• 한국균학회지
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• 제1권2호
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• pp.31-33
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• 1973

On September 1972, a blight disease of turf (Arostis canina L.)was found in a golf link in Seoul Country Club at Seoul, Korea. Yellow circular patches of 15-20cm in diameter were observed and spreaded irregulary to collapse of themselves. The roots of the diseased plants were dark in color and were in a final state of decay. We isolated Curvularia sp. from the diseased plants and investigated the morphological and cultural characters. Its characters as follows: Mycelia septate, branched, hyaline or yellowish brown colored. Conidiophores septate, thin brown, unbranched. $65-270{\times}3.5-5{\mu}$. Conidia clustered at the tips of conidiophores, boat form or slightly curved with 1-5 septa, brown; both end cells hyaline; the third cell much larger than the others. $26.1-33.3{\times}9.5-10.1{\mu}$ (4 cell's conidium). The pathogenicity of the fungus to host plant was confirmed by soil inoculation method. We classified the fungus according to Gilman's method as a species Curvularia geniculata (Tracy and Earle) Boedjin.

• Journal of Animal Science and Technology
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• 제58권10호
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• pp.38.1-38.6
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• 2016

Background: Despite the importance of relationships between somatic cell score (SCS) and currently selected traits (milk, fat and protein yield) of Holstein cows, there was a lack of comprehensive literature for it in Iran. Therefore we tried to examine heritabilities and relationships between these traits using a fixed-regression animal model and Bayesian inference. The data set consisted of 1,078,966 test-day observations from 146,765 primiparous daughters of 1930 sires, with calvings from 2002 to 2013. Results: Marginal posterior means of heritability estimates for SCS ($0.03{\pm}0.002$) were distinctly lower than those for milk ($0.204{\pm}0.006$), fat ($0.096{\pm}0.004$) and protein ($0.147{\pm}0.005$) yields. In the case of phenotypic correlations, the relationships between production and SCS were near zero at the beginning of lactation but become increasingly negative as days in milk increased. Although all environmental correlations between production and SCS were negative ($-0.177{\pm}0.007$, $-0.165{\pm}0.008$ and $-0.152{\pm}0.007$ between SCS and milk, fat, and protein yield, respectively), slightly antagonistic genetic correlations were found; with posterior mean of relationships ranging from $0.01{\pm}0.039$ to $0.11{\pm}0.036$. This genetic opposition was distinctly higher for protein than for fat. Conclusion: Although small, the positive genetic correlations suggest some genetic antagonism between desired increased milk production and reduced SCS (i.e., single-trait selection for increased milk production will also increase SCS).

• Applied Microscopy
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• 제34권2호
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• pp.83-93
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• 2004

붉은쏨뱅이의 피부 상피층은 다층상피층으로 지지세포, 선세포, 과립세포 그리고 mitochodria-rich cell들로 구성된다. 상피층은 지지세포의 형태와 구조에 따라 표면층, 중간층 및 기저층으로 구분할 수 있다. 점액세포들은 단세포선으로 상피의 표면층과 중간층에 분포하며, 산성의 비황화 뮤코다당류로 구성된 점액을 가진다. 곤봉상세포는 세포질에 잘 발달된 중심공포, 조면소포체 및 골지체를 가진다. 과립세포는 표면층에 존재하며, 전자밀도가 높은 과립을 가진다. mitochodria-rich cell의 주변부 세포질에는 미세섬유 다발이 발달되어 있으며, 수질부에는 다수의 관상 미토콘드리아를 가진다. 색소세포는 세포질에 존재하는 함유물의 전자밀도에 따라 세 종류로 구분할 수 있다.

• 아시안잔디학회지
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• 제25권2호
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• pp.125-132
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• 2011

잔디가 건조 스트레스를 받은 상태에서 잔디의 생리학적 메커니즘과 건조 상태에서 식물이 회복하는 생리학적 메커니즘을 보다 깊이 이해하고자 한다. 증산작용과 Stomatal Conductance의 상호 관계로 인한 광합성량의 변화, 식물 세포 내부의 변화, 삼투압 조절능력의 변화, 호르몬의 변화, 단백질 변성 등의 생리학적 반응들을 이해하고 건조 스트레스 상태에서 회복하는데 세포내부의 적응 과정, 뿌리의 반응과 같은 생리학적인 측면에 대해 이해하고 건조 스트레스 상태에서 엽록소가 흡수하고 반사하는 Spectral Reflectance의 변화를 이해하고자 한다. 하지만 건조스트레스로 인한 식물의 생리학적 메커니즘에는 아직 많은 의문점을 가지고 있으며 향 후 외부환경 스트레스에 의한 식물의 Self-defense 메커니즘을 더욱 깊게 이해하여 보다 수준 높은 관리기법들을 연구하는데 초점을 맞추어야 할 것이다.

