• Journal of the Korean Geotechnical Society
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• v.34 no.10
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• pp.29-38
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• 2018

The slime formed at the bottom of the borehole causes the excessive displacement and loss of the bearing capacity of the drilled shaft. In this study, the slime meter is developed for the evaluation of the slime based on the electrical properties of the fluid and the slime in the borehole. The slime meter is composed of a probe instrumented with electrodes and temperature sensor and a frame with rotary encoder, so that the slime meter profiles the electrical resistivity compensated with temperature effect along the depth. For the application of the slime meter, three field tests are conducted at a borehole with a diameter of 3 m and a depth of 46.9 m with different testing time and locations. For all the tests, the experimental results show that while electrical resistivities are constantly measured in the fluid, the electrical resistivities sharply increase at the surface of the slime. Therefore, the slime thicknesses are estimated by the differences in the depths of the slime surface and the ground excavation. The experimental results obtained at the same testing point with different testing time show that the estimated thickness of the slime increases by the elapsed time. Also, the estimated slime at the side of the borehole is thicker than that at the center of the borehole. As the slime meter estimates the slime in the borehole by measuring the electrical resistivity with simple equipment, the slime meter may be effectively used for the evaluation of the slime formed at the bottom of the borehole.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.172-180
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• 2007

Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.302-311
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• 2004

Comamonas testosteroni (formerly Pseudomonas sp.) NCIMB 10643 can grow on biphenyl and alkylbenzenes $(C_2-C_7)$ via 3-substituted catechols. Thus, to identify the genes encoding the degradation, transposon-mutagenesis was carried out using pAG408, a promoter-probe mini-transposon with a green fluorescent protein (GFP), as a reporter. A mutant, NT-1, which was unable to grow on alkylbenzenes and biphenyl, accumulated catechols and exhibited an enhanced expression of GFP upon exposure to these substrates, indicating that the gfp had been inserted in a gene encoding a broad substrate range catechol 2,3-dioxygenase. The genes (2,826 bp) flanking the gfp cloned from an SphI-digested fragment contained three complete open reading frames that were designated bphCDorfl. The deduced amino acid sequences of bphCDorfl were identical to 2,3-dihydroxybiphenyl 1,2-dioxygenase (BphC), 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase (BphD), and OrfI, respectively, that are all involved in the degradation of biphenyl/4-chlorobiphenyl (bph) by Ralstonia oxalatica A5. The deduced amino acid sequence of the orfl revealed a similarity to those of outer membrane proteins belonging to the OmpW family. The introduction of the bphCDorfl genes enabled the NT-l mutant to grow on aromatic hydrocarbons. In addition, PCR analysis indicated that the DNA sequence and gene organization of the bph operon were closely related to those in the bph operon from Tn4371 identified in strain A5. Furthermore, strain A5 was also able to grow on a similar set of alkylbenzenes as strain NCIMB 10643, demonstrating that, among the identified aromatic hydrocarbon degradation pathways, the bph degradation pathway related to Tn4371 was the most versatile in catabolizing a variety of aromatic hydrocarbons of mono- and bicyclic benzenes.

• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.93-98
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• 2002

A VP6 fragments was subcloned with BamHI in the binary pMBP-1 vector under Califlower Mosaic Virus (CaMV) 355 promoter and neomycin phosphotransferase II (npt II) gene. The recombinant binary vector was mobilized into Agrobacterium-tumefaciens LBA4404 by the freeze-thaw method and potato (Solanum tubensum L. cv Desiree) was transformed by modified leaf-disc cocultivation. Shoots were induced on MS medium with 0.01 mg/L NAA, 0.1 mg/L GA$_3$, 2.0 mg/L Zeatin, 100.0 mg/L kanamycin, 500.0 mg/L carbenicillin. In order to identify the copy number of VP6 into potato plant, total genomic DNA was isolated from transgenic potato and analysed by Southern blotting. Genomic DNA and total mRNA analysis demonstrated the incorporation of the foreign gene into the potato genome, as well as their transcription.

