Diagnosis of osteochondral lesions of the talus on Dual-layer spectral detector CT arthrography: clinical feasibility of virtual noncontrast images

AIM

To compare the image quality of virtual noncontrast (VNC) and true noncontrast (TNC) CT images and to evaluate the clinical feasibility of VNC CT images for assessing osteochondral lesions of the talus (OLTs).

MATERIALS AND METHODS

Forty-five OLT patients who underwent ankle CT arthrography (CTA) using dual-layer spectral detector CT were enrolled. Reconstruction of VNC and three-dimensional volume rendering images was performed. Afterward, image noise, the signal-to-noise ratio (SNR), and the contrast-to-noise ratio (CNR) were measured. For the subjective evaluation, two board-certified musculoskeletal radiologists [R2-1] assessed spatial resolution, overall image quality, and lesion conspicuity. The accuracy rate for OLT grading was determined in 23 patients who underwent arthroscopic surgery.

RESULTS

While VNC images showed significantly less noise than TNC images, TNC images showed better SNRs and CNRs (p<.01). In the subjective analysis, TNC images showed better overall image quality (p<.001). For the 3D volume rendering images, VNC images scored significantly higher for lesion conspicuity (p<.001). The accuracy rates of CTA and CTA with VNC images for OLT grading were 79.2% and 83.3%, respectively. Regarding confidence level, when CTA and VNC images were evaluated together, the confidence level was significantly higher than that when only CTA images were evaluated (p<.001).

CONCLUSION

VNC imaging can provide better confidence level of OLT grading and evaluation of the integrity of the subchondral bone plate when combined with conventional CTA without additional radiation dose to the patient. In addition, VNC images-based 3D volume rendering reconstruction would be helpful for preoperative planning in OLT patients.

Synthesis of Graphitic Carbon Coated ZnPS3 and its Superior Electrochemical Properties for Lithium and Sodium Ion Storage

Graphitic carbon-coated ZnPS3 is prepared via direct phosphosulfurization and high energy mechanical milling (HEMM) with multiwall carbon nanotubes (MWCNTs) and first introduced as an anode for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The HEMM process with MWCNTs reduces the particle size of as-synthesized ZnPS3 bulk to 100-500 nm and yields the ≈5 nm thick graphitic carbon coated ZnPS3 nanoparticles, which are the nanocomposites of 5 nm sized nanocrystallites embedded in the amorphous matrix. The ZnPS3 electrode undergoes the combined conversion and alloying reactions with Li and Na ions and exhibits high initial discharge and charge capacities in both LIBs and SIBs. The graphitic carbon-coated ZnPS3 electrode exhibits excellent high-rate capability and long-term cyclability. The superior electrochemical properties can be attributed to high electrical conductivity, high Li ion mobility, and high reversibility and structural stability derived from the graphitic carbon-coated nanoparticles. This study demonstrates that the novel graphitic carbon-coated ZnPS3 is a promising anode material for both LIBs and SIBs and the graphitic carbon coating methodology by HEMM is expected to apply to the various metal oxides, sulfides, and phosphides.

Anti-diabetic effect of quercetin in type 2 diabetes mellitus by regulating the microRNA-92b-3p/EGR1 axis

Insulin resistance (IR) is predominantly causal for type 2 diabetes mellitus (T2DM). To solve this problem, this study particularly determined the role of quercetin (Que) in controlling IR in T2DM mice. The T2DM mouse model was established, and given 20 mg/kg/d Que by gavage for 6 weeks, and the lentiviral vector that interfered with microRNA-92b-3p (miR-92b-3p) or early growth response 1 (EGR1) expression was injected into the tail vein of T2DM mice. Blood glucose homeostasis and histopathological changes in the pancreas were observed after the corresponding treatment. miR-92b-3p and EGR1 expressions were assessed in T2DM mice, as well as their interlink. In results we found that Que could improve IR and pancreatic histopathological changes in T2DM mice. Low miR-92b-3p and high EGR1 were expressed in T2DM mice, while Que could upregulate miR-92b-3p to target EGR1. Enhancing miR-92b-3p or reducing EGR1 could further improve IR and pancreatic histopathological changes in T2DM mice after Que administration. Nevertheless, silencing miR-92b-3p or overexpressing EGR1 contributed to the opposite results. We concluded that Que exerted anti-diabetic effects in T2DM mice by regulating the miR-92b-3p/EGR1 axis.

Mapping the electrocatalytic water splitting activity of VO2 across its insulator-to-metal phase transition

The electrocatalytic water splitting activity of V-based oxides has been rarely investigated, even though several polymorphs in VO₂ are expected to exhibit different electrocatalytic activities depending on their crystal and electronic structures. The rutile structure of VO₂(R), showing metallic character, is a good candidate for a new electrocatalyst since it undergoes insulator-to-metal transition (IMT) from the insulating VO₂(M1) at a low temperature of 68 °C, and involves a substantially increased electrical conductivity by three orders of magnitude. The extensive improvements in the electrocatalytic activity for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) are confirmed when the IMT is induced where the overpotential (η₁₀) is reduced from 1056 mV to 598 mV in the OER and 411 mV to 136 mV in the HER, respectively. This improvement is attributed to the increased electrochemically active surface area (ECSA), reduced charge transfer resistance, and increased electron density, driven by the IMT to the metallic VO₂(R) phase.

COVID-19 susceptibility and clinical outcomes in autoimmune inflammatory rheumatic diseases (AIRDs): a systematic review and meta-analysis

OBJECTIVE

This meta-analysis aims to assess the susceptibility to and clinical outcomes of COVID-19 in autoimmune inflammatory rheumatic disease (AIRD) and following AIRD drug use.

MATERIALS AND METHODS

We included observational and case-controlled studies assessing susceptibility and clinical outcomes of COVID-19 in patients with AIRD as well as the clinical outcomes of COVID-19 with or without use of steroids and conventional synthetic disease-modifying antirheumatic drugs (csDMARDs).

RESULTS

Meta-analysis including three studies showed that patients with AIRD are not more susceptible to COVID-19 compared to patients without AIRD or the general population (OR: 1.11, 95% CI: 0.58 to 2.14). Incidence of severe outcomes of COVID-19 (OR: 1.34, 95% CI: 0.76 to 2.35) and COVID-19 related death (OR: 1.21, 95% CI: 0.68 to 2.16) also did not show significant difference. The clinical outcomes of COVID-19 among AIRD patients with and without csDMARD or steroid showed that both use of steroid (OR: 1.69, 95% CI: 0.96 to 2.98) or csDMARD (OR: 1.35, 95% CI: 0.63 to 3.08) had no effect on clinical outcomes of COVID-19.

CONCLUSIONS

AIRD does not increase susceptibility to COVID-19, not affecting the clinical outcome of COVID-19. Similarly, the use of steroids or csDMARDs for AIRD does not worsen the clinical outcome.

Continuing perioperative estrogen therapy does not increase venous thromboembolic events in transgender patients: a systematic review and meta-analysis

OBJECTIVE

The aim of this study is to compare the risk of venous thromboembolic events (VTE) between patients suspending and continuing estrogen therapy perioperatively, in male to female gender-affirming surgery (vaginoplasty).

MATERIALS AND METHODS

The authors conducted a systematic review and meta-analysis of existing research on male to female gender-affirming study, which compared the risk of VTE among the usage of estrogen perioperatively.

RESULTS

A total of 209 studies were identified as potentially eligible among PubMed, Embase, and Cochrane library databases. Among the studies, 191 studies were excluded due to their abstract inappropriateness. Out of the remaining 18 studies, only 3 articles were eligible and were finally included. Meta-analysis was performed and showed odds ratio of 0.77 (95% CI: 0.04, 14.01).

CONCLUSIONS

Perioperative estrogen therapy does not increase VTE risk on male to female gender-affirming surgery. Therefore, estrogen therapy may be continued perioperatively in vaginoplasty. More prospective studies are needed.

