as oxidants.

First report of soybean root rot caused by Fusarium falciforme in the Republic of Korea.

Phytopathogenic Fusarium species causing root and stem rot diseases in susceptible soybean (Glycine max (L.) Merrill) are a major threat to soybean production worldwide. Several Fusarium species have been reported to infect soybean plants in the Republic of Korea, including F. solani, F. oxysporum, F. fujikuroi, and F. graminearum (Cho et al., 2004; Choi et al., 2019; Kang et al., 2020). During the nationwide survey of soybean diseases in 2015, soybean plants showing symptoms of leaf chlorosis, wilting, and shoot death were found in soybean fields in Seosan, Chungnam. Fusarium isolates were obtained from the margins of sterilized necrotic symptomatic and asymptomatic regions of the stem tissues of diseased samples by culturing on potato dextrose agar (PDA). To examine the morphological characteristics, isolates were cultured on PDA at 25°C in the darkness for 10 days. Colonies produced white aerial mycelia with apricot pigments in the medium. Macroconidia were hyaline, slightly curved in shape with 3 or 4 septa, and their average length and width were 34.6± 0.56 µm (31.4 to 37.8 µm) and 4.7±0.16 µm (4.1 to 5.8 µm), respectively (n = 20). Microconidia were elongated, oval with 0 or 1 septum, and their average length and width were 11.4±0.87 and 5.2±0.32 µm, respectively (n = 20). The colonies and conidia exhibited morphological similarities to those of F. falciforme (Xu et al., 2022). Using the primers described by O'Donnell et al. (2008), identity of a representative strain '15-110' was further confirmed by sequencing portions of two genes, the translation elongation factor 1-alpha (EF-1α) and the second largest subunit of RNA polymerase II (RPB2). The two sequences (GenBank accession No. OQ992718 and OR060664) of 15-110 were 99% similar to those of two F. falciforme strains, 21BeanYC6-14 (GenBank accession nos. ON375419 and ON331931), and 21BeanYC6-16 (GenBank accession nos. ON697187 and ON331933). To test the pathogenicity, a single-spore isolate was cultured on carnation leaf agar (CLA) at 25℃ for 10 days. Pathogenicity test was performed by root-cutting assays using 14-day-old soybean seedlings of 'Daewon' and 'Taekwang'. Ten-day-old mycelia of 15-110 were collected from the CLA plates by scraping with distilled water, and the spore suspension was filtered and diluted to 1 × 106 conidia/mL. The roots of the soybean seedlings were partially cut and inoculated by soaking in the diluted spore suspension for two hours. The seedlings were then transplanted into 12 cm plastic pots (11 cm in height) and grown in a growth chamber at 25°C, 14h light/10h dark for 2 weeks. The infected plants exhibited wilting, observed brown discoloration on the root, and eventually died within 2 weeks, whereas the control plants inoculated with sterile water remained healthy. F. falciforme 15-110 was reisolated from infected plants, but not from the uninoculated controls. The morphology of the re-isolated fungus on PDA and its target gene sequences were identical to those of the original colony. To the best of our knowledge, this is the first report of root rot in soybean caused by F. falciforme in the Republic of Korea. Fusarium spp. induce a range of diseases in soybean plants, including root rot, damping-off, and wilt. Given the variable aggressiveness and susceptibility to fungicides among different Fusarium species, it is imperative to identify the Fusarium species posing a threat to soybean production. This understanding is crucial for developing a targeted and tailored disease management strategy to control Fusarium diseases.

First report of soybean root rot caused by Fusarium proliferatum in the Republic of Korea.

