• Journal of Yeungnam Medical Science
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• 제16권2호
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• pp.237-243
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• 1999

We conducted this study to find the optimal correction factor(${\alpha}$) of Lassen's linearization algorithm which has been applied for correction of flow-limited uptake at a high flow range in $^{99m}Tc$ d,l-hexamethylpropy leneamine oxime(HMPAO) and $^{99m}Tc$ ethyl cysteinate dimer(ECD). Ten patients with chronic cerebral infarction were involved in this study. We obtained the corrected $^{99m}Tc$ HMPAO and $^{99m}Tc$-ECD brain SPECT(single photon emission computed tomography) using the algorithm with ${\alpha}$ values that varied from 0.1 to 10 and compared the results with regional cerebral blood flow determined by positron emission tomography (PET-rCBF). The multi-modal volume registration by maximization of mutual information was used for matching between PET-rCBF and SPECT images. The highest correlation coefficient between $^{99m}Tc$-HMPAO and $^{99m}Tc$-ECD brain uptake and PET-rCBF was revealed at ${\alpha}$ 1.4 and 2.1, respectively. We concluded that the ${\alpha}$ values of Lassen's linearization algorithm for $^{99m}Tc$-HMPAO and $^{99m}Tc$-ECD brain SPECT images were 1.4 and 2.1, respectively to indicate cerebral blood flow with comparison of PET-rCBF.

• Korean Journal of Environment and Ecology
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• 제18권4호
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• pp.369-381
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• 2004

This study was achieved to present the way to restore the Seonheulgot pasture-grassland damaged by landuse and interference for a long time to evergreen broad-leaved forests as the native vegetation structure. As a result of analyzing ecological succession tendency of structure in survey area, we established the optimal restoration model. The total of survey sites were 26, and the classified plant community types were four types by M.I.P of dominant woody species. Finally we classified the four types based on diameter of dominant woody species in canopy layer. The six community types are as follows: Community I was runner-shrub forest, community II was evergreen broad-leaved shrub forest, and community III was evergreen broad-leaved forest of small diameter. Community IV and V were evergreen broad-leaved forest of middle diameter. Community Ⅵ was evergreen broad-leaved forest of large diameter. The number of constituent species was 24 in community I, 28 in community II as the shrub forest, 16 as the evergreen broad-leaved forest of small diameter, 29 in community III, 30 in community IV as the evergreen broad-leaved forest of middle diameter and 27 in community Ⅵ as the evergreen broad-leaved forest of large diameter. The range of Shannon's index of all communitys was from 0.8763 to 1.2630 and the Similarity index between the community composed of middle diameter woody species and large diameter woody species. The ecological succession of community I, II, and III were changed from pasture-grassland to broad-leaved forest and the structure of community IV, V, and Ⅵ was similar to evergreen broad-leaved forest in warm temperate region. We suggest the restoration planting model evergreen broad-leaved forest of in Seonheulgot pasture-grassland, as follows: The target restoration vegetation were Castanopsis cuspidata var. sievoldii community and Queycus glauca community. Castanopsis cuspidata var. sievoldii and Quercus glauca should be dominant woody species in canopy layer, the number of trees was 10 per 100$m^2$, and Castanopsis cuspidata var, sievoldii, Quercus glauca, Camellia japonica, and Eurya japonica should be dominant woody species in the understory layer, the number of trees was 14 per 100$m^2$.

• Radiation Oncology Journal
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• 제15권3호
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• pp.207-213
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• 1997

