• Korean journal of food and cookery science
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• v.30 no.3
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• pp.278-283
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• 2014

This study was investigated the antibacterial activities of Cirsium japonicum from extracts five regions(Chungnam, Gyeonggi, Gangwon, Jeju and Jeonnam) extract against six food-borne pathogenes(Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Salmonella enterica and Vibrio vulnificus) using the broth dilution and agar diffusion method. At concentrations between 0 and $750{\mu}g/mL$ the extracts showed an antibacterial effect against all tested bacteria. The antibacterial activities of Cirsium japonicum from Jeju and Gangwon are stronger than others. The minimum inhibitory concentration(MIC) values against the six bacteria ranged from 93.75 to $750{\mu}g/mL$. In time killing assay(cell growth curves), the tested bacteria inactivated upon exposure to the extracts for 24h. At the 24h exposure to the extracts, all bacteria were inhibited to over 70% for growth. In particular, Bacillus subtilis, Salmonella enterica and Vibrio vulnificus conveyed an inhibition of growth to almost complete. It is anticipated that Cirsium japonicum extracts may have greater potential as natural food preservatives.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.95-99
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• 2001

Giardia lamblia is a parasitic protozoa which is transmitted in the form of a cyst through untreated water and also treated drinking water. Since its presence in water has led to frequent outbreaks of giardiasis and death in many countries, the removal and disinfection of this protozoan cyst from the water supply are of great concern for public health. This study examined the disinfection characteristics of G. lamblia cysts isolated from a Korean patient with giardiasis. When using sodium hypochlorite including 5 or 10 ppm chlorine, the killing rate was initially rapid, however, the disinfection slowed down and a 3log reduction could not be achieved even after 2h. The disinfection effectiveness was also reduced at a lower temperature, thereby implying that the risk o a giardiasis outbreak will be higher in the winter season. A CT (concentration$.$time) curve was constructed based on the results with sodium hypochlorite for use in designing and predicting disinfection performance. The organic chlorination disinfectant SDIS (sodium dichloroisocyanurate) produced a lower pH and a much higher residual effect than sodium hypochlorite. The disinfection of cysts by SDIC continued steadily throughout 2h of contact, although the initial killing rate was lower than that with sodium hypochlorite.

• Journal of Dairy Science and Biotechnology
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• v.35 no.2
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• pp.121-133
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• 2017

A small amount of milk is sold as 'untreated' or raw in the US; the two most commonly used heat-treatments for milk sold in retail markets are pasteurization (LTLT, low-temperature long time; HTST, high-temperature short time) and sterilization (UHT, ultra-high temperature). These treatments extend the shelf life of milk. The main purpose of heat treatment is to reduce pathogenic and perishable microbial populations, inactivate enzymes, and minimize chemical reactions and physical changes. Milk UHT processing combined with aseptic packaging has been introduced to produce shelf-stable products with less chemical damage than sterile milk in containers. Two basic principles of UHT treatment distinguish this method from in-container sterilization. First, for the same germicidal effect, HTST treatments (as in UHT) use less chemicals than cold-long treatment (as in in-container sterilization). This is because Q10, the relative change in the reaction rate with a temperature change of $10^{\circ}C$, is lower than the chemical change during bacterial killing. Based on Q10 values of 3 and 10, the chemical change at $145^{\circ}C$ for the same germicidal effect is only 2.7% at $115^{\circ}C$. The second principle is that the need to inactivate thermophilic bacterial spores (Bacillus cereus and Clostridium perfringens, etc.) determines the minimum time and temperature, while determining the maximum time and temperature at which undesirable chemical changes such as undesirable flavors, color changes, and vitamin breakdown should be minimized.

• The Plant Pathology Journal
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• v.40 no.3
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• pp.261-271
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• 2024

Sulfur is one of the inorganic elements used by plants to develop and produce phytoalexin to resist certain diseases. This study reported a method for preparing a material for plant disease resistance. Sulfur nanoparticles (SNPs) stabilized in the chitosan-Cu²⁺ (CS-Cu²⁺) complex were synthesized by hydrolysis of Na₂S₂O₃ in an acidic medium. The obtained SNPs/CS-Cu²⁺ complex consisting of 0.32% S, 4% CS, and 0.7% Cu (w/v), contained SNPs with an average size of ~28 nm as measured by transmission electron microscopy images. The X-ray diffraction pattern of the SNPs/CS-Cu²⁺ complex showed that SNPs had orthorhombic crystal structures. Interaction between SNPs and the CS-Cu²⁺ complex was also investigated by ultraviolet-visible. Results in vitro nematicidal effect of materials against Meloidogyne incognita showed that SNPs/CS-Cu²⁺ complex was more effective in killing second-stage juveniles (J2) nematodes and inhibiting egg hatching than that of CS and CS-Cu²⁺ complex. The values of LC₅₀ in killing J2 nematodes and EC₅₀ in inhibiting egg hatching of SNPs/CS-Cu²⁺ complex were 75 and 51 mg/l, respectively. These values were lower than those of CS and the CS-Cu²⁺ complex. The test results on the nematicidal effect against M. incognita on coffee pots showed that the SNPs/CS-Cu²⁺ complex was 100% effective at a concentration of 150 mg/l. Therefore, the SNPs/CS-Cu²⁺ complex could be considered as a biochemical material with potential for agricultural applications to control root-knot nematodes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.998-1005
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• 1997

Kimchi showed protective effect from oxidative damage generated by hydrogen peroxide and paraquat. To investigate the major components of kimchi which reduce the cytotoxicity against reactive oxygen species, keratinocyte(A431, epidermoid carcinoma, human) and fibroblast(CCD-986SK, normal control, human) were cultured under oxidative stress condition provoked by paraquat, a superoxide anion generator, and hydrogen peroxide in the absence or presence of kimchi ingredients. Most keratinocyte and fibroblast cells were killed by hydrogen peroxide and paraquat over 1mM concentration, but kimchi ingredients showed protective effects from oxidative damage generated by hydrogen peroxide and onion, among those, garlic showed the most remarkable preventive effect. Most of kimchi ingredients showed protective effect against paraquat, especially leek notably increased cell survival. For fibroblast cells, ginger had the preventive effect against paraquat, especially leek notably increased cell survival. For fibroblast cells, ginger had the preventive effect from cell killing by high dose of hydrogen peroxide, but most ingredients were not effective against paraquat.

