• Journal of Korean Society for Atmospheric Environment
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• 제17권E1호
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• pp.9-16
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• 2001

To evaluate the correct separation capacity of cascade impactor for liquid aerosol, theoretical and experimental calculations of 50% cut-off diameter(ECOD(sub)50) were performed. A recalculation method of original diameter for hemispheric liquid aerosol collected on casecad impactor is also proposed newly using fixation technique. Calculated values for theoretical (ECOD(sub)50) of 40stage cascade impactor are 20, 6.4, 2.8, and 1.4$\mu\textrm{m}$ at 1st- ,2nd-, 3rd- and 4th-stage, respectively. A good agreement between the result of theoretical (ECOD(sub)50) and that og experimental ones was obtained at Stage 2 and 3. On the other hand, relatively large differences were found at Stage 1 and 4. Fixation for liquid aerosols using ${\alpha}$-cyanoacrylate monomer was performed successfully. The orignal diameter of liquid aerosols collected on each stage was calculated. The maximum levels of number size distribution curves at each stage are 19.8, 6.5, 3.1 and 1.5 $\mu\textrm{m}$ at 1st-, 2nd-, 3rd- and 4th-stage, respectively. The distortion of separation capacity of cascade impactor due to the split, merger, disappearance, and evaporation of liquid aerosols in the fluid did not occur.

• KSBB Journal
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• 제5권2호
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• pp.151-158
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• 1990

부질소 1-B5 배지에서 단독 배양한 담배 배양세표의 nitrate reductase 활성은 1-B5 배지에서 배양한 담배 배양세포에 비해 50% 이상 감소되었으나 $10^{-4}$ sper-mine 처리구에서는 그 활성이 가장 증가되었으며, N.muscorum파 혼합 배양시 그 활성이 현저히 증가한 반면 polyamine은 거의 영향을 미치지 않았다. Glutamate dehydrogenase 는 혼합 배양시 담배 배양세포플 단독 배양하였플 때보다 약 4배 감소 되었으며, glutamate synthas$\xi$의 활성은 $10^{-4}M$ spermlne 처리구에서 혼합 배양 하였을 때 그 활성이 가장 높았다.

• Journal of Korean Neurosurgical Society
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• 제30권2호
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• pp.180-185
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• 2001

Objectives : We retrospectively studied the efficacy of anterior cervical discectomy and interbody fusion without plate fixation in degenerative cervical disease. Methods : Thirty two consecutive patients with degenerative cervical disease treated by decompression and interbody fusion(Smith-Robinson technique) without anterior cervical plating were studied for postoperative complication rate as well as the clinical and radiologic outcomes and were compared the result of ours with other reported series where the anterior cervical plating was used. Results : All cases were reviewed after average period of 13 months for the purpose of this study. There were 4 postoperative complications related to grafting. A solid fusion was obtained in all cases with single-level fusion(n=21) and 81.8 % of the cases with a two-level fusion(n=11). The overall fusion rate was 93.8 % and fusion rate per level fused was 95.3%. The clinical outcome of the patients was comparable with that in the literature, with one patient having a poor result. Comparing the result of this study with others of the anterior cervical plating, clinical outcome and fusion rate were not superior in plate fixation group in single-level fusion, but increased fusion rate and decreased graft-related complication rate were noted in multilevel fusion with plate fixation. However, the clinical outcome was not superior to noninstrumented fusion group of this study. Conclusion : These results demonstrate that anterior cervical discectomy and interbody fusion(Smith-Robinson technique) without instrumentation is safe and reliable method of single-level fusion in degenerative cervical disease. Plate fixation system doesn't seem necessary in single level fusion in degenerative cervical disease.

• Archives of Plastic Surgery
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• 제38권3호
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• pp.257-262
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• 2011

