• Title/Summary/Keyword: abnormal growth

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Acute Toxicity of Recombinant Human Epidermal Growth Factor, DWP-401 in Rats (Recombinant Human Epidermal Growth Factor, DWP-401의 랫드에서의 급성 독성)

  • 심점순;오미현;서경원;선우유신;이경민;김효정
    • Journal of Food Hygiene and Safety
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    • v.9 no.1
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    • pp.31-36
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    • 1994
  • The acute toxicity of recombinant human epidermal growth factor, DWP-401 was evaluated in SD rats. Male and female rats aging 6 weeks were administered orally or subcutaneously with 0, 0.125, 0.25, 0.5, 1 and 2 mg/kg of DWP-401. No deaths and no toxic symptoms related to the DWP-401 were observed. The body weights of treated animals were not significantly different from the controls. The results of necropsy revealed no abnormal gross findings of the organs in treated animals. LD50 values of DWP-401 for male and female rats were estimated to be over 2 mg/kg, which is approximately 2, 000 times of expected clinical dose.

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Height Growth Models for Pinus thunbergii in Jeju Island

  • Park, Gildong;Lee, Daesung;Seo, Yeongwan;Choi, Jungkee
    • Journal of Forest and Environmental Science
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    • v.31 no.4
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    • pp.255-260
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    • 2015
  • Height growth models for Pinus thunbergii in Jeju Island were developed in this study using four widely used nonlinear growth models; Exponential, Modified Logistic, Chapman-Richards, and Weibull. All functions were found to be significant at the 1% level. Chapman-Richards model for height-DBH allometry and Weibull model for height-age allometry was chosen as the best model on the all validation. All the model curves showed the similar pattern. Additionally, there was no abnormal pattern when the previous studies were compared. Therefore, these models are highly expected to be used to estimate the tree height using DBH or age for Pinus thunbergii especially in Jeju Island.

Particle Growth in Oxalate Process II; Control of Barium Titanyl Oxalate Particle Size

  • Hyo-Soon Shin;Zee Hoon Park;Chang Hyun Kim;Byung Kyo Lee
    • The Korean Journal of Ceramics
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    • v.2 no.2
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    • pp.70-75
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    • 1996
  • On the basis of growth mechanism proposed by recent work, partile of barium titanyl oxalate was controlled by aging in water. From aging at $25^{\circ}C$ for 3 hours, uniform particles of 0.3 ${\mu}$m were obtained. During aging, abnormal particle growth was observed, which were thought to be caused by impurities in water. With increase of aging time and temperature, particle grows more, and differential growth was promoted. In aging for long time, grown particles were cracked.

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Study on the Diagnosis of Abnormal Prosthetic Valve

  • Lee, Hyuk-Soo
    • Journal of the Institute of Convergence Signal Processing
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    • v.14 no.1
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    • pp.1-5
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    • 2013
  • The two major problems related to the blood flow in replaced prosthetic heart valve are thrombus formation and hemolysis. Reliability of prosthetic valve is very important because its failure means the death of patient. There are many factors affecting the valvular failures and their representatives are mechanical failure and thrombosis, so early noninvasive detection is essentially required. The purpose of this study is to detect the various thromboses formation by using acoustic signal acquisition and its spectral analysis on the frequency domain. We made the thrombosis models using Polydimethylsiloxane (PDMS) and they are thrombosis model on the disc, around the sewing ring and fibrous tissue growth across the orifice of valve. Using microphone and amplifier, we measured the acoustic signal from the prosthetic valve, which is attached to the pulsatile mock circulation system. A/D converter sampled the acoustic signal and the spectral analysis is the main algorithm for obtaining spectrum. Then the spectrum of normal and 5 different kinds of abnormal valve were obtained. Each spectrum waveform shows a primary and secondary peak. The secondary peak changes according to the thrombus model. To quantitatively distinguish the frequency peak of the normal valve from that of the thrombosed valves, analysis using a neural network was employed. Acoustic measurement has been used as a noninvasive diagnostic tool and is thought to be a good method for detecting possible mechanical failure or thrombus.

