제주도 문섬 산호서식지 주변의 생물생태학적 특성 Ⅱ. 식물플랑크톤의 군집동태와 1차생산력

이준백,좌종헌,강동우,고유봉,오봉철 제주대학교 방사능이용연구소 2000 연구보고 Vol.14 No.-

Community dynamics of phytoplankton and primary productivity have been investigated bimonthly from February 1997 to December 1997 in the coastal area around Moonsom of the southern Cheju Island, which is well-known for soft coral habitats in Korea. Average water temperature was 18.5℃ , being stratified from May to September by the seasonal thermocline, while vertically homogeneous in the winter. Euphotic depths ranged from 18.9 m to 45.9 m (average 33.7 m). Chlorophyll α concentrations varied from 0.02 to 0.92 ㎍ · ℓ-1 Standing crops of phytoplankton ranged from 2×103 to 3.9×105 cells · ℓ-1, showing a peak only in the spring. Diatoms occupied 67.5% of the total standing crops, while phytoflagellates, dinoflagellates and others 24.3%, 7.1% and 1%, respectively. However phytoflagellates and dinoflagellates were predominated with 36.6% and 38.7% in June, respectively. There was four dominant species in the study area. Chaetoceros sociales Lauder was dominant species from December to April, Prorocentrum micans Ehrenberg in June. In August, Chaetoceros socialis Lauder dominated in inshore but Paralia sulcata (Ehrenberg) Cleve in offshore. In October, Skeletonema costatum (Greville) Gran dominated the whole area. Daily primary productivity varied from 32.3 to 364.9 mg C · m-2 . day-1 (average 180.7 mgC · m-2 . day-1). Contribution of nanoplankton (<20 ㎛) to daily primary productivity was very high, accounting for 28.0-82.8%. Annual primary productivity is estimated 65.97 gC · m-2 ·yr-1, which is lower than those of the coast of Yellow Sea and the southern waters. Nanoplankton seemed to adopt higher irradiances with Ik values of 190-1,000 □· m-2·s-1 (mean 526.7 □ · m-2·s-1) than total phytoplankton with 140-850 □ ·m-2·s-1 (mean 466.7 □· m-2·s-1).

논유구 조사법 재론

곽종철,문백성 한국고고학회 2003 湖南考古學報 Vol.18 No.-

이 글은 1997년에 소개한 논유구 조사법의 일부를 보완한 것으로, 특히 가공면(加工面) 개념과 층상하면의 계단상단차 개념을 새로이 추가하거나 보완하였다. 가공면 개념은 논층으로서 인정할 수 있는 요소가 됨과 동시에, 해당 논층이 삭평ㆍ변형되었는지를 살펴보는 개념이기도 하다. 따라서 가공면 개념은 논유구 발굴조사에 있어서 중요한 지침이 되며, 더욱이 기존 조사되었던 계단식 논에 보이는 여러 의문점, 예를 들면 기존 조사되었던 계단식 논에서는 거의 확인되지 않았던 논둑, 사람ㆍ소발자국 흔적, 경작구 흔적, 작물재배 흔적 등의 문제나, 논 하나의 폭이 너무 좁으며, 벼의 plant-opal 기준치가 너무 낮게 나오는 점 등에 대한 해명의 실마리를 얻을 수 있게 되었다. 한편, 이 가공면 개념에 기초해 이후의 논유구 발굴 조사는 해당 논층의 상면과 하면을 대상으로 2회에 걸쳐 실시할 필요성도 아울러 제기하였다.

