• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.585-597
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• 2007

The present study was performed to evaluate the effect of Tetracycline-HCI and Saline on the change of implant surface microstructure and surface roughness according to application time. Implants with resorbable blasting media surface were utilized. Before test all 13 implants were measured surface roughness. Among them, 6 implants were rubbed with 50mg/ml Tetracycline-HCl solution and other 6 implants with saline for $\frac{1}{2}$min., 1min., $1\frac{1}{2}$min., 2min., $2\frac{1}{2}$min and 3min. Then, specimens were processed for scanning electron microscopic observation and surface roughness after test. The results of this study were as follows. 1. Control group showed a few irregular, rough, uneven surface with crater-like depression. 2. The test group with Tetracycline-HCl conditioning showed an altered surface when Tetracycline-HCl was applied for 30secs, and showed a various surface alteration as application times go on. 3. The test group with Saline conditioning showed no significant surface differences and surface roughness. 4. The significant increase of Ra value was showed when Tetracycline-HCl was applied for 30secs. In conclusion, the 50mg/ml Tetracycline-HCl must not be applied for the RBM surface implant for surface treatment.

• Archives of Plastic Surgery
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• 제38권4호
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• pp.383-390
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• 2011

Purpose: To correct the upper lip depression after the correction of unilateral cleft lip, autologous grafts such as bone, dermal, fascial grafts and fat injections or alloplastic implants are used. Transplanted bones, dermis and fascia have a tendency to be absorbed and have donor morbidity. Fat injections are absorbed inconsistently and alloplastic implants have problems such as foreign body reactions, protrusions and infections. Authors corrected the upper lip depression using conchal cartilage graft in unilateral cleft lip deformity and the results was analysed with photos. Methods: 26-unilateral cleft lip and 2-microform cleft lip cases, totally 28 cases were performed. Their mean age was 21.89 years. The male and female cases were 12 and 16, respectively. Under anesthesia (general: 18 cases and local: 10 cases), cavum conchae (n=8), cymba conchae (n=16) and whole conchae (n=4) were harvested. Transversely cut the margin of the obtained cartilage, we cut out the most bent portion and put a partial-thickness incision on concave surface in cases of excessive convexity. Then, we performed the onlay graft of the conchal cartilage via scar revision site in unilateral cleft lip and via the reconstruction site of the cupid bow in microform cleft lip. The augmentation of the upper lip was evaluated with photos. Adapting the baseline connecting between the both cheilions as a horizontal standard line, we measured the highest point among the tangents between the upper lip and nose (point a), the lowest point (point c), the middle point between a and c (point b) and the vertical line from the alare (point d) to the horizontal standard line. To assess the postoperative symmetry, we compared cleft side upper lip contour index (%) A,B,C,D=(a,b,c,d)-ch ${\times}$ 100/(ch-ch) and non-cleft side upper lip contour index (%) A',B',C',D'= (a',b',c',d')-ch ${\times}$ 100 / (ch-ch).h) Results: After the surgery, no complication was found except in one case which double layers graft performed in the cleft lip deformity, the lateral portion was protruded. The upper lip contour index, the difference of A and A' were-0.83%, and thus the mild depression was persisted. Difference of B and B', C and C', D and D' were 0.83%, 1.07%, 0.90%. There were statistically significant difference, and thus the depression of upper lip were improved generally. Conclusion: Authors performed the onlay graft of the conchal cartilage in unilateral cleft lip deformity and found that the depression of the upper lip was well corrected except the uppermost part when photogrammetrically analyzed.

• Imaging Science in Dentistry
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• 제42권4호
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• pp.249-253
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• 2012

