• Title, Summary, Keyword: 현상학적 연구

Search Result 2,471, Processing Time 0.059 seconds

Reflectance and Microhardness Characteristics of Sulfide Minerals from the Sambong Copper Mine (삼봉동광산산(三峰銅鑛山産) 유화광물(硫化鑛物)의 반사도(反射度)와 미경도(微硬度) 특성(特性))

  • Chi, Se Jung
    • Economic and Environmental Geology
    • /
    • v.17 no.2
    • /
    • pp.115-139
    • /
    • 1984
  • The Cu-Pb-Zn-Ag hydrothermal vein-type deposits which comprise the Sambong mine occur within calc-alkaline volcanics of the Cretaceous Gyeongsang Basin. The ore mineralization took place through three distinct stages of quartz (I and II stages) and calcite veins (III stage) which fill the pre-existing fault breccia zones. These stages were separated in time by tectonic fracturing and brecciation events. The reflection variations of one mineral depending on mineralization sequence are considered to be resulted from variation in its chemical composition due to different physico-chemical conditions in the hydrothermal system. The reflection power of sphalerite increases with the content of Fe substituted for Zn. Reflectances of the sphalerite grain are lower on (111) than on (100) surface. The spectral profiles depend on the internal reflection color. Sphalerite, showing green, yellow and reddish brown internal reflection, have the highest reflection power at $544m{\mu}$ (green), $593m{\mu}$ (yellow) and $615m{\mu}$ (red) wavelength, respectively. Chalcopyrite is recognized as biaxial negative from the reflectivity data of randomly oriented grains measured at the most sensitivity at $544m{\mu}$. The microindentation hardness against the Fe content (wt. %) for the sphalerite increases to 8.05% Fe and then decreases toward 9.5% Fe content. Vickers hardness of the sphalerite is considerably higher on surface of (100) than on (111). The relationship between Vickers hardness and crystal orientation of the galena was determined to be $VHN_{(111)}$ > $VHN_{(210)}$ > $VHN_{(100)}$. The softer sulfides have the wider variation of the diagonal length in the indentation. Diagonal length in the indentation is pyrite

  • PDF

Effects of Propylthiouracil and Thyroxine on Thyroid Function and Body Growth in Rats (Propylthiouracil 및 Thyroxine의 처리(處理)가 흰쥐의 갑상선기능(甲狀腺機能)과 체성장(體成長)에 미치는 영향(影響))

  • Seo, Kil Woong;Lee, Kyu Seung;Park, Chang Sik
    • Korean Journal of Agricultural Science
    • /
    • v.13 no.2
    • /
    • pp.210-218
    • /
    • 1986
  • This study was conducted to find out the effects of propylthiouracil and thyroxine on thyroid function and body growth in female rats. One hundred and forty-four female rats (Wistar-imamichi albino rats) of 25 days old were divided into 4 groups; thyroidectomy (Thx), propylthiouracil (PTU), thyroxine (Thyro.)and control (Cont.) groups. Thirty-six rats were allotted to each group, and changes of body weights were weekly checked. In addition, 6 rats in each group were sacrificed at 1, 2, 3, 5 and 6 weeks after treatments with time elapse for investigating changes of thyroid weights and tissues. The results obtained were as follows: 1. The weights of thyroid gland showed significant differences among all the compared groups at all observation times. The weights of thyroid glands in PTU group were higher than those in control group, but those in the Thyro. group were lower than those in control group. 2. In the histological changes of thyroid glands in the PTU group, the follicle epithelium showed columnar cells following hype trophy and hyperplasia from 1 week after treatment. The follicle epithelium in the Thyro. group were recognized inactive showing squamous cells. 3. The body weights showed significant differences among the compared groups from 2 weeks after treatment. The body weights decreased significantly in PTU and Thx. groups, while those in Thyro. group increased significantly in comparison with those in control group. No significant difference in body weight was noted between PTU and Thx. groups.

