• Title/Summary/Keyword: degradation agent

Search Result 342, Processing Time 0.026 seconds

Development of Anti-Melanogenic Agent for Skin Whitening

  • Ahn, Soo-Mi
    • Proceedings of the Korean Society of Applied Pharmacology
    • /
    • 2007.11a
    • /
    • pp.129-139
    • /
    • 2007
  • Many modalities of treatment for acquired skin hyperpigmentation are available including chemical agents or physical therapies, but none are completely satisfactory. The ideal depigmenting compound should have a potent. rapid and selective bleaching effect on hyperactivated melanocytes, carry no short- or long-term side-effects and lead to a permanent removal of undesired pigment. acting at one or more steps of the pigmentation process. Depigmentation can be achieved by regulating (i) the transcription and activity of tyrosinase, tyrosinase related protein-1 (TRP-1), tyrosinase related protein-2 (TRP-2), and/or peroxidase; (ii) the uptake and distribution of melanosomes in recipient keratinocytes and (iii) melanin and melanosome degradation and turnover of pigmented keratinocytes. One of the interesting point for development of skin whitening agent is Mitf(Microphthalmia-associated transcription factor). Mitf belongs to the basic helix-loop-helix-zip family of trabscription factors and it is crucial as it regulates both melanocyte proliferation as well as melanogenesis and is the major regulator of tyrosinase and the related enzymes (TRPs), as well as many melanosome structural proteins such as pMel17. Recently, we developed MITF-down-regulating agents from natural and synthetic sources, which have anti-melanogenic effect on in vitro and in vivo. We suggested that potent MITF-down regulating agents might be used for skin whitening cosmeceuticals.

  • PDF

Characteristics of odorous VOCs removal by using electrolytic oxidant (전해 산화제에 의한 악취 원인 VOCs 제거 특성)

  • Lee, Tae Ho;Ryu, Hee Wook
    • Journal of odor and indoor environment
    • /
    • v.17 no.4
    • /
    • pp.381-388
    • /
    • 2018
  • In this study, various conditions and phenomena that occur in the process of removing odorous VOCs by using electrolyzed oxidant were examined. The formation of hypochlorous acid, which is an oxidant produced by electrolysis, was investigated and the properties of the oxidizing agent used to decompose toluene, xylene, and cyclohexane were investigated. As a result, it was found that the production rate and the final concentration of the oxidizing agent increased with the current density. It was found that the degree of removal varies depending on the property of each pollutant. Interestingly, in the batch experiments in which the pH of the produced oxidant was controlled, it was found that the degree of elimination varied depending on the pH of the substance. These results suggest that the difference in the concentration and distribution of hypochlorous acid (HOCl) and hypochlorite ($OCl^-$) due to the pH change leads to the difference in oxidizing power on the oxidation characteristics of each substance. Styrene and terpineol showed better degradation characteristics than toluene and xylene in odorous VOC removal experiments by spraying electrolytic oxidant using a lab-scale continuous reactor. In conclusion, the removal of odorous VOCs by the electrolytic oxidant can have various applications in that it can oxidize pollutants of various spectra.

Degradation effect of carbendazim in soil by application with the microbial agent, Rhodococcus sp. 3-2 (미생물제(Rhodococcus sp. 3-2) 처리에 따른 토양 중 카벤다짐의 분해효과)