Purpose : Intracranial germinoma is the most radiocurable tumor of theprimary intracranial neoplasm. But, the optimum radiation dose and target volume remain controversial In this retrospective study, we analysed the spreading pattern at presentation and the pattern of the failure and survival of intracranial germinoma, Materials and Methods : From 1989 to 1996, 23 Patients were treated for intracranial germinoma at Department of Radiation Oncology, Twenty-one Patients were treated at their initial Presentation and 2 Patients were treated for recurrent disease. Six patients had multiple tumor masses on MRI and 7patients had ventricular seeding on MRI. The examination of cerebrospinal fluid cytology was done in 15 patients and 3 out of 15 patients had positive cerebrospinal cytology. In tumor marker study of $\alpha-FP\;and\;\beta-hCG$, 6 patients had mildly elevated $\beta-hCG$ in serum or cerebrospinal fluid. Twentyone Patients were treated with whole craniospinal axis irradiation and 2 Patients were given whole ventricular radiation therapy. The total dose was ranged between 4500cGy and 5600cGy to primary tumor site (median 5580cGy) Dose to the entire ventricular system ranged from 1980cGy to 3960 cGy (median 2700cGy) and dose to the spinal axis ranged from 2160cGy to 3900cGy (median 2700cGy) Results : Of 23 patients, 21 Patients are alive without evidence of diseasefor median 4 years follow-up. One Patient who had markedly elevated $\alpha-FP\;and\;\beta-hCG$, suffered from Persistent disease after radiation therapy and received 2 cycles of chemotherapy. She died 9 months after chemotherapy One patient who developed ventricular seeding after gamma-knife was treated with whole craniospinal irradiation, he died after 1 year due to probably brain necrosis. The hematologic toxicity of 3 or 4 grade were seen in 7 patients and patient's endocrinologic dysfunction was not deteriorated after radiation therapy. One patient had been treated with growth hormone replacement due to short stature. Conclusions : This retrospective study has confirmed the excellent result of radiation therapy in intracranial germinoma. The complication rate during or after radiation therapy is considered within acceptable range. ft is necessary to further investigate the optimal dose and treatment volume of radiation therapy. The role of chemotherapy in the treatment of intracranial germinoma should be further investigated.

• Journal of Chest Surgery
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• 제35권11호
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• pp.792-798
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• 2002

Although there is a controversy on the optimal timing for active infective endocarditis(IE), recently good results of early surgical intervention have been published. Herein, we analyzed the results of surgery for active IE according to the duration of preoperative antibiotic treatment. Material and Method : Retrospectively, we analyzed 51 patients who underwent operation for active IE at the department of thoracic and cardiovascular surgery of Samsung medical center from Mar. 1995 to Oct. 2001. Male to female ratio was 39:12, mean age of the patients was 44.5$\pm$17.8 years(range : 13~74). Infected valves were mitral valve in 17(33.3%), aortic valve in 15(29.4%), mitral and aortic valve in 12(23.5), and tricuspid valve in 5(9.8%) cases. Among them, prosthetic valve endocarditis was present in 10(19.6%) cases. Infecting organism was Staphylococcus in 19(37.3%), Streptococcus in 17(33.3%), Enterococcus in 3(5.9%), fungus in 3(5.9%), and other bacteria in 5(9.8%) cases. Organism was not isolated in 6(11.8%) cases, and two organisms were isolated in 4(7.8%) cases. Dividing these patients into two groups according to the duration of preoperative antibiotic treatment(A: less than 7 days, B: more than 8 days), we compared the surgical results between the two groups. Result : There were 16 cases in group A and 35 in group B. Annular reconstruction was performed in 10(62.5%) cases in group A and 10(28.6%) cases in group B, which has statistically significance(p＜0.05). There was one early death in group B. Forty nine patients(96.1%) except two were followed up with mean follow-up duration of 28.7 $\pm$ 23.6 months. Endocarditis was recurred in one in group A, and two in group B. Three late deaths occurred in group B. Recurrence rate and survival were not statistically different between the two groups. Conclusion : Early surgery for active IE showed good results as the result of that which was performed after prolonged antibiotic treatment; therefore, we believe that early surgery for active If could effectively eradicate the infection.

• Korean journal of food and cookery science
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• 제29권6호
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• pp.661-669
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• 2013

This study was performed to determine the optimal composition of Cheonggukjang added with garlic. The experiment utilized a central composite design (CCD). The evaluation was carried out by means of response surface methodology (RSM), which included 18 experimental points with three independent variables : the content of the garlic (1.3~9.7%, $X_1$), the steaming time of garlic (0~15.1 min, $X_2$), and the fermentation time of Cheonggukjang (48.2~71.8 h, $X_3$). The viscous substance ($Y_1$), acidity ($Y_2$), amino-type nitrogen ($Y_3$), ${\gamma}$-GTP activity ($Y_4$) and ABTS radical scavenging activity ($Y_5$). were assessed in four replicates with five dependent variables. The maximum content of the viscous substance was 13.02% at 6.53% ($X_1$), 6.81 min ($X_2$) and 55.18 h ($X_3$). The acidity was increased when the fermentation time was longer, and the minimum acidity point was 0.50% at 7.75% ($X_1$), 3.42 min ($X_2$) and 58.60 h ($X_3$), respectively. The content of the amino-type nitrogen at the experimental range studied was was 80.58~158.82 mg%, and the stationary point was at saddle point. Using ridge analysis, the maximum point was 156.97 mg% at 6.21% ($X_1$), 14.85 min ($X_2$) and 58.04 h($X_3$). The optimum conditions of ${\gamma}$-GTP activity was 5.73% ($X_1$), 6.99 min ($X_2$) and 57.96 h($X_3$), respectively, at the maximum point was 353.66 mU/mL. The maximum point of ABTS radical scavenging activity was 76.43% at 3.78% ($X_1$), 14.28 min ($X_2$) and 57.99 h($X_3$) at the saddle point, when the garlic steaming time was longer.

