• 한국미생물·생명공학회지
• /
• 제32권3호
• /
• pp.212-217
• /
• 2004

Glycosyl hydrolase family 26에 속하는 Bacillus subtilis WL-7 mannanase를 코드하는 유전자를 대장균에서 과잉 발현하였다. 아미노 말단의 signal peptide를 포함하거나 포함하지 않은 mannanase 유전자를 각각 pET24a(＋)에 도입하여 재조합 플라스미드 pETMAN과 pENS7를 제조하였다. 이들 플라스미드를 함유하는 Escherichia coli BL21(DE3)에서 mannanase를 발현시킨 결과 signal peptide가 제거된 mannanase유전자의 발현량이 매우 높았다. 그러나 배양온도 $37^{\circ}C$에서 pENS7를 함유한 재조합 대장균에서 과잉 발현된 mannanase는 대부분이 불활성 형태로 존재하였으며, 배양온도를 $31^{\circ}C$이하로 하였을 때 수용화 형태의 효소량이 증가하면서 효소활성이 높아졌다. IPTG에 의해 발현된 재조합 대장균의 균체파쇄 상등액 중에 존재하는 mannanase 활성은 배양온도 $25^{\circ}C$～28$^{\circ}C$에서 가장 높았으며, 전체 단백질량을 기준으로 볼 때는 배양온도 $31^{\circ}C$에서 비활성이 가장 높은 것으로 확인되었다.

• 대한수학회논문집
• /
• 제12권2호
• /
• pp.275-285
• /
• 1997

Let E be a uniformly convex Banach space with a uniformly G$\hat{a}teaux differentiable norm, C a nonempty closed convex subset of $E, T : C \to E$ a nonexpansive mapping, and Q a sunny nonexpansive retraction of E onto C. For $u \in C$ and $t \in (0,1)$, let $x_t$ be a unique fixed point of a contraction $R_t : C \to C$, defined by $R_tx = Q(tTx + (1-t)u), x \in C$. It is proved that if ${x_t}$ is bounded, then the strong $lim_{t\to1}x_t$ exists and belongs to the fixed point set of T. Furthermore, the strong convergence of ${x_t}$ in a reflexive and strictly convex Banach space with a uniformly G$\hat{a}$teaux differentiable norm is also given in case that the fixed point set of T is nonempty.

• 대한임상검사과학회지
• /
• 제50권4호
• /
• pp.422-430
• /
• 2018

퀴놀론 항균제가 사람과 동물에게 부적절하고 광범위하게 사용될 경우 항균제내성인자의 출현 및 확산이 가속화 될 수 있다. 본 연구에서는 돼지의 직장면봉 검체(N=40) 및 임상 검체로(N=25)부터 분리된 총 65균주의 nalidixic acid 내성 대장균을 대상으로 quinolone 내성 기전을 조사하였다. 항균제 감수성은 디스크 확산법에 의해 결정되었다. Quinolone 내성과 관련된 유전자와 돌연변이를 조사하기 위해 PCR 및 DNA sequencing이 수행되었다. 총 65균주의 nalidixic acid 내성 대장균 중 62균주가 gyrA, parC, parE 유전자에 돌연변이를 포함하고 있었는데, gyrA 유전자에 돌연변이를 포함하고 있는 균주는 62균주(95.4%)였고, 35균주(53.8%)가 parC 유전자에 돌연변이를 갖고 있었으며, 7균주(10.8%)가 parE 유전자에 돌연변이를 포함하고 있었다. 35균주는 gyrA 와 parC 유전자에 모두 돌연변이를 가지고 있는 것으로 나타났다. 총 65균주의 대장균을 대상으로 plasmid-mediated quinolone resistance (PMQR) determinants를 조사하였다. 65균주의 nalidixic acid 내성 대장균 중 13균주에서 qnrS 유전자가 검출되었으나 이 중 10균주는 gyrA, parC, parE 유전자에 돌연변이를 포함하고 있는 것을 나타났다. 본 연구에서는 사람과 돼지로부터 분리된 대장균이 quinolone 계열 항균제에 내성을 나타내는데 중요한 역할을 하는 기전이 gyrA, parC, parE 유전자에 염색체 돌연변이가 발생하는 경우임을 확인하였는데 이 돌연변이들은 치료목적 또는 동물의 성장촉진을 위한 항균제의 과다사용으로 유발될 수 있다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권2호
• /
• pp.252-256
• /
• 2007

