Kondo screening in a Majorana metal.

Kondo impurities provide a nontrivial probe to unravel the character of the excitations of a quantum spin liquid. In the S = 1/2 Kitaev model on the honeycomb lattice, Kondo impurities embedded in the spin-liquid host can be screened by itinerant Majorana fermions via gauge-flux binding. Here, we report experimental signatures of metallic-like Kondo screening at intermediate temperatures in the Kitaev honeycomb material α-RuCl3 with dilute Cr3+ (S = 3/2) impurities. The static magnetic susceptibility, the muon Knight shift, and the muon spin-relaxation rate all feature logarithmic divergences, a hallmark of a metallic Kondo effect. Concurrently, the linear coefficient of the magnetic specific heat is large in the same temperature regime, indicating the presence of a host Majorana metal. This observation opens new avenues for exploring uncharted Kondo physics in insulating quantum magnets.

National prevalence and determinants of COVID-19 vaccine hesitancy during the initial phase pandemic.

OBJECTIVE: Although previous studies have explored the causes of COVID-19 vaccine hesitancy during the pandemic, there is a lack of generality and reproducibility in these studies. Therefore, we aimed to comprehensively identify the determinants of COVID-19 vaccine hesitancy through a representative nationwide cross-sectional study conducted in South Korea. SUBJECTS AND METHODS: We used a nationwide, representative, and large-scale dataset from the 2021 Community Health Survey. By analyzing 193,495 participants, we investigated the nationwide incidence of COVID-19 vaccine hesitancy and the various causes thereof. RESULTS: The national prevalence of COVID-19 vaccine hesitancy was 5.7% (95% CI, 5.5-5.8). COVID-19 vaccine hesitancy was associated with an increased incidence of the following factors: (1) demographic factors including early-middle adulthood [vs. late; odds ratio (OR), 1.51; 95% CI, 1.38-1.65] and male sex (vs. female sex; OR, 1.08; 95% CI, 1.01-1.14); (2) physically healthy subjects; (3) lower socio-economic status (vs. high household income; OR, 1.28; 95% CI, 1.19-1.38); (4) having mental illness (vs. normal mental status; OR, 1.25; 95% CI, 1.13-1.38); and (5) unhealthy habits such as current smoking (vs. non-smoking; OR, 1.22; 95% CI, 1.13-1.31); and insufficient physical activity (vs. sufficient; OR, 1.08; 95% CI, 1.01-1.17). Common reasons for vaccine hesitancy were concerns about side effects (41.34%), health problems (24.60%), and inability to select the type of vaccine (14.13%). CONCLUSIONS: This representative large-scale nationwide study conducted in South Korea investigated the nationwide prevalence and determinants of vaccine hesitancy. Our results provide useful public health information, especially on novel aspects of vaccination strategies, for policymakers to improve the acceptance of COVID-19 vaccines.

17-year trends of body mass index, overweight, and obesity among adolescents from 2005 to 2021, including the COVID-19 pandemic: a Korean national representative study.

OBJECTIVE: There is a lack of pediatric studies that have analyzed trends in mean body mass index (BMI) and the prevalence of obesity and overweight over a period that includes the mid-stage of the COVID-19 pandemic. Thus, we aimed to investigate trends in BMI, overweight, and obesity among Korean adolescents from 2005 to 2021, including the COVID-19 pandemic. SUBJECTS AND METHODS: We used data from the Korea Youth Risk Behavior Web-based Survey (KYRBS), which is nationally representative of South Korea. The study included middle- and high-school students between the ages of 12 and 18. We examined trends in mean BMI and prevalence of obesity and/or overweight during the COVID-19 pandemic and compared these to those of pre-pandemic trends in each subgroup by gender, grade, and residential region. RESULTS: Data from 1,111,300 adolescents (mean age: 15.04 years) were analyzed. The estimated weighted mean BMI was 20.48 kg/m2 (95% CI, 20.46-20.51) between 2005 and 2007, and this was 21.61 kg/m2 (95% CI, 21.54-21.68) in 2021. The prevalence of overweight and obesity was 13.1% (95% CI, 12.9-13.3%) between 2005 and 2007 and 23.4% (95% CI, 22.8-24.0%) in 2021. The mean BMI and prevalence of obesity and overweight have gradually increased over the past 17 years; however, the extent of change in mean BMI and in the prevalence of obesity and overweight during the pandemic was distinctly less than before. The 17-year trends in the mean BMI, obesity, and overweight exhibited a considerable rise from 2005 to 2021; however, the slope during the COVID-19 pandemic (2020-2021) was significantly less prominent than in the pre-pandemic (2005-2019). CONCLUSIONS: These findings enable us to comprehend long-term trends in the mean BMI of Korean adolescents and further emphasize the need for practical prevention measures against youth obesity and overweight.

