• Progress in Medical Physics
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• v.14 no.4
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• pp.211-217
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• 2003

The Principal component analysis (PCA) is a well-known data analysis method that is useful in linear feature extraction and data compression. The PCA is a linear transformation that applies an orthogonal rotation to the original data, so as to maximize the retained variance. PCA is a classical technique for obtaining an optimal overall mapping of linearly dependent patterns of correlation between variables (e.g. neurons). PCA provides, in the mean-squared error sense, an optimal linear mapping of the signals which are spread across a group of variables. These signals are concentrated into the first few components, while the noise, i.e. variance which is uncorrelated across variables, is sequestered in the remaining components. PCA has been used extensively to resolve temporal patterns in neurophysiological recordings. Because the retinal signal is stochastic process, PCA can be used to identify the retinal spikes. With excised rabbit eye, retina was isolated. A piece of retina was attached with the ganglion cell side to the surface of the microelectrode array (MEA). The MEA consisted of glass plate with 60 substrate integrated and insulated golden connection lanes terminating in an 8${\times}$8 array (spacing 200 $\mu$m, electrode diameter 30 $\mu$m) in the center of the plate. The MEA 60 system was used for the recording of retinal ganglion cell activity. The action potentials of each channel were sorted by off­line analysis tool. Spikes were detected with a threshold criterion and sorted according to their principal component composition. The first (PC1) and second principal component values (PC2) were calculated using all the waveforms of the each channel and all n time points in the waveform, where several clusters could be separated clearly in two dimension. We verified that PCA-based waveform detection was effective as an initial approach for spike sorting method.

• Tuberculosis and Respiratory Diseases
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• v.63 no.3
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• pp.251-260
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• 2007

Purpose: An imbalance of cell proliferation and cell apoptosis is an important mechanism in carcinogenesis. Capase 3, survivin and p53 have been identified as important members of the apoptotic related proteins. This study evaluated the proliferating cell nuclear antigen(PCNA), apoptosis, apoptotic related protein such as capase 3, survivin and p53 using urethane-induced mouse lung carcinogenesis, which provides reproducible steps from hyperplasia to adenocarcinoma. Methods: Urethane was administered to the ICR mice through an intra-peritoneal injection, The mice were sacrificed at 5, 15, and 25 weeks after urethane intervention. The sequential morphological changes and immunohistochemical expression of PCNA, apoptosis, capase 3, survivin, and p53 were examined during mouse lung carcinogenesis. Results: During carcinogenesis, the sequential histological changes were observed from hyperplasia of type II pneumocytes, to anadenoma, and ultimately to an overt adenocarcinoma. The PCNA Labeling index (LI) was 9.6% in hyperplasia, 23.2% in adenoma, and 55.7% in adenocarcinoma, respectively. The apoptotic LI was 0.24% in hyperplasia, 1.25% in adenoma, and 5.27% in adenocarcinoma. A good correlation was observed between the PCNA LI and apoptotic LI. The expression of caspase 3 was remarkable- i.e., 46.7% in adenocarcinoma, in contrast to 15% in hyperplasia and 16% in adenoma. Survivin was detected weakly in the alveolar hyperplasia and showed an increasing expressional pattern in adenoma and adenocarcinoma. p53 expression was detected only in the adenocarcinoma lesions with an expression rate of 13.3%. The level of caspase 3 expression correlated with the increase in the apoptotic index. The positive expression of caspase 3 was associated with an increased apoptotic index. Conclusions: These results suggest that the PCNA LI and apoptotic LI might be useful markers for evaluating the risk of a malignant transformation. In addition, caspase, survivin and p53 might play a role in the early and late steges of urethane-induced mouse lung carcinogenesis.

• IMMUNE NETWORK
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• v.1 no.2
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• pp.143-150
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• 2001

Background : Many investigators have found transforming growth factor-${\beta}1$ (TGF-${\beta}1$) to be elevated in tumors. Changes in responsiveness to TGF-${\beta}1$ have been linked to malignant transformation, tumor progression and tumor regression. Many malignant cell lines of epithelial or hematopoietic origin are refractory to the antiproliferative effects of TGF-${\beta}1$. However, a little is known about the association of TGF-${\beta}1$ with progression of malignant tumor. Methods : In this study, we measured the plasma level of TGF-${\beta}1$ in various cancer patients and evaluated the utility of plasma TGF-${\beta}1$ as a possible tumor marker. Plasma TGF-${\beta}1$ levels were measured using enzyme-linked immunosorbent assay in cancer patients and normal controls. Carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) as tumor marker were compared with TGF-${\beta}1$ in the aspects of sensitivity and specificity. Results : The mean of plasma TGF-${\beta}1$ levels was $1.219{\pm}0.834ng/ml$ in normal controls, $5.491{\pm}3.598ng/ml$ in breast cancer, $12.670{\pm}10.386ng/ml$ in lung cancer, $5.747{\pm}3.228ng/ml$ in hepatocellular carcinoma and $10.854{\pm}7.996ng/ml$ in cervical cancer. In comparison with CEA and AFP, TGF-${\beta}1$ is more sensitive. Conclusion : We conclude that the high levels of TGF-${\beta}1$ are common in the plasma of cancer patients. These results suggest that the plasma TGF-${\beta}1$ level can be a potent tumor marker in various cancer patients.