This study was carried out to determine the effect of vitamin E and vitamin C on the performance of Japanese quails (Coturnix coturnix japonica) reared under heat stress during the growth and egg production period. A total of 810 seven-day-old Japanese quails were used in the trial. The birds received a diet with either three levels of vitamin E (DL-${\alpha}$Tocopheryl acetate) (60, 120 and 240 mg/kg of diet) and vitamin C (ROVIMIX STAY-C 35) (60, 120 and 240 mg/kg of diet). Live weight on day 35 and weight gain were the lowest in the group of chicks on a combination of 60 mg of vitamin E and 60 mg of vitamin C, whereas the highest live weight was demonstrated in chicks on a combination of 240 mg of vitamin E and 240 mg of vitamin C (p<0.01). The effects of treatments on cumulative feed consumption, feed conversion ratio, age at 5% lay, sexual maturity weight, rate of lay and mean egg weight values were found to be significant (p<0.01). The highest feed consumption, feed conversion ratio, age at 5% lay, sexual maturity weight, rate of lay and mean egg weight values were found in the group on a combination of 240 mg of vitamin E and 240 mg of vitamin C. The effect of treatments on the mortality ratio was found to be insignificant (p>0.01). The cost of supplementing diets with vitamin E and vitamin C is very low. Therefore such a combination of supplement can offer a potential protective management practice in preventing heat stress related losses in performance of Japanese quails.

• 대한간호학회지
• /
• 제32권4호
• /
• pp.550-559
• /
• 2002

This study was conducted to determine whether low intensity regular exercise following dexamethasone treatment could attenuate steroid-induced muscle atrophy. Method: 36 Wistar-rats(90-110g) were divided into six groups: control group(C), dexamethasone treatment group(D), sedentary group after normal sedentary period(C+S), sedentary group after dexamethasone treatment period(D+S), exercise group after normal sedentary period(C+E), and excercise group after dexamethasone treatment period(D+E). D, D+S, and D+E groups received dexamethasone injection(5mg/Kg) for seven days whereas C, C+S, and C+E groups received normal saline injection. Both C+E and D+E groups ran on a treadmill for 60 minutes/day(20minutes/4hours) at 15m/min and a 10$^{\circ}$grade for seven recovery days. Result: Post-weight(body weight before muscle dissection) of D group significantly decreased by 16.03%, and that of D+E group significantly increased by 15.51% compared with pre-weight(body weight before steroid treatment). TypeII muscle(plantaris and gastrocnemius) weights of D group were significantly lower than those of C group. Myofibrillar protein contents of typeII muscles of D group tended to decrease comparing with C group. In D+E groups, body weights and relative weights of typeII muscles(muscle weight(mg)/post-weight(g)) tended to increase comparing with D+S group. Conclusion: It is suggested that steroid- induced muscle atrophy can be ameliorated through low intensity regular exercise after dexamethasone treatment.

• 공업화학
• /
• 제20권6호
• /
• pp.696-699
• /
• 2009

본 연구에서는 은 나노 입자와 탄산은(Silver Carbonate)을 이용하여 제조된 은나노/셀라이트(SN/C)와 탄산은/셀라이트(SC/C) 복합체의 대장균에 대한 항균특성을 조사하였다. SN/C와 SC/C 복합체의 특성은 주사전자현미경, X-선 회절법, 그리고 원자흡수분광법에 의해 알아보았다. SN/C와 SC/C 복합체의 대장균에 대한 최소 억제농도는 0.541과 0.344 ppm이었고 완전 사멸농도는 1.427과 1.623 ppm으로 나타났다. 상기의 결과로 SN/C와 SC/C 복합체의 대장균에 대한 항균효과를 확인할 수 있었다.

• Advances in nano research
• /
• 제10권4호
• /
• pp.339-347
• /
• 2021

In the framework of the density functional theory combined with the method of non-equilibrium Green functions (DFT + NEGF), the electric transport properties of a one-dimensional nanodevice consisting of telescoping polyprismanes with various types of electrical conductivity were studied. Its transmission spectra, density of state, current-voltage characteristic, and differential conductivity are determined. It was shown that C_[14,17], C_[14,11], C_[14,16], C_[14,10] show a metallic nature, and polyprismanes C_[14,5], C_[14,4] possess semiconductor properties and has a band gap of 0.4 eV and 0.6 eV, respectively. It was found that, when metal C_[14,11], C_[14,10] and semiconductor C_[14,5], C_[14,4] polyprismanes are coaxially connected, a Schottky barrier is formed and a weak diode effect is observed, i.e., manifested valve (rectifying) property of telescoping polyprismanes. The enhancement of this effect occurs in the nanodevices C_[14,17] - C_[14,11] - C_[14,5] and C_[14,16] - C_[14,10] - C_[14,4], which have the properties of nanodiode and back nanodiode, respectively. The simulation results can be useful in creating promising active one-dimensional elements of nanoelectronics.

