• Elastomers and Composites
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• 제34권2호
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• pp.147-155
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• 1999

고무와 혼합된 왁스는 고무 표면으로 이동하여 방어막을 형성한다. 일반적으로 고무의 오존화를 방지하기 위해 오존노화방지제를 왁스와 함께 사용하고 있다. 다양한 종류의 왁스가 첨가된 천연고무 가류물을 이용하여 왁스막이 오존노화방지제의 이동에 미치는 영향을 연구하였다 오존노화방지제로 IPPD (N-isopropyl-N'-phenyl-p-phenylenediamine), HPPD (N-l,3-dimethylbutyl-N'-phenyl-p-phenylenediamine), SBPPD (N,N'-di(sec-butyl)-p-phenylenediamine), 그리고 DMPPD (N,N'-di(1,4-dimethylpentyl)-p-phenylenediamine)를 사용하였다. 노화방지제 이동 실험은 $60^{\circ}C$ 와 $80^{\circ}C$에서 10, 20, 30일간 실시하였다. 노화방지제의 이동속도는 고무가류물에 왁스가 없을 때가 있을 때보다 빨랐으며 분자량이 큰 왁스가 혼합되었을 때가 분자량이 작은 왁스가 혼합되었을 때보다 느렸다. DMPPD와 SBPPD의 이동속도가 HPPD와 IPPD의 이동속도보다 빨랐다.

• Nutritional Sciences
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• 제6권3호
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• pp.148-154
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• 2003

Although various raw plant materials have been demonstrated to exert anti-obesity effects to a greater or lesser extent in both humans and animals when they are used to supplement the diet, it has not been shown extensively that they influence adipocyte cell differentiation involving lipid metabolic gene expressions. Using a well-established 3T3-L1 preadipocyte differentiation system, we decided to look into molecular and cellular event occurring during adipocyte differentiation when raw plant materials aye included in the process, in an effort to demonstrate the potential use of a screening system to define the functions of traditionally well-known materials. To these ends, the effects of ethanol (EtOH) or EtOH/distilled water (DW) extracts of Wax Gourd were examined using cytochemical and molecular analyses to determine whether components of the extracts modulate adipocyte differentiation of 3T3-Ll preadipocytes in vitro. The cytochemical results demonstrated that EtOH or EtOH/DW extracts did not affect lipid accumulation and cell proliferation, although the degree of lipid accumulation was influenced slightly depending on the extract. EtOH extract was highly effective in apoptotic induction during differentiation of 3T3-Ll preadipocytes (p<0.05). Reverse transcription-polymerase chain reaction (RT-PCR) analysis of lipoprotein lipase (LPL), Uncoupling protein (Ucp) 2, 3 and 4 also showed that while LPL expression was not influenced, Ucp2, 3 and 4 were up regulated in the EtOH extract-treated group and down regulated in the EtOH/DW extract-treated group. These changes in gene expressions suggest that the components in different fractions of Wax Gourd extracts may modulate lipid metabolism by either direct or indirect action. Taking these results together, it was concluded that molecular and cellular analyses of adipocyte differentiation involving lipid metabolic genes should facilitate understanding of cellular events occurring during adipocyte differentiation. Furthermore, the experimental scheme and analytical methods used in this study should provide a screening system for the functional study of raw plant materials in obesity research.

• Journal of the Korean Wood Science and Technology
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• 제46권4호
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• pp.393-401
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• 2018

Natural fibers derived from lignocellulosic materials are considered to be more environment-friendly than petroleum-based synthetic fibers. Several natural fibers, such as seedpod fibers, have a potential for development, including kapok and balsa fibers. The characteristics of both fibers were evaluated to determine their suitability for specific valuable applications. The purpose of this study was to analyze some important fundamental properties of kapok and balsa fibers, including their dimensions, morphology, chemical components, and wettability. The results showed that the average fiber lengths for kapok and balsa were 1.63 and 1.30 cm, respectively. Kapok and balsa fibers had thin cell walls and large lumens filled with air. The kapok fiber was composed of 38.09% ${\alpha}-cellulose$, 14.09% lignin, and 2.34% wax content, whereas the balsa fiber was composed 44.62% ${\alpha}-cellulose$, 16.60% lignin, and 2.29% wax content. The characteristics of kapok and balsa fibers were examined by X-ray diffraction, Fourier-transform infrared spectroscopy and differential scanning calorimetry analyses. The contact angle of the distilled water on kapok and balsa fibers was more than $90^{\circ}$, indicating that both fibers are hydrophobic with low wettability properties because of to the presence of wax on the fiber surface.

