• 환경생물
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• 제26권4호
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• pp.292-302
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• 2008

본 연구는 Ecopath 모델을 이용하여 유수생태계인 낙동강 하류 생태계의 영양구조와 에너지 흐름을 알아보고자 하였다. 이를 위해 2007년 갈수기(5월)와 풍수기(8월)에 낙동강 하류 삼랑진 일대의 6개 지점에서 조사를 실시하였으며, 어류의 각 어종별 밀도와 자원량 자료를 위해 2007년 3월에서 11월까지 매달 2회씩 조사를 실시하였다. 낙동강 하류 생태계는 수온이 $20.9\sim31.4^{\circ}C$, 전기전도도 $135\sim364{\mu}s\;cm^{-1}$, 용존산소 $9.0\sim10.5mg\;L^{-1}$, pH는 10.4$\sim$10.7, TOC 2.3$\sim$2.7 mg L$^{-1}$, DOC 2.2$\sim$2.6 mg L$^{-1}$, 수심 0.5$\sim$9.0 m, 투명도 0.3$\sim$0.5 m등의 범위를 보이는 것으로 조사되었다. 낙동강 하류 생태계는 크게 3단계 즉, 생산자와 1차 소비자, 2차 소비자로 나누어지는 영양단계를 보였다. 생산자에 해당하는 생물군은 유기패설물, 식물플랑크톤, 대형수생식물이었고, 1차 소비자는 동물플랑크톤, 저서동물, 잉어, 누치, 기타어류 등이었으며, 2차 소비자는 배스였다. 낙동강 하류 생태계의 총에너지량은 2.7 kg m$^{-2}$로 나타났으며, 52.0%는 섭식으로, 9.1%는 이출, 18.0%는 호흡, 20.9%는 유기쇄설물로 전환되는 것으로 나타났다. 또한, 혼합영양영향(MTI)결과 최고포식자로 추정된 배스의 생체량 증감은 배스와 기타 어류에게는 음의 효과를, 누치와 잉어, 저서동물, 동물플랑크톤, 식물플랑크톤 등에게는 양의 효과를 직 간접적으로 미치는 것으로 나타났으며, 각 그룹의 생체량증가는 각 생물그룹별 생체량을 감소시키는 음의 효과를 보이는 것으로 나타났다.

• 자원환경지질
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• 제30권6호
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• pp.553-566
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• 1997

Origin, behavior and enrichment of environmental toxic elements from the Deokpyeong area were investigated on the basis of major, trace and rare earth element geochemistry. Coaly metapelites of the Deokpyeong area are subdivided into grey phyllite, dark grey phyllite, coaly slate and black slate, which are interbedded along the Ogcheon Supergroup. The coaly slate had been mined for coal, but mining is closed. The coaly and black slates are lower contents of $SiO_2$ and $Al_2O_3$, and higher contents of LOI, CaO, $Na_2O$ and BaO as compared with the phyllitic rocks. Rare earth elements are highly enriched in the coaly and black slate. Average compositions (ppm) of minor and/or environmental toxic elements in the coaly and black slate are revealed as As=127, Ba=30,163, Cd=18, Cr=740, Cu=84, Mo=378, Pb=43, Sb=12, Se=44, U=144, V=8,147 and Zn=292, which are extremely high concentrations than those in the NASC compositions. Major elements (average enrichment index; 5.34) in the coaly metapelites are mostly depleted, excepting $P_2O_5$ and BaO, normalized by NASC. Rare earth elements (average enrichment index; 1.48) are enriched in the coaly slate. On the basis of NASC, minor and/or environmental toxic elements in the coaly metapelites were strongly enriched of all the elements with the exception of Co, Cs, Ni and Sr. Average enrichment index of trace elements in coaly metapelite is 31.51 (coaly slate; 51.94 and black slate; 15.46). Especially, enrichment index of potentially toxic elements (As, Ba, Cr, Cu, Mo, Ni, Sb, Se, U, V and Zn) of the rock is 46.10 (grey phyllite; 7.15, dark grey phyllite; 4.77, coaly slate; 88.96 and black slate; 22.11). These coal formations were deposited in basin of boundary between terrestrial and marine environments deduced to carbon, sulfur (C/S=2.2 to 275.7), trace and rare earth elements characteristics. Irregular behavior and dispersion between major, minor and rare earth elements of those metapelites indicates a variable source materials, incomplete mixing of differential source and/or reequilibrium of diagenesis and metamorphism.

