• Journal of Biomedical Engineering Research
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• v.39 no.5
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• pp.188-207
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• 2018

Recently, three-dimensional (3D) printing of biological tissues and organ has become an attractive interdisciplinary research topic that combines a broad range of fields including engineering, biomaterials science, cell biology, physics, and medicine. The 3D bioprinting can be used to produce complex tissue engineering scaffolds based on computer designs obtained from patient-specific anatomical data. It is a powerful tool for building structures by printing cells together with matrix materials and biochemical factors in spatially predefined positions within confined 3D structures. In the field of the 3D bioprinting, three major categories of the 3D bioprinting include the stereolithography-based, inkjet-based, and dispensing-based bioprinting. Some of them have made significant process. Each technique has its own advantages and limitations. Compared with non-biological printing, the 3D bioprinting should consider additional complexities: biocompatibility, degradability of printing materials, cell types, cell growth, cell viability, and cell proliferation factors. Numerous 3D bioprinting technologies have been proposed, and some of them have been making great progress in printing several tissues including multilayered skin, cartilaginous structures, bone, vasculature even heart and liver. This review summarizes basic principles and key aspects of some frequently utilized printing technologies, and introduces current challenges, and prospects in the 3D bioprinting.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.274-279
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• 2015

Receptor activator of nuclear factor-kappa B ligand (RANKL) is a critical factor in osteoclastogenesis. It makes osteoclasts differentiate and multinucleate in bone remodeling. In the present study, RANKL was expressed as a soluble maltose binding protein (MBP)-fusion protein using the Escherichia coli maltose binding domain tag system (pMAL) expression vector system. The host cell E. coli DH5α was cultured and induced by isopropyl β-_D-1-thiogalactopyranoside for rRANKL expression. Cells were disrupted by sonication to collect soluble MBP-fused rRANKL. The MBP-fusion rRANKL was purified with MBP Trap affinity chromatography and treated with Tobacco Etch Virus nuclear inclusion endopeptidase (TEV protease) to remove the MBP fusion protein. Dialysis was then carried out to remove binding maltose from the cleaved rRANKL solution. The cleaved rRANKL was purified with a second MBP Trap affinity chromatography to separate unsevered MBP-fusion rRANKL and cleaved MBP fusion protein. The purified rRANKL was shown to have biological activity by performing in vitro cell tests. In conclusion, biologically active rRANKL was successfully purified by a simple two-step chromatography purification process with one column.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2341-2346
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• 2017

The relative position of the eyeballs in the orbit can be a criterion for estimating multiple pathological conditions. Especially, it is useful to diagnose orbital fracture, thyroid eye disease, orbital tumor, and to evaluate the result of drug and surgical treatment. The Hertel and Naugle exophthalmometer, which are the most commonly used measuring instruments for measuring the prominence of the eye, are different from each other. Even if the same examiner repeatedly measures, it is inevitable. Also, even if the same exophthalmometer is different from the manufacturing company, the design of the fixed part of the orbit is different, and a measurement error is caused by the inspectors. In this paper, we propose a method of automatic measurement that can increase the accuracy and repeatability of measurement of exophthalmos using white light scanning interferometer, which is a 3D image measurement technique.

• Korean Journal of Veterinary Service
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• v.32 no.3
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• pp.265-273
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• 2009

A cross-sectional survey was undertaken to identify risk factors and clinical signs associated with parasitic helminth infections of cattle in Mymensignh district of Bangladesh. A nonrandom convenience sampling method was used to select 138 animals from 40 farmers/herds. The eggs per gram of faeces (epg) for nematodes and trematodes were determined by McMaster and Stoll's methods respectively. Animal-level and herd-level data were recorded by means of a questionnaire. Multi-collinearity amongst explanatory variables were assessed using $2{\times}2{\times}\;X^2$ test and one variable in a pair was dropped if $P{\leq}0.05$ formultiple logistic regression models. Association study between outcome and explanatory variables was conducted using classification tree, random forests and multiple logistic regression. A positive epg was considered as infected. Analyses were performed using $STATA^{(R)}$, version 8.0/Intercooled and $R^{(R)}$, Version 2.3.0. Seventy eight percent of the cattle were found to be infected with at least one type of helminth. Twenty four pairs of combinations of explanatory variables showed significant associations. Male animals (OR=3.3, P=.006, 95% CI=1.4, 7.7) were associated with significantly increased prevalence of nematode infection. Female cattle of the study area are mostly cross-breed, kept indoor, fed relatively good diet and not used for draught purpose. Males are used for draught purpose thereby more exposed to nematode infective stage and provided with relatively poor diet. So stressed male cattle may become more susceptible to nematode infection. All of the three statistical techniques selected gender and lumen motility as most important variables in association with nematode infection in cattle. The result of this survey can only be extrapolated to the periurban cattle population of traditional management system.

