Critical ionic transport across an oxygen-vacancy ordering transition.

Phase transition points can be used to critically reduce the ionic migration activation energy, which is important for realizing high-performance electrolytes at low temperatures. Here, we demonstrate a route toward low-temperature thermionic conduction in solids, by exploiting the critically lowered activation energy associated with oxygen transport in Ca-substituted bismuth ferrite (Bi1-xCaxFeO3-δ) films. Our demonstration relies on the finding that a compositional phase transition occurs by varying Ca doping ratio across xCa ≃ 0.45 between two structural phases with oxygen-vacancy channel ordering along <100> or <110> crystal axis, respectively. Regardless of the atomic-scale irregularity in defect distribution at the doping ratio, the activation energy is largely suppressed to 0.43 eV, compared with ~0.9 eV measured in otherwise rigid phases. From first-principles calculations, we propose that the effective short-range attraction between two positively charged oxygen vacancies sharing lattice deformation not only forms the defect orders but also suppresses the activation energy through concerted hopping.

Baseline Sensitivity of Echinochloa crus-gall and E. oryzicola to Florpyrauxifen-Benzyl, a New Synthetic Auxin Herbicide, in Korea.

Echinochloa species is one of the most problematic weed species due to its high competitiveness and increasing herbicide resistance. Florpyrauxifen-benzyl, a new auxin herbicide, was recently introduced for Echinochloa management; however, the potential risk for the development of herbicide resistance in Echinochloa species has not been well-investigated. Thus, this study was conducted to evaluate the baseline sensitivity of Echinochloa species to florpyrauxifen-benzyl to estimate the risk of future resistance development. A total of 70 and 71 accessions of Echinochloa crus-galli and Echinochloa oryzicola were collected from paddy fields in Korea, respectively. These two Echinochloa species were grown in plastic pots up to the 5-leaf stage, and treated with florpyrauxifen-benzyl at a range of doses from 2.2 g to 70.0 g a.i. ha-1. Nonlinear regression analyses revealed that GR50 values for E. oryzicola ranged from 4.54 g to 29.66 g a.i. ha-1, giving a baseline sensitivity index (BSI) of 6.53, while those for E. crus-galli ranged from 6.15 g to 16.06 g a.i. ha-1, giving a BSI of 2.61. Our findings suggest that E. oryzicola has a greater potential risk than E. crus-galli for the development of metabolism-based resistance to florpyrauxifen-benzyl.

Harnessing the topotactic transition in oxide heterostructures for fast and high-efficiency electrochromic applications.

Mobile oxygen vacancies offer a substantial potential to broaden the range of optical functionalities of complex transition metal oxides due to their high mobility and the interplay with correlated electrons. Here, we report a large electro-absorptive optical variation induced by a topotactic transition via oxygen vacancy fluidic motion in calcium ferrite with large-scale uniformity. The coloration efficiency reaches ~80 cm2 C-1, which means that a 300-nm-thick layer blocks 99% of transmitted visible light by the electrical switching. By tracking the color propagation, oxygen vacancy mobility can be estimated to be 10-8 cm2 s-1 V-1 near 300°C, which is a giant value attained due to the mosaic pseudomonoclinic film stabilized on LaAlO3 substrate. First-principles calculations reveal that the defect density modulation associated with hole charge injection causes a prominent change in electron correlation, resulting in the light absorption modulation. Our findings will pave the pathway for practical topotactic electrochromic applications.

Film-thickness-driven superconductor to insulator transition in cuprate superconductors.

The superconductor-insulator transition induced by film thickness control is investigated for the optimally doped cuprate superconductor La1.85Sr0.15CuO4. Epitaxial thin films are grown on an almost exactly matched substrate LaAlO3 (001). Despite the wide thickness range of 6 nm to 300 nm, all films are grown coherently without significant relaxation of the misfit strain. Electronic transport measurement exhibits systematic suppression of the superconducting phase by reducing the film thickness, thereby inducing a superconductor-insulator transition at a critical thickness of ~10 nm. The emergence of a resistance peak preceding the superconducting transition is discussed based on the weak localization. X-ray photoelectron spectroscopy results show the possibility that oxygen vacancies are present near the interface.

