• Title/Summary/Keyword: Stem cell characteristics

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Changes in Transpiration Rates and Growth of Cucumber and Tomato Scions and Rootstocks Grown Under Different Light Intensity Conditions in a Closed Transplant Production System (식물공장형육묘시스템 내 광량에 따른 오이와 토마토 접수 및 대목의 증발산량 및 생육 변화)

  • Park, Seon Woo;An, Sewoong;Kwack, Yurina
    • Journal of Bio-Environment Control
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    • v.29 no.4
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    • pp.399-405
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    • 2020
  • Recently, it is difficult to produce uniform scions and rootstocks with high quality in a greenhouse due to weather extremes. The closed transplant production system is useful for producing scions and rootstocks with desirable morphological characteristics by environment control regardless of weather outside. In this study, we investigated transpiration rates and growth of cucumber and tomato scions and rootstocks grown under different light intensity conditions for precise irrigation control in a closed transplant production system. Hanging system to measure continuously the weight of plug tray consisting of seedlings and substrate with load-cell was installed in each growing bed. Using this system, we confirmed initial wilting point of cucumber and tomato seedlings, and conducted subirrigation when moisture content of substrate was not below 50%. The irrigation time of cucumber scions and rootstocks were 7 and 6 days after sowing, respectively. In tomato scions and rootstocks grown under PPF (photosynthetic photon flux) 300 μmol·m-2·s-1, the irrigation time were 5, 8, 11, and 13 days after sowing. Increasing light intensity increased transpiration rates and differences of transpiration rates by light intensity was higher in tomato seedlings. The growth of cucumber and tomato seedlings was promoted by increasing light intensity, especially, hypocotyl elongation and stem thickening was affected by light intensity. Cumulative transpiration rate of plug tray in cucumber and tomato seedlings was increased by increasing light intensity, and daily transpiration rate per seedling was regressed by 1st-order linear equation with high correlation coefficient. Estimation of transpiration rates by weighing continuously plug tray of vegetable seedlings can be useful to control more accurately irrigation schedule in a closed transplant production system.

Characteristics of bioethanol production using sweet sorghum juice as a medium of the seed culture (단수수 착즙액이용 배양종균의 바이오에탄올 생산 특성 연구)

  • Cha, Young-Lok;Moon, Youn-Ho;Yu, Gyeong-Dan;Lee, Ji-Eun;Choi, In-Seung;Song, Yeon-Sang;Lee, Kyeong-Bo
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.4
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    • pp.627-633
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    • 2016
  • Sweet sorghum [Sorghum bicolor (L)] is one of the major crops for biofuels such as sugarcane and sugar beet which raw materials rich in saccharide. Sweet sorghum juice was extracted from the stem. It's composed of fermentable sugars such as glucose, fructose and sucrose. Ethanol from the extracted sweet sorghum juice can be easily produced by yeast fermentation process. Sweet sorghum juice is consisted of not only sugars but also various nutrients like nitrogen and phosphate. For commercial production of bioethanol, seed culture is one of the important parts of fermentation, so that optimal culture medium should be selected for the reduction of processing costs. In this study, sweet sorghum juice was estimated as a culture medium for seed culture of cellulosic bioethanol. For the comparison of cultures with various substrates, it used YPD including each 5 g/L yeast extract and peptone, sweet sorghum juice and hydrolyzed Miscanthus was taken part in the culture with 2%, 5% and 10% sugar conditions. Based on media of YPD and sweet sorghum juice, cell-mass concentration was obtained maximum more than $2.5{\times}10^8CFU/mL$ after 24 h of cultivation. Consequently sweet sorghum juice is suitable for the cell culture with more than $1.0{\times}10^8CFU/mL$ after 12 h of cultivation. This can be used as a culture medium for the cellulosic bioethanol industry.

Clinical Characteristics, Prognostic Factors and Influence of Prophylaxis in Children with Pneumocystis jirovecii Pneumonia (소아 주폐포자충 폐렴의 임상양상, 위험인자 및 예방요법의 효과 연구)

  • Kim, Seohee;Yoo, Reenar;Sung, Hungseop;Lee, Jina
    • Pediatric Infection and Vaccine
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    • v.23 no.1
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    • pp.31-39
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    • 2016
  • Purpose: The aim of this study was to investigate the prognostic factors for Pneumocystis jirovecii pneumonia (PCP) and to evaluate the influence of PCP prophylaxis in pediatric patients. Methods: From January 2002 to April 2015, patients aged <18 years with a diagnosis of confirmed PCP at our institute were reviewed retrospectively. Clinical characteristics and outcomes were compared according to the groups with or without PCP prophylaxis. Risk factors associated with PCP-related death were analyzed by logistic regression analysis. Results: During study period, a total of 24 patients were diagnosed with PCP by immunofluorescence assay and/or PCR. The median age of the patients was 5 years (range, 3 months-18 years) and 23 (96%) had immunocompromised conditions including hematologic disorders with or without hematopoietic stem cell transplantation (n=15), solid organ transplantation (n=4), and primary immune deficiency (n=4). Most common presenting symptoms were tachypnea and cough (92%, each). At the time of diagnosis, 79% (19/24) and 25% (6/24) suffered from respiratory failure and multi-organ dysfunction syndrome (MODS), respectively. Mechanical ventilation was required in 8 (33%) patients and 5 (21%) patients died of PCP. Multivariate analysis showed that MODS at initial presentation was an indicator of poor prognosis (OR, 17.1 [95% CI 1.13-257.67]; P=0.04). Compared to the patients without PCP prophylaxis, the frequency of MODS at diagnosis, need for mechanical ventilation and length of hospital days were significantly less common in the children who received PCP prophylaxis. Conclusions: MODS at presentation was a significant predictor for poor outcome and PCP prophylaxis could alleviate the clinical courses of pediatric PCP. Prospective study will be mandatory to determine the risk factors for development and deterioration of PCP in children.

