• Biomolecules & Therapeutics
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• v.32 no.4
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• pp.474-480
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• 2024

Streptomyces avermitilis genome includes 33 genes encoding monooxygenation-catalyzing cytochrome P450 enzymes. We investigated the structure of CYP107P2 and its interactions with terpenoid compounds. The recombinant CYP107P2 protein was expressed in Escherichia coli and the purified enzyme exhibited a typical P450 spectrum upon CO-binding in its reduced state. Type-I substrate-binding spectral titrations were observed with various terpenoid compounds, including α-pinene, β-pinene, α-terpinyl acetate, and (+)-3-carene. The calculated binding affinities (Kd) ranged from 15.9 to 50.8 µM. The X-ray crystal structure of CYP107P2 was determined at 1.99 Å resolution, with a well-conserved overall P450 folding conformation. The terpenoid compound docking models illustrated that the structural interaction between monoterpenes and CYP107P2, with the distance between heme and terpenes ranging from 3.4 to 5.4 Å, indicates potential substrate binding for P450 enzyme. This study suggests that CYP107P2 is a Streptomyces P450 enzyme capable of catalyzing terpenes as substrates, signifying noteworthy advancements in comprehending a novel P450 enzyme's involvement in terpene reactions.

• Journal of Microbiology
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• v.39 no.2
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• pp.126-132
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• 2001

For rapid and secure differentiation of P. infestans from other Phytophthora species, two fragments obtained from randomly amplified polymorphic DNA (RAPD) profiles were selected as markers. Also, primers for in polymerase chain reaction (PCR) to detect P. infestans specifically were developed by analyzing the sequences of ITSII regions in rDNA of Phytophthora species. The primers, PISP-1 and ITS3 amplified a single. Fragment 450 bp of about in P. infestans, but not in other fungal or bacterial isolates. Annealing temperatures and template DNA quantities were varied for the optimization of PCR conditions. From the result of the PCR detection study, species-specific primers were selected under annealing temperatures ranging from 55$^{\circ}C$ to 61$^{\circ}C$, and template DNA levels ranging from 10 pg to 100 ng.

• The Journal of the Korean dental association
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• v.9 no.12
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• pp.841-845
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• 1971

Author has made the studies on the pH of pus in the 53 suppurative disesed patients who had admitted to department of ora surgery, Infirmary of Schoo of Dentistry, Seoul National University. The results were obtained as follows; 1. The average pH of pus in the patients with suppurative oral diseases was 6.46 and the pH of pus was ranging 5.0 to 7.2. 2. The pH value of pus was not significant between the males(pH: 6.58) and females (pH: 6.40). 3. The pH vaule of pus in patients treated by antibiotics trend to slightly alkaline than that of untreated patients. 4.The pH vaule of pus in the pericoronitis, periodontal abscess and other localized oral infections were slightly alkaline than buccal abscess and osteomyelitis, and acute suppurative diseases of jaws was more acid than chronic diseases. In general, it was seemed the early stages of inflammation was alkaline, and the later stages was acid.

• Journal of Preventive Medicine and Public Health
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• v.15 no.1
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• pp.75-82
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• 1982

Normal range of mercury contents in blood and its relationship with urinary mercury excretion were studies with 68 healthy male adults living in Seoul city, who had no obvious evidence of .either occupational exposure to mercury or therapeutic use of mercurial agents. Mercury analysis was made by means of dithizone colorimetric method with coefficient of variation of 10.9% in .an average ranging from 5.1% to 18.0%. 1. Mercury contents in normal human blood were both normally and log-normally distributed, and better fitted to the latter. 2. Geometric mean and standard deviation of the mercury contents were $24.0(log^{-1}1.38){\pm}1.66{\mu}g/100ml(log^{-1}0.22{\mu}g/100ml)$ ranging from 7.2 to 79.7 ${\mu}g/100ml$ with 95% confidence interval. 3. Mercury contents in normal human blood differed from person to person (p<0.01), and the variability of the measurements was negligible (p>0.05). 4. Mercury in the blood was contained much higher in erythrocytes than in plasma (p<0.01), showing the geometric means of $21.0{\pm}1.25{\mu}g/100ml$ in red blood cells and $14.3{\pm}1.62{\mu}g/100ml$ in plasma, respectively. 5. Mercury contents in normal human blood had a relationship of power function with mercury excretion in urine corrected with a gram of creatinine excretion per liter of urine (p<0.10).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.473-478
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• 2003

