• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.1-7
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• 2003

The phase transformation from cellulose I into cellulose II in woods by way of Na-cellulose I was examined by x-ray diffraction analysis.The formation of Na-cellulose I in woods increased with the increase of treating time in alkali solution. When compression wood was treated with 20% NaOH solution at room temperature for 1 day, the x-ray diagram showed only Na-cellulose I. On the other hand, the x-ray diagram of tension wood showed a mixture of cellulose I and Na-cellulose I. Cellulose I of tension wood could not be transformed completely into Na-cellulose I even after 10-day treatment, but was transformed into Na-cellulose I after 30-day treatment. Na-cellulose I of compression and tension woods was converted to the cellulose I pattern and the mixture of cellulose I and cellulose II, respectively, after washing with water and drying at 20℃. Cellulose I regenerated from Na-cellulose I in wood could not be converted to cellulose II by delignification. Thus, it revealed that the delignification of the alkali-treated wood did not affect their cellulose structures. From the results, therefore, it can be concluded that lignin in woods prevents the formation of the stable Na-cellulose I and the conversion from cellulose I to cellulose II. This means that the conversion of chain polarity of wood cellulose hardly occurs during mercerization because cellulose microfibrils are fixed by lignin which not to be intermingled.

• 대한수의학회지
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• 제35권2호
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• pp.229-236
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• 1995

The effect of ${\alpha}_1$-adrenoceptor(${\alpha}_1$-AR) stimulation on intracellular pH($pH_i$), $Na^+$ activity($a_{Na}{^i}$) and contractility were investigated in isolated papillary muscles of euthyroid or hyperthyroid guinea pig with conventional microelectrode, $Na^+$ or $H^+$-selective microelectrodes, and tension transducer. Stimulation of the ${\alpha}_1$-AR by phenylephrine produced a decrease in $a_{Na}{^i}$ in euthyroid preparations. This decrease in $a_{Na}{^i}$ was abolished in presence of PKC activator, phorbol dibutyrate, and increased contrary to decrease. Phenylephrine also increased $a_{Na}{^i}$ in hyperthyroid ones. However, phenylrephtine produced an increase in $pH_i$ in both euthyroid and hyperthyroid ones. These changes were blocked by prazosin, an antagonist of ${\alpha}_1$-AR. These findings suggest that the changes in $a_{Na}{^i}$ and $pH_i$ are mediated by a stimulation of $Na^+-H^+$ exchange via ${\alpha}_1$-AR stimulation. This study focused on the increase in $a_{Na}{^i}$, $pH_i$ and contractility. The increase in $pH_i$ was blocked by amiloride or EIPA, $Na^+-H^+$ exchange inhibitors. Therefore, the increase in $a_{Na}{^i}$ and $pH_i$ mediated by ${\alpha}_1$-AR appeared to be due to an influx of $Na^+$ and a reduction of $H^+$ through $Na^+-H^+$ exchange. This study also revealed that the increase in $pH_i$ and $a_{Na}{^i}$ might be related to the sustained positive inotropic response. The $a_{Na}{^i}$ increase may contribute to the intracellular $Ca^{2+}$ through the $Na^+-Ca^{2+}$ exchange, and the $pH_i$ increase could cause an increase in the $Ca^{2+}$ sensitivity of myofilaments and may augment the ${\alpha}_1$-AR-mediated positive inotropic response.

• Journal of the Korean Wood Science and Technology
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• 제27권1호
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• pp.18-23
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• 1999

3회축을 갖는 Na-cellulose II의 형성조건을 X선회절법을 이용하여 검토하였다. 그 결과 Na-cellulose II는 Na-cellulose I 을 거쳐서 형성되며 결정중의 알칼리농도가 Na-cellulose I 이나 III보다 높은 조건에서 형성되는 것으로 생각되었다. 2회축에서 3회축으로의 섬유주기의 급격한 변화는 알칼리 처리 후의 수분제거방법에 의해 크게 영향받는 것으로 생각되었다. 동(銅)-알칼리셀룰로오스 복합체의 결정은 팽윤상태에서 안정된 구조를 가지며 건조에 의해 결정구조가 변화되었다.

