• Korean Journal of Plant Tissue Culture
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• v.25 no.1
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• pp.13-19
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• 1998

We have reported previously that intact embryogenic cells can be used instead of protoplasts for electroporation-mediated transformation of zoysiagrass and rice. In this study, conditions of the tissue electroporation were examined to optimize the procedures. Embryogenic cell suspensions were established in liquid MS medium containing 2 mg/L of 2,4-D with embryogenic calluses induced from mature embryos of Z. japonica. The suspension-cultured cell clumps were electroporated with 35S-gusA expression vector DNA, and degrees of DNA introduction into the cells were determined by histological expression rates of the gusA marker gene. DNA transfer into the cell clumps occurred in wide range of voltage (100-400 V) and capacitance (10-1980 $\mu\textrm{F}$), but more in the ranges of 200-300 V and 330-800 $\mu\textrm{F}$ DNA concentrations higher than 6 $\mu\textrm{g}$/mL were adequate for GUS expression of the electroporated cells. DNA transfers were confirmed in all three embryogenic cell lines but only in one out of eleven non-embryogenic lines. Positive GUS expressions occurred with DNAs added even 20-40 h after pulse treatments. As a promoter of gusA, Act1 and Ubi1 were effective 7 and 5 times than 35S respectively in number of GUS expression units on electroporated cell clumps. Embryogenic cell clumps survived and regenerated into plantlets after pulse treatments of wide range of conditions.

• Korean Journal of Plant Tissue Culture
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• v.21 no.4
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• pp.201-206
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• 1994

The influx of glycine, valine, alanine, and histidine was inhibited by all tested neutral amino acids competitively and the reciprocal inhibitory studies showed the neutral amino acids possess the same transport system as neutral amino acids process to the same catalytic site of one carrier to each other, The molecules of histidine were transported actively as a neutral form through the neutral amino acid transport system but were not transported as a charged form. The Km values of the neutral amino acid transport system have been divided into three different category on basis of the affinity to the carrier, below 0.1mM, etween 0.1ImM-0.5mM and above 0.5mM. The $V_{max}$ was between $3.12{\mu}mole{\cdot}h^{-1}{\cdot}g$ fresh $weight^{-1}\;-\;15.1\;{\mu}mole{\cdot}h^{-1}{\cdot}g$ fresh $weight^{-1}$. Neutral amino acids cotransported with one $H^{+}per$ one molecule and one $K^{+}-efflux$ per one molecule for charge compensation. Histidine cotransported with proton per one molecule, however the movement of cotransported proton can't detectable because of the release of proton from the charged molecules of histidine in the medium.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.1072-1077
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• 2010

Plant diseases including gray mold caused by Botrytis cinerea are often reduced when calcium compounds are used as alternative materials in paprika. However, much less information is available about the effects of calcium compounds on controlling of $B.$ $cinerea$. Seven calcium compounds such as calcium sulfate dihydrate, calcium chloride, calcium nitrate, calcium oxide, calcium hydroxide, calcium carbonate, and calcium hydride were evaluated for their effectiveness against $B.$ $cinerea$ on potato dextrose agar medium. The pH of selected calcium compounds was higher (pH 8.2-10) than that of the control (pH 6.6). Calcium carbonate, calcium oxide, calcium hydride, and calcium hydroxide among seven calcium compounds were more effectively inhibited the growth of $B.$ $cinerea$ than other calcium compounds. In the case of spraying the spore suspension on paprika applied with the selected four calcium compounds and supplied with the selected calcium supplements in a hydroponic culture system, the paprika treated with calcium compounds showed less severity of disease than those untreated plants. On the basis of our results, we propose that the suppressive effects of calcium compounds on $B.$ $cinerea$ in paprika resulted from the supply of calcium and a certain degree of salt stress.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.705-713
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• 2018

An automotive ball joint connects the suspension system to the steering system and helps to enable rotational and linear motion between the two elements for steering. This study examines a ball joint used in medium and large-sized pickup trucks. Ball joints consist of a stud, socket, bearing, and plug. The main structural performance metrics of ball joints are the pull-out strength and push-out strength. These structural parameters must meet certain criteria to avoid serious accidents. Test and simulation methods are used to investigate the design requirements, but tests are time-consuming and costly. In this study, we modeled ball joints in SolidWorks and performed a finite element analysis in Abaqus to predict structural performance. The analysis was used to obtain the structural performance required for the static analysis of a 2D axisymmetric model. The uncertainties in the manufacturing of the ball joint were assumed to be the manufacturing tolerances, and the dimensional design variables were identified through case studies. The manufacturing tolerances at each level were defined, and the results were compared with experimental results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.3
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• pp.1-7
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• 1983