Magnetocaloric effect and Griffiths phase analysis in a nanocrystalline Ho2NiMnO6 and Ho2CoMnO6 double perovskite.

Rare-earth double perovskite oxides have intriguing magnetocaloric properties at cryogenic temperatures. In this study, Ho2NiMnO6 and Ho2CoMnO6 were synthesized using the sol-gel method, which crystallized in a monoclinic structure in the P21/n space group. The magnetic phase transition was observed at 81.2 K for Ho2NiMnO6 and 73.5 K for Ho2CoMnO6. The presence of a paramagnetic matrix and short-range ferromagnetic clusters causes magnetic disorder in these double perovskites, resulting in Griffiths phase formation. The Arrott plot confirms that compounds undergo second-order phase transition. At an applied magnetic field of 5 T, the maximum magnetic entropy change (-ΔS) for the studied compounds is 1.7 and 2.2 J kg-1 K-1, respectively. The transition metals Ni and Co in a double perovskite cause lattice distortion in the structural parameters and oxidation states of manganese (Mn3+/Mn4+), which changes the magnetic and magnetocaloric properties. The quantitative approach provides a systematic study of magnetocaloric properties of the rare earth double perovskite compounds with ferromagnetic 3d transition elements.

Risk factors for musculoskeletal-related occupational disability among US Army soldiers.

INTRODUCTION: Minimising temporary and permanent disability associated with musculoskeletal conditions (MSK-D) is critical to the mission of the US Army. Prior research has identified potentially actionable risk factors for overall military disability and its MSK-D subset, including elevated body mass index, tobacco use and physical fitness. However, prior work does not appear to have addressed the impact of these factors on MSK-D when controlling for a full range of factors that may affect health behaviours, including aptitude scores that may serve as a proxy for health literacy. Identifying risk factors for MSK-D when providing control for all such factors may inform efforts to improve military readiness. METHODS: We studied 494 757 enlisted Army soldiers from 2014 to 2017 using a combined medical and administrative database. Leveraging data from the Army's digital 'eProfile' system of duty restriction records, we defined MSK-D as the first restriction associated with musculoskeletal conditions and resulting in the inability to deploy or train. We used multivariable Cox proportional hazards regression to assess the associations between incident MSK-D and selected risk factors including aptitude scores, physical fitness test scores, body mass index and tobacco use. RESULTS: Among the subjects, 281 278 (45.14%) experienced MSK-D. In the MSK-D hazards model, the highest effect size was for failing the physical fitness test (adjusted HR=1.63, 95% CI 1.58 to 1.67, p<0.001) compared with scoring ≥290 points. CONCLUSIONS: The analysis revealed the strongest associations between physical fitness and MSK-D. Additional efforts are warranted to determine potential mechanisms for the observed associations between selected factors and MSK-D.

Ion beam figuring with focused anode layer thruster.

This work presents the peculiarities of cone ion beam formation with a focused thruster with anode layer (TAL) and its application to silicon carbide (SiC) ion beam figuring. Modeling results of Lorentz E × B force distribution in the discharge gap are presented. 3D particle tracing for keV Ar ions is carried out for the first time in the beam drift region of TAL with magnetic lens. Extracted ion beam full width at half maxima is about 2 mm in the focal plane, where the SiC etching rate reaches 0.5 µm/min. The SiC sputter yields are measured as a function of the Ar ion impact energy and beam incidence angle. The maximum sputter yield of 2.8 atom/ion is observed at 45° of the beam-sample angle for the Si targets. Furthermore, the maximum sputter yield value of 1.7 atom/ion is measured at 30° of the beam-sample angle for the SiC targets. The novelty of present research is in the application of focused TAL keV Ar ion beam to the SiC ion beam figuring.