Purpose: Diagnosis of osteoarthritis most commonly depends on clinical and radiographic findings. The present study attempted to observe the bony changes in temporomandibular joint (TMJ) patients from all age groups. Materials and Methods: The first-visit clinical records and cone beam computed tomography (CBCT) data of 440 TMJs from 220 consecutive TMJ patients were reviewed retrospectively. Results: The most frequent condylar bony change observed was sclerosis (133 joints, 30.2%) followed by surface erosion (129 joints, 29.3%), flattening of the articular surface (112 joints, 25.5%), and deviation in form (58 joints, 13.2%), which included 33 TMJs in a cane-shape, 16 with a lateral or medial pole depression, 6 with posterior condylar surface flattening, and 3 with a bifid-shaped condyle. Fifty-three joints (12.0%) showed hypoplastic condyles but only 1 joint showed hyperplasia. Osteophyte was found in 35 joints (8.0%) and subcortical cyst in 24 joints (5.5%), 5 of which had surface erosion as well. One hundred nineteen joints (27.0%) had only one kind of condylar bony change, 66 joints (15.0%) had two, 52 joints (11.8%) had three, 12 joints (5.0%) had four, and 6 joints (1.4%) had five kinds of condylar bony changes at the same time. Eighty-five (65.9%) of 129 joints with surface erosion had pain recorded at the chief complaint. Conclusion: With more widespread use of CBCT, more specific or detailed guidelines for osteoarthritis are needed.

• 한국공작기계학회논문집
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• 제12권5호
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• pp.34-39
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• 2003

The paper will present chip formation mechanism and surface integrity generation mechanism based on the systematical experimental tests. Some basic factors such as the end milling cutter tooth number, cutting forces, cutting temperature, cutting vibration the chip status, the surface roughness, the hardness distribution and the metallographic texture of the machined surface layer are involved. The chip formation mechanism is typical thermal plastic shear localization at high cutting speed with less number of shear ribbons and bigger shear angle than that at low speed, which means lack of chip deformation. The high cutting speed with much more cutting teeth will be beneficial to the reduction of cutting forces, enlarge machining stability mot depression of temperature increment anti-fatigability as well as surface roughness. The burrs always exist both at low cutting speed and at high cutting speed. So the deburring process should be arranged for milling titanium alloy in my case.

• The Korean Journal of Physiology
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• 제2권2호
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• pp.63-73
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• 1968

It is well known that mammalian alveolar membrane is covered with a very thin layer of surfactant film which characteristically reduces surface tension of alveolar membrane, and maintains alveolar stability. Since Clements in 1957 demonstrated that the surfactant is extractable by mincing the lung tissue in saline, various studies on the subject have been succeeded by many workers. However, the effect of radiation on the surfactant is not well clarified. Present study was attempted to observe the effect of x-irradiation on the activity of surfactant in rabbits. X-ray in dose of 300 r, 600 r or 900 r was irradiated to the chest of rabbits. The lung was removed from normal or irradiated rabbits sacrificed by arterial blood shedding, and lung-saline extract, adding 3 grams of lung tissue to 50 mili-liters of saline, was prepared by means of Vertis homogenizer. Tension-area diagram of lung extract was recorded automatically by a modified Langmuir-Wilhelmy balance with a synchronized recording system designed in this department. The surface tension of lung extract was measured at 1st, 2 nd, 3 rd, 7 th and 15 th post-radiation day in 300 r irradiated group, at 3 rd, 7 th and 15 th post-radiation day in 600 r irradiated group, 3 rd and 7 th post-radiation day in 900 r irradiated group respectively. For the histo-pathological study, lung tissue preparations were made in all irradiatiated groups on the day of experiment and in normal group. The results obtained are summarized as follows: 1. The minimal surface tension, maximal surface tension and stability index of normal rabbits lung extracts were 7.68 dynes/cm, 38.84 dynes/cm, and 1.39 respectively. 2. The activity of surfactant was depressed prominently by x-irradiation. However, increase in the dose of x-irradiation did not show any significant change in the degree of surfactant activity suppression. The most marked depression in surfactant was observed at the third post-radiation day in all irradiated groups. 3. Activity of surfactant depressed by x-irradiation showed a tendency of recovering to normal on 15 th post-radiation day. 4. The tendency of change in activity of surfactant following x-irradiation was somewhat correlative with histo-pathological changes. But the degree of depression of surfactant by x-irradiation did not correspond to the degree of histo-pathological changes, and recovery of lung tissue from radiation damage, tissue edema and congestion, seemed to be followed by restoration of surfactant activity. 5. The width of the tension-area diagram was measured at the surface area of 40% in lung extract of normal and x-irradiated rabbits. And it was found that the changes of the width corresponded well with that of minimum surface tension and of stability index in all normal and x-irradiated groups.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 1995년도 정기학술강연회 발표논문 초록집
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• pp.1-4
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• 1995

