• Title/Summary/Keyword: LuxO

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Conditions for Stable light Production of Recombinant Escherichia coli Containing Lux Operon and Sensitivity to Toxic Chemicals (Lux operon을 함유한 유전자 재조합 Escherichia coli의 발광 안정화 조건 및 독성물질에 대한 민감성)

  • 배희경;이상민;정윤철;송방호;신평균
    • KSBB Journal
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    • v.17 no.6
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    • pp.571-576
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    • 2002
  • Recombinant E. coli DH5 ${\alpha}$/pSB311 was made by cloning the genes encoding bacterial luciferase and aldehyde substrate proteins from Photohabdus luminescense, to complement defects of Lumistox, which is normally used in bioassays to monitor toxic substances in water environmental systems. The conditions for stable light production by the recombinant strains were investigated with respect to cell growth stage, cell number, and buffer conditions. The optimum growth stage was a middle-exponential stage with an OD$_{660nm}$ value of 0.6-0.7. ADout 10$^{6}$-10$^{7}$ cells per test tube was optimum for stable light emission. The effect of buffer was not significant if an optimum viable cell number was maintained. The bioluminescence of the recombinant E. coli harboring the lux operon of Photohabdus luminescense was not affected by temperature, while the bioluminescence of Lumistox was temperature sensitive. The recombinant E. coli was more sensitive to heavy metals (Cd, Cu, Hg, Zn) than Lumistox, because it does not require high concentrations of NaCl in the buffer.

Fabrication and Characteristics of Photoconductive Amorphous Silicon Film for Facsimile (팩시밀리용 비정질 실리콘 광도전막의 제작 및 특성)

  • Kim, Jeong-Seob;Oh, Sang-Kwang;Kim, Ki-Wan;Lee, Wu-Il
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.6
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    • pp.48-56
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    • 1989
  • Contact-type linear image sensors for facsimile have been fabricated by means of rf glow discharge decomposition method of silane. The dependence of their electrical and optical properties on rf power, $SiH_4$ flow rate, ambient gas pressure, $H_2SiH_4$ ratio and substrate temperature are described. The a-Si:H monolayer demonstriated photosensitivity of 0.85 and $I_{ph}/I_d$ ratio of 100 unger 100 lux illumination. However, this monolayer has relatively high dark current due to carrier injection from both electrodes, resulting in low $I_{ph}/I_{dd}$ ratio. To suppress the dark current we have fabricated $SiO_2/i-a-Si:H/p-a-Si:H:B$ multilayer film with blocking structure. The photocurrent of this multilayer sensor with 6 V bias became saturated ar about 20nA under 10 lux illumination, while the dark current was less than 0.2 nA. Moreover, the spectral sensitivity of the multilayer film was enhanced for short wavelength visible region, compared with that of the a-Si:H monolayer. These results show that the fabricated photocon-ductive film can be used as the linear image sensor of the facsimile.

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Optimum Culture Environment of the Benthic Copepod, Tigriopus japonicus (부착성요각류 Tigriopus japonicus의 최적배양환경)

  • PARK Huem Gi;HUR Sung Bum
    • Journal of Aquaculture
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    • v.6 no.3
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    • pp.147-157
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    • 1993
  • The harpacticoid copepod, Tigriopus japonicus is one of the most important zooplankton as a live food for the production of marine fish fry. Thus, the salinity tolerance and the optimum culture environment of this copepod in terms of salinity, temperature and light were examined. The food values of 6 kinds of phytoplankters and 2 kinds of yeast were also investigated for mass culture of this copepod. The results are as follows: After 5 day culture in the experiment of salinity tolerance, the survival rates of the gravid female at $0\%\;and\;90%o\;were\;40\%\;and\;70\%$, respectively. However, at salinity ranging from $2\%o\;to\;80\%o$, high survival rates above $85\%$ were observed. It means T. japonicus is very euryhalinous species. Temperature was more important factor than salinity for the fecundity of T. japonicus. The optimum culture conditions of this species were $24^{\circ}C,\;24\%o$, and 3,000 lux with 24 L: 0D. Under these culture conditions, the average fecundity from a gravid female per spawning was 38 nauplii, and the interval time between spawnings were 2.05 days. Phaeodactylum tircornutum seemed to be the most suitable phytoplankton as a live food for T. japonicus, and the large chlorophyta, Tetraselmis suecica showed the lowest food value among 6 phytoplankters and 2 yeasts. The food value of w-yeast was better than that of baker's yeast, and it is similar to that of phytoplankton such as Amphora sp., Chlorella ellipsoidea and Nannochloris oculata. So, the w-yeast seems to be appropriate food source for mass culture of T. japonicus.

