Red seabream (Pagrus major) has been one of the most popular fish in East Asia since early times. However, the discharge of nuclear wastewater into the sea following the Fukushima nuclear disaster in Japan has led to violations of the country of origin labeling. Therefore, the aim of the present study was to determine the origin of fish based on fatty acid, amino acid, and mineral analyses, and to develop biomarkers that can discriminate between Japanese and Korean red seabream. To identify the differences between the two groups, 29 fatty acid families, 17 amino acids, and 4 minerals were analyzed in 60 fish samples (standard sample collected in autumn), and fatty acid profiles were analyzed using heatmap with hierarchical clustering analysis and orthogonal projections to latent structures discriminant analysis. The top 10 fatty acids that were different between the two groups were selected from all seasonal fish samples by combining variable importance in projection scores and p-values. According to the receiver operating characteristic curve analysis results, we proposed percentage linoleic acid (C18:2n-6, cis) as a candidate biomarker with excellent sensitivity and specificity. This study introduces a strategy to identify the origins of red seabream using linoleic acid obtained from fatty acid analysis.
Perciformes , Sea Bream , Humans , Animals , Fatty Acids/analysis , Japan , Amino Acids/metabolism , Linoleic Acid , Minerals/analysis , Republic of Korea
Accurate estimation of emissions from industrial point sources is crucial in understanding the effectiveness of reduction efforts and establishing reliable emission inventories. In this study, we employ an airborne Chemical Ionization Mass Spectrometry (CIMS) instrument to quantify sulfur dioxide (SO2) emissions from prominent industrial facilities in South Korea, including power plants, a steel mill, and a petrochemical facility. Our analysis utilizes the box mass balance technique to derive SO2 emissions and associated uncertainty. We evaluate the interpolation methods between 2D kriging and 3D radial basis function. The results demonstrate that the total uncertainty of the box mass balance technique ranges from 5 % to 28 %, with an average of 20 %. Mixing ratio ground extrapolation from the lowest altitude of the airborne sampling to the ground emerges as the dominant source of uncertainty, followed by the determination of the boundary layer height. Adequate sampling at multiple altitudes is found to be essential in reducing the overall uncertainty by capturing the full extent of the plume. Furthermore, we assess the uncertainty of the single-height transect mass balance method commonly employed in previous studies. Our findings reveal an average precision of 47 % for this method, with the potential for overestimating emissions by up to 206 %. Samplings at fewer altitudes or with larger altitude gaps increase the risk of under-sampling and elevate method uncertainties. Therefore, this study provides a quantitative basis to evaluate previously airborne observational emission constraints.
Semiconductor-based photocatalyst materials played an important role in the degradation of organic compounds in recent years. Photocatalysis is a simple, cost-effective, and environmentally friendly process for degrading organic compounds. In this work, vanadium pentoxide (V2O5) and V2O5/RGO (reduced graphene oxide) composite were synthesized by a hydrothermal method. The prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Raman spectroscopy, and UV-Vis spectroscopic analysis, etc. Raman analysis shows the occurrence of RGO characteristic peaks in the composite and different vibrational modes of V2O5. The band gap of flake-shaped V2O5 is reduced and its light absorption capacity is enhanced by making its composite with RGO. The photocatalytic degradation of methylene blue (MB) was studied using both V2O5 and V2O5/RGO composite photocatalyst materials. The V2O5/RGO composite exhibits a superior photocatalytic performance to V2O5. Both catalyst and light play an important role in the degradation process.
Transition-metal sulfides exaggerate higher theoretical capacities and were considered a type of prospective nanomaterials for energy storage; their inherent weaker conductivities and lower electrochemical active sites limited the commercial applications of the electrodes. The sheet-like nickel cobalt sulfide nanoparticles with richer sulfur vacancies were fabricated by a two-step hydrothermal technique. The sheet-like nanoparticles self-combination by ultrathin nanoparticles brought active electrodes entirely contacted with the electrolytes, benefiting ion diffusion and charges/discharges. Nevertheless, defect engineers of sulfur vacancy at the atomic level raise the intrinsic conductivities and improve the active sites for energy storage functions. As a result, the gained sulfur-deficient NiCo2S4 nanosheets consist of good specific capacitances of 971 F g-1 at 2 A g-1 and an excellent cycle span, retaining 88.7% of the initial capacitance over 3500 cyclings. Moreover, the values of capacitance results exhibited that the fulfilling characteristic of the sample was a combination of the hydrothermal procedure and the surface capacitances behavior. This novel investigation proposes a new perspective to importantly improve the electrochemical performances of the electrode by the absolute engineering of defects and morphologies in the supercapacitor field.