• Journal of the Korean Chemical Society
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• v.63 no.6
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• pp.453-458
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• 2019

Synthesis of ZnCo₂O₃ oxide is performed by sol-gel method via nitrate-citrate route. Powder X-ray diffraction (XRD) study shows monoclinic unit cell having lattice parameters: a = 5.721(1) Å, b = 8.073(2) Å, c = 5.670(1) Å, β = 93.221(8)°, space group P_2/m and Z = 4. Average crystallite sizes determined by Scherrer equation are the range ~14-32 nm, whereas SEM micrographs show nano-micro meter size particles formed in ZnCo₂O₃. Endothermic peak at ~798 K in the Differential scanning calorimetric (DSC) trace without weight loss could be due to structural transformation and the endothermic peak ~1143 K with weight loss is due to reversible loss of O₂ in air atmosphere. Energy Dispersive X-ray (EDX) analysis profile shows the presence of elements Zn, Co and O which indicates the purity of the sample. Magnetic measurements in the range of +12 kOe to -12 kOe at 10 K, 77 K, 120 K and at 300 K by PPMS-II Physical Property Measurement System (PPMS) shows hysteresis loops having very low values of the coercivity and retentivity which indicates the weakly ferromagnetic nature of the oxide. Observed X-band EPR isotropic lineshapes at 300 K and 77 K show positive g-shift at g_iso ~2.230 and g_iso ~2.217, respectively which is in agreement with the presence of paramagnetic site Co²⁺(3d⁷) in the oxide. DC conductivity value of 2.875 ×10^-8 S/cm indicates very weakly semiconducting nature of ZnCo₂O₃ at 300 K. DRS absorption bands ~357 nm, ~572 nm, ~619 nm and ~654 nm are due to the d-d transitions ⁴T_1g(⁴F)→²E_g(²G), ⁴T_1g(⁴F)→⁴T_1g(⁴P), ⁴T_1g(⁴F)→⁴A_2g(⁴F), ⁴T_1g(⁴F)→⁴T_2g(⁴F), respectively in octahedral ligand field around Co²⁺ ions. Direct band gap energy, E_g~ 1.5 eV in the oxide is obtained by extrapolating the linear part of the Tauc plot to the energy axis indicates fairly strong semiconducting nature of ZnCo₂O₃.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.6
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• pp.1163-1170
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• 2016

A hardware implementation of ultra-lightweight block cipher algorithm PRESENT which was specified as a standard for lightweight cryptography ISO/IEC 29192-2 is described. The PRESENT crypto-processor supports two key lengths of 80 and 128 bits, as well as four modes of operation including ECB, CBC, OFB, and CTR. The PRESENT crypto-processor has on-the-fly key scheduler with master key register, and it can process consecutive blocks of plaintext/ciphertext without reloading master key. In order to achieve a lightweight implementation, the key scheduler was optimized to share circuits for key lengths of 80 bits and 128 bits. The round block was designed with a data-path of 64 bits, so that one round transformation for encryption/decryption is processed in a clock cycle. The PRESENT crypto-processor was verified using Virtex5 FPGA device. The crypto-processor that was synthesized using a $0.18{\mu}m$ CMOS cell library has 8,100 gate equivalents(GE), and the estimated throughput is about 908 Mbps with a maximum operating clock frequency of 454 MHz.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.20-26
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• 2015

This study aimed to establish a rapid system for discriminating the cultivation origins and cultivars of dry persimmons, using metabolite fingerprinting by Fourier transform infrared (FT-IR) spectroscopy combined with multivariate analysis. Whole-cell extracts from the sepals of four Korean cultivars and two different Chinese dry persimmons were subjected to FT-IR spectroscopy. Principle component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) of the FT-IR spectral data successfully discriminated six dry persimmons into two groups depending on their cultivation origins. Principal component loading values showed that the 1750-1420 and $1190-950cm^{-1}$ regions of the FT-IR spectra were significantly important for the discrimination of cultivation origins. The accuracy of prediction of the cultivation origins and cultivars by PLS regression was 100% (p<0.01) and 85.9% (p<0.05), respectively. These results clearly show that metabolic fingerprinting of FT-IR spectra can be applied for rapid discrimination of the cultivation origins and cultivars of commercial dry persimmons.

