• Nuclear Engineering and Technology
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• 제48권5호
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• pp.1120-1125
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• 2016

The neutron decay constant, ${\alpha}$, and effective delayed neutron fraction, ${\beta}_{eff}$, are important parameters for the control of the dynamic behavior of nuclear reactors. For the heavy water zero power reactor (HWZPR), this document describes the measurements of the neutron decay constant by noise analysis methods, including variance to mean (VTM) ratio and endogenous pulse source (EPS) methods. The measured ${\alpha}$ is successively used to determine the experimental value of the effective delayed neutron fraction as well. According to the experimental results, ${\beta}_{eff}$ of the HWZPR reactor under study is equal to 7.84e-3. This value is finally used to validate the calculation of the effective delayed neutron fraction by the Monte Carlo methods that are discussed in the document. Using the Monte Carlo N-Particle (MCNP)-4C code, a ${\beta}_{eff}$ value of 7.58e-3 was obtained for the reactor under study. Thus, the relative difference between the ${\beta}_{eff}$ values determined experimentally and by Monte Carlo methods was estimated to be < 4%.

• Journal of Korean Biological Nursing Science
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• 제10권1호
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• pp.80-87
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• 2008

Purpose: Hypoestrogenism caused by ovariectomy, disease, or menopause is associated with increased obesity in women. Altered fat distribution and weight gain are consequences of menopausal hypoestrogenism, but the mechanisms responsible are not completely known. This study examined the effect of estrogen on obesity in ovariectomized rats. Method: The groups of female rats were 4 weeks post ovariectomy (OVX) or, 4 weeks post-sham operation (SHAM), and 2 weeks post ovariectomy followed by 2 weeks replacement with estradiol benzoate (ER-$16{\mu}g$/kg, subq, qd). Serum ghrelin level was measured by radioimmunoassay (RIA). The expression of adrenergic receptors in adipose tissue was measured by Western blotting assay. Result: OVX significantly increased body weight, serum cholesterol. Two weeks estrogen replacement reduced body weight accompanied by the increment of serum ghrelin and the reduction of the receptor ratio of adrenergic ${\alpha}_{2A}/{\beta}_1$, and ${\alpha}_{2A}/{\beta}_3$. Conclusion: We provide evidence that estrogen reduces obesity through the altered receptor ratio of adrenergic ${\alpha}_{2A}/{\beta}_1$, and ${\alpha}_{2A}/{\beta}_3$ in adipose tissue in ovariectomized rats.

• 한국세라믹학회지
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• 제53권6호
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• pp.670-675
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• 2016

Calcium phosphate crystallites were prepared by wet chemical method for use in artificial bone. In order to obtain ${\beta}$-tricalcium phosphate (TCP), nano-crystalline calcium phosphate (CaP) was precipitated at $37^{\circ}C$ and at $pH5.0{\pm}0.1$ under stirring using highly active $Ca(OH)_2$ in DI water and an aqueous solution of $H_3PO_4$. The precipitated nano-crystalline CaP solution was kept at $90^{\circ}C$ for the growth of CaP crystallites. Through the growing process of CaP crystallites, we were able to obtain various sizes of rectangular CaP crystallites according to the crystal growing times. Dry nano-crystalline CaP powders at $37^{\circ}C$ were mixed with dry macro-crystalline CaP crystallites and the shaped mixture sample was fired at $1150^{\circ}C$ to make a ${\beta}-TCP$ block. Several tens of nm powders were uniformly coated on the surface, which was comprised of powders of several tens of ${\mu}m$, using a vibrator. The mixing ratio between the nanometer powders and the micrometer powders greatly affected the mechanical strength of the mixture block; the most appropriate ratio of these two materials was 50 wt% to 50 wt%. The sintered block showed improved mechanical strength, which was caused by the solid state interaction between the nano-crystalline ${\beta}-TCP$ and the macro-crystalline ${\beta}-TCP$.

• Journal of Pharmaceutical Investigation
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• 제13권1호
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• pp.10-22
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• 1983

The interactions of ${\alpha}-cyclodextrin({\alpha}-CyD)$ and ${\beta}-cyclodextrin({\beta}-CyD)$ with several non-steroidal antiinflammatory drugs were studied on the effects of ${\alpha}-$ and ${\beta}-CyD$ on the solubility of the drugs in aqueous medium. Indoprofen, niflumic acid, alclofenac, and naproxen were chosen as representatives of antiinflammatory drugs. The solubility of all drugs studied increased with the addition of ${\beta}-CyD$, while not with glucose or ${\alpha}-CyD$. The increase of the solubility with ${\beta}-CyD$ was considered due mainly to the formation of inclusion complexes between ${\beta}-CyD$ and drugs. From the solubility data, the apparent stability constants K of the complex could be calculated. Ultraviolet absorption and circular dichroism confirmed the inclusion of indoprofen, niflumic acid and naproxen with ${\beta}-CyD$ in the molar ratio of 1 : 1. Inclusion complexes in solid powder form were obtained by the freeze-drying method and the inclusion formation was confirmed again by infrared, diffential thermal analysis, and X-ray diffraction measurements.

