• 한국환경성돌연변이발암원학회지
• /
• 제15권2호
• /
• pp.100-105
• /
• 1995

The effects of DNA polymerase $\beta$ on the somatic chromosome mutations and mitotic recombinations were investigated using the transgenic Drosophila beating chimetic gene consisting of a promoter region of Drosophila actin 5C gene and rat DNA polymerase $\beta$. For detecting the somatic chromosome mutations and mitotic recombinations, the heterozygous (mwh/+) strains possessing or lacking transgene poi 13 were used. The spontaneous frequency of small mwh spots, due to deletion or nondisjunction etc., in the non-transgenic w strain and the transgenic p[pol $\beta$]-130 strain was 0.351 and 0.606, respectively. The spontaneous frequency (0.063) of large mwh spots, arises mostly from somatic recombination between the centromere and the locus mwh, in the transgenic p[pol $\beta$]-130 strain was about three times higher than that (0.021) of the non-transgenic w strain. The mutant clone frequencies of small and large mwh spots induced by N-methyl-N'-nitro-N-nitrosoguanidine and ethyl methanesulfonate in the transformant p[pol $\beta$]-130 were higher than those in the host strain w. The present results suggest that rat DNA polymerase $\beta$ participate at least in the somatic chromosome mutations and mitotic recombination processes.

• Journal of Electrical Engineering and Technology
• /
• 제5권4호
• /
• pp.637-639
• /
• 2010

Hexagonal boron nitride (BN) films were prepared. The process involved, spraying BN powder-dispersed $H_3BO_4-BCl_3$-ethyl alcohol solution on quartz plates, and the drying off quartz plates before, and annealing at $1070^{\circ}C$ in a nitrogen atmosphere. The optical energy band gap of the BN films was 5.28 eV. Photoluminescence peaks with energies of 3.44, 3.16, 2.97, and 2.35 eV at 10 K were observed and analyzed. Accordingly, these have resulted from donor-acceptor pair recombinations.

• 한국응용곤충학회지
• /
• 제35권4호
• /
• pp.315-320
• /
• 1996

Drosophila의 actin 5C 유전자 promoter에 쥐의 DNA polymerase $\beta$cDNA를 도입시킨 형질전환 초파리가 고감수성 환경성 변이원 검출계로 사용할 수 있는지를 조사하였다. 체세포 염색체 재조환과 체세포 염색체 돌연변이의 검출을 위해서는 geterozygous(mwh/+) 계통을 사용하였다. 염색체상의 결실이나 비분리 등에 의한 small mwh spot의 자연 발생적 빈도는 non-transgenic w 계통과 transgenic p[pol $\beta$]-130 계통에서 각각 0.351 및 0.606 정도였다. 체세포 염색체 재조환에 의한 large mwh spot의 자연 발생적 빈도의 경우는 transgenic p[pol $\beta$]-130 계통(0.063)이 non-transgenic w 계통(0.021)에 비해 약 3배 정도 높게 나타났다. IQ, Glu-P-1 및 {TEX}$AFB_{1}${/TEX} 등의 돌연변이원의 처리에 의한 경우, 두 종류의 mutant clone의 발생 빈도는 쥐의 DNA polymerase $\beta$가 도입된 transgenic p[pol $\beta$]-130 계통이 non-transgenic w 계통에 비하여 모두 약 2-3배 정도 높게 나타났다. 본 연구의 결과는 쥐의 DNA polymerase $\beta$가 최소한 체세포 염색체 돌연변이 유발이나 체세포 염색체 재조환의 생성 과정에 관여함을 의미하며, 형질전환 초파리 계통이 환경성 변이원 검출계로서 충분한 응용가능성이 있음을 보여 주었다.

• Journal of Microbiology and Biotechnology
• /
• 제5권3호
• /
• pp.132-137
• /
• 1995

The lambda integrase (lnt) is believed to bind to several arm and core sites of attP DNA in order to facilitate intasome formation. We have done systematic mutagenic analysis on all 5 arm sites and found that P1 is absolutely required for integration while P2 is not. We also found that all 3 P' arm sites(P'1, P'2, and P'3) are required for efficient integrative recombination. P'1, which is an important binding site for excision, also seems to be crucial for integration when preincubation of attP DNA with Int and IHF is performed before recombination. Preincubation assay revealed that preincubation with Int and IHF improved the efficiency of recombination of wild type attP DNA and demolished recombinations of P'1 mutant attP DNAs.

