• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.783-794
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• 2024

The antifungal activity of fisetin against Candida albicans is explored, elucidating a mechanism centered on membrane permeabilization and ensuing disruption of pH homeostasis. The Minimum Inhibitory Concentration (MIC) of fisetin, indicative of its interaction with the fungal membrane, increases in the presence of ergosterol. Hoechst 33342 and propidium-iodide staining reveal substantial propidium-iodide accumulation in fisetin-treated C. albicans cells at their MIC, with crystal violet uptake assays confirming fisetin-induced membrane permeabilization. Leakage analysis demonstrates a significant release of DNA and proteins in fisetin-treated cells compared to controls, underscoring the antifungal effect through membrane disruption. Green fluorescence, evident in both the cytoplasm and vacuoles of fisetin-treated cells under BCECF, AM staining, stands in contrast to controls where only acidic vacuoles exhibit staining. Ratiometric pH measurements using BCECF, AM reveal a noteworthy reduction in intracellular pH in fisetin-treated cells, emphasizing its impact on pH homeostasis. DiBAC4(3) uptake assays demonstrate membrane hyperpolarization in fisetintreated cells, suggesting potential disruptions in ion flux and cellular homeostasis. These results provide comprehensive insights into the antifungal mechanisms of fisetin, positioning it as a promising therapeutic agent against Candida infections.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.4
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• pp.413-418
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• 1985

Tobacco plant(8-leaf seedlings) were grown on water culture fertilized with different N sources ($NO_3-N$, $NH_4-N$, $NO_3+NH_4-N$) during 15 days. Daily uptake of nutrients and inorganic constituents in plants were investigated in relation to growth responses of them. 1. Nitrate-fed plant showed higher daily uptake of inorganic cations than those in other treatments, and reached about two times higher uptake of nitrogen and three times more uptake of cations (K, Ca, Mg). Potassium was preferentially uptaken at a very fast rate from the beginning after treatment. Also $NO_3-N$ tended to be taken up selectively by the plant from the mixture of nitrate and $NH_4-N$. 2. The initial pH (pH 6.0) of culture medium drastically changed into acid (pH 4.0) in the $NH_4-N$ medium, but into slightly higher (pH 6.4) in the nitrate when measured after exposure of 24 hours. The mixture also tended to show an acidity but much weaker than $NH_4-N$ solution. 3. Nitrate-fed plant had a normal growth pattern but $NH_4-N$ fed plant almost stopped growing. Those plants containing both nitrate and ammonium N were also showed very poor growth.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.112-119
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• 2023

In this study, the variations in CO₂ uptake according to the type and amount of alkali-based activator (Ca(OH)₂, CSA) of geopolymer paste were evaluated. As the amount of activator added to the geopolymer paste increased, the fluidity of the paste is decreased and the compressive strength increased. According to the type of activator, it was confirmed that the addition of Ca(OH)₂ had a greater effect on improving the compressive strength than CSA. As a result of changes in chemical properties according to carbonation curing, the amount of C-S-H and C-A-S-H gels produced before carbonation increased as the amount of activator increased, and amount of CaCO₃ produced after carbonation increased. The reactivity of the blast furnace slag and zeolite increased due to the addition of the activator, and the reactivity tended to increase as the amount of addition increased. As a result of CO₂ uptake, 10.3 wt% when Ca(OH)₂ 10 % was added and 8.77 wt% when CSA 10 % was added was confirmed. It increased by 421 % and 388 % respectively, compared to the case where no activator was added.

