• 생명과학회지
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• 제25권6호
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• pp.656-662
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• 2015

천연물을 기반으로 한 신약 개발은 일반적으로 오랜 기간 동안의 원료 약물로써 사용해 온 경험에 의한 다양한 임상적 결과의 축적과 이로 인한 안정성(stability)과 안전성(safety)의 확보 및 신약 개발 시간의 단축과 같은 이점을 가지고 있어, 천연물 유래 약물 연구는 꼭 필요한 실정이다. 다양한 신경질환에서 신경세포의 사멸과 미세아교세포의 과도한 활성화 즉 뇌염증이 관찰되며 이를 억제할 수 있는 물질에 대한 연구는 활발히 진행 중이지만, 현재까지 신경세포 사멸과 뇌염증을 동시에 억제하는 물질 개발 시도는 거의 없었다. 따라서, 본 연구에서는 천연물에서 추출한 물질로 총 240개로 구성된 라이브러리로부터 신경전달물질 중의 하나인 glutamate 과잉처리에 의한 산화적 스트레스 유도 신경세포(HT22) 사멸과 LPS에 의한 미세아교세포(BV2)의 과도한 활성화 즉 뇌염증의 표지 인자 중 하나인 NO의 생산량의 감소 효과가 동시에 나타나는 물질을 검출한 결과, 대황에서 추출한 Chrysophanol이 검출되었으며 더욱이 Chrysophanol이 신경세포와 미세아교세포 모두에서 glutamate와 LPS에 의해 각각 유도된 세포내 활성산소(ROS) 발생을 억제하는 것을 확인하였다. 앞으로 Chrysophanol에 대한 보다 깊은 연구를 통하여 산화적 스트레스에 의한 신경세포 사멸과 미세아교세포의 과잉 활성화에 따른 뇌염증의 발생을 동시에 억제하는 신경질환의 치료 및 예방 신약개발 후보 물질 가능성을 제시 하고자 한다.

• 대한한방내과학회지
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• 제42권4호
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• pp.605-621
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• 2021

Objectives: The purpose of this review is to assess the efficacy and safety of Hwangryunhaedok-tang for type 2 diabetes without complications by systemic review and meta-analysis of randomized controlled trials (RCTs). Methods: We searched the following up to March 31. 2021: PubMed, EMBASE, The Cochrane Library, CNKI, CiNii, KISS, KMBASE, OASIS, ScienceON. Data extraction and assessment of Cochrane's risk of bias (RoB) tool were performed by two independent authors, and if there was disagreement between two researchers, it was resolved through the intervention of a third researcher. Results: A total of seven trials are included in this systemic review. The treatment group (Hwangryunhaedok-tang plus conventional treatment) showed more statistically significant effects than did the control group (conventional treatment only) in fasting plasma glucose level, 2-hour postprandial plasma glucose level, glycated hemoglobin A1c, fasting insulin level, and HOMA-IR. There was no significant difference between the treatment group (Hwangryunhaedok-tang alone) and the control group (metformin alone). Conclusion: Hwangryunhaedok-tang might have efficacy and safety in controlling blood sugar level and improving insulin-resistance. However, the number of studies included in the meta-analysis was insufficient, and the Hwangryunhaedok-tang used in the included studies was not standardized. Also, the quality of the involved studies was generally low. Therefore, further studies are needed to determine the efficacy and safety of Hwangryunhaedok-tang treatment for type 2 diabetes mellitus.

• Clinical Psychopharmacology and Neuroscience
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• 제16권4호
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• pp.361-375
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• 2018

We aimed to compare the efficacy and safety of long-acting injectable (LAI) and oral second-generation antipsychotics (SGAs) in treating schizophrenia by performing a systematic review and meta-analysis. MEDLINE, EMBASE, PsycINFO, CINAHL, and the Cochrane Library, as well as five Korean databases, were systemically searched to identify studies published from 2000 to 16 April 2015, which compared the efficacy and safety of LAI and oral SGAs. Using data from randomized controlled trials (RCTs), meta-analyses were conducted. In addition, the GRADE (the Grading of Recommendations, Assessment, Development and Evaluation) approach was applied to explicitly assess the quality of the evidence. A total of 30 studies including 17 RCTs and 13 observational studies were selected. The group treated with LAI SGAs was characterized by significantly lower relapse rates, longer times to relapse and fewer hospital days, but also by a higher occurrence of extrapyramidal syndrome and prolactin-related symptoms than that in the group treated with oral SGAs. Our findings demonstrate that there is moderate to high level of evidence suggesting that in the treatment of schizophrenia, LAI SGAs have higher efficacy and are associated with higher rates of extrapyramidal syndrome and prolactin-related symptoms. Additionally, the use of LAI SGAs should be combined with appropriate measures to reduce dopamine $D_2$ antagonism-related symptoms.

• Mycobiology
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• 제47권2호
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• pp.242-249
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• 2019

Betaine derivatives are considered major ingredients of shampoos and are commonly used as antistatic and viscosity-increasing agents. Several studies have also suggested that betaine derivatives can be used as antimicrobial agents. However, the antifