• Title/Summary/Keyword: PSA velocity

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Review of measurement of prostate specific antigen: in the aspect of insurance medicine (전립선암 선별을 위한 PSA 측정의 보험의학적 의미)

  • Park, Kwang-Il
    • The Journal of the Korean life insurance medical association
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    • v.29 no.1
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    • pp.16-21
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    • 2010
  • The measurement of prostate specific antigen (PSA) in screening for prostate cancer is recently performed as a routine check-up in clinical medicine and insurance medicine. Several factors may affect serum PSA levels. As prostate size increases with increasing age, the PSA concentration also rises. Increasing body mass index (BMI) is associated with a lower mean PSA concentration. Inhibitors of 5-alpha-reductase such as finasteride and dutasteride produce a 50 percent or greater decrease in serum PSA during the first three months of therapy, which persists as long as the drug is continued. Men who are regularly taking non-steroidal antiinflammatory drugs (NSAIDs) or acetaminophen have lower PSA levels. Emerging concepts regarding PSA testing that may help refine the interpretation of an elevated concentration include: PSA density, PSA velocity, and Free versus complexed or bound PSA. With many insurance companies, PSA level has become part of a standard battery of blood tests, along with HIV, cholesterol, liver enzymes, and other predictors of premature death. But, there is no clear proof of benefit, so we have to monitor the value of PSA test as a prostate cancer screening test in insurance medicine.

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Hydrogen Separation from Multi-Component Mixture Gases by Pressure Swing Adsorption Process (PSA 공정을 이용한 다성분 혼합가스의 수소 분리)

  • Yang, Se-Il;Ahn, Eui-Sub;Jang, Seong-Cheol;Choi, Do-Young;Choi, Dae-Ki
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.447-450
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    • 2006
  • Hydrogen separation from multi-component mixture gases by the four-bed PSA process was studied experimentally and theoretically using layered bed of activated carbon and zeolited 5A. Effects of the adsorption time, the linear velocity on the process performance were investigated. The adsorption time and linear velocity affected the purity and recovery of the product $H_2$ purity is increases according as the adsorption time and linear velocity decrease; however, $H_2$ recovery shows an opposite phenomena to the purity. PSA process simulation studied to find optimum operation condition. In the results, 50sec adsorption time, 3cm/s linear velocity might be optimal values to obtain more than 99.999% purity and 65% recovery hydrogen.

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Comparison between Use of PSA Kinetics and Bone Marrow Micrometastasis to Define Local or Systemic Relapse in Men with Biochemical Failure after Radical Prostatectomy for Prostate Cancer

  • Murray, Nigel P;Reyes, Eduardo;Fuentealba, Cynthia;Orellana, Nelson;Jacob, Omar
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8387-8390
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    • 2016
  • Background: Treatment of biochemical failure after radical prostatectomy for prostate cancer is largely empirically based. The use of PSA kinetics has been used as a guide to determine local or systemic treatment of biochemical failure. We here compared PSA kinetics with detection of bone marrow micrometastasis as methods to determine local or systemic relapse. Materials and Methods: A transversal study was conducted of men with biochemical failure, defined as a serum PSA >0.2ng/ml after radical prostatectomy. Consecutive patients having undergone radical prostatectomy and with biochemical failure were enrolled and clinical and pathological details were recorded. Bone marrow biopsies were obtained from the iliac crest and touch prints made, micrometastasis (mM) being detected using anti-PSA. The clinical parameters of total serum PSA, PSA velocity, PSA doubling time and time to biochemical failure, age, Gleason score and pathological stage were registered. Results: A total of 147 men, mean age $71.6{\pm}8.2years$, with a median time to biochemical failure of 5.5 years (IQR 1.0-6.3 years) participated in the study. Bone marrow samples were positive for micrometastasis in 98/147 (67%) of patients at the time of biochemical failure. The results of bone marrow micrometastasis detected by immunocytochemistry were not concordant with local relapse as defined by PSA velocity, time to biochemical failure or Gleason score. In men with a PSA doubling time of < six months or a total serum PSA of >2,5ng/ml at the time of biochemical failure the detection of bone marrow micrometastasis was significantly higher. Conclusions: The detection of bone marrow micrometastasis could be useful in defining systemic relapse, this minimally invasive procedure warranting further studies with a larger group of patients.

Hydrogen Purification by the Four-Bed Pressure Swing Adsorption Process from Steam Methane Reforming Off-Gas (4탑 PSA 공정의 의한 SMR off-gas로부터 수소 정제)

  • Yang, Se-Il;Park, Ju-Yong;Jang, Seong-Cheol;Kim, Sung-Hyun;Choi, Dae-Ki
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.10a
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    • pp.383-386
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    • 2008
  • The four-bed PSA process using a layered bed of activated carbon and zeolite 5A was studied to produce a high purity hydrogen product from SMR off-gas. At a desired product purity (99.999%+), the recovery increased with decreasing the linear velocity. However, the difference of the increasing of the recovery became smaller with the decreasing of the linear velocity and then was similar from below the linear velocity 3.9 cm/s. When the adsorbents, the feed gas composition, and the operating conditions are given, the residence time is mainly a function for design of the PSA bed size. The minimum residence time exists to obtain the maximum recovery at desired product purity.

