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Seasonal variations in the concentrations of eight ultraviolet (UV) filters and 22 illicit drugs including their metabolites in the Korean aquatic environment were investigated. Seawater samples from three beaches, water samples from two rivers, and influents and effluents from three wastewater treatment plants were analyzed. The UV filter concentrations in the seawater, river water, and effluent samples were 39.4–296, 35.4–117, and 6.84–51.1 ng L -1 , respectively. The total UV filter concentrations in the seawater samples were 1.9–4.4 times higher at the peak of the holiday season than outside the peak holiday season. An environmental risk assessment showed that ethylhexyl methoxy cinnamate (EHMC) could cause adverse effects on aquatic organisms in the seawater at the three beaches during the holiday period. Seven of the 22 target illicit drugs including their metabolites were detected in the wastewater influent samples, and the total illicit drug concentrations in the influent samples were 0.08–65.4 ng L -1 . The estimated daily consumption rates for cis -tramadol ( Cis -TRM), methamphetamine (MTP), meperidine (MEP), and codeine (COD) were 25.7–118.4, 13.8–36.1, 1.36–12.6, and 1.75–8.64 mg d -1 (1000 people) −1 , respectively. In popular vacation area, the illicit drug consumption rates ( Cis -TRM, MTP and MEP) were 1.6–2.6 times higher at the peak of the summer holiday season than at the beginning of the summer. [ABSTRACT FROM AUTHOR]

Abstract: Clean chemical vapor deposition (CVD)-grown graphene surfaces with intrinsic electrical properties were obtained by a modified poly(methylmethacrylate) (PMMA) transfer method. The modified method entails UV irradiation, followed by wet cleaning of the UV-irradiated PMMA layer using a mixture of isopropyl alcohol (IPA), acetone, and methyl isobutyl ketone (MIBK). The chemical structure of the PMMA layer degrades following UV irradiation under atmospheric conditions, via side-chain cleavage of the ester groups, resulting in reduced intermolecular interactions between the PMMA layer and the underlying graphene film. Furthermore, the IPA/MIBK/acetone mixture is shown to be a powerful solvent that can effectively remove the PMMA layer without leaving any PMMA residue, which could act as a source of cracks and scattering centers for charge carrier transport, on the graphene surface. Graphene transistors fabricated by this modified transfer method show high electron and hole mobilities with ideal threshold voltages of near 0V. [Copyright &y& Elsevier]

Abstract: Cytoplasmic male sterility (CMS) is the maternally inherited inability to produce functional pollens. Although the CMS cytoplasm from the pepper Capsicum annuum (PI164835) has been widely used to produce F1 hybrid seeds, the origin of this cytoplasm has not been studied at the DNA sequence level. Because the plastid genome is co-transmitted with and is highly stable compared to mitochondrial genome, we used plastid barcode sequences to deduce the CMS cytoplasm origin. Two intergenic plastid sequences, trnH–psbA and rpl16–rpl18, were used to analyze pepper germplasm cytoplasm types from six different Capsicum species. Cytoplasm types could be divided into six and four different types for the trnH–psbA and rpl16–rpl18 intergenic sequences, respectively. Sequences of these two regions in CMS pepper lines were identical to those of pepper lines belonging to a particular C. annuum clade. This identity was confirmed by investigation using a larger germplasm number and markers derived from mitochondrial sequences. Our results suggest that the CMS cytoplasm of C. annuum PI164835 may have originated from a female plant belonging to the C. annuum clade. [Copyright &y& Elsevier]

Abstract: Thin multiwalled carbon nanotube (t-MWCNTs)-based field emitters are made by use of a spray method. The number of tube walls is between 2 and 6, with the corresponding outer diameters between 3 and 6nm. They were dispersed in dichloroethane and sprayed onto metal-deposited indium tin oxide glass. After heat treatment, they were found to be tightly adhered to metal electrode. Excellent field emission characteristics were exhibited, with a large field enhancement factor and low turn-on voltage, comparable to those of singlewalled CNTs. However, the t-MWCNTs demonstrated a significantly lower degradation rate than SWCNTs in the emission current. This high emission stability was attributed to their stable edge structures, similar to conventional large-diameter MWCNTs. Therefore, t-MWCNTs could be utilized as an alternative material for field emitters. [Copyright &y& Elsevier]

