• Elastomers and Composites
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• v.27 no.3
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• pp.174-182
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• 1992

Main components of manufactured sealant were vinylester resin, polybutadiene rubber, asphalt and inorganic filler. For manufactured sealant, liquid and cure properties were tested experimantally. It showed better mechanical properties at rubber content $5{\sim}15phr$. Blown asphalt represented better properties than streight asphalt, showed the highest cohesive strength at asphalt content $6{\sim}8phr$. Appropriate usage of filler was $60{\pm}2%$ of total components, and $Al(OH)_3$ showed better flame-retardancy than $CaCO_3$.

• The Journal of the Korean life insurance medical association
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• v.2 no.1
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• pp.182-194
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• 1985

Cholelithiasis, one of the digestive, disease is one of the subject to have to be solved in the medical field because it is very important health problem in clinic and gives people much pain. The formulative process of gall stone is not certainly known yet, but an approach to the size, location, bile sludge of gall ston and the existence of pus is very contributive to the cure and prediction of the disease. As above, the early diagnosis of gall stone is very important. A few study on the possessing rate of gall stone in normal Korean Group is reported. But no report has submitted to the Korean Life Insurance Medical Association until now. We, the Medical Dept. of Dae Han Kyouk Life Insurance Co. Ltd., practiced ultrasonic examination for the recent 17 months and obtained 84 data of gall stone potency out of 4201 examples. We analyzed them on the basis of sex, age, gall stone incidence rate and the results are as follows; 1) The possessing rate of gall stone in female showed 1.22 times higher than in in male. 2) The older the medical examined group grow, the more the frequency of gall stone incidence increase regardless of sex. 3) Our report coincides with foreign one in sex and age, but in total gall stone incident frequency our country has 2%, which is much less than foreign one.

• Corrosion Science and Technology
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• v.2 no.4
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• pp.202-206
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• 2003

Fusion Bonded Epoxy(FBE) systems have been widely used to protect pipelines for over 30 years. Numerous attempts have so far been made to improve the properties of FBE coatings such as chemical resistance, adhesion, water resistance, cathodic disbondment resistance, impact resistance, and flexibility to protect pipelines at a wet and a high temperature condition. But these attempts have not been successful in reducing some weakness, for instance, in pipeline operating at high temperature due to poor hot water resistance and cathodic protection. The purpose here is to build a basis for getting better corrosion resistance of FBE systems. Cresol-novolac epoxy coating systems were studied compared to bisphenol A type epoxy systems. After the immersion of the film in water at a high temperature for a long period, good adhesion to metal substrate and excellent cathodic disbond resistance were observed in the cresol-novolac epoxy resin systems. It is well known that the adhesion of organic coatings to metal substrate might be decreased due to the disruption of a chemical bond across the film and metal interface induced by water molecules. A high crosslinking density might decrease water permeability and improve cathodic disbonding protection in the coatings. Other factors are studied to understand anti-corrosion mechanism of Cresol-novolac epoxy coatings. In addition, the water absorption rate and the effect of cure temperature on the adhesion and cathodic disbonding resistance ofthe films were studied in different epoxy coatings and the effect of substrate was evaluated. The results of field application are proved that the Cresol-novolac epoxy coating system developed recently is one of the most suitable coatings for protection of pipelines.

• Elastomers and Composites
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• v.45 no.3
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• pp.223-229
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• 2010

We investigated the effects of processing geometry of silica-filled isobutylene-isoprene rubber (IIR) compounds on its mechanical properties and silica dispersion, using a two roll mill and an internal mixer (banbury mixer). The compound processed with the two roll mill showed the longer induction time ($t_2$), higher maximum torque ($T_{max}$), and better silica dispersion than the compound processed with the internal mixer; however, showed slightly the lower cure index ($t_{90}$). The mechanical properties (hardness, 300% modulus, tensile strength, elongation) of the compound processed with two roll mill were higher than compound done with the internal mixer.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.2
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• pp.67-79
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• 2022

