• Molecules and Cells
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• v.42 no.6
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• pp.460-469
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• 2019

Bacterial ${\alpha}-type$ carbonic anhydrase (${\alpha}-CA$) is a zinc metalloenzyme that catalyzes the reversible and extremely rapid interconversion of carbon dioxide to bicarbonate. In this study, we report the first crystal structure of a hyperthermostable ${\alpha}-CA$ from Persephonella marina EX-H1 (pmCA) in the absence and presence of competitive inhibitor, acetazolamide. The structure reveals a compactly folded pmCA homodimer in which each monomer consists of a 10-stranded ${\beta}-sheet$ in the center. The catalytic zinc ion is coordinated by three highly conserved histidine residues with an exchangeable fourth ligand (a water molecule, a bicarbonate anion, or the sulfonamide group of acetazolamide). Together with an intramolecular disulfide bond, extensive interfacial networks of hydrogen bonds, ionic and hydrophobic interactions stabilize the dimeric structure and are likely responsible for the high thermal stability. We also identified novel binding sites for calcium ions at the crystallographic interface, which serve as molecular glue linking negatively charged and otherwise repulsive surfaces. Furthermore, this large negatively charged patch appears to further increase the thermostability at alkaline pH range via favorable charge-charge interactions between pmCA and solvent molecules. These findings may assist development of novel ${\alpha}-CAs$ with improved thermal and/or alkaline stability for applications such as $CO_2$ capture and sequestration.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.3
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• pp.99-108
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• 2023

Background: Efficient gene editing technology is needed for successful knock-in. Homologous recombination (HR) is a major double-strand break repair pathway that can be utilized for accurately inserting foreign genes into the genome. HR occurs during the S/G2 phase, and the DNA mismatch repair (MMR) pathway is inextricably linked to HR to maintain HR fidelity. This study was conducted to investigate the effect of inhibiting MMR-related genes using CdCl₂, an MMR-related gene inhibitor, on HR efficiency in HC11 cells. Methods: The mRNA and protein expression levels of MMR-related genes (Msh2, Msh3, Msh6, Mlh1, Pms2), the HR-related gene Rad51, and the NHEJ-related gene DNA Ligase IV were assessed in HC11 cells treated with 10 μM of CdCl₂ for 48 hours. In addition, HC11 cells were transfected with a CRISPR/sgRNA expression vector and a knock-in vector targeting Exon3 of the mouse-beta casein locus, and treated with 10 μM cadmium for 48 hours. The knock-in efficiency was monitored through PCR. Results: The treatment of HC11 cells with a high-dose of CdCl₂ decreased the mRNA expression of the HR-related gene Rad51 in HC11 cells. In addition, the inhibition of MMR-related genes through CdCl₂ treatment did not lead to an increase in knock-in efficiency. Conclusions: The inhibition of MMR-related gene expression through high-dose CdCl₂ treatment reduces the expression of the HR-related gene Rad51, which is active during recombination. Therefore, it was determined that CdCl₂ is an inappropriate compound for improving HR efficiency.

• Journal of Microbiology and Biotechnology
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• v.13 no.3
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• pp.415-421
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• 2003

A bacterium, Pseudomonas fluorescens 2112, that is antagonistic against a red-pepper blight-causing fungus, Phytophthora capsici, was isolated from the local soil of Gyongju, Korea. This strain formed an orange-colored clear halo zone on chrome azurol S (CAS) blue agar, suggesting the production of a siderophore in addition to an antifungal antibiotic. The optimal culture conditions for siderophore production by P. fluorescens 2112 were 30-h cultivation at $25^{\circ}C$ and pH 6.5 in King's B medium. The presence of $20{\mu}g/ml\;of\;Fe^3+$ ion or EDDHA promoted the production of siderophore in King's B medium. The siderophore was purified from culture broth by CM-Sephadex C-25 and Sephadex G-25 column chromatographies. The UV spectra of the purified siderophore was the same as that of pyoverdins or pseudobactins. The molecular mass was 1,958 Da determined by FAB-rlass spectrometer, and the amino acid composition analysis showed that the purified siderophore consisted of glycine/threonine/serine/glutamic acid/alanine/lysine with the molar ratio of 3:2:1:1:1:1, DL-Threo-${\beta}$-hydroxyaspartic acid and $N^{\delta}$-hydroxyornithine, two of the essential constituents of pyoverdin, were also found. The purified siderophore pyoverdin showed strong in vitro and in vivo antagonistic activities against phytophthora blight-causing P. capsici. Especially in an in vivo pot test, the siderophore protected red-pepper Capsicum annum L. very well from the attack of P. capsici. These results indicated that the purified siderophore of P. fluorescens 2112 played a critical role in the biocontrol of the red-pepper blight disease, equivalent to treatment by P.fluorescens 2112 cells.

