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Human adipose stem cell-derived extracellular vesicles (hASC-EVs) are key mediators of paracrine signaling with promising therapeutic applications. Although hASC-EVs are derived from human cells and are less immunogenic, their immunogenicity cannot be completely excluded. Here, we evaluate the immune responses of ICR and C57BL/6 mice to high doses of hASC-EVs for 10 days after injection. Lymphocyte subpopulations are analyzed using flow cytometry at 0.5, 1, 3 and 24 h post injection. In the spleen and blood of C57BL/6 mice, neutrophils sharply increased at 0.5 h and decreased at 3 h following hASC-EV treatment. We observe increased proportions of monocytes, macrophages, and natural killer cells at 3 h but returned to similar level of vehicle control at 24 h post injection in the spleen and blood of ICR mice. Although the in vivo experiments reveal different immune responses to hASC-EV treatment in C57BL/6 and ICR strains, no major changes occur in human peripheral blood mononuclear cell composition after applying hASC-EVs in vitro. In conclusion, unlike those in mice, immune responses to hASC-EVs in humans are not detectable, indicating a minimal risk of fatal side-effects from hASC-EV-based therapies.

BACKGROUND: Extracellular vesicles (EVs) derived from plants have emerged as potential candidates for cosmetic and therapeutic applications. In this study, we isolated EVs from Aloe vera peels (A-EVs) and investigated the antioxidant and wound healing potential of A-EVs. METHODS: A-EVs were isolated by ultracentrifugation and tangential flow filtration and were characterized using transmission electron microscopy, nanoparticle tracking analysis. The cytotoxicity and cellular uptake of A-EVs were investigated by WST-1 assay and flow cytometry. The antioxidant effect of A-EVs was evaluated by superoxide dismutase (SOD) activity assay and cellular antioxidant activity (CAA) assay. The wound healing potential was assessed by in vitro scratch assay using human keratinocytes (HaCaT) and fibroblasts (HDF). The expression of nuclear factor erythroid 2–related factor 2 (Nrf2) and their associated genes was analyzed by quantitative RT-PCR. RESULTS: A-EVs displayed a round shape and had diameters from 50 to 200 nm. A-EVs showed good cytocompatibility on human skin cells and were internalized into HaCaT cells via clathrin-, caveolae-mediated endocytosis, and membrane fusion. The SOD activity and CAA assays exhibited that A-EVs had antioxidant activity and reduced intracellular ROS levels in H(2)O(2)-treated HaCaT cells in a dose-dependent manner. A scratch assay showed that A-EVs enhanced the migration ability of HaCaT and HDF. Moreover, A-EVs significantly upregulated the mRNA expression of Nrf2, HO-1, CAT, and SOD genes in H(2)O(2)-treated HaCaT cells. Our findings reveal that A-EVs could activate the antioxidant defense mechanisms and wound healing process via the Nrf2 activation. CONCLUSION: Overall results suggest that the A-EVs are promising as a potential agent for skin regeneration.

Due to its greater physical-chemical stability, ceramic nanofiltration (NF) membranes were used in a number of industrial applications. In this study, a novel NF membrane was prepared by co-depositing a titanium dioxide (TiO

The microwave power transfer (MPT) system requires a massive Tx array for building a focused radio wave to efficiently transfer power to the Rx. Beamforming IC is one of the core elements for the massive Tx array. This paper presents a 5.8 GHz 4-channel beamforming Tx IC based on a CMOS process. The beamforming Tx IC includes a resistive 4-way power splitter, 5-bit differential phase shifters, drive amplifiers, and power amplifiers. Each channel is designed to transmit a power of no less than 100 mW. To verify the Tx IC, a 16-channel beamforming Tx module based on 16 patch antennas and four 4-channel Tx ICs was designed. The module also includes a PLL, a frequency doubler, and a 4-way Wilkinson power divider. MPT experiments to verify the beamforming IC and module were carried out using the implemented 16-channel Tx module at 5.8 GHz. Received power levels of 13 dBm and 2.1 dBm were achieved at distances of 0.4 and 1.4 m, respectively. The results are almost similar to the values acquired from the calculation using the Friis equation.

