• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.1041-1046
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• 2022

Nucleoside deoxyribosyltransferase (NDT) is an enzyme that replaces the purine or pyrimidine base of 2'-deoxyribonucleoside. This enzyme is generally used in the nucleotide salvage pathway in vivo and synthesizes many nucleoside analogs in vitro for various biotechnological purposes. Since NDT is known to exhibit relatively low reactivity toward nucleoside analogs such as 2'-fluoro-2'-deoxynucleoside, it is necessary to develop an enhanced NDT mutant enzyme suitable for nucleoside analogs. In this study, molecular evolution strategy via error-prone PCR was performed with ndt gene derived from Lactobacillus leichmannii as a template to obtain an engineered NDT with higher substrate specificity to 2FDU (2'-fluoro-2'-deoxyuridine). A mutant library of 214 ndt genes with different sequences was obtained and performed for the conversion of 2FDU to 2FDA (2'-fluoro-2'-deoxyadenosine). The E. coli containing a mutant NDT, named NDT^L59Q, showed 1.7-fold (at 40℃) and 4.4-fold (at 50℃) higher 2FDU-to-2FDA conversions compared to the NDT^WT, respectively. Subsequently, both NDT^WT and NDT^L59Q enzymes were over-expressed and purified using a His-tag system in E. coli. Characterization and enzyme kinetics revealed that the NDT^L59Q mutant enzyme containing a single point mutation of leucine to glutamine at the 59^th position exhibited superior thermal stability with enhanced substrate specificity to 2FDU.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.4
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• pp.625-632
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• 2021

This paper studies the effect of the number of filters in the CNN (Convolutional Neural Network) layer on the performance of a noise attenuator. Speech is estimated from a noised speech signal using a 64-neuron, 16-kernel CNN filter and an error back-propagation algorithm. In this study, in order to verify the performance of the noise attenuator with respect to the number of filters, a program using Keras library was written and simulation was performed. As a result of simulation, it can be seen that this system has the smallest MSE (Mean Squared Error) and MAE (Mean Absolute Error) values when the number of filters is 16, and the performance is the lowest when there are 4 filters. And when there are more than 8 filters, it was shown that the MSE and MAE values do not differ significantly depending on the number of filters. From these results, it can be seen that about 8 or more filters must be used to express the characteristics of the speech signal.

• Acta Via Serica
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• v.7 no.2
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• pp.109-132
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• 2022

Two of the main elements of Persian tangible heritage are rugs and gardens, which have evolved together from the dawn of Iranian history. Emerging from the same system of thought and geographical location, together they represent the Persians' world views, desires, dreams, and design paradigms. In this study, the Persian Garden's patterns, elements, typology, and meanings are introduced and compared with the same aspects of Persian rugs. This paper uses a qualitative comparative methodology to analyze rugs' designs and patterns in relation to Persian Gardens' design principles. Data is collected primarily through library study and observation. The author uses two categories for comparison: meanings and forms. First, the author identifies underlying meanings common to the two art forms and then introduces form, function, and general principal patterns into the analysis. There is a type of rug pattern, known as Chahar-Bagh (literally, "four gardens"), that mirrors a garden design, down to the details, which is the focus of this paper. Additionally, other representations of Persian Gardens in rug design, such as Shekargah ("hunting pattern"), are discussed, as are other rug patterns with fewer elements borrowed from garden design. The paper also considers several motifs that represent flora common in gardening on the Iranian plateau, some of which have symbolic meanings dating to the Zoroastrian era. By comparing these two mediums of art (garden and rug) in the context of Persian history and geography, it becomes clear that the Persian rug design, in its roots, is an attempt to bring a garden into interior space. The study shows that the forms, patterns, and meanings reflected in Persian rugs render the study of their designs incomplete without considering the history of gardens.

