• Korean Journal of Plant Tissue Culture
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• 제27권4호
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• pp.299-307
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• 2000

A large amount of information is currently available for somatic embryogenesis of plants. However, one common problem related to somatic embryos is that the conversion rate can be low for some species. Apical meristems are responsible for post-embryonic growth of the embryo. The low percentage observed is most likely a result of poor apical meristem development or defects in the meristem organization during somatic embryogenesis. In flowering plants, apical meristems are well developed by the late heart stage of zygotic embryo development. In conifers, such as white spruce, apical meristems are formed at the pre-cotyledon stage. Thus, apical meristem development occurs very early, prior to the maturation stage of embryo development. Once formed, meristems are stably determined. In the somatic embryo, as exemplified by white spruce, since embryo development is not synchronous, tissue differentiation including apical meristem formation occurs throughout the“maturation”stage. Different apical meristem organizations can be found among different individuals within a population. In contrast to their zygotic counterparts, the apical meristems appear not to be stably determined as their organization, as the shoot apical meristem especially, can be easily modified or disrupted. Precocious germination seldom results in functional plantlets. All these observations suggest that the conditions for somatic embryo maturation have not been optimized or are not suitable for meristem formation and development. The following strategies could improve meristem development and hence conversion: 1. Simulate in ouuio conditions to promote meristem development prior to the“maturation”treatment.2. Prevent deterioration of apical meristem organization during somatic embryo maturation.3. Promote further meristem development during embryo germination.

• Journal of Families and Better Life
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• 제28권2호
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• pp.193-202
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• 2010

The purpose of this study is to investigate the prevalence of children's somatic symptoms and the relationships among parent and child variables such as parenting attitude, children's anxiety, emotional expressiveness and somatic symptoms. The subjects were 523 6th grade students in four elementary schools located in Seoul, Busan and Daejeon. All subjects were tested with the Korean version of Children's Somatization Inventory (K-CSI), Parental Rearing Attitude Inventory, State-Trait Anxiety for Children (STAIC), and The Emotional Expressiveness Questionnaire. The collected data were analyzed by the frequency and percentage of somatic symptoms the children had experienced during the last 2 weeks; Pearson's correlation and multiple regression were used for the selected data of 10 somatic symptoms which were experienced by over 10% of the children. The results are summarized as follows: First, abdominal pain, headache, dizziness, and memory failure, in that order, were experienced in over 20% of the children. Second, children's somatic symptoms had significant relations with mothers' and fathers' loving-denial attitudes and their anxiety and emotional expressiveness. Third, children's somatic symptoms were influenced by their anxiety and emotional expressiveness, but not by parenting attitude.

• Journal of Ginseng Research
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• 제36권4호
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• pp.442-448
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• 2012

Somatic embryogenesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology such as medicinally important plants. Single embryos develop into normal plantlets with shoots and roots. Therefore, direct single embryogenesis derived from single cells is highly important for normal plant regeneration. Here we demonstrate that the cyclic secondary somatic embryogenesis in Panax ginseng Meyer is a permanent source of embryogenic material that can be used for genetic manipulations. Secondary somatic embryos were originated directly from the primary somatic embryos on hormone-free Murashige and Skoog medium, and proliferated further in a cyclic manner. EM medium (one third of modified MS medium [MS medium containing half amount of NH4NO3 and KNO3] with 2% to 3% sucrose) favored further development of proliferated secondary somatic embryos into plantlets with root system. The plantlets developed into plants with well-developed taproots in half-strength Schenk and Hildebrandt basal medium supplemented with 0.5% activated charcoal.

• Journal of Plant Biology
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• 제39권2호
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• pp.127-135
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• 1996

An efficient system of somatic embryogenesis was established for the red pepper plant (Capsicum annuum L. cv. Nokkwang) usign immature zygotic embryos. The size of the immature zygotic embryos and the concentrations of 2, 4-D and sucrose were found to be critical. Somatic embryos were induced via callus or directly from explants and regenerated into plantlets successfully. When zygotic embryos 1~2 mm long were cultured on the modified Murashige-Skoong (MS) medium supplemented with 2 mg/L 2, 4-D for 3 weeks in the dark, somatic embryos were induced directly from the apical region of zygotic embryos with the highest frequency being approximately 90%. To mature the somatic embryos, ABA and an ethylene inhibitor AgNO3 were used. The highest frequency of shoot regeneration (25% in each) resulted at 2$\mu$M ABA or 20$\mu$M AgNO3 treatment at rates 3.7 and 1.6 times control, respectively. Shoots developed mainly from the cotyledonary node on CoCl2-containing medium, and from the upper side of cotyledon on medium containing AgNO3 while the embryos on the control medium produced shoots from both the cotyledonary node and the upper region of cotyledons both at frequencies of 50%. Indirect somatic embryogenesis via callus was induced at an efficiency of approximately 10% with zygotic embryos 3~4 mm long cultured on MS medium containing 5~10 mg/L, 2, 4-D for 5~7 weeks under a continuous light condition. The plants regenerated from the somatic embryos were morphologically normal. Using scanning electron microscopy, the direct and indirect somatic embryogeneses were observed to follow the globular, heart and torpedo stages, similar to zygotic embryogenesis. Also, suspensors appeared in the early globular and ovoid-shaped late globular embryos during indirect somatic embryogenesis.