Abstract: We have characterized the emission properties of multi-walled carbon nanotubes (MWCNTs) grown by thermal chemical vapor deposition (CVD). Our characterizations have been conducted in the thermal-field (T-F) zone, a narrow transition zone between field emission and thermionic emission. The characteristic I–V curve in T-F zone, designated to Christov plot, is advantageous to extract independently the field enhancement factor and work function at the emitting site. Our approach is more reliable than Fowler–Nordheim (F–N) plot whose linear region provides the solution with two unknowns. On the other hand, the Christov plot in the T-F zone provides the solution with only the field enhancement factor. Using the general theory of electron emission, we find that the work function and field enhancement factor of the CVD-grown MWCNTs are 4.7±0.4eV and 3300±200, respectively. [Copyright &y& Elsevier]

Vertically aligned carbon nanotubes (CNTs) were successfully synthesized at 550 °C on Ni-coated Si substrate placed parallel to Pd plate as a dual catalyst and a tungsten wire filament. The CNT length increased with increasing gas flow rates even at such a low growth temperature, suggesting that the hydrocarbon gases were sufficiently decomposed in the presence of tungsten wire filament and dual Pd catalyst. The difference of growth behavior from that at high temperature was explained by introducing the Ni–C solid solution, which enables the carbon atoms to diffuse more easily even at low temperature. [Copyright &y& Elsevier]

A key requirement for wearable electronics is an adequate and sustainable power source. Accordingly, a self-powering unit that replaces rechargeable secondary batteries is a promising solution. However, to realize permanent, maintenance-free, and highly durable wearable electronics, stretchable self-powering units that can harvest and store energy should be developed. In this study, we developed a fully stretchable self-charging power unit that integrates a micro-supercapacitor and triboelectric nanogenerator using oxidized single-walled carbon nanotube/polymer electrodes. The fully stretchable micro-supercapacitor with oxidized single-walled carbon nanotube/polyvinylalcohol electrodes exhibited a double layer capacitance of 20 mF cm−2 at 0.1 mA cm−2 and improved mechanical flexibility and stretchability over 10,000 cycles of stretching tests. A stretchable, polydimethylsiloxane-based current collector employing silver nanoparticles embedded with oxidized single-walled carbon nanotubes enabled the fully stretchable, freestanding-triboelectric-layer based nanogenerators to produce a maximum instantaneous power density of 84.4 mW m−2 under periodic and round-trip sliding of a Nylon fabric while stretching up to 40% without significant performance degradation. Furthermore, a micro-supercapacitor of fully stretchable self-charging power unit could be successfully charged by the nanogenerator from 0 to 2.2 V in 1200 s and powered commercial digital clock for approximately 10 s. These results demonstrate that stretchable polymer composites with oxidized single-walled carbon nanotubes are suitable electrodes and active materials for fully stretchable and self-powered wearable electronics. [Display omitted] • Ag NPs embedded with Ox-SWCNTs for current collectors of fully stretchable FTENG and MSC. • Intrinsically stretchable Ox-SWCNT/PVA/H 3 PO 4 electrode for fully stretchable MSCs. • Highly durable, fully stretchable self-charging power unit that integrates MSC and FTENG. • Simultaneous energy harvesting and storage functions of the FS-SCPU from repetitive human motion. [ABSTRACT FROM AUTHOR]

