• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.738-743
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• 2000

Objectives : The less invasive stereotactic surgery of hypertensive intracerebral hematoma has been preferred. Many techniques were developed to facilitate aspiration of a dense blood clot in acute stage. Authors describe a method for evacuation of putaminal hematoma via computerized tomography(CT)-aided free-hand stereotactic infusion of urokinase and frequent negative pressure aspiration. Patients and Methods : A total of ten patients with spontaneous putaminal hematoma underwent surgery with negative pressure aspiration in the three-year period. All procedures were performed within 12 hours of insult. A silicone ventricular catheter was inserted into the center of hematoma through a burr hole at the Kocher's point under local anesthesia. In a typical case of putaminal hematoma, the trajectory of catheter was pointed the center of hematoma parallel to sagittal plane vertically and the external auditory meatus posteriorly. Immediately after the first trial of hematoma aspiration low-dose urokinase solution(2,000IU/5ml saline) was administrated through the catheter and drain was clipped for 30 minutes. Subsequently, the partially liquified hematoma was manually aspirated using a 10ml syringe with a negative pressure of less than 2 to 3ml. The procedure was carefully repeated every 1 hour until the hematoma was near totally evacuated. Results : The patients population consisted composed of 4 men and 6 women with a mean age of 61.6 years. All had major neurological deficits preoperatively. The mean hematoma volume was 44.3 ml and hematoma was drained for 20 to 48 hours. No complications such as rebleeding, meningitis, or malplaced catheter were noted. Outcome was moderately disabled in four patients and good recovery in three patients. Conclusion : Although the frequent negative pressure aspiration and low-dose urokinase infusion has the disadvantage of possbility of rebleeding and infection, it is consisdered to be an effective method because it allows a simple, safe, and complete removal of hematoma.

• Journal of Korean Neurosurgical Society
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• v.57 no.1
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• pp.42-49
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• 2015

Objective : The cervicothoracic junction (CTJ) is a biomechanically and anatomically complex region that has traditionally posed problems for surgical access. In this retrospective study, we describe our clinical experiences of the treatment of metastatic spinal tumors at the CTJ and the results. Methods : From June 2006 to December 2011, 23 patients who underwent surgery for spinal tumors involving the CTJ were enrolled in our study. All of the patients were operated on through the posterior approach, and extent of resection was classified as radical, debulking, and simple neural decompression. Adjuvant radiation therapy (RT) was also considered. Visual analog scale score for pain assessment and Medical Research Council (MRC) grade for motor weakness were used, while pre- and post-operative performance status was evaluated using the Eastern Cooperative Oncology Group (ECOG). Results : Almost all of the patients were operated using palliative surgical methods (91.3%, 21/23). Ten complications following surgery occurred and revision was performed in four patients. Of the 23 patients of this study, 22 showed significant pain relief according to their visual analogue scale scores. Concerning the aspect of neurological and functional recovery, mean MRC grade and ECOG score was significantly improved after surgery (p<0.05). In terms of survival, radiation therapy had a significant role. Median overall survival was 124 days after surgery, and the adjuvant-RT group (median 214 days) had longer survival times than prior-RT (63 days) group. Conclusion : Although surgical procedure in CTJ may be difficult, we expect good clinical results by adopting a palliative posterior surgical method with appropriate preoperative preparation and postoperative treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.6
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• pp.529-537
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• 1993

Several methods were examined for purification of docosahexaenoic acid (DHA, 22:6n-3) from skipjack Euthynnus pelamis orbital tissue oil, a marine by-product, and a modified method for isolation of a high purity DHA was proposed. Skipjack orbital tissue contained $55.4\%$ of total lipid(TL), and DHA accounted for $23.7\%$ of the TL. Application of low-temperature crystallization and urea inclusion compound methods to the orbital fatty acid mixture resulted in increases of DHA concentrations to approximately $46\%\;and\;61\%$, respectively. These methods were suitable for large production of DHA with relative low purity because of the simple purification procedure. DHA of approximately $74\%$ in purity was obtained by silver nitrate aqueous solution method, but the method gave a very low recovery($<10\%$). Silver nitrate-impregnated silica column chromatography was suitable for purification of a high purity DHA(purity, $>98\%$ and recovery, $>90\%$) A modified method, silver nitrate-impregnated silica column chromatography combined with low-temperature crystallization(two step purication method) was proposed as the most effective method to obtain DHA with high purity($99.9\%$) from the skipjack orbital oil.

