• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.601-606
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• 2015

Background: Prostate cancer is predominately a disease of older men, with a median age of diagnosis of 68 years and 71% of cancer deaths occurring in those over 75 years of age. While prostate cancer screening is not recommended for men >70 years, fit elderly men with controlled comorbidities may have a relatively long life expectancy. We compare the use of age related PSA with the detection of primary malignant circulating prostate cells mCPCs to detect clinically significant PC in this population. Materials and Methods: All men undergoing PC screening with a PSA >4.0ng/ml underwent TRUS 12 core prostate biopsy (PB). Age, PSA, PB results defined as cancer/no-cancer, Gleason, number of positive cores and percentage infiltration were registered. Men had an 8ml blood sample taken for mCPC detection; mononuclear cells were obtained using differential gel centrifugation and mCPCs were identified using immunocytochemistry with anti-PSA and anti-P504S. A mCPC was defined as a cell expressing PSA and P504S; a positive test as at least one mCPC detected/sample. Diagnostic yields for subgroups were calculated and the number of avoided PBs registered. Esptein criteria were used to define small grade tumours. Results: A total of 610 men underwent PB, 398 of whom were aged <70yrs. Men over 70 yrs had: a higher median PSA, 6.24ng/ml versus 5.59ng/ml (p=0.04); and a higher frequency of cancer detected 90/212 (43%) versus 134/398 (34%) (p=0.032). Some 34/134 cancers in men <70yrs versus 22/90 (24%) of men >70yrs complied with criteria for active surveillance. CPC detection: 154/398 (39%) men <70yrs were CPC (+), specificity for cancer 86%, sensitivity 88%, 14/16 with a false (-) result had a small low grade PC. In men >70 years, 88/212 (42%) were CPC (+); specificity 92%, sensitivity 87%, 10/12 with a false (-) had small low grade tumours. False (+) results were more common in younger men 36/154 versus 10/88 (p<0.02). With a PSA cutoff of 6.5ng/ml, in men <70yrs, 108 PB would be avoided, missing 56 cancers of which 48 were clinically significant. Using CPC detection, 124 biopsies would be avoided, missing only 2 clinically significant cancers. In men >70 yrs using a PSA >6.5ng/ml would have resulted in 108 PB with 34 PC detected, of which 14(41%) were small low grade tumours. Conclusions: The use of CPC detection in the fit elderly significantly decreases the number of PBs without missing clinically significant cancers, indicating superiority to the use of age-related PSA.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.270-274
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• 2001

With Increasing importance of electroless nickel plating technology in many fields such as electronic and automobile industries, the treatment of the spent baths is becoming a serious problem. These spent baths contain iron and zinc as impurities, organic acids as complexing reagents, and phosphonate ions as oxidized species of tile reducing reagent. as well as several grams per liter of nickel. The spent baths are currently treated by conventional precipitation method. but a mettled with no sludge generation is desired. This work aims at establishing a recycling process of nickel from tile spent baths using solvent extraction. Extraction behaviors of nickel. iron. and zinc in various 쇼pes of real spent baths are investigated as a function of pH using LIX841, di (2-ethylhexyl)phosphoric acid (D2EHPA), and PC88A as tile extractants. Nickel is extracted by LIX84I at the equilibrium pH of more than 6 with high efficiency. For the weakly acid baths. iron and zinc are extracted by D2EHPA or PC88A without adjusting the pH of the baths leaving nickel in the aqueous phase. Stripping of nickel from LIX84I with sulfuric acid is also investigated. It is shown that concentrated nickel sulfate solution (> 100 ㎏-Ni/㎥) is obtained. This solution can be reused in the electroless plating process. Based on these findings, flow sheets for recovering nickel from the spent baths are proposed.

