• Journal of the Mineralogical Society of Korea
• /
• v.21 no.3
• /
• pp.283-287
• /
• 2008

The imogolite synthesis wore performed by using tetraethoxysilane (TEOS) and aluminium-sec-butoxide (ASB) at < $100^{\circ}C$. A mixure of TEOS and ASB in a molar ratio of 1:2 was prepared under vigorous stirring and the experiments were performed under the hydrothemal refluxing condition. When the concentration of TEOS and ASB in solution was 0.5 M, a well-crystallized imogolite was synthesized, and the reflections wore shown at d = 22.4, $9.5\;\AA$ etc., after XRD analysis. DTA analysis shows 2 exothemal peaks at 68 and $249^{\circ}C$, suggesting the dehydration and the dehyroxylation reaction, respectively. The result of TG indicates 41% weight loss. And the weak and unsymmetrical peaks by the Si-O-Al stretching vibrations at 953 and $993cm^{-1}$ and by O-Si-O bending vibration at $562cm^{-1}$ were observed after IR analysis. The synthetic imogolite was fibrous and shows a spiders web like network structure.

• Korean Journal of Materials Research
• /
• v.15 no.5
• /
• pp.353-360
• /
• 2005

Surface treatment play an important role in nucleating calcium phosphate deposition on surgical Ti implant. Therefore, the purpose of this study is to examine whether the precipitation of apatite on cp-Ti and Ti alloys are affected by surface modification in HCl and $H_2O_2$ solution. Specimens were then chemically treated with a solution containing 0.1 M HCl and 8.8M $H_2O_2$ at $80^{\circ}C$ for 30 mins, and subsequently heat-treated at $400^{\circ}C$ for 1 hour. All specimens were immersed in the HBSS with pH 7.4 at $36.5^{\circ}C$ for 15 days, and the surface was examined with XRD, SEM, EDX ana XPS. Also, pure Ti, Ti-6Al-4V and Ti-6Al-7Nb alloy specimens with and without surface treatment were implanted in the abdominal connective tissue of mice for 4 weeks. All specimens chemically treated with HCl and $H_2O_2$ solution have the ability to form a apatite layer in the HBSS which has inorganic ion composition similar to human blood plasma. The average thickness of the fibrous capsule surrounding the specimens implanted in the connective tissue was $38.57\;{\mu}m,\;62.27\;{\mu}m\;and\;45.64\;{\mu}m$ in the cp-Ti, Ti-6Al-4V ana Ti-6Al-7Nb alloy specimens with the chemical treatment respectively, and $52.20\;{\mu}m,\;75.62\;{\mu}m\;and\;66.56\;{\mu}m$ in the commercial specimens of cp-Ti, Ti-6Al-4V and Ti-6Al-7Nb without any treatment respectively. The results of this evaluation indicate that the chemically treated cp-Ti, Ti-6Al-4V ana Ti-6Al-7Nb alloys have better bioactivity and biocompatibility compared to the other metals tested.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
• /
• 2001.06a
• /
• pp.1265-1265
• /
• 2001

The organic materials included in excreta of livestock are important resources for organic manure and for improving soil quality, although there is still far from effective using. One reason for this is still unclearly standard of quality for evaluation of manure made from excreta of livestock. Therefore, the objective of this study is to develop rapid and accurate analytical method for analyzing organic compositions of manure made from excreta of livestock, and to establish quality evaluation method based on the compositions predicted by near infrared reflectance spectroscopy (NIRS). Sixteen samples of manure, each eight samples prepared from two treatments, were used in this study. The manure samples were prepared by mixing 560 kg feces of swine,60 kg sawdust with moisture content was adjusted to be 65%. The mixture was then keep under two kinds of shelter, black and clear sheets, as a treatment on the effect of sunlight. Samples were taken in every week (form week-0 to 7) during the process of manure making. Samples were analyzed to determine neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) by detergent methods, and organic cell wall (OCW) and fibrous content of low digestibility in OCW (Ob) by enzymatic methods. Biological oxygen demand (BOD) was analyzed by coulometric respirometer method. These compositions were carbohydrateds and lignin that were hardly digested. Spectra of samples were scanned by NIR instrument model 6500 (Pacific Scientific) and read over the range of wavelength between 400 and 2500nm. Calibration equations were developed using eight manure samples collected from black sheet shelter, while prediction was conducted to the other eight samples from clear sheet shelter. Accuracy of NTRS prediction was evaluated by correlation coefficients (r), standard error of prediction (SEP) and ration of standard deviation of reference data in prediction sample set to SEP (RPD). The r, SEP and RPD value of forage were 0.99, 0.69 and 7.6 for ADL, 0.96, 1.03 and 4.1 for NDF, 0.98, 0.60 and 4.9 for ADF, 0.92, 1.24 and 2.6 for Ob, and 0.91, 1.02 and 7.3 for BOD, respectively. The results indicated that NIRS could be used to measure the organic composition of forage used in manure samples.