Mucosal involvement is a risk factor for poor clinical outcomes and relapse in patients with pemphigus treated with rituximab.

Many studies have reported the outcome of rituximab use in pemphigus but studies regarding the clinical risk factors for poor clinical outcomes or relapse are lacking. To clarify the risk factors for poor clinical outcomes or relapse in patients with pemphigus treated with rituximab, a retrospective chart analysis was performed on patients with pemphigus who were treated with rituximab in the dermatology clinic of Seoul National University Hospital. Forty patients with pemphigus were treated with rituximab, of which 39 (97.5%) experienced remission and 19 (48.7%) experienced relapse. Patients with mucosal lesions demonstrated poor clinical outcomes. The risk for relapse was 4.626 (confidence interval: 1.126-19.001, p = .034) times higher in patients with mucosal lesions than in those without lesions. In patients with pemphigus treated with rituximab, the presence of mucosal lesions resulted in poor clinical outcomes and frequent recurrence.

Antibiotic Susceptibility and Treatment Response in Bacterial Skin Infection.

BACKGROUND: Bacterial skin infections occur secondarily in conditions involving a vulnerable skin barrier such as atopic eczema, as well as primarily such as impetigo. They are mainly caused by Staphylococcus aureus and Streptococci. Recently, the prevalence of methicillin-resistant S. aureus has been increasing. OBJECTIVE: To determine the characteristics of community-acquired bacterial skin infections, to observe their antibiotic susceptibility patterns, and to evaluate factors contributing to the treatment response. METHODS: We retrospectively reviewed outpatients under 30 years old from 2010 to 2015, from whom we had taken skin swabs for antibiotic susceptibility testing. We collected clinical and microbiological characteristics from the medical records. RESULTS: We evaluated the culture results of 197 patients and reviewed their medical records. Overall, 86.3% (n=170) of the patients responded to the initial treatment regimen. S. aureus was the most commonly isolated pathogen (52.6%) and showed a high resistance rate to penicillin (90.9%) and oxacillin (36.3%). In the multivariable logistic regression analysis, resistance to 3 or more antibiotics (p=0.044), culture amounts described as "many" (p=0.040), and non-systemic antibiotic use (p<0.001) were significantly associated with lower treatment response. However, methicillin resistance was not associated with lower treatment response both in univariable and multivariable analyses. CONCLUSION: Among young patients, S. aureus was the most predominant pathogen present in bacterial skin infections. Resistance to high numbers of antibiotics and the use of non-systemic antibiotics were associated with lower treatment response. First-generation cephalosporins may be the most effective first-line empirical regimen for bacterial skin infections treated in outpatient settings, regardless of methicillin resistance.

Epstein-Barr Virus-Associated Vesiculopapular Eruption on the Face of a Patient with Natural Killer T Cell Lymphoma.

Unlike typical hydroa vacciniforme (HV), Epstein-Barr virus (EBV)-associated HV-like eruption is more variable in its clinical manifestations. In some patients, progression to lymphoma or leukemia has been reported, which are characterized by the T-cell immunophenotype. Here, we report the first Korean case of EBV-associated vesiculopapular eruption on the face of a patient with natural killer (NK)/T cell lymphoma. A 32-year-old Korean man presented with a late adolescent-onset recurrent necrotic papulovesicles on his face. The patient was previously diagnosed with EBV-associated NK/T cell lymphoma of the oral cavity and also had childhood-onset hypersensitivity to mosquito bites. Biopsy of his facial skin showed EBV-associated vesiculopapular eruptions, though ultraviolet provocation did not reproduce the skin lesions. EBV viral load in his peripheral blood was detected but low. The patient was treated with systemic chemotherapy. The lymphoma went into remission, but the facial EBV-associated vesiculopapular eruption had a relapsing and remitting course.