  • Yeon, Jehyeong;Kim, Hyeon-su;Ahn, Jae-Hyung;Han, Gui Hwan;Oh, Young Goun;Cho, Il Kyu;Park, In-Cheol
    • Korean Journal of Environmental Agriculture
    • /
    • v.40 no.4
    • /
    • pp.322-329
    • /
    • 2021
  • BACKGROUND: The fungicide of benomyl, a benzimidazole group, has been commonly used for pesticides against fungal diseases in the world. However, benomyl is rapidly hydrolyzed in the environment after using to control plant diseases and has adverse effects by generating carbendazim, which is toxic to plants, humans, and the environment. METHODS AND RESULTS: In this study, the decomposition effect of carbendazim, a degradation product of benomyl was conducted in pot and field after making a prototype of benomyl-degrading microbial agent (BDMA). We found that the carbendazim-degrading microbial agent (CDMA) (105, 106, and 107 cfu/g soil) decomposed carbendazim by 50% or more in all the treatments, compared to the untreated control in the pot tests after four weeks. The effect of 100% decomposition of carbendazim was observed at 7 days after treatment, when the prototype of BDMA was apllied at 10-folds dilution in the field. The decomposition effect at more than 60% and plant growth promoting effect were observed after 7 days of the treatment, compared with the untreated group in the second field experiment,treated with commercially available concentrations of 500-folds and 1,000-folds. CONCLUSION(S): These results might represent that the BDMA would decompose carbendazim effectively, a decomposition product of the fungicide benomyl, remaining in agricultural area, and it could be utilized practically by using a low dilution rate.

Antimicrobial Peptide, Lumbricusin, Ameliorates Motor Dysfunction and Dopaminergic Neurodegeneration in a Mouse Model of Parkinson's Disease

  • Kim, Dae Hong;Lee, Ik Hwan;Nam, Seung Taek;Hong, Ji;Zhang, Peng;Lu, Li Fang;Hwang, Jae Sam;Park, Ki Cheol;Kim, Ho
    • Journal of Microbiology and Biotechnology
    • /
    • v.25 no.10
    • /
    • pp.1640-1647
    • /
    • 2015
  • We recently reported that the antimicrobial peptide Lumbricusin (NH2-RNRRWCIDQQA), isolated from the earthworm, increases cell proliferation in neuroblastoma SH-SY5Y cells. Here, we investigated whether Lumbricusin has neurotropic activity in mouse neural stem cells (MNSCs) and a protective effect in a mouse model of Parkinson's disease (PD). In MNSCs isolated from mouse brains, Lumbricusin treatment significantly increased cell proliferation (up to 12%) and reduced the protein expression of p27Kip1 through proteasomal protein degradation but not transcriptional regulation. Lumbricusin inhibited the 6-OHDA-induced apoptosis of MNSCs, and also showed neuroprotective effects in a mouse PD model, ameliorating the motor impairments seen in the pole, elevated body swing, and rotation tests. These results suggest that the Lumbricusin-induced promotion of neural cell proliferation via p27Kip1 degradation has a protective effect in an experimental PD model. Thus, the antimicrobial peptide Lumbricusin could possibly be developed as a potential therapeutic agent for the treatment of PD.

Oxidative Degradation of Phenol Using Zero-Valent Iron-Based Fenton-Like Systems (영가철 기반 펜톤 시스템을 활용한 페놀의 산화분해)

  • Kim, Hak-Hyeon;Lee, Hye-Jin;Kim, Hyung-Eun;Lee, Hongshin;Lee, Byeong-Dae;Lee, Changha
    • Journal of Soil and Groundwater Environment
    • /
    • v.18 no.4
    • /
    • pp.50-57
    • /
    • 2013
  • For the last couple of decades, the Fenton (-like) systems have been extensively studied for oxidation of organic contaminants in water. Recently, zero-valent iron (ZVI) has received attention as a Fenton catalyst as well as a reducing agent capable of producing reactive oxidants from oxygen. In this study, the ZVI-based Fenton reaction was assessed for the oxidative degradation of phenol using $ZVI/O_2$, $ZVI/H_2O_2$, ZVI/Oxalate/$O_2$ and hv/ZVI/Oxalate/$O_2$ systems. Reaction parameters such as pH and reagent dose (e.g., ZVI, $H_2O_2$, and oxalate) were examined. In the presence of oxalate (ZVI/Oxalate/$O_2$ and hv/ZVI/Oxalate/$O_2$ systems), the degradation of phenol was greatly enhanced at neutral pH values. It was found that ZVI accelerates the Fenton reaction by reducing Fe(III) into Fe(II). The conversion of Fe(III) into Fe(II) by ZVI was more stimulated at acidic pH than at near-neutral pH values.

