A New Theranostic System Based on Gold Nanocages and Phase-Change Materials with Unique Features for Photoacoustic Imaging and Controlled Release

This communication reports a new theranostic system with a combination of capabilities to both enhance the contrast of photoacoustic (PA) imaging and control the release of a chemical or biological effector by high-intensity focused ultrasound (HIFU). The fabrication of this system simply involves filling the hollow interiors of gold nanocages with a phase-change material (PCM) such as 1-tetradecanol that has a melting point of 38−39 °C. The PCM can be premixed and thus loaded with a dye, as well as other chemical or biological effectors. When exposed to direct heating or HIFU, the PCM will melt and escape from the interiors of nanocages through small pores on the surface, concurrently releasing the encapsulated molecules into the surrounding medium. We can control the release profile by varying the power of HIFU, the duration of exposure to HIFU, or both

A New Theranostic System Based on Gold Nanocages and Phase-Change Materials with Unique Features for Photoacoustic Imaging and Controlled Release

This communication reports a new theranostic system with a combination of capabilities to both enhance the contrast of photoacoustic (PA) imaging and control the release of a chemical or biological effector by high-intensity focused ultrasound (HIFU). The fabrication of this system simply involves filling the hollow interiors of gold nanocages with a phase-change material (PCM) such as 1-tetradecanol that has a melting point of 38−39 °C. The PCM can be premixed and thus loaded with a dye, as well as other chemical or biological effectors. When exposed to direct heating or HIFU, the PCM will melt and escape from the interiors of nanocages through small pores on the surface, concurrently releasing the encapsulated molecules into the surrounding medium. We can control the release profile by varying the power of HIFU, the duration of exposure to HIFU, or both

Initial Biopsy Outcome Prediction in Korean Patients-Comparison of a Noble Web-based Korean Prostate Cancer Risk Calculator versus Prostate-specific Antigen Testing

We developed and validated a novel Korean prostate cancer risk calculator (KPCRC) for predicting the probability of a positive initial prostate biopsy in a Korean population. Data were collected from 602 Koreans who underwent initial prostate biopsies due to an increased level of prostate-specific antigen (PSA), a palpable nodule upon digital rectal examination (DRE), or a hypoechoic lesion upon transrectal ultrasound (TRUS). The clinical and laboratory variables were analyzed by simple and multiple logistic regression analysis. The area under the receiver operating characteristic curve (AUC) was computed to compare its performance to PSA testing alone. Prostate cancer was detected in 172 (28.6%) men. Independent predictors included age, DRE findings, PSA level, and prostate transitional zone volume. We developed the KPCRC using these variables. The AUC for the selected model was 0.91, and that of PSA testing alone was 0.83 (P < 0.001). The AUC for the selected model with an additional dataset was 0.79, and that of PSA testing alone was 0.73 (P = 0.004). The calculator is available on the website: http://pcrc.korea.ac.kr. The KPCRC improved the performance of PSA testing alone in predicting the risk of prostate cancer in a Korean population. This calculator would be a practical tool for physicians and patients

Multifunctional Metal‐oxide Integrated Monolayer Graphene Heterostructures for Planar, Flexible, and Skin‐mountable Device Applications

The adoption of nanostructured metal-oxides integrated graphene monolayers-based heterostructures appears to be a promising approach for enhancing the performance of various devices. However, precisely controlled growth of such unique heterostructures without disturbing the monolayer graphene characteristics remains a challenging task especially over a large area with good uniformity. Herein, ultrathin metal-oxide (p-Co3O4 and n-ZnO) nanostructures (MONSs) integrated graphene monolayer (GML) heterostructures are carefully developed by fascinating the graphene native defects while nucleation and growth of MONSs. Metal-oxides integrated graphene monolayers with lower material densities (≤ 30 μg/cm2) significantly enhanced the quality (2D/G ~5–9) and reduced the electrical resistance (11–17 Ω/sq.) of graphene layers, whereas the heterostructures developed with higher densities possess predominant water-oxidation characteristics than that of their individual components. Further, the Co3O4/GML heterostructures-based micro-supercapacitors, fabricated over 25 µm polyimide sheets, showed excellent mechanical stability and flexibility with a volumetric and specific capacitance of 7.76 F/cm3 and 1.27 F/g, respectively. The ZnO/GML heterostructures designed over micron thick parylene film displayed exciting photoresistor characteristics with photosensitivity of ~1.54 and superb flexibility and skin-mountability. Synergistic multifunctional characteristics of these ultrathin heterostructures offer the possibility to realize various eco-friendly ultrathin as well as skin-mountable energy and health monitoring devices. © 2021FALS

Optimizing PET Glycolysis with an Oyster Shell-Derived Catalyst Using Response Surface Methodology

