• Applied Microscopy
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• v.36 no.1
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• pp.35-45
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• 2006

Plants of Vitex negundo are known to develop numerous trichomes throughout their body, where certain trichome types have been believed to be one of the plausible structures for the unique scents. In the current study. structural aspects of the trichomes have been examined in leaves and stems of Vitex negundo using TEM and SEM. Trichome types as well as structural changes that occurred in certain trichomes during secretion have been mainly focused. Three type of glandular trichomes and two types of non-glandular trichomes were developed in the epidermis of young and mature Vitex negundo plants. The glandular trichomes included the peltate type (Type 1), the capitate type (Type 2), and degraded capitate type (Type 3), whereas the non-glandular warty trichomes contained the multicellular (Types 4) and unicellular type (Type 5). Type 1 and 2 consisted of head and stalk cells, but their number and size were different. One secretory cavity was formed from the four head cells in the former, but only two head cells were involved in the latter. The cytoplasmic density in the head cell was quite high and in particular, sER and Golgi bodies were well developed. At initiation of their development, the cuticle layer of the head cells separated from the outer tangential wall to form a secretory cavity. Subsequently the cavity expanded acropetally and a large number of secretory vesicles continuously produced from the head cells until they filled the entire cavity. The cavity contained materials that would be soon discharged into intercellular spaces and/or into the air. The cavity began to decrease the volume by contracting at initial secretion but degrade rapidly within short time. It has been suggested that the mode of secretion in V. negundo is probably the eccrine secretion, since no break or rupture of the cavity has been observed during examination. Contrastingly Type 3 exhibited deterioration of the head cell at early stage. Type 4 was about $110{\sim}190{\mu}m$ long, consisting of $2{\sim}3$ cells, and distributed more in the adaxial epidermis compared to the abaxial surface. However, $20{\sim}30{\mu}m$ long Type 5 was extremely dense in both epidermis. Among several trichome types, Type 1 and 2 probably play an important role in discharging unique aromatic scents in plants of V. negundo.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.98-104
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• 2010

Excess nitrogen (N) uptake of rice, which could cause much lodging, disease and reduction of rice quality, could be occurred at the paddy field with previous upland condition at which much soil N could be mineralized by soil-drying effect. N fertilizers of 0, 3, and 6 kg N $10a^{-1}$ were applied to early-maturity rice, cultivar Joanbyeo at the paddy field of first and second year after upland condition, and rice growth and nitrogen uptake were investigated to know the increase of rice N uptake at the paddy field with previous upland condition for one-year. Total dry matter (DM) and N uptake of rice at the paddy field with previous upland condition increased more than continuous paddy field. Total DM and N uptake of rice at the paddy field with previous upland condition increased linearly to N fertilizer 6 kg $10a^{-1}$ at the paddy field owing to vigorous growth compared to continuous paddy field. Rice N uptake was higher at the paddy field of the first year than the second year after upland condition in considering N uptake at the plot of no N fertilizer. Vigorous growth at the paddy field with previous upland condition resulted in higher rice yield which was related with high panicle and spikelet, but much N fertilizer as much as 6 kg $10a^{-1}$ at the paddy field with previous upland condition resulted in higher lodging and protein content of brown and milled rice. Particularly, protein content of brown and milled rice increased more when the same N fertilizer was applied two times splitly at transplanting and panicle initiation stage than when N fertilizer was applied one time at transplanting as basal N. N application with under 3 kg $10a^{-1}$ as only basal N was recommended at the paddy field with previous upland condition to obtain high quality rice without lodging.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.1
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• pp.22-29
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• 2001

