Functional Characterization of Endo- and Exo-Hydrolase Genes in Arabinan Degradation Gene Cluster of Bifidobacterium longum subsp. suis.

Bifidobacteria are probiotic microorganisms commonly found in the gastrointestinal tract, some of which are known to utilize linear arabino-oligosaccharides (AOS) as prebiotic carbohydrates. In general, the synergistic actions of exo-type α-l-arabinofuranosidases (ABFs) and endo-α-1,5-l-arabinanases (ABNs) are required for efficient arabinan degradation. In this study, the putative gene cluster for arabinan degradation was discovered in the genome of Bifidobacterium longum subsp. suis. It consists of a variety of genes encoding exo- and endo-hydrolases, sugar-binding proteins, ABC-binding cassettes, and transcriptional regulators. Among them, two endo-ABNs GH43 (BflsABN43A and BflsABN43B), two exo-ABFs GH43 (BflsABF43A and BflsABF43B), and an exo-ABF GH51 (BflsABF51) were predicted to be the key hydrolases for arabinan degradation. These hydrolase genes were functionally expressed in Escherichia coli, and their enzymatic properties were characterized. Their synergism in arabinan degradation has been proposed from the detailed modes of action. Extracellular endo-BflsABN43A hydrolyzes sugar beet and debranched arabinans into the short-chain branched and linear AOS. Intracellularly, AOS can be further degraded into l-arabinose via the cooperative actions of endo-BflsABN43B, exo-BflsABF43A with debranching activity, α-1,5-linkage-specific exo-BflsABF43B, and exo-BflsABF51 with dual activities. The resulting l-arabinose is expected to be metabolized into energy through the pentose phosphate pathway by three enzymes expressed from the ara operon of bifidobacteria. It is anticipated that uncovering arabinan utilization gene clusters and their detailed functions in the genomes of diverse microorganisms will facilitate the development of customized synbiotics.

Synthesis of the Tetrasaccharide Glycone Part of Tetrocarcin A.

A de novo synthesis of the tetrasaccharide fragment of tetrocarcin A is described. The key feature of this approach is highlighted by the regio- and diastereoselective Pd-catalyzed hydroalkoxylation of ene-alkoxyallenes with an unprotected l-digitoxose glycoside. The subsequent reaction with digitoxal in combination with chemoselective hydrogenation generated the target molecule.

Relationship between obstructive sleep apnea, insulin resistance, and metabolic syndrome: a nationwide population-based survey.

We aimed to identify the association between obstructive sleep apnea (OSA), insulin resistance (IR), and metabolic syndrome (MetS) in a nationwide population-based sample. A total of 7,900 adults with information on the STOP-Bang score and MetS (3,341 men and 4,469 women) were identified from the dataset of the Korea National Health and Nutrition Examination Survey 2019-2020. The association between OSA, IR, MetS, and its components was estimated using complex sample logistic regression analysis with adjustments for age, body mass index, residence, smoking status, alcohol consumption, household income, education, and the presence of diabetes. Participants with a high OSA score were more likely to have IR (odds ratio [OR] 2.78, 95% confidence interval [CI] 1.96-3.95 in men and OR 2.64, 95% CI 0.55-12.80 in women), MetS (OR 6.05, 95% CI 4.23-8.69 in men and OR 4.20, 95% CI 1.23-15.70 in women), and components of MetS, compared to individuals with a low OSA score. Compared to premenopausal women, postmenopausal women had a more intense association between OSA and IR (OR 1.78, 95% CI 0.13-24.43 for premenopausal women and OR 3.64, 95% CI 0.60-22.28 for postmenopausal women) and MetS (OR 2.58, 95% CI 0.23-29.55 for premenopausal women and OR 5.36, 95% CI 1.42-20.21 for postmenopausal women). OSA was associated with abdominal obesity and hypertension in premenopausal women, while all components of MetS were associated with OSA in postmenopausal women. Further studies are necessary to elucidate the underlying mechanisms of these findings.

Prevalence, Trend, and Risk Factors for Early Chronic Obstructive Pulmonary Disease: An Analysis of the Nationwide Population-Based Survey from 2010 to 2019 in South Korea.