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Biomarkers for Evaluation of Prostate Cancer Prognosis

  • Esfahani, Maryam;Ataei, Negar;Panjehpour, Mojtaba
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.2601-2611
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    • 2015
  • Prostate cancer, with a lifetime prevalence of one in six men, is the second cause of malignancy-related death and the most prevalent cancer in men in many countries. Nowadays, prostate cancer diagnosis is often based on the use of biomarkers, especially prostate-specific antigen (PSA) which can result in enhanced detection at earlier stage and decreasing in the number of metastatic patients. However, because of the low specificity of PSA, unnecessary biopsies and mistaken diagnoses frequently occur. Prostate cancer has various features so prognosis following diagnosis is greatly variable. There is a requirement for new prognostic biomarkers, particularly to differentiate between inactive and aggressive forms of disease, to improve clinical management of prostate cancer. Research continues into finding additional markers that may allow this goal to be attained. We here selected a group of candidate biomarkers including PSA, PSA velocity, percentage free PSA, $TGF{\beta}1$, AMACR, chromogranin A, IL-6, IGFBPs, PSCA, biomarkers related to cell cycle regulation, apoptosis, PTEN, androgen receptor, cellular adhesion and angiogenesis, and also prognostic biomarkers with Genomic tests for discussion. This provides an outline of biomarkers that are presently of prognostic interest in prostate cancer investigation.

PSA: A Photon Search Algorithm

  • Liu, Yongli;Li, Renjie
    • Journal of Information Processing Systems
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    • v.16 no.2
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    • pp.478-493
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    • 2020
  • We designed a new meta-heuristic algorithm named Photon Search Algorithm (PSA) in this paper, which is motivated by photon properties in the field of physics. The physical knowledge involved in this paper includes three main concepts: Principle of Constancy of Light Velocity, Uncertainty Principle and Pauli Exclusion Principle. Based on these physical knowledges, we developed mathematical formulations and models of the proposed algorithm. Moreover, in order to confirm the convergence capability of the algorithm proposed, we compared it with 7 unimodal benchmark functions and 23 multimodal benchmark functions. Experimental results indicate that PSA has better global convergence and higher searching efficiency. Although the performance of the algorithm in solving the optimal solution of certain functions is slightly inferior to that of the existing heuristic algorithm, it is better than the existing algorithm in solving most functions. On balance, PSA has relatively better convergence performance than the existing metaheuristic algorithms.

Prostate-specific Antigen Velocity (PSAV) and PSAV per Initial Volume (PSAVD) for Early Detection of Prostate Cancer in Chinese Men

  • Zheng, Xiang-Yi;Zhang, Peng;Xie, Li-Ping;You, Qi-Han;Cai, Bo-Sen;Qin, Jie
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5529-5533
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    • 2012
  • Aim: To investigate the utility of prostate-specific antigen velocity (PSAV) and PSAV per initial volume (PSAVD) for early detection of prostate cancer (PCa) in Chinese men. Methods: Between January 2009 and June 2012, a total of 193 men (aged 49-84 years, median 67 years) with at least 2 transrectal ultrasonography (TRUS) procedures and concurrent serum PSA measurements underwent prostate biopsy because of suspicion of PCa. The total group were classified into PCa and non-PCa groups, and the variables of the two groups were compared. Univariate and multivariate analyses were used to investigate which variables were predictove. The diagnostic values of PSAV, PSAVD and prostate-specific antigen density (PSAD) were compared using receiver operating characteristic (ROC) analysis. Results: Prostate cancer was diagnosed in 44 (22.8%) of the 193 men. There were significant differences between the groups in last and initial prostate volumes determined by TRUS, initial age, last serum PSA levels, PSAV, PSAD and PSAVD. After adjusting for confounding factors, the odds ratios of PCa across the quartile of PSAVD were 1, 4.06, 10.6, and 18.9 (P for trend <0.001).The area under the ROC curves (AUCs) of PSAD (0.779) and PSAVD (0.776) were similar and both significantly greater than that of PSA (AUC 0.667). PSAVD was a significantly better indicator of PCa than PSAV (AUC 0.736). There was no statistical significant difference between the AUC of PSAV and that of last serum PSA level. The sensitivity and specificity of PSAVD at a cutoff of 0.023ng in participants with last serum PSA levels of 4.0ng/mL-10.0ng was 73.7% and 70.7%, respectively. Conclusions: The results of this study demonstrated PSAVD may be a useful tool in PCa detection, especially in those undergoing previous TRUS examination.

