• 한국재료학회지
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• 제18권2호
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• pp.84-91
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• 2008

The effects of the deposition and annealing temperature on the structural, electrical and optical properties of Ag doped ZnO (ZnO : Ag) thin films were investigated. All of the films were deposited with a 2wt% $Ag_2O-doped$ ZnO target using an e-beam evaporator. The substrate temperature varied from room temperature (RT) to $250^{\circ}C$. An undoped ZnO thin film was also fabricated at $150^{\circ}C$ as a reference. The as-grown films were annealed in temperatures ranging from 350 to $650^{\circ}C$ for 5 h in air. The Ag content in the film decreased as the deposition and the post-annealing temperature increased due to the evaporation of the Ag in the film. During the annealing process, grain growth occurred, as confirmed from XRD and SEM results. The as-grown film deposited at RT showed n-type conduction; however, the films deposited at higher temperatures showed p-type conduction. The films fabricated at $150^{\circ}C$ revealed the highest hole concentration of $3.98{\times}1019\;cm^{-3}$ and a resistivity of $0.347\;{\Omega}{\cdot}cm$. The RT PL spectra of the as-grown ZnO : Ag films exhibited very weak emission intensity compared to undoped ZnO; moreover, the emission intensities became stronger as the annealing temperature increased with two main emission bands of near band-edge UV and defect-related green luminescence exhibited. The film deposited at $150^{\circ}C$ and annealed at $350^{\circ}C$ exhibited the lowest value of $I_{vis}/I_{uv}$ of 0.05.

• Journal of Life Science
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• 제10권2호
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• pp.39-44
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• 2000

Trichostatin A (TSA) is a Streptomyces product, which inhibits the enzyme activity of histone deacetylase. It is also known as an inducer of apoptosis in several human cancer cell lines. In this study, we investigated the mechanism of apoptosis induced by TSA in MDA-MB-231 human breast carcinoma cells. The cytotoxicity of TSA on MDA-MB-231 cells was assessed by MTT assay. The cell viability was decreased dose-dependently and the IC\ulcorner value was about 100 ng/ml after 48 h treatment with TSA. Morphological change and DNA ladder formation, the biochemical hallmarks of apoptotic cell death, were observed after treatment of TSA in a concentration-dependent manner, which was accompanied with cleavage of poly(ADP-ribose) polymerase and $\beta$-catenin, and activation of caspase-3. TSA treatment up-regulated the expression of a cyclin-dependent kinase inhibitor p21 (Wafl/Cip1) protein, a key regulatory protein of the cell cycle. However, there is no detectable change of both Bcl-2 and Bax expressions. These results demonstrated that TSA might inhibit cell growth through apoptosis in human breast carcinoma MDA-MB-231 cells.

• Journal of Animal Science and Technology
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• 제63권4호
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• pp.919-933
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• 2021

We hypothesized that the unsaturated fatty acid palmitoleic acid (POA) could promote the expression of adipogenic/lipogenic genes in bovine skeletal muscle satellite cells (BSCs). The BSCs were cultured in a growth medium containing 10% fetal bovine serum. When the cells reached 80%-90% confluence, we used the differentiation medium with 5% horse serum for differentiation for 96 h. The differentiation medium contained 50 µM, 100 µM and 200 µM POA. Control BSC were cultured only in differentiation media. Compared with the control BSC, the POA BSC significantly up-regulated the expression of paired box 3 (Pax3) and paired box 7 (Pax7) and down-regulated myogenin gene expression (p < 0.01), which indicates a depression in muscle fiber development. However, all POA treatments up-regulated the expression of the adipocyte transcription factors peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein alpha and beta (C/EBP α and C/EBP β), and other genes (p < 0.01) and increased the expression of PAT-family proteins and the concentration of adiponectin in the media. These results indicate that POA can convert part of BSCs into adipocytes.

