Amphiphilic Graft Copolymers as Templates for the Generation of Binary Metal Oxide Mesoporous Interfacial Layers for Solid-State Photovoltaic Cells.

The binary metal oxide mesoporous interfacial layers (bi-MO meso IF layer) templated by a graft copolymer are synthesized between a fluorine-doped tin oxide (FTO) substrate and nanocrystalline TiO2 (nc-TiO2). Amphiphilic graft copolymers, Poly(epichlorohydrin)-graft-poly(styrene), PECH-g-PS, were used as a structure-directing agent, and the fabricated bi-MO meso IF layer exhibits good interconnectivity and high porosity. Even if the amount of ZnO in bi-MO meso IF layer increased, it was confirmed that the morphology and porosity of the bi-MO meso IF layer were well-maintained. In addtion, the bi-MO meso IF layer coated onto FTO substrates shows higher transmittance compared with a pristine FTO substrate and dense-TiO2/FTO, due to the reduced surface roughness of FTO. The overall conversion efficiency (η) of solid-state photovoltaic cells, dye-sensitized solar cells (DSSCs) fabricated with nc-TiO2 layer/bi-MO meso IF layer TZ1 used as a photoanode, reaches 5.0% at 100 mW cm-2, which is higher than that of DSSCs with an nc-TiO2 layer/dense-TiO2 layer (4.2%), resulting from enhanced light harvesting, good interconnectivity, and reduced interfacial resistance. The cell efficiency of the device did not change after 15 days, indicating that the bi-MO meso IF layer with solid-state electrolyte has improved electrode/electrolyte interface and electrochemical stability. Additionally, commercial scattering layer/nc-TiO2 layer/bi-MO meso IF layer TZ1 photoanode-fabricated solid-state photovoltaic cells (DSSCs) achieved an overall conversion efficiency (η) of 6.4% at 100 mW cm-2.

Alveoli-Like Multifunctional Scaffolds for Optical and Electrochemical In Situ Monitoring of Cellular Responses from Type II Pneumocytes.

While breathing, alveoli are exposed to external irritants, which contribute to the pathogenesis of lung disease. Therefore, in situ monitoring of alveolar responses to stimuli of toxicants under in vivo environments is important to understand lung disease. For this purpose, 3D cell cultures are recently employed for examining cellular responses of pulmonary systems exposed to irritants; however, most of them have used ex situ assays requiring cell lysis and fluorescent labeling. Here, an alveoli-like multifunctional scaffold is demonstrated for optical and electrochemical monitoring of cellular responses of pneumocytes. Porous foam with dimensions like the alveoli structure is used as a backbone for the scaffold, wherein electroactive metal-organic framework crystals, optically active gold nanoparticles, and biocompatible hyaluronic acid are integrated. The fabricated multifunctional scaffold allows for label-free detection and real-time monitoring of oxidative stress released in pneumocytes under toxic-conditions via redox-active amperometry and nanospectroscopy. Moreover, cellular behavior can be statistically classified based on fingerprint Raman signals collected from the cells on the scaffold. The developed scaffold is expected to serve as a promising platform to investigate cellular responses and disease pathogenesis, owing to its versatility in monitoring electrical and optical signals from cells in situ in the 3D microenvironments.

Photoactive MOF-Derived Bimetallic Silver and Cobalt Nanocomposite with Enhanced Antibacterial Activity.

Conventional antibiotic-based treatment of bacterial infections remains one of the most difficult challenges in medicine because of the threat of multidrug resistance caused by indiscriminate abuse. To solve these problems, it is essential to develop an effective antibacterial agent that can be used at a small dose while minimizing the occurrence of multiple resistance. Metal-organic frameworks (MOFs), which are hyper-porous hybrid materials containing metal ions linked by organic ligands, have recently attracted attention because of their strong antibacterial activity through metal-ion release, unlike conventional antibiotics. In this study, we developed a photoactive MOF-derived cobalt-silver bimetallic nanocomposite (Ag@CoMOF) by simply depositing silver nanoparticles on a cobalt-based MOF through nanoscale galvanic replacement. The nanocomposite structure continuously releases antibacterial metal ions (i.e., Ag and Co ions) in the aqueous phase and exhibits a strong photothermal conversion effect of Ag nanoparticles, accompanied by a rapid temperature increase of 25-80 °C under near-infrared (NIR) irradiation. Using this MOF-based bimetallic nanocomposite, superior antibacterial activities were achieved by 22.1-fold for Escherichia coli and 18.3-fold for Bacillus subtilis enhanced inhibition of bacterial growth in a liquid culture environment compared with the generally used chemical antibiotics. In addition, we confirmed the synergistic enhancement of the antibacterial ability of the bimetallic nanocomposite induced by NIR-triggered photothermal heating and bacterial membrane disruption even when using a small amount of the nanocomposites. We envision that this novel antibacterial agent using MOF-based nanostructures will replace traditional antibiotics to circumvent multidrug resistance and present a new approach to antibiotic development.

