• 식물조직배양학회지
• /
• 제24권6호
• /
• pp.323-327
• /
• 1997

배지내 생장억제제의 첨가는 투명화 방지에 효과가 없었다. 기내에서 생산된 건전묘와 투명화묘에 있어서 잎과 기공의 구조적 및 형태적 특징을 조사해본 결과 기내건전묘나 포장활착묘는 책상 및 해면세포의 발달이 양호하고 세포간극이 차지하는 면적이 적었으나 기내 투명화묘는 책상세포의 발달이 불량하고 세포간극이 차지하는 면적이 현저히 많았다. 기공의 특성을 조사해본 결과 기내 건전묘는 포장활착묘에 비해 기공의 크기가 작았으며 둥근형태를 띄고 있었으나 투명화묘에 비해 공변세포와 부세포의 구별이 명확하였다. 또한 투명화묘에서는 기공의 형태가 비정상적이었고 표피 왁스의 발달이 전혀 관찰되지 않았다.

• Applied Microscopy
• /
• 제15권1호
• /
• pp.86-100
• /
• 1985

A observation of the ovarian development and oogenesis of Pieris rapae Linne has been carried out during metamorphosis using stereo-microscope, light microscope and electron microscope. The results obtained through this experiment are as follows: 1. The ovarian development and vitellogenesis begin at the 3-day old pupa and the 6-day old pupa respectively, and the adult ovary right after their emergence contains a few mature eggs. 2. The species described above are further observed at six different stages in oogenesis, and the results are summarized as follows. 1) Pieris rapae has polytrophic ovarioles. The cell organelles of the nurse cells are transfered to the oocyte through the ring canal at the early oogenesis. 2) At stage 2, the nuclear envelope of oocyte nucleus is less infolding than that of nurse cell nucleus. In the oocyte cytoplasm a large number of ribosomes are observed. 3) At stage 3 and 4, many micropinocytotic vesicles are observed in the oocyte cytoplasm. These vesicles are fused together to form large proteid yolks. 4) At stage 5, the vitelline membrane is laid down in the intercellular space between the follicle cells and oocyte. 5) At stage 6, the chorion is formed by the follicle cells. 6) A micropyle and a number of aeropyle are observed on the surface of a mature egg.

• Journal of Plant Biotechnology
• /
• 제33권2호
• /
• pp.117-122
• /
• 2006

Comparative studies on medium supply in bioreactors (raft, immersion and ebb and flood) have revealed that multiplication and growth of Alocasia Amazonica were greatest in the raft system, while lowest in ebb and flood system. In the raft system, the basal part of the shoots was continuously in contact with medium, which enabled a constant uptake of nutrients as well as aeration to the explants. The number and the size of leaf stomata were higher in the raft system compared with immersion and ebb&flood system. In the immersion system, plantlets were deformed and epidermal cells in leaves were irregular with a large intercellular space. The results suggested that the medium supply should be controlled properly to maintain normal and healthy plantlets during liquid cultures in bioreactors Which affects morphology and physiology Of the plantlets.

• 미생물학회지
• /
• 제17권1호
• /
• pp.1-15
• /
• 1979

Mycoplasma pneumoniae strain CL-s attached to broth-covered surfaces was examined sequentially during growth from single cells for morphologic and ultrastructural changes using several different electron microscopic techniques. Changes in morphology revealed both round and spindle shapes and observation of cell transitions suggested some type of morphological cycle. The round to-ovoid cells observed in the early stages of growth appeared to be viable, and morphologically and ultrastructurally different from the spherical fors which were produced during the latter stage of growth. The spindle segments were detected appeared to be structurally the same as the terminal cored structure seen in thin sections and may be a growing point or an attachment site of the cell. A tubular structure was observed in the core of the terminal structure and a microtubule-like element appeared to bridge between some spindle segments. A matrix sunstance was observed around single cells as well in the intercellular space of the colonies prepared by critical point metrical triple-layered cytoplasmic mermbranes, surfaces, of which appeared to be structurally different each other, were observed in young cells, whereas symmetrical and thicker membranes were seen in older cells. Small bodies were found in 4d or older cultures and did not appear to contain any internal structures or an easily detectable unit membrane.