Storm surges are defined as abnormal changes of sea surface elevation whose periods range from several hours to days. The generation mechanism is separated into two. One is sea water suction due to atmospheric depression and the other is wind-driven sea water circulation. The former is a forced long-wave motion which is accompanied by a typhoon. (omitted)

• 한국자원식물학회지
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• 제6권1호
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• pp.83-86
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• 1993

Four sterigmata of papillaform E. violaceobrunneum are developed from crator-shaped basidium. The apex of sterigma is swollen to a small globeform. And then it is swollen to a clubform. The clubform is again swollen to a ellipticalform, and then more than six spots of spore surfaces are ramdomly depressed with hilum axes. When the depression of surface of a elliptical spore is over, the spore is a heterodiametrical spore of multi-angular.

• Journal of Periodontal and Implant Science
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• 제32권2호
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• pp.303-314
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• 2002

This study was performed to evaluate the usability of Er:YAG laser for periodontal therapy. Forty dental root slabs ($5{\times}5{\times}2mm^3$) were prepared from human periodontally diseased extracted teeth and grouped into 4 groups: 1) control (root planing only), 2) root planing and irradiated with laser at 30mJ, 3) root planing and irradiated with laser at 60mJ, and 4) root planing and irradiated with laser at 100mJ. The root slabs were embedded in resin block before laser treatment. Er:YAG laser was irradiated under water irrigation with the tip held perpendicular to the root surface in contact mode. After Er:YAG laser irradiation or planing on the root surface, morphological changes have been observed under SEM, and the micro-hardness and Ca/P ratio were compared. 1. In the Control group, the root surface showed the directional change caused by root planing instrumentation, and the presence of smear layer, and no exposure of dentinal tubule was observed. Laser irradiated group showed surface changes with rough dentin surface of niche and depression and dentinal tubule exposure by the elimination of smear layer. 2. The micro-hardness of root surface in the laser irradiated group was higher than the control group. The higher energy output was applied, the higher micro-hardness on root surface was resulted. 3. The higher energy output was applied, the higher Ca/P ratio was observed. The higher Ca/P ratio in 60mJ group and 100mJ group was statistically significantly compared to the control group and the 30mJ group. These results suggest that Er:YAG laser irradiation on the periodontally diseased root surface could remove smear layer and increase the micro-hardness on root surface and Ca/P ratio which contribute to enhance the acid resistance of periodontally treated root surface.

• Journal of Chest Surgery
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• 제19권4호
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• pp.699-706
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• 1986

We have experienced 5 cases of Pectus excavatum corrected by Ravitch method without use of K-wire or metal bar from Jan. 1985 to Apr. 1986. All cases were male. The symmetric depression was in 4 cases, asymmetric one was in one case. The chief complaints were dyspnea on exertion, frequent U.R.I. and inferiority. The flail chest was developed in all cases, but it was insignificant in all cases except one who needed assist ventilation. Mediastinitis was developed in one case one week postoperatively but well managed with drainage. A distance from the posterior surface of sternum to the anterior surface of vertebral body was estimated preoperatively and postoperatively. Postoperative result was evaluated as the change of distance postoperatively. The change was 1.5cm minimally to 3.5cm maximally. Late results were "Excellent" in 3 cases and "Good" in 2 cases.uot; in 2 cases.

• 한국암반공학회:학술대회논문집
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• 한국암반공학회 2004년도 추계학술발표 논문집
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• pp.171-180
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• 2004

Underground mining causes surface subsidence long after the mining operation had been ceased. Surface subsidence can be in the form of saucer-shaped depression or collapsed chimneys or sinkholes. Sinkhole formations are predominant over shallow-depth room and pillar mines having weak overburden strata. In this study, occurrences of sinkholes due to mining activity are assessed based on local geological conditions and mining parameters using fuzzy reasoning techniques. All input and output parameters are represented with linguistic hedges. Numerous fuzzy rules are developed to relate sinkhole occurrences with input parameters using fuzzy relational matrix. Based on the combined fuzzy rules, possibility of sinkhole occurrences can be ascertained once the geological and mining parameters of any area are known.