Visible Light Driven Ultrasensitive and Selective NO2 Detection in Tin Oxide Nanoparticles with Sulfur Doping Assisted by l-Cysteine

In the pandemic era, the development of high-performance indoor air quality monitoring sensors has become more critical than ever. NO₂ is one of the most toxic gases in daily life, which induces severe respiratory diseases. Thus, the real-time monitoring of low concentrations of NO₂ is highly required. Herein, a visible light-driven ultrasensitive and selective chemoresistive NO₂ sensor is presented based on sulfur-doped SnO₂ nanoparticles. Sulfur-doped SnO₂ nanoparticles are synthesized by incorporating l-cysteine as a sulfur doping agent, which also increases the surface area. The cationic and anionic doping of sulfur induces the formation of intermediate states in the band gap, highly contributing to the substantial enhancement of gas sensing performance under visible light illumination. Extraordinary gas sensing performances such as the gas response of 418 to 5 ppm of NO₂ and a detection limit of 0.9 ppt are achieved under blue light illumination. Even under red light illumination, sulfur-doped SnO₂ nanoparticles exhibit stable gas sensing. The endurance to humidity and long-term stability of the sensor are outstanding, which amplify the capability as an indoor air quality monitoring sensor. Overall, this study suggests an innovative strategy for developing the next generation of electronic noses.

Suicide associated with COVID-19 infection: an immunological point of view

OBJECTIVE

Coronavirus disease 2019 (COVID-19) is a pandemic and leading cause of death. Beyond the deaths directly caused by the virus and the suicides related to the psychological response to the dramatic changes as socioeconomic related to the pandemic, there might also be suicides related to the inflammatory responses of the infection. Infection induces inflammation as a cytokine storm, and there is an increasing number of studies that report a relationship between infection and suicide.

MATERIALS AND METHODS

We searched the World Health Organization status report and the PubMed database for keywords (COVID-19, suicide, infection, inflammation, cytokines), and reviewed five cytokine pathways between suicide and inflammation using two meta-analyses and two observational studies starting from November 31, 2020, focusing on the relationship between suicide and inflammation by infection. First, we discussed existing evidence explaining the relationship between suicidal behaviors and inflammation. Second, we summarized the inflammatory features found in COVID-19 patients. Finally, we highlight the potential for these factors to affect the risk of suicide in COVID-19 patients.

RESULTS

Patients infected with COVID-19 have high amounts of IL-1β, IFN-γ, IP10, and MCP1, which may lead to Th1 cell response activation. Also, Th2 cytokines (e.g., IL-4 and IL-10) were increased in COVID-19 infection. In COVID-19 patients, neurological conditions, like headache, dizziness, ataxia, seizures, and others have been observed.

CONCLUSIONS

COVID-19 pandemic can serve as a significant environmental factor contributing directly to increased suicide risk; the role of inflammation by an infection should not be overlooked.

Efficacy and safety of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) monotherapy for advanced EGFR-mutated non-small cell lung cancer: systematic review and meta-analysis

OBJECTIVE

It is controversial whether there is efficacy or safety benefit of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) in advanced EGFR-mutated non-small cell lung cancer (NSCLC) compared to standard chemotherapy. We aim to assess the efficacy and safety of EGFR-TKIs compared to other chemotherapeutics in EGFR-mutated NSCLC.

MATERIALS AND METHODS

Up to April 27th, 2020, PubMed, Embase, Medline, Scopus, Cochrane library, and ClinicalTrials.gov were searched for articles or trials meeting the inclusion criteria. After filtering, 230 eligible studies were initially identified. Data extraction followed PRISMA and included outcomes were progression-free survival (PFS), overall survival (OS), and severe adverse events (SAEs). Direct and indirect meta-analyses were generated in the context of log-linear mixed-effects models, with fixed effects for each relative comparison and random effects for each study.

RESULTS

The results showed that EGFR-TKI therapy had improved PFS with a hazard ratio (HR) of 0.40 (95% CI: 0.36-0.44, p<0.001) compared to standard chemotherapy. Nevertheless, the EGFR-TKIs showed no benefit on OS (HR: 0.96, 95% CI: 0.83-1.10, p=0.556). In the analysis of adverse events, EGFR-TKIs had fewer SAEs than standard chemotherapy (HR: 0.29, 95% CI: 0.26-0.33, p<0.001).

CONCLUSIONS

Our systemic review indicates that EGFR-TKI therapy has improved PFS, and reduced SAEs compared to standard chemotherapy in advanced EGFR-mutated NSCLC.

Transcriptome Analysis of Testicular Aging in Mice

Male reproductive aging, or andropause, is associated with gradual age-related changes in testicular properties, sperm production, and erectile function. The testis, which is the primary male reproductive organ, produces sperm and androgens. To understand the transcriptional changes underlying male reproductive aging, we performed transcriptome analysis of aging testes in mice. A total of 31,386 mRNAs and 9387 long non-coding RNAs (lncRNAs) were identified in the mouse testes of diverse age groups (3, 6, 12, and 18 months old) by total RNA sequencing. Of them, 1571 mRNAs and 715 lncRNAs exhibited changes in their levels during testicular aging. Most of these aging-related transcripts exhibited slight and continuous expression changes during aging, whereas some (9.6%) showed larger expression changes. The aging-related transcripts could be classified into diverse expression patterns, in which the transcripts changed mainly at 3-6 months or at 12-18 months. Our subsequent in silico analysis provided insight into the potential features of testicular aging-related mRNAs and lncRNAs. We identified testis-specific aging-related transcripts (121 mRNAs and 25 lncRNAs) by comparison with a known testis-specific transcript profile, and then predicted the potential reproduction-related functions of the mRNAs. By selecting transcripts that are altered only between 3 and 18 months, we identified 46 mRNAs and 34 lncRNAs that are stringently related to the terminal stage of male reproductive aging. Some of these mRNAs were related to hormonal regulation. Finally, our in silico analysis of the 34 aging-related lncRNAs revealed that they co-localized with 19 testis-expressed protein-coding genes, 13 of which are considered to show testis-specific or -predominant expression. These nearby genes could be potential targets of cis-regulation by the aging-related lncRNAs. Collectively, our results identify a number of testicular aging-related mRNAs and lncRNAs in mice and provide a basis for the future investigation of these transcripts in the context of aging-associated testicular dysfunction.

Empirical assessment of biases in cerebrospinal fluid biomarkers of Alzheimer's disease: an umbrella review and re-analysis of data from meta-analyses

OBJECTIVE

Alzheimer's disease (AD) is a leading cause of years lived with disability in older age, and several cerebrospinal fluid (CSF) markers have been proposed in individual meta-analyses to be associated with AD but field-wide evaluation and scrutiny of the literature is not available.

MATERIALS AND METHODS

We performed an umbrella review for the reported associations between CSF biomarkers and AD. Data from available meta-analyses were reanalyzed using both random and fixed effects models. We also estimated between-study heterogeneity, small-study effects, excess significance, and prediction interval.

RESULTS

A total of 38 meta-analyses on CSF markers from 11 eligible articles were identified and reanalyzed. In 14 (36%) of the meta-analyses, the summary estimate and the results of the largest study showed non-concordant results in terms of statistical significance. Large heterogeneity (I2≥75%) was observed in 73% and small-study effects under Egger's test were shown in 28% of CSF biomarkers.

CONCLUSIONS

Our results suggest that there is an excess of statistically significant results and significant biases in the literature of CSF biomarkers for AD. Therefore, the results of CSF biomarkers should be interpreted with caution.

Body mass index and mortality in patients with cardiovascular disease: an umbrella review of meta-analyses

OBJECTIVE

Although many previous meta-analyses of epidemiological studies have demonstrated a relationship between body mass index (BMI) and mortality, inconsistent findings among cardiovascular disease patients have been observed. Thus, we performed an umbrella review to understand the strength of evidence and validity of claimed associations between BMI and mortality in patients with cardiovascular diseases.

