• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.13 no.1
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• pp.76-84
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• 2002

Objectives：This study was conducted to investigate the effect of oxygen on attention and memory functions in healthy adolescents. Methods：The participant subjects were recruited from local advertisement. All subjects are students attending ordinary middle and high school. Their degree of achievement was average or below average. Before the study, its nature and purpose were fully explained to the patients and their parents, and a written informed consent was obtained from each child's parent and a written assent from each child for entire the procedure. The Ethics Committee and Clinical Research Committee of Gyeongsang National University Hospital approved the protocol. For baseline assessment, all subjects received tests for attention and memory. All tests were conducted by a certified psychologist. Stroop test, continuous performance test and trail making test A and B were used for evaluation of attention. As memory tests, we used memory assessment scale(MAS), standardized memory assessment tools. Ten to fourteen days after initial assessments, same tests was applied to the same subjects after prior 5 minute oxygen inhalation. Results：1) Attention test：Improved performances in trail making part B, and stroop test were found in normobaric oxygen inhalation group compared to air inhalation group. Improved reaction time in those tests seemed to reflect the enhanced executive prefrontal activity. 2) Memory test：More words and digits memorization were found in short-term memory subscale score in MAS in oxygen inhalation group compared to air inhalation group. This finding suggested the improved working memory function after oxygen inhalation. Conclusion：Though interpreted cautiously, these results suggested that normobaric oxygen inhalation could enhance executive function and working memory of prefrontal lobe. Further study, however, should be performed to investigate the mechanism of effects of oxygen on cognitive enhancement.

• Archives of design research
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• v.18 no.4 s.62
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• pp.95-104
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• 2005

The purpose of this study is to estimate the determinants of product design and analyze the impacts of product design on quality competitiveness, product reliability, and consumer satisfaction in an attempt to provide a foundation for the theory of design management. For this empirical analysis, this study has derived the relevant measurement variables from a survey on 400 Korean manufacturing firms during the period of $August{\sim}October$ 2003. The empirical findings are summarized as follows: First, the determinants of product design are very significantly (at p<0.001) estimated to be the R&D capability, the level of R&D expenditure, the level of innovative activities(5S, TQM, 6Sigma, QC, etc.). This empirical result can support Pawar and Driva(1999)'s two principles by which the performance of product design and product development can be simultaneously evaluated in the context of CE(concurrent engineering) of NPD(newly product development) activities. Second, the hypothesis on the causality: product design${\rightarrow}$quality competitiveness${\rightarrow}$customer satisfaction${\rightarrow}$customer loyalty is very significantly (at p<0.001) accepted. This implies that product design positively affects consumer satisfaction, not directly but indirectly, by influencing quality competitiveness. This empirical result of this study can also support the studies of for example Flynn et al.(1994), Ahire et at.(1996), Afire and Dreyfus(2000) which conclude that design management is a significant determinant of product quality. The aforementioned empirical results are important in the following sense: the empirical result that quality competitiveness plays a bridging role between product design and consumer satisfaction can reconcile the traditional debate between QFD(quality function development) approach asserted by product developers and conjoint analysis maintained by marketers. The first empirical result is related to QFD approach whereas the second empirical result is related to conjoint analysis. At the same time, the empirical results of this study can support the rationale of design integration(DI) of Ettlie(1997), i.e., the coordination of the timing and substance of product development activities performed by the various disciplines and organizational functions of a product's life cycle. Finally, the policy implication (at the corporate level) from the empirical results is that successful design management(DM) requires not only the support of top management but also the removal of communication barriers, (i.e. the adoption of cross-functional teams) so that concurrent engineering(CE), the simultaneous development of product and process designs can assure product development speed, design quality, and market success.

