• 한국세라믹학회지
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• 제30권12호
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• pp.999-1006
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• 1993

Si3N4(p)-SiC(p) composites were prepared by gas pressure sintering at 190$0^{\circ}C$ for 1 hour. $\alpha$-SiC with average particle size of 0.48${\mu}{\textrm}{m}$ were dispersed from zero to 50vol% in $\alpha$-Si3N4 with average particle size of 0.5${\mu}{\textrm}{m}$. Y2O3-Al2O3 system was used as sintering aids. When 10vol% of SiC was added to Si3N4, optimum mechanical properties were observed; relative density of 98.8%, flextural strength of 930MPa, fracture toughness of 5.9MPa.m1/2 and hardness value of 1429kg/$\textrm{mm}^2$. Grain growth of $\beta$-Si3N4 was inhibited as the amount of added SiC was increased. SiC particles were found inside the $\beta$-Si3N4 intragrains in case of 10, 20 and 30vol%SiC added composites.

• 동아시아식생활학회지
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• 제9권1호
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• pp.93-99
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• 1999

The purpose of this study was to investigate the antioxidant and synergistic effects upon different concentrations(0.02, 0.1, l%) of histidine and alanine in soybean oil during incubation at 6$0^{\circ}C$. Acid value(AV), peroxide value (POV) and thiobarbituric acid(TBA) value of each oil was monitored. Histidine and alanine showed antioxidative effects in all concentrations. In the case of the incubating antioxidative effect of histidine was lower than that of TBHQ. That of alanine was considerably higher than that of $\alpha$-tocopherol, but was lower than that of histidine. Synergistic effects among histidine, alanine and some food antioxidants were shown to exist available in all substrates and the best effect was shown in substrate added compound of histidine and $\alpha$-tocopherol.

• 한국조경학회지
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• 제21권2호
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• pp.1-7
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• 1993

This study suggests one hypothesis: The strength between the catchment foreces of urban community parks can be represented to a gravity model. The gravity model is derived from the related of two subjects, witch is related with their distance. A grvity model for the catchments between parks is represented as followed formula: Iij=${\alpha}$${\times}$ $\frac{Pi$.$Pj}{${\beta}$r}$(formula) Here, Iij is a total number of the vistors of park i and j in a year. Pi is population of the catchment area of park i. Pj is population of the catchment area of park j. ${\alpha}$and, ${\beta}$ are parameters. This formula is testified in the case of Chong-ju community parks.

• Journal of Chest Surgery
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• 제25권5호
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• pp.555-561
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• 1992

Endodermal sinus tumor[EST] of the mediastinum is a rare germ cell neoplasm. It usually arises from the ovaries and testes but also arises from multiple extragonadal site including the mediastinum. Characteristically, alpha feto protein level is high and used for monitoring the clinical course. EST of the mediastinum is poor prognosis because of its direct invasion. The patient was 18 month old female with chief complaints of cough and fever. In the chest X-ray and CT, large encapsulated, 7x6cm sized, mass of anterior med-iastinum was found, and we could excise it completely because it was well encapsulated and not invaded but only adhered to aortic arch, pericardium and left upper lung. And confirmed it as EST by histopathology. Pre-operative alpha feto protein[AFP] level as 41,748ng/ml and decreased to 2, 663ng /ml at 14th postoperative day, 644ng /ml at 31th postoperative day. From 17th post-operative day, chemotherapy was started and keep going now.

• Kyungpook Mathematical Journal
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• 제56권2호
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• pp.597-610
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• 2016

For a sufficiently adequate special case of the Dziok-Srivastava linear operator defined by means of the Hadamard product (or convolution) with Srivastava-Wright convolution operator, the authors investigate several mapping properties involving various subclasses of analytic and univalent functions, $G({\lambda},{\alpha})$ and $M({\lambda},{\alpha})$. Furthermore we discuss some inclusion relations for these subclasses to be in the classes of k-uniformly convex and k-starlike functions.