Fusarium species are widespread soilborne pathogens that can cause damping-off, root rot, and wilting in soybean [Glycine max (L.) Merrill], subsequently leading to significant yield suppression. Several Fusarium spp. have already been documented for their pathogenicity on soybean plants in the Republic of Korea. The nationwide monitoring of soybean diseases continues to identify new pathogenic Fusarium spp. In 2016, five plant samples at R3-R4 growth stages, showing symptoms of wilting in the upper parts and root rot, were collected in Suwon, Gyeonggi, Republic of Korea. Fungal colonies were obtained from the diseased root samples, with the surface sterilized in 1% sodium hypochlorite for 2 min, rinsed thrice with sterile distilled water, and placed on water agar at 25°C. Five isolates were collected and purified by single-spore isolation. The fungal mycelium was subsequently cultivated on potato dextrose agar for ten days. The isolates produced abundant, aerial, and white mycelium and became purple in old cultures. Macroconidia were slender, falcate to almost straight, usually 3 to 5 septated, and thin-walled. Microconidia were formed in chains from polyphalides, clavate or oval, usually single-celled with a flattened base. These characteristics of isolates were consistent with the description of F. proliferatum (Leslie and Summerrell 2006), and the representative isolate 16-19 was selected for molecular identification to confirm its identity as F. proliferatum. Two evolutionarily conserved genes, the translation elongation factor 1-alpha (EF-1α) and the second-largest subunit of RNA polymerase II (RPB2) genes, were partially amplified using the primers described by O'Donnell et al. (2008), resulting in nucleotide sequences of 680 and 382 base pairs, respectively. These two sequences (GenBank accession numbers: OQ992720 and OR060666) showed 100 and 99.5% identity to the EF-1α and RPB2 of F. proliferatum A40 (GenBank accession numbers: KP964907 and KP964842). For the Petri-dish pathogenicity assay (Broders et al. 2007), five surface-sterilized seeds were placed on water agar media with either sterile water or actively growing '16-19' culture. After 7 days of incubation in a growth chamber (25°C; 12-hour photoperiod), brown lesions were observed on the roots of the inoculated plants, while no symptoms were observed in the sterile water-treated controls. The experiment was conducted three times. For root-cut pathogenicity assay, conidial suspension (1×106 conidia/ml) of the isolate '16-19' was prepared with harvested mycelia cultured on PDA for 10 days with sterile water. The roots of 10-day-old soybean seedlings were partially cut and soaked in either the suspension or sterile water for 2 hours. The seedlings were transplanted into 12 cm plastic pots (11 cm in height) and grew in a greenhouse (26 ± 3°C, 13-h photoperiod). The experiment followed a completely randomized design with three replicates (i.e. three plants in a pot), and it was repeated twice. The inoculated plants began to wilt 7 days after inoculation, while the sterile water-treated controls remained healthy. Ten days after inoculation, all plants were collected, washed under running tap water, and evaluated for the presence and severity of root rot using a 0-4 scale (Chang et al. 2015). The inoculated plants exhibited reduced vigor and developed dark brown lesions on their roots. F. proliferatum was reisolated from symptomatic root tissues of the infected plants, while not from those of the controls. Its colony and spores were morphologically identical to those of the original isolate. F. proliferatum was previously reported as a causative agent of soybean root rot in the United States (Díaz Arias et al. 2011) and Canada (Chang et al. 2015). This is the first report of soybean root rot caused by F. proliferatum in the Republic of Korea. This finding implies that F. proliferatum may potentially threaten soybean production in the Republic of Korea and suggests that effective disease management strategies should be established for soybean protection against the disease, along with continuous surveillance.

Octahedron in a Cubic Nanoframe: Strong Near-Field Focusing and Surface-Enhanced Raman Scattering.

Here, we describe the synthesis of a plasmonic particle-in-a-frame architecture in which a solid Au octahedron is enclosed by a Au cubic nanoframe. The octahedra are positioned inside and surrounded by outer Au cubic nanoframes, creating intra-nanogaps within a single entity. Six sharp vertexes in the Au octahedra point toward the open (100) facets of the cubic nanoframes. This allows not only efficient interactions with the surroundings but also tip-enhanced electromagnetic near-field focusing at the sharp tips of the octahedra, combined with intraparticle coupling. The solid core-frame shell structure enhances near-field focusing, giving rise to a heightened concentration of "hot spots". This effect enables highly sensitive detection of 2-naphthalenethiol and thiram, indicating these substrates for use in surface-enhanced Raman spectroscopy-related applications.

Prediction of xerostomia in elderly based on clinical characteristics and salivary flow rate with machine learning.

Xerostomia may be accompanied by changes in salivary flow rate and the incidence increases in elderly. We aimed to use machine learning algorithms, to identify significant predictors for the presence of xerostomia. This study is the first to predict xerostomia with salivary flow rate in elderly based on artificial intelligence. In a cross-sectional study, 829 patients with oral discomfort were enrolled, and six features (sex, age, unstimulated and stimulated salivary flow rates (UFR and SFR, respectively), number of systemic diseases, and medication usage) were used in four machine learning algorithms to predict the presence of xerostomia. The incidence of xerostomia increased with age. The SFR was significantly higher than the UFR, and the UFR and SFR were significantly correlated. The UFR, but not SFR, decreased with age significantly. In patients more than 60 years of age, the UFR had a significantly higher predictive accuracy for xerostomia than the SFR. Using machine learning algorithms with tenfold cross-validation, the prediction accuracy increased significantly. In particular, the prediction accuracy of the multilayer perceptron (MLP) algorithm that combined UFR and SFR data was significantly better than either UFR or SFR individually. Moreover, when sex, age, number of systemic diseases, and number of medications were added to the MLP model, the prediction accuracy increased from 56 to 68%.

Step-by-Step Nanoscale Top-Down Blocking and Etching Lead to Nanohexapods with Cartesian Geometry.

