• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1610-1620
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• 2015

A major problem in conventional multilevel inverter is that an increase in power semiconductor switches causes an increase in cost and switching losses of the inverter. The multicarrier strategy adopted for the multilevel inverters has become more popular due to reduced cost, lower harmonic distortion, and higher voltage capability than the conventional switching strategy applied to inverters. Various topologies and modulation strategies have been reported for utility and drive applications. Level shifted based pulse width modulation techniques are proposed to investigate the performance of the multilevel inverter. The proposed work focuses on reducing the utilized switches so that the cost and the switching losses of the inverter do not go up and the consistent efficiency could be achieved. This paper presents the detailed analysis of these topologies. The analysis is based on the number of switches, DC sources, output level, maximum voltage, and the efficiency. As an illustration, single phase cascaded multilevel inverter topologies are simulated using MATLAB/SIMULINK and the experimental results demonstrate the viability of these inverters.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.493-498
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• 1996

A PC window-based computer code, CONPAS(CONtainment Performance Analysis System), has been developed to integrate the numerical, graphical and results-operation aspects of Level 2 probabilistic safety assessments (PSA) for nuclear power plants automatically. As a main logic for accident progression analysis, it employs a concept of the small containment phenomenological event tree(CPET) helpful to trace out visually individual accident progressions and of the large supporting event tree(LSET) for its detailed quantification. Compared with other existing computer codes for Level 2 PSA, the CONPAS code provides several advanced features: computational aspects including systematic uncertainty analysis, importance analysis, and sensitivity analysis, reporting aspects including tabling and graphic, and user-friend interface.

• Medical Lasers
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• v.10 no.1
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• pp.1-6
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• 2021

Intravital microscopy is a high-resolution imaging technique based on laser-scanning two-photon and confocal microscopy, which allows dynamic 3D cellular-level imaging of various biological processes in a living animal in vivo. This unique capability allows biomedical researchers to directly verify a hypothesis in a natural in vivo microenvironment at the cellular level in a physiological setting. During the last decade, intravital microscopy has become an indispensable technique in several fields of biomedical sciences such as molecular and cell biology, immunology, neuroscience, developmental, and tumor biology. The most distinct advantage of intravital microscopy is its capability to provide a longitudinal view of disease progression at the cellular-level with repeated intravital imaging of a single animal over time by saving the images after each session.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.269.2-270
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• 2002

Atherosclerosis is a main cause of cardiovascular diseases (that is angina. hypertension. cardiac infarction) and stroke. High level of low-density lipoproteins (LDL) in blood has been implicated as an important factor of atherosclerosis progression. Recently researches in endothelial cells unveiled the roles of Iysophosphatidylcholine (LPC). a constituent of oxidized LDL in atherosclerosis. (omitted)

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.4
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• pp.745-755
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• 2002

To examine the effects of Yunpyesan on the cell proliferation of A549 human lung carcinoma cell line, we performed various experiments such as dose-dependent effect of Yunpyesan on cell proliferation and viability, morphological changes, quantification of apoptotic cell death and alterations of apoptosis/cell cycle-regulatory gene products. Yunpyesan declined cell viability and proliferation in both a dose- and a time-dependent manner. The anti-proliferative effect by Yunpyesan treatment in A459 cells was associated with morphological changes such as membrane shrinking and cell rounding up. Yunpyesan Induced apoptotic cell death in a time-dependent manner, which was associated with degradation of poly-(ADP-ribose) polymerase (PARP), an apoptotic target protein, without alterations of the balance between Bcl-2 and Bax expressions. DNA flow cytometric histograms showed that population of G1 phase of the cell cycle was increased by Yunpyesan treatment in a dose-dependent manner. Western blot analysis revealed that cyclin D1 and A were reduced by Yunpyesan treatment, whereas cyclin dependent kinase (Cdk) inhibitor p27 was markedly increased in a time-dependent fashion. The level of tumor suppressor p53 proteins was also increased by Yunpyesan treatment and its increase might be linked to increase of Cdk inhibitor p27. In addition, Mdm2, negative regulator of p53, was down-regulated by Yunpyesan treatment. Since the expression of retinoblastome protein (pRB), a key regulator of G1/S progression, was reduced by Yunpyesan treatment, we supposed that phosphorylation of pRB might be also blocked. The present results indicated that Yunpyesan-induced inhibition of lung cancer cell proliferation is associated with the induction of apoptosis and the blockage of G1/S progression.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.3
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• pp.297-304
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• 2016

Klotho functions as a tumor suppressor predominantly expressed in renal tubular cells, the origin of clear cell renal cell carcinoma (ccRCC). Altered expression and/or activity of growth factor receptor have been implicated in ccRCC development. Although Klotho suppresses a tumor progression through growth factor receptor signaling including insulin-like growth factor-1 receptor (IGF-1R), the role of Klotho acting on IGF-1R in ccRCC and its clinical relevance remains obscure. Here, we show that Klotho is favorable prognostic factor for ccRCC and exerts tumor suppressive role for ccRCC through inhibiting IGF-1R signaling. Our data shows the following key findings. First, in tumor tissues, the level of Klotho and IGF-1R expression are low or high, respectively, compared to that of adjacent non-neoplastic parenchyma. Second, the Klotho expression is clearly low in higher grade of ccRCC and is closely associated with clinical outcomes in tumor progression. Third, Klotho suppresses IGF-1-stimulated cell proliferation and migration by inhibiting PI3K/Akt pathway. These results provide compelling evidence supporting that Klotho acting on IGF-1R signaling functions as tumor suppressor in ccRCC and suggest that Klotho is a potential carcinostatis substance for ccRCC.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3437-3441
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• 2012