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THE TEMPERATURE RISING IN PULP CHAMBER DURING COMPOSITE RESIN POLYMERIZATION (광중합 기전에 따른 복합레진 중합 시 치수강 내 온도변화)

  • Hwang, Dong-Hwan;Lee, Ju-Hyun;Park, Ho-Won
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.3
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    • pp.431-438
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    • 2003
  • This study investigates pulp chamber temperature rise during composite resin polymerization by plasma arc(Group III : Flipo 3 sec, Group IV : Flipo 5 sec) and LED curing units(Group V : Lux-O-Max, 40 sec) as well as conventional halogen lamp curing units(Group I : VIP mode3, 20 sec, Group II : VIP mode6, 20 sec). The results are as follows : 1. All of the investigated pulp chamber temperature rises are lower than the boundary temperature could result in irreversible damage to the pulpal tissue ($5.5^{\circ}C$). 2. In the group II, it is found the significantly higher pulp chamber temperature rise than any other groups(p<0.05). 3. In the group of composite resin light-cured with VIP, it is found the significantly higher pulp chamber temperature rise in the group II than group I(p<0.05). 4. In the group of composite resin light-cured with Flipo, it is found the significantly higher pulp chamber temperature rise in the group IV than group III (p<0.05). 5. In the case of comparing VIP and Flipo, group II is significantly higher pulp chamber temperature rise than group III, IV(p<0.05), and group IV is significantly higher pulp chamber temperature rise than group I(p<0.05), and it does not significantly differ between group I and III. 6. In the group of composite resin light-cured with Lux-O-Max, it is found the significantly lower pulp chamber temperature rise than any other groups (p<0.05).

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Semiconductor coupled solar photo-Fenton's treatment of dyes and textile effluent

  • Raji, Jeevitha R.;Palanivelu, Kandasamy
    • Advances in environmental research
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    • v.5 no.1
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    • pp.61-77
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    • 2016
  • $NanoTiO_2$ was synthesized by ultrasonication assisted sol-gel process and subjected to iron doping and carbon-iron codoping. The synthesized catalysts were characterized by XRD, HR-SEM, EDX, UV-Vis absorption spectroscopy and BET specific surface area analysis. The average crystallite size of pure $TiO_2$ was in the range of 30 - 33 nm, and that of Fe-$TiO_2$ and C-Fe $TiO_2$ was in the range of 7 - 13 nm respectively. The specific surface area of the iron doped and carbon-iron codoped nanoparticles was around $105m^2/g$ and $91m^2/g$ respectively. The coupled semiconductor photo-Fenton's activity of the synthesized catalysts was evaluated by the degradation of a cationic dye (C.I. Basic blue 9) and an anionic dye (C.I. Acid orange 52) with concurrent investigation on the operating variables such as pH, catalyst dosage, oxidant concentration and initial pollutant concentration. The most efficient C-Fe codoped catalyst was found to effectively destruct synthetic dyes and potentially treat real textile effluent achieving 93.4% of COD removal under minimal solar intensity (35-40 kiloLUX). This reveals the practical applicability of the process for the treatment of real wastewater in both high and low insolation regimes.

Optical Properties of Sea Water 1 Variation of the Coastal Sea Water Near Busan in Summer and Autumn (해수의 광학적 성질에 관한 연구 ( 1 ) - 부산근해의 하계 및 추계변화)

  • 양용림
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.11 no.1
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    • pp.8-14
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    • 1975
  • The optical properties of the sea water were studied by use of underwater lux-meters in the coastal waters of Busan from May to November 1975. The absorption coefficient of the sea water in the area ranges from O. 169 to 1. 049 and the mean absorpflOn coefficient is 0.413. Maximum monthly mean absorption coefficient (0. 56) was observed in August, while the minimum was O. 338 in September. There was a distinct discontinuity layer of the absorption coefficient in accordance with the thermocline and the halocline in summer. The mean transparency of the area was 3. 8 meters, and transparency in autumn was higher than that in summer. The relation between absorption coefficient (m) and transparency (D) was deduced, m=1. 57/ D. The rate of light penetration at 5 m-layer of sea water was 2. 5 percent when the solar altitude was six degree in July 1975.