  • PDF

Behavior of Cadmium, Zinc, and Copper in soils -I. Effect of Organic Matter Treatment on Adsorption of Cadmium, Zinc, and Copper in soils- (토양내(土壤內) 카드뮴, 아연(亞鉛) 및 구리의 행동(行動)에 관한 연구(硏究) -제2보(第-報). 토양내(土壤內) 카드뮴, 아연(亞鉛) 및 구리의 흡착(吸着)에 미치는 유기물처리(有機物處理)의 영향(影響)-)

  • Yoo, Sun-Ho;Hyun, Hae-Nam
    • Applied Biological Chemistry
    • /
    • v.28 no.2
    • /
    • pp.68-75
    • /
    • 1985
  • Laboratory experiments were conducted to investigate the effect of compost and humic acid treatment on adsorption of Cd, Zn, and Cu in soils. Three soils differing in physical and chemical properties used in this experiments were Bonyrang (Typic Udifluvents) SL, Gangseo (Aquatic Eutrochrepts) L, and Gyorae (Typic Distrandepts) SiL. Adsorption of Cd, Zn, ana Cu on the soils followed Langmuir isotherm up to 75 ppm of initial concentration. The adsorption maxima of Cd, Zn, and Cu for the Bonryang soil, the lowest in pH, organic matter content, and CEC, were the lowest of the three soils. Although the Gyorae soil derived from volcanic ash was the highest in organic matter content and CEC, the adsorption maxima of heavy metals for the Gyorae soil were lower than those for the Gangseo soil of which organic content and CEC were intermidiate. The adsorption maxima/CEC ratios for the Bonryang, the Gangseo, the Gyorae soils were found to be in the range of $23{\sim}27%,\;28{\sim}57%$, and $11{\sim}14%$ respectively The bonding energy constants of Cd, Zn, and Cu for the soils were in the order of Gangseo>Bonryang>Gyorae soils. The adsorption maxima of Cd, Zu, and Cu for the Bonryang soil increased with compost treatment by $100{\sim}210%,\;90{\sim}230%$, and $130{\sim}290%$ respectively, while little difference was observed when the soil was treated with humic acid Bonding energy constants of Cd, Zn, and Cu for the Bonryang soil increased significantly with compost treatment, and showed insignificant correlation with humic acid treatment.

  • PDF

Mytilin B, an Antimicrobial Peptide from the Hemocyte of the Hard-shelled Mussel, Mytilus coruscus : Isolation, Purification, and Characterization (참담치(Mytilus coruscus) 혈구(hemocyte) 유래 항균 펩타이드 mytilin B의 정제 및 특성 분석)

  • Lee, Min Jeong;Oh, Ryunkyoung;Kim, Young-Ok;Nam, Bo-Hye;Kong, Hee Jeong;Kim, Joo-Won;Park, Jung Youn;Seo, Jung-Kil;Kim, Dong-Gyun
    • Journal of Life Science
    • /
    • v.28 no.11
    • /
    • pp.1301-1315
    • /
    • 2018
  • We purified an antimicrobial peptide from the acidified hemocyte extract of Mytilus coruscus by $C_{18}$ reversed-phase high-performance liquid chromatography (RP-HPLC). The peptide was 4041.866 Da based on matrix-assisted laser desorption ionization time-of-flight mass spectrophotometer (MALDI-TOF/MS) and the 25 amino acids of the N-terminus sequence were identified. Comparison of this sequence of the purified peptide with the N-terminus sequences of other antimicrobial peptides revealed 100% identity with the mytilin B precursor of Mytilus coruscus. We also identified a 312 bp open-reading frame (ORF) encoding 103 amino acids based on the obtained amino acid residues. The nucleotide sequence of this ORF and the amino acid sequence also revealed 100% identity with the mytilin B precursor of Mytilus coruscus. We synthesized two antimicrobial peptides with an alanine residue in the C-terminus, and designated them mytilin B1 and B2. These two antimicrobial peptides showed antimicrobial activity against gram-positive bacteria, including Bacillus cereus and Streptococcus parauberis (minimal effective concentration, MECs $41.6-89.7{\mu}g/ml$), gram-negative bacteria, including Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Providencia stuartii, Pseudomonas aeruginosa, and Vibrio ichthyoenteri (MECs $7.4-39.5{\mu}g/ml$), and the fungus Candida albicans (MECs $26.0-31.8{\mu}g/ml$). This antimicrobial activity was stable under heat and salt conditions. Furthermore, the peptides did not exhibit significant hemolytic activity or cytotoxic effects. These results suggest that mytilin B could be applied as alternative antibiotic agent, and they add to the understanding of the innate immunity of hard-shelled mussels.