• 한국어류학회지
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• 제32권2호
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• pp.103-109
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• 2020

붕장어(Conger myriaster)는 2018년 6월부터 2019년 5월까지 거제 구조라, 망치 인근해역에서 장구형통발을 이용하여 매달 1회 채집해 이용하였으며, 항문장(Preanus length)과 습중량을 각각 0.1 cm, 0.1 g까지 측정한 뒤 위를 적출하여 가능한 종 수준까지 분석하였다. 위내용물 분석결과는 각 먹이생물에 대한 출현빈도(%F), 개체수비(%N), 습중량비(%W)를 구하여 상대 중요도지수비(%IRI)로 수치화하여 주 먹이생물과 크기군에 따른 먹이조성 변화를 알아보았다. 붕장어의 가장 중요한 먹이생물은 어류(Pisces)였으며, 그중 멸치(Engraulis japonicus)가 가장 우점한 먹이생물로 확인되었다. 그 외, 새우류(Macrura), 패충류(Ostracoda), 갯지렁이류(Polychaeta), 게류(Brachyura) 등 다양한 먹이생물을 섭식하였지만 그 양은 많지 않았다. 과거 광양만에서 이루어진 연구에서는 붕장어의 주 먹이생물이 날개망둑(Favonigobius gymnauchen)으로 나타나 이번 연구결과와 다소 차이가 있었다. 성장에 따른 위내용물 조성의 변화를 살펴본 결과, 뚜렷한 먹이전환이 나타나지 않았다. 붕장어는 성장함에 따라 개체당 평균 먹이생물의 개체수(mN/ST)는 통계적으로 유의한 차이를 보이지 않았으나, 평균 먹이생물의 중량(mW/ST)은 붕장어의 항문장이 증가함에 따라 유의하게 증가하는 경향을 보였다.

• 대한간호학회지
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• 제29권2호
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• pp.215-224
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• 1999

The study was conducted to centum the construct of individual perception and preference for work characteristics as personal factors influencing Korean nurses' job satisfaction. The subjects of the study were 231 nurses who are currently working in intensive care units and have been for a minimum of 6 months. The study used the Staff Perception and Preference Scale(Song et al., 1997) to measure the individual's perception and preference on the technical. practice. and management components of the ideal work environment. The Korean version of the Staff Perception and Preference Scale consists of 16 items on perception and 13 on preference with each item related on a scale from 1(not at all) to 4(a great deal). Psychometric testing revealed that the preference and perception scale is internally consistent with Chronbach's alphas of .83 for perception scale arid .80 for preference scale. The subscales of the perception and preference scale also showed acceptable reliability for the early stage of the development of the instruments with Chronbach alphas of .62-.76 and .69-.83 respectively. Criterion-related validity of the scale was tested by examining correlations with individual growth need that is conceptually close to individual preference. but not to individual perception. Individual growth need was significantly related to individual preference(r＝.63, p<.05), but the correlation with the perception scale was not significant. A separate factor analysis for the each of perception and preference scales was performed with a three-factor loading solution based on a previous study. The results on the staff perception scale confirmed with varimax rotation that the items were cleanly and strongly loaded on technique. practice and management components, which together explained 50.7% of the variance. The factor analysis on the staff preference scale also yielded a three factor solution that explained 56.7% of the variance. but items on technique and management components were loaded together. This phenomena may due to the current nursing delivery system in Korea where nurses never experience either shared governance nor case management, and as a results they may not be able to consider management roles as their potential extended roles. Therefore, more efforts should be given to enhance nurses' autonomy and decision making in the technique, practice and management components of their work environment. Meanwhile, there is a need for continuously confirming and developing tools for individual perception and preferences to effectively enhance job satisfaction among Korean nurses through innovative work environments.

• Bulletin of the Korean Chemical Society
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• 제26권11호
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• pp.1807-1818
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• 2005

New PPV based conjugated polymers, containing terphenyl units, were prepared as the electroluminescent (EL) layer in light-emitting diodes (LEDs). The prepared polymers, poly[2,5-bis(4-(2-etylhexyloxy)phenyl)-1,4-phenylenevinylene] (BEHP-PPV), poly[2-(2-ethylhexyloxy)-5-(4-(4-(2-etylhexyloxy)phenyl)phenyl)-1,4-phenylenevinylene] (EEPP-PPV) and poly[2-(2-ethylhexyloxy)-5-(9,9-bis(2-etylhexyl)fluorenyl)-1,4 phenylenevinylene] (EHF-PPV), were soluble in common organic solvents and used as the EL layer in double layer light-emitting diodes (LEDs) (ITO/PEDOT/polymer/Al). The polymers were prepared by the Gilch reaction. The number-average molecular weight $(M_n)$, weight-average molecular weight $(M_w)$, and the polydispersities (PDI) of these polymers were in the range of 9000-58000, 27000-231000, 2.9-3.9, respectively. These polymers have quite good thermal stability with decomposition starting above 320-350. The polymers show photoluminescence (PL) with maximum peaks at around 526-562 nm (exciting wavelength, 410 nm) and blue EL with maximum peaks at around $\lambda_{max}$ = 526-552 nm. The current-voltageluminance (I-V-L) characteristics of polymers show turn-on voltages of 5 V. Even though both of EEPP-PPV and BEHP-PPV have the same terphenyl group in the repeating unit, EEPP-PPV with directly substituted alkoxy group in the back bone has longer effective conjugation length than BEHP-PPV, and exhibits red shift in the PL spectra. Both of EEPP-PPV and EHF-PPV have ter-phenyl units and directly substituted alkoxy group in back bone. EHF-PPV with fluorenyl unit attached to the PPV backbone has shorter effective conjugation length than EEPP-PPV with biphenyl unit, and exhibits blue shift in the PL spectra.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.406-406
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• 2016

