• Title/Summary/Keyword: Droplet density

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Histological and Ultrastructural Differentiations of the Neuroepithelial Cells in the Mouse Embryo during Early Neurulation (마우스 초기 신경배형성과정에서 신경상피세포의 조직학적 및 미세구조적 분화)

  • Kim, Yul-A;Chung, Young-Wha
    • Applied Microscopy
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    • v.29 no.1
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    • pp.105-124
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    • 1999
  • Histological and ultrastructural differentiations of the neuroepithelial cells in the mouse embryo during neurulation were observed. The neural plates and grooves consisted of pseudostratified columnar epithelium in the embryonic day (ED) 8 embryo were developed. In the ED 9 embryo, the neural tube was developed in all body length of embryo except both the cephalic and caudal ends. Secondary neurulation was shown at the tail bud of the ED 10 embryo. In the ED 8 embryo, the primitive streak was shown in the posterior end of the embryonic disc. The neuroepithelium, notochord and mesenchyme were well differentiated in the cephalic and cervical portions. In the ED 9 and 10 embryos, the roof plates of neural tubes were constituted of the closing of the surface ectodermal cells in the hindbrain and the neuroepithelial cells in the spinal cord. The floor plate of neural tube were consisted of the low pseudostratified columnar epithelium. The spinal motor nerve fibers were initially differentiated in the ED 10 embryo. According to the electron density of the cell and the differentiation of tell organelles, the neuroepithelial cells in the ED 9 and 10 embryos were classified into three types: dark, intermediate and light types. All types in the ED 9 embryo were observed but the dark cell in the ED 10 embryo was not done. The free ribosomes and polysomes in all neuroepithelial cells were developed. The RER and lipid droplets in the dark cell and the Golgi complex in the intermediate and light cells were observed. Many microfilaments in the cytoplasmic processes of intermediate cell and the microfilaments and microtubules in the light cell processes were observed to be well differentiated.

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Effects of Jaeumkanghwa-tang on the Rat Hypothyroidism Induced by Propylthiouracil (PTU) (자음강화탕(滋陰降火湯)이 Propylthiouracil(PTU)로 유발된 Rat의 갑상선기능저하증에 미치는 영향)

  • Kim, Seok-Jung;Kim, Dong-Chul
    • The Journal of Korean Obstetrics and Gynecology
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    • v.27 no.1
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    • pp.41-64
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    • 2014
  • Objectives: This study was to evaluate the effect of Jaeumkanghwa-tang (JEKHT) on the propylthiouracil (PTU)-induced rat hypothyroidism. Methods: Six groups, each of 8 rats per group were used in the present study - intact vehicle control, PTU control, Levothyroxine ($LT_4$), JEKHT 500, 250 and 125 mg/kg treated groups. JEKHT were administered once a day for 42 days as an oral dose of 500, 250 and 125 mg/kg, and hypothyroidism was induced by daily subcutaneous treatment of PTU 10 mg/kg for 28 days. The changes on the body and organ weight, serum hormone and lipid profiles, liver and testis antioxidant defense factors were observed with histopathology of organs. Results were compared with $LT_4$ 0.5 mg/kg intraperitoneally treated rats in this experiment. Results: PTU treatment, marked decrease of body weight, increases of thyroid weight, decreases of liver, testis, epididymis and prostate weights, decreases of serum Tri-iodothyronine ($T_3$), and Thyroxine ($T_4$) level with increase of serum Thyroid-stimulating hormone (TSH) level, decreases of serum testosterone and dihydrotestosterone (DHT) level with increases of serum Follicular stimulating hormone (FSH) level, increases of serum High density lipoprotein (HDL), decrease of triglyceride content, increase of serum Aspartate aminotransferase (AST) level, decreases of liver and testis antioxidant defense factors were observed. In addition, marked hyperplasia of follicular cells with decreases of follicular colloid contents and diameters was additionally demonstrated with the decrease of hepatocyte numbers per unit area due to hypertrophy of hepatocytes related to lipid droplet depositions, increase of a/oligospermatic epididymal tubules with epididymal atrophic changes, seminiferous tubular atrophy with decrease of stage I~II seminiferous tubules in testis, prostate tubular atrophic changes at histopathological inspections. However, these PTU induced hypothyroidism and related hepatic and male reproductive organ damages were favorably and dose-dependently inhibited by treatment of JEKHT 500, 250 and 125 mg/kg, and JEKHT also effectively regulated the PTU-induced abnormal antioxidant defense factor changes in the both liver and testis. Conclusions: JEKHT 500, 250 and 125 mg/kg dose-dependently inhibited PTU-induced hypothyroidism and related liver and male reproductive organ damages in rats.