In Korean high yielding varieties developed by crosses between indica and japonica rice, the most limiting factor for yield may be attributed to the less number of the tillers in the unit area. The goals of this study is to find out the effect of the temperature factors as well as cultural practices on the development and increase of tillers of Dasanbyeo, the high yielding indica crossed japonica cultivar. The effect of temperature was examined under controlled phytotron condition with 6 levels of temperature, 15, 17, 19, 22, 24 and 26$^{\circ}C$, respectively, For the experiment, the leading japonica variety in Korea, Hwaseongbyeo, was used for the check cultivar for the comparison with Dasanbyeo. The high temperature also accelerated the initiation and termination of tiller development. The cultivar difference in the speed of tiller development was observed, for example, more rapid development of tiller in Dasanbyeo than in Hwaseongbyeo was observed at the high temperature range of 24-26$^{\circ}C$, while the vice versa phenomena was observed at lower temperature range of 17-22$^{\circ}C$. The first secondary tiller of Dasanbyeo was observed on the 16, 17, 23, 27 and 38 days after transplanting (DAT) at 26$^{\circ}C$, 24$^{\circ}C$, 22$^{\circ}C$, 19$^{\circ}C$, and 17$^{\circ}C$, respectively. Those of Hwaseongbyeo was 19-22, and 26 DAT at 19-26$^{\circ}C$ and 17$^{\circ}C$, respectively. The last effective tiller of Dasanbyeo was observed on 27-33 DAT for the primary tiller, 20-41 DAT for the secondary tiller. Those of Hwaseongbyeo were 23-40 DAT for primary tiller, and 24-40 DAT for the secondary tiller, and 24-40 DAT for the secondary tiller.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.3
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• pp.151-158
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• 2002

In Korean high yielding varieties developed by crosses between indica and japonica rice, the most limiting factor for yield increase may be attributed to the less number of tillers per unit area. The goal of this study is to find out the effect of the environmental factors as well as cultivation practice on the development and increase of tillers of Dasanbyeo, the high yielding indica / japonica hybrid cultivar. The effect of temperature was examined with 3 different light intensity, 220,600, and 1220 $\mu$㏖/s/$m^2$, respectively. For all the experiments, the leading japonica variety in Korea, Hwaseongbyeo, was used fur the check cultivar for the comparison with Dasanbyeo. The increase of the tillers was more prominent in Dasanbyeo than in Hwaseongbyeo at 220 $\mu$㏖/s/$m^2$ of light intensity, while the similar increase of tiller no. was found at 600 $\mu$㏖/s/$m^2$ of light intensity treatment. However, Hwaseongbyeo showed more rapid increase of tiller at 1220 $\mu$㏖/s/$m^2$ of light intensity. The mean number of the primary tiller ranged 5 to 7 in Dasanbyeo, and 2 to 7 in Hwaseongbyeo, showing greater variation in the latter case. However, the secondary tiller number ranged from 2 to 13 for the former, and 2 to 12 for the latter. The earliest initiation of tiller node of Dasanbyeo and Hwaseongbyeo was observed on 6 and 4 days after transplanting(DAT), respectively, at 600 $\mu$㏖/s/$m^2$ of light intensity, while 10, and 7 DAT, respectively, at 1,220 $\mu$㏖/s/$m^2$. No cultivar difference was observed at 600 $\mu$㏖/s/$m^2$ with the 18 DAT. The ratio of effective tiller was lower in Dasanbyeo, ranging from 47 to 55% than in Hwaseongbyeo, ranging from 72 to 100%.

• Korean Security Journal
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• no.28
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• pp.153-179
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• 2011