Sequential galvanic replacement mediated Pd-doped hollow Ru-Te nanorods for enhanced hydrogen evolution reaction mass activity in alkaline media.

High catalytic activity, long-term stability, and economical Pt-free catalysts for the hydrogen evolution reaction (HER) are required for the conversion of renewable energy systems. Noble nanomaterial Pt is a superior electrolysis catalyst for water splitting under typical experimental conditions with a relatively low overpotential. However, the use of Pt is limited by its high cost and activity degradation over time. Among several prospective alternatives, Ru has emerged as a promising alkaline electrolysis catalyst because of its significant catalytic activity and reduced cost compared to Pt. We designed and suggested Pd-doped hollow Ru-Te nanorods (PdRuTeNRs) via successive galvanic replacement reactions of sacrificial Te nanotemplates to further boost efficiency. The Pd/partially oxidized RuO2/Ru/Te hetero-interfaced composition exhibited an HER mass activity of 11.3 A g-1 Ru, twice that of Pt. In addition, the present PdRuTeNRs sufficiently maintained the activity from the 2000-cycle continuous test, greatly reducing the required cost by a quarter.

Quasi-Solid-State SiO2 Electrolyte Prepared from Raw Fly Ash for Enhanced Solar Energy Conversion.

Quasi-solid-state electrolytes in dye-sensitized solar cells (DSSCs) prevent solvent leakage or evaporation and stability issues that conventional electrolytes cannot; however, there are no known reports that use such an electrolyte based on fly ash SiO2 (FA_SiO2) from raw fly ash (RFA) for solar energy conversion applications. Hence, in this study, quasi-solid-state electrolytes based on FA_SiO2 are prepared from RFA and poly(ethylene glycol) (PEG) for solar energy conversion. The structural, morphological, chemical, and electrochemical properties of the DSSCs using this electrolyte are characterized by X-ray diffraction (XRD), high-resolution field-emission scanning electron microscopy (HR-FESEM), X-ray fluorescence (XRF), diffuse reflectance spectroscopy, electrochemical impedance spectroscopy (EIS), and incident photon-to-electron conversion efficiency (IPCE) measurements. The DSSCs based on the quasi-solid-state electrolyte (SiO2) show a cell efficiency of 5.5%, which is higher than those of nanogel electrolytes (5.0%). The enhancement of the cell efficiency is primarily due to the increase in the open circuit voltage and fill factor caused by the reduced electron recombination and improved electron transfer properties. The findings confirm that the RFA-based quasi-solid-state (SiO2) electrolyte is an alternative to conventional liquid-state electrolytes, making this approach among the most promising strategies for use in low-cost solar energy conversion devices.

Shape-Controlled TiO2 Nanomaterials-Based Hybrid Solid-State Electrolytes for Solar Energy Conversion with a Mesoporous Carbon Electrocatalyst.

One-dimensional (1D) titanium dioxide (TiO2) is prepared by hydrothermal method and incorporated as nanofiller into a hybrid polymer matrix of polyethylene glycol (PEG) and employed as a solid-electrolyte in dye-sensitized solar cells (DSSCs). Mesoporous carbon electrocatalyst with a high surface area is obtained by the carbonization of the PVDC-g-POEM double comb copolymer. The 1D TiO2 nanofiller is found to increase the photoelectrochemical performance. As a result, for the mesoporous carbon-based DSSCs, 1D TiO2 hybrid solid-state electrolyte yielded the highest efficiencies, with 6.1% under 1 sun illumination, in comparison with the efficiencies of 3.9% for quasi solid-state electrolyte and 4.8% for commercial TiO2 hybrid solid-state electrolyte, respectively. The excellent photovoltaic performance is attributed to the improved ion diffusion, scattering effect, effective path for redox couple transfer, and sufficient penetration of 1D TiO2 hybrid solid-state electrolyte into the electrode, which results in improved light-harvesting, enhanced electron transport, decreased charge recombination, and decreased resistance at the electrode/electrolyte interface.

