• Title/Summary/Keyword: Growth retardation

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Analysis on Short Crack Growth Rate after Single Overload under Cyclic Bending Moment

  • Song, Sam-Hong;Lee, Kyeong-Ro;Kim, Amkee
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.3
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    • pp.19-26
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    • 2001
  • In order to investigate the effect of single tensile overload on the short crack growth behavior under the out-of-plane cyclic bending moment, crack opening stresses were continuously measured by an elastic compliance method using strain gages. The characteristics of short crack growth after the single tensile overload are analyzed by the effective stress range ratio. Futhermore, the investigation was carried out with respect to various fatigue crack growth behaviors such as the plastic zone size effect on crack retardation, the retarded crack length and the number of cycles.

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A comparative study of methods to predict fatigue crack growth under random loading (랜덤하중 하에서 피로균열진전예측 방법들의 비교)

  • Choi, Byung-Ik;Kang, Jae-Youn;Lee, Hak-Joo;Kim, Chung-Youb
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.235-240
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    • 2003
  • Methods to predict fatigue crack growth are compared in a quantitative manner for crack growth test data of 2024-T351 aluminum alloy under narrow and wide band random loading. In order to account for the effect of load ratio, crack closure model, Hater's equation and NASGRO's equation have been employed. Load interaction effect under random loading has been considered by crack closure model, Willenborg's model and Wheeler's model. The prediction method using the measured crack opening results provides the best result among the prediction methods discussed for narrow and wide band random loading data.

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A Comparative Study of Methods to Predict Fatigue Crack Growth under Random Loading (랜덤하중 하에서 피로균열진전예측 방법들의 비교)

  • Lee, Hak-Joo;Kang, Jae-Youn;Choi, Byung-Ik;Kim, Chung-Youb
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.10
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    • pp.1785-1792
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    • 2003
  • Methods to predict fatigue crack growth are compared in a quantitative manner for crack growth test data of 2024- T351 aluninum alloy under narrow and wide band random loading. In order to account for the effect of load ratio, crack closure model, Hater's equation and NASGRO's equation have been employed. Load interaction effect under random loading has been considered by crack closure model, Willenborg's model and Wheeler's model. The prediction method using the measured crack opening results provides the best result among the prediction methods discussed for narrow and wide band random loading data.

Effect of Light Conditions on the Seasonal Growth and Photosynthetic Ability in Several Wintergrasses (광환경의 차이가 한지형 잔디의 연중 생육 및 광합성 능력에 미치는 영향)

  • 허건양
    • Asian Journal of Turfgrass Science
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    • v.11 no.4
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    • pp.271-280
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    • 1997
  • The short green period of zoysiagrass has been a problem in using for turf. This study was performed to check growth response of several wintergrasses under sunny and shady area in Korea. Wintergrasses of 5 species, 27 cultivars introduced from U.S.D.A., were used in this study. After establishment, two fluctuations of top growth were observed which varied according to the species; first, due to drought in May, second, due to high temperature and humidity from July to August. Red fescues and perennial ryegrasses showed severe growth retardation in sunny area during summer period. Kentucky bluegrasses and tall fescues maintained good Qualities nearly all the year round arid showed slight disease infections. Kentucky bluegrass 'Kenblue' and red fescue 'Agram' grown under shady area showed higher photosynthetic ability than under sunny area, except the temperature range from 30˚C to 40 ˚C under 40,000 lux light in red fescue 'Agram'. And the phorosynthesis was decreased at the temperature range from 35 ˚C to 40 ˚C. Key words: Wintergrass, Top growth, Visual rating, Photosynthesis, Poa pratensis. Festuca arundinacea, Pestuca rubra. Lolium perenne, Agrostis stolonifera.

