• Title/Summary/Keyword: 표면편평도

Search Result 70, Processing Time 0.035 seconds

Reconsideration of the taxonomic characteristics of Callicarpa japonica Thunb. and C. dichotoma (Lour.) K. Koch (Verbenaceae) in Korea (한국산 작살나무와 좀작살나무(마편초과)의 분류학적 형질 재검토)

  • Yoon, Min-Ji;Choi, Bo-Kyung;Hong, Suk-Pyo
    • Korean Journal of Plant Taxonomy
    • /
    • v.42 no.2
    • /
    • pp.141-149
    • /
    • 2012
  • To clarify some ambiguous diagnostic characters of Callicarpa japonica Thunb. and Callicarpa dichotoma (Lour.) K. Koch in Korea (Verbenaceae), the external morphology and micromorphology (leaf, anther, pollen, fruit, in particular endocarp surface and structure) of two taxa are studied and described in detail. It is confirmed that the following characteristics (e.g., the stem outline in a cross-section, the bud shape and length, the corolla tube length and the lobe length, the pattern of the anther dehiscence and length, and the endocarp morphology) are useful for distinguishing these two taxa. In particular, following three characteristics are most useful for an identification: (1) the corolla tube length of C. japonica (2.5-4.6 mm) is longer than that of C. dichotoma (0.7-1.0 mm); (2) the anther is dehiscing by an apical pore at the anthesis of C. japonica, while it is opening by a long fissure from the apex to the base in C. dichotoma; and (3) the edge of the endocarp (lateral view) in C. japonica is concave, while in C. dichotoma it is shown to be flat. On the other hand, the teeth state on the leaf margin and the position of inflorescence are not good diagnostic characteristics for identification. Additionally, the keys for all known Callicarpa taxa in Korea are provided.

Development and Characterization of High Frequency Ultrasonic Transducer Using PVDF and P(VDF-TrFE) (PVDF 및 P(VDF-TrFE)를 이용한 고주파수 수침용 초음파 탐촉자 개발 및 평가)

  • Kim, Ki-Bok;Kim, Byoung-Geuk;Lee, Seung-Seok
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.22 no.1
    • /
    • pp.1-8
    • /
    • 2002
  • The high frequency ultrasonic transducers using polyvinyliden fluoride(PVDF) and polyvinylidene fluoride trifluorethyylene(P(VDF-TrFE)) were developed. The characteristics of fabricated high frequency ultrasonic transducer such as beam diameter, high frequency ultrasonic detection field and amplitude of the first pulse echo signal from the test target in the water were analyzed. The high frequency ultrasonic detection field was affected by the length of coaxial cable between high frequency transducer and ultrasonic pulser/receiver. As the size of the test target increased, the high frequency detection field decreased and the amplitude of a reflection signal increased. The peak amplitude of the first pulse echo signal of P(VDF-TrFE) transducer was higher than that of PVDF transducer. The high frequency ultrasonic detection field of PVDF transducer was wider than that of P(VDF-TrFE) transducer. With C-scan testing, the developed high frequency ultrasonic transducer could detect the 30 to $100{\mu}m$ of hydrogen induced crack of steel specimen by C-scan testing.

A Comparative Anatomical and Histological Study of the Olfactory Organ of Amphidromous and Land-locked Sweet Fish, Plecoglossus altivelis(Osmeriformes, Osmeridae), in Seomjingang River System, Korea (섬진강 수계에 출현하는 양측회유성과 육봉형 은어 Plecoglossus altivelis 후각기관의 해부 및 조직학적 구조 비교 연구)

