Publications by authors named "Junkyu Han"

Recent advances in soft materials and mechanics activate development of many new types of electrical medical implants. Electronic implants that provide exceptional functions, however, usually require more electrical power, resulting in shorter period of usages although many approaches have been suggested to harvest electrical power in human bodies by resolving the issues related to power density, biocompatibility, tissue damage, and others. Here, we report an active photonic power transfer approach at the level of a full system to secure sustainable electrical power in human bodies.

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We measured the thermal conductivity of Araneus ventricosus' spider dragline silk using a suspended microdevice. The thermal conductivity of the silk fiber was approximately 0.4WmK at room temperature and gradually increased with an increasing temperature in a manner similar to that of other disordered crystals or proteins.

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Combining bioassays and analytical chemistry screening is a powerful approach to assess organic micropollutants which are the main contributors to toxic potential in complex mixtures of treated wastewater (TWW). The aim of this study was to perform a comprehensive toxicity assessment of treated effluents using stress response bioassays and then to assess the occurrence of the organic micropollutants which were responsible for this biological response using gas chromatography coupled with a mass spectrometry detector (GC/MS). Results showed that TWW samples induced significant stress response on Chinese hamster ovary cells, stably transfected with heat shock protein 47 promoter, at 0.

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The merging of high-throughput gene expression techniques, such as microarray, in the screening of natural products as anticancer agents, is considered the optimal solution for gaining a better understanding of the intervention mechanism. Red yeast rice (RYR), a Chinese dietary product, contains a mixture of hypocholesterolemia agents such as statins. Typically, statins have this effect via the inhibition of HMG‑CoA reductase, the key enzyme in the biosynthesis of cholesterol.

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The generation of blood cellular components from hematopoietic stem cells is important for the therapy of a broad spectrum of hematological disorders. In recent years, several lines of evidence suggested that certain nutrients, vitamins and flavonoids may have important roles in controlling the stem cell fate decision by maintaining their self-renewal or stimulating the lineage-specific differentiation. In this study, main olive leaf phytochemicals oleuropein (Olp), apigenin 7-glucoside (Api7G) and luteolin 7-glucoside (Lut7G) were investigated for their potential effects on hematopoietic stem cell differentiation using both phenotypic and molecular analysis.

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To date, numerous studies have reported on the antidiabetic properties of various plant extracts through inhibition of carbohydrate-hydrolysing enzymes. The objective of this research was to evaluate the inhibitory effect of the hydroxytyrosol and the oleuropein against α-amylase and α-glucosidase. The hydroxytyrosol was purified from olive leaves.

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Linear alkylbenzene sulfonate (LAS) is a cytotoxic synthetic anionic surfactant widely present in the environment due to its large-scale production and intensive use in the detergency field. In this study, we investigated the effect of LAS (CAS No. 25155-30-0) at non cytotoxic concentrations on human intestinal Caco-2 cells using different in vitro bioassays.

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Nitraria retusa is a halophyte species that is distributed in North Africa and used as a traditional medicinal plant. In this study, N. retusa ethanol extract and its constituent isorhamnetin (IRA) protected against amyloid β (Aβ)-induced cytotoxicity in human neuroblastoma SH-SY5Y cells.

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Black soybean is a health food has been reported to have antidiabetes effect. The onset of diabetes is closely associated with adipocyte differentiation, and at present, the effect of black soybean on adipocyte differentiation is unknown. Here, we investigated the antidiabetes effect of black soybean, and its anthocyanin cyanidin-3-glucoside (Cy3G), on adipocyte differentiation.

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The medicinal plants can be used in the prevention or treatment of many diseases. Several studies concerning the potential of bioactive components in plants and food products and their link to obesity and related metabolic disorders, have been gaining big interest. Diabetes is a serious metabolic syndrome.

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The erythroid differentiation-inducing effect of apigenin and its derivatives on human chronic myeloid leukemia K562 has been reported but the functional group in its structure responsible for the effect has not yet been elucidated. Here, we determined the moiety responsible for the erythroid differentiation induction effect of apigenin by using different flavonoids to represent the functional groups in its structure. In addition, we compared apigenin and apigetrin, a flavonoid similar in structure to apigenin except for the glycoside in its structure.

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Linear alkylbenzene sulfonate (LAS) is a synthetic anionic surfactant widely present in the environment due to its intensive production and use in the detergency field. Admitting that current procedure of risk assessment has limits in providing realistic risk assessment data and predicting the cumulative effect of the toxicant mixtures, the incorporation of information regarding the mode of action and cell response mechanism seems to be a potential solution to overcome these limits. In this regard, we investigated in this study the LAS cytotoxicity on human intestinal Caco-2 cells, trying to unveil the protein actors implicated in the cell response using proteomics approach in order to give a better understanding of the toxicological effect and allow the identification of appropriate biomarkers reflecting the mode of action associated with LAS.

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Differentiation therapy is an attractive approach aiming at reversing malignancy and reactivating endogenous differentiation programs in cancer cells. Olive leaf extract, known for its antioxidant activity, has been demonstrated to induce apoptosis in several cancer cells. However, its differentiation inducing properties and the mechanisms involved are still poorly understood.