MATERIALS AND METHODS

We comprehensively re-analyzed the data of meta-analyses of observational studies and randomized controlled trials on associations between BMI and mortality among patients with cardiovascular diseases. We also assessed the strength of evidence of the re-analyzed outcomes, which were determined from the criteria including statistical significance of the p-value of random-effects, as well as fixed-effects meta-analyses, small-study effects, between-study heterogeneity, and a 95% prediction interval.

RESULTS

We ran comprehensive re-analysis of the data from the 21 selected studies, which contained a total of 108 meta-analyses; 23 were graded as convincing evidence and 12 were suggestive, 42 were weak, and 23 were non-significant.

CONCLUSIONS

Underweight increased mortality in acute coronary syndrome (ACS), heart failure, and after therapeutic intervention for patients with cardiovascular diseases. Overweight, on the other hand decreased mortality in patient's ACS, atrial fibrillation, and heart failure with convincing evidence.

Data analysis scheme for correcting general misalignments of an optics configuration for a voltage measurement system based on the Pockels electro-optic effect

Having a sub-ns response time and not requiring physical contacts to the measurement points, a voltage measurement system based on the Pockels electro-optic effect, referred to as a PE (Pockels effect)-based voltmeter, is widely used for pulsed high voltage devices such as accelerators and X-pinch systems. To correct for the misalignment of a Pockels cell and the transmittance ratio of a beam splitter, a polar-coordinate-based data analysis scheme has been proposed. This scheme also overcomes a limitation on the measurable range of a PE-based voltmeter without ambiguity and can measure the half-wave voltage of a Pockels cell. We present an improved polar-coordinate-based data analysis scheme using an ellipse fitting method, which can correct for misalignments of all the optics components of a PE-based voltmeter while keeping the advantages of the previous scheme. We show the results of the improved data analysis scheme for measuring a slowly modulated voltage up to approximately 5 kV in about 30 s and a pulsed high voltage up to 7 kV with a rise time of less than 20 ns.

Risk factors of COVID-19 mortality: a systematic review of current literature and lessons from recent retracted articles

OBJECTIVE

Recently, two influential articles that reported the association of (hydroxy)chloroquine or angiotensin converting enzyme (ACE) inhibitors and coronavirus disease 2019 (COVID-19) mortality were retracted due to significant methodological issues. Therefore, we aimed to analyze the same clinical issues through an improved research method and to find out the differences from the retracted papers. We systematically reviewed pre-existing literature, and compared the results with those of the retracted papers to gain a novel insight.

MATERIALS AND METHODS

We extracted common risk factors identified in two retracted papers, and conducted relevant publication search until June 26, 2020 in PubMed. Then, we analyzed the risk factors for COVID-19 mortality and compared them to those of the retracted papers.

RESULTS

Our systematic review demonstrated that most demographic and clinical risk factors for COVID-19 mortality were similar to those of the retracted papers. However, while the retracted paper indicated that both (hydroxy)chloroquine monotherapy and combination therapy with macrolide were associated with higher risk of mortality, our study showed that only combination therapy of hydroxychloroquine and macrolide was associated with higher risk of mortality (odds ratio 2.33; 95% confidence interval 1.63-3.34). In addition, our study demonstrated that use of ACE inhibitors or angiotensin receptor blockers (ARBs) was associated with reduced risk of mortality (0.77; 0.65-0.91).

CONCLUSIONS

When analyzing the same clinical issues with the two retracted papers through a systematic review of randomized controlled trials and relevant cohort studies, we found out that (hydroxy)chloroquine monotherapy was not associated with higher risk of mortality, and that the use of ACE inhibitors or ARBs was associated with reduced risk of mortality in COVID-19 patients.

Clinical characteristics and mortality of patients with hematologic malignancies and COVID-19: a systematic review

OBJECTIVE

Hematologic cancer patients with Coronavirus Disease 2019 (COVID-19) tend to have a more serious disease course than observed in the general population. Herein, we comprehensively reviewed existing literature and analyzed clinical characteristics and mortality of patients with hematologic malignancies and COVID-19.

MATERIALS AND METHODS

Through searching PubMed until June 03, 2020, we identified 16 relevant case studies (33 cases) from a total of 45 studies that have reported on patients with COVID-19 and hematologic malignancies. We investigated the clinical and laboratory characteristics including type of hematologic malignancies, initial symptoms, laboratory findings, and clinical outcomes. Then, we compared those characteristics and outcomes of patients with hematologic malignancies and COVID-19 to the general population infected with COVID-19.

RESULTS

The median age was 66-year-old. Chronic lymphocytic leukemia was the most common type of hematologic malignancy (39.4%). Fever was the most common symptom (75.9%). Most patients had normal leukocyte counts (55.6%), lymphocytosis (45.4%), and normal platelet counts (68.8%). In comparison to patients with COVID-19 without underlying hematologic malignancies, dyspnea was more prevalent (45.0 vs. 24.9%, p=0.025). Leukocytosis (38.9 vs. 9.8%, p=0.001), lymphocytosis (45.4 vs. 8.2%, p=0.001), and thrombocytopenia (31.3 vs. 11.4%, p=0.036) were significantly more prevalent and lymphopenia (18.2 vs. 57.4%, p=0.012) less prevalent in patients with hematologic malignancies. There were no clinical and laboratory characteristics predicting mortality in patients with hematologic malignancies. Mortality was much higher in patients with hematologic malignancies compared to those without this condition (40.0 vs. 3.6%, p<0.001).

CONCLUSIONS

Co-occurrence of hematologic malignancies and COVID-19 is rare. However, due to the high mortality rate from COVID-19 in this vulnerable population, further investigation on tailored treatment and management is required.

A MnV2O6/graphene nanocomposite as an efficient electrocatalyst for the oxygen evolution reaction

A MnV2O6/graphene nanocomposite was fabricated through hydrothermal synthesis and high energy milling to introduce it as an efficient OER electrocatalyst. The MnV2O6/graphene nanocomposite with 20 wt% graphene exhibited superior electrocatalytic OER performance with a low overpotential and high stability and durability in 1 M KOH aqueous solution, exhibiting even after 1000 CV cycles.

Psychoacoustics and neurophysiological auditory processing in patients with Charcot-Marie-Tooth disease types 1A and 2A

BACKGROUND AND PURPOSE

Hidden hearing loss has been reported in patients with Charcot-Marie-Tooth (CMT) disease; however, the auditory-processing deficits have not been widely explored. We investigated the psychoacoustic and neurophysiological aspects of auditory processing in patients with CMT disease type 1A (CMT1A) and type 2A (CMT2A).

METHODS

A total of 43 patients with CMT1A and 15 patients with CMT2A were prospectively enrolled. All patients with CMT disease had normal sound-detection ability by using pure-tone audiometry. Spectral-ripple discrimination, temporal modulation detection and auditory frequency-following response were compared between CMT1A, CMT2A and control groups.

RESULTS

Although all participants had normal audiograms, patients with CMT disease had difficulty understanding speech in noise. The psychoacoustic auditory processing was somewhat different depending on the underlying pathophysiology of CMT disease. Patients with CMT1A had degraded auditory temporal and spectral processing. Patients with CMT2A had no reduced spectral resolution, but they showed further reduced temporal resolution than the patients with CMT1A. The amplitudes of the frequency-following response were reduced in patients with CMT1A and CMT2A, but the neural timing remained relatively intact.

CONCLUSIONS

When we first assessed the neural representation to speech at the brainstem level, the grand average brainstem responses were reduced in both patients with CMT1A and CMT2A compared with healthy controls. As the psychoacoustic aspects of auditory dysfunctions in CMT1A and CMT2A were somewhat different, it is necessary to consider future auditory rehabilitation methods based on their pathophysiology.

