• The Korean Journal of Mycology
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• v.49 no.4
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• pp.455-467
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• 2021

Macrofungi are valuable resources as novel drug candidates, new biomaterials, and edible materials. Recently, genetic approaches pertaining to macrofungi have been continuously growing for their identification, molecular breeding, and genetic engineering. However, purification and amplification of fungal DNA is challenging because of the rigid cell wall and presence of PCR inhibitory metabolites. Here, we established a direct PCR method to provide a rapid and efficient method for PCR-grade macrofungal DNA preparation applicable to both conventional PCR and real-time PCR. We first optimized the procedure of lysis and PCR using the mycelia of Lentinula edodes, one of the most widely consumed macrofungal species. Lysates prepared by neutralizing with (NH₄)₂SO₄ after heating the mycelia in a mixture of TE buffer and KOH at 65℃ for 10 min showed successful amplification in both conventional and real-time PCR. Moreover, the addition of bovine serum albumin to the PCR mixture enhanced the amplification in conventional PCR. Using this method, we successfully amplified not only internal transcribed spacer fragments but also low-copy genes ranging in length from 500 to 3,000 bp. Next, we applied this method to 62 different species (54 genera) of macrofungi, including edible mushrooms, such as Pleurotus ostreatus, and medicinal mushrooms such as Cordyceps militaris. It was found that our method is widely applicable to both ascomycetes and basidiomycetes. We expect that our method will contribute to accelerating PCR-based approaches, such as molecular identification, DNA marker typing, gene cloning, and transformant screening, in macrofungal studies.

• Journal of the Korean Society of Food Culture
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• v.19 no.3
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• pp.295-312
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• 2004

This study is to investigate the trend of researches on food and culture from 1990 to 2003. With a literary approach, this paper analyzes how many papers were published and what was the major research subject. We classified the journals published during this time into 10 different categories and we are to grasp a research trend. 1) Historical approach on the traditional food and food habit; 2) Globalization of Koran food; 3) Use and preparation for traditional food; 4) Table setting and table manner; 5) Provincial cuisine; 6) Traditional festive food or celebratory meal; 7) Religious food; 8) Fusion food; 9) Food and culture in foreign countries and food habit of Korean people living abroad; 10) Studies related with satins out. It was revealed that 268 papers(=ps) were published. Eating out was the most frequently reported subject(100 ps), followed by provincial cuisine(54 ps), use and preparation for traditional food(49 ps), food habit for foreign people and Korean people living abroad(22 ps). Researches on these 4 topics have been accelerated since the late half of 1990s. This reflects the social factors such as rapid growth of food service industry, settlement of local autonomy, popularization of leisure activities and accelerated introduction of foreign food and culture. Half of the studies on the eating out dealt with eating out behavior. And 30 papers were reports on the food service industry situations. More than half of the studies on the provincial cuisine(26 ps) were concentrated on digging out recipes. Studies on the use and preparation for traditional food were mainly about what kind of food and how often the food is used(17 ps). Kimchi was the most frequently studied food. There were 11 papers regarding food and culture in foreign countries. Most of the authors were historians or linguists. Food habit of Korean people living abroad were investigated in 7 papers. There was few studies on fusion food, table setting and table manner. This doesn't meet with increasing demand for specialized information in then fields. Researches on the traditional festive food or celebratory meal(5 ps) and religious food(9 ps) were negligible. Papers on the historical approach to the traditional food and food habit were limited(12 ps). Moreover, most of them were patchwork of existing literatures. Continuous researches to exploit the historical facts based on literary proof should be tried with patience. Otherwise, the papers will copy the hackneyed knowledge repeatedly. Globalization of Korean food means the development of Korean food for foreign people and export of them worldwide. Only 16 papers were reported on this subject, 14 of them were published after 2000, 8 of them were surveys on the foreigners' food preference. In order to get practical informations on what we develope and how we sell for the foreign customers, profound research on their food habit should be done.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.547-551
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• 1998

Sixty isolates of lactic acid bacteria found in kimchi, a traditional Korean dish of fermented vegetables, were tested for nisin sensitivity. Of the sixty isolates, all belonging to the genera Leuconostoc, Lactobacillus, and Pediococcus, fifty isolates were sensitive to nisin at a concentration of 100 IU/$m\ell$, and four isolates appeared to be resistant to nisin. This demonstrated that the nisin sensitivity of lactic acid bacteria found in kimchi varied considerably among isolates. In MRS broth containing nisin at concentrations of 100 to 300 IV/$m\ell$, the growth of sensitive isolates of Leuconostoc mesenteroides and Lactobacillus plantarum was inhibited for two to three days at 2$0^{\circ}C$. When nisin was added to kimchi preparations at a concentration of 100 IU/$m\ell$, the growth of lactic acid bacteria was delayed and reached a maximum two days later than that in kimchi without nisin. These results suggest the possible use of nisin in kimchi preparation, at recommended levels, to control the lactic acid fermentation. Scanning electron micrographs of a sensitive isolate L. plantarum revealed the formation of pores on cell surfaces followed by rapid cell wall destruction 1 h after the addition of nisin.

