• The Journal of the Petrological Society of Korea
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• v.28 no.3
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• pp.157-169
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• 2019

Pseudotachylytes, produced by frictional heating during seismic slip, provide information that is critical to understanding the physics of earthquakes. We report the results of occurrence, structural characteristics, scanning electron microscopic observation and geochemical analysis of pseudotachylytes, which is presumed to have formed after the Late Cretaceous in outcrops of the Paleoproterozoic granitic gneiss on the Bulil waterfall of the Jirisan area, Yeongnam massif, Korea. Fault rocks, which are the products of brittle deformation under the same shear stress regime in the study area, are classified as pseudotachylyte and foliated cataclasite. The occurrences of pseudotachylyte identified on the basis of thickness and morphology are fault vein-type and injection vein-type pseudotachylyte. A number of fault vein-type pseudotachylytes occur as thin (as thick as 2 cm) layers generated on the fault plane, and are cutting general foliation and sheared foliation developed in granitic gneiss. Smaller injection vein-type pseudotachylytes are found along the fault vein-type pseudotachylytes, and appear in a variety of shapes based on field occurrence and vein geometry. At a first glance fault vein-type seudotachylyte looks like a mafic vein, but it has a chemical composition almost identical to the wall rock of granitic gneiss. Also, it has many subrounded clasts which consist predominantly of quartz, feldspar, biotite and secondary minerals including clay minerals, calcite and glassy materials. Embayed clasts, phenocryst with reaction rim, oxide droplets, amygdules, and flow structures are also observed. All of these evidences indicate the pseudotachylyte formed due to frictional melting of the wall rock minerals during fault slip related to strong seismic faulting events in the shallow depth of low temperature-low pressure. Further studies will be conducted to determine the age and mechanical aspect of the pseudotachylyte formation.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.105-115
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• 2021

The geological CO2 sequestration in underground geological formation such as deep saline aquifers and depleted hydrocarbon reservoirs is one of the most promising options for reducing the atmospheric CO2 emissions. The process in geological CO2 sequestration involves injection of supercritical CO2 (scCO2) into porous media saturated with pore water and initiates CO2 flooding with immiscible displacement. The CO2 migration and distribution, and, consequently, the displacement efficiency is governed by the interaction of fluids. Especially, the viscous force and capillary force are controlled by geological formation conditions and injection conditions. This study aimed to estimate the effects of surfactant on interfacial tension between the immiscible fluids, scCO2 and porewater, under high pressure and high temperature conditions by using a pair of proxy fluids under standard conditions through pendant drop method. It also aimed to observe migration and distribution patterns of the immiscible fluids and estimate the effects of surfactant concentrations on the displacement efficiency of scCO2. Micromodel experiments were conducted by applying n-hexane and deionized water as proxy fluids for scCO2 and porewater. In order to quantitatively analyze the immiscible displacement phenomena by n-hexane injection in pore network, the images of migration and distribution pattern of the two fluids are acquired through a imaging system. The experimental results revealed that the addition of surfactants sharply reduces the interfacial tension between hexane and deionized water at low concentrations and approaches a constant value as the concentration increases. Also it was found that, by directly affecting the flow path of the flooding fluid at the pore scale in the porous medium, the surfactant showed the identical effect on the displacement efficiency of n-hexane at equilibrium state. The experimental observation results could provide important fundamental information on immiscible displacement of fluids in porous media and suggest the potential to improve the displacement efficiency of scCO2 by using surfactants.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.4
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• pp.554-562
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• 2007