Among energy storage devices, supercapacitors have received considerable attention in recent years owing to their high-power density and extended cycle life. Researchers are currently making efforts to improve energy density using different asymmetric cell configurations, which may provide a wider potential window. Many studies have been conducted on positive electrodes for asymmetric supercapacitor devices; however, studies on negative electrodes have been limited. In this study, iron oxides with different morphologies were synthesized at various deposition temperatures using a simple chemical bath deposition method. A nanosphere-like morphology was obtained for α-Fe2O3. The obtained specific capacitance (Cs) of α-Fe2O3 was 2021 F/g at a current density of 4 A/g. The negative electrode showed an excellent capacitance retention of 96% over 5000 CV cycles. The fabricated asymmetric solid-state supercapacitor device based on α-Fe2O3-NF//Co3O4-NF exhibited a Cs of 155 F/g and an energy density of 21 Wh/kg at 4 A/g.
Recently, polymer-based materials have been used in various filed of applications, but their low thermal conductivity restricts their uses due to the high interfacial thermal resistance. Therefore, in this study, one-dimensional thin-walled carbon nanotube (1D-TWCNT) and two-dimensional boron nitride nanosheet (2D-BNNS) fillers were used to enhance the thermal properties of polyvinyl alcohol (PVA). An important factor to be considered in enhancing the thermal properties of PVA is the interfacial configuration strategy, which provides sufficient pathways for phonon transport and the controlled loss of the intrinsic thermal properties of the filler nanomaterial. In this study, the effect of sodium tetraborate (borax) additive on the thermal properties of 1D-TWCNT/PVA and 2D-BNNS/PVA nanocomposites was explored. Borax is a well-known crosslinking additive that can be used with PVA. The crosslink density of the PVA-borax nanocomposite was controlled by changing its borate ion concentration. The addition of borax into nanocomposites improves the conductivity of 1D-TWCNT/PVA nanocomposites up to 14.5% (4 wt.% borax) and of 2D-BNNS/PVA nanocomposite up to 30.6% for BNNS (2 wt.% borax). Thus, when borax was added, the 2D-BNNS/PVA nanocomposite showed better results than the 1D-TWCNT/PVA nanocomposite.
Tetracycline (TC) is a persistent antibiotic used in many countries, including China, India, and the United States of America (USA), because of its low price and effectiveness in enhancing livestock production. However, such antibiotics can have toxic effects on living organisms via complexation with metals, and their accumulation leading to teratogenicity and carcinogenicity. In this study, two-dimensional molybdenum disulfide/titanium dioxide (MoS2/TiO2) composites with different amounts of molybdenum disulfide (MoS2) were prepared via a simple, cost-effective, and pollution-free hydrothermal route. The synthesized MoS2/TiO2 microstructures were thoroughly characterized and their performance for the photocatalytic degradation of antibiotics such as TC was investigated. In the degradation experiments, the photocatalytic activities of TiO2 and the MoS2/TiO2 composites were compared, and the effects of different parameters, such as catalyst dose and electrolyte solution pH, were investigated. Under irradiation, the MoS2/TiO2 composites possessed superior photodegradation activity toward TC because of their excellent adsorption abilities, suitable band positions, and large surface areas as well as the effective charge-transfer ability of MoS2. Kinetics studies revealed that the photocatalytic degradation process followed pseudo-first-order reaction kinetics. In addition, a degradation mechanism for TC was proposed.