This study aimed to evaluate the prevalence, trends, and risk factors of early chronic obstructive pulmonary disease (COPD) by using a nationally representative sample. The datasets of the Korea National Health and Nutrition Examination Survey 2010-2019 were used, where 80,860 individuals were identified; of these, 9,045 participants aged 40-49 years who underwent spirometry with no missing data were analyzed. Early COPD was defined as forced expiratory volume in 1 s /forced vital capacity ratio < the lower limit of normal (2.5th percentile) in individuals aged <50 years without a history of asthma, inhaler therapy, or persistent respiratory symptoms. The prevalence and trend of early COPD were estimated according to features such as smoking status and pack-years. Joinpoint regression analysis was used to analyze the significant annual change in the trend according to sex, smoking status, and pack-years. A complex sample multivariable-adjusted regression model was used to identify factors affecting early COPD. The estimated population size during 2010-2019 was 82,326,178. Early COPD was present in 4.5% of patients (6.5% of men and 2.3% of women). It was present in 7.7% of current smokers, followed by former and never smokers. Among smokers with ≥ 10 pack-years, early COPD was present in 8.2%, whereas it was present in 2.6% of smokers with < 10 pack-years. Joinpoint regression analyses found a recent decrease in the trend of prevalence in males who were former and current smokers. The multivariable-adjusted logistic regression model showed that being male, lower educational level, smoking status, and pack-years were factors that affected the presence of early COPD. Continued surveillance of this pre-disease condition is required, and further research are warrant.

Enhancement of Electromagnetic Wave Shielding Effectiveness by the Incorporation of Carbon Nanofibers-Carbon Microcoils Hybrid into Commercial Carbon Paste for Heating Films.

Carbon microcoils (CMCs) were formed on stainless steel substrates using C2H2 + SF6 gas flows in a thermal chemical vapor deposition (CVD) system. The manipulation of the SF6 gas flow rate and the SF6 gas flow injection time was carried out to obtain controllable CMC geometries. The change in CMC geometry, especially CMC diameter as a function of SF6 gas flow injection time, was remarkable. In addition, the incorporation of H2 gas into the C2H2 + SF6 gas flow system with cyclic SF6 gas flow caused the formation of the hybrid of carbon nanofibers-carbon microcoils (CNFs-CMCs). The hybrid of CNFs-CMCs was composed of numerous small-sized CNFs, which formed on the CMCs surfaces. The electromagnetic wave shielding effectiveness (SE) of the heating film, made by the hybrids of CNFs-CMCs incorporated carbon paste film, was investigated across operating frequencies in the 1.5-40 GHz range. It was compared to heating films made from commercial carbon paste or the controllable CMCs incorporated carbon paste. Although the electrical conductivity of the native commercial carbon paste was lowered by both the incorporation of the CMCs and the hybrids of CNFs-CMCs, the total SE values of the manufactured heating film increased following the incorporation of these materials. Considering the thickness of the heating film, the presently measured values rank highly among the previously reported total SE values. This dramatic improvement in the total SE values was mainly ascribed to the intrinsic characteristics of CMC and/or the hybrid of CNFs-CMCs contributing to the absorption shielding route of electromagnetic waves.

Genome-wide meta-analysis revealed several genetic loci associated with serum uric acid levels in Korean population: an analysis of Korea Biobank data.

The serum uric acid (SUA) level is an important determinant of gout, hypertension, metabolic syndrome, and cardiovascular disease. Although previous genome-wide studies have identified multiple genetic variants associated with SUA, most genetic analyses have focused on individuals with European ancestry; thus, understanding of the genetic architecture of SUA is currently limited for Asian populations. We conducted a genome-wide meta-analysis based on Korea Biobank data consistent with three cohorts; namely, the Korean Genome and Epidemiology Study (KoGES) Ansan and Ansung, KoGES Health Examinee, and KoGES Cardiovascular Disease Association studies. In total, 60,585 participants aged ≥40 years were included in the analysis of the three cohorts. We used logistic regression analyses to perform genome-wide association study (GWAS) adjustments for confounding variables. Subsequently, a meta-analysis was conducted by combining the analyses of the three GWASs. We identified 8,105 variants at 22 genetic loci with a P value < 5 × 10-8. Among these, six novel genetic loci associated with SUA in the Korean population were identified (rs4715517 in HCRTR2, rs145099458 in 3.2 kb 3' of MLXIPL, rs1137642 in B4GALT1, rs659107 in LOC105378410, rs7919329 in LOC107984274, and rs2240751 in MFSD12). Our meta-analysis provides insights into the genetic architecture of SUA in the Korean population. Further studies are warranted to replicate the study results and elucidate the specific role of these variants in SUA homeostasis.