In spite of extensive knowledge of the surface chemistry and the transport mechanism in filtration systems, there is still insufficient understanding of the physical characteristics of suspensions and the system components. Because of this, no filtration mechanisms are mathematically generalized to the full extent. The purpose of this paper is to propose experimental equations for the filtration process. using the tracer study in filter layer. Some of results are as follows. (1) The Volume of the specific deposit (${\sigma}$) in filtration was directly measurable using the tracer study without interrupting the filtration. (2) It was also confirmed that the head loss in filtration was greatly in fluenced by the micro-air babbles. (3) The correction coefficient(f) was introduced into the Kozeny-Carman equation in order to apply it for the clogging filter media. The coefficient(f) was experimentally obtained. The total head loss of the filter media is given by next equation. $${\frac{h}{h_0}}={\frac{1}{L}}{\int}^{z=L}_{z=0}f({\sigma})g({\varepsilon}_0,{\sigma})dz$$ $$f=aexp(-b{\sigma})$$ The above equation was applicable without regard to the variation of the suspension concentration, the filter medium diameter, the filter depth, the filtration velocity, and the amount of aluminum in all continuous filtration experiments. (4) The total head loss was graphically generalized assuming mathematical filtration models I II (see fig. 7,8) (5) The total head loss was obtained from the filtration model in the field filtration conditions. (see fig. 9,10)

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.151-156
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• 1994

Acifluorfen-tolerant cell lines of S, ptycanthum were isolated by stepwise selection using suspension culture. Growth of unselected line was completely inhibited at $0.5\;\mu\textrm{M}$, while some selected lines grew at $8\;\mu\textrm{M}$ acifluorfen. After subculturing on acifluorfen-free medium for 4 passages, six of the eleven cell lines screened and maintained their tolerance to $2\;\mu\textrm{M}$ acifluorfen. The regeneration capacity of selected cell lines in Solanum ptycanthum differed depending on the tell line. The acifluorfen tolerance of the somarclones regenerated from acifluorfen-tolerant cell lines differed depending on the somarclone. When plants were heated with $16\;\mu\textrm{M}$ acifluorfen, unselected control plane had over 75% phytotoxicity Many selected cell lines had less phytotoxicity than the seed-grown control plants. Tolerance to acifluorfen was inherited to the self-pollinated progenies. The inheritance patterns differed depending on the clone. Acifluorfen tolerance was inherited as a semidominant trait. Other segregation patterns were also observed. acifluorfen tolerance was recessive and acifluorfen sensitivity was dominant.

• KSBB Journal
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• v.11 no.1
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• pp.22-29
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• 1996

Immobilized bioprocess was carried out for continuous production of cyclosporin A (CyA) produced intracellularly as a secondary metabolite by a filamentous fungus, Tolypocladium inflatum. Immobilization procedure for entrapping conidiospores of the producer was significantly simplified by use of a modified immobilization technique. A newly-designed immobilized perfusion reactor system (IPRS) showed good process benefits as demonstrated by the role of the high density immobilized cells as an efficient biomass generator, continuously supplying highly active CyA-producing free cells (1.0g/$\ell$/hr) even at very high dilution rate ($0.1hr^{-1}$). IPRS bioprocess was possible since efficient decantor system developed in our laboratory separated the sloughed-off free cells from the immobilized biomass effectively, thus overcoming wash-out phenomenon frequently encountered in continuous free cell cultures. Furthermore the released-free cells remaining in the bulk solution did not appear to cause substrate mass transfer limitation which was often experienced in suspended mycelial fungal cell fermentations. The primary reason for this was that the suspension broth of the IPRS mainly consisted of roundshaped short mycelial fragments and conidiospores, still remaining Newtonian even at high cell density. In parallel with IPRS bioprocess development, other key factors to be considered necessarily for significant increase in CyA productivity would be strain improvement and medium optimization for the immobilized cells.

