• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.26-32
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• 2021

The photovoltaic properties and microstructure changes were observed while perovskite solar cells (PSCs) with a fabricated carbon electrode were formed using the following annealing processes: hot-plate, oven, and rapid thermal annealing (RTA). Perovskite solar cells with a glass/FTO/compact TiO2/meso TiO2/meso ZrO2/carbon structure were prepared. The photovoltaic properties and microstructure changes in the PSCs were analyzed using a solar simulator, optical microscopy, and field emission scanning electron microscopy. An analysis of the photovoltaic properties revealed outstanding properties when RTA was applied to the cells. Microstructure analysis showed that perovskite was formed locally on the carbon electrode surface when hot-plate and oven annealing were applied. On the other hand, PSC with RTA showed a flat surface without extra perovskite agglomeration. Denser perovskite formed on the porous carbon electrode layer with RTA showed superior photovoltaic properties. These results suggest that the RTA process might be appropriate for the massive production of carbon electrode PSCs considering the processing time.

• Journal of Nutrition and Health
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• v.54 no.4
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• pp.342-354
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• 2021

Purpose: Obesity is a serious public health issue for the modern society and is considered a chronic health hazard. There are many surgical and pharmacological approaches to treat obesity. However, various potentially hazardous side effects remain the biggest challenge. Therefore, diets based on foods derived from natural products have gained increasing attention compared to anti-obesity drugs. Recently, research on edible insects as a food source has been a topic of considerable interest in the scientific communities. This study examined the anti-obesity effects of ingesting an edible insect by feeding a high-fat diet (HFD)-induced obese mouse models with a diet containing Tenebrio molitor larvae powder (TMLP). Methods: Six-week-old female C57BL/6J mice were divided into 4 groups according to treatment: 100% normal diet (ND), 100% HFD (HFD), HFD 99% + TMLP 1% (TMLP), and HFD 97% + TMLP 3% (TMLP 3%). TMLP was added to the HFD for 6 weeks for the latter two groups. Results: Compared to the HFD group, mice in the TMLP group showed weight loss, and micro-computed tomographic imaging revealed that the volume of the adipose tissue in the abdominal area also showed significant reduction. After an autopsy, the fat weight was found to be significantly reduced in the TMLP group compared to the HFD group. In addition, the degree of fat cell deposition in the liver tissue and the size of the adipocytes significantly decreased in the TMLP group. Reverse transcription polymerase chain reaction analysis for the mRNA expression of adipogenesis-related genes namely CCAAT-enhancer-binding proteins (C/EBP-β, C/EBP-δ), and fatty acid-binding protein 4 (FABP4) showed that the expression levels of these genes were significantly reduced in the TMLP group compared to the HFD group. Serum leptin level also decreased significantly in the TMLP group in the comparison with the HFD group. In addition, total cholesterol, triglyceride, and glucose levels in mouse serum also decreased in the TMLP group. Conclusion: Taken together, our results showed that TMLP effectively inhibited adipocyte growth and reduced body weight in obese mice.

• Molecules and Cells
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• v.45 no.6
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• pp.403-412
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• 2022

Hypoxia leads to significant cellular stress that has diverse pathological consequences such as cardiovascular diseases and cancers. MicroRNAs (miRNAs) are one of regulators of the adaptive pathway in hypoxia. We identified a hypoxia-induced miRNA, miR-34c, that was significantly upregulated in hypoxic human umbilical cord vein endothelial cells (HUVECs) and in murine blood vessels on day 3 of hindlimb ischemia (HLI). miR-34c directly inhibited BCL2 expression, acting as a toggle switch between apoptosis and autophagy in vitro and in vivo. BCL2 repression by miR-34c activated autophagy, which was evaluated by the expression of LC3-II. Overexpression of miR-34c inhibited apoptosis in HUVEC as well as in a murine model of HLI, and increased cell viability in HUVEC. Importantly, the number of viable cells in the blood vessels following HLI was increased by miR-34c overexpression. Collectively, our findings show that miR-34c plays a protective role in hypoxia, suggesting a novel therapeutic target for hypoxic and ischemic diseases in the blood vessels.