• 한국식물병리학회지
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• 제14권5호
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• pp.458-462
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• 1998

Stem rot symptomof lily caused by Phytophthora was observed in Chilkok, Korea in 1997. Oogonia of Phytophthora were abundantly developed on epidermal tissues of stem and leaves of the diseased plants. The casual fungus was identified as Phytophthora cactorum based on their cultural and morphological characteristics. Sporangia were markedly papillate and the shape was broadly spherical to ovoid both on agar and in water. The size was 28~44$\times$20~28 ${\mu}{\textrm}{m}$ (av. 36~24) and a short pedicel was attached to each sporangium. The fungus was homothallic and oogonia were 28~32 ${\mu}{\textrm}{m}$ (av. 30) in size and slightly yellow. Antheridia were paragynous and spherical or irregularly club shaped. Optimal temperature for mycelial growth was 25~27$^{\circ}C$. The fungus did not grow under 6$^{\circ}C$ and over 34$^{\circ}C$. The fungus was highly pathogenic to three cultivars of lily. Symptom was developed at 4-day after artificial inoculation with zoospores (103 cell/ml) on the stem of lily. The symptom was identical to those produced by natural infection in the field and the plant was blighted within 14 days after inoculation.

• Steel and Composite Structures
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• 제39권3호
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• pp.275-290
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• 2021

The main purpose of this research work is to investigate the critical buckling load of functionally graded (FG) porous plates with graphene platelets (GPLs) reinforcement using generalized differential quadrature (GDQ) method at thermal condition. It is supposed that the GPL nanofillers and the porosity coefficient vary continuously along the plate thickness direction. Generally, the thermal distribution is considered to be nonlinear and the temperature changing continuously through the thickness of the nanocomposite plates according to the power-law distribution. To model closed cell FG porous material reinforced with GPLs, Halpin-Tsai micromechanical modeling in conjunction with Gaussian-Random field scheme are used, through which mechanical properties of the structures can be extracted. Based on the third order shear deformation theory (TSDT) and the Hamilton's principle, the equations of motion are established and solved for various boundary conditions (B.Cs). The fast rate of convergence and accuracy of the method are investigated through the different solved examples and validity of the present study is evaluated by comparing its numerical results with those available in the literature. A special attention is drawn to the role of GPLs weight fraction, GPLs patterns through the thickness, porosity coefficient and distribution of porosity on critical buckling load. Results reveal that the importance of thermal condition on of the critical load of FGP-GPL reinforced nanocomposite plates.

• 한국수정란이식학회지
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• 제12권3호
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• pp.229-246
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• 1997

Implantation is a most important biological process during pregnancy whereby conceptus establishes its survival as well as maintenance of pregnancy. During the periimplantation period, both uterine endometriurn and conceptus synthesize and secrete a host of growth factors and cytokines which mediate the actions of estrogen and /or progesterone and also exert their steroid-independent actions. Growth factors expressed by the materno-conceptal unit en masse have important roles in cell migration, stimulation or inhibition of cell proliferation, cellular differentiation, maintenance of pregnancy and materno-conceptal communications in an autorcrine /paracrine manner. The present review focuses on the role of the intrauterine IGF system during periimplantation conceptus development. The IGF system comprises of IGF- I and IGF- II ligands, types I and II IGF receptors and six or more IGF-binding proteins(IGFBPs). IGFs and IGFBPs are expressed and secreted by uterine endometrium with tissue, pregnancy stage and species specificities under the influence of estrogen, progesterone and other growth factor(s). Conceptus also synthesizes components of the IGF system beginning from a period between 2-cell and blastocyst stages. Maternal IGFs are utilized by both maternal and conceptal tissues; conceptus-derived growth factors are believed to be taken up primarily by conceptus. IGFs enhance the development of both maternal and conceptal compartments in a wide range of biological processes. They stimulate proliferation and differentiation of endometrial cells and placental precursor cells including decidual transformation from stromal cells, placental formation and the synthesis of some steroid and protein hormones by differentiated endometrial cells or placenta. It is also well-documented in a number of experimental settings that both IGFs stimulate preimplantation embryo development. In slight contrast to these, prenatal mice carrying a null mutation of IGF and /or IGF receptor gene do not exhibit any apparent growth retardation until after implantation. Reason (s) for this discrepancy between the knock-out result and the in vitro ones, however, is not known. IGFBPs, in general, are believed to inhibit IGF action within the materno-conceptal unit, thereby allowing endometrial stromal cell differentiation as well as dampening ex cessive placental invasion into maternal tissue. There is evidence, however, indicating that IGFBP can enhance IGF action depending on environrnental conditions perhaps by directioning IGF ligand to the target cell. There is also a third possibility that certain IGFBPs and their proteolytic fragments may have their own biological activities independent of the IGF. In addition to IGFBPs, IGFBP proteases including those found within the uterine tissue or lumen are thought to enhance IGF bioavailability by degrading their substrates without affecting their bound ligand. In this regard, preliminary results in early pregnant pigs suggest that a partially characterized IGFBP protease activity in uterine luminal fluid enhances intrauterine IGF bioavailability during conceptus morphological development. In summary, a number of in vitro results indicate that IGFs stimulates the development of the rnaterno-conceptal unit during the periimplantation period. IGFBPs appear to inhibit IGF action by sequestering their ligands, whereas IGFBP proteases are thought to enhance intrauterine bioavailability of IGFs. Much is remaining to be clarified, however, regarding the roles of the individual IGF system components. These include in vivo evidence for the role of IGFs in early conceptus development, identification of IGF-regulated genes and their functions, specific roles for individual IGFBPs, identification and characterization of IGFBP proteases. The intrauterine IGF club house thus will be paying a lot of attention to forthcoming results in above and other areas, with its door wide-open!

