• Journal of the Korean Chemical Society
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• v.20 no.3
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• pp.221-228
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• 1976

The kinetics of hydrolysis of hydrazonyl bromides $(p-H,\;p-CH_3,\;p-OCH_3,\;p-Br,\;p-Cl\;&\;p-NO_2)$ have been investigated by UV spectrometry in $60{\%}$ dioxane-water at $25^{\circ}C$ and a rate equation which can be applied over wide pH range was obtained. Below pH2, the rate of hydrolysis of a series of hydrazonyl bromide is accelerated by electrondonating group (${\rho}$ = -0. 94) whereas at the pH values greater than 4, the ${\rho}$-value is 0.54. The rate equation, solvent-, substituent-and bromide ion-effect on the rate of hydrolysis are rationalized in terms of $S_N1$ and $S_N2$ mechanism: below pH 2, the hydrolysis proceed through $S_N2$, however, above pH 4, the hydrolysis is started by the attack of hydroxide ion and in the range pH 2{\sim}$4, these two reactions occur competitively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.1
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• pp.71-76
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• 2022

In this study, we investigated the antioxidant activity, wound healing, moisturizing and anti-pollution effects of fermented Citrus junos (FCJ) with Lactobacillus rhamnosus as a cosmetic material. For the anti-oxidative activities, the FCJ showed potent DPPH radical scavenging activities. In addition, FCJ increased cell migration compared to the untreated group in scratch-induced wound healing assay. It was confirmed that the amount of filagrin (FLG), a moisturizing factor, increased in FCJ. FCJ prevented the decrease in cell viability, stimulated by PM₁₀ at in vitro. Based on these results, it is believed that various effects of FCJ can provide a scientific basis for the development of cosmetic raw materials.

• Journal of Practical Agriculture & Fisheries Research
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• v.11 no.1
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• pp.125-135
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• 2009

Shading with silver-coated strips in combination with water spraying over the roof was more effective than others in lowering air-temperatures while the soil temperatures were more efficiently lowered by the silver-coated PE film in combination with water-flowing treatment on the soil surface. Significantly better growth and higher yield of spinach were recorded in the plots having lower soil termperatures. Whitewash spray with lime mixture resulted in higher yield of spinach as compared to the white water-soluble painting, possibly because of the better light penetration toward the end of the growing season by the natural weather off phenomenon.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.466-472
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• 2019

This study was conducted to investigate anti-photoaging effects of collagen hydrolysate containing collagen tripeptides (CTP) in both HaCaT cells and SKH-1 hairless mice. CTP treatment was nontoxic to HaCaT cells and improved expression of biomarkers associated with aging of skin, such as, collagen 1A, metalloproteinase (MMP)-1, and MMP-13 after subjecting mice to ultraviolet B (UVB) irradiation. In animal studies, the depth and width of wrinkles in the skin of mice were determined upon subjecting them to UVB irradiation. However, positive effects on wrinkles on the skin of mice were seen following CTP supplementation. Collagen content and density of mouse skin were restored following CTP supplementation for 14 weeks after UVB irradiation. These results were based on the effects of CTP on protein levels of collagen 1A, MMP-1, and MMP-13. Therefore, CTP might have positive effects on the number, depth, and width of wrinkles caused by UVB irradiation in SKH-1 hairless mice.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.391-398
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• 2004

Far-ultraviolet Imaging Spectrograph (FIMS) is the main payload of the Korea's first scientific micro satellite STSAT-1, which was launched at Sep. 27 2003 successfully. Major objective of FIMS is observing hot gas in the Galaxy in FUV bands to diagnose the energy flow models of the interstellar medium. Supernova remnants, molecular clouds, and Aurora emission in the geomagnetic pole regions are specific targets for pointing observation. Although the whole system was calibrated before launch, it is essential to perform on-orbit calibration for data analysis. For spectral calibration, we observed airglow lines in the atmosphere since they provide good spectral references. We identify and compare the observed airglow lines with model calculations, and correct the spectral distortion appeared in the detector system to improve the spectral resolution of the system.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.247-251
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• 2004

UV radiation exerts various influences in the skin, including photoaging and inflammation (1). The MMPs (Matrix metalloproteinases), which are induced by UV irradiation, can degrade matrix proteins, and these results in a collagen deficiency in photodamaged skin that leads to skin wrinkling. It has been known that the production of PGE$_2$ stimulates MMPs expression, and inhibits procollagen (2). Thus, it is possible that the induction of MMPs and the inhibition of matrix protein synthesis by UV -induced PGE$_2$ may play some role in UV-induced collagen deficiency in photoaged skin. Fructose-1,6-diphosphate (FDP), a glycolytic metabolite, is reported to have cytoprotective effects against ischemia and postischemic reperfusion injury of brain and heart, presumably by augmenting anaerobic carbohydrate metabolism (3). And also, FDP significantly prevent skin aging by decreasing facial winkle compared with vehicle alone after 6 months of use. We studied the mechanism of anti-aging effect of FDP on UVB-irradiated HaCaT keratinocyte model. FDP has protective role in UVB injured keratinocyte by attenuating prostaglandin E$_2$ (PGE$_2$) production and COX-2 expression. And FDP also suppressed UVB-induced MMP-2 expression. Further, to delineate the inhibition of UVB-induced COX-2 and MMPs expression with cell signaling pathways, treatment of FDP to HaCaT keratinocytes resulted in marked inhibition of UVB-induced phosphorylation of ERK1/2, JNK. It also prevents UV induced NFB translocation, which are activated by cellular inflammatory signal. Our results indicate that FDP has protecting effects in UV-injured skin aging by decreasing UVB-induced COX-2 and MMPs expression, which are possibly through blocking UVB-induced signal cascades.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.441-445
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• 2009

