• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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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.

• 한국환경과학회지
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• 제32권1호
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• pp.77-88
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• 2023

Kadsura coccinea (Lem.) A.C. Smith is used as a medicinal plant and cosmetic material in China and Southeast Asia. To mass-produce Kadsura coccinea seedlings, the effects of gibberellic acid (GA₃) and cold stratification treatments on seed germination were investigated. Seed germination rate with GA₃ treatment was most effective at concentrations of 250 or 500 mg/L. With respect to mean germination time (MGT), mean daily germination, and T₅₀ (days to reach 50% seed germination), the germination-promoting effect was improved as the concentration of GA₃ increased. Stem growth of seedlings was the highest following GA₃ treatments of 250 and 500 mg/L, and the growth promoting effect gradually decreased as the concentration of GA₃ decreased. Root growth was stimulated at GA₃ concentrations of 250-1,000 mg/L. Examination of the effect of stratification treatment for 15, 30 and 60 days at temperatures of 0, 5 and 10℃ on the germination rate revealed that the most stratification treatment temperature was 10℃, and the results improved with longer treatment periods. Altogether, GA₃ and stratification treatments improved the seed germination rate, shortened the MGT, improved germination uniformity, and produced healthy seedlings.

• 한국작물학회지
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• 제38권4호
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• pp.297-303
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• 1993

식물생장조절제가 벼 건답직파재배시 출아 및 초기생육 촉진에 미치는 효과를 구명하기 위하여, 화성벼를 공시하고 3가지 약제를 사용하여 종자침종 또는 종자분무처리하였을 때 이들의 출아 및 초장신장에 대한 효과를 조사하여 다음과 같은 결과를 얻었다. 1. Gibberellin (GA$_3$ 4% 액제)은 건답직파재배에서 벼의 출아 및 초장신장 촉진에 현저히 효과가 없었다. 2. GA$_3$ 종자침종처리의 적정 농도는 약 100ppm이었고, 종자분무처리의 적정 농도는 약 200ppm이었다. 3. GA$_3$(200ppm)의 종자분무처리는 무처리에 비하여 출아를 1～2일 단축시켰고, 출아율이 높았으며 초장신장 효과가 인정되었다. 4. GA$_3$의 종자처리는 묘의 초엽과 엽신 및 엽초의 신장을 촉진시켰다.

• 한국자원식물학회지
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• 제37권1호
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• pp.79-86
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• 2024

본 연구는 북한 식물자원 큰금매화의 종자 번식을 위해 발아에 대한 기초자료를 제시하고자 수행되었다. 큰금매화 종자의 형태적 특성과 활력을 검정하였고, 변온 조건(15/6℃ & 25/15℃), 저온층적처리 및 GA₃ 처리에 따른 발아 특성을 조사하였다. 연구 결과, 저온층적처리는 큰금매화 종자의 휴면타파에 효과가 없었다. GA₃ 처리는 큰금매화 종자의 발아율을 현저히 증가시켰고, 평균발아일수와 발아세 또한 유의미하게 향상시켰다. 한편, 15/6℃ 조건에 비해 25/15℃ 조건에서는 큰금매화 종자에 대한 GA₃ 처리의 효과가 감소하였다. 큰금매화 종자는 Nondeep-type의 형태·생리적휴면(MPD)을 가지는 것으로 판단되었고, 본 연구에서 가장 효율적인 발아 조건은 15/6℃ 변온조건과 GA₃ 500 mg·L^-1 처리로 확인되었다. 이러한 본 연구의 결과는 고산성 북방계 식물인 큰금매화의 대량증식에 유용한 자료가 될 것이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.181-184
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• 2004

The green emitting phosphor, $ZnGa_2O_4:Mn$ thin film with spinel structure were deposited by rf magnetron sputtering. Thin film phosphors were heat-treated in nitrogen, vacuum and air atmosphere, respectively. The effects of the substrates, heat-treatment conditions and the sputtering parameters were investigated. The growing behavior and luminescent properties of thin films depend on the crystallinity of the substrates. The Ga/Zn atomic ratios and luminescent characteristics were dependent on the annealing conditions.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1993년도 제4회 학술발표회 논문개요집
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• pp.29-31
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• 1993

NH3-pplasma treatment has been used for ppassivation of native-oxide-contaminated GaAs surface. Ex-situ band-gapp pphotoluminescence(ppL) measurement shows enhanced intensity for the treated surfaces. Auger electron sppectroscoppy(AES) shows that the treated surface contains nitrogen atoms but no arsenic atoms, which leads us to sppeculate that the graded GaN thin layer was formed on the surface. Based on these results, new metal-insulator-GaAs structure is ppropposed.

• 한국분말재료학회지
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• 제18권6호
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• pp.552-561
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• 2011

This study attempted to manufacture a Cu-15 at.%Ga coating layer via the cold spray process and investigated the effect of heat treatment environment on the properties of cold sprayed coating material. Three kinds of heat treatment environments, $5%H_2$+argon, pure argon, and vacuum were used in this study. Annealing treatments were conducted at $200{\sim}800^{\circ}C$/1 hr. With the cold sprayed coating layer, pure ${\alpha}$-Cu and small amounts of $Ga_2O_3$ were detected in the XRD, EDS, EPMA analyses. Porosity significantly decreased and hardness also decreased with increasing annealing temperature. The inhomogeneous dendritic microstructure of cold sprayed coating material changed to the homogeneous and dense one (microstructural evolution) with annealing heat treatment. Oxides near the interface of particles could be reduced by heat treatment especially in vacuum and argon environments. Vacuum environment during heat treatment was suggested to be most effective one to improve the densification and purification properties of cold sprayed Cu-15 at.%Ga coating material.

