• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.299-308
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• 1999

Purpose: The purpose of this study was to compare the qualities of the four different processing chemicals (solutions). Materials and Methods: With EP 21 films(Ektaspeed plus film, Kodak Co., USA), nine unexposed and nine exposed films of a step wedge were processed utilizing automatic film processor(XR 24, Durr Co., Germany) for 5 days. During 5 days, the total number of processed films including out-patient' s intraoral films were about 400-500 for each brand. Base plus fog density, film density, contrast of processed films were measured with densitometer(model 07-443 digital densitometer, Victoreen Co., USA). These measurements were analyzed for comparison. Results: The results were as follows, 1. For the base plus fog density. there was significant difference among the four chemicals (p<0.05). The sequence of the base plus fog densities was in ascending order by Kodak, X-dol 90. Agfa and Konica. 2. For the film density. all chemicals showed useful range of photographic densities(0.25-2.5). The sequence of the film densities was in ascending order by Kodak, X-dol 90, Konica and Agfa. But there was no statistically significant difference of film density between X-dol and Kodak (p<0.05). 3. The sequence of the contrasts was in ascending order by Konica, X-dol 90, Kodak and Agfa. But there was no statistically significant difference of contrast between X-dol and Konica (p<0.05). Conclusion: These results indicated that the four processing chemicals had clinically useful film density and contrast. but only Kodak processing chemical had useful base plus fog density.

• Food Science and Preservation
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• v.6 no.3
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• pp.255-259
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• 1999

This study was measured weight loss, total ascorbic acids, titratable acidity and soluble solids contents to investigate the effect of EPS(expended polystrene foam) box, double wall corrugated paperboard box and LDPE film pouches during storage at 25oC. The rate of weight loss was 5.9% in corrugated paperboard box after 7 days, but those of 20LD, 40LD film and EPS box were 1.1, 1.0, and 1.1% , respectively. Total ascorbic acid content of EPS box was 20% higher than that in corrugated paperboard box, but the obvious differents were not observed among the LDPE film pouches and EPS box. The titratable acidity was decrease during storage, but total soluble solids content was increase. Overall appearences of LDPE pouches and EPS box were better than those of corrugated paperboard box.

• Food Science and Preservation
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• v.6 no.3
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• pp.260-263
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• 1999

This study was measured weight loss, total ascorbic acids, titratable acidity and soluble solids contents to investigate the effect of EPS(expended polystyrene foam) box. double wall corrugated paperboard box and LDPE film pouches during storage at 25$^{\circ}C$. The rate of weight loss was 5.7% in corrugated paperboard box after 10 days. but those of 20LD, 40LD film and EPS box were 1.0, 0.8, and 0.9%, respectively. Total ascorbic acid content and titratable acidity of EPS box was 15.0% and 24.4% higher than that in corrugated paperboard box, but the obvious differents were not observed among the LDPE film pouches and EPS box. The titratable acidity was decrease during storage, but total soluble solids content was slightly increase. Overall appearences of LDPE pouches and EPS box were boner than those of corrugated paperboard box.

• Food Science and Preservation
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• v.7 no.3
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• pp.285-290
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• 2000

Color values of anthocyanins from seven natural food colorants, such as purple-fleshed sweet potato (PSP), red flower cabbage (RFC), red cabbage (RC), grape skin (GS), black rice (BR), egg plant (EP), and fig fruit (FF) were evaluated, resulting in the selection of four color sources with higher color values including PSP, RFC, RC and GS. The stabilities of anthocyanins from the selected colorant sources against metal ions, ascorbic acid, ultra-violet light, and heating were investigated. Anthocyanins from PSP and GS were degraded significantly by $Mn^{2+}$, while those from RFC and RC were degraded by $Cu^{2+}$. Asthocyanins from PSP were the most stable against the color-degrading factors, followed by RFC, RC, and GS in descending order.

• YAKHAK HOEJI
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• v.53 no.3
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• pp.101-106
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• 2009

Recombinant interferon alpha-2a is an active formula for the treatment of various cancer cells like malignant melanoma and a variety of virus infection diseases like acute or chronic hepatitis. The bioassay system based on the measurement of virus inhibitory activity by interferon has been used for interferon analysis with low repeatability. Here, we developed the HPLC assay to measure reproducibly interferon alpha-2a protein content which is replaceable to the reported bioassay. This method separated interferon alpha-2a from its oxidized forms and human serum albumin used as excipients. The regression coefficient using interferon alpha-2a EP CRS is more than 0.9 in the range from 5 ${\mu}g/ml$ to 200 ${\mu}g/ml$. The recovery result in the range from 15 ${\mu}g/ml$ to 60 ${\mu}g/ml$ is $97{\sim}104%$ and the precision is $0.2{\sim}1.7%$. The interferon alpha contents of 5 products are about 30 ${\mu}g/ml$.

