• Tuberculosis and Respiratory Diseases
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• v.49 no.4
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• pp.453-465
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• 2000

Background : Lung carcinogenesis is a multistage process involving alterations in multiple genes and diverse pathway. Mutational activation of oncogenes and inactivation of tumor suppressor genes, and subsequent increased genetic instability are the major genetic events. The p53 gene and FHIT gene as tumor suppressor genes contribute to the pathogenesis of lung cancer, evidenced by mutation, microsatellite instability(MI) and loss of heterozygosity(LOH). Methods : We analysed genetic mutations of p53 and FHIT gene in 29 surgical specimens of nonsmall cell lung cancer using PCR-single strand conformation polymorphism, DNA sequencing and RT-PCR. MI and LOH were analyzed in loci of D3S1285, D9S171, and TP53. Results : In 2 cases, point mutation of p53 gene was observed on exon 5. MI of 3 times and LOH of 14 times were observed in at least one locus. In terms of the location of microsatellite, D3S1285 as a marker of FH1T was observed in 5 cases out of 26 specimens; D9S171 as a marker of p16 in 5 out of 17; and TP53 as a marker of p53 in 7 out of 27. In view of histologic type, squamous cell carcinoma presented higher frequency of microsatellite alteration, compared to others. Mutation of FHIT gene was observed in 11 cases and 6 cases of those were point mutation as a silent substitution on exon 8. FHIT mRNA expression exhibited deletion on exon 6 to 9 in 4 cases among 15 specimens, presenting beta-actin normally. Conclusion : Our results show comparable frequency of genetic alteration in nonsmall cell lung cancer to previous studies of Western countries. Microsatellite analysis might have a role as a tumor marker especially in squamous cell carcinoma. Understanding molecular abnormalities involved in the pathogenesis could potentially lead to prevention, earlier diagnosis and the development of novel investigational approaches to the treatment of lung cancer.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.2
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• pp.60-64
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• 2011

High sensitivity IR image sensors require materials characteristics with temperature coefficient of resistance (TCR) and IR range absorption. In this study, the metal-dielectric thermo sensitive films (MDTF) based on $(SiO_2)_x-(Ti)_y$ composition were deposited on substrates of germanium and glass by thermal evaporator. The $SiO_2$ : Ti mixture was made from the ratio of 9 : 1, 8 : 2, 7 : 3, 6 : 4, respectively. $(SiO_2)_x-(Ti)_y$ mixture powder was loaded on tungsten boat in evaporator and was 15.5 cm from the substrate. Resistance of $(SiO_2)_x-(Ti)_y$ in the range of 273~333K were measured as a function of temperature. Temperature coefficient of resistance (TCR) was calculated by the resistance variation. Under the various mixture ratios condition, it is possible to obtain $SiO_2$-Ti layers with resistance from units kilo-ohm to hundreds kilo-ohm. Finally, our results showed that Temperature coefficient of resistance (TCR) of these films varies from -1.4 to $-2.6%K^{-1}$.

• Journal of Digital Convergence
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• v.15 no.11
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• pp.261-269
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• 2017

The purpose of this paper is to provide a search system using a method of accessing the web in real time without using a database server in order to guarantee the up-to-date information in a single network, rather than using a plurality of bots connected by a wide area network Design. The method of the research is to design and analyze the system which can search the person and keyword quickly and accurately in crepe system. In the crepe server, when the user registers information, the body tag matching conversion process stores all the information as it is, since various styles are applied to each user, such as a font, a font size, and a color. The crepe server does not cause a problem of body tag matching. However, when executing the crepe retrieval system, the style and characteristics of users can not be formalized. This problem can be solved by using the html_img_parser function and the Go language html parser package. By applying queues and multiple threads to a general-purpose web crawler, rather than a web crawler design that targets a specific site, it is possible to utilize a multiplier that quickly and efficiently searches and collects various web sites in various applications.

• Journal of Life Science
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• v.32 no.5
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• pp.391-410
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• 2022

Human microbiota is a community of microorganisms, including bacteria, fungi, and viruses, that inhabit various locations of the body, such as the gut, oral, and skin. Along with the development of metabolomic analysis and next-generation sequencing techniques for 16S ribosomal RNA, it has become possible to analyze the population for subtypes of microbiota, and with these techniques, it has been demonstrated that bacterial microbiota are involved in the metabolic and immunological processes of the hosts. While specific bacteria of microbiota, called commensal bacteria, positively affect hosts by producing essential nutrients and protecting hosts against other pathogenic microorganisms, dysbiosis, an abnormal microbiota composition, disrupts homeostasis and thereby has a detrimental effect on the development and progression of various types of diseases. Recently, several studies have reported that oral and gut bacteria of microbiota are involved in the carcinogenesis of gastrointestinal tumors and the therapeutic effects of anticancer therapy, such as radiation, chemotherapy, targeted therapy, and immunotherapy. Studying the complex relationships (bacterial microbiota-cancer-immunity) and microbiota-related carcinogenic mechanisms can provide important clues for understanding cancer and developing new cancer treatments. This review provides a summary of current studies focused on how bacterial microbiota affect gastrointestinal cancer and anticancer therapy and discusses compelling possibilities for using microbiota as a combinatorial therapy to improve the therapeutic effects of existing anticancer treatments.

