• 제목/요약/키워드: LM & SEM

검색결과 74건 처리시간 0.018초

마요네즈 저장 중 미세구조의 변화 (Microstructural Changes of Mayonnaise during Storage)

  • 송영선
    • 한국식품과학회지
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    • 제22권3호
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    • pp.300-306
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    • 1990
  • 마요네즈 저장 중 미세구조의 변화를 광학현미경과 주사 전자현미경으로 관찰하였다. 신선한 마요네즈는 다양한 크기의 지방구로 이루어져 있었으며 지방구의 크기 분포는 정규분포를 보였다. $60^{\circ}C$$-10^{\circ}C$에서 저장하는 동안 지방구의 합일(合一)에 의해 지방구가 커지는 경향을 보였으며, 탁도에 의한 실험결과 또한 이러한 지방구의 합일(合一)현상을 확인시켜 주었다. 전자현미경은 광학현미경에 비해 크기가 작은 지방구를 측정하기가 용이하였으며, 따라서 지방구의 평균 입경이 작았다. 이것은 전자현미경의 높은 해상력과 심도 때문이며, 더욱이 시료를 회석할 필요가 없어 균일한 지방구의 분포를 보여주는 전자현미경 방법은 광학현미경에 비해 유화제품의 지방구 분포를 측정하기에 유리한 방법이라 하겠다.

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브레이크 마모입자의 하전 및 자성 특성 분석 (Analysis of charge and magnetic characteristics of brake wear particles)

  • 조채연;신동호;이건희;우상희;이석환;한방우;황정호
    • 한국입자에어로졸학회지
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    • 제19권2호
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    • pp.31-42
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    • 2023
  • The charge and magnetic characteristics of LM (Low-metallic) and NAO (Non-asbestos-organic) brake wear particles were analyzed. The ratio of charged particles from total particles is about 86% of the LM pad and about 92% of the NAO pad. Number of charge per particle from the NAO pad is also higher than that of the LM pad. The ratio of magnetic particles from total particles increases with the particle size. The ratio of magnetic particles from the LM pad is about 15% for the particles with the size of 1 ㎛, and about 74% for ones with 5 ㎛. The ratio from the NAO pad is about 5% for the particles with the size from 0.5 ㎛ to 2 ㎛, and about 80% for the particles with 5 ㎛. Through the analysis of the components of the two pads with SEM-EDS (Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy), it was found that the LM pad was occupied with more iron fraction than the NAO pad and that PM2.5-10 was occupied with more iron fraction than PM2.5. The particles smaller than 10 ㎛ (i.e. PM10) from the LM pad contained about 83% of charged particles, about 43% of magnetic particles, and about 93% of charged or magnetic particles. PM10 from the NAO pad contained about 88% of charged particles, about 15% of magnetic particles, and about 89% of charged or magnetic particles.

New Record of Thapariella anastomusa (Trematoda: Thapariellidae) Metacercariae in Northern Thailand

  • Phalee, Waraporn;Phalee, Anawat;Wongsawad, Chalobol
    • Parasites, Hosts and Diseases
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    • 제56권1호
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    • pp.49-52
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    • 2018
  • The family Thapariellidae has been reported in only 3 countries since 1990. The objective of this study was to identify Thapariella anastomusa metacercariae in snails in Thailand based on morphological traits using a light (LM) and a scanning electron microscope (SEM). A total of 94 Filopaludina snails were collected and identified as 50 F. martensi martensi and 44 F. doliaris. Metacercariae of T. anastomusa were recovered from the snails by the crushing method. The overall prevalence was 22.3% (21/94), and the mean intensity was 17.0 per snail. The prevalence in F. martensi martensi was 24.0% (12/50) and F. doliaris 20.5% (9/44) with the mean intensity of 18.8 and 14.8 per snail, respectively. SEM revealed traits such as a concave ventral body and well-developed oral and ventral suckers. This study represents the first report of T. anastomusa in South East Asia. While LM and SEM observations provide novel insights into T. anastomusa metacercarial morphology and life history, the trematode's life cycle remains unclear. To date, there has been no report of T. anastomusa causing infections in humans. However, the snails F. martensi martensi and F. doliaris carrying the infective stages of T. anastomosa are frequently consumed by Thai people. This consumption, particularly uncooked snails, may present a risk of Thapariella infections in humans.

First Record of Cosmocephalus obvelatus (Acuariidae) in Common Gulls (Larus canus) from Gangneung, Korea

  • Kim, Se-Min;Park, Bae-Keun;Jung, Bae Dong;Kim, Hyeon-Cheol
    • Parasites, Hosts and Diseases
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    • 제53권1호
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    • pp.101-104
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    • 2015
  • A nematode species belonging to the genus Cosmocephalus was collected from the stomach of 2 common gulls, Larus canus. The common gulls were found dead on the seaside of Gangneung City, the Republic of Korea. The worms were identified and classified by light (LM) and scanning electron microscopy (SEM) on the basis of important taxonomic characters. The nematodes were characterized by a body length 9.1-9.3 mm (males) and 15.5-15.9 mm (females) and cordons recurrent in anterior direction and anastomosing laterally at about the level of anterior quarter of the buccal cavity. The salient bicuspid deirids were located on the posterior to the cordons. Lateral alae were well-developed, extending from the level just posterior of deirids to the level about middle of the body. LM and SEM observations identified the worms as C. obvelatus. This is the first reported case of C. obvelatus infection in common gulls in Korea.

