• Journal of Korean Neurosurgical Society
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• v.30 no.5
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• pp.586-591
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• 2001

Objective : Transseptal or sublabial transsphenoidal surgery has been standard teatment for pituitary tumors for decades. However, as an alternative to this surgery endonasal endoscopic technique has been reported with encouraging results. We have started endoscopy-assisted transsphednoidal surgery from May 1998. In this paper we analyzed the methods, outcome, advantage and disadvantage of this surgical approach for the purpose of planning optimal treatment of pituitary tumors. Methods : This study consisits of 13 cases of pituitary tumors who were treated by endoscopy-assisted transsphenoidal surgery using one nostril from May 1998 to July 1999. Mean follow up period was 12.9 months. Results : There was no septal or sublabial incision and little surgical damage to nasal structure. With this technique, rapid surgical approach and short hospital day were possible, being 3-6 days in patients without CSF leakage. Using various angled endoscope, good surgical view was obtained. Initially it was difficult to use various instruments in narrow nasal cavity, but became feasible after several procedures. Among 13 cases, total removal was possible in 11 cases. One of two cases in whom tumor was incompletely removed underwent gamma-knife radiosurgery and second underwent reoperation through subfrontal approach. There were 6 cases of hormone secreting tumors and hormonal remission was achived in all of these cases. Postoperative complications were CSF leakage(6 cases), diabetes insipidus(2 cases) and panhypopituitarysm(1 case). Lumbar drainage was done in all cases of CSF leakage. Conclusion : The advantage of endoscopy-assisted transsphenoidal surgery are rapid surgical approach, low postoperative morbidity, short hospital day and good surgical view. The disadvantage of this appoach are difficulty in manupulating various instruments in narrow nostril and difficulty in distance perception but these problems can be overcome by practice and using stereoscopic endoscope.

• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.221-228
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• 1998

Enhancement of adhesion between polymer films and metal films are obtained by forming the hydrophilic functional groups on the polymer surfaces by ion assisted reaction which uses ion beam in reactive gas environments. In ion assisted reaction, ion dose, blown gas flow rate and ion energy were changed from $5\times 10^{14}$ to $1\times 10^{17}\textrm{ions/cm}^2$, from 0 to 8 sccm, and 0.3 to 1.2 kV, respectively. Wetting angle of water on polymer films modified by $ Ar^+$ ion without blowing oxygen decreases to ~$40^{\circ}$. Contact angle of water on polymer films modified by $ Ar^+$ ion with blowing oxygen decreases to ~$20^{\circ}$, and the surface free energy increases to ~70 dyne/$\textrm{cm}^2$. However, contact angle of water on polytetraflouroethylene (PTFE) modified by ion assisted reaction increases with ion dose. The adhesion strength of metal film deposited on the polymer surface was investigated. In the case of the metal film deposited on the untreated polymers, the metal films are detached from the polymer surface. While, In the case of the metal film deposited on the polymers treated by ion assisted reaction, the metal films are strongly adhere to the polymer surfaces.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.5077-5081
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• 2014

To clarify whether gastric cancer patients can benefit from laparoscopy-assisted surgery completed by junior surgeons under supervision of expert surgeons, data of 232 patients with gastric cancer underwent operation performed by inexperienced junior surgeons were reviewed. Of the 232 patients, 137 underwent laparoscopy-assisted resection and in 118 cases this approach was successful. All of these 118 patients were assigned to laparoscopic group in this study, 19 patients who were switched to open resection were excluded. All laparoscopic operations were performed under the supervision of expert laparoscopic surgeons. Some 95 patients receiving open resection were assigned to the open group. All open operations were completed independently by the same surgeons. Short-term outcomes including oncologic outcomes, operative time intra-operative blood loss, time to first flatus, time to first defecation, postoperative hospital stay and perioperative complication were compared between the two groups. The numbers of lymph nodes harvested in the laparoscopic and open groups were $21.1{\pm}9.6$ and $18.2{\pm}9.7$ (p=0.029). There was no significant difference in the length of margins. The mean operative time was $215.9{\pm}32.2$ min in laparoscopic group and $220.1{\pm}34.6min$ in the open group (p=0.866), and the mean blood loss in laparoscopic group was obviously less than that in open group ($200.9{\pm}197.0ml$ vs $291.1{\pm}191.4ml$; p=0.001). Time to first flatus in laparoscopic and open groups was $4.0{\pm}1.0$ days and $4.3{\pm}1.2$ days respectively and the difference was not significant (p=0.135). Similarly no statically significant difference was noted for time to first defecation ($4.7{\pm}1.6$ vs $4.8{\pm}1.6$, p=0.586). Eleven patients in the laparoscopic group and 19 in the open group suffered from peri-operative complications and the difference between the two groups was significant (9.3% vs 20.0%, p=0.026). The conversion rate for laparoscopic surgery was 13.9%. Patients with gastric cancer can benefit from laparoscopy-assisted operations completed by inexperienced junior surgeons under supervision of expert laparoscopic surgeons.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.1
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• pp.58-66
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• 2020