Effects of Silibinin and Resveratrol on Degradation of $I{\kappa}B$ and Translocation of NF-${\kappa}B$ p65 Induced by Tumor Necrosis Factor-${\alpha}$ in Cultured Airway Epithelial Cells (배양된 기도 상피세포에서 종양괴사인자에 의한 $I{\kappa}B$의 분해와 NF-${\kappa}B$ p65의 핵으로의 이동에 미치는 실리비닌과 레스베라트롤의 영향)

  • Park, Su Hyun;Lee, Hyun Jae;Ryu, Jiho;Lee, Su Yel;Shin, Hyun-Dae;Hong, Jang-Hee;Seok, Jeong Ho;Lee, Choong Jae
    • YAKHAK HOEJI
    • /
    • v.58 no.1
    • /
    • pp.1-6
    • /
    • 2014
  • We examined whether silibinin and resveratrol affect airway mucin production, degradation of $I{\kappa}B$ and translocation of NF-${\kappa}B$ p65 induced by TNF-${\alpha}$ in NCI-H292 cells. Cells were pretreated with each agent for 30 min and then stimulated with TNF-${\alpha}$ for 24 h or the indicated periods. The two compounds suppressed TNF-${\alpha}$-induced airway mucin production, degradation of $I{\kappa}B$ and translocation of NF-${\kappa}B$ p65. This result suggests that silibinin and resveratrol can regulate the production of mucin induced by TNF-${\alpha}$ through the inactivation of NF-${\kappa}B$ pathway in airway epithelial cells.

Characterization of Hyaluronic Acid Membrane Containing Lactic Acid (젖산이 결합된 히아루론산 막의 특성)

  • Cheong Seong Ihl;Kwon Ji Young
    • Membrane Journal
    • /
    • v.15 no.1
    • /
    • pp.8-14
    • /
    • 2005
  • The hyaluronic acid (HA) with excellent biocompatibility can be combined with the monomer polylactide with good biodegradability to produce biocompatible materials which can control the period of degradation in a human body. By freeze drying method, HA and the lactic acid, monomer of polylactide, or lactide, the ester dimer of polylactide, were crosslinked with crosslinking agent, l-ethyl-3-(3-dimethyl aminopropyl) carbodiimide. The analysis of infrared spectroscopy showed that the ester linkage was formed and the analysis of nuclear magnetic resonance (NMR) spectroscopy showed that the ester linkage was due to the reaction of lactic acid and HA. The conversion (6∼32%) and degree of crosslinking (4∼19%) increased but the selectivity was almost constant at 62% as the mole ratio of LA to HA increased from 1 to 10 in the crosslinking reaction. The brittleness became more pronounced and the rate of degradation became faster with more addition of lactic acid resulting from the higher ratio of LA to HA, and the swelling ratio was in the range of 500 to 2000%.

Degradation Kinetic and Mechanism of Methyl Tert-butyl Ether (MTBE) by the Modified Photo-Fenton Reaction (Modified Photo-Fenton Reaction을 이용한 Methyl Tert-butyl Ether (MTBE)의 분해 Kinetic 및 메커니즘 규명에 관한 연구)

