• Journal of Chest Surgery
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• v.46 no.2
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• pp.117-123
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• 2013

Background: We examined perioperative predictors of sustained sinus rhythm (SR) in patients undergoing the Cox maze operation and concomitant cardiac surgery for structural heart disease. Materials and Methods: From October 1999 to December 2008, 90 patients with atrial fibrillation (AF) underwent the Cox maze operation and other concomitant cardiac surgery. Eighty-nine patients, all except for one postoperative death, were followed-up with serial electrocardiographic studies, 24-hour Holter monitoring tests, and regular echocardiographic studies. Results: Eighty-nine patients undergoing the maze operation were divided into two groups according to the presence of SR. At the time of last follow-up (mean follow-up period, $51.0{\pm}30.8$ months), 79 patients (88.8%) showed SR (SR group) and 10 patients (11.2%) had recurrent AF (AF group). Factors predictive of sustained SR were the immediate postoperative conversion to SR (odds ratio, 97.2; p=0.001) and the presence of SR at the 6th month postoperatively (odds ratio, 155.7; p=0.002). Duration of AF, mitral valve surgery, number of valves undergoing surgery, left atrial dimension, and perioperative left ventricular dimensions and ejection fractions were not predictors of postoperative maintenance of SR. Conclusion: Immediate postoperative SR conversion and the presence of SR at the 6th postoperative month were independent predictors of sustained SR after the maze operation.

• Analytical Science and Technology
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• v.33 no.1
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• pp.11-22
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• 2020

When extracting semi-volatile components of herbal medicines using hot water vapor, some substances may react with water vapor or oxygen, and some volatile substances may be lost, when using an organic solvent extraction method has the disadvantage that it may contain a non-volatile material and residual organic solvent. In addition, it is inefficient to separate semi-volatile substances from herbal medicines into each single component and conduct biological activity research for each component to determine the effective ingredient, and some components may be lost in the separation process. In this study, semi-volatile substances evaporated under two pressure-reduced conditions in Chinese herbal medicines such as Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were separated by cooling with liquid nitrogen. Those were analyzed by gas chromatography-mass spectrometry (GC-MS) to identify the components, and this method may be used to study biological activities at the cellular level. The substances separated under reduced pressure, essential oil obtained by simultaneous distillation extraction (SDE) method and substances by using solid phase micro-extraction (SPME) from Cnidii Rhizoma, Aucklandiae Radix and Amomum Fructus were analyzed by GC-MS. In the case of Cnidii Rhizoma and Aucklandiae Radix, there were some differences among the essential oil components obtained by SDE and those identified by low temperature capture (CT) and SPME method, these were believed to be produced by some volatiles reacting with water or oxygen at the boiling point temperature of water.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.6
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• pp.45-50
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• 2005

To determine precise position GPS carrier phase measurements are used. In addition, the multi-antenna system consisting of 2 or more GPS antennas can make attitude determination effectively. When GPS carrier phase measurements are used the integer ambiguity must be fixed. The success rate is used to validate the integer ambiguity. For LEO satellite attitude determination the double difference carrier phase measurements are used, the success rate is calculated using the covariance matrix and the measurement matrix. The constraint that LEO satellite position vector and attitude vector is orthogonal is suggested for improving the success rate. The LEO satellite orbit model is KITSAT3. The results of the simulation are shown and analyzed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.363-372
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• 1999

This experiment was carried out to estimate an optimal lime and nitrogen levels on the growth control of sheep sorrel in mountainous pastures of Taekwalyon areas. The dry matter yield of sheep sorrel was recongnized significantly differences between the N levels and lime levels, respectively. Most effective growth control of sheep sorrel showed an over the N levels of 21kg/10a under the ranges of lime levels of 200~300kg/10a per annum. The highest dry matter yield of sheep sorrel was obtained at the N level of 16kg/10a under the N level of 48kg/10a per annum. The highest growth control effect of sheep sorrel was obtained at 2nd and 4th cuts, and 1st, 2nd and 4th cuts under the ranges of lime levels of 200~300kg/10a, and the N level of 48kg/10a per annum, respectively.