  • Min Jeong Choi;Jong Young Park
    • Korean Journal of Ichthyology
    • /
    • v.36 no.3
    • /
    • pp.230-239
    • /
    • 2024
  • This study was carried out the anatomical and histological investigation of the olfactory organ on a land-locked and an amphidromous Plecoglossus altivelis in Deokam-ri, Shinpyeong-myeon, Imsil-gun, Jeollabuk-do and Daeduk-ri, Gojeon-myeon, Hadong-gun, Gyeongsangnam-do, August, 2021, Korea. The external morphology of the two types of P. altivelis was indistinguishable, featuring a pair of the elliptical anterior nostrils, the semicircular posterior nostrils, and the nasal flaps on the snout. The olfactory organ consisted of 20 to 22 olfactory lamellae forming a rosette structure in the nasal chamber. The secondary folds appeared on the lamellae. The histological results were also uniform. The sensory epithelium was a continuous type, consisting of olfactory receptor neurons, supporting cells, basal cells, cilia, and an unidentified cell. The non-sensory epithelium found only in the terminal part of lamellae, consist of stratified epithelial cells, basal cells, and mucous cells. For the olfactory organ between a land-lock type and an amphidromous type, no difference was observed in external and histological structure between amphidromous and land-locked type. However, it is considered that P. altivelis has higher olfactory sensitivity than other anadromous fish due to more number of olfactory lamellae and the presence of the secondary folds.

Development of a Thermoplastic Oral Compensator for Improving Dose Uniformity in Radiation Therapy for Head and Neck Cancer (두경부암 방사선치료 시 선량 균일도 향상을 위한 Thermoplastic 구강 보상체의 개발)

  • Choi, Joon-Yong;Won, Young-Jin;Park, Ji-Yeon;Kim, Jong-Won;Moon, Bong-Ki;Yoon, Hyong-Geun;Moon, Soo-Ho;Jeon, Jong-Byeong;Suh, Tae-Suk
    • Progress in Medical Physics
    • /
    • v.23 no.4
    • /
    • pp.269-278
    • /
    • 2012
  • Aquaplast Thermoplastic (AT) is a tissue-equivalent oral compensator that has been developed to improve dose uniformity at the common boundary and around the treated area during radiotherapy in patients with head and neck cancer. In order to assess the usefulness of AT, the degree of improvement in dose distribution and physical properties were compared to those of oral compensators made using paraffin, alginate, and putty, which are materials conventionally used in dental imprinting. To assess the physical properties, strength evaluations (compression and drop evaluations) and natural deformation evaluations (volume change over time) were performed; a Gafchromic EBT2 film and a glass dosimeter inserted into a developed phantom for dose verification were used to measure the common boundary dose and the beam profile to assess the dose delivery. When the natural deformation of the oral compensators was assessed over a two-month period, alginate exhibited a maximum of 80% change in volume from moisture evaporation, while the remaining tissue-equivalent properties, including those of AT, showed a change in volume that was less than 3%. In a free-fall test at a height of 1.5 m (repeated 5 times as a strength evaluation), paraffin was easily damaged by the impact, but AT exhibited no damage from the fall. In compressive strength testing, AT was not destroyed even at 8 times the force needed for paraffin. In dose verification using a glass dosimeter, the results showed that in a single test, the tissue-equivalent (about 80 Hounsfield Units [HU]) AT delivered about 4.9% lower surface dose in terms of delivery of an output coefficient (monitor unit), which was 4% lower than putty and exhibited a value of about 1,000 HU or higher during a dose delivery of the same formulation. In addition, when the incident direction of the beam was used as a reference, the uniformity of the dose, as assessed from the beam profile at the boundary after passing through the oral compensators, was 11.41, 3.98, and 4.30 for air, AT, and putty, respectively. The AT oral compensator had a higher strength and lower probability of material transformation than the oral compensators conventionally used as a tissue-equivalent material, and a uniform dose distribution was successfully formed at the boundary and surrounding area including the mouth. It was also possible to deliver a uniformly formulated dose and reduce the skin dose delivery.

