• 기술혁신연구
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• 제29권3호
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• pp.91-119
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• 2021

공공조달에 대한 산업정책과 혁신정책 관점의 중요성이 최근 부각되고 있다. 특히, 공공조달이 중소기업의 성장과 혁신에 직접 영향을 끼치는지에 대한 논의와 연구가 있어 왔다. 이러한 연구의 연장선상에서, 본 연구는 공공조달에 참여하는 기업의 특성 중 기업의 연령이 성장에 대한 공공조달의 효과를 조절하는지를 분석한다. 분석 자료는 2006년부터 2017년까지 조달청 우수제품으로 지정된 약 1,247개 기업의 재무적 성과와 공공조달 매출 성과를 연계하여 구축하였다. 패널회귀모형을 통해 분석한 결과, 공공조달 참여 정도가 큰 기업일수록 높은 성장률을 보였을 뿐만 아니라, 이 관계는 젊은 기업일수록 더 강하게 나타났다. 이 결과는 공공조달의 효과에 대한 기존 학술적 논의에 기여할 뿐만 아니라 공공조달 정책 수립에 있어서도 의의를 가진다.

• Advances in environmental research
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• 제12권1호
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• pp.51-64
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• 2023

The sustainable management of rice straw is essential for protection of human health and environment. This study assesses the impact of stock density of earthworm (Eisenia fetida) and Neem leaves (Azadirachta indica) on the quality of the final vermicompost. The vermicompost is produced using different combinations of rice straw, Neem leaves, and cow dung (bulking agent) by varying stock density of earthworms. The vermicomposting experiments are performed in plastic containers (32 cm × 28 cm × 28 cm) in open for 90 days under laboratory conditions. The stock density of the earthworm is found to be an important factor to influence nutritional quality of the final vermicompost. There is observed significant improvement in the total nitrogen (91.8%), phosphate (73.4%), potassium (38.8%), and calcium (59.05%) content of the vermicompost produced with the highest stock density of the earthworms. All the treatments showed decrease in TOC and C:N content after 90 days of vermicomposting. The treatment with Neem leaves showed maximum growth of earthworms (2.65 fold). Neem leaves brought positive changes in the quality of final vermicompost by enhancing the growth and reproduction of the earthworms. The calcium content increased by 39% in the final vermicompost with the addition of Neem leaves at the same stock density of the earthworms. The stock density of the earthworms and Neem leaves are found to significantly improve quality of the final vermicompost as compared with the compost (control). The surface morphology in SEM images showed high degree of fragmentation in the vermicompost as compared with the compost. The combined action of microbes and earthworms resulted in high degree of disintegration in the vermicompost.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.84-88
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• 2002

The effect of chitosan on the growth of plant pathogenic fungi was investigated. Chitosan solubilized in acetic acid showed much higher and more consistent antifungal activity than that solubilized in HCl. The antifungal activity was not significantly affected within a DA (degree of deacetylation) range of $57.3-99.2\%$ tested. Water-soluble and low molecular weight chitosan ($57.3\%$ DA) against 6 plant pathogens showed that Monosporascus canonballus and Pythium irregulare were the most susceptible to the chitosan, while Fusarium oxysporum and F. graminearum were the most resistant. At a concentration of 2.5 mg/ml, the growth of pathogens was completely inhibited except for F. oxysporum. The $MIC_50$ values varied depending on both the DA of the chitosan and the plant pathogens. A chitosan with $57.3\%$ DA exhibited the lowest $MIC_50$ (ranging <0.1-1.8 mg/ml) and that with $84.7\%$ DA the highest $MIC_50$ (ranging <0.4-4.0 mg/ml) depending on the pathogen.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권1호
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• pp.1-12
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• 2013

