• 제목/요약/키워드: absence

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고정성 교정장치를 이용한 치아이동시 발생되는 마찰력 (FRICTIONAL FORCES IN THE FIXED ORTHODONTIC APPLIANCE DURING TOOTH MOVEMENT)

  • 조명숙;김종철
    • 대한치과교정학회지
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    • 제20권2호
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    • pp.409-417
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    • 1990
  • Tooth movement would be impeded by frictional force arised between archwire and tube, bracket or elastics in the fixed orthodontic appliances, which could be changed variably by such several factors as the contact area, normal (perpendicular) force and the condition of contact surface. There were many literatures about frictional force in the orthodontic region, but different results were obtained from little controlled research so that was very difficult in clinical application. Therefore we have reviewed comprehensively previous literatures about frictional force and thus several results were obtained as follows: 1. For use species of the orthodontic wire, frictional force was influenced mainly by surface roughness of wire in the absence of binding, while that was influenced mainly by normal force in high binding angulation. 2. For the cross-section and diameter of the wire, the contact area influenced mainly on frictional force in the absence of binding, while wire stiffness influenced mainly on frictional force in high binding angulation. 3. The greater the bracket width, the greater frictional force, and frictional force of the plastic bracket was larger than that of the metal bracket. 4. For ligation type, frictional force of the stainless steel ligation was larger than that of the elastic ligation, and frictional force was directly proportional to ligation force. 5. Variable frictional force were occured from the saliva combined with such another factors as normal force and mode of surface oxide et al.

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하악골에 발생한 원발성 골내암종의 치험례 (PRIMARY INTRAOSSEOUS CARCINOMA ON MANDIBLE : A CASE REPORT)

  • 김학렬;류동목;오정환
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제33권3호
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    • pp.263-267
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    • 2007
  • Primary intraosseous carcinoma (PIOC) is a rare odontogenic carcinoma defined as a squamous cell carcinoma arising within a jaw having no initial connection with the oral mucosa, and probably developing from residues of the odontogenic epithelium. PIOC appears more common in male than female, especially at posterior portion of the mandible. Radiographic features of PIOC show irregular patterns of bone destruction with ill defined margins. It could be sometimes misdiagnosed as the cyst or benign tumor because it shows well defined margins. If it couldn't be done appropriate treatment initially, PIOC shows extremely aggressive involvement, extensive local destruction and spreads to the overlying soft tissue. Therefore accurate diagnosis in early state is necessary. The diagnosis criteria proposed for PIOC are : (1) absence of ulcer formation, except when caused by other factors, (2) histologic evidence of squamous cell carcinoma without a cystic component or other odontogenic tumor cell, and (3) absence of another primary tumor on chest radiograph obtained at the time of diagnosis and during a follow-up period of more than 6 month(Suei et al., 1994).

Rescue of Oxidative Stress by Molecular Chaperones in Yeast

  • Ueom Jeonghoon;Kang Sooim;Lee Kyunghee
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2002년도 추계학술대회
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    • pp.76-78
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    • 2002
  • Heat shock proteins (HSPs) are induced in most living cells by mild heat treatment, ethanol, heavy metal ions and hypoxia. In yeast Saccharomyces cerevisiae, mild heat pretreatment strongly induces Hsp104 and thus provide acquired thermotolerance. The ability of hsp104 deleted mutant $({\triangle}hsp104)$ to acquire tolerance to extreme temperature is severely impaired. In providing thermotolerance, two ATP binding domains are indispensible, as demonstrated in ClpA and ClpB proteases of E. coli. The mechanisms by which Hsp104 protects cells from severe heat stress are not yet completely elucidated. We have investigated regulation of mitochondrial metabolic pathways controlled by the functional Hsp104 protein using $^{13}C_NMR$ spectroscopy and observed that the turnover rate of TCA cycle was enhanced in the absence of Hsp104. Production of ROS, which are toxic to kill cells radiply via oxidative stress, was also examined by fluorescence assay. Mitochondrial dysfunction was manifested in increased ROS levels and higher sensitivity for oxidative stress in the absence of Hsp104 protein expressed. Finally, we have identified mitochondrial complex I and Ferritin as binding protein(s) of Hsp104 by yeast two hybrid experiment. Based on these observations, we suggest that Hsp104 protein functions as a protector of oxidative stress via either keeping mitochondrial integrity, direct binding to mitochonrial components or regulating metal-catalyzed redox chemistry.