The Delivery Rates of Pathology Test Results to Patients: A Single-Center Experience in a Secondary Referral Center.

BACKGROUND: Delivery of pathology reports to the patient is a key step in the biopsy pathway, which is important for patient safety in dermatology. Automated systems for facilitating such medical process began in 2010 in our hospital, sending short message service to scheduled patients. OBJECTIVE: The purpose of this study was to evaluate the delivery of pathology reports to patients and investigate factors that influence this process and annual trends. METHODS: We retrospectively reviewed the medical records of all outpatients (n=2,452) who underwent skin biopsy at our department of dermatology in 2009 and 2014. In each year group, we analyzed the proportion of revisiting patients in terms of year, sex, age, season, biopsy method and diagnosis. RESULTS: In 2009, a smaller proportion of patients (205; 91.5%) who had undergone shave or excisional biopsy than of those who had undergone punch biopsy returned (781; 98.0%; p<0.001). This trend was not significant in 2014. Whereas there was no significant difference of return visit ratio between men and women in 2009, a higher proportion of women (754; 98.0%) than men (633; 95.6%) re-visited after skin biopsy to confirm their diagnosis in 2014 (p=0.008). Three patients with either a malignant tumor or suspected malignant lesion that required complete excision did not return to our clinic. CONCLUSION: Pathology report delivery rates were fairly satisfactory, regardless of year, age, season, and diagnosis. Sex and biopsy method influenced the return visit ratio. More organized follow-up protocols are required to strengthen patient safety and prevent critical patient drop-out.

Acral Lentiginous Melanoma, Indolent Subtype Diagnosed by En Bloc Excision: A Case Report.

Nail unit melanoma is a type of acral lentiginous melanoma and requires histopathologic examination for a confirmed diagnosis. However, inadequate biopsy techniques make definitive diagnosis difficult. A 61-year-old man presented with progressive nail pigmentation for 15 years, which was clinically highly suspicious for malignancy. Acral lentiginous melanoma was not detected in punch and longitudinal biopsy specimens, but en bloc excision tissue revealed melanoma. Acral lentiginous melanoma is known to have a heterogeneous pathologic manifestation depending on the pigmented region and the time it takes to progress. In this regard, en bloc excision can be considered as a first-line biopsy technique to diagnose acral lentiginous melanoma, indolent subtype.

Investigation of continuous changes in the electric-field-induced electronic state in Bi(1-x)Ca(x)FeO(3-δ).

Amongst the most interesting phenomena in correlated oxide systems are the doping-driven competitions between energetically similar ground states found in, e.g., high-Tc superconductors and colossal magnetoresistance manganites. It has recently been reported that doped multiferroics also exhibit this generic concept of phase competition. Here, we employ photoelectron emission microscopy (PEEM) to demonstrate evidence of systematic changes in the electronic structure of Bi(1-x)Ca(x)FeO(3-δ) treated by electrically controlled hole carrier doping, the outcome of which clearly correlates with the local modulation of electronic conductivity observed in the same material.

Topical administration of cyclosporin A in a solid lipid nanoparticle formulation.

Cyclosporin A (CsA)-loaded solid lipid nanoparticles (SLN) were developed for improved skin penetration. CsA-loaded SLN, prepared using a hot homogenization method, were nano-sized (about 73 nm) with a slightly negative surface charge (about -16 mV) and stable under physiological conditions regardless of CsA incorporation. In vitro permeation studies using murine skin mounted in the Franz-type vertical diffusion assembly revealed that the skin permeation efficiency of CsA-loaded SLN was 2-fold higher than that of CsA-oil mixture in viable skin. Furthermore, topically administered CsA-loaded SLN relieved symptoms of atopic dermatitis (AD) in an in vivo murine model of AD by decreasing the T helper (Th) 2 cell-related cytokines interleukin (IL)-4 and -5. These results suggest that SLN are effective drug carriers for topical delivery andthat CsA-loaded SLN can be therapeutically applied in allergy-related skin disorders.