• Journal of the Korean Chemical Society
• /
• v.33 no.5
• /
• pp.484-495
• /
• 1989

Reactions of $(Et_4N)_2[MoOCl_5]$ with multidentate ligands containing nitrogen or/and oxygen donor atom (EDTA, DTPA, IDA, CyDTA, OX) produce a series of binuclear molybdate (V) complexes. The prepared Mo (V) complexes has been identified by Elemental Analysis, Infrared Spectra, Proton Magnetic Resonance Spectra, and Electronic Spectra. The electrochemical reduction mechanism has been studied by Cyclic voltammetry, Controlled Potential Coulometry, and Spectrophotometry in pH 3.571-10.375 acetate, borate, phosphate/sodium hydroxide, phosphate, ammonium/ammonia buffers. The cyclic voltammogram of the Mo-EDTA, DTPA, IDA, CyDTA complexes at pH < ca. 6.00 have shown two reduction waves. The first reduction wave shows two electron process and the second reduction wave shows two electron process. The cyclic voltammogram of the Mo-EDTA, DTPA, IDA, CyDTA complexes at pH < ca. 8.00 has shown one reduction wave. This reduction wave show four electron process. The cyclic voltammogram of the Mo-OX complex at pH < ca. 7.2 has shown one reduction wave. This reduction wave show four electron process.

• The Korea Journal of Herbology
• /
• v.26 no.4
• /
• pp.75-81
• /
• 2011

Objectives : Magnoliae officinalis Cortex (MOC) has been used in traditional medicine for digestive diseases in Korea, China and Japan. However, Machili thunbergii Cortex (MTC) also has been used as a substitute of MOC in Korea sometimes. Thus, this study was carried out to investigate and compare the effects of MOC and MTC on intestinal motility of isolated small intestinal segments from ICR mouse. Methods : Changes in motility were recorded via isometric transducers connected to a data acquisition system and amplitude, frequency and area under the curve (AUC) of intestinal spontaneous phasic contraction were compared. Results : The MOC extracts ($1{\sim}{\mu}g/mL$) dose-dependently decreased both amplitudes and frequencies of the spontaneous phasic contraction, but not AUC. However, high concentration of MOC (100 ${\mu}g$/mL) evoked tonic contraction. And it was not inhibited by tetrodotoxin, a sodium channel blocker, and nifedipine, a L-type $Ca^{2+}$ channel antagonist. These results suggested that MOC (100 ${\mu}g$/mL)-induced tonic contraction is not mediated by nerve or L-type $Ca^{2+}$ channel. On the other hand, the MTC extracts dose-dependently inhibited amplitude and AUC, but not the frequency. Conclusions : Although both MOC and MTC affected intestinal motility, MOC is more effective on intestinal motility than MTC. And MOC has been used as a traditional medicine for a long time but not MTC. Thus, we suggested that MTC should not be used in Korea as a substitute of MOC and MOC might be useful traditional medicine for gastrointestinal disease. The mechanism of MOC is still remained to elucidate.

• Applied Biological Chemistry
• /
• v.20 no.1
• /
• pp.26-32
• /
• 1977

The multiple 7S globulins composed of two fractions (A and B) in the electrophoresis with Davis' method were isolated at different stages of the soybean seed development. Electrophoresis of their subunits liberated in PAWU solvent [phenol-acetic acid-water (2 : 1 : 1) solution plus 5M urea] yielded 4 major bands. Observation of both the electrophoretic bands of the multiple 7S fractions(7S-A and 7S-B) and those of their subunits was suggestive of a similarity of the subunit pattern between two 7S fractions. The two fractions in multiple 7S globulins were isolated with DEAE-Sephadex A-50 column$(2.0{\sim}100cm)$ chromatography. They were separated into 2 fractions in a linear gradient concentration of 0.28 to 0.40M NaCl with phosphate buffer (pH 7.8) containing 10mM ${\beta}-mercaptoethanol$(ME). The isolated protein was dissociated into subunits with two different solvent systems; in PAWU solvent and in Tris-HCl buffer(pH 8.0) containing 1% sodium dodecyl sulfate (SDS) and 40mM ME. The dissociated subunits were subjected to electrophoresis in PAWU-treated 7.5% acrylamide gel and in 1% SDS-treated 5.6% acrylamide gel. In PAWU gel electrophoresis, total 7S globulin was separated into 5 major bands, two of which were occupied in common by two 7S fractions(7S-A and 7S-B). In SDS gel electrophoresis, total 7S globulin was separated into 7 major bands, three of which were overlapped with the subunit of the two 7S fractions. The above results alluded us to the presence of a common and/or similar subunit between the multiple 7S globulins.