This study was performed to provide basic data for predicting the usefulness of Gastrodiae rhizoma as a materials for functional foods. Changes in regional cerebral blood flow(rCBF) and blood pressure(BP) were measured in rats, following the intravenous injection of processed Gastrodiae rhizoma water extract. In its processing, we used rice water, Sderotium Poriae Cocos and Radix Ligustici Chuanxiaong. The rCBF and BP measurements were continually monitored by a laser-doppler flowmeter and a pressure transducer in the anesthetized adult Sprague-Dawley rats for approximately about two to two and a half hours, through a data acquisition system composed of a MacLab and Macintosh computer. The results of the experiment are as follows: the processed Gastrodiae rhizoma significantly increased changes in rCBF in the rats. The rCBF with processed Gastrodiae rhizoma did not change by pretreatment with propranolol, atropin, methylene blue, and indomethacin. But the rCBF of the processed Gastrodiae rhizoma was increased by pretreatment with L-NNA. The processed Gastrodiae rhizoma significantly decreased the changes in BP. However, BP with the processed Gastrodiae rhizoma did not change by pretreatment with propranolol, atropin, methylene blue and indomethacin. On the other hand, BP decreased with the processed Gastrodiae rhizoma pretreatment with L-NNA. These results indicate that processed Gastrodiae rhizoma might increase the rCBF and the BP which are related to nitric oxide synthesis. Also these results indicate that the used of processed Gastrodiae rhizoma in safe, as well as clinically applicable in diet therapy for cerebral related disease and hypertension.

• The Journal of Internal Korean Medicine
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• v.15 no.1
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• pp.22-44
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• 1994

Clinical observations were done on 67 cases with Diabetes Mellitus in CVA patients who were confirmed by CT scan and observed for over 1 week, admitted to the Dept. of Internal Medicine in Oriental Medical Hospital of Dongguk University from January 1992 to December 1993. The results were as follows; 1. 86 patients (15.3%) with Diabetes Mellitus were found in 561 CVA patients, the 6th decade of age was 40.2%, the ratio of male to female was 0.72:1. 2. The local distribution of CVA was similar to common CVA, and occlusive CVD was 83.6%, cerebral hemorrhage was 16.4% in this study. 3. The association between blood glucose and years were not significant. The largest ratio of fasting blood glucose were 140-199 mg/dl (44.6%) in admission, below 139 mg/dl (51.8%) in discharge in case of occlusive CVD. In cerebral hemorrhage, that were 140-199 mg/dl(45.5%) in dmission, below 139 mg/dl (45.5%) in discharge. The largest ratio of pp2hrs blood glucose were 200-299mg/dl in admission and discharge both occlusive CVD and cerebral hemorrhage. 4. The total sensitivity of urine glucose was 71.6%, and sensitivity of urine glucose in cerebral hemorrhage (81.8%) was more higher than that of occlusive CVD (69.6%). 5. Below 4 years had the highest prevalence(44.8%) in duration of diabetes mellitus. Patients usually used oral hypoglycemic agents(41.8%), insulin injection(23.9%) treatment and non-therapeutic was 17.9% in this study. 6. Predisposing factors and symptoms in admissin were similar to common CVA. The conscious disturbance on attacck was 41.1% in occlusive CVD, and that was 63.7% in cerebral hemorrhage. 7. The most common ratio of the season's attack was spring (44.8%), 8. The frequency of post history was as follows, hypertension (44.8%), heart disease (10.4%), and they were in below 199 mg/dl (83.3%) of fasting blood glucose. 9. The family history of CVA was 46.3%, and they was higher than nondiabetic patients. 10. The recurrence rate of CVA was 28.4%, and that of occlusive CVD(28.6%) was higer than cerebral hemorrhage's (18.2%). 11. The smoker was 52.2%, the drinker was 38.9%. 12. The complications was occured in 10 cases (14.9%) after admission, and they frequently occured than common CVA. 13. In admission, the ratio of systolic blood pressure in over l60mmHg was 42.9%, that of diastolic blood pressure in over l00mmHg was 12.5% in occlusive CVD. In cerebral hemorrhage, the ratio of systolic blood pressure in over l60mmHg was 54.5%, that of diastolic blood pressure in over l00mmHg was 27.3%. 14. The average beginned time of physical theraphy was, generally lated, 8.3 days in occlusive CVD, 11.2 days in cerebral hemorrhage. Average admitted period was longer than common CVA, and was 29.2 days in occlusive CVD, 11.2 days in cerebral hemorrhage. 15. The degree of recovery were 82.1% in occlusive CVD, 72.7% in cerebral hemorrhage. 16. The herb medications were various Sunghyanggeonggisans, Sopungtang, Ganghwalyupungtang, Yanggyuksan etc. were used most frequently, and Yukmijihwangtang, Gamidaebotang, Mangeumtang etc. were used as discharge.

