• 대한치과교정학회지
• /
• 제15권2호
• /
• pp.175-195
• /
• 1985

Vertical and horizontal growth occur in the craniofacial complex which ensues continuous changes in facial morphology, until the end of active growth period. Longitudinal study for individual is essential, in the research on growth and development, however, the difficulties in obtaining long term subjects in Korea, the research has been limited. The author analyzed the cephalometric roentgenogrems of 43 boys and 47 girls taken from the ages 6 to 10. The subjects were divided into 3 groups according to SN-MP angle and 2 groups according to gonial angle. In this longitudinal study, 21 variables were measure 4. The obtained results were as follows: 1. SN-MP angle and genial angle had no significant changes in each group with age. 2. With age, facial convexity of hard tissue decreased in all groups, facial angle of hard tissue increased in low SN-MP angle group, but facial convexity of soft tissue had no significant changes in all groups with age. 3. In comparison of high SN-MP angle group and low SN-MP angle group, the former had greater facial convexity and smaller facial angle than the latter. 4. SN-MP angle and the ratio of posterior dental height to anterior dental height had reverse correlation in all groups. 5. High genial angle group revealed larger SN-MP angle, anterior dental height facial convexity, but smaller mandibular length, and the ratio of posterior dental height to anterior dental height compared with low genial angle group.

• Journal of Microbiology and Biotechnology
• /
• 제2권2호
• /
• pp.141-151
• /
• 1992

Physiological changes of the murine hybridoma cell line $S3H5/\gamma{2bA2}$ during adaptation to RPMI 1640 medium with 1%(v/v) fetal bovine serum were characterized in terms of cell growth, antibody production, morphology, and metabolic quotients. Cells adapted to 1% serum medium in T-flasks became sensitive to shear induced by mechanical agitation and required at least 5% serum in the medium or spent medium for cell growth in spinner flasks, while cells adapted to 10% serum medium in T-flasks could grow in 1% serum medium in spinner flasks. Consequently, long-term adaptation to low serum media may not give the expected growth enhancement. After adaptation to 1% serum medium, changes in cell morphology were observed. The cells in 10% serum medium were uniform and circular, while cells in 1% medium were irregularly shaped. The DNA contents, which were measured by flow cytometry, were almost constant among the cells in the range of 1% to 10%. Further, no significant changes in energy metabolism and specific monoclonal antibody production rate were observed among these cells.

• 한국환경보건학회지
• /
• 제50권3호
• /
• pp.212-220
• /
• 2024

Background: 2-Ethylhexyl diphenyl phosphate (EHDPP) is widely used as a flame-retardant plasticizer in the production of polyvinyl chloride, adhesives, and food packaging. This chemical has been frequently detected in water, sediment, and indoor environments, and its lipophilicity raises concerns about bioaccumulation. Objectives: In this study, the effects of EHDPP on the development, behavioral changes, and growth hormone (GH) endocrine system of zebrafish larvae were investigated. Methods: Fertilized embryos were exposed to various concentrations (control, solvent control, 0.07, 0.7, 7, 70, and 700 ㎍/L) of EHDPP for 96 h. Developmental toxicity endpoints were observed daily. Behavioral changes under light-dark-light conditions and changes in hormones and genes related to GH/insulin-like growth factors (IGFs) axis were determined. Results: Significant decreases in survival, body length and moving distance were observed in zebrafish larvae exposed to 70 and 700 ㎍/L EHDPP. The concentrations of GH and IGF-1 were significantly decreased in zebrafish larvae exposed to 70 and 700 ㎍/L EHDPP. This change was well supported by changes in the transcription of genes involved in GH, IGF, IGF receptors, and IGF binding proteins. Conclusions: Our observations showed that exposure to 70 and 700 ㎍/L EHDPP could disrupt the feedback circuits of the GH/IGFs axis, ultimately leading to developmental toxicity, hypoactivity, and mortality.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제5권5호
• /
• pp.382-385
• /
• 2000

A mathematical model was developed, based on the time dependent changes of the specific growth rate, for prediction of the typical microbial cell growth in batch cultures. This model could predict both the lag growth phase and the stationary growth phase of batch cultures, and it was tested with the batch growth of Trichoderma reesei and Lactobacillus delbrueckii.

• 한국가금학회지
• /
• 제22권4호
• /
• pp.203-211
• /
• 1995

In order to investigate the effect of feeding live yeast on growth performance, nutrients utilization, tibia mineral deposit and intestinal microorganism changes, a growth assay was conducted with 360 broiler chicks. Treatments were four levels of yeast as 0, 0.025, 0.05 and 0.1% in 1.83% tricalcium phosphate and two levels of yeast as 0 and 0.05% in 1.15% tricalcium phosphate. The crude protein content of live yeast was 45%, and 97% of it was in the pure protein form, with 46.6% of essential amino acids and 53.4% of non-essential amino acids. Growth performance was tended to increase by feeding the yeast but there was no significant difference(P>.05). The protein digestibility was increased as the feeding level of yeast increased. However, digestibilities of fat, fiber, calcium and phosphorus were not affected by the yeast. Ash and calcium content of tibia were increased as the level of yeast increased. Total number of E. coli in small intestine was significantly decreased(P<.05) in chicks fed yeast. Total number of Lactobaci1lus was significantly increased by the yeast feeding. The changes of microorganism in cecum had the same trend with the changes of microorganism in small intestine.