• Journal of the Korean Geotechnical Society
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• v.23 no.7
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• pp.5-16
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• 2007

The monitoring and investigation of underwater landslide help to understand its mechanism, increase the usefuless of design and construction and reduce the losses. This paper presents three high resolution geophysical techniques electrical resisitance, ultrasonic wave reflection imaging, and shear wave tomography conducted to determine the lab-scaled submerged landslide. Electrical resistance profiles of a soil mass obtained by an electrical resistance probe provide detailed information to assess the spatial distribution of the soil mass with milimetric resolution. An ultrasonic wave image obtained by recording the reflections from interfaces of different impedance materials permits detecting layers and landslide with submilimetric resolution. The pixel based image of immersed landslides is created by the inversion of the boundary information achieved from the traveling time of shear waves. The experimental results show that the ultrasonic wave imaging and the electrical resistance can provide complementary information; and their association with S-wave tomography image can produce a 3-D view of the underwater landslide. This study suggests that geophysical techniques may be effective tools for the detection of the underwater landslides and spatial distribution offshore.

• Korean Journal of Poultry Science
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• v.33 no.2
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• pp.97-103
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• 2006

Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Even though telomere length and telomerase activity have been studied extensively, very little is known to analyze the telomere dynamics in chicken cells. This study was carried out to analyze the telomere distribution and telomerase activity of Korean Native Chicken cells along with aging. The cells were collected from brain, heart, liver, kidney and germinal tissues during physiological stages. Telomere distribution was analyzed by Quantitative-Fluorescence in situ Hybridization (Q-FISH) techniques using the chicken telomeric DNA probe. Telomerase activity was performed by Telomeric Repeat Amplification Protocol (TRAP) assay. In results, the telomeres of chicken were found at the ends of all chromosomes with the interstitial telomeres on chromosomes 1, 2 and 3. The amount of telomeres on chicken cells was decreased along with aging in most tissues. Furthermore, the telomere quantity was significantly different among tissues. The relative amount of telomeres in proliferous cells such as testis cells had much more than those of liver, brain, heart, blood and kidney cells. The telomerase activity was down-regulated in cells of brain, heart and liver tissues. Whereas gonadal cells showed a constitutive activity of telomerase during all stage of life. In conclusions, the telomere quantity and telomerase activity in chicken are closely relate to cell proliferation and tissue specificity during developmental stages and aging. There is also closely correlated between the amounts of telomeric DNA and telomerase activity in chicken tissues.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.75-79
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• 2019

Purpose Cadmium-zinc-telluride (CZT) camera with semiconductor detector is capable of dynamic myocardial perfusion SPECT for coronary flow reserve (CFR). Image acquisition with the heart positioned within 2 cm in the center of the quality field of view (QFOV) is recommended because the CZT detector based on focused multi-pinhole collimators and is stationary gantry without rotation. The aim of this study was to investigate the optimal method for measuring position of the heart within the center of the QFOV when performing dynamic myocardial perfusion SPECT with the Discovery NM 530c camera. Materials and Methods From June to September 2018, 45 patients were subject to dynamic myocardial perfusion SPECT with D530c. For accurate heart positioning, the patient's heart was scanned with a mobile ultrasound and marked at the top of the probe where the mitral valve (MV) was visible in the parasternal long-axis view (PLAX). And, the marked point on the patient's body matched with the reference point indicated CZT detector in dynamic stress. The heart was positioned to be in the center of the QFOV in rest. The coordinates of dynamic stress and rest were compared statistically. Results The coordinates of the dynamic stress using mobile ultrasound and those taken of the rest were recorded for comparative analysis with regard to the position of the couch and analyzed. There were no statistically significant differences in the coordinates of Table in & out, Table up & down, and Detector in & out (P > 0.05). The difference in distance between the 2 groups was measured at $0.25{\pm}1.00$, $0.24{\pm}0.96$ and $0.25{\pm}0.82cm$ respectively, with no difference greater than 2 cm in all categories. Conclusion The position of the heart taken using mobile ultrasound did not differ significantly from that of the center of the QFOV. Therefore, The use of mobile ultrasound in dynamic stress will help to select the correct position of the heart, which will be effective in clinical diagnosis by minimizing the image quality improvement and the patient's exposure to radiation.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.129-129
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• 2016

