• Title/Summary/Keyword: II-VI

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A Study on the Kinetics of Copper Ions Reduction and Deposition Morphology with the Rotating Disk Electrode (RDE를 이용한 구리이온의 환원속도 및 전착형태에 관한 고찰)

  • Nam, Sang Cheol;Um, Sung Hyun;Lee, Choong Young;Tak, Yongsug;Nam, Chong Woo
    • Applied Chemistry for Engineering
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    • v.8 no.4
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    • pp.645-652
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    • 1997
  • Electrochemical characteristics and kinetic parameters of copper ion reduction were investigated with a platinum rotating disk electrode (RDE) in a diffusion controlled region. Reduction of Cu(II) in sulfate had one-step two-xelectron process, while the reduction of Cu(II) in chloride solution was involved two one-electron processes. The transfer coefficient of Cu(II) in sulfate solution was lowest, and the transfer coefficient of Cu(I) in halide solutions had the value of nearly one. In chloride solutions, electrodeposition rate of Cu(II) was about one hundred times faster than Cu(I). Diffusion coefficient increased in the order of Cu(II) in chloride solution, Cu(I) in the iodide, bromide, chloride solution, Cu(II) in sulfate solution. The calculated ionic radii and activation energy for diffusion decreased in the same order as above. Morphological study on the copper electrodeposition indicated that the electrode surface became rougher as both concentration and reduction potential increases, and the roughness of the surface was analyzed with UV/VIS spectrophotometer.

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Isolation of a Quinone-rich Fraction from Ardisia crispa Roots and its Attenuating Effects on Murine Skin Tumorigenesis

  • Yeong, Looi Ting;Hamid, Roslida Abdul;Yazan, Latifah Saiful;Khaza'ai, Huzwah
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2301-2305
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    • 2013
  • Ardisia crispa (Family: Myrsinaceae) is an evergreen, fruiting shrub that has been traditionally used as folklore medicine. Despite a scarcity of research publications, we have succeeded in showing suppressive effects on murine skin papillomagenesis. In extension, the present research was aimed at determining the effect of a quinone-rich fraction (QRF) isolated from the same root hexane extract on both initiation and promotion stages of carcinogenesis, at the selected dose of 30 mg/kg. Mice (groups I-IV) were initiated with a single dose of 7,12-dimethylbenz(${\alpha}$)anthracene (DMBA, $100{\mu}g/100{\mu}l$) followed by repeated promotion of croton oil (1%) twice weekly for 20 weeks. In addition, group I (anti-initiation) received QRF 7 days before and after DMBA; group II (anti-promotion) received QRF 30 minutes before each croton oil application; group III (anti-initiation/promotion) was treated with QRF as a combination of group I and II. A further two groups served as vehicle control (group V) and treated control (group VI). As carcinogen control, group IV showed the highest tumor volume ($8.79{\pm}5.44$) and tumor burden ($3.60{\pm}1.17$). Comparatively, group III revealed only 20% of tumor incidence, tumor burden ($3.00{\pm}1.00$) and tumor volume ($2.40{\pm}1.12$), which were significantly different from group IV. Group II also showed significant reduction of tumor volume (3.11), tumor burden (3.00) and tumor incidence (11.11%), along with prominent increase of latency period of tumor formation (week 12). Group I, nonetheless, demonstrated marked increment of tumor incidence by 40% with prompted latency period of tumor formation (week 7). No tumor formation was observed in groups V and VI. This study provided clear evidence of inhibitory effects of QRF during promotion period which was in agreement with our previous findings. The mechanism(s) underlying such effects have yet to be elucidated.

A STUDY ON THE FRACTURE RESISTANCE AND CHARACTERISTICS OF TEETH IN CLASS II CAVITY RESTORATIONS (2급(級) 와동(窩洞) 수복시(修復時) 치아파괴(齒牙破壞) 저항성(抵抗性) 및 귀열양상(龜裂樣相)에 관(關)한 연구(硏究))