This article presents a hybrid envelope tracking (ET) supply modulator (SM) integrated circuit (IC) based on a Class-AB linear amplifier (LA) with supply voltage and temperature insensitive quiescent current. For ET mode, to further improve efficiency of the ET-SM, the supply voltage of the LA can be modulated using an additional dc-dc converter according to the average output power. An adaptive quiescent current controller for the LA of the ET-SM is proposed to maintain its quiescent current for large variations in voltage and temperature. Due to the insensitive quiescent current over the voltage of the LA, the supply voltage to the LA can be controlled in a wider range for the average output power, which allows the power amplifier (PA) in the ET mode to have a greater improvement in efficiency. The size of the output stage of the LA is also discretely reconfigured using 3-bit digital control to reduce the power consumption of the LA according to the output power level. For the low average output power levels, the operation mode is changed to APT mode, which supplies a reduced dc voltage according to the reduced average output power to the PA. The proposed SM, dc/dc converter and PA ICs were designed and implemented using CMOS processes for 0.9 GHz LTE application. Using an LTE uplink signal with a signal bandwidth of 5 MHz and a PAPR of 7.5 dB, a PAE of 38.4% at an average output power of 24.0 dBm was obtained under an ACLR of −30.0 dBc for the overall ET-PA. At a 6 dB back-off for the average output power, a PAE of 24.6% was achieved using the ET mode. A maximum PAE improvement of 8.0% point using the proposed SM IC was achieved compared to the stand-alone PA.

The objective of this article is twofold: first to argue that Philip Jaisohn, upon his return from the United States to Korea in 1896, sought to subvert, if not overthrow, the monarchical government, and second, to argue that Jaisohn drew on specifically Christian intellectual and ideological resources to articulate his arguments. The rhetoric of loyalty, love, lawful resistance, private property, and slavery are, as such, in need of analysis through the Protestant conceptual prism. Previous studies analyzing modern political thought have focused on the nature of translation from the West; this study focuses on the conceptual aspect of the political language Jaisohn introduced in order to effect revolutionary changes in the popular vernacular. His goal was not just to present resistance against the incumbent governing authority as morally defensible, but to frame it in terms of the right of individual property. Finally the article suggests avenues through which religious thinking affected the reception and dissemination of Western political thought in Korea, and concludes by reflecting on the relevance of religious thought in the analysis of modern Korean political thought.

Hydrogen production from renewable resources, such as lignocellulosic biomass, is highly desired, under the most sustainable and mildest reaction conditions. In this study, a new sustainable three-step process for the production of hydrogen has been proposed. In the first step, a crude formic acid (CF) solution, which included typical reaction byproducts, in particular, acetic acid, levulinic acid, saccharides, 5-hydroxymethylfurfural, furfural, and lignin, was obtained through the combined hydrolysis/oxidation of the biomass, in the presence of diluted sulfuric acid/hydrogen peroxide, as homogeneous catalysts. In the second one, the distilled formic acid (DF) solution was obtained by distillation of the CF solution, for example, by isolating liquid byproducts, or the lignin-free CF (LCF) solution was recovered by CF filtration for the elimination of only solid lignin particles. In the final step, hydrogen was produced from the DF or LCF solutions through formic acid dehydrogenation over Pd supported on amine-functionalized mesoporous silica catalysts, in the presence of sodium formate, as an additive. The clean hydrogen, which is produced from biomass passing through formic acid, could be applied as an energy source of fuel cells. This new hydrogen production process is smart, allowing the hydrogen production with mild reaction conditions, eventually starting from different lignocellulosic feedstocks, and it could be integrated within the existing hydrothermal technology for levulinic acid production, which has been already recognized as efficient and sustainable. In addition to the production of hydrogen as an energy source of fuel cells, formic acid derived from biomass could be utilized as a platform chemical for chemical, agricultural, textile, leather, pharmaceutical, and rubber industries.

This paper proposes an ensemble deep learning model that can identify each person using pressure sensor data acquired from smart insoles. The ensemble model consists of CNN, LSTM, and self-attention to effectively learn the relationship between gait data. The model was trained using a triplet loss to map each data to a better embedding vector of latent space. The experimental results showed that the accuracy was improved in recognizing people by using the proposed ensemble learning while reducing the size of the model by half.

The molasses embedded hybrid coal (Hybrid Coal by Korea Institute of Energy Research; HCK) was previously proposed as an attractive alternative to low-rank coals that tend to show low calorific values and high CO2 emissions. HCK was synthesized by mixing molasses with a low-rank coal to enhance its heating value. Nevertheless, food ethics regarding molasses additives still have impeded its commercial acceptance. In this study, we propose a glycerol (nonfood)-based coal upgrading process to improve the combustion kinetics and heating value of hybrid coal in comparison to the previous HCK. The process involves drying at 105 °C followed by torrefaction process at 250 °C. During torrefaction, the glycerol additive starts to evaporate at about 180 °C and then is almost vaporized out to the coal surface. To avoid glycerol loss, we employ sulfuric acid as a torrefaction catalyst to suppress glycerol evaporation. In comparison to the molasses yield of 65% after torrefaction in the previous HCK synthesis process, ...