• Restorative Dentistry and Endodontics
• /
• v.9 no.1
• /
• pp.25-35
• /
• 1983

The purpose of this study was the observe the toxic effects of root canal sealers in 108 white rats. Experimental animals were divided into control and experimental groups. Theree representative types of materials, such as AH26, Z.O.E. and F.R. were used in this study. Cavities were prepared on the left mandibular area of 108 white rats. Three different sealers were placed in as experiment and bone cavities were left without filling as control. The experimental animals were sacrificed by cervical dislocation at the intervals of 1, 3, 7, 14, 28 and 49 days after filling. Each specimen was fixed with 10% neutral formalin solution, decalcified with 5% nitric acid, embedded in paraffin and sectioned 5-7${\mu}$. in thickness. The paraffin sections stained with Hematoxylin - Eosin were observed through the ordinary light microscope. The results were as follows; 1. Slight toxic effect to surrounding tissue were found in every experimental specimen. 2. AH26 showed the highest inflammatory response, and F.R. showed the lowest inflammatory response which subsided and replaced by fibrosis at 4 weeks after filling. 3. The cavity filled materials, such as implanted root canal sealers, blood clots and necrotic tissue, showed a tendency to be absorbed gradually proportioned to the experimental periods. A small amount of cavity filled materials were observed in the bone cavities after 4 weeks. 4. Fibroblastic proliferation began to produce fibrous capsule around the bone cavity in 2 weeks after filling. Fibrosis was prominent at 4 weeks after filling. 5. Osteoblastic activity of surrounding bone was observed at first in 2 weeks after filling and prominent in 4 weeks after filling. Osteoblastic activity showed an increasing effect as the time prolonged. 6. Surrounding tissue of the bone cavities showed the features of tissue destruction and had very severe inflammatory response at an initial stage. Above-mentioned appeared to be recovered gradually proportioned to the experimental periods.

• The Journal of the Korean bone and joint tumor society
• /
• v.2 no.1
• /
• pp.8-17
• /
• 1996

The purpose of this study is a comparative evaluation of range motion, especially extension deficit between the group of total patellectomy and that of intact patella, after reconstruction of the patellar tendon in the prosthetic replacement of a proximal tibia. Between 1990 and 1994, 15 patients who had a primary malignancy on proximal tibia were operated on. All patients were evaluated clinically and radiographically. Two patients were excluded because one had a deep infection treated with arthrodesis of the knee and the other was a composite allograft. The mean follow-up of the 13 patients was 27 months(15-47), including 10 osteosarcomas, 1 chondrosarcoma, 1 malignant fibrous histiocytoma and 1 malignant giant cell tumor. Eleven patients had a resection of the proximal tibia and 2 had an extracapsular total knee resection with distal femur. Reconstruction of the defect was done in 8 cases with a custom-made Link Endo-Model Total Rotation Knee Joint Prosthesis, and in 5 with How Medica Modular Resection System (HMRS). We used two methods to reconstruct the ligamentum patellae. Fixation of the patellar tendon to the prosthesis only with suturing and/or stapling(group SS) was done in 7. Transposition of gastrocnemius muscle to enhance fixation and to cover the prosthesis(group TG) was done in 6. Regardless of fixation methods, total patellectomy was done in 5 either to lengthen the patellar tendon or to make primary skin closure easier or for both. In 8 cases, patella was left intact or resurfaced with polyethylene prosthesis. Active extension was measured while the patient was in a sitting position. There is no statistically meaningful difference in terms of extension deficit (Wilcoxon rank test, p=0.8800) between patellectomy group and intact patella group, and between group of fixation only with suturing and that of gastrocnemius transposition. Two cases of extension deficit over 30 degree were seen in group SS and in the group of intact patella. Conclusively, total patellectomy could be an option without increasing the risk of extension deficit when primary skin closure is difficult or patellar tendon is a little bit short to be fixed. There is no rating in the Enneking system of functional evaluation that this finding into consideration.

