• Journal of the Korean Wood Science and Technology
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• v.33 no.5 s.133
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• pp.29-37
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• 2005

A previous study verified that the SIRT (simultaneous iterative reconstruction technique) method is more efficient than the back-projection method as a CT algorithm for wood. However, it was expected that the determination of the initial model function of the SIRT method would influence the quality of CT image. Therefore, in this study, we intended to develop a technique that could be used to determine an adequate initial model function. For this purpose, we proposed several techniques, and for each technique we examined the effects of the initial model function on the average errors and the CT image at each iteration. Through this study, it was shown that the average error was decreased and the image quality was improved using the proposed techniques. This tendency was most pronounced when the back-projection method was used to determine the initial model function. From the results of this study, we drew the following conclusions: 1) The initial model function of the SIRT method should be determined with careful attention, and 2) the back-projection method efficiently determines the initial model function of the SIRT method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.3
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• pp.119-126
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• 2005

Electrical resistance tomography(ERT) maps resistivity values of the soil subsurface and characterizes buried objects. The characterization includes location, size and resistivity of buried objects. In this paper, Gauss-Newton, truncated least squares(TLS) and simultaneous iterative reconstruction technique(SIRT) methods are presented for the solution of the ERT image reconstruction. Computer simulations show that the spatial resolution of the reconstructed images by the TLS approach is improved as compared to those obtained by the Gauss-Newton and SIRT method.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.10015-10020
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• 2014

Background: Fentanyl is used as an analgesic to treat pain in a variety of patients with cancer and recently it has become considered to also act as an antitumor agent. The study present was designed to investigate the effects of fentanyl on colorectal cancer cell growth and plausible mechanisms. Materials and Methods: The human colorectal carcinoma cell line HCT116 was subcutaneously injected into nude mice. The viability of HCT116 was tested by MTT assay, and apoptosis by flow cytometry and caspase-3 activity. The expression of Sirt1 and NF-${\kappa}B$ were evaluated by Western blotting and the levels of Sirt1 and NF-${\kappa}B$ by fluorescence method. SiRNA was used to silence and Ad-Sirt1 to overexpress Sirt1. Results: Our data showed that fentanyl could inhibit tumor growth, with increased expression of Sirt1 and down-regulation of Ac-p65 in tumors. Compared with control cells without treatment, HCT116 cells that were incubated with fentanyl had a higher apoptotic rate. Moreover, fentanyl could increase expression and activity of Sirt1 and inhibitor expression and activity of NF-${\kappa}B$, which might be mechanisms of fentanyl action. Conclusions: Fentanyl increased colorectal carcinoma cell apoptosis by inhibition of NF-${\kappa}B$ activation in a Sirt1-dependent manner.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3460-3467
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• 2013

The In this paper, we have made numerical experiments to compare 2D image reconstruction algorithm of earth model by electrical resistance tomograpy (ERT). Gauss-Newton, simultaneous iterative reconstruction technieque (SIRT) and truncated least squares (TLS) approaches for Wenner and Schlumberger electrode arrays are presented for the solution of the ERT image reconstruction. Computer simulations show that the Gauss-Newton and TLS approach in ERT are proper for 2D image reconstruction of an earth model.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.155-160
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• 2016

Breast cancer (BC) is the second most common cancer in the world and by far the most frequent cancer among women, with an estimated 1.67 million new cancer cases diagnosed in 2012 (25% of all cancers). Polygene expression analysis is used to predict the prognosis and determine the most appropriate treatment regimen. The objective of this study was to examine the gene expression profiles of SIRT3, HRAS, LSP1, SCUBE2 and AP2A2 in Iranian women with BC.A total of 136 patients including healthy controls were categorized into three groups based on the relapse of the disease. Expression of desired genes in formalin-fixed, paraffin embedded tissues collected from all groups of participants was analyzed via the RT PCR method. RNA extraction and cDNA synthesis were performed then real-time quantitative PCR was carried out. Gene expression analysis revealed that the expression of SIRT3 was equal among patient and control groups. LSP1 was down regulated in all patient groups relative to controls but reduced expression in the metastatic group relative to the non-metastatic one was not significant. HRAS was significantly overexpressed in total and metastatic tumor samples versus normal but not in non-metastatic cases. SCUBE2 expression showed significant over-expression in both overall tumor samples and the non-metastatic group as compared to normal tissues. Gene expression level of AP2A2 in all groups was not detectable. Our data are compatible with a tumor suppressor role of LSP1 related to potential prognostic factor for tumor recurrence and outcome. This study for the first time assayed the prognostic value and changes in the expression of SIRT3, LSP1, HRAS, SCUBE2 and AP2A2 genes in women with breast cancer in the Iranian population and findings confirmed potential biomarker and prognostic capability of these genes. Such expression profiling data can critically improve prognosis and treatment decisions in cancer patients.

