• Journal of Korea Water Resources Association
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• v.34 no.6
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• pp.659-672
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• 2001

Generally, design flood for a hydraulic structure is estimated using statistical analysis of runoff data. However, due to the lack of runoff data, it is difficult that the statistical method is applied for estimation of design flood. In this case, the synthetic unit hydrograph method is used generally and the models such as NYMO method, Snyder method, SCS method, and HYMO method have been widely used in Korea. In this study, these methods and KICT method, which is developed in year 2000, are compared and analyzed in 10 study areas. Firstly, peak flow and peak time of representative unit hydrograph and synthetic unit hydrograph in study area are compared, and secondly, the shape of unit hydrograph is compared using a root mean square error(RMSE). In Nakayasu method developed in Japan, synthetic unit hydrograph is very different from peak flow, peak time, and the shape of representative unit hydrograph, and KICT method(2000) is superior to others. Also, KICT method(2000) is superior to others in the aspects of using hydrologic and topographical data. Therefore, Nakayasu method is not a proper in hydrological practice. Moreover, it is considered that KICT model is a better method for the estimation of design flood. However, if other model, i.e. SCS method, Nakayasu method, and HYMO method, is used, parameters or regression equations must be adjusted by analysis of real data in Korea.

• Geophysics and Geophysical Exploration
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• v.9 no.1
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• pp.60-66
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• 2006

Three differing sandstones, two synthetic and one field sample, have been tested ultrasonically under a range of confining pressures and pore pressures representative of in-situ reservoir pressures. These sandstones include: a synthetic sandstone with calcite intergranular cement produced using the CSIRO Calcite In-situ Precipitation Process (CIPS); a synthetic sandstone with silica intergranular cement; and a core sample from the Otway Basin Waarre Formation, Boggy Creek 1 well, from the target lithology for a trial $CO_2$ pilot project. Initial testing was carried on the cores at "room-dried" conditions, with confining pressures up to 65 MPa in steps of 5 MPa. All cores were then flooded with $CO_2$, initially in the gas phase at 6 MPa, $22^{\circ}C$, then with liquid-phase $CO_2$ at a temperature of $22^{\circ}C$ and pressures from 7 MPa to 17 MPa in steps of 5 MPa. Confining pressures varied from 10 MPa to 65 MPa. Ultrasonic waveforms for both P- and S-waves were recorded at each effective pressure increment. Velocity versus effective pressure responses were calculated from the experimental data for both P- and S-waves. Attenuations $(1/Q_p)$ were calculated from the waveform data using spectral ratio methods. Theoretical calculations of velocity as a function of effective pressure for each sandstone were made using the $CO_2$ pressure-density and $CO_2$ bulk modulus-pressure phase diagrams and Gassmann effective medium theory. Flooding the cores with gaseous phase $CO_2$ produced negligible change in velocity-effective stress relationships compared to the dry state (air saturated). Flooding with liquid-phase $CO_2$ at various pore pressures lowered velocities by approximately 8% on average compared to the air-saturated state. Attenuations increased with liquid-phase $CO_2$ flooding compared to the air-saturated case. Experimental data agreed with the Gassmann calculations at high effective pressures. The "critical" effective pressure, at which agreement with theory occurred, varied with sandstone type. Discrepancies are thought to be due to differing micro-crack populations in the microstructure of each sandstone type. The agreement with theory at high effective pressures is significant and gives some confidence in predicting seismic behaviour under field conditions when $CO_2$ is injected.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.69-74
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• 1996