• Journal of Information Processing Systems
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• v.18 no.4
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• pp.549-561
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• 2022

In the Khmer writing system, the Khmer script is the official letter of Cambodia, written from left to right without a space separator; it is complicated and requires more analysis studies. Without clear standard guidelines, a space separator in the Khmer language is used inconsistently and informally to separate words in sentences. Therefore, a segmented method should be discussed with the combination of the future Khmer natural language processing (NLP) to define the appropriate rule for Khmer sentences. The critical process in NLP with the capability of extensive data language analysis necessitates applying in this scenario. One of the essential components in Khmer language processing is how to split the word into a series of sentences and count the words used in the sentences. Currently, Microsoft Word cannot count Khmer words correctly. So, this study presents a systematic library to segment Khmer phrases using the bi-directional maximal matching (BiMM) method to address these problematic constraints. In the BiMM algorithm, the paper focuses on the Bidirectional implementation of forward maximal matching (FMM) and backward maximal matching (BMM) to improve word segmentation accuracy. A digital or prefix tree of data structure algorithm, also known as a trie, enhances the segmentation accuracy procedure by finding the children of each word parent node. The accuracy of BiMM is higher than using FMM or BMM independently; moreover, the proposed approach improves dictionary structures and reduces the number of errors. The result of this study can reduce the error by 8.57% compared to FMM and BFF algorithms with 94,807 Khmer words.

• Journal of Microbiology and Biotechnology
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• v.32 no.11
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• pp.1471-1478
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• 2022

2'-Fucosyllactose (2'-FL), the most abundant fucosylated oligosaccharide in human milk, has multiple beneficial effects on human health. However, its biosynthesis by metabolically engineered Escherichia coli is often hampered owing to the insolubility and instability of α-1,2-fucosyltransferase (the rate-limiting enzyme). In this study, we aimed to enhance 2'-FL production by increasing the expression of soluble α-1,2-fucosyltransferase from Helicobacter pylori (FucT2). Because structural information regarding FucT2 has not been unveiled, we decided to improve the expression of soluble FucT2 in E. coli via directed evolution using a protein solubility biosensor that links protein solubility to antimicrobial resistance. For such a system to be viable, the activity of kanamycin resistance protein (Kan^R) should be dependent on FucT2 solubility. Kan^R was fused to the C-terminus of mutant libraries of FucT2, which were generated using a combination of error-prone PCR and DNA shuffling. Notably, one round of the directed evolution process, which consisted of mutant library generation and selection based on kanamycin resistance, resulted in a significant increase in the expression level of soluble FucT2. As a result, a batch fermentation with the ΔL M15 pBCGW strain, expressing the FucT2 mutant (F#1-5) isolated from the first round of the directed evolution process, resulted in the production of 0.31 g/l 2'-FL with a yield of 0.22 g 2'-FL/g lactose, showing 1.72- and 1.51-fold increase in the titer and yield, respectively, compared to those of the control strain. The simple and powerful method developed in this study could be applied to enhance the solubility of other unstable enzymes.

• The Journal of Korean Obstetrics and Gynecology
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• v.36 no.2
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• pp.55-68
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• 2023

Objectives: The purpose of this study is to analyze the effectiveness of Guibi-tang that are used for postpartum depression. Methods: We searched on five databases [Korean studies Information Service (KISS), Oriental medicine advanced searching integrated system (OASIS), The Cochrane Library, PubMed, and China national knowledge infrastructure (CNKI)] with keywords for Postpartum depression (English, Korean, and Chinese) and evaluated the risk of bias. Meta-analysis was performed on the selected studies. Results: 8 potentially relevant articles were retrieved for further evaluation. There was evidence that Guibi-tang compared with Western medicine was significantly higher rate in total effect rate (RR 1.20, 95% CI 1.04, 1.39, p=0.01). Also, the combined therapeutic effects of Guibi-tang and Psychological intervention compared with Psychological intervention were statistically significant in total effect rate (RR 1.14, 95% CI 1.05, 1.24, p=0.002). And they showed improvement on scores of HAMD (Hamilton depression scale, HAMD) and SF-36 (36-Item short form health survey, SF-36). Conclusion: Guibi-tang appears to be more effective compared to Western medicine in the treatment of postpartum depression. The combination Guibi-tang and Psychological intervention was more effective than psychological intervention alone treated for postpartum depression. However, since unclear risk of bias, the result of this study should be considered carefully. Further clinical trials should be carried out in order to academical clinical progress regarding treatment of Postpartum Depression.