• Journal of Yeungnam Medical Science
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• 제35권1호
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• pp.94-98
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• 2018

The radial artery is generally the preferred access route in coronary angiography and coronary intervention. However, small size, spasm, and anatomical variations concerning the radial artery are major limitations of transradial coronary intervention (TRI). We describe a successful case involving a patient with coronary artery disease who underwent TRI via a well-developed radial recurrent artery branch from the radioulnar alpha loop using a sheathless guiding catheter.

• Bulletin of the Korean Chemical Society
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• 제22권2호
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• pp.149-153
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• 2001

A new methodology for construction of dihydro-1,4-dioxin skeleton was described. Introduction of thio group at the ${\alpha}-position$ of 8 followed by chlorination gave 11, which was to prevent an enolization as well as to promote the facile nucleophilic substitution reaction of ethylene glycol giving 16 in equilibrium with cyclic ether 19. Removal of thio group of 19 and dehydration in the presence of an acid catalyst gave dihydro-1,4-dioxin 21. In case of electron withdrawing trifluoromethyl group is subsituted in C-2, 18 was converted to the corresponding dihydro-1,4-dioxin 20 by the halogenation of hydroxy followed by treatment of triethylamine.

• Journal of Yeungnam Medical Science
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• 제14권2호
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• pp.474-482
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• 1997

There have been some case reports of the coexistence of extraadrenal pheochromocytoma and renal artery stenosis. Some reporters proposed that their coexistence may be associated through a common pathophysiological mechanism mediated by catecholamine secretion. Also some noted that trasient renal artery stenosis due to a spasm was induced by the catecholamines released from pheochromacytoma. We report a case of left paraaortic extraadrenal pheochromacytoma that had a transient oral captopril test positive result. After 5 days ${\alpha}$-antagonist reduced the vasospastic response of catecholamines. After surgical removal of the tumor, plasma catecholamines and urinary vanillyhnandelic acid concentrations as well as the blood pressure level, were restored to normal.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제6권2호
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• pp.197-201
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• 2003

위기형종은 모든 기형종의 1% 미만을 차지하며, 대부분 1세 미만의 남아에서 발생하고, 상복부 종괴나 복부 팽만을 주소로 내원하여 방사선학적으로 US나 CT 소견에서 위 주위에 낭성 그리고 고형성분이 섞여 있는 종괴가 지방이나 석회화를 함유한 경우 진단이 가능하며, 보고된 대부분의 경우가 양성으로 완전한 수술적 절제 후에는 추가적인 치료가 필요하지 않고 예후는 매우 양호하다. 알파 태아 단백(AFP, ${\alpha}$-fetoprotein)이 종양 표지자로 사용되며, 추적 검사에서 점차적으로 증가하거나 또는 감소하지 않는 경우 재발이나 불완전한 절제를 생각할 수 있다.

• Journal of Gastric Cancer
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• 제21권2호
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• pp.213-219
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• 2021

Plexiform fibromyxoma (PF) of the stomach is a very rare mesenchymal tumor of the gastrointestinal tract. We report the first case of PF with 2 different growth patterns pathologically confirmed after surgical resection. The tumor was characterized microscopically as infiltrative; it demonstrated diffuse growth into the smooth muscle bundles of the muscularis propria and was also multinodular and plexiform within the myxoid stroma. Immunohistochemical analysis revealed that the tumor cells were positive or weakly positive for smooth muscle actin, vimentin, and H-caldesmon and negative for desmin, CD117, CD34, CK-20, Pan-CK, Dog1, S100, ER, PR, and CD10. No mutations of C-kit and platelet-derived growth factor receptor alpha were detected. No genetic disruption of glioma-associated oncogene homolog 1 was detected by fluorescence in situ hybridization. The final diagnosis of PF was mainly based on the morphological and immunohistochemical findings.