• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.1
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• pp.29-35
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• 2023

Purpose The concentration of PSA (Prostate Specific Antigen) after radical prostatectomy in prostate cancer patients is a predictor of biochemical recurrence, and the AUA (American Urological Association) is defined as biochemical recurrence when the concentration of PSA is measured at 0.2 ng/mL or more, and when the concentration is measured at 0.2 ng/mL or more at the retest. This standard is also applied our hospital. In this laboratory, the PSA reagent using IRMA (Immunoradiometric Assay) is used, and the sensitivity at a very low value was not as good as the reagent used in the department of laboratory medicine. This study aims to increase the reliability of the results by improving the precision and sensitivity of very low values. Materials and Methods As a reagent for the study, PSA reagent using IRMA was used. As a method to improve the precision and sensitivity of very low values, a variation method on the serum volume(25 uL, 50 uL, 100 uL, 200 uL) was studied, and variation usefulness evaluation was conducted. The evaluation items were compared the results of precision, analytical sensitivity, recovery rate, dilution test, high-dose hook effect test, parallel test and very low concentration values(n = 20). Results The validation results were displayed in the order of 25 uL, 50 uL, 100 uL, 200 uL. As the serum volume increased, it was confirmed that CV (Coefficient of Variation)(%) improved. Analytical sensitivity(ng/mL) was 0.038, 0.041, 0.017, 0.015 and recovery rate(%) was 101±3, 101±3, 99±2, 97±4. very low concentration values(ng/mL) between each volume(n=20) were 0.135±0.068, 0.076±0.050, 0.048±0.034, 0.046±0.034. and high dose hook effect appeared as the serum volume increased. Conclusion Through the variation usefulness evaluation, it was confirmed that as the serum volume increased, the precision and sensitivity improved at very low concentration values. However, it is necessary to pay special attention to the occurrence of high-dose hook effect as the serum volume increases. In the case of tests that requires very low concentration values, it is thought that the reliability of the result will be increased if the variation method is properly used after the variation usefulness evaluation.

• Clean Technology
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• v.26 no.2
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• pp.137-144
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• 2020

Metal-impregnated activated carbons were prepared via ultrasonic-assisted impregnation method for regeneration and low ammonia concentration. Magnesium and copper were selected as metals, while chloride (Cl^-) and nitrate (NO₃^-) precursors were used to impregnate the surface of activated carbon. The physical and chemical properties of the prepared adsorbents were characterized by TGA, BET, and NH₃-TPD. The ammonia breakthrough test was carried out using a fixed bed and flowing ammonia gas (1000 mg L^-1 NH₃, balanced N₂) at 100 mL min^-1, under conditions of temperature swing adsorption (TSA) and pressure swing adsorption (PSA, 0.3, 0.5, 0.7, 0.9 Mpa). The adsorption and desorption performance of ammonia were in the order of AC-Mg(Cl) > AC-Cu(Cl) > AC-Mg(N) > AC-Cu(N) > AC through NH₃-TPD and TSA and PSA processes. AC-Mg(Cl) using MgCl₂ showed the average adsorption amount of 2.138 mmol/g at TSA process. Also, AC-Mg(Cl) showed the highest initial adsorption amount of 3.848 mmol/g at PSA 0.9 Mpa. When metal impregnated the surface of the activated carbon, it was confirmed that not only physical adsorption, but also chemical adsorption increased, making enhancement in adsorption and desorption performances possible. Also, the prepared adsorbents showed stable adsorption and desorption performances despite repeated processes, confirming their applicability in the TSA and PSA processes.

• ALGAE
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• v.19 no.3
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• pp.175-190
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• 2004

The morphological and molecular characteristics of Pachydictyon coriaceum (Holmes) Okamura (1899) are described. Plants are collected from Korea all year round and have maximum height from August to September. The monthly variability of thallus growth is in the way with that of the seawater temperature. Two types of thallus structures, thick cortical layer tallus type and thin cortical cell layer type, are distinguished according to growing seasons. The habit of Korean plants is also classified into two thallus types, slender type and wide type, based on the length and the width of internodes, but this distinction between two types is not supported by either anatomical or molecular characteristics. P. coriaceum shares typical morphology in branching pattern and morphogenetic processes with the other species of Dictyota: 1) multi-cellular cortical and medullar layer in the partial of thallus, 2) same development of thallus from apical meristem cell, and 3) sub-lineage within Dictyota species lineage in rbcL, psaA and psbA gene sequences analyses. These characteristics lead to propose the new combination of Dictyota coriacea (Homes) I.K. Hwang, H.S. Kim et W.J. Lee, comb. nov.

• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.676-679
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• 2010

Nano composite particles were synthesized from a bulk ZrVFe alloy ingot by transferred DC thermal plasma. Effects of plasma gas flow rate on the characteristics of the produced nano composite particles were investigated. The characteristics of the synthesized powder were analyzed by field scanning electron microscopy (FE-SEM), light scattering particle size analyzer (PSA), energy dispersive X-ray spectroscopy (EDS), X-ray diffractometer (XRD), and Brunauer-Emmett-Teller (BET) surface area analyzer. As the flow rate of plasma gas increased from 20 L/min to 40 L/min, the average particle size decreased from 91 nm to 55 nm, the particle size distribution became narrower, the surface area increased from $200\;m^2/g$ to $255\;m^2/g$, the particle composition was nearly unaffected, and the particle crystallinity was improved.

• Radiation Oncology Journal
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• v.32 no.3
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• pp.179-186
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• 2014

Purpose: To study the long-term outcomes and tolerance in our patients who received dose escalated radiotherapy in the early salvage post-prostatectomy setting. Materials and Methods: The medical records of 54 consecutive patients who underwent radical prostatectomy subsequently followed by salvage radiation therapy (SRT) to the prostate bed between 2003-2010 were analyzed. Patients included were required to have a pre-radiation prostate specific antigen level (PSA) of 2 ng/mL or less. The median SRT dose was 70.2 Gy. Biochemical failure after salvage radiation was defined as a PSA level >0.2 ng/mL. Biochemical control and survival endpoints were analyzed using the Kaplan-Meier method. Univariate and multivariate Cox regression analysis were used to identify the potential impact of confounding factors on outcomes. Results: The median pre-SRT PSA was 0.45 ng/mL and the median follow-up time was 71 months. The 4- and 7-year actuarial biochemical control rates were 75.7% and 63.2%, respectively. The actuarial 4- and 7-year distant metastasis-free survival was 93.7% and 87.0%, respectively, and the actuarial 7-year prostate cancer specific survival was 94.9%. Grade 3 late genitourinary toxicity developed in 14 patients (25.9%), while grade 4 late genitourinary toxicity developed in 2 patients (3.7%). Grade 3 late gastrointestinal toxicity developed in 1 patient (1.9%), and grade 4 late gastrointestinal toxicity developed in 1 patient (1.9%). Conclusion: In this series with long-term follow-up, early SRT provided outcomes and toxicity profiles similar to those reported from the three major randomized trials studying adjuvant radiation therapy.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.71-82
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• 2011

Purpose: To evaluate the biochemical control rate and the rate of side effects after performing permanent brachytherapy of localized prostate cancer. Materials and Methods: 67 patients with localized prostate cancer were treated with brachytherapy between April 2007 and December 2008. Of these, 43 patients who were followed up and did not receive external radiotherapy were evaluated for the change in prostate specific antigen (PSA) level and the occurrence of side effects. In total, 18 patients were classified as low risk, 19 patients as intermediate risk, and 6 patients as high risk. The prescription dose was 145 Gy. Results: A PSA increase greater than 2 ng/mL occurred in 2 patients (4.7%). Radiation Therapy Oncology Group (RTOG) grade 1 and 2 acute urologic complications (UC) occurred in 40 and 3 patients, respectively. Further, 5 patients had RTOG grade 1 acute rectal complication (RC). The numbers of RTOG grade 1, 2, and 3 chronic UC were 1, 4, and 1, respectively. The numbers of RTOG grade 1, 2, and 4 chronic RC were 5, 10, and 3, respectively. The statistically significant risk factors (RF) of acute RC were the minimal dose in the most irradiated 0.1 cc volume ($D_{0.1cc}$, p=0.041) and absolute volume receiving 150% of the prescribed dose ($V_{150cc}$, p=0.038) in the entire rectum (ER). The percentage ($V_{100%}$, p=0.019) and absolute volume ($V_{100cc}$, p=0.047) in the involved rectum (IR) were also statistically significant. The RF of chronic RC were $V_{100%}$ (p=0.011) in the ER and the $D_{0.1cc}$ (p=0.049), $V_{100cc}$ (p=0.023) in the IR. The number of used seeds were related with acute UC (p=0.028). Conclusion: Permanent brachytherpy of localized prostate cancer showed a favorable short term biochemical control rate. As such, selective intermediate and high risk patients can be managed with permanent brachytherapy. The effort to reduce rectal complication is also necessary.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.1813-1816
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• 2015

Background: The aim of this study was to research the importance of the neutrophil to lymphocyte ratio (NLR) in prediction of PSA recurrence after radical prostatectomy, which has not been reported so far. Materials and Methods: The data of 175 patients who were diagnosed with localised prostate cancer and underwent retropubic radical prostatectomy was retrospectively examined. Patient pre-operative hemogram parameters of neutrophil count, lymphocyte count and NLR were assessed. The patients whose PSAs were too low to measure after radical prostatectomy in their follow-ups, and then had PSAs of 0,2 ng/mL were considered as patients with PSA recurrence. Patients with recurrence made up Group A and patients without recurrence made up Group B. Results: In terms of the power of NLR value in distinguishing recurrence, the area under OCC was statistically significant (p<0.001) .The value of 2.494 for NLR was found to be a cut-off value which can be used in order to distinguish recurrence according to Youden index. According to this, patients with a higher NLR value than 2.494 had higher rates of PSA recurrence with 89.7% sensitivity and 92.6% specificity. Conclusions: There are certain parameters used in order to predict recurrence with today's literature data.We think that because NLR is easy to use in clinics and inexpensive, and also has high sensitivity and specificity values, it has the potential to be one of the parameters used in order to predict biochemical recurrence in future.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6913-6917
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• 2013