The main concerns of coal power plants are related to high thermal efficiency and biomass utilization for the reduction of CO2 emissions. In this work, the fuel characteristics of a hybrid coal (HCK) impregnated by sugar impurities extracted from a lignocellulosic biomass were investigated. First, an optimized extraction condition for the sugar impurities was chosen among the various reaction temperatures and times using a hydrothermal pre-treatment (HTP) reactor. The extracted sugar impurities were consisted of 21.76 wt% glucan, 75.88 wt% XMG (xylan + mannan + galactan) and 2.36 wt% arabinan at the optimized reaction condition (190 °C and 30 min). 5 wt% sugar impurities based on the coal weight (dry basis) was used to prepare the HCK and the fuel characteristics were compared. According to the H/C and O/C ratios, raw coals were upgraded. In addition, the calorific value of the raw coals was enhanced by HCK production process. The HCKs had a low moisture re-adsorption rate in an excessive water immersion condition compared to the raw coals. To clarify the combustion behavior of the HCKs, thermogravimetric analysis (TGA) was carried out. The HCKs had a single-stage combustion pattern on the differential thermogravimetric (DTG) curve, even though they were composed of a coal and biomass resource. During the kinetic study of the raw coals and HCKs, a high reaction rate constant (k) and low activation energy (Ea) for the HCKs were identified compared to that of the raw coals.

Biomass combustion technology is widely considered as an attractive option to remove carbon dioxide emissions and thus could become a viable option for next generation co-combustion power plants with coal. Among biomasses, the faster growing herbaceous biomass (Miscanthus) is relatively inexpensive as a solid fuel but has higher mineral contents (especially high levels of alkali metals) than that of a lignocellulosic biomass (Pitch pine) which leads to ultrafine particle emissions during combustion. This study proposes a dual stage treatment method to extract the inherent minerals in a herbaceous biomass prior to the combustion test. The method consists of an initial treatment with a basic (NaOH) solution and a sequential treatment with an acidic (CH3COOH) solution. To verify the proposed method, we investigated the variations in both the mineral contents and the PM, NOx and SO2 emissions between raw- and treated samples. The experimental results show that sodium, potassium and chloride in the treated herbaceous sample, which are the major minerals that generate ultrafine particles, were removed up to 96.3, 99.4 and 98.3%, respectively. The proposed method is more effective for herbaceous biomasses due to its higher Brunauer–Emmett–Teller (BET) value. Furthermore, the treated herbaceous biomass is even environmentally superior to raw lignocellulosic biomasses currently used in co-combustion power plants with coal in terms of the PM2.5, NOx and SO2 emissions, for which their rejection was measured as 60, 25 and 46%, respectively. These results will help to reduce the energy and costs for De-NOx (selective catalytic reduction, SCR system) and De-SO2 (scrubber) units.

Allogeneic transplantation of mesenchymal stem cell-derived extracellular vesicles (EVs) offers great potential for treating liver fibrosis. However, owing to their intrinsic surface characteristics, bare EVs are non-specifically distributed in the liver tissue after systemic administration, leading to limited therapeutic efficacy. To target activated hepatic stellate cells (HSCs), which are responsible for hepatic fibrogenesis, vitamin A-coupled small EVs (V-EVs) were prepared by incorporating vitamin A derivative into the membrane of bare EVs. No significant differences were found in the particle size and morphology between bare and V-EVs. In addition, surface engineering of EVs did not affect the expression of surface marker proteins (e.g., CD63 and CD9), as demonstrated by flow cytometry. Owing to the surface incorporation of vitamin A, V-EVs were selectively taken up by activated HSCs via receptor-mediated endocytosis. When systemically administered to mice with liver fibrosis, V-EVs effectively targeted activated HSCs in the liver tissue, resulting in reversal of the fibrotic cascade. Consequently, even at a 10-fold lower dose, V-EVs exhibited comparable anti-fibrotic effects to those of bare EVs, substantiating their therapeutic potential for liver fibrosis.