"Elbow-Lock" Chest Compression Method in the Setting of Single Rescuer Pediatric Cardiopulmonary Resuscitation: A Crossover Simulation Study.

BACKGROUND: We designed a new 1-handed chest compression method, the "elbow-lock" chest compression (ELCC), for a single rescuer in pediatric cardiopulmonary resuscitation (CPR). Then, we compared the effectiveness between the ELCC and standard chest compression (SCC) method. METHODS: This prospective, randomized controlled, crossover simulation trial studied 34 emergency medical professionals, including physicians, nurses, and EMTs. We compare the quality of chest compression and fatigue point time between the ELCC and the SCC. RESULTS: Participants who performed the ELCC method maintained a proper depth of compression compared with SCC method (50.0 ± 0.3 mm vs 40.5 ± 0.4 mm, P < 0.001). However, the 2 methods did not differ in terms of compression velocity since neither reached the standard velocity (96.7 ± 7.1/minutes vs 91.7 ± 7.0/minutes, P < 0.016). With respect to the overall score, ELCC was more effective than the SCC (91.6 ± 3.7% vs 85.3 ± 8.8%, P = 0.002). In addition, the fatigue point time was slower in the ELCC group than the SCC group (7.3 ± 0.3/minutes vs 6.1 ± 0.4/minutes, P < 0.001). CONCLUSIONS: The single rescuer ELCC method is an effective alternative to the SCC method for pediatric CPR because the ELCC method can prevent elbow flexion.Trial registration: Our research is simulation manikin study. So we do not need to "trial registration".

COVID-19 vaccination-related small vessel vasculitis with multiorgan involvement.

Since its first outbreak in 2019, coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2, has been ongoing, and the pandemic is not over yet. Vaccines developed against COVID-19 have been approved and widely used since 2020; however, vaccine safety concerns need to be addressed. Autoimmune symptoms have been reported as a side effect of many COVID-19 vaccines. In particular, several cases of COVID-19 vaccine-induced vasculitis have recently been reported. Herein, we report the case of a 77-year-old woman who developed small-vessel vasculitis with multiorgan involvement after receiving the BNT162b2 COVID-19 vaccine (Pfizer and BioNTech, New York City, NY, USA).

Changes in the pattern of suicide attempters visiting the emergency room after COVID-19 pandemic: an observational cross sectional study.

BACKGROUND: This study aimed to find out the change in the rate and pattern of suicide attempts during severe acute respiratory syndrome COVID-19 pandemic period. METHODS: This study was a retrospective analysis of data collected as a part of an emergency room-based post-suicide management program. The data were collected through interviews and from medical records of suicide attempts, maintained in the emergency room, from January 19 to October 31, 2020, during the "COVID-19 period," and those who attempted suicide from January 19 to October 31, 2019 "pre-COVID-19 period." We extracted educational background, marital status, occupation, presence of domestic partner, history of mental illness, alcohol consumption, history of previous suicide attempts; suicide attempt method and location (i.e., at home or a place other than home) at the time of attempt, and whether the attempt was a mass suicide. In addition, we compared patient severity between "COVID-19 period" and "pre-COVID-19 period" using the initial KTAS (South Korean triage and acuity scale) level, consciousness level, and systolic blood pressure. In 2012, KTAS was developed through the Ministry of Health and Welfare's research project to establish triage system in South Korea. RESULTS: The analysis of the number of suicide attempts during "pre-COVID-19 period" and " COVID-19 period" showed that the number of suicide attempts during "COVID-19 period" (n = 440) increased compared to the "pre-COVID-19 period" (n = 400). Moreover, the method of suicide attempts during "COVID-19 period" included overdose of drugs such as hypnotics, antipsychotics, and pesticides that were already possessed by the patient increased compared to the "pre-COVID-19 period" (P < 0.05). At the time of the visit to the emergency room, high KTAS level, low level of consciousness, and low systolic blood pressure, were observed, which were significantly different between "COVID-19 period" and "pre-COVID-19 period" (P < 0.05). CONCLUSION: With the worldwide COVID-19 virus spread, suicide rate and suicide attempts at home have significantly increased. In addition, patient severity was higher in the "COVID-19 period" than that in the "pre-COVID-19 period." The increasing suicide attempt rate should be controlled by cooperation between the emergency room and regional organizations.