• Bulletin of the Korean Chemical Society
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• 제16권3호
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• pp.265-269
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• 1995

Complexation of ortho-xylyl-17-crown-5 (X17C5) with alkali metal ions in acetonitrile was studied by 7Li and 23Na NMR spectroscopy. The complex formation constants of X17C5 with LiI, LiSCN, NaI, and NaSCN were determined by investigating the changes in the chemical shifts as a function of the concentration ratio of X17C5 to metal ion. It was found that X17C5 forms 1:1 complex with Li+ and Na+ ions and the log Kf's for the complexation with LiI, LiSCN, NaI, and NaSCN were determined to be 2.88, 2.43, 2.53, and 2.30, respectively. In particular, the kinetics of complexation of X17C5 with Na+ was investigated by the method of 23Na NMR lineshape analysis. Activation energies were determined from Arrhenius plot of the resultant rate constant data to be 25.4 kJ/mol for NaI and 15.1 kJ/mol for NaSCN. Other kinetic parameters were also calculated by employing the Eyring equation. The decomplexation rates measured were 1.82 × 104 M-1s-1 for NaI and 1.50 × 104 M-1s-1 for NaSCN. It is concluded that the decomplexation mechanism is predominantly a bimolecular cation exchange for both cases.

• 대한화학회지
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• 제36권1호
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• pp.107-112
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• 1992

rose bengal(RB)과 NaI를 각각 감응제 및 초감응제로 사용하여 광전기 화학쎌 ITO/$SnO_2$/RB, NaI, $NaClO_4$/Pt로부터 얻은 광전류는 광조사시간의 경과에 따라 비교적 서서히 감소하였다. RB 염료 용액을 광조사하여 분광학적인 방법으로 분석한 결과, 들뜬 RB 분자는 분자내에 있는 요오드에 의해 삼중항 상태, $^3RB^*$로 바뀌고 iodide를 산화시킨 후 환원된 상태가 되어 $SnO_2$ 반도체에 전자를 주입하는 것으로 확인되었다. NaI 대신 $I_2$가 포함되면 $^3RB^*$ 상태에서 전자를 주입하고 염료는 빠르게 분해되므로 광전류는 급격히 감소하였다.

• Journal of the Korean Wood Science and Technology
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• 제24권3호
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• pp.72-79
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• 1996

Cellulose I에서 Cellulose II로의 결정변태기구를 X선 및 전자선 회절법과 현미경적 방법을 이용하여 구명하였다. X선 회절 결과, Na-cellulose I을 고온에서 수세할 경우 Cellulose I과 Cellulose II의 혼합형 회절도가, 저온에서 수세할 경우 Na-cellulose IV의 회절도가 얻어졌다. 전자선회절 결과, 고온수세의 시료는 Cellulose I과 Cellulose II의 혼합형이 저온수세의 시료는 Cellulose II의 회절도가 얻어졌다. 또한 고온수세 시료의 전자선회절도로부터 섬유벽의 내측부가 외측부보다 재생 Cellulose I의 양이 많은 것이 확인되었다. 따라서 알칼리 팽윤시 섬유벽내에는 불완전한 팽윤이 발생하는데 그 정도는 내측부가 더욱 심한 것으로 생각된다. 이때 형성되는 불완전한 Na-cellulose I 은 고온 수세의 경우는 탈수에 의해 Cellulose I로, 저온수세의 경우는 수화에 의해 Cellulose II로 변태되지만 완전히 팽윤된 Na-cellulose I은 Cellulose I로 재생될 수 없는 것으로 생각된다. 현미경적 실험결과, mercerization과정에서 cellulose 분자쇄의 packing이나 conformation의 변화와 관련하여 microfibril 의 흐트러짐은 발생하지 않는 것으로 생각되었다.

• Biomolecules & Therapeutics
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• 제10권4호
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• pp.230-235
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• 2002