Poly(l-lactic acid) (PLLA) based piezoelectric polymers are gradually becoming the substitute for the conventional piezoelectric ceramic and polymeric materials due to their low cost and biodegradable, non-toxic, piezoelectric and non-pyroelectric nature. To improve the piezoelectric properties of melt-spun poly(l-lactic acid) (PLLA)/BaTiO3, we optimized the post-processing conditions to increase the proportion of the β crystalline phase. The α → β phase transition behaviour was determined by two-dimensional wide-angle x-ray diffraction and differential scanning calorimetry. The piezoelectric properties of PLLA/BaTiO3 fibres were characterised in their yarn and textile form through a tapping method. From these results, we confirmed that the crystalline phase transition of PLLA/BaTiO3 fibres was significantly enhanced under the optimised post-processing conditions at a draw ratio of 3 and temperature of 120 °C during the melt-spinning process. The results indicated that PLLA/BaTiO3 fibres could be a one of the material for organic-based piezoelectric sensors for application in textile-based wearable piezoelectric devices.

High-speed melt spinning of island-in-the-sea (SI) type bicomponent fibers with 74 islands consisting of high-molecular-weight poly(ethylene terephthalate) (HMW-PET) and polypropylene (PP) was achieved. The structure and mechanical properties of the HMW-PET component (islands) in the SI fibers were significantly enhanced with increasing the take-up velocity, while those of PP component (Sea) were suppressed. These results were attributed to the concentration of spinning stress on the HMW-PET component exhibiting higher elongational viscosity in the spinline. Considerable interaction between the two components in the SI fibers contributed to uniform structure development of the island parts in the fibers and improvement of the melt structure in the spinline. These results further enhanced the mechanical property and spinnability of the island parts. The thermoplastic composites, manufactured using the high-speed spun SI fibers with the islands of fine diameter (approximately 1.9 μm), exhibited a high tensile strength of approximately 1.0 GPa by microfiber-reinforced effect.

Poly(L-lactic acid) (PLLA) based piezoelectric polymers are gradually becoming the substitute for the conventional piezoelectric ceramic and polymeric materials due to their low cost and biodegradable, non-toxic, piezoelectric and non-pyroelectric nature. To improve the piezoelectric properties of melt-spun poly(L-lactic acid) (PLLA)/BaTiO

Gelatin is extensively used as a biomaterial for diverse pharmaceutical and medical applications due to its excellent biocompatibility and biodegradability. Here we present bio-inspired tissue-adhesive gelatin hydrogels prepared by the enzyme-mediated synthesis of l-3,4-dihydroxyphenylalanine (l-DOPA) and Fe

Nowadays, it is widely recognized that biomass combustion processes can contribute to the mitigation of greenhouse gas emissions, and thus, these processes have become a viable option as an alternative energy source for the power industry. Among various biomasses, the herbaceous biomass is regarded as an abundant and relatively inexpensive fuel. However, it contains high ashes (especially high levels of alkali metals), leading to operation troubles such as slagging and fouling inside a heat exchanger or deterioration in efficiency. Accordingly, we herein propose an economical method to remove the inherent ashes in the biomass using 16.6 M acetic acid pretreatment at 60 °C for 10 min. Seven different biomasses were investigated to validate the effects of method. The Kenaf shows the total mineral rejection of 93.48%. In particular, the potassium and sodium elements in the Kenaf, which are major factors influencing fouling and slagging in a boiler, were removed up to 99.46 and 100%, respectively. Furthermore...

Synthetic methods of mesoporous silica using surfactants or ionic liquids as a template have several disadvantages to commercialization such as low economic feasibility and low sustainability. Thus...

The co-combustion of sewage sludge and woody biomass is a key issue in coal power plants. Different combustion and ash behaviors of sewage sludge and woody biomass cause unpredictable operating concerns. In this study, the combustion and ash agglomeration behavior of blended fuel of sewage sludge and woody biomass (BSW) were investigated while coal co-combusted with it. Thermogravimetric analysis (TGA) revealed that adding a high amount of BSW into the coal lowered volatilization, ignition, and burn-out temperature. The char combustion reactivity of coal differed from that of BSW. The shrinking core model (SCM) and volumetric reaction model (VRM) were used to fit the char combustion reactivity of coal and BSW. In the case of ash agglomeration behavior, BSW addition led to increasing particle agglomeration at fouling temperatures. In particular, phosphorus composition influenced particle growth, which was verified using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX) analysis. Furthermore, the ash mixture ratio of BSW and coal changed the intensity of the phosphorus-bearing mineral phase from X-ray diffraction (XRD) analysis, and finally influenced the melting temperature of the ash.