• KSBB Journal
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• 제14권3호
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• pp.309-314
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• 1999

In order to produce high concentration of sodium gluconate, optimization of the fermentation conditions, such as glucose concentration, inoculum size, dissolved oxygen concentration and glucose feeding method, was examined. When the glucose concentration was maintained in the range of 30∼50 g/L during the batch fermentation, glucose conversion yield and productivity were 92.2% and 6.0 g/L/hr, respectively. In the case of the low concentration below 30 g/L, the yield decreased by about 25%. As the inoculum size increased above 20%(w/v), lag phase was shortened but the productivity decreased. The dissolved oxygen level of 60∼70% was shown to be the threshold point for 75% of increase in the productivity of sodium gluconate. Finally, optimal glucose feeding rate was determined using various feeding methods such as exponential feeding, feeding based on the average glucose consumption rate and was determined using various feeding methods such as exponential feeding, feeding based on the average glucose consumption rate and on the oxygen uptake rate and etc. Our result shows that glucose feeding, based on the oxygen uptake rate is a very simple, efficient and robust method, especially when oxygen is consumed as a substrate for the bioconversion. Using the above glucose feeding strategy under the optimized condition, 255 g/L of sodium gluconate concentration, 12 g/L/hr of productivity and 95% of glucose conversion yield were achieved with A. niger ACM53.

• Journal of Aquaculture
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• 제15권3호
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• pp.145-155
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• 2002

Effect of density (30, 40, 65, 90 or 120/cage) of lantern and bottom cages on growth of the ark shell, Scapharca satowi was studied in the Korean west coast from April 2000 to October 2001, when the following range of environmental conditions prevailed : temperature : 4.2 -25.5 $^{\circ}C, salinity : 30.23-32.$15\textperthousand, dissolved oxygen : 5.12-7.16 $ml$/l, pH : 7.84-8.17, phosphate : 0.22-0.56 $\mu $M, dissolved inorganic nitrogen : 3.16-9.10 $\mu $M, suspended solid : 7.6-17.9 mg/l, chemical oxygen demand: 0.46-1.61 mg/l and chlorophyll-a : 0.92-5.93 $\mug/l. Daily growth rate of shell length ranged from 0.066 to 0.071 mm/day for the lantern net cages, and from 0.079 to 0.082 mm/day for the bottom cages. Total weight also ranged from 0.067 to 0.082 g/day in the lantern net cages, as against 0.099 to 0.114 g/day in the bottom cages. Hemoglobin content of S. satowi (55 mm shell length), which was about 3.9 g/dl during february, 2001, increased to 6.0 and 7.0 g/dl during October, 2001 in animals culture in the lantern and bottom cages, respectively. ANOVA test of the growth rate showed that the growth rate of S. satowi, was significantly dependent on rearing density and the tested culture methods (P < 0.0001). The daily growth rate of the shell length was more significantly correlated with water temperature; the growth rate of shell length and total weight showed a tendency decrease with decreasing temperature. In cages suspended at the bottom, not only the increase shell weight but also the meat obtainable from comparable sized S. satowi was greater. Survival decreased with increasing density and was optimal at the density of 30 individual/cage.