• The Journal of Korean Medicine
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• v.29 no.2
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• pp.81-95
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• 2008

Objectives: Whitmania pigra whitman (WP) has been used in herbal medicine to treat various conditions, such as eczema, skin burns and frostbites in herbal medicine. The purpose of this study is was to investigate the effect of WP on anti-allergy mechanism. Methods: To clarify the mechanism, the effect of WP on vascular permeability of rat cutaneous tissue and histamine and cytokines (IL-6, IL-8, $TNF-{\alpha}$) released from mast cells were observed. Results: The results were 1. the pretreatment with WP significantly decreased the compound 48/80-induced degranulation and histamine release from RPMC 2. WP did not inhibit the anti-DNP IgE-induced increment of vascular permeability of rat cutaneous tissue 3. WP significantly reduced the PMA plus A23187-induced increment of expression of IL-6, IL-8, and $TNF-{\alpha}$ in HMC-1 cells. Conclusions: The present study providesevidence that WP acid inhibits mast cell-derived inflammatory allergic reactions by blocking histamine release and pro-inflammatory cytokine expression, and suggest the mechanisms of action. Furthermore, in vivo and in vitro anti-allergic effect of WP suggests a possible therapeutic application of this agent in inflammatory allergic diseases.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.12
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• pp.1332-1339
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• 2005

The purpose of this study is to the distributive property of organic pollutants in effluents of domestic sewage treatment plants around Youngsan River using simultaneous analysis method of 310 chemicals. The numerous organic pollutants were detected in five sampling sites, and the major chemicals were pesticides, CH type chemicals such as benzenes and polycyclic compounds, ande CHO type chemicals such as phenols and phthalates. About 14 pesticides were detected in the effluent and most of them were found in summer. 1-Chlorobenzen and p-octylphenol were frequently detected in the concentration range of $0.52{\sim}0.61\;{\mu}g/L$ and $0.04{\sim}0.89\;{\mu}g/L$, respectively. Moreover, 18 kinds of endocrine disrupters include diethylphthalate were detected in effluents. From the results of this study, therefore, we confirmed that the pesticides, CH and CHO type chemicals in domestic effluents throughout Youngsan River are required specific regulation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.2
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• pp.98-104
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• 2004

Early development and metamorphosis of the ascidian (Halocynthia hilgendorfi ritteri) were investigated from fertilized egg. The samples were collected in the coastal waters of Yongdam, northwest of Jeju Island in November 2002. H. hilgendorfi ritteri was solitary ascidian and produced spheral eggs with egg size ranging from $0.33\pm0.01\;mm.$ On the outer surface of the vitelline coat are attached many follicle cells. At $21.0\pm0.5^{\circ}C$ of water temperature, first cleavage took place in about 1.5 hrs after fertilization, and gastrulation followed in about 12.5 hrs. The formation of tailbud embryos and free swimming larvae were observed 13.3 hrs and 20.5 hrs after fertilization, respectively. The size of newly hatched tadpole larva was 1.30-1.45 mm, the larva swam for 2 hrs to 14 hrs. At 4 hrs after hatching, the palpi were lost and tail absorption began with an abrupt rupture of the anterior end of the notochord. At 17-18 hrs after hatching, tail completely absorption and remained trunk. The coniform adhesive papilla began protrusion at 30 hrs after hatching. The oral and atrial siphon formed at 6-7 days after settlement. At 17-18 days after settlement, metamorphosed the larvae developed into protoascidian of which the external morphology was similar to their adult.

