• Journal of Environmental Health Sciences
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• v.25 no.3
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• pp.58-63
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• 1999

Biodegradable films were prepared by solution blend method in the weight ratio of chitosan for the purpose of useful biomaterials. The possibility of biomaterials prepared from natural polymer as a skin substitute was evaluated by measuring biocompatibility. These films were inserts in the back of rat and their biodegradability was investigated by the film weight and hematology as a function of time for the biotransformation. The result of rat test showed that medium, high viscosity chitosan induced some suspects of inbiocompatibility in the tissue by goreign body reaction 48 and 72 hours after implantation. Also, we prepared the official burn ointment which is made by low viscosity chitosan. This burn ointment was covered on the skin wound of artificial burn and their effect of healing was investigated by the evaluation of the naked eye and hematological change as a function of time. The result of rats test showed that burn ointments made from chitosan was effective reductio of inflammation than negative group.

• Mycobiology
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• v.31 no.1
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• pp.32-35
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• 2003

Restriction enzyme-mediated integration(REMI) was used to transform uracil auxotrophs of Pleurotus ostreatus to prototrophy. When protoplasts of Pleurotus ostreatus were treated by the reaction mixture containing 10 units of BamHI, the frequency of REMI was about 64 transformants per 1 ${\mu}g$ of DNA. This efficiency was increased by 14.2 times compared with that of the conventional PEG transformation. The optimal condition for REMI of P. ostreatus was achieved when 1 ${\mu}g$ of linearized pTRura3-2 DNA was added into $1{\times}10^7$ protoplasts along with 10 units BamHI. Southern blot analysis revealed that about 50% of transformants examined were caused by REMI event and 30% carried single copy insertion at the genome. This suggested that the REMI method might be a useful tool for efficient transformation and tagging mutagenesis of P. ostreatus.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.209-209
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• 2003

The adventages of Li alloys have attracted the attention of many research groups, many of which have investigated tin-based alloys [1-2], Despite interesting performances of these, the irreversible capacity loss systematically observed on the first cycle for these compounds is a main drawback for their use as anode materials in lithium ion cells. Not only Sn is efficient in forming alloys with Li, Si can also react with Li to form alloys with a high Li/Si ratio, like Li$\_$22/Si$\_$5/ at 400$^{\circ}C$. It corresponds to a capacity of 4200mAh/g. Electrochemical Li-Si reaction occurs between 0 and 0.3 V against Li/Li$\^$+/, so that high-energy density battery can be realized. Despite the high theoretical capacity of elements like Si, however, particles of the alloys crack and fragment due to the repeated alloying and do-alloying which occurs as cell are charged and discharged. The research groups of Muggins [3] and Besenhard [4] have proposed that the volume expansion due to the insertion of Li can be reduced in micro- and submicro-structured matrix alloys. For this reason, the research group of J.R. Dahn investigated Sn/Mo sequential sputter deposition to prepare nanocomposites [5]. In this study, we investigated the characterization and the electrochemical characteristics of sequentially sputtered Si/Mo multilayer for microbattery anode.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.901-906
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• 2013

We examined the availability of the lacZ gene (${\beta}$-galactosidase gene) as a reporter of foreign gene transfer in the cysts of Artemia franciscana (A. franciscana) to conduct a risk assessment of living genetically modified organisms (LMOs) in the marine ecosystem. The LacZ gene was transferred to decapsulated cysts by particle bombardment, and its insertion and expression were assessed by means of polymerase chain reaction (PCR) and X-gal staining. X-gal staining indicated lacZ expression in all A. franciscana examined (including the control group), which exhibited not only negative but also positive PCR amplification. Endogenous ${\beta}$-galactosidase is highly active in the whole body of A. franciscana during all stages of the life cycle. Thus, the lacZ gene is unsuitable as a reporter for foreign gene transfer in A. franciscana cysts, because it is difficult to discriminate between exogenous and endogenous ${\beta}$-galactosidase activity.

• Journal of Periodontal and Implant Science
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• v.49 no.6
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• pp.346-354
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• 2019

Maxillary implants are inserted in the upward direction, meaning that they oppose gravity, and achieving stable support is difficult if the alveolar bone facing the maxillary sinus is thin. Correspondingly, several sinus-lifting procedures conducted with or without bone graft materials have been used to place implants in the posterior area of the maxilla. Even with these procedures available, it has been reported that in about 5% of cases, complications occurred after implantation, including acute and chronic sinusitis, penetration of the sinus by the implant, implant dislocation, oroantral fistula formation, infection, bone graft dislocation, foreign-body reaction, Schneiderian membrane perforation, and ostium plugging by a dislodged bone graft. This review summarizes common maxillary sinus pathologies related to implants and suggests an appropriate management plan for patients requiring dental implantation.

• Parasites, Hosts and Diseases
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• v.39 no.4
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• pp.313-318
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• 2001

The identification , characterization and quantification of Plasmodium sp. genetic polymorphism are becoming increasingly important in the vaccine development. We investigated polymorphism of Plasmodium vivax GAM-1 (PvGAM-1) gene in 30 Korean isolates. The polymorphic region of the PvGAM-1 gene, corresponding to nt 3792-4029, was amplified using polymerase chain reaction (PCR) followed by sequencing. All of the P. viuax Korean isolates were one type of GAM-1 gene, which were identical to that of the Belem strain. It is suggested that PvGAM-1 could not be used as a genetic marker for identifying or classifying P. vivax Korean isolates. It revealed that the polymorphic pattern as acquired basically by duplication and modification or deletion event of a 33 bp-motif fragment ended by poly guanine (G) and that there were at least three complete and one partial 33 Up-motif sequences within the polymorphic region in the longest cases such as those of South Korean and Belem isolates. In addition, we clustered P. vivax isolates with parsimonious criteria on the basis of PvGAM- 1 polymorphic patterns (insertion/deletion patterns) .