Comparative Study of the Ablation Rates of Er: YAG Laser Irradiation on Dentin and Enamel (Er:YAG 레이저를 이용한 법랑질과 상아질의 절삭율 연구)

  • Kim, Kun-A;Ahn, Yong-Woo;Ko, Myung-Yun;Park, June-Sang
    • Journal of Oral Medicine and Pain
    • /
    • v.30 no.1
    • /
    • pp.131-140
    • /
    • 2005
  • The purpose of this study was to examine the ablation rate of Er: YAG laser irradiation on dentin and enamel and to observe the microscopic structures of cavities formed after ablation of enamel and dentin in using a bur and cavities formed after ablation using laser. Er:YAG laser irradiated at 200 mJ, 250mJ, 300mJ at the frequency of 20Hz, 15Hz. The following results were obtained : 1. The ablation rate of dentin groups at power of 3 W-6 W was about $1.103{\sim}2.639mm^3/sec$ and there were no significant differences between power of 4.5 W$\sim$6 W. 2. The ablation rate of enamel groups at power of 3 W-6 W was about $0.413{\sim}0.969mm^3/sec$ and there were no significant differences between power of 4 W$\sim$6 W. 3. With SEM examination of the cavity surface treated with the conventional high speed bur revealed relatively flat appearance almost covered with a debris like smear layer. 4. With SEM examination of the lased surface of dentin groups revealed no smear layer and no debris and openings of dentinal tubules were clearly opened. But the lased surfaces of the groups over 3 W were irregular and particles were loosely attached on it. 5. With SEM examination of the lased surface of enamel groups revealed severely destructed surface at the 6 W group and melting drop materials at the 3 W group. But the lased surface of 4 W group revealed clearly ablated surface. Therefore when cutting teeth using Er:YAG laser, the lasing power which can make effective ablation rate and minimize the thermal effect could be 3W at dentin and 4W at enamel. But, further studies and additional data collection will be necessary for appropriate lasing condition of Er:YAG laser.

A Comparison of Illness Behavior among Patients with Somatoform Disorders, Depressive Disorders and Psychosomatic Disorders (신체형장애, 우울장애 및 정신신체장애 환자들간의 질병행동의 비교)

  • Koh, Kyung-Bong;Ki, Sun-Wan
    • Korean Journal of Psychosomatic Medicine
    • /
    • v.5 no.2
    • /
    • pp.185-194
    • /
    • 1997
  • A comparison was made regarding illness behavior among patients with somatoform disorders, depressive disorders and psychosomatic disorders. The subjects consisted of out-patients with somatoform disorders(N=52), depressive disorders(N=52) and psychosomatic disorders(N=51). illness behavior was assessed by illness Behavior Assessment Schedule and the questionnaire about help-seeking behavior. The patients with somatoform disorders and psychosomatic disorders more often affirmed the presence of somatic disease, were more likely to have phobia of disease, had more preoccupation with ideas of disease and more frequently shopped around oriental clinics than the patients with depressive disorders. The patients with somatoform disorders more often attributed its cause to physical factors, less often attributed the origin of affective disturbance to psychological causes, showed Less depression and irritability, and were less likely to accept psychiatric treatment recommended by other physicians than depressive patients. The patients with somatoform disorders were more likely to report having been told that they suffered from a mild illness than those with psychosomatic disorders. The patients with somatoform disorders with psychological problems tended to inhibit expression of their emotion. Female patients with somatoform disorders more often affirmed the presence of psychological disorder and attributed its cause to psychological factors than male ones. These results suggest that in illness behavior, patients with somatoform disorders are different from depressive patients, whereas the former patients are similar to psychosomatic patients except the discrepancy between therapists and patients regarding evaluation of their symptoms. Thus, it is emphasized that first, therapists need to approach patients with somatoform disorders somatically with understanding of their underlying need to deny psychological problems, followed by either psychological or biopsychosocial approach.

  • PDF

Study on the Photoneutrons Produced in 15 MV Medical Linear Accelerators : Comparison of Three-Dimensional Conformal Radiotherapy and Intensity-Modulated Radiotherapy (15 MV 의료용 선형가속기에서 발생되는 광중성자의 선량 평가 - 3차원입체조형방사선치료와 세기조절방사선치료의 비교 -)