• 대한소아치과학회지
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• 제36권4호
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• pp.619-624
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• 2009

Pyknodysostosis(PKND)는 파골세포의 기능 이상으로 인해 발생하는 상염색체 열성의 매우 드문 경화성 골질환으로 Toulouse-Lautrec syndrome으로 불리기도 한다. PKND의 원인으로는 파골세포 내 cathepsin K의 결핍으로 인해 파골세포의 골개조와 골흡수 기능의 실패가 생기게 되어 연골의 축적과 과도한 골의 광화가 나타나는 것으로 알려져 있는데, 이로 인해 골수염의 위험이 높고 빈번한 골의 파절이 나타난다. 150 cm 이하의 작은 신장, 개방된 천문과 두개골 봉합의 실패, 곤 봉형의 손가락과 중안모의 발달이 저하된 특징적인 안모를 보인다. 본 증례는 전반적인 총생과 전치부 개방교합을 주소로 본과에 내원한 7세 1개월의 여아로, 정형외과에서 PKND로 진단받은 상태였다. 임상 및 방사전 사진 검사상 천문과 두개골 봉합 폐쾌의 실패, 곤봉모양의 손가락, 구개의 고랑,짧은사지와 작은 신장 등의 PKND의 전형적인 임상적 특성을 나타내고 있었다. 비정상적인 골흡수와 골재생기능의 문제로 주소인 총생과 개방교합에 대한 교정적 처치는 시행하지 못했다. 탈락 시기의 유치 발거와 불소도포를 시행한 후 정기 검진을 시행 중인 상태로 PKND에 대한 문헌고찰과 함께 본 증례를 보고하고자 한다.

• 한국어류학회지
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• 제19권3호
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• pp.201-209
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• 2007

광학현미경상에서 복섬, Takifugu niphobles의 피부 표면은 불규칙한 주름을 가지는데, 이들 주름은 등 쪽보다 배 쪽에서 훨씬 뚜렷했다. 피부계는 외부로부터 상피층과 진피층으로 구분되며, 상피층은 다층상피층으로 상피세포, 점액세포, 곤봉상세포, 과립세포 그리고 multivacuolar gland들로 구성되어 있었다. 상피세포는 표면세포, 중간세포, 기저세포로 구분되며, 표면상피의 자유면은 미세융기로 덮여 있었다. 상피층의 선세포는 단세포선과 다세포선으로 구분되었다. 점액분비선은 다세포선의 형태로 점액세포들은 중성 당단백질의 점액물질을 함유하고 있었다. Multivacuolar gland들은 장경 약 $20{\mu}m$의 vacuole cell들로 구성되어 있었다. Vacuole cell들은 커다란 중심공포를 가지며, 잘 발달된 desmosome으로 연결되어 있었다. 점액분비선과 multivacuolar gland는 등 쪽에 비해 배 쪽에서 훨씬 발달되어 있었다. 진피층의 두께는 배 쪽 피부계의 경우에는 상피세포층의 3~5배였다. 진피층은 치밀결합조직으로 교원섬유, 섬유세포, 가시의 기저부, 색소세포 및 다수의 신경세포 분포가 확인되었다.

• 대한수의학회지
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• 제32권3호
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• pp.381-387
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• 1992

건강한 무지개송어의 치어와 실험적으로 세균성 아가미병을 감염시킨 무지개송어의 치어에 있어서 아가미 조직과 그 병원균인 Flavobacterium branchiophila에 대하여 주사형 전자현미경(SEM)과 투과형 전자현미경(TEM)으로 관찰하였다. F branchiophila는 길이 $5{\sim}8{\mu}m$, 폭 약$0.5{\mu}m$의, 2~3균체가 서로 연결된 길고 가는 장간균으로서 균체의 주위에는 다수의 선모(pili)를 갖고있었다. 세균성 아가미병의 초기병소는 초미세 형태학적으로 이차새변의 비후에 의해 시작되며 병원균은 아가미 표면과 일정한 거리를 유지하며 부착되어 있었다. 주사형 전자현미경의 관찰에서 건강한 물고기의 아가미 표면은 미로와 같은 모양과 미세 섬모상의 돌기로 특정지어 질 수 있는 상피세포가 보이나 실험적으로 감염된 아가미 표면에서는 새변의 선단에서 부터의 증생 융합과 함께 표면의 미세구조가 붕괴되어 잘 관찰되지 않았다. F branchiophila는 표면에 실뭉치와 같이 엉클어져 부착되어 있었으며 5% 식염처리후에는 그 형태가 일정치 않았다.