Gold sodium thiomalate (GST, gold compound) is a widely used anti-arthritic, anti-rheumatic and anti-inflammatory drug that is considered a good alternative to sodium salicylate (NaSA) for individuals who cannot tolerate salicylates. Nitric oxide (NO) synthesized by inducible nitric oxide synthase (iNOS) has been implicated as a mediator of inflammation. Recent evidence suggests that anti-inflammatory effect of NaSA lies in the inhibition of iNOS, but nothing has been reported about the direct effect of iNOS expression by GST. The present study was designed to elucidate sequentially the action mechanisms of GST and NaSA on lipopolysaccharide (LPS) plus interferon-gamma (IFN-$\gamma$) induced iNOS expression in RAW 264.7 macrophages. Both GST and NaSA inhibited NO production and iNOS protein expression in a dose dependent manner. GST inhibited iNOS mRNA expression induced by LPS plus IFN-$\gamma$, whereas NaSA did not. These findings suggest that GST may exert anti-arthritic, anti-rheumatic and anti-inflammatory effect by inhibiting iNOS expression induced by LPS plus IFN-$\gamma$ at transcriptional level, whereas NaSA exert its effect by inhibiting iNOS expression at the translational or posttranslational level.

• 한국세라믹학회지
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• 제21권3호
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• pp.217-220
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• 1984

The leaching of Na-fluor-tetrasilicic mica $NaMg_{2.5}(Si_4O_{10})F_2$ (Na-TSM) in the deionized water was investigated by measuring the pH released Na and Mg contents in the suspension. According to the results it was found that $Na^+$ ions of interlayer in the Na-TSM were easily replaced by $H^+$ ions from the deionized water because $Na^+$ ions of I were repidly diffused to form a large hydrated electric double layer in the suspension.

• The Korean Journal of Physiology and Pharmacology
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• 제3권5호
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• pp.529-538
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• 1999

This study was undertaken to examine the effect of ethanol on $Na^+ -dependent$ phosphate $(Na^+-P_i)$ uptake in opossum kidney (OK) cells, an established renal proximal tubular cell line. Ethanol inhibited ^Na^+-dependent$ component of phosphate uptake in a dose-dependent manner with $I_{50}$ of 8.4%, but it did not affect $Na^+-independent$ component. Similarly, ethanol inhibited $Na^+-dependent$ uptakes of glucose and amino acids (AIB, glycine, alanine, and leucine). Microsomal $Na^+-K^+-ATPase$ activity was not significantly altered when cells were treated with 8% ethanol. Kinetic analysis showed that ethanol increased $K_m$ without a change in $V_{max}$ of $Na^+-P_i$ uptake. Inhibitory effect of n-alcohols on $Na^+-P_i$ uptake was dependent on the length of the hydrocarbon chain, and it resulted from the binding of one molecule of alcohol, as indicated by the Hill coefficient (n) of 0.8-1.04. Catalase significantly prevented the inhibition, but superoxide dismutase and hydroxyl radical scavengers did not alter the ethanol effect. A potent antioxidant DPPD and iron chelators did not prevent the inhibition. Pyrazole, an inhibitor of alcohol dehydrogenase, did not attenuate ethanol-induced inhibition of $Na^+-P_i$ uptake, but it prevented ethanol-induced cell death. These results suggest that ethanol may inhibit $Na^+-P_i$ uptake through a direct action on the carrier protein, although the transport system is affected by alterations in the lipid environment of the membrane.

• Nuclear Engineering and Technology
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• 제3권3호
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• pp.141-147
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• 1971

Tetrachloro-p-tetraiodo-R-Fluorescein 및 sodium orthoiodohippurate등 요오드화 합물과 요오드화합물이 아닌 human serum Albumin을 요오드 표지함에 있어서 표지속도와 수율등을 비교 검토하였다. 위의 각각의 화합물들을 여러가지 다른 조건하에 있는 $Na^{131}$ I, 즉, 환원제를 함유한것, 환원제를 함유하지 않으며 거의 순수하게 131 I$^{-}$형으로 있는것, 및 환원제를 함유하지 않으며 상당량이 131 IO$_3$$^{-}$형으로 있는것 등을 써서 표지 반응시켰다. 환원제인 $Na_2$S$_2$O$_3$를 함유한 $Na^{131}$ I를 쓰는 경우는 위의 세가지 화합물들의 표지수율이 10% 내외로 매우 저조하였으며 환원제는 없지만 상당량이 $Na^{131}$ I$^{-}$로 존재하는 $Na^{131}$ I를 쓰는 경우도 50~60%의 낮은 수율이었다. 환원제가 없으며 대부분 $Na^{131}$ I$^{-}$로 존재하는 $Na^{131}$ I를 쓰는 경우에만 70~90%의 높은 표지수율을 보였다. 이들 반응에 관여하는 중간체에 대해서도 토의하였다.