  • Yang, Oh-Nam;Lim, Cheong-Hwan
    • Journal of radiological science and technology
    • /
    • v.35 no.4
    • /
    • pp.335-343
    • /
    • 2012
  • Intensity-modulated radiotherapy(IMRT) have the ability to provide better dose conformity and sparing of critical normal tissues than three-dimensional radiotherapy(3DCRT). Especially, with the benefit of health insurance in 2011, its use now increasingly in many modern radiotherapy departments. Also the use of linear accelerator with high-energy photon beams over 10 MV is increasing. As is well known, these linacs have the capacity to produce photonueutrons due to photonuclear reactions in materials with a large atomic number such as the target, flattening filters, collimators, and multi-leaf collimators(MLC). MLC-based IMRT treatments increase the monitor units and the probability of production of photoneutrons from photon-induced nuclear reactions. The purpose of this study is to quantitatively evaluate the dose of photoneutrons produced from 3DCRT and IMRT technique for Rando phantom in cervical cancer. We performed the treatment plans with 3DCRT and IMRT technique using Rando phantom for treatment of cervical cancer. An Rando phantom placed on the couch in the supine position was irradiated using 15 MV photon beams. Optically stimulated luminescence dosimeters(OSLD) were attached to 4 different locations (abdomen, chest, head and neck, eyes) and from center of field size and measured 5 times each of locations. Measured neutron dose from IMRT technique increased by 9.0, 8.6, 8.8, and 14 times than 3DCRT technique for abdomen, chest, head and neck, and eyes, respectively. When using IMRT with 15 MV photonbeams, the photoneutrons contributed a significant portion on out-of-field. It is difficult to prevent high energy photon beams to produce the phtoneutrons due to physical properties, if necessary, It is difficult to prevent high energy photon beams to produce the phtoneutrons due to physical properties, if necessary, it is need to provide the additional safe shielding on a linear accelerator and should therefore reduce the out-of-field dose.

Effect of Chitosan-Trimer on the Prevention of Postoperative Intraperitoneal Adhesion Formation in Rats (랫트에서 Chitosan-Trimer가 복강유착에 미치는 영향)

  • Kwon, Eun-ju;Jang, Kwang-ho;Jang, In-ho
    • Journal of Veterinary Clinics
    • /
    • v.18 no.3
    • /
    • pp.257-264
    • /
    • 2001
  • This study was performed to investigate the effects of chitosan-trimer (CT) on the prevention of postoperative adhesion formation in the rate model. All animals divided into PBS (control), 1% CT, 3% CT, and chitin treated group. The mean adhesion score in 1% CT group (1.03$\pm$0.63), 3% CT group (0.64$\pm$0.53) and chitin group (1.67$\pm$0.71) was found to be lower than that in control group (2.07$\pm$0.81). More favorable adhesion prevention was achieved in 3% CT group (0.64$\pm$0.53) in comparison with the control group, 1% CT group, and chitin group without any hemorrhagic complications. A statistically significant difference was observed in adhesion formation between control group and 3% CT group (p<0.001). In control group, 44 of 45 sites (97.7%) formed adhesions between the intestine defects. In contrast, 3% CT was effective in reducing the incidence of adhesion formation to 17 to 45 sites (62.2%) (p<0.05). The locations of adhesions were observed in serosa-serosa (60%), serosa-mesentery (13.3%), serosa-connective tissue of testis (10%), omentum-liver (10%), serosa-omentum (3.3%), serosa-cecum (3.3%), and serosa-incision (0%). On the results of histological analysis, grade of inflammation and fibrosis at the sites of postoperative peritoneal adhesion formation were not significantly different in all groups. But, 3% CT showed the lowest score of inflammation and fibrosis. In 3% CT group, the rate of increase of plasma fibrinogen was significantly lower compared with that in control group from pre-operation to 10 days later (p<0.05). There were no appreciable difference in the CBC, leukocyte differential counts and total protein concentrations among four groups. In conclusion, our data suggested that CT should be effective on reducing adhesion formation in experimental rat models. The results also showed that 3% CT does not adversely affect normal wound healing and healthy recovery after operation.