• Fisheries and Aquatic Sciences
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• v.20 no.11
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• pp.29.1-29.7
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• 2017

The objective of this study was to determine a simple and reliable ploidy identification protocol for the rainbow trout (RT), Oncorhynchus mykiss, in the field condition. To evaluate the ploidy level and compare different detection protocols, triploid RT and gynogenesis were induced by UV irradiation and/or heat shock. The hatching rate at day 30 was 85.2% and the survival rate at day 90 was 69.4% (fingerling). The sex ratio of female RT was 93.75% in the gynogenesis group, illustrating that the UV irradiation inactivated the sperm DNA. The hatching rate and survival rate were 82.0 and 74.7%, respectively, in the triploid-induced group. The triploid induction rate by heat shock procedure was 73.9%. Cytogenetic protocols for ploidy identification such as chromosome counting, erythrocyte nuclear size comparison, and analysis of nucleolar organizing regions (NORs) by silver staining were compared. Silver nitrate staining showed the greatest success rate (22/23 and 32/32 for the triploid-induced group and gynogenesis group, respectively), followed by erythrocyte nuclear size comparison (16/23 and 19/32 for the triploid-induced group and gynogenesis group, respectively) and, lastly, chromosome preparation (2/23 and 6/32 for the triploid-induced group and gynogenesis group, respectively) with the lowest success rate. Based on our findings, silver staining for RT ploidy identification is speculated to be highly applicable in a wide range of research conditions, due to its cost-effectiveness and simplicity compared to other numerous ploidy detection protocols.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1079-1082
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• 2007

Chromosome microdissection and the reverse FISH technique is one of the most useful methods for the identification of structurally abnormal chromosomes. In particular, the laser microbeam microdissection (LMM) method allows rapid isolation of a target chromosome or a specific region of chromosomes without damage of genetic materials and contamination. Isolated chromosomes were directly amplified by the degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR), and then the FISH probes labeled with spectrum green- or spectrum red-dUTP were generated by nick-translation. Whole chromosome painting (WCP) probes were successfully generated from only 5 copies of the chromosome. With this method, we produced 24 WCP probes for each human chromosome. We also tried to characterize a marker chromosome, which seemed to be originated from chromosome 11 on conventional banding technique. The marker chromosomes were isolated by the LMM method and analyzed by reverse FISH. We elucidated that the marker chromosome was originated from the short arm of chromosome 5 ($5p11{\to}pter$). A fully automated and computer-controlled LMM method is a very simple laboratory procedure, and enables rapid and precise characterization of various chromosome abnormalities.

• Journal of Advanced Navigation Technology
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• v.16 no.4
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• pp.635-640
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• 2012

In this paper, The TE (Transverse Electric) scattering problems by a perfectly conducting strip grating over a grounded two dielectric layers are analyzed by applying the conductive boundary condition and the FGMM (Fourier-Galerkin Moment Method) known as a numerical procedure, then the induced surface current density is expanded in a series of the multiplication of the unknown coefficient and the exponential function as a simple function. Generally, the reflected power gets increased according as the relative permittivity ${\epsilon}_{r2}$ and the thickness of dielectric layer $t_2$ of the region-2 in the presented structure gets increased, respectively. The sharp variations of the reflected power are due to resonance effects were previously called wood's anomaly, the numerical results show in good agreement with those of the existing papers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.586-592
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• 2018

SRMs are difficult to design using a simple mathematical model and, consequently, numerical analysis based characteristics analysis is used including drive circuits. In this process, it is necessary to analyze the trends according to the change of the design factors, however, many of the design factors affect each other. In order to shorten the design time and achieve a proper design, a modeling technique based on the design parameters is needed. For this purpose, this paper summarizes the formulas employed for shape modeling by minimizing the number of major design factors of the SRM, and proposes a methodology for SRM design using these formulas. In particular, we propose a design method for a 6/4-pole model, one which has been studied for a long time, and showed an example of a design produced by the proposed method.

