• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6211-6216
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• 2012

Objective: To investigate the effects of gambogic acid (GA) on the growth of human malignant glioma cells. Methods: U251MG and U87MG human glioma cell lines were treated with GA and growth and proliferation were investigated by MTT and colony formation assays. Cell apoptosis was analyzed by annexin V FITC/PI flow cytometry, mitochondrial membrane potential assays and DAPI nuclear staining. Monodansylcadaverine (MDC) staining and GFP-LC3 localisation were used to detect autophagy. Western blotting was used to investigate the molecular changes that occurred in the course of GA treatment. Results: GA treatment significantly suppressed cell proliferation and colony formation, induced apoptosis in U251 and U87MG glioblastoma cells in a time- and dose-dependent manner. GA treatment also lead to the accumulation of monodansylcadaverine (MDC) in autophagic vacuoles, upregulated expressions of Atg5, Beclin 1 and LC3-II, and the increase of punctate fluorescent signals in glioblastoma cells pre-transfected with GFP-tagged LC3 plasmid. After the combination treatment of autophagy inhitors and GA, GA mediated growth inhibition and apoptotic cell death was further potentiated. Conclusion: Our results suggested that autophagic responses play roles as a self-protective mechanism in GA-treated glioblastoma cells, and autophagy inhibition could be a novel adjunctive strategy for enhancing chemotherapeutic effect of GA as an anti-malignant glioma agent.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.186-195
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• 2015

This research was conducted to investigate effect the plant growth regulators (PGRs) on the characteristics of fruit and flesh softening, using GA3 and thidiazuron (TDZ) treatments in 'Heukboseok' grapes. The total yield obtained under PGR treatment was 88.3% lower than the target production when a single treatment with $GA_3$ of low concentrations was used, but the expected yield was recovered by combined treatment with TDZ and $GA_3$. When harvested on the basis of color, the harvest rate up to 100 days after full bloom (DAFB) was low with the $GA_3$ single treatment, but was increased by the addition of TDZ, with the second TDZ mixed treatment being particularly effective. The soluble solids content in the PGR-treated samples demonstrated no significant changes after 90 DAFB, while the acidity content decreased rapidly starting from 90 DAFB. Measured on the basis of sugar and acidity content, maturity was reached much earlier in treated fruit than in the non-treated fruit. Firmness was maintained at a higher level until the final harvest time after PGR treatment compared to untreated grapes according to epidermis thickness and flesh density increase to activity cell division and expansion by $GA_3$ and TDZ. In particular, the fruit quality was improved based on the delay of softening in primary and secondary treatments of $25mg{\cdot}L^{-1}\;GA_3+2.5mg{\cdot}L^{-1}$ TDZ. The production of seedless fruit was difficult, even with the inclusion of TDZ, reaching the highest seedless rate of only 65.5%. Fruit cracking was rare, occurring at a rate of about 0.0~0.9% in all treatments. Accordingly, 'Heukboseok' grapes should be harvested within 100 days after full bloom (DBFB) before a rapid decrease of firmness, conferred by primary and secondary treatments with $25mg{\cdot}L^{-1}\;GA_3+2.5mg{\cdot}L^{-1}$ TDZ.

• Journal of Electrochemical Science and Technology
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• v.14 no.4
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• pp.388-396
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• 2023

Photoelectrochemical (PEC) water splitting is a vital source of clean and sustainable hydrogen energy. Moreover, the large-scale H₂ production is currently necessary, while long-term stability and high PEC activity still remain important issues. In this study, a GaN-based photoelectrode was modified by an additional NH₃ treatment (900℃ for 10 min) and its PEC behavior was monitored. The bare GaN exhibited a highly crystalline wurtzite structure with the (002) plane and the optical bandgap was approximately 3.2 eV. In comparison, the NH₃-treated GaN film exhibited slightly reduced crystallinity and a small improvement in light absorption, resulting from the lattice stress or cracks induced by the excessive N supply. The minor surface nanotexturing created more surface area, providing electroactive reacting sites. From the surface XPS analysis, the formation of an N-Ga-O phase on the surface region of the GaN film was confirmed, which suppressed the charge recombination process and the positive shift of E_FB. Therefore, these effects boosted the PEC activity of the NH₃-treated GaN film, with J values of approximately 0.35 and 0.78 mA·cm^-2 at 0.0 and 1.23 V_RHE, respectively, and an onset potential (V_on) of -0.24 V_RHE. In addition, there was an approximate 50% improvement in the J value within the highly applied potential region with a positive shift of V_on. This result could be explained by the increased nanotexturing on the surface structure, the newly formed defect/trap states correlated to the positive V_on shift, and the formation of a GaO_xN_1-x phase, which partially blocked the charge recombination reaction.

• Korean Journal of Medicinal Crop Science
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• v.9 no.2
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• pp.124-129
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• 2001

Crotalaria sessiflora is one of a few medicinal herbs among the legumes used as antitumor herb medicine but has lower seed germination and afterward seedling emergence. This study was carried out to elucidate the effects of cold stratification as presown treatment as well as $GA_3$, $KNO_3$ and acetone on its seed germination and seedling emergence. Cold stratification, $GA_3$, $KNO_3$ and acetone treatments were performed with different concentrations and period levels. Cold treatment was done under 14 hour red light illumination a day or darkness and the two others under darkness. On the basis of the best germination rate of each treatment, $GA_3$ and cold stratification treatments showed the highest germination rates at 0.1 mM but 12 hours and 2 week periods under darkness, respectively. $KNO_3$ and acetone treatments came out at 400 mM and 200 mM lasted for, respectively. The best germination rates from $KNO_3$ and acetone were comparatively higher than those from the former $GA_3$ and cold treatments. In evaluation of seedling emergence using the last two treatments, $KNO_3$ treated seeds were better performed than acetone treated seeds showed somewhat higher germination rate, implying that presown seed treatments must be evaluated by the combination with indoor and field tests.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.106-111
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• 2008

