• Journal of the Korean Wood Science and Technology
• /
• v.37 no.1
• /
• pp.65-72
• /
• 2009

Variation of wood rays within a growth ring and along axial direction in Pinus koraiensis and Larix kaempferi, which are important Korean commercial softwoods, was examined to get some useful information for their effective utilization. Ray height in cell number and ray number per $0.25mm^2$ in tangential section were investigated by optical microscopy. The average heights of uniseriate rays in Pinus koraiensis and Larix kaempferi were 6.3 and 9.1 cells, respectively. The average numbers of uniseriate rays per $0.25mm^2$ in Pinus koraiensis and Larix kaempferi were 6.5 and 7.5, respectively. The average heights of fusiform rays were about 20 cells but were not significantly different in both species. From earlywood to latewood within a growth ring, the heights of uniseriate and fusiform rays decreased but their numbers remained almost constant. Along axial direction, the heights of uniseriate rays in both species increased with the increase of stem height, and the numbers of uniseriate rays per $0.25mm^2$ in Pinus koraiensis were nearly constant from 0.2 m to 5.2 m but increased up to 19.2 m beyond 5.2 m. However, a constant pattern in the numbers of uniseriate rays was not observed in Larix kaempferi. The heights of fusiform rays in both species were the highest in middle part of stems but were the lowest in base and top of trees. In conclusion, the ray variation pattern was comparatively clear within a growth ring but not clear along axial direction.

• Journal of the Korean Wood Science and Technology
• /
• v.48 no.4
• /
• pp.513-526
• /
• 2020

The existing preservation methods are difficult to be applied to a large dimension log which is needed for making traditional wooden ship 'Jalur' in Riau Province. Novel techniques to provide the use of readily available species to replace traditional species alternative were investigated. These included infusion and a combination of injection and bandage-wrapping methods for preserving living trees of Balam (Macaranga conifera (Rchb.f. & Zoll.) Müll.Arg.) and Bintangor (Calophyllum soulattri Burm.f.). Water-based boron compounds were applied as wood preservatives. In total, 18 discs from the bottom, middle, and top of four trees and two controls were used. Trees undergoing treatment were also used to see how wood anatomical structure might affect the boron penetration. The overall aim was to identify the best method for use in Jalur manufacturing. The results showed that in infused Balam tree where the hose position for the preservative intake was deep (10-15 cm from the bark), no boron compound was observed in the outer sapwood. Combination of injection and bandage-wrapping method gave higher percentage of boron penetration at bottom and middle of Balam tree. However, infused Bintangor showed 100% boron penetration. The larger vessel diameter, the absence of tyloses, and the simple perforation plates in Bintangor wood were likely to have contributed to the higher penetration of boron. The combination of bandage-wrapping and infusion, or alternatively by infusing the living trees close to the bark, and at as low as position in the stem gives better protection when treatments are applied to living trees.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.5
• /
• pp.503-514
• /
• 1997

The morphogenesis of panicle and spikelet in paddy rice has been studied in high yielding Indica$\times$Japonica hybrid cultivar, Milyang 23 and a Japonica type cultivar, Koshihikari. Germinated seeds planted in $5000^{-1}$ a pots filled with submerged soil and cultured under natural conditions. The young panicle of main stem were continuously dissected and observered by Cryo-SEM from the panicle initiation stage until heading stage. Although the date of panicle differentiation and heading in Koshihikari earlier than those of Milyang 23. the sequence of panicle development in two cultivars begins when first bract primordium at opposite side of flag-leaf primordium differentiated, synchronously followed by growth of the primary branch primordia (PBPs) and secondary branch primordia (SBPs), spikelet primordia(SPs), glumes as lateral organs on rachilla and organs composing single floret, and successive sporogenesis in the young spikelets continue after the enclosure by lemma and palea. The PBPs are acropetally initiated from the base of the panicle primordium, and the SBPs alternately differentiate from the base of upper PBP which differentiate later than the lower PBP. Spikelet development starts at the top of upper side PBP of the young panicle and continue basipetally even though SBPs continue to develop at the lower primary branch. Each PBP, SBP and SP differentiate with differentiation bract or bract hair cell around the base of each their primordia. The observation could confirm that Milyang 23 has not only 2~3 more defferentiated PBPs, but also more SBPs and SPs especially from middle-lower primary branch, at end of their differentiation stages, as compared to those of Koshihikari.