Electrical Transport and Thermoelectric Properties of SnSe-SnTe Solid Solution

SnSe is considered as a promising thermoelectric (TE) material since the discovery of the record figure of merit (ZT) of 2.6 at 926 K in single crystal SnSe. It is, however, difficult to use single crystal SnSe for practical applications due to the poor mechanical properties and the difficulty and cost of fabricating a single crystal. It is highly desirable to improve the properties of polycrystalline SnSe whose TE properties are still not near to that of single crystal SnSe. In this study, in order to control the TE properties of polycrystalline SnSe, polycrystalline SnSe–SnTe solid solutions were fabricated, and the effect of the solid solution on the electrical transport and TE properties was investigated. The SnSe_1−xTe_x samples were fabricated using mechanical alloying and spark plasma sintering. X-ray diffraction (XRD) analyses revealed that the solubility limit of Te in SnSe_1−xTe_x is somewhere between x = 0.3 and 0.5. With increasing Te content, the electrical conductivity was increased due to the increase of carrier concentration, while the lattice thermal conductivity was suppressed by the increased amount of phonon scattering. The change of carrier concentration and electrical conductivity is explained using the measured band gap energy and the calculated band structure. The change of thermal conductivity is explained using the change of lattice thermal conductivity from the increased amount of phonon scattering at the point defect sites. A ZT of ~0.78 was obtained at 823 K from SnSe_0.7Te_0.3, which is an ~11% improvement compared to that of SnSe.

Mesoporous Si-Cu nanocomposite anode for a lithium ion battery produced by magnesiothermic reduction and electroless deposition

Copper deposited mesoporous silicon was fabricated by magnesiothermic reduction and electroless deposition and its electrochemical properties as an anode for lithium ion batteries were investigated. The 300-400 nm sized mesoporous Si particles were synthesized by magnesiothermic reduction of SiO₂ nanospheres prepared by the Stöber method. The mesopores of Si particles were effectively decorated with Cu using Sn sensitization/Pd activation and subsequent Cu electroless deposition. The homogeneous distribution of Cu inside the mesoporous Si particles was confirmed by high resolution transmission electron microscopy images and energy dispersive spectroscopy mapping on the cross-sectional specimen prepared by a focused ion beam. The mesoporous Si-Cu nanocomposite exhibited high initial Coulombic efficiency, long cycle stability, and high rate capability, delivering a high capacity of 1569 mAh g^-1 after 200 cycles at the current density of 1000 mA g^-1. The improved electrochemical performance in a mesoporous Si-Cu nanocomposite was attributed to the high electrical conductivity, high Li⁺ ion mobility, and structural stability to restrict the aggregation and pulverization of active materials.

Stable Silicon Anode for Lithium-Ion Batteries through Covalent Bond Formation with a Binder via Esterification

Silicon (Si) is considered to be one of the most promising anode candidates for next-generation lithium-ion batteries because of its high theoretical specific capacity and low discharge potential. However, its poor cyclability, caused by tremendous volume change during cycling, prevents commercial use of the Si anode. Herein, we demonstrate a high-performance Si anode produced via covalent bond formation between a commercially available Si nanopowder and a linear polymeric binder through an esterification reaction. For efficient ester bonding, polyacrylic acid, composed of -COOH groups, is selected as the binder, Si is treated with piranha solution to produce abundant -OH groups on its surface, and sodium hypophosphite is employed as a catalyst. The as-fabricated electrode exhibits excellent high rate capability and long cycle stability, delivering a high capacity of 1500 mA h g^-1 after 500 cycles at a high current density of 1000 mA g^-1 by effectively restraining the susceptible sliding of the binder, stabilizing the solid electrolyte interface layer, preventing the electrode delamination, and suppressing the Si aggregation. Furthermore, a full cell is fabricated with as-fabricated Si as an anode and commercially available LiNi_0.6Mn_0.2Co_0.2O₂ as a cathode, and its electrochemical properties are investigated for the possibility of practical use.

Solid solution phosphide (Mn1-xFexP) as a tunable conversion/alloying hybrid anode for lithium-ion batteries

The substitutional solid solution Mn1-xFexP compounds between alloying reaction-type MnP and conversion reaction-type FeP are successfully synthesized via facile high energy mechanical milling and their electrochemical properties as an anode for lithium ion batteries (LIBs) are investigated. A complete solid solution is formed between two end members and the Mn1-xFexP solid solution phosphide electrodes show an enhanced electrochemical performance, delivering a capacity of 360 mA h g-1 after 100 cycles at a high current density of 2 A g-1 when the advantages of the two reaction mechanisms are beneficially combined. These synergistic effects resulted from the in situ generated nanocomposite of the Li-Mn-P alloying element and the Fe nano-network in combination with the surrounding amorphous lithium phosphide, which effectively buffers the accompanying volume variation, hinders the aggregation of the alloying element, and ensures the electron and ion transport.

The Role of Zr Doping in Stabilizing Li[Ni0.6 Co0.2 Mn0.2 ]O2 as a Cathode Material for Lithium-Ion Batteries

Ni-rich layered LiNi_1-x-y Co_x Mn_y O₂ systems are the most promising cathode materials for high energy density Li-ion batteries (LIBs). However, Ni-rich cathode materials inevitably suffer from rapid capacity fading and poor rate capability owing to structural instability and unstable surface side reactions. Zr doping has proven to be an effective method to enhance the cycle and rate performances by stabilizing the structure and increasing the Li⁺ diffusion rate. Herein, effects of Zr-doping on the structural stability and Li⁺ diffusion kinetics are thoroughly investigated in LiNi_0.6 Co_0.2 Mn_0.2 O₂ (LNCM) cathode material using atomic-resolution scanning transmission electron microscopy imaging, XRD Rietveld refinement, and density functional theory calculations. Zr doping mitigates the degree of cation mixing, decreases the structural transformation, and facilitates Li⁺ diffusion resulting in improved cyclic performance and rate capability. Based on the obtained results, an atomistic model is proposed to explain the effects of Zr doping on the structural stability and Li⁺ diffusion kinetics in LNCM cathode materials.

Intraoperative Management to Prevent Cardiac Collapse in a Patient With a Recurrent, Large-volume Pericardial Effusion and Paroxysmal Atrial Fibrillation During Liver Transplantation: A Case Report

BACKGROUND

Pericardial effusion is a common feature of end-stage liver disease. In this case report we describe the intraoperative management of recurrent pericardial effusion, without re-pericardiocentesis, to prevent circulatory collapse during a critical surgical time-point; that is, during manipulation of the major vessels and graft reperfusion.

METHODS

A 47-year-old woman with hepatitis B was scheduled to undergo deceased donor liver transplantation (LT). A large pericardial effusion was preoperatively identified using transthoracic echocardiography (TTE). The patient also had paroxysmal atrial fibrillation. Two days before surgery, preemptive pericardiocentesis was performed and the 1150-mL effusion was drained. Intraoperatively, recurrence of the large pericardial effusion was identified using transesophageal echocardiography (TEE). During inferior vena cava manipulation, the surgeon consulted the anesthesiologist to evaluate the hemodynamic changes in the patient. After 3 attempts, the transplant team was able to determine the most appropriate anastomosis site, defined as that with the least impact on cardiac function. To prevent the development of severe postreperfusion syndrome, 10% MgSO₄ (2 g) was gradually infused 20 minutes before portal vein declamping, and immediately before graft reperfusion a 100-μg bolus of epinephrine was administered.

RESULTS

During graft reperfusion, there was no evidence of heart chamber collapse or flow disturbance, as seen on the TEE findings. Postoperatively, the patient recovered completely and was discharged from the hospital. Six months after surgery, there was no sign of pericardial effusion on follow-up TTE.