Study on Three-Dimensional Analysis of Agricultural Plants and Drone-Spray Pesticide (농작물을 위한 드론 분무 농약 살포의 3차원 분석에 관한 연구)

  • Moon, In Sik;Kown, Hyun Jin;Kim, Mi Hyeon;Chang, Se Myong;Ra, In Ho;Kim, Heung Tae
    • Smart Media Journal
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    • v.9 no.4
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    • pp.176-186
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    • 2020
  • The size and shape of crops are diverse, and the growing environment is also different. Therefore, when one uses a drone to spray pesticides, the characteristics of each crop must be considered, and flight conditions such as the flight height and forwarding velocity of the drone should be changed. The droplet flow of pesticides is affected by various flight conditions, and a large change occurs in the sprayed area. As a result, an uneven distribution of liquid may be formed at the wake, and the transport efficiency will be decreased as well as there would be a risk of toxic scatter. Therefore, this paper analyzes the degree of distribution of pesticides to the crops through numerical analysis when pesticide is sprayed onto the selected three crops with different characteristics by using agricultural drones with different flight conditions. On the purpose of establishing a guideline for spraying pesticides using a drone in accordance with the characteristics of crops, this paper compares the amount of pesticides distributed in the crops at the wake of nozzle flow using the figure of merit, and the sum of transported liquid rate divided by the root mean square of the probability density function.

A Study on the Characteristics of Oil-water Separation in Non-point Source Control Facility by Coalescence Mechanism of Spiral Buoyant Media (나선형 부유 고분자 여재의 Coalescence 특성을 이용한 비점오염원 저감시설의 유수분리특성 연구)

  • Kang, Sung-Won;Kim, Seog-Ku;Kim, Young-Im;Yun, Sang-Leen;Kim, Soo-Hae;Kim, Mee-Kyung
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.8
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    • pp.950-955
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    • 2007
  • Non-point source control system which had been designed only for oil-water separation in the fields of oil refinery and garage was upgraded in this research for the removal of runoff pollutants in impervious urban area. Pollutants including oil from driveway and bridge were eliminated by two types of pathway in the system. One is the coalescence mechanism that the oil droplets in the runoff come into contact with each other in the spiral buoyant media surface and form larger coalesced droplets of oil that are carried upstream to the oil layer. The other is the precipitation that solids in runoff were settled by gravity in the system. In this research, coalescing characteristics of oil and water separation were investigated through image analyses, and efficiencies of the non-point source control system were evaluated using dust in driveway and waste engine oil. Media made of high density and high molecular weight polyethylene was indeterminate helical shape and had sleek surface by analysing SEM photographs and BET. Surface area and specific gravity of media which were measured directly were 1,428 $mm^2$ and 45.3 $kg/m^3$ respectively. From the image analyses of the oil droplets photographs which were taken by using microscope, it was proved clearly that the coalescence was the main pathway in the removal of oil from the runoff. Finally, the performances of the non-point source control system filled up with the media were suspended solid $86.6\sim95.2%$, $COD_{Cr}$, $87.3\sim95.4%$, n-Hexane extractable materials $71.8\sim94.8%$ respectively.