• Archives of Pharmacal Research
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• 제9권4호
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• pp.215-217
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• 1986

Steroidal nitrosoureas have been synthesized and their antitumor activity on L 1210 cells was evaluated, N-(2-Chloroethyl)-N-nitrosocarbamoyl-3-aza-A-homo-5$\alpha$-cholestane (5a) showed significantly low $ED_{50}$ value of 1.6 $\nu$g/ml whose activity is equivalent to that of methyl-CCNU ($ED_{50}$ = 1.7 mg/ml).

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 추계총회 및 연구발표회 초록집
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• pp.55.1-55
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• 2003

• 약학회지
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• 제27권2호
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• pp.181-184
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• 1983

DMSO-oxalyl chloride at low temperature in methylene chloride reacted with isolated secondary hydroxyl groups in some monosaccharides to give alkoxysulfonium salts, convertible to carbonyls in high yields upon addition of triethylamine. And 1, 2:5, 6-di-O-isopropylidene-.alpha.- D-allofuranose which is the key intermediate in the synthesis of 3-O-acetyl-5-O-benzoyl- 2-deoxy-2- fluoro-D-arabinofuranosyl bromide, was also obtained by oxidizing 1, 2:5, 6-di-O-isopropylidene-.alpha.- D-glucofuranose with the oxidizing reagent, followed by reduction with sodium borohydride.

• 산업기술연구
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• 제21권B호
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• pp.341-348
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• 2001

The effect of initial ${\alpha}^{\prime}$ in STS 304 Stainless Steel on fatigue resistance, and fatigue crack propagation behavior was studied with using C-T specimens. Higher ${\Delta}K_{th}$ was observed in the specimens with the content of 0% initial ${\alpha}^{\prime}$ than in the contents of 2% and 33% initial ${\alpha}^{\prime}$. The difference of da/dN at the same level of ${\Delta}K$ was distinctive in low and intermediate level of ${\Delta}K$ however became less different as the level of ${\Delta}K$ increased. It is because the formation of strain induced martensite occurred readily in lower ${\alpha}^{\prime}$ at the vicinity of the fatigue crack tip, which causes compressive residual stresses resulting in the enhancement of crack closure. In general fatigue cracks propagated transgranular mode and many segments of ridges were observed on the fracture surfaces. At the higher contents of initial ${\alpha}^{\prime}$ appeared the smaller size of ridge segments. Slips in austenite were blocked more frequently by the martensite colonies formed in austenite.

• 약학회지
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• 제28권6호
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• pp.305-311
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• 1984

Relationship between hypertension and monoamine oxidase (MAO) activity in rat brain and the change of this relationship by presynaptic ${\alpha}-receptor$ agonist were studied. Animals were divided into three groups. Group I was composed of normotensive Sprague-Dawley rats (NR), group II of spontaneously hypertensive rats (SHR) and group III of acquired hypertensive rats induced by deoxycorticosterone acetate (DOCA) and NaCl treatment. Clonidine, a presynaptic ${\alpha}-receptor$ agonist, was administered to groups II and III. Blood pressures and MAO activities were measured in each group. MAO activities in the brain of SHR were lower than those of NR. Animals in group II received clonidine which lowered blood pressures but did not change MAO activities in the brain. DOCA and NaCl induced hypertension 21 days after these treatments in group III and did not cause any changes in brain MAO activity. Clonidine lowered blood pressures of group III but did not change MAO activities. The data from the present study suggest that abnormaly low MAO activities in SHR brain may be one of the underlying factors for the susceptibility to hypertension and that the decrease in noradrenergic neuronal activities through presynaptic ${\alpha}-receptor$ activation by clonidine may not be related to the changes of brain MAO activities.

• 한국약용작물학회지
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• 제15권4호
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• pp.271-275
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• 2007

Naturally occurring substances are important biomedical resources with low toxicity and ethnopharmacology-based efficacy. Four out of 45 extracts (Celastrus orbiculatus, Cercis chinensis, Stephanadra incisa, and Weigela subsessilis) prepared from the bark of Korea Forest plants exhibited more than 50% of inhibition on $TNF-{\alpha}$ production in lipopolysaccharide (LPS)-activated RAW264.7 cells at $100\;{\mu}g/m{\ell}$. In particular, potential inhibitory components of 4 extracts showed more than 50% inhibition seemed to be concentrated in methylene chloride (MC) fraction from C. orbiculatus, in ethyl acetate (EtOAc) fraction from C. chinensis and in hexane (Hx) fraction from S. incisa, whereas inhibitory activities of W. subssilis were broadly seen in non-polar solvent fractions such as Hx, MC and EtOAc. Therefore, our results suggest that extracts from C. orbiculatus, C. chinensis, S. incisa and W. subsessilis may be developed as a therapeutic remedy against $TNF-{\alpha}-mediated$ diseases such as rheumatoid arthritis or further fractionated to isolate active components having $antiTNF-{\alpha}$ inhibitory activity.