Predictive Value of the Platelet-To-Lymphocyte Ratio in Diagnosis of Prostate Cancer

  • Yuksel, Ozgur Haki;Urkmez, Ahmet;Akan, Serkan;Yldirim, Caglar;Verit, Ayhan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6407-6412
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    • 2015
  • Purpose: To predict prostatic carcinoma using a logistic regression model on prebiopsy peripheral blood samples. Materials and Methods: Data of a total of 873 patients who consulted Urology Outpatient Clinics of Fatih Sultan Mehmet Training and Research Hospital between February 2008 and April 2014 scheduled for prostate biopsy were screened retrospectively. PSA levels, prostate volumes, prebiopsy whole blood cell counts, neutrophil and platelet counts, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), biopsy results and Gleason scores in patients who had established diagnosis of prostate cancer (PCa) were evaluated. Results: This study was performed on a total of 873 cases, with an age range 48-76 years, divided into three groups as for biopsy results. with diagnoses of benign prostatic hyperplasia (BPH) (n=304, 34.8 %), PCa (n=265, 30.4 %) and histological prostatitis (n=304; 34.8 %). Intra- and intergroup comparative evaluations were performed. White blood cell and neutrophil counts in the histological prostatitis group were significantly higher than those of the BPH and PCa groups (p=0.001; p=0.004; p<0.01). A statistically significant intergroup difference was found for PLR (p=0.041; p<0.05) but not lymphocyte count (p>0.05). According to pairwise comparisons, PLR were significantly higher in the PCa group relative to BPH group (p=0.018, p<0.05, respectively). Though not statistically significant, higher PLR in cases with PCa in comparison with the prostatitis group was remarkable (p=0.067, and p>0.05, respectively). Conclusions: Meta-analyses showed that in patients with PSA levels over 4 ng/ml, positive predictive value of PSA is only 25 percent. Therefore, novel markers which can both detect clinically significant prostate cancer, and also prevent unnecessary biopsies are needed. Relevant to this issue in addition to PSA density, velocity, and PCA3, various markers have been analyzed. In the present study, PLR were found to be the additional predictor of prostatic carcinoma.

Optimization of biomethane production by biogas upgrading process using response surface mothodolgy (반응표면분석을 이용한 바이오가스 고질화공정을 통한 바이오메탄)

  • Park, Seong-Bum;Sung, Hyun-Je;Shim, Dong-Min;Kim, Nack-Joo
    • Journal of Energy Engineering
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    • v.23 no.2
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    • pp.62-73
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    • 2014
  • This research was focused to apply response surface methodology for optimization of bio-methane production by biogas upgrading process. Methane concentration(Y1) and methane efficiency(Y2) on biogas upgrading process were mathematically described as being modeled by the use of the Box-Behnken design on response surface methodology. The results of ANOVA(analysis of variance) about models, the probability value of the methane concentration and methane recovery response surface model are 0.0001 and 0.0001, respectively and coefficient of determination($R^2$) are 0.9788 and 0.9710, respectively. The response surface model is proved of high reliability and suitability. The operation pressure had the greatest influence to methane concentration than other operation parameters and the PSA rotary valve velocity had the greatest influence to methane recovery than other operation parameters. Optimal condition of biogas upgrading process for production of $100Nm^3/hr$ bio-methane were operation pressure 8.0bar and outlet flow rate 31.55RPM, respectively. At that operation condition the methane concentration of bio-methane was 97.13% and methane recovery in biogas upgrading process was 75.89%.

Measurement of mass Transfer Coefficients for Adsorptive Bulk Gas Separation with Velocity Variations (기체속도가 변하는 벌크기체의 흡착공정에서 물질전달계수의 측정)

  • Min, Jun-Ho;Choi, Min-Ho;Suh, Sung-Sup
    • Applied Chemistry for Engineering
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    • v.10 no.2
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    • pp.310-318
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    • 1999
  • The concentration breakthrough curves were examined to predict mass transfer coefficients of nitrogen and oxygen in adsorption column for design data of PSA process. Experimental breakthrough curves for bulk gas flow were compared with theoretical simulation results. For quantitative analysis of the adsorption, coupled Langmuir isotherm was considered and LDF model was used to describe the mass transfer effect. In the experimental and theoretical results, it was found that mass transfer coefficient was not affected by flow rate but strongly affected by pressure. As a result of this tendency, mass transfer resistance in this system was proved to belong to the macropore diffusion controlling region and the mass transfer coefficients could be expressed by exponential functions of pressure change. The mass transfer coefficients for one component, nitrogen or oxygen, were successfully applied to breakthrough curves for bulk mixed gases. The experimental curves were reasonably in consistent with the theoretical curves and the error time was less than 5 percent.

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