• Nutrition Research and Practice
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• v.15 no.3
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• pp.279-293
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• 2021

BACKGROUND/OBJECTIVES: The steamed ginger has been shown to have antioxidative effects and a protective effect against obesity. In the present study, we investigated the effects of ethanolic extract of steamed ginger (SGE) on adipogenesis in 3T3-L1 preadipocytes and diet-induced obesity (DIO) mouse model. MATERIALS/METHODS: The protective effects of SGE on adipogenesis were examined in 3T3-L1 adipocytes by measuring lipid accumulations and genes involved in adipogenesis. Male C57BL/6J mice were fed a normal diet (ND, 10% fat w/w), a high-fat diet (HFD, 60% fat w/w), and HFD supplemented with either 40 mg/kg or 80 mg/kg of SGE for 12 weeks. Serum chemistry was measured, and the expression of genes involved in lipid metabolism was determined in the adipose tissue. Histological analysis and micro-computed tomography were performed to identify lipid accumulations in epididymal fat pads. RESULTS: In 3T3-L1 cells, SGE significantly decreased lipid accumulation, with concomitant decreases in the expression of adipogenesis-related genes. SGE significantly attenuated the increase in body, liver, and epididymal adipose tissue weights by HFD. Serum total cholesterol and triglyceride levels were significantly lower in SGE fed groups compared to HFD. In adipose tissue, SGE significantly decreased adipocyte size than that of HFD and altered adipogenesis-related genes. CONCLUSIONS: In conclusion, steamed ginger exerted anti-obesity effects by regulating genes involved in adipogenesis and lipogenesis in 3T3-L1 cell and epididymal adipose tissue of DIO mice.

• The Korea Journal of Herbology
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• v.33 no.3
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• pp.11-18
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• 2018

Objectives : Saururus chinensis and Houttuynia cordata (Saururaceae) are perennial herbs using for medicinal purposes in Korea. The objectives of this study are to compare anatomical key characters between two medicinal plants and to provide fundamental information for the identification of two herbal medicines by using anatomical features. Methods : Cross-sections of root, rhizome, stem, petiole, and leaf for each species were observed in this study. Materials were analyzed through dehydration, paraffin embedding and micro-sectioning, and double staining with Safranin O and Fast-Green FCF. Observations of permanent preparation were conducted using light microscope. Results : S. chinensis and H. cordata were distinguished with anatomical differentiations; Idioblasts with essential oil were scattered in the parenchyma cell of cortex, pith, and phloem of S. chinensis, on the other hand, in H. cordata, idioblasts were distributed ring-shaped in the cortex of the root. S. chinensis had two cycles of vascular bundles in the stem while H. cordata had one cycle. Hypodermis layer was conspicuous in a stem of H. cordata, crystals were observed the only parenchyma in a stem of S. chinensis, and epidermal oil cells were developed in the epidermis of H. cordata. S. chinensis had air cavity at the cortex and pith of the stem. The shape of cross-section was polygonal in the stem of S. chinensis and was circular in the stem of H. cordata. Conclusions : We investigated anatomical study of Korean S. chinensis and H. cordata. To identify two herbal medicines, we considered main anatomical features and provided identification key here.

• Korean Journal of Exercise Nutrition
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• v.24 no.3
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• pp.25-31
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• 2020

[Purpose] Epidemiological evidence has shown that leisure-time physical activity and structured exercise before and after breast cancer diagnosis contribute to reducing the risk of breast cancer recurrence and mortality. Thus, in this review, we aimed to summarize the physical activity-dependent regulation of systemic factors to understand the biological and molecular mechanisms involved in the initiation, progression, and survival of breast cancer. [Methods] We systematically reviewed the studies on 1) the relationship between physical activity and the risk of breast cancer, and 2) various systemic factors induced by physical activity and exercise that are potentially linked to breast cancer outcomes. To perform this literature review, PubMed database was searched using the terms "Physical activity OR exercise" and "breast cancer", until August 5th, 2020; then, we reviewed those articles related to biological mechanisms after examining the resulting search list. [Results] There is strong evidence that physical activity reduces the risk of breast cancer, and the protective effect of physical activity on breast cancer has been achieved by long-term regulation of various circulatory factors, such as sex hormones, metabolic hormones, inflammatory factors, adipokines, and myokines. In addition, physical activity substantially alters wholebody homeostasis by affecting numerous other factors, including plasma metabolites, reactive oxygen species, and microRNAs as well as exosomes and gut microbiota profile, and thereby every cell and organ in the whole body might be ultimately affected by the biological perturbation induced by physical activity and exercise. [Conclusion] The understanding of integrative mechanisms will enhance how physical activity can ultimately influence the risk and prognosis of various cancers, including breast cancer. Furthermore, physical activity could be considered an efficacious non-pharmacological therapy, and the promotion of physical activity is probably an effective strategy in primary cancer prevention.

