• Journal of the Korean Society for Precision Engineering
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• v.31 no.6
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• pp.521-525
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• 2014

Circulating tumor cells (CTCs) in the bloodstream of cancer patients provide an accessible source for detection, characterization, and monitoring of nonhematological cancers. The effectiveness of the CTC-Chip for the isolation of ovarian cancer cells was demonstrated by adapting the herringbone-chip (HB-Chip). The motions of the particles on the HB chip were simulated by a unique combination of buoyant, gravitational forces, and helical flows with a computational modeling. The motions of cells are demonstrated by applying polystylene bead and ovarian cancer cells into the microfabricated HB-Chip. The experimental results from beads and cells are well accordance with the simulated ones, as previously reported by Toner group. Thus, I expect that these modeling and experimental skills will play key roles in the clinical applications on CTC isolation as well as the basic research on characterization of CTCs under flow.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.293-299
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• 2000

Purpose :We conducted a prospective non-randomized clinical study to evaluate the efficacy and toxic of the preoperative concurrent chemoradiotherapy for locally advanced unresectable rectal cancer. Materials and Methods: Between January 1995 and June 1998, 37 conecutive patients with locally unresectable advanced rectal cancer were entered into the study. With 3- or 4- fields technique, a total of 45 Gy radiation was delivered on whole pelvis, followed by 5.4 Gy boost to the primary tumor in some cases. Chemotherapy was done at the first and fifth week of radiation with bolus i.v. 5-Fluorouracil (FU) 370$\~$450 mg/m$^{2}$, days 1$\~$5, plus Leucovorin 20 mg/m$^{2}$, days 1$\~$5. OF 37 patients, 6 patients did not receive all planned treatment course (refusal in 4, disease progression in 1, metastasis to lung in 1). Surgical resection was undergone 4$\~$6 weeks after preoperative concurrent chemoradiotherapy. Results :Complete resection rate with negative margins was 94$\%$ (29/31). Complete response was seen in 7 patients (23$\%$) clinically and 2 patients (6$\%$) pathologically. Down staging of tumor occured in 21 patients (68$\%$). Treatment related toxicity was minimal except grade III & IV leukopenia in 2 patients, respectively. Conclusion : Preoperative concurrent chemoradiotherapy in locally advanced rectal cancer was effective in inducing down staging and complete resection rate. Treatment related toxicity was minimal. Further follow up is on-going to determine long term survival following this treatment.

• Journal of the Korean Society of Food Culture
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• v.31 no.6
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• pp.634-642
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• 2016

Chinese cabbage is produced and consumed as a main material for kimchi and as a staple vegetable in Korea throughout the year. However, due to environmental changes unbalance between supply and demand is repeated annually, requiring development of long-term storage technologies. Chinese cabbages, were harvested, put in plastic boxes, and precooled at $2^{\circ}C$ for 24 hours using forced air precooler. After precooling, Chinese cabbages were MAP-treated with 0.02 mm HDPE film and functional film and stored at low temperature ($1{\pm}0.5^{\circ}C$). The weight-loss rates after 9-weeks of storage were 8.47% in the control group, 4.07% in the HDPE film-treated group, and 3.07% in the functional film-treated group, respectively, suppressing weight loss. Trimming loss rate after 6-weeks of storage was 6.86% in the functional film MAP-treated group and lower than 7.50% in the control group. In the sensory test with 7 points as the limit of commodity, the control group lost it after 6-weeks of storage while the MAP-treated groups retained over 7 points. The functional film MAP-treated group showed over 6 points for processing as kimchi until 9-weeks of storage, proving that Pallet-type MAP storage is effective for extending storage life of spring Chinese cabbage.

