• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.8
• /
• pp.571-578
• /
• 2013

In this study, the performance and microbial community of anaerobic digestion fed by food waste leachate at low organic loading rate were investigated with and without internal pH control. Experimental results show that similar biogas yield was achieved in both reactors regardless of increase in pH, the concentrations of free ammonia and volatile fatty acids in case of without internal pH controlled one. The results of a methanogenic community analysis by Polymerase Chain Reaction and Denaturing Gradient Gel Electrophoresis revealed that the apparent preponderance of Methanosarcina sp. could be one of reasons for the maintenance of reactor stability.

• Tuberculosis and Respiratory Diseases
• /
• v.40 no.5
• /
• pp.509-518
• /
• 1993

Background: By amplifying small amount of DNA, polymerase chain reaction (PCR) can be used for the detection of very small amount of microbial agent, and may be especially useful in certain cases which are difficult to be diagnosed microbiologically or serologically. Tuberculous pleurisy is a disease that can be diagnosed in only 70% of cases by conventional diagnostic tools, and PCR would be a very rapid, easy, and sensitive diagnostic method. Method: The specificity and sensitivity of PCR to detect Mycobacterium tuberculosis DNA were evaluated using various strains of Mycobacteria. To evaluate the diagnostic usefulness of PCR in tuberculous pleurisy, we used PCR to detect Mycobacterium tuberculosis DNA in pleural fluid. The amplification target was 123 base pair DNA, a part of IS6110 fragment, 10~16 copies of which are known to exist per genome. The diagnostic yield of PCR was compared with conventional methods, including pleural fluid adenosine deaminase (ADA) activity. Also, the significance of PCR in undiagnosed pleural effusion was evaluated prospectively with antituberculosis treatment. Results: 1) Using cultured Mycobacterium tuberculosis and other strains, PCR could detect upto 1 fg DNA and specific for only Mycobacterium tuberculosis and Mycobacterium bovis. 2) Using pleural effusions of proven tuberculosis cases, the sensitivity of PCR was 80.0% (16/20), and the specificity 95.0% (19/20). 3) Among 13 undiagnosed, but suspected tuberculous effusion, the positive rate was 60% in 10 improved cases after antituberculosis medications, and 0% in 3 cases of proven malignancy later. 4) Adenosine deaminase level of proven and clinically diagnosed tuberculous pleurisy patients was significantly higher than that of excluded patients, and correlated well with PCR results. Conclusion: We can conclude that PCR detection of Mycobacterium tuberculosis in pleural effusion has acceptable sensitivity and specificity, and could be an additional diagnostic tool for the diagnosis of tuberculous pleurisy.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.40 no.9
• /
• pp.827-832
• /
• 2012

In this paper, we will design the speed measurement board of LEO Satellite's reaction wheel which has two speed measuring methods as M-Method type and T-Method type. therefore we can use the advantage of two methods. and we will verify the availability of design on the on-board computer at the real LEO Satellite(KOMPSAT-3). In the reaction wheels satellite that can change the satellite's attitude is one of the leading drivers by the rotational inertia of the motor will perform attitude control. Reaction methods for detecting wheel rotation speed generated during a certain period T internal reaction wheel tacho pulse counting M-Method to detect wheel speed and wheel tacho pulses are generated by measuring the time between the detection rate can be divided into T-Method. M-method is simple to implement and benefit measurement time is constant, but slow fall in the velocity measurement accuracy is a disadvantage. In contrast, the time between tacho pulses to measure the T-Method to measure the precise speed at low speed and to measure the time delay is small, has the advantage. However, this method also in the actual implementation and the complexity of the operation at different speeds depending on the speed of operation has the disadvantage.

• Journal of Veterinary Clinics
• /
• v.30 no.5
• /
• pp.333-338
• /
• 2013

We investigated the prevalence of feline panleukopenia virus (FPV) in stray and household cats in different regions of Seoul, Republic of Korea. Blood samples were collected from a total of 200 cats (100 stray cats and 100 household cats) and examined by polymerase chain reaction (PCR). The overall prevalence of FPV was 2%. Among test-positive cats, 3% (3/100) were stray cats and 1% (1/100) was a household cat. The incidence of FPV was higher in juvenile cats (< 1 year, 1.5%) than in adult cats (> 1-year-old, 0.5%). The FPV-positive rates of healthy infected cats and sick cats were 1.9% (3/156) and 2.2% (1/44), respectively. We found the positive rate of vaccinated and unvaccinated cats to be 1.3% (1/77) and 2.4% (3/123), respectively. Unlike antibody tests, FPV antigen tests detected current infections in stray and household cats. Therefore, these tests can help in disease diagnosis and treatment. To our knowledge, our study is the first to survey the prevalence of FPV in different cat populations across Seoul. We found a high prevalence of FPV infection in stray and juvenile cats. Therefore, proper vaccination and surveillance are important to prevent FPV outbreaks.