Association between dual use of e-cigarette and cigarette and chronic obstructive pulmonary disease: an analysis of a nationwide representative sample from 2013 to 2018.

BACKGROUND: The association between the dual use of electronic cigarette (e-cigarette) and conventional cigarettes (c-cigarette) and spirometry-defined chronic obstructive pulmonary disease (COPD) has not been studied thoroughly. METHODS: A total of 47,217 participants were identified in the 2013-2018 Korea National Health and Nutrition Examination Survey; of them, 12,919 participants aged ≥ 40 who underwent spirometry and had no missing data were enrolled. Pulmonary function testing, urinary cotinine, and urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) levels were compared between dual users, current smokers, former smokers, and non-users using complex sample linear regression analysis. The odds ratio (OR) for COPD was calculated using a complex sample logistic regression model after adjusting for covariates. RESULTS: Among current e-cigarette users, approximately 85% of the participants used c-cigarette concurrently, and 1.3% of all the participants were dual users (2.3% in males and 0.1% in females). Both dual users and current smokers showed higher levels of urine cotinine and NNAL than non-users and former smokers. The weighted prevalence of COPD was the highest in dual users (13.8% for all participants and 14.1% for males). The multivariate-adjusted OR of COPD for male dual users, compared to non-users, was 3.46 (Ptrend < 0.001). The OR for COPD was 3.10 (Ptrend < 0.001) in middle-aged (40-64 years) and 3.70 (Ptrend < 0.001) in older (≥ 65 years) men. In females, the association was not observed and could not be precisely measured because of the small proportion of the smoking population. CONCLUSIONS: Dual use of e-cigarette and c-cigarette is associated with COPD in males.

Tunable Cherenkov Radiation of Phonon Polaritons in Silver Nanowire/Hexagonal Boron Nitride Heterostructures.

Polaritons in two-dimensional (2D) materials have shown their unique capabilities to concentrate light into deep subwavelength scales. Precise control of the excitation and propagation of 2D polaritons has remained a central challenge for future on-chip nanophotonic devices and circuits. To solve this issue, we exploit Cherenkov radiation, a classic physical phenomenon that occurs when a charged particle moves at a velocity greater than the phase velocity of light in that medium, in low-dimensional material heterostructures. Here, we report an experimental observation of Cherenkov phonon polariton wakes emitted by superluminal one-dimensional plasmon polaritons in a silver nanowire and hexagonal boron nitride heterostructure using near-field infrared nanoscopy. The observed Cherenkov radiation direction and radiation rate exhibit large tunability through varying the excitation frequency. Such tunable Cherenkov phonon polaritons provide opportunities for novel deep subwavelength-scale manipulation of light and nanoscale control of energy flow in low-dimensional material heterostructures.

Selective and ATP-competitive kinesin KIF18A inhibitor suppresses the replication of influenza A virus.

The influenza virus is one of the major public health threats. However, the development of efficient vaccines and therapeutic drugs to combat this virus is greatly limited by its frequent genetic mutations. Because of this, targeting the host factors required for influenza virus replication may be a more effective strategy for inhibiting a broader spectrum of variants. Here, we demonstrated that inhibition of a motor protein kinesin family member 18A (KIF18A) suppresses the replication of the influenza A virus (IAV). The expression of KIF18A in host cells was increased following IAV infection. Intriguingly, treatment with the selective and ATP-competitive mitotic kinesin KIF18A inhibitor BTB-1 substantially decreased the expression of viral RNAs and proteins, and the production of infectious viral particles, while overexpression of KIF18A enhanced the replication of IAV. Importantly, BTB-1 treatment attenuated the activation of AKT, p38 MAPK, SAPK and Ran-binding protein 3 (RanBP3), which led to the prevention of the nuclear export of viral ribonucleoprotein complexes. Notably, administration of BTB-1 greatly improved the viability of IAV-infected mice. Collectively, our results unveiled a beneficial role of KIF18A in IAV replication, and thus, KIF18A could be a potential therapeutic target for the control of IAV infection.