Korea has been a victim of State supporting terrorism by North Korea even before international society realize the terrorism threats because of 9.11 in US. However, state supporting terrorism against South Korea by North Korea went along with East/West Cold War System by US and the Soviet Union. It is because socialism that Kim Il-sung who established a separate government in North Korea with the political, economic, social and military support of the Soviet Union selected as his political ideology justifies terrorism as the tool to complete the proletariat revolution. North Korea's state supporting terrorism is being operated systematically and efficiently by military of North Korea. It gives big worries to international society not only by performing terrorism against Korea but also by dispatching terrorists and exporting terrorism strategies to the third world countries. In this situation, terrorism against Korea has met a new transition point at 9${\cdot}$11 in US. As South Korea is confronting North Korea and the war has not ended but suspended, the alliance between US and Korea is more important than anything else. Because of this Korea decided to support the anti-terrorism wars against Afghanistan and Iraq of US and other western countries and send military force there. The preface of the anti-terrorism war has begun as such. On October 7, 2001, US and UK started to attack Afghanistan and Taleban government in Afghanistan was dethroned on December 7, 2001. US and western countries started a war against Iraq on March 20, 2003. On April 9, 2003 Baghdad, the capital of Iraq fell, and Saddam Hussein al-Majid al-Awja government was expelled. During the process, the terrorism threat against South Korea has expanded to Arab terrorists and terrorism organizations as well as North Korea. Consequently, although Korean government, scholars and working level public servants made discussions and tried to seek countermeasures, the damages are extending. Accordingly, terrorism against Korean companies in overseas after 9${\cdot}$11 were analyzed focusing on Nation, Region, Victimology, and Weapons used for the attacks. Especially, the trend of terrorism against the Korean companies in overseas was discussed by classifying them chronologically such as initiation and termination of anti-terrorism wars against Afghanistan and Iraq, and from the execution of Iraqi President, Saddam Hussein al-Majid al-Awja to December 2010. Through this, possible terrorism incidents after the execution of Osama bin Laden, the leader of Al-Qaeda, on May 2, 2011 were projected and proposals were made for the countermeasures.

• Research in Plant Disease
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• v.18 no.2
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• pp.117-122
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• 2012

In 2006, the effect of soil pH adjustment on control of common scab of potato caused by Streptomyces spp. was evaluated in the field. Soil with an original pH 5.7 was treated with sulfur of 42 kg/10a and calcium hydroxide of 81.6 kg/10a and 184.5 kg/10a to adjust pH 5.0, 6.0 and 6.5, respectively. Additionally, the effect of gypsum (522 kg/10a) on soil pH and disease severity was examined. The soil pH of sulfur treatment plot was continuously declined from 5.13 at tuber initiation time to 5.01 at harvest. The disease severity of sulfur treatment plot was relatively low (22.8%) and the marketable yield of that was high (90.5%). By contrast, the soil pHs treated with calcium hydroxide (81.6 kg/10a and 184.5 kg/10a) were increased (pH 6.06 and 6.49, respectively) at harvest. In addition, calcium hydroxide treatment plots showed higher disease severities (51.0% and 61.1%), and lower marketable yields (55.7% and 37.0%). Meanwhile, the soil pH of gypsum treatment plot was not changed until harvest, and the disease severity and the marketable yield were not significantly different from those of control. The effect of crop rotation was also evaluated with four crops such as welsh onion, soybean, corn and Chinese cabbage. These crops were planted in the infested field from 2005 to 2007, and potatoes were planted in the same field in 2008. The disease severities of potatoes produced after rotations with welsh onion, soybean, corn and Chinese cabbage for 3 years were 13.1%, 16.7%, 28.9% and 30.2%, respectively. However, the disease severity of 73.1% was shown in continuous cropping of potato for 3 years. In addition, similar effects were exhibited in the marketable yield. These results demonstrate that the adjustment of soil pH and crop rotation might be very useful tools to control common scab of potato.