흰쥐의 중추성 Serotonin 고갈이 강제수영 중 부동자세 시간, 불안 및 수동적 회피 학습에 미치는 효과

박제민,김종백,강철중 大韓神經精神醫學會 1996 신경정신의학 Vol.35 No.3

흰쥐에서 p-chlorphenylalanine(PCPA)로 인한 강제수영 중 부동자세 시간의 단축이 불안이나 수동적 회피 학습 능력의 변화와 관련된 것인가를 검증하고자 하였다. 흰쥐에게 PCPA 300mg/kg 혹은 생리식염수를 하루 한 번 연속 3회 복강내 주사하였다. 마지막 주사 24시간 후에 공간에서의 활동성(ACT0), 높은 십자 통로 실험에서 개방 통로에 머무는 시간(ANX0), 왕복 회피상자에서 통과 지연 시간(STL0) 등을 측정하고 0.5mA 전기자극을 3초간 주어 회피 반응을 학습시켰다. 그리고 15분간 강제수영시켰다. 다음 날 같은 방법으로 활동성(ACT1), 불안(ANX1), 수동적 회피 반응 학습 정도(STL1), 5분간의 강제수영 중 총 부동 자세 시간 등을 측정하였다. 마지막 약물 혹은 대조액 투여 7일 후 수동적 회피 학습 유지 정도(STL7)를 다시 측정하였다. 결과는 아래와 같다. 1) 전체 대상군에서 ACT1은 ACT0보다 감소하였다. PCPA는 개방공간에서의 활동성에 영향을 주지 않았다. 2) PCPA 군은 높은 십자 통로 실험에서 ANX0와 ANX1 둘 다 대조군 보다 유의하게 길었다. 3) STL1은 PCPA군과 대조군 모두 STL0 보다 유의하게 지연되었다. PCPA는 STL0 이나 STL1에 영향을 주지 않았다. 그러나 대조군은 수동적 회피 학습 7일 후에도 통과 지연 시간이 유의하게 연장되어 있는데 반하여 PCPA군은 STL7이 STL0과 유의한 차이가 없었다. 4) 강제수영 중 부동자세 시간은 PCPA군이 대조군보다 유의하게 짧았다. 이상의 결과에서 PCPA 투여로 인한 강제수영 중 부동자세 시간의 단축은 PCPA가 비특이적 신체 활동을 증가시키거나 수동적 회피 반응 습득을 방해함으로써 일어나는 현상이 아니며, 진정 작용없이 탐색 행동을 증가시키거나, 스트레스 하에서의 행동 억제 현상을 차단함으로써 강제수영 중 부동자세 시간을 단축시킨다고 추론한다. 아울러 PCPA가 기억 고정 과정을 방해할 가능성이 있음을 제안한다. Purpose : The test if p-chlorophenylalanine(PCPA) induced decrease of immobility time during forced swimming test in rats is an epiphenomenon related with PCPA-induced changes in anxiety level or learning ability. Methods : 22 male rats(Sprague Dawley, weighting 180-280gm) were randomly assigned to PCPA or control group and treated with 300mg/kg of PCPA or saline i.p. at -72, -48, and -24 hrs. Number of segment(ACT0) entered with 4 limbs on the open field(L100×W100×H40cm, 25 segments), time(ANX0, sec) spent on the open arm(L110×W10cm, 50cm from the ground) in the elevated plus maze, and step-through latency(STL0, cut-off time : 300sec) in the shuttle box(L76.2×W34.3×H50.8cm, 7.5w electric bulb in the light chamber, 0.5mA for 3 sec in the dark chamber) were measured consequently at 24hrs after the last injection of PCPA or saline. After 20min of rest, animals were forced to swim for 15 min(cylinder : φ18×H40cm ; water : H15cm, 25℃). On the next day, the second trial of open field test(ACT1), elevated plus maze test(ANX1), passive avoidance learning test(STL1), and measurement of total immobility time(IT, sec) during the 5min of forced swim were done in the same manner as the first trial except that electrical shock was not given to the animals in the passive avoidance learning test and duration of forced swimming was shortened from 15min to 5min. To evaluate longterm effect of PCPA on maintenance of memory, measurement of step-through latency was repeated 7 days after the first trial(STL7). Result: 1) ACT1 was significantly decreased in the pooled sample, but the effect of PCPA on the general motor activity was not significant. 2) PCPA significantly prolonged the time spent on the open arms in the elevated plus maze test. 3) Comparing to STL0, STL1 was significantly prolonged in both groups. PCPA did not affect STL0 or STL1. STL7 was significantly prolonged in the control group, but not in the PCPA group. 4) PCPA shortened IT significantly. Conclusion : PCPA-induced decrease of immobility time during the forced swimming test in rats seems to be related with disinhibition of stress-related behavioral suppression. PCPA does not affect acquisition and short-term maintenance of passive avoidance learning, but necessity of further studies about its effect on long-term maintenance on memory is raised.