  • PDF

THE EFFECT OF C-FACTOR AND VOLUME ON MICROLEAKAGE OF COMPOSITE RESIN RESTORATIONS WITH ENAMEL MARGINS (법랑질 변연으로 이루어진 복합레진 수복물의 체적과 C-factor가 미세누출에 미치는 영향)

  • Koo, Bong-Joo;Shin, Dong-Hoon
    • Restorative Dentistry and Endodontics
    • /
    • v.31 no.6
    • /
    • pp.452-459
    • /
    • 2006
  • Competition will usually develop between the opposing walls as the restorative resin shrinks during polymerization. Magnitude of this phenomenon may be depended upon cavity configuration and volume. The purpose of this sturdy was to evaluate the effect of cavity configuration and volume on microleakage of composite resin restoration that has margins on the enamel site only. The labial enamel of forty bovine teeth was ground using a model trimmer to expose a flat enamel surface. Four groups with cylindrical cavities were defined, according to volume and configuration factor(Depth x Diameter / C-factor) - Group I : 1.5 mm ${\times}$ 2.0 mm / 4.0, Group II : 1.5 mm ${\times}$ 6.0 mm / 2.0, Group III : 2.Omm ${\times}$ 1.72 mm / 5.62, Group IV : 2.0 mm ${\times}$ 5.23 mm / 2.54. After treating with fifth-generation one-bottle adhesive - BC Plus$^{TM}$ (Vericom, AnYang, Korea), cavities were bulk flted with microhybrid composite resin - Denfill$^{TM}$ (Vericom). Teeth were stored in distilled water for one day at room temperature and were finished and polished with Sof-Lex system. Specimens were thermocycled 500 times between 5$^{\circ}$C and 55$^{\circ}$C for 30 second at each temperature. Teeth were isolated with two layers of nail varnish except the restoration surface and 1 mm surrounding margins. Electrical conductivity (${\mu}$A) was recorded in distilled water by electrochemical method. Microleakage scores were compared and analyzed using two-way ANOVA at 95% level. The results were as follows: 1. Small cavity volume showed lower microleakage score than large one, however, there was no statistically significant difference. 2. There was no relationship between cavity configuration and microleakage. Factors of cavity configuration and volume did not affect on microleakage of resin restorations with enamel margins only.

The Influence of AH-26 and Zinc Oxide-Eugenol Root Canal Sealer on the Shear Bond Strength of Composite Resin to Dentin (AH-26 및 산화아연유지놀 근관실러가 상아질에 대한 복합레진의 전단결합강도에 미치는 영향)

  • Cho, Ju-Yeon;Jin, Myoung-Uk;Kim, Young-Kyung;Kim, Sung-Kyo
    • Restorative Dentistry and Endodontics
    • /
    • v.31 no.3
    • /
    • pp.147-152
    • /
    • 2006
  • The purpose of this study was to evaluate the influence of the AH-26 root canal sealer on the shear bond strength of composite resin to dentin. One hundred and forty four (144) extracted, sound human molars were used. After embedding in a cylindrical mold, the occlusal part of the anatomical crown was cut away and trimmed in order to create a flat dentin surface. The teeth were randomly divided into three groups; the AH-26 sealer was applied to the AH-26 group, and zinc-oxide eugenol (ZOE) paste was applied to the ZOE group. The dentin surface of the control group did not receive any sealer. A mount jig was placed against the surface of the teeth and the One-step dentin bonding agent was applied after acid etching. Charisma composite resin was packed into the mold and light cured. After polymerization, the alignment tube and mold were removed and the specimens were placed in distilled water at $37^{\circ}C$ for twenty four hours. The shear bond strength was measured by an Instron testing machine. The data for each group were subjected to one-way ANOVA and Tukey's studentized rank test so as to make comparisons between the groups. The AH-26 group and the control group showed significantly higher shear bond strength than the ZOE group (p<0.05). There were no significant differences between the AH-26 group and the control one (p>0.05). Under the conditions of this study, the AH-26 root canal sealer did not seem to affect the shear bond strength of the composite resin to dentin while the ZOE sealer did. Therefore, there may be no decrease in bond strength when the composite resin core is built up immediately after a canal filling with AH-26 as a root canal sealer.