• Journal of the Korean Society of Food Culture
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• v.31 no.6
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• pp.661-674
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• 2016

We analyzed information provided by diet-related programs of comprehensive programming channels and the relationship between composition of professional panelists and quality of provided information. We selected 82 items among eight programs by MBN, JTBC, and TV chosun. All 82 items provided information about food & nutrition and health & disease, but only 32 items (39.0%) and 35 items (42.7%) provided information on food culture and food safety, respectively. Among the food ingredients, phytochemicals (81.7%) were the most frequently mentioned, and the contents of functional ingredients occupied a large part. The inappropriate information on programs were broadcast on an average of 1.2 episodes per program, and the most pointed out item was information that could confuse viewers with drugs (29.3%). Among the professional panelists, medical doctors (38.9%) and Oriental medicine doctors (16.6%) had the highest number of appearances, and professors of food & nutrition constituted only 7.1%. However, the increase in the number of appearances of professors showed a positive effect on the quality of program information. Contents focused on balanced nutrient intake and dietary culture of Korea should be increased rather than focusing on the function of each nutrient in comprehensive programming channels.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.679-683
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• 1998

From June 1995 to May 1997, we have implanted 52 Sorin Bicarbon mechanical valves in 41 patients. They were 16 men and 25 women, and their mean age was 47.4${\pm}$14.8(range; 18∼74 y.o.). 35(27 mm∼31 mm) were in mitral position, 15(19 mm∼25 mm) in aortic position, and 2(31 mm) in tricuspid position. 3 CABGs and a tumor excision were taken concomittantly. 35 patients were primary operation, and 6 were re-do operations. By intraoperative transesophageal doppler echocardiography, transvalvular peak/mean pressure gradient was 6.1${\pm}$2.7/2.4${\pm}$1.4 mmHg in mitral position and 27.6/10.7 mmHg in aortic position. The effective valve opening area in mitral position was 3.2${\pm}$0.6 cm2. Follow-up was total 508.6 patient-months, and mean follw-up was 12.7${\pm}$9.2 months. NYHA class was improved from 2.6${\pm}$0.6 to 1.2${\pm}$0.3 in average postoperatively. During that period, there was no operative death. 2 late non-valve related deaths were occurred. One was died of COPD, and the other was possible acute myocardial infarction. Among 7 postoperative complications, one valve related complication(minimal paravalvular leakage) was noticed. In conclusion, Sorin Bicarbon mechanical valve is believed one of the safe choice in clinical settings. It showed excellent hemodynamic and mechanical functions, and very low postoperative valve related complications in short term clinical experience.

• Journal of the Korean Society for Heat Treatment
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• v.31 no.6
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• pp.290-299
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• 2018

The microstructure of a newly developed alloy tool steel (KV1) for casting cold-work press dies was analyzed using advanced scanning electron microscopy. Its mechanical properties and durability in use as piercing inserts were tested. It contained a continuous network structure which originated from the micro-segregation during solidification and was composed of retained austenite and primary carbides. However, after quenching and tempering, its continuity was destroyed due to the decomposition of austenite. The discontinuous spatial distribution and the smaller amount of primary carbide in the network presented KV1 enhanced ductility compared to the common alloy (HK700). The reduced C and Cr, the addition of V resulted in a small amount of primary carbides which primarily consisted of MC, as well as fine and uniform dispersion of precipitates. Owing to these features, KV1 exhibited delayed initiation of chipping when used for piercing inserts.

• Structural Engineering and Mechanics
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• v.31 no.6
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• pp.697-716
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• 2009

This paper summarizes an experimental and analytical study on the seismic behavior of high strength reinforced concrete columns under cyclic loading. In total six cantilever columns with different sizes and concrete compressive strengths were tested. Three columns, small size, had a $325{\times}325$ mm cross section and the three other columns, medium size, were $520{\times}520$ mm. Concrete compressive strength was 80, 130 and 180 MPa. All specimens were designed in accordance with the Japanese design guidelines. The tests demonstrated that, for specimens made of 180 MPa concrete compressive strength, spalling of cover concrete was very brittle followed by a significant decrease in strength. Curvature was much important for the small size than for the medium size columns. Concrete compressive strength had no effect on the curvature distribution for a drift varying between -2% and +2%. However, it had an effect on the drift corresponding to the peak moment and on the equivalent viscous damping variation. Simple equations are proposed for 1) evaluating the concrete Young's modulus for high strength concrete and for 2) evaluating the moment-drift envelope curves for the medium size columns knowing that of the small size columns. Experimental moment-drift and axial strain-drift histories were well predicted using a fiber model developed by the authors.