• 한국약용작물학회지
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• 제7권1호
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• pp.16-21
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• 1999

파종부터 유묘출현까지 2년이 소요되는 둥굴레의 종자번식에서 육묘기간을 단축하기 위하여는 우선적으로 적절한 상배축 휴면타파 방법이 설정되어야 할 것이다. 본 시험은 둥굴레의 상배축 휴면타파 방법 을 설정 하고자 $GA_3\;1.0\;mM$을 2일 간격으로 2회 또는 4회 (4일 : 8일) 관주하거나, 4, 6, 8, 12주간 $3^{\circ}C$의 저온처리를 가한 후 유묘 출현과 생장에 관련된 형질을 조사하였던 바 그 결과를 요약하면 다음과 같다. $GA_{3}$ 처리시 자엽(子葉) 파열수(破裂數)는 처리 직후에는 4일 보다 8일 처리에서 높았으나 시간이 경과할수록 처리효과가 소멸된 반면, 상배축 신장이 이루어지지 않아 출현 유묘가 전혀 없었다. 따라서 $GA_3$을 이용한 둥굴레의 상배축 휴면타파는 실험실에서 소규모로 행할 경우는 가능하다고 할지라도 상토를 이용한 다량육묘에서는 적용이 불가능한 것으로 나타났다. 이러한 원인은 $GA_3$ 용액의 관주처리시 자엽초는 파열되나 상배축이 여러 겸의 자엽초로 싸여져 있기 때문에 $GA_3$ 용액에 노출되지 않은 결과로 해석된다. 한편 자엽초 파열과 상배축 신장이 원활히 이루어지는 저온처리는 다량육묘에 이용이 가능하다고 할 수 있다. 그러나 입묘 정도는 저온처리 기간에 의하여 영향을 받는 것으로 나타났는데 적어도 6주의 저온처리가 가하여져야 할 것으로 분석되었다.

• Macromolecular Research
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• 제10권3호
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• pp.158-167
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• 2002

In order to endow with new bioactive functionality from small intestine submucosa (SIS) powder as natural source to poly (L-lactide) (PLA) and poly (lactide-co-glycolide) (PLGA) synthetic biodegradable polymer, porous SIS/PLA and SIS/PLGA as natural/synthetic composite scaffolds were prepared by means of the solvent casting/salt leaching methods for the possibility of the application of tissue engineered bone and cartilage. A uniform distribution of good interconnected pores from the surface to core region was observed the pore size of 40~500 ${\mu}{\textrm}{m}$ independent with SIS amount using the solvent casting/salt leaching method. Porosities, specific pore areas as well as pore size distribution also were almost same. After the fabrication of SIS/PLA hybrid scaffolds, the wetting properties was greatly enhanced resulting in more uniform cell seeding and distribution. Five groups as PGA non-woven mesh without glutaraldehyde (GA) treatment, PLA scaffold without or with GA treatment, and SIS/PLA (Code No.3 ; 1 : 12 of salt content, (0.4 : 1 of SIS content, and 144 ${\mu}{\textrm}{m}$ of median pore size) without or with GA treatment were implanted into the back of nude mouse to observe the effect of SIS on the induction of cells proliferation by hematoxylin and eosin, and von Kossa staining for 8 weeks. It was observed that the effect of SIS/PLA scaffolds with GA treatment on bone induction are stronger than PLA scaffolds, that is to say, in the order of PLA/SIS scaffolds with GA treatment > PLA/SIS scaffolds without GA treatment > PGA nonwoven > PLA scaffolds only with GA treatment = PLA scaffolds only without GA treatment for the osteoinduction activity. The possible explanations are (1) many kinds of secreted, circulating, and extracellular matrix-bound growth factors from SIS to significantly affect critical processes of tissue development and differentiation, (2) the exposure of SIS to GA resulted in significantly calcification, and (3) peri-implant fibrosis due to covalent bonding between collagen molecule by crosslinking reaction. In conclusion, it seems that SIS plays an important role for bone induction in SIS/PLA scaffolds for the application of tissue engineering area.

• 한국전기전자재료학회논문지
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• 제15권7호
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• pp.564-569
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• 2002

Heteroepitaxial GaN films were grown on sapphire substrates in order to study the effects of the buffer layer's surface roughness and thermal treatment on the epitaxial layer's quality. For this, GaN buffer layers were grown at $550^{\circ}C$ with various TMGa flow rates and durations of growth, and annealed at $1010^{\circ}C$ for 3 min after the temperature was raised by 23 ~ $92^{\circ}C/min$, and then GaN epitaxial layers were grown at $1000^{\circ}C$. It has been found that the buffer layer's surface roughness and the thermal treatment condition are critical factors on the quality of the epitaxial layer. When a buffer layer was frown with a TMGa flow rate of $24\mu mole/min$ for 30 sec, the surface roughness of the buffer lather was minimum and when the thermal ramping rate was $30.6^{\circ}C/min$ on this layer, the successively grown epitaxial layer's crystalline and optical qualities were optimized with a specular morphology. The minimum full width at half maximum(FWHM) of GaN(0002) x-ray diffraction peak and that of near-band-edge(NBE) peak from a room temperature photoluminescence (PL) were 5 arcmin and 9 nm, respectively.