• Korean Journal of Plant Resources
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• v.15 no.1
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• pp.18-25
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• 2002

These experiments were conducted to evaluate the variability of seed germination, and seedling growth of PEG priming barley. The average germination percentage(AGP) of PEG priming seed was higher than control, but those were low with extend the treatment period. The AGP of washing seed after PEG priming was higher than unwashed seed, and that of redried seed after priming was lower than control. The germination time of priming seed was short compare to control seed, and that was prolonged with extend the priming period, and that of washing seed after priming was shortening, and that of redried seed after priming was prolonging. The emergence percentage(EP) of priming seed was higher than control, and the emergence time was shortest in 50％ field moisture capacity soil. The seedling and root length of priming seed was shorter than control.

• The Korean Journal of Mycology
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• v.14 no.1
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• pp.79-84
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• 1986

A cellulose-degrading enzyme from Ganoderma lucidum was partially purified by ammonium sulfate precipitation and its enzymatic properties were studied. The enzyme had an optimum pH for activity at 4.0, and its stability range was pH $4.0{\sim}7.0$. The optimum temperature was $55^{circ}C$ and the enzyme retained 80% original activity after heated at $50^{\circ}C$ for 60 min. The activation energy of the enzyme for CMC degradation was caculated and found to be 6.2 Kcal/mole. The enzyme was activited by the addition of $Co^{++},\;Mn^{++}$, but slightly inactivated by $Hg^{++}$. Various enzyme inhibitors and chemical reagents did not affect the enzyme activity. The enzyme acted on native celluose as well as CMC. The Michaelis constant for CMC was calculated to be 2.4 mg glucose ep/ml.

• Korean Journal of Veterinary Research
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• v.41 no.2
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• pp.189-195
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• 2001

Single base substitution and deletion mutation have been introducted into the verotoxin 2 (VT2)A subunit gene from O157:H7 isolates to reduce cytotoxicity of VT2 and the cytotoxicity between wild type toxin and mutant toxoid were compared. A M13-derived recombinant plasmid pEP19RF containing a 940bp EcoRI-PstI fragment of VT2A gene was constructed for oligonucleotide-directed mutagenesis. The duoble mutant pDOEX was constructed by point and deletion mutation of two different highly conserved regions of VT2A encoding active site cleft of enzymatic domain. The key residue, Glu 167(GAA) and the pentamer(WGRIS) consisting of the enzymatic domain were replaced by ASP(GAC) and completely deleted in nucleotide sequence analysis of mutant, respectively. In the comparision of vero cell cytotoxicity between wide type toxin and toxoid from mutant, the wild type toxin expressed cytotoxicity in dilution of $10^{-6}$, but the toxid from mutant did not show cytotoxicity to vero cells.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.877-881
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• 2007

The genetic diversity and population structure of Potentilla freyniana in Korea were determined using genetic variations at 19 allozyme loci. Thirteen of the 19 loci (68.4%) showed detectable polymorphism. Genetic diversity at the population level was high ($H_{EP}$ = 0.270). Total genetic diversity values ($H_T$) varied between 0.190 and 0.584, giving an average overall polymorphic loci of 0.371. The interlocus variation of genetic diversity within populations ($H_S$) was high (0.354). On a per locus basis, the proportion of total genetic variation due to differences among populations ($G_{ST}$) ranged from 0.008 for Fe-2 to 0.310 for Gpi with a mean of 0.065, indicating that about 6.5% of the total allozyme variation was among populations. Wide geographic ranges, perennial herbaceous nature and the persistence of multiple generations are associated with the high level of genetic variation in P. freyniana. The estimate of gene flow based on $G_{ST}$, was high among Korean populations of P. freyniana (Nm =3.57). Although P. freyniana usually propagated by asexually-produced ramets, I could not rule out the possibility that sexual reproduction occurred at a low rate because each ramet may produce terminal flowers.

• Korean Journal of Medicinal Crop Science
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• v.10 no.1
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• pp.5-11
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• 2002

The study of genetic diversity was carried out in Atractylodes japonica $K_{OIDZ}$. Although this species has been regarded as medically important one, there is no report on population structure in Korea. Starch gel electrophoresis was used to investigate the allozyme variation and genetic structure of eight Korean populations of this species. Of the 15 genetic loci surveyed, nine (60.0%) was polymorphic in at least one population. Genetic diversity was high at the species level $(H_{es}=0.144)$, whereas, that of the population level was relatively low $(H_{ep}=0.128)$. Nearly 87% of the total genetic diversity in A. japonica was apportioned within populations. The sexual reproduction, high fecundity, and perennials are proposed as possible factors contributing to high genetic diversity. The indirect estimated of gene flow based on Gst was 1.69.