• Korean Journal of Plant Resources
• /
• v.12 no.2
• /
• pp.107-119
• /
• 1999

In this study, the induction regeneration of callus from immature embryo in trifoliata orange (Poncirus trifoliata RAFIN.) were accomplished. The embryogenic calli were induced from the immature embryo derived from seed when the calli were irradiated for 16hr at about 2,000 Lux in $\frac{1}{2}$ MS medium supplemented with 3% sucrose, and 44.4$\mu$M BA. Regeneration to whole plants was the most successful in MS medium containing 5.0$\mu$M BA. The yellowish callus was developed at 2 to 3 weeks of culture and the callus was changed from yellow to green at 5 to 6 weeks culture. In vitro regeneration was directly induced from embryogenic callus in MS medium containing 3% sucrose and 5.0$\mu$M BA. Multishoot was formed at 16 weeks culture. Moreover, when the root-formed plantlet was transplanted to soil, they grew to a whole plant. The compact cultured-cells were observed by light microscope after 4 weeks of cultivation and the embryogenic clumps were formed about the 5 weeks. At the same time, the neighboring cells were liquefied. In addition, differentiation of leaf and stem from the callus was observed after 12 weeks. The developed oil sacs and the profacicular cambium of the immature leaf were observed after 18 weeks. Therefore, we can see the considerable changes of cell arrangements according to the developmental stages of calli from trifoliata orange.

• Korean Journal of Plant Resources
• /
• v.24 no.2
• /
• pp.121-129
• /
• 2011

As the molecular breeding was progressed, many plant transformation techniques were attained for improving transformation accuracy and used to produce useful transgenic plants. Day by day, new varieties were developed so new transformation techniques required for these newly developed varieties. Carnation (Dianthus caryophyllus L.) is a popular and economically important ornamental plant, all over the world. Keeping this in view, we selected 18 varieties of D. caryophyllus L. commonly available in the market and did optimization of culture conditions for more efficient tissue culture and to get higher number of plants via micro-propagation. Four varieties namely Yellowdotcom, Jakarta, Belmonte, Polartessino etc. were selected for organ culture studies from single cell line. The optimum growth was recorded in the MS media supplied with sucrose 3%, NAA 1.0 mg/L and TDZ 1.0 mg/L. except Belmonte, in which, BA 1.0 mg/L was found to be the best combination, in place of TDZ, rest ingredients were same. The most efficient coagulating agent used to obtain higher number of plant from callus was phytagel 0.3%. The most effective explant for higher shoot formation was stem in which 80.2% shoot formation was recorded. It also reduced culture periods by 6 days.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.16 no.2
• /
• pp.154-159
• /
• 1983

A Gymnophallid cercaria was found in the gonadal tissue of Tapes philippinarum, and was described as a new species, Cercaria tapes n. sp. The host clams were collected from the intertidal zone of Seo-myon, Seo-chon gun, Korea from September 1980 to August 1981. The size of sporocysts was $380-650{\times}130-160{\mu}m$. The anterior part of the cercaria bears a subterminal opening and pharynx. The sporocyst bears ca. 30 cercariae and germ balls. The cercaria is elliptical in shape. The dimension of body is $160-187{\times}62-77{\mu}m$. the tail stem is $47-52{\times}17{\mu}m$, and the tail furcae is $67-72{\times}12-15{\mu}m$. Excretory bladder is Y-shaped, and the flame cell formula is 2(1)+(1)=4. The infection rate of the cercaria to the host clam was $2.01\%$ (42 infected/2,086 short-necked clams observed). The highest infection rate ($5.74\%$) was found in March, and the lowest one ($0.4\%$) observed in January. No infection was detected in May and June. The infection rates varied with the size of the short-necked clam. It was the clams of host of 2.1-3.0 cm, 3.1-4.0 cm and 4.1-5.0 cm in shell length are $0.38\%,\;15.3\%$ and $0.09\%$ respectively. The cercaria was not observed in the specimens smaller than 2.0 cm in shell length.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.12 no.2
• /
• pp.96-100
• /
• 2016

Metachromatic leukodystrophy (MLD) is a progressive and degenerative neurological disease caused by a deficiency of the catabolic enzyme arylsulfatase A. Deficiency of arylsulfatase A results in accumulation of sulfatide in the white matter of the peripheral and central nervous system and it occurs demyelination as a result. The patient gradually goes through mental and motor failure. General symptoms of MLD include gait disturbance, mental deterioration, muscle rigidity and impaired swallowing. Inheritance of the disease is autosomal recessive. We report a dental caries treatment of a 3-year old boy with MLD. The patient underwent hematopoietic stem cell transplantation (HSCT) to slow the progression of the disease. He was suffered from difficulties of mastication and swallowing from the degenerative neurological symptom. He was ingesting food by both oral feeding and tubal feeding after he took percutaneous endoscopic gastrostomy (PEG). The cause of multiple caries was mainly presumed as patient's prolonged time of meal. The treatment was performed under general anesthesia considering patient's incompliance. Severely affected lower primary molars were treated with pulp treatment and restored with stainless steel crown. Others were restored with composite resin. There were no postoperative complications. MLD is life threatening progressive disease and also has an impact on unfavorable condition for oral health. Routine home oral care and periodic professional dental care should be emphasized to the caregiver of patient considering the susceptibility of dental caries. Not only the medical care, but periodic dental office visit would benefit the quality of life of the patient.