Currently, there is no treatment to reverse or cure heart failure caused by ischemic heart disease and myocardial infarction despite the remarkable advances in modern medicine. In addition, there is a lack of evidence regarding the existence of stem cells involved in the proliferation and regeneration of cardiomyocytes in adult hearts. As an alternative solution to overcome this problem, protocols for differentiating human pluripotent stem cell (hPSC) into cardiomyocyte have been established, which further led to the development of cell therapy in major leading countries in this field. Recently, clinical studies have confirmed the safety of hPSC-derived cardiac progenitor cells (CPCs). Although several institutions have shown progress in their research on cell therapy using hPSC-derived cardiomyocytes, the functions of cardiomyocytes used for transplantation remain to be those of immature cardiomyocytes, which poses a risk of graft-induced arrhythmias in the early stage of transplantation. Over the last decade, research aimed at achieving maturation of immature cardiomyocytes, showing same characteristics as those of mature cardiomyocytes, has been actively conducted using various approaches at leading research institutes worldwide. However, challenges remain in technological development for effective generation of mature cardiomyocytes with the same properties as those present in the adult hearts. Therefore, in this review, we provide an overview of the technological development status for maturation methods of hPSC-derived cardiomyocytes and present a direction for future development of maturation techniques.

• Korean Journal of Pharmacognosy
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• v.30 no.4
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• pp.368-376
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• 1999

Twenty-four Oriental herbal medicines including Platycodi Radix and Scutellariae Radix, etc., which have been used for the cure of hyperlipidemia, coronary heart, disease were evaluated for the 3-hydroxy-3-methylglutaryl coenzyme A(HMG-CoA) reductase inhibition and antioxidant effect on a free radical, 1,1-diphenyl-2-picrylhydrazyl(DPPH) in vitro, and antihyperlipidemic effect on hyperlipidemic rats induced by Triton WR-1339 in vivo. 80% MeOH extract of eight herbs including Scutellariae Radix, Coptidis Rhizoma, Paeoniae Radix Rubra, Moutan Cortex Radicis, Angelicae Gigantis Radix, Bambusae Caulis in Taeniam, Cinnamomi Ramulus and Crataegi Fructus inhibited the HMG-CoA reductase activities and exhibited a radical-trapping action on a stable free radical, DPPH. On Triton WR-1339-induced hyperlipidemic rats, four herbs including Scutellariae Radix, Angelicae Gigantis Radix, Bambusae Caulis in Taeniam and Cinnamomi Ramulus showed respectively the significant suppression of serum total cholesterol, triglyceride, phospholipid and LDL-cholesterol levels and serum transaminase(ALT and AST) activities. From these results, it is suggested that each 80% MeOH extract of Scutellariae Radix, Angelicae Gigantis Radix, Bambusae Caulis in Taeniam and Cinnamomi Ramulus have effective antihyperlipidemic action against hyperlipidemia.

• Polymer(Korea)
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• v.39 no.2
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• pp.240-246
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• 2015

Formation of a strong 3-dimensional interfacial network structure via chemical reaction between hydroxyl group on silica surface and NR chain by the addition of bis(triethoxysilylpropyl)tetrasulfide (TESPT) into silica-filled NR compound was observed by using Py-GC/MS and SEM. Addition of TESPT into silica-filled NR compound decreased scorch time ($t_{10}$) due to increased sulfur content, and reduced cure rate index (CRI) via continuous reaction between sulfur atoms in TESPT, which acted as a sulfur donor, and activators and/or accelerators. Addition of TESPT in the compound improved processability and mechanical properties of the compound. Overall, we observed that the addition of TESPT into the silica-filled NR compound formed a silica-TESPT-NR network, and thus the degree of crosslinking was increased resulting in improved mechanical properties.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.1
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• pp.1-7
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• 2015