• Journal of the Korean Vacuum Society
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• v.18 no.2
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• pp.85-91
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• 2009

There has been a rapid progress for flexible polymer-based MEMS(Microelectromechanical Systems) technology. Polycarbonate (PC) and Poly Methyl Methacrylate (PMMA), so-called acrylic, have many advantages for optical, non-toxic and micro-device application. We studied dry etching of PC and PMMA as a function of % gas ratio in the $O_2/SF_6/CH_4$ temary plasma. A photoresist pattern was defined on the polymer samples with a mask using a conventional lithography. Plasma etching was done at 100 W RIE chuck power and 10 sccm total gas flow rate. The etch rates of PMMA were typically 2 times higher than those of PC in the whole experimental range. The result would be related to higher melting point of PC compared to that of PMMA. The highest etch rates of PMMA and PC were found in the $O_2/SF_6$ discharges among $O_2/SF_6$, $O_2/CH_4$ and $SF_6/CH_4$ and $O_2/SF_6/CH_4$ plasma composition (PC: ${\sim}350\;nm/min$ at 5 sccm $O_2/5$ sccm $SF_6$, PMMA: ${\sim}570\;nm/min$ at 2.5 sccm $O_2/7.5$ sccm $SF_6$). PC has smoother surface morphology than PMMA after etching in the $O_2/SF_6/CH_4$ discharges. The surface roughness of PC was in the range of 1.9$\sim$3.88 nm. However, that of PMMA was 17.3$\sim$26.1 nm.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.10a
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• pp.168-172
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• 2005

동일한 추출제가 함유된 3종의 추출레진을 대상으로 중희토류인 Gd의 추출특성을 비교하였다. 실험조건은 $20^{\circ}C$에서 평형 pH, Gd 농도, 추출시간으로 하여 다음과 같은 결과를 얻었다. 추출레진에서 추출시간 5분이내에 $Gd^{3+}$ 이온이 90%이상 추출되며, 추출시간 30분 이후에 변화가 거의 없어 추출반응이 종결된 것으로 판단된다. 평형 pH. 2.2이하에서 분배비는 평형 pH에 대해 선형적으로 감소하였다. Freundlich's 흡착등온식을 도입하여 3종의 추출레진에 대해 적용해 본 결과 결정계수$(R^2)$ 0.95이상으로 나와, Freundlich's 흡착등온식에 부합됨을 알 수 있었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12
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• pp.1091-1096
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• 2003

Ion implantation in polymeric materials can induce dramatic chemical modifications, such as bond breaking, cross linking, formation of new chemical products, which have strong influences on the macroscopic properties of the materials. In this study ion implantation was performed onto polymer, PC(polycarbonate), in order to investigate change of the optical transmittance property focusing ultraviolet ray range(200-400nm). PC was irradiated with N, Ar, Kr, Xe ions at the ion energy of 50keV and the dose range of 5 ${\times}$ 10$\^$15/, 1 ${\times}$ 10$\^$16/, 7${\times}$10$\^$16/ ions/$\textrm{cm}^2$. FT-IR, XPS, UV/Vis transmittance spectroscopy measurement technologies were employed to obtain chemical. structural properties and optical transmittance of irradiated polymer. The original PC(unimplanted) is quite transparent that it has more than 88% transmittance in the range UV-A(320∼400nm), but after ion implantation, surface colors were changed to the dark brown and the transmittance of UV ray decreased for all implantation condition, and the absorption edge was shift to visible range with increasing mass of implanted ion species and dose.

• Journal of Korean Association for Spatial Structures
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• v.22 no.4
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• pp.81-88
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• 2022

The paper introduces an experimental program for the newly developed vertical joints between Precast Concrete (PC) walls to improve their in-plane shear capacity. Compared to the existing vertical joints, two types of vertical joints were developed by increasing the transverse reinforcement ratio and improving frictional force at the joint interface. A total of four specimens including the Reinforced Concrete (RC) wall and PC walls with developed vertical joints were designed and constructed. The constructed specimens were experimentally investigated through monotonic shear tests. The observed damage, load-deformation relationship, strain and strength are investigated and compared with the cases of RC wall specimen. Experimental results indicate that the maximum force and initial stiffness of the PC wall with proposed vertical joints were decreased by comparing with those of RC wall. However, the ultimate displacement increased by up to 217.30% compared to the RC wall specimen. In addition, brittle failure did not occurred and relatively few cracks and damages occurred.