• 한국축산식품학회지
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• 제39권3호
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• pp.355-370
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• 2019

The present study aimed at evaluating effects of traditional sauce type and storage time on shelf-life and flavor compounds of marinated pork cooked by Sous-Vide method. Five different traditional sauces (Meju soy sauce, Brewed soy sauce, Fish-soy sauce, Ishiru fish sauce and Anchovy fish sauce) purchased from Asian countries were used. After marination with the sauces, polyvinylchloride film bags containing the marinated pork samples were cooked using Sous-Vide method for $55^{\circ}C$ for 5 h and $60^{\circ}C$ for 30 min, and were then stored for 8 wk at $10^{\circ}C$. Results showed that the pork samples marinated with the sauces retarded the growth of total plate counts (TPC) during storage. At $8^{th}$ wk storage, TPC counts were significantly lower in all samples marinated with the sauces compared to control (p<0.05). Lipid oxidation level was significantly lower in the T2 (Meju soy sauce) and T6 (Anchovy fish sauce) compared to those of T3 (Brewed soy sauce) and T5 (Ishiru fish sauce) or control after 8 wk storage (p>0.05). Forty volatile flavor compounds were detected from the control and marinated samples at $4^{th}$ wk of storage. The pork marinated with Anchovy fish sauce presented significantly higher amounts of importantly pleasant flavor compounds such as; pyrazines and sulfurcontaining compounds than those marinated with other remaining sauces and control. It is concluded that the marination with Anchovy fish sauce partly improved the shelf-life and increased amounts of pleasant flavor compounds of Sous-Vide cooked pork products during storage in comparison to the other remaining sauces.

• 식물병연구
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• 제27권2호
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• pp.49-60
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• 2021

Cashew (Anacardium occidentale L.) is an important cash crop in Tanzania as a source of income to cashew growers and provides foreign exchange for the country. Despite its significance, the crop is threatened by fast spreading disease known as cashew Fusarium wilt caused by Fusarium oxysporum. Field assessment and laboratory tests were conducted to determine incidences of the disease, severity, ecological factors that influence them and explored the pathogen host specificity in six cashew growing districts. The results revealed significant (P<0.001) variation of disease incidences and severity among the studied districts. The results further revealed that there is both positive and negative correlation between the incidence and severity of the disease versus the evaluated ecological factors. The soil pH, soil temperature, air temperature, and relative humidity depicted positive correlation of disease incidence and severity versus ecological factors at ρ=0.50 and ρ=0.60, ρ=0.20 and ρ=0.94, ρ=0.11 and ρ=0.812, ρ=0.05 and ρ=0.771 respectively while nitrogen, phosphorus, and carbon depicted negative correlations at ρ=-0.22 and ρ=-0.58, ρ=-0.15 and ρ=-0.94, ρ=-0.19 and ρ=-0.12 respectively. In terms of host range, none of the weed species was found to be a carrier of Fusarium pathogen implying that it is host specific or semi selective. The results revealed that the tested ecological parameters favor the growth and development of Fusarium pathogen. Thus, management of the disease requires nutrients replenishment and soil shading as essential components in developing appropriate strategies for the control and prevention of further spread of the disease.

• Journal of Ginseng Research
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• 제45권1호
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• pp.75-85
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• 2021

Background: Invasive infections due to foodborne pathogens, including Salmonella enterica serovar Typhimurium, are prevalent and life-threatening. This study aimed to evaluate the effects of ginsenoside Rg3 (Rg3) on the adhesion, invasion, and intracellular survival of S. Typhimurium. Methods: The impacts of Rg3 on bacterial growth and host cell viability were determined using the time kill and the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays, respectively. Gentamicin assay and confocal microscopic examination were undertaken to determine the effects of Rg3 on the adhesive and invasive abilities of S. Typhimurium to Caco-2 and RAW 264.7 cells. Quantitative reverse transcription polymerase chain reaction was performed to assess the expression of genes correlated with the adhesion, invasion, and virulence of S. Typhimurium. Results: Subinhibitory concentrations of Rg3 significantly reduced (p < 0.05) the adhesion, invasion, and intracellular survival of S. Typhimurium. Rg3 considerably reduced (p < 0.05) the bacterial motility as well as the release of nitrite from infected macrophages in a concentration-dependent manner. The expression of genes related to the adhesion, invasion, quorum sensing, and virulence of S. Typhimurium including cheY, hilA, OmpD, PrgK, rsgE, SdiA, and SipB was significantly reduced after Rg3 treatment. Besides, the compound downregulated rac-1 and Cdc-42 that are essential for actin remodeling and membrane ruffling, thereby facilitating Salmonella entry into host cells. This report is the first to describe the effects of Rg3 on "trigger" entry mechanism and intracellular survival S. Typhimurium. Conclusion: Rg3 could be considered as a supplement agent to prevent S. Typhimurium infection.

