• Journal of Gastric Cancer
• /
• v.18 no.1
• /
• pp.90-98
• /
• 2018

Purpose: We evaluated the learning curve and short-term surgical outcomes of robot-assisted distal gastrectomy (RADG) performed by a single surgeon experienced in open, but not laparoscopic, gastrectomy. We aimed to verify the feasibility of performing RADG without extensive laparoscopic experience. Materials and Methods: Between July 2012 and December 2016, 60 RADG procedures were performed by a single surgeon using the da $Vinci^{(R)}$ Surgical System (Intuitive Surgical). Patient characteristics, the length of the learning curve, surgical parameters, and short-term postoperative outcomes were analyzed and compared before and after the learning curve had been overcome. Results: The duration of surgery rapidly decreased from the first to the fourth case; after 25 procedures, the duration of surgery was stabilized, suggesting that the learning curve had been overcome. Cases were divided into 2 groups: 25 cases before the learning curve had been overcome (early cases) and 35 later cases. The mean duration of surgery was 420.8 minutes for the initial cases and 281.7 minutes for the later cases (P<0.001). The console time was significantly shorter during the later cases (168.6 minutes) than during the early cases (247.1 minutes) (P<0.001). Although the volume of blood loss during surgery declined over time, there was no significant difference between the early and later cases. No other postoperative outcomes differed between the 2 groups. Pathology reports revealed the presence of mucosal invasion in 58 patients and submucosal invasion in 2 patients. Conclusions: RADG can be performed safely with acceptable surgical outcomes by experts in open gastrectomy.

• Journal of Yeungnam Medical Science
• /
• v.24 no.2
• /
• pp.344-350
• /
• 2007

Laryngo-tracheal perforation caused by the use of a stylet during tracheal intubation is a rare complication. We present a case of subcutaneous emphysema and connective tissue inflammation after tracheal intubation. The patient was a 41-year-old male undergoing general anesthesia for an appendectomy. The intubation was difficult during laryngoscopy (Cormack- Lehane Grade III). An assistant provided an endotracheal tube with a stylet inside while the laryngoscope was in place. During intubation, a short, dull sound was heard with a sudden loss of resistance after the distal tip of the endotracheal tube passed the rima glottis. A sonogram and computerized tomography revealed subcutaneous emphysema from the neck to the upper mediastinum and fluid collection between the trachea and the thyroid. This lesion appeared to have been caused by the protruded, loose stylet. Anesthesiologists should be aware of the damage a loose stylet protruding beyond the tip of the endotracheal tube can cause.

• Polymer(Korea)
• /
• v.33 no.1
• /
• pp.26-32
• /
• 2009

The aim of this research was to prepare microparticulate systems based on poly (lactide-co-glycolide)(PLGA) for the local release of ipriflavone in order to reduce bone loss. We developed the IP loaded PLGA microspheres using relatively simple oil-in-water(O/W) solvent evaporation method. HPLC was used to perform the in vitro release test of IP and morphology of cell attached on the micro-spheres was investigated using SEM. Cytotoxicity was assayed by cell counting kit-8 (CCK-8) test. Osteogenic differential cells were analyzed by ALP activity. Through RT-PCR analysis, we observed osteocalcin, ALP, and Type I collagen mRNA expression. The release of IP in vitro was more prolonged over 42 days and IP/PLGA microspheres showed the improvement on the cell proliferation, ALP activity and RT-PCR comparing with control (only PLGA). This initial research will be used to direct future work involved in developing this composite injectable bone tissue engineering system.

• The Journal of the Society of Stroke on Korean Medicine
• /
• v.19 no.1
• /
• pp.21-30
• /
• 2018

■ Objectives This case study is to report the two cases of Gami-Guibitang on cognitive impairment after stroke with improved recall memory. ■ Methods We used Korean medicine treatments including Gami-guibitang, acupuncture and moxibustion to treat patients who had cognitive impairment after stroke for at least two months. We observed the changes of symptoms by measuring Korean version of Mini-mental status examination (MMSE-K), Clinical Dementia Rating (CDR) and Global Detration Scale (GDS). ■ Results After treatment, the patient's symptoms were improved including MMSE-K, CDR and GDS. Improvement appeared to be prominent in recall memory. The general condition were also improved after treatment. ■ Conclusion This clinical case study suggests that Korean medicine including Gami-guibitang could be used to treat patients who had cognitive impairment after stroke especially suffering from degraded recall memory.