Mesozoic Granitoids and Associated Gold-Silver Mineralization in Korea (한국 중생대 화강암류와 이에 수반된 금-은광화작용)

  • 최선규;박상준;최상훈;신홍자
    • Economic and Environmental Geology
    • /
    • v.34 no.1
    • /
    • pp.25-38
    • /
    • 2001
  • Contrasts in the style of the gold-silver mineralization in geologic and tectonic settings in Korea, together with radiometric age data, reflect the genetically different nature of hydrothermal activities, coinciding with the emplacement age and depth of Mesozoic magmatic activities. It represents a clear distinction between the plutonic settings of the Jurassic Daebo orogeny and the subvolcanic environments of the Cretaceous Bulgugsa igneous activities. During the Daebo igneous activities (about 200-130 Ma) coincident with orogenic time, gold mineralization took place between 197 and 127 Ma. The Jurassic deposits commonly show several characteristics: prominent association with pegmatites, low Ag/Au ratios in the ore-concentrating parts, massive vein morphology and a distinctively simple mineralogy including Fe-rich sphalerite, galena, chalcopyrite, Au-rich eIectrum. pyrrhotite and/or pyrite. During the Bulgugsa igneous activities (120-60 Ma), the precious-metal deposits are generally characterized by such features as complex vein morphology, medium to high AgiAu ratios in the ore concentrates, and abundance of ore minerals including base-metal sulfides, Ag sulfides, native silver, Ag sulfosalts and Ag tellurides. Vein morphology, mineralogical, fluid inclusion and stable isotope results indicate the diverse genetic natures of hydrothermal systems. The Jurassic Au-dominant deposits were formed at the relatively high temperature (about 300 to 450$^{\circ}$C) and deep-crustal level (>3.0 kb) from the hydrothermal fluids containing more amounts of magmatic waters (3180; 5-10 %0). It can be explained by the dominant ore-depositing mechanisms as CO2 boiling and sulfidation, suggestive of hypo/mesothermal environments. In contrast, mineralization of the Cretaceous Au-Ag type (108-71 Ma) and Agdominant type (98-71 Ma) occurred at relatively low temperature (about 200 to 350$^{\circ}$C) and shallow-crustal level «1.0 kb) from the ore-fonning fluids containing more amounts of less-evolved meteoric waters (15180; -10-5%0). These characteristics of the Cretaceous precious-metal deposits can be attributed to the complexities in the ore-precipitating mechanisms (mixing, boiling, cooling), suggestive of epilmesothermal environments. Therefore, the differences of the emplacement depth between the Daebo and the Bulgugsa igneous activities directly influence the unique temporal and spatial association of the deposit type.

  • PDF

Ser326Cys Polymorphism of hOGG1 Gene and Risk of Primary Lung Cancer in Koreans (한국인에서 hOGG1 유전자의 Ser326Cys 다형성과 원발성 폐암의 위험도)

  • Chae, Sang-Chul;Kim, Kyung-Rock;Joo, So-Young;Lee, Su-Yean;Kang, Kyung-Hee;Jeon, Kyung-Neoyh;Cha, Seung-Ick;Kim, Chang-Ho;Jung, Tae-Hoon;Park, Jae-Yang
    • Tuberculosis and Respiratory Diseases
    • /
    • v.52 no.1
    • /
    • pp.5-13
    • /
    • 2002
  • Background: DNA repair plays a crucial role in protecting the genome from cancer-causing agents. Therefore, a reduced DNA repair capacity can increase the susceptibility to cancer. The human OGG1 (hOGG1) gene encodes DNA glycosylase/apurinic lyase and excise 8-hydroxyguanine, one of the major premutagenic DNA lesions, which is produced by oxygen radical forming agents including smoking. Recently several polymorphisms in the hOGG1 gene were identified, and it is possible that these polymorphism') may affect the DNA repair capacity and thus modulate cancer susceptibility. The relationship between the codon 326 polymorphism (Ser to Cys) in the hOGG1 gene and lung cancer risk was investigated. Materials and Method: The Ser326Cys genotypes were determined using PCR-RFLP analysis in 299 primary lung cancer patients and 186 healthy controls who were frequency (case:control=3:2) matched according to age and sex. Result: The frequencies of the Ser326Cys genotypes (Ser/Ser, Ser/Cys and Cys/Cys) among cases (23.4%, 51.8%, and 24.7%, respectively) were not significantly different from those among the controls (22.6%,52.1% and 25.3%, respectively). When the analyses were stratified according to age, sex, smoking status and packyears of smoking, no significant association between this polymorphism and lung cancer risk was found. Moreover, the Ser326Cys genotype showed no apparent relationship with any of the histological types of lung cancer. Conclusion: These result suggest that the hOGG1 Ser326Cys polymorphism is not a major contributor to individual lung cancer susceptibility in Koreans.