  • Joo, Ik-Nam;Park, Sang-Jin;Min, Byung-Soon;Choi, Ho-Young
    • Restorative Dentistry and Endodontics
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    • v.13 no.2
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    • pp.337-348
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    • 1988
  • The purpose of this study was to examine the fracture strength and characteristics of teeth with MOD cavity preparation. Freshly extracted sound maxillary premolars were cleaned and stored in normal saline solution $37^{\circ}C$ for 72 hours before experiments. The roots of teeth were embedded in a self-curing resin, and the exposed crown were maintained in a vertical position by a modelling wax in a brass ring. The MOD cavities were prepared with No. 57 carbide bur under high speed to a depth of 2.0mm and a width of 2.0mm(Fig.1). All the prepared teeth specimens were divided into 7 groups according to the mode of cavity form and restorative materials (Table 1, 2): Group I, unpreapred, intact teeth as control Group II, prepared cavity without restoration Group III, prepared teeth restored with amalgam Group IV, prepared teeth restored with composite resin (P-10) Group V, prepared teeth with beveled enamel margins restored with composite resin (P-10) Group VI, prepared teeth restored with light-cured composite resin (P-30) Group VII, prepard teeth with beveled enamel margins restored with light-cured composite resin (P-30) After placement of restorations, all of the specimens were stored in water at $37^{\circ}C$ for 72 hours before testing. All of the specimens were tested on the Instron Universal Testing machine (No. 6025) in order to evaluate the strength of fracture. One metal ball 5.0mm in diameter contacting the specimens parallel to the occlusal surface was used to in this study (Fig. 1). The fracture characteristics of the specimens were examined with naked eye and in the scanning electron microscope (JSM-20). The results obtained from this study were as follows: 1. The mean fracture strength was the highest in group VI and that in group II was the lowest. 2. The progress of crack of teeth propagated into the pulp cavity. 3. In case of the group of the restored teeth, the crack occurred to be accompanied with cuspal fracture. 4. The crack of restored teeth was initiated along the pulpo-axial line angle of the cavity.

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Anti-inflammatory Action of Phenolic Compounds from Gastrodia elata Root

  • Lee, Ji-Yun;Jang, Young-Woon;Kang, Hyo-Sook;Moon, Hee;Sim, Sang-Soo;Kim, Chang-Jong
    • Archives of Pharmacal Research
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    • v.29 no.10
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    • pp.849-858
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    • 2006
  • Previous screening of the pharmacological action of Gastrodia elata (GE) root (Orchidaceae) showed that methanol (MeOH) extracts have significant anti-inflammatory properties. The antiinflammatory agents of GE, however, remain unclear. In this experiment, MeOH extracts of GE were fractionated with organic solvents for the anti-inflammatory activity-guided separation of GE. Eight phenolic compounds from the ether (EtOEt) and ethyl acetate (EtOAc) fractions were isolated by column chromatography: 4-hydroxybenzaldehyde (I), 4-hydroxybenzyl alcohol (II), benzyl alcohol (III), bis-(4-hydroxyphenyl) methane (IV), 4(4'-hydroxybenzyloxy)benzyl-methylether (V), 4-hydroxy-3-methoxybenzyl alcohol (VI), 4-hydroxy-3-methoxybenzaldehyde (VII), and 4-hydroxy-3-methoxybenzoic acid (VIII). To investigate the anti-inflammatory and anti-oxidant activity of these compounds, their effects on carrageenan-induced paw edema, arachidonic acid (AA)-induced ear edema and analgesic activity in acetic acid (HAc)-induced writhing response were carried out in vivo; cyclooxygenase (COX) activity, reactive oxygen species (ROS) generation in rat basophilic leukemia (RBL 2H3) cells and 1,1-diphenyl-2-picryl-hydroazyl (DPPH) scavenging activity were determined in vitro. These phenolic compounds not only had anti-inflammatory and analgesic properties in vivo, but also inhibited COX activity and silica-induced ROS generation in a dose-dependent manner. Among these phenolic compounds, compound VII was the most potent anti-inflammatory and analgesic. Compound VII significantly inhibited silica-induced ROS generation and compound VI significantly increased DPPH radical scavenging activity. Compounds I, II and III significantly inhibited the activity of COX-I and II. These results indicate that phenolic compounds of GE are anti-inflammatory, which may be related to inhibition of COX activity and to anti-oxidant activity. Consideration of the structure-activity relationship of the phenolic derivatives from GE on the anti-inflammatory action revealed that both C-4 hydroxy and C-3 methoxy radicals of benzyl aldehyde play an important role in anti-inflammatory activities.

