• Journal of Microbiology
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• v.43 no.5
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• pp.398-405
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• 2005

Polyamines such as putrescine are small, ubiquitous polycationic molecules that are required for optimal growth of eukaryotic and prokaryotic cells. These molecules have diverse effects on cell physiology and their intracellular content is regulated by de novo synthesis and uptake from the environment. The studies presented here examined the structure of a putative polyamine transporter (Pot) operon in Streptococcus pneumoniae (pneumococcus) and growth of pneumococci in medium containing putrescine substituted for choline. RT-PCR experiments demonstrated that the four genes encoding the Pot system are co-transcribed with murB, a gene involved in an intermediary step of peptidoglycan synthesis. Pneumococci grown in chemically-defined media (CDM) containing putrescine without choline enter logarithmic phase growth after 36-48 hs. However, culture density at stationary phase eventually reaches that of choline-containing medium. Cells grown in CDM-putrescine formed abnormally elongated chains in which the daughter cells failed to separate and the choline-binding protein PspA was no longer cell-associated. Experiments with CDM containing radiolabeled putrescine demonstrated that pneumococci concentrate this polyamine in cell walls. These data suggest that pneumococci can replicate without choline if putrescine is available and this polyamine may substitute for aminoalcohols in the cell wall teichoic acids.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.255-259
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• 2002

To reduce the uncertainty in the calibration of radiation beams, absorbed dose to water for high energy electrons is recommended as the standards and reference absorbed dose by AAPM Report no.51 and IAEA Technical Reports no.398. In these recommendations, water is, defined as the reference medium, however, the water substitute solid phantoms are discouraged. Nevertheless, when accurate chamber positioning in water is not possible, or when no waterproof chamber is available, their use is permitted at beam qualities R$\_$50/ < 4 g/cm$^2$ (E$\_$0/ < 10 MeV). For the electron dosimetry using solid phantom, a depth-scaling factor is used for the conversion of depth in solid phantoms to depth in water, and a fluence-scaling factor is used for the conversion of ionization chamber reading in plastic phantom to reading in water. In this work, the properties, especially depth-scaling factors c$\_$p1/ and fluence-scaling factors h$\_$pl/ of several commercially available water substitute solid phantoms were determined, and the electron dosimetry using these scaling method was evaluated. As a result, it is obviously that dose-distribution in solid phantom can be converted to appropriate dose-distribution in water by means of IAEA depth-scaling.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.414-423
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• 2016

Growers in plug seedling production think that root media in which rockwool is a component has given rise to several environmental problems. Therefore, the demand for new materials as a substitute for rockwool has been increased. This study examined the possibility of cultivation of tomato plug seedlings using a newly developed growing medium with phenolic foam. Plug seeds of tomato cultivar 'Madison' were sown in four pellet-type growing media: Grodan rockwool (GRW), UR rockwool (URW), phenolic foam LC (LC) or phenolic foam LC-lite (LC-lite). Then, the seedlings were transplanted to the four cube-type growing media 19 days after sowing. Seeds were germinated in a growth chamber ($25{\pm}2^{\circ}C$, 80% relative humidity, and dark) for 4 days and then the seedlings were grown with a nutrient solution supplied by an overhead irrigation system in a greenhouse. Plant height, number of leaves, leaf area, and fresh or dry weight of tomato seedlings were the greatest for the seedlings transplanted to URW cube media after being grown on LC-lite pellets. Root grade was the greatest for the seedlings transplanted on LC or LC-lite cube media after being grown on LC pellets. Chemical properties of all media tested for tomato growth were maintained within a stable range, while physical properties of URW showed high values in container capacity, air space, and total porosity. These results demonstrated that the phenolic foam media were effective for seedling growth and can substitute for rockwool as a root medium.