• The Korean Journal of Mycology
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• v.36 no.2
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• pp.148-152
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• 2008

We inoculated hypal suspension of Tricholoma matsutake and T. magnivelare were examined on Pinus densiflora seedlings grown in a granite soil substrate with 1/2 PDMP (12 g/l potato dextrose broth, 1.5 g/l malt extract, and 0.5 g/l peptone) medium. Four months after inoculation, the pine seedlings were examined for infection rate, matsutake aroma, and Hartig-net formation. The roots of pine seedling formed ectomycorrhizal roots in the 9 isolates from 12 isolates of T. matsutake and T. magnivelare. However, the seedlings showed different ectomycorrhizae forming rates among the 9 isolates. While matsutake aroma was confirmed from the ectomycorrhizal seedlings, the pine seedling contaminated by bacteria or fungi did not form matsutake ectomycorrhizae with sickening smell. Thus, the aroma was chosen as a good way for the verification of mycorrhizal infection. At the early stage, the mycorrhizal roots showed unramified and branched types without root hair. They also showed thin mantle layers, Hartig-nets, and turned into black color at later stage. Among the examined strains, that of Yecheon isolated in 1995 showed the best infection rate, which indicated that we need to pay attention to the selection of isolates for better result.

• Parasites, Hosts and Diseases
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• v.26 no.3
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• pp.169-174
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• 1988

The role of passive cell-mediated transfer of immunity against primary amoebic meningoen- cephalitis(PAME) in mice was studied. Waegleria fowleri, ITMAP 359, were cultured in CGVS medium. The ICR mice used were six week-old males of average weight of 15 g. Immunization was done by three intraperitoneal injections of $1{\times}10^6$ N. fowleri trophozoites at the interval of one week. Splenocytes were obtained from normal and immune mice spleens, and Ix107 cells were administered intraperitoneally into mice 3 days before challenge infection. Mice were infected intranasally with $7{\times}10^4$ N. fowleri trophozoites in a $3{\;}{\mu}l$ suspension under secobarbiturate anesthesia. Transplants of normal or immune splenocytes seem to alter the pattern of the PAME level- opment. The splenocytcs transferred from immune mice reduced the mortality rate in the JV. fowleri infected mice, as compared with the mice transferred with the same number of normal splenocytes or without splenocyte, The blastogenic response of the splenocytes to both lipopoly- saccharide and concanavalin A was elevated on duty 7 after infection the mice transinoculated with immune splenocytes. The serum antibody titers in the mice transferred with immune spleno- cytes were increased gradually from day 7 up to day 20 after infections by mean of ELISA. It is suggested that the transfer of splenocytes from immuniged mice conferred immunity against N. fowleri infection.

• Parasites, Hosts and Diseases
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• v.23 no.2
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• pp.293-299
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• 1985

This study is to verify the protective ability against experimental Naegleria meningoencephalitis by immunization with Naegleria fowleri in mice. Naegleria fewleri, strain 0359, and Naegleria gruberi, strain EGB, were used in this study, and cultured in CGVS medium akenically. Inbred BALB/C mice, weighing about 20g, were immunized by three intraperitoneal injection of $1{\times}10^6$ N. fowleri trophozoites at the interval of one week. This N. fowleri trophozoites antigen was fixed with 5% formaldehyde. N. fowleri trophozoites from culture were homogenized with soiicator at $4^{\circ}C$ as monitored by phase contrast microscopy, and their membrane and cell content preparations were made for the immunization of mice. Their inoculation dose in volume was equivalent to the $1{\times}10^6$ trophozoites in each injection for immunization. And N. gruberi trophosoites, whieh was fixed with 5% formaldehyde, were also used for immunisation. Mice were inoculated intranasally with $5{\times}10^4$ N. fowleri trophozoites in a 511 suspension under anesthesia by as intraperitoneal injection of about 1 mg secobarbiturate. Nervousness, rotation or sluggish behaviour were observed in the mice which were infected with N. fewleri. Necrotic lesion was demonstrated in the anterior portion of brain, especially in the olfactory lobe. The inflammatory cell infiltration with numerous H. fowleri trophozoites was noticed. This pathological changes were more extensive in the control than in the experimental groups. Mice were dead due to experimental primary amoebic meningoencephalitis that developed between 8 days and 23 days after inoculation. Mortality rate of the mice was low in the immunized experimental group. Mean survival time, which is the survival duration of mice from the infection to death, was prolonged significantly in the immunized mice except in the mice immunized with JV, fowleri membrane. Even in the mice immunized with N. gruberi, survival time was delayed. In summary, the effectiveness of immunization is demonstrated in terms of protective immunity against Naegleria meningoencephalitis in mice.