Seed morphology of Euphorbia section Zygophyllidium and related taxa (대극속 Zygophy llidium절과 근연 분류군의 종자 형태)

  • Jin , Sun-Mi;Park, Ki-Ryong
    • Korean Journal of Plant Taxonomy
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    • v.38 no.4
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    • pp.389-403
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    • 2008
  • Seed morphological studies of 12 species of sect. Zygophyllidium and related Poinsettia using light and scanning electron microscopy were conducted to test the hypotheses of the sectional boundaries and species relationships. Characteristics of seeds, and the keys of identification of 12 species were presented. Seeds of 12 species were divided into 6 types based on the UPGMA tree from numerical analyses using nine seed characters. Type I, including E. uniglandulosa, is characterized by the foveolate seed with granulate testa cells. Type II, including species E. exstipulata, E. lagunensis, E. bilobata, E. hexagonoides and E. chersonesa, was recognized by the presence of inter-cellular granules among testa cells. Type III, including E. cyathophora, has a seed with acute apex, and concentric circles on the surface of testa cells. Type IV, including species of E. dentata and E. pentadactyla, has a seed with caruncle and lacking inter-cellular granules among testa cells. Type V, including E. hexagona, was characterized by the ovate seeds and lacking inter-cellular granules. Type VI, including E. eriantha and E. lacera, was recognized by the seeds with rectangular shape with caruncle. Based on the seed morphology, sect. Zygophyllidium should be defined only species with E. exstipulata, E. lagunensis, E. bilobata, E. hexagonoides and E. chersonesa. E. hexagona, traditionally included in this section, was closely related to E. dentata from Poinsettia.

Seminiferous Epithelium Cycle of Apodemus speciosus peninsulae (흰넓적다리 붉은쥐(Apodemus speciosus peninsulae)의 세정관 상피주기)

  • Kim, Mi-Jin;Lee, Jung-Hun
    • Development and Reproduction
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    • v.13 no.1
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    • pp.25-33
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    • 2009
  • The cycle of the seminiferous epithelium and development of spermatids of Apodemus speciosus peninsulae were observed using a light microscope. On the basis of developing spermatocyte and spermatid, the cycle of the seminiferous epithelium was divided into 9 stages. Type Ad spermatogonia were appeared in all stages ($I{\sim}IX$). The Ap, In, and B types of spermatogonia were appeared from stage I, II and III, and IV, respectively. In prophase of first meiosis, the leptotene spermatocytes appeared from stage V and VI, zygotene spermatocytes from stages I, II, VII, VIII, and IX, pachytene spermatocytes from stage III to VII, diplotene spermatocytes in the stage VIII, and secondary spermatocytes in stage IX. On the basis of morphology of spermatid head, developing of nuclear and acrosome and the morphological change of cytoplasm, the developing of spermatids was divided into 12 steps. Considering all the results, A. s. peninsulae displayed very similar result with A. agrarius coreae that is allied species when compare correct characters developing of spermatids with spermatogonia and appearance time of the spermatocyte. Appearance time of the same cell and number of spermatogonial generation was thought that characters of the species, and information may be useful in identifying the species.

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Improving Physical Therapy Services of Health Centers in Korea (전국 보건소 물리치료실 운영 실태와 활성화 방안)

  • Chang, Eun-Ju
    • Journal of Korean Physical Therapy Science
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    • v.3 no.2
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    • pp.1021-1036
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    • 1996
  • The purpose of this study are ( i ) to examine operating situation of physical therapy department and job satisfaction of physical therapists in health centers, (ii) to analyze utilization patterns and patient satisfaction of physical therapy services among health center visitors, and finally, (iii) to suggest policy implications in facilitating improvement on physical therapy services of health centers. The materials are collected from 105 physical therapists among nationwide health centers and 203 patients of 5 health centers in Pusan, Korea. The survey is conducted from February 13 to March 30, 1996 with a structured self - administered questionnaire. Major results of the study are as follows. First, the result of regression analysis between job satisfaction and affecting factors identify following variables as the significant determinants; self-development(+), job itself(+), and co-worker support (+). Second, the current operating situation of physical therapy department shows such problem as; i )shortage and unstable job security of physical therapists, ii )absence of rehabilitation specialist, iii )lack of understanding on physical therapy of co-workers, iv)shortage of physical therapy equipment and facility, v)burdensome task of physical therapists, and vi) inappropriate purchase process of equipment. Third, patient satisfaction for physical therapy services are revealed relatively high. And the result of regression analysis between patient satisfaction and affecting factors identify following variables as the significant determinants; credibility of physical therapist(+), satisfaction for waiting time(+), cleanliness(+). Fourth, the patients appeal about physical therapy services such problem as; i) shortage of physical therapists, physical therapy equipment, and facility, ii) inconvenient administrative procedure for utilization physical therapy services. Fifth and last, recommendations for the improvement of physical therapy services of health centers are as follows; i )recruiting more physical therapists, ii )regular employment of physical therapists instead of daily use employment, iii )re-arrangement of facility for patient's convenience, iv )establishing reasonable purchasing system of equipment for physical therapy, v) reforming administrative procedure for patient focused care.