• The Korean Journal of Applied Statistics
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• v.31 no.5
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• pp.587-597
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• 2018

Procedures, such as sampling technique, survey method, and questionnaire preparation, are required in order to obtain sample data in accordance with the purpose of a survey. An important procedure is the decision of the sample size formula. The sample size formula is determined by setting the target error and total cost according to the sampling method. In this paper, we propose a sample size formula using population changes over time, estimation error of the previous time and response rate of past data when the target error and the expected response rate are given in the simple random sampling. In actual research, we use estimators that apply complex weights in addition to design-based weights. Therefore, we induce a sample size formula for estimators using design-based weights and nonresponse adjustment coefficients, that can be a formula that reflects differences in response rates when survey methods are changed over time. In addition, we use simulations to compare the proposed formula with the existing sample size formula.

• Journal of Ship and Ocean Technology
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• v.1 no.1
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• pp.35-47
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• 1997

The consequences associated with ships running aground depend very much on the soil characteristics of the sea bed and the geometrical shape of the ship bow. The penetration into the sea bed depends on these factors and the penetration is an important factor for the ship motion because it influences the ship heave and pitch motions as well as the friction between the ship and the soil. In this paper a rational calculation model is presented for the sea bed soil reaction forces on the ship bottom. The model is based on the assumption that the penetration of the ship bow generates a flow of pore water through the grain skeleton of the soil. The flow is governed by Darcy\`s law and it is driven by the pressure of the pore water at the bow. In addition to this pore water pressure, the bow is subjected to the effective stresses in the grain skeleton at the bow surface. These stresses are determined by the theory of frictional soils in rupture. Frictional stresses on the bow surface are assumed to be related to the normal pressure by a simple Coulomb relation. The total soil reaction as a function of velocity and penetration is found by integration of normal pressure and frictional stresses over the surface of the bow. The analysis procedure is implemented in a computer program for time domain rigid body analysis of ships running aground and it is verified in the paper through a comparison of calculated stopping lengths, effective coefficients of friction, and sea bed penetrations with corresponding experimental results obtained by model tests as well as large, scale tests.

• Journal of Trauma and Injury
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• v.33 no.2
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• pp.104-111
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• 2020

Purpose: Although exchange nailing is a standard method of treating femoral shaft nonunion, various rates of healing, ranging from 72% to 100%, have been reported. The purpose of this study was to evaluate the efficacy of exchange nailing in femoral shaft nonunion. Methods: We retrospectively reviewed 30 cases of aseptic femoral shaft nonunion after intramedullary nailing. The mean postsurgical period of nonunion was 66.8 weeks. A nail at least 2 mm larger in diameter was selected to replace the previous nail after reaming. Distal fixation was performed using at least two interlocking screws. The success of the procedure was determined by the finding of union on simple radiographs. Possible reasons for failure were analyzed, including the location of nonunion, the type of nonunion, and the number of screws used for distal fixation. Results: Of the 30 cases, 27 achieved primary healing with the technique of exchange nailing. The average time to achieve union was 23.1 weeks (range, 13.7-36.9 weeks). The three failures involved nonunion at the isthmic level (three of 15 cases), not at the infraisthmic level (zero of 15 cases). Of eight cases of oligotrophic nonunion, two (25%) failed to heal, and of 22 cases of hypertrophic nonunion, one (4.5%) failed to heal. Of 11 cases involving two screws at the distal fixation, two (18.2%) failed to heal, and of 19 cases involving three or more screws, one (5.3%) failed to heal. None of these findings was statistically significant. Conclusions: Exchange nailing may enable successful healing in cases of aseptic nonunion of the femoral shaft. Although nonunion at the isthmic level, oligotrophic nonunion, and weaker distal fixation seemed to be associated with a higher chance of failure, further study is needed to confirm those findings.