• Journal of Yeungnam Medical Science
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• v.7 no.1
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• pp.29-37
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• 1990

The effects of insulin and exercise on glucose uptake of skeletal muscle were investigated in soleus muscle isolated from low dose streptozotocin induced diabetic rats in vitro. Glucose uptake was assessed by measuring $^3H$-methylglucose uptake in vitro. Basal glucose uptake in diabetes was reduced by approximately one-third of the control value($5.6{\pm}0.73{\mu}Mol$/g/20min. in diabetes versus $8.4{\pm}0.77$ in control, P<0.01). There was also a significant decrease(P<0.01) in glucose uptake of diabetes at physiologic insulin concentration ($200{\mu}IU$/ml) by 40% ($6.1{\pm}1.20$ versus $10.0{\pm}0.81$). Furthermore, maximal insulin($20000{\mu}IU$/ml)-stimulated glucose uptake was 36% lower in diabetes as compared with control($7.3{\pm}1.29$ versus $11.4{\pm}1.29$, P<0.01). In contrast, exercise(1.0km/hr, treadmill running for 45min.) effect on glucose uptake was so dramatic in diabetes that glucose uptake at basal state was 8.4+1.09 and insulin stimulated-glucose uptake were $10.2{\pm}1.47$ and $11.9{\pm}1.64$, in 200 and $20000{\mu}IU$/ml added insulin, respectively. These results suggest that insulin insensitivity develops in skeletal muscle after 2 weeks of streptozotocin-induced diabetes, but these insensitivity was recovered significantly by single session of running exercise.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.111-111
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• 2005

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2005.10a
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• pp.111-111
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• 2005

• Korean Journal of Microbiology
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• v.13 no.2
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• pp.45-50
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• 1975

Uptake of $^{14}C$-sorbose and $^{14}C$-3-O-methylglucose by ungerminated conidia of Neurospora crassa was measured by means of the millipore filter technique. Initial rates of jptake of both sorbose and 3-O-methylglucose show a marked dependence optimal pH for uptake of both sugars is close to 4.75. When ungerminated conidia are "starved" with buffer for a prolonged period of time prior to assaying their transport capacity and mycelia, no de-repression of the glucose-repressible sugar transport system is effectuated in contrast to the findings for germinated conidia.d conidia.

• Proceedings of the Korean Society of Crop Science Conference
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• 1988.02a
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• pp.14-15
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• 1988

• KSBB Journal
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• v.11 no.2
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• pp.173-180
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• 1996

The contamination of the environment by heavy metals results in a serious public health problem due to the toxicity of those pollutants even at low concentrations. Microorganisms may be used to remediate wastewaters contamlialtd with heavy metals. The waste S. cerevisiae is an inexpensive readily available source of biomass for bioremediation of wastewater. S. cerevisiae was investigated for their ability to absorb Pb. The crushed biomass of S. cerevisiae exhibited higher Pb uptake capacity than the living S. cerevisiae and the sterilized S. cerevisiae. At the same metal concentration, metal uptake per unit concentration or adsorbent decreased when the biomass concentration rises. The order of the biosorption capacity of the living S. cerevisiae was Pb>Cu>Cd=Co>Cr. When S. cerevisiae was pretreated with 0.1 M NaOH, Pb uptake was increased by 150 percent and 0.1 M HC1, 0.1 M $H_2S_O4$ solutions were efficient in the desorption of Pb. The sorption equilibrium of Pb ions can be described by the Freundlich and Langmuir models.

• Journal of Oral Medicine and Pain
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• v.21 no.1
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• pp.7-14
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• 1996

This study was performed to compare the anticarious effects of different fluoride agents(NaF, $NH_4F, TIF_4,$ APF gel, Elmex gel ) on artificial carious lesion. Enamel samples treated with 5 kinds of fluoride agents by pH cycling method were evaluated for fluorine uptake, enamel solubility, and microhardness. The results were as follows : 1. Greater fluoride uptakes were obtained in carious lesion treated with APF gel and $TiF_4$ solution than in that treated with other fluoride solutions. 2. TiF4 group was more resistant to acid than otter groups, but it was not significantly different with APF gel group. 3. Surface of enamel specimen was harkened by fluoride application and pH cycling. APF gel was more effective on enhancing surface hardness than control group. 4. APF gel, $NH_4F, TIF_4,$ solution were effective on fluoride uptake, enamel solubility, and microhardness.