• Journal of Mushroom
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• v.20 no.4
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• pp.270-273
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• 2022

The present study investigated the optimum additive ratio of wheat straw pellet as a substitute for beet pulp during oyster mushroom cultivation. The chemical properties across treatments were pH of 4.8-5.5, total carbon content of 45.9-46.5%, total nitrogen content of 1.5-1.7%, and carbon-to-nitrogen ratio of 27.8-31.0. Mycelial growth was the fastest in a medium containing 20% wheat straw pellet (at 88.2 mm in 'Heuktari' and 70.3-79.6 mm in 'Suhan-1Ho'); however, there were no significant differences in mycelial density among the treatments. The characteristics of fruiting bodies by variety were as follows. In 'Heuktari', the valid stipe number per bottle (1,100 cc) was 22.5 and yield was 177.1 g/1,100 cc in the mixed medium containing 10% wheat straw pellet, with the values being comparable to those of controls. In 'Suhan-1Ho', the valid stipe number per bottle (1,100 cc) was 14.0 and yield was 151.2 g/1,100 cc in the mixed medium containing 10% wheat straw pellet, with the values being comparable to those of controls.

• Korean journal of food and cookery science
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• v.31 no.1
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• pp.41-52
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• 2015

The substitute tea was manufactured from the leaves of Salvia plebeia R. Br. (SPR) that have anti-inflammatory and antioxidative activities. Total polyphenols and flavonoids in SPR were $71.8{\pm}4.74GAE\;mg/g$ and $38.7{\pm}2.95QUE\;mg/g$, respectively. DPPH radical scavenging activity of SPR water extract had an $RC_{50}$ of $16.9{\mu}g/mL$. SPR inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) production with an $IC_{50}$ of > $100{\mu}g/mL$. Medium and large leaves were used in the SPR substitute tea (SPRT). The water content was dissipated on roasting within approximately 10 minutes, and the tea obtained from fan-firing for a total 120 minutes was evaluated as most superior. Flavor was positively correlated with the taste and general preference. SPRT maintained its anti-oxidative activity without significant changes on roasting or fan-firing even after the heat treatment. The appropriate weight of a tea bag for one serving was 1.0 g. The study results indicated that SPR is a potential resource for the development of food or ingredients with anti-inflammatory properties.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.1
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• pp.49-62
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• 1994

In mammalian development, the embryo which is in the process of compaction, involves a progressive flattening of blastomeres against each other with the consequence that the embryo assumes a spherical shape. This stage happens in the first differentiation. The present study was aimed to examine the involvement of other metal ions in compaction by treating with various divalent cations in the absence of $Ca^{++}$. When 8-cell embryos were cultured in $Ca^{++}$-free medium for 24hrs, they developed to 16-cell stage but did not compaction, and degenerated after 48hrs of culture. Embryos were cultured in $Ca^{++}$-free medium for 24hrs and then transferred to the control medium showed the normal compaction afterwards. When 8-cell embryos were cultured in the presence of $Ni^{++}$, known as a $Ca^{++}$ inhibitor, they cleaved to 16-cell stage but did not compact in the absence of $Ca^{++}$. On the other hand, embryos cultured in the media containing both $Ca^{++}$ and $Ni^{++}$ developed normally so that they underwent compaction during culture for 48hrs. However, they failed to hatch during further 24hrs in the same medium, indicationg that $Ni^{++}$ may exert some harmful effects. Embryos grow in the control medium that contained $Ca^{++}$ but not $Ni^{++}$, developed to the hatched blastocysts. The treatment with $Cd^{++}$ $10^{-1}$,$10^{-2}{\mu}M$, $Mn^{++}$ or $Ba^{++}$ 10,100, $1000{\mu}M$ in $Ca^{++}$-free medium, respectively, inhibited compaction and embryonic degeneration began as in $Ca^{++}$-free medium. When 3, 5, 10mM of $Sr^{++}$, known as a substitute for $Ca^{++}$ in cell, was added to $Ca^{++}$-free medium, respectively, compaction was induced unlike the above metal ions. Embryos were cultured in $Sr^{++}$ developed to blastocysts, but failed to hatch after 72hrs and degenrated. On the other hand, when embryos were cultured in 3, 5, 10mM of $Sr^{++}$ but in $Ca^{++}$-free medium for 24hrs respectively and then transferred to the control, they showed the similiar development as that in the control.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.245-248
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• 2003