Taxonomy and distribution of two small negligible diatoms of Plagiogrammopsis minima and Diploneis aestuarii from Northeast Asian tidal flats

  • Kim, Bongho;Khim, Jong Seong;Park, Jinsoon
    • Journal of Species Research
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    • 제10권3호
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    • pp.237-245
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    • 2021
  • Tidal flats are well developed in and around the Yellow Sea of Northeast Asia, and benthic diatoms are the most important primary producers in corresponding habitats. In the present study, the taxonomy and distribution of small negligible diatom species from Northeast Asian tidal flats are investigated for better understanding of the diversity of Korean marine benthic diatoms. The presence of Plagiogrammopsis minima and Diploneis aestuarii, which may have been ignored and/or misidentified due to their small size, were identified by both means of light microscopy (LM) and scanning electron microscopy (SEM). Plagiogrammopsis minima has never been reported from Korea before the present study, while Diploneis aestuarii was only once mentioned without any photographic information. Accordingly, we provide the morphological characteristics of the two species in detail with LM and SEM observation. Information on the regional distribution of the two species is also provided. Results of the present study contribute to the better understanding of the biodiversity of the Korean marine benthic diatoms.

한국산 사초과 3속(검정방동산이속, 좀바늘사초속, 너도고랭이속)의 분류학적 검토 (A taxonomic study on the Fuirena, Kobresia, and Scleria of Korea(Cyperaceae))

  • 오용자;이창숙;이재경
    • 식물분류학회지
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    • 제32권4호
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    • pp.363-382
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    • 2002
  • 한국산 사초과 3속, 검정방동산이속(Fuirena), 좀바늘사초속(Kobresia), 너도고랭이속(Scleria) 식물 3분류군을 대상으로 외부형태학적 형질을 재검토하였다. 또한 광학현미경(LM)과 주사전자현미경(SEM)을 사용하여, 줄기와 잎의 단면, 수과와 잎의 표피형을 비교 분석하였다. 줄기의 길이와 너비, 잎의 너비, 비늘조각의 길이, 포의 길이와 너비, 수과의 길이, 모양, 부리의 모양, 화피의 유무, 암술머리 등의 외부형태형질과 수과와 잎의 표피형(수과의 표피세포의 모양, 잎표피의 규소체형, 잎표피세포, 기동세포의 유무), 잎과 줄기의 횡단 모양 등이 속, 종을 구별하는 유효형질이었다. 이들 분류형질을 기준으로 학명과 국명을 재정리하였다.

The Study on the Phase Transition and Piezoelectric Properties of Bi0.5(Na0.78K0.22)0.5TiO3-LaMnO3 Lead-free Piezoelectric Ceramics

  • Lee, Ku Tak;Park, Jung Soo;Cho, Jeong Ho;Jeong, Young Hun;Paik, Jong Hoo;Yun, Ji Sun
    • 한국세라믹학회지
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    • 제52권4호
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    • pp.237-242
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    • 2015
  • $Bi_{0.5}(Na_{0.78}K_{0.22})_{0.5}TiO_3$ (BNKT) lead-free piezoelectric ceramics modified by $LaMnO_3$ (LM) were fabricated by conventional solid-state method. The crystal structure and the morphology of the lead free ceramics were analyzed by XRD (X-ray diffraction) and FE-SEM (Field Emission Scanning Electron Microscopy). The LM modified BNKT ceramics have a phase transition from ferroelectric tetragonal to non-polar pseudo-cubic. Despite decreases in the remnant polarization ($P_r$) and coercive field ($E_c$) in the P-E hysteresis loops, the electric-field induced strain properties were significantly enhanced by the LM modification. The highest value of $S_{max}/E_{max}=412pm/V$ at an applied electric field of 5 kV/mm was found in BNKT-0.01LM ceramic.

한국산 팥꽃나무과의 화분형태학적 연구 (Pollen morphology of Thymelaeaceae in Korea)