• Journal of Yeungnam Medical Science
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• v.23 no.1
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• pp.52-61
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• 2006

Background: Korean ginseng (KG) has been used as a general tonic, and for voiding dysfunction for a long time in oriental society. However, scientific basic studies on the use of KG, have been rare, especially for voiding and erectile dysfunction. This study was performed to investigate the effects of KG on voiding and erectile function by examining the effects of total saponin (TS) on the bladder, urethral and penile cavernosal smooth muscle. Materials and methods: To examine the effects of TS, NewZeland white rabbits were used to obtain tissue strips from the smooth muscle of the bladder, proximal urethra and corpus cavernosum. Adult Sprague Dawley rats were used to examine the changes in urodynamic findings and penile erection after administration of TS. Results: In proximal urethral strips, the rate of relaxation of the proximal urethra was increased from $9.0{\pm}2.9$ to $33.7{\pm}4.8%$ in a dose-dependent manner when the concentration of TS was added accumulatively from 0.25 mg/ml to 4.0 mg/ml (p<0.05). However, no significant response was observed in the bladder strips within these concentration ranges. For the corpus cavernosal strips, the rate of relaxation ranged from $5.8{\pm}2.1$ to $36.7{\pm}5.8%$, increasing in a dose-dependent manner when TS was increased from 1.0 mg/ml to 4.0 mg/ml (p<0.05). After administration of 0.1 ml of TS (32 mg/ml) in the rat, the bladder pressure was $37.5{\pm}8.5$ mmHg at $52.1{\pm}7.0$ sec. during isovolumetric bladder contraction, showing no significant differences from $35.7{\pm}7.8mmHg$ and $50.7{\pm}7.2$ sec, respectively, before treatment. However, when 0.1 ml of TS (32 mg/ml) was administered, the relative reduction of urethral pressure was $6.9{\pm}0.5mmHg$ at $62{\pm}7.5$ sec, which was significantly higher compared to $4.6{\pm}1.1mmHg$ at $45{\pm}10$ sec before treatment (p<0.05). For the cavernosal injection study, the change in intracavernosal pressure (${\Delta}ICP$) was examined after administering 0.1 ml of TS. The cumulative additions of TS at concentrations from 0.5 mg/ml to 32 mg/ml increased ${\Delta}ICP$ from $1.3{\pm}0.5$ to $21.3{\pm}7.8mmHg$ in a dose-dependent manner (p<0.05). The duration of tumescence was from $0.3{\pm}0.1$ to $5.2{\pm}0.2$ min, showing dose-dependent increase (p<0.05). Furthermore, the cumulative addition of TS at concentrations from 0.5 mg/ml upto 32 mg/ml did not cause any significant change in systemic blood pressure. Conclusion: These results suggest that ginseng improves voiding functions, which is mainly achieved by TS relaxing the proximal urethra, the most important part of the bladder outlet function. In addition, ginseng safely induced a penile erection hemodynamically by relaxing the corpus cavernosum.

• Economic and Environmental Geology
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• v.53 no.1
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• pp.23-32
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• 2020

Geological CO₂ sequestration is a global warming response technology to limit atmospheric emissions by injecting CO₂ captured on a large scale into deep geological formations. The presented results concern mineralogical and hydrogeological investigations (FE-SEM, XRD, XRF, and MICP) of mudstone samples from drilling cores of the Pohang basin, which is the research area for the first demonstration-scale CO₂ storage project in Korea. They aim to identify the mineral properties of the mudstone constituting the caprock and to quantitatively evaluate the hydrogeologic sealing capacity that directly affects the stability and reliability of geological CO₂ storage. Mineralogical analysis showed that the mudstone samples are mainly composed of quartz, K-feldspar, plagioclase and a small amount of pyrite, calcite, clay minerals, etc. Mercury intrusion capillary pressure analysis also showed that the samples generally had uniform particle configurations and pore distribution and there was no distinct correlation between the estimated porosity and air permeability. The allowable CO₂ column heights based on the estimated pore-entry pressures and breakthrough pressures were found to be significantly higher than the thickness of the targeting CO₂ injection layer. These results showed that the mudstone layers in the Yeongil group, Pohang basin, Korea have sufficient sealing capacity to suppress the leakage of CO₂ injected during the demonstration-scale CO₂ storage project. It should be noticed, however, that the applicability of results and analyses in this study is limited by the lack of available samples. For rigorous assessment of the sealing efficiency for geological CO₂ storage operations, significant efforts on collection and multi-aspect evaluation for core samples over entire caprock formations should be accompanied.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.433-445
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• 2021