• Journal of Chest Surgery
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• v.40 no.1 s.270
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• pp.32-36
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• 2007

Background: Although acute renal failure (ARF) after coronary artery bypass graft (CABG) is relatively rare, but devastating complication with high mortality. Our study aims to evaluate the effectiveness of early application of CRRT in patients with ARF which developed after on-pump CABG. Material and Method: Two hundred and eighty seven patients underwent isolated on-pump CABG between May 2002 and Feb. 2006 at our institution, of whom 15 (5.2%) needed CRRT (11 patients for postoperatively developed ARF and the remaining 4 patients with preexisting dialysis-dependent chronic renal failure (CRF) for postoperative hemodynamic and metabolic control). Criteria for early application of CRRT were as follows; decreased urine output less than 0.5cc/h/kg for 2 consecutive hours and elevated serum creatinine level greater than 2.0 mg/dL. Result: The incidence of ARF requiring CRRT after on-pump CABG was 3.9% (11/283) and the overall hospital mortality of patient with CRRT was 33.3% (5/15). Of 5 deaths, 4 were patients with postoperatively developed ARF, and 1 was a patient with pre-existing dialysis-dependent CRF patient. The mean time between the operation and the initiation of CRRT was $25.8{\pm}5.8$ hours and the mean duration of CRRT was $62.1{\pm}41.2$ hours. Of the 7 survivors who were not on dialysis-dependent preoperatively, 6 patients fully recovered renal function during hospital stay and 1 patient required permanent renal supportive treatment after discharge from hospital. Conclusion: Early application of CRRT could maintain stable postoperative hemodynamic status and make outcomes better than those of previous reports in patients with ARF which developed after on-pump CABG.

• Radiation Oncology Journal
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• v.7 no.2
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• pp.213-225
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• 1989

An analysis has been made of two hundred seven patients who were treated at the department of Radiation Oncology of Korea University Hospital for lung cancer from January 1981 through December 1986. There were 137 patients of nonsmall cell carcinoma (137/207, 66%), 26 patients of small cell carcinoma (26/207, 12.5%) and 44 patients of unproven histology. By aims of treatment, there were 104 patients (104/207, 50%) treated for cure, 89 patients (89/207, 42.9%) for palliation and 14 patients treated postoperatively. In 22 out of 207 patients, chemotherapy was done with radiotherapy, 12 of which were patients with small cell carcinoma. Stage II patients were 49 (49/207, 23.6%), stage III patients were 157 (157/207, 75.8%) and one patient had an occult cancer The tumor was initial Iy measured by CAT scan and chest X-rays in the 165 (165/207, 79.7%) patients, among which 117 patients had tumor diameter more than 5cm and 48 patients less than 5cm. Radiation therapy was given with Cobalt 60 teletherapy unit and the treatment volume encompassed primary tumor and the mediastinum. For curative aim, daily tumor dose of 180 cGy was given up to the range of 5,400~6,120cGy/30~34F/6~7 week period and for palliative aim, daily tumor dose of 300 cGy was given up to the range of 3,600~4,500 cGy/12~15F/2~3 week period. Postoperatively, mediastinum was treated for total dose of 5,040 cGy/28F/5.5 week period. 123 patients (123/207, 59%) were followed up after completion of radiotherapy for 14 months to 7 years. Local tumor response to the irradiation was measured by chest X-ray taken at one month follow up and was evaluated for response rate, if they were regressed more than 50% or less than 50% of the initial tumor size. The treatment results were as follows; 1. The median survival time was 8.5 months and survival rates for 1 year, 2 year and 5 year was 25%, 3.5% and 1% of nonsmall cell lung ca of 74 evaluable patients. 2. More than 50% of local tumor response rate was obtained in about half of overall cases; 90.5% for small cell ca, 50% for squamous cell ca, 25% for adenoca and 57% for large cell ca. 3. Response rate more than 50% was seen in the 50% of the patient group with tumor diameter more than 5cm and in the 55% of those with tumor diameter less than 5cm. 4. By total raidation dose given, patient group which was given 5,400~6,120 cGy equivalent dose or higher showed tumor response rate more than 50% in 53% of the patients, whereas the group with dose less than 5,400cGy equivalent, in 25% of the patients. 5. Survival rate for 6 month, 1 year and 2 year was compared between the group of local tumor response rate more than 50% vs. group with response rate less than 50%; 74% vs. 43%, 33% vs, 23%, 10% vs. 1%, respectively. 6. Local failure was seen in 21%(44/207) of the patients, which occured mostly within 15 months after completion of radiation therapy. Distant metastases were seen in 49.7%(103/207) of the patients, of which 43 cases were found before initiation of radiotherapy. The most common metastatic sites were bone and brain. In this sutdy, 1 year,2 year and S year survival rates were somewhat poor compared to the other studies. It mainly seems to be due to the poor general status of the patients and the far-advanced stage of the disease. In nonsmall cell cancer patients who had limited local disease and had small primary tumor size, we observed better local response. In addition, dose higher than 6,000 cGy group showed better tumor control than lower dose group. Survival rate was better for the local control group. For imporvement of local control of the lung cancer and hence, the survival of the patients with lung cancer, proper radical radiotherapy with high dose for localized disease is needed. New modality of treatment such as high LET beam in radiation therapy or drugs for the advanced disease as well as early diagnosis is also needed.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.2
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• pp.143-149
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• 2002