• Korean Journal of Plant Resources
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• v.13 no.1
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• pp.80-88
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• 2000

External morphology and numerical taxonomy by principal component analysis and cluster analysis were investigated to understand the taxonomic relationships on the populations of Hanabusaya asiatica from 6 different habitats. Additionally H. latisepala was used as a outgroup. The distinct characters to each habitat were not present in the measurement of 21 qualitative characters except for some native individuals in the top of Mt. Sorak and Hyangrobong based on leaf shape and bracts. This results were recognized as the continuous variations of external morphology. The populations of H. latisepala and H. asiatica were identified by calyx lobe shape. The results obtained based on the principal component(PC) analysis of treated 78 OTU were divided into two groups by PC 1,2,3, and the sums of contributions for the total variance were 50.07% (PC1 22.3% , PC2 15.7%, PC3 12.0%, respectively), and six populations were not distinctly identified as illustrated in two dimensions with PC1 and PC2. In cluster analysis based on average linkage cluster analysis and Ward's method, there were similarities in the composition of clustered taxa, and each populations were not identified.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.4
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• pp.79-88
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• 1998

This study deals with the development of CAM system which can machine and measure any shape of mold and die by machining center and coordinate measureing machine . The overall goal of the CAM system is to achieve the mold and die machining , from digitizing through to final cutting. The hardware of the system comprises PC and machining center. CMM. There are three steps in the mold and die machining. (1) measuring of physical model by the CMM, (2) geometric modeling by the CAD system, (3) generation of NC code by the tool path compensated for tool radius. It is developed a software package, with which can conduct a micro CAM system in the PC without economical burden.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.87-88
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• 2015

We present results of our R-band polarimetry of a bright-rimmed cloud, IC1396A (with BRC 36), associated with the H II region S131 and the cometary globule LDN 1616 to study their magnetic field geometry. The distances of these clouds have been reported to be ~ 750 pc and ~ 450 pc, respectively in the literature. The young open cluster Trumpler 37 in the vicinity of IC1396A and the high mass stars in the Orion belt near L1616 are found to be responsible for the structure of these clouds. We made polarimetry of foreground stars inferred from their distances measured by the Hipparcos satellite to subtract the foreground contribution to the observed polarization results. We discuss the optical polarimetric results and compare our findings with MHD simulations towards BRCs and CGs.

• Natural Product Sciences
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• v.9 no.1
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• pp.22-27
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• 2003

This study was designed to investigate the effects of main constituents of Nigella sativa (NS) seed on the survival and CNS responses in experimental animals. The toxicological investigations were conducted for the determination of median lethal doses $(LD_{50})$ of NS seed constituents [i.e. aqueous extract (AE), fixed oil (FO), volatile oil (VO)] and main components of its VO [i.e. thymoquinone (TQ), ${\alpha}-pinene$ (AP) and p-cymene (PC)]. A part of this study includes evaluation NS constituents in the induction of minimal neurological deficit (MND) as a parameter for neurotoxicity using chimney test. In this study, the i.p. $LD_{50}$ values of AE, FO, VO, TQ (suspended In 0.5%CMC), TQ (dissolved in corn oil), AP and PC, were 3020, 3371, 1853, 616.6, 90.3, 1726 and 1523 mg/kg, respectively. All the NS constituents can be considered moderately toxic ($LD_{50}$ ranged from 616.6 to 3371 mg/kg), except the oily solution of TQ, which was very toxic ($LD_{50}$ was 90.3 mg/kg). It appeared that the toxicity of the whole VO is mainly due to its content of TQ and to some extent PC. All the NS constituents induced different degrees of MND at certain dose levels. The median neurotoxic (or sedating) doses $(TD_{50})$ of AE, FO, VO, TQ (suspended in CMC) and AP and PC, were 950, 1403, 306, 88.1, >173 and 368 mg/kg, respectively. TQ was the most potent component in inducing MND, whereas the FO and AE were the least. Neurotoxicity induced by the VO in the chimney test may refer basically to its contents of TQ and to some extent PC and AP.