CONCLUSION

Our intraoperative strategy may prevent cardiac collapse in patients with pericardial effusion detected during LT. Intraoperative TEE plays an important role in guiding hemodynamic management.

A P2-type Na0.7(Ni0.6Co0.2Mn0.2)O2 cathode with excellent cyclability and rate capability for sodium ion batteries

P2-type Na_0.7(Ni_0.6Co_0.2Mn_0.2)O₂ is synthesized and introduced as a cathode for sodium-ion batteries, which exhibits high reversible capacity, excellent high rate capability and superior long term cyclability.

Superior electrochemical sodium storage of V4P7 nanoparticles as an anode for rechargeable sodium-ion batteries

V₄P₇ nanoparticles as an insertion type anode were synthesized via high-energy milling and introduced as an anode for sodium-ion batteries for the first time.

Intraoperative Management of a Patient With Impaired Cardiac Function Undergoing Simultaneous ABO-Compatible Liver and ABO-Incompatible Kidney Transplant From 2 Living Donors: A Case Report

BACKGROUND

Combined liver and kidney transplant is a very complex surgery. To date, there has been no report on the intraoperative management of patients with impaired cardiac function undergoing simultaneous ABO-compatible liver and ABO-incompatible kidney transplant from 2 living donors.

CASE REPORT

A 60-year-old man underwent simultaneous ABO-compatible liver and ABO-incompatible kidney transplant from 2 living donors because of IgA nephropathy and alcoholic liver cirrhosis. The preoperative cardiac findings revealed continuous aggravation, shown by large left atrial enlargement, severe left ventricular hypertrophy, a very prolonged QT interval, and a calcified left anterior descending coronary artery. Severe hypotension with very weak pulsation and severe bradycardia developed, with an irregular junctional rhythm noted immediately after the liver graft was reperfused. Although epinephrine was administered as a rescue drug, hemodynamics did not improve, and central venous pressure and mean pulmonary arterial pressure increased to potentially fatal levels. Emergency phlebotomy via the central line was performed. Thereafter, hypotension and bradycardia recovered gradually as the central venous pressure and mean pulmonary arterial pressure decreased. The irregular junctional rhythm returned to a sinus rhythm, but the QTc interval was slightly more prolonged. Because of poor cardiac capacity, the volume and rate of fluid infusion were increased aggressively to maintain appropriate kidney graft perfusion after confirming vigorous urine production of the graft.

CONCLUSIONS

A heart with impaired function due to both end-stage liver and kidney diseases may be less able to withstand surgical stress. Further study on cardiac dysfunction will be helpful for the management of patients undergoing complex transplant surgery.

Canavalia ensiformis-derived lectin inhibits biofilm formation of enterohemorrhagic Escherichia coli and Listeria monocytogenes

AIM

A lectin Concanavalin A (ConA) derived from Canavalia ensiformis (jack bean) exhibits high-binding affinity to carbohydrates on bacterial cell surfaces. The objective of this study was to inhibit the biofilm formation of the foodborne pathogens enterohemorrhagic Escherichia coli and Listeria monocytogenes using ConA prepared by a membrane-based extraction method.

METHODS AND RESULTS

ConA was extracted using a simple and inexpensive membrane method instead of a chromatography approach. The extracted ConA was effective in inhibiting biofilms of E. coli by 30-fold and L. monocytogenes by 140-fold. In addition, ConA decreased the swimming motility of enterohemorrhagic E. coli EDL933 (EHEC) by 37%, resulting in low biofilm formation, as ConA binding to the bacterial cell surfaces might cause a reduced capability to adhere due to low cellular motility. We confirmed that the extracted ConA contains active components at less than 10 kDa as well as ConA multimers (>30 kDa) that repress EHEC biofilms. Additionally, noncell-based mannose reduced the activity of ConA in inhibiting biofilms.

CONCLUSIONS

ConA extracted using the membrane-based method is active in inhibiting the biofilm formation by E. coli and L. monocytogenes via the mannose-binding affinity of ConA.

SIGNIFICANCE AND IMPACT OF THE STUDY

ConA can be used as a promising anti-adherent and antibiofilm agent in inhibiting biofilm formation by enterohemorrhagic E. coli and L. monocytogenes. The membrane-based extraction approach may be applied for the economic production of biologically active lectins.

Synthetic Mechanism Discovery of Monophase Cuprous Oxide for Record High Photoelectrochemical Conversion of CO2 to Methanol in Water

Precise control of the oxidation state of transition-metal oxides, such as copper, is important for high selectivity of CO₂ reduction in an aqueous condition to compete with the reduction of water. The phase of copper oxide nanofibers was controlled by predictive synthesis, which controls the nanoscale gas-solid reaction by considering thermodynamics and kinetics. The driving force of the phase transformation between the different oxidation states of copper oxide is calculated by comparing the Gibbs free energy of each of the oxidation states. From the calculation, the kinetically processable window for the fabrication of Cu₂O in which monophase Cu₂O can be fabricated in a reasonable reaction time scale is discovered. Herein, we report the monophase Cu₂O nanofiber photocathode, which photoelectrochemically converted CO₂ into methanol with over 90% selectivity in an aqueous electrolyte, and a hierarchical structure is developed to optimize the photoactivity and stability of the electrode. Our work suggests a rational design of the calcination strategy for precisely controlling the oxidation states of transition metals that can be applied to various applications in which the phase of the materials plays an important role.

Highly-Sensitive Refractive Index Sensing by Near-infrared Metatronic Nanocircuits

In this work, we present a highly-sensitive refractive index sensor based on metatronic nanocircuits operating at near-infrared spectral range. The structure is designed based on simple nanorod geometry and fabricated by nanopatterning of transparent conducting oxides. The functionality of these polarization dependent metatronic nanocircuits is enhanced by applying tunable response. This feature is investigated by depositing NH₂ (Amine) groups via plasma polymerization technique on top of indium-tin-oxide nanorods. The dielectric constant of Amine groups is a function of their thickness, which can be controlled by the RF power and the time duration of the applied plasma polymerization process. The resonance wavelengths of nanocircuits shift to higher wavelength, as the dielectric constant of the deposited material increases. An excellent agreement between the design and experimental results are obtained. Our metatronic based nanosensor offers a high-sensitive performance of 1587 nm/RIU with a satisfactory figure of merit for this class of sensors.

[A cohort study on body mass index and risk of all-cause mortality among hypertensive population]

Objective: To investigate the relationship between body mass index (BMI) and all-cause mortality in hypertensive population. Methods: All participants were selected from a prospective cohort study based on a rural population from Henan province, China. Cox proportional hazards regression models were used to estimate the associations of different levels of BMI stratification with all-cause mortality. Restricted cubic spline models were used to detect the dose-response relation. Results: Among the 5 461 hypertensive patients, a total of 31 048.38 person-years follow-up was conducted. The median of follow-up time was 6 years, and 589 deaths occurred during the follow-up period. Compared to normal weight group (18.5 kg/m(2)<BMI<24.0 kg/m(2)) the multivariate-adjusted hazard ratios for all-cause mortality associated with BMI levels (<18.5 kg/m(2), 24-28 kg/m(2), and ≥28 kg/m(2)) were 0.83 (95%CI: 0.37-1.87), 0.81 (95%CI: 0.67-0.97), and 0.72 (95%CI: 0.56-0.91), respectively. The dose-response analysis showed a nonlinear, reverse "S" shaped relationship (non-linearity P<0.001). Conclusion: Overweight or obese might have a protective effect on all-cause mortality in hypertensive population, which supports the "obesity paradox" phenomenon.

