Unusual Raman Enhancement Effect of Ultrathin Copper Sulfide.

In surface-enhanced Raman spectroscopy (SERS), 2D materials are explored as substrates owing to their chemical stability and reproducibility. However, they exhibit lower enhancement factors (EFs) compared to noble metal-based SERS substrates. This study demonstrates the application of ultrathin covellite copper sulfide (CuS) as a cost-effective SERS substrate with a high EF value of 7.2 × 104 . The CuS substrate is readily synthesized by sulfurizing a Cu thin film at room temperature, exhibiting a Raman signal enhancement comparable to that of an Au noble metal substrate of similar thickness. Furthermore, computational simulations using the density functional theory are employed and time-resolved photoluminescence measurements are performed to investigate the enhancement mechanisms. The results indicate that polar covalent bonds (Cu─S) and strong interlayer interactions in the ultrathin CuS substrate increase the probability of charge transfer between the analyte molecules and the CuS surface, thereby producing enhanced SERS signals. The CuS SERS substrate demonstrates the selective detection of various dye molecules, including rhodamine 6G, methylene blue, and safranine O. Furthermore, the simplicity of CuS synthesis facilitates large-scale production of SERS substrates with high spatial uniformity, exhibiting a signal variation of less than 5% on a 4-inch wafer.

An observational, prospective, open label, multicenter study to evaluate the safety and effectiveness of pegfilgrastim as secondary prophylaxis to decrease the incidence of febrile neutropenia in Korean female patients with breast cancer.

PURPOSE: Pegfilgrastim is a widely used long-acting granulocyte colony-stimulating factor (G-CSF) that prevents febrile neutropenia (FN) in patients with breast cancer receiving chemotherapy. This study aimed to evaluate the incidence of chemotherapy-related FN events and other adverse events (AEs) during chemotherapy in Korean patients with breast cancer treated with pegfilgrastim as secondary prophylactic support. MATERIALS AND METHODS: This was a multicenter, open-label, prospective, observational study. A total of 1255 patients were enrolled from 43 institutions. The incidence of FN was evaluated as the primary endpoint. The secondary endpoints included (1) incidence of bone pain, (2) proportion of patients with a relative dose intensity (RDI) of ≥85%, and (3) proportion of patients with AE. RESULTS: Pegfilgrastim administration reduced FN by 11.8-1.6%. The highest incidence of bone pain was observed at the time point of the 1st day after the administration and mild bone pain was the most common of all bone pain severity. The mean RDI was 98.5 ± 7.3%, and the proportion of the patients with and RDI≥85% was 96.9% (1169/1233). AEs were reported in 52.6% of the patients, and serious drug reactions occurred in only 0.7%. CONCLUSION: The use of pegfilgrastim as secondary prophylaxis was effective and safe for preventing FN in patients with breast cancer who were treated with chemotherapy.

A Redox-Mediator-Integrated Flexible Micro-Supercapacitor with Improved Energy Storage Capability and Suppressed Self-Discharge Rate.

To effectively improve the energy density and reduce the self-discharging rate of micro-supercapacitors, an advanced strategy is required. In this study, we developed a hydroquinone (HQ)-based polymer-gel electrolyte (HQ-gel) for micro-supercapacitors. The introduced HQ redox mediators (HQ-RMs) in the gel electrolyte composites underwent additional Faradaic redox reactions and synergistically increased the overall energy density of the micro-supercapacitors. Moreover, the HQ-RMs in the gel electrolyte weakened the self-discharging behavior by providing a strong binding attachment of charged ions on the porous graphitized carbon electrodes after the redox reactions. The micro-supercapacitors with HQ gel (HQ-MSCs) showed excellent energy storage performance, including a high energy volumetric capacitance of 255 mF cm-3 at a current of 1 µA, which is 2.7 times higher than the micro-supercapacitors based on bare-gel electrolyte composites without HQ-RMs (b-MSCs). The HQ-MSCs showed comparatively low self-discharging behavior with an open circuit potential drop of 37% compared to the b-MSCs with an open circuit potential drop of 60% after 2000 s. The assembled HQ-MSCs exhibited high mechanical flexibility over the applied external tensile and compressive strains. Additionally, the HQ-MSCs show the adequate circuit compatibility within series and parallel connections and the good cycling performance of capacitance retention of 95% after 3000 cycles.

Electrochemically active hydroquinone-based redox mediator for flexible energy storage system with improved charge storing ability.