• Spatial Information Research
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• v.11 no.3
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• pp.261-274
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• 2003

The effective probability-based tile pre-fetching algorithm and the collaborative cache replacement algorithm are able to reduce the response time for user's requests by transferring tiles which will be used in advance and determining tiles which should be removed from the restrictive cache space of a client based on the future access probabilities in Web GISs(Geographical Information Systems). The Web GISs have multi-level abstracted data for the quick response time when zoom-in and zoom-out queries are requested. But, the previous pre-fetching algorithm is applied on only two-dimensional pre-fetching space, and doesn't consider expanded pre-fetching space for multi-level abstracted data in Web GISs. In this thesis, a probability-based pre-fetching algorithm for multi-level abstracted in Web GISs was proposed. This algorithm expanded the previous two-dimensional pre-fetching space into three-dimensional one for pre-fetching tiles of the upper levels or lower levels. Moreover, we evaluated the effect of the proposed pre-fetching algorithm by using a simulation method. Through the experimental results, the response time for user requests was improved 1.8%∼21.6% on the average. Consequently, in Web GISs with multi-level abstracted data, the proposed pre-fetching algorithm and the collaborative cache replacement algorithm can reduce the response time for user requests substantially.

• The Korean Journal of Nuclear Medicine
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• v.35 no.5
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• pp.334-341
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• 2001

Purpose: Ascorbic acid us known to act as an antioxidant. Therefore, it can be used in increasing the efficiency of radiochemical labeling of Technetium-99m setamibi by inhibition of oxidation of $Sn^{2+}$ at low concentration. We intended to estimate the efficiency of radiochemical labeling and the stability of the newly formed formulation when ascorbic acid was added to a commercial kit. Materials and Methods: Synthesis of sestamibi was performed according to Dong-A's patent procedure (No.10-2001-0012877). First, we undertook a study to evaluate the efficiency of radiochemical labeling of sestamibi containing ascorbic acid. The stability of the vials was assessed using either $7.5{\mu}g\;or\;75{\mu}g$ of ascorbic acid, added to commercial vials under the accelerated condition(Temp : $40^{\circ}C{\pm}2^{\circ}C$, Relative humidity : $75{\pm}5%$). Results: Sestamibi was synthesized in overall 35-40% yield over 5 steps from a commercially available methallyl chloride as a starling material. When ascorbic acid was added, the efficiency of radiochemical labeling was maintained compared to the vial with no ascorbic acid. The accelerated test showed that the addition of ascorbic acid inhibited the oxidation of $Sn^{2+}$ ion by antioxidation mechanism. Also, the efficiency of radiochemical labeling of this vial after 9 months was nearly the same as the starting point. Therefore, the storage period of the kit is likely to be extended. Taken together, it suggests that the addition of ascorbic acid as a stabilizer is desirable. Conclusion: To increase the stability of a sestamibi cold kit, it is desirable to add ascorbic acid as a stabilizer to the commercial formulation.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.3
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• pp.135-152
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• 1975

The following informations are known from physical and chemical characteristics of orchard soils and nutritional diagnosis of orange leaves in Jeju. 1. Most orange orchards are located on terrace and cindercone thus soil moisture and microclimate of an orchard will greatly be affected by its topography. 2. Excessive well drainage, shallow soil depth, high content of gravels, low solid phase ratio and strong wind will give severe problem of soil moisture and wind errosion, thus the exte- nsion of soil depth is necessary for maintain nutrients, water and sufficient root volume. 3. Available soil water was significantly and positively correlated with organic matter content and clay content also contributes to available soil water. Vinyl mulching was greatly helpful for soil water conservation, wind errosion prevention, soil temperature increases during winter. 4. Abundant amphoteric amorphous allophane take a key role to fix phosphorus and also rations and thus it is the major factor to determine fertilizer efficiency. Lime and phosphorus must be applied in deeper soil layer. Release of filed phosphorus must be reevluated for availability. 5. Organic matter such as see weeds will greatly increase fertilizer efficiency and low fertilizer efficiency during spring may be related to available soil water. 6. Nitrogen was in superoptimum and Mg was enough but P and Ca were somewhat deficient according to leaf analysies while K was deficient according to fruit analysis. Phosphorus application increased sugar/acid ratio and potassium decreases rind percentage. 7. Manganese deficiency and toxicity appeared in a few places. Iron and boron were enough. Most places showed tendency of copper excess but some places showed copper deficiency. 8. Soiling after elimination of rock base, application of slow release fertilizer and abundant organic matter, vinyl mulching and drip irrigation will increase fertilizer efficiency greatly and fruit yield drastically.