CuBi2O4 Prepared by the Polymerized Complex Method for Gas-Sensing Applications

Multicomponent oxides can be extensively explored as alternative gas-sensing materials to binary oxides with their structural and compositional versatilities. In this work, the gas-sensing properties of CuBi₂O₄ have been investigated toward various reducing gases (C₂H₅OH, NH₃, H₂, CO, and H₂S) and oxidizing gas (NO₂) for the first time. For this, the powder synthesis has been developed using the polymerized complex method (Pechini method) to obtain a single-phase polycrystalline CuBi₂O₄. The defect, optical, and electronic properties in the prepared CuBi₂O₄ powder were modulated by varying the calcination temperature from 500 to 700 °C. Noticeably, a high concentration of Cu⁺-oxygen vacancy ([Formula: see text]) defect complexes and isolated Cu²⁺ ion clusters was found in the 500 °C-calcined CuBi₂O₄, where they were removed through air calcination at higher temperatures (up to 700 °C) while making the compound more stoichiometric. The change in the intrinsic defect concentration with the calcination temperature led to the variation of the electronic band gap energy and hole concentration in CuBi₂O₄ with the polaronic hopping conduction (activation energy = 0.43 eV). The CuBi₂O₄ sensor with 500 °C-calcined powder showed the highest gas responses (specifically, 10.4 toward 1000 ppm C₂H₅OH at the operating temperature of 400 °C) with the highest defect concentration. As a result, the gas-sensing characteristics of CuBi₂O₄ are found to be dominantly affected by the intrinsic defect concentration, which is controlled by the calcination temperature. Toward reducing H₂S and oxidizing NO₂ gases, the multiple reactions arising simultaneously on the surface of the CuBi₂O₄ sensor govern its response behavior, depending on the gas concentration and the operating temperature. We believe that this work can be a cornerstone for understanding the effect of chemical defect on the gas-sensing characteristics in multicomponent oxides.

Highly stable SnO2-Fe2O3-C hollow spheres for reversible lithium storage with extremely long cycle life

SnO₂-Fe₂O₃-C triple-shell hollow nano-spheres are fabricated by combining the template-based sol-gel coating technique and hydrothermal method, and their electrochemical performance as an anode for lithium ion batteries (LIBs) is investigated, particularly focusing on their structural stability and long term cyclability. To accomplish this, same-sized SnO₂ solid spheres, Fe₂O₃ solid spheres, SnO₂-Fe₂O₃ solid spheres, SnO₂-Fe₂O₃-C solid spheres, SnO₂ hollow spheres and SnO₂-Fe₂O₃ hollow spheres are prepared in a similar manner and their cyclic performances are compared. It is found that the as-synthesized 80 nm-sized SnO₂-Fe₂O₃-C hollow sphere electrode exhibits an extraordinary reversible capacity (1100 mA h g^-1 after 100 cycles at 200 mA g^-1) and excellent long cycle stability (475 mA h g^-1 after 1000 cycles at 2000 mA g^-1), which are attributed to the Fe-enhanced reversibility of the Li₂O reduction reaction, high electrical conductivity, high Li⁺ ion mobility, and structural stability of the carbon-coated triple-shell hollow spheres.

Microscopic Evidence for Strong Interaction between Pd and Graphene Oxide that Results in Metal-Decoration-Induced Reduction of Graphene Oxide

Graphene oxide (GO) is reduced spontaneously when palladium nanoparticles are decorated on the surface. The oxygen functional groups at the GO surface near the nanoparticles are absorbed to the palladium to produce a palladium oxide interlayer. Palladium therefore grows on the GO with preferred orientations, resulting in unique microstructural and electrical properties.

Ossicular chain reconstruction improves bone conduction threshold in chronic otitis media

This study aimed to assess the elevation of bone conduction threshold in patients with chronic otitis media and to investigate the mechanism of this phenomenon. One hundred and six patients with unilateral chronic otitis media who had undergone a tympanomastoidectomy were reviewed retrospectively. The differences in the bone conduction thresholds between the diseased and normal sides were assessed and compared according to the duration of the disease and the presence of cholesteatoma. Post-operative changes in the bone conduction threshold were also assessed. The mean bone conduction thresholds were significantly elevated on the diseased side, ranging from 3.4 to 11.6 dB across frequencies, with a maximal elevation at 2000 Hz. The duration of disease and the presence of cholesteatoma did not affect the degree of the bone conduction elevation. After ossicular reconstruction, bone conduction thresholds improved significantly at all frequencies, with the greatest improvement being observed at 2000 Hz. These results suggest that the elevation in the bone conduction threshold in chronic otitis media is mainly caused by a change in the conductive mechanism in the middle ear.

Deformation mechanisms to ameliorate the mechanical properties of novel TRIP/TWIP Co-Cr-Mo-(Cu) ultrafine eutectic alloys

In the present study, the microstructural evolution and the modulation of the mechanical properties have been investigated for a Co-Cr-Mo (CCM) ternary eutectic alloy by addition of a small amount of copper (0.5 and 1 at.%). The microstructural observations reveal a distinct dissimilarity in the eutectic structure such as a broken lamellar structure and a well-aligned lamellar structure and an increasing volume fraction of Co lamellae as increasing amount of copper addition. This microstructural evolution leads to improved plasticity from 1% to 10% without the typical tradeoff between the overall strength and compressive plasticity. Moreover, investigation of the fractured samples indicates that the CCMCu alloy exhibits higher plastic deformability and combinatorial mechanisms for improved plastic behavior. The improved plasticity of CCMCu alloys originates from several deformation mechanisms; i) slip, ii) deformation twinning, iii) strain-induced transformation and iv) shear banding. These results reveal that the mechanical properties of eutectic alloys in the Co-Cr-Mo system can be ameliorated by micro-alloying such as Cu addition.

Superior sodium storage performance of reduced graphene oxide-supported Na3.12Fe2.44(P2O7)2/C nanocomposites

We prepared a rGO-supported Na_3.12Fe_2.44(P₂O₇)₂/C nanocomposite showing superior rate capability and a long lifespan as a NIB cathode material.

Enhanced Lithium Storage in Reduced Graphene Oxide-supported M-phase Vanadium(IV) Dioxide Nanoparticles

Vanadium(IV) dioxide (VO₂) has drawn attention as one of the most attractive electrode materials for lithium-ion batteries (LIBs), hence, much research has been conducted in various sectors in this field. However, to date, most of this research has focused on the VO₂(B) polymorph, whereas electrochemical information on the use of VO₂(M) in LIB electrodes is insufficient. Thus, it is worthwhile to explore the possibility of using VO₂(M) for LIB electrode application, and to investigate whether its electrochemical properties can be improved. In this study, VO₂(M) nanoparticles, incorporated with a reduced graphene oxide composite (NP-VO₂/rGO), were successfully synthesized via a sol–gel assisted hydrothermal process by the chemical reduction of V₂O₅ gel, using hydrazine as the reducing agent. The particle size was less than 50 nm regardless of the presence of rGO. Also, NP-VO₂/rGO exhibited a specific capacity of 283 mA h g⁻¹ up to the 200^th cycle at a current density of 60 mA g⁻¹, indicating its potential to be used in LIBs.

Hepatic differentiation of porcine embryonic stem cells for translational research of hepatocyte transplantation

Porcine embryonic stem cells (ES) are considered attractive preclinical research tools for human liver diseases. Although several studies previously reported generation of porcine ES, none of these studies has described hepatic differentiation from porcine ES. The aim of this study was to generate hepatocytes from porcine ES and analyze their characteristics. We optimized conditions for definitive endoderm induction and developed a 4-step hepatic differentiation protocol. A brief serum-free condition with activin A efficiently induced definitive endoderm differentiation from porcine ES. The porcine ES-derived hepatocyte-like cells highly expressed hepatic markers including albumin and α-fetoprotein, and displayed liver characteristics such as glycogen storage, lipid production, and low-density lipoprotein uptake. For the first time, we describe a highly efficient protocol for hepatic differentiation from porcine ES. Our findings provide valuable information for translational liver research using porcine models, including hepatic regeneration and transplant studies, drug screening, and toxicology.