• The Journal of the Korean bone and joint tumor society
• /
• v.14 no.2
• /
• pp.119-124
• /
• 2008

Purpose: To present our experience with soft tissue reconstruction using anterolateral thigh free flap after resection of soft tissue sarcoma. Materials and Methods: Between January of 2003 and June of 2007, we treated 7 patients with soft tissue reconstruction using anterolateral thigh free flap after wide resection for soft tissue sarcoma. We retrospectively analyzed type and size of tumors, resection margin, size of defect after resection, time of operation, flap survival and complication. Results: The type of sarcoma was 3 synovial sarcoma, 2 malignant fibrous histiocytoma, 1 leimyosarcoma and 1 fibrosarcoma. The size of tumor varied from $3{\times}5\;cm$ to $7{\times}8\;cm$. The resection margins of tumors were negative in all cases. The size of soft tissue defect after resection varied from $6{\times}8\;cm$ to $15{\times}10\;cm$. The mean time of operation was 3.6 hours. All flaps were survived. Conclusion: Anterolateral thigh free flap appear to be ideal for reconstruction after wide resection of soft tissue sarcoma.

• Archives of Plastic Surgery
• /
• v.37 no.2
• /
• pp.129-136
• /
• 2010

Purpose: Anatomically, the foot is provided with insufficient blood supply and is relatively vulnerable to venous congestion compared to other parts of the body. Soft tissue defects are more difficult to manage and palliative treatments can cause hyperkeratosis or ulcer formation, which subsequently requires repeated surgeries. For weight bearing area such as the heel, not only is it important to provide wound coverage but also to restore the protective senses. In these cases, application of flaps for hind foot reconstruction is widely recognized as an effective treatment. In this study, we report the cases of soft tissue reconstruction for which various types of flaps were used to produce good results in both functional and cosmetic aspects. Methods: Data from 37 cases of hind foot operation utilizing flaps performed between from June 2000 to June 2008 were analyzed. Results: Burn related factors were the most common cause of defects, accounting for 19 cases. In addition, chronic ulceration was responsible for 8 cases and so forth. Types of flaps used for the operations, listed in descending order are radial forearm free flap (18), medial plantar island flap (6), rotation flap (5), sural island flap (3), anterolateral thigh free flap (2), lattisimus dorsi muscular flap (2), and contra lateral medial plantar free flap (1). 37 cases were successful, but 8 cases required skin graft due to partial necrosis in small areas. Conclusion : Hind foot reconstruction surgeries that utilize flaps are advantageous in protecting the internal structure, restoring functions, and achieving proper contour aesthetically. Generally, medial plantar skin is preferred because of the anatomical characteristics of the foot (e.g. fibrous septa, soft tissue for cushion). However alternative methods must be applied for defects larger than medial plantar skin and cases in which injuries exist in the flap donor / recipient site (scars in the vicinity of the wound, combined vascular injury). We used various types of flaps including radial forearm neurosensory free flap in order to reconstruct hind foot defects, and report good results in both functional and cosmetic aspects.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.31 no.5
• /
• pp.379-389
• /
• 2005

Obstructive adenitis of the salivary gland following salivary stone or infectious disease of the gland and surrounding tissues is a common disease. It is often difficult to decide whether to perform total excision of the gland or to consider conservative treatment. The present study was designed to investigate histological, histochemical changes of submandibular gland after ligating the excretory duct for identifying the results of gland duct obstruction. A group of 40 rat of Sprague-Dawley weighing about $200{\sim}220gm$ were used in the present study. 30 rats had ligation of the main excretory ducts of submandibular glands just at the exit from the glands. For controls, 10 rats had a sham operation without duct ligation. They were inducted into euthanagia state by intracardial Ketamine injection in 1, 2, 3, 5, 7, 14, 21, 28, 35 and 42 days after the ligation. In each ligation period, 3 animals were used for ligation and one animal was for control. The submandibular glands were dissected out at sacrifice and stained with H&E, PAS, mucicarmine stain and histological examination were carried out under the light microscope. After examination and comparison of all specimens, the results were as follows: 1. In the features of H&E stain, acini disappeared by degrees after the ligation of the excretary duct and interstitial cells were displaced into fibrous connective tissue. Salivary gland had been atrophied with enlarging ducts and proliferating ductal cells. 2. Through total experimental period, a lot of vessels were observed and the atrophy of serous gland was severer than that of mucous gland. 3. The deep portion of submandibular glands showed severe degeneration rather than superficial portion of them after the ligation. 4. The changes which had enlarged ducts and proliferating ductal cells were observed in entire gland and more prominent in serous gland than mucous gland after the ligation. 5. Although PAS and mucicarmine reactions were decreased gradually after the ligation with the lapse of time, since 2 to 3 weeks they were strong positive reactions on entire gland, especially on duct-like structure. So, we can suggest that salivary gland will be atrophied but, survived acini will be redistributed around the ducts.