Purpose: In neurofibromatosis patients, complete surgical excision of the mass is almost impossible and surgical treatment usually consists of multiple serial excisions that only result in a debulking effect. Remnant tumor mass has a gravitational effect on facial soft tissues that leads to sagging of skin and soft tissue, and eventually, facial disfigurement and asymmetry. The purpose of our surgical method is to perform soft tissue lifting with longer lasting effect with less surgical risk of damaging facial nerve and vessels. With external fixation using K-wire or surgical screw, the procedure only called for a short incision length and had additional adhesive properties that enabled anchoring of soft tissue in a lifted position for a longer postoperative period. Methods: A total of 5 neurofibromatosis patients (NF-1) visited our clinic for mass reduction and face lifting. The age of patients ranged from 13 to 42 (mean 28.8 years), and most patients had a long history of multiple excisions in the past. Face lifting was performed in 2 different areas, the periorbital area in 3 patients, and the midface in 2 patients. The materials used in fixation of retaining ligament were K-wire (n=3) and titanium screw (n=2). Results: Follow up period was from 5 month to 3 years and 1 month (mean=2 years and 1 month). All patients conveyed satisfaction with the results and no major complications were reported. The lifting effect lasted for as long as 3 years, and there were no complaints of relapse of soft tissue depression or sagging within the operated area. 1 patient (M/13) needed secondary k-wire insertion and additional mass excision in 1 year and 10 months postoperatively due to tumor growth. In two patients with K-wire fixation, mild dimpling and tenderness were observed in the follow up period, but in about 2 months postoperatively, dimpling was relieved and there was no need for removal of fixating material. Conclusion: Surgical lifting in neurofibromatosis patients can be challenging, for mass excision cannot be done completely and gravitational effect by residual mass can be persistent. External fixation of the retaining ligament in patients with neurofibromatosis can give satisfactory results-for incision length is relatively shorter, and the lifting effect can last longer compared to other various face lifting techniques.

• 한국산림과학회지
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• 제84권3호
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• pp.306-318
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• 1995

광결핍(光缺乏)과 Frankia 질소고정균(窒素固定菌), 그리고 Alpova diplophloeus 외생균근균(外生菌根菌)이 루브라 오리나무(Alnus rubra Bong.) 묘목의 생장, 공중질소고정(空中窒素固定), 균근발달(菌根發達)에 미치는 영향을 구명(究明)하기 위하여, 파종묘(播種苗)에 Frankia 질소고정균(窒素固定菌)을 접종하거나 질소(窒素)를 시비(施肥)하고, 또는 A. diplophloeus 외생균근균(外生菌根菌) 포자(胞子)를 접종하여 여과된 공기로 순환시키는 인공생장실에서 길렀다. 20주가 지난 묘목을 3 수준의 광도(光度) 680, 320, $220{\mu}mol/m^2/s$ PPFD(photosynthetic photon flux density)에서 3주일 동안 기른 결과, 광도(光度) 220 PPFD에서는 균근(菌根)과 뿌리흑의 발달, 광합성(光合成) 및 질소고정(窒素固定)속도 그리고 식물생장량이 감소하였고, 320 PPFD에서는 광합성(光合成) 속도만이 감소하였다. Frankia로 접종된 묘목은 질소(窒素)가 시비(施肥)된 묘목보다 균근형성율(菌根形成率)과 묘목생장율이 높았다. A. diplophloeus 포자(胞子)를 접종된 묘목은 비접종보다 생장율은 높았으나 뿌리혹은 발달과 질소고정량(窒素固定量)에서는 차이가 없었다. 두 공생균(共生菌)이 묘목의 광합성(光合成)속도에는 영향을 미치지 않았다. A. diplophloeus 균근균(菌根菌)이 묘목의 생장과 뿌리혹 발달에 기여하는 것 보다는 Frankia 질소고정균(窒素固定菌)이 묘목의 생장과 균근(菌根)발달에 더 크게 기여하였다.

• Journal of Microbiology and Biotechnology
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• 제18권11호
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• pp.1747-1754
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• 2008

Acidithiobaeillus ferrooxidans ATCC 23270 is an important model organism for bioleaching and bioremediation studies owing to its diverse metabolic capabilities, whereas lix984n is a widely used extractant. Little is known about the response of cbb genes in A. ferrooxidans to lix984n shock. Thus, to elucidate the response of the $CO_2$ fixation genes in A. ferrooxidans ATCC 23270 to the addition of lix984n, the gene expression of cbb genes was examined using a real-time PCR. Although a natural increase or decrease in the expression of most cbb genes was observed after 5 min of shock with 3% (v/v) lix984n, sdhC and cbbR exhibited quick responses to the shock. Ten min of shock had a greater effect on the cbb gene expression, yet 15 min of shock had a significant effect on the Calvin cycle in A. ferrooxidans ATCC 23270, as the expression of all the cbb genes reached a very high level. Therefore, after a short lix984n shock, a solution of A. ferrooxidans can be re-used for bioleaching.