To get high efficiency n-type crystalline silicon solar cells, passivation is one of the key factor. Tunnel oxide (SiO2) reduce surface recombination as a passivation layer and it does not constrict the majority carrier flow. In this work, the passivation quality enhanced by different chemical solution such as HNO3, H2SO4:H2O2 and DI-water to make thin tunnel oxide layer on n-type crystalline silicon wafer and changes of characteristics by subsequent annealing process and firing process after phosphorus doped amorphous silicon (a-Si:H) deposition. The tunneling of carrier through oxide layer is checked through I-V measurement when the voltage is from -1 V to 1 V and interface state density also be calculated about $1{\times}1012cm-2eV-1$ using MIS (Metal-Insulator-Semiconductor) structure . Tunnel oxide produced by 68 wt% HNO3 for 5 min on $100^{\circ}C$, H2SO4:H2O2 for 5 min on $100^{\circ}C$ and DI-water for 60 min on $95^{\circ}C$. The oxide layer is measured thickness about 1.4~2.2 nm by spectral ellipsometry (SE) and properties as passivation layer by QSSPC (Quasi-Steady-state Photo Conductance). Tunnel oxide layer is capped with phosphorus doped amorphous silicon on both sides and additional annealing process improve lifetime from $3.25{\mu}s$ to $397{\mu}s$ and implied Voc from 544 mV to 690 mV after P-doped a-Si deposition, respectively. It will be expected that amorphous silicon is changed to poly silicon phase. Furthermore, lifetime and implied Voc were recovered by forming gas annealing (FGA) after firing process from $192{\mu}s$ to $786{\mu}s$. It is shown that the tunnel oxide layer is thermally stable.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1371-1382
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• 2016

MicroRNAs (miRNAs) are short non-coding RNAs that post-transcriptionally regulate expression of mRNAs in many biological pathways. Liver plays an important role in the feed efficiency of animals and high and low efficient cattle demonstrated different gene expression profiles by microarray. Here we report comprehensive miRNAs profiles by next-gen deep sequencing in Angus cattle divergently selected for residual feed intake (RFI) and identify miRNAs related to feed efficiency in beef cattle. Two microRNA libraries were constructed from pooled RNA extracted from livers of low and high RFI cattle, and sequenced by Illumina genome analyser. In total, 23,628,103 high quality short sequence reads were obtained and more than half of these reads were matched to the bovine genome (UMD 3.1). We identified 305 known bovine miRNAs. Bta-miR-143, bta-miR-30, bta-miR-122, bta-miR-378, and bta-let-7 were the top five most abundant miRNAs families expressed in liver, representing more than 63% of expressed miRNAs. We also identified 52 homologous miRNAs and 10 novel putative bovine-specific miRNAs, based on precursor sequence and the secondary structure and utilizing the miRBase (v. 21). We compared the miRNAs profile between high and low RFI animals and ranked the most differentially expressed bovine known miRNAs. Bovine miR-143 was the most abundant miRNA in the bovine liver and comprised 20% of total expressed mapped miRNAs. The most highly expressed miRNA in liver of mice and humans, miR-122, was the third most abundant in our cattle liver samples. We also identified 10 putative novel bovine-specific miRNA candidates. Differentially expressed miRNAs between high and low RFI cattle were identified with 18 miRNAs being up-regulated and 7 other miRNAs down-regulated in low RFI cattle. Our study has identified comprehensive miRNAs expressed in bovine liver. Some of the expressed miRNAs are novel in cattle. The differentially expressed miRNAs between high and low RFI give some insights into liver miRNAs regulating physiological pathways underlying variation in this measure of feed efficiency in bovines.

