• Journal of Fisheries and Marine Sciences Education
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• v.18 no.1
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• pp.1-10
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• 2006

A total of 480 questionnaires were sent out for this study and 414 collected, and 410 analyzed excluding inadequate ones. The major findings were as follows:First, the middle school teachers recognized their schooling culture to be neither positive nor negative in nature, rather neutral. They felt administrative work was over emphasized in schools. Second, their overall job satisfaction was slightly above neutral. Factors of organizational structure, human relations, and work-itself showed above neutral and only 'reward and self-actualization' factor below neutral: The 'reward and self-actualization' factor was hindrance to job satisfaction.Third, schooling culture and job satisfaction showed negative correlation: a toxic culture.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.4
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• pp.185-193
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• 2002

With Increasing awareness towards environment-friendly and non-toxic pesticide azadirachtin obtained from neon tree (Azadirachta indica) is gaining more and more importance. Its broad-spectrum activity, Peculiar mode of action. eco-friendly and non-toxic action towards beneficial organisms has offered many advantages over chemical pesticides. All currently use commercial formulations based on azadirachtin contains azadirachtin extracted from seeds of naturally grown whole plants which is labour intensive process depending upon many uncontrollable geographical and climatic factors. Plant tissue culture can be a potential process for the pro-duction, offering consistent, stable and controlled supply of this bioactive compound, However the research on tissue culture aspects of production are in preliminary stage and requires culture and process optimization for the development of a commercially viable process. This review states the present status and future challenges of plant tissue culture for azadirachtin production.

• Applied Biological Chemistry
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• v.37 no.5
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• pp.392-396
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• 1994

The toxic substance causing blown blotching on the mushroom cap was extracted and purified from the culture broth of P.tolaasii. Purification and identification of the toxic compound was carried out with the silica gel chromatography, mass spectrum and NMR and appeared to be an aminobenzene in amylamine group. The purified toxic substance showed UV spectrum at 234nm and melting point at $76^{\circ}C$, respectively.

• Animal cells and systems
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• v.5 no.2
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• pp.139-143
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• 2001

Alzheimer's disease is the most common form of dementia and no cure is known so far. Extensive genetic works and in vitro experiments combined with clinical observations link amyloid $\beta$--protein (A$\beta$-) to the pathogenesis of Alzheimer's disease (AD). It was hypothesized that $A\beta$- becomes toxic when it adopts a fibrillar conformation. Recently, non-fibrillar form of $A\beta$- was observed and the potential role in the pathogenesis of AD became an interesting subject. In this study, the cytotoxicity of non-fibrillar $A\beta$- and fibrillar $A\beta$- was compared on oxidative stress, membrane damage, or nucleosome break down. Non-fibrillar $A\beta$- was not toxic in peripheral nervous system-derived cells but significantly toxic in central nervous system-derived cells while fibrillar $A\beta$- was non-selectively toxic in both cell culture. The neurotoxicity of non-fibrillar $A\beta$- was reproduced in semi-in vivo culture of mouse brain slice. In conclusion, non-fibrillar $A\beta$- could be more relevant to the selective neurodegeneration in Alzheimer's brains than fibrillar $A\beta$- and further research needs to be done for identification of the cause of AD.

• International Journal of Advanced Culture Technology
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• v.12 no.2
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• pp.236-248
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• 2024

This study aims to empirically analyze the effects of leadership level and toxic leadership on leadership performance results among male and female military leaders in the Army, and to verify whether the leader's gender has a moderating effect in this process. Additionally, by comparing and analyzing the leadership level, toxic leadership, and leadership performance results of female military leaders by position, this study seeks to examine the characteristics of female military leadership according to position. The research model was established with leadership level and toxic leadership as independent variables, leadership performance results as the dependent variable, and the leader's gender as a moderating variable. Data were collected through a survey of 216 male and female officers serving in the positions of platoon leader, company commander, and battalion commander in the Army. The collected data were analyzed using descriptive statistics, reliability analysis, correlation analysis, and hierarchical regression analysis. The results showed that leadership level had a significant positive effect on leadership performance results, while toxic leadership had a significant negative effect. The leader's gender moderated the relationship between leadership level and leadership performance results, with female leaders receiving lower evaluations than male leaders at the same level of leadership competency. Gender also moderated the relationship between toxic leadership and leadership performance results, with female leaders exhibiting the same level of toxic leadership receiving lower performance evaluations than male leaders. In the comparative analysis of female military leadership characteristics by position, the leadership level of the platoon leader and company commander groups was not significantly different from that of male soldiers, but the battalion commander group showed slightly lower leadership competency compared to male soldiers. Based on these results, this study suggests ways to improve the leadership level of female military leaders, reduce toxic leadership, and prepare support measures to strengthen the leadership competency of female military officers at the battalion commander level and above from policy, institutional, and educational perspectives.