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Nitraria retusa is an edible halophyte, used in Tunisia for several traditional medicine purposes. The present study investigated the antiobesity effects of Nitraria retusa ethanol extract (NRE) in 3T3-L1 cells using different doses and in high-fat diet-induced obesity in mice. Male C57B6J/L mice were separately fed a normal diet (ND) or a high-fat diet (HFD) and daily administrated with NRE (50, 100 mg/kg) or one for 2 days with Naringenin (10 mg/kg).

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Heavy metal contamination of soil resulting from treated wastewater irrigation can cause serious concerns resulting from consuming contaminated crops. Therefore, it is crucial to assess hazard related to wastewater reuse. In the present investigation, we suggest the use of biomarker approach as a new tool for risk assessment of wastewater reuse in irrigation as an improvement to the conventional detection of physicochemical accumulation in irrigated sites.

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This study aimed to determinate phenolic contents and antioxidant activities of the halophyte Arthrocnemum indicum shoot extracts. Moreover, the anticancer effect of this plant on human colon cancer cells and the likely underlying mechanisms were also investigated, and the major phenols were identified by LC-ESI-TOF-MS. Results showed that shoot extracts had an antiproliferative effect of about 55% as compared to the control and were characterised by substantial total polyphenol content (19 mg GAE/g DW) and high antioxidant activity (IC50 = 40  μ g/mL for DPPH test).

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Previous results demonstrated that capsaicin induces the reversible tight junctions (TJ) opening via cofilin activation. The present study investigated the mechanisms underlying the reversible TJ opening and compared the effect to the irreversible opening induced by actin inhibitors. Capsaicin treatment induced the F-actin alteration unique to capsaicin compared to actin-interacting agents such as latrunculin A, which opens TJ irreversibly.

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This study aimed to investigate the antistress properties of the ethanol extract of Cymbopogon schoenanthus (CSEE), growing wild in the southern part of Tunisia. The effect of extracts on H2O2-induced cytotoxicity and stress in human neuroblastoma SH-SY5Y cells. Its effect on stress-induced in ICR mice was exposed to force swim and tail suspension, in concordance with heat shock protein expression (HSP27 and HSP90), corticosterone, and catecholamine neurotransmitters level.

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6-Octadecynoic acid (6-ODA), a fatty acid with a triple bond, was identified in the methanol extract of Marrubium vulgare L. as an agonist of peroxisome proliferator-activated receptor γ (PPARγ). Fibrogenesis caused by hepatic stellate cells is inhibited by PPARγ whose ligands are clinically used for the treatment of diabetes.

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Argan (Argania spinosa L.) oil has been used for centuries in Morocco as cosmetic oil to maintain a fair complexion and to cure skin pimples and chicken pox pustules scars. Although it is popular, the scientific basis for its effect on the skin has not yet been established.

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Taking into account that oxidative stress is among the factors causing cancer-related death; chemoprevention which consists in using antioxidant substances such as phenolics could prevent cancer formation and progression. In the present study, phenolic contents and antioxidant activities of methanolic extracts from the halophyte Tamarix gallica shoots were determined. Moreover, the anticancer effect of this species on human colon cancer cells and the likely underlying mechanisms were also investigated.

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Genistein is an isoflavonic phyto-oestrogen contained in soya beans. It is thought to display anti-cancer effects. This study was designed to investigate its effect on human intestinal colon cancer Caco-2 cells.

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We examined the effects of acteoside (1a), which was isolated from Orobanche minor, and its derivatives on the aggregation of a 42-mer amyloid β protein (Aβ42) in our search for anti-amyloidogenic compounds for Alzheimer's disease (AD) therapy. Acteoside (1a) strongly inhibited the aggregation of Aβ42 in a dose-dependent manner. The structure-activity relationship for acteoside (1a) and related compounds suggests the catechol moiety of phenylethanoid glycosides to be essential for this inhibitory activity.

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The effects of caffeoylquinic acid (CQA)-rich purple sweet potato (PSP) extract, with (PSPEa) or without (PSPEb) anthocyanin, on the improvement of spatial learning and memory of senescence-accelerated prone mouse strain (SAMP) 8 was determined. SAMP8 was treated with 20 mg/kg/day of PSPEa or PSPEb for 30 days. The effect on spatial learning and memory and the molecular mechanism of this effect were determined in vivo (SAMP8) and in vitro (SH-SY5Y cells).

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We have previously reported that acteoside inhibits the release of β-hexosaminidase from immunoglobulin E (IgE)-sensitized and bovine serum albumin-stimulated rat basophilic leukemia cells as well as the intracellular calcium level, release of histamine from, and production of tumor necrosis factor-alpha and interleukin-4 in human basophilic (KU812) cells. However, the molecular mechanism underlying the anti-allergic effects of acteoside has not yet been elucidated. Here, we used microarray analysis to determine the global gene expression profile of KU812 cells treated with acteoside and calcium ionophore A23187 plus phorbol-12-myristate 13-acetate (A23187+PMA), and the results were validated by real-time polymerase chain reaction (PCR) and Western blotting.

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