• 대한수학회보
• /
• 제42권1호
• /
• pp.169-177
• /
• 2005

A Hilbert Space operator T is of class Q if $T^2{\ast}T^2-2T{\ast}T + I$ is nonnegative. Every paranormal operator is of class Q, but class-Q operators are not necessarily normaloid. It is shown that if a class-Q contraction T has no nontrivial invariant subspace, then it is a proper contraction. Moreover, the nonnegative operator Q = $T^2{\ast}T^2-2T{\ast}T + I$ also is a proper contraction.

• 한국식품위생안전성학회지
• /
• 제9권2호
• /
• pp.75-80
• /
• 1994

The effects of ursodeoxycholic acid (UDCA) were studied on the hepatotoxicity induced by several hepatotoxicants such as carbonte trachloride, thioacetamide and 1-naphthylisothiocyanate in ICR male mice. UDCA (50 mg/kg, 100 mg/kg) decreased the elevated serum bilirubin in carbon tetrachloride intoxicated mice, the elevated serum AST, alkaline phosphatase in thioacetamide intoxicated mice, the elevated serum AST and bilirubin in 1-naphthylisothiocyanate intoxicated mice.

• 동의생리병리학회지
• /
• 제32권5호
• /
• pp.347-353
• /
• 2018

There are some controversies about the safety of herbal medicine. In order to examine the safety of herbal medicine, this study investigated the level of liver function test(AST/ALT) in patients taking herbal medicine for more than 6 months We checked liver function in 121 patients who took herbal medicine for more than 6 months. AST/ALT were measured before treatment and every 3 months (from 3 month to 9 month). In 121 patients taking herbal medicine for more than 6 months, mean AST level after 6 months was lower than before treatment and mean ALT level after 6 months was lower than before treatment. In 20 patients with abnormal AST/ALT before herbal treatment, 18 patients's AST/ALT changed to normal after 6 month herbal treatment. 2 patients's AST/ALT was slightly higher than normal. One woman patient met the criteria for herb-induced liver injury(HILI) with RUCAM scores 4 after taking herbal medicine for 6 months. Although her RUCAM score decreased to zero after taking herbal medicine for 9 months. This study suggests that long-term herbal medicine for 6 months or longer is very unlikely to injury liver function. Individual-specific liver damage may occur, it can be recovered.

• 한국축산식품학회지
• /
• 제26권3호
• /
• pp.386-393
• /
• 2006

본 연구는 국내산 울금 추출물, 둥굴레 및 말토덱스트린 혼합물을 이용하여 건강 기능성 식품을 제조한 결과 건강 기능성뿐만 아니라 기호적 품질 향상에도 기여하였다. 울금추출물을 $4{\sim}40mg/kg$ 으로 7일 동안 후 투여(post-treatment)한 SD계 랫트는 정상군과 비교하여 ALT(GPT)의 유의적 차이가 없었다(p>0.05). 울금 추출물을 40 mg/kg으로 7일 동안 후 투여(post-treatment)한 SD계 랫트는 정상군과 비교하여 AST(GOT)의 유의적 감소(p<0.05)를 나타내었다. 또한 울금 추출물을 $4{\sim}40$ mg/kg으로 7일 동안 후 투여(post-treatment)한 SD계 랫트는 대조군과 비교하여 ALT(GPT)와 AST(GOT)의 유의적 감소(p<0.05)를 나타내었다. 울금 추출물을4 mg/kg과 40 mg/kg으로 7일 동안 후 투여(post-treatment)한 SD계 랫트는 대조군과 비교하여 AST(GOT)와 ALT(GPT)의 효소 활성을 각각 82.6%와 78.7% 그리고 78.0%와 79.3%까지 감소함을 보였다. 본 연구 결과 울금 추출물의 경구 투여는 AST(GOT), ALT(GPT) 및 ALKP를 감소하였으며 사염화탄소($CCl_4$)에 의해 손상된 간 기능을 개선할 수 있는 유용한 건강 기능성 식품으로 사용할 수 있다는 것을 입증하였다. 둥굴레 및 말토덱스트린 혼합물은 간 기능 개선 효과는 없었으나 울금 특유의 강한 불쾌 취(off-flavor)감소에 의하여 관능적 품질 향상으로 소비자의 기호성 향상에 기여할 수 있다는 것을 입증하였다.