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The Effect of Recombinant Human Growth Hormone on Growth in Children with Nephropathy Receiving Long-term Steroid Therapy (장기간의 스테로이드 치료를 받고 있는 신병증 환아에서 Recombinant Human Growth Hormone의 효과)

  • Kim, Se-Jin;Kim, Sun-Kyoung;Kim, Sung-Do;Cho, Byoung-Soo
    • Childhood Kidney Diseases
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    • v.10 no.2
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    • pp.142-151
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    • 2006
  • Purpose : Growth retardation is one of the serious problems in children with nephropathy requiring long-term steroid therapy. We observed the efficacy and safety of recombinant human growth hormone(rhGH) on the growth in children with long-term steroid therapy. Methods : We studied 60 children(male 47, female 13) with nephropathy who received rhGH(1 U/kg/week) for more than 0.5 years($1.39{\pm}1.12$). Their mean age was 11.0 years($11.17{\pm}2.62$). They received steroid therapy from January 1987 through July 2005, and the mean duration of steroid therapy was $4.32{\pm}2.97$ years. Among the patients, there were 32 nephrotic syndrome, 9 IgA nephropathy, 4 mesangial proliferative glomerulonephritis, 4 focal segmental glomerulosclerosis, 2 Henoch $Sch\ddot{o}nlein$ nephritis, 2 Alport syndrome and 7 other cases. Data were gathered on the growth parameters, such as growth velocity, height standard deviation score(SDS), IGF-1, IGFBP-3, bone mass density(BMD) and general chemistry changes. Results : Height velocity increased significantly with rhGH therapy from $3.29{\pm}1.95$ to $8.66{\pm}3.75$(cm/yr) and height SDS decreased from $-0.72{\pm}0.93$ to $-1.04{\pm}0.86$ at one year after steroid therapy but increased to $-0.55{\pm}0.96$ at one year after rhGH administration(P<0.05). BMD improved from $0.71{\pm}0.14$ to $0.79{\pm}0.15g/cm^2$(P<0.05). IGF-1 increased from $445.09{\pm}138.01$ to $506.62{\pm}181.31ng/mL$(P<0.05). IGFBP-3 decreased from $4073.75{\pm}700.78$ to $3933.61{\pm}789.25ug/L$ numerically, but there was no statistically significant difference(P=0.533). Conclusion : The administration of rhGH in the short stature patients who received long-term steroid therapy showed improvement in growth parameters such as SDS, growth velocity, and BMD without significant side-effects or changes in the biochemical parameters.

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Growth and Development of Children with Disabilities in Registered Early Educational Institutions (장애아전담시설기관의 장애아에 대한 신체성장 및 발달평가)

  • Eo, Yong-Sook
    • Child Health Nursing Research
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    • v.13 no.1
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    • pp.51-57
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    • 2007
  • Purpose: The purpose of this study was to look for physical growth and developmental retardation of the disabled children in registered educational institutions. Method: The participants in this study were 103 children. The data was collected from January to September 2006. Body weight, height and head circumference were measured and the Denver II developmental screening tool was used to measure personal-social development. Results: For 40.8% of the children body weight was less than the average for Korean children of the same age, for 49.5% height was lower than average and for 44.7% head circumference was lower. For 84.5% of the children there was a delay in personal-social development, for 87.4% a delay in fine motor-adaptive development, for 80.6% a delay in speech development and for 81.6% a delay in gross motor development. Conclusion: Based on the findings of this study, it is necessary to develop an individual developmental programs for these children based on their growth and development status.

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Growth Hormone Treatment in Children with Chronic Kidney Disease (만성 소아 신질환 환자에서의 성장호르몬 치료 인제의대 부산백병원 소아청소년과)

  • Chung, Woo-Yeong
    • Childhood Kidney Diseases
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    • v.13 no.1
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    • pp.14-20
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    • 2009
  • Growth retardation is a common consequenc of chronic kidney disease (CKD) in childhood. Many recent clinical and experimental data indicate that growth failure in CKD is mainly due to a relative GH insensitivity and functional IGF-I deficiency. Glucocorticoids also glucocorticoids interfere with the integrity of the somatotropic hormone axis at various levels. Over the past 10 years, recombinant growth hormone (rhGH) has been used to help short children with chronic kidney disease. A GH dosage of 0.35 mg/kg/week (28 IU/$m^2$/week) appears efficient and safe. Some clinical trial data show that final height will be within the normal target height range when GH treatment is continued for many years without remarkable adverse events.