Background: Although the PSA test has been used in Korea for over 20 years, the incidence of prostate cancer has risen, and the associated mortality has increased about 13-fold over the 20-year period. Also, several investigators have suggested that Asians in America are more likely to present with more advanced prostate cancer than Caucasians. We compared the characteristics of native Koreans and Americans (Caucasians and African-Americans) undergoing radical prostatectomies in Korea and the US. Materials and Methods: Study subjects comprised patients at Korean and US hospitals from 2004 to 2012 who had undergone radical prostatectomies. We compared the characteristics of the subjects, including age, preoperative prostate-specific antigen (PSA) levels, body mass index (BMI), Gleason score, and pathological T stage. Results: In total, 1,159 males (502 Koreans, 657 Americans) were included. The Korean and American patients had mean ages of $67.1{\pm}6.6$ and $59.2{\pm}6.7$ years, respectively. The mean preoperative PSAs were $15.4{\pm}17.9$ and $6.2{\pm}4.6ng/mL$ (p=0.0001) and the mean BMIs were $23.6{\pm}2.6$ and $28.7{\pm}4.4kg/m^2$ (p=0.0001), respectively. Pathological localized prostate cancer represented 71.7% of cases for Koreans and 77.6% for Americans (p=0.07). According to age, Koreans had higher T stages than Americans in their 50s (p=0.021) and higher Gleason scores than Americans in all age groups. According to PSA, Koreans had higher Gleason scores than Americans for PSA >10 ng/mL (p<0.05). According to prostate size and Gleason scores, Koreans had higher PSA values than Americans (p<0.01). Conclusions: These results show that Korean patients have elevated risk of malignant prostate cancers, as indicated by the significantly higher Gleason scores and PSAs, suggesting a need for novel prostate cancer treatment strategies in Korea.

• Biomedical Science Letters
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• v.14 no.3
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• pp.157-165
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• 2008

Recently, the number of patients with prostate cancer has been increased gradually by both the change of living environment and the increase of aged population. In this study the serum prostate specific antigen (PSA) level was compared to the Gleason score known as a prognostic factor for the prostate cancer. In the Gleason score 6 and $9{\sim}10$, the average age was 69.68 years old and 69.52 years old, respectively and there was no statistically difference in both of age and Gleason score. the PSA serum consistency appeared <4 ng/mL as example 1, $4{\sim}20ng/mL$ as example 17 and ${\geq}20ng/mL$ as example 4 in the Gleason score 6, and In the Gleason score $9{\sim}10$, it appeared <4 ng/mL as example 1, $4{\sim}20ng/mL$ as example 6 and ${\geq}20ng/mL$ as example 15. PSA serum consistency in the Gleason score $9{\sim}10$ showed higher value than those of Gleason score 6 (P<0.05). Next, expression ratios of bcl-2, Ki-67 and p53 were examined in the Gleason score 6 and $9{\sim}10$. the p53 expression ratio, a tumor suppression gene, appeared the significance statistically by the classification of the Gleason score as example 7 (28%) in the Gleason score 6 and as example 16 (64%) in the Gleason score $9{\sim}10$ (P<0.05). but not different in the expression ratios of the Ki-67 and bcl-2. The expression ratio of p53 by the expression ratio of bcl-2 and the expression ratio of Ki-67 by the expression ratio of p53 had a positive relationship in all of the Gleason score 6 and the Gleason score $9{\sim}10$ (P<0.05). However, the expression ratio of Ki-67 by the expression ratio of bcl-2 did not show any significance in the Gleason score $9{\sim}10$ (P<0.05). Therefore, the results suggested that p53 expression could be used as an independent prognostic factor.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.10
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• pp.41-50
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• 1993

This paper describes the fabrication process and electrical characteristics of PSA (Polysilicon Self-Align) bipolar transistors with a thin base width of 1100.angs.. To realize this shallow junction depth, one-step rapid thermal annealing(RTA) technology has been applied instead of conventional furnace annealing process. It has been shown that the series resistances and parasitic capacitances are significantly reduced in the device with emitter area of 1${\times}4{\mu}m^{2}$. The switching speed of 2.4ns/gate was obtained by measuring the minimum propagation delay time in the I$^{2}$L ring oscillator with 31 stages.