Purpose: The following study was performed to reveal the relationship between Clostridium difficile colitis in childhood and associated antibiotics. Methods: From January 2000 to June 2002 at Seoul National University Children's Hospital, 85 symptomatic pediatric patients who showed positive stool culture for Clostridium difficile were included. The implicated antibiotics within 2 months before stool culture were analyzed. Of the 85 patients, there were 50 males and 35 females, and their average age was 2.5 years. Results: There was a history of implicated antibiotics within 2 months in 55 cases (67%). Forty-three patients (78%) of them showed Clostridium difficile in stool culture during antibiotics treatment. The time interval between the initiation of antibiotics and stool culture ranged from one day to 7 weeks (mean 10 days) in these patients. In the remaining 12 patients, Clostridium difficile was detected after the discontinuation of antibiotics. The time interval between the discontinuation and stool culture ranged from one day to 7 weeks (mean 12 days). The associated antibiotics were cefotaxime (20 cases), amikacin(15 cases), ampicillin (13 cases), cefazolin (8 cases), vancomycin (8 cases), etc. In 31 cases, more than one antibiotics were prescribed. Conclusion: When diarrhea occurred in young children during antibiotic usage or with a past history of recent antibiotic usage, Clostridium difficile should be investigated as a cause of diarrhea for proper management.

• Fire Science and Engineering
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• v.31 no.5
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• pp.53-62
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• 2017

Electric power which is the energy source of economy and industries requires long distance transportation due to regional difference between its production and consumption, and it is supplied through the multi-loop transmission and distribution system. Prior to its actual use, electric power flows through several transformations by voltage transformers in substations depending on the characteristics of each usage, and a transformer has the structure consisting of the main body, winding wire, insulating oil and bushings. A transformer fire that breaks out in substations entails the primary damage that interrupts the power supply to houses and commercial facilities and causes various safety accidents as well as the secondary economic losses. It is considered that causes of such fire include the leak of insulating oil resulting from the destruction of bottom part of bushings, and the chain reaction of fire due to insulating oil that reaches its ignition point within 1 second. The smoke detector and automatic fire extinguishing system are established in order to minimize fire damage, but a difficulty in securing golden time for extinguishing fire due to delay in the operation of detector and release of gas from the extinguishing system has become a problem. Accordingly, this study was carried out according to needs of active mechanism to prevent the spread of fire and block the leak of insulating oil, in accordance with the importance of securing golden time in extinguishing a fire in its early stage. A bushings fireproof structure was developed by applying the high temperature shape retention materials, which are expanded by flame, and mechanical flame cutoff devices. The bushings fireproof structure was installed on the transformer model produced by applying the actual standards of bushings and flange, and the full scale fire test was carried out. It was confirmed that the bushings fireproof structure operated at accurate position and height within 3 seconds from the flame initiation. It is considered that it could block the spread of flame effectively in the event of actual transformer fire.