• Clinical and Experimental Reproductive Medicine
• /
• v.25 no.2
• /
• pp.109-113
• /
• 1998

Objective: To ananlyze the direct effect of nitric oxide (NO), generated from sodium prusside (SNP) on the embryo developments in reproductive process. Design: Ova from mouse were treated to allow fertilization in in vitro culture. And the samples of fertilized ova were alloted into five alliqutos. Each alliquot was cultured in media treated with either concentration at 0 (n=92), $25{\mu}M$ (n=84), $50{\mu}M$ (n=80), $100{\mu}M$ (n=77), $500{\mu}M$ (n=54) of SNP. Main Outcome Measure: Rates of embryonal cell cleavages, viability and cell morphology were assessed during in vitro fertilization and culture. Results: As analyse the cell cleavage at 24 hours after in vitro culture of fertilised egg in variuos NO concentration, all of egg cells of each alliquot were developed to $2\sim4$ cell stage. But the alliquot of egg cells treated with $50{\mu}M$, which were totally degenerated. And also all embryonal cells of each alliquot were developed to 8 cell stage and morula stage on culture continuosly. And the embryonal cells of each alliquot were analysed at 24 and 48 hours following the in vitro culture. The rates of cell fragmentation and fusion were $4.2{\pm}3.4%$ in control group which is not treated with NO, while experimental groups was high, as rated $23.4{\pm}6.2%$ in $25{\mu}M$, $28.2{\pm}5.7%$ in $50{\mu}M$ and $32.1{\pm}6.4%$ in $100{\mu}M$ concentration of NO. Accordingly the rate of abnormal morphology of embryonal cell in control was lower significantly than that in each alliquot of experimental groups (p<0.05). And the degenerated rates of embryonal cells were 0% in control, $17.8{\pm}6.7%$ in $25{\mu}M$, $23.6{\pm}4.7%$ in $50{\mu}M$ and $26.8{\pm}11.2%$ in $100{\mu}M$ at 8 cells and morula on culture of 48 and 72 hours. On the examination of embryonal cells developed to blastocyst through in vitro culture, the rates of degenerated cells were $16.8{\pm}7.2%$ in control, $37.5{\pm}6.2%$ in $25{\mu}M$, $73.4{\pm}4.6%$ in $50{\mu}M$, 100% in $100{\mu}M$. Conclusion: This results suggeted that the NO in any concentrations is harmful on embryos in view of morphology as well as viability of cell, and the toxicity of NO on embryo is stronger at condition in higher concentration of NO.

• Clinical and Experimental Reproductive Medicine
• /
• v.23 no.3
• /
• pp.351-355
• /
• 1996

