• 한국식품영양과학회지
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• 제29권5호
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• pp.908-916
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• 2000

This study was undertaken to purify the anticoagulant polysaccharide from Pachymeniopsis elliptica. The anticoagulant compound (PE-2IVc-2-1) was isolated from the crude polysaccharide (PE-2) by the sequential steps such as ultrafiltration (PE-2IV), anion-exchange chromatography of DEAE-Toyopearl 650C(PE-2IVc), size-exclusion chromatography of Sepharose CL-6B (PE-2IVc), and HPLC Shodex OHpak column chromatography (PE-2IVc-2-1). The apparent molecular weight of purified polysaccharide (PE-2IVc-2-1) was approximately 710 kDa. It was mainly composed of galactose (48.6%) and 3,6-anhydrogalactose (44.0%) with 27.1% of sulfate residue, in addition a trace amount of xylose (3.6%), glucose (1.1%), mannose (1.1%), arabinose (0.8%) and fucose (0.8%). The IR spectrum of the polysaccharide showed the characteristic bands of S=O(1116.74 and 1143.17 $cm^{-1}$) and C-O-S (828.19 $cm^{-1}$) stretching, respectively. The anticoagulant effect of PE-2 in ex vivo was proportional to the concentration of intravenously injected dose, up to 100 mg/kg.

• Journal of Microbiology and Biotechnology
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• 제31권10호
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• pp.1393-1400
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• 2021

Acetone-butanol-ethanol (ABE) fermentation by the anaerobic bacterium Clostridium acetobutylicum has been considered a promising process of industrial biofuel production. Phosphotransbutyrylase (phosphate butyryltransferase, PTB) plays a crucial role in butyrate metabolism by catalyzing the reversible conversion of butyryl-CoA into butyryl phosphate. Here, we report the crystal structure of PTB from the Clostridial host for ABE fermentation, C. acetobutylicum, (CaPTB) at a 2.9 Å resolution. The overall structure of the CaPTB monomer is quite similar to those of other acyltransferases, with some regional structural differences. The monomeric structure of CaPTB consists of two distinct domains, the N- and C-terminal domains. The active site cleft was formed at the interface between the two domains. Interestingly, the crystal structure of CaPTB contained eight molecules per asymmetric unit, forming an octamer, and the size-exclusion chromatography experiment also suggested that the enzyme exists as an octamer in solution. The structural analysis of CaPTB identifies the substrate binding mode of the enzyme and comparisons with other acyltransferase structures lead us to speculate that the enzyme undergoes a conformational change upon binding of its substrate.

• Molecules and Cells
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• 제45권7호
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• pp.495-501
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• 2022

Leucine dehydrogenase (LDH, EC 1.4.1.9) catalyzes the reversible deamination of branched-chain L-amino acids to their corresponding keto acids using NAD⁺ as a cofactor. LDH generally adopts an octameric structure with D4 symmetry, generating a molecular mass of approximately 400 kDa. Here, the crystal structure of the LDH from Pseudomonas aeruginosa (Pa-LDH) was determined at 2.5 Å resolution. Interestingly, the crystal structure shows that the enzyme exists as a dimer with C2 symmetry in a crystal lattice. The dimeric structure was also observed in solution using multiangle light scattering coupled with size-exclusion chromatography. The enzyme assay revealed that the specific activity was maximal at 60℃ and pH 8.5. The kinetic parameters for three different amino acid and the cofactor (NAD⁺) were determined. The crystal structure represents that the subunit has more compact structure than homologs' structure. In addition, the crystal structure along with sequence alignments indicates a set of non-conserved arginine residues which are important in stability. Subsequent mutation analysis for those residues revealed that the enzyme activity reduced to one third of the wild type. These results provide structural and biochemical insights for its future studies on its application for industrial purposes.