• Advances in nano research
• /
• 제10권5호
• /
• pp.471-479
• /
• 2021

In the framework of the density functional theory combined with the method of non-equilibrium Green functions (DFT + NEGF), the electric transport properties of a one-dimensional nanodevice consisting of telescoping polyprismanes with various types of electrical conductivity were studied. Its transmission spectra, density of state, current-voltage characteristic, and differential conductivity are determined. It was shown that C_[14,17], C_[14,11], C_[14,16], C_[14,10] show a metallic nature, and polyprismanes C_[14,5], C_[14,4] possess semiconductor properties and has a band gap of 0.4 eV and 0.6 eV, respectively. It was found that, when metal C_[14,11], C_[14,10] and semiconductor C_[14,5], C_[14,4] polyprismanes are coaxially connected, a Schottky barrier is formed and a weak diode effect is observed, i.e., manifested valve (rectifying) property of telescoping polyprismanes. The enhancement of this effect occurs in the nanodevices C_[14,17] - C_[14,11] - C_[14,5] and C_[14,16] - C_[14,10] - C_[14,4], which have the properties of nanodiode and back nanodiode, respectively. The simulation results can be useful in creating promising active one-dimensional elements of nanoelectronics.

• 아태비즈니스연구
• /
• 제13권4호
• /
• pp.61-77
• /
• 2022

Purpose - The purpose of this study was to explore the relationship between C2C logistics service quality(convenience, responsiveness, reliability, information and empathy) customer satisfaction and customer loyalty. Design/methodology/approach - This study collected 252 survey data from consumers who use C2C platform in China. Then using SPSS 24.0 in order to analyze the data. This study used SPSS 24.0 to perform empirical analysis with 252 people who use C2C platform in China. Findings - First, it was confirmed that the quality of logistics service(convenience, responsiveness, reliability, information and empathy) had a positive effect on customer satisfaction. Second, logistics service quality(convenience, responsiveness, reliability, information and empathy) positively affects the customer loyalty. Third, there is also a strong relationship between customer satisfaction and customer loyalty. Research implications or Originality - It is well known that logistics is an important part of e-commerce. Research on the influence of B2B logistics service quality on customer satisfaction and customer loyalty is more currently, but research on C2C is relatively less. Our study contributes the related research area by doing empirical analysis of the relationship between the logistics service quality and customer satisfaction and customer loyalty to provide development suggestions for C2C sellers.

• 천문학회보
• /
• 제44권2호
• /
• pp.77.3-77.3
• /
• 2019

We present an analysis of the stellar population of compact elliptical galaxies (cEs) in various environments. Following conventional selection criteria of cEs, we created a list of cE candidates in the redshift range of z < 0.05 using SDSS DR12 catalog. We finally selected cEs with low-luminosity (Mg > 18.7 mag), small effective radius (Re < 600 pc), and high velocity dispersion (> 60 kms-1). We divide our cE sample into those inside and outside of the one virial radius of the bright (Mr < -21 mag) nearby host galaxy which is then defined as cEs with (cEw) and without (cEw/o) host galaxy, respectively. We investigated the stellar population properties of cEs based on the Hb, Mgb, Fe 5270, and Fe 5335 line strengths from the OSSY catalog. We found that cEw has a systematically higher metallicity than cEw/o. In the velocity dispersion-Mgb distribution, while cEw/o follows the relation of early-type galaxies, cEw are found to have a systematically higher metallicity than cEw/o at a given velocity dispersion. The different feature in the metallicity between cEw and cEw/o can suggest that two different scenarios can be provided in the formation of cEs. cEw would be the remnant cores of the massive progenitor galaxies that their outer parts have been tidally stripped by massive neighbor galaxies (i.e., nurture origin). On the other hand, cEw/o are likely to be faint-end of early-type galaxies maintaining in-situ evolution (i.e., nurture origin).