Outcome of patients with neuroblastoma aged less than 1 year at diagnosis (진단 시 1세 이하인 신경모세포종 환자의 치료성적)

  • Suh, Jung Min;Lee, Sang Goo;Yoo, Keon Hee;Sung, Ki Woong;Koo, Hong Hoe;Kim, Ju Youn;Cho, Eun Joo;Lee, Suk Koo;Kim, Jhingook;Lim, Do Hoon
    • Clinical and Experimental Pediatrics
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    • v.52 no.1
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    • pp.93-98
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    • 2009
  • Purpose : The purpose of this study was to evaluate the clinical characteristics and outcomes of patients with neuroblastoma aged less than 1 year. Methods : From January 1997 to December 2007, 41 patients aged less than 1 year were diagnosed with neuroblastoma. Patients were divided into 3 risk groups according to the stage of the disease and N-myc amplification. Low-risk patients underwent surgery with (stage 2) or without (stage 1) short-term chemotherapy. Intermediate-risk patients underwent chemotherapy and surgery with or without local radiation therapy. High-risk patients underwent chemotherapy, surgery, radiation therapy, and high-dose chemotherapy/autologous stem cell rescue (HDCT/ASCR). Results : While tumor relapse occurred in only 1 patient, 7 patients died of treatment-related toxicities. Causes of treatment- related death included infection during conventional chemotherapy in 5 patients and acute myocarditis during HDCT/ASCR in 2 patients. The overall 5-year survival (${\pm}$ standard error) and 5-year event-free survival (EFS) rates after diagnosis for all 41 patients were $82.8{\pm}5.9%$ and $80.0{\pm}$6.3%$, respectively, with a median follow-up of 58 (9-137) months. The 5-year EFS rates for low-risk, intermediate-risk, and high-risk patients were 100%, $68.4{\pm}10.8%$, and $66.7{\pm}19.3%$, respectively. Conclusion : Increased efforts to reduce infection-associated toxicity deaths during conventional chemotherapy are needed to further improve the survival of patients with neuroblastoma aged less than 1 year.

Protoplast Fusion of Nicotiana glauca and Solanum tuberosum Using Selectable Marker Genes (표식유전자를 이용한 담배와 감자의 원형질체 융합)

  • Park, Tae-Eun;Chung, Hae-Joun
    • The Journal of Natural Sciences
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    • v.4
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    • pp.103-142
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    • 1991
  • These studies were carried out to select somatic hybrid using selectable marker genes of Nicotiana glauca transformed by NPTII gene and Solanum tuberosum transformed by T- DNA, and to study characteristics of transformant. The results are summarized as follows. 1. Crown gall tumors and hairy roots were formed on potato tuber disc infected by A. tumefaciens Ach5 and A. rhizogenes ATCC15834. These tumors and roots could be grown on the phytohormone free media. 2. Callus formation from hairy root was prompted on the medium containing 2, 4 D 2mg/I with casein hydrolysate lg/l. 3. The survival ratio of crown gall tumor callus derived from potato increased on the medium containing the activated charcoal 0. 5-2. 0mg/I because of the preventions on the other hand, hairy roots were necrosis on the same medium. 4. Callus derived from hairy root were excellently grown for a short time by suspension culture on liquid medium containing 2, 4-D 2mg/I and casein hydrolysate lg/l. 5. The binary vector pGA643 was mobilized from E. coli MC1000 into wild type Agrobacteriurn tumefaciens Ach5, A. tumefaciens $A_4T$ and disarmed A. tuniefaciens LBA4404 using a triparental mating method with E. ccli HB1O1/pRK2013. Transconjugants were obtained on the minimal media containing tetracycline and kanamycin. pGA643 vectors were confirmed by electrophoresis on 0.7% agarose gel. 6. Kanamycin resistant calli were selected on the media supplemented with 2, 4-D 0.5mg/1 and kanamycin $100\mug$/ml after co- cultivating with tobacco stem explants and A. tumefaciens LBA4404/pGA643, and selected calli propagated on the same medium. 7. The multiple shoots were regenerated from kanamycin resistant calli on the MS medium containing BA 2mg/l. 8. Leaf segments of transformed shoot were able to grow vigorusly on the medium supplemented with high concentration of kanamycin $1000\mug$/ml. 9. Kanamycin resistant shoots were rooting and elongated on medium containing kanamycin $100\mug$/ml, but normal shoot were not. 10. For the production of protoplast from potato calli transformed by T-DNA and mesophyll tissue transformed by NPTII gene, the former was isolated in the enzyme mixture of 2.0% celluase Onozuka R-10, 1.0% dricelase, 1.0% macerozyme. and 0.5M mannitol, the latter was isolated in the enzyme mixture 1.0% Celluase Onozuka R-10, 0.3% macerozyme, and 0.7M mannitol. 11. The optimal concentrationn of mannitol in the enzyme mixture for high protoplast yield was 0.8M at both transformed tobacco mesophyll and potato callus. The viabilities of protoplast were shown above 90%, respectively. 12. Both tobacco mesophyll and potato callus protoplasts were fused by using PEG solution. Cell walls were regenerated on hormone free media supplemented with kanamycin after 5 days, and colonies were observed after 4 weeks culture.

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