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The Taxonomy of Psilocybe fagicola-complex

  • Guzmanl Gaston;Jacobs James Q.;Florencia Ramirez Guillenl;Murrietal Dulce;Gandaral Etelvina
    • Journal of Microbiology
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    • 제43권2호
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    • pp.158-165
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    • 2005
  • Psilocybe fagicola comprises a complex of more than eight species, six of them in Mexico, and all of them possessing a long pseudorhiza, a characteristic not listed by Heim and Cailleux in 1959 in the original description of the type species, but described by Guzman in 1978 and 1983. The description of Psilocybe fagicola s.s. is here emended to include the length of the cheilocystidia of(6-) 12-20 (-30) llm, as well as the absence or scarcity of pleurocystidia. Psilocybe xalapensis and P. wassoniorum are considered to be synonymous with P. fagicola s.s. However, Psilocybe banderillensis and P. herrerae from Mexico, P. columbiana from Colombia, and P. keralensis from India are considered to be valid species within this complex. Moreover, P. novoxalapensis and P. teofilae, both from Mexico, are described as new species. Length of spores, presence or absence of pleurocystidia and their variations, and type of cheilocystidia constitute the principal defining characteristics of the species. Setaceous hyphae at the base of the stipe, as well as caulocystidia, lack taxonomic value, as do other morphological characteristics, including pileipellis and subpileipellis. A key to the eight considered species is also presented within the paper.

Characterizations of Denitrifying Polyphosphate-accumulating Bacterium Paracoccus sp. Strain YKP-9

  • Lee, Han-Woong;Park, Yong-Keun
    • Journal of Microbiology and Biotechnology
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    • 제18권12호
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    • pp.1958-1965
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    • 2008
  • A denitrifying polyphosphate-accumulating bacterium (YKP-9) was isolated from activated sludge of a 5-stage biological nutrient removal process with step feed system. This organism was a Gram-negative, coccus-shaped, facultative aerobic chemoorganotroph. It had a respiratory type of metabolism with oxygen, nitrate, and nitrite as terminal electron acceptors. The 16S rRNA gene sequence of strain YKP-9 was most similar to the 16S rRNA gene sequence of Paracoccus sp. OL18 (AY312056) (similarity level, 97%). Denitrifying polyphosphate accumulation by strain YKP-9 was examined under anaerobic-anoxic and anaerobic-oxic batch conditions. It was able to use external carbon sources for polyhydroxyalkanoates(PHA) synthesis and to release phosphate under anaerobic condition. It accumulated polyphosphate and grew a little on energy provided by external carbon sources under anoxic condition, but did neither accumulate polyphosphate nor grow in the absence of external carbon sources under anoxic condition. Cells with intracellular PHA cannot accumulate polyphosphate in the absence of external carbon sources under anoxic condition. Under oxic condition, it grew but could not accumulate polyphosphate with external carbon sources. Based on the results from this study, strain YKP-9 is a new-type denitrifying polyphosphate-accumulating bacterium that accumulates polyphosphate only under anoxic condition, with nitrate and nitrite as the electron acceptors in the presence of external carbon sources.

치과위생사의 일회용 치과진료용품 감염관리 인지도와 재사용자율의 차이 (Differences in dental hygienists' infection control awareness and re-user rate of disposable dental care supplies)

  • 박보영;노희진
    • 한국치위생학회지
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    • 제20권5호
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    • pp.645-653
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    • 2020
  • Objectives: The purpose of this study is to identify the difference between the awareness and reuser rate of infection control t for disposable dental care supplies (DDCS) according to general characteristics and infection management-related characteristics. Methods: A questionnaire was used for 277 dental hygienists to check the general characteristics, infection management-related characteristics, awareness of infection control disposable dental care products, syringe needle, prophylaxis cup, prophylaxis brush, plastic saliva ejector, orthodontic bracket, and gloves reuse rate. Results: The awareness of infection control for DDCS differed according to 'hospital type', 'average number of patients per day', 'presence or absence of infection control guidelines', and 'experience in infection management training in the last two years' (p<0.05). Reuser rates of disposable dental care products differed according to 'hospital type', 'average number of patients per day', 'presence or absence of infection control guidelines', and 'experience in infection management training in the last two years' (p<0.05). Conclusions: In order to manage infection of DDCS, the level of infection control system in the workplace is improved and support for related education is needed. In addition, guidelines and regulations on prohibition of reuse and classification criteria for various DDCS should be prepared.