Polymorpshisms of XPC Gene and Risk of Primary Lung Cancer in Koreans (한국인에서 XPC 유전자의 다형성과 원발성 폐암의 위험도)

  • Kim, Kyung-Rock;Lee, Su-Yeon;Choi, Jin-Eun;Kim, Kyung-Mee;Jang, Sang-Soo;Jung, Chi-Young;Kang, Kyung-Hee;Jeon, Kyung-Neoyh;Cha, Sung-Ick;Kim, Chang-Ho;Kam, Sin;Jung, Tae-Hoon;Park, Jae-Yong
    • Tuberculosis and Respiratory Diseases
    • /
    • v.53 no.2
    • /
    • pp.113-126
    • /
    • 2002
  • Background : DNA repair plays a crucial role in protection from cancer-causing agents. Therefore, a reduced DNA repair capacity can increase the susceptibility to lung cancer. The XPC gene contains 15 exons and encodes a 940 amino acid protein that plays a central role in DNA damage recognition of the nucleotide excision repair pathway, which is a major DNA repair mechanisim removing the bulky-helix distorting DNA lesions caused by smoking. Recently several polymorphisms in the XPC gene were identified. In addition, it is possible that these polymorphisms may affect the DNA repair capacity, which modulate cancer susceptibility. The relationship between codon 499 and 939 polymorphisms, and a poly(AT) insertion/deletion polymorphism in the XPC gene, and the lung cancer risk were investigated. Materials and Methods : The genotypes were determined using either PCR or PCR-RFLP analysis in 219 male lung cancer patients and 150 healthy males controls. Results : The frequencies of the genotypes (Val499Ala, PAT and Lys939Gln) among the cases were not significantly different from those of the controls. There was no significant associantion between these polymorphi는 and the lung cancer risk when the analyses were stratified according to age, smoking status and the pack-years of smoking. Moreover, the genotypes had no apparent relationship with any of the histological types of lung cancer. There was a linkage disequilibrium among the Val499Ala, PAT and Lys939Gln polymorphisms. The PAT polymorphism had a strong linkage disequilibrium with the Lys939Gln polymorphism (kappa value=0.87). The XPC haplotypes showed no significant association with the lung cancer risk. Conclusion : These results suggest that XPC Val499Ala, PAT and Lys939Gln polymorphisms are not major contributors to the individual lung cancer susceptibility in Koreans.

User's Impacts on Environmental Deteriorations of Trail in Tôkyusan National Park (덕유산(德裕山) 국립공원(國立公園) 등산로(登山路)의 환경훼손(環境毁損)에 대(對)한 이용영향(利用影響))

  • Seo, Byung Soo;Kim, Sei Cheon;Park, Chong Min;Lee, Chang Heon;Lee, Kyu Wan
    • Journal of Korean Society of Forest Science
    • /
    • v.83 no.3
    • /
    • pp.286-298
    • /
    • 1994
  • The object of this study was to examine the user's impacts on the environmental deteriorations of trail at Ticket Office - Paekryunsa (Temple) Hyangch$\hat{o}$kpong - Dongyupryung - Chilyun Fall area in T$\hat{o}$kyusan National Park. Four trails were sampled in the study area according to the amount of users. Then the user's impacts on trail were measured at each trail. The Ticket Office-Paekryunsa trail was the most used district and followed at Paekryunsa-Hyangch$\hat{o}$kpong trail, Hyangch$\hat{o}$kpong-Dongyupryung trail in descending order. Dongyupryung-Chilyun Fall trail is not used by people because of rest rotation system. The entire width of trail was greater at the more heavily used trail. Maximum depth, cross-sectional area loss, and surface texture and roughness of trail were the highest at Paekryunsa-Hyangch$\hat{o}$kpong trail. Soil hardness, soil acidity, soil moisture content, organic matter content, and exchange canon were influenced by trampling. Soil hardness, soil acidity and exchange canon increased in tramples soil, but content of soil moisture and organic matter decreased therein. Environmental deteriorations of trail were significantly influenced by the amount of users and the slope of trail. Bared lands about $2.000m^2$ were appeared by trampling and camping around Hyangch$\hat{o}$kpong. Effects of carrying of rest rotation system for National Park were partly recognized at Dongyupryung-Chilyun Fall trail.