• Journal of the Korean Arthroscopy Society
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• 제10권2호
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• pp.148-152
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• 2006

Purpose: The purpose of this study was to investigate the distribution of the diameter of four strand autologous hamstring tendon and to identify the factors related to the diameter. Materials and Methods: Between December 2004 and July 2006, 66 patients underwent anterior cruciate ligament reconstruction using autologous hamstring tendon. Sixty one patients were male and the other 5 patients were female. Both semitendinosus and gracilis tendon were harvested in every case. Harvested two tendons were folded once together to create a four strand double loop graft and were passed through cylindrical sizer to measure their diameter. Parameters such as sex, age, height and weight were analyzed for their correlation with the diameter of the graft. Results: The diameter of the graft ranged from 6 mm to 10 mm. The graft with the diameter of 8 mm was most common and the average diameter of all the grafts was $7.85{\pm}0.92mm$. Seven patients (10.6%) had a graft with the diameter of 6 mm, which is considered too thin to be ideal one. No statistically significant correlation was found between age of the patient and the diameter of the graft. However, the diameter of the graft was significantly correlated with sex, height and weight of the patient. Female patients had a significant tendency to have thinner hamstring tendons. Both small height and light weight of the patients were correlated with thinner hamstring tendons significantly. Conclusion: Sex, height and weight of the patients were the factors that had a statistically significant correlation with the diameter of the graft. Being aware of the risk factors related with harvesting exceedingly thin hamstring tendon prior to anterior cruciate ligament reconstruction, one can utilize wide range of options in selecting an optimal graft.

• KSBB Journal
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• 제15권2호
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• pp.125-133
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• 2000

Specific carotenoids and astaxanthin biosynthesis power of Phaffia rhodozyma mutant 876, which was obtained after NTG a and UV treatments, was higher than those of the wild type by 40% and 50%, respectively. The mutant strain did not show t the catabolite repression even at 22% (w/v) glucose concentration. The optimum C{N ratio was 2.0, and the optimum t temperature and initial pH were $22^{\circ}C$ and 6.0, respectively. 80th cell growth and astaxanthin formation decreased drastically a as the fermentation temperature was increased over $22^{\circ}C$, whereas they were comparable in the pH range between 5.0 and 7 7.0. Inoculum size did not affect the final cell density nor the carotenoids biosynthesis, and 3%(v/v) was selected as optimal. H Higher dissolved oxygen concentration facilitated astaxanthin biosynthesis, and aeration rate of 1.0 v/0/m and agitation speed of 400 rpm were selected as optimum. The final cell dens때 of 43.3 g/L and the volumetric astaxanthin and carotenoids concentrations of 110.6 mg/L and 149.4 mg/L, respectively, were obtained. The specific carotenoids concentration was 3.45 m mg{g-yeast(dry). Yx/s and Yp/s values of 0.37 and 1.08 were obtained. The result of this study will provide basic information u useful for mass production of astaxanthin from P. rhodozyma fermentation.

• Journal of Korean Society of Disaster and Security
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• 제12권4호
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• pp.1-13
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• 2019

Recently, as the occurrence frequency of sudden floods due to climate change increased, it is necessary to install the facilities that can cope with the initial stormwater. Most researches have been conducted on the design of facilities applying the Low Impact Development (LID) and the reduction effect on rainfall runoff to examine with 1D or 2D numerical models. However, the studies on the examination about flow characteristics and stability of pipe network systems were relatively insufficient in the literature. In this study, the stability of the pipe network system in rainwater storage tank was examined by using 3D numerical model, FLOW-3D. The changes of velocity and dynamic pressure were examined according to the number of rainwater storage tank and compared with the design criteria to derive the optimal design plan for a rainwater storage tank. As a results of numerical simulation with the design values in the previous study, it was confirmed that the velocity became increased as the number of rainwater storage tank increased. And magnitude of the velocity in pipes was formed within the design criteria. However, the velocity in the additional rainwater storage pipe was about 3.44 m/s exceeding the allowable range of the design criteria, when three or more additional rainwater storage tanks were installed. In the case of turbulence intensity and bottom shear stress, the bottom shear stress was larger than the critical shear stress as the additional rainwater storage was increased. So, the deposition of sediment was unlikely to occur, but it should be considered that the floc was formed by the reduction of the turbulence intensity. In addition, the dynamic pressure was also satisfied with the design criteria when the results were compared with the allowable internal pressure of the pipes generally used in the design of rainwater storage tank. Based on these results, it was suitable to install up to two additional rainwater storage tanks because the drainage becomes well when increasing of the number of storage tank and the velocity in the pipe becomes faster to be vulnerable to damage the pipe. However, this study has a assumption about the specifications of the rainwater storage tanks and the inflow of stormwater and has a limitation such that deriving the suitable rainwater storage tank design by simply adding the storage tank. Therefore, the various storage tank types and stormwater inflow scenarios will be asked to derive more efficient design plans in the future.