• Journal of Microbiology and Biotechnology
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• 제32권10호
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• pp.1325-1334
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• 2022

Global warming has accelerated in recent decades due to the continuous consumption of petroleum-based fuels. Cyanobacteria-derived biofuels are a promising carbon-neutral alternative to fossil fuels that may help achieve a cleaner environment. Here, we propose an effective strategy based on the large-scale cultivation of a newly isolated cyanobacterial strain to produce phycobiliprotein and biodiesel, thus demonstrating the potential commercial applicability of the isolated microalgal strain. A native cyanobacterium was isolated from Goryeong, Korea, and identified as Pseudanabaena mucicola GO0704 through 16s RNA analysis. The potential exploitation of P. mucicola GO0704 was explored by analyzing several parameters for mixotrophic culture, and optimal growth was achieved through the addition of sodium acetate (1 g/l) to the BG-11 medium. Next, the cultures were scaled up to a stirred-tank bioreactor in mixotrophic conditions to maximize the productivity of biomass and metabolites. The biomass, phycobiliprotein, and fatty acids concentrations in sodium acetate-treated cells were enhanced, and the highest biodiesel productivity (8.1 mg/l/d) was achieved at 96 h. Finally, the properties of the fuel derived from P. mucicola GO0704 were estimated with converted biodiesels according to the composition of fatty acids. Most of the characteristics of the final product, except for the cloud point, were compliant with international biodiesel standards [ASTM 6761 (US) and EN 14214 (Europe)].

• Fisheries and Aquatic Sciences
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• 제26권8호
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• pp.470-481
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• 2023

Algal overgrowth in shrimp culture ponds can affect the quality of the aquatic environment, thereby adversely affecting the shrimp and causing economic losses. The objective of this study was to evaluate the variation in phytoplankton composition in intensive shrimp ponds in Bac Lieu province, Vietnam. Phytoplankton samples were collected in three black tiger shrimp (Penaeus monodon) ponds and three whiteleg shrimp (Litopenaeus vannamei) ponds. The collected data were analyzed using SPSS and canonical correlation analysis softwares. In total, 75 species of phytoplankton were recorded in black tiger shrimp ponds and 64 species in whiteleg shrimp ponds. Diatoms had the highest species diversity with 29-30 species (39%-47%), followed by green algae with 9-19 species (14%-25%); species numbers of other phyla varied from 5-12 (8%-16%). The total number of phytoplankton species throughout the study varied from 34-50 species. Algal density was relatively high and ranged from 497,091-2,229,500 ind./L and 1,301,134-2,237,758 ind./L in black tiger shrimp and whiteleg shrimp ponds, respectively. The diatom density tended to increase during the final stage of the production cycle in black tiger shrimp ponds. Blue-green algae and dinoflagellates also increased in abundance at the end of the cycle, which can affect shrimp growth. Diatoms were significantly positively correlated with pH, salinity, total ammonia nitrogen, and nitrate (NO₃^-) concentrations (p < 0.05). Blue-green algae and dinoflagellates were positively correlated with salinity, phosphate (PO₄^3-), and NO₃^-. Algal species diversity was lower in the whiteleg shrimp ponds than in the black tiger shrimp ponds. Several dominant algal genera were recorded in the shrimp ponds, including Nannochloropsis, Gyrosigma, Chaetoceros, Alexandrium, and Microcystis. The results of this study provide basic data for further investigations, and they contribute to the management of algae in brackish-water shrimp ponds.