• Korean Journal of Mathematics
• /
• 제24권4호
• /
• pp.647-662
• /
• 2016

In this paper, we study Lipschitz continuous, the boundedness and compactness of the composition operator $C_{\phi}$ acting between the general hyperbolic Bloch type-classes ${\mathcal{B}}^{\ast}_{p,{\log},{\alpha}}$ and general hyperbolic Besov-type classes $F^{\ast}_{p,{\log}}(p,q,s)$. Moreover, these classes are shown to be complete metric spaces with respect to the corresponding metrics.

• Bulletin of the Korean Chemical Society
• /
• 제23권2호
• /
• pp.201-204
• /
• 2002

The rates of the aminolysis of S-phenyl substituted-acetate series $(RC(=O)SC_6H_4Z$, with R=Me, Et, i-Pr, t-Bu and Bn) with benzylamines $(XC_6H_4CH_2NH_2)$ are not correlated simply with the Taft's polar $({\sigma}^{\ast})$ and/or steric effect constants $(E_s)$ of the substituents due to abnormally enhanced rate of the substrate with R=Et. Furthermore, the cross-interaction constant, ${\rho}x_z$ , is the largest with R=Et. These anomalous behaviors can only be explained by invoking the vicinal bond $({\sigma})$-antibond $({\sigma}^{\ast})$ charge transfer interaction between C-$C{\alpha}$ and C-S bonds. In the tetrahedral zwitterionic intermediate, $T^{\pm}$ , formed with R=Et the vicinal ${\sigma}_{c-c}-{\sigma}^{\ast}_{c-s}$ delocalization is the strongest with an optimum antiperiplanar arrangement and a narrow energy gap, ${\Delta}{\varepsilon}={\varepsilon}_{{\sigma}^{\ast}}-{\varepsilon}_{\sigma}$. Due to this charge transfer interaction, the stability of the intermediate increases (with the concomitant increase in the equilibrium constant K (= $k_a/k_{-a}$)) and also the leaving ability of the thiophenolate leaving group increases (and hence $k_b$ increases) so that the overall rate, $k_n\;=\;Kk_b$, is strongly enhanced. Theoretical support is provided by the natural bond orbital (NBO) analyses at the B3LYP/6-31+$G^{\ast}$ level. The anomaly exhibited by R=Et attests to the stepwise reaction mechanism in which the leaving group departure is rate limiting.

• Journal of applied mathematics & informatics
• /
• 제4권2호
• /
• pp.513-528
• /
• 1997

A sort sequence $S_n$ is a sequence of all unordered pairs of indices in $I_n\;=\;{1,\;2,v...,\;n}$. With a sort sequence Sn we assicuate a sorting algorithm ($AS_n$) to sort input set $X\;=\;{x_1,\;x_2,\;...,\;x_n}$ as follows. An execution of the algorithm performs pairwise comparisons of elements in the input set X as defined by the sort sequence $S_n$, except that the comparisons whose outcomes can be inferred from the outcomes of the previous comparisons are not performed. Let $X(S_n)$ denote the acverage number of comparisons required by the algorithm $AS_n$ assuming all input orderings are equally likely. Let $X^{\ast}(n)\;and\;X^{\circ}(n)$ denote the minimum and maximum value respectively of $X(S_n)$ over all sort sequences $S_n$. Exact determination of $X^{\ast}(n),\;X^{\circ}(n)$ and associated extremal sort sequenes seems difficult. Here, we obtain bounds on $X^{\ast}(n)\;and\;X^{\circ}(n)$.