• Radiation Oncology Journal
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• v.28 no.1
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• pp.16-22
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• 2010

Purpose: We analyzed the incidence and related factors of radiation dermatitis; at first, to recognize whether a decrease in radiation dermatitis is possible or not in breast cancer patients who received radiation therapy. Materials and Methods: Of 338 patients, 284 with invasive breast cancer who received breast conservation surgery with radiotherapy at Chonbuk National University Hospital from January 2007 to June 2009 were evaluated. Patients who also underwent bolus, previous contralateral breast irradiation and irradiation on both breasts were excluded. For patients who appeared to have greater than moderate radiation dermatitis, the incidence and relating factors for radiation dermatitis were analyzed retrospectively. Results: A total of 207 and 77 patients appeared to have RTOG grade 0/1 or above RTOG grade 2 radiation dermatitis, respectively. The factors found to be statistically significant for the 77 patients who appeared to have greater than moderate radiation dermatitis include the presence of lymphocele due to the stasis of lymph and lymph edema which affect the healing disturbance of radiation dermatitis (p=0.003, p=0.001). Moreover, an allergic reaction to plaster due to the immune cells of skin and the activation of cytokine and concomitant hormonal therapy were also statistically significant factors (p=0.001, p=0.025). Conclusion: Most of the breast cancer patients who received radiation therapy appeared to have a greater than mild case of radiation dermatitis. Lymphocele, lymphedema, an allergy to plaster and concomitant hormonal therapy which affect radiation dermatitis were found to be significant factors. Consequently, we should eliminate lymphocele prior to radiation treatment for patients who appear to have an allergic reaction to plaster. We should also instruct patients of methods to maintain skin moisture if they appear to have a greater than moderate case of radiation dermatitis.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.2
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• pp.163-171
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• 2008

Purpose: We analyze the characteristics of soft tissue sarcomas presented with hematoma, which were misdiagnosed as simple hematoma initially and the proper management were delayed. Materials and Methods: The 7 patients with histologically proven soft tissue sarcoma with hematoma presented since February 1997 were evaluated retrospectively. Neither patient had a medical history of bleeding tendency nor anticoagulant therapy. Two of them had minor traumas. There were 2 men and 5 women. Average follow up period was 58 months. MRI findings, provided treatments and oncologic outcome were reviewed with the reference of related articles. Results: Retrospective review of initial MR images revealed deep seated intramuscular masses with focal solid enhanced nodules at the peripheral margin. The diagnoses were delayed at least 1 month in 3 of them which included 2 cases of simple hematoma evacuation without biopsy initially. After histologic diagnosis of soft tissue sarcoma, wide resections were performed in 4 cases. one patient underwent above knee amputation and the remained 2 patients were managed with wide resection followed by amputation due to local recurrence. At last follow up there were CDF and NED in 2 cases, respectively and AWD in 3 cases. Conclusion: To avoid the delay of diagnosis and treatment of soft tissue sarcomas presented with hematoma, high degree of clinical suspicion, careful analysis of MR images and early biopsy were important.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.31-42
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• 2009

Purpose: As the number of domestic medical institutions installing PET/CT is increasing rapidly, the transfer of PET/CT images among medical institutions is also increasing. Thus, it is necessary to collect the comparative SUV data from several medical institutions' PET/CT systems through a phantom study which semi-quantitatively compares the SUV on one bed, the change scale of the SUV on the slices, and the time of measuring. The phantom study to find differences among the SUVs from various PET/CT offers the opportunity to obtain the reliability of the SUV in PET/CT images. Materials and Methods: Ten PET/CT systems from medical institutions in Korea were used. To obtain the accurate data, the study has been using the radiation detector of Korea Research Institute of Standards and Science to verify. The internal structures of NEMA $phantom^{TM}$ were removed and Six thousand milliliters of distilled water which has 1mCi of $^{18}F$-FDG put into the phantom. The water was properly integrated with $^{18}F$-FDG using magnetic stirrer. The images were acquired at 60, 70, 80, 90, 100, 110 and 120-minutes for 3 minute each. Two hundred square centimeters of region of interests were placed and analyzed. To confirm the usefulness, the correction-table came out from patients' data. Results: The coefficient of variability of the SUV from -11.0 to 9.90 % fell into the range of international standards(${\pm}10%$) along with the SUV on a bed, the change scale of the SUV on the slices, and the time of measuring, except one PET/CT system. Using the data of the differences among the SUVs, we came to withdraw the correction-table ranging from 0.803 to 1.246. The correction-table was confirmed its usefulness through Linear Regression Analysis which was applied to normal cases. Conclusions: Although studies have been made on the variation of the SUV, there is little attention on the standardization of the SUV. Based on this study of the quantitatively comparable data about the SUV accommodating the correction-table, it would help to have more corrective diagnosis.