Polyethylene terephthalate (PET) waste was depolymerized into bis(2-hydroxyethyl) terephthalate (BHET) through glycolysis with the aid of oyster shell-derived catalysts. The equilibrium yield of BHET was as high as 68.6% under the reaction conditions of mass ratios (EG to PET = 5, catalyst to PET = 0.01) at 195 °C for 1 h. Although biomass-derived Ca-based catalysts were used for PET glycolysis to obtain BHET monomers, no statistical analysis was performed to optimize the reaction conditions. Thus, in this study, we applied response surface methodology (RSM) based on three-factor Box–Behnken design (BBD) to investigate the optimal conditions for glycolysis by analyzing the independent and interactive effects of the factors, respectively. Three independent factors of interest include reaction time, temperature, and mass ratio of catalyst to PET under a fixed amount of ethylene glycol (mass ratio of EG to PET = 5) due to the saturation of the yield above the mass ratio. The quadratic regression equation was calculated for predicting the yield of BHET, which was in good agreement with the experimental data (R2 = 0.989). The contour and response surface plots showed the interaction effect between three variables and the BHET yield with the maximum average yield of monomer (64.98%) under reaction conditions of 1 wt% of mass ratio (catalyst to PET), 195 °C, and 45 min. Both the experimental results and the analyses of the response surfaces revealed that the interaction effects of reaction temperature vs. time and temperature vs. mass ratio of the catalyst to the PET were more prominent in comparison to reaction time vs. mass ratio of the catalyst to the PET

Shape control of cadmium hydroxides (Cd(OH)(2)) sensitive to pH quenching depth and massive production of CdSe nanocrystals by their chemical transformation

This study demonstrates that the structure of cadmium hydroxides (Cd(OH)(2)) precipitated from a basic cadmium nitrate solution can be finely controlled by adjusting the pH of the precursor solution. The synthesis process involves only pouring the saturated solution into pure water to quench the pH and the total process is finished within 30 s. At a shallow pH quenching, the unstable nanoparticles turned into microparticles via a ripening process. Cd(OH)(2) was precipitated in the form of one-dimensional nanowires and then two-dimensional plates as the pH quenching was increased. At a large pH quenching, porous aggregates of Cd(OH)(2) were obtained due to the too fast precipitation. The ultrafine Cd(OH)(2) nanowires were readily transformed into CdSe chain-like nanocrystals. The transformation was quick and gave 100% yield, facilitating massive production of CdSe nanocrystals in an aqueous condition. The Cd(OH)(2) nanowires were directly grown on Si nanowires and transformed into CdSe chain-like nanocrystals, decorating the surface of each Si nanowire.close

Ultrathin silver telluride nanowire films and gold nanosheet electrodes for a flexible resistive switching device

We demonstrated a flexible resistive switching device based on ultrathin Ag2Te nanowire (NW) films and Au nanosheet (NS) electrodes by exploiting a monolayer assembly on the water surface for macroscale two-dimensional structures. Firstly, ultrathin TeNWs (diameter ≈ 10 nm) are rapidly assembled on the water surface as a form of monolayer and transferred to fabricate TeNW films on various substrates with any available size. An assembled TeNW film was used as a template to produce a Ag2TeNW film through chemical transformation. A well-aligned Ag2TeNW film device showed reversible resistive switching properties when the Ag composition of the silver telluride NW becomes stoichiometric Ag2Te. Additionally, a non-stoichiometric Ag2+δTeNW film shows an increased On/Off ratio. For a flexible memory device, ultrathin AuNSs (thickness ≤20 nm) were adopted as working electrodes, since thermally deposited gold electrodes tend to crack under strain, which can fail to maintain the electrical properties. A paper-like flexibility of AuNS proved its capability as optimal electrodes of ultrathin Ag2TeNW film-based resistive memory devices. © 2018 The Royal Society of Chemistry.1

???Water-in-salt ???and NASICON Electrolyte-Based Na???CO 2 Battery

Super concentrated electrolytes, referred to as &quot;water-in-salt (WiS) electrolytes&quot;, are being increasingly employed because of their wide electrochemical stability window, cost-effectiveness, and non-flammability. However, the free water molecules present in WiS electrolytes prevent the use of highly abundant, low-cost Na metal as the anode for various Na-gas batteries. In this study, we develop a WiS-based hybrid Na-CO2 battery that utilizes CO2 and serves as an energy storage cell, where a Na super-ionic conductor enables us to directly use Na metal as the anode component and a WiS electrolyte for the cathode electrolyte. In particular, linear sweep voltammetry with corresponding differential electrochemical mass spectrometry ensures an expanded electrochemical stability window, which guarantees Na-CO2 operation without electrolyte degradation during the charge process. Furthermore, we introduce a nano-sized Ru catalyst to the current collector using the Joule-heating method for lowering the discharge-charge gap. Consequently, the Na-CO2 batteries with these Ru@carbon current collectors reduce the overpotential gap and exhibit a cycling endurance of over 75 cycles (50 days) without significant alteration. These promising results demonstrate the potential of cost-effective, WiS-based Na-CO2 batteries that utilize CO2 and can be employed as energy storage cells