• Title/Summary/Keyword: stainless steel wire

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Electrodeposition of some Alpha-Emitting Nuclides and its Isotope Determination by Alpha Spectrometry (몇가지 알파입자 방출 핵종의 전해석출 및 알파 스펙트럼 측정에 의한 그의 동위원소 정량)

  • Key-Suck Jung;In-Suck Suh
    • Journal of the Korean Chemical Society
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    • v.27 no.4
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    • pp.279-286
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    • 1983
  • An apparatus was made for the electrodeposition of alpha emitting actinide nuclides, $^{207}Bi$ and $^{210}Po$. The electrodeposition was made on a polished stainless steel plate cathode. The anode was made of platinum wire and to stir the solution. With the ammonium chloride as electrolyte initial pH = 4, chloride concentration = 0.6M and solution volume = 15ml, a current of 1.5 ampere(current density = 0.59A/$cm^2$) was flowed for 100 minutes for the quantitative recovery of electrodeposition and on average recovery of 98.3% was obtained within ${\pm}$0.7% uncertainty. Alpha spectrometry of the electrodeposited sample showed alpha peaks from $^{210}Po, ^{234}U$ and $^{239}Pu$ having energy resolution (FWHM) of 18.3, 21.8 and 36.0 keV respectively. The electrodeposition and alpha spectrometry for a natural uranium sample of domestic origin gave $^{238}U : ^{234}U = 1 : 6.1{\times}10^{-5}$ and for a neutron-irradiated uranium sample did $^{238}U : ^{239}Pu : ^{241}Am = 100 : 0.0263 : 5.20{times}10^{-5}$. The result of $^{238}U$ determination in the irradiated sample by electrodeposition-alpha spectrometry was in accord within ${\pm}1.6%$ of relative error with the results of solid fluorimetry and mass spectrometry. For $^{239}Pu$ the result of electrodeposition-alpha spectrometry was in accord within ${\pm}$4.0% of relative error with the results of anion exchange separation and the thenoyltrifluoroacetone(TTA) extraction both followed by alpha spectrometries.

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TRAUMATIC ROOT FRACTURE IN YOUNG PERMANENT TEETH : A CASE REPORT (미완성된 근첨을 가진 영구치 치근 파절의 치유에 관한 증례)

  • Kang, Sun-Hee;Kim, Dae-Eop;Lee, Kwang-Hee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.4
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    • pp.576-580
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    • 2003
  • A 7-year-old male was refered to Department of Pediatric Dentistry, Wonkwang Dental Hospital for treatment of a traumatic injury to the teeth of the maxillary anterior region of the mouth. His right central incisor presented subluxation and root fracture, the left central incisor had suffered intrusive luxation and root fracture. The initial treatment involved reposition and fixation of the teeth with 0.5mm stainless steel wire and composite resin. The patient was submitted for clinical and radiographic fallow-up. After 4 years, radiographically the right central incisor seemed to be healed by hard tissue union and showed to be indistinct fracture line, intact lamina dura. The left central incisor radiographically was healed by interposition of bone and connective tissue and showed to be distinct horizontal fracture line separating the fragments, and pulp canal obliteration. In clinical examination, the teeth showed a normal response to elective pulp test, percussion and mobility test. Pulp survival after injuries appears to be dependent upon the type of luxation injury, age of patient, stage of root development and degree of dislocation. In this case, the two teeth with incomplete root formation were suffered different type of injury by trauma and has showed different healing aspect.

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Variation of Nephrotoxicity Biomarkers by Urinary Storage Condition in Rats

  • Lee, Jung-Min;Han, Young-Hwan;Choi, Su-Jeong;Park, Ju-Seong;Jang, Jeong-Jun;Bae, Re-Ji-Na;Lee, Mi Ju;Kim, Myoung Jun;Lee, Yong-Hoon;Kim, Duyeol;Lee, Hye-Young;Park, Sun-Hee;Park, Cheol-Beom;Kang, Jin Seok;Kang, Jong-Koo
    • Toxicological Research
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    • v.30 no.4
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    • pp.305-309
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    • 2014
  • Recently, there has been an increase in the use of several nephrotoxicity biomarkers in preclinical experiments. In addition, it has been indicated that the result may have been influenced by secondary factors, such as sample storage condition or storage period. In this study, we have assessed the variation in urinary nephrotoxicity biomarkers as a result of urine storage conditions and storage period of the urine. Urine was sampled from specific pathogen-free Sprague-Dawley rats (19 weeks old), which were housed individually in hanged stainless steel wire mesh cages. Urine was stored at $20^{\circ}C$, at $4^{\circ}C$, or at $-70^{\circ}C$ after sampling. The levels of the biomarkers such as beta-2 microglobulin (B2M), cystatin-C (Cys-C), N-acetyl-${\beta}$-D-glucosaminidase (NAG), micro albumin (MA), micro protein (MP) were measured at 6, 24, 48 and 144 hr after sampling. The B2M level was significantly decreased at 6, 24, 48, and 144 hr compared to 0 hr at $-70^{\circ}C$ (p < 0.05, p < 0.01, p < 0.05, and p < 0.05, respectively) and 24 and 144 hr at $20^{\circ}C$ (p < 0.01, p < 0.01, respectively). The Cys-C level was significantly decreased at 144 hr compared to 0 hr at $4^{\circ}C$ (p < 0.01), at $20^{\circ}C$ (p < 0.05) and at $70^{\circ}C$ (p < 0.01). MP and MA levels were not different for 144 hr in all storage conditions. Taken together, B2M and Cys-C levels were modulated by storage temperature and period. For the enhancement of test accuracy, it is suggested that strict protocols be established for samples to minimize the effects of the storage conditions on the detected levels of biomarkers.

Effect of Sweet Persimmon Wine on Alcoholic Fatty Livers in Rats (흰쥐에서 단감발효주가 알코올성 지방간 형성에 미치는 영향)

  • Nam, Kyung-Sook;Kim, Ju-Youn;Noh, Sang-K.;Park, Joong-Hyeop;Sung, Eon-Gi
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.11
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    • pp.1548-1555
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    • 2011
  • Persimmons are shown to contain high levels of phenolics. The present study was designed to investigate if a sweet persimmon wine (SPW) would affect the development of alcoholic fatty liver in rats. Initially, male Sprague-Dawley rats were housed singly in stainless steel wire-bottomed cages in a room of controlled temperature and lighting. The rats had free access to a nutritionally adequate AIN-93G diet and deionized water. After the acclimatization period, rats were weight-matched and assigned to the following three groups: two groups were fed 6.7% ethanol or the caloric equivalent of maltose-dextrin in a Lieber-DeCarli diet and the other group was fed the isocaloric Lieber-DeCarli diet containing SPW at the same ethanol level. All three groups were fed their respective diets for 6 weeks. Serum transaminase, cholesterol, and triglyceride levels were measured. Liver lipids and histology were assessed at 6 weeks. The total phenolic content and the antioxidant and free radical scavenging activities of SPW were determined. SPW significantly increased antioxidant and free radical scavenging activities. As markers of liver injury, serum alanine and aspartate transminases were markedly lowered by SPW at 6 weeks. SPW significantly reduced the serum levels of serum cholesterol and triglyceride compared to ethanol treatment. SPW delayed the development of an alcoholic fatty liver by reversing fat accumulation in the liver, as evidenced in histological observations. Taken together, SPW seems to protect the liver from becoming fatty by alleviating fatty liver symptoms and lowering hepatic and serum lipid levels. Such a protective effect of SPW appears to be in part due to its phenolics.

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
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    • v.25 no.5 s.52
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    • pp.525-541
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    • 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.

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