• Child Health Nursing Research
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• 제29권1호
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• pp.24-36
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• 2023

Purpose: This systematic literature review and meta-analysis explored extended reality (XR)-based pediatric nursing simulation programs and analyzed their effectiveness. Methods: A literature search was conducted between May 1 and 30, 2022 in the following electronic databases: MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL. The search period was from 2000 to 2022. In total, 6,095 articles were reviewed according to the inclusion and exclusion criteria, and 14 articles were selected for the final content analysis and 10 for the meta-analysis. Data analysis was performed using descriptive statistics and the Comprehensive Meta-Analysis program. Results: XR-based pediatric nursing simulation programs have increased since 2019. Studies using virtual reality with manikins or high-fidelity simulators were the most common, with six studies. The total effect size was statistically significant at 0.84 (95% confidence interval=0.50-1.19, z=4.82, p<.001). Conclusion: Based on the findings, we suggest developing standardized guidelines for the operation of virtual pediatric nursing simulation education and practice. Simultaneously, the application of more sophisticated research designs for effect measurement and the combined applications of various virtual simulation methods are needed to validate the most effective simulation methodology.

• 천문학회보
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• 제46권1호
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• pp.47.2-47.2
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• 2021

Focusing on both small separations and baryonic acoustic oscillation scales, the cosmic evolution of the clustering properties of peak, void, wall, and filament-type critical points is measured using two-point correlation functions in ΛCDM dark matter simulations as a function of their relative rarity. A qualitative comparison to the corresponding theory for Gaussian random fields allows us to understand the following observed features: (i) the appearance of an exclusion zone at small separation, whose size depends both on rarity and signature (i.e. the number of negative eigenvalues) of the critical points involved; (ii) the amplification of the baryonic acoustic oscillation bump with rarity and its reversal for cross-correlations involving negatively biased critical points; (iii) the orientation-dependent small-separation divergence of the cross-correlations of peaks and filaments (respectively voids and walls) that reflects the relative loci of such points in the filament's (respectively wall's) eigenframe. The (cross-) correlations involving the most non-linear critical points (peaks, voids) display significant variation with redshift, while those involving less non-linear critical points seem mostly insensitive to redshift evolution, which should prove advantageous to model. The ratios of distances to the maxima of the peak-to-wall and peak-to-void over that of the peak-to-filament cross-correlation are ~2-√~2 and ~3-√~3WJ, respectively, which could be interpreted as the cosmic crystal being on average close to a cubic lattice. The insensitivity to redshift evolution suggests that the absolute and relative clustering of critical points could become a topologically robust alternative to standard clustering techniques when analysing upcoming surveys such as Euclid or Large Synoptic Survey Telescope (LSST).

• Journal of Microbiology and Biotechnology
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• 제33권5호
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• pp.656-661
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• 2023

The aims of this study were to optimize the preparation of low-molecular-weight collagen using a proteolytic enzyme (alcalase) derived from the feet of Korean native chickens, and to characterize the process of collagen hydrolysis. Foreign bodies from chicken feet were removed using ultrasonication at 28 kHz with 1.36 kW for more than 25 min. The hydrolytic pattern and molecular weight distribution of enzyme-treated collagen from chicken feet were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-performance liquid chromatography, respectively. Ideally, chicken feet should be treated at 100℃ for 8 h to obtain a high collagen content using hot water extraction. The collagen content of the chicken foot extract was 13.9 g/100 g, and the proportion of low-molecular-weight collagen increased with increasing proteolytic enzyme concentration and reaction time. When treated with 1% alcalase, the average molecular weight of collagen decreased rapidly to 4,929 Da within 5 h and thereafter decreased at a slower rate, reaching 4,916 Da after 7 h. Size exclusion chromatography revealed that low-molecular-weight collagen peptides of approximately 1,000-5,000 Da were obtained after hydrolysis with 1% alcalase for 1 h.