• Journal of the Korean Data and Information Science Society
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• v.28 no.1
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• pp.163-171
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• 2017

With the advance of function of smart phone system and internet services, mobile trade grows more popular in the area of e-business or banking. These environmental changes, it makes the needs of authorized certificates. Authorized certificate is not only important in these days but also future society. In 2015, 27 millions of Korean people used public key certificate, but most of them does not know the details on the public key certificate. Therefore, in this paper, we explain and investigate the characteristics on the public certificate and explain the relation ship between authorized certificate and public key encrytion. By investigating several papers, internet data, newspapers and books, we found the historical changes, substantial aspects, the encryption systems on the authorized certificate. Also we study the pros and cons of authorized certificate. Finally we predict the number of issued authorized certificate for the future society based on nonparametric statistical method.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.381-385
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• 2011

The degree of maturity of rice greatly affects the quality of the rice, including factors such as the integrity of grains, color, and the nutritive components. Green Rice$^{(R)}$ is rice (Oryza sativa L.) that has been harvested earlier than brown rice and appears green in color. To determine suitable harvesting time of the Jinbu variety of Green Rice$^{(R)}$ in Gyeonggido, rice samples harvested on 23, 26 and 42 days after heading (DAH) were compared on their yield, color intensity, and proximate compositions. The maximum paddy yield of Green Rice$^{(R)}$ was 61.4% at 23 DAH, which decreased to 45.4%, 5.5% at 26 and 42 DAH, respectively. Greenness was darker at 23 DAH ($-0.27{\pm}0.03$), and significantly weaker (p<0.05) at 26 DAH ($0.07{\pm}0.01$) and at 42 DAH ($5.25{\pm}0.08$). All proximate compositions, except carbohydrate, including moisture, crude fat, protein, ash and total minerals were higher in the earlier-harvested Green rice$^{(R)}$ than in brown rice, without variations among the 23 and 26 DAH Green rice$^{(R)}$. Overall, the optimum harvest time of Jinbu Green Rice$^{(R)}$ at Gyeonggido would be 23 DAH. We suggest that timely harvesting could be a potent determinant of the quality of Green Rice$^{(R)}$.

• Interdisciplinary Bio Central
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• v.4 no.2
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• pp.4.1-4.4
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• 2012

Background: Serum concentration of cystatin C, a marker of glomerular filtration has been associated with cardiovascular disease (CVD). The aim of this study was to evaluate cystatin C as a marker of obese patients without chronic kidney disease (CKD). Materials and Methods: The study population consisted of 36 subjects with metabolic syndrome and 32 subjects free of metabolic syndrome (the control group). HDL-C, LDL-C, blood urea, triglycerides, glucose, HbA1c, serum cystatin C and serum creatinine were measured in both groups. GFR was calculated in both groups using Cockroft-Gault equation. Results: Obese patients showed higher cystatin C levels than normal samples ($1.28{\pm}0.29$, P < 0.05). In the binary logistic regression, obese patients were significantly associated with elevated cystatin C levels. Conclusion: Our results suggest that cystatin C may be a marker for obese patients and may identify a certain degree of renal dysfunction even when serum creatinine does not exceed the normal level. In this study, we demonstrated that serum creatinineand GFR did not differ significantly between the diabetic and the control groups. Serum concentration of cystatin C was significantly higher in the diabetic group compared with the control group. The strengths of this study are the evaluation of reliability and sensivity in comparison with a 'routine test of GFR'. The methodology used allows an appropriate statistical comparison of reliability in contrast to most other previous evaluations of GFR.

