• 제목/요약/키워드: small organisms

검색결과 218건 처리시간 0.024초

넙치(Paralichthys olivaceus) 치어조직의 나프탈렌(Naphthalene) 생물농축 (The Bioconcentration of Naphthalene in Tissues of Juvenile Olive flounder, Paralichthys olivaceus)

  • 이경선;류향미
    • 해양환경안전학회지
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    • 제18권6호
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    • pp.530-535
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    • 2012
  • 나프탈렌(Naphthalene)과 같은 다환방향족탄화수소류(Polycyclic aromatic hydrocarbons, PAHs)는 수계에 유입되어 해양생물들에게 영향을 미치게 된다. 나프탈렌은 유류속의 PAHs 내에서 함량이 가장 높으며, 독성이 강하다. 본 연구에서는 대조구(0 ${\mu}g/L$), 1000, 1800, 3200, 5600, 10000 ${\mu}g/L$의 6개 나프탈렌 농도구를 설정하고 넙치 치어에 대한 나프탈렌의 24시간 반수치사농도(24h-$LC_{50}$)을 구했으며, 아가미, 간, 신장, 근육내의 나프탈렌 농도를 분석하였다. 넙치 치어의 24h-$LC_{50}$은 Large 그룹에서 2410.76 ${\mu}g/L$, Small 그룹에서 2230.67 ${\mu}g/L$을 나타내었다. 각 조직에서의 나프탈렌 농도는 간 및 신장에서 아가미 및 근육보다 높았다.

Feasibility of Early Definitive Internal Fixation of Pelvic Bone Fractures in Therapeutic Open Abdomen

  • Choi, Kyunghak;Jung, Kwang-Hwan;Keum, Min Ae;Kim, Sungjeep;Kim, Jihoon T;Kyoung, Kyu-Hyouck
    • Journal of Trauma and Injury
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    • 제33권1호
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    • pp.18-22
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    • 2020
  • Purpose: Damage control laparotomy has contributed to improved survival rates for severe abdominal injuries. A large part of severe abdominal injury occurs with a concomitant pelvic bone fracture. The safety and effectiveness of internal fixation of pelvic bone fracture(s) has not been established. The aim of the present study was to evaluate infection risk in the pelvic surgical site in patients who underwent emergent abdominal surgery. Methods: This single-center retrospective observational study was based on data collected from a prospectively maintained registry between January 2015 and June 2019. Patients who underwent laparotomy and pelvic internal fixation were included. Individuals <18 and ≥80 years of age, those with no microbiological investigations, and those who underwent one-stage abdominal surgery were excluded. Comprehensive statistical comparative analysis was not performed due to the small number of enrolled patients. Results: A total of six patients met the inclusion criteria, and the most common injury mechanism was anterior-posterior compression (67%). The average duration of open abdomen was 98 hours (range, 44-98), and the time interval between abdominal closure and pelvic surgery was 98 hours. One patient (16.7%) died due to multi-organ dysfunction syndrome. Micro-organisms were identified in the abdominal surgical site in five patients (83%), with no micro-organisms in pelvic surgical sites. There was no unplanned implant removal. Conclusions: Internal fixation of pelvic bone fracture(s) could be performed in the state of open abdomen, and the advantages of early fixation may countervail the risks for cross contamination.

광양만 잘피밭에 서식하는 볼낙(Sebastes inermis)의 식성 (Feeding Habits of Sebastes inermis in the Eelgrass (Zostera marina) Bed in Kwangyang Bay)

  • 허성회;곽석남
    • 한국수산과학회지
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    • 제31권2호
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    • pp.168-175
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    • 1998
  • 1994년 1월부터 1994년 12월까지 광양만 대도주변 잘피밭에서 채집된 볼낙의 식성을 조사하였다. 조사기간 동안 채집된 볼낙은 거의 대부분이 $1\~9\;cm$의 체장 범위였다. 볼낙은 잘피밭에서 주로 단각류(옆새우류와 카프렐라류)와 요각류를 먹었으며, 그 외 새우류, 게류, 복족류, 어류 등을 소량씩 먹었다. 볼낙은 성장함에 따라 먹이생물의 조성이 변하였다 크게 3단계로 구분해 볼 수 있었는데, 작은 크기 (2cm SL 이하)에서는 요각류를 가장 많이 먹었다. 체장이 증가하면서 요각류가 차지하는 비율은 크게 낮아진 반면, 단각류가 차지하는 비율이 크게 증가하여 중간 크기 ($2\~9\;cm\;SL$)에서는 단각류가 가장 중요한 먹이생물이 되었다. 그러다가 일정 크기 (10 cm SL) 이상이 되면 잘피밭을 떠나 인근 바위 해안으로 이동하면서 단각류 대신 새우류나 어류로 먹이 전환이 이루어지는 것으로 추정된다. 대체적으로 계절에 관계없이 단각류를 지속적으로 가장 많이 먹었으며, $2\~3\;cm$ 소형 볼낙이 많이 유입된 봄에는 요각류를 비교적 많이 먹었다.