A highly efficient nanofibrous air filter membrane fabricated using electrospun amphiphilic PVDF-g-POEM double comb copolymer.

Current global emergencies, such as the COVID-19 pandemic and particulate matter (PM) pollution, require urgent protective measures. Nanofibrous air filter membranes that can capture PM0.3 and simultaneously help in preventing the spread of COVID-19 are essential. Therefore, a highly efficient nanofibrous air filter membrane based on amphiphilic poly(vinylidene fluoride)-graft-poly(oxyethylene methacrylate) (PVDF-g-POEM) double comb copolymer was fabricated using atomic transfer radical polymerization (ATRP) and electrospinning. Fourier transform infrared spectroscopy, X-ray diffraction, proton nuclear magnetic resonance, transmission electron microscopy, differential scanning calorimetry, and thermogravimetric analysis were employed to successfully characterize the molecular structure of the fabricated amphiphilic PVDF-g-POEM double comb copolymer. The nanofibrous air filter membrane based on amphiphilic PVDF-g-POEM double comb copolymer achieved a low air resistance of 4.69 mm H2O and a high filtration efficiency of 93.56 % due to enhanced chemical and physical adsorption properties.

Solid-State Solar Energy Conversion from WO3 Nano and Microstructures with Charge Transportation and Light-Scattering Characteristics.

Solar energy conversion devices composed of highly crystalline gel polymers with disk-WO3 nanostructure and plate-WO3 microstructures (D-WO3 and P-WO3, respectively) exhibited higher power conversion efficiency than those with a gel electrolyte. In this study, D-WO3 and P-WO3 were prepared using a hydrothermal process and their structural and morphological features were investigated for application in solar energy conversion devices. The P-WO3 solid-state electrolyte significantly enhanced the cell performance owing to its charge transportation and light-scattering characteristics. The P-WO3 solid-state electrolyte showed a power conversion efficiency of 6.3%, which is higher than those of the gel (4.2%) and D-WO3 solid-state (5.5%) electrolytes. The electro-chemical impedance spectroscopy (EIS), intensity-modulated voltage spectroscopy (IMVS), diffuse reflectance, and incident photon-to-current conversion efficiency (IPCE) analysis results showed that the P-WO3 solid-state electrolyte showed improved charge transportation and light scattering, and hence enhanced the cell performance.

Surface Carbon Shell-Functionalized ZrO2 as Nanofiller in Polymer Gel Electrolyte-Based Dye-Sensitized Solar Cells.

We prepare dye-sensitized solar cells (DSSCs) fabricated with a poly (ethylene glycol) based polymer gel electrolytes (PGEs) incorporating surface carbon shell-functionalized ZrO2 nanoparticles (ZrO2-C) as nanofillers (NFs). ZrO2 are polymerized via atom transfer radical polymerization (ATRP) using poly (ethylene glycol) methyl ether methacrylate (POEM) as a scaffold to prepare the ZrO2-C through carbonization. The power conversion efficiency of DSSC with 12 wt% ZrO2-C/PGEs is 5.6%, exceeding that with PGEs (4.4%). The enhanced efficiency is attributed to Lewis acid-base interactions of ZrO2-C and poly (ethylene glycol), catalytic effect of the carbon shells of ZrO2-C, which results in reduced crystallinity, enhanced ion conductivity of electrolytes, decreased counterelectrode/electrolyte interfacial resistance, and improved charge transfer rate. These results demonstrate that ZrO2-C introduction to PGEs effectively improves the performance of DSSCs.

Synthesis of Ag2O decorated hierarchical TiO2 templated by double comb copolymers for efficient solar water splitting.

Synthesis of Ag2O decorated hierarchical TiO2 was realised in this study by employing a facile hydrothermal method, which involved the use of a double comb copolymer templated sol-gel and a chemical bath. The synthesized Ag2O@HNR demonstrated a photocurrent density of 1.78 mA cm-2 at 1.23 V against RHE under an illumination of 1 sun. This observed value of photocurrent density exceeded that of TiO2 nanorods by 2.18 times.

The efficacy of micro-insulated needle radiofrequency system for the treatment of lower eyelid fat bulging.