BREEDING EXPERIMENT ON MUTATION INDUCTION BY IRRADIATION (2) Effects of X-ray and Thermal Neutron Irradiation on Dry Seeds of Chinese Cabbage and Radish.

  • Kim, Dawng Woo;Kim, Yang Choon;Cho, Mi Kyung
    • Journal of Plant Biology
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    • v.5 no.1
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    • pp.1-6
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    • 1962
  • 1) Germination rate was rather irregular than decreasing as increasing dose of radiation and there were no differences between Kyong-Sam and Chuong-Bang of Chinese cabbage. 2) In R1 generation, abnormal leaves from seedling of irradiated seeds were observed. These were more apparent in X-ray irradiation than in thermal neutron. 3) Seedling height was inhibited with increasing dose of X-ray and thermal neutrons. Growth inhibition was more remarkable in X-ray than in thermal neutron. Kyong-Sam demonstrated more sensitivity than Chyong-Bang in both X-ray and thermal neutron. 4) Seedling height produced from seeds subjected to thermal neutrons showed small variation around its mean value, while in X-irradiation there was a greater deviaton from the mean value. 5) Fertility was decreased as increasing with dose, while the frequency of abortive pollen was increased. There were variability of the fertility and frequency of abortive pollen among plants or branches of a plant. 6) The mutants were obtained more in thermal neutron irradiation than in X-ray. The types of mutations obtained in Chinese radish of R2 generation were abnormal leaf, densely glowing leaf, degeneration in growing point and dwarf. The maximum frequency of phenotypic mutations was abnormal leaf mutation.

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Effect of Y2O3 and La2O3 on the Sintering Behavior of Alumina (Y2O3 및 La2O3 첨가가 알루미나의 소결거동에 미치는 영향)

  • Lee, Keun Bong;Kang, Jong Bong
    • Korean Journal of Materials Research
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    • v.26 no.2
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    • pp.90-94
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    • 2016
  • In this study, to increase the strength and enhance the sintering property of $Al_2O_3$, $Y_2O_3$ and $La_2O_3$ were added; the effects of these additions on the sintering characteristics of $Al_2O_3$ were observed. Adding 1% of $Y_2O_3$ to $Al_2O_3$ repressed the development of abnormal particles and reduced the grain boundary migration of $Al_2O_3$, curbing pores to capture particles; as such, the material showed a fine microstructure. But, when over 2% of $Y_2O_3$ was added, the sintering property was reduced because of abnormal particle grain growth and pore formation in particles. Adding 1% of $Y_2O_3$ and $La_2O_3$ to $Al_2O_3$ led to the development of abnormal particles and formed pores in the particles; when over 3% of $La_2O_3$ was added, the sintering property was reduced because the shape of the $Al_2O_3$ particles changed to angled plates.

Information Effect of New Office Investments and Determinant of Firm Value (사옥신축의 정보효과와 기업가치 결정요인에 대한 연구)

  • Lee, Jin-Hwon;Lee, Po-Sang
    • Asia-Pacific Journal of Business
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    • v.11 no.3
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    • pp.95-106
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    • 2020
  • Purpose - This study examines the information effect of the disclosure of new office investments on the Korean stock market and investigates determinant of performance of sample firms. Design/methodology/approach - The sample consists of companies listed on the Korean Exchange that announced investments in new office construction for eleven-years from January 2007 to December 2017. It analyzes excess return using event study methodology and studies the determinants of abnormal return with multiple regression analysis. Findings - We find that abnormal returns of the short and long window are positive on average and statistically significant. In particular, CAR of high growth subsample is a larger positive return than that of the low one both short and long window. Difference in abnormal returns by investment size is observed only in short time window. But there is not observed difference by cash holding level. Research implications or Originality - This finding is able to be added to the evidence of the theory of corporate value maximization academically. Moreover, it shows the possibility that building a new office can have a positive effect on corporate value. It is expected to help investors make decisions because it can provide useful information to market participants in practice.