• KSBB Journal
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• v.23 no.2
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• pp.183-185
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• 2008

Studies were made to remove the toxic phytohormone, 2,4-D, in suspension cultures of Panax vietnamensis. Cells grown in normal MS medium with 2,4-D were inoculated and grown in the MS medium without hormone. Not a big difference was observed in growth characteristics between media with and without 2,4-D. The 2,4-D in the culture, however, was completely removed. During the culture, the residual 2,4-D was consumed rapidly at the early growth stage. The intra-cellular 2,4-D was consumed first and the 2,4-D in the medium was used afterward.

• Korean Journal of Microbiology
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• v.12 no.2
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• pp.59-68
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• 1974

With an aim to disclose causal factors scably grains intoxications, the screening of toxic Fusaria and the detection of toxic priniciples were performed in respect of cultured cells bioassay with HeLa cells, skin-necrotizing effect, histopathological investigation and also chromatographic analysis sith following results ; 1. Among the fungi, Fusarium sp. F-27, F-63 and F-61 were highly toxic to mice, causing liver injury characterized necrosis and inflammation. 2. HeLa cell culture bioassay demonstrated that the cell of the isolated strains of Fusaria were suspected to produce toxic material (Fusarenon-X). 3. The culture filtrates of Fusarium nivale Fn-2B, F-27, and F-63, were injected subcutaneously, and caused inflammation followed by crust on the skin ICR-mice. 4. The observation method of skin-necrotizing effect to the mice can be used to the screening to the toxin-producing fungi isolated from many fusarial contaminations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.1
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• pp.51-60
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• 1990

Some species of dinoflagellates were considered as one of the causative organisms of PSP(Paralytic Shellfish Poison) or DSP(Diarrhetic Shellfish Poison). Fish and shellfish are intoxicated by feeding of toxic plankton, sometimes human is intoxicated by feeding on these intoxicated fish and shellfish. In past ten years, the physiological and ecological studies of the toxic plankton has been investigated for development of monitoring system and preventation and control measures of PSP. However, in our country still little is known on a research for the toxic dinoflagellates. This paper reviews the general biology, taxonomic problem, physioecology and culture method of the toxic planktons such as Protogony-aulax and Dinophysis.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.2
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• pp.84-91
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• 2000

Mycopasma contamination of tissue culture cells easily evades detection and, thus, represents a continous therat to cell biologists. In case where infected cell can not simply be replaced, attempts have to be made to eradicate mycoplacma from the tissue culture cells. A variety of anti-microbial agents have been shown to be toxic to mycoplasma strains ; however, cell associated mycoplasma are often protected from antibiotics at concentrations shown to be effective in vitro. Antibiotic concentrations high enough to be lethal to cell as sociated mycoplasmas frequently are also detrimentrations to the host cells, while moderately increased antibiotic levels tolerated by the host cells often lead to only temporary growth suppression and/or to the emergence of mycoplasma strains resistanct even to high concentrations of the antibiotis applied. Hare, a genetic approach for the elimination of mycoplasma from tissue culture cells that overcomes thens limitations is described. By expression of a selection marker conferring resistance to an otherwise toxic agent, Acholeplasma laidlawii infected BHK-21 cells used as the model system were enabled to temporarily tolerate antibiotic concentrations high enough to be lethal to cell associated mycopalsma while leaving the host cells unharmed. Upon successful mycoplasma eradicated, cultvation of the cured host cells in the absence of the selective agent yielded revertant cell clones that had regained susceptibillity to the toxic agent. Cressation of the selection marker expression was shown to result from the loss of the selection marker DNA, which is a consequence of the fact that the stable and permanent integration of foreign DNA in eucaryotic cell chrosomes is highly inefficient. Thus, the cells were cured from mycoplasma yet remained biochemically unaltered.

• Journal of Life Science
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• v.9 no.3
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• pp.293-299
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• 1999

Accumulation of toxic waste byproducts in hybridoma culture can limit cell growth and monoclonal antibody (MAb) productivity, and one of the major toxic metabolites is lactate produced via glycolytic pathway of glucose metabolism. The factors affecting the glucose to lactate conversion rate were investigated. The conditions of high initial glucose concentration and high growth rate stimulated glucose to lactate conversion rate. The glucose-controlled fed-batch culture was investigated, and 19% reduction in lactate formation and 41% enhancement of MAb titer could be achieved by fed-batch culture.