• Journal of the Korean Society for Library and Information Science
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• v.32 no.2
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• pp.97-120
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• 1998

Library takes its way to digitalization to fill its role in modern information society. This study discusses social environment of this trend and investigates library circumstances, and refines the meaning of a library. A digital library is led by current stream of new media, rapid development of digital technology and recording methods, and revolution of information circulation and production such as electronic publishing. However, rich information sources in printed forms are even significant as a ground of a digital library. The digital library is not a brand-new feature of a library but the result of digitalization of information resources to accomplish the purpose of the library.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.3 no.2
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• pp.87-90
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• 2007

It's important that detect early caries of deciduous and permanent teeth to prevent dental caries and prevserve teeth, especially on proximal surface of deciduous teeth. The reason is that their prominent pulp horn lead to pulp treatment easily due to rapid caries progression. There are conventional exploring, visual inspection and radiographic exam for early caries detection. But, the standard method for diagnosing dental caries is subject and cavitation may be accelerated during exploring procedure. Caries can be diagnosed up to 40% mineral loss with radiograph. $DIFOTI^{(R)}$ (Digital Imaging Fiber-Optic TransIllumination) is diagnostic imaging system for early caries detection using fiber-optic illumination. It is possible that remineralize the tooth surface without tooth preparation and conserve the tooth structure by using $DIFOTI^{(R)}$.

• Journal of Korea Multimedia Society
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• v.21 no.5
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• pp.599-608
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• 2018

As natural disasters are increasing due to the unusual weather and the modern society is getting complicated, the rapid change of the urban environment has increased human disasters. Thus, citizens are becoming more anxious about social safety. The importance of preparation for safety has been suggested by providing the disaster safety services such as regional safety index, life safety map, and disaster safety portal application. In this paper, we propose an application framework to predict the urban safety index based on user's location with realtime weather/atmosphere data after creating a predication model based on the machine learning using number of occurrence cases and weather/atmosphere history data. Also, we implement an application to provide traffic safety index with executing preprocessing occurrence cases of traffic and weather/atmosphere data. The existing regional safety index, which is displayed on the Si-gun-gu area, has been mainly utilized to establish safety plans for districts vulnerable to national policies on safety. The proposed system has an advantage to service useful information to citizens by providing urban safety index based on location of interests and current position with realtime related data.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.11 s.188
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• pp.116-125
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• 2006

MEMS and LIGA technologies have been used for fabricating microstructures, but their shape is not 3D because of difficulty for preparation of many masks. To fabricate 3D microstructures, microstereolithography technology based on Digital Micromirror Device($DMD^{TM}$) was introduced. It has no need of masks and is capable of fabricating high aspect ratio microstructures. In this technology, STL file is the standard format as the same of conventional rapid prototyping system, and 3D parts are fabricated by layer-by-layer according to 2D section sliced from STL file. The UV light source is illuminated to DMD which makes bitmap images of 2D section, and they are transferred and focused on resin surface. In this paper, we addressed optical design of microstereolithography system in consideration of light path according to DMD operation and image-forming on the resin surface using optical design program. To verify the performance of implemented microstereolithography system, 3D microstructures with complexity and high aspect ratio were fabricated.

• Computational Structural Engineering
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• v.6 no.4
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• pp.57-66
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• 1993

The p-version crack model based on integrals of Legendre polynomial and virtual crack extension method is proposed with its potential for application to stress intensity factor computations in linear elastic fracture mechanics. The main advantage of this model is that the data preparation effort is minimal because only a small number of elements are used and high accuracy and the rapid convergence can be achieved in the vicinity of crack tip. There are two important findings from this study. Firstly, the limit value, the strain energy of the exact solution, can be estimated with successive three p-version approximations by ascertaining that the approximations enter the asymptotic range. Secondly, the rate of convergence of p-version model is almost twice that of h-version model on the basis of uniform or quasiuniform mesh refinement for the cracked panel problem subjected to tension.

• Journal of the Korean Ceramic Society
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• v.35 no.9
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• pp.945-952
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• 1998

Ferroelectric Sr0.8Bi2.4Ta2O9 stock solutions were prepared by MOD(Metaloganic Decompostion) process. The phase transformation for the layered perovskite of the SBT thin films by changing RTA(Rapid her-mal Annealing) temperatuer from 700$^{\circ}C$to 780$^{\circ}C$ were observed using XRD and SEM. Layered perovskite phase began to appear above 740$^{\circ}C$ and then SBT thin films were annealed at 800$^{\circ}C$ for 1hr for its com-plete crystallization. The specimens showed well shaped hysteresis curves without post annealing that car-ried out after deposition of Pt top electrode. The SBT thin films showed the asymmetric ferroelectric pro-perties. It was confirmed that the properties were caused by interface effect to SBT and electrode by leak-age current density measurement and asymmetric properties reduced by post annealing. At post annealing temperature of 800$^{\circ}C$ remanant polarization values (2Pr) were 6.7 9 ${\mu}$C/cm2 and those of leakage current densities were 3.73${\times}$10-7 1.32${\times}$10-6 A/cm2 at 3, 5V respectively. Also bismuth bonding types of SBT thin film surface were observed by XPS.

• The Journal of the Korean dental association
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• v.54 no.5
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• pp.348-355
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• 2016

Ideal autogenous or allogenic bone graft materials should provide 1) stabilization of blood clot, 2) scaffolds for cellular proliferation and differentiation, 3) release of osteogenic growth factors, 4) appropriate resorption profile for remodeling of new bone. Teeth, especially dentin, mostly contain hydroxyapatite and type I collagen which are similar to bone, and could be valuable graft material. Clinically teeth are used as calcined or demineralized forms. Demineralized form of dentin can be more effective as a graft material. But a conventional decalcification method takes time and long treatment time may give negative effects to various osteogenic proteins in dentin. Author used a new clinical method to prepare autogenous teeth, which could be grafted into the removal defects immediately after extraction using vacuum ultrasonic system. The process could be finished within two hours regardless of the form (powder, chip or block). Teeth were processed to graft materials in block, chip, or powder types immediately after extraction. It took 120 minutes to prepare block types and 40 minutes to prepare powder. Clinical cases did not show any adverse response and the healing was favorable. Rapid preparation of autogenous teeth with the vacuum ultrasonic system could make the immediate one-day extraction and graft possible.