Implant-Assisted Removable Partial Dentures (IARPDs) treatment is being performed in a fully edentulous patient using implant surveyed prosthesis as an abutment. Implant-supported prosthesis as an abutment of IARPDs is classified into screw-retained and cement-retained type according to the retention type, and each has advantages and disadvantages. The EZ crown system (Samwon DMP, Yangsan, Korea) has a cylinder combined with abutment, and the nickel-titanium spring in this cylinder provides a constant force on the zirconia ball to obtain retention in EZ crown system. In this patient, the natural abutment teeth of the mandibular overdenture was hopeless. We planned implant assisted removable partial denture using anterior implant surveyed prosthesis considering functional and esthetical rehabilitation, cost and patient's needs. When fabricating IARPDs using implant as abutment, we could compensate for the shortcomings of existing implant-supported prosthesis retention type and made the design of removable partial denture easy due to using EZ crown system.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.160-165
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• 2004

Successful treatment of multi-loculated pleural effusion or thoracic empyema requires effective drainage and definitive diagnosis of causative organism. The purpose of this study was to assess the efficacy of the video-assisted thoracoscopic surgery in the management of thoracic empyema or multi-loculated pleural effusion after chest tube drainage treatment had failed. Material and Method: Between April 2000 and July 2002, 20 patients with thoracic empyema or multi-loculated pleural effusion that failed to chest tube drainage or other procedures who underwent an operation. All patients were assessed by chest-computed tomogram and underwent video assisted thoracoscopic drainage, debridement, biopsy and irrigation of pleural cavity. Result: In 18 cases (90%), underwent successful video-assisted thoracoscopic surgery. In 2 cases, decortications by mini-thoracotomy were necessary. The ratio of sex was 4 : 1 (16 male: 4 female), mean age was 48.9 years old (range, 17∼72 years), mean duration of postoperative chest tube placement was 8.2 days (range, 4∼22 days), mean postoperative hospital stay was 15.2 days (range, 7∼33 days). Causative disease was tuberculosis, pneumonia, trauma and metastatic breast cancer, There were no major postoperative complications. Symptoms improved in all patients and were discharged with OPD follow up. Conclusion: In an early organizing phase of empyema or multi loculated pleural effusion, video-assisted thoracoscopic drainage and debridement are safe and suitable treatment.

• Journal of Gastric Cancer
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• v.7 no.2
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• pp.97-101
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• 2007

We report our experience with a case of performing laparoscopy-assisted total gastrectomy along with pancreas-preserving splenectomy for treating early gastric cancer. laparoscopy-assisted total gastrectomy was planned for a 62-year-old male patient with a double early gastric cancer located in the upper and lower third of the stomach. Five trocars were placed and we used a harmonic scalpel to dissect the greater curvature. Enlarged splenic hilar lymph node was encountered and they were proved to be metastasis by frozen section biopsy. We then performed total gastrectomy with pancreas-preserving splenectomy for the purpose of completely dissecting the lymph nodes along the splenic artery and splenic hilum. We created a 4 cm sized longitudinal mini-laparotomy below the xiphoid process to remove the specimen, and anastomosis was done via the Roux-en-Y method. The patient was discharged on the 9th postoperative days after an uneventful recovery. Our experience shows that laparoscopy-assisted total gastrectomy with pancreas-preserving splenectomy is a relatively safe procedure for treating upper third early gastric cancer with metastatic splenic hilar lymph nodes.

• Korean Journal of Materials Research
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• v.13 no.6
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• pp.347-351
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• 2003

II-Ⅵ ZnO compound semiconductor thin films were grown on $\alpha$-Al$_2$O$_3$(0001) single crystal substrate by radical beam assisted molecular beam epitaxy and the optical properties were investigated. Zn(6N) was evaporated using Knudsen cell and O radical was assisted at the partial pressure of 1$\times$10$^{4}$ Torr and radical beam source of 250-450 W RF power. In $\theta$-2$\theta$ x-ray diffraction analysis, ZnO thin film with 500 nm thickness showed only ZnO(0002)and ZnO(0004) peaks is believed to be well grown along c-axis orientation. Photoluminescence (PL) measurement using He-Cd ($\lambda$=325 nm) laser is obtained in the temperature range of 9 K-300 K. At 9 K and 300 K, only near band edge (NBE) is observed and the FWHM's of PL peak of the ZnO deposited at 450 RF power are 45 meV and 145 meV respectively. From no observation of any weak deep level peak even at room temperature PL, the ZnO grains are regarded to contain very low defect density and impurity to cause the deep-level defects. The peak position of free exciton showed slightly red-shift as temperature was increased, and from this result the binding energy of free exciton can be experimentally determined as much as $58\pm$0.5 meV, which is very closed to that of ZnO bulk. By van der Pauw 4-point probe measurement, the grown ZnO is proved to be n-type with the electron concentration($n_{e}$ ) $1.69$\times$10^{18}$$cm^3$, mobility($\mu$) $-12.3\textrm{cm}^2$/Vㆍs, and resistivity($\rho$) 0.30 $\Omega$$\cdot$cm.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.123-128
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• 1998