• Mycobiology
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• v.34 no.4
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• pp.219-229
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• 2006

Seventeen microbial species including 10 fungal taxa, two yeasts and five bacteria, were isolated from freshly prepared orange, guava and banana juices kept in open bottles at room temperature for 7 days. Eight different essential oils, from local herbs, were tested for their antimicrobial activity against these test organisms. The essential oils of Cymbopogon citratus, Ocimum basilicum and Origanum majorana were found to be highly effective against these microorganisms. Aspergillus niger, A. flavus and Saccharomyces cerevisiae, the most prevalent microorganisms in juice, showed the highest resistance against these essential oils. GC-MS analysis showed that while e-citral, a'-myrcene, and z-citral represent the major components (75.1 %) of the essential oil of Cymbopogon citratus; bezynen,l-methyl-4-(2-propenyl), 1,8-cineole and trans-a'-bisabolene were the main components (90.6%) of Ocimum basilicum; whereas 3-cyclohexen-l-0l,4-methyl-l(l-methylethyl)-(CAS), c-terpinene and trans-caryophyllene represent the major components (65.1%) of Origanum majorana. These three essential oils were introduced into juices by two techniques namely, fumigation and direct contact. The former technique showed more fungicidal effect than the latter one against A. flavus, A. niger, and S. cerevisiae. The essential oil of Cymbopogon citratus by comparison to other test oils showed the strongest effect against these fungi with a minimum inhibitory concentration of $1.5\;{\mu}l/ml$ medium and a sublethal concentration of $1.0\;{\mu}l/ml$. The antimicrobial activity of this oil is thermostable at $121^{\circ}C$ for 30 min.

• Journal of the Korean Magnetics Society
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• v.4 no.3
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• pp.272-276
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• 1994

A new Galvanomagnetic electrorootive force effect of $Ni_{53}-Fe_{47}$ thin films is studied. The dependence of this effect on $\theta$, angle between the current and the magnetic field, is found to be the form of sin $2\theta$, in contrast with that of the magneto resistance effect cas $2\theta$ and that of the Hall effect sin $\theta$. Property of this effect is that lthe rate of the voltage variation depending on the magnetic field is extremely large as compared with the magnetiresistance effect. It is theoretically confirmed that this effect is well understood on the basis of the two carrier types model.

• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.777-788
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• 2021

Since aerosol has a relatively short duration and significant spatial variation, satellite observations become more important for the spatially and temporally continuous quantification of aerosol. However, optical remote sensing has the disadvantage that it cannot detect AOD (Aerosol Optical Depth) for the regions covered by clouds or the regions with extremely high concentrations. Such missing values can increase the data uncertainty in the analyses of the Earth's environment. This paper presents a spatial gap-filling framework using a univariate statistical method such as DCT-PLS (Discrete Cosine Transform-based Penalized Least Square Regression) and FMM (Fast Matching Method) inpainting. We conducted a feasibility test for the hourly AOD product from AHI (Advanced Himawari Imager) between January 1 and December 31, 2019, and compared the accuracy statistics of the two spatial gap-filling methods. When the null-pixel area is not very large (null-pixel ratio < 0.6), the validation statistics of DCT-PLS and FMM techniques showed high accuracy of CC=0.988 (MAE=0.020) and CC=0.980 (MAE=0.028), respectively. Together with the AI-based gap-filling method using extra explanatory variables, the DCT-PLS and FMM techniques can be tested for the low-resolution images from the AMI (Advanced Meteorological Imager) of GK2A (Geostationary Korea Multi-purpose Satellite 2A), GEMS (Geostationary Environment Monitoring Spectrometer) and GOCI2 (Geostationary Ocean Color Imager) of GK2B (Geostationary Korea Multi-purpose Satellite 2B) and the high-resolution images from the CAS500 (Compact Advanced Satellite) series soon.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.1
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• pp.13-21
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• 2021

High-resolution satellites such as Kompsat-3 and CAS-500 include optical cameras of MS (Multispectral) and PAN (Panchromatic) CCD (Charge Coupled Device) sensors installed with certain offsets. The offsets between the CCD sensors produce geometric discrepancy between MS and PAN images because a ground target is imaged at slightly different times for MS and PAN sensors. For precise pan-sharpening process, we propose a co-registration process consisting the physical sensor modeling and image matching. The physical sensor model enables the initial co-registration and the image matching is carried out for further refinement. An experiment with Kompsat-3 images produced RMSE (Root Mean Square Error) 0.2pixels level of geometric discrepancy between MS and PAN images.