• 대한치과기공학회지
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• 제17권1호
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• pp.26-40
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• 1995

A survey has been performed for the dental technicians and office workers in small cities of Julla buk-do on theis problem of cough, phlegm, wheezing, nasal cattarrh & cold, and breathlessness by using SUN-81-AL survey form which is a guletionaire on respiratory symptons The results of the analysis are as follaus. 1. The complaint on cough was made by 15 dental technicians(21.4% and by 10 office workerr(16.7%). Dental technicians showed higher complaint on cough than office workers. The predietor variable for cough was the working hours for dental technicians and the period of smoking for the office sorkess. 2. The complaints on phelgm was made by 34 dental technicians(48.6%) and by 9 office workers(15.0%). The predictor variable on phelgm was the working hour for dental techniume and the period of smoking for the office workers. There was no statistically significant difference between two group on their complaint level. 3. The complaint on the breathlessnesr was made by 24 dental technicians(34.3%) and by 22 office workers(36.7%). The predictor variable on breathlessness was the period of smoking for dental technicians and the working hour for office workers. 4. The wmplaing on nasal catarrh & cold wax made by 29 dental technicians(41.4%) and 22 office workers(36.7%). The predictr variable on nasal catarrh & cold was the working hour for dental workerr, and the perird of smoking for the office workers. 5. The complaint on wheezing was made by 9 dental technicians(12.9%) and 8 office workers(13.3%). The primary predictor variable on wheezing was the working hour for both groups, and the secondary predictor variable was the period of smoking. 6. The complaint on the chest and lung dislase was made by 12 dental technicians(17.1%) and 4 office workers(6.7%) dental technicians showed bigher complaint. on chest and lung disease than the office workers. Bronchitis was the higher frequency illuess reported from both of the groups among chest and lung disease. 7. In conclusion, the predictor variable on respiratory illness was the working hour for dental techniciane, and the period of smoking for the office workers 8. 25 dental technicians(35.7%) and 9 office workers(15.0%) selected air pllution as the most urgent problem that working environment, has had. There was statistically significant difference between two groups(P<0.001)

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 Proceedings of KSEH.Minamata Forum
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• pp.87-94
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• 2005

Results from previous studies revealed that metal level in the body is related to certain types of diseases. For example. serum copper level with chronic heart failure, iron and transferrin in the blood serum with acute cerebral vascular diseases, Zn in the CNS, lead with neurotoxicity, hypertension, genetic damage, arsenic with cancer skin lesion, Al with neurobehavioral function (cognitive impairment and memory disorder), and etc. The rate of stroke has increased in recent years and several metals were found to be responsible for causing stroke. This study compared several blood metal concentrations between stroke and non-stroke patients. Patients with stroke (116 samples) and non-stroke (111 samples including lowback pain and others) participated in this study. Total of 227 blood samples were collected and participants completed questionnaires regarding age, gender, occupation, residence, alcohol, smoking, and etc. To be qualified into the stroke group, patients have never experienced stroke previously. Subjects only included ischemic stroke and intracerebral hemorrhage patients diagnosed by brain CT and brain MRI. Patients with high risk of metal exposure such as herbal intake and job related exposure were excluded. 10ml of blood samples were analyzed by ICP-MS method at the Center of Nature and Science at Sangji University. Metal geometric mean (SD) concentrations in blood of study subjects showed higher values, 2.64-36.12%, than WHO reference values in Mn, Ni, Hg, Se, and As. Metal concentration in blood of stroke patients non-adjusted for potential confounders was higher except for Hg and also higher except for Ni in adjusted for potential confounders. Co was significantly higher in stroke patients (p=0.002) than non-stroke patients adjusted for potential confounders. Regression coefficient values of stroke patients was 0.17-8.25 in each metals. Odd ratio of stroke patients had 0.96 (Ni)-2.68 (Co) compared to non-stroke cases. This result means that Co increase of 1 raises the risk ratio of stroke by 2.86 times. Based on the results, metal concentration in blood seems to affect incidence of stroke.

• 한국가축번식학회지
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• 제22권4호
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• pp.419-424
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• 1998

토끼 수정란의 전핵에 MT-hGH 유전자를 주입하고 핵이식 기법으로 형질전환 복제수정란의 생산효율과 PCR 검색으로 복제수정란에서 유전자존재 여부를 조사한 바 다음과 같은 결론을 얻었다. 1. MT-hGH 유전자를 주입하여 8- 및 16- 세포기로 자란 수정란을 공핵란으로 사용하여 핵이식을 실시하였던 바, 세포융합률은 각각 60.0%, 62.8% 로 비슷하였으나 정상수정란을 공급핵으로 사용한 80.4% 보다 유의적으로 낮은 융합률을 보였다. 그러나 이들 복제수정란의 체외발달률은 처리군간에 유의적인 차이는 인정되지 않았다. 2. 유전자 주입 후 8- 및 16- 세포기로 자란 수정란의 할구를 이용하여 핵이식으로 복제하고 체외에서 배반포까지 자란 수정란을 PCR -screening으로 유전자를 검출한 결과, 각각 23% 와 33% 의 유전자 양성 수정란을 감별하였다.