BACKGROUND AND OBJECTIVES: Conventional treatment options for eyelid fat bulging are generally limited to surgical approaches. However, many attempts have been made recently to manage this disfigurement using non-surgical interventions. The purpose of this study was to evaluate the efficacy and safety of a micro-insulated needle radiofrequency system for the treatment of lower eyelid fat bulging. METHODS: This is a single center pre-post comparative study. Twenty-two subjects with lower eyelid fat bulging were treated twice using the needle radiofrequency system, at an interval of four weeks. Two types of partially insulated needles with different lengths were used in each session. A three-dimensional photogrammetry system was used to objectively measure changes in the extent of the fat bulge. The investigator's global assessment (IGA) of the severity of fat bulging was also evaluated. RESULTS: The average extent of fat bulging was decreased significantly after twelve weeks, and was maintained until 24 weeks. The IGA score was significantly decreased after four weeks and further decreased after twelve weeks, and then maintained until 24 weeks. There were no side effects, except for lower eyelid swelling and bruising that lasted for about a week. CONCLUSION: The micro-insulated needle radiofrequency system can be a beneficial and well-tolerated treatment for lower eyelid fat bulging.

Signal detection of benzodiazepine use and risk of dementia: sequence symmetry analysis using South Korean national healthcare database.

Background Benzodiazepine use can potentially cause confusion and delays in mental processes. These well-known side effects appear to be linked to an increased risk of being diagnosed with dementia. Objective To evaluate the possibility of an association between benzodiazepine and dementia. Setting Korean healthcare database from 2002 to 2013. Methods Sequence symmetry analysis was conducted to investigate whether benzodiazepine use increases the risk of dementia or not. We defined exposure as new benzodiazepine users and outcome as new diagnosis of dementia (ICD-10: F00-03, G30, and G318). Benzodiazepines were categorized into two groups (long-acting and short-acting) based on the duration of action. Antidepressants, opioid analgesic, and statin were used as active comparators to rule out any possible non-causal interpretations of our results. The time-trend adjusted sequence ratio (ASR) with 95% confidence intervals (CI) was measured to identify possible associations. Main outcome measure Adjusted sequence ratio. Results Benzodiazepine users were shown to be associated with dementia [benzodiazepine: 4212 pairs, ASR = 2.27 (95% CI 2.11-2.44)]. In addition, long-acting benzodiazepines had a higher ASR than that of short-acting benzodiazepines [long-acting: 3972 pairs, ASR = 2.22 (95% CI 2.06-2.39] and [short-acting: 5213 pairs, ASR = 1.88 (95% CI 1.77-2.00)]. However, our SSA found no duration-response relationship. Conclusion Our signal detection suggests that there is a possible association between benzodiazepines and dementia. Additionally, it proposes that persons receiving long-acting benzodiazepines are at a higher risk of developing dementia than those receiving short-acting benzodiazepines. Further studies are recommended to confirm whether this epidemiological association is a causal effect or not.

Assessment of age- and sex-related changes in baggy lower eyelids using a novel objective image analysis method: Orbital gray scale analysis.

BACKGROUND: Baggy lower eyelids (BLEs) are a common aesthetic problem of aging. Valid and reliable assessment tools for BLEs are required to evaluate the current status and treatment outcome. AIMS: Age- and sex-related changes in BLEs were assessed with the orbital gray scale (OGS), a novel objective image analysis method. METHODS: We gathered frontal-view photographs of the faces of the patients who sought for correction of BLEs. Based on the clinical pattern, we classified the BLEs of the subjects into medial (M), medial and central (MC), and medial to lateral (MCL) types. Severity was evaluated using the OGS, a modified method of the linear gray scale analysis. RESULTS: The BLEs of 1034 subjects were classified. The most common types were MCL type in the men and MC type in the women, respectively. The M and MC types were common in the young subjects, whereas the MCL type was more common in the old subjects (P < .001). The measurements of OGS in 104 subjects showed positive correlation with age, a higher mean value in the men, and a trend toward higher values in the order of M, MC, and MCL types (P < .001 for central and lateral OGS scores). In a multiple linear regression analysis, central and lateral OGS values were significantly related with age, sex, and M-C-L classification type (P < .001). CONCLUSION: The M-C-L classification and OGS were significantly associated with both age and sex, proving that they could be potent objective assessment tools for BLEs.

SnO2 hollow nanotubes: a novel and efficient support matrix for enzyme immobilization.