• The Korean Journal of Ecology
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• 제24권6호
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• pp.349-352
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• 2001

The beekeeping pest insect Galleria mellonella larvae(greater wax moth) were reared on an artificial diet contaminated indipendently with cadmium chloride($CdCl_2$) at different concentrations(1.25, 2.50, 5.00, 10.0 20.0, 40.0 ${\mu}g/g$ food fresh weight). Results of these studies suggested that Cd exposure of G. mellonella may influence its whole body lipid contents. We decided, therefore, to analyze lipid content of G. mellonella exposed to different concentrations of Cd. Lipid concentrations were measured photometrically by phosphovanillin method. Significant decrease in the total lipid content was found in Cd-contaminated larvae and pupae. In this study, six kinds of lipids were separated, and they were phospholipid, monoglyceride, diglyceride, sterol, fatty acids, triglyceride. And fatty acids were proved to consist of palmitic acid, stearic acid, oleic acid and linolenic acid. Palmitic acid, linoleic acid and oleic acid were found high rate in all groups, but stearic acid was low. In conclusion, lipid contents decreased in Cd-contaminated groups in comparison to the control group.

• 대한치과기공학회지
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• 제45권3호
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• pp.81-86
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• 2023

Purpose: This study aimed to observe the effect of laminate veneer on patient's teeth based on the manufacturing of laminate veneer restorations, which are produced by fabricating a ceramic cast body using IPS Empress, a pressure casting method and then forming the veneer by layering. Subsequently, we assessed the potential of its clinical application. Methods: This study discusses and preserves various treatment plans, such as diagnostic wax-up and treatment room diagnosis, for patients who visit the hospital to improve the appearance of teeth due to diastema of maxillary teeth, inexperienced resin filling, lack of esthetics, and external teeth. A ceramic cast body is constructed using IPS Empress, which is an effective and aesthetic restoration pressure casting method to restore the veneer with a laminate made by layering. Results: Compared with the preoperative state, the frontal view of the patient after the final restoration showed the formation of a natural smile line; the space between the central and lateral incisors was filled in synchronously with the adjacent teeth. In addition, the emergence profile is maintained by reducing the over-contour as much as possible. Conclusion: The patient's quality of life is improved by providing them with a satisfactory natural smile.

• Applied Microscopy
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• 제42권2호
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• pp.95-103
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• 2012

연잎효과는 연꽃의 잎에서 규명된 현상으로 표피세포에서 기원하는 미세구조에 의해 물방울이 잎 표면이나 내부조직에 침투하지 않고 경사면으로 흘러내리며 표면 위 먼지나 이물질을 함께 떨어지게 한다. 잎 표면을 항상 깨끗한 상태로 유지하는 자기정화 능력인 연잎효과에 대해서는 여러 영역에서 연구되고 다방면으로 응용되고 있으나 구조적인 측면에서 연잎을 생장단계별 또는 표피조직 부위별로 비교 조사한 연구는 거의 없는 실정이다. 이에 본 연구에서는 연잎과 줄기를 대상으로 생장단계별, 부위별 표피조직의 미세 표면구조를 연구하여 연잎효과 표면 특성을 조사하였다. 본 연구에서 조사된 연잎효과는 미세돌기와 왁스결정체가 발달한 잎의 상피조직에서만 나타나고, 왁스결정체만 발달한 하피 및 줄기의 표피조직에서는 확인되지 않았다. 이는 미세돌기의 발달이 연잎효과를 나타내는데 가장 중요한 요인이고, 왁스결정체가 돌기표면 위에 축적되면 연잎효과는 더 증가하는 것으로 밝혀졌다.