Background: The diagnosis of pulmonary embolism (PE) based on clinical findings is often elusive and therefore requires confirmative diagnostic method. Pulmonary angiography, though the gold standard for the diagnosis of pulmonary embolism, is an invasive method and requires trained personnel and special equipment. Lung V/Q scan, on the other hand, is a noninvasive method but the diagnostic specificity and sensitivity arc not satisfactory in case that the results are either intermediate or low probability scan. Plasma D-dimer is generated when a thrombus is fibrinolysed by plasmin and is known to be increased in various thrombotic disorders. The aim of this study was to investigate the value of the determination of plasma D-dimer level in the diagnosis of pulmonary embolism. Methods: Pulmonary angiography was performed in 17 patients who were clinically suspected to have pulmonary embolism. 9 patients(PE, $56{\pm}13.4$ yrs, M:F=8:1) were diagnosed to have pulmonary embolism by pulmonary angiography. The control group were the 8 patients with negative pulmonary angiography and 13 orthopedic patients with no evidence of pulmonary embolism on scintigraphic and impedance plethysmographic studies(n=21) (non-PE, $54.5{\pm}11.1$ yrs, M:F=11:10). Plasma D-dimer was measured by latex agglutination method in study subjects and the results were analyzed according to the presence or absence of pulmonary embolism. Results: 1) The increased level of plasma D-dimer was more frequently observed in the patients with pulmonary embolism than in the controls(>0.5 mg/L, 8 in PE, 10 in non-PE; <0.5 mg/L, 1 in PE, 11 in non-PE, p=0.049). 2) The diagnostic value of plasma D-dimer level higher than 0.5 mg/L were as follows: sensitivity 88.9%(8/9), specificity 52.4%(11/21), positive predictive value 44.4%(8/18), and negative predictive value 91.7%(11/12). Conclusion: Plasma D-dimer determination showed high sensitivity and negative predictive value in the diagnosis of pulmonary embolism and is therefore thought to be useful in excluding the possibility of pulmonary embolism.

• Journal of Oral Medicine and Pain
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• v.33 no.1
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• pp.15-26
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• 2008

Purpose : To investigate the actual conditions of diagnosis and treatment of oral medicine inpatient with systemic disease. Methods : A total of 110 subjects, inpatient due to systemic disease for diagnosis and treatment of oral disease was requested to answer the medical history and dental treatment record. Results : Systemic disease is composed of Non-insulin-dependent diabetes mellitus 26%, Cerebral infarction 25.2%, Intracerebral hemorrhage, Polyarthrosis, Coxarthrosis 4.7%, Nerve root and plexus disorders, Hypertensive heart and renal diseases, Ankylosing spondylitis 2.4%. Chief complain of oral disease is composed of toothache 28.6%, routine check 23%, tooth mobility 8.7%, hypersensitivity 7.1%, periodontal bleeding 6.4%. Oral disease is composed of Gingivitis and periodontal diseases 28.9%, Dental caries 17.1%, Diseases of pulp and periapical tissues 15.1%, Diseases of salivary glands 10.5%, Other diseases of hard tissues of teeth 8.6%, Within Normal Limit 5.3%. Treatment of oral disease is composed of periodontal treatment 17.95%, rejection of treatment 16.67%, medication for halitosis & dry mouth 13.46%, extraction 12.18%, prosthetic treatment 8.97%. Chief complain in oral medicine is composed of oral soft tissue problem 6.4%, craniomandibular disorders 5.6%, halitosis 4%, total 16%. Conclusion : These findings indicate that inpatient due to the systemic disease is significantly correlated to the oral disease. The patients of oral disease interrelationship between inpatient and outpatient of systemic disease should be validated by future research.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.87-92
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• 2009

Purpose : Many gene polymorphisms are associated with coronary artery abnormalities in Kawasaki disease. Catechol-O- methyltransferase (COMT) plays an important role in the metabolism of catecholamines, catechol estrogen, and catechol drugs. Polymorphisms of the COMT gene are reported to be associated with myocardial infarction and coronary artery abnormalities. The aim of this study was to evaluate the relationship between COMT gene polymorphisms and coronary artery abnormalities in Kawasaki disease patients. Methods : One hundred and one Korean children with Kawasaki disease and 306 healthy Korean control subjects were enrolled in this study. The polymorphisms of the COMT gene were analyzed by direct sequencing. Results : There were no differences in the genotype and allelic frequency of the rs4680 and rs769224 polymorphic sites between Kawasaki disease and control subjects. Further, no significant difference was found in the rs4680 polymorphism between patients with coronary artery abnormalities and patients without coronary artery abnormalities (codominant P=0.32, dominant P=0.74, recessive P=0.13). However, the distribution of the rs769224 polymorphism was significantly different between patients with coronary artery abnormalities and patients without coronary artery abnormalities (codominant P= 0.0077, dominant P=0.0021, recessive P=0.16). Conclusion : Our results indicate that the polymorphisms of the rs769224 gene might be related to the development of coronary artery abnormalities in Kawasaki disease.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6627-6632
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• 2015

