• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.263-271
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• 2001

Objective : Glioblastomas, the most common type of primary brain tumors, are highly invasive and cause massive tissue destruction at both the tumor invading edges and in areas that are not in direct contact with glioma cells. As a result, patients with high-grade gliomas are faced with a poor prognosis. Such grim statistics emphasize the need to better understand the mechanisms that underlie glioma invasion, as these may lead to the identification of novel targets in the therapy of high grade gliomas. Protein kinase C(PKC) is a family of serine/threonine kinases and an important signal transduction enzyme that conveys signals generated by ligand-receptor interaction at the cell surface to the nucleus. PKC appears to be critical in regulating many aspects of glioma biology. The purpose of this study was to assess accurately the role of PKC in the invasion regulation of human gliomas based on hypothesis that protein kinase C(PKC) is functional in the process of glial tumor cell invasion. Method : To test this hypothesis, U-87 malignant glioma cell line intracellular PKC levels were up and down regulated and their invasiveness was tested. Intracellular PKC level was characterized using PKC activity assays. Invasion assays including barrier migration and spheroid confrontation were used to study the relationship between PKC concentration and invasiveness. Result : The cell line which were treated by PKC inhibitor tamoxifen and hypericin exhibited decreased PKC activity and decreased invasive abilities dose dependently both in matrigel invasion assay and tumor spheroid fetal rat brain aggregates(FRBA) confrontation assay. However, the cell line that was treated by PKC activator 12-O-tetradecanylphorbol-13acetate(TPA) did not exhibit increases in either PKC activity or invasive ability. Conclusion : These studies suggest that PKC may be a useful molecular target for the chemotherapy of glioblastoma and other malignancies and that a therapeutic approach based on the ability of PKC inhibitors may be helpful in preventing invasion.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.4
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• pp.313-320
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• 2020

Purpose: The purpose of this study was to evaluate the machining precision and the marginal and internal fit of single restorations fabricated with three types of lithium disilicate ceramic blocks and to evaluate the correlation. Materials and methods: Single restorations were designed using a CAD software program. The crown designed model file was extracted from the CAD software program. Three types of lithium disilicate blocks (Rosetta; HASS, IPS e.max CAD; Ivoclar vivadent, VITA Suprinity; VITA) were milled using a milling machine. For the fabrication of the crown scanned model file, the intaglio surface of the restoration was digitized using a contact scanner. Then, using the three-dimensional inspection software (Geomagic control X; 3D Systems), the process of the overlap of the crown designed model and the scanned model and 3-dimensional analysis was conducted. In addition, the marginal and internal fit of the crowns was evaluated by a silicone replication method. The difference among three types of single ceramic crown was analyzed using a Kruskal-Wallis H test, and Spearman correlation analysis was performed to analyze the correlation between machining precision and fitness (α=.05). Results: There was a significant difference in the machining precision and the marginal and internal fit according to the type of ceramic block (P<.001). In addition, the machining precision and the marginal and internal fit were positively correlated (P<.001). Conclusion: The marginal fit of crowns fabricated according to the types of ceramic blocks was within the clinically acceptable range (< 120 ㎛), so it can be regarded as appropriate machining precision applicable to all clinical as aspects in terms of the marginal fit.

• Journal of Chest Surgery
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• v.35 no.3
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• pp.171-176
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• 2002

Background: Blood-foreign interaction cause activation of coagulation and inflammatory process that may lead to multiorgan dysfunction and determine the surgical outcomes. Of the methods for assessing the biocompatibility, the platelet adhesion study is considered as the most valuable evaluation step in blood-foreign interaction. As the most studies have used in-vitro or ex-vivo conditions, we have developed a technique of quantification for platelet adhesion on the blood contact surface by using in-vivo injection of radioactive platelets. Material and Method: A coupled bypass circuit was designed to connect the proximal and descending thoracic aorta in 6 piglets(20∼25 Kg). One side of the circuit tube was consisted of a heparin coated PVC tube(10mm in ID, n=6, Experimental group), and the other, a non-heparin coated PVC tube(10mm in ID, n=6, Control group). After cannulation, the blood was circulated through the circuit for 2 hours. Platelet concentrate was prepared from homologous pig blood 24 hours before the experiment. The platelet concentrate was incubated with Tc-99m-HMPAO for 30 min and then centrifuged for 10 min. The supernatant was discarded and the radio-labeling efficacy was measured. The radio-labeled platelet concentrate was mixed with the autologous plasma to make the volume 5 ml, and the mixture was injected intravenously into the experimental animal. After 2 hour circulation, 5 pieces of the specimen(10mm in length each) were obtained from each PVC tube. The radioisotopes were counted with a gamma counter(Cobra ll, Packard, USA), and the ratio of radioisotope count was compared between the control and experimental group. Result: The radioisotope count number was 537.3221.1 Ci/min in the control group and 311.1 184.5 Ci/min in the experimental group(p=0.0104). The ratio between the groups was 1 to 0.58 (p=0.004). Conclusion: In vivo quantification using technetium-99m-HMPAO labeled platelets is simple and reproducible in evaluating platelet adhesion on a foreign surface. We suggest this technique to be a useful tool for blood compatibility test.