• Journal of Pharmaceutical Investigation
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• 제18권1호
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• pp.15-21
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• 1988

An inclusion complex of phenytoin (PT) with ${\beta}-cyclodextrin\;({\beta}-CyD)$ in molar ratio of 1 : 1 was prepared, and the interaction between host and guest molecules was confirmed by infrared spectrometry, differential scanning calorimetry and X-ray diffractometry. Suppositories were prepared by the fusion method. PT and $PT-{\beta}-CyD$ complex were added to PEG 1540 and Witepsol H-15 under the vigorous stirring at $40^{\circ}C$. Content uniformity was tested for different formulations of the PT suppositories. The release rates were dependent on the K.P. V dissolution apparatus and the dialyzing tubing method. Then, the release rates were increased in the following order: $PT-{\beta}-CyD$ complex in PEG 1540>PT in PEG 1540>$PT-{\beta}-CyD$ complex in Witepsol H-15>PT in Witepsol H-15. The area under the curve and maximum blood concentration after rectal administration were increased in the following order: $PT-{\beta}-CyD$ complex in PEG 1540>PT in PEG 1540>$PT-{\beta}-CyD$ complex in Witepsol H-15>PT in Witepsol-15.

• 한국미생물·생명공학회지
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• 제19권5호
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• pp.444-449
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• 1991

Pullulanase의 역반응능을 이용하여 maltose와 $\beta$-cyclodextrin으로부터 maltosyl-$\beta$-cyclodextrin을 중합합성하기 위한 최적효소반응조건을 검토하였다. Maltose와 $\beta$-CD를 기질로 maltosyl-$\beta$-CD을 합성하였을 경우, 기질의 농도 70( w/w, 70g/100ml $H2_O$ ), malto-loigo당 /$\beta$-CD의 혼합비 12.7, 그리고 사용효소량 350 units/100ml일 때 최대전융인 43(w/w, g branched-CD/g CD)를 얻었고, 생성량은 2.31g/100ml였다. Maltosyl-$\beta$-CD의 효소합성의 적정 pH 및 온도는 각각 4.9와 $60^{\circ}C$ 였다. 또한 maltose와 $\alpha ,\beta$-그리고 $\gamma$-CD 각각을 기질로하여 maltosyl $\Alpha, \beta$ 그리고 $\gamma$-CD를 합성하였을 경우 전환율은 51.8, 42.6, 그리고 48.1로써, 생성량은 각각 2.8, 2.3 그리고 2.6g/100ml였다.

• 폴리머
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• 제31권3호
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• pp.206-214
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• 2007

3차원적 타원체 형태 ($a_1>a_2>a_3$)를 사용하여, 2가지의 종횡비 (1차 종횡비 $\rho_{\alpha}$와 2차 종횡비 $\rho_{\beta}$)를 갖는 배열된 3차원 형태의 충전제를 포함하는 복합체의 열팽창 변화를 이론적으로 예측하는 모델을 연구하였다. Eshelby의 등가 텐서를 이용하여 배열된 타원형 충전제를 기지재의 이론에 의해 열팽창 계수를 예측할 수 있었다. 종단방향 열팽창 계수 ${\alpha}_{11}$는 두 가지 종횡비 모두 증가하면, 감소하여 충전제의 열팽창에 접근한다. 수직방향 열팽창 계수 ${\alpha}_{33}$는 충전제 함유량에 따라 초기에는 증가하여 최대값을 갖는 경향을 보인다. 1차 종횡비 $\rho_{\alpha}$가 증가하면, 횡단방향 열팽창 계수는 감소하나, 2차 종횡비 $\rho_{\beta}$가 증가하면, 같이 증가한다. 또한, 수직방향 열팽창 계수 ${\alpha}_{33}$는 $\rho_{\alpha}$가 증가하면 증가하나, $\rho_{\beta}$가 증가하면, ${\alpha}_{33}$는 반대로 감소한다.