• Molecules and Cells
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• v.43 no.11
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• pp.921-934
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• 2020

Lck-interacting transmembrane adaptor 1 (LIME) has been previously identified as a raft-associated transmembrane protein expressed predominantly in T and B lymphocytes. Although LIME is shown to transduce the immunoreceptor signaling and immunological synapse formation via its tyrosine phosphorylation by Lck, a Src-family kinase, the in vivo function of LIME has remained elusive in the previous studies. Here we report that LIME is preferentially expressed in effector T cells and mediates chemokine-mediated T cell migration. Interestingly, in LIME^-/- mice, while T cell receptor stimulation-dependent proliferation, differentiation to effector T cells, cytotoxic T lymphocyte (CTL) function and regulatory T lymphocyte (Treg) function were normal, only T cell-mediated inflammatory response was significantly defective. The reduced inflammation was accompanied by the impaired infiltration of leukocytes and T cells to the inflammatory sites of LIME^-/- mice. More specifically, the absence of LIME in effector T cells resulted in the reduced migration and defective morphological polarization in response to inflammatory chemokines such as CCL5 and CXCL10. Consistently, LIME^-/- effector T cells were found to be defective in chemokine-mediated activation of Rac1 and Rap1, and dysregulated phosphorylation of Pyk2 and Cas. Taken together, the present findings show that LIME is a critical regulator of inflammatory chemokine-mediated signaling and the subsequent migration of effector T cells to inflammatory sites.

• Journal of Microbiology and Biotechnology
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• v.31 no.4
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• pp.570-583
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• 2021

Pyrococcus furiosus α-amylase can hydrolyze α-1,4 linkages in starch and related carbohydrates under hyperthermophilic condition (~ 100℃), showing great potential in a wide range of industrial applications, while its relatively low productivity from heterologous hosts has limited the industrial applications. Bacillus subtilis, a gram-positive bacterium, has been widely used in industrial production for its non-pathogenic and powerful secretory characteristics. This study was conducted to increase production of P. furiosus α-amylase in B. subtilis through three strategies. Initial experiments showed that co-expression of P. furiosus molecular chaperone peptidyl-prolyl cis-trans isomerase through genomic integration mode, using a CRISPR/Cas9 system, increased soluble amylase production. Therefore, considering that native P. furiosus α-amylase is produced within a hyperthermophilic environment and is highly thermostable, heat treatment of intact culture at 90℃ for 15 min was performed, thereby greatly increasing soluble amylase production. After optimization of the culture conditions (nitrogen source, carbon source, metal ion, temperature and pH), experiments in a 3-L fermenter yielded a soluble activity of 3,806.7 U/ml, which was 3.3- and 28.2-fold those of a control without heat treatment (1,155.1 U/ml) and an empty expression vector control (135.1 U/ml), respectively. This represents the highest P. furiosus α-amylase production reported to date and should promote innovation in the starch liquefaction process and related industrial productions. Meanwhile, heat treatment, which may promote folding of aggregated P. furiosus α-amylase into a soluble, active form through the transfer of kinetic energy, may be of general benefit when producing proteins from thermophilic archaea.

• Journal of Korean Academy of Nursing
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• v.29 no.2
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• pp.445-455
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• 1999

This study has been conducted on the nonequivalent control group pretest-posttest design in quasi experimental basis and newly born premature infants from intensive care unit of G Medical University Hospital in Inchon Metropolitan were selected in two groups of 21 infants each. The first group for experimental and the other for control. Data has been collected form October 30, 1997 to August 29, 1998. For the experimental group tactile and kinesthetic stimulation was applied 2 times a day for 10 days(10 : 00~11 : 00 hours in the morning and 17 : 00~18 : 00 in the afternoon). As a weight weighing instrument. electronic indicator scale(Cas Co. korea) was used. To determine urine cortisol concentration level in stress hormone, radio immune assay method was used. And high performance liquid chlomatography was used to determine urine norepinephrine, concentration level To determine behavior status, tools developed by Anderson et at(1990) and remodeled by Kim Hee-Sook(1996) were used. Collected data were analyzed with the SAS program using x$^2$-test, student t-test, repeated measures ANOVA and paired t -test. The result were as follow. 1. As for the daily weight gain. the experimental group showed first change in weight and this group also showed higher weight in the average weight than the control group. Statistically, however, there was no significant factor between the two group. 2. The cortisol concentration in urine showed decrease in the experimental group norepinephrine concentration in urine showed increase in both experimental and control groups. No statistical significance was shown between the two groups. 3. In the aspect of behavior status. the experimental group showed statistical significance by showing inactive in the state of alert and conversion to a positive state than the control group. In conclusion, the sensory stimulation in this study showed a positive aspect through there was no statistical significance in the weight gain and urine stress hormone concentration. In the behavior status, there was statistical significance in the frequency of staying inactive in the state of alert and conversion to a positive state.