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Clinical Evaluation of Mandibular Condyle Fractures (하악 과두 골절 환자의 임상분석)

  • Lim, Hyoung-Sup;Kim, Su-Gwan;Oh, Ji-Su;Jeong, Mi-Ae
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.34 no.1
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    • pp.53-57
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    • 2012
  • Purpose: This study considered the effects and proper treatments of mandibular condyle fractures by comparing clinical differences and complications according to analysis and treatment plan. Methods: From September 2007 to August 2010, patients who were diagnosed with condylar fracture and monitored for more than 3 months were selected. Cases were divided in a reductive manner and evaluated by type and period of intermaxillary fixation (IMF), status of occlusion and trismus according to the Spiessle/Schroll method. A total 50 patients were examined. Results: The number of the unilateral condyle fractures was 45 and 30 patients had multiple fractures. Type of fracture was categorized by the Spiessle/Schroll method. There were 21 patients with type I, 11 patients with type II, 3 patients with type 3, 10 patients with type V and 5 patients with type VI; there were no patients with a type IV fracture. 11 patients were operated on with open reduction. Among them, 9 patients were type II and 2 patients were type I. For type I patients, an intra-oral approach was conducted with an endoscope and trocar. For 3 of the type II patients, an retromandibular approach was conducted and for the rest of the type II patients, the same approach as type I was used. The periods of IMF were 2.36 weeks (mean) in open reduction group and 2.9 weeks (mean) in closed reduction group and the total mean period is 2.78 weeks. All patients had stable occlusion after removing the IMF. Trismus occurred in 1 patient for open reduction and 5 patients for closed reduction. Facial nerve palsy was observed in one patient postoperatively that resolved after 6 months. Conclusion: In this study, similar prognosis was shown after an open and closed reduction was conducted. Therefore, treatments need to be planned depending on the degree of condyle fracture and the amount of displacement. Additionally, the period of IMF could be shortened with open reduction.

Effect of Humic acid on the Distribution of the Contaminants with Black Shale (휴믹산이 black shale과 오염물질의 분포에 미치는 영향에 대한 연구)

  • Min, Jee-Eun;Park, Jae-Woo
    • Journal of Korean Society on Water Environment
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    • v.20 no.6
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    • pp.670-675
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    • 2004
  • Humic acids are macromolecules originated from natural water, soil, and sediment. The characteristics of humic acid enable it to change the distribution of metals as well as many kinds of organic contaminants and to determine the sorption of them from soil solution. To see the effect of humic acid on the removal rate of organic contaminants and heavy metals, batch-scale experiments were performed. As a natural geosorbent, black shale was used as a sorbent media, which showed hight sorption capacity of trichloroethylene (TCE), lead, cadmium and chromium. The effect of sorption-desorption, pH, ionic strength and the concentration of humic acid was taken into consideration. TCE sorption capacity by black shale was compared to natural bentonite and hexadecyltrimethylammonium (HDTMA) modified bentonite. The removal rate was good and humic acid also sorbed onto black shale very well. The organic part of humic acid could effectively enhance the partition of TCE and it act as an electron donor to reduce Cr(VI) to Cr(III). Cationic metal of Pb(II) and Cd(II) also removed from the water by black shale. With 3 mg/L of humic acid, both Pb(II) and Cd(II) were removed more than without humic acid. That could be explained by sorption and complexation with humic acid and that was possible when humic acid could change the hydrophobicity and solubility of heavy metals. Humic acid exhibited desorption-resistivity with black shale, which implied that black shale could be an alternative sorbent or material for remediation of organic contaminants and heavy metals.

A Case of Hunter Syndrome Diagnosed at Age of 2.5 Year (2.5세에 진단된 헌터증후군 1례)

  • Choi, Miran;Kwun, Younghee;Jin, Dongkyu;Lee, Jieun
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.14 no.2
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    • pp.178-181
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    • 2014
  • Hunter syndrome (mucopolysaccharidosis type II, MPS II) is a X-linked lysosomal storage disease caused by a deficiency in the lysosomal enzyme, iduronate-2-sulfatase (IDS), leading to accumulation of glycosaminoglycans within lysosomes of many organs and tissues. Since the enzyme replacement therapy was approved and available in the treatment of MPS I, II, VI, early diagnosis and early therapy can bring the better prognosis of disease and the better quality of life in patients. We described a 2.5 year old child presented with frequent otitis media and developmental delay including speech impairment, who was diagnosed as Hunter syndrome with IDS NM_000202.5:c. 263G>A(p.Arg88His) mutation.