  • 정은희;홍석표
    • 식물분류학회지
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    • 제33권3호
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    • pp.255-270
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    • 2003
  • 한국산 팥꽃나무과(Thymelaeaceae Adans.)의 1속(아마풀속: 1종)을 제외한 4속(팥꽃나무속: 4종, 삼지닥나무속 1종, 피뿌리풀속 1종, 산닥나무속 2종)의 화분을 광학현미경(LM)과 주사전자현미경(SEM)으로 관찰하였다. 화분의 크기는 $11.3-60.0{\mu}m$로 소립(피뿌리풀속)에서 중립(팥꽃나무속, 산닥나무속), 대립(삼지닥나무속)까지 다양하게 나타났다. 조사된 분류군의 화분은 모두 단립으로 구형이고, 발아구의 형태는 산공형(10-20개)이다. 외표벽의 표면 무늬는 다소 차이는 있지만 삼면각(trihedral)의 부속요소(subunit)들이 원으로 배열하여 망상의 전형적인 "croton pattern"을 가지고 있다. 모든 부속요소의 중앙에는 하나의 미세돌기가 있고 부속요소의 표면은 평활상(psilate)이다. 팥꽃나무속 화분은 부속요소의 배열에 따라 세가지 유형으로 구별되어진다; (1) Type I: 부속요소들이 서로 붙어서 원을 이루고 부분적으로 연결이 끊어져 있는 형태, (2) Type II: 하나의 독립된 부속요소가 세 개의 면이 뚜렷한 삼면각을 이루는 형태, (3) Type III: 각 부속요소는 독립적으로 존재하나 뚜렷하지 못한 형태. 또한 한국산 팥꽃나무과에 대한 화분형질의 분류학적 적용에 대하여 간단하게 검토하였다.

하악두(下顎頭)의 부분절제(部分切除)된 연골(軟骨) 및 골(骨)의 치유과정(治癒課程)에서 비교원성(非膠原性) 단백질(蛋白質) 분포(分布)에 관(關)한 연구(硏究);주사전자현미경적(走査電子顯微鏡的) 및 면역조직화학적(免疫組織化學的) 연구(硏究) (DISTRIBUTION OF NONCOLLAGENOUS PROTEIN DURING REPAIR OF PARTIALLY RESECTED CONDYLAR CARTILAGE AND BONE;SEM AND IMMUNOHISTOCHEMICAL STUDY)

  • 김명환;이상철
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제18권3호
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    • pp.411-427
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    • 1996
  • The purpose of this study was to observe the healing process and the distribution of fibronectin in injured condylar cartilage and bone by using LM and SEM. In order to perform this study, 40 male rat, weighing about 250g were selected. Under general anesthesia with Pentobarbital sodium, condylar cartilage and neck bone were resected. Then, the wound was irrigated with saline and closed with 5-0 chromic catgut and 4-0 silk by layer-to-layer suturing. The experimental rats were sacrificed by perfusion with 3% paraformaldehyde at 1st and 4th week after operation. The condylar process and surrounding tissues were cut, demineralized, dehydrated and embedded in paraffin. The histological observation of the specimens in LM level was performed after H-E stain and Azan stain. For localization of fibronectin, immunostaining was achieved by the avidin-biotin complex method. To study the change on condylar surface, the specimens were dehydrated, dried, gold coated and were observed with a scanning electron microscope(Hitachi S-2300). The results were as follows ; 1. The cartilage group and the bone group were repaired with epiphyseal cartilage layer on the cut surface as the normal control group. 2. The cut surface was repaired more quickly in the cartilage group than in the bone group. 3. Chondrocytes, diferentiated during healing, were stained strongly to anti-fibronectin, and fibronectin was supposed to participatein chondrocyte differentiation and cartilagenous matrix formation. 4. Fibronectin was distributed more in the new bone than in the old bone, and the osteoblasts surrounding it were also stained strongly. Fibronectin was supposed to participate in new bone matrix formation. 5. Fibronectin is supposed to be associated with the differentiation, migration and adhesion of chondrocyte and osteoblast and to participate in endochondral bone formation.

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Morphology and Molecular Phylogeny of Raillietina spp. (Cestoda: Cyclophyllidea: Davaineidae) from Domestic Chickens in Thailand

  • Butboonchoo, Preeyaporn;Wongsawad, Chalobol;Rojanapaibul, Amnat;Chai, Jong-Yil
    • Parasites, Hosts and Diseases
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    • 제54권6호
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    • pp.777-786
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    • 2016
  • Raillietina species are prevalent in domestic chickens (Gallus gallus domesticus) in Phayao province, northern Thailand. Their infection may cause disease and death, which affects the public health and economic situation in chicken farms. The identification of Raillietina has been based on morphology and molecular analysis. In this study, morphological observations using light (LM) and scanning electron microscopies (SEM) coupled with molecular analysis of the internal transcribed spacer 2 (ITS2) region and the nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1) gene were employed for precise identification and phylogenetic relationship studies of Raillietina spp. Four Raillietina species, including R. echinobothrida, R. tetragona, R. cesticillus, and Raillietina sp., were recovered in domestic chickens from 4 districts in Phayao province, Thailand. LM and SEM observations revealed differences in the morphology of the scolex, position of the genital pore, number of eggs per egg capsule, and rostellar opening surface structures in all 4 species. Phylogenetic relationships were found among the phylogenetic trees obtained by the maximum likelihood and distance-based neighbor-joining methods. ITS2 and ND1 sequence data recorded from Raillietina sp. appeared to be monophyletic. The query sequences of R. echinobothrida, R. tetragona, R. cesticillus, and Raillietina sp. were separated according to the different morphological characters. This study confirmed that morphological studies combined with molecular analyses can differentiate related species within the genus Raillietina in Thailand.