A Study of the Practical Knowledge Regarding Osteoporosis and Health Promoting Behavior Among University Students

  • Hwang, Hyun Sook
    • 국제물리치료학회지
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    • 제5권2호
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    • pp.772-780
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    • 2014
  • The purpose of this study is to identify the practical knowledge about osteoporosis and health promoting behavior possessed by male and female university students in their twenties. Next, the study seeks to analyze the difference in the degree of knowledge and practice of health promoting behavior depending on the students' area of study (health-related or non-health-related major) and previous education about osteoporosis. A survey was given to 300 male and female university students in Jeju Island from November 18 to December 6, 2013. Regarding knowledge about osteoporosis, the accuracy rate of health science major participants was 16.8 % higher than that of those of non-health science, and the accuracy rate of participants with previous education about osteoporosis was 12.9 % higher than those who had not. Health promoting behavior showed a higher degree of practice among students in health-related majors and those with previous applicable education. There were significant differences between the knowledge of osteoporosis and major and the presence and absence of prior education. Regarding the degree of health promoting behavior and major, the presence or absence of prior education showed significant differences. Among male and female students in their twenties, the recognition of knowledge about osteoporosis is very low. There is a need to develop various programs that focus on osteoporosis prevention rather than treatment, to improve the quality of education and training content according to the individual, and to lower the target age for osteoporosis education.

펩티드성분을 함유하는 블록공중합체막의 세포접착성 (Attachment of Fibroblast Cells on the Block Copdymer Membrane containing Peptide Segments)

  • 강인규;강신성;임학상
    • 대한의용생체공학회:의공학회지
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    • 제13권2호
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    • pp.155-164
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    • 1992
  • Attachment and growth of mouse flbroblast cells on block copolypeptides were studied in the pres once or absence of serum proteins. Cells are rapidly attached to she polymer surface within 30 min regardless of substrate in the presence of serum. The number of flbroblast cells attached on the poly mer surface coated by collagen was larger than thats on the bare surface. Attachment of cells Is as a whole suppressed to a low level by the addltion of sodium azide in the absence of serum. Thls suE gests that the active attachment of cells requires the biological metabolism taking place on polymer substrates. In the presence of serum protein, flbroblast cells are more rapidly grown on the bolck co polymer consisting of poly(T-benzyl L-glutamate) (PBLG) and polyoxypropylene(POP) than on other block copolymers. These results were in agreement wish the data obatlned by an Inverted ml croscope.

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GLUT Phosphorylation May be Required to GLUT Translocation Mechanism

  • Hah, Jong-Sik
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권6호
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    • pp.497-506
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    • 2000
  • In this work, GLUTs phosphorylations by a downstream effector of PI3-kinase, $PKC-{\zeta},$ were studied, and GLUT4 phosphorylation was compared with GLUT2 phosphorylation in relation to the translocation mechanism. Prior to phosphorylation experiment, $PKC-{\zeta}$ kinase activity was determined as $20.76{\pm}4.09$ pmoles Pi/min/25 ng enzymes. GLUT4 was phosphorylated by $PKC-{\zeta}$ and the phosphorylation was increased on the vesicles immunoadsorpted from LDM and on GLUT4 immunoprecipitated from GLUT4- contianing vesicles of adipocytes treated with insulin. However, GLUT2 in hepatocytes was neither phosphorylated by $PKC-{\zeta}$ nor changed in response to insulin treatment. It was confirmed by measuring the subcellular distribution of GLUT2 based on GLUT2 immunoblot density among the four membrane fractions before and after insulin treatment. Total GLUT2 distributions at PM, LYSO, HDM and LDM were $37.7{\pm}12.0%,\;42.4{\pm}12.1%,\;19.2{\pm}5.0%\;and\;0.7{\pm}1.2%$ in the absence of insulin. Total GLUT2 distribution in the presence of insulin was almost same as that in the absence of insulin. Present data with previous findings suggest that GLUT4 translocation may be attributed to GLUT4 phosphorylation by $PKC-{\zeta}$ but GLUT2 does not translocate because GLUT2 is not phosphorylated by the kinase. Therefore, GLUT phosphorylation may be required in GLUT translocation mechanism.

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Four Flaps Technique for Neoumbilicoplasty

  • Lee, Young Taek;Kwon, Chan;Rhee, Seung Chul;Cho, Sang Hun;Eo, Su Rak
    • Archives of Plastic Surgery
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    • 제42권3호
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    • pp.351-355
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    • 2015
  • The absence or disfigurement of the umbilicus is both cosmetically and psychologically distressing to patients. The goal of aesthetically pleasing umbilical reconstruction is to create a neoumbilicus with sufficient depth and good morphology, with natural-looking superior hooding and minimal scarring. Although many reports have presented techniques for creating new and attractive umbilici, we developed a technique that we term the "four flaps technique" for creating a neoumbilicus in circumstances such as the congenital absence of the umbilicus or the lack of remaining umbilical tissue following the excision of a hypertrophic or scarred umbilicus. This method uses the neighboring tissue by simply elevating four flaps and can yield sufficient depth and an aesthetically pleasing shape with appropriate superior hooding.