Herein, we present a potential approach for the qualitative production of quasi-defect-free reduced graphene oxide (QrGO) with semimetallic transport behavior. In rGO, the formation of defects is highly dependent on the oxidation process of graphite. Subsequent exfoliation of graphite oxide, the quasi-defect-free graphene oxide (QGO) shows abundant epoxy and hydroxyl groups which confirmed the suppressed structural deformation. Typical rGO and QrGO are compared to characterize the remarkable electrical, optical, and thermal properties of QrGO. In particular, under low temperature, the unusual carrier transport phenomena of QrGO exhibits a metal-like behavior, unlike typical rGO, which shows an insulator-to-semimetal transition with variable-range hopping conduction behavior. This conduction mechanism, resembling that of mechanically exfoliated graphene, facilitates the fabrication of a QrGO-based conducting film with a high electrical conductivity of ∼1000 S/cm. Moreover, during a 200-h test with temperature and moisture conditions of 85 °C and 85%, respectively, QrGO shows environmental stability with minimal fluctuations in resistance. Furthermore, a conducting paste was fabricated from QrGO in an aqueous solution, showing a highly concentrated solid content and excellent electrical conductivity. It shows great potential for the large-scale production of high-quality chemically exfoliated graphene for practical applications. A promising approach for the high-quality scalable production of QrGO is proposed. The remarkable electrical, optical, and thermal characteristics of QGO and QrGO are examined, showing a semicrystalline graphene structure. The transport phenomena exhibit a metal-like behavior, resembling that of mechanically exfoliated graphene, unlike the variable-range hopping behavior of general rGO. The electrical conductivity of QrGO is considerably high at almost 1000 S/cm. [Display omitted] [ABSTRACT FROM AUTHOR]

The slow sodium-ion storage kinetics of battery-type electrodes limits the performance of sodium-ion capacitors (SICs) operating under high-power conditions. In this study, ultrafast laser micromachining was utilized to accelerate the sodium-ion storage kinetics of hard carbon/fumed silica (HC/f-SiO 2) anodes. The ablation process involving an ultrafast femtosecond laser source enabled three-dimensional microstructuring of hot-short HC/f-SiO 2 anodes with minimal photothermal damage. The microporous structure of the HC/f-SiO 2 anodes facilitated the electrolyte wetting of the active materials as well as the diffusion-limited supply of sodium-ions from the bulk electrolytes. The microstructured HC/f-SiO 2 anode exhibited a sodium-ion storage capacity of 370 mAh g−1, which was higher than those of unstructured HC/f-SiO 2 anodes of comparable mass (298 mAh g−1) or thickness (248 mAh g−1). In addition, the rate capability of the microstructured HC/f-SiO 2 anode was superior to that of the unstructured samples. Comparative full-cell tests with oxidized single-walled carbon nanotube cathodes confirmed that micromachining of the HC/f-SiO 2 anode was crucial for improving the performance of the SIC full cells. This study demonstrates that ultrafast laser micromachining of HC/f-SiO 2 electrodes is a facile and reliable strategy for the development of high-performance SICs. [Display omitted] • Cold ablation of hard carbons using scalable femtosecond laser micromachining. • Micropatterned hard carbons facilitating electrolyte wetting and diffusion of Na-ion. • Demonstration of ultrafast laser micromachining for high performance Na-ion capacitor. [ABSTRACT FROM AUTHOR]

[Display omitted] Ectonucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1) negatively regulates the anti-cancer Stimulator of Interferon Genes (STING) pathway. We discovered that 3,4-dihydropyrimido[4,5- d ]pyrimidin-2(1 H)-one and 3,4-dihydropyrido[2,3- d ]pyrimidin-2(1 H)-one derivatives possessed inhibitory activities on ENPP1. A structure–activity relationship (SAR) study led to the identification of 46 and 23 as potent ENPP1 inhibitors. Also, compounds 46 and 23 possessed high microsomal stabilities in human, rat, and mouse liver microsome. Additionally, CYPs (1A2, 2C9, 2C19, 2D6, and 3A4) were not inhibited by 46 and 23. Molecular dynamics simulations provided an insight of binding modes between ENPP1 and compounds (46 and 23). [ABSTRACT FROM AUTHOR]

Abstract: A method of how to form a strong adhesion of carbon nanotubes (CNTs) to substrate by introducing an intermediate metal layer in fabricating spray-based field emitters and its effect to the field-emission properties were addressed. An Indium or tin layer was deposited on an indium-tin-oxide glass substrate and thermally annealed to hold the CNTs tightly. This underlying metal layer forms a strong bond to CNTs by wetting while melting without any detectable evaporation of metal atoms. This gave rise to a stable field-emission current at high voltage, which was confirmed by a mass spectrometer. The tube density and field-emission characteristics strongly depend on the annealing temperature of metal layers. [Copyright &y& Elsevier]