  • Kim, Min-Kyoung;Kong, Sung-Ho
    • Journal of Soil and Groundwater Environment
    • /
    • v.11 no.6
    • /
    • pp.69-75
    • /
    • 2006
  • Improper disposal of petroleum and spills from underground storage tanks have created large areas with highly toxic contamination of the soil and groundwater. Methyl tert-butyl ether (MTBE) is widely used as a fuel additive because of its advantageous properties of increasing the octane value and reducing carbon monoxide and hydrocarbon exhausts. However, MTBE is categorized as a possible human carcinogen. This research investigated the Modified Photo-Fenton system which is based on the Modified Fenton reaction and UV light irradiation. The Modified Fenton reaction is effective for MTBE degradation near a neutral pH, using the ferric ion complex composed of a ferric ion and environmentally friendly organic chelating agents. This research was intended to treat high concentrations of MTBE; thus, 1,000 mg/L MTBE was chosen. The objectives of this research are to find the optimal reaction conditions and to elucidate the kinetic and mechanism of MTBE degradation by the Modified Photo-Fenton reaction. Based on the results of experiments, citrate was chosen among eight chelating agents as the candidate for the Modified Photo-Fenton reaction because it has a relatively higher final pH and MTBE removal efficiency than the others, and it has a relatively low toxicity and is rapidly biodegradable. MTBE degradation was found to follow pseudo-first-order kinetics. Under the optimum conditions, [$Fe^{3+}$] : [Citrate] = 1 mM: 4 mM, 3% $H_2O_2$, 17.4 kWh/L UV dose, and initial pH 6.0, the 1000 ppm MTBE was degraded by 86.75% within 6 hours and 99.99% within 16 hours. The final pH value was 6.02. The degradation mechanism of MTBE by the Modified Photo-Fenton Reaction included two diverse pathways and tert-butyl formate (TBF) was identified to be the major degradation intermediate. Attributed to the high solubility, stability, and reactivity of the ferric-citrate complexes in the near neutral condition, this Modified Photo-Fenton reaction is a promising treatment process for high concentrations of MTBE under or near a neutral pH.

Association-Based Conceptual Modeling for Smart Database Design (스마트 데이터베이스 설계를 위한 연관성 기반 개념적 모형화)

  • Lee, Sang-Won
    • Journal of Intelligence and Information Systems
    • /
    • v.17 no.3
    • /
    • pp.169-185
    • /
    • 2011
  • Data redundancy is problematic in that it not only induces heavy storage management cost but also could bring critical degradation of information systems. Unfortunately, to our knowledge, only few enterprises willingly afford time and efforts for the faithful conceptual design to prevent the degree of inappropriate data as much as they could, while most of enterprises pay rare attention to the notion of that sort of data quality. Wondering if there would be any other way to design the enterprise.wide data design without prior knowledge about business works is our major motivation for this study. In this paper, we present our data modeling methodology in which associations among objects in each sentences of a business job descriptions are treated as the focal point in database design. A proposed agent for automated design tool simply takes a business job description written in natural language as an input, and then designs an entity relationship diagram with some smart rules. We introduce the scope of the proposed agent and its detailed logics with several examples. And then, we verify the appropriateness of the resulted associations among objects. Lastly, we perform case studies to evaluate the devised agent's applicability to a business field.

Tracking Performance Test of Polymer Insulator with Salt Solution which is added Surface Active Agent (계면활성제가 첨가된 염수용액에 따른 폴리머 애자의 트래킹 성능 평가)

  • Cho, Han-Goo;Lee, Un-Yong;Han, Dong-Hee;Kang, Sung-Hwa;Choi, In-Hyuk;Lim, Kee-Joe
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.18 no.1
    • /
    • pp.62-67
    • /
    • 2005
  • Recently, polymer insulators that are used for high voltage applications have some advantages such as light weight, small size, vandalism resistance, hydrophobicity and easy making process. During outdoor service of polymer insulators, the surface of the insulating material is frequently subjected to moisture and contamination that lead to dry band arcing. Their tracking resistance, erosion resistance, end sealing and shed design are very important because dry band arcing causes degradation of polymer surface. Aging test to estimate life property of polymer insulator is executed through several international standard such as IEC 61109 and CEA tracking wheel test, but is not getting clear conclusion yet. There are two methods in the diagnosis method of polymer insulator such as off-line and on-line. The diagnosis methods in off-line are external condition analysis by the eye, contaminant analysis on surface, surface analysis, pollution withstand voltage test, power frequency flashover voltage test, lightning impulse flashover test, tensile fracture load test and flexural load test. Polymer material is also investigated it's tracking resistance by adding surface active agent in IEC 587. In this paper, the tracking performance of polymer insulator with salt solution which is added surface active agent. The diagnosis of insulator sample has been analyzed by leakage current and visual examination, STRI guide and thermal image camera.