• 대한한방내과학회지
• /
• 제21권1호
• /
• pp.108-115
• /
• 2000

Objective : To investigate the hepatoprotective effects of Gami-oryungsan on the liver damage induced by bromobenzene. Method : The development of fibrosis and acute liver injury was examined by the chemical analysis of AST, AL T, ${\gamma}$-GTP . and epoxide hydrolase glutathione S-transferase glutathione peroxidase enzyme activity, lipidoperoxide levels, glutathione levels were measured and oberved. Results : The increasing levels of lipidoperoxide was decreased proportionally according to dose of extract GO. Epoxide hydrolase glutathioneS-transferase glutathione peroxidase enzyme activity highly increased in GO pre-acupunctured group compared with the group treated with only bromobenzene. The increase of serum AST, AL T, ${\gamma}$-GTP enzyme activity of mice by bromobenzene was inhibited by the administration of GO. Lipidoperoxide levels in rat's liver decreased compared to the case of bromobenzene-treated group. The levels of Glutathione decreased by bromo benzene were increased highly in GO pre-acupunctured group. Conclusion : These results suggest that GO extract recovers the damage of liver due to bromobenzene intoxication by decreasing the lipid peroxidation AST AL T ${\gamma}$-GTP enzyme activity and increasing epoxide hydrolase glutathioneS-transferase glutathione peroxidase enzyme activity, glutathione levels.

• 한국식품영양과학회지
• /
• 제36권7호
• /
• pp.896-901
• /
• 2007

본 연구는 올리브유 및 대두유의 첨가가 돼지 분쇄육의 냉장 중 품질에 미치는 영향을 검토하기 위하여 돼지지방을 첨가한 분쇄육(GP-P), 올리브유를 첨가한 분쇄육(GP-O) 및 대두유를 첨가한 분쇄육(GP-S) 등 세 종류의 분쇄육을 제조하고 냉장 중 색깔, 보수력, 가열감량, 두께의 증가율, 직경의 감소율, pH, VBV함량 및 TBARS값을 측정하였다. 저장 중 $L^{\ast}$ 및 $b^{\ast}$값의 변화는 없었으나, 돼지지방을 첨가한 분쇄육의 $L^{\ast}$, $a^{\ast}$ 및 $b^{\ast}$값이 올리브유나 대두유를 첨가한 것보다 높았다. 보수력은 저장 중 증가하는 경향이었으며, GP-P의 보수력이 GP-O 및 GP-S보다 높았다. 그리고 가열감량은 GP-P가 GP-O 및 GP-S보다 낮았다(p<0.05). 두께의 증가는 저장 중 높아졌고, 직경의 감소는 저장 중 낮아지는 경향이었다(P<0.05). 그리고 GP-P의 두께 증가율 및 직경 감소율이 GP-O 및 GP-S보다 더 컸다(p<0.05). pH는 저장 5일째 감소하였다가 그 후 저장말기까지 증가하였다(p<0.05). 분쇄육의 VBN함량은 저장 중 증가하였으며, GP-P가 GP-O 및 GP-S보다 함량이 높았다(p<0.05). TBARS값은 저장 중 증가하였으며, GP-P가 가장 높고, GP-O가 가장 낮았다.

• Korean Chemical Engineering Research
• /
• 제59권1호
• /
• pp.16-20
• /
• 2021

PEMFC 고분자막의 내구성 향상을 위한 내구성 평가는 PEMFC 발전을 위해 매우 중요하므로 고분자막 내구성 평가 프로토콜(AST) 연구개발이 계속 되고 있다. 최근에 DOE의 고분자막 화학적/기계적 내구성 평가 AST가 개발되어 Nafion XL에 적용해 검토하였다. 평가시간을 단축시키기 위해 공기대신 산소를 Cathode 가스로 사용해 144시간만에 종료하였다. DOE AST가 가습 45초/건조 30초로 전압변화 횟수가 많아서 전극의 열화가 MEA 내구성에 더 많은 영향을 미쳤다. 그래서 가습 60초/건조 300초로 1사이클 시간을 길게하고 가습시간 대비 건조시간도 길게 하여 고분자막을 더 열화시키게 하였고, 240시간에 종료하였다. 고분자막 내구성 평가를 위한 DOE AST가 전극 열화도 동반됨을 확인하였다.