• 한국대기환경학회지
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• 제18권3호
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• pp.183-192
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• 2002

Concentrations of $\alpha$- and ${\gamma}$-hexachlorocyclohexane (HCH) were measured in ambient air samples at a two week intervals between July 1999 and February 2000 at Ansung, Kyonggi province. Their concentration levels averaged at 78 ($\alpha$-HCH) and 18 pg/m$^3$(${\gamma}$-HCH). Although the use of HCHs was ceased in South Korea since 1979, their residues are still present in air even after nearly 20 years. Given the composition of the two main HCH pesticide formulation (technical HCH antral lindane), the $\alpha$/${\gamma}$-HCH ratio in air is a useful indicator on the regional scale. The moderately low $\alpha$/${\gamma}$-HCH ration in this study indicates previous usage of both technical HCH and lindane. The relationship of temperature with gas-phase partial pressures was also examined using the Clausius-Clapeyron equation. Slopes generated by linear regression analysis between partial pressure (In P) and 1/T were considerably steep thor HCHs. It is thus suggested that their concentrations are controlled by re-volatilization processes from surfaces in the local surroundings of the sampling site.

• Clinical and Experimental Pediatrics
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• 제54권2호
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• pp.51-54
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• 2011

Vitamin D is present in two forms, ergocalciferol (vitamin $D_2$) produced by plants and cholecalciferol (vitamin $D_3$) produced by animal tissues or by the action of ultraviolet light on 7-dehydrocholesterol in human skin. Both forms of vitamin D are biologically inactive pro-hormones that must undergo sequential hydroxylations in the liver and the kidney before they can bind to and activate the vitamin D receptor. The hormonally active form of vitamin D, 1,25-dihydroxyvitamin D3 $[1,25(OH)_2D]$, plays an essential role in calcium and phosphate metabolism, bone growth, and cellular differentiation. Renal synthesis of $1,25(OH)_2D$ from its endogenous precursor, 25-hydroxyvitamin D (25OHD), is the rate-limiting and is catalyzed by the $1{\alpha}$-hydroxylase. Vitamin D dependent rickets type I (VDDR-I), also referred to as vitamin D $1{\alpha}$-hydroxylase deficiency or pseudovitamin D deficiency rickets, is an autosomal recessive disorder characterized clinically by hypotonia, muscle weakness, growth failure, hypocalcemic seizures in early infancy, and radiographic findings of rickets. Characteristic laboratory features are hypocalcemia, increased serum concentrations of parathyroid hormone (PTH), and low or undetectable serum concentrations of $1,25(OH)_2D$ despite normal or increased concentrations of 25OHD. Recent advances have showed in the cloning of the human $1{\alpha}$-hydroxylase and revealed mutations in its gene that cause VDDR-I. This review presents the biology of vitamin D, and $1{\alpha}$-hydroxylase mutations with clinical findings.

• Nutrition Research and Practice
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• 제8권2호
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• pp.151-157
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• 2014

BACKGROUND/OBJECTIVES: In Asia, various medicinal plants have been used as the primary sources in the health care regimen for thousands of years. In recent decades, various studies have investigated the biological activity and potential medicinal value of the medicinal plants. In this study, 100 methanol extracts from 98 plant species were evaluated for their biological activities. MATERIALS/METHODS: The research properties, including 1,1-diphenyl-2-pic-rylhydrazyl (DPPH) radical scavenging activity, ${\alpha}$-glucosidase and ${\alpha}$-tyrosinase inhibitory effects, anti-inflammatory activity, and anticancer activity were evaluated for the selected extracts. RESULTS: Fifteen of the extracts scavenged more than 90% of the DPPH radical. Among the extracts, approximately 20 extracts showed a strong inhibitory effect on ${\alpha}$-glucosidase, while most had no effect on ${\alpha}$-tyrosinase. In addition, 52% of the extracts showed low toxicity to normal cells, and parts of the extracts exhibited high anti-inflammatory and anticancer activities on the murine macrophage cell (RAW 264.7) and human colon cancer cell (HT-29) lines, respectively. CONCLUSIONS: Our findings may contribute to further nutrition and pharmacological studies. Detailed investigations of the outstanding samples are currently underway.

• 한국세라믹학회지
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• 제34권11호
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• pp.1187-1197
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• 1997

Dry gel composed of primary particles more homogeneous than starting boehmite powder was prepared by dispersing and gelling the boehmite powder. The transformation temperatures of boehmite powder, dry gel seeded with 0, 1, 3, 5 wt% $\alpha$-Al2O3, and ball milled gel were 1192$^{\circ}C$, 1184$^{\circ}C$, 1141$^{\circ}C$, 1119$^{\circ}C$, 1117$^{\circ}C$, and 1106$^{\circ}C$, respectively. Sintering behavior of dry gel without seed was similar to that of boehmite powder, but the sintered density of dry gel was improved as much as 10%~15% than boehmite powder. In the case of dry gel seeded with 5 wt% $\alpha$-Al2O3, sintering behavior was much improved. The relative density of the gel seeded with 5 wt% $\alpha$-Al2O3 was 96% when sintered at 140$0^{\circ}C$ for 1h. On the other hand, ball milling of the non-seeded sol for 48h resulted in the relative density of 97% when sintered at 130$0^{\circ}C$ for 1h. The size and amount of $\alpha$-Al2O3 particles added by ball milling were 0.107 ${\mu}{\textrm}{m}$ and 0.5 wt%.