• Structural Engineering and Mechanics
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• v.31 no.6
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• pp.639-662
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• 2009

A comprehensive investigation of the stochastic response of an isolated cable-stayed bridge subjected to spatially varying earthquake ground motion is performed. In this study, the Jindo Bridge built in South Korea is chosen as a numerical example. The bridge deck is assumed to be continuous from one end to the other end. The vertical movement of the stiffening girder is restrained and freedom of rotational movement on the transverse axis is provided for all piers and abutments. The longitudinal restraint is provided at the mainland pier. The A-frame towers are fixed at the base. To implement the base isolation procedure, the double concave friction pendulum bearings are placed at each of the four support points of the deck. Thus, the deck of the cable-stayed bridge is isolated from the towers using the double concave friction pendulum bearings which are sliding devices that utilize two spherical concave surfaces. The spatially varying earthquake ground motion is characterized by the incoherence and wave-passage effects. Mean of maximum response values obtained from the spatially varying earthquake ground motion case are compared for the isolated and non-isolated bridge models. It is pointed out that the base isolation of the considered cable-stayed bridge model subjected to the spatially varying earthquake ground motion significantly underestimates the deck and the tower responses.

• Journal of Korean Society on Water Environment
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• v.31 no.6
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• pp.700-714
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• 2015

The characteristic of the water quality and pollutant discharge was analyzed at the units watershed of the total amount management in Han-river basin, and after classified in a similar area by multivariate statistical analysis, the main trend such as the water quality trend and pollutant discharge characteristic were analyzed. As a result of this study, the density of the pollutant at the unit watershed is not necessarily identified as discharge density, and the primary management watershed and targeted substances were analyzed depending on the operating status of the environmental infrastructure in watershed and the main pollution factor and discharge path per pollutants. As a result of cluster analysis, watersheds were classified into four groups according to discharge characteristics. It will be used when selecting target area of primary management that is appropriate to the characteristics of each river and establishing efficient water quality improvement plans.

• Childhood Kidney Diseases
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• v.2 no.1
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• pp.1-8
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• 1998

Purpose : To evaluate the diagnostic value of dipstick urinalysis($Multistix^{(R)}$) as a screening test for urinary tract infection(UTI) in acute febrile children. Methods : We compared dipstick uinalysis (leukocyte estease(LE) and nitrite) with microscopic urinalysis (WBC and bacteria) and urine culture in 80 children with UTI and 605 children without UTI, who were admitted due to acute fever at EWHA Womans University Hospital between Oct. 1994 and Feb. 1996. Results : 1) In dipstick urinalysis, LE and nitrite were positive in 38.7%, and 13.8% of 80 children with UTI and in 2.1%. and 1.2% of 605 children without UTI. 2) In microscopic urinalysis, WBC and bacteria were positive in 31.2%, and 17.5% of 80 children with UTI and in 4.1%, and 0.6% of 605 children without UTI. 3) Positive rate of LE on dipstick urinalysis was 38.7%, which was significantly higher than 31.5% of WBC on microscopic urinalysis (P<0.05). Positive rate of nitrite was not significantly different to that of bacteria. 4) Sensitivity, specificity, positive predictive value, negative predictive value of dipstick urinalysis were 43.7%, 98.3%, 63.6%, 92.9% which were not significant different to 40.0%, 99.0%, 54.0%, 92.3% of microscopic urinalysis. The sensitivity of combined dipstick and microscopic urinalysis were still low(50%). 5) Additional positive rate of microscopic urinalysis to negative dipstick urinalysis was 6.3%(5/80) in 80 children with UTI. Conclusion : The sensitivity of dipstick urinalysis was low and additional value of microscopic urinalysis was minimal in febrile UTI. So urine culture is mandatory in acute febrile children even though dipstick and microscopic urinalysis are negative.