Growth Behavior of (Ti,W)(C,N) and WC grains in a Co Matrix (Co 액상 내에 공존하는 (Ti,W)(C,N)과 WC입자의 성장 거동)

  • 이보아;윤병권;강석중
    • Journal of Powder Materials
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    • v.11 no.2
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    • pp.165-170
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    • 2004
  • Growth behavior of two different types of grains, faceted and rounded, in a liquid matrix has been studied in the (75WC-25TiCN)-30Co system. Powder samples were sintered above the eutectic temperature for various times under a carbon saturated condition. (Ti,W)(C,N) grains with a rounded shape and WC grains with a faceted shape coexisted in the same Co based liquid. With increasing sintering time, the average size of (Ti.W)(C,N) grains increased continuously and very large WC grains appeared. The growth of rounded (Ti,W)(C,N) grains followed a cubic law, r^3-r^3_0$=kt, where r is the average size of the grains, $r_0$ the initial average size, k the proportionality constant and t the sintering time. indicating a diffusion-controlled growth. On the other hand, the growth of the faceted WC grains resulted in a bimodal grain size distribution, showing an abnormal grain growth. These observations show that the growth behavior of different types of grains is governed by their shape, faceted or rounded, even in the same liquid matrix.

The Effect of Taxol and Ethyl-N-phenylcarbamate (EPC) on Growth and Gravitropism in Zea mays L

  • Park, Yun-Hee;Choy, Yoon-Hi;Lee, June-Seung
    • Journal of Plant Biology
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    • v.39 no.4
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    • pp.287-293
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    • 1996
  • The effect of taxol and ethyl-N-phenylcarbamate (EPC) on the growth and gravitropism of maize roots and coleoptiles was studied. Taxol is known to promote the assembly of microtubules (MTs) and stabilizes MTs by preventing depolymerization. EPC, on the contrary, is an anti-microtubule drug that promotes disassembly of MTs. Taxol, at 1 $\mu$M, inhibited gravitropic response of maize roots to about 40%, but did not inhibit growth; at 10 $\mu$M, it inhibited the gravitropic response of coleoptile segments of maize by approximately 50%, but did not inhibit growth, while 0.5 mM EPC inhibited both the gravitropic response and growth of maize roots by approximately 50%. Taxol, which inhibited the gravitropic response of maize roots and coleoptile segments, had no effect on either the polar or the bilateral transport of auxin. These results indicated that MT polymerization could not occur normally with taxol or EPC, so that if there was any abnormal rearrangement of MT, the gravitropic response was inhibited, which resulted from the inhibition of neither growth nor auxin transport. This results suggested that gravitropic response was related to the MT arrangement, and that both straight growth and the differential growth in gravitropic response could be regulated by different mechanisms.

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Growth Mechanism Evolution of ZnO Nanostructures by Leidenfrost Effect in Ultrasonic Spray Pyrolysis Deposition (초음파 분무 열분해법에 의한 ZnO 나노구조 성장시 Leidenfrost 효과에 의한 성장 거동 변화)

  • Han, In Sub;Park, Il-Kyu
    • Korean Journal of Materials Research
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    • v.27 no.11
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    • pp.609-616
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    • 2017
  • We investigated a Leidenfrost effect in the growth of ZnO nanostructures on silicon substrates by ultrasonic-assisted spray pyrolysis deposition(SPD). Structural and optical properties of the ZnO nanostructures grown by varying the growth parameters, such as substrate temperature, source concentration, and suction rate of the mist in the chambers, were investigated using field-emission scanning electron microscopy, X-ray diffraction, and photoluminescence spectrum analysis. Structural investigations of the ZnO nanostructures showed abnormal evolution of the morphologies with variation of the substrate temperatures. The shape of the ZnO nanostructures transformed from nanoplate, nanorod, nanopencil, and nanoprism shapes with increasing of the substrate temperature from 250 to $450^{\circ}C$; these shapes were significantly different from those seen for the conventional growth mechanisms in SPD. The observed growth behavior showed that a Leidenfrost effect dominantly affected the growth mechanism of the ZnO nanostructures.