Molybdenum , Titanium , Anti-Bacterial Agents , Disulfides , Tetracycline
Partial sensing is used to reduce the power consumption of pedestrian user equipment (P-UE) that operates in the signal environment of a mode-2 sidelink. However, because the data trans-mission is allowed only for the window duration of each corresponding P-UE, the throughput of the P-UE decreases by the ratio between the width of the window and the entire data period. This paper presents a novel method for enhancing the throughput of the P-UE that operates with partial sensing in the mode-2 sidelink. The proposed technique employs an additional UE, denoted the roadside unit (RSU), to collect the sensing results from each P-UE that operates with partial sensing. The proposed RSU sequentially aligns all of the partial sensing windows, such that the combination of each partial sensing window can eventually provide an almost complete sensing result. In this study, extensive computer simulations were performed. The results reveal that the proposed method enhances the throughput of each P-UE operating with partial sensing almost to that of full sensing without increasing the required power consumption.
Catalytic reduction of nitroaromatic compounds present in wastewater by nanostructured materials is a promising process for wastewater treatment. A multifunctional electrode based on ternary spinal nickel cobalt oxide is used in the catalytic reduction of a nitroaromatic compound and supercapacitor application. In this study, we designed nanoflakes- like nickel cobaltite (NiCo2O4) using a simple, chemical, cost-effective hydrothermal method. Nanoflakes- like NiCo2O4 samples are tested as catalysts toward rapid reduction of 4-nitrophenol and as electrode materials for supercapacitors. The conversion of 4-nitrophenol into 4-aminophenol is achieved using a reducing agents like sodium borohydride and NiCo2O4 catalyst. Effect of catalyst loading, 4-nitrophenol and sodium borohydride concentrations on the catalytic performance of 4-nitrophenol is studied. As sodium borohydride concentration increases the catalytic efficiency of 4-nitrophenol increased due to more BH4- ions available which provides more electrons for catalytic reduction of 4-nitrophenol. Catalytic reduction of 4-nitrophenol using sodium borohydride as a reducing agent was based on the Langmuir-Hinshelwood mechanism. This mechanism follows the apparent pseudo first order reaction kinetics. Additionally, NiCo2O4 electrode is used for energy storage application. The nanoflakes-like NiCo2O4 electrode deposited at 120 °C shows a higher specific capacitance than samples synthesized at 100 and 140 °C. The maximum specific capacitance observed for NiCo2O4 electrode is 1505 Fg-1 at a scan rate of 5 mV s-1 with high stability of 95% for 5000 CV cycles.
Nickel , Nitrophenols , Electrodes , Minerals
The characteristics of primary gas/aerosol and secondary aerosol emissions were identified for small passenger vehicles using typical fuel types in South Korea (gasoline, liquefied petroleum gas (LPG), and diesel). The generation of secondary organic aerosol (SOA) was explored using the potential aerosol mass (PAM) oxidation flow reactor. The primary emissions did not vary significantly between fuel types, combustion technologies, or aftertreatment systems, while the amount of NH3 was higher in gasoline and LPG vehicle emissions than that in diesel vehicle emissions. The SOA emission factor was 11.7-66 mg kg-fuel-1 for gasoline vehicles, 2.4-50 mg kg-fuel-1 for non-diesel particulate filter (non-DPF) diesel vehicles (EURO 2-3), 0.4-40 mg kg-fuel-1 for DPF diesel vehicles (EURO 4-6), and 3-11 mg kg-fuel-1 for LPG vehicles (lowest). The carbonaceous aerosols (equivalent black carbon (eBC) + primary organic aerosol + SOA) of diesel vehicles in EURO 4-6 were reduced by up to 95% compared to those in EURO 2-3. The expected SOA yield increased through the hot-condition combustion section of a vehicle, over the SOA range of 0.2-155 µg m-3. These results provide the necessary data to analyze all types of SOA generated by the gas-phase oxidation in vehicle emissions in metropolitan areas.
Air Pollutants , Petroleum , Aerosols/analysis , Air Pollutants/analysis , Gasoline/analysis , Motor Vehicles , Technology , Vehicle Emissions/analysis
The use of halogen-based materials has been regulated since toxic substances are released during combustion. In this study, polyurethane foam was coated with cationic starch (CS) and montmorillonite (MMT) nano-clay using a spray-assisted layer-by-layer (LbL) assembly to develop an eco-friendly, high-performance flame-retardant coating agent. The thickness of the CS/MMT coating layer was confirmed to have increased uniformly as the layers were stacked. Likewise, a cone calorimetry test confirmed that the heat release rate and total heat release of the coated foam decreased by about 1/2, and a flame test showed improved fire retardancy based on the analysis of combustion speed, flame size, and residues of the LbL-coated foam. More importantly, an additional cone calorimeter test was performed after conducting more than 1000 compressions to assess the durability of the flame-retardant coating layer when applied in real life, confirming the durability of the LbL coating by the lasting flame retardancy.