• Membrane Journal
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• v.32 no.6
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• pp.442-455
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• 2022

High-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) has been studied as an alternative to low-temperature PEMFC due to its fast activation of electrodes and high resistance to electrode poisoning by carbon monoxide. It is highly required to develop stable PEMs operating at high temperatures even doped by ion-conducting materials for the development of high-performance and durable HT-PEMFC systems. A number of studies have been conducted to develop polybenzimidazole (PBI)-based PEMs for applications in HT-PEMFC due to their high interaction with doped ion-conducting materials and outstanding thermomechanical stability under high-temperature operation. This review focused on the development of PBI-based PEMs showing high performance and durability. Firstly, the characteristic behavior of PBI-based PEMs doped with various ion-conducting materials including phosphoric acid was systematically investigated. And then, a comparison of the physicochemical properties of the PEMs according to the different membrane manufacturing processes was conducted. Secondly, the incorporation of porous polytetrafluoroethylene substrate and/or inorganic composites to PBI matrix to improve the membrane performances was studied. Finally, the construction of cross-linked structures into PBI-based PEM systems by polymer blending method was introduced to improve the PEM properties.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.4
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• pp.9-14
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• 2022

Silica aerogel is a porous material with a very low density and high specific surface area. Still, its application is limited due to its weak mechanical properties due to structural features. To solve this problem, a method of complexing it with various polymers has been proposed. We synthesized polyimide cross-linked silica aerogel by the sol-gel process to obtain high mechanical properties. Tetraethyl orthosilicate (TEOS) was used as a precursor to make silica aerogel, and 3- aminopropyltriethoxysilane (APTES) was used as a coupling agent for cross-linking polyimide. Polyimide was synthesized using pyromellitic dianhydride and 3,5-diaminobenzoic acid, and mechanical properties were improved by crosslinking polyimide with 10 repeating units in the polyimide chain using the reaction formula ${\frac{n_1}{n_2}}={\frac{n}{n+1}}$ To realize silica aerogel, polyimide having various weight ratios was added before gelation, resulting in a 19-fold or greater increase in maximum compressive strength compared to pure silica aerogel. From this study, an enhancement of silica aerogel could be enhanced through polymer cross-linking bonds.

• Journal of Life Science
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• v.33 no.10
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• pp.808-819
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• 2023

This study was conducted to develop a selection marker for the identification of the Bacillus licheniformis K12 strain in microbial communities. The strain not only demonstrates good growth at moderate temperatures but also contains enzymes that catalyze the decomposition of various polymer materials, such as proteases, amylases, cellulases, lipases, and xylanases. To identify molecular markers appropriate for use in a microbial community, a search was conducted to identify variable gene regions that show considerable genetic mutations, such as recombinase, integration, and transposase sites, as well as phase-related genes. As a result, five areas were identified that have potential as selection markers. The candidate markers were two recombinase sites (BLK1 and BLK2), two integration sites (BLK3 and BLK4), and one phase-related site (BLK5). A PCR analysis performed with different Bacillus species (e.g., B. licheniformis, Bacillus velezensis, Bacillus subtilis, and Bacillus cereus) confirmed that PCR products appeared at specific locations in B. licheniformis: BLK1 in recombinase, BLK2 in recombinase family protein, and BLK3 and BLK4 as site-specific integrations. In addition, BLK1 and BLK3 were identified as good candidate markers via a PCR analysis performed on subspecies of standard B. licheniformis strains. Therefore, the findings suggest that BLK1 can be used as a selection marker for B. licheniformis species and subspecies in the microbiome.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.503-510
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• 2005