As a result of broth substitutions when each culture-mediums were difference, whole culture-medium was found to be best feeding solution for production of PS-7 by B. indica. Maximal production of PS-7 was 1$10.0\;g/{\ell}$ and its conversion rate from 2% (w/v) glucose to PS-7 was 50%. After 48 hr, 50%(v/v) medium of working volume began to substitute in 7L jar fermenter. Production of PS-7 increased after 48hr, recovered productivity of PS-7. Following this preliminary culture, the resultant culture was subjected to continuous flow conditions controlled that the dilution rate were $0.01\;{\sim}\;0.04\;h^{-1}$. Production of PS-7 increased at dilution rate $0.0100\;h^{-1}$ whereas productivity of PS-7 decreased gradually in dilution rate $0.0200\;{\sim}\;0.0400\;h^{-1}$. Maximal production of PS-7 was $10.0\;g/{\ell}$ in continuous culture.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.5
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• pp.1-11
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• 2000

This study is aimed to develop a proto-type LPG engine for medium-duty commercial vehicles in order to substitute for conventional diesel engine. Recently, it is recognized that diesel engines are main cause for smoke pollution in urban site. So, it is expected to reduce this environmental emission by developing and substituting LPG engine which has the advantage of practical use in a short development period in aspects of infrastructures. For that, after analysing the specifications and performance characteristics of a base diesel engine, parts of combustion chamber, intake system, fuel supply and ignition systems suitable for LPG combustion were re-designed and manufactured. And and engine controller for fuel supply and ignition distributions was matched by feedback mapping based on the speed-load conditions. The torque and power of LPG engine were increased by 6∼12% on the overall driving conditions compared to the base diesel engine, and fuel consumption rate marked the similar level based on the fuel price. Exhaust emissions such as THC, CO, NOx recorded the same order with conventional LPG engine for passenger car.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.82-92
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• 2021

Purpose: It has been reported that the diversity and abundance of microbes in the vagina decrease due to the use of antimicrobial agents, and the high recurrence rate of female vaginitis due to this suggests that a new treatment is needed. Methods: In the experiment, we detected that 10% potassium sorbate solution, 1% eucalyptus oil solution, 1% tea tree oil solution, 400 µL/10 mL grapefruit seed extract solution, 100% lactic acid, 10% acetic acid solution, and 10% lactic acid solution were prepared and used. After adjusting the pH to 4, 5, and 6 with lactic acid and acetic acid in the mixed culture medium, each bacterium was inoculated into the medium and incubated for 72 h at 35℃. Incubate and 0 h each. 24 h. 48 h. The number of bacteria was measured after 72 h. Results: In the mixed culture test between lactic acid bacteria and pathogenic microorganisms, lactic acid bacteria showed good results at pH 5-5.5. Potassium sorbate, which has varying antibacterial activity based on the pH, killed pathogenic bacteria and allowed lactic acid bacteria to survive at pH 5.5. Conclusion: The formulation ratio obtained through this study could be used for the development of a feminine cleanser that can be used as a substitute for antibacterial agents. Further, the findings of this study may be able to solve the problem of antimicrobial resistance in the future.

• Journal of Photoscience
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• v.7 no.4
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• pp.135-138
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• 2000

The photochemical behavior of haloarene tethered to alkyl by an amide bone(1,2) was studied. The photoreaction of N-(2-bromophenyl) cyclohexanecarboxamide (1b) in basic medium afforded intramolecular substitute product, 2-cyclohexylbenzoxazole (4) and reduced product, N-phenylcyclohexanecarboxamide (5)in 33 and 26% yield, respectively. The chloro analogue(1a) produced photo-Fries type and photosubstituted products(6,4), whereas the iodo analogue produced extensively photoreduced product 5. N-(2-bromophenyl)-N-methylcyclohexanecarboxamide (2), which can not exist as imidol form, produced a photocyclized product, supporting as imidol form is involved in the intramolecular photosubstitution. since the photoreduction but the photosubstitution reaction is retarded by the presence of oxygen, a trilpet state for the photoreduction and a singlet state for the photosubstitution are involved.