부산·울산·경남지역 직업병 감시체계

김정일,김병권,김정원,채창호,이철호,강동묵,김지홍,김진하,김영욱,이영하,이지호,김정호,윤형렬,유철인,정백근,장태원,김운규,윤동영,강진욱,김종은,안진홍,이동준,장준호,이광영,송혜란,최영희,이용환,조병만,최홍렬,고상백,김은아,이유진,홍영습,정갑열,김정만,김준연 大韓産業醫學會 2004 대한직업환경의학회지 Vol.16 No.1

Objective: Occupational medicine specialists in the Busan, Ulsan and Kyung-Nam areas established an area-based occupational disease surveillance system and used this system to collected case information for the purpose of preventing occupational diseases Methods: l l hospital participated in this system. The authors selected five main diseases, which were hand-arm vibration syndrome (HAVS), work-related musculoskeletal disorder (WRMSD), occupational asthma, occupational skin disease and occupational and occupational lung cancer and established their case definitions. All cases were reported on the web, and real time analysis was conducted. Results: Between April 2001 and April 2003, 192 cases of HAVS, 118 cases of WRMSD, 33 cases of occupational asthma, 17 cases of occupational skin disease and 17 cases of occupational lung cancer (for a total of 377 cases of these five main diseases) were reported. most of the HAVS cases came from shipbuilding, and 172 of them (92.7%) were associated with grinding. Of the four main types of WRMSD, carpal tunnel syndrome (CTS) was the most prevalent with 46 cases and shipbuilding was also the main industry involved (83.9%). The ergonomic risk factors involved mainly associated with the hand. In 19 (57.6%) and 4 (12.1%) cases of occupational asthma, the agents involved. The causative agents of occupational lung cancer included Cr, welding fume, PAH, Ni, etc. 10(58.8%) of the cases were diagnosed as squamous cell carcinoma and 5(29.4%) as adenoma. Conclusion: This result showed that an area-based occupational disease surveillance system might provide an effective method of evaluating the prevalence of such diseases, however the Busan, Ulsan and Kyung-Nam provinces are too large to be treated as individual areas. Therefore, the authors suggest that each province should establish its own surveillance system.

한국산 먼지벌레

Baek, Jong-Cheol 한국토양동물학회 1997 한국토양동물학회지 Vol.2 No.1

A total of 27 species of Carabidae from Korea is listed. Of these, 9 species, Badister ussuriensis, Bembidion aurefuscum, Bradycellus anchomenoides, Desera geniculata, Diplocheila elongata, Harpalus quadripunctatus, Odacantha aegrote, Trichotichnus longitarsis, and Trichotichnus nishioi are reported for the first time from Korea.

Recovery of Undersampled Signals with Higher-Order Multilayer Neural Networks

Jong Cheol Baek,Cheol Hoon Park,Min Ho Lee,Soo Young Lee 한국통신학회 1993 Asia-Pacific Conference on Communications Vol.2 No.2

Radioprotective Effect of HME-Mulberry Leaves against Electromagnetic Radiation-Induced Damage in Rats

Cheol-Ha Baek,Su-Ji Ryu,Hye-Min Kim,Seoul-Hee Nam,Jong-Suep Baek,Byung-In Min,Jang-Oh Kim 한국자기학회 2023 Journal of Magnetics Vol.28 No.4

In this study, a solid dispersion containing mulberry leaves and additives was manufactured by hot-melt extrusion (HME) to develop a radioprotective agent against electromagnetic radiation. The prepared formulations were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and electrophoretic light scattering (ELS). The formation of regular dispersions was confirmed through SEM and TEM analysis. To explore the radioprotective effect, animals were randomly classified into four groups: normal control (NC), irradiation (IR), irradiation after administration with mulberry leaves (MR), and irradiation after administration with HME-mulberry leaves (HR). Each sample was orally administered at 100 ㎎/㎏/day, and 7 Gy of 6 MV electromagnetic radiation (X-ray) was used once for the whole body. Lymphocytes seemed to recover in the HR group, but none of the groups recovered at a normal range by the seventh day after irradiation. There was also no change in all groups of the red blood cells. The spleen index tended to recover in the HR group compared to the IR group, which was consistent with histological analysis. The spleen of the radiation-exposed groups (IR, MR, and HR) showed relatively atrophied white pulp and decreased lymphocytes. These symptoms further increased on the third day after irradiation and gradually alleviated on the seventh day. Compared to the IR group, the MR and HR groups had less loss of lymphocytes caused by damage to the white pulp. Specifically, the HR group demonstrated a higher recovery rate than the MR group, confirming the potential of HME-Mulberry as a radioprotective agent. The study’s findings suggest further studies on health supplements and medicines to supplement the current research.