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Mixotrophic 배양조건에 따른 Euglena gracilis의 성장과 지질에 미치는 영향 (Effect of Growth Conditions on the Biomass and Lipid Production of Euglena gracilis Cells Raised in Mixotrophic Culture)

  • 정우철;최종국;강창민;최병대;강석중
    • 한국수산과학회지
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    • 제49권1호
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    • pp.30-37
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    • 2016
  • Microalgae are functional foods because they contain special anti-aging inhibitors and other functional components, such as ecosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and omega-3 polyunsaturated fatty acids. Many of these functional dietary components are absent in animals and terrestrial plants. Thus, microalgae are widely utilized in human functional foods and in the feed provided to farmed fish and terrestrial livestock. Many marine organisms consume microalgae, often because they are in an appropriate portion of the cell size spectrum, but also because of their nutritional content. The nutritional requirements of marine organisms differ from those of terrestrial animals. After hatching, marine animals need small live forage species that have high omega-3 polyunsaturated fatty acid contents, including EPA and DHA. Euglena cells have both plant and animal characteristics; they are motile, elliptical in shape, 15-500 μm in diameter, and have a valuable nutritional content. Mixotrophic cell cultivation provided the best growth rates and nutritional content. Diverse carbon (fructose, lactose, glucose, maltose and sucrose) and nitrogen (tryptone, peptone, yeast extract, urea and sodium glutamate) supported the growth of microalgae with high lipid contents. We found that the best carbon and nitrogen sources for the production of high quality Euglena cells were glucose (10 g L–1) and sodium glutamate (1.0 g L–1), respectively.

북동 대서양에서의 중심층 및 상부점심층산 앨퉁이과 어류 마이크로넥톤의 섭이양식 (Food and feeding activity of micronektonic fish, Gonostomatidae, from meso-and upper bathypelagic layers in the northeastern Atlantic)

  • 고유봉;쥴리안
    • 한국해양학회지
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    • 제21권2호
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    • pp.85-91
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    • 1986
  • 북동대서양 Rockall Trough(수심 약 3,000m)과 Poucupine seabight(수심 약 4,000m)의 중심층 및 상부 점심층에서 채집된 어류 micronekton 중, 우점생물인 Gonostomatidae과 10개 종에 대해 먹이 및 식성을 조사했다. 양해역 모두에서 2종 류에 대해서는 상세히 기술했다. 이들 생물은 일정한 섭이시간대가 없이 비주기적 으로 섭이했고, 한번에 조금씩 섭이하는 경향을 보였으며, 주요먹이생물은 요각류 (약 72% 이상) 및 패충류(약 13% 이상)로서 대부분이 어체장의 10%미만인 소형생 물이었다. 이러한 경향은 먹이생물이 풍부치 못한 환경인 심층에서의 서식에 매우 적합한 적용현상이라고 생각된다. 시식층과 먹이생물을 둘러싼 종간 관계가 역시 논의 되었다.

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Suppression of nitric oxide (NO) production by traditional medicine

  • Lee, Jin Soo;Jeong, Hyun-Ja
    • 셀메드
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    • 제8권2호
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    • pp.8.1-8.5
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    • 2018
  • Nitric oxide (NO) is a small diffusible molecule which plays an important role in various physiological activities. NO is a notable molecule, functioning as a cytotoxic agent and cellular messenger. There has been considerable interest in NO production by activated macrophages because this gaseous metabolite plays a fundamental role in the cytotoxic and cytostatic effects of macrophages towards invasive micro-organisms and tumour cells. No is a bioactive free radical that has been implicated in many physiological functions, plays a critical role during inflammation and therefore constitutes a potential target for developing therapeutics for inflammatory diseases. The use of medicinal plants by the population has been an important alternative the resource in the treatment of various diseases. Its growing acceptance in the medical community has been due to the fact that several plants with biological activities have been scientifically investigated and their efficacy and safety have been proven. In this review, discussed suppressive effects of No production by traditional medicines in RAW 264.7 and THP-1 macrophages.

