• Journal of the Korean Chemical Society
• /
• v.42 no.6
• /
• pp.672-678
• /
• 1998

Chitin was extracted from crab shell of Portuns triberculatus and deacethylated to yield chitosan with various molecular weights. The absorption and the fluorescence spectra of Rhodamine 6G(Rh 6G)-sodium dodecyl sulfate(SDS) and Rh 6G-chitosan systems were obtained. From the spectra, we observed that the absorption and the fluorescence intensity of Rh 6G-SDS system decreased when S/D(the concentration of SDS to that of Rh 6G ratio) was below or at 32, while they increased when S/D was above 32. From the suspended solid(SS) removal rate and the transmittance of Rh 6G-SDS-chitosan system, we found that when S/D ratio was 32 its flocculating behaviour was much stronger than Rh 6G-SDS system. As the concentration and the molecular weight of chitosan increased, we also found that S/D range was extended from 32 to 100. With increasing the molecular weight of chitosan, the SS removal rate increased around pH 2~9 but decreased remarkably at pH>12.

• Journal of the Korean Society of Radiology
• /
• v.17 no.1
• /
• pp.25-30
• /
• 2023

As 3D printing technology is used in the medical field, interest in metal materials is increasing. The Department of Radiation Oncology uses a shielding block to shield the patient's normal tissue from unnecessary exposure during electron beam therapy. However, problems such as handling of heavy metal materials such as lead and cadmium, reproducibility according to skill level and uncertainty of arrangement have been reported. In this study, candidate materials that can be used for metal 3D printing are selected, and the physical properties and radiation dose of each material are analyzed to develop a customized shielding block that can be used in electron beam therapy. As candidate materials, aluminum alloy (d = 2.68 g/cm³), titanium alloy (d = 4.42 g/cm³), and cobalt chromium alloy (d = 8.3 g/cm³) were selected. The thickness of the 95% shielding rate point was derived using the Monte Carlo Simulation with the irradiation surface and 6, 9, 12, and 16 energies. As a result of the simulation, among the metal 3D printing materials, cobalt chromium alloy (d = 8.3 g/cm³) was similar to the existing shielding block (d = 9.4 g/cm³) in shielding thickness for each energy. In a follow-on study, it is necessary to evaluate the usefulness in clinical practice using customized shielding blocks made by metal 3D printing and to verify experiments through various radiation treatment plan conditions.

• Journal of Animal Reproduction and Biotechnology
• /
• v.37 no.1
• /
• pp.62-66
• /
• 2022

To date, the development of anticancer drugs has been conducted using two-dimensional (2D) cell culture systems. However, since cancer cells in the body are generated and developed in three-dimensional (3D) microenvironments, the use of 2D anticancer drug screening can make it difficult to accurately evaluate the anticancer effects of drug candidates. Therefore, as a step towards developing a cancer cell-friendly 3D microenvironment based on a combination of vinylsulfone-functionalized polyethylene glycol (PEG-VS) with dicysteine-containing crosslinker peptides with an intervening matrix metalloproteinase (MMP)-specific cleavage site, the types of MMPs secreted from human hepatocarcinoma HepG2 cells, a representative cancer cell, were analyzed transcriptionally and translationally. MMP3 was confirmed to be the most highly expressed protease secreted by HepG2 cells. This knowledge will be important in the design of a crosslinker necessary for the construction of PEG-based hydrogels customized for the 3D culture of HepG2 cells.

• Food Science and Biotechnology
• /
• v.18 no.6
• /
• pp.1464-1469
• /
• 2009

Jiwhang (Rehmannia glutinosa), one of the most widely used medicinal herbs, was dried with various methods such as sun drying, hot air drying, vacuum drying, and freeze drying methods, and their effects on the antioxidant capacity in relation with the content of total phenolic compounds were studied with a steamed-and-dried rehmannia (sookjiwhang) for comparison. Generally, total phenolic contents decreased significantly by all of the drying treatments except the steamed-and-dried rehmannia, in which total phenolic contents increased 2.4 fold compared with fresh rehmannia. Content of verbascoside, a functional phenolic compound, was the highest in the freeze-dried rehmannia ($177.97{\pm}0.02\;{\mu}g/g$ d.m.) followed by vacuum-dried ($105.55{\pm}0.07\;{\mu}g/g$ d.m.), hot air-dried ($23.01{\pm}0.02\;{\mu}g/g$ d.m.), and sun-dried ($4.89{\pm}0.13\;{\mu}g/g$ d.m.) ones comparable to the fresh rehmannia ($80.15{\pm}1.26\;{\mu}g/g$ d.m.). Antioxidant capacity determined by both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethyl-benzthiazoline-6-sulphonic acid) (ABTS) methods agreed with the result of total phenolic contents, that is, the antioxidant capacity was the highest in the steamed-and-dried rehmannia followed by fresh rehmannia, vacuum-dried, hot air-dried, sun-dried, and freeze-dried ones. Conclusively, the total phenolic contents and antioxidant capacity of rehmannia were greatly affected by the drying methods used.