Electrochemically active redox mediators have been widely investigated in energy conversion/storage system to improve overall catalytic activities and energy storing ability by inducing favorable surface redox reactions. However, the enhancement of electrochemical activity from the utilization of redox mediators (RMs) is only confirmed through theoretical computation and laboratory-scale experiment. The use of RMs for practical, wearable, and flexible applications has been scarcely researched. Herein, for the first time, a wearable fiber-based flexible energy storage system (f-FESS) with hydroquinone (HQ) composites as a catalytically active RM is introduced to demonstrate its energy-storing roles. The as-prepared f-FESS-HQ shows the superior electrochemical performance, such as the improved energy storage ability (211.16 F L-1 and 29.3 mWh L-1) and long-term cyclability with a capacitance retention of 95.1% over 5000 cycles. Furthermore, the f-FESS-HQ can well maintain its original electrochemical properties under harsh mechanical stress (bending, knotting, and weaving conditions) as well as humid conditions in water and detergent solutions. Thus, the strategical use of electrochemically active RMs can provide the advanced solution for future wearable energy storage system.

Biocompatible liquid-type carbon nanodots (C-paints) as light delivery materials for cell growth and astaxanthin induction of Haematococcus pluvialis.

In this study, we aimed to demonstrate the feasibility of the application of biocompatible liquid type fluorescent carbon nanodots (C-paints) to microalgae by improving microalgae productivity. C-paints were prepared by a simple process of ultrasound irradiation using polyethylene glycol (PEG) as a passivation agent. The resulting C-paints exhibited a carbonyl-rich surface with good uniformity of particle size, excellent water solubility, photo-stability, fluorescence efficiency, and good biocompatibility (<10.0 mg mL-1 of C-paints concentration). In the practical application of C-paints to microalgae culture, the most effective and optimized condition leading to growth promoting effect was observed at a C-paints concentration of 1.0 mg mL-1 (>20% higher than the control cell content). A C-paints concentration of 1-10.0 mg mL-1 induced an approximately >1.8 times higher astaxanthin content than the control cells. The high light delivery effect of non-cytotoxic C-paints was applied as a stress condition for H. pluvialis growth and was found to play a major role in enhancing productivity. Notably, the results from this study are an essential approach to improve astaxanthin production, which can be used in various applications because of its therapeutic effects such as cancer prevention, anti-inflammation, immune stimulation, and treatment of muscle-soreness.

Large area patterning of residue-free metal oxide nanostructures by liquid transfer imprint lithography.

One-dimensional (1D) and three-dimensional (3D) residue-free metal oxide patterns are directly fabricated over large areas using liquid transfer imprint lithography (LTIL) with an ultraviolet-curable metal oxide precursor resist. A 1D line or pillar array of metal oxides nano-patterns without a residual layer is formed by LTIL and annealing processes. A 3D layer-by-layer nanomesh structure is successfully constructed by repeating the LTIL method without a complex etching process. In addition, it is possible to form a hierarchical structure in which zinc oxide nanowires are selectively grown on a desired zinc oxide (ZnO) seed pattern formed by LTIL via a hydrothermal method. Unlike the pattern fabricated by the conventional nanoimprint lithography method, in the case of the pattern formed by LTIL the residues accumulated between the patterns during the patterning procedure can be removed, and thus it is possible to easily form various types of nanostructures.

An innovative scheme for sub-50 nm patterning via electrohydrodynamic lithography.

The fabrication of large-area and well-ordered nanostructures using lithographic techniques is challenging. We have developed novel approaches for sub-50 nm nanopatterning using an electrohydrodynamic lithography (EHL) technique by tailoring experimental parameters such as applied voltage, stamp features, filling ratio, and choice of resist film. We obtain a sub-50 nm pattern replica from a master stamp that contains an array of line patterns having 50 nm widths. Moreover, we show that a far-smaller pattern replication than the original pattern size can be readily obtained by carefully adjusting the experimental conditions. Perfect- and much smaller-pattern replicas have been realized from the master stamp with an array of hole patterns having a 400 nm hole size by tuning the filling ratio. We also demonstrate that an array of 30 nm graphene nanoribbons can be easily fabricated by exploring a hierarchical core-shell template structure employing a bilayer resist film via an EHL technique. The proposed minimal-contact patterning method is simple, versatile, and inexpensive and has potential to become a powerful technique for realizing feasible ultrafine nanostructures on a wafer scale.