• Journal of Chest Surgery
• /
• v.27 no.11
• /
• pp.893-901
• /
• 1994

Forty nine patients [M: 31, F: 18], age from 2 months to 17 years [mean= 4.9 years], underwent operations, from April 1986 to December 1992, for the relief of subvalvular aortic stenosis in normal atrioventricular and ventriculoarterial connections.There were 4 anatomic types of subaortic stenosis : membranous in 29 cases [59.2%], fibromuscular in 11 [22.4%], diffuse tunnel type in 7 [14.3%], and miscellaneous in 2 cases. Thirty four patients [69.4%] had associated cardiac anomalies, of which ventricular septal defect was the most common [27 cases]. Other anomalies were patent ductus arteriosus, coarctation of the aorta, valvular aortic stenosis, double chambered right ventricle [DCRV], infundibular pulmonic stenosis, persistent left superior vena cava, and rigt aortic arch. Mean systolic pressure gradient between the left ventricle and ascending aorta was 26.4$\pm$17.6 mmHg : 13.1$\pm$17.6mmHg in the membranous type, 22.0$\pm$18.4mmHg in the fibromucular type, and 56.1$\pm$38.4mmHg in the diffuse tunnel type. Operative procedures were determined according to the type of subvalvular aortic stenosis : simple excision of subaortic membrane in the membranous type [29 cases], left ventricular myectomy with or without myotomy or fibrous tissue excision in the fibromuscular type [11 cases]. Among the 7 of diffuse tunnel type cases, ventricular myectomy was performed in 2 and a modified Konno operation was performed in 5 . Postoperative follow up was made with periodic echocardiography. The Mean postoperative follow up period was 33.8 months. There were 2 hospital mortalities [4.1%] and 2 late deaths. Residual stenosis remained in 3 cases and recurrence developed in 2 cases during the follow up period. 5 years actuarial survival rate was 91.8$\pm$3.9% and 5 year complication free rate was 72.3$\pm$10.4%. Conclusions : 1. Subvalvular aortic stenosis should be relieved completely as soon as possible when diagnosed, regardless of left ventricular outflow tract pressure gradient. 2. Good results were obtained using only simple excision of subaortic membrane in the membranous type of subaortic stenosis. However, aortoventriculoplasty [modified Konno prodedure] was necessary for good results in the diffuse tunnel type. 3. Periodic postoperative echocardiography was helpful in detecting the progression of residual stenosis and development of new stenosis.

• The Journal of Korean Academy of Prosthodontics
• /
• v.35 no.1
• /
• pp.43-66
• /
• 1997

Dental implant may be immediately placed in postextraction socket which has alveolar bone defect. The purpose of this study was to compare the bone regeneration and bone quality around defects adjacent to implants that were placed into extraction sockets according to EFEB, GTAM barrier and GTAM barrier with DFDB. Mandibular P2, P3 and P4 were extracted bilaterally in dogs, and buccal defects were created about 4mm in depth and 3.3mm in width. Screwed pure titanium implants, 3.8mm in diameter and 10mm in length, were placed into the extraction sockets. The experimental groups were divided into four groups : the G group was covered with a GTAM barrier on the defective area, the D+G group was filled with DFEB and covered with a GTAM barrier, the D group was filled with DFDB only and the control group was sutured without any special treatment on the defective area. The experimental animals were killed after 12 weeks and specimens were prepared for light microscopic evaluation and fluorescent dyes were administered daily for 2 weeks after implantation, and injected on the 4th and 11th week for fluorescent microscopic examination to observe new bone formation and bone remodeling. The new Bone height of the buccal defect was measured and compared with the another for bone gain and the removal torque for the implant was measured for the comparison of bone density and bone-implant osseointegration. Results obtained were as follows : 1. Experimental groups showed bone regeneration in oder from D+G, G, D group and control. D+G and G group was significantly from D group and control(P<0.01). 2. In the defective area of control the regenerated alveolar bone showed poorly developed lamellated structure and fibrous tissue intervention into the bone-implant interface but the others showed well developed lamellated structure and osseointegration. 3. All implant groups showed no significaant difference in the removal torque for implant(P>0.05) These results suggest that immediate implants placed in defective sockets were successfully osseointegrated and utilizing placed in defective sockets were successfully osseointegrated and utilizing not only the combination of GTAM and DFDB but also only the GTAM was favorable for the predictable regeneration of the defective area.