Background: We conducted a study exploring the clinical safety and efficacy of decitabine in patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS), combined with a complex karyotype. Materials and Methods: From April 2009 to September 2013, a total of 35 patients with AML/MDS combined with a complex karyotype diagnosed in the First Affiliated Hospital of Soochow University were included for retrospective analysis. All patients were treated with decitabine alone ($20mg/m^2$ daily for 5 days) or combination AAG chemotherapy (Acla 20mg qod*4d, Ara-C $10mg/m^2$ q12h*7d, G-CSF $300{\mu}g$ qd, the dose of G-CSF adjusted to the amount in blood routinely). Results: In 35 patients, 15 exhibited a complete response (CR), and 6 a partial response (PR), the overall response rate (CR+PR) being 60% (21 of 35). Median disease-free survival was 18 months and overall survival was 14 months. In the 15 MDS patients with a complex karyotype, the CR rate was 53.3% (8 of 15); in 20 AML patients with complex karyotype, the overall response rate was 65% (13 of 20). The response rate of decitabine alone (22 cases) was 56.5% (13 of 22), while in the combination chemotherapy group (13 cases), the effective rate was 61.5% (8 of 13)(P>0.05). There are 15 patients with chromosome 7 aberration, after treatment with decitabine, 7 CR, 3 PR, overall response rate was 66.7% (10 of 15). Of 18 patients with 3 to 5 kinds of chromosomal abnormalities, 66.7% demonstrated a response; of 17 with more than 5 chromosomal abnormalities, 52.9% had a response. In the total of 35 patients, with one course (23 patients) and ${\geq}$two courses (12 patients), the overall response rate was 40.9% and 92.3% (P<0.05). Grade III to IV hematological toxicity was observed in 27 cases (75%). Grade III to IV infections were clinically documented in 7 (20%). Grades I to II non-hematological toxicity were infections (18 patients), haematuria (2 patients), and bleeding (3 patients). With follow-up until September 2013, 7 patients were surviving, 18 had died and 10 were lost to follow-up. In the 6 cases who underwent allogeneic hematopoietic stem cell transplantation (HSCT) all were still relapse-free survivors. Conclusions: Decitabine alone or combination with AAG can improve outcome of AML/MDS with a complex karyotype, there being no significant difference decitabine in inducing remission rates in patients with different karyotype. Increasing the number of courses can improve efficiency. This approach with fewer treatment side effects in patients with a better tolerance should be employed in order to create an improved subsequent chance for HSCT.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7633-7640
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• 2015

Background: Human papillomavirus (HPV) is the most common sexually transmitted infection worldwide and it is responsible for most cases of cervical uterine cancer. Although HPV infections of the cervix do not always progress to cancer, 90% of cervical cancer cases have been found to be associated with high risk HPV (HR-HPV) infection. HPV DNA testing is widely used, along with Papanicolaou (Pap) testing, to screen for cervical abnormalities. However, there are no data on the prevalence of genotype-specific HPV infections assessed by measuring HPV E6/E7 mRNA in women representative of the Chinese population across a broad age range. Materials and Methods: In the present study, we compared the results with the CervicGen HPV RT-qDx assay, which detects 16 HR-HPV genotypes (Alpha-9: HPV 16, 31, 33, 35, 52, and 58; Alpha-7: HPV 18, 39, 45, 51, 59, and 68; and Alpha-5, 6: HPV 53, 56, 66, and 69), and the REBA HPV-ID assay, which detects 32 HPV genotypes based on the reverse blot hybridization assay (REBA) for the detection of oncogenic HPV infection according to cytological diagnosis. We also investigated the prevalence and genotype distribution of HPV infection with a total of 324 liquid-based cytology samples collected in western Shandong province, East China. Results: The overall HPV prevalences determined by HPV DNA and HPV E6/E7 mRNA assays in this study were 79.9% (259/324) and 55.6% (180/324), respectively. Although the positivity of HPV E6/E7 mRNA expression was significantly lower than HPV DNA positivity, the HPV E6/E7 mRNA assay showed greater specificity than the HPV DNA assay (88.6% vs. 48.1%) in normal cytology samples. The prevalence of Alpha-9 (HPV 16, 31, 33, 35, 52, and 58) HPV infection among these women accounted for up to 80.3% and 76.1% of the high-grade lesions detected in the HPV mRNA and DNA tests, respectively. The HR-HPV genotype distribution, based on HPV DNA and E6/E7 mRNA expression by age group in patients with cytologically confirmed lesions, was highest in women aged 40 to 49 years (35.9% for cytologically confirmed cases, Pearson correlation r value=0.993, p<0.001) for high-grade lesions. Among the oncogenic HR-HPV genotypes for all age groups, there was little difference in the distribution of HPV genotypes between the HPV DNA (HPV -16, 53, 18, 58, and 33) and HPV E6/E7 mRNA (HPV -16, 53, 33, 58, and 18) assays. HPV 16 was the most common HPV genotype among women with high-grade lesions. Conclusions: Our results suggest that the HPV E6/E7 mRNA assay can be a sensitive and specific tool for the screening and investigation of cervical cancer. Furthermore, it may provide useful information regarding the necessity for early cervical cancer screenings and the development of additional effective HPV vaccines, such as one for HPV 53 and 58. Additionally, gaining knowledge of HPV distribution may also inform us about ecological changes in HPV after the vaccination.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7849-7855
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• 2014

