• Journal of Adhesion and Interface
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• v.25 no.1
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• pp.169-274
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• 2024

Recent attention has been drawn to materials that undergo reversible expansion and contraction in response to external stimuli, leading to morphological changes. These materials hold potential applications in various fields including soft robotics, sensors, and artificial muscles. In this study, a novel material capable of responding to high temperatures for protection or encapsulation is proposed. To achieve this, liquid crystal elastomer (LCE) with nematic-isotropic transition properties and polyimide (PI) with high mechanical strength and thermal stability were utilized. To utilize a solution process, a dope solution was synthesized and introduced into micro-printing techniques to develop a two-dimensional pattern of LCE/PI bilayer structures with sub-millimeter widths. The honeycomb-patterned LCE/PI bilayer mesh combined the mechanical strength of PI with the high-temperature contraction behavior of LCE, and selective printing of LCE facilitated deformation in desired directions at high temperatures. Consequently, the functionality of selectively and reversibly encapsulating specific high-temperature materials was achieved. This study suggests potential applications in various actuator fields where functionalities can be implemented across different temperature ranges without the need for electrical energy input, contingent upon molecular changes in LCE.

• The Journal of Korean Medicine
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• v.31 no.4
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• pp.79-100
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• 2010

Objective: Production of ROS from glucose toxicity results in injury of pancreatic $\beta$-cells in diabetes models. This study was undertaken to examine the influence of Lespedeza Cuneata extract (LCE) on cytoprotective effects on glucose toxicity, insulin secretion and gene expression in RIN-m5F cells. Methods: First, we measured LCE's antioxidant activity by DPPH free radical-scavenging activity and SOD activity. After the various concentrations of LCE were added to the RIN-m5F cells, we measured cell viability with glucose stimulation by MTT assay and glucose-stimulated insulin secretion. We analyzed gene expression with Agilent whole mouse genome 44K oligo DNA microarray and searched for related pathways in KEGG (Kyoto Encyclopedia of Genes and Genomes). Lastly we measured INS-1, INS-2, INS-R, IRS-1, IRS-2, IRS-3, GLP-1R, and GLP-2R mRNA expression by real time RT-PCR. Results: Free radical-scavenging activity, SOD activity and insulin secretion increased dependent on LCE concentration, but LCE did not show considerable cytoprotective effect on RIN-m5F cells. More than twice expressed gene was 6362 in Oligo DNA chip. In KEGG, the most related pathway was the metabolic pathway. In the insulin signaling pathway, up expressed genes were Irs1, Mapk8, Akt1, and Lipe and down expressed genes were Rhoq, Fbp2, Prkar2b, Gck, and Prkag1. In real time RT-PCR, IRS-2, and IRS-3 expression increased significantly compared to the control group on LCE $12{\mu}g/m{\ell}$ concentration and GCK expression decreased significantly compared to the control group. Conclusions: These results show that LCE encourages insulin secretion and insulin metabolism by complicated gene mechanisms. Further mechanism study and clinical study seem to be necessary about Lespedeza Cuneata.

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.05a
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• pp.161-161
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• 2001

• Elastomers and Composites
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• v.57 no.2
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• pp.55-61
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• 2022

In this work, we report a highly deformable covalent adaptable-liquid crystal elastomer (CA-LCE) comprising dynamic thiourea bonds that enable macromolecular network rearrangement at elevated temperatures. The exchange of chain network is verified through stress-relaxation analyses and follows Arrhenius-type behavior. The unique capability of rearranging the chain network in the CA-LCE provides useful properties, such as welding, melt reprocessing, and shape reprogramming, that cannot be achieved by the conventional LCE comprising permanent crosslinks. Reversible actuation is further demonstrated by reprogramming the polydomain CA-LCE into a monodomain via mechanical stretching at elevated temperatures.