• The Korean Journal of Ecology
• /
• 제21권3호
• /
• pp.187-193
• /
• 1998

Seasonal changes of nitrogen fixation and growth characteristics of Melilotus suaveolens population under different light conditions were quantitatively analyzed during growting period. Height growth of M. suaveolens population was promoted after April and the shade (site 2) showed 10-20% increase of height growth in compared with that of sunny (site 1). Seasonal changes of biomass were in creased after March, the biomass at site 1 attained 78.5% that of site 2 in May. Chlorophyll content was maintained high value from March to April but, Chlorophyll content of leaf at site 1 was decreased 11.7% compared to that of site 2 in May. The nitrogen content of each organ of M. suaveolens showed higher value in March and then decreased, the high nitrogen contents of reproductive organ were achieved at the flowering stage at site 1. The root nodule of M. suaveolens population appeared in March and showed maximum value in early June and decreased remarkably after July, the amount of nodule formation of M. suaveolens at site 2 showed higher than that of site 1. The nitrogen fixation activity of root nodule of M. suaveolens initiated with shoot growth and showed maximum value in mid April, and attained second peak in early June and then decreased after July. The total nitrogen fixation of the plant showed higher value at site 2 than that of site 1. From the overall results, M. suaveolens showed increased growth under half-shady, well ventilated barren soil than fertile sunny site.

• 대한치과교정학회지
• /
• 제26권6호
• /
• pp.677-689
• /
• 1996

• 대한치과교정학회지
• /
• 제19권3호
• /
• pp.15-33
• /
• 1989

The purpose of this study was to investigate changes of the mandible of a growing rat when they are subjected to a retractive force and those after removal of the retractive force. The experimental animals were Sprague-Dawley male rats of four weeks of age. A mandible was retracted with 50 grams of force on each side in the posterior and superior direction for 8 hours per day. The animals were sacrificed after 1 week, 2-week and 4-week force application, and after 4-week force application-4-week force removal period. The changes of rat mandibular growth following retractive force on the growing rat mandible were observed histologically and biometrically. The findings were as follows ; 1. Histologically, the thickness of the condylar cartilage was slightly reduced in the anterosuperior region with the retractive force. However, in the group of 4-week force application-4-week force removal, there was no significant difference in the thickness of the condylar cartilage. 2. There were no significant histological changes in the articular disk and glenoid fossa through the experimental period. 3. The length and anterior height of the mandible subjected to the retractive force were significantly smaller and greater than those of the control group. 4. There were no significant differences in the mandibular length between 4-week force application - 4-week force removal and the control group. 5. It was concluded that a mandibular retractive force produced inhibitory effects in the growth of the mandible, but that these effects were not sustained during mandibular growth in this experimental model.

• 동아시아식생활학회지
• /
• 제19권2호
• /
• pp.169-179
• /
• 2009

The purpose of this study was to investigate nutritional component changes (chlorophylls, vitamin C, and minerals) in two Korean spinach cultivars (Cheongrok, Ddangddali) according to different growth periods, as well as differences in the components of three plant parts (leaves, stems, and roots). Chlorophyll, vitamin C, Na, and Hunter‘s color a/b values reached maximum levels in the spinach leaves after 35 days of planting, while these components did not significantly change in the stems and roots during the growth period. Chlorophyll and vitamin C contents were higher in the leaves than in thestems and roots. On the other hand, moisture content was higher in the stems than in the leaves and roots, and Fe content was highest in the roots. The vitamin C content of this fresh harvested spinach was 2.5 times higher compared to the existing data (Food Nutritive Value Table 2005).

• 생물환경조절학회지
• /
• 제32권3호
• /
• pp.205-209
• /
• 2023

기계적 자극은 식물체의 형태적 변화를 유도하는 것으로 알려져 있다. 본 연구에서는 기계적 자극을 적용한 토마토의 육묘기 동안의 생육 변화를 확인하기 위해 수행되었다. 브러싱 처리가 기계적 자극으로 이용되었으며, 아크릴이 부착된 이송장치를 이용하여 2시간 간격으로 파종 후 10일 이후부터 처리를 진행하였다. 브러싱 처리 동안 생육 변화를 확인하기 위해 3일 간격으로 생육을 조사하였다. 초장과 엽면적은 브러싱 처리에서 대조구에 비해 감소하는 결과를 보였으며 지상부의 생체중과 건물중은 대조구와 유사한 값을 보였다. 총 근장과 지하부 표면적은 브러싱 처리에서 대조구에 비해 증가하였으며, 지하부 부피는 대조구와 브러싱 처리가 유사한 값을 보였다. 결론적으로 토마토 공정묘에 브러싱 처리는 지상부의 생육 감소를 유도하였으며 지하부의 형태적 발달을 증가시키는 것으로 판단된다.