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Adaptive Responses of Escherichia coli for Oxidative and Protein Damage Using Bioluminescence Reporters

  • Min, Ji-Ho;Gu, Man-Bock
    • Journal of Microbiology and Biotechnology
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    • v.14 no.3
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    • pp.466-469
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    • 2004
  • The recombinant bioluminescent Escherichia coli strains, DPD2511 and TV 1061 containing the katG and grpE promoters, respectively, from Vibrio fischeri fused to luxCDABE, were used to detect the adaptive and repair responses to oxidative damage caused by hydrogen peroxide $(H_2O_2)$, and protein damage due to phenol. The response ratio, represented as the bioluminescence induced in subsequent inductions of DPD2511 and TV1061 with the mother cells previously induced by each chemical, i.e., $H_2O_2$ and phenol during the previous induction stage, decreased suddenly compared with the ratio of the control culture of each strain, meaning there is a possible adaptive response to stress caused by chemicals. Protein damage due to phenol was completely repaired by the second culturing after the initial induction, as was oxidative damage caused by $H_2O_2$ which was also rapidly repaired, as detected by the recovery of bioluminescence level. This result suggests that E. coli promptly adapt and repair oxidative and protein damage by $H_2O_2$ and phenol completely.

Study on Stabilization of Promazine Hydrochloride Injection (염산(鹽酸)Promazine 주사제(注射劑)의 안정화(安定化)에 관한 연구(硏究))

  • Lee, Wan-Ha;Chi, Ung-Kil;Young, Jae-Hun
    • Journal of Pharmaceutical Investigation
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    • v.3 no.3
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    • pp.5-15
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    • 1973
  • The stabilizing effect of promazine hydrochloride injectin was tested by irradiation of sun lamp(5,000 Lux) on their acid solution sealed in ampules under various stabilizers. The result of experimentation on the color change, the remaining proportion and the half life of promazine hydrochloride solution is as follows. 1. Instability of promazine hydrochloride solution is mainly caused by the sunlight and oxygen. 2. The pH range of promazine hydrochloride injection is recommended to $pH\;4.4{\sim}5.2$ 3. The decomposition of promazine hydrochloride by the sunlight is composed of pseudo zero order reaction when It maintains colorless solution. 4. The half life of 0.5% promazine hydrochloride injection was 30 hrs. under sun lamp irradiation, but it was delayed to 84 hrs. by the simple stabilizer and to 175 hrs. by compound stabilizer. 5. The stabilizing effect of promazine .hydrochloride injection adding sod. metabisulfite$(Na_2S_2O_5)$ was most excellent in various simple stabilizers and adding $Na_2S_2O_5$ to nicotinic acid, $Na_2S_2O_5$ to nicotinamide were more excellent than other compound stabilizers.

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Isolation of New Strain of Cordyceps militaris HB8 and Optimal Condition for Production of Adenosine and Cordycepin in Fruit Body

  • Li, Jin Feng;Hoang, Van An;Ahn, Jong Chan;Yang, Dong Uk;Lee, Dong Wook;Yang, Deok Chun
    • Korean Journal of Plant Resources
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    • v.33 no.6
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    • pp.696-706
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    • 2020
  • Cordyceps has been used in traditional Chinese medicine more than 2000 year ago. In this study, the new Cordyceps militaris was founded and isolated from O-dae mountain in Korea, and was identified its genetic characteristics. The newly isolation strain HB8 was most closet to Cordyceps militaris W141449 (99.82%), Cordyceps militaris JLCY-LI819 (99.82%) and Cordyceps militaris 4642 (99.81%), respectively. the genotypic result was show that train HB8 was belonging to the Cordyceps militaris genus, therefore, Cordycep militaris HB8 proposed with accession number MT835161. This study we find the optimal condition for production of cordycepin from Cordyceps militaris HB8 was 8 mg/g (200 g of pupa, 1 g of KH2PO4, 0.5 g of K2HPO4, 20 g of glucose, 1 g of MgSO4, 0.05 g of vitamin B1, and 1 mg of NAA per liter; light condition 300-700 Lux and day/night was 14 h/10 h) and the optimum condition for the production of adenosine was 2.6 mg/g (15 g of skim milk powder, 1 g of KH2PO4, 0.5 g of K2HPO4, 20 g of glucose, 1 g of MgSO4, 0.05 g of vitamin B1, and 1 mg of NAA per liter; light condition 300-700 Lux and day/night was 14 h/10 h).