Purpose: Vascular endothelial growth factor (VEGF)-C and its tyrosine kinase receptor, VEGF receptor (VEGFR)-3 are recently known to have lymphangiogenic activities in various tumor types. In this study, we determined whether the expression of lymphangiogenic factors correlate with nodal metastasis or survival in a nude mouse model of oral squamous cell carcinoma (OSCC). Methods: Three OSCC cells (KB, SCC4, SCC9) were xenografted into the right mandibular gland of athymic nude mice. The mice were followed for tumor development and growth, and the mice were sacrificed when they had lost more than 20% of their initial body weight, or the diameter of the induced tumor exceeds 20 mm. After necropsy, the murine tumors were examined histologically and radiologically (micro-positron emission tomography computed tomography) for regional or distant metastasis. We performed immunohistochemical assays with anti-VEGF-C, VEGFR-3, CD105, and D2-40 antibodies. Immunofluorescence double staining for LYVE-1/CD31 was also performed. To quantify the VEGF-C and VEGFR-3 level in the cancer tissue, Western blotting was performed. Finally, we determined the correlation between the degree of expression of VEGF-C/VEGFR-3 and the mean survival time. Results: OSCC tumor cells into the mandibular gland of the nude mice successfully resulted in the formation of recapitulating orthotopic tumor. Tumor cells of the induced tumor did not express VEGF-C. VEGF-C/VEGFR-3 expression was mainly distributed in the endothelial cells of the stromal area. There were no correlation between the degree of expression of VEGF-C/VEGFR-3 and the mean survival time of mice injected with different OSCC cell lines. Conclusion: An recapitulating orthotopic model of OSCC in nude mice was established, which copies the cervical nodal metastasis of human OSCC. Overexpression of lymphangiogenic factors seems to have no effect on survival of hosts in this in vivo experiment.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2021년도 춘계학술대회
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• pp.18-18
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• 2021

Gomchwi using stuffed leaves is many cultivated for 'Gondalbi(Ligularia stenocephala)' among Gomchwi species. 'Gondalbi' species like to be cultivation on farm because of low the incense and the bitter taste, and high yield. But 'Gondalbi' caused to curtail yield that susceptibility of powdery mildew disease and shriveling and death of plant on summer season. To solve this problems, we crossed a Gomchwi and 'Handeari-gomchwi' to have resistance of powdery mildew disease and high yield. A new Gomchwi cultivar 'Jinmani' was bred by crossing between Gomchwi (Ligularia fischeri (Ledeb.) Turcz.) and Handaeri-gomchwi (Ligularia fischeri var. spiciformis Nakai). The selection and investigation of growth and yield characteristics were conducted from 2007 to 2020 in field and greenhouse of Highland Agriculture Research Institute, NICS, Rural Development Administration. The color of petiole ear was purple. trichome of petiole and leaf back non-existed, and luster of leaf back existed. Density of leaf vein was 4 degree among 1-5 degree in a newly developed cultivar 'Jinmani'. Plant height, leaf length, leaf width and petiole length were 55.7, 21.8, 22.2, and 33.9 cm, respectively in the 2nd year of growth characteristics. Plant size was similar with that of 'Gommany'. Bolting and flowering time were Aug. 5 and Sept. 5, respectively, and Bolting and flowering time of 'Gommany' showed similar to Aug. 8 and Sept. 1, respectively. 'Jinmani' showed higher number of leaves (202 ea.) per plant compared to 'Gommany' (159 ea.). Furthermore, yield was 67.9% higher in 'Jinmani' (2,569 g/plant) than in 'Gommany' (1,530 g/plant). 'Jinmani' showed lower leaf thickness (0.66mm) than 'Gommany' (0.69 mm), and consequently showed more hardness in leaf characteristics (25.1 kg/²) compared to 'Gommany' (24.3kg/cm²). 'Jinmani' showed similar strong resistance compared to 'Gommany' in the susceptibility of powdery mildew disease.

• 한국식물병리학회지
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• 제1권2호
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• pp.122-127
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• 1985

도열병 저항성유전자 $Pi-\alpha$를 가지고 있는 Aichi-asahi, Toyotama, Yamabiko를 공시하여 접종전$\cdot$접종후 $23/15^{\circ}C\;,\;29/21^{\circ}C$에 각각 3일간 처리하였다. 도열병균 6개 균주를 접종한 후, 도열병균의 침입$\cdot$균사신전$\cdot$병반수를 조사한 결과, $29/21^{\circ}C$에 처리한 유균에서 침입율이 높고 형성 병반수도 많았다. 균사신전도와 피침입세포수는 $29/21^{\circ}C$ 경우 접종후 72시간에서 96시간 사이에 현저히 증가하였다. 그러나 $23/15^{\circ}C$에 처리한 유균에서 침입$\cdot$균사신전이 억제되어 병반형성이 지연되었다

• 한국산림과학회지
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• 제86권1호
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• pp.1-8
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• 1997

뉴질랜드 북섬의 다우지역에서 라디아타소나무 유묘생장이 일련의 주요 잡초종과의 경쟁으로 인하여 감소함을 계량화(計量化)하기 위하여 계획된 실험의 2차년도 결과이다. 라디아타소나무 유묘(1/0)들을 각각 잡초제거구와 활엽성초본, 목초, broom, pampas, buddleia, gorse와 함께 생육시켰다. 양료와 수분공급은 각 요인에 관수와 시비, 무관수와 무시비로 다양화하였다. 식재 21개월 후 라디아타소나무 유묘의 재적생장량은 잡초제거구와 gorse와 함께 생육된 구에서 최대였고 buddleia나 pampas와 함께 생육된 곳에서는 최소였다. 유묘생장에 대한 잡초의 영향이 수분이나 양료 경쟁에 의해 조정된다는 증거가 없었다. 유묘를 능가하여 치솟는 키크고 빨리 자라는 종(broom, buddleia, pampas)들이 유묘 생장에 가장 큰 영향력을 갖고 있고 그 영향력의 크기는 유묘 위에 뒤덮는 정도와 상관관계가 있었다. 이것은 피음 혹은 광경쟁이 아마도 중요한 인자임을 암시해 주고 있다.