• Journal of Life Science
• /
• v.22 no.12
• /
• pp.1600-1607
• /
• 2012

The matrix metalloproteinase (MMP) family plays essential roles in physiological processes such as embryonic development, angiogenesis, wound healing, and tissue homeostasis as a consequence of MMPr capacity for breaking down many types of extracellular matrix proteins. Imbalanced regulation of MMP expression can also lead to pathological conditions such as tumor progression. We recently reported that the Drosophila Mmp1 gene is highly expressed in the digestive tract and is required for the maintenance of intestinal homeostasis such as by restriction of uncontrolled intestinal stem cell proliferation. However, the regulatory mechanisms of MMP gene expression in the intestine remain unclear. In this study, we determined that the expression of Mmp1 is regulated by the homeodomain transcription factor Caudal. Experiments using the targeted expression of Caudal under the regulation of Gal4-UAS system indicated that endogenous Caudal is required for the Mmp1 gene expression in the adult Drosophila intestine and that exogenous Caudal induces Mmp1 expression. Transient transfection experiments indicated that Caudal can activate the promoter activity of Mmp1 and that several putative Caudal binding sites in the 5'-flanking region of the Mmp1 gene may be critical to the upregulation by Caudal. Our data suggest that Mmp1 is one of the target genes of Caudal in physiological normal condition and in tumorigenesis.

• Korean Journal of Microbiology
• /
• v.52 no.2
• /
• pp.148-156
• /
• 2016

This study examined effects of Enterobacter ludwigii SJR3 showing a high 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, on growth of tomato plant and its expression of stress-related genes under drought and salt stress. SJR3 strain was inoculated at $10^6cell/g$ soil to 4-week grown tomato plants, and drought and salt stresses were treated. After additional incubation for 1 week, root length, stem length, fresh weight and dry weight of tomato plants treated with SJR3 increased by 37.8, 37.2, 96.8 and 146.6%, respectively compared to those of uninoculated plants in drought stress environment, and they increased by 19.2, 25.4, 19.5, and 105.8%, respectively in salt stress environment. Proline content in tomato leaves increased significantly under stress conditions as one of a protecting substance against stresses, but proline contents in tomato treated with SJR3 decreased by 62.1 and 54.1%, respectively. Relative expression of genes encoding ACC oxidase, ACO1 and ACO4, ethylene response factor genes ERF1 and ERF4, and some other stress-related genes were examined from tomato leaves. Compared to the non-stressed tomato, expressions of all stress-related genes increased significantly in the stressed tomato, but gene expressions in the inoculated tomato were similar to those of no-stressed control tomato. Therefore, E. ludwigii SJR3 may play an important role in mitigating drought and salt stress in plants, and can increase productivity of crops under various abiotic stresses.

• The Journal of Korean Academy of Prosthodontics
• /
• v.44 no.2
• /
• pp.250-263
• /
• 2006

Statement of problem: Ti-alloy has been used widely since it was produced in the United States in 1947 because it has high biocompatibility and anticorrosive characteristics. Purpose: The pure titanium, however, was used limitedly due to insufficient mechanical charateristics and difficult manufacturing process. Our previous study was focused on the development of a new titanium alloy. In the previous study we found that the Ti-Ta-Nb alloy had better mechanical characteristics and similar anticorrosive characteristics to Ti-6Al-4V Material and methods: In this study, the cytotoxicity of the Ti-Ta-Nb alloy was evaluated by MTT assay using MSCs(Mesenchaimal stem cells) and L929 cells(fibroblast cell line). The biocompatibility of the Ti-Ta-Nb alloy was performed by inserting the alloy into the femur of the rabbits and observing the radiological and histological changes surrounding the alloy implant. Results: 1. In the cytotoxicity test using MSCs, the 60% survival rate was observed in pure titanium, 84% in Ti-6Al-4V alloy and 95% in Ti-10Ta-10Nb alloy. 2. In the animal study, the serial follow-up of the radiographs showed no separation or migration revealing gradual bone ingrowth surrounding the implants. Similar radiographic results were obtained among three implant groups pure titanium, Ti-6Al-4V alloy and Ti-10Ta-10Nb alloy. 3. In the histologic examination of the bone block containing the implants. the bone ingrowth was prominent around the implants with the lapse of time. There was no signs of any tissue rejection, degeneration, or inflammation. Active bone ingrowth was observed around the implants. In the comparison of the three groups, the rate of bone ingrowth was better in the Ti-10Ta-10Nb alloy group than those in pure titanium group or Ti-6Al-4V alloy group. In conclusion, Ti-10Ta-10Nb alloy revealed better biocompatibility in survival rate of the cells and bone ingrowth around the implants. Therefore we believe a newly developed Ti-10Ta-10Nb alloy can replace currently used Ti-6Al-4V alloy to increase biocompatibility and to decrease side effects. Conclusion: In conclusion, Ti-10Ta-10Nb alloy revealed better biocompatibility in survival rate of the cells and bone ingrowth around the implants. Therefore we believe a newly developed Ti-10Ta-10Nb alloy can replace currently used Ti-6Al-4V alloy to increase biocompatibility and to decrease side effects.