• Korean Journal of Plant Tissue Culture
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• 제22권3호
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• pp.157-164
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• 1995

Intact mature zygotic embryos or their excised cotyledons of ginseng, were cultured on media containing various growth regulators such as auxin (2,4D, IAA) and cytokinin(BAP kinetin). In the culture of intact zygotic embryos, auxin inhibited germination but cytokinin did not Somatic embryogenesis occurred only from those of ungerminated embryos. In the culture of cotyledon segment, medium without growth regulators was the most appropriate to somatic embryogenesis. Somatic embryos were produced sporadically over the surfaces of zygotic embryos on medium containing auxin, while on medium without growth regulators, or media containing cytokinin, somatic embryos formed only on the proximal region of cotyledon. on medium containing 2,4-D, somatic embryos originated from multiple cells which comprised epidermal and subepidermal layers of cotyledon, which resulted in poly-somatic embryogenesis. When these somatic embryos were cultured on the same medium, the primary somatic embryos procured secondary embryos, which arose from epidermal or subepidermal single cells.

• Journal of Korean Society of Forest Science
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• 제102권4호
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• pp.537-542
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• 2013

Field performance of somatic plants (somatic embryo derived-plants) of yellow-poplar (Liriodendron tulipifera) produced from somatic embryogenesis was compared with that of seedlings at age 5. In comparison of photosynthetic rate (seedling, $10.67{\mu}mol$ $CO_2m^{-2}s^{-1}$; somatic plant, $9.04{\mu}mol$ $CO_2m^{-2}s^{-1}$), stomatal conductance rate (seedling, 0.2 $H_2Om^{-2}s^{-1}$; somatic plant, 0.166 $H_2Om^{-2}s^{-1}$) and respiration rate (seedling, 1.71 mmol $H_2Om^{-2}s^{-1}$; somatic plant, 1.513 mmol $H_2Om^{-2}s^{-1}$), no significant differences were found between plants. The seedlings were a little higher in comparison of stomatal density (seedling, $23.33/mm^2$; somatic plant, $22.43/mm^2$), length (seedling, $25.83{\mu}m$; somatic plant, $23.46{\mu}m$) and width (seedling, $15.87{\mu}m$; somatic plant, $15.3{\mu}m$). In comparison of DNA content of the leaves using flow cytometry, no differences in ploidy level were found between the seedlings and somatic plants.

• Korean Journal of Animal Reproduction
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• 제23권4호
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• pp.393-398
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• 1999

Somatic cell nuclear transfer is an efficient technique for the multiplication of elite livestock, engineering of transgenic animals, cell therapy and xenotransplantation, and analyzing the interactions between nucleus and cytoplasm, for various agricultural, biomedical and research purposes. Since the first somatic cell clone lamb was born, tremendous progress has been made toward developing technology for animal cloning. Viable farm animals and mice have now been produced by nuclear transfer using various fetal and adult somatic cells as nuclei donors. Transgenic clones were also produced from nuclear transfer of transfected somatic cells. In the future, somatic cell nuclear transfer will provide more numerous opportunities, both in basic and appled research as well as immediate uses in the generations of superior clone and transgenic animals. However, further technology refinement and improved understanding of the process are essential for commercial and basic research applications.

• Environmental Mutagens and Carcinogens
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• 제7권2호
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• pp.103-111
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• 1987

The effects of LET (linear energy transfer) of radiation on the induction of somatic chromosome mutations or gene mutations of Drosophila melanogaster were studied. For detecting somatic chromosome mutations and gene mutations, Drosophila wing spot system and eye-color spot system were used, respectively. The frequencies of somatic chromosome mutations or gene mutations induced after third instar larval treatment with 23 MeV neutrons, thermal neutrons, X-rays were examined. From these data, the RBE(relative biological effectiveness) values of 23 MeV neutrons relative to X-rays for induction of somatic chromosome mutations or gene mutations were calculated. The present results suggest that high LET radiations are efficient than X-ray in producing not only somatic chromosome mutations but also gene mutations.

• Journal of Veterinary Clinics
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• 제24권2호
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• pp.172-176
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• 2007

The objective of this study was to determine the relationship between udder and teat characteristics and somatic cell count (SCC). A total of 749 (73.1%) milk samples from 1,024 quarters of 259 Holstein cows contained less than 200,000 somatic cells/ml, while 132 (12.9%) quarters contained more than 500,000 somatic cells/ml. Prior to data analysis, somatic cell counts were transformed to natural logarithm. The mean SCS {$log_e(SCS/10^3)$} of milk samples from the front quarters was lower than milk samples from the rear quarters. The highest SCS was observed from cows with the step-shaped udder and the pear-shaped teats, respectively. Increased SCS was observed from cows with large teat diameter, short teat length, short distance between the teat tip to floor (p<0.05) and with increase in parity, respectively.

• Journal of Oriental Neuropsychiatry
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• 제32권1호
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• pp.67-79
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• 2021

Objectives: The purpose of this study was to report the effect of Korean medicine treatment on a patient with somatic symptom disorder hospitalized after a traffic accident. Methods: The subject for this study was a patient diagnosed with somatic symptom disorder that worsened after a traffic accident. During hospitalization, herbal medicine, acupuncture, psychotherapy, and other treatments were performed. Clinical effect was evaluated using Heart Rate Variability (HRV), BDI (Beck Depression Inventory)-II, BAI (Beck Anxiety Inventory), Global assessment (G/A), and Numerical rating scale (NRS). Results: After 36 days of treatment, BDI-II score was reduced from 17 to 5. BAI score was reduced from 23 to 8. Overall somatic symptoms and pain showed decreases. Conclusions: Korean medicine treatment might be effective for somatic symptom disorder that is worsened after a traffic accident.