• Korean Journal of Veterinary Service
• /
• v.45 no.1
• /
• pp.1-11
• /
• 2022

A novel porcine circovirus 4 (PCV4) was recently identified in Chinese and Korean pig herds. Although several conventional polymerase chain reaction (cPCR) and real-time PCR (qPCR) assays were used for PCV4 detection, more sensitive and reliable qPCR assay is needed that can simultaneously detect PCV4 and internal positive control (IPC) to avoid false-negative results. In the present study, a duplex qPCR (dqPCR) assay was developed using primers/probe sets targeting the PCV4 Cap gene and pig (glyceraldehyde-3-phosphate dehydrogenase) GAPDH gene as an IPC. The developed dqPCR assay was specifically detected PCV4 but not other PCVs and porcine pathogens, indicating that the newly designed primers/probe set is specific to the PCV4 Cap gene. Furthermore, GAPDH was stably amplified by the dqPCR in all tested viral and clinical samples containing pig cellular materials, indicating the high reliability of the dqPCR assay. The limit of detection of the assay 5 copies of the target PCV4 genes, but the sensitivity of the assay was higher than that of the previously described assays. The assay demonstrated high repeatability and reproducibility, with coefficients of intra-assay and inter-assay variation of less than 1.0%. Clinical evaluation using 102 diseased pig samples from 18 pig farms showed that PCV4 circulated in the Korean pig population. The detection rate of PCV4 obtained using the newly developed dqPCR was 26.5% (27/102), which was higher than that obtained using the previously described cPCR and TaqMan probe-based qPCR and similar to that obtained using the previously described SYBR Green-based qPCR. The dqPCR assay with IPC is highly specific, sensitive, and reliable for detecting PCV4 from clinical samples, and it will be useful for etiological diagnosis, epidemiological study, and control of the PCV4 infections.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.6
• /
• pp.3370-3375
• /
• 2014

MILD combustion is a highly favored technology for solving the trade-off relation between high thermal efficiency and low pollutant emissions. The system has low NOx concentration in high temperature combustion by recirculating the combustion gas, as well as improving the thermal efficiency by making the internal temperature in a combustion furnace uniform. This study describes the combustion characteristics of a conical MILD combustor in a laboratory-scale furnace by adjusting the equivalence ratio with the fuel gas flow rate while maintaining a constant air flow rate of the furnace. The MILD regime in the furnace is well characterized and the in-furnace temperature and emissions were predicted, respectively, for the range of equivalence of 0.69 - 0.83. For the range of equivalence ratios, this study confirmed the existence of a stable flame region that has an approximately $300^{\circ}C$ temperature difference between the maximum flame temperature region and main reaction region.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.5
• /
• pp.449-456
• /
• 2010

The HCCI engine is a prospective internal combustion engine with which high diesel-like efficiencies and very low NOx and particulate emissions can be achieved. However, several technical issues must be resolved before HCCI engines can be used for different applications. One of the issues concerning the HCCI engine is that the operating range of this engine is limited by the rapid pressure rise caused by the release of excessive heat. This heat release is because of the self-accelerated combustion reaction occurring in the engine and the resulting engine knock in the high-load region. The purpose of this study is to evaluate the role of thermal stratification and fuel stratification in reducing the pressure rise rate in an HCCI engine. The concentrations of NOx and CO in the exhaust gas are also evaluated to confirm combustion completeness and NOx emission. The computation is carried out with the help of a multizone code, by using the information on the detailed chemical kinetics and the effect of thermal and fuel stratification on the onset of ignition and rate of combustion. The engine is fueled with dimethyl ether (DME), which allows heat release to occur in two stages, as opposed to methane, which allows for heat release in a single stage.

• KSBB Journal
• /
• v.16 no.4
• /
• pp.398-402
• /
• 2001

Enzymatic hydrolysis of agar was carried out continuously to produce agarooligosaccharides by immobilized agarase in Packed-Bed Reactor. The reactor was constructed using a acryl tube with an internal diameter of 10 mm and a useful height of 140 mm. The Packed-Bed Reactor was 11 mL reactor volume as its length : diameter ratio was 14 : 1. The operation condition of reaction was performed with an 1 g/L agar concentration at 40$^{\circ}C$, 10 mM MOPS buffer(pH 7.0) and with the flow rate 3 mL∼48 mL/h at a dilution rate of 1.09∼5.45 h$\^$-1/. The hydrolysis products was identified DP6, DP4 and DP2 by HPLC. The conversion rate of agar was about 80% and amount of total agarooligosaccharide was 0.88 mg/mL at Packed-Bed Reactor.