• Applied Biological Chemistry
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• 제48권3호
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• pp.189-200
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• 2005

생물학적 질소고정과정의 연구는 학문적으로나 산업적으로 매우 중요한 과정이다. 본 총설에서는 공업적 질소고정과 비교되는 생물학적 질소고정의 특징을 간단히 살펴보고, Azotobacter vinelandii에서 연구되고 있는 생물학적 질소고정효소의 특징을 다룬다. 생물학적 질소고정과정은 다양한 생명체에서 일어나며, 최근에는 미생물인 A. vinelandii에 그 작용 메커니즘에 관한 연구가 집중되어 있다. 공기중의 질소를 암모니아로 변환시키는 질소고정은 화학적으로 환원 반응에 해당하므로 전자의 공급이 필요하다. 생물학적 질소고정을 담당하는 질소고정효소는 촉매반응을 위해 생물학적인 환원력을 사용하여 전자를 공급받아, Fe 단백질의 $Fe_4S_4$ cluster와 MoFe 단백질의 P-cluster를 거쳐 질소 환원 반응이 일어나는 FeMo-cofactor로 전달한다. 이러한 전자전달의 과정과 수소이온의 전달 과정은 질소고정효소의 반응 메커니즘 이해에 매우 중요한 과정이며, FeMo-cofactor와 질소분자의 상호작용은 생물학적 질소고정 메커니즘의 중심에 있다. 질소고정 작용 메커니즘의 연구에는 X-선 단백질 결정학, EPR과 $M{\ddot{u}}ssbauer$ 등의 다양한 분광학적 방법과, 효소의 기질과 저해제의 상호작용을 연구하고 mutant와 비교하는 생화학적 접근방법, 그리고 FeMo-cofactor의 모델 화합물을 합성하여 연구하는 화학적 방법 등이 적용되었다. 이들 분야의 최근 연구결과를 소개하며, 마지막으로, 다양한 연구 결과에 바탕하여 새로운 질소고정효소의 작용 기작이 제안하였다.

• 한국토양비료학회지
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• 제23권3호
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• pp.227-231
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• 1990

밭 토양(土壤)에서 개량제(改良劑)로써 Zeolite시용(施用)이 완두(豌豆)의 생육(生育) 및 질소고정(窒素固定)에 미치는 영향(影響)을 검토(檢討)코져 N. P. K 및 Zeolite등(等) 6개처리(個處理)를 vinyl house內에서 pot시험(試驗)으로 수행(遂行)한 결과(結果)는 다음과 같다. 1. 건물중(乾物重)은 질소비료(窒素肥料) 시용구(施用區)가 질소(窒素) 무시용구(無施用區)에 비(比)하여 감소(減少)되는 경향(傾向)이나 Zeolite시용구(施用區)는 오히려 증가(增加)되었다. 2. 식물체중(植物體中) 질소함량(窒素含量)은 질소(窒素)와 Zeolite을 병용(倂用)함으로써 증가(增加)되었고 Zeolite시용량(施用量)은 2%시용(施用)이 1%보다 질소함량(窒素含量)이 낮았다. 그러나 토양중(土壤中)의 질소잔재량(窒素殘在量)은 2% 구(區)에서 많았다. 3. 식물체중(植物體中)의 표식질소(標識窒素)($^{15}N$)비료(肥料)의 유래(由來)된 질소량(窒素量)은 Zeolite를 병용(倂用)하는 편이 감소(減少)되는 경향(傾向)이며 이러한 경향(傾向)은 식물체(植物體) 각(各) 부위(部位)에서도 같은 양상(樣相)을 보였다. 4. 식물체중(植物體中)의 질소고정(窒素固定)에 유래(由來)된 질소량(窒素量)은 Zeolite시용구(施用區)에서 많았다. 그러나 질소비료(窒素肥料) 시용구(施用區)에서는 그 증가량(增加量)이 적었다.

• Journal of the Korean Wood Science and Technology
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• 제39권3호
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• pp.206-212
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• 2011

라디에타 소나무(Pinus radiata D.Don)를 이용하여 압체 온도와 시간에 따른 압밀화 목재의 경도와 치수안 정성을 조사하였다. 압체 온도가 상승함에 따라 표면경도도 함께 증가하였다. 열압체 시간 30분을 기준으로 압체 온도 $70^{\circ}C$에서는 경도 값이 5.0 N/$mm^2$, $220^{\circ}C$에서 15.6 N/$mm^2$으로 312% 향상되었으며, 60분에서는 313%, 90분에서는 224% 향상되는 것으로 나타났다. 치수회복실험 결과 열압체 온도가 상승함에 따라 치수고정효과는 상승한 반면 압체 시간의 증가에 의한 치수고정효과는 미약하였다. 접촉각 측정결과 압체 온도와 시간의 증가와 함께 접촉각도 증가했으며 압체 온도 $220^{\circ}C$에서는 $90^{\circ}$ 이상의 접촉각을 나타내어 표면이 소수성을 나타냄을 알 수 있었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권2호
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• pp.122-124
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• 2022

Various techniques are well documented to obtain anatomic reduction, such as reduction forceps, manual reduction, or a combination of these methods. However, these techniques have inherent drawbacks. We propose a new intra-operative technique for anatomic reduction using screw-wire traction for open reduction and internal fixation of mandibular fractures.