• Korean Journal of Environmental Agriculture
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• v.1 no.1
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• pp.59-64
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• 1982

Studies on the effect of soil moisture, different seasons, harvesting periods and nitrogen application on the nitrate content of radish(Raphanus sativus L. var. niger(Mill.) S. Kerner) were carried out in pot and green house. The results are as follows; The low level of soil moisture leads to an increased nitrate accumulation in radish root. The nitrate content was found to be higher in spring crops and lower in summer ones. It was decreased during harvesting period. The application of nitrogen fertilizer increased the nitrate content in radish root. We found the highest content in petioles with lesser content in roots and leaf blades in that order. The multiple regression analysis and the nutritional value of nitrate content in radish were discussed.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.45-49
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• 2002

The leaf and petiole segments of Farfugium japonica were cultured to investigate the influence of growth regulators on their callus induction and plant regeneration. The callus induction and growth showed a good response both leaf and petiole on MS media supplemented with 1∼2 mg/L 2,4-D and 1∼2 mg/L BA. Callus induction and growth were more effective in petiole segments than leaf one. The highest percentage of plant regeneration was obtained from 60-day-old calli on MS medium supplemented with 1 mg/L NAA and 2 mg/L BA. When subcultured to the same medium for about 60 days, multiple shoots were developed from regenerating callus. The shoots produced roots after transferring to rooting medium containing 0.5 mg/L IAA. The plantlets over 50 mm in height were successfully acclimatized in vermiculite, and the survival rate was over 95%.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.131-132
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• 2003

Leaf discs and apical meristems were cultured in Murashige and Skoog (MS) medium supplemented with cytokinin and auxin at different concentrations. Callus production was observed in all tested media after six days of incubation. Callus produced in the presence of high concentration of NAA (2.0mg/1) was fragile in texture and yellow in colour. Highest callus formation was observed from leaf discs in the medium supplemented with 1.0mg/1 NAA and 0.5 mg/l BAP in dark at $25{\pm}1{\circ}C$. Percentage of callus formation was 95% and mean callus fresh weight was 654.88 43.53 mg. Shoots were induced from the callus after 4 weeks in 1/2MS medium supplemented with BAP and kinetin both at 0.5mg/1. When elongated shoots were separated and transferred into multiplication medium (MS+0.5mg/1 BAP+0.5mg/1 kinetin) multiplication rate was 6.4 after 6 weeks. Higher concentrations of BAP caused callus production at the base. Direct shoot induction was observed from apical meristems in MS medium in the presence of 0.175 mg/1 IAA + 2.25mg/1 BAP and 0.175 mg/1 IAA + 3.0 mg/1 BAP in 16 hour day at $25{\pm}1{\circ}C$. Explants (apical meristems) elongated to form a single shoot forming a callus at the base. Adventitious buds were sprouted out from the base. Percentage explants which producing shoots was 28.57 and 65.5 respectively. Multiple shoot induction was also observed in the same media. Highest multiple shoot production was observed in the presence of 0.175 mg/l IAA and 3.0mg/l BAP, Mean number of shoots per explant was 5.36 and the mean shoot length was $16.66{\pm}4.15$mm. Shoots (20 30m length) were tested for root induction. Excised shoots were transferred into rooting media, which contains different concentrations of NAA and IAA. Best rooting performance was observed in 1/2MS medium supplemented with 0.1mg/1 NAA after 10 days of incubation in 16 hr photoperiod at $25{\pm}1{\circ}C$. Mean number of roots per shoot was 6 and the mean root length was 252mm. Rooted plantlets were transferred into sterile coir dust:sand (1:4) mixture and maintained in a humid chamber for two weeks, They were gradually exposed to the natural environment. After three weeks they were transferred to pots containing coir dust:sand (1:2) mixture for further development where the 90% survival was observed.

• 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.

• Korean Journal of Social Welfare Studies
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• v.41 no.4
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• pp.369-393
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• 2010

This study examines the factors influencing Korean international adoptee's search for their birthparents. Considering that the search for birthparents is general needs for adoptees, Korean government should support their searching activities and, first of all, understand their characteristics. The research model was constructed based on the results of previous studies, and the data set of conducted by ministry of health and welfare was reanalyzed for this study. The subjects of the survey were Korean-born adoptees (who are more than 16 years old) in North America, Europe, and Australia. The research questionnaire was translated to English and French, and the survey was conducted on line. A total of 290 questionnaires were included in the analysis. Since survey was conducted on line, the missing rate of the data was relatively high. So, multiply imputed five data sets were used for analysis. Among the variables included in research model, the age group of adoptees, experience of identity crisis in their life, the first time when they became actively interested in Korean roots, the age at the time of adoption, and the attitudes of adoptive parents toward their search were significantly related to their search for birthparents. Adoptees in the age group of 30~34 had more actively participated in search compared to their reference group (which is the age group of more than 35 years old). The earlier they became actively interested in Korean roots, they tended to be more active in searching activities. Also, the experience of identity crisis in life and the age at the time of adoption were positively related to their search. Although most of adoptive parents have supported their search, the adoptees who reported that they didn't know their adoptive parents' attitude toward search, or their parents deceased had more actively participated in search for their birthparents. Some implications for adoption policy and practice were discussed based on the results of the study.

