• Nuclear Engineering and Technology
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• v.33 no.6
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• pp.596-604
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• 2001

This paper quantitatively presents the effects of important factors of the probabilistic safety assessment (PSA) of safety-critical digital systems. The result which is quantified using fault tree analysis methodology shows that these factors remarkably affect the system safety. In this paper we list the factors which should be represented by the model for PSA. Based on the PSA experience, we select three important factors which are expected to dominate the system unavailability. They are the avoidance of common cause failure, the coverage of fault tolerant mechanisms and software failure probability. We Quantitatively demonstrate the effect of these three factors. The broader usage of digital equipment in nuclear power plants gives rise to the safety problems. Even though conventional PSA methods are immature for applying to microprocessor-based digital systems, practical needs force us to apply it because the result of PSA plays an important role in proving the safety of a designed system. We expect the analysis result to provide valuable feedback to the designers of digital safety- critical systems.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6121-6125
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• 2014

Background: Prostate-specific antigen (PSA) is a potential biomarker for early detection of prostate cancer (PCa) but its level is known to be affected by many background factors and roles of ubiquitous toxicants have not been determined. Endocrine disrupting chemicals (EDCs) are ubiquitous reproductive toxicants used in consumer products, which promote tumor formation in some reproductive model systems by binding to AhR, but human data on its expression in prostate cancer as well as its association with PSA levels are not clear. This study aimed to evaluate the expression levels of AhR and its association with serological levels of PSA and to detect possible effects of background factors and EDC exposure history on PSA levels in PCa cases. Materials and Methods: A cross-sectional study was conducted on the tissue levels of AhR and serum levels of PSA in 53 PCa cases from 2008-2011 and associations between each and background and lifestyle related factors were determined. Results: Although the AhR was overexpressed in PCa and correlated with the age of patients, it did not correlate with PSA levels.Of nutritional factors, increased intake of polysaturated fats and fish in the routine regimen of PCa cases increased the PSA levels significantly. Conclusions: AhR overexpression in PCa pontws to roles of EDCs in PCa but without any direct association with PSA levels. However, PSA levels are affected by exposure to possible toxicants in foods whichneed to be assessed as possible risk factors of PCa in future studies.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.221-223
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• 2012

Prostate cancer (CaP) is a common reproductive cancer among men. This study was conducted to correlate the cancer incidence with Gangetic zone and to correlate the tumor marker prostate specific antigen (PSA) level in serum with different age groups and stage of malignancy. Patients suffering from CaP in the pathology unit of Mahavir Cancer Sansthan (Hospital and Research Centre), Patna, Bihar, India were studied from June 2009 to May 2010. PSA level in the serum of CaP patients was estimated by ELISA method. CaP incidence was highly recorded in Gangetic zone than the non-Gangetic zone. Maximum patients were in the 56 - 75 years age group with a marked predominance. Results of PSA examination showed that serum PSA level was not correlating with the age of patient and stage of malignancy. Significantly, elevated level of more than 10 ng/ml of PSA was recorded among the studied cancer patients. In this study, it is concluded that Gangetic zone habitat have high risk of CaP and elevated level of PSA was marked in Bihar, India.

• Clean Technology
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• v.10 no.2
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• pp.101-109
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• 2004

PSA and VSA processes have been used broadly to produce oxygen from ambient air in midium- or small-sized plants. PSA and VSA processes are the separation methods which use difference of amount adsorbed as pressure is changed periodically, but they have the differences in pressurization and regeneration. In this study, the performance of 6-step PSA process was compared with that of 5-step VSA process with respect to purity and recovery. In addition, the effects of each step (pressurization step, adsorption step, and pressure equalization step) on purity and recovery were investigated. As a result, the VSA process using zeolite 10X showed better performance than the zeolite 5A PSA and zeolite 13X VSA process in comparison with purity, recovery and productivity. And it was enough to apply the vacuum pressure of 200 torr for the VSA, which produced over 90% oxygen with 70% recovery.

• The Plant Pathology Journal
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• v.33 no.4
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• pp.351-361
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• 2017

Bacterial canker is the largest limiting factor in the cultivation and production of kiwifruit worldwide. Typical symptoms comprise necrotic spots on leaves, canker and dieback on canes and trunks, twig wilting, and blossom necrosis. Pseudomonas syringae pv. actinidiae (Psa), which is the causal agent of kiwifruit bacterial canker, is divided into four biovars based on multilocus sequence analysis of different genes, additional PCR testing of pathogenic genes (argKtox cluster, cfl, and various effector genes), and biochemical and physiological characterization. Bacterial canker caused by Psa biovar 2 designated Psa2 was detected for the first time on the green-fleshed kiwifruit cultivar Hayward in 1988 and the yellow-fleshed kiwifruit cultivar Hort16A in 2006 in Korea. Psa biovar 3 designated Psa3, responsible for the current global pandemics of kiwifruit bacterial canker, began to appear in Korea in 2011 and caused tremendous economic losses by destroying many vines or orchards of yellow-fleshed kiwifruit cultivars in one or several growing seasons. Bacterial canker epidemics caused by both Psa2 and Psa3 are prevalent in Korea in recent years. In this review, we summarize the symptomatology, etiology, disease cycle, diagnosis, and epidemiology of kiwifruit bacterial canker in Korea.