Objective: To analyze the direct effect of nitre oxide, generated from sodium nitroprusside, on sperm motility and reactive oxygen species. Design: Human sperm samples were treated to allow swim-up and washing. And the samples were devided into four aliquots. Each aliquot was incubated with either concentration at 0, 100nM, $10{\mu}M$, 1mM of nitroprusside. Intervention: Samples were measured chemiluminosence for reactive oxygen species of each aliquot with concentrations at 0, 100nM, $10{\mu}M$, 1mM of nitroprusside at allowing swim-up and washing of sperm. Main Outcome Measures: Percent motion parameters and viability were asse-ssed at 0, 3, 6, 12, 24 hours incubation. Results: The percent viablity was lower slightly in control group (50.2%) than that in sperm treated with 100nM of nitroprusside(57.5%) at 24 hours after incubation, while was reduced significantly in sperm with concentra-tion of $10{\mu}M(42.1%)$ and 1mM(21.3%)of nitroprusside at 6 hours after incubation. And the sperm treated with 1mM of nitroprusside was immotile totally at 6 hours after incubation. The straight line$(35.3{\pm}5.6%)$, the rapid forward$(37.2{\pm}6.4%)$ and the weak curvilinear velocity$(9.6{\pm}2.4%)$were more favorable comparing with those ($32.4{\pm}4.2%$, $30.0{\pm}7.8%$ and $18.0{\pm}4.6%$ respectively) in control group at 3 hours after incubation, but reduced significantly in sperm treated with $10{\mu}M$ and 1mM of nitroprusside. The levels of reactive oxygen species in control(700 c.p.m.) is lower significantly than that in each experimental groups of sperm treated with nitroprusside. And the levels of reactive oxygen species were 2200 c.p.m. in 100nM, 6200c.p.m. in $1{\mu}M$ and 12800c.p.m. in 1mM respectively. Conclusion: These results suggested that the concentration of 100nM of nitroprusside on sperm is beneficial to the maintanance of viablity and motile velocity, but detriment in high concentration of $10{\mu}M$ or 1mM of nitroprusside.

• Nuclear Engineering and Technology
• /
• v.47 no.3
• /
• pp.240-252
• /
• 2015

In the original licensing application for the prototype fast-breeder reactor, MONJU, the event progression during an unprotected loss of flow (ULOF), which is one of the technically inconceivable events postulated beyond design basis, was evaluated. Through this evaluation, it was confirmed that radiological consequences could be suitably limited even if mechanical energy was released. Following the Fukushima-Daiichi accident, a new nuclear safety regulation has become effective in Japan. The conformity of MONJU to this new regulation should hence be investigated. The objectives of the present study are to conduct a preliminary evaluation of ULOF for MONJU, reflecting the knowledge obtained after the original licensing application through CABRI experiments and EAGLE projects, and to gain the prospect of in-vessel retention for the conformity of MONJU to the new regulation. The preliminary evaluation in the present study showed that no significant mechanical energy release would take place, and that thermal failure of the reactor vessel could be avoided by the stable cooling of disrupted-core materials. This result suggests that the prospect of in-vessel retention against ULOF, which lies within the bounds of the original licensing evaluation and conforms to the new nuclear safety regulation, will be gained.

• Korean Journal of Optics and Photonics
• /
• v.8 no.1
• /
• pp.31-36
• /
• 1997

We measured refractive indices and thicknesses of SiO$_2$ thin films that have been plated on LCD glass substrate for the purpose of preventing the out-diffusion of sodium ions. The best experimental condition to determine refractive index and thickness of SiO$_2$ thin film by using ellipsometry is searched for, where ⅰ) the film thickness is increased uniformly by 20 $\AA$ from 0 $\AA$ to the period thickness while the angle of incidence is fixed and ⅱ) the angle of incidence is increased uniformly by 1$^{\circ}$ from 45$^{\circ}$ to 70$^{\circ}$ while the film thickness is fixed. We estimated the errors in determining the refractive index and thickness by comparing the measurement error of $\Delta$ and Ψ with the calculated one. The ellipsometric constants of SiO$_2$ thin film on LCD glass substrate are measured at several angle of incidence around the Brewster angle, which is the best angle if the experimental error of ellipsometer is not sensitive to the incident angle. Also the best fit refractive index and thickness of SiO$_2$ thin film to these ellipsometric constants measured at several angle of incidenc eas well as the best fit ones to the SE data are obtained using regressional analysis.