• Journal of Photoscience
• /
• 제4권1호
• /
• pp.11-16
• /
• 1997

We measured, using femtosecond pump-probe experiment, the time evolution of transient absorption in aqueous CdS colloids. The signal rises within the time resolution (= 0.5 ps) of the experiment and decays with two exponential time constants, 4.8 ps and 132 ps. The ultrafast rise of the transient absorption is considered to be for shallowly trapped conduction band electrons after photoexcitation. The amplitude ratio of the two decaying components varies with the pump intensity and the decay times increase in the presence of hole scavengers. Even though a biexponential function fits the decay well, we object hat two independent first order processes (geminate and nongeminate recombinations) are responsible for the decay. A function with an integrated rate equation for second order nongeminate recombination plus a long background fits the decay well. The long background is considered to be for deeply trapped charges at the CdS particle.

• 한국광학회지
• /
• 제18권1호
• /
• pp.24-30
• /
• 2007

3차원 영상 재생을 위한 집적결상법에서 기본영상의 재조합을 통한 재생영상의 깊이변환에 관하여 연구하였다. 렌즈 배열 또는 카메라 배열 등을 통하여 획득된 영상 배열을 적절한 조건 하에서 재조합하여 재생함으로써 재생영상의 깊이에 대해 도치(pseudoscopic) 영상 또는 정치(orthoscopic) 영상, 허상, 실상 뿐만 아니라 임의의 깊이로의 왜곡 없는 변환이 가능하다. 본 논문에서는 각 변환에 대한 재조합 조건을 이론적으로 유도하고 실험을 통하여 확인하였다.

• 한국응용곤충학회지
• /
• 제50권4호
• /
• pp.295-299
• /
• 2011

본 연구는 한국산 바늘이리응애아과 (Typhlodrominae)에 대한 종과 속의 검색표와 각 종에 대한 목록을 작성하였다. Typhlodromus coryli Wu and Lan, 1991 (생강이리응애)는 한국에서 처음으로 보고된다. 바늘이리응애아과에는 바늘이리응애속 (Kuzinellus Wainstein), 느릅이리응애속 (Paraseiulus Muma), 서양이리응애속 (Galendromus Muma), 그리고 대중이리응애속 (Typhlodromus Scheuten) 등 4 속이 있다.

• Applied Science and Convergence Technology
• /
• 제27권4호
• /
• pp.61-64
• /
• 2018

The basic principle and concept for hydrogen production via water-splitting process are introduced. In particular, recent research activities and their progress in the photoelectrochemical water-splitting process are investigated. The material perspectives of semiconducting photocatalysts are considered from metal oxides, including titanium oxides, to carbon compounds and perovskites. Various structural configurations, from conventional photoanodes with metal cathodes to tandem and nanostructures, are also studied. The pros and cons of each are described in terms of light absorption, charge separation/photoexcited electron-hole pair recombinations and further solar-to-hydrogen efficiency. In this research, we attempt to provide a broad view of up-to-date research and development as well as, possibly, future directions in the photoelectrochemical water-splitting field.

• Bulletin of the Korean Chemical Society
• /
• 제20권3호
• /
• pp.337-340
• /
• 1999

Luminescence of bismuth activated CaS, CaS:Bi, prepared in sodium polysulfide is studied. Excitation spectrum of CaS:Bi shows a band at 350 nm due to the recombination process between holes in Na+Ca2+ and electrons in conduction bands, in addition to bands at 260 nm from band gap of CaS, and at 320 nm (1S0→1P1) and at 420 nm (1S0→3P1) from electronic energy transitions of Bi. Emission band at 450 nm is from 3P1→1S0 transition of Bi3+, bands at 500 nm and 580 nm correspond to recombinations of electron donors (Bi3+Ca2+ and VS2-) with acceptors (VCa2+ and Na+Ca2+). Emission band of 3P1→1S0 transition is shifted to longer wavelength from CaS:Bi to BaS:Bi, due to the increase of the Stokes shift by the decrease of the crystal field parameter from CaS:Bi to BaS:Bi.

• Biomolecules & Therapeutics
• /
• 제6권1호
• /
• pp.63-72
• /
• 1998

-4-Quinolone antibiotics (pefloxacin, ciprofloxacin, norfoxacin, ofloxacin and enoxacin) were tested for mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537, TA1538 and TA102, for chromosomal aberrations in cultured Chinese hamster lung (CHL) cells, and for wing somatic mutations and recombinations (wing spot) in Drosophila. Five 4-quinolones did not show any mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537 and TA1538. However, they were mutagenic inSalmonella typhimurium TA102 with and without metabolic activation in both plate incorporation method and preincubation method. Ciprofloxacin induced structural chromosome aberrations in CHL cells both with and without metabolic activation, and the frequencies were 6% and up to 28%, respectively. Pefloxacin showed equivocal evidence, however, norfloxacin, ofloxacin and enoxacin did not induce the structural chromosome aberrations both in the presence and absence of metabolic activation. In the wing spot assay in Drosophila, ofloxacin increased the frequency of small single spots significantly in a dose-dependent manner but there was no dose-dependent increase of single or twin spots in the others.