• Journal of Veterinary Science
• /
• v.24 no.5
• /
• pp.54.1-54.13
• /
• 2023

Background: Porcine reproductive and respiratory syndrome virus (PRRSV) vaccines do not provide full cross-protection, mainly due to the virus genetic variability. Despite this, vaccines based on modified-live PRRSV (PRRSV-MLV) reduce the disease impact. Objectives: To assess the efficacy of two commercial vaccines-one based on PRRSV1 (PRRSV1-MLV) and another on PRRSV2 (PRRSV2-MLV)-against a Japanese PRRSV2 field strain. Methods: Two groups of three-week-old piglets were vaccinated (G1: PRRSV1-MLV; G2: PRRSV2-MLV) and two were kept as non-vaccinated (INF and CTRL). One month later, G1, G2, and INF were challenged with a PRRSV2 field strain. Results: After the challenge, clinical signs were only observed in INF. Moreover, the highest rectal temperatures and values for the area under the curve (AUC) were observed in INF. Regarding viral detection, both AUC and the proportion of positive samples in blood were higher in INF. In G1, viremic animals never reached 100%. At necropsy (21 d after the challenge), differences for titers among groups were only found in tonsils (G1 < G2 and INF). One animal (belonging to G1) was negative in all tissues. Regarding humoral responses, G1 and G2 seroconverted after vaccination, as detected in the corresponding enzyme-linked immunosorbent assay. Specific neutralizing antibodies (NA) against PRRSV1-MLV were already detected at 14 d after vaccination in G1, showing a significant booster after the challenge, while PRRSV2-MLV NA were detected in G2 at the end of the experiment. Conclusions: Despite genetic differences, PRRSV1-MLV has been demonstrated to confer partial protection against a Japanese PRRSV2 strain, at least as good as PRRSV2-MLV.

• Journal of Mushroom
• /
• v.21 no.4
• /
• pp.222-227
• /
• 2023

Mushrooms have a unique taste and aroma, so in the processing of mushroom products with other ingredients, a separate pre-processing step is often taken to eliminate the mushroom aroma. In this study, we analyzed the changes in the concentration of volatile compounds according to drying conditions to promote the activation of processing using the fruiting bodies of yellow oyster mushrooms(Pleurotus citrinopileatus) and pink oyster mushrooms(P. djamor). The caps and stipes of yellow oyster and pink oyster mushrooms were separated and freeze-dried at -70℃ for 120 hours. Subsequently, they were hot air-dried at temperatures of 40, 50, 60, and 70℃ for 24, 24, 16, and 12 hours, respectively. The dried samples were pulverized and quantitatively analyzed by SPME-GC-MS. In the case of yellow oyster mushrooms, the concentration of t-2-nonenal in caps and stipes during freeze-drying was 164.43 ㎍/g d.w. and 174.80 ㎍/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 0.35~3.41 ㎍/g d.w. and 0.98~59.88 ㎍/g d.w. In a similar manner, for pink oyster mushrooms, the concentration of 1-octen-3-ol during freeze-drying in caps and stipes was 31.05 ㎍/g d.w. and 176.17 ㎍/g d.w., respectively, whereas during hot air-drying, it significantly decreased to 1.59~9.66 ㎍/g d.w. and 1.96~15.77 ㎍/g d.w. Furthermore, most volatile compounds showed a tendency to decrease in concentration as the temperature during hot air-drying increased.

• Bulletin of Food Technology
• /
• v.15 no.2
• /
• pp.76-84
• /
• 2002

일부 야생 및 배양 버섯중의 sterol 및 vitamin $D_2함량을 측정하였다. 야생버섯의 부위별 이들 성분의 분포 또한 평가되었다. 또 야생버섯의 자실체의 vitamin $D_2함량의 변화도 연구되었다. vitamin $D_2는 비누화 및 반예비 순상 HPLC 정제를 포함하는 방법을 사용한 후 HPLC법을 사용하여 측정하였는데, 내부 표준품을 이용한 분석용 역상컬럼을 이용한 정량을 하였다. Sterol 함량은 GC로 분석되었으며, 내부표준품을 사용하였다. 비누화 후에 sterol을 trimethylsily1 ester로 유도체화하여 분석의 시료로 하였다. 질량분석이 sterol류의 동정을 확인하기 위하여 사용되었다. 배양 버섯에서는 vitamin $D_2는 거의 존재하지 않았으나, 일부 야생 버섯은 이들 vitamin을 다량(4.7- 194$\mug$/ 100g 건물중) 함유하고 있었다. Ergosterol은 버섯류 중에 가장 많이 존재하는 sterol이었으며, 야생버섯류(296-489 mg/ 100g 건물중)보다 배양버섯류(602.1-678.6 mg/ 100g 건물중)에서 높은 함량을 보였다. Vitamin D2와 ergosterol의 함량은 버섯류의 부위에 따라 아주 다양하거나 적당한 변화를 보였으며, 자루부위에서 가장 낮은 함량을 보였다. 더욱이 개체별 자실체간의 vitamin $D_2함량간에도 많은 차이를 보였다.