• 한국환경농학회지
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• 제16권3호
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• pp.207-211
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• 1997

Bentazon의 잔류를 제거하기 위한 미나리의 생물학적 정화능력을 검정코자 $^{14}C-Bentazon$의 흡수(uptake)와 이행(translocation), 그리고 분해(metabolism) 실험을 통하여 비교 실험하였다. 잎에 처리한지 2일 후에 있어서 $^{14}C$의 21%가 처리된 잎에서 관측되었고, 66%는 잎 표면을 물로 세척한 곳에 잔류하고 있었으며, 나머지 13%는 epicuticular wax층에서 발견되었다. Bentazon을 처리한 잎으로부터 $^{14}C$의 79%가 검출되었으며, 뿌리에는 9%만이 검출되어 잎으로부터 뿌리로의 이행은 매우 적었다. 처리한 2일후에 $^{14}C$의 methanol 추출물 분석에서 잎에 처리된 제초제의 60% 이상이 모든 식물체 부위에서 분해되었다. 본 실험에서 발견된 주요 bentazon의 분해물(Metabolites)은 bentazon이나 6-hydroxy 혹은 8-hydroxy bentazon 보다 덜 이온화(Polar)된 알려지지 않은 신 물질(unknown compound)이었다.

• Natural Product Sciences
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• 제7권4호
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• pp.110-113
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• 2001

The lipid classes constituents; hydrocarbons, wax esters, sterol esters, triacylglycerols, free fatty acids, 1,3-diacylglycerols, 1,2-diacylglycerols, free sterols, 2-monoacylglycerols, 1-monoacylglycerols, phosphatidylethanolamines, phosphatidylcholines, lysophosphatidylethanolamines and phosphatidylinositols of Nicotiana tabacum L. seeds oil were investigated by thin layer and gas chromatography. Palmitic, oleic and linoleic acids were the major components in all lipid classes studied.

• 생약학회지
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• 제33권2호통권129호
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• pp.105-109
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• 2002

Besides chrysophanol and friedelin, mixtures of n-hydrocarbons [pentacosane (72.6%), heptacosane (14.6%), tetracosane (5.8%), nonacosane (4.1 %) and hexacosane (2.9%)], n-hydrocarbon alcohols [octacosanol (70.5%) and hexacosanol (29.5%)], l-monoacyl glycerols [acyl part; behenic acid (43.5%), lignoceric acid (32.4%), cerotic acid (9.3%), tricosanoic acid (8.9%), pentacosanoic acid (2.6%), octacosanoic acid (2.3%), heneicosanoic acid (1.0%)], wax esters [behenic acid (56.3%), lignoceric acid (23.0%), cerotic acid (19.8%), tricosanoic acid (4.6%), octacosanoic acid (4.0%), pentacosanoic acid (1.7%), triacontanoic acid (0.6%)/ octacosanol (33.7%), hexacosanol (21.0%), tetracosanol (15.6%), triacontanol (10.5%), docosanol (6.0%), tricosanol (6.0%), heptacosanol (4.2%), nonacosanol (3.0%)] and sterols [${\beta}-sitosterol$ (73.2%), stigmasterol (14.6%), campesterol (12.2%)] were isolated from the roots of Hemerocallis fulva. The acid : alcohol combinations of the major wax esters were $C_{48}$: 22 : 26, 24 : 24, $C_{46}$: 22 : 24, and $C_{44}$: 22 : 22. This is the first report of l-monoacyl glycerols and friedelin from this plant. All isolates were identified on the basis of spectral data and chemical reactions.

• 한국결정성장학회지
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• 제13권1호
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• pp.41-45
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• 2003

FT-IR은 보석을 감별하고 연구하는데 있어서 아주 유용한 장비이다. 그러므로 본 연구에서는 FT-IR을 이용하여 자수정. 황수정, 백수정 그리고 비취를 감별하는 데에 중점을 두었다 FT-IR은 자수정, 황수정과 백수정의 천연과 합성의 진위를 가리는데 매우 효과적이었으며, 천연 비취(A-Jade)와 왁스가 주입된 비취, 폴리머가 주입된 비취(B-Jade)를 식별하는 데 매우 유용하였다. 이러한 기술은 처리와 합성에 의해 새롭게 변화되어 나타나는 보석의 감별에 있어, 결정적으로 도움이 될 것이다.