Implantation rates remain low following human in vitro fertilization (IVF). Suboptimal culture conditions may limit the ability of embryos to hatch as blastocysts, and artificial opening of the zona pellucida has been proposed as a means to promote subsequent hatching (assisted hatching). In this study, assisted hatching (AH) by zona drilling using acidic Tyrode's solution was performed in 320 patients, due to their age of more than 38 years (group A), the thick zona pellucida (group Z; $ZP\geq0.18{\mu}m$), and failures in implantation more than 3 times in previous IVF-ET trial (group P). This study was designed firstly, to study the effects of AH on the outcomes of IVF-ET according to the indications and secondly, to verify the appropriate application of AH. The results were as follows; 1. There was no difference in pregnancy rate between AH group (26.6%) and non-AH group (26.5%). 2. Assisted hatching (AH) showed significantly higher pregnancy rate of the patients with thick zona pellucid a than those of the patients with age factor and with the history of repeated implantation failure. But in the patients with age factor only, AH resulted in higher pregnancy rate. 3. Interestingly, the patients with complex factors including zona factor (Z: 33.9%; ZA: 30.4%; ZP: 31.6%; ZAP: 21.4%) showed higher pregnancy rates than other complex factors excluding zona factor (A: 24.4%, P: 0%; AP: 10.8%). From these results, AH is more helpful to the patients with thick zona pellucida rather than patients with older age and/or previous repeated implantation failure.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.223-234
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• 2013

Poultry industry is abounding day by day as it engrosses less cost of investment per bird as compared to large animals. Poultry have the most copious genomic tool box amongst domestic animals for the detection of quantitative trait loci (QTL) and marker assisted selection (MAS). Use of multiple markers and least square techniques for mapping of QTL affecting quality and production traits in poultry is in vogue. Examples of genetic tests that are available to or used in industry programs are documented and classified into causative mutations (direct markers), linked markers in population-wide linkage disequilibrium (LD) with the QTL (LD markers), and linked markers in population wide equilibrium with the QTL (LE markers). Development of genome-wide SNP assays, role of 42 K, 60 K (Illumina) and 600 K (Affymetrix$^{(R)}$ Axim$^{(R)}$) SNP chip with next generation sequencing for identification of single nucleotide polymorphism (SNP) has been documented. Hybridization based, PCR based, DNA chip and sequencing based are the major segments of DNA markers which help in conducting of MAS in poultry. Economic index-marker assisted selection (EI-MAS) provides platform for simultaneous selection for production traits while giving due weightage to their marginal economic values by calculating predicted breeding value, using information on DNA markers which are normally associated with relevant QTL. Understanding of linkage equilibrium, linkage dis-equilibrium, relation between the markers and gene of interest are quite important for success of MAS. This kind of selection is the most useful tool in enhancing disease resistance by identifying candidate genes to improve the immune response. The application of marker assisted selection in selection procedures would help in improvement of economic traits in poultry.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.2
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• pp.212-234
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• 1999

Dental restorative materials must have the physical properties to withstand wear and corrosion. Base metal alloys possess better mechanical properties and lower price than the gold alloys. For these reasons such alloys have largely replaced the precious metal alloys. One aspect to con-sider is the release of metal substances to oral environment. The release of elements from dental alloys is a continuing concern because the elements may have the potentially harmful biological effects on local tissues. The purpose of this study was to minimize metal release on the nonprecious metal surfaces by ion beam assisted deposition(IBAD) of titanium nitride (TiN) Ni-Cr-Be alloys with and without TiN coatings were secured in an wear test machine opposing ruby ball to determine their relative resistance to wear with loom, 200m, 300m and 400m sliding distance. And the corrosion behavior of the Ni-Cr-Be alloys with and without TiN coatings and 3 dental noble alloys have been studied. Potentiodynamic curves were used to analyse the corrosion characteristics of the alloys. The measurement of the released Ni and Cr ions was conducted by analysis of the electrolyte solution with atomic absorption spectroscopy. The results were as follows : 1. The critical sliding distance that wore down TiN coatings of $2.5{\mu}m$ thickness in this study condition was 300m. 2. Ion beam assisted deposition of TiN showed a good surface modification with respect to the properties of wear and corrosion resistance. 3. X-ray diffraction showed that the strongest peak of TiN is TiN(111) in the coatings. 4. The release of Ni and Cr ions from alloys measured by means of atomic absorption spectroscopy was reduced by ion beam assisted deposition of TiN.