• The Journal of Internal Korean Medicine
• /
• v.25 no.1
• /
• pp.28-45
• /
• 2004

Objectives : The main purpose of this study is to evaluate the effect of Injinchunggan-tang on $TNF-{\alpha}$ signal transmission system. Materials and Methods : We analyzed the following with quantitative RT-PCR method; the effect of Injinchunggan-tang on secretion of $TNF-\alpha$ mRNA/protein and stability, the effect on gene revelation that consists of signal transmission system (TRAIL, NIK, A20, TRADD, RAIDD, RIP TNFR-I, TNFR-II, TRAF1, TRAF2, FADD), the one on activation of p38, Erk1/2 MAPK and the rate of nuclear $NF-{\kappa}B/cytosolic\;NF-{\kappa}B$ in HepG2 cell. We also analyzed the inhibitory effect of Injinchunggan-tang on the apoptosis of HepG2 cell that $TNF-{\alpha}$ induces and the $NF-{\kappa}B$ restraint effected by transfection of $I{\kappa}B{\Delta}N$ through tryphan blue exclusion assay. Results : Injinchunggan-tang prohibits revelation of $TNF-{\alpha}$ mRNA in HepG2 cell and the creation of protein. However, it has no effect on the stability of $TNF-{\alpha}$ mRNA. While it did not have any effect on the generation of TRAIL, NIK, A20, TRADD, RAIDD and RIP genes, Injinchunggan-tang reduces the revelation of TNFR-I, TNFR-II, TRAF1, TRAF2 and FADD genes. It has been confirmed that Injinchunggan-tang restraints the revelation of $TNF-{\alpha}$ mRNA that is promoted by ethanol, acetaldehyde, lipopolysaccharide, in proportion to the treatment density and time. It activated $NF-{\kappa}B$ of HepG2 cell and promoted activation of $NF-{\kappa}B$ that is occurred by $TNF-{\alpha}$. It has been observed that the restraint effect against the $TNF-{\alpha}$ inducing apoptosis is lost when it is intercepted the function of $NF-{\kappa}B$ in HepG2 cell. Conclusion: It has been confirmed that Injinchunggan-tang has restraining effect against the revelation of $TNF-{\alpha}$ and mRNA that is constituent element of TNF-a signal transmission system. It also has been revealed that it restraints the activation of p38, Erk1/2 by $TNF-{\alpha}$. Through this prohibiting effect, it is inferred that it restraints signal transmission among various cells that are related to inflammation reaction. Meanwhile, Injinchunggan-tang protects liver cell from apoptosis that is caused by $TNF-{\alpha}$, by maintaining the activating function for $NF-{\kappa}B$.

• The Journal of Internal Korean Medicine
• /
• v.31 no.3
• /
• pp.650-666
• /
• 2010

Objectives : In this study, the author tried to investigate whether wood vinegar produced from Morus alba (MA) significantly affects the increase in airway epithelial mucosubstances and hyperplasia of tracheal goblet cells of rats, and in vitro airway mucin secretion and PMA- or EGF- or TNF-alpha-induced MUC5AC mucin production / gene expression from human airway epithelial cells. Materials and Methods : For the in vivo experiment, the author induced hypersecretion of airway mucus and goblet cell hyperplasia by exposure of rats to SO2 over 3 weeks. Effect of orally-administered MA over 2 weeks on increase in airway epithelial mucosubstances from tracheal goblet cells of rats and hyperplasia of goblet cells were assessed using histopathological analysis after staining the epithelial tissue with alcian blue. For the in vitro experiment, confluent RTSE cells were chased for 30 min in the presence of MA to assess the effect of MA on mucin secretion by enzyme-linked immunosorbent assay (ELISA). Also, effects of MA on PMA- or EGF- or TNF-alpha-induced MUC5AC mucin production and gene expression from human airway epithelial cells (NCI-H292) were investigated. Confluent NCI-H292 cells were pretreated for 30 min in the presence of MA and treated with PMA (10 ng/ml), EGF (25 ng/ml) or TNF-alpha (0.2 nm) for 24 hrs, to assess both effects of MA on PMA- or EGF- or TNF-alpha-induced MUC5AC mucin production by enzyme-linked immunosorbent assay (ELISA) and gene expression by reverse transcription-polymerase chain reaction (RT-PCR). Possible cytotoxicities of MA in vitro were assessed by examining LDH release from RTSE cells and the rate of survival and proliferation of NCI-H292 cells. In vivo liver and kidney toxicities of MA were evaluated by measuring serum GOT/GPT activities and serum BUN/creatinine concentrations of rats after administering MA orally. Results : 1. MA decreased the amount of intraepithelial mucosubstances of rats exposed to sulfur dioxide inhalationally. 2. MA decreased in vitro mucin secretion from cultured RTSE cells. 3. MA significantly inhibited PMA-, EGF-, and TNF-alpha-induced MUC5AC mucin productions and the expression levels of MUC5AC mRNA from NCI-H292 cells. 4. MA did not show either in vitro or in vivo hepatic or renal toxicities. Conclusion : The results from this study suggests that MA can regulate the secretion, production and gene expression of airway mucin observed in diverse respiratory diseases accompanied by mucus hypersecretion and does not show in vivo toxicity to liver and kidney functions after oral administration. Effects of MA should be further studied using animal experimental models that simulate the diverse pathophysiology of respiratory diseases via future research.