• Journal of Korean Medicine Rehabilitation
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• v.33 no.2
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• pp.19-32
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• 2023

Objectives The purpose of this study is to systematically review the degree of pain and function improvement in acupuncture treatment for patellofemoral pain syndrome (PFPS). Methods Randomized controlled trials (RCTs) were searched from Medline/PubMed, Cochrane Library, Embase, WanFang Data, China National Knowledge Infrastructure (CNKI), Citation Information by NII (CiNII), Koreanstudies Information Service System (KISS), ScienceON, KoreaMed, and Korean Medical Database (KMbase). The methodological quality of selected RCTs' were evaluated according to Cochrane RoB2 tool. Results Total of 158 studies were identified and 7 RCTs were selected for systematic review. Frequently used evaluation method were visual analogue scale and Kujala scores. All studies showed significant effect on pain reduction and knee function between before and after treatment, but showed partial significance between the intervention and control group. Conclusions Research showed that acupuncture treatment is an effective treatment for improving the pain and function of PFPS, but it is difficult to conclude that it has a significant effect compared to other treatments. Selected studies included subjective evaluation indicators and the total of selected studies were small, so the interpretation of the results is limited. Also most of the included studies are evaluated to have some concerns of bias. Therefore, subsequent research should continously be done in more objective and systematic method.

• The Journal of Korean Obstetrics and Gynecology
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• v.36 no.3
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• pp.196-210
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• 2023

Objectives: The purpose of this study is to review the research trends of infertile women with uterine myoma in Korean medicine and to recognize the efficacy of Korean medicine intervention. Methods: A search was conducted on November 18, 2022, using six databases, including Research Information Sharing Service (RISS), Oriental Medicine Advanced Searching Integrated System (OASIS), Cochrane Library Central, Pubmed, China National Knowledge Infrastructure (CNKI) and WangFang Med Online. We analyzed the studies using Korean medicine on women with uterine myoma preparing for pregnancy or complaining infertility. Results: Total 4 studies were selected and all of which were case reports. Among 6 cases, Korean medicine treatment including herbal medicine, acupuncture, electroacupuncture, moxibustion was used alone. Ikgibohyeol-tang-gami-bang, Gyejibokryeong-hwan, Saenghwa-tang-gami-bang were prescribed in 2 cases each. Angelicae Gigantis Radix and CV4 were most frequently used herb and acupoint. All subjects were successful in becoming pregnant. Conclusion: This review shows that Korean medicine treatment can be effective in infertile women with uterine myoma. However, the number of included studies is small, so the level of evidence needs to be raised through more clinical studies in the future.

• Nutrition Research and Practice
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• v.16 no.sup1
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• pp.57-69
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• 2022

BACKGROUND/OBJECTIVES: Vitamin D is produced in the skin during sun exposure and is also ingested from foods. The role of vitamin D needs to be considered in the prevention and management of various diseases. Moreover, since the majority of Koreans spend their days indoors, becoming susceptible to the risk of vitamin D deficiency. The current study aims to prepare a basis for determining dietary reference intake of vitamin D in Korea, by reviewing the evidence against various diseases and risks. MATERIALS/METHODS: Literature published in Korea and other countries between 2014 and 2018 was prioritized based on their study design and other criteria, and evaluated using the RoB 2.0 assessment form and United States Department of Agriculture Nutrition Evidence Library Conclusion Statement Evaluation Criteria. RESULTS: Of the 1,709 studies, 128 studies were included in the final systematic analysis after screening. To set the dietary reference intakes of vitamin D based on the selected articles, blood 25(OH)D levels and indicators of bone health were used collectively. Blood vitamin D levels and ultraviolet (UV) exposure time derived from the Korean National Health and Nutrition Examination Survey were analyzed to establish the dietary reference intakes of vitamin D for each stage of the life cycle. The adequate intake levels of vitamin D, according to age and gender, were determined to be in the range of 5-15 ㎍/day, and the tolerable upper intake level was established at 25-100 ㎍/day. CONCLUSIONS: The most important variable for vitamin D nutrition is lifestyle. A balanced diet comprising foods with high contents of vitamin D is important, as is vitamin D synthesis after UV exposure. The adequate intake level of vitamin D mentioned in the 2015 Dietary Reference Intakes for Korean (KDRI) remained unchanged in the 2020 KDRI for the management of vitamin D nutrition in Koreans.