Plasma blasting by high voltage arc discharge were performed in laboratory-scale soil samples to investigate the fluid penetration efficiency. A plasma blasting device with a large-capacity capacitor and columnar soil samples with a diameter of 80 cm and a height of 60 cm were prepared. Columnar soil samples consist of seven A-samples mixed with sand and silt by ratio of 7:3 and three B-samples by ratio of 9:1. When fluid was injected into A-sample by pressure without plasma blasting, fluid penetrated into soil only near around the borehole, and penetration area ratio was less than 5%. Fluid was injected by plasma blasting with three different discharge energies of 1 kJ, 4 kJ and 9 kJ. When plasma blasting was performed once in the A-samples, penetration area ratios of the fluid were 16-25%. Penetration area ratios were 30-48% when blastings were executed five times consecutively. The largest penetration area by plasma blasting was 9.6 times larger than that by fluid injection by pressure. This indicates that the higher discharge energy of plasma blasting and the more numbers of blasting are, the larger are fluid penetration areas. When five consecutive plasma blasting were carried out in B-sample, fluid penetration area ratios were 33-59%. Penetration areas into B-samples were 1.1-1.4 times larger than those in A-samples when test conditions were the same, indicating that the higher permeability of soil is, the larger is fluid penetration area. The fluid penetration radius was calculated to figure out fluid penetration volume. When the fluid was injected by pressure, the penetration radius was 9 cm. Whereas, the penetration radius was 27-30 cm when blasting were performed 5 times with energy of 9 kJ. The radius increased up to 333% by plasma blasting. All these results indicate that cleaning agent penetrates further and remediation efficiency of contaminated soil will be improved if plasma blasting technology is applied to in situ cleaning of contaminated soil with low permeability.

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.147-156
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• 1997

Ultrasound-guided follicular aspiration was performed in Holstein heifers once weekly with or without pretreatment of single or multiple decreasing doses using a total of 400 mg FSH. Oocytes were aspirated with a 6.5 MHz convex-array ultrasound trasducer designed for intravaginal use. All the visible follicles larger than 4 mm in diameter were punctured with a 17 gauge, 55 cm needle at each aspiration session and the follicular fluids containing oocytes were obtained by vacuum suction. The results obtained were as follows: As a preliminary experiment, the recovery rates of folicular oocytes by ultrasound-guided aspiration from the isolated ovaries of Korean native cows were compared between suction methods using manual syringe or vacuum pump. The recovery rate of oocytes using vacuum pump (80.7%) was significantly (P<0.05) higher than that using manual syringe (47.1%). The follicles were counted by their size in diameter with ultrasound image, and recovery rates and grades of follicular oocytes collected by ultrasound-guided aspiration were investigated in Holstein heifers pretreated with or without FSH. A group of heifiers were injected with multiple decreasing doses (twice a day for 3 days) of a total of 400 mg FSH. The other 2 groups were injected with a single dose of 400 mg FSH mixed with 25% PVP. Ultrasound observation of follicle population and/or ultrasound-guided transvaginal oocyte aspiration were performed 12 hrs following the last FSH injection in the multiple dose group, and 48 or 60 hrs after FSH injection in the single dose groups. Most of the visible follicles had small size of less than 3 mm in diameter in unstimulated heifers (71.0%), but medium size in all the heifers treated with FSH. (70.5 to 92.8%). The number of OPU follicles per session (4.6$\pm$1.9) were much less, compared to the vilsible follicle counts (9.7$\pm$2.2), in the nustimulated heifers due to the small dominant follicles. Among 4 goups of heifers the most visible as well as OPU follicles were observed in the heifers at 60 hrs following treatment of a single dose of 400 mg FSH (21.2$\pm$2.3 and 21.0$\pm$2.0), and the differences in both the follicle counts between the groups was found significant (P<0.05) The rates of oocyte recovery from the follicles by ultrasound-guilded aspiration were varied 46.3 to 75.0% in the heifers unstimulated and treated with a single dose of 400 mg FSH, but the group difference was not significant. The number of recovered oocytes per session a, pp.ared to be highest at aspiration at 60 hrs following single FSH (10.6$\pm$2.2) than at aspiration at 48 hrs after single FSH (7.8$\pm$2.7) or in the unstimulated heifers (3.4$\pm$3.0). The proportion of grade I and II oocytes to all oocytes collected was varied 31.8 to 64.0% between the groups. However, there was found no significant difference in both the number of oocytes recovered per session and the percentage and the percentage of grade I and II oocytes. From the above results it was concluded that the more oocytes of superior quality might be recovered economically by ultrasound-guided aspiration at 60 hrs following the pretreatment of a single dose of 400 mg FSH and by suction using a vacuum pump system of about negative pressure of 75 to 85 mmHg.