Effects of Phytohormone on the Root Formation of Stem Cuttings in Panax ginseng C.A. Meyer (묘삼경의 근형성에 미치는 식물 생장 조절물질의 영향)

  • 최광태;양덕춘;양덕조
    • Journal of Ginseng Research
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    • v.9 no.1
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    • pp.42-53
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    • 1985
  • This study was carried out to obtain the basic information about the large scale propagation of ginseng (Panax ginseng C.A. Meyer). Therefore, the stem cuttings of 1-year old ginseng, treated with various concentrations of plant growth regulators for 5 seconds (quick dipping) and 24 hours (prolonged soaking), were cultured. The root formation of stem cuttings was varied with the concentrations, kinds, and treatment methods of plant growth regulators. Besides normal-looking roots various malformed roots were observed. In the prolonged soaking method, the culture of stem cuttings, treated with 10 ppm of IBA or NAA, resulted in profuse root regeneration. And stem cuttings, in quick dipping method, treated with 2000 ppm of IBA or NAA resulted in more excellent root regeneration. In general, IBA was more vigorous for the root formation than NAA, The treatment with 50 ppm kinetin or 100 ppm BA brought good result for the retardation of senescence of stem cuttings and BA treatment was more effective than kinetin. As for the saponin content of roots derived from stem cutting culture, the roots, formed by non-treatment of growth regulators, were higher in saponin content than those formed by treatment of growth regulators.

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A Case of Partial Inverted Duplication of Chromosome 7q (염색체 7번 장완의 부분적 역위 중복 1례)

  • Kim, Hyun Ji;Lee, So Young;Kim, Mi Young;Baek, Chung Sun;Kim, Won Duck;Lee, Dong Seok;Kim, Doo Kwun;Choi, Sung Min
    • Clinical and Experimental Pediatrics
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    • v.46 no.5
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    • pp.510-513
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    • 2003
  • Duplication of chromosome 7q has been reported as either partial or complete. Partial 7q duplication was first described by Carpentier in 1972. Pure partial duplication of the long arm of chromosome 7 is extremely rare and only 16 cases with a pure partial duplication of different 7q segment have been described in the literature. Pure partial duplication of the long arm of chromosome 7 is characterized by growth and developmental retardation, muscular hypotonia, distinct craniofacial dysmorphic features, a short neck and skeletal abnormalities. A 3 month-old male was referred to our department of Pediatrics because of dyspnea, hypotonia and delayed development. He shows growth and developmental delay, hypertelorism, a depressed nasal bridge, low set ears, a short neck and muscular hypotonia. Karyotype revealed 46, XY, dup(7)(q36q33) by GTC-banding. We report a case of a partial inverted duplication of chromosome 7q.

Role of plastidic glucose transporter in source metabolism of Arabidopsis

  • Lee, Youn-Hyung;Hong, Soon-Won;Lee, Jang-Wook;Bhoo, Seong-Hee;Jeon, Jong-Seong;Hahn, Tae-Ryong
    • Proceedings of the Korean Society of Plant Biotechnology Conference
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    • 2005.11a
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    • pp.9-21
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    • 2005
  • To study the biochemical and physiological role of the plastidic glucose transporter (pGlcT) in carbohydrate metabolism, we characterized transgenic plants with mutations in the pGlcT gene (GT), gt-1 and gt-2, as well double mutants of GT and the maltose transporter (MEX1) and GT and the triose phosphate/phosphate translocator (TPT), GT and the cytosolic fructose-1,6-bisphosphatase gene (cFBP), and MEX1 and TPT, gt-1/mex2, gt-1/tpt-2, gt-1/cfbp-1, mex1-1/tpt-2, respectively. Compared to the wild type, all mutants except the gt-1/cfbp-1 mutant lines displayed higher starch accumulation and higher levels of maltose. Starch accumulation is due to a decrease in starch turnover, leading to an imbalance between the rates of synthesis and degradation. Sucrose levels of gt alleles were higher than those in wild-type plants during the light period, suggesting possible nightly supplementation via the maltose transport pathway to maintain proper carbohydrate partitioning in the plant leaves. The gt plants displayed less growth retardation than mex1-1 mutant and gt-1/mex2 double mutant displayed accumulativesevere growth retardation as compared to individual gt-1 and mex1-1 mutants, implying that the maltose transporter-mediated pathway is a major route for carbohydrate partitioning at night. The gt-1/tpt-2, mex1-1/tpt-2 and gt-1/cfbp-1 double mutants had retarded growth and low chlorophyll content to differing degrees, indicating that photosynthetic capacity had diminished. Interestingly, the gt-1/tpt-2 line displayed a glucose-insensitive phenotype and higher germination rates than wild type, suggesting its involvement not only in carbon partitioning, but also in the sugar signaling network of the pGlcT and TPT.

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