Facial erythema in patients with atopic dermatitis treated with Dupilumab - a descriptive study of morphology and Aetiology.

BACKGROUND: The development of dermatitis on face and neck, which was not described in phase 3 clinical trials, has been reported in the literature in patients treated with dupilumab. Little is known regarding the causes or defining features of the facial dermatitis. OBJECTIVES: We conducted surveys of consecutive patients with AD on dupilumab to describe its clinical features, morphology and aetiology. METHODS: A multi-centre prospective cohort study was conducted from 1 January 2020, to 31 December 31 2020. A total of 162 patients under dupilumab treatment were asked to complete a questionnaire and patients were evaluated by dermatologists. RESULTS: Of all 162 patients, 137 (84.6%) patients reported pre-existing facial dermatitis prior to dupilumab therapy. One hundred and twenty-one (88.3%) patients with pre-existing facial dermatitis reported improvement of their facial dermatitis with dupilumab therapy, nine (6.6%) patients reported no change after the treatment and seven (4.3%) patients of them got worse after the treatment (exacerbation group). Of 25 patients who reported no pre-existing active facial dermatitis, six (24%) patients reported new-onset facial erythema after the starting dupilumab therapy (new-onset group). A large proportion of the patients in both the exacerbation (86%) and new-onset groups (67%) had a history of facial TCS use. Both groups showed similar clinical manifestations and distribution with few differences. CONCLUSIONS: The vast majority of patients treated with dupilumab in academic institutions from Korea and the United States experienced improvement in their facial dermatitis with dupilumab therapy. A small proportion of patients had new onset and exacerbation. Although the mechanisms of this adverse event remain unclear, steroid withdrawal should be considered as a diagnosis of the erythema in some patients.

Adjuvant durvalumab for esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy: a placebo-controlled, randomized, double-blind, phase II study.

BACKGROUND: We evaluated the efficacy of adjuvant durvalumab after neoadjuvant concurrent chemoradiotherapy (CCRT) in patients with esophageal squamous cell carcinoma (ESCC). PATIENTS AND METHODS: This randomized, double-blind, phase II study included patients with ESCC who underwent curative surgery after neoadjuvant CCRT. Patients were randomized to receive either durvalumab (20 mg/kg/i.v. every 4 weeks for 12 months) or placebo in a 1:1 ratio and were stratified by age and pathologic tumor stage. The primary endpoint was disease-free survival (DFS). RESULTS: Between March 2016 and June 2018, 86 patients were randomized to the durvalumab (n = 45) or placebo (n = 41) arm. The median follow-up duration was 38.7 months. There was no difference in DFS [hazard ratio (HR) 1.18, 95% confidence interval (CI) 0.62-2.27, P = 0.61] or overall survival (HR 1.08, 95% CI 0.52-2.24, P = 0.85) between the two arms. Subgroup analysis was performed for patients for whom the post-CCRT programmed death-ligand 1 (PD-L1) expression profile could be assessed (n = 54). In the PD-L1-positive group, based on tumor proportion score ≥1%, durvalumab was associated with longer overall survival compared with the placebo (36-month survival rate: 94% versus 64%; HR 0.42, 95% CI 0.10-1.76), while in the PD-L1-negative group, it was associated with shorter overall survival (42% versus 55%; HR 1.53, 95% CI 0.48-4.83), showing the tendency of interaction between post-CCRT PD-L1 status and adjuvant durvalumab therapy for overall survival (interaction P = 0.18). CONCLUSIONS: We failed to demonstrate that adjuvant durvalumab improved survival after neoadjuvant CCRT in patients with ESCC. However, post-CCRT PD-L1 expression could predict the survival of patients who receive adjuvant durvalumab after neoadjuvant CCRT, which needs to be validated.

[MUC4 Silencing Inhibits TGF-ß1-induced Epithelial-mesenchymal Transition VIA the ERK1/2 Pathway in Human Airway Epithelial NCI-H292 Cells].