Purpose: To investigate the effect of deacetylase inhibitory trichostatin A (TSA) on anti HepG2 liver carcinoma cells and explore the underlying mechanisms. Materials and Methods: HepG2 cells exposed to different concentrations of TSA for 24, 48, or 72h were examined for cell growth inhibition using CCK8, changes in cell cycle distribution with flow cytometry, cell apoptosis with annexin V-FTIC/PI double staining, and cell morphology changes under an inverted microscope. Expression of ${\beta}$-catenin, HDAC1, HDAC3, H3K9, CyclinD1 and Bax proteins was tested by Western blotting. Gene expression for ${\beta}$-catenin, HDAC1and HDAC3 was tested by q-PCR. ${\beta}$-catenin and H3K9 proteins were also tested by immunofluorescence. Activity of Renilla luciferase (pTCF/LEF-luc) was assessed using the Luciferase Reporter Assay system reagent. The activity of total HDACs was detected with a HDACs colorimetric kit. Results: Exposure to TSA caused significant dose-and time-dependent inhibition of HepG2 cell proliferation (p<0.05) and resulted in increased cell percentages in G0/G1 and G2/M phases and decrease in the S phase. The apoptotic index in the control group was $6.22{\pm}0.25%$, which increased to $7.17{\pm}0.20%$ and $18.1{\pm}0.42%$ in the treatment group. Exposure to 250 and 500nmol/L TSA also caused cell morphology changes with numerous floating cells. Expression of ${\beta}$-catenin, H3K9and Bax proteins was significantly increased, expression levels of CyclinD1, HDAC1, HDAC3 were decreased. Expression of ${\beta}$-catenin at the genetic level was significantly increased, with no significant difference in HDAC1and HDAC3 genes. In the cytoplasm, expression of ${\beta}$-catenin fluorescence protein was not obvious changed and in the nucleus, small amounts of green fluorescence were observed. H3K9 fluorescence protein were increased. Expression levels of the transcription factor TCF werealso increased in HepG2 cells following induction by TSA, whikle the activity of total HDACs was decreased. Conclusions: TSA inhibits HDAC activity, promotes histone acetylation, and activates Wnt/${\beta}$-catenin signaling to inhibit proliferation of HepG2 cell, arrest cell cycling and induce apoptosis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6721-6726
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• 2013