Recent research has revealed that hydrolyzed collagen peptides have beneficial effects in various diseases such as osteoarthritis and human rheumatoid arthritis and also play a protective role in skin by improving the activity of antioxidants. In this study, we investigated the effects of a novel mixture (AP-CPM01) containing collagen peptides and elastin peptides on photoaged hairless mice skin both in vivo and in vitro. To evaluate the effects of AP-CPM01 on UVBinduced skin wrinkle formation in vivo, the hairless mice were exposed to UVB irradiation and orally administered the AP-CPM01 at 333 mg/kg per day for 10 weeks. The effects on skin appearance and epidermal thickness were measured using bioengineering and histochemical methods. In addition, the influence of AP-CPM01 on collagen metabolism in human skin fibroblasts was also investigated. The skin of mice in the AP-CPM01 treated group had better appearance and less wrinkling than that of mice in the control group. In the human fibroblast cells, the amount of de novo procollagen synthesis was increased after AP-CPM01 treatment, reflecting that AP-CPM01 can induce de novo procollagen synthesis and reduce UVB-induced skin wrinkle formation. These results suggest that AP-CPM01 is a potent candidate for antiphotoaging functions.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.358-366
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• 2011

A homologous series of linear liquid crystal dimers, the ${\alpha},{\omega}$-bis(4-cyano-azobenzene-4'-oxy)alkanes (CATWETn, where n, the number of methylene units in the spacer, is 2~10) were synthesized, and their thermotropic liquid crystalline phase behavior were investigated. The CATWETn with n of 3 and 6 exhibited monotropic nematic phases, whereas other derivatives showed enantiotropic nematic phases. The nematic-isotropic transition temperatures of the dimers and their entropy variation at the phase transition showed a large odd-even effect as a function of n. This phase transition behavior was rationalized in terms of the change in the average shape of the spacer on varying the parity of the spacer. The thermal stability and degree of order in the nematic phase and the magnitude of the odd-even effect of CATWETn were similar to those for the methoxy-, nitro-, and pentyl-substituted dimers, while they were significantly different from those for the monomesogenic compounds, 1-{4-(4'-cyanophenylazo)phenoxy}alkylbromides and the side-chain liquid-crystalline polymers, the poly[1-{4-(4'-cyanophenylazo)phenoxyalkyloxy}ethylene]s. The results were discussed in terms of 'virtual trimer model' by Imrie.

• Journal of Life Science
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• v.33 no.4
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• pp.305-314
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• 2023

Ultraviolet B (UVB) irradiation causes skin diseases by inducing cellular oxidative stress, photoaging, and inflammation. This study aimed to investigate the protective effects of morin against UVB-induced oxidative stress in normal human dermal fibroblasts (NHDFs). Morin has been reported to be a potential therapeutic candidate for oxidative stress-mediated diseases, neurodegenerative diseases, and inflammation. Since morin has been identified as a potential antioxidant, we speculated that morin could alleviate UVB-induced apoptosis in NHDFs. Cell viability and intracellular reactive oxygen species (ROS) levels were measured using the MTT assay, H2DCFDA, and the DHE staining method, respectively. Lipid peroxidation and protein carbonyl formation were tested using ELISA kits. DNA fragmentation and comet assay were used to assess DNA damage. Apoptotic bodies were analyzed using Hoechst 33342 staining and TUNEL assay. The expression of apoptosis-related proteins was examined using Western blot analysis. Morin showed a cyto-protective effect by scavenging UVB-induced ROS, increasing the expression of antioxidant-related proteins and inhibiting UVB-induced oxidative alterations such as lipid peroxidation, protein carbonylation, and DNA damage. Morin protects against UVB-induced cell apoptosis by inhibiting Bcl-2-associated X protein, caspase-9, and caspase-3 expression, while increasing the expression of the anti-apoptotic protein Bcl-2. These effects of morin were conferred through decreased phosphorylation of p38 and c-Jun N-terminal kinase 1/2. The results demonstrated that morin may be developed as a preventive/therapeutic drug to be used to prevent UVB-induced skin damage.

• The Korean Journal of Zoology
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• v.30 no.1
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• pp.89-98
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• 1987

The research of fused oocytes was conducted to investigate the in vitro mejotic maturation of immature oocytes (GV oocytes) fused with oocytes in germinal vesicle breakdown (GVBD oocytes) in the presence of dbcAMP which is known as one of the strong inhibitors to GVBD. The immature oocytes fused together as well as those fused with GVBD oocytes proceeded to GVBD in 3 hr culture in plain medium. But in the medium containing dbcAMP (100$\mu$g/ml), the immature oocytes fused together did not show any GVBD and thus the fusion itself could not affect the inhibitory activity of dbcAMP. However, all of the immature oocytes fused with GVBD oocytes underwent GVBD in 3 hr culture despite of the presence of dbcAMP. When the culture was extended to 20 hr, nearly all of the immature oocytes fused together were still arrested at the GV stage in the presence of dbcAMP. But most of the fused oocytes which had shown GVBD during 3 hr culture developed to metaphase II stage extruding one or two polar bodies regardless of the presence of dbcAMP. In this experiment, it was found that two sets of the metaphase chromosomes were somewhat concomitant with a pair of the polar bodies in the fused egg. Upon the results of the present studies, it is assumed that there may be a maturation promoting factor(s) in the cytoplasm of the GVBD occytes, and this factor(s) possibly nullifies the function of dbcAMP.