This study was conducted to clarify the effects of duck free-ranging time on the growth and behavior patterns of duck, pH and dissolved oxygen of irrigation water, and growth and yield of the rice plants in paddy fields. Two paddy fields with each 5 aye were used for 12 hours duck free-ranging plot (12HFR) and 24 hours duck free-ranging plot(24HFR). Body weight gain of the duck was not different between 12HFR and 24HFR. Eating and feather grooming behavior in the 12HFR were significantly longer than those of 24HFR, but other behavior patterns were not so. Working behavior and activities of duck in paddy fields tended to be longer in the 12HFR than in 24HFR. However, any difference was not found on staying time of duck in paddy fields. Although it was not statistically significant, pH and dissolved oxygen of irrigation water tended to be higher in the 12HFR than in 24HFR. The plant height of rice in the 12HFR was significantly shorter than that of 24HFR during the latter half period. The number of tillers per hill was significantly increased in the 24HFR than in 12HFR. The shoot dry weight of rice in the 12HFR was significantly less than in the 24HFR during the heading stage of rice plant, but the root dry weight was not different. The number of spikelets per panicle was significantly less in the 12HFR than in 24HFR, however the percentage of ripened grains was significantly higher in the 12HFR. The yield of rice was not significantly different between the treatments. In conclusion, the free-ranging time of duck for 12 hours in paddy fields promoted eating and working behavior of the ducks. Free-ranging time did give effects on rice traits such as the number of tillers per hill, plant height, shoot dry weight of the rice plant, and spikelet number and percentage of ripened grain. However, the duck growth, pH and dissolved oxygen of irrigation water, and paddy rice yield were not affected by duck free-ranging time. These results might suggest that almost same effect as in 24 hours of free-ranging can be obtained with only 12 hours of free-ranging in daytime.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.611-614
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• 2003

The rheological properties of exopolysaccharide, p-KG03, produced by marine microalgae Gyrodinium impudicum strain KG03 had been studied. The intrinsic viscosity of this p-KG03 was calculated to 65.22 and 50.75 $d{\ell}/g$ using Huggins and Kramer equations (xanthan gum 24.41 and 24.03). Aqueous dispersions at p-KG03 concentrations ranging from 0.1 to 1.0 % (w/w) showed marked shear-thinning properties as Power-Law behavior. In aqueous dispersions of p-KG03 1.0 %, consistency index (K) and flow behavior index (n) were 2,172 and 0.52. The apparent viscosity and the influence of shear rate on different conditions as p-KG03 concentrations, pH, NaCl, $CaCl_2$ and temperature in aqueous solutions were measured. And p-KG03 had mixed with aqueous solutions of xanthan gum and gellan gum, and invested the change of mixed aqueous solution behavior.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1130-1135
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• 2008

The effect of pH on anaerobic hydrogen production was investigated under various pH conditions ranging from pH 3 to 10. When the modified Gompertz equation was applied to the statistical analysis of the experimental data, the hydrogen production potential and specific hydrogen production rate at pH 5 were 1,182 ml and 112.5 ml/g biomass-h, respectively. In this experiment, the maximum theoretical hydrogen conversion ratio was 22.56%. The Haldane equation model was used to find the optimum pH for hydrogen production and the maximum specific hydrogen production rate. The optimum pH predicted by this model is 5.5 and the maximum specific hydrogen production rate is 119.6 ml/g VSS-h. These data fit well with the experimented data($r^2=0.98$).