• The Korea Journal of Herbology
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• v.28 no.4
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• pp.83-92
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• 2013

Objectives : Lespedeza Cuneata has been used to treat leukorrhea, asthma, stomach pain, diarrhea, acute mastitis, in Korean traditional medicine. According to recent studies, Lespedeza Cuneata has antioxidation, hypoglycemia, cell protective, insulin secretion, whitening, corpora cavernosa smooth muscle relaxation and antimicrobial activities, but it has been rarely conducted to evaluate the immuno-biological activity. The present study was examined to evaluate the anti-inflammatory effects of the Lespedeza Cuneata MeOH extract (LCE) in vivo and in vitro. Methods : In vitro, inflammatory mediators, such as cytokines, nitric oxide and prostaglandin $E_2$ were detected after the addition of LPS with or without LCE in Raw 264.7 macrophage cell line. In vivo, anti-edema effect of LCE was determined in the carrageenan-induced paw edema model in rats. Results : In vitro assay, LCE decreased release of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) via suppression of iNOS and COX-2 expression. LCE inhibited the phosphorylation of $I{\kappa}B$ indicating the suppression of NF-${\kappa}B$ pathway. In vivo assay, LCE significantly inhibited the formation of paw edema induced by carrageenan injection in rats. LCE effectively inhibited increases of hind paw skin thickness and inflammatory cell infilterations. Conclusion : These findings demonstrate that LCE has inhibitory effect on inflammatory mediators in LPS-activated Raw 264.7 cells and on paw edema in carrageenan-stimulated rats, showing the possibility of anti-inflammatory use of Lespedeza Cuneata.

• The Korea Journal of Herbology
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• v.30 no.6
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• pp.63-68
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• 2015

Objectives : Gastric lesions affect many people around the world and their development are results of the imbalance between destructive and protective factors in the gastric mucosa. Lycium chinense has been widely used as a traditional Korean medicine, it was recently reported that they have potent anti-inflammatory effects in chronic hepatitis models. Therefore, this study aimed to investigate the anti-inflammatory activity of Lycium chinense extract (LCE) on HCl-Ethanol induced gastric lesion mice.Methods : The ICR mice were divided randomly into five groups of six animals each. Group A was normal mice, and group B was treated orally with 0.5 ml 150 mM HCl-60% Ethanol. Mice in group C and D were pre-treatment of LCE (100 mg/kg and 200 mg/kg bodyweight, p.o before HCl/ethanol treatment) and group E was orally administered sucralfate (10 mg/kg).Results : 150mM HCl/60% ethanol-induced gastric mucosal injury mice were ameliorated mucosal damage upon histological evaluation by treatment of LCE. Pre-treatment of LCE attenuated reactive oxidative species (ROS) and produces peroxynitrite (ONOO^-) in stomach tissues. As results of stomach protein analyses, LCE effectively reduce inflammatory-related factors such as cyclooxygenase-2 (COX-2), tumor necrosis factor alpha (TNF-α), inducible nitric oxide synthase (iNOS) and interleukin-6 (IL-6) in gastric lesion mice. In addition, nuclear factor kappa B (NF-κB) and inhibitor of phosphorylation of nuclear factor kappa B (p-IκB) were down-regulated in LCE-administrated gastric lesion mice.Conclusions : Our discovery supports that the therapeutic activity of LCE ameliorate the development of gastric lesion via suppressing the oxidative stress and gastric partial inflammation induced by 150 mM HCl/60% ethanol.

• Proceedings of the KAIS Fall Conference
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• 2004.06a
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• pp.335-338
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• 2004

Life-Cycle Engineering(LCE) is a decision-making methodology that considers environmental and cost needs during the product life-cycle. Environmental conscious design and manufacturing has become more and more important and it has been enforced by governmental regulations and used as trade restriction. LCE involves integrating environmental consideration into new product development including design, material selection, manufacturing processes and distribution of the product to the consumers, plus the end-of-life management such as disassembly, material recovery, remanufacturing of the product after discarding it. In this paper, a state-of-the-art survey of LCE is presented.