• Journal of Plant Biotechnology
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• v.41 no.2
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• pp.94-99
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• 2014

This study was conducted to elucidate the effect of light sources and explant types on in vitro shoot multiplication and rooting of a rare and endangered plant Abeliophyllum distichum. Both apical buds and axillary buds were used as explants under 4 different light sources, cool white florescent light (F), 100% blue light-emitting diode (LED) (B), 50% blue and 50% red LED mixture (BR), and 100% red LED (R). Clear difference was observed in terms of shoot proliferation by light sources types but not by position-dependent explant types. Multiple shoot induction rates were enhanced under both B and BR light sources. Spontaneous rooting was induced in shoot induction medium under B light source. Both the rates of rooting and numbers of roots per explant were higher in apical bud explants compared to axillary bud explants. Interestingly R light source stimulated shoot elongation but inhibited root development. Therefore, our results suggest that the use of apical bud explants under B or BR light sources is suitable for in vitro micropropagation of a rare and endangered plant species, Abeliophyllum distichum.

• Journal of Life Science
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• v.25 no.9
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• pp.984-992
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• 2015

Sanguinarine is a benzophenanthridine alkaloid originally isolated from the roots of Sanguinaria canadensis. It has multiple biological activities (e.g., antioxidant and antiproliferative) and immune-enhancing potential. In this study, we explored the proapoptotic properties and modes of action of sanguinarine in human hepatocellular carcinoma HepG2 cells. Our results revealed that sanguinarine inhibited HepG2 cell growth and induced apoptosis in a dose-dependent manner. The induction of apoptosis by sanguinarine was associated with the up-regulation of Fas and Bax, the release of cytochrome c from the mitochondria to the cytosol, and the loss of the mitochondrial membrane potential. In addition, sanguinarine activated caspase-9 and -8, initiator caspases of the intrinsic and death extrinsic pathways, respectively, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose) polymerase. Sanguinarine also triggered the generation of reactive oxygen species (ROS). The elimination of ROS by N-acetylcysteine reversed sanguinarine-induced apoptosis. Furthermore, sanguinarine induced the dephosphorylation of Akt and the phosphorylation of mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38. The growth inhibition was enhanced by the combined treatment of sanguinarine with a phosphatidylinositol 3'-kinase (PI3K) inhibitor and an ERK inhibitor but not JNK and p38 inhibitors. Overall, our data indicate that the proapoptotic effects of sanguinarine in HepG2 cells depend on ROS production and the activation of both intrinsic and extrinsic signaling pathways, which is mediated by blocking PI3K/Akt and activating the ERK pathway. Thus, our data suggest that sanguinarine may be a natural compound with potential for use as an antitumor agent in liver cancer.

• Korean Journal of Microbiology
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• v.49 no.1
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• pp.17-23
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• 2013

Candida biofilms are organized microbial communities growing on the surfaces of host tissues or indwelling medical devices, and the biofilms show enhanced resistance against the conventional antifungal agents. The roots of Coptidis chinensis have been widely used for medicinal purposes in East Asia. The present study was aimed to assess the effect of C. chinensis aqueous extract upon preformed biofilms of 10 clinical Candida albicans isolates and the antifungal activities which contribute to inhibit the C. albicans biofilm formation. Its effect on preformed biofilms was judged using XTT [2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide)] reduction assay, and metabolic activity of all tested strains was reduced significantly ($57.3{\pm}14.7%$) at $98{\mu}g/ml$ of the C. chinensis extract. The extract damaged the cell membrane of C. albicans which was analyzed by fluorescein diacetate and propidium iodide staining. The anticandidal activity was fungicidal, and the extract obstructed the adhesion of C. albicans biofilms to polystyrene surfaces, arrested C. albicans cells at $G_o/G_1$ as well, and reduced the growth of biofilms or budding yeasts finally. The data suggest that C. chinensis has multiple antifungal effects on target fungi resulting in preventing the formation of biofilms. Therefore, C. chinensis holds great promise for exploring antifungal agents from natural products in treating and eliminating biofilm-associated Candida infection.

• Journal of Korean Neurosurgical Society
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• v.48 no.2
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• pp.119-124
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• 2010

Objective : Disc herniations at the L1-L2 and L2-L3 levels are different from those at lower levels of the lumbar spine with regard to clinical characteristics and surgical outcome. Spinal canals are narrower than those of lower levels, which may compromise multiple spinal nerve roots or conus medullaris. The aim of this study was to evaluate the clinical features and surgical outcomes of upper lumbar disc herniations. Methods : We retrospectively reviewed the clinical features of 41 patients who had undergone surgery for single disc herniations at the L1-L2 and L2-3 levels from 1998 to 2007. The affected levels were L1-L2 in 14 patients and L2-L3 in 27 patients. Presenting symptoms and signs, patient characteristics, radiologic findings, operative methods, and surgical outcomes were investigated. Results : The mean age of patients with upper lumbar disc was 55.5 years (ranged 31 to 78). The mean follow-up period was 16.6 months. Most patients complained of back and buttock pain (38 patients, 92%), and radiating pain in areas such as the anterior or anterolateral aspect of the thigh (32 patients, 78%). Weakness of lower extremities was observed in 16 patients (39%) and sensory disturbance was presented in 19 patients (46%). Only 6 patients (14%) had undergone previous lumbar disc surgery. Discectomy was performed using three methods : unilateral laminectomy in 27 cases, bilateral laminectomy in 3 cases, and the transdural approach in 11 cases, which were performed through total laminectomy in 10 cases and unilateral laminectomy in 1 case. With regard to surgical outcomes, preoperative symptoms improved significantly in 33 patients (80.5%), partially in 7 patients (17%), and were aggravated in 1 patient (2.5%). Conclusion : Clinical features of disc herniations at the L1-L2 and L2-L3 levels were variable, and localized sensory change or pain was rarely demonstrated. In most cases, the discectomy was performed successfully by conventional posterior laminectomy. On the other hand, in large central broad based disc herniation, when the neural elements are severely compromised, the posterior transdural approach could be an alternative.

• Journal of Korean Neurosurgical Society
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• v.61 no.3
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• pp.363-375
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• 2018

Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal age-adjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.