A major challenge in the industrial use of enzymes is maintaining their stability at elevated temperatures and in harsh organic solvents. In order to address this issue, we investigated the use of nanotubes as a support material for the immobilization and stabilization of enzymes in this work. SnO2 hollow nanotubes with a high surface area were synthesized by electrospinning the SnCl2 precursor and polyvinylpyrrolidone (dissolved in dimethyl formamide and ethanol). The electrospun product was used for the covalent immobilization of enzymes such as lipase, horseradish peroxidase, and glucose oxidase. The use of SnO2 hollow nanotubes as a support was promising for all immobilized enzymes, with lipase having the highest protein loading value of 217 mg/g, immobilization yield of 93%, and immobilization efficiency of 89%. The immobilized enzymes were fully characterized by various analytical methods. The covalently bonded lipase showed a half-life value of 4.5 h at 70 °C and retained ~91% of its original activity even after 10 repetitive cycles of use. Thus, the SnO2 hollow nanotubes with their high surface area are promising as a support material for the immobilization of enzymes, leading to improved thermal stability and a higher residual activity of the immobilized enzyme under harsh solvent conditions, as compared to the free enzyme.

Periostin in Mature Stage Localized Scleroderma.

BACKGROUND: Periostin is a novel matricellular protein expressed in many tissues, including bone, periodontal ligament, and skin. Although its expression is prominent in various fibrotic conditions, studies of periostin in localized scleroderma are rare. OBJECTIVE: To investigate the expression of periostin and other molecules in localized scleroderma. METHODS: A retrospective study of 14 patients with confirmed mature stage localized scleroderma was undertaken. Fourteen age-matched and biopsy site-matched subjects with normal skin were included as controls. Collagen fiber deposition, periostin, procollagen, transforming growth factor-ß, and matrix metalloproteinase (MMP)-1 expression were assessed and compared between the two groups. Co-localization of α-smooth muscle actin and periostin was evaluated using confocal microscopy. RESULTS: Periostin was predominantly expressed along the dermo-epidermal junction in the controls. Conversely, patients with localized scleroderma demonstrated increased collagen fiber deposition and periostin expression that was more widely distributed along the entire dermis. MMP-1 staining showed increased expression in the epidermis and dermis of patients compared to scanty expression in the controls. A semi-quantitative evaluation showed a higher proportion of excessive collagen bundle deposition (57.1% vs. 7.1%, p=0.013), diffuse periostin positivity (42.9% vs. 0%, p=0.016), and moderate MMP-1 positivity (71.4% vs. 7.1%, p=0.001) in patients than in the controls. CONCLUSION: Compared to the controls, patients with localized scleroderma had enhanced periostin expression corresponding to increased collagen fiber deposition and unexpected overexpression of MMP-1. The results of this human in vivo study may implicate the pathogenesis of localized scleroderma.

The efficacy and safety of cold-induced lipolysis in the treatment of pseudogynecomastia.

BACKGROUND: The treatment options for pseudogynecomastia have been limited. Cold-induced lipolysis provides a noninvasive, localized subcutaneous adipocyte destruction by inducing adipocyte apoptosis. OBJECTIVE: This study has been designed to evaluate the efficacy of cold-induced lipolysis as a treatment modality for pseudogynecomastia. METHODS: In this 28-week prospective trial, a total of 12 male pseudogynecomastia patients (Korean) were treated twice with cold-induced lipolysis. Efficacy was determined by chest circumference, ultrasonographic measurement of fat thickness, Simon's Gynecomastia class (SGC), photographic assessment, and the patient's satisfaction (baseline, weeks 4, 8, 16, and 28). Using a questionnaire, safety was evaluated at each visit. RESULTS: For 10 subjects that completed the trial, chest circumference and fat thickness significantly improved by week 8. This same improvement was gradually noticed through week 28. The patients SGC scores continuously decreased after two sessions. Photographic assessment showed an improvement until week 28. The result of the patient's satisfaction score was also meaningful. While there were no adverse events observed, transient pain and bruising at the treatment site were noticed. LIMITATIONS: We recruited a limited number of participants. Also, we could not exclude there might be other individual factors in association with the patients pseudogynecomastia. CONCLUSION: Cold-induced lipolysis is a safe, effective therapeutic option in the treatment of pseudogynecomastia. Lasers Surg. Med. 48:584-589, 2016. © 2016 Wiley Periodicals, Inc.