• International Journal of Korean Welding Society
• /
• v.4 no.1
• /
• pp.15-22
• /
• 2004

Metal transfer behavior of three shielded metal arc welding electrodes, AWS El1018, E6013 and E6010, were investigated through the characterization of size distribution of droplets and measurement of arc voltage signals. Of the three electrodes, Ell018 electrode showed the largest droplet size with the smallest amount of spatter, while E6010 electrode showed the smallest droplet size with the largest amount of spatter. Even though Ell0l8 electrode showed a good agreement between the frequencies of voltage drop in FFT processed voltage signals and the transfer rate of droplets, E6013 and E6010 electrodes showed weaker correlation because of their dominant explosive transfer behavior. The type of cathode used and electrode baking time also influenced the metal transfer behavior. Compared to bead-on-plate welding using steel plate as a cathode, welding on a water-cooled copper pipe showed less short-circuiting and higher melting rate in all electrodes because of higher arc potential and/or anode drop. When baked for a long time, E6010 electrode showed much more stable arc with less short-circuiting and explosion due to the loss of gas formation ingredients.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.11
• /
• pp.1511-1519
• /
• 2013

This paper proposes the allocation method for capacitor-reactor banks in a distribution system with dispersed generators to reduce the installation costs, the maintenance costs and minimize the loss of electrical energy. The expected lifetime and maintenance period of devices with moving parts depends on the total number of operations, which affects the replacement and maintenance period for aging equipment under a limited budget. In this paper, the expected device lifetimes and the maintenance period are included in the formulation, and the optimal operation status of the devices is determined using a genetic algorithm. The optimal numbers and locations for capacitor-reactor banks are determined based on the optimal operation status. Simulation results in a 69-bus distribution system with the dispersed generator show that the proposed technique performs better than conventional methods.

• Journal of the Korea Safety Management & Science
• /
• v.15 no.4
• /
• pp.253-260
• /
• 2013

The importance of environmental protection has been increased recently. Thus the environmental management was settled in an important global competition factor. In the meantime logistics cost occupied the 8.03% of sales at 2011. This portion was greater than the portion of other countries and it was needed the reduction of logistics cost to secure the competition power. As thus in this paper we prepared the process which diminish the environmental discharge and decrease the logistics cost. We proposed the process to apply the MFCA to SCM, until now the MFCA had been used generally in manufacturing process. We defined the loss in SCM and the plus logistic, minus logistic, logistic center and the classification of cost to adopt the MFCA to SCM.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.3
• /
• pp.445-450
• /
• 2017

In this paper, the directional coupler with half-power division is designed and fabricated by using the vertical coupling structure based on the CPW transmission-line. Even-mode and odd-mode of the vertical coupling structure can be analyzed by the conventional CPW-line and the CBCPW-line, respectively, with half thickness of the substrate. The directional coupler is designed by using the tefron substrate with the dielectric constant of 2.55 and the thickness of 0.76mm. Manufactured directional coupler has the center frequency of 2.45 GHz and the bandwidth of 66.1%. Also, the return loss and isolation are 19.52dB and 19.47dB, respectively, at the center frequency.

• 한국연소학회:학술대회논문집
• /
• 2014.11a
• /
• pp.379-381
• /
• 2014

Influence of fuel concentration gradient was investigated near flame extinction limit in buoyancy-suppressed non-premixed counterflow flame with triple co-flow burner. The use of He curtain flow produced a microgravity level of $10^{-2}-10^{-3}g$ in He-diluted non-premixed counter triple co-flow flame experiments. Flame stability map was presented based on flame extinction and oscillation near extinction limit. The stability map via critical diluent mole fraction with global strain rate was represented by varying outer and inner He-diluted mole fractions. The flame extinction modes could be classified into five: an extinction through the shrinkage of the outmost edge flame forward the flame center with and without self-excitation, respectively ((I) and (II)), an extinction via the rapid expansion of a flame hole while the outmost edge flame is stationary (III), both the outermost and the center edge flames oscillate, and then a donut shaped flame is formed or the flame is entirely extinguished (IV), a shrinkage of the outermost edge flame without self-excitation followed by shrinking or sustain the inner flame (V).

• Radiation Oncology Journal
• /
• v.33 no.3
• /
• pp.172-178
• /
• 2015

Purpose: To investigate clinical outcomes of synchronous head and neck and esophageal cancer (SHNEC). Materials and Methods: We retrospectively reviewed 27 SHNEC patients treated with curative intent at a single institution. The treatment modality for individual cases was usually determined on a case by case basis. Results: The median follow-up duration for the surviving patients was 28.2 months. The most common site of head and neck cancer was hypopharyngeal carcinoma (n = 21, 77.7%). The lower esophagus was the most common location of esophageal carcinoma (n = 16, 59.3%). The 2-year progression-free survival (PFS) and overall survival (OS) rates were 57.5% and 39.6%. Major pattern of failure was locoregional recurrence in the study patients. Esophageal cancer stage, the Eastern Cooperative Oncology Group (ECOG) performance status, and pretreatment weight loss were significant prognostic factors for OS in univariate analysis. Treatment-related death was observed in two patients, and one patient developed a grade 4 late treatment-related complication. Conclusion: Although the survival outcome for SHNEC is poor, long-term survival might be achievable with aggressive treatment with stage I-II esophageal cancer and good performance.