• 한국환경과학회지
• /
• 제26권10호
• /
• pp.1147-1153
• /
• 2017

To maintain a rich biological diversity is important to develop for biomaterial resources such as Korean evergreen broad-leaved tree species, the distribution of which is restricted to the southern part of Korean peninsula. We assessed photosynthetic characteristics of Quercus acuta and Castanopsis sieboldii, the representative evergreen broad-leaved trees in Korea, in order to establish a basis for conservation strategy related to distributional change in evergreen broad-leaved tree species according to climate change. Photosynthetic characteristics were evaluated in the sun and shade leaves of the two species. Sun leaves in both species revealed higher light compensation point and maximum photosynthetic rate compared to the shade leaves. In addition, photosynthetic rate was higher in Q. acuta than C. sieboldii, which was supported by a higher leaf nitrogen content and leaf mass per area. Water use efficiency was also higher in Q. acuta as compared to that in C. sieboldii. Similar photosynthetic rate, however, was shown in photosynthetic response to $CO_2$ concentration in the intercellular space. These results suggest that both species could respond differently to the changing environmental factors including climate change, suggesting the possibility of distributional changes resulting from a differential growth rate.

• 치과방사선
• /
• 제25권2호
• /
• pp.343-362
• /
• 1995

The purpose of this study was to investigate chronic radiation effects on the basal cell of the rat tongue epithelium according to different irradiation timing. Forty-two female rats were devided into 5 experimental groups according to different irradiation timing and were irradiated single dose of 396cGy by MK cell irradiator using Cs-137. Experimental rats were sacrificed at the 2nd week, 4th week and 6th week after birth. The specimens were examined with light microscope and transmission electron microscope. The following results were obtained. 1. The first changes after irraditation were vacuoles. The vacuoles were chiefly observed in the cytoplasm, perinuclei area, and nuclei. 2. The most severe degenerative changes in the basal cell layer were observed in all experimental groups. ; cellular disarrangement, vacuole formation, widening of intercellular space, enlarged mitochondria & rER, and chromatin clumping were seen. 3. The cellular degenerative changes were most severe at the 4th week after birth in all experimental group, and the basal cell hyperplasia was seen at the 6th week in the most of experimental groups 4. The experimental groups 3 and 4 show more severe and more prolonged cellular degeneration than experimental groups 1 and 2, which were irradiated in pregnancy, and experimental group 5, which was irradiated after tongue maturation.

• 치과방사선
• /
• 제18권1호
• /
• pp.31-45
• /
• 1988

The author studied the histopathologic changes according to a single or a split dose and the time after irradiation on the acinar cells of rat parotid gland. 99 Sprague Dawley rats, weighing about l20gm, were divided into control and 3 experimental groups. In experimental groups, GroupⅠ and Ⅱ were delivered a single dose of l5Gy, 18Gy and Group Ⅲ and Ⅳ were delivered two equal split doses of 9Gy, 10.5Gy for a 4 hours interval, respectively. The experimental groups were delivered by a cobalt-60 teletherapy unit with a dose rate of 222cGy/min, source-skin distance of 50㎝, depth of l㎝ and a field size of l2×5㎝. The animals were sacrificed at 1, 2, 3, 6, 12 hours, 1, 3, 7 days after irradiation and examined by light and electron microscopy. The results were as follows: 1. As the radiation dose increased and the acinar cells delivered a single dose exposure were more damaged, and the change of acinar cells appeared faster than those of a split dose exposure. 2. The histopathologic change of acinar cells appeared at 1 hour after irradiation. The recovery from damaged acinar cells appeared at 1 day after irradiation and there was a tendency that the recovery from damage of a split dose exposure was somewhat later than that of a single dose exposure. 3. Light microscope showed atrophic change of acinar cells and nucleus, degeneration and vesicle formation of cytoplasm, widening of intercellular space and interlobular space. 4. Electron microscope showed loss of nuclear membrane, degeneration of nucleus and nucleoli, clumping of cytoplasm, widening and degeneration of rough endoplasmic reticulum, loss of cristae of mitochondria, lysosome, autophagosome and lipid droplet. 5. Electron microscopically, the change of rough endoplasmic reticulum was the most prominent and this appeared at 1 hour after irradiation as early changes of acinar cells. The nuclear change appeared at 2 hours after irradiation and the loss of cristae of mitochondria was observed at 2 hours after irradiation in all experimental groups.