In this research, we designed a stepwise synthetic method for Au@Pt hexapods where six elongated Au pods are arranged in a pairwise perpendicular fashion, sharing a common point (the central origin in a Cartesian-coordinate-like hexapod shape), featured with tip-selectively decorated Pt square nanoplates. Au@Pt hexapods were successfully synthesized by applying three distinctive chemical reactions in a stepwise manner. The Pt adatoms formed discontinuous thin nanoplates that selectively covered six concave facets of a Au truncated octahedron and served as etching masks in the succeeding etching process, which prevented underlying Au atoms from being oxidized. The subsequent isotropic etching proceeded radially, starting from the bare Au surface, carving the central nanocrystal in a concave manner. By controlling the etching conditions, Au@Pt hexapods were successfully fabricated, wherein the core Au domain is connected to six protruding arms, which hold Pt nanoplates at the ends. Due to their morphology, Au@Pt hexapods feature distinctive optical properties in the near-infrared region, as a proof of concept, allowing for surface-enhanced Raman spectroscopy (SERS)-based monitoring of in situ CO electrooxidation. We further extended our synthetic library by tailoring the size of the Pt nanoplates and neck widths of Au branches, demonstrating the validity of selective blocking and etching-based colloidal synthesis.

Prognostic factors for clinical outcomes after arthroscopic treatment of traumatic central tears of the triangular fibrocartilage complex.

Aims: The study aimed to assess the clinical outcomes of arthroscopic debridement and partial excision in patients with traumatic central tears of the triangular fibrocartilage complex (TFCC), and to identify prognostic factors associated with unfavourable clinical outcomes. Methods: A retrospective analysis was conducted on patients arthroscopically diagnosed with Palmer 1 A lesions who underwent arthroscopic debridement and partial excision from March 2009 to February 2021, with a minimum follow-up of 24 months. Patients were assessed using the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, Mayo Wrist Score (MWS), and visual analogue scale (VAS) for pain. The poor outcome group was defined as patients whose preoperative and last follow-up clinical score difference was less than the minimal clinically important difference of the DASH score (10.83). Baseline characteristics, arthroscopic findings, and radiological factors (ulnar variance, MRI, or arthrography) were evaluated to predict poor clinical outcomes. Results: A total of 114 patients were enrolled in this study, with a mean follow-up period of 29.8 months (SD 14.4). The mean DASH score improved from 36.5 (SD 21.5) to 16.7 (SD 14.3), the mean MWS from 59.7 (SD 17.9) to 79.3 (SD 14.3), and the mean VAS pain score improved from 5.9 (SD 1.8) to 2.2 (SD 2.0) at the last follow-up (all p < 0.001). Among the 114 patients, 16 (14%) experienced poor clinical outcomes and ten (8.8%) required secondary ulnar shortening osteotomy. Positive ulnar variance was the only factor significantly associated with poor clinical outcomes (p < 0.001). Positive ulnar variance was present in 38 patients (33%); among them, eight patients (21%) required additional operations. Conclusion: Arthroscopic debridement alone appears to be an effective and safe initial treatment for patients with traumatic central TFCC tears. The presence of positive ulnar variance was associated with poor clinical outcomes, but close observation after arthroscopic debridement is more likely to be recommended than ulnar shortening osteotomy as a primary treatment.

Developmental self-reactivity determines pathogenic Tc17 differentiation potential of naive CD8+ T cells in murine models of inflammation.

The differentiation of naive CD8+ T cells into effector cells is important for establishing immunity. However, the effect of heterogeneous naive CD8+ T cell populations is not fully understood. Here, we demonstrate that steady-state naive CD8+ T cells are composed of functionally heterogeneous subpopulations that differ in their ability to differentiate into type 17 cytotoxic effector cells (Tc17) in a context of murine inflammatory disease models, such as inflammatory bowel disease and graft-versus-host disease. The differential ability of Tc17 differentiation is not related to T-cell receptor (TCR) diversity and antigen specificity but is inversely correlated with self-reactivity acquired during development. Mechanistically, this phenomenon is linked to differential levels of intrinsic TCR sensitivity and basal Suppressor of Mothers Against Decapentaplegic 3 (SMAD3) expression, generating a wide spectrum of Tc17 differentiation potential within naive CD8+ T cell populations. These findings suggest that developmental self-reactivity can determine the fate of naive CD8+ T cells to generate functionally distinct effector populations and achieve immense diversity and complexity in antigen-specific T-cell immune responses.

Identification of New Isolates of Phytophthora sojae and Selection of Resistant Soybean Genotypes.

Phytophthora root and stem rot (PRR), caused by Phytophthora sojae, can occur at any growth stage under poorly drained and humid conditions. The expansion of soybean cultivation in South Korean paddy fields has increased the frequency of PRR outbreaks. This study aimed to identify four P. sojae isolates newly collected from domestic fields and evaluate race-specific resistance using the hypocotyl inoculation technique. The four isolates exhibited various pathotypes, with GJ3053 exhibiting the highest virulence complexity. Two isolates, GJ3053 and AD3617, were screened from 205 soybeans, and 182 and 190 genotypes (88.8 and 92.7%, respectively) were susceptible to each isolate. Among these accessions, five genotypes resistant to both isolates were selected. These promising genotypes are candidates for the development of resistant soybean cultivars that can effectively control PRR through gene stacking.