MUC4 is a predominant membrane-tethered mucin lubricating and protecting the epithelial surface and playing various biological roles in the renewal and differentiation of epithelial cells, cell signaling, cell adhesion, and carcinogenesis. Interestingly, recent studies have demonstrated that MUC4 expression regulates the epithelial-mesenchymal transition (EMT) of cancer cells in ovarian, pancreatic, and lung cancer. However, the effects of MUC4 expression on EMT in human airway epithelial cells are not yet well known. Here, we describe the effects of transforming growth factor beta 1 (TGF-ß1)-induced MUC4 expression on EMT and evaluate its downstream signaling pathway in human airway epithelial cells. In human airway epithelial NCI-H292 cells, exposure to TGF-ß1 induced expression of MUC4, CDH2, VIM and SNAI1 genes and encoded by them proteins, MUC4, N-cadherin, vimentin and Snail, and reduced the level of CDH1 and its product, E-cadherin. In MUC4-knockdown cells, TGF-ß1-induced expression levels of MUC4, CDH2, VIM and SNAI1 and corresponding proteins were suppressed, but CDH1 and E-cadherin levels were not. In addition, TGF-ß1-induced phosphorylation of extracellular signal regulated kinase 1/2 (ERK1/2) was suppressed, but that of Smad2/3, Akt, and p38 was not. The results of this study suggest that MUC4 silencing inhibits TGF-ß1 -induced EMT via the ERK1/2 pathway, and a possible role of MUC4 in the induction of EMT in human airway epithelial cells.

Chronic rhinosinusitis and progression of cognitive impairment in dementia.

AIM: The relationship between chronic inflammatory disease and cognitive decline is still unclear, but there is increasing evidence to support the role of systemic inflammation. The aim of this study was to investigate if chronic rhinosinusitis (CRS) in dementia or mild cognitive impairment (MCI) is associated with the progression of cognitive decline. MATERIAL AND METHODS: We retrospectively reviewed the data of patients who complained of memory impairment, and underwent brain magnetic resonance imaging (MRI) from January 2006 to April 2019. According to the Mini-Mental State Examination (MMSE) score, subjects (n=661) were divided into three groups: dementia (≤17), MCI (18-23), and normal (≥24). CRS was defined as a total score of greater than or equal to 4 according to the Lund-Mackay scoring system using brain MRI. Multiple logistic regression analyses estimated adjusted odds ratio (aOR) for the association between CRS and dementia or MCI. Among the subjects with follow-up MMSE (n=286), a repeated-measures ANOVA was used to assess the difference of changes in MMSE scores between the groups with and without CRS. RESULTS: According to the initial MMSE score, there were 221 subjects with dementia, 195 with MCI, and 245 with normal results. CRS was not significantly associated with dementia (aOR=1.519, CI=0.909-2.538, P=0.111), while being suggestively associated with MCI (aOR=1.740, CI=1.041-2.906, P=0.034). The MMSE scores at follow-up decreased further in subjects with CRS than in those without CRS (P=0.009). Especially, in the initial dementia group, there was a significant between-group difference in the MMSE score from baseline to follow-up (13.6±4.3 to 11.1±6.3 in CRS group vs. 13.5±3.3 to 14.4±5.4 in no CRS group, P=0.002). CONCLUSION: The result of the present study implies a potential association between CRS and progression of cognitive decline. Physicians should be aware of this possibility in patients with clinically diagnosed CRS.

Randomly Hopping Majorana Fermions in the Diluted Kitaev System α-Ru_{0.8}Ir_{0.2}Cl_{3}.

dc and ac magnetic susceptibility, magnetization, specific heat, and Raman scattering measurements are combined to probe low-lying spin excitations in α-Ru_{1-x}Ir_{x}Cl_{3} (x≈0.2), which realizes a disordered spin liquid. At intermediate energies (ℏω>3 meV), Raman spectroscopy evidences linearly ω-dependent Majorana-like excitations, obeying Fermi statistics. This points to robustness of a Kitaev paramagnetic state under spin vacancies. At low energies below 3 meV, we observe power-law dependences and quantum-critical-like scalings of the thermodynamic quantities, implying the presence of a weakly divergent low-energy density of states. This scaling phenomenology is interpreted in terms of the random hoppings of Majorana fermions. Our results demonstrate an emergent hierarchy of spin excitations in a diluted Kitaev honeycomb system subject to spin vacancies and bond randomness.