The inclusion of conducting nanomaterials in superhydrophobic surfaces can widen their potential applications in terms of Joule heating, electromagnetic interference shielding, oil/water separation, and self-cleaning. Here, we demonstrate the fabrication of multifunctional superhydrophobic surfaces using dispersant-free conducting inks containing highly oxidized long multiwalled carbon nanotubes (Ox-LMWCNTs). Superhydrophobic surfaces with a high water contact angle (WCA) (>150°) were realized by deposition of a perfluorosilane sol and silica nanoparticle mixture solution onto the Ox-LMWCNT surface and subsequent thermal treatment. Importantly, the electrical conductivities of the Ox-LMWCNT films were dramatically increased from 78 S/m to more than 2000 S/m by thermal deoxygenation, even at low temperatures (<200 °C) in ambient air. The superhydrophobic LMWCNT films showed high electrical conductivity of more than 1000 S/m following thermal treatment at 150 °C in ambient air. These electrically conducting and self-cleaning surfaces also showed fast heating behavior when a direct current voltage was applied to the film. Moreover, sequential deposition of the LMWCNT and perfluorosilane sol solutions on a metal mesh produced an oil/water separation filter owing to the oleophilic properties of the LMWCNTs. As they are easily dispersed in solution and can undergo efficient thermal deoxygenation, Ox-LMWCNTs are promising for the realization of multifunctional surfaces. Conductive and superhydrophobic films with multi-functionality are fabricated by using efficiently oxidized long multi-walled carbon nanotubes. Highly oxidized carbon nanotubes with less permanent defect can be thermally deoxygenated in ambient air. Dispersant-free carbon nanotube inks were utilized to fabricate superhydrophobic film heaters and oil/water separation filters. Image 1 [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) exfoliated from graphite oxide is a precursor of graphene, which is a highly promising two-dimensional material for energy storage, printing electronics, composites, conducting fibers, etc. However, during the fabrication of GO by chemical oxidation, large amounts of oxidants and acid are used, which lead to many concerns, such as severe environmental pollution and high processing cost. In this study, we propose a highly efficient and rational oxidation of various-sized graphite powder by minimizing the amount of acid used (reducing 1/10 times) through kneading, inspired by the concept of kneading dough. First, NaClO 3 and graphite were mixed together. Then, a small amount of fuming nitric acid was added, and the mixture was kneaded for several minutes. The ratio of oxidant to graphite and the reaction time, with and without kneading, were investigated based on the lateral size of graphite, because large-sized graphite requires more diffusion time for oxidizing the species through the graphitic layers. The chemically-reduced GO nanosheets exhibit highly crystalline structures based on the Raman spectroscopy and transmission electron microscopy studies, and their films exhibit a high electrical conductivity of over 45,000 S/m from large graphite, which is promising for electrical and electrochemical applications. To fabricate high quality graphene nanosheets, various sized graphite powders were rationally oxidized by minimizing the amount of acid used (reducing 1/10 times) through kneading. Graphene films bar-coated with reduced graphene oxide pastes exhibit a high electrical conductivity of over 45,000 S/m from large graphite, which is promising for electrical and electrochemical applications. Image 1 [ABSTRACT FROM AUTHOR]

Abstract Heteroatom doping can enhance the electrochemical properties of graphene. However, unstable C N bonding at high temperature limits the concentration of nitrogen dopants. Intense pulsed light (IPL) was used to prepare heavily nitrogen-doped reduced graphene oxide (NrGO). Unlike general heating methods like thermal annealing, IPL provides ultrafast direct heating and cooling in the graphene layers because they serve as the heating source after light absorption. As this heat originates from the photothermal effect of surface plasmons on the graphene layers, nitrogen precursors are effectively decomposed. The fast cooling also generates a corrugated graphene structure with high specific surface area owing to thermal quenching. The electronic and structural properties of flash-heated NrGO (FH-NrGO) were investigated by X-ray photoelectron spectroscopy, Raman spectroscopy, and ultraviolet photoelectron spectroscopy, which revealed a high total nitrogen content of 26 at.% after flash heating at 1500 °C. Moreover, the nitrogen content could be varied by controlling the irradiation energy, and the electrochemical performance of FH-NrGO was better than that of NrGO prepared by general heating. Therefore, flash heating by IPL can be used to produce heavily nitrogen-doped graphene with superior electrochemical performance as an anode material for energy-storage devices. Graphical abstract Flash heating method was used to prepare heavily nitrogen-doped reduced graphene oxide (NrGO). Unlike general heating methods like thermal annealing, this method provides ultrafast direct heating and cooling in the graphene layers because they serve as the heating source after light absorption. This easy and straightforward method offered doping of graphene layers with a high concentration of about 26 at.% of nitrogen in a few milliseconds. Image 1 [ABSTRACT FROM AUTHOR]