• 멤브레인
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• 제34권2호
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• pp.124-131
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• 2024

바이러스는 생물 의약 산업에서 다양한 응용 분야를 가지고 있다. 그들은 살충제 생산, 백신 생산, 유전자 전달, 암 치료제 등에 사용된다. 바이러스의 하류 처리는 그들의 생물학적 및 의약적 응용을 위한 필수 단계이다. 다양한 과정 중에서 바이러스의 정제는 매우 중요하다. 막 크로마토그래피는 이 과정에서 중요한 역할을 한다. 이온 교환 막 크로마토그래피는 주로 사용되는 방법이지만 크기 배제 및 불충분한 정제에 관한 다양한 제한을 가지고 있다. 또한, 이는 인플루엔자와 같은 빠르게 변화하는 바이러스의 균주에 적용될 수 없다. 이 검토는 막 크로마토그래피의 다양한 개선된 방법 또는 대안을 검토한다. 이는 정제, 바이러스 회수율 및 방법의 확장성에 초점을 맞추고 있다.

• 한국생활과학회지
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• 제20권1호
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• pp.205-223
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• 2011

This study examines diagrams of space organization and classroom activity zoning through Korean Childcare Accreditation Criteria, and compares space diagrams with childcare facilities in Daejeon, and looks at similarities and differences between them. Space diagram from accreditation criteria show the classroom, adjoining toilets, napping areas, and community areas for playing, reading, cooking, teaching and holding materials. Classroom zone diagrams show 8 activity zones for entering, washing and toilet, making art, playing, reading, studying science, resting, playing role and wooden block. Six case studies in Daejeon, Korea were surveyed and classified into big, medium and small size facilities by the number of children. The space organization of case studies are similar to the diagrams, except that outdoor playground and indoor playrooms were not large enough at the small and medium size facilities. Classroom activity zoning was very similar to the conceptions, excluding the playarea from classroom, integrating the rest areas for reading, subdividing art into music and art, science, and into math and science, roleplay into roleplay and wooden block. In conclusion childcare centers in Daejeon are designed to the concept diagram of the accreditation criteria, with some flexibility, exclusion, integration, and subdivision of space and activity zones. It has been requested as to make each criteria fit to the facility sizes-big, medium and small.

• BMB Reports
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• 제44권12호
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• pp.816-820
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• 2011

There is a broad range of different small heat shock proteins (sHSPs) that have diverse structural and functional characteristics. To better understand the functional role of mitochondrial sHSP, NtHSP24.6 was expressed in Escherichia coli with a hexahistidine tag and purified. The protein was analyzed by non-denaturing PAGE, chemical cross-linking and size exclusion chromatography and the $H_6NtHSP24.6$ protein was found to form a dimer in solution. The in vitro functional analysis of $H_6NtHSP24.6$ using firefly luciferase and citrate synthase demonstrated that this protein displays typical molecular chaperone activity. When cell lysates of E. coli were heated after the addition of $H_6NtHSP24.6$, a broad range of proteins from 10 to 160 kD in size remained in the soluble state. These results suggest that NtHSP24.6 forms a dimer and can function as a molecular chaperone to protect a diverse range of proteins from thermal aggregation.

• 근관절건강학회지
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• 제21권3호
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• pp.173-183
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• 2014

Purpose: This study examined the effects of exercise programs on the pain and quality of life in patients with knee osteoarthritis. Methods: Electronic bibliographic databases of KiSTi, KoreaMed, KISS and KERIS were searched to identify studies of randomized controlled trials and non-randomized controlled trials. As a result, 1213 publications identified and 16 studies met inclusion and exclusion criteria. All studies examined for quality assessment of studies using Cochrane's risk of bias. Results: The 16 studies were eligible for inclusion criteria, then the meta-analysis was conducted to examine effectiveness of exercise programs on pain and quality of life in patients with knee osteoarthritis. The meta- analysis based on the random effect model showed that the exercise program was beneficial in decreasing pain (effect size .69; 95% confidence interval 0.45~0.91). Also, the exercise programs have been shown to be effective in significantly improving the quality of life. However, it was not statistically significant due to severe deviations of studies (effect size 1.06; 95% confidence interval -0.34~2.46). Conclusion: Exercise programs had positive effects on pain relief and improvement of the quality of life in patients with knee osteoarthritis, although the quality of life was not statistically significant due to severe deviations of studies.