• Economic and Environmental Geology
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• v.43 no.4
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• pp.417-427
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• 2010

The Lankawi archipelago is located in 30 km western offshore near the Thailand-Malaysia border in west coast of the Malay Peninsula and consists of 99 (+5) tropical islands, covering an area of about $479km^2$. Together with biodiversity in flora and fauna, the Lankawi archipelago displays also geodiversity that includes rock diversity, landform diversity, and fossil diversity. These biodiversity and geodiversity have led to the Lankawi islands as a newly emerging hub for ecotourism in Southeast Asia. As a result, the Lankawi islands have been designated the first Global Geopark in Southeast Asia by UNESCO since July 1st, 2007. The geodiversity of Lankawi Geopark today is a result of a very long depositional history under the various sedimentological regimes and paleoenvironments during the Paleozoic, followed by tectonic and magmatic activities until the early Mesozoic, and finally by surface processes that etched to the present beautiful landscape. Paleozoic strata exposed in the Lankawi Geopark are subdivided into four formations that include the Machinchang (Cambrian), Setul (Ordovician to Early Devonian), Singa (Late Devonian to Carboniferous), and Chuping (Permian) formations in ascending order. These strata are younging to the east, but they are truncated by the Kisap Thrust in the eastern part of the islands. Top-to-the-westward transportation of the Kisap Thrust has brought the older Setul Formation (and possibly Machinchang Formation) from the east to overlay the younger Chuping and Singa formations in the central axis of the Lankawi islands. Triassic Gunung Raya Granite intruded into these sedimentary strata, and turned them partially into various types of contact metamorphic rocks that locally contain tin mineral deposits. Since Triassic, not much geologic records are known for the Lankawi islands. Tropical weathering upon rocks of the Lankawi islands might have taken place since the Early Jurassic and continues until the present. This weathering process played a very important role in producing beautiful landscapes of the Lankawi islands today.

• Applied Microscopy
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• v.39 no.1
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• pp.57-64
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• 2009

The trapping leaves of Drosera capture insects by secreting sticky mucilage from numerous glandular trichomes (GTs) that are developed on the leaf epidermis. The present study examines and compares the structural features of those trichomes in Drosera binata and D. pygmy with the use of light and electron microscopy. The study focuses primarily on the development and differentiation pattern of the GTs during growth. Upon examination, the upper and lower epidermis were readily distinguishable by the features of GTs in developing leaves. In particular, the GTs were dense in the upper epidermis and along the leaf margin. In D. binata, the capitate GTs with elongated stalk and sessile peltate GTs were found most commonly, whereas only capitate GTs with varying degrees of the stalk length were observed in D. pygmy. Up to ca. $2.2{\sim}3.4\;mm$ long capitate GTs were seen in the leaf margins of D. binata and ca. $3.7{\sim}4.2\;mm$ long GTs having racket-like head with adaxial hemispheric structures, otherwise known as tentacles, were noted in the leaf margin of D. pygmy. The peltate GTs were found to be distributed in the lower epidermis of D. binata. In both species, head cells were dense with cytoplasm containing high numbers of Golgi bodies, ER, mitochondria and small vesicles. Secretory materials accumulated within numerous small vacuoles, then fused together to form a single large vacuole, which serves as a secretory cavity. Flection movement of the marginal GTs and leaf blade GTs, and increased mucilage secretion from the head cells upon contact with prey during the capturing process are considered to be major factors in their active insectivorous mechanism. The findings of this study will be useful in comparisons to similar findings in other species that form adhesive trapping leaves, such as Drosophyllum or Pinguicula., further contributing a better understanding of the function and structure of the trapping leaves of carnivorous plants.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.445-466
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• 2017