The applications of solution-exfoliated graphene oxide (GO) as an electrical/electrochemical conductor require rational design–based approaches. Herein, we show that reduced GO nanosheets with highly ordered or nanoporous structures can be fabricated by treatment of graphite oxide (GrO) having variable-oxidation-degree with hot KOH solution. As model systems, GrO powders fabricated by modified Brodie and Hummers methods (B-GrO and H-GrO, respectively) were exfoliated into GO in alkaline solutions (to afford B-KGO and H-KGO, respectively), followed by 2.5-h refluxing at 100 °C. Notably, B-KGO was exceptionally resistant to hot KOH solution, whereas H-KGO was partially reduced under these conditions, as confirmed by 13 C solid-state NMR, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy analyses. Moreover, reduced B-KGO featured highly ordered structures, whereas reduced H-KGO contained nanopores resulting from low-temperature activation in KOH solution. These extraordinary reactions of KGO nanosheets were translated into different electrical properties of reduced KGO nanosheets and different rheological properties of the corresponding pastes. [ABSTRACT FROM AUTHOR]

[Display omitted] Specific inhibition of ALK5 provides a novel method for controlling the development of cancers and fibrotic diseases. In this work, a novel series of N -(3-fluorobenzyl)-4-(1-(methyl-d 3)-1 H -indazol-5-yl)-5-(6-methylpyridin-2-yl)-1 H -imidazol-2-amine (11), a potential clinical candidate, was synthesized by strategic incorporation of deuterium at potential metabolic soft spots and identified as ALK5 inhibitors. This compound has a low potential for CYP-mediated drug-drug interactions as a CYP450 inhibitor (IC 50 = >10 μM) and showed potent inhibitory effects in cellular assay (IC 50 = 3.5 ± 0.4 nM). The pharmacokinetic evaluation of 11 in mice demonstrated moderate clearance (29.0 mL/min/kg) and also revealed high oral bioavailability in mice (F = 67.6%). [ABSTRACT FROM AUTHOR]

Electrode contact resistance is an important factor that seriously affects the performance of organic thin film transistors (OTFTs). In this paper, new low contact resistance carbon nanotube (CNT) based hybrid electrodes are introduced for the source and drain electrodes of OTFTs. The hybrid electrodes consist of solution-processed CNTs and a metal (Al; CNT/Al or Au; CNT/Au) layer evaporated on the CNTs. The contact resistance of the CNT/Al and CNT/Au hybrid electrodes was found to vary depending on the thickness of the Al and Au layer. The contact resistance of the CNT/Al hybrid electrodes exhibited a minimum of 2.9 kΩ cm at an Al thickness of 5 nm. It is notable that the minimum contact resistance of the CNT/Au was 0.9 kΩ cm at an Au thickness of 5 nm, and is the lowest value ever reported. It was lower than the 13 kΩ cm of the bare CNT electrodes, and tremendously less than the 4 MΩ cm of the pure Au electrode. The mobility of the OTFTs, which used pentacene as the semiconductor and polyvinylphenol as the gate dielectric, also followed the same dependence on metal thickness as the contact resistance. The maximum mobility of the OTFTs using CNT/Al and CNT/Au electrodes was 0.76 cm 2 /V sec and 1.0 cm 2 /V sec, respectively, at the same metal thickness of 5 nm, which was larger than 0.3 cm 2 /V sec of the bare CNT electrodes. The major origin of these enhancements was found to be the small energy difference between the work function of the CNT/metal hybrid electrodes and pentacene HOMO (5.1 eV), which was obtained at the metal thickness of 5 nm. [ABSTRACT FROM AUTHOR]