• 한국식품영양과학회지
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• 제45권5호
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• pp.736-745
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• 2016

유해균인 Bacillus cereus와 독소 생성 곰팡이 증식 억제 능력을 지닌 Bacillus amyloliquefaciens EMD17(EMD17)과 Bacillus subtilis EMD4(EMD4)를 단독 혹은 1:1로 대두에 접종하여 청국장을 제조하였다. 대조구로는 나토균주로 알려진 Bacillus subtilis KACC16450 균을 접종한 청국장을 제조하였다. B. amyloliquefaciens EMD17 접종 청국장에서는 오염시킨 B. cereus 증식이 즉시 억제되어 $37^{\circ}C$ 발효 12시간에 검출되지 않았다. EMD4 접종 청국장에서도 B. cereus 증식 억제가 관찰되었으나 억제 정도는 약했다. 48시간 발효 후 청국장 시료들은 $4^{\circ}C$에서 10일간 저장하였고 B. cereus는 EMD4 접종 청국장에서 검출되지 않았다. 그러나 대조구에서는 상당수 B. cereus 균수가 유지되었다. 청국장의 pH 값은 시료 간 유의차가 없었고 혈전용해능은 발효 중에는 EMD17을 접종한 청국장이 그리고 저장 중에는 나토균주를 접종한 것이 높았다. 총 페놀성 화합물도 나토균주 청국장에서 높았다. 이상 결과들에서 B. amyloliquefaciens EMD17 같은 균주들을 종균으로 사용함으로써 청국장에서 B. cereus 억제가 가능함을 알 수 있다.

• KSBB Journal
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• 제18권1호
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• pp.55-61
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• 2003

항균 및 항암성 물질을 탐색하기 위하여 도꼬마리 열수 추출액을 ether 및 ethylacetate를 이용하여 중성, 산성, 염기성조건에서 추출한 후, 각각의 추출물을 세균 16균주 및 곰팡이와 효모 2균주를 대상으로 항균활성을 조사하였다. Ether 중성 추출물(XE-N)은 항균효과가 가장 우수하였으며, 특히 그람 양성세균(7균주), 그람 음성세균(7균주)을 비롯하여 진균중 Cryptococcus neoformans에도 뚜렷한 항균효과를 나타내었다. XE-N 및 XEA-N을 대상으로 FDA method에 의한 항균효과를 검토한 결과, p. aeruginosa를 제외한 3균주에 대해 30 ng/mL에서도 저해효과를 나타내었다 XE-N으로부터 XE-N-S1, XE-N-S3을, Ether 산성 추출물(XE-A)로부터 XE-N-S3 을, ethylacetate 중성 추출물(XEA-N)로부터 XEA-N-S2를 항균, 항암성 물질로 정제하였으나, XE-N-S1을 제외한 다른 물질들은 빠른 시간 내에 모두 분해되었다 도꼬마리 추출물 및 정제된 생리활성물질에 대한 항암효과를 검토한 결과, HeLa 자궁암 세포에 대해서는 XE-N-S1이 가장 우수하였다. HepG2간암세포에 대한 항암효과는 XE-N-S, XE-N-S3가 우수하였고, HT29 대장암세포에 대한 항암효과는 XE-N, XE-N-S1이 우수하였다. Saos2 골육종 암세포, NCI H522 폐선 암세포, NCI H1703 폐 편평세포 암세포와 Clone M3 흑색종 암세포에 대한 항암효과는 XE-N-S1이 가장 우수하였다. LN CAP 전립선 암세포에 대한 항암효과는 XE-N-S3가 가장 우수한 효과를 나타내었다. 또한 HSF 인간 정상 피부 섬유아세포에 대한 각종 추출물 및 정제물의 세포독성을 기존의 항암제인 etoposide와 cisplatin과 비교·검토한 결과, XE-A, XEA-A 및 XEA-B가 가장 독성이 낮았으며, XE-B도 etoposide에 비해 독성이 낮았다. 한편 XE-N-S1, XE-N-S3은 etoposide보다 높은 독성을 나타내었으며, XE-A-S3은 etoposide보다는 독성이 높았으나, cisplatin보다는 낮았다.