• Molecules and Cells
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• v.27 no.2
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• pp.225-235
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• 2009

Antibody phage display provides a powerful and efficient tool for the discovery and development of monoclonal antibodies for therapeutic and other applications. Antibody clones from synthetic libraries with optimized design features have several distinct advantages that include high stability, high levels of expression, and ease of downstream optimization and engineering. In this study, a fully synthetic human scFv library with six diversified CDRs was constructed by polymerase chain reaction assembly of overlapping oligonucleotides. In order to maximize the functional diversity of the library, a ${\beta}$-lactamase selection strategy was employed in which the assembled scFv gene repertoire was fused to the 5'-end of the ${\beta}$-lactamase gene, and in-frame scFv clones were enriched by carbenicillin selection. A final library with an estimated total diversity of $7.6{\times}10^9$, greater than 70% functional diversity, and diversification of all six CDRs was obtained after insertion of fully randomized CDR-H3 sequences into this proofread repertoire. The performance of the library was validated using a number of target antigens, against which multiple unique scFv sequences with dissociation constants in the nanomolar range were isolated.

• Preventive Nutrition and Food Science
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• v.9 no.4
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• pp.324-329
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• 2004

In order to investigate the molecular mechanism of $\gamma$-aminobutyric acid (GABA) production in lactic acid bacteria, we cloned a glutamate decarboxylase (GAD) gene from Lactobacillus plantarum using polymerase chain reaction (PCR). One PCR product DNA was obtained and inserted into a TA cloning vector with a T7 promoter. The recombinant plasmid was used to transform E. coli. The insertion of the product was con­firmed by EcoRI digestion of the plasmid purified from the transformed E. coli. Nucleotide sequence analysis showed that the insert is a full-length Lactobacillus plantarum GAD and that the sequence is $100\%$ and $72\%$ identical to the regions of Lactobacillus plantarum GAD and Lactococcus lactis GAD sequences deposited in GenBank, accession nos: NP786643 and NP267446, respectively. The amino acid sequence deduced from the cloned Lactobacillus plantarum GAD gene showed $100\%$ and $68\%$ identities to the GAD sequences deduced from the genes of the NP786643 and NP267446, respectively. To express the GAD protein in E. coli, an expression vector with the GAD gene (pkk/GAD) was constructed and used to transform the UT481 E. coli strain and the expression was confirmed by analyzing the enzyme activity. The Lactobacillus plantarum GAD gene obtained may facilitate the study of the molecular mechanisms regulating GABA metabolism in lactic acid bacteria.

• Plant Biotechnology Reports
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• v.2 no.1
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• pp.13-20
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• 2008

Potato (Solanum tuberosum L.), one of the most important food crops, is susceptible to a number of devastating fungal pathogens in addition to bacterial and other pathogens. Producing disease-resistant cultivars has been an effective and useful strategy to combat the attack of pathogens. Potato was transformed with Agrobacterium tumefaciens strain EHA101 harboring chitinase, (ChiC) isolated from Streptomyces griseus strain HUT 6037 and bialaphos resistance (bar) genes in a binary plasmid vector, pEKH1. Polymerase chain reaction (PCR) analysis revealed that the ChiC and bar genes are integrated into the genome of transgenic plants. Different insertion sites of the transgenes (one to six sites for ChiC and three to seven for bar) were indicated by Southern blot analysis of genomic DNA from the transgenic plants. Expression of the ChiC gene at the messenger RNA (mRNA) level was confirmed by Northern blot analysis and that of the bar gene by herbicide resistance assay. The results obviously confirmed that the ChiC and bar genes are successfully integrated and expressed into the genome, resulting in the production of bialaphos-resistant transgenic plants. Disease-resistance assay of the in vitro and greenhouse-grown transgenic plants demonstrated enhanced resistance against the fungal pathogen Alternaria solani (causal agent of early blight).

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.1-13
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• 2014

Lithium ion batteries (LIBs) are the state-of-the-art technology among electrochemical energy storage and conversion cells, and are still considered the most attractive class of battery in the future due to their high specific energy density, high efficiency, and long cycle life. Rapid development of power-hungry commercial electronics and large-scale energy storage applications (e.g. off-peak electrical energy storage), however, requires novel anode materials that have higher energy densities to replace conventional graphite electrodes. Germanium (Ge) and silicon (Si) are thought to be ideal prospect candidates for next generation LIB anodes due to their extremely high theoretical energy capacities. For instance, Ge offers relatively lower volume change during cycling, better Li insertion/extraction kinetics, and higher electronic conductivity than Si. In this focused review, we briefly describe the basic concepts of LIBs and then look at the characteristics of ideal anode materials that can provide greatly improved electrochemical performance, including high capacity, better cycling behavior, and rate capability. We then discuss how, in the future, Ge anode materials (Ge and Ge oxides, Ge-carbon composites, and other Ge-based composites) could increase the capacity of today's Li batteries. In recent years, considerable efforts have been made to fulfill the requirements of excellent anode materials, especially using these materials at the nanoscale. This article shall serve as a handy reference, as well as starting point, for future research related to high capacity LIB anodes, especially based on semiconductor Ge and Si.