Abstract: We have created a field emitter composed of a carbon nanotube (CNT) yarn, which was prepared by direct spinning through chemical vapor deposition and then formed into a carpet structure by tying the yarn to a conductive substrate before cutting it. The structure of the carpet is arranged to induce the tips of the CNT yarn to protrude toward the anode for maximum electron emission. The turn-on field, threshold field, and field enhancement factor of the device are 0.33, 0.48V/μm, and 19,141, respectively. Extremely low operating electric fields and a high field enhancement factor result from the high density of CNT emitters with high crystallinity, the electrically good contact between the emitters and the substrate, and the effects of the multistage structure. The emission is stable even at a high current density of 2.13mA/cm2, attributed to the strong adhesion between the emitters and the substrate. The emission performance is found to be customizable by adjusting the structure, for example, the CNT pile density. These results are relevant for practical applications, such as large-area flat-panel displays, large-area low-voltage lamps, and X-ray sources. [Copyright &y& Elsevier]

Quenchbody (Q-body) is a fluorescent biosensor in which a fluorescent dye is tagged near the antigen binding site of an antibody. The fluorescence of the dye is quenched by the tryptophan residues present in the variable region of the antibody, and is recovered when the antigen binds. Q-bodies have been prepared using recombinant DNA technology by introducing one or more tag sequence(s) at either the N-terminal of the Fab or the single chain variable region fragment of the antibody, and labeling the tag with a fluorescent dye. However, preparation of recombinant antibody fragments is time-consuming and the performance of the Q-body is unpredictable. Here we report an antibody-binding quenching probe made from protein M from Mycoplasma genitalium that can transform the IgG antibody into an immunosensor. By using bacterially expressed and purified protein M and labeling the C-terminal cysteine-containing tag, we prepared a TAMRA-labeled PM Q-probe. When the Q-probe was incubated with Fab or IgG recognizing the bone Gla protein, the fluorescence of the probe was quenched and subsequently recovered by the adding of antigens in a dose-dependent manner. We also succeeded in detecting several small biomarkers with nanomolar sensitivity, including thyroxine extracted from human serum. The clone found to be suitable for the detection of cortisol was confirmed to work as a recombinant Q-body as well, which also worked in 50% human serum. The results suggest that the Q-probe can quickly convert an IgG to a biosensor, which will be useful in rapid diagnosis of small biomarkers. • A fluorescent probe that transforms antibodies to an immunosensor is made. • Protein M from mycoplasma was C-terminally labeled with TAMRA. • The resultant Q-probe showed quenching upon binding with many antibodies. • The quenched complex showed antigen-dependent fluorescence recovery. • Biomarkers including thyroxine extracted from human serum was readily detected. [ABSTRACT FROM AUTHOR]

• The laser irradiation method for manufacturing molybdenum disulfide quantum dots with a size of 10 nm which is simpler than the conventional method was devised. • The n-butyllithium-intercalated laser ablation technique will be useful for the mass production of molybdenum disulfide quantum dots and become a promising candidate for next-generation applications in electronics and catalysis. Molybdenum disulfide (MoS 2) is rapidly emerging in a wide range of applications owing to its superior optical, electrical, and catalytic properties. In particular, aside from the current great interest in monolayer MoS 2 , MoS 2 quantum dots (QDs) have received much attention in the electronics and optoelectronics fields owing to their inherent electrical and optical properties arising from the quantum confinement effect. Thus, various methods for producing MoS 2 QDs, such as exfoliation, substrate growth, and colloidal synthesis, have been attempted. In this study, the method for manufacturing MoS 2 QD with a size of 10 nm which is simpler than the conventional method was devised. On the basis of characterization of the prepared MoS 2 QD samples, resistive switching devices was fabricated. These devices demonstrated stable unipolar resistive switching behavior without an electroforming process. This study provides a new approach for the mass production of MoS 2 QD and one of their potential applications. [ABSTRACT FROM AUTHOR]