The role of the gut microbiota in the pathogenesis of inflammatory bowel disease (IBD) has been in focus for decades. Although metagenomic observations in patients/animal colitis models have been attempted, the microbiome results were still indefinite and broad taxonomic presumptions were made due to the cross-sectional studies. Herein, we conducted a longitudinal microbiome analysis in a dextran sulfate sodium (DSS)-induced colitis mouse model with a two-factor design based on serial DSS dose (0, 1, 2, and 3%) and duration for 12 days, and four mice from each group were sacrificed at two-day intervals. During the colitis development, a transition of the cecal microbial diversity from the normal state to dysbiosis and dynamic changes of the populations were observed. We identified genera that significantly induced or depleted depending on DSS exposure, and confirmed the correlations of the individual taxa to the colitis severity indicated by inflammatory biomarkers (intestinal bleeding and neutrophil-derived indicators). Of note, each taxonomic population showed its own susceptibility to the changing colitis status. Our findings suggest that an understanding of the individual susceptibility to colitis conditions may contribute to identifying the role of the gut microbes in the pathogenesis of IBD.
Rapid technological development requires sustainable, pure, and clean energy systems, such as hydrogen energy. It is difficult to fabricate efficient, highly active, and inexpensive electrocatalysts for the overall water splitting reaction: the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The present research work deals with a simple hydrothermal synthesis route assisted with ultrasound that was used to fabricate a 3D nanoflower-like porous CoMoS4 electrocatalyst. A symmetric electrolyzer cell was fabricated using a CoMoS4 electrode as both the anode and cathode, with a cell voltage of 1.51 V, to obtain a current density of 10 mA/cm2. Low overpotentials were observed for the CoMoS4 electrode (250 mV for OER and 141 mV for HER) at a current density of 10 mA/cm2.
The study deals with the hydrothermal growth of a CuCo2O4 hierarchical 3D nanoflower-like array on carbon cloth (CuCo2O4@CC), which is a useful multifunctional electrode. The electrocatalytic oxygen evolution reaction (OER) study of the CuCo2O4@CC electrode shows high durability and good activity in 1 M KOH. As an energy storage electrode, it shows a high specific capacitance of 1438 Fg-1 at 10 mA cm-2 in a 3 M KOH electrolyte. The electrochemical stability of the CuCo2O4@CC electrode was tested for 5000 cycles at 10 mA cm-2, and it showed 98.6% stability. This CuCo2O4@CC electrode produces a capacitance of 10 mA cm-2 at an overpotential of 288 mV for the OER, with a Tafel slope of 64.2 mV dev-1. The electrochemical stability measured at an overpotential of 292 mV for 12 h at 10 mA cm-2 shows good electronic stability in an alkaline medium. The enhanced electrochemical performance of the CuCo2O4@CC electrode may be due to the Cu and Co counterparts in addition to the high surface area. The CuCo2O4@CC electrode is a simple, flexible, and cost-effectivive electrode in both electrocatalytic OER and energy storage applications.
This paper presents a design optimization method based on theoretical analysis and numerical calculations, using a commercial multi-physics solver (e.g., ANSYS and ESI CFD-ACE+), for a 3D continuous model, to analyze the bending characteristics of an electrically heated bimorph microcantilever. The results from the theoretical calculation and numerical analysis are compared with those measured using a CCD camera and magnification lenses for a chip level microcantilever array fabricated in this study. The bimorph microcantilevers are thermally actuated by joule heating generated by a 0.4 µm thin-film Au heater deposited on 0.6 µm Si3N4 microcantilevers. The initial deflections caused by residual stress resulting from the thermal bonding of two metallic layers with different coefficients of thermal expansion (CTEs) are additionally considered, to find the exact deflected position. The numerically calculated total deflections caused by electrical actuation show differences of 10%, on average, with experimental measurements in the operating current region (i.e., ~25 mA) to prevent deterioration by overheating. Bimorph microcantilevers are promising components for use in various MEMS (Micro-Electro-Mechanical System) sensing applications, and their deflection characteristics in static mode sensing are essential for detecting changes in thermal stress on the surface of microcantilevers.