• 한국한의학연구원논문집
• /
• 제12권1호
• /
• pp.39-48
• /
• 2006

The Following is a list of specific external and internal morphology of Rheum palmatum L. and R. undulatum L. in Rhei Rhizoma. 1. For the original plants of Rhei Rhizoma in the literatures. 18 plants are reported. 2. The external characteristics of original plant : R. palmatum has a large palmate leaf, its petiole of radical leaf has a simple bristle and its flower is purple and pink color. Whereas R. undulatum has a medium ovate leaf, its petiole of radical leaf is purphish, its stem leaf surrounds a half of stem and its flower is yellowish white color. 3. The character of herbal states : a. diameter and size-- R. palmaum is bigger and heavier than R. undulatum. b. in section--R. palmatum is dark brown color, R. undulatum is bright brown color Fibrovascular bundle is arranged in circle shape in R. patmatum. R. undulatum shows a distingushed wheel shape. 4. The internal characteristics : R. palmatum has a large intercellular space of cork layer, its cambium is clear and a xylem medullary ray is comparatively tight, Whereas R. undulatum has a tight intercettular space of cork layer., its cambium is a few clear and xylem medullary ray is verty tight. As these results, additional study is required to distinguish herbs and their effect among many kinds of same genus-degree of relatedness.

• 원예과학기술지
• /
• 제30권1호
• /
• pp.1-5
• /
• 2012

본 연구는 복숭아 '진미'의 미세균열 발생원인을 구명하기 위하여 시기별로 외과피 조직의 발달양상을 관찰하였으며, 수확기에는 '가납암백도', '천중도백도', '유명'과 외과피 조직의 차이를 비교하였다. 미세균열 발생은 '진미'에서 59.1%로 가장 높았고, '가납암백도' 30.6%, '천중도백도' 21.5%, '유명' 6.4%의 순이었다. '진미'는 만개 후 69일부터 외표피 바로 아래에서 공동화 현상이 쉽게 관찰되었으며, 생육이 진전될수록 공동화 현상이 확대되었다. 또한 수확기에 '진미' 품종은 외과피 층의 수가 다른 품종들에 비하여 적었으며, '천중도백도'와 '유명'에 비하여 외과피층의 두께가 얇고, 아표피 세포들의 크기가 작으며, 모양이 납작하였다. 따라서 복숭아 '진미'의 미세균열은 다른 품종에 비해서 외표피층의 발달 불량과 외과피 바로 아래 부분의 공동화 현상 발달에 기인한 것으로 판단되었다.

• Journal of the Korean Wood Science and Technology
• /
• 제48권6호
• /
• pp.780-790
• /
• 2020

본 연구에서는 낙엽송 열처리재의 세포벽 미세구조와 항팽윤효율을 평가하고, 이들 간의 상호관계를 분석하고자 하였다. 이를 위하여 낙엽송 판재를 190℃와 220℃의 온도 조건에서 12시간, 18시간, 24시간 동안 열처리하였다. 열처리된 낙엽송재의 횡단면을 1,000배 확대하여 관찰한 결과, 열처리재의 경우 세포가 원래의 형태를 유지하지 못 했으며, 세포의 단면이 거칠게 절단되었고, 세포 간 결합이 끊어지면서 세포간극이 늘어났음을 확인할 수 있었다. 또한, 처리 조건 별 팽윤 실험 결과, 열처리 온도와 시간이 증가함에 따라 수분 흡수량과 팽윤량이 감소하였으며, 항팽윤효율은 증가하는 경향을 보였다. 수분 흡수량의 감소는 열처리에 의한 세포벽의 화학적 변화에 영향을 받은 것으로 보이며, 팽윤량의 감소 및 항팽윤효율의 증가는 화학적 변화 뿐만 아니라 세포벽의 구조적인 변화와 같은 물리적인 변화가 복합적으로 영향을 미쳤기 때문인 것으로 생각된다.