• BMB Reports
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• v.42 no.2
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• pp.72-80
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• 2009

In mammals, major progress has recently been made with the dissection of early embryonic cell specification, the isolation of stem cells from early embryos, and the production of embryonic-like stem cells from adult cells. These studies have overcome long-standing species barriers for stem cell isolation, have revealed a deeper than expected similarity of embryo cell types across species, and have led to a better understanding of the lineage identities of embryo-derived stem cells, most notably of mouse and human embryonic stem (ES) cells. Thus, it has now become possible to propose a species-overarching classification of embryo stem cells, which are defined here as pre- to early post-implantation conceptus-derived stem cell types that maintain embryonic lineage identities in vitro. The present article gives an overview of these cells and discusses their relationships with each other and the conceptus. Consequently, it is debated whether further embryo stem cell types await isolation, and the study of the earliest extraembryonically committed stem cells is identified as a promising new research field.

• Plant Resources
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• v.8 no.1
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• pp.71-74
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• 2005

Activated carbon(AC) can be utilized as a soil conditioner in agricultural crop areas. This study was conducted to investigate the effect of AC on Leaf and Stem Production of Angelica acutiloba as affected by different amounts of AC. The results obtained are summarized as follows. Growth characteristics including plant height and leaf length were the highest when activated carbon added with 10, suggesting that optimum amount of activated carbon was ranged from 10 to $20\%$. Growth and enlargement of the root were improved by $10\%$ AC.

• Journal of Bio-Environment Control
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• v.14 no.4
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• pp.298-301
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• 2005

Potato (Solamum tuberosum 'Dejima') plantlets were investigated on culture type and initial quantity of inoculation in bioreactor and survival rate by hydroponics for mass production. rode stems (1 to 1.5cm in length) of potato plantlets multiplied in vitro were grown for 3 weeks in liquid Murashige and Skoog (MS) medium with sucrose $30 g\; L^{-1}$. When plantlets (80-node inoculation) were raised in 10L balloon type bubble (BB) bioreactor, the healthiest growth of plantlets was obtained from explants cultured in ebb & flow culture with medium supplied periodically 12 times per day. The suitable inoculation quantity of 20L BB bioreactor was 120 pieces of stem segments (mean 2.2g fresh weight) in ebb & flow culture. Number of nodal shoot was eight on the average. In controlled culture room, survival rate of plantlets at 7 days after stem cutting was above $70\%$ when they were acclimatized by hydroponics grown in deep flow and solid medium culture. The highest survival rate of the stem cutting plantlets was in nutrient solution adjusted to EC $1.4dS{\cdot}m^{-1}$. Stem cutting plantlets through one culture could be obtained $670\~900$, when plantlets were grown in ebb & flow culture during 3 weeks using a 20L bioreactor with initial 120 pieces of nodal segments. 11 is possible In do mass production of seedlings cultured in bioreactor and hydroponics.

• KSBB Journal
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• v.25 no.4
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• pp.401-407
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• 2010

We established a strategy for bioethanol production using the hydrolysate of rape stem, in which the inhibitor cocktail was added intentionally. The final goal of this study was to circumvent the detoxification process when the hydrolysate of lignocelluloisic biomass contained the toxic substances in high concentration. When six yeast strains were examined, Sacchromyces cerevisiae ATCC 96581 and Pichia stipitis CBS 7126 were relatively resistant to inhibitor cocktail. Then, using strains 96581 and 7126, we designed a process strategy for bioethanol production, assuming that the concentration of toxic substance in the hydrolysate of rape stem was remarkably high. When strains 96581 and 7126 were inoculated simultaneously, it was observed that strain 7126 produced bioethanol as well as strain 96581, although the concentration of inhibitor cocktail was 18.2% (v/v). Finally, throughout this co-cultivation of strains 96581 and 7126, bioethanol was produced about 6.0 (g/L), and bioethanol yield reached at 0.4 (g-bioethanol/g-reducing sugar) (78.4% of theoretical value).

• Journal of Plant Biotechnology
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• v.4 no.1
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• pp.33-37
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• 2002

Micropropagation and adventitious root production via the culture of Polygonatum odoratum were performed. Stem segments of seedlings of Polygonatum odoratum were the most efficient explants for adventitious shoot formation compared to leaf and root segments. Exogenous cytokinin treatment was required for adventitious shoot formation. Among the cytokinin (BA, Kinetin and Zeatin) tested, BA was most effective for shoot formation from stem segments. Auxin (NAA or IBA) in combination with cytokinin significantly enhanced adventitious shoot formation. Twenty five percent of explants produced adventitious shoots on medium with 2.0 mg/L BAP alone, while 83% of explants produced adventitious shoots on medium with the combination of 2.0 mg/L BAP and 0.1 mg/L IBA. Rooting of adventitious shoots was achieved after transferring to 112 MS medium supplemented with 0.1 mg/L IBA and 0.5 mg/L zeatin. When stem segments were cultured on MS medium with various kinds of auxin (IBA, NAA and 2,4-D), adventitious roots were formed from callus. frequency of adventitious root formation was highest in 2,4-D than NAA and IBA. When roots were in clusters together with parental stem segments, growth of roots actively occurred in hormone-free MS liquid medium. The above results represent that possible application for the mass production of roots and plantlets through in vitro culture system of Polygonatum odoratum.