• Geophysics and Geophysical Exploration
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• v.14 no.2
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• pp.140-145
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• 2011

In order to analyze the influence of the noise on a cross-well traveltime tomography to detect a small scale low velocity body in a homogeneous medium, the first arrival travel times were computed one a tunnel model by a finite-difference ray tracing scheme. Three different types and four different intensity levels of white noises were added to the computed first arrival travel times, and velocity tomograms were constructed using an iterative inversion method (SIRT). Tomograms with the noise intensity up to 10% of the maximum traveltime delay in the tunnel model, showed the exact location of the tunnel. However, the velocity shown at the tunnel location was not close to air velocity but only slightly less than the velocity of the background medium. The additive random noise showed significantly less degree of influence on the resulting tomogram than the source- and receiver consistent noise.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.577-584
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• 2000

Seismic refraction survey was peformed for 10 lines along NE-SW and NW-SE directions above Nampoong gallery at Makyo-ri, Dogye, Samcheok, Kangwon-do. 48 geophones were laid in line with the interval of 1m, and a 5Kg hammer was used as a source at 5 points for each line. Data processing was done using reciprocal time method, GRM, and traveltime tomography which utilizes wavefront expansion method for forward process and SIRT for inversion. The result shows that the first layer has its lower boundary between 3.49m and 8.88m. The P-wave velocity of the first and the second layer were estimated as 270 360m/s and 1550 1940m/s respectively. When the boundary of the first and second layer is smooth enough and the velocity difference is large enough, GRM has little advantage over reciprocal time method. The result of reciprocal method and traveltime tomography shows consistency. The northeast part of the boundary has syncline structure, which is similar to the topography above. This implies that the collapse of the cavities of Nampoong gallery result in the subsidence of the ground surface. The subsidence is in progress across the Youngdong railroad, therefore a proper reinforcement work is required.

• Journal of the Korean Wood Science and Technology
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• v.33 no.5 s.133
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• pp.21-28
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• 2005

For the proper conservation of wooden cultural properties, non-destructive evaluation (NDE) method, which can be used to quantitatively evaluate the internal state of wood members, are needed. In this study, an ultrasonic CT system composed of portable devices was attempted, and the capacity of this system was verified by reconstructing the CT images for two phantoms and two artificially defected specimens. Results from this study showed that the sizes of detected defects were enlarged and the shapes were distorted on the CT images. Also, the positions were shifted somewhat toward the surface of specimen, which is regarded due to the anisotropic property of wood. Compared to the filtered back-projection method, SIRT (simultaneous iterative reconstruction technique) method was determined to be more efficient as the algorithm of image reconstruction for wood. A new ultrasonic CT system is thought to be used as a NDE method for wood. However wood characteristics and wave diffraction within wood made it difficult to accurately evaluate the size, shape and position of defects. To improve the quality of CT image of wood, more research including the relationship between wood and ultrasound is needed, and wood properties should be taken into consideration on the image reconstruction algorithm.

• 한국지구물리탐사학회:학술대회논문집
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• 2007.06a
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• pp.317-322
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• 2007

Seismic exploration is divided by reflection and refraction method greatly, and reflection method can analyze complicated underground structure in the basis high resolution image, and refraction method can grasp the velocity structure of underground accurately. This thesis confirmed application of mixed exploration techniques using advantages of reflection and refraction. Reflection data processing applied conventional technique, and inversion of refraction data applied travel time tomographic technique that using SIRT method. Also, could establish initial information in model variable and improved the result of inversion by restricting model parameter value and dimension of area. Confirmed efficient fact in sequence and velocity structure grasping by utilizing accurate initial velocity model made out on the basis of marine reflection data, and mixed exploration technique using reflection and refraction have propriety that can trust in field application.

• KSBB Journal
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• v.30 no.4
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• pp.166-174
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• 2015

In this study, an efficient whole cell-based biotransformation for the production of liquiritigenin was developed using Laetiporus sulphureus CS0218 as biocatalyst and aqueous extracts of Glycyrrhiza uralensis as co-substrate, respectively. In order to determine the efficacy of this method, the optimal bioconversion conditions including mycelial growth, three important enzyme activities (${\beta}$-glucosidase, ${\alpha}$-rhamnosidase and ${\beta}$-xylosidase), and apparent viscosity of culture broth were monitored. After optimization, aqueous extracts of G. uralensis were added to the culture medium to directly produce algycone liquiritigenin. By applying this strategy, 67.5% of liquiritin was converted to liquiritigenin at pH 3.0 after 9 days of incubation and finally liquiritigenin was purified from the reaction mixture. And then, their biological activities including anti-oxidant and superoxide dismutase were observed. In fact, purified liquiritigenin was capable of bi-directional functions (i.e., either up-regulation or down-regulation of SIRT1 which is associated with aging). The results indicate that this strategy would be beneficial to produce biologically active liquiritigenin and could be used in pharmaceutical, cosmetic and food applications.