• The Journal of Korean Physical Therapy
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• v.27 no.1
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• pp.50-54
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• 2015

Purpose: The purpose of this study is to investigate differences of cervical flexor muscle thickness (i.e., sternocleidomastoid muscle and deep cervical flexor muscles) depending on levels of pressure bio-feedback unit and eye directions during cranial-cervical flexor exercise in healthy subjects. Methods: A total of 30 subjects (12 males and 18 females) who had no medical history related to musculoskeletal and neurological disorders were enrolled in this study. They were instructed to perform cranial-cervical flexion exercise with adjustment of five different pressures (i.e., 22 mmHg, 24 mmHg, 26 mmHg, 28 mmHg, and 30 mmHg) using a pressure biofeedback unit, according to three different eye directions (i.e., $0^{\circ}$, $20^{\circ}C$, and $40^{\circ}C$). Muscle thickness of sternocleidomastoid muscle and deep cervical flexor muscles was measured according to pressure levels and eye directions using ultrasonography. Results: In results of muscle thickness in sternocleidomastoid muscle and deep cervical flexor muscles, the thickness of those muscles was gradually increased compared to the baseline pressure level (22 mmHg), as levels in the pressure biofeedback unit during cranial-cervical flexion exercise were increasing. In addition, at the same pressure levels, muscle thickness was increased depending on ascending eye direction. Conclusion: Our findings showed that muscle thickness of sternocleidomastoid muscle and deep cervical flexor muscles was generally increased during cranial-cervical flexion exercise, according to increase of eye directions and pressure levels. Therefore, we suggested that lower eye direction could induce more effective muscle activity than the upper eye direction in the same environment during cranial-cervical flexion exercise.

• The Journal of Korean Physical Therapy
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• v.32 no.1
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• pp.58-63
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• 2020

Purpose: This study examined the effects of the right or left knee lift during push up plus in the quadruped position on the serratus anterior (SA) muscle activity. Methods: Twenty-one subjects (male 11, female 10) performed the quadruped position on push up plus. The muscle activities of the lower trapezius (LT), SA, and upper trapezius (UT) were measured by surface electromyography. Repeated measurements of one-way ANOVA were performed for statistical analysis of the data, and the criterion for statistical significance was set to p<0.05 and comparative analysis of the UT and SA ratio using a Paired t-test. Results: The right SA increased the muscle activity of the right knee lift during quadruped position push up plus (p<0.05). In particular, the right SA muscle activity was higher than the left. In addition, comparative analysis of the UT and SA ratio to the right knee lift during quadruped position push up plus was performed (p<0.05). The right was found to be a significant statistic compared to the left, but the left SA increased the muscle activity of the left knee lift during quadruped position push up plus (p<0.05). The left SA muscle activity was higher than right. In addition, comparative analysis of UT and SA ratio to the left knee lift during quadruped position push up plus was performed (p<0.05). The left was found to be a significance statistic than the right. In addition, the interaction effect between the groups showed significant differences (p<0.05). Conclusion: Knee lift during push up plus is recommended for the selective activation of a research exercise protocol of one side of the serratus anterior.

• Journal of Life Science
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• v.18 no.11
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• pp.1617-1624
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• 2008

Chitin and chitosan, which is deacetylated form of chitin, are one of the most abundant biomass on the earth. They showed various biological activities including antimicrobial activity, heavy metal chelating, immune system activation, and have very diverse applications in food, pharmaceutical, medicinal, and environmental industry. There have been reported many chitin/chitosan-hydrolyzing enzymes, their structures and genes from three domains, archaea, bacteria, and eukarya. Carbohydrate hydrolyzing enzymes are classified in CAZy (Carbohydrate Active Enzymes) database according to their amino acid sequence similarity. Interestingly, chitinases and chitosanases are classified in various glycosyl hydrolase(GH) families, GH2, GH5, GH7, GH8, GH18, GH19, GH20, GH46, GH48, GH73, GH75, GH80, GH84, and GH85. Here, we review characteristics and structures of chitin/chitosan hydrolyzing enzymes according to glycosyl hydrolase families in order to provide information about gene mining.