This study was carried out to elucidate the influence of gibberellin soak and seed dressing with Toros wp. on the dehiscence of Eleutherococcus senticossus seeds. $GA_3$ treatment was effective on promoting after-ripening seed of Eleutherococcus senticossus whose concentration was higher until $500\;mg{\cdot}L^{-1}$, after-ripening period became shorter. But rotting percentage increased gradually up above $500\; mg{\cdot}L^{-1}\;GA_3$After all, $300\;mg{\cdot}L^{-1}\;GA_3$ was the most effective treatment for promoting after-ripening seed. Dressing treatment with Toros wp. on seeds reduced the dehiscent rate of E. senticosius. by suppressing activity of fungi living on the endocarp surface of seed.

• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.508-516
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• 2023

Germination, growth characteristics, and content of useful components were analyzed through GA₃ treatment of Angelica acutiloba (Siebold & Zucc.) Kitagawa seeds, to provide basic data for cultivation technology. The moisture absorption rate of the seeds was 62.07% after 2 hours of soaking, and the highest value was 122.15% after 48 hours. The appropriate seed germination temperature for the species ranged from 10℃ to 25℃. It was confirmed that the growth of seedlings increased as the GA₃ concentration increased, but there was no significant difference in the content of useful components according to the GA₃ treatment.

• Journal of Powder Materials
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• v.21 no.3
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• pp.229-234
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• 2014

This study manufactured a CIG-based composite coating layer utilizing a new warm spray process, and a mixed powder of Cu-20at.%Ga and Cu-20at.%In. In order to obtain the mixed powder with desired composition, the Cu-20at.%Ga and Cu-20at.%In powders were mixed with a 7:1 ratio. The mixed powder had an average particle size of $35.4{\mu}m$. Through the utilization of a warm spray process, a CIG-based composite coating layer of $180{\mu}m$ thickness could be manufactured on a pure Al matrix. To analyze the microstructure and phase, the warm sprayed coating layer underwent XRD, SEM/EDS and EMPA analyses. In addition, to improve the physical properties of the coating layer, an annealing heat treatment was conducted at temperatures of $200^{\circ}C$, $400^{\circ}C$ and $600^{\circ}C$ for 1 hour each. The microstructure analysis identified ${\alpha}$-Cu, $Cu_4In$ and $Cu_3Ga$ phases in the early mixed powder, while $Cu_4In$ disappeared, and additional $Cu_9In_4$ and $Cu_9Ga_4$ phases were identified in the warm sprayed coating layer. Porosity after annealing heat treatment reduced from 0.75% (warm sprayed coating layer) to 0.6% (after $600^{\circ}C/1hr$. heat treatment), and hardness reduced from 288 Hv to 190 Hv. No significant phase changes were found after annealing heat treatment.

• Applied Biological Chemistry
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• v.31 no.2
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• pp.205-210
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• 1988

The changes in peroxidase and catalase activities, and isoperoxidase patterns in different parts of mung bean seedling caused by the treatment with plant growth substances, $GA_3$ and ABA, were examined. As germination proceeded, the activity of peroxidase in all part except hypocotyl was increased, while that of catalase decreased. The separate application of $GA_3$ and ABA increased the activity of peroxidase which was more influenced by $GA_3$ than by ABA only in cotyledon, while that of catalase was more affected by ABA than by $GA_3$. Electrophoretic study revealed that the number of isoperoxidase was increased continuously in all parts during development. A greater influence was exerted on the intensity of isozyme than the number of isozyme by the hormonal treatment.

• Korean Journal of Agricultural Science
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• v.31 no.1
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• pp.1-8
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• 2004

This study was carried out to identify the effects of seaweed extracts(GA14) on growth of two rice cultivars, Junambyo and Donganbyo. Seedling qualities of two cultivars were better in all items including heading dates at early stage treated at seedling plus 2-3 leaf stages than at single treatment of seedling. Ripening ratio of Junambyo in paddy field was increased 0.3% by seaweed extracts(GA14) treatment, but that of Donganbyo decreased 0.5%. 1,000 grain weight of Junambyo and Donanbyo by seaweed extracts(GA14) treatment was two to four grams higher and the yield of two cultivars was also higher by three to four percent. Appearance characters of two rice cultivars was high in head, while damaged, chalky and crack rate were low at seaweed extracts(GA14) treatment. Protein, moisture and amylose characteristics related to table quality of Junambyo were not different by seaweed extracts treatment, but table values was high in only treatment. Donganbyo was also similar to Junambyo, but table quality was slightly high at non-treatment.

• Journal of Plant Biology
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• v.34 no.2
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• pp.159-163
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• 1991

The effect of dimethipin, one of the synthesized plant growth regulators, on the gibberellic acid-induced a-amylase activity in the barley de-embryonated seed system was investigated in order to elucidate the possible action mechanism of dimethipin. Dimethipin markedly inhibited the increase of mRNA and protein content, and a-amylase activity induced by gibberellic acid. The inhibitory effects were gradually decreased as the time interval between gibberellic acid treatment and dimethipin addition was made larger. Dimethipin inhibited the increase of mRNA content when added within 18 h from gibberellic acid treatment; however, it inhibited the increase of soluble protein content and a-amylase activity even added after 18 h from the treatment. These results suggest the possibility that dimethipin inhibit both mRNA synthesis and a-amylase protein synthesis.thesis.