Flexible Total Synthesis of 11-Deoxylandomycins and Their Non-Natural Analogues by Way of Asymmetric Metal Catalysis.

A de novo first collective total synthesis of 11-deoxylandomycins is reported. A signature step is featured by the Pd-catalyzed asymmetric addition of alcohol to ene-alkoxyallenes that assembles oligomeric 2,3,6-trideoxyoligosaccharides. The unique feature of the protocol is illustrated by a flexible access to various natural 11-deoxylandomycins as well as non-natural analogues.

Stereoselective Total Syntheses of (+)-Castanospermine and Neu5Ac Methyl Ester.

Concise and stereocontrolled total syntheses of (+)-castanospermine and N-acetylneuraminic acid methyl ester were achieved from diastereomerically enriched anti, syn, syn-1,3-oxazine and anti, syn, anti-1,3-oxazine, respectively. The key step in this strategy was the stereoselective BF3·OEt2-mediated allylation.

Anti-viral activity of compounds from Agrimonia pilosa and Galla rhois extract mixture.

Hepatitis C virus (HCV) infection is a significant health problem, with a worldwide prevalence of about 170 million. Recently, the development of direct acting antiviral (DAA) as a therapeutic agent for HCV has been rapidly increasing. However, DAA has a side effect and is costly. Therefore, it is still necessary to develop a therapeutic agent to treat HCV infection using products. Agrimonia pilosa (AP) and Galla rhois (RG) are traditional medicines and are known to display therapeutic activity on various diseases. Notably, they have been reported to have an anti-viral effect on HBV and influenza virus infections. It is expected that anti-viral activity will increase when two extracts are mixed. To investigate their anti-viral activity, the expression level of HCV Core 1b and NS5A was measured. Remarkably, AP, RG, and their mixed compound (APRG64) strongly inhibited the expression of viral proteins, which led us to identify their metabolites. A total of 14 metabolites were identified using liquid chromatography mass spectrometry (LC-MS). These metabolites were evaluated for their anti-HCV activity to identify active ingredients. In conclusion, our results unveiled that anti-HCV activity of Agrimonia pilosa and Galla rhois extract mixture could lead to the development of a novel therapy for HCV infection.

Global transcriptomic response of Listeria monocytogenes during growth on cantaloupe slices.

Understanding a pathogen's response to food environments is imperative to develop effective control strategies as well as to elucidate the impact of foods on virulence potential. The purpose of this study was to assess transcriptional response of Listeria monocytogenes after growth in cantaloupe, as well as its impact on survival in synthetic gastric fluid (SGF). The transcriptional profiles of L. monocytogenes grown in cantaloupe or Brain Heart Infusion (BHI) under refrigeration were compared by a custom-designed microarray. A total of 286 and 175 genes were significantly up- and down-regulated, respectively, in L. monocytogenes grown in cantaloupe as compared to BHI (fold change ≥ 2.5 and adj. P < 0.05). The majority of upregulated genes belonged to functions related to amino acid and nucleotide metabolism, flagellar biosynthesis, and iron acquisition, while most downregulated genes belonged to carbohydrate metabolism. Notably, the branched chain amino acid (BCAA: leucine, isoleucine, valine) biosynthesis operon was shown to be highly upregulated as well as the purine and pyrimidine biosynthesis pathways. Transcript levels of several stress- and virulence-related genes were significantly altered, implying an impact of growth in cantaloupe on the virulence potential of L. monocytogenes. Enhanced survival of L. monocytogenes in SGF following growth in cantaloupe further demonstrated the impact of cantaloupe-associated growth on the pathogen's subsequent response to a host relevant stress.

Mid-IR broadband supercontinuum generation from a suspended silicon waveguide.