• International Journal of Stem Cells
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• v.17 no.2
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• pp.102-112
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• 2024

An organoid is a self-organized three-dimensional structure derived from stem cells that mimics the structure, cell composition, and functional characteristics of specific organs and tissues and is used for evaluating the safety and effectiveness of drugs and the toxicity of industrial chemicals. Organoid technology is a new methodology that could replace testing on animals testing and accelerate development of precision and regenerative medicine. However, large variations in production can occur between laboratories with low reproducibility of the production process and no internationally agreed standards for quality evaluation factors at endpoints. To overcome these barriers that hinder the regulatory acceptance and commercialization of organoids, Korea established the Organoid Standards Initiative in September 2023 with various stakeholders, including industry, academia, regulatory agencies, and standard development experts, through public and private partnerships. This developed general guidelines for organoid manufacturing and quality evaluation and for quality evaluation guidelines for organoid-specific manufacturing for the liver, intestines, and heart through extensive evidence analysis and consensus among experts. This report is based on the common standard guideline v1.0, which is a general organoid manufacturing and quality evaluation to promote the practical use of organoids. This guideline does not focus on specific organoids or specific contexts of use but provides guidance to organoid makers and users on materials, procedures, and essential quality assessment methods at end points that are essential for organoid production applicable at the current technology level.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.229-234
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• 2017

Photoperiod is one of the factors affecting productivity of cucumber plant by inducing ethylene hormone production and so triggering flower sex differentiation into female flower. However, only few studies have been perfomed in order to reveal the effect of photoperiod in molecular level in relation to the flower differentiation. Therefore, in this study, Mercy cultivar of cucumber (andromonoecious) was treated with photoperiod of 8, 12, 16 hours of light, while control received no treatment of additional light. Photoperiod of 8 hours was achieved by blocking the sunlight with shade net and 16 hours by giving longer light exposure using white LEDs. Cucumber's flowers were quantified and the apical and lateral shoots were extracted to evaluate the gene profile related to the photoperiod, ethylene production, and female flower differentiation, which were CsACS2, CsETR1, CsCaN, and CsPIF4 using PCR method. Photoperiod of 8 hours affected the production of female flower with average number of 6.7 flowers in main stem and 8.0 flowers in lateral stem, compared to photoperiod of 12 and 16 hours which produced 3.7 and 2.0 flowers in main stem with 7.0 and 11.3 in lateral stem, respectively. In silico studies in this experiment resulted in proposed model of signal transduction that showed the connection between ethylene production and flower differentiation. PCR analysis confirmed the expression of CsACS2, CsETR1, and CsCaN, that was positively correlated with numbers of female flowers in cucumber, but the expression of CsPIF4 that represent photoperiod haven't been confirmed correlated with the ethylene production and flower differentiation.

• Archives of Plastic Surgery
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• v.39 no.6
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• pp.585-592
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• 2012

During the past decade, many studies using platelet-rich plasma (PRP) or adipose-derived stem cells (ASCs) have been conducted in various medical fields, from cardiovascular research to applications for corneal diseases. Nonetheless, there are several limitations of practical applications of PRP and ASCs. Most reports of PRP are anecdotal and few include controls to determine the specific role of PRP. There is little consensus regarding PRP production and characterization. Some have reported the development of an antibody to bovine thrombin, which was the initiator of platelet activation. In the case of ASCs, good manufacturing practices are needed for the production of clinical-grade human stem cells, and in vitro expansion of ASCs requires approval of the Korea Food and Drug Administration, such that considerable expense and time are required. Additionally, some have reported that ASCs could have a potential risk of transformation to malignant cells. Therefore, the authors tried to investigate the latest research on the efficacy and safety of PRP and ASCs and report on the current state and regulation of these stem cell-based therapies.

• Korean Journal Plant Pathology
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• v.13 no.2
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• pp.105-112
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• 1997

Didymella bryoniae, gummy stem blight fungus of cucurbits, has been known not to produce its pycnidium in vitro without irradiation. Various methods for producing pycnidiospores of the fungus as an inoculum have been used. However, those methods have not been verified in terms of efficiency of the productivity, activity and synchronous maturation of the inoculum. Therefore, a pycnidiospore production method in vitro that is highly reliable and reproducible has to be developed to obtain a large amount of inoculum for screening disease resistant varieties or effective fungicides. Here we standardized a mass-production technique for pycnidiospores of D. bryoniae in vitro by comprehensively finding the optimal conditions such as kinds and thickness of cultural medium, growing temperature, and quality and duration of irradiation as well as examining the activity and pathogenicity of the pycnidiospores reproduced. In brief, mycelial colony on the PDA plate was cultured at 26$^{\circ}C$ for 2 days under the darkness, and then the plate was irradiated under the UV light (12 hr/a day) for 2~3 days at the same temperature(26$^{\circ}C$). Two days after UV irradiation, a great number of pycnidia was simultaneously formed. This plate was subjected to darkness again for 4~5 days to mature pycnidiospores. We could obtain a large amount of inoculum that is synchronously matured in a short period of time through the above procedures.

• Plant Resources
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• v.7 no.3
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• pp.233-237
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• 2004

This study was conducted to develop effective production system in greenhouse for leaves and stems of Angelica acutiloba by using connect pots in 2003 and 2004. Seed germination rate and plant biomass of Angelica acutiloba collected in 2004 were higher than those harvested in 2003. Germination rate of Angelica acutiloba seeds collected in 2003 was 10％, while germination rate of seeds collected in 2004 was above 90％. Especially, plant growth and yield of Angelica acutiloba grown in connect pots sized with 4 ${\times}$ 4 ${\times}$ 5cm(length ${\times}$ width ${\times}$ height) were the highest. These results indicate that leaf and stem production of Angelica acutiloba can be improved by using connect pots and optimizing seed collecting time in greenhouse.