• Physical Therapy Korea
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• v.27 no.4
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• pp.272-277
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• 2020

Background: Forward head posture (FHP) is common postural malalignment. FHP is described relatively extension to upper cervical and lower cervical is relatively flexion. Although several researchers mentioned the lower cervical flexion posture in FHP, most of the studies related to FHP is focused on the deep cervical flexor function. Objects: The purposes of present study is to compare the cervical strength (upper cervical extension [UCE], lower cervical extension [LCE], upper cervical flexion [UCF], lower cervical flexion [LCF]) between individuals with and without FHP. Methods: Fifty-one participants are recruited. Participants who have the craniovertebral angle (CVA) less than 48 degree were classified to the FHP group (n = 24) and the others were included in without FHP group (n = 27). The cervical strength (UCE, LCE, UCF, LCF) were measured using Smart KEMA strength sensor and the strength data was normalized by body weight. All strength measurement conducted at head and neck neutral position in sitting. Independent t-test was used to compare the cervical strength between individuals with and without FHP. Results: The mean value of CVA was greater in without FHP group than with FHP group (p < 0.000). The strength value of UCF (p < 0.002) and LCE (p < 0.001) was significant less in FHP group than without FHP group. But no significant differences were seen in the LCF and UCE strength between two groups. Conclusion: UCF and LCE weakness in FHP group should be considered to evaluate and manage the individuals with FHP.

• Toxicological Research
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• v.30 no.1
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• pp.19-25
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• 2014

Licochalcone (LC), a major phenolic retrochalcone from licorice, has anti-inflammatory activity. This study investigated the effects of licochalcone A (LCA) and licochalcone E (LCE) on Liver X receptor-${\alpha}$ ($LXR{\alpha}$)-mediated lipogenic gene expression and the molecular mechanisms underlying those effects. LCA and LCE antagonized the ability of $LXR{\alpha}$ agonists (T0901317 or GW3965) to increase sterol regulatory element binding protein-1c (SREBP-1c) expression and thereby inhibited target gene expression (e.g., FAS and ACC) in HepG2 cells. Moreover, treatment with LCA and LCE impaired $LXR{\alpha}/RXR{\alpha}$-induced CYP7A1-LXRE-luciferase (CYP7A1) transactivation. The AMPK-Sirt1 signaling pathway is an important regulator of energy metabolism and, therefore, a potential therapeutic target for metabolic diseases, including hepatic steatosis. We found here that LCE increased AMPK phosphorylation and Sirt1 expression. We conclude that LC inhibits SREBP-1c-mediated hepatic lipogenesis via activation of the AMPK/Sirt1 signaling pathway.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.733-738
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• 2012

Physiochemical characteristics of Luffa cylindrica (L.) Roem and antioxidant activities of its four extracts were analyzed. The chemical composition of L. Roem contained 93.69% moisture, 1.64% crude fiber, 0.52% crude protein, 0.27% crude fat, and 0.06% crude ash. The major minerals were potassium, phosphrous, and calcium. We also analyzed the major organic acids, acetic acid and succinic acid. In free amino acids, ${\beta}$-aminoisobutyric acid showed the highest concentration (100.74 mg/100 g), followed by phosphoethanolamine, urea, asparagine, and valine. Glutamic acid was the highest hydrolyzed amino acid with 1,039.99 mg/100 g followed by aspartic acid, lysine, and arginine. Four extracts from L. Roam, hot-water (LCH), cold-water (LCC), 80% ethanol (LCE), and methanol (LCM), were prepared. Total phenolic and flavonoid levels of LCE exhibited higher than three extracts. The antioxidant potential of extracts from L. Roem were investigated using DPPH, ABTS, and NBT assays. Of the four extracts, LCE had relatively high antioxidant capability on DPPH and superoxide anion radical scavenging activities (12.13%, 16.88%, and 26.61%). Based on the above results, it is suggested that an 80% ethanolic extract from L. Roem was a natural antioxidant material for health food and should be a good ingredient for functional food.