Fipronil upregulates inflammatory cytokines and MUC5AC expression in human nasal epithelial cells.

BACKGROUND: Airway inflammation and excessive mucin production are pathophysiological characteristics of airway diseases. Fipronil, a pesticide, is being extensively used in agriculture and veterinary medicine worldwide. However, this compound impairs immune function in non-target organisms. The present study aimed to evaluate the effect of fipronil on pro-inflammatory cytokine and mucus production and signalling pathways in human primary nasal METHODOLOGY: The effect of fipronil on pro-inflammatory cytokine and MUC5AC expression and the signalling pathway of fipronil were investigated using real-time PCR, enzyme immunoassays, immunofluorescence, and immunoblot analysis with specific inhibitors and small interfering RNA. RESULTS: Fipronil treatment increased pro-inflammatory cytokine interleukin (IL)-1beta, IL-6, IL-8, and MUC5AC expression in human primary nasal epithelial cells. It also induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) mitogenactivated protein kinase (MAPK), p38 MAPK, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB). MAPK and NF-kB inhibitor treatment significantly inhibited increases in IL-1beta, IL-6, IL-8, and MUC5AC expression. Ex vivo data confirmed that fipronil-induced MUC5AC expression occurs through ERK1/2, p38, and NF-kB signalling pathways in nasal inferior turbinate tissue. CONCLUSIONS: Fipronil induced pro-inflammatory cytokine IL-1beta, IL-6, IL-8, and MUC5AC expression via ERK1/2 MAPK, p38 MAPK, and NF-kB in human primary nasal epithelial cells.

Exotic Low-Energy Excitations Emergent in the Random Kitaev Magnet Cu_{2}IrO_{3}.

We report on magnetization M(H), dc and ac magnetic susceptibility χ(T), specific heat C_{m}(T) and muon spin relaxation (µSR) measurements of the Kitaev honeycomb iridate Cu_{2}IrO_{3} with quenched disorder. In spite of the chemical disorders, we find no indication of spin glass down to 260 mK from the C_{m}(T) and µSR data. Furthermore, a persistent spin dynamics observed by the zero-field muon spin relaxation evidences an absence of static magnetism. The remarkable observation is a scaling relation of χ[H,T] and M[H,T] in H/T with the scaling exponent α=0.26-0.28, expected from bond randomness. However, C_{m}[H,T]/T disobeys the predicted universal scaling law, pointing towards the presence of additional low-lying excitations on the background of bond-disordered spin liquid. Our results signify a many-faceted impact of quenched disorder in a Kitaev spin system due to its peculiar bond character.

Carotid ultrasound measurements for assessing fluid responsiveness in spontaneously breathing patients: corrected flow time and respirophasic variation in blood flow peak velocity.

BACKGROUND: This study evaluated the ability of two Doppler ultrasound-derived parameters, the carotid corrected flow time (FTc) and respirophasic variation in carotid artery blood flow peak velocity (ΔVpeak), to predict fluid responsiveness in spontaneously breathing patients. METHODS: A total of 53 spontaneously breathing patients were studied before anaesthetic induction for neurosurgery. Carotid FTc, ΔVpeak, and haemodynamic data were measured before and after administration of 6 ml kg-1 colloid. Fluid responsiveness was defined as a 15% or more increase in stroke volume index as assessed by transthoracic echocardiography after the fluid challenge. RESULTS: Twenty-two (42%) patients were fluid responders. The areas under the receiver operating characteristic curves for FTc and ΔVpeak were 0.842 [95% confidence interval (CI) 0.735-0.948, P<0.001] and 0.818 (95% CI: 0.701-0.935, P<0.001), respectively. The optimal cut-off values of FTc and ΔVpeak for fluid responsiveness were 349.4 ms (sensitivity of 72.7%; specificity of 83.9%) and 9.1% (sensitivity of 72.7%; specificity of 87.1%), respectively. The grey zone for FTc was 346.9-361.0 ms and included 28% of the patients, and the grey zone for ΔVpeak was 6.5-10.2% and included 50% of the patients. CONCLUSIONS: Using Doppler ultrasound-derived parameters measured at the carotid artery, FTc predicted fluid responsiveness in spontaneously breathing patients better than ΔVpeak. However, further studies are warranted before these parameters are recommended for clinical use. CLINICAL TRIAL REGISTRATION: NCT 02843477.