• Nuclear Engineering and Technology
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• v.39 no.3
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• pp.215-220
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• 2007

The existing flooding Probabilistic Safety Analysis(PSA) was updated to reflect the Korean plant specific operating experience data into the flooding frequency to improve the PSA quality. Both the Nuclear Power Experience(NPE) database and the Korea Nuclear Pipe Failure Database(NuPIPE) databases were used in this study, and from these databases, only the Pressurized Water Reactor(PWR) data were used for the flooding frequencies of the flooding areas in the primary auxiliary building. With these databases and a Bayesian method, the flooding frequencies for the flooding areas were estimated. Subsequently, the Core Damage Frequency(CDF) for the flooding PSA of the Ulchin(UCN) unit 3 and 4 plants based on the Korean Standard Nuclear Power Plant(KSNP) internal full-power PSA model was recalculated. The evaluation results showed that sixteen flooding events are potentially significant according to the screening criterion, while there were two flooding events exceeding the screening criterion of the existing UCN 3 and 4 flooding PSA. The result was compared with two kinds of cases: (1) the flooding frequency and CDF from the method of the existing flooding PSA with the PWR and Boiled Water Reactor(BWR) data of the NPE database and the Maximum Likelihood Estimate(MLE) method and (2) the flooding frequency and CDF with the NPE database(PWR and BWR data), NuPIPE database, and a Bayesian method. From the comparison, a difference in CDF results was revealed more clearly between the CDF from this study and case (2) than between case (1) and case (2). That is, the number of flooding events exceeding the screen criterion further increased when only the PWR data were used for the primary auxiliary building than when the Korean specific data were used.

• Imaging Science in Dentistry
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• v.51 no.1
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• pp.35-40
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• 2021

Purpose: This study was conducted to evaluate the accuracy of cone-beam computed tomography (CBCT) in detecting the posterior superior alveolar(PSA) artery canal in a sample of the Egyptian population. Materials and Methods: CBCT images of 600 maxillary sinuses of patients were examined for the presence or absence of the PSA artery along the lateral wall of the maxillary sinus, and for the diameter and type of the canal in relation to age and sex. The distances from the canal to the alveolar crest and sinus floor were also measured. Each canal was assessed to determine whether it was bifid. Results: The PSA artery canal could be detected in 92.0% of the sinuses. The mean distance from the inferior border of the PSA artery canal to the sinus floor was 8.2±2.2 mm (range, 3.2-13.6 mm) in males and 7.3±2.1 mm (range, 3.0-13.1 mm) in females. The mean distance from the inferior border of the PSA artery canal to the alveolar crest was 18.2±2.7 mm (range, 11.0-23.9 mm) in males and 17.4±2.3 mm (range, 10.8-23.5 mm) in females. The mean diameter of the PSA artery canal was larger in male subjects. The PSA artery canal was bifid in 8.7% of cases. The most frequently observed location of the PSA artery canal was intraosseous(82.2%). Conclusion: CBCT was confirmed to be a valuable tool for evaluation and localization of the PSA artery before maxillary sinus lift surgery to avoid intraoperative bleeding.

• Membrane Journal
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• v.4 no.1
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• pp.1-8
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• 1994

There are growing needs to produce relatively high purity(99.0% or higher) oxygen at low cost. For small scale production, both pressure swing adsorption(PSA) and membrane process are competitive and less expensive or more convenient than well known cryogenic fractionation technology. A continuous membrane column(CMC) combined with a PSA oxygen generator can be employed to produce high purity oxygen continuously. The oxygen enriched gas generated by a PSA unit, with a concentration of 93~94%, is fed to the CMC that consism of three modules of poly(imide) hollow fibers. Several experiments were conducted by varying parameters, such as feed flow rate, transmembrane pressure drop, stage cut, and feed location in order to obtain a high oxygen concentration above 99.0%. A two-series unit mode was also employed with CMC operation to optimize the given membrane area.

• Journal of Adhesion and Interface
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• v.4 no.4
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• pp.7-14
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• 2003

"Tack" is defined as "the property that enables an adhesive to form a bond with the surface of another material upon brief contact under light pressure". The tack depends on a number of experimental parameters. We can control various experimental factors (contact force, dwell time, pretest speed) using probe tack tester. We are here concerned with pretest speed of experimental factors using SIS-based hotmelt PSA and water-borne acrylic PSA.

• Journal of Yeungnam Medical Science
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• v.40 no.4
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• pp.412-418
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• 2023

Background: The aim of this study was to evaluate the risk factors for prostate-specific antigen (PSA) persistence in pathological stage T3aN0 prostate cancer (PCa) after robot-assisted laparoscopic radical prostatectomy (RALP). Methods: A retrospective study was performed on 326 patients with pT3aN0 PCa who underwent RALP between March 2020 and February 2022. PSA persistence was defined as nadir PSA of >0.1 ng/mL after RALP, and the risk factors for PSA persistence were evaluated using logistic regression analysis. Results: Among 326 patients, 61 (18.71%) had PSA persistence and 265 (81.29%) had PSA of <0.1 ng/mL after RALP (successful radical prostatectomy [RP] group). In the PSA persistence group, 51 patients (83.61%) received adjuvant treatment. Biochemical recurrence occurred in 27 patients (10.19%) in the successful RP group during the mean follow-up period of 15.22 months. Multivariate analysis showed that the risk factors for PSA persistence were large prostate volume (hazard ratio [HR], 1.017; 95% confidence interval [CI], 1.002-1.036; p=0.046), lymphovascular invasion (LVI) (HR, 2.605; 95% CI, 1.022-6.643; p=0.045), and surgical margin involvement (HR, 2.220; 95% CI, 1.110-4.438; p=0.024). Conclusion: Adjuvant treatment may be needed for improved prognosis in patients with pT3aN0 PCa after RALP with a large prostate size, LVI, or surgical margin involvement.