Background: Oncogenic Bmi-1 (B-lymphoma Moloney murine leukemia virus insertion region-1) belongs to the Polycomb-group (PcG) family of proteins and plays an important role in the regulation of proliferation, senescence, cell cycle and apoptosis, chromosome stability, activation of gene transcription. Methods: To clarify the roles of Bmi-1 in tumourigenesis and progression of gastric carcinomas, it was examined by immunohistochemistry (IHC) and real-time RT-PCR in gastric carcinomas, dysplasia, intestinal metaplasia (IM), and gastritis with a comparison of its expression with clinicopathological parameters of carcinomas. Results: There was gradually increased Bmi-1 protein expression from gastritis, IM, dyplasia to carcinoma (p<0.001). Bmi-1 expression was positively linked to tumor size, depth of invasion, lymph node metastasis and worse prognosis of carcinomas (p<0.001), but not to age or sex of carcinoma patients (p>0.05). There was higher Bmi-1 protein expression in intestinal-type carcinomas than diffuse-type ones (p<0.001). At mRNA level, Bmi-1 protein expression was increased from gastritis, IM, dysplasia and carcinoma (p<0.001). Bmi-1 overexpression was observed in gastric carcinoma with larger diameter, deeper invasion, lymph node metastasis, and intestinal-type carcinoma (p<0.05). Conclusion: These findings indicate that up-regulated Bmi-1 expression is positively linked to pathogenesis, growth, invasion, metastasis and differentiation of gastric carcinomas. It was considered as a promising marker to indicate the aggressive behaviors and prognosis of gastric carcinomas.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3083-3088
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• 2012

We investigated the prognostic value of pituitary tumor transforming gene 1 (PTTG1) expression according to clinicopathological features among localized or locally advanced prostate cancer cases receiving hormone therapy. A retrospective study involved 64 patients receiving combined androgen blockade treatment was performed. PTTG1 expression was determined by immunohistochemical staining using initial needle biopsy specimens for diagnosis. Associations of PTTG1 with various clinicopathological features and disease-free survival were examined via uni- and multivariate analyses. No association between PTTG1 expression and clinical T stage, Gleason score, pretreatment PSA levels, risk groups was found (p =0.682, 0.184, 0.487, 0.571, respectively). Univariate analysis revealed that increased PTTG1 expression, T3 stage and high risk group were associated with increased risk of disease progression (p =0.000, 0.042, and 0.001), and high PSA level had a tendency to predict disease progression (p =0.056). Cox hazard ratio analysis showed that PTTG1 low expression (p =0.002), PTTG1 high expression (p =0.000) and high risk group (p =0.0147) were significantly related to decreased disease-free survival. In conclusion, PTTG1 expression determined by immunohistochemical staining in needle biopsy specimens for diagnosis is a negative prognostic factor for progression in localized or locally advanced prostate cancer receiving hormone therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.10
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• pp.4317-4321
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• 2015

Background: Prognostic biomarkers in breast cancer are routinely investigated in the primary tumors to guide further management. However, it is proposed that the expression may change during the disease progression, and may result in a different immune profile in the metastatic nodes. This work aimed to investigate the expression of breast prognostic biomarkers in primary tumors and in its axillary nodal metastasis, to estimate the possible discordant expression. Materials and Methods: 60 paired primary and axillary nodal metastasis samples were collected from patients with primary breast cancer with positive nodal deposits, diagnosed at the Maadi Military Hospital, Cairo, Egypt, during the year 2013. ER, PR and HER2 expression was assessed by immunohistochemistry in all samples Results: 48.3% of the included cases showed concordant results for both ER and PR receptors between the primary tumor and its nodal metastasis while 51.7% showed discordant results and the discordance level was statistically significant. On the other hand, 70% of the cases showed concordant Her2 results between the primary tumors and the nodal deposits, 30% showed discordant results and the difference was significant. Conclusions: The study indicated that the discordance in ER and PR receptor expression between the primary breast tumor and their nodal metastasis may be significant. The possible switch in the biomarker status during the disease progression is worth noting and may change the patient therapeutic planning. So, whether the treatment selection should be based on biomarkers in the lymph node is a topic for further studies and future clinical trials.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.2
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• pp.129-134
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• 2014

It has been suggested that transition metal ions such as iron can produce an oxidative injuries to nigrostriatal dopaminergic neurons, like Parkinson's disease (PD) and subsequent compensative increase of tetrahydrobiopterin ($BH_4$) during the disease progression induces the aggravation of dopaminergic neurodegeneration in striatum. It had been established that the direct administration of $BH_4$ into neuron would induce the neuronal toxicity in vitro. To elucidate a role of $BH_4$ in pathogenesis in the PD in vivo, we assessed the changes of dopamine (DA) and $BH_4$ at striatum in unilateral intranigral iron infused PD rat model. The ipsistriatal DA and $BH_4$ levels were significantly increased at 0.5 to 1 d and were continually depleting during 2 to 7 d after intranigral iron infusion. The turnover rate of $BH_4$ was higher than that of DA in early phase. However, the expression level of GTP-cyclohydrolase I mRNA in striatum was steadily increased after iron administration. These results suggest that the accumulation of intranigral iron leads to generation of oxidative stress which damage to dopaminergic neurons and causes increased release of $BH_4$ in the dopaminergic neuron. The degenerating dopaminergic neurons decrease the synthesis and release of both $BH_4$ and DA in vivo that are relevance to the progression of PD. Based on these data, we propose that the increase of $BH_4$ can deteriorate the disease progression in early phase of PD, and the inhibition of $BH_4$ increase could be a strategy for PD treatment.