• Journal of Dairy Science and Biotechnology
• /
• 제35권2호
• /
• pp.121-133
• /
• 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
• /
• 제40권3호
• /
• pp.261-271
• /
• 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.

• 한국식품영양과학회지
• /
• 제26권6호
• /
• pp.998-1005
• /
• 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
• /
• 제37권1호
• /
• pp.82-82
• /
• 2019

• 대한수학회논문집
• /
• 제38권2호
• /
• pp.589-598
• /
• 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
• /
• 제28권6호
• /
• pp.874-882
• /
• 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.

• 치위생과학회지
• /
• 제14권1호
• /
• pp.1-6
• /
• 2014

본 연구는 저온 상압 플라즈마 장치를 이용하여 구강점막질환을 일으키는 C. albicans 균을 효과적으로 사멸하기 위해 시행하였다. 조직에 적합하게 처리될 수 있도록 저온 상압 플라즈마 장치를 고안하고, 먼저 agar plate에 C. albicans 균을 처리하여 플라즈마를 조사한 결과 agar plate표면에 C. albicans 균을 처리 후 저온 상압 플라즈마 장치를 적용한 결과 60초 처리시 1.2 cm, 180초 처리시 1.4 cm, 300초 처리시 1.7 cm의 박테리아 생장 억제 구간이 나타나는 것을 확인하였다. 또한, 조직에서의 구강병원균 사멸 효과를 확인하기 위해 HRM-2 마우스 조직에 C. albicans 균을 처리하여 저온 상압 플라즈마를 조사 시 마우스 조직 표면에 C. albicans 균을 오염시켜 저온 상압 플라즈마 처리 후 CFU 방법으로 측정한 결과 300초간 1회 처리시 2 log CFU/ml, 300초간 2회 처리시 3 log CFU/ml, 300초간 3 회 처리시 6 log CFU/ml의 균 수 감소 효과가 나타나는 것을 확인하였다(p<0.05). 따라서, 저온의 저온 상압 플라즈마 장치는 효과적으로 구강 병원균을 사멸시킬 수 있으며, 구강점막질환 치료 장비로서 사용될 수 있을 것으로 생각된다.

• 대한임상검사과학회지
• /
• 제38권3호
• /
• pp.166-172
• /
• 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.

• 한국수산과학회지
• /
• 제31권4호
• /
• pp.523-528
• /
• 1998

즉살 활어 수송방법을 확립시키기 위한 연구의 일부로, 냉각시키기 전에 활 넙치의 생사의 차이가 냉각저장 ($0^{\circ}C$)중에 넙치육의 사후조기의 물리$\cdot$화학적 변화에 미치는 영향에 대하여 실험한 결과를 요약하면 다음과 같다. 1. 냉각시키기 전에 살아있는 것이 마취사 시킨 것보다 경직개시시간 및 완전경직에 도달하는 시간이 빨랐다. 2. ATP 분해도 냉각시키기 전에 살아있는 것이 마취시킨 것보다 빨랐다. 즉, 냉각시키기 전에 살아있는 것은 냉각저장 17.5시간 후에 완전히 분해되었지만, 마취사 시킨 것은 20시간까지 서서히 감소하다가 그 후에 급속히 분해되어 30시간 후에 완전히 분해되었다. 3. 육의 파괴강도는 냉각시키기 전에 살아있는 것이 냉각저장 7.5시간후에 대조구보다 약 $26\%$증가하여 최대값을 나타내었으며, 마취사 시킨 것은 저장 20시간 후에 약 $22\%$만큼 증가하여 최대값을 나타내었다. 4. 유산의 증가는 냉각시키기 전에 마취사 시킨 것은 저장 10시간까지 유산생성이 억제되었으며, 그 이후로 증가하여 저장 25시간 후에 최대값에 도달하였다 한편, 살아있는 것은 유산의 증가가 빨라 저장 15시간 후에 최대 값에 도달하였다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권7호
• /
• pp.3477-3481
• /
• 2012

Purpose: To investigate the killing effect on OS cells of a combination of oxaliplatin and TRAIL and related molecular mechanisms. Methods: TRAIL and oxaliplatin were applied to OS732 cells singly or jointly and survival inhibition rates were measured by MTT assay, changes of cellular shape being assessed with inverted phase contrast and fluorescence microscopy. Apoptotic rates were analyzed by flow cytometry (FCM) and immunocytochemistry was used to examine Mcl1 expression of OS732 cells. Results: The survival inhibition rate of combined application of $100{\mu}g/ml$ TRAIL and $1{\mu}g/ml$ oxaliplatin on OS-732 cells was significantly higher than that of either agent singly (p<0.01). Changes of cellular shape and apoptotic rates also indicated apoptosis-inducing effects of combined application to be much stronger than those of individual application. Oxaliplatin had the effect of down-regulating Mcl1 expression and sensitizing OS cells to TRAIL-induced apoptosis. Conclusion: A combination of TRAIL and oxaliplatin exerts strong killing effects on OS-732 cells which might be related to down-regulation of Mcl1 expression.