Formation of High-Performance Polymer Walls in a Liquid Crystal Cell by Phase Separation of Fluorinated Polymer Mixture

Baek, Jong-In,Shin, Jong-Ba,Oh, Min-Cheol,Kim, Jae-Chang,Yoon, Tae-Boon The Korean Infomation Display Society 2006 Journal of information display Vol.7 No.1

In this paper, we report the fabrication of high quality polymer walls by using a monomer containing fluorine (F-monomer). Polymer walls with no phase retardation were fabricated by using photo-polymerization induced anisotropic phase separation of the mixture composed of liquid crystal (LC) and F-monomer. Thanks to the immiscibility of fluoride, we could form high quality polymer walls with no light leakage. We measured electro-optic characteristics of a twisted-nematic (TN) LC cell whose polymer walls were fabricated by using the F-monomer, and the measurements were compared with that fabricated by using the monomer without fluorine.

Visible-Light-Responsive High-Detectivity Organic Photodetectors with a 1 μm Thick Active Layer

Park, Jong Baek,Ha, Jong-Woon,Yoon, Sung Cheol,Lee, Changjin,Jung, In Hwan,Hwang, Do-Hoon American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.44

<P>Organic photodetectors (OPDs) are attracting attention for use in flexible and portable electronic applications such as image sensors, remote sensing, optical communications, and medical sensors because of their strong photon responsivity in thin films over a broad range of wavelengths. In particular, the efficient photon-to-current conversion of OPDs under visible light allows their use in indirect X-ray detectors using scintillators to convert X-rays to visible light. The polymer poly(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-<I>b</I>:4,5-<I>b</I>′]dithiophene-<I>co</I>-5-(2-hexyldecyl)-1,3-bis(6-octylthieno[3,2-<I>b</I>]thiophen-2-yl)-4<I>H</I>-thieno[3,4-<I>c</I>]pyrrole-4,6(5<I>H</I>)-dione) (PBDTT-8ttTPD) shows strong absorption bands in the region of 500-650 nm, as well as high hole mobility, which provides excellent photoresponsivity and photon-to-current conversion efficiency. A p-n junction photodetector was fabricated by blending PBDTT-8ttTPD and [6,6]-phenyl C<SUB>71</SUB> butyric acid methyl ester (PC<SUB>71</SUB>BM) and varying the thickness of the active layer (260-1100 nm). The PBDTT-8ttTPD:PC<SUB>71</SUB>BM-based OPDs show promising photodetecting properties having a low dark current of 3.72 × 10<SUP>-9</SUP> A cm<SUP>-2</SUP> and high responsivity of 0.39 A W<SUP>-1</SUP> because of the well-controlled morphology, high molar absorption coefficient, and excellent carrier mobility of the PBDTT-8ttTPD:PC<SUB>71</SUB>BM layer. Consequently, the specific detectivity of the PBDTT-8ttTPD-based OPD devices was 1.13 × 10<SUP>13</SUP> Jones at −2 V on irradiation with a light-emitting diode (530 nm wavelength) with a power density of 55.6 μW cm<SUP>-2</SUP>.</P> [FIG OMISSION]</BR>

Effect of Hispidulin 7-O-neohesperidoside on Lipid Peroxidation in Rat Liver and NMR Assignment

Park, Jong-Cheol,Baek, Nam-In,Chung, Shin-Kyo,Hur, Jong-Moon,Lee, Jong-Ho,Yu, Young-Beob,Chol, Jong-Won The Korean Society of Pharmacognosy 1997 생약학회지 Vol.28 No.2

The full NMR assignment of hispidulin 7-0-neohesperidoside (1) isolated from Cirsium japonicum var. ussuriense was made with the aid of 2D correlation NMR techniques such as HMQC and HMBC. To investigate detoxification of bromobenzene-induced hepatic lipid peroxidation by compound 1, hepatic lipid peroxide level and the activities of enzymes responsible for production and removal of epoxide were studied. The level of lipid peroxide elevated by bromobenzene was significantly reduced by compound 1. This compound administered daily over one week before intoxication with bromobenzene did not affect the activities of aminopyrine N-demethylase, aniline hydroxylase, glutathione S-transferase. Epoxide hydrolase activity was decreased significantly by bromobenzene, which was restored to the control level by pretreatment of persicarin. The results suggest that the bromobenzene-induced hepatic lipid peroxidation by compound 1 is reduced by enhancing the activity of epoxide hydrolase, an enzyme removing bromobenzene epoxide.