Identification of transfusion-transmitted hepatitis A through postdonation information in Korea: results of an HAV lookback (2007-2012).

BACKGROUND AND OBJECTIVES: Despite safety measures to minimize the risk of transfusion-transmitted infections, a residual risk remains. To trace and review some such cases, we ask donors to notify the blood centre if they are diagnosed with an infection after they donate blood. MATERIALS AND METHODS: We analysed all data on postdonation cases of hepatitis A reported between 2007 and 2012. Archived specimens from these donors were tested for hepatitis A virus (HAV) using anti-HAV IgM/IgG and HAV-PCR as markers. If any of the test results were positive, we reviewed the medical records of the recipients and, if necessary, tested them for hepatitis A. RESULTS: Fifteen blood donors notified the blood centres of having been diagnosed with hepatitis A after donation. All archived samples except for one were HAV-PCR-positive and anti-HAV IgM/IgG-negative. Of the donated components, four RBCs and 14 FFPs had not been transfused to patients and were recalled. Among 26 recipients of the implicated components, fourteen were still alive when they were notified. Two patients showed clinical symptoms of hepatitis A and had positive results with anti-HAV IgM. CONCLUSION: Transfusion-transmitted hepatitis A is rare but exists. To reduce the risk, donors should be told to notify the blood centre if they are diagnosed with blood-borne diseases after they donate blood. Physicians should consider the possibility of transfusion-transmitted hepatitis A if a transfused patient has hepatitis A but no history of travel or route of faecal-oral infection.

Whole-Tumor Histogram and Texture Analyses of DTI for Evaluation of IDH1-Mutation and 1p/19q-Codeletion Status in World Health Organization Grade II Gliomas.

BACKGROUND AND PURPOSE: Prediction of the isocitrate dehydrogenase 1 (IDH1)-mutation and 1p/19q-codeletion status of World Health Organization grade ll gliomas preoperatively may assist in predicting prognosis and planning treatment strategies. Our aim was to characterize the histogram and texture analyses of apparent diffusion coefficient and fractional anisotropy maps to determine IDH1-mutation and 1p/19q-codeletion status in World Health Organization grade II gliomas. MATERIALS AND METHODS: Ninety-three patients with World Health Organization grade II gliomas with known IDH1-mutation and 1p/19q-codeletion status (18 IDH1 wild-type, 45 IDH1 mutant and no 1p/19q codeletion, 30 IDH1-mutant and 1p/19q codeleted tumors) underwent DTI. ROIs were drawn on every section of the T2-weighted images and transferred to the ADC and the fractional anisotropy maps to derive volume-based data of the entire tumor. Histogram and texture analyses were correlated with the IDH1-mutation and 1p/19q-codeletion status. The predictive powers of imaging features for IDH1 wild-type tumors and 1p/19q-codeletion status in IDH1-mutant subgroups were evaluated using the least absolute shrinkage and selection operator. RESULTS: Various histogram and texture parameters differed significantly according to IDH1-mutation and 1p/19q-codeletion status. The skewness and energy of ADC, 10th and 25th percentiles, and correlation of fractional anisotropy were independent predictors of an IDH1 wild-type in the least absolute shrinkage and selection operator. The area under the receiver operating curve for the prediction model was 0.853. The skewness and cluster shade of ADC, energy, and correlation of fractional anisotropy were independent predictors of a 1p/19q codeletion in IDH1-mutant tumors in the least absolute shrinkage and selection operator. The area under the receiver operating curve was 0.807. CONCLUSIONS: Whole-tumor histogram and texture features of the ADC and fractional anisotropy maps are useful for predicting the IDH1-mutation and 1p/19q-codeletion status in World Health Organization grade II gliomas.