• Journal of Mushroom
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• v.12 no.4
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• pp.330-340
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• 2014

Coprinellus micaceus, belongs to family Psathyrellaceae of Agaricales, Basidiomycota, has been used for edible purposes in the world. This study was initiated to evaluate the antioxidant, anti-diabetic, anti-cholinesterase, anti-tyrosinase, and nitric oxide inhibitory activities of fruiting bodies from C. micaceus extracted with methanol and hot water. The HPLC analysis of phenolic compounds from the mushroom extracts identified 4 phenolic compounds including procatechuic acid, chlorogenic acid, (-)-epicatechin, and naringin. In 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging assay, the scavenging activities of methanol and hot water extracts were lower than that of positive control, BHT. The chelating effects of methanol and hot water extracts were significantly higher than that of BHT, the positive control at the all concentrations tested. In the reducing power assay, methanol and hot water extracts exhibited the lower activities compared with positive control at the 0.125-0.2 mg/ml. The methanol and hot water extracts of the mushroom inhibited the ${\alpha}$-glucosidase activity by 62.26% and 67.59%, respectively at the 2.0 mg/ml, while acarbose, the positive control, inhibited the ${\alpha}$-glucosidase activity by 81.81% at the same concentration. In the acetylcholinesterase(AChE) inhibitory activity assay, methanol and hot water extracts of the mushroom inhibited the AChE by 94.64% and 74.19%, respectively at 1.0 mg/ml, whereas the galanthamine, standard drug, inhibited the AChE activity by 97.80% at the same concentration. The tyrosinase inhibitory activities of methanol and hot water extracts were 91.33% and 91.99% at 2.0 mg/ml, while the inhibitory activity of kojic acid, the positive control, was 99.61% at the same concentration. Nitric oxide(NO) production in lipopolysaccahride (LPS) activated RAW 264.7 cells were inhibited by the methanol and hot water extracts in a concentration dependent manner. Therefore, it is concluded that fruiting bodies of C. micaceus contained natural antioxidant, anti-acetylcholinesterase and ${\alpha}$-glucosidase inhibitory, anti-inflammatory, anti-tyrosinase substances which might be used for promoting human health.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.34-40
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• 2009

Background: The principal surgical technique for treating an abdominal aortic aneurysm since the 1960s has been the transperitoneal approach, yet there have been some recent studies that have reported improved surgical results with using the retroperitoneal approach. However, there are only limited clinical Korean studies that have, compared between the transperitoneal and retroperitoneal approaches. Material and Method: This study included 36 patients who had been diagnosed as having an aneurysm of the abdominal aorta and they were surgically treated between January 2001 and July 2007. The patients were subdivided into the retroperitoneal approach group (n=17) and the transperitoneal approach group (n=19), and they were compared in terms of the preoperative risk factors, the postoperative complications and the operative mortality. The risk factors of operative mortality risk and long-term survival for the 36 patients were assessed by the Kaplan-Meier method. Result: There were no significant differences between the groups in terms of gender, age, the underlying disease, a history of smoking, rupture of aneurysm, the preoperative symptoms, the operation time and the incidence of postoperative complications. However, the duration of postoperative fasting, the number of days of having an indwelling nasogastric tube and the length of the stay in the intensive care unit were significantly short for the retroperitoneal approach group (p<0.05). There was a 16.7% rate of operative mortality (6/36) and five of the deaths were attributed to preoperative ruptured aneurysm. On univariate analysis, a higher preoperative serum creatinine level (SCr ${\geq}$1.8 mg/dL, p=0.016) and ruptured aneurysm (p<0.001) were the significant risk factors of operative mortality. As assessed by the Kaplan-Meier method, the long-term survival was comparable between the groups and the five-year survival rate of all the patients was 57.5%. Conclusion: In the present study, a retroperitoneal approach has several advantages such as a shorter intensive care unit stay, a shorter duration of postoperative fasting and a shorter duration of an indwelling nasogastric tube. Therefore, unless there is any contraindication for a retroperitoneal approach, it could be considered as a primary surgical access for repairing an abdominal aortic aneurysm.