• 한방재활의학과학회지
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• 제20권3호
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• pp.27-35
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• 2010

Objectives : The present study investigated anti-inflammatory effect of Artemisia Capilaris Thunberg in lipopolysaccharide-exposed rats. Methods : We divided lipopolysaccharide-exposed Sprague-Dawley rats into 4 groups. They were normal group, feed with 100 mg/kg Artemisia Capillaris Thunberg group, feed with 200 mg/kg Artemisia Capillaris Thunberg group and feed with 300 mg/kg Artemisia capilaris Thunberg group. They were administered for 6 weeks. We measured counts of red blood cell(RBC), the values of hemoglobin(Hb) and packed cell volume(PCV), plasma total protein concentration, albumin concentration, the ratio of albumin/globulin, the activities of plasma glutamic oxaloacetic transaminase(GOT), glutamic pyruvic transaminase(GPT), lactate dehydrogenase(LDH), the counts of white blood cell(WBC), the ratio of neutrophils, lymphocytes, monocytes, basophils, eosinophils, the concentration of plasma interleukin-$1{\beta}$($IL-1{\beta}$), plasma interleukin-6(IL-6), plasma tumor necrosis factor-$\alpha$($TNF-{\alpha}$), plasma interleukin-10(IL-10), the concentration of liver $IL-1{\beta}$ and IL-6, $TNF-{\alpha}$, IL-10. Results : Counts of RBC and the values of Hb and PCV, plasma total protein concentration and albumin concentration, the activities of plasma GOT, GPT and LDH showed no significant difference in the treatment groups. and the ratio of albumin/globulin was increased in Artemisia Capillaris Thunberg groups. The counts of WBC showed lower values in Artemisia Capillaris Thunberg groups than those of control group, In the ratio of neutrophils Thunberg groups. The ration of monocytes, basophils and eosinophils were below 5%, and showed no characteristic trend. The concentration of plasma interleukin-$1{\beta}$($IL-1{\beta}$), plasma inerleukin-6(IL-6) and plasma tumor necrosis factor-$\alpha$($TNF-{\alpha}$) showed a lower values in the Artemisia Capillaris Thunberg groups than those of control group, and the concentration of plasma interleukin-10(IL-10) showed no significant difference in the treatment groups. The concentration of liver $IL-1{\beta}$ and IL-6 showed a lower values in the Artemisia Capillaris Thunberg groups than those of control group, however the concentration of liver $TNF-{\alpha}$ and IL-10 showed no significant difference in the treatment groups. Conclusions : The Artemisia Capillaris Thunberg groups gives positive results of anti-inflammatory response by lipopolysaccharide(LPS) derivation.

• 한국세라믹학회지
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• 제30권2호
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• pp.85-92
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• 1993

Oxynitride glasses in Na-Ca-Si-O-N system were prepared by melting at 135$0^{\circ}C$ for 2 hours in N2 gas. The effects of Si/Na mole ratio and the various Si3N4 contents were investigated. Stable oxynitride glasses can be obtained up to 9wt.% Si3N4 content in case the Si/Na mole ratio was 2.12 and 1.62, but $\beta$-Si3N4 was precipitated at 9wt.% Si3N4 content in case the Si/Na mole rtio was 1.12. Density (p), chemical durability, hardness (Hv), and fracture toughness (KIC) increased with increasing Si3N4 content. In cae the Si/Na mole ratio was 1.12, the increment of properties was remarkable but hardness and fracture toughness did not increase no longer owing to precipitation of $\beta$-Si3N4.

• Journal of Pharmaceutical Investigation
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• 제28권1호
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• pp.15-23
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• 1998

Extract of Centella asiatica(ECA), which is poorly water-soluble extract from the Centella asiatica is known to express excellent wound healing properties. $ECA-{\beta}-cyclodextrin$ $(asiaticoside-{\beta}-cyclodextrin\;and\;genin-{\beta}-cyc1odextrin)$ solid dispersion system, which was prepared by freezedrying method, was formulated as gels containing poloxamer 407 and propylene glycol, and evaluated with respect to their viscosity, stability, skin permeation and drug amount in the skin of hairless mouse. The average molar ratio $asiaticoside-{\beta}-CD$ and $genin-{\beta}-CD$ was 1:1.7 and 1:22, respectively. When the molar ratio of genin and ${\beta}-CD$ was 1:5, madecassic acid made 100% solid dispersion system and asiatic acid about 65%. In dissolution study, >99% of asiaticoside from $asiaticoside-{\beta}-CD$ was dissolved in 5 minutes, and >99% madecassic acid and >64% asiatic acid from $genin-{\beta}-CD$. The apparent viscosity of poloxamer 407 gels with $ECA-{\beta}-CD$ solid dispersion system increased in proportion to poloxamer 407 and propylene glycol concentration. In the accelerated stability test, all $ECA-{\beta}-CD$ poloxamer 407 gels showed that asiaticoside was most stable and madecassic acid stable and asiatic acid similar to stability of gel with free ECA. The permeation amount of asiaticoside in poloxamer gels through hairless mouse skin decreased as the concentration of poloxamer 407 increased. When propylene glycol was added at the level of 10%, the permeation amount of asiaticoside at poloxamer gels through hairless mouse skin increased but from 15% it decreased. The permeation of asiaticoside into the skin of hairless mouse was estimated to be about $0.10\;{\mu}g/cm^2$.