Conversion of lignin to higher value-added materials, such as hierarchically porous carbon, is very important for improving economic feasibility of lignocellulosic biomass-based refinery processes....

Sustainable and efficient hydrogen production from biomass resources have been highly desired. Here, we report a low-temperature hydrogen production process from lignocellulosic biomass passing through formic acid (the biomass-formic acid-hydrogen conversion process) with improved sustainability and formic acid yield. In the biomass oxidation/hydrolysis step, toxic sulfuric acid has been replaced by sustainable citric acid. In addition, mechanocatalytic depolymerization of biomass has been applied to the biomass pretreatment step, resulting in the remarkable improvement in formic acid yield. In the first step, the citric-acid-impregnated biomass was subjected to a mechanocatalytic depolymerization process for facilitating contact between the substrate and catalysts (MD-CIB). In the second step, the crude formic acid (CF) solution was obtained via combined hydrolysis-oxidation process of the MD-CIB in the presence of dimethyl sulfoxide (DMSO), and hydrogen peroxide (H2O2). The yield of formic acid were measured up to be 50.03%. In the third step, the lignin-free crude formic acid (LCF) solution was recovered by filtration, or distilled formic acid (DF) solution was obtained by distillation of the CF solution. In the final step, hydrogen was generated from LCF or DF solutions through dehydrogenation of formic acid over Pd catalysts supported on amine-functionalized mesoporous silica (KIE-6) with a sodium formate. The turnover frequency (TOF) at 10 min were measured up to be 279.24 mol H2 mol Pd-1h−1. The clean hydrogen, which is produced from biomass passing through formic acid, could be directly applied in fuel cell as an energy source. Our hydrogen production process is expected to be much more efficient, sustainable and economical process for hydrogen production from biomass. In addition, organic acids as a byproduct could be utilized as a platform chemical.

The application of biomass resources and sewage sludge is currently the most important issue in the field of coal combustion systems. The main drawback for operating a boiler system is its varied firing characteristics and low heating value. In this study, we have developed new synthetic fuels, namely hybrid sludge fuel (HSF), using coal and sewage sludge impregnated bioliquid (molasses) and evaluated their properties by comparison with conventional fuels. To prepare the HSF, it was treated in a carbonization system at 250 °C. Depending on the van Krevelen diagram, the fuel quality of HSF was superior to that of raw bioliquid and sewage sludge. In addition, its fuel characteristic was similar to sub-bituminous and bituminous coal. Thermogravimetric analysis (TGA) indicated only a single-stage combustion pattern for HSF during non-isothermal heating. To clarify the unburned carbon (UBC) content, an ultimate analysis was conducted. The amount of UBC of the HSF was much more than that of sewage sludge, but less than that of coal. To investigate the surface hydrophobicity of HSF, Fourier transform infrared spectroscopy (FT-IR) analysis and a moisture re-adsorption test were carried out. The HSF possessed high hydrophobicity and presented a low moisture re-adsorption rate compared to conventional fuels.

Biomass combustion is a promising method in combustion facilities to reduce CO2 emissions. Biomass fuel has unfavorable characteristics, such as low temperature ash minerals and high particulate matter (PM) emission in the combustion facility, which influences operation and creates environmental issues. In this work, different types of empty fruit bunch (EFB) and palm kernel shell (PKS) biomass samples, such as raw biomass, demineralized biomass, and its biomass pretreated by torrefaction were studied to identify their char combustion characteristics by thermogravimetric analysis (TGA) and their ash deposition behaviors and PM emissions in a drop tube furnace (DTF) experiment. Regarding the char combustion characteristic results obtained by TGA, demineralization pretreatment did not clearly influence the char combustion reactivity compared to that of raw biomass, but torrefaction pretreatment lowered the char combustion reactivity at low temperatures. In the DTF experiments, torrefaction pretreatment led to increasing ash deposition and PM emissions during biomass combustion. However, demineralization pretreatment clearly lowered the amount of ash deposition and PM emissions because potassium (K), chlorine (Cl), and sulfur (S) were significantly removed by demineralization pretreatment. In particular, scanning electron microscopy with dispersive X-ray spectroscopy (SEM-EDX) analysis results showed that the demineralized biomass samples having low K, Cl, and S components emitted relatively large PM compared to untreated biomass. Therefore, demineralization pretreatment might be a good method to produce cleaner biomass fuel.