• 한국지구물리탐사학회:학술대회논문집
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• 2001.09a
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• pp.122-140
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• 2001

We have applied the geophysical survey, mainly electric and electromagnetic (EM) methods, to a test site contaminated by hydrocarbon waste disposal and local spill. The multi-frequency, moving source & receiver EM survey along with ground penetrating radar (GPR) showed a fairly good performance in detection of buried metal pipes and objects. Magnetic survey measuring vertical and horizontal gradients were so sensitive to the small metallic objects spread over the surface that it's hard to discriminate the buried pipe. We chose electrical resistivity, EM and GPR survey to examine the soil contamination. Depth slices of resistivity distribution as the results of the inversion of resistivity and EM data coincided each other and closely matched the contaminated area determined by chemical analysis of the soil samples. GPR images did not show the reflection events related with contamination plume since there are no distinct spill in this site. We inferred the contamination using the penetration depth of the GPR energy, which could be used as auxiliary information to the resistivity and EM results. We summarized the applicability of each survey methods based on this results and proposed a desirable survey scheme for the determination of hydrocarbon contaminated site.

• Journal of Korean Society of Spine Surgery
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• v.25 no.4
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• pp.180-184
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• 2018

Study Design: Case report Objectives: To document fistula formation between the disc and dura by an unrecognized dural tear after percutaneous endoscopic lumbar discectomy (PELD). Summary of Literature Review: The risk of durotomy is relatively low with PELD, but cases of unrecognized durotomies have been reported. An effective diagnostic tool for such situations has not yet been identified. Materials and Methods: A patient twice underwent transforaminal PELD under the diagnosis of a herniated lumbar disc at L4-5. She still complained of intractable pain and motor weakness around the left lower extremity at 6 months postoperatively. Magnetic resonance imaging showed no specific findings suggestive of violation of the nerve root. However, L5 and S1 nerve root injury was noted on electromyography. An exploratory operation was planned to characterize damage to the neural structures. Results: In the exploration, a dural tear was found at the previous operative site, along with a fistula between the disc and dura was also found at the dural tear site. The durotomy site was located on the ventrolateral side of the dura and measured approximately 5 mm. The durotomy site was repaired with Nylon 5-0 and adhesive sealants. The patient's preoperative symptoms diminished considerably. Conclusions: Fistula formation between the disc and dura can be caused by an unrecognized dural tear after PELD. Discography is a reliable diagnostic tool for fistulas formed by an unrecognized durotomy.

• Progress in Superconductivity and Cryogenics
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• v.25 no.2
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• pp.10-13
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• 2023

High-T_C superconductivity (HTSC) has been the central issue in the field of condensed matter physics for decades. An essential part of the research on superconductivity is finding new exotic superconductors. It was recently suggested that Ir-substituted La_0.7Sr_0.3MnO₃ (LSMIO) is a new high-T_C superconductor. However, systematic studies to experimentally verify the superconductivity have not been done. Here, we report the growth processes of LSMIO thin films and their electrical transport properties. We observed a clear negative correlation between the intensity of the laser utilized for film deposition and the Curie temperature of the deposited film. We attributed this effect to the suppression of Sr concentration in the LSMIO films as the laser intensity increased. However, our LSMIO films show conventional ferromagnetism instead of HTSC. To realize the HTSC in LSMIO systems, further exploration of diverse compositions of LSMIO compounds is essential.

• Journal of Korean Neurosurgical Society
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• v.30 no.5
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• pp.611-621
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• 2001

Objective : We analyzed the clinical and endocrinological results of the transsphenoidal microsurgery for ACTH secreting pituitary adenomas. Marerials and Methods : From October 1995 to August 2000, 18 patients underwent transsphenoidal microsurgery for Cushing's disease. We analyzed the surgical results of 17 patients, one patient who was previously operated from other hospital was excluded. Age of the patients were 18 to 61 years old(mean 37.7), male to female ratio was 1 : 3.3, and follow-up period was 3 to 50 months(mean 20.3). The selection of candidates for transsphenoidal exploration was based on endocrinologic criteria. Magnetic resonance imaging was the preferred radiologic test. Selective inferior petrosal sinus sampling of adrenocorticotropic hormone futher refined the diagnosis when endocrinologic and radiologic procedures were not definitive. Results : Results of the preoperative endocrinological test were : level of serum ACTH 29.4 to $225{\mu}g/dL$(mean $93.88{\mu}g/dL$) ; serum cortisol 11.9 to $47.5{\mu}g/dL$(mean $27.49{\mu}g/dL$) ; 24-hour urine free cortisol 235 to $1019{\mu}g/day$(mean $571.0{\mu}g/day$). Inferior petrosal sinus sampling for ACTH was performed in 11 patients and all were confirmed by Cushing's disease and we could predict the laterality of the tumor in 9 of 11 patients. We performed transsphenoidal selective adenomectomy in 5 patients, adenomectomy and subtotal hypophysectomy in 2 patients, adenomectomy and partial hypophysectomy in 9 patients, and in the remaining one patient, hemihypophysectomy followed by total hypophysectomy due to remission failure. Fifteen of 17 patients(88.2%) showed endocrinological remission. Glucocorticoid replacement therapy was performed in all the patients who showed remission for 1 to 24 months(mean 5.9 months), and 6 patients received steroid over 6 months. Conclusion : We conclude that the direct demonstration of a tumor in the pituitary gland by MRI is the most important and definitive diagnostic tool and the location of a mass should be confirmed with increased level of ACTH by the inferior petrosal sinus sampling. Transsphenoidal microsurgery is effective treatment modality for Cushing's disease and the immediate postoperative evaluation of the surgical resection of the tumor is very important. The patients should show hypocortisolism, decreased, subnormal serum ACTH and cortisol levels and 24-hours urine free cortisol. We performed 18 transsphenoidal microsurgery for Cushing's disease in 17 patients and 15 patients(88.2%) showed endocrinological remission.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.600-605
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• 2019

Background: The leaves and roots of Panax ginseng are rich in ginsenosides. However, the chemical compositions of the leaves and roots of P. ginseng differ, resulting in different medicinal functions. In recent years, the aerial parts of members of the Panax genus have received great attention from natural product chemists as producers of bioactive ginsenosides. The aim of this study was the isolation and structural elucidation of novel, minor ginsenosides in the leaves of P. ginseng and evaluation of their antiinflammatory activity in vitro. Methods: Various chromatographic techniques were applied to obtain pure individual compounds, and their structures were determined by nuclear magnetic resonance and high-resolution mass spectrometry, as well as chemical methods. The antiinflammatory effect of the new compounds was evaluated on lipopolysaccharide-stimulated RAW 264.7 cells. Results and conclusions: Two novel, minor triterpenoid saponins, ginsenoside $LS_1$ (1) and 5,6-didehydroginsenoside $Rg_3$ (2), were isolated from the leaves of P. ginseng. The isolated compounds 1 and 2 were assayed for their inhibitory effect on nitric oxide production in LPS-stimulated RAW 264.7 cells, and Compound 2 showed a significant inhibitory effect with $IC_{50}$ of $37.38{\mu}M$ compared with that of NG-monomethyl-L-arginine ($IC_{50}=90.76{\mu}M$). Moreover, Compound 2 significantly decreased secretion of cytokines such as prostaglandin $E_2$ and tumor necrosis factor-${\alpha}$. In addition, Compound 2 significantly suppressed protein expression of inducible nitric oxide synthase and cyclooxygenase-2. These results suggested that Compound 2 could be used as a valuable candidate for medicinal use or functional food, and the mechanism is warranted for further exploration.