Cornus walteri Wanger has been used in folk medicine in Korea. Ultraviolet (UV) irradiation has been known as a major cause of photo damage in skin. In the present study, research on how to cure damaged cells by UVB was conducted using an extract of Cornus walteri Wanger leaves (CWE), which was treated with an enzyme. CWE was applied to human dermal fibroblasts (HDFs) affected by UVB. UVB-irradiated HS68 cells showed increased caspase-3 activity, phosphorylation of p53, ${\gamma}H2AX$, cyclobutane pyrimidine dimers (CPDs) formation, and DNA fragmentation compared with non-irradiated cells. However, all these effects were inhibited by treatment with CWE for 12 h after UVB irradiation. Furthermore, CWE has proved not to cause primary skin irritation through the human patch test. Collectively, these results suggest that CWE could be a new potential candidate as photoprotective agent against UVB-induced cellular damage in HDFs.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.557-563
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• 2017

Gastrodia elata (Orchidaceae) is a perennial parasitic plant that has a unique lifestyle of being in a symbiotic interaction with fungi. The underground root of Gastrodia is used for medicinal treatment to cure high blood pressure, stroke, leukemia, headaches, and especially neurasthenia. This study is intended to investigate the effect of the global warming on the ecological responses of Gastrodia. We cultivated the small tuber of Gastrodia with the oak wood lot and mulberry fungus under control (ambient $CO_2$ concentration + ambient temperature, ACAT), temperature treatment (ambient $CO_2$ concentration+elevated temperature, ACET), and $CO_2$+temperature treatment (elevated $CO_2$ concentration+elevated temperature, ECET). The elevated $CO_2$ concentration was about twice in the ambient air while the elevated temperature was about $2^{\circ}C$ higher than the control group. And then we observed the growth and production of reproductive organs and the underground root. The observation showed that the number of flower stalk was highest at ACET and lowest at ECET. The flower stalk was longest at ACET and shortest at ECET. The inflorescence was longest at ACAT and shortest at ECET. The seed capsule was heaviest at ACET and lightest at ECET. The aboveground biomass was highest at ACET and lowest at ECET. The number of rhizomes was highest at ACET and lowest at ECET. The total rhizome biomass was highest at ACET and lowest at ECET. The average rhizome biomass was highest at ACET and lowest at ECET. The results showed that the growth of Gastrodia increased because of more active growth of Gastrodia elata when only the temperature increased and decreased when both $CO_2$ concentration and temperature increased, indicating the poor growth of Gastrodia elata under the global warming condition. Therefore, the Gastrodia elata plantation should be maintained at the temperature of $20-25^{\circ}C$ and not be exposed to a high $CO_2$ concentration.

• BMB Reports
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• v.45 no.3
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• pp.133-140
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• 2012

Cancers claim millions of lives each year. Early detection that can enable a higher chance of cure is of paramount importance to cancer patients. However, diagnostic tools for many forms of tumors have been lacking. Over the last few years, studies of chimeric RNAs as biomarkers have emerged. Numerous reports using bioinformatics and screening methodologies have described more than 30,000 expressed sequence tags (EST) or cDNA sequences as putative chimeric RNAs. While cancer cells have been well known to contain fusion genes derived from chromosomal translocations, rearrangements or deletions, recent studies suggest that trans-splicing in cells may be another source of chimeric RNA production. Unlike cis-splicing, trans-splicing takes place between two pre-mRNA molecules, which are in most cases derived from two different genes, generating a chimeric non-co-linear RNA. It is possible that trans-splicing occurs in normal cells at high frequencies but the resulting chimeric RNAs exist only at low levels. However the levels of certain RNA chimeras may be elevated in cancers, leading to the formation of fusion genes. In light of the fact that chimeric RNAs have been shown to be overrepresented in various tumors, studies of the mechanisms that produce chimeric RNAs and identification of signature RNA chimeras as biomarkers present an opportunity for the development of diagnoses for early tumor detection.