• The Korean Journal of Nuclear Medicine
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• v.32 no.6
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• pp.482-489
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• 1998

Purpose: Radionuclide cisternography may be helpful in understanding pathophysiology of postural head-ache and low CSF pressure in patients with spontaneous intracranial hypotension. The purpose of this study was to characterize radionuclide cisternographic findings of spontaneous intracranial hypotension. Materials and Methods: The study population consists of 15 patients with spontaneous intracranial hypotension. Diagnosis was based on their clinical symptoms and results of lumbar puncture. All patients underwent radionuclide cisternography following injection of 111 to 222 MBq of Tc-99m DTPA into the lumbar subarachnoid space. Sequential images were obtained between 112 hour and 24 hour after the injection of Tc-99m DTPA. Radioactivity of the bladder, soft tissue uptake, migration of radionuclide in the subarachnoid space, and extradural leakage of radionuclide were evaluated according to the scan time. Results: Radionuclide cisternogram showed delayed migration of radionuclide into the cerebral convexity (14/15), increased soft tissue uptake (11/15), and early visualization of bladder activity at 30min (6/10) and 2hr (13/13). Cisternography also demonstrated leakage site of CSF in 4 cases and 2 of these were depicted at 30min. Epidural blood patch was done in 11 patients and headache was improved in all cases. Conclusion: The characteristic findings of spontaneous intracranial hypotension were delayed migration of radionuclide and early visualization of the soft tissue and bladder activity. These scintigraphic findings suggest that CSF leakage rather than increased CSF absorption or decreased production may be the main pathophysiology of spontaneous intracranial hypotension. Early and multiple imaging including the bladder and soft tissue is required to observe the entire dynamics of radionuclide migration.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1142-1151
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• 2018

Purpose: We assessed the visual and anatomical outcomes, and the safety profile of long-term intravitreal anti-vascular endothelial growth factor (VEGF) injections (aflibercept, ranibizumab, and bevacizumab) given to treat neovascular age-related macular degeneration (NAMD). Methods: We analyzed medical records collected over 7 years of treatment-naive NAMD patients who received outpatient clinic-based intravitreal anti-VEGF injections. All were treated employing either "treat-and-extend" or "as needed" protocols at the discretion of the retinal specialist. The number of injections, adverse events associated with injection, and measures of visual acuity (VA), central foveal thickness (CFT), and intraocular pressure (IOP) were recorded. Results: Overall, we assessed 196 eyes of 196 patients (average age $68.6{\pm}9.6years$; 77 females). Patients received an average of $17.3{\pm}13.5$ injections over $78.0{\pm}16.5months$ of clinical follow-up. The initial mean VA (logMAR) was $0.75{\pm}0.58$ and the CFT was $349.7{\pm}152.6{\mu}m$. Both parameters exhibited maximal improvements at the 6-month visit (p < 0.05). However, the clinical outcomes worsened over the 7-year clinical course; the best-corrected visual acuity (BCVA) was $0.91{\pm}0.78$ and the CFT was $284.5{\pm}105.8{\mu}m$ at 7 years. The BCVA at 7 years was significantly correlated with the initial BCVA. IOP-related events increased 11-fold and anterior chamber reactions increased 3-fold over the years, but no significant complications such as endophthalmitis were recorded. Conclusions: The use of intravitreal anti-VEGF agents was associated with initial visual improvements over 6 months but did not prevent the worsening of NAMD over 5 years. The BCVA at the initial visit was a strong predictor of the final BCVA. A more intensive injection schedule might improve long-term outcomes.