• Journal of Powder Materials
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• v.20 no.4
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• pp.264-268
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• 2013

Nickel-based superalloy IN 713C powders have been consolidated by hot isostatic pressing (HIPing). The microstructure and mechanical properties of the superalloys were investigated at the HIPing temperature ranging from $1030^{\circ}C$ to $1230^{\circ}C$. When the IN 713C powder was heated above ${\gamma}^{\prime}$ solvus temperature (about $1180^{\circ}C$), the microstructure was composed of the austenitic FCC matrix phase ${\gamma}$ plus a variety of secondary phases, such as ${\gamma}^{\prime}$ precipitates in ${\gamma}$ matrix and MC carbides at grain boundaries. The yield and tensile strengths of HIPed specimens at room temperature were decreased while the elongation and reduction of area were increased as the processing temperature increased. At $700^{\circ}C$, the strength was similar regardless of HIPing temperature; however, the ductility was drastically increased with increasing the temperature. It is considered that these properties compared to those of cast products are originated from the homogeneity of microstructure obtained from a PM process.

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.325-333
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• 2001

Objective : To clarify the benefits and therapeutic effects of intra-arterial papaverine infusion on the symptomatic cerebral vasospasm, we analyzed the results of treatment in 32 patients retrospectively. Methods : A total of 510 patients underwent surgical clipping or endovascular intra-aneurysmal treatment for ruptured intracranial aneurysm between May, 1996 and June, 1999. The delayed ischemic deficit(DID) was developed in 90 of 510 patients. Of these 90 patients, 32 developed symptomatic vasospasm inspite of using modest "3H therapy". The brain CT scan was taken before the intra-arterial infusion of papaverine. The 32 patients underwent 42 intra-arterial papaverine infusion. The symptomatic vasospasm was divided into three groups : deterioration of mental status(Group 1), appearance of a focal neurologic deficit(Group 2), or both(Group 3). We measured Glasgow Coma Scale(GCS), arterial diameters, and cerebral circulation time(CCT) at the time of pre- and postangioplasty. Results : The number of patients in group 1, 2 and 3 were 26, 7, 9 respectively. Eighteen cases showed improvement of GCS more than 2 scores, 16 more than 1, and 8 showed no change of GCS. Average cerebral circulation time(CCT) was decreased ranging from 0.0%-67.5%, and arterial diameters were increased in 21 cases ranging from 1 to 4 folds. Conclusion : Intra-arterial papaverine infusion seemed to have therapeutic effects on symptomatic vasospasm by improving the neurological signs and increasing the arterial diameter. We suggest that intra-arterial papaverine infusion would be an useful adjunctive therapeutic modality in symptomatic vasospasm.

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.278-283
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• 2001

Objective : Massive cerebral infarction could be accompanied by severe brain swelling and death secondary to transtentorial herniation. Approximately 10% to 15% of middle cerebral artery infarctions are associated with this phenomenon. However, the effectiveness and timing of decompressive surgery are still controversial. In this study, we present our results on the effect of decompressive craniectomy in life threatening cerebral infarction. Method : We retrospectively analyzed 15 patients who underwent decompressive craniectomy for massive cerebral infarction from January 1997 to April 1999. Surgical indication was based on the clinical signs such as neurological deterioration, pupillary reflex, and radiological findings. Clinical outcome was assessed by Glasgow Outcome Scale (GOS). Results : All 15 patients(five men, ten women ; mean age, 52.3 years ; right 11, left 4) were treated with wide craniectomy and duroplasty. The average time interval between onset of symptom and surgical decompression was 2.9 days. Clinical signs of uncal herniation(anisocoria, or fixed and dilated pupils) were presented in 13 of 15 patients. Mean Glasgow coma scale(GCS) was 12.4 points on admission, 8.1 points on preoperative state and 11.8 points postoperatively. Overall outcomes were favorable in 5 cases(Glasgow outcome scale : GOS I, II), unfavorable in 6 cases(Glasgow outcome scale : GOS III, IV) and dead in 4 cases. Conclusion : Early decompressive craniectomy before brain stem compression is considered as an effective lifesaving procedure for massive cerebral infarction unresponsive to aggressive medical therapy.