• Journal of Microbiology and Biotechnology
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• 제29권12호
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• pp.1957-1968
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• 2019

Tetraselmis is a green algal genus, some of whose species are important in aquaculture as well as biotechnology. In algal culture, fluorescent lamps, traditional light source for culturing algae, are now being replaced by a cost-effective light-emitting diodes (LEDs). In this study, we investigated the effect of LED light of different wavelengths (white, red, yellow, and blue) on the growth of Tetraselmis suecica and its associated microbial community structures using the next-generation sequencing (NGS). The fastest growth rate of T. suecica was shown in the red light, whereas the slowest was in yellow. The highest OTUs (3426) were identified on day 0, whereas the lowest ones (308) were found on day 15 under red light. The top 100 OTUs associated with day 0 and day 5 cultures of T. suecica under the red and yellow LED were compared. Only 26 OTUs were commonly identified among four samples. The highest numbers of unique OTUs were identified at day 0, indicating the high degree of initial microbial diversity of the T. suecica inoculum. The red light-unique OTUs occupied 34.98%, whereas the yellow-specific OTUs accounted for only 2.2%. This result suggested a higher degree of interaction in T. suecica culture under the red light, where stronger photosynthesis occurs. Apparently, the microbial community associated with T. suecica related to the oxygen produced by algal photosynthesis. This result may expand our knowledge about the algae-bacteria consortia, which would be useful for various biotechnological applications including wastewater treatment, bioremediation, and sustainable aquaculture.

• 한국결정성장학회지
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• 제25권4호
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• pp.140-144
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• 2015

Tonpilz 트랜스듀서에서 head mass에 영향을 미치는 요소로써 그 형상과 무게 및 소재의 영향을 연구하였다. 형상 요소로는 head mass의 옆면이 대칭 축과 이루는 각도를 그 인자로 하여 0도, 35.5도, 60도로 변화시키면서 대역폭과 출력의 변화를 모사하였다. 그 결과 Al의 경우에는 35.5도에서 대역폭이 최대 값이 되었으며 그 때의 대역폭은 86.4 %로 계산되었다. Head mass의 중량은 대역폭에는 큰 영향이 없이 출력에만 영향을 미치는데 중량이 25 % 감소하였을 때 20 % 정도 출력이 증가하였다. 끝으로 head mass의 소재를 Ti로 변경하였을 때에는 밀도의 차이에 의한 무게의 증가에도 불구하고 출력이 100 % 향상되었는데 이는 Ti의 탄성률 같은 기계적 특성의 영향으로 판단되며 최대의 대역폭을 얻기 위한 형상은 45도에서 얻어졌고 대역폭은 88.1 %이었다.

• Animal cells and systems
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• 제16권3호
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• pp.207-214
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• 2012

Burns are one of the most devastating forms of trauma and wound healing is a complex and multicellular process, which is executed and regulated by signaling networks involving numerous growth factors, cytokines, and chemokines. Recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) was specifically produced from rice cell culture through use of a recombinant technique in our laboratory. The effect of rhGM-CSF on promotion of deep second-degree burn wound healing on the back skin of a hamster model was evaluated through a randomized and double-blind trial. As macroscopic results, hamster skins of the experimental groups showed earlier recovery by new epidermis than the control groups. Immunohistochemical reactions of proliferating cell nuclear antigen and transforming growth factor-b1, which are indicators of cell proliferation, were more active in the experimental group, compared with the control group. On electron microscopy, basal cells in the epidermis of the experimental group showed oval nuclei, prominent nucleoli, numerous mitochondria and abundant free ribosomes. In addition, fibroblasts contained well-developed rough endoplasmic reticulum with dilated cisternae. Bundles of collagen fibrils filled the extracellular spaces. Particularly, ultrastructural features indicating active metabolism for regeneration of injured skin at 15 days after burn injury, including abundant euchromatin, plentiful free ribosomes, and numerous mitochondria, were observed. These findings suggest that use of rhGM-CSF could result in accelerated deep second-degree burn wound healing in animal models.