• Journal of the Semiconductor & Display Technology
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• v.22 no.1
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• pp.28-32
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• 2023

Recently, the use of stable lithium nanostructures as substrates and electrodes for secondary batteries can be a fundamental alternative to the development of next-generation system semiconductor devices. However, lithium structures pose safety concerns by severely limiting battery life due to the growth of Li dendrites during rapid charge/discharge cycles. Also, enabling long cyclability of high-voltage oxide cathodes is a persistent challenge for all-solid-state batteries, largely because of their poor interfacial stabilities against oxide solid electrolytes. For the development of next-generation system semiconductor devices, solid electrolyte nanostructures, which are used in high-density micro-energy storage devices and avoid the instability of liquid electrolytes, can be promising alternatives for next-generation batteries. Nevertheless, poor lithium ion conductivity and structural defects at room temperature have been pointed out as limitations. In this study, a low-dimensional Graphene Oxide (GO) structure was applied to demonstrate stable operation characteristics based on Li+ ion conductivity and excellent electrochemical performance. The low-dimensional structure of GO-based solid electrolytes can provide an important strategy for stable scalable solid-state power system semiconductor applications at room temperature. The device using uncoated bare NCA delivers a low capacity of 89 mA h g-1, while the cell using GO-coated NCA delivers a high capacity of 158 mA h g−1 and a low polarization. A full Li GO-based device was fabricated to demonstrate the practicality of the modified Li structure using the Li-GO heterointerface. This study promises that the lowdimensional structure of Li-GO can be an effective approach for the stabilization of solid-state power system semiconductor architectures.

• Journal of Photoscience
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• v.9 no.2
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• pp.186-189
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• 2002

Many of the adverse effects of solar UV exposure appear to be directly attributable to damage to epidermal DNA. In particular, cyclobutane pyrimidine dimers (CPD) may initiate mutagenic changes as well as induce signal transduction responses that lead to a loss of skin immune surveillance and micro-destruction of skin structure. Our approach is to reverse the DNA damage using prokaryotic DNA repair enzymes delivered into skin using specially engineered liposomes. T4 endonuclease V encapsulated in liposomes (T4N5 liposome lotion) enhanced DNA repair by shifting repair of CPD from the nucleotide excision to the base excision repair pathway. Following topical application to humans, increased repair limited UV-induction of cytokines, many of which are immunosuppressive. In a recent clinical study, topical treatment of UV-irradiated human skin with T4N5 liposome lotion reduced the suppression of the nickel sulfate contact hypersensitivity response. Similarly, the photoreactivating enzyme enhances repair by directly reversing CPDs after absorbing activating light. Here also treatment of UV-irradiated human skin with photoreactivating enzyme in liposomes and photoreactivating light restored the response to the contact allergen nickel sulfate. These findings confirm in humans the observation in mice that UV induced suppression of contact hypersensitivity is caused in part by CPDs. We have tested the ability of T4N5 liposome lotion to prevent UV-induced skin cancer in patients with xeroderma pigmentosum (XP), who have an elevated incidence of skin cancer resulting from a genetic defect in DNA repair. Daily use of the lotion for one year in a group of 20 XP patients reduced the average number of actinic keratoses by 68% and basal cell cancers by 30% compared to 9 patients in the placebo control group. Delivery of DNA repair enzymes to skin is a promising new approach to photoprotection.

• Journal of Hydrogen and New Energy
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• v.33 no.6
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• pp.845-855
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• 2022

In response to climate change, the world is continuing efforts to reduce fossil fuels, expand renewable energy, and improve energy efficiency with the goal of achieving carbon neutrality. In particular, R&D is being made on the value chain covering the entire cycle of hydrogen production, storage, transportation, and utilization in order to shift the energy supply system to focus on hydrogen energy. Hydrogen-based energy sources can produce heat and electricity at the same time, so it is possible to utilize heat energy, which can increase overall efficiency. In this study, calculation of the optimal scale for hydrogen-based cogeneration and the composition of heat sources were reviewed. It refers to a method of the optimal heat source size according to the external heat supply and heat storage to be considered. The results of this study can be used as basic data for establishing a hydrogen-based energy supply model in the future.

• Molecules and Cells
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• v.46 no.6
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• pp.351-359
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• 2023

Deamination of adenine or cytosine in RNA, called RNA editing, is a constitutively active and common modification. The primary role of RNA editing is tagging RNA right after its synthesis so that the endogenous RNA is recognized as self and distinguished from exogenous RNA, such as viral RNA. In addition to this primary function, the direct or indirect effects on gene expression can be utilized in cancer where a high level of RNA editing activity persists. This report identified actin-related protein 2/3 complex inhibitor (ARPIN) as a target of ADAR1 in breast cancer cells. Our comparative RNA sequencing analysis in MCF7 cells revealed that the expression of ARPIN was decreased upon ADAR1 depletion with altered editing on its 3'UTR. However, the expression changes of ARPIN were not dependent on 3'UTR editing but relied on three microRNAs acting on ARPIN. As a result, we found that the migration and invasion of cancer cells were profoundly increased by ADAR1 depletion, and this cellular phenotype was reversed by the exogenous ARPIN expression. Altogether, our data suggest that ADAR1 suppresses breast cancer cell mobility via the upregulation of ARPIN.