• Journal of Dairy Science and Biotechnology
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• v.37 no.1
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• pp.82-82
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• 2019

• Communications of the Korean Mathematical Society
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• v.38 no.2
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• pp.589-598
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• 2023

Magnetic curves are the trajectories of charged particals which are influenced by magnetic fields and they satisfy the Lorentz equation. It is important to find relationships between magnetic curves and other special curves. This paper is a study of magnetic curves and this kind of relationships. We give the relationship between β-magnetic curves and Mannheim, Bertrand, involute-evolute curves and we give some geometric properties about them. Then, we study this subject for γ-magnetic curves. Finally, we give an evaluation of what we did.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.874-882
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• 2018

Curcumin is known to possess various biological functions, including anti-inflammatory, anti-oxidative, and anti-cancer activities. Natural killer (NK) cells are large lymphocytes that directly kill cancer cells. However, many aggressive cancers, including breast cancer, were reported to escape the successful killing of NK cells in a tumor microenvironment. In this study, we investigated the anti-cancer effect of curcumin in coculture of human breast carcinoma MDA-MB-231 and NK (NK-92) cells. We found that curcumin had an immune-stimulatory effect on NK-92 by increasing the surface expression of the $CD16^+$ and $CD56^{dim}$ population of NK-92. We confirmed that the cytotoxic effect of NK-92 on MDA-MB-231 was significantly enhanced in the presence of curcumin, which was highly associated with the activation of Stat4 and Stat5 proteins in NK-92. Finally, this improved anticancer effect of curcumin was correlated with decreased expression of pErk and PI3K in MDA-MB-231.

• Journal of dental hygiene science
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• v.14 no.1
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• pp.1-6
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• 2014

The purpose of this study was to investigate the killing effect of Candida albicans on hairless mouse-2 (HRM-2) mouse tissues. We tested the effectiveness of a non-thermal atmospheric pressure plasma in killing C. albicans strains. The viability of C. albicans was determined by counting the colony forming units (CFU), after non-thermal atmospheric pressure plasma treatment. When non-thermal atmospheric pressure plasma was repeatedly treated on mouse skin which inoculated with C. albicans. The C. albicans cells were planted on skin tissue, and then the infected mouse tissue was exposed to non-thermal atmospheric pressure plasma for 0 sec, 60 sec, 180 sec and 300 sec. The death rate of C. albicans was increased in dependent with treatment times. The three times of non-thermal atmospheric pressure plasma at the interval of 10 minutes significantly showed the 6 log CFU/ml reduction of death rate on HRM-2 mouse tissues. Thus, non-thermal atmospheric pressure plasma could be used for the disinfection of C. albicans on oral surface.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.3
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• pp.166-172
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• 2006

Metallo-${\beta}$-lactamase (MBL) can hydrolyze all ${\beta}$-lactams except monobactams and frequently coexists with various antibiotic resistance genes such as aminoglycoside resistance, sulfonamide resistance gene, etc. Therefore, the effective antibiotics against infections by these bacteria are markedly limited or can't even be found. We tried to search in-vitro antimicrobial combinations with synergistic effects for a VIM-2 type MBL producing Pseudomonas aeruginosa, isolated from clinical specimen. On the selection of antibiotic combinations with synergistic effects, we performed a one disk synergy test, modified Pestel's method, in agar without aztreonam (AZT). The bacteriostatic synergistic effects of this tests were scored as $S_1$ (by susceptibility pattern in agar without antibiotics), $S_2$ (by the change of susceptibility in agar with or without antibiotics) and $S_3$ ($S_1$ + $S_2$) and was classified into weak (1 point), moderate (2 points) and strong (3 points) by $S_3$ score. Subsequently, we carried out the time-killing curve for the antibiotic combinations with the strong synergistic bacteriostatic effect. One VIM-2 type MBL producing P. aeruginosa confirmed by the PCR showed all resistance against all ${\beta}$-lactams except AZT, aminoglycoside and ciprofloxacin. In the one disk synergy test, this isolate showed a strong bacteriostatic synergistic effect for the antibiotic combination of AZT and piperacillin-tazobactam (PIP-TZP) or AZT and amikacin (AN). On the time-killing curve after six hours of incubation, the colony forming units (CFUs/mL) of this bacteria in the medium broth with both combination antibiotics were decreased to 1/18.7, 1/17.1 of the least CFUs of each single antibiotics. The triple antibiotic combination therapy including AZT, PIP-TZP and AN was shown to be significantly synergistic after 8 hrs of exposure. In a VIM-2 MBL producing P. aeruginosa with susceptibility for AZT, the triple antibiotic combination therapy including AZT, PIP-TZP and AN may be considered as an alternative antibiotics modality against the infection by some MBL type. But the antimicrobial combination therapy for many more MBL producing isolates is essential to know as soon as possible for the selection of effective treatment against the infection by this bacteria.