In this research, composite alumina was prepared to add the various promoters by sol-gel method and examined its thermal stability. After sintering at $1,200^{\circ}C$, the thermal stability resulted in following order, $Si{\fallingdotseq}La$ > Ti > $Ba{\fallingdotseq}Ce$ > Y > $Zr{\fallingdotseq}Mg$, in accordance with adding the promoters. Especially in case of silica-added alumina, a phase transformation temperature to ${\alpha}$-alumina increased about $150^{\circ}C$ and after sintering at $1,200^{\circ}C$, it showed to maintain in ${\gamma}$-form and ${\delta}$-form alumina phase. Also it showed an increase of surface area from $3m^2/g$ to $71m^2/g$ compared with pure ${\alpha}$-alumina. In the case of silicaadded alumina, the characterization change of this alumina particle resulted in a delay of phase transformation because Si-O-Al bond was increased when sintered at high temperature. In case of lanthanum-added alumina, there was a sintering delay phenomenon in inter-particles as $LaAlO_3$ structure existed. The existence of lanthanum structure was confirmed by XRD and XPS analysis. It appeared on the alumina surface as $La_2O_3$ structure when it was sintered under $1,000^{\circ}C$, as the perovskite structure of $LaAlO_3$ at above $1,000^{\circ}C$ and as the magneto-plumbite structure of $LaAl_{11}O_{18}$ at above $1,300^{\circ}C$.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.6
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• pp.96-109
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• 2022

This study aims to identify the role and the use of landscape architects as a core strategy in urban regeneration projects by project type. This study attempted to find ways to promote landscape architects' participation patterns and characteristics in promoting urban regeneration and revitalization plans. Among the New Deal projects, from 2017 to 2019, when the urban regeneration projects were promoted, a total of 822 projects with terms such as park, garden, landscaping, rest space, forest, greening, planting, and flowers were included, In this study, an integrated approach was applied, considering the status of landscape architects participation, a literature survey by project entity, analysis of prior research, revitalization plan reports, and interviews by project entity, and aspects and characteristics of landscape architects participation according to project type. The results were classified. In the urban regeneration projects, the landscape characteristics were analyzed in terms of hardware or software participation methods according to the project type, and the participation patterns and promotion measures of landscape architecture and ways to promote them identified in the course of the project are as follows. First, the role and participation pattern of landscape architects in urban regeneration projects differed depending on the type of project. As the prerequisites for each type of project, the subject of the project, the direction, the differentiation of the regeneration strategy for each project, and the level of participation of residents interacted in a complex way. The participation of landscape architects has changed and expanded its meaning and role. Second, the change and value of the expanded the participation method of landscape architects in the urban regeneration project and appeared as a multi-purpose and complex role in the process of a project, indicating that the value of landscape in the classical sense is changing and its substantive aspect depends on the type of project. Third, this study confirmed the importance of recognizing the role and value of 'landscape architecture' as a strategic and practical means of regeneration that can be utilized. Therefore, in order to promote the participation of landscape architects, diversification is required through changes in participation methods according to urban regeneration strategies for each project, rather than participation focused on hardware projects, such as park creation in terms of form and place. In addition, it was confirmed that the participation of landscape architects, which play an important role in fostering a sense of community among residents as an experience and activity program, should be further activated in terms of the process of the ideal way of existence. This study is meaningful in that it substantially grasps that the role of landscape architects is expanding as the subject of urban regeneration projects, and presents the direction for its promotion. Participation and research should be continued.

• Development and Reproduction
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• v.12 no.1
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• pp.1-8
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• 2008

Specific protocols to increase the differentiation of neuronal cells from embryonic stem (ES) cells have been well established, such as retinoic acid induction and lineage selection of neuronal cells. For the neuropathological studies, ES-derived neurons (ES neurons) must show normal physiological characteristics related to cell death and survival and should be maintained in vitro for a sufficient time to show insults-specific cell death without spontaneous death. When mouse ES cells were plated onto astrocytes monolayer after retinoic acid induction, most ES cells differentiated into neuronal cells, which were confirmed by the presence of specific neuronal markers, and the cultures were viable for at least four weeks. When these cultures were examined for vulnerability to glutamate excitotoxicity, ES neurons were vulnerable to excitotoxic insults mediated by agonist-specific receptors. The vulnerability to excitotoxic death increased with developmental age of ES neurons in vitro. Specific receptors for Neurotrophin and GDNF family ligands were present in ES neurons. GDNF and NT-3 could modulate the survival and excitotoxic vulnerability of ES neurons. The vulnerability and resistance to toxic insults, which are essential requirements of model culture systems for neuropathological studies, make ES neurons to a useful model culture system. Especially ES cell are highly amenable to genetic modification unlikely to primary neuronal cells, which will give us a chance to answer more complicated neurophysiological questions. Recently there was an outstanding attempt to explore the cellular toxicity using human ES cells (Schrattenholz & Klemm, 2007) and it suggested that ES cells could be a new model system for neurophysiological studies soon and go further a large-scale screening system for pharmacological compounds in the future.