Background: Changes in DNA methylation patterns are believed to be early events in hepatocarcinogenesis. A better understanding of methylation states and how they correlate with disease progression will aid in finding potential strategies for early detection of HCC. The aim of our study was to analyze the methylation frequency of tumor suppressor genes, P14, P15, and P73, and a mismatch repair gene (O6MGMT) in HCV related chronic liver disease and HCC to identify candidate epigenetic biomarkers for HCC prediction. Materials and Methods: 516 Egyptian patients with HCV-related liver disease were recruited from Kasr Alaini multidisciplinary HCC clinic from April 2010 to January 2012. Subjects were divided into 4 different clinically defined groups - HCC group (n=208), liver cirrhosis group (n=108), chronic hepatitis C group (n=100), and control group (n=100) - to analyze the methylation status of the target genes in patient plasma using EpiTect Methyl qPCR Array technology. Methylation was considered to be hypermethylated if >10% and/or intermediately methylated if >60%. Results: In our series, a significant difference in the hypermethylation status of all studied genes was noted within the different stages of chronic liver disease and ultimately HCC. Hypermethylation of the P14 gene was detected in 100/208 (48.1%), 52/108 (48.1%), 16/100 (16%) and 8/100 (8%) among HCC, liver cirrhosis, chronic hepatitis and control groups, respectively, with a statistically significant difference between the studied groups (p-value 0.008). We also detected P15 hypermethylation in 92/208 (44.2%), 36/108 (33.3%), 20/100 (20%) and 4/100 (4%), respectively (p-value 0.006). In addition, hypermethylation of P73 was detected in 136/208 (65.4%), 72/108 (66.7%), 32/100 (32%) and 4/100 (4%) (p-value <0.001). Also, we detected O6MGMT hypermethylation in 84/208 (40.4%), 60/108 (55.3%), 20/100 (20%) and 4/100 (4%), respectively (p value <0.001. Conclusions: The epigenetic changes observed in this study indicate that HCC tumors exhibit specific DNA methylation signatures with potential clinical applications in diagnosis and prognosis. In addition, methylation frequency could be used to monitor whether a patient with chronic hepatitis C is likely to progress to liver cirrhosis or even HCC. We can conclude that methylation processes are not just early events in hepatocarcinogenesis but accumulate with progression to cancer.

• Management & Information Systems Review
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• v.23
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• pp.41-74
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• 2007

In Korea, corporate merger activities were activated since 1980, and nowadays(particuarly since 1986) the changes in domestic and international economic circumstances have made corporate managers have strong interests in merger. Korea and America have different business environments and it is easily conceivable that there exists many differences in motives, methods, and effects of mergers between the two countries. According to recent studies on takeover bids in America, takeover bids have information effects, tax implications, and co-insurance effects, and the form of payment(cash versus securities), the relative size of target and bidder, the leverage effect, Tobin's q, number of bidders(single versus multiple bidder), the time period (before 1968, 1968-1980, 1981 and later), and the target firm reaction (hostile versus friendly) are important determinants of the magnitude of takeover gains and their distribution between targets and bidders at the announcement of takeover bids. This study examines the theory of takeover bids, the status quo and problems of merger in Korea, and then investigates how the announcement of merger are reflected in common stock returns of bidding firms, finally explores empirically the factors influencing abnormal returns of bidding firms' stock price. The hypotheses of this study are as follows ; Shareholders of bidding firms benefit from mergers. And common stock returns of bidding firms at the announcement of takeover bids, shows significant differences according to the condition of the ratio of target size relative to bidding firm, whether the target being a member of the conglomerate to which bidding firm belongs, whether the target being a listed company, the time period(before 1986, 1986, and later), the number of bidding firm's stock in exchange for a stock of the target, whether the merger being a horizontal and vertical merger or a conglomerate merger, and the ratios of debt to equity capital of target and bidding firm. The data analyzed in this study were drawn from public announcements of proposals to acquire a target firm by means of merger. The sample contains all bidding firms which were listed in the stock market and also engaged in successful mergers in the period 1980 through 1992 for which there are daily stock returns. A merger bid was considered successful if it resulted in a completed merger and the target firm disappeared as a separate entity. The final sample contains 113 acquiring firms. The research hypotheses examined in this study are tested by applying an event-type methodology similar to that described in Dodd and Warner. The ordinary-least-squares coefficients of the market-model regression were estimated over the period t=-135 to t=-16 relative to the date of the proposal's initial announcement, t=0. Daily abnormal common stock returns were calculated for each firm i over the interval t=-15 to t=+15. A daily average abnormal return(AR) for each day t was computed. Average cumulative abnormal returns($CART_{T_1,T_2}$) were also derived by summing the $AR_t's$ over various intervals. The expected values of $AR_t$ and $CART_{T_1,T_2}$ are zero in the absence of abnormal performance. The test statistics of $AR_t$ and $CAR_{T_1,T_2}$ are based on the average standardized abnormal return($ASAR_t$) and the average standardized cumulative abnormal return ($ASCAR_{T_1,T_2}$), respectively. Assuming that the individual abnormal returns are normal and independent across t and across securities, the statistics $Z_t$ and $Z_{T_1,T_2}$ which follow a unit-normal distribution(Dodd and Warner), are used to test the hypotheses that the average standardized abnormal returns and the average cumulative standardized abnormal returns equal zero.