Purine Derivatives Excreted in Urine as an Indicator Estimating Microbial Yield from the Rumen: A - Review

  • Kanjanapruthipong, J.;Len, R.A.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권3호
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    • pp.209-216
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    • 1998
  • The paper presented here is aimed at increasing knowledge on purine metabolism in ruminants and hence the quantification of microbial cells entering the small intestine from urinaη excretion of purine derivatives. Nucleic acid metabolisms of micro-organisms in the rumen, digestion and absorption of nucleic acids entering the intestines, metabolisms of absorbed and endogenous purines involving de novo synthesis of nucleic acids in the ruminants host, and the relationship between absorbed and excreted purines are reviewed. Principal concerns about an amount of purine derivatives excreted in urine in relation to a change in purine-N: total-N ratios in rumen microbes that leave the rumen are discussed. The use of urinary excretion of purine derivatives as an indicator of the amount of microbial biomass leaving the rumen has to be done with some caution since it may be impossible to get a representative sample of microbes entering the intestine and thus yield estimates are relative rather than absolute.

Pesticide Risk and Benefit Assessment

  • Birtley, Robin D.N.
    • 한국잡초학회지
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    • 제13권4호
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    • pp.195-202
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    • 1993
  • The benefits of pesticides in improving the food quantity and quality requirements for an increasing world population are significant, and they can be described in agronomic, economic and social terms. The risks are assessed from the hazards which are likely to occur in practice ; the hazards are defined by the toxicity of the pesticide to non-target organisms at various exposure levels. There are ways of reducing the risks (mainly by reducing exposure in practice) and improving the benefits of pesticides ; these are known as risk management and benefit management respectively. The overall risk-benefit assessment is facilitated if each component can be expressed in financial terms, but it must be made nationally or locally on a sound technical basis against the prevailing agronomic, socio-economic and political circumstances. Paraquat is used to illustrate the risk-benefit assessment process in general terms, and the conclusion is that the benefits greatly outweigh the risks. It is important to keep the risks of pesticides in perspective with those associated with other naturally occurring chemicals in our diet and with other everyday aspects of life. In an overall context, the pesticide risk is small.

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스크래치 프로그래밍을 활용한 '작은 생물' STEAM 수업이 초등과학 영재에게 미치는 효과 (Effects of STEAM Lessons Using Scratch Programming Regarding Small Organisms in Elementary Science-Gifted Education)

  • 최영미;홍승호
    • 한국초등과학교육학회지:초등과학교육
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    • 제34권2호
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    • pp.194-209
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    • 2015
  • 본 연구의 목적은 스크래치 프로그래밍을 활용한 초등과학 '작은 생물' STEAM 수업을 개발하고 적용하여, 초등 영재학생의 창의적 인성, 창의적 문제해결력, 과학적 태도의 향상에 어떠한 영향을 미치는지 알아보고자 하였다. 개발한 STEAM 수업은 과학 지식과 스크래치 프로그래밍을 통합한 내용적 융합의 방법을 통해 학습자가 창의적 설계와 감성적 체험을 효과적으로 경험할 수 있도록 설계되었다. 연구 대상은 26명의 초등과학 영재학생들이었으며, 양적 및 질적 접근을 통해 자료를 수집하였다. 7차시의 수업을 적용한 결과, 개발한 STEAM 수업이 창의적 인성 및 과학적 태도에 효과가 있었다. 창의적 인성 하위 요소 중, 독립성에서 효과가 있었으며, 과학적 태도 측면에서는 자발성 및 인내심에서 유의한 상승을 보였다. 본 연구는 생명 과학 및 컴퓨터 프로그래밍처럼 STEAM 수업을 위한 효과적인 수단을 통합하는 일이 과학 기술에 대한 학생들의 창의성과 흥미를 신장시킬 수 있음을 제안한다.

폐조직내 Pneumocystis carinii의 전자현미경적 관찰 (Ultrastructural observation of Pneumocystis Carinii in the human lung tissue)

  • 권태정;서영훈;김정숙
    • Applied Microscopy
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    • 제12권2호
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    • pp.1-10
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    • 1982
  • P. carinii is a protozoan which induces an often fatal pneumonitis in a variety of compromised patients. The ultrastructure of P. carinii was studied in a male infant with pneumocystitis pneumonia associated with hypogammaglobulinemia. Four principal structural varieties-small trophozoites, large trophozoites, mature cyst and empty cyst were identified. The ultrastructure of these organisms was similar to the cases previously reported. Relevance of the morphologic findings to the functional aspect were discussed.

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