Effect of the Amine Concentration on Phase Evolution and Densification in Printed Films Using Cu(II) Complex Ink

The nucleation and growth behavior of Cu nanoparticles during thermal heating of Cu(II) complex inks for printed Cu metallization were investigated, particularly focusing on the effects of the amine concentration on the microstructure evolution and electrical conductivity. Herein, the dual effects of hexylamine as a reducing agent dissociating the carboxyl group from the precursor and a capping agent hindering the subsequent growth of Cu nuclei were confirmed. On the basis of such dual effects of amine, the sufficient complexation of the Cu(II) precursor with a high amine concentration in the ink led to the single-route growth of Cu nanoparticles during thermal heating, which resulted in the dense film with a narrow particle size distribution exhibiting a high electrical conductivity. The electrical conductivity of the film could be further enhanced by a reducing atmosphere with formic acid. Significantly, the understanding of the ink chemistry and the nucleation and growth kinetics in the metal ion complex or metal-organic decomposition (MOD) ink can provide the design rules for the formulation of the solution-type inks to control the microstructure of printed metallization.

Tumour volume changes assessed with high-quality KVCT in lung cancer patients undergoing concurrent chemoradiotherapy

OBJECTIVE

We evaluated tumour volume changes in patients with lung cancer undergoing concurrent chemoradiotherapy using image-guided radiotherapy (RT).

METHODS

The kilovoltage image was obtained using CT on rail at every five fractions. The gross tumour volumes (GTVs), including the primary tumour and lymph nodes (LNs), were contoured to analyse the time and degree of tumour regression.

RESULTS

46 patients [32, non-small-cell lung cancer (NSCLC), and 14, small-cell lung cancer (SCLC)] were included in this study. In total, 281 CT scans and 82 sites of GTVs were evaluated. Significant volume changes occurred in both the NSCLC and SCLC groups (p < 0.001 and 0.002), and the average GTV change compared with baseline was 49.85 ± 3.65 [standard error (SE)]% and 65.95 ± 4.60 (SE)% for the NSCLC and SCLC groups, respectively. A significant difference in the degree of volume reduction between the primary tumour and LNs was observed in only the NSCLC group (p < 0.0001) but not in the SCLC group (p = 0.735). The greatest volume regression compared with the volume before the five fractions occurred between the 15 and 20 fractions in the NSCLC group and between the 5 and 10 fractions in the SCLC group.

CONCLUSION

Both primary tumour and LNs were well defined using CT on rail. Significant volume changes occurred during RT, and there was a difference in volume reduction between the NSCLC and SCLC groups, regarding the degree and timing of the tumour reduction in the primary tumour and LNs.

ADVANCES IN KNOWLEDGE

NSCLC and SCLC groups showed differences in the degree and timing of volume reduction. The primary tumour and LNs in NSCLC regressed differently.

Giant Electroresistive Ferroelectric Diode on 2DEG

Manipulation of electrons in a solid through transmitting, storing, and switching is the fundamental basis for the microelectronic devices. Recently, the electroresistance effect in the ferroelectric capacitors has provided a novel way to modulate the electron transport by polarization reversal. Here, we demonstrate a giant electroresistive ferroelectric diode integrating a ferroelectric capacitor into two-dimensional electron gas (2DEG) at oxide interface. As a model system, we fabricate an epitaxial Au/Pb(Zr(0.2)Ti(0.8))O3/LaAlO3/SrTiO3 heterostructure, where 2DEG is formed at LaAlO3/SrTiO3 interface. This device functions as a two-terminal, non-volatile memory of 1 diode-1 resistor with a large I+/I- ratio (>10(8) at ± 6 V) and I(on)/I(off) ratio (>10(7)). This is attributed to not only Schottky barrier modulation at metal/ferroelectric interface by polarization reversal but also the field-effect metal-insulator transition of 2DEG. Moreover, using this heterostructure, we can demonstrate a memristive behavior for an artificial synapse memory, where the resistance can be continuously tuned by partial polarization switching, and the electrons are only unidirectionally transmitted. Beyond non-volatile memory and logic devices, our results will provide new opportunities to emerging electronic devices such as multifunctional nanoelectronics and neuromorphic electronics.

The MRI appearances of cancellous allograft bone chips after the excision of bone tumours

Cancellous allograft bone chips are commonly used in the reconstruction of defects in bone after removal of benign tumours. We investigated the MRI features of grafted bone chips and their change over time, and compared them with those with recurrent tumour. We retrospectively reviewed 66 post-operative MRIs from 34 patients who had undergone curettage and grafting with cancellous bone chips to fill the defect after excision of a tumour. All grafts showed consistent features at least six months after grafting: homogeneous intermediate or low signal intensities with or without scattered hyperintense foci (speckled hyperintensities) on T1 images; high signal intensities with scattered hypointense foci (speckled hypointensities) on T2 images, and peripheral rim enhancement with or without central heterogeneous enhancements on enhanced images. Incorporation of the graft occurred from the periphery to the centre, and was completed within three years. Recurrent lesions consistently showed the same signal intensities as those of pre-operative MRIs of the primary lesions. There were four misdiagnoses, three of which were chondroid tumours. We identified typical MRI features and clarified the incorporation process of grafted cancellous allograft bone chips. The most important characteristics of recurrent tumours were that they showed the same signal intensities as the primary tumours. It might sometimes be difficult to differentiate grafted cancellous allograft bone chips from a recurrent chondroid tumour.

First Report of Powdery Mildew Caused by Erysiphe heraclei on Peucedanum japonicum in Korea

Peucedanum japonicum Thunb., belonging to the family Apiaceae, is distributed in many Asian countries, including Korea. This plant was recently developed as an edible green and is cultivated under organic farming in Korea. In June 2013, plants showing typical symptoms of powdery mildew were found with approximately 50% disease incidence in polyethylene-film-covered greenhouses in Iksan City, Korea. Symptoms first appeared as circular white colonies, which subsequently showed abundant mycelial growth on the leaves, often covering the whole surface. Infected plants were unmarketable mainly due to signs of white fungal growths and reddish discoloration on the leaves. The same symptoms were found on P. japonicum in poly-tunnels in Iksan City and Jinan County of Korea in 2014. Voucher specimens (n = 3) were deposited in the Korea University Herbarium (KUS). Appressoria were lobed, and solitary or in opposite pairs. Conidiophores were cylindrical, 80 to 145 × 8 to 10 μm, and composed of three to four cells. Foot-cells of conidiophores were straight to substraight, cylindrical, and 25 to 63 μm long. Singly produced conidia were oblong-elliptical to oblong, occasionally ovate, 35 to 50 × 13 to 16 μm with a length/width ratio of 2.3:3.1, with angular/rectangular wrinkling of outer walls, and lacked distinct fibrosin bodies. Germ tubes were produced on the perihilar position of conidia. Primary conidia were apically conical, basally truncate, and generally smaller than the secondary conidia. No chasmothecia were found. These structures are typical of the powdery mildew Pseudoidium anamorph of the genus Erysiphe. The specific measurements and morphological characteristics were consistent with those of E. heraclei DC. (2). To confirm the identification, the complete internal transcribed spacer (ITS) region of rDNA from KUS-F27872 was amplified with primers ITS1/ITS4 and sequenced. The resulting 560-bp sequence was deposited in GenBank (Accession No. KM491178). The obtained ITS sequence shared >99% similarity with those of E. heraclei from apiaceous hosts, e.g., Daucus carota (KC480605), Pimpinella affinis (AB104513), and Petroselinum crispum (KF931139). Pathogenicity was confirmed through inoculation by gently dusting conidia onto leaves of five healthy potted plants. Five non-inoculated plants served as controls. Inoculated plants developed symptoms after 6 days, whereas the control plants remained symptomless. The fungus present on the inoculated plants was identical in morphology to those observed in the field. Powdery mildew of P. japonicum caused by E. heraclei has been reported in Japan (4), and numerous reports of E. heraclei on various species of Peucedanum plants have been made in most part of Europe and East Asia (Japan and far eastern Russia) (1,3). However, this is the first report of powdery mildew caused by E. heraclei on P. japonicum in Korea. Occurrence of powdery mildews is a threat to the quality and marketability of this plant, especially in organic farming. References: (1) K. Amano. Host Range and Geographical Distribution of the Powdery Mildew Fungi. Japan Scientific Societies Press, Tokyo, 1986. (2) U. Braun and R. T. A. Cook. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No.11. CBS, Utrecht, 2012. (3) D. F. Farr and A. Y. Rossman. Fungal Databases, Syst. Mycol. Microbiol. Lab., online publication. ARS, USDA. Retrieved August 18, 2014. (4) S. Tanda and C. Nakashima. J. Agric. Sci., Tokyo Univ. Agric. 47:54, 2002.