• Geophysics and Geophysical Exploration
• /
• v.12 no.1
• /
• pp.163-171
• /
• 2009

Subcritical crack growth is one of the main causes of time-dependent fracturing in rock. In the present study, we investigated subcritical crack growth in rock in distilled water (pH = 5.7) and in an aqueous solution of sodium hydroxide (NaOHaq, pH = 12), comparing the results to those in air. We also investigated the effect of the pH in an aqueous environment. We used andesite and granite for all our tests. We determined the relationship between the crack velocity and the stress intensity factor using the double-torsion test under conditions of controlled temperature. We showed that crack velocities in water were higher than those in air, in agreement with other research results indicating that crack velocity increases in water. When we compared our results for NaOHaq with those for water, however, we found that the crack velocity at the same stress intensity factor did not change even though the pH of the surrounding environment was different. This result does not agree with the accepted understanding that hydroxide ions accelerate subcritical crack growth in rocks. We concluded that the pH at the crack tip influences subcritical crack growth, and not the bulk pH, which has little effect.

• Journal of Plant Biology
• /
• v.2 no.1
• /
• pp.1-12
• /
• 1959

1) The comparative studies of the quantitative measurement of growth characteristics and utilization of substrates by Euglena gracilis var. bacilla 10616 in the light and in darkness have been carried out. Eodogenous respiration, effect of respiratory inhibitors and responses to the added substrates for the exogenous respiration are also investigated. 2) All cultures are grown in the open air under the continuous illumination of fluorescent light of 3500 lux at room termperature, the growth rate of the culture in the basal medium added 0.5% lactate is found to be the highest. The growth rate decreases successively for the cultures of 0.5% sucinate, 0.5% Na-acetate, 0.5% malate, and control. There is no growth in the basal meidum added 0.5% butyrate and 0.5% hydroquinone. The similar results are obtained for the mentioned cultures in the darkness. However, the growth rate in basal medium added 0.5% glucose and 0.5% sucrose does seem to increase in the darkness unlike the illumination. 3) The endogenous rate of respiration for the organism cultured photosynthetically is about 12.94ul 02/mg/hr, in basal medium and the respiratory quotient is about 0.84. The rate is decreased by starvations to 6.5ul 02/mg/hr, about to a half, but the respiratory quotient does net change. 4) The oxygen consomption during initial 2 hours in suspending solution ranging from pH 4.5 to pH 9.3 is highest at pH 4.5 in which the algae had grown, at pH 5.5 and at pH 6.9. 5) Endogenous respiration of the cells is strongly inhibited by 0.1M of potassium cyanide, malomic acid, sodium fluoride and iodo-acetic acid. It is also strongly inhibited by 0.01M of potassium cyanide. 6) The respiratory response to added substrates for the exogenous respiration in the organism is coincided with the rate in the basal medium added the substrate in light and in darkness, whether the cells are fed or starved. 7) According to the results of this study, there seems to be the flexibility of the interconversion between photosynthesis and chemosynthesis, heterotropic mode of metabolism, in Euglena gracilis var. bacillaris, and that this organism utilizes the lactate most. It also may be suggested that the enayme systems linked in the each steps of Embden-Myerhof-Parnas path way and TCA cycle seem to exist in this organism.

• Food Science and Preservation
• /
• v.19 no.5
• /
• pp.727-734
• /
• 2012

For developing calcium supplement from the harmful marine organism starfish, the physiochemical property of the powdered starfish skeletal plate and the hydrolysis condition of the starfish digestive enzyme were studied. The optimal hydrolysis condition of the starfish digestive enzymes was at $55^{\circ}C$ for 12 h. The bulk densities of the powdered starfish skeletal plates of Asterias amurensis and Asterina pectinifera were $1.1{\pm}0.0$ and $1.2{\pm}0.0g/cm^3$, respectively. As for the median size, the values were 10.738 and $11.799{\mu}m$, respectively. According to the added concentration of sodium polyacrylate, the dispersibility rate of the powdered starfish skeletal plate was shown to be 6h at 0.0%, 3 days at 0.1%, 20 days at 0.2%, and until 30 days at 0.4%. The elementary composition of the powdered starfish skeletal plates from A. amurensis and A. pectinifera mainly consisted of calcium, and it formed 98.95 and 98.52% of the powdered starfish skeletal plates, respectively. The results of the X-ray diffraction (XRD) analysis showed that they were present in the form of $CaCO_3$. Based on these results, it is suggested that starfish skeletal plate can be utilized as a functional material for a calcium supplement.