Graphene, as a single layer of $sp^2$-bonded carbon atoms packed into a 2D honeycomb crystal lattice, has attracted much attention due to its outstanding properties. In order to synthesize high quality graphene, transition metals, such as nickel and copper, have been widely employed as catalysts, which needs transfer to desired substrates for various applications. However, the transfer steps are not only complicated but also inevitably induce defects, impurities, wrinkles, and cracks of graphene. Furthermore, the direct synthesis of graphene on dielectric surfaces has still been a premature field for practical applications. Therefore, cost effective and concise methods for transfer-free graphene are essentially required for commercialization. Here, we report a facile transfer-free graphene synthesis method through nickel and carbon co-deposited layer. In order to fabricate 100 nm thick NiC layer on the top of $SiO_2/Si$ substrates, DC reactive magnetron sputtering was performed at a gas pressure of 2 mTorr with various Ar : $CH_4$ gas flow ratio and the 200 W DC input power was applied to a Ni target at room temperature. Then, the sample was annealed under 200 sccm Ar flow and pressure of 1 Torr at $1000^{\circ}C$ for 4 min employing a rapid thermal annealing (RTA) equipment. During the RTA process, the carbon atoms diffused through the NiC layer and deposited on both sides of the NiC layer to form graphene upon cooling. The remained NiC layer was removed by using a 0.5 M $FeCl_3$ aqueous solution, and graphene was then directly obtained on $SiO_2/Si$ without any transfer process. In order to confirm the quality of resulted graphene layer, Raman spectroscopy was implemented. Raman mapping revealed that the resulted graphene was at high quality with low degree of $sp^3$-type structural defects. Additionally, sheet resistance and transmittance of the produced graphene were analyzed by a four-point probe method and UV-vis spectroscopy, respectively. This facile non-transfer process would consequently facilitate the future graphene research and industrial applications.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.19-25
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• 2006

With the use of Agrobacterium and gene-gun, cold regulated gene (BN115) has been injected in Chrysanthemum leaf disc and transgenic plants have been produced successfully on the selection media containing phytohormone. To determine the presence of the transferred cold regulated gene (BN115) in the transgenic Chrysanthemum, PCR-amplification indicated the presence of that gene. Real-Time PCR for confirmation of the putative transgenic plants was established. The copy number of cold regulated gene (BN115) is extrapolated on the basis of a standard curve. Serial dilutions of known number of gene copies were in triplicates. In this diagram, PCR cycles are plotted against the fluorescence intensity. The cycle at which the fluorescence reaches a threshold cycle is inversely proportional to the starting amount of target DNA.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.7-12
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• 1999

By SDS-polyacrylamide gel elcctrophoresis (SDS-PAGE) and immunoblot analysis that a protein with 66,000 daltons in size was recognized by P. aeruginosa anti-exotoxin A from P. sp. PY002. The yields of exotoxin A in P. sp. PY002 culture were influenced by the concentration of iron in the culture media. Increasing of the exotoxin A production and siderophore production was made slight increasing in the MKB medium. On the other hand, to clone the gene encoding the exoloxin A genomic library of P. sp. PY002 was constructed in pBluescript SK(+). From this library a exotoxin A homologous gene was isolated by immunological hybridization method using P. aemginosa anti-exoloxin A as a probe. Two putative clones were isolated and designated pETA23 and pETA42. Thc restriction analysis ol pETA42 demonstrated that thc 1760 bp insert contained one NcoI, PvuII, SstI, Kpnl and EcoRI site and three SmaI and HaeD sites.