• Journal of the Korean Applied Science and Technology
• /
• v.10 no.2
• /
• pp.11-18
• /
• 1993

Contents of vitamin $D_3$ and 25-OH-vitamin $D_3$ in marine animal products(20 species) were determined by HPLC. The isomers of vitamin D, $D_2$ and $D_3$, were not clearly separated on a reversed phase, ${\mu}$ Bonda Pak, with 20% methanol-acetonitrile, and on a normal phase, Zorbax SIL. with 0.4% isopropanol-hexane, but 25-OH-vitamin $D_2$ and-$D_3$ were separated on either ${\mu}$ Bonda Pak with 10% methanol-acetonitrile, or on Zorbax SIL with 2.2% isopropanol-hexane, respectively. Although levels of vitamin $D_3$ and 25-OH-vitamin $D_3$ varied remarkably according to species, their average value(fish : $l,l87{sim}36,007$ I.U/sample 100g, mussel : $58{\sim}1,706$ I.U/sample 100g, pickle: $1,208{\sim}79,358$ I.U/sample 100g) was greatly higher than that of meat($80{\sim}100$ I.U/sample 100g) and dairy products($400{\sim}800$ I.U/sample 100g). Fatty tissues of fish and pickled fish intestines contained high level of vitamin $D_3$ and 25-OH-vitamin $D_3$, while the clam and mussel known to have various kinds of sterol including ${\Delta}^7$-sterol showed very low levels of vitamin $D_3$ and its derivative.

• KSBB Journal
• /
• v.27 no.2
• /
• pp.97-102
• /
• 2012

In the present study, the biomass productivity of two green microalgae (Chlorella sp. and Dunaliella salina DCCBC2) were assessed in a 12 L tubular photobioreactor under optimum culture conditions. In the batch culture optimization process, the Chlorella sp. biomass was obtained as 1.2 g/L under atmospheric air as a sole $CO_2$ source and other culture conditions as follows: light intensity, temperature, pH, $NH_4Cl$ and $K_2HPO_4$ were 100 ${\mu}E/m^2/s$, $27^{\circ}C$, 7.0, 20.0 mM and 2.0 mM, respectively. On the other hand, 2.9 g/L of D. salina DCCBC2 biomass production was observed under the following conditions: light intensity, temperature, pH, $KNO_3$ and $K_2HPO_4$were 80 ${\mu}E/m^2/s$, $27^{\circ}C$, 8.0, 3.0 mM and 0.025 mM, respectively. At 1% $CO_2$ supply to the reactor, the Chlorella sp. production was reached 1.53 g/L with 25% increment under the same operating conditions. In addition, the maximum D. salina DCCBC2 biomass was observed as 3.40 g/L at 3% $CO_2$ concentration. Based on the aforementioned optimized conditions, the dilution rate and maximal biomass productivity of Chlorella sp. and D. salina DCCBC2 in the continuous cultivation were 0.4/d and 0.6 g/L/d and 0.6/d and 1.5 g/L/d, respectively.

• Journal of the Korean Chemical Society
• /
• v.44 no.1
• /
• pp.45-51
• /
• 2000

The binding mode of anthryl derivatives to synthetic polynucleotides were investigated by various spectroscopic methods. The spectroscopic properties of anthracence with metbylamine and methylethylenediamine side chains, complexed with $poly[d(A-T)_2]$ and $poly[d(G-C)_2]$, can be summarized as a red-shift, with a strong hypochromism in the absortion spectrum, similar induced CD spectra, and a strong negative LD spectrum with an $LD^r$ magnitude comparable to the DNA absorption region. These observations indicate that anthracene moiety is intercalated between the nucleo-bases of $poly[d(A-T)_2]$ and $poly[d(G-C)_2]$. The side chains did not alter the spectroscopic properties, demonstrating that the binding mode was not affected by them. A strong energy transfer was observed from poly[d(A-T),] and $poly[d(I-C)_2]$ but not from $poly[d(G-C)_2]$, as reported by Kumar et al. (J. Am. Chem. Soc.(1993) 115, 8547). Since the binding mode is the same for all the polynucleotides, the amine group of the guanine base, which protrudes into the minor groove of $poly[d(G-C)_2]$, is concluded to disrupt the energy transfer.