In this report, magnetically recoverable sulfur-doped SnFe2O4/graphene (S-SFO/GR) nanohybrids have been successfully developed via a facile solvothermal method. The characterizations on the structural, morphology, and optical properties of the nanohybrids indicate that S-SFO particles are successfully embedded on the GR nanosheets. The photocatalytic activity has been evaluated by photocatalytic degradation of chlorotetracycline under visible light irradiation. Among the composites with various mass ratios, the quasi-first-order rate constant of the nanohybrids formed with 9wt% S in SFO and 15wt% GR (9S-SFO/GR-15) can reach as high as 1.83min-1, which is much higher than that of SFO (0.68min-1) and SFO/GR (0.91min-1), confirming the important role of S and GR for the photocatalytic process. The combination of the three components of S, SFO, and GR has enhanced the visible light absorption capability and inhibited the recombination of photogenerated electron-hole. The 9S-SFO/GR-15 nanohybrids can be recovered easily by a magnet and reused for five times with remained photocatalytic efficiency about 70%. A possible catalytic mechanism explaining the efficient photocatalytic performances of the prepared nanohybrids has been proposed.
Cyclosporine A (CsA) and tacrolimus (FK506) are the most important immunosuppressive compounds that block the activation of helper T-cells. In this study, we investigated the effects of CsA and FK506 on growth and senescence of articular chondrocytes. Chondrocytes from young rabbit cartilage entered senescence after 8.6 ± 0.8 population doublings (PDs), while chondrocytes treated with CsA and FK506 entered senescence after 12.3 ± 1.4 and 13.7 ± 0.6 PDs, respectively. Furthermore, chondrocytes from the cartilage of old rabbits were senescent after 2.6 ± 0.9 PDs, whereas those treated with CsA and FK506 were senescent after 8.2 ± 1.8 and 6.9 ± 1.6 PDs, respectively. These compounds also inhibited senescence induction of chondrocytes in a high-cell density pellet culture system. We previously reported that p38MAPK plays a critical role in the onset of senescence in chondrocyte. This study revealed that the phosphorylation of p38MAPK was inhibited by either CsA or FK506. The early onset of senescence in chondrocyte harboring MKK6E, which is a constitutively-active form of MKK6 and increases p38MAPK phosphorylation, was blocked by CsA. These results suggest that CsA and FK506 increase the proliferation and inhibit the senescence of articular chondrocytes through inactivation of p38MAPK.
Cartilage, Articular/pathology , Chondrocytes/cytology , Cyclosporine/chemistry , Tacrolimus/chemistry , Animals , Calcineurin Inhibitors/chemistry , Cell Proliferation , Cellular Senescence/drug effects , Chondrocytes/drug effects , Immunosuppressive Agents/chemistry , Osteoarthritis/drug therapy , Phosphoric Monoester Hydrolases/metabolism , Phosphorylation , Rabbits , Retroviridae/genetics , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/metabolism
The real-time recognition of absolute (or relative) position and orientation on a network of roads is a core technology for fully automated or driving-assisted vehicles. This paper presents an empirical investigation of the design, implementation, and evaluation of a self-positioning system based on a magnetic marker reference sensing method for an autonomous vehicle. Specifically, the estimation accuracy of the magnetic sensing ruler (MSR) in the up-to-date estimation of the actual position was successfully enhanced by compensating for time delays in signal processing when detecting the vertical magnetic field (VMF) in an array of signals. In this study, the signal processing scheme was developed to minimize the effects of the distortion of measured signals when estimating the relative positional information based on magnetic signals obtained using the MSR. In other words, the center point in a 2D magnetic field contour plot corresponding to the actual position of magnetic markers was estimated by tracking the errors between pre-defined reference models and measured magnetic signals. The algorithm proposed in this study was validated by experimental measurements using a test vehicle on a pilot network of roads. From the results, the positioning error was found to be less than 0.04 m on average in an operational test.