Mid-infrared light provides numerous unexpected opportunities in scientific discoveries because this wavelength region covers the fingerprints of various molecular vibrational resonances. However, the light generation efficiency and bandwidth have been a long-standing bottleneck which has limited the development so far. Moreover, the light source that can be integrated with other components such as wavelength filters, detectors, and electronics, will be the key factor toward the future practical applications. Here, we propose an all-air-cladding silicon-rib waveguide to experimentally reveal the nonlinear performance of supercontinuum generation. By tuning the waveguide dispersion parameters with simulation, a continuous broad spectrum of 1.32 octave (2-5 µm) was observed with a pump pulse wavelength of 4 µm. To further investigate our device characteristics, multiple conditions were set by varying the interaction length, pump power, and waveguide dimension, which revealed the nonlinear phenomenon in the waveguide.

Goos-Hänchen Shift and Even-Odd Peak Oscillations in Edge-Reflections of Surface Polaritons in Atomically Thin Crystals.

Two-dimensional surface polaritons (2DSPs), such as graphene plasmons, exhibit various unusual properties, including electrical tunability and strong spatial confinement with high Q-factor, which can enable tunable photonic devices for deep subwavelength light manipulations. Reflection of plasmons at the graphene's edge plays a critical role in the manipulation of 2DSP and enables their direct visualization in near-field infrared microscopy. However, a quantitative understanding of the edge-reflections, including reflection phases and diffraction effects, has remained elusive. Here, we show theoretically and experimentally that edge-reflection of 2DSP exhibits unusual behaviors due to the presence of the evanescent waves, including an anomalous Goos-Hänchen phase shift as in total internal reflections and an unexpected even-odd peak amplitude oscillation from the wave diffraction at the edge. Our theory is not only valid for plasmons in graphene but also for other 2D polaritons, such as phonon polaritons in ultrathin boron nitride flakes and exciton polariton in two-dimensional semiconductors.

Coupled One-Dimensional Plasmons and Two-Dimensional Phonon Polaritons in Hybrid Silver Nanowire/Silicon Carbide Structures.

Surface plasmons (SPs) and phonon polaritons (PhPs) are two distinctive quasiparticles resulting from the strong coupling of photons with electrons and optical phonons, respectively. In this Letter, we investigate the interactions between one-dimensional (1D) plasmons in silver nanowires with two-dimensional (2D) surface phonon polaritons of the silicon carbide (SiC) substrate. Using near-field infrared spectroscopy of the silver nanowire-SiC heterostructure at wavelengths close to the phonon resonance of SiC, we observe that the 1D plasmon dispersion is strongly modified by the 2D phonon polaritons in SiC. In particular, we observe for the first time well-defined 1D plasmon oscillations with the plasmon wavelengths longer than the free-space photon wavelengths due to the 1D plasmon-2D phonon polariton coupling. Our work demonstrates that unusual polariton behavior can emerge from interactions between polariton excitons of different dimensionality, which can enable new ways to engineer plasmons in hybrid structures.

Soliton-dependent plasmon reflection at bilayer graphene domain walls.

Layer-stacking domain walls in bilayer graphene are emerging as a fascinating one-dimensional system that features stacking solitons structurally and quantum valley Hall boundary states electronically. The interactions between electrons in the 2D graphene domains and the one-dimensional domain-wall solitons can lead to further new quantum phenomena. Domain-wall solitons of varied local structures exist along different crystallographic orientations, which can exhibit distinct electrical, mechanical and optical properties. Here we report soliton-dependent 2D graphene plasmon reflection at different 1D domain-wall solitons in bilayer graphene using near-field infrared nanoscopy. We observe various domain-wall structures in mechanically exfoliated graphene bilayers, including network-forming triangular lattices, individual straight or bent lines, and even closed circles. The near-field infrared contrast of domain-wall solitons arises from plasmon reflection at domain walls, and exhibits markedly different behaviours at the tensile- and shear-type domain-wall solitons. In addition, the plasmon reflection at domain walls exhibits a peculiar dependence on electrostatic gating. Our study demonstrates the unusual and tunable coupling between 2D graphene plasmons and domain-wall solitons.