• Membrane and Water Treatment
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• v.2 no.4
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• pp.251-266
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• 2011

This work deals with the use of High Resolution Scanning Electron Microscopy (HRSEM) to verify ultrafiltration membrane selectivity at the end of the production line as well as membrane ageing. The first part of this work is focused on new membranes. It is shown that it is better to use sputtering metallization than vacuum deposition, as this latter technique entails thermal damage to the skin layer. Moreover, the impact of the metallization layer on the determination of the membrane pore size is studied and it is observed that no impact of the metallization step can be clearly defined for a metallization layer ranging from 3 to 12 nm. For example, an average pore size of 16.9 nm and a recovery rate of 6.5 % are observed for a 150 kDa cellulose acetate membrane. These results are in agreement with those given by the manufacturer: pore size ranging from 10 to 15 nm and recovery rate ranging from 5 to 10 %. The second part of this work focuses on the study of membrane ageing. A PVDF hollow fibre membrane is studied. It is shown that a 65 % decrease in the permeate flux can be linked to a decrease in the number of pores at the surface of the membrane and a decrease in the recovery rate. In conclusion, a mapping of the pores is performed for several new hollow fibre membranes used to produce drinking water, made of different materials, with different geometries and molecular weight cut-off. These results provide reference data that will help better understand the phenomena of membrane fouling and membrane ageing.

• Journal of Preventive Medicine and Public Health
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• v.19 no.1 s.19
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• pp.76-84
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• 1986

Analyses of lead and zinc were made by means of standard addition method using atomic absorption spectrophotometer(Baird Ltd., Model A5100) with flameless method for lead and flame method for zinc. The blood samples used were merely diluted with triton x-100, because it was simple, rapid and minimal risk of contamination. Mean recovery rate for lead added to the blood ranged from 97.7 to 101.3% with coefficient of variation ranging from 1.9 to 10.7%, and that for the added zinc ranged from 99.0 to 102.2% with coefficient of variation ranging from 2.1 to 9.1%. In repeated measurements of zinc in the blood, good reproducibility and interindividual variation were proved(p<0.01). In comparison of the lead and zinc concentrations in the blood determined by the standard addition method and standard method, there were good correlations between 2 sets of data (r=0.9731 for lead and r=0.9785 for zinc), although lead levels were estimated higher by the former method(p<0.01) and zinc levels by the latter method(p<0.01). It can be concluded that lead and zinc levels in blood standard addition method is reliable for determination of lead and zinc in the blood with good accuracy and reproducibility.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.78-84
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• 2013

To reproduce the brewing process of Hongkuk-ju and to identify the functional properties of it, Hongkuk-ju was brewed using different additions of Hongkuk (100%, 90%, 70%, 50%) and Nuruk (0%, 10%, 30%, 50%). The quality elements, including pH, total acidity, reducing sugar content, alcohol content and pigments (yellow, red, monacolin K and citrinin), were measured. The pH values of Hongkuk-ju showed a slight difference (pH 4.08~4.58) right after the $1^{st}$ stage mash; further, the pH on all groups (H1, H2, H3 and H4) in the terminal of the $2^{nd}$ stage mash (9 days in fermentation) were similar, ranging approximately at pH 3.70. The total acidity change did not show a difference directly the $1^{st}$ stage mash (nearby 0.2 %); however, it began to show a slight difference at the terminal of the $2^{nd}$ stage mash between the range of 0.69~0.76%. The residual reducing sugar of the content was decreased with the increased Nuruk content. The alcohol concentrations of the treatment brew with Nuruk ranging from 12.3% to 13.7% were higher than Hongkuk on its own. The yellow and red pigment contents of Hongkuk-ju ranged from 7.2~8.8 O.D. units (yellow pigment) and from 4.4~5.1 O.D. units (red pigment). The production of monacolin K and citrinin was the highest (9.48 mg/kg and 10.14 mg/kg) when the treatment solely brewed Hongkuk. The concentration of Nuruk and the preparation of the seed mash from it were critical factors compared to the treatment of rice in brewing Hongkuk-ju.