Yeongdong area is located in the contact zone between central southeastern Ogcheon belt and Yeongnam massif, in which Cretaceous Yeongdong basin exists. Therefore, the study area has complex geological environment of various geological age and rock types such as Precambrian metamorphic rocks, age-unknown Ogcheon Supergroup, Paleozoic/Mesozoic sedimentary rocks, Mesozoic igneous rocks and Quaternary alluvial deposits. This study focuses on the link between the various geology and water type, and discussed the source of some major ions and their related water-rock interaction. For this study, the field parameters and ion concentrations for twenty alluvial/weathered and eighty bedrock aquifer wells were used. Statistical analysis indicates that there was no significant differences in groundwater quality between wet and dry seasons. Although various types were observed due to complex geology, 80 to 84 % of samples showed $Ca-HCO_3$ water type. Some wells placed in alluvial/weathered aquifers of Precambrian metamorphic and Jurassic granitic terrains showed somewhat elevated $NO_3$ and Cl concentrations. $Mg-HCO_3$ typed waters prevailed in Cretaceous Yeongdong sedimentary rocks. The deeper wells placed in bedrock aquifers showed complicated water types varying from $Ca-HCO_3$ through $Ca-Cl/SO_4/NO_3$ to $Na-HCO_3$ and Na-Cl type. Groundwater samples with $Na-HCO_3$ or Na-Cl types are generally high in F concentrations, indicating more influences of water-rock interaction within mineralized/hydrothermal alteration zone by Cretaceous porphyry or granites. This study revealed that many deep-seated aquifer had been contaminated by $NO_3$, especially prominent in Jurassic granites area. Based on molar ratios of $HCO_3/Ca$, $HCO_3/Na$, Na/Si, it can be inferred that Ca and $HCO_3$ components of most groundwater in alluvial/weathered aquifer wells were definitely related with dissolution of calcite. On the other hand, Ca and $HCO_3$ in bedrock aquifer seem to be due to dissolution of feldspar besides calcite. However, these molar ratios require other mechanism except simple weathering process causing feldspar to be broken into kaolinite. The origin of $HCO_3$ of some groundwater occurring in Cretaceous Yeongdong sedimentary rock area seems to be from dissolution of dolomite($MgCO_3$) or strontianite($SrCO_3$) as well.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.329-336
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• 2006

Iron manufacturing process involves production of various by-product including slag, sludge, sintering and EAF(Electric Arc furnace dust). Some of the by-products such as EAF and sintering dust are disposed of as waste due to their high heavy metal contents. It has been notice for many years that the EAF dust also contain about 65% of Fe(0) and Fe(II) and then the possible utilization of the iron. One possibility is to apply the EAF as a lining material in conjunction with clay or HDPE liners, in waste landfill. The probable reaction between the leachate containing toxic elements such as TCE, PCE dioxine and $Cr^{6+}$ is reduction of the toxic materials in corresponding to the oxidation of the reduced iron and therefore diminishing the toxicity of the leachate. It is, however, prerequisite to evaluate the leaching characteristics of the EAF dust before application. Amelioration of the leachate would be archived only when the level of toxic elements in the treated leachate is less than that of in the untreated leachate. Several leaching techniques were selected to cover different conditions and variable environments including time, pH and contact method. The testing methods include availability test, pH-stat test and continuous column test. Cr and Zn are potentially leachable elements among the trace metals. The pH of the EAF dust is highly alkaline, recording around 12 and Zn is unlikely to be leached under the condition. On the contrary Cr is more leachable under alkaline environment. However, the released Cr should be reduced to $Cr^{3+}$ and then removed as $Cr(OH)_3$. Removal of the Cr is observed in the column test and further study on the specific reaction of Cr and EAF dust is underway.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.31-34
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• 1979

In this study, enzymatic hydrolysis of the substrate of the waste wood of Cortinellus edodes was investigated using crude cellulase preparation of Trichoderma viride Pers. ex. Fr. SANK 16374. The crude cellulase was produced by the submerged culture process and produced in the culture fluid was salted out quantitatively by the use of ammonium sulfate. Reducing sugar was determined by the dinitrosalisylic acid (DNS) method. 1. The chemical composition of the waste wood was crude protein 2.26%, c. fat 2.57%, c. fibre 44.60%, c. ash 5.58% and lignin 13.62%. In amino acid composition, no cystine and methionine was showed, but trace amount of Vitamin A, $B_1$, and $B_2$, niacine and chloride were detected. (Table 1) 2. As heat treatment of the substrate was found to produce the highest reducing sugar yield being reacted for 48hr. with T.v cellulase, the substrate was heated to $190{\pm}5^{\circ}C$. for 45 min. either before or immediately after milling. 3. The substrate heated and ball milled at $190{\pm}5^{\circ}C$. for 45 min. the reducing sugar yield reached to 11.5%. 4. The substrate without any treatment was found to produce the highest reducing sugar yield being reacted 72hr. with T. v cellulase, the reducing sugar yield reached to 10.1%. 5. The rate of reducing sugar per each treated substrate was decreased by the order of the substrated, heated and then ball milled at $190{\pm}5^{\circ}C$. for 45 min. (11.5%)> without any treatment (10.1)> ball milled and heated at $190{\pm}5^{\circ}C$. for 45 min. (6.9%). 6. Saccharification of waste wood has been shown to be possible by heat treated and milling the substrate in contact with cellulase. And it is likely to be recommended that the waste wood may be valuable for raw materials of saccharification.

• Journal of Acupuncture Research
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• v.18 no.6
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• pp.171-187
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• 2001

Objective : Moxibustion has been proved efficacious for many diseases, but isn't widespread in the clinics due to a danger of skin burning, the smoke produced while burning a moxa combustion and so on. Therefore, another type of moxa that can be resolved these troubles is required. To improve the effect of moxibustion and develop the new thermal stimulating treatment, the performance of commercial moxibustion widely used are studied systematically and found out quantitatively. Methods : We have selected two types (small-size moxa A(sMA), small-size moxa B (sMB)) among small-size moxaes used widely in the clinic. We examined combustion time, various temperatures, temperature gradient in each period during a combustion of moxa. Results : 1. The combustion time in the preheating period appeared somewhat longer in sMA than in sMB. 2, The combustion time in the heating period appeared longer in sMA by 26% than in sMB. 3. The average temperature in the heating period was $37.6{\sim}37.8^{\circ}C\;in\;sMA\;and\;36.2{\sim}36.8^{\circ}C$ in sMB and the maximum temperature measured at a center of contact surface in sMA was $48.6^{\circ}C$, higher by over $2.8^{\circ}C$ than that of sMB moxibustion. 4. The average ascending temperature gradient in the heating period was $0.08{\sim}0.1^{\circ}C/sec$ in both moxaes, and the average ascending temperature gradient of heating period in sMB appeared larger. The maximum ascending temperature gradient appeared higher in sMB, and the time reaching maximum ascending temperature gradient appeared much earlier in sMA than in sMB. 5. The combustion time in the retaining period was around 100 sec in sMA and around 275 sec in sMB. 6. The average temperature in the retaining period was $42.2{\sim}46.0^{\circ}C\;in\;sMA\;and\;39.3{\sim}41.4^{\circ}C/sec$ in sMB. The minimum temperature in the retaining period was over $38.80^{\circ}C$ in sMA but just $34.7^{\circ}C$ in sMB. 7. The average descending temperature gradient in sMA was $-0.050{\sim}0.067^{\circ}C/sec$ and in sMB was $-0.030{\sim}0.037^{\circ}C/sec$ 8. The combustion time in the cooling period appeared longer over two times in sMA than in sMB, and the time which the cooling period (minimum temperature) finished at appeared later in sMB by 55 sec. 9. We classified the combustion process that the measured temperature rose over body heat($37^{\circ}C$) into the effective combustion period. The effective combustion time was 233.3 sec in sMA and 300.4 sec in sMB respectively, and was longer by about 29% in sMB. The average temperature and maximum temperature in the effective combustion time appeared higher in sMA. The time taken until the maximum temperature was reached was 225.1 sec in sMA and 244.5 sec in sMB, faster by about 20 sec in sMA. The maximum ascending temperature gradient during the effective combustion period appeared larger about 1.4 times in sMB, but the time when the maximum ascending temperature gradient happened was faster in sMA. Conclusion : It appears that sMB, compared with sMA, is proper if necessary to apply the long time and weak stimulus, because of the gentle stimulus during the relatively longer time. In contrast, sMA that the symmetrical combustion happened is proper if necessary to apply the short time and strong stimulus.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.411-415
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• 2009

Some microorganisms are capable of leaching Mn(II) from nonsulfidic manganese ores indirectly via nonenzymatic processes. Such reductive dissolution requires organic substrates, such as glucose, sucrose, or galactose, as a source of carbon and energy for microbial growth. This study investigated characteristics of Mn(II) leaching from manganese nodules by using heterotrophic Bacillus sp. strain MR2 provided with corn starch as a less-expensive substrate. Leaching of Mn(II) at 25.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$ was accompanied with cell growth, but part of the produced Mn(II) re-adsorbed onto residual $MnO_2$ particles after 24 h. Direct contact of cells to manganese nodule was not necessary as a separation between them with a dialysis tube produced similar amount [24.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$]. These results indicated an involvement of extracellular diffusible compound(s) during Mn(II) leaching by strain MR2. In order to optimize a leaching process we tested factors that influence the reaction, and the most efficient conditions were $25\sim35^{\circ}C$, pH 5~7, inoculum density of 1.5~2.5% (v/v), pulp density of 2~3 g/L, and particle size <75 ${\mu}m$. Although Mn(II) leaching was enhanced as particle size decrease, we suggest <212 ${\mu}m$ as a proper size range since more grinding means more energy consumption The results would help for the improvement of bioleaching of manganese nodule as a less expensive, energy-efficient, and environment-friendly technology as compared to the existing physicochemical metal recovery technologies.