Nonvolatile resistance switching on two-dimensional electron gas

Two-dimensional electron gas (2DEG) at the complex oxide interfaces have brought about considerable interest for the application of the next-generation multifunctional oxide electronics due to the exotic properties that do not exist in the bulk. In this study, we report the integration of 2DEG into the nonvolatile resistance switching cell as a bottom electrode, where the metal-insulator transition of 2DEG by an external field serves to significantly reduce the OFF-state leakage current while enhancing the on/off ratio. Using the Pt/Ta2O5-y/Ta2O5-x/SrTiO3 heterostructure as a model system, we demonstrate the nonvolatile resistance switching memory cell with a large on/off ratio (>10(6)) and a low leakage current at the OFF state (∼10(-13) A). Beyond exploring nonvolatile memory, our work also provides an excellent framework for exploring the fundamental understanding of novel physics in which electronic and ionic processes are coupled in the complex heterostructures.

First Report of Powdery Mildew Caused by Golovinomyces biocellatus on Agastache rugosa in Korea

Agastache rugosa (Fisch. & C.A. Mey.) Kuntze, known as Korean mint, is an aromatic plant in the Lamiaceae. It is widely distributed in East Asian countries and is used as a Chinese traditional medicine. In Korea, fresh leaves are commonly added to fish soups and stews (3). In November 2008, several dozen Korean mints plants growing outdoors in Gimhae City, Korea, were found to be severely infected with a powdery mildew. The same symptoms had been observed in Korean mint plots in Busan and Miryang cities from 2008 to 2013. Symptoms first appeared as thin white colonies, which subsequently developed into abundant hyphal growth on stems and both sides of the leaves. Severe disease pressure caused withering and senescence of the leaves. Voucher specimens (n = 5) were deposited in the Korea University Herbarium (KUS). Appressoria on the mycelium were nipple-shaped or nearly absent. Conidiophores were 105 to 188 × 10 to 13 μm and produced 2 to 4 immature conidia in chains with a sinuate outline, followed by 2 to 3 cells. Foot-cells of the conidiophores were straight, cylindrical, slightly constricted at the base, and 37 to 58 μm long. Conidia were hyaline, ellipsoid to barrel-shaped, measured 25 to 40 × 15 to 23 μm (length/width ratio = 1.4 to 2.1), lacked distinct fibrosin bodies, and showed reticulate wrinkling of the outer walls. Primary conidia were obconically rounded at the apex and subtruncate at the base. Germ tubes were produced at the perihilar position of conidia. No chasmothecia were observed. The structures described above were typical of the Oidium subgenus Reticuloidium anamorph of the genus Golovinomyces. The measurements and morphological characteristics were compatible with those of G. biocellatus (Ehrenb.) V.P. Heluta (1). To confirm the identification, molecular analysis of the sequence of the internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) of isolate KUS-F27200 was conducted. The complete ITS rDNA sequence was amplified using primers ITS5 and P3 (4). The resulting 514-bp sequence was deposited in GenBank (Accession No. KJ585415). A GenBank BLAST search of the Korean isolate sequence showed >99% similarity with the ITS sequence of many G. biocellatus isolates on plants in the Lamiaceae (e.g., Accession Nos. AB307669, AB769437, and JQ340358). Pathogenicity was confirmed by gently pressing diseased leaf onto leaves of five healthy, potted Korean mint plants. Five non-inoculated plants served as a control treatment. Inoculated plants developed symptoms after 7 days, whereas the control plants remained symptomless. The fungus present on inoculated plants was identical morphologically to that observed on the original diseased plants. The pathogenicity test was repeated with identical results. A powdery mildew on A. rugosa caused by G. biocellatus was reported from Romania (2). To our knowledge, this is the first report of powdery mildew caused by G. biocellatus on A. rugosa in Korea. The plant is mostly grown using organic farming methods with limited chemical control options. Therefore, alternative control measures should be considered. References: (1) U. Braun and R. T. A. Cook. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No. 11. CBS, Utrecht, 2012. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab., online publication, USDA ARS, retrieved 17 February 2014. (3) T. H. Kim et al. J. Sci. Food Agric. 81:569, 2001. (4) S. Takamatsu et al. Mycol. Res. 113:117, 2009.

Brookite TiO2 thin film epitaxially grown on (110) YSZ substrate by atomic layer deposition

Epitaxial brookite TiO2 (B-TiO2) film was deposited on (110) yttria-stabilized zirconia (YSZ) substrate using plasma-enhanced atomic layer deposition, and its structural, optical, and gas sensing properties were investigated. As-deposited TiO2 film was a pure brookite and (120) oriented. The determined in-plane orientation relationships were [21̅0]B-TiO2//[1̅10]YSZ and [001]B-TiO2 //[001]YSZ. The B-TiO2 film showed ∼70% transmittance and the optical band gap energy was 3.29 eV. The B-TiO2 film-based gas sensor responded to H2 gas even at room temperature and the highest magnitude of the gas response was determined to be ∼150 toward 1000 ppm of H2/air at 150 °C. In addition, B-TiO2 sensor showed a high selectivity for H2 against CO, EtOH, and NH3.

Rubi Fructus (Rubus coreanus) activates the expression of thermogenic genes in vivo and in vitro

OBJECTIVE

To investigate the anti-obesity effect of Rubi Fructus (RF) extract using brown adipose tissue (BAT) and primary brown preadipocytes in vivo and in vitro.

METHODS

Male C57BL/6 J mice (n=5 per group) were fed a high-fat diet (HFD) for 10 weeks with or without RF. Brown preadipocytes from the interscapular BAT of mice (age, post-natal days 1-3) were cultured with differentiation media (DM) including isobutylmethylxanthine, dexamethasone, T3, indomethacin and insulin with or without RF.

RESULTS

In HFD-induced obese C57BL/6 J mice, long-term RF treatment significantly reduced weight gain as well as the weights of the white adipose tissue, liver and spleen. Serum levels of total cholesterol and low-density lipoprotein cholesterol were also reduced in the HFD group which received RF treatment. Furthermore, RF induced thermogenic-, adipogenic- and mitochondria-related gene expressions in BAT. In primary brown adipocytes, RF effectively stimulated the expressions of thermogenic- and mitochondria-related genes. In addition, to examine whether LIPIN1, a regulator of adipocyte differentiation, is regulated by RF, Lipin1 small interfering RNA (siRNA) and RF were pretreated in primary brown adipocytes. Pretreatment with Lipin1 siRNA and RF downregulated the DM-induced expression levels of thermogenic- and mitochondria-related genes. Moreover, RF markedly upregulated AMP-activated protein kinase. Our study shows that RF is capable of stimulating the differentiation of brown adipocytes through the modulation of thermogenic genes.

CONCLUSIONS

This study demonstrates that RF prevents the development of obesity in mice fed with a HFD and that it is also capable of stimulating the differentiation of brown adipocytes through the modulation of thermogenic genes, which suggests that RF has potential as a therapeutic application for the treatment or prevention of obesity.