• KSBB Journal
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• v.22 no.1
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• pp.16-21
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• 2007

Although Energy demands of modern society increase rapidly, current energy would be exhausted shortly. Therefore development of bio-ethanol production process from cellulose containing materials was extremly demanded. Therefore development of highly functional cellulase is requisite for this purpose. In this study cellobio-hydrolase (CBH1) gene from Trichorderma reesei was used to increase cellulase activity by directed evolution and highly functional cellobio-hydrolase was obtained and characterized.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.324-330
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• 2016

To determine whether FT-IR spectral analysis based on multivariate analysis for whole cell extracts can be used to discriminate between artichoke (Cynara cardunculus var. scolymus L.) plants at the metabolic level, leaves of ten artichoke plants were subjected to Fourier transform infrared(FT-IR) spectroscopy. FT-IR spectral data from leaves were analyzed by principal component analysis (PCA), partial least square discriminant analysis (PLS-DA) and hierarchical clustering analysis (HCA). FT-IR spectra confirmed typical spectral differences between the frequency regions of 1,700-1,500, 1,500-1,300 and $1,100-950cm^{-1}$, respectively. These spectral regions reflect the quantitative and qualitative variations of amide I, II from amino acids and proteins ($1,700-1,500cm^{-1}$), phosphodiester groups from nucleic acid and phospholipid ($1,500-1,300cm^{-1}$) and carbohydrate compounds ($1,100-950cm^{-1}$). PCA revealed separate clusters that corresponded to their species relationship. Thus, PCA could be used to distinguish between artichoke species with different metabolite contents. PLS-DA showed similar species classification of artichoke. Furthermore these metabolic discrimination systems could be used for the rapid selection and classification of useful artichoke cultivars.

• Journal of the Korean Wood Science and Technology
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• v.29 no.1
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• pp.60-67
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• 2001

The microscopic characteristics and cellulose structures of primary and secondary tissues in Pinus densiflora S. et Z. were examined. Cells of primary tissue in cross section showed an irregular arrangement and round shape. Fiber lengths were 200 to $250{\mu}m$ in primary tissue, and 1,500 to $1,600{\mu}m$ in secondary tissue. Cell diameters in primary tissue were larger than those in secondary tissue; 40 to $50{\mu}m$ in former and 10 to $20{\mu}m$ in latter. Crystallite width and d-spacing of (200) in both tissues did not show any significant differences. However, crystallinity indices by Segal's method showed significant differences as 23% in primary tissue and 35% in secondary tissue. In the orientation of cellulose microfibril, primary tissues had a random pattern, whereas, secondary tissues presented an oriented pattern with 20 to 30 degree. The cellulose crystalline of primary tissue was easily transformed into cellulose II by mercerization, but that of secondary tissue hardly transformed. It is considered that the difference of crystal transformation in both tissues could be caused by the difference of lignification.

• Journal of Korean Neurosurgical Society
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• v.30 no.4
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• pp.443-450
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• 2001

Objective : The cyclin-dependent kinase inhibitor $p27^{kip1}$ protein is a negative regulator of the cell cycle, and its degradation is required for entry into the S phase. Loss of $p27^{kip1}$ expression has been reported to be associated with aggressive behavior in a variety of tumors of epithelial and lymphoid origin. However, its association with various astrocytic tumors has not been clearly demonstrated. We studied to investigate the relationship of $p27^{kip1}$ expression with the biological behavior of astrocytic tumors in addition to study on the role of $p27^{kip1}$ in the tumorigenesis of these tumors. Patients and Methods : From 1990 to 1998, a total of 29 astrocytic tumor of all grades obtained by operative resection were included for evaluation. We studied the expression of $p27^{kip1}$ protein immunohistochemical assay in astrocytic tumors and compared the findings with the clinicopathologic parameters. Immunohistochemical staining was performed on formalin-fixed paraffin-embedded sections by the avidin-biotin-peroxidase complex method. According to WHO classification, all cases were divided into astrocytomas(4 cases), anaplastic astrocytomas(9 cases), and glioblastomas(16 cases) by 3 pathologists. Clinical information was obtained from medical records, and others such as location and size of tumors from imaging studies. Results : Mean $p27^{kip1}$ protein labeling indexes(LI, mean${\pm}$standard deviation) of astrocytomas, anaplastic astrocytomas, and glioblastomas were $80.6{\pm}9.1$, $63.6{\pm}21.0$, and $28.9{\pm}18.7$, respectively, and were inversely correlated with grade of glial tumors(p<0.0001). Mean $p27^{kip1}$ protein LI in the recurrent group was lower than that in the nonrecurrent group, but there was no significant difference statistically(p=0.464). Additionally, $p27^{kip1}$ protein expression did not show any significant relationship to other prognostic factors such as age(p=0.1643), tumor size(p=0.8), or location(p=0.8). Conclusion : These results suggested that reduced expression of $p27^{kip1}$ protein may play a important role in the malignant transformation process of astrocytic tumor cells.