  • PDF

HISTOLOGIC CHANGES IN MANDIBULAR PERIODONTIUM OF THE MONKEY FOLLOWING EXPERIMENTAL EXTRUSION OF ANTERIOR TEETH (실험적 전치 정출시 원숭이 하악 치주 조직의 변화)

  • Lee, Sung-Youn;Kim, Tae-Woo;Chang, Young-Il
    • The korean journal of orthodontics
    • /
    • v.25 no.4
    • /
    • pp.403-414
    • /
    • 1995
  • The purpose of this study was to investigate the histologic changes in mandibular periodontium during overbite closure for openbite treatment by continuous arch wires and anterior vertical elastics. Two female monkey(Macaca nemestrina) with permanent dentition were used. Posterior bite block was fixed to each of their maxillae, which made the animal temporary anterior openbite as well as stabilized the whole maxillary anchorage. In each mandible, all the teeth except the second molars which had been extracted, were prepared for cast crowns. 018 inch Standard brackets were welded on these crowns. After cementation, two types of the $016{\times}022$ inch continuous arch wires, the plain ideal arch to the control animal and the MEAW(multiloop edgewise archwire) to the other experimental one were inserted. Then anterior vertical elastics were applied for two weeks. The overbite depth changes in the monkeys and histologic examinations of the mandibular periodontiums suggested the following conclusions. 1. During two weeks of the experimental period, the overbite increased + 0.3 mm in the control and + 1.3 mm in the experimental one. 2. In both the control and the experimental animal, histologic examinations showed that incisors, canines and first premolars were subject to extrusive force and the rest of posteriors were subject to intrusive one. 3. In periodontiums of the extruded incisors of the experimental one, reorientation of the periodontal fiber structures reflected the direction of force and the alveolar bone surfaces including apical and crestal areas which had been subject to tension, were the front of new bone formation. 4. In periodontiums of the extruded incisors of the experimental one, neither excessive hyalinization nor gross root resorption was observed. 5. Alveolar bone remodeling of anteriors and posteriors was more remarkable in the experimental one than the control.

  • PDF

THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS OF THE PHENOMENON PRODUCED DURING RETRACTION OF FOUR MAXILLARY INCISORS (상악 4절치의 후방견인시 나타나는 현상에 관한 유한요소법적 분석)

  • Cheon, Ok-Jin;Kim, Tae-Woo;Suhr, Cheong-Hoon
    • The korean journal of orthodontics
    • /
    • v.25 no.5
    • /
    • pp.525-541
    • /
    • 1995
  • This study was designed to investigate force systems and tooth movements produced by retraction archwire during retraction of four maxillary incisors after the maxillary canine retraction into the maxillary first premolar extraction space using the computer-aided three-dimensional finite element method. A three-dimensional finite element model, consisting of 2248 elements and 3194 nodes, was constructed. The model consisted of maxillary teeth and surrounding periodontal membranes, .022'$\times$.028'-slot brackets, and 5 types of retraction archwires(.019'$\times$.025' stainless steel archwire) modeled using the beam elements. The contact between the wire and the bracket slot was modeled using the gap elements because of the non-linear elastic behaviors of the contact between them. The forces and moments, End displacements produced by retraction archwire were measured at various conditions to investigate the difference according to types of loops, magnitudes of activation force, gable angle, and anterior lingual root torque. The results were expressed quantitative and visual ways in the three-dimensional method. The following conclusions can be drawn from this study.1. When the tear-drop loop archwire was activated, the mesio-distal and lingual translational movements of the teeth helped to close the extraction space, but unwanted movements of the teeth including intrusions and extrusions, and rotational movements in each direction occurred. 2. Activation of T-loop archwire compared with those of other types of retraction archwires produced the least translational movements of the teeth helped to space closure and also the least unwanted movements of the teeth. 3. Increasing amount of activation in the tear-drop archwire led not only to increase of translational movements of the teeth helped to space closure, but also to increase of unwanted movements of the teeth. 4. Addition of gable bend in the tear-drop archwire helped anterior teeth to translational movements in the mesio-distal direction, but increased unwanted movements of the teeth 5. Addition of anterior lingual root torque in the tear-drop archwire helped central and lateral incisor to improve their facio-lingual inclination, but increased unwanted movements of the teeth.

  • PDF