• Journal of Ginseng Research
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• 제40권2호
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• pp.121-126
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• 2016

Background: Ginsenoside F1, a pharmaceutical component of ginseng, is known to have antiaging, antioxidant, anticancer, and keratinocyte protective effects. However, the usage of ginsenoside F1 is restricted owing to the small amount found in Korean ginseng. Methods: To enhance the production of ginsenoside F1 as a 10 g unit with high specificity, yield, and purity, an enzymatic bioconversion method was developed to adopt the commercial enzyme Cellulase KN from Aspergillus niger with food grade, which has ginsenoside-transforming ability. The proposed optimum reaction conditions of Cellulase KN were pH 5.0 and $50^{\circ}C$. Results: Cellulase KN could effectively transform the ginsenosides Re and Rg1 into F1. A scaled-up biotransformation reaction was performed in a 10 L jar fermenter at pH 5.0 and $50^{\circ}C$ for 48 h with protopanaxatriol-type ginsenoside mixture (at a concentration of 10 mg/mL) from ginseng roots. Finally, 13.0 g of F1 was produced from 50 g of protopanaxatriol-type ginsenoside mixture with $91.5{\pm}1.1%$ chromatographic purity. Conclusion: The results suggest that this enzymatic method could be exploited usefully for the preparation of ginsenoside F1 to be used in cosmetic, functional food, and pharmaceutical industries.

• Bulletin of the Korean Chemical Society
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• 제16권7호
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• pp.634-641
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• 1995

The metal-carbon σ-bond cluster complexes 1-Mn(CO)5-2-R-1,2-C2B10H10 (R=CH3 Ia, C6H5 Ib) have been prepared in good yields from readily available carboranyl lithium complexes, 1-Li+-2-R-1,2-C2B10H10- (R=CH3, C6H5), by direct reaction with (CO)5MnBr. These manganese metal complexes are rapidly converted to the corresponding manganese metal carbene complexes, 1-[(CO)4Mn=C(OCH3)(CH3)]-2-R-1,2-C2B10H10 (R=CH3 IIIa, C6H5 IIIb), via alkylation with methyllithium followed by O-methylation with CF3SO3CH3. The crystal structure of IIIb was determined by X-ray diffraction. Thus, complex IIIb crystallizes in the orthorhombic space group P212121 with cell parameters a=15.5537(5), b=19.0697(5), c=7.4286(3) Å, V=2203.4(1) Å3, and Z=4. Of the reflections measured a total of 3805 unique reflections with F2>3σ(F2) was used during subsequent structure refinement. Refinement converged to R1=0.053 and R2=0.091. Structural studies showed that the manganese atom had a slightly distorted pseudo-octahedral configuration about the metal center with the carbene and ortho-carborane occupying the equatorial plane cis-orientation to each other.

• Journal of Electrochemical Science and Technology
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• 제5권2호
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• pp.58-64
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• 2014

The surface of an ordered mesoporous silica (OMS) was functionalized using 1H,1H,2H,2H-perfluorooctyltrimethoxysilane at $20^{\circ}C$ and $60^{\circ}C$. It was shown that only elevated temperature allows lyophobic properties on the walls of OMS, eventually preventing pore flooding with nonaqueous electrolytes. The functionalized OMSs (OMS-F) were characterized with various techniques: wettability test, $N_2$ sorption measurement, high-resolution transmission electron microscopy (HR-TEM). Cathodes of $10mg/cm^2$ loading were prepared with a commercial Pt/C catalyst and polyvinylidene fluoride (PVDF, 2.5 wt.%) binder using a typical doctor blade method on a commercial gas diffusion layer (GDL) in the presence or in the absence of OMS-F additives. Subsequent discharge-charge curves were taken in a 1M LiTFSI-TEGDME electrolyte at 60oC in pure oxygen atmosphere. It was found that the discharge capacity was significantly affected by OMS-F: 5 wt.% of additive extended discharge capacity by a factor 1.5. On the other hand, a similar OMS material but synthesized at $20^{\circ}C$ did not show lyophobic properties and deteriorated cathode capacity.

• 한국결정성장학회지
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• 제9권4호
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• pp.353-359
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• 1999

• 한국결정학회지
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• 제13권3_4호
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• pp.152-157
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• 2002

X선 회절법을 이용하여 Tricyclazole, C/sub9/H/sub7/N₃S 분자 및 결정 구조를 규명하였다. 화합물의 결정학 자료: Orthorhombic 공간군 Pca2₁, a=14.889(1) Å, b=7.444(1) Å, c=15.189(2) Å, V=1683.3(3) ų, Z= 8분자 구조는 직접법으로 풀었고 완전최소자승법으로 정밀화하여 1533(F/sub o//sup 2/>4σ(F/sub o//sup 2/))인 독립회절반점에 대하여 최종 신뢰도값 R=0.047을 얻었다. 구조 해석 결과 두 분자가 asymmetric 단위로 구성되어 있으며 각각의 분자는 서로 거의 평형을 이루면서 b축 방향으로 유사 4-fold screw를 이루고 있었다.

• 한국결정학회지
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• 제6권1호
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• pp.36-42
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• 1995

상기제목의 화합물의 두가지 단결정이 n-hexane/CH2C12 과 n-hexane/Et2O 의 용매에 의하여 얻어졌으며, 그들의 서로 다른 공간군에도 불구하고 그들의 분자구조는 동일함이 밝혀졌다. C22H18N2O2 (I), Mr=343.70, Monoclinic, Pa, a=14.595(2), b=5.413(2), c=12.218(2)Å, β=96.86(1)°, V=958.3Å3, Z=2, Dx=1.19 Mgm-3, λ(MoKα)=0.71069Å, μ=0.072mm-1, F(000)=360.0, T=292K, 756 유일한 반사강도에 대하여 R=0.104이다. 한 비대칭단위는 분자간의 두 개의 N-H…O 수소결합으로 연결된 dimer이다. C11H9NO (II), Mr=171.85, Monoclinic, P21/a, a=14.611(2), b=5.423(6), c=12.191(2)Å, β=96.89(1)°, V=959.0Å3, Z=4, Dx=1.19 Mgm-3, λ(MoKα)=0.71069Å, μ=0.072mm-1, F(000)=360.0, T=293K, 824 개의 유일한 반사강도에 대한 R=0.066이다. 한 분자가 비대칭단위를 이루고 있으며 대칭중심관계에 있는 두 개의 N-H…O 수소결합으로 dimer 를 형성한다. 양쪽 구조에서 공히 선형인 diyne chain에 의하여 연결된 pyridyl 고리와 C(10)-C(11)-O가 만드는 평면간의 이면각은 수직에 가까우며, 그 분자들은 b-축을 반복주기로하여 b-축을 따라 쌓여있다.

• Journal of Chest Surgery
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• 제17권1호
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• pp.67-73
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• 1984

A 25 years old male patient with traumatic aneurysm of descending thoracic aorta was treated successfully. He was admitted due to blunt trauma to the chest wall as falling down into water. He has been treated with closed thoracotomy and close observation. After a month simple chest film showed abnormal mass shadow around the aortic knob. Aortogram revealed aneurysm of descending thoracic aorta. Aneurysm was resected and replaced with woven Dacron graft with aid of Gotts shunt. His postoperative course was uneventful.

• 한국인터넷방송통신학회논문지
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• 제23권4호
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• pp.59-64
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• 2023

본 논문은 전자기기에 사용되는 전원의 노이즈 저감을 위한 전도성(Conducted) EMI 필터의 경험적 설계를 통하여 제안하였다. 제안된 구조는 A형, B형, C형, D형의 구조를 설계하였으며, 다양한 X-커패스터와, Y-커패스터, Air-인덕터로 LC 네트워크 사용으로 전도성 노이즈 저감을 확인하였다. L1, L2는 10[μH]를 사용하였으며, C1, C2는 4.7[nF]를 사용하였다. 공통모드(Common Mode)용 L3는 13[μH]를 사용하였으며, C5, C6, C7은 10[nF]을 사용하여 설계하였다. 설계된 EMI 필터의 측정된 삽입손실 값은 3.2MHz에서 -74.4[dB], 4MHz에서 -75.4[dB], 13.56MHz에서 -75.3[dB]로 나타났다. 따라서 제안한 EMI 필터는 다양한 전자기기에 사용되는 전원 노이즈 저감에 이용될 것이다.

• 한국결정학회지
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• 제13권2호
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• pp.91-95
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• 2002

X-선 회절법을 이용하여 Cantharidin(Hexahydro-3a,7a-dimethyl-4,7-epoxyisobenzofuran-1,3-dione, C/sub 10/H/sub 12/O/sub 4/)의 결정구조를 규명하였다. 이 결정의 결정계는 사방정계이며 공간군은 Pna2/sub 1/ 이다. 단위포 상수는 a＝11.0731(9) (equation omitted), b＝6.7344(4) (equation omitted), c＝12.5000(9) (equation omitted), α＝β＝γ＝90°, V＝932.13(12) (equation omitted), T=296K, Z＝4, D/sub c/＝1.398Mgm/sup -3/이다. 회절반점들의 세기는 Enraf-Nonius CAD-4 Diffractometer로 얻었으며 MoKα선(λ＝0.71073(equation omitted))을 사용하였다 분자구조는 직접법으로 풀었으며, F/sub o/>4σ(F/sub o/)인 759개의 독립 회절 데이터에 대하여 최소자승법으로 140개의 변수를 정밀화하여 최종 신뢰도 값 R＝4.42%을 얻었다.

• 충청수학회지
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• 제26권2호
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• pp.357-365
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• 2013

Fix $n-2$ elements $h_1,{\cdots},h_{n-2}$ of the quotient field B of the polynomial algebra $\mathbb{C}[x_1,x_2,{\cdots},x_n]$. It is proved that B is a Poisson algebra with Poisson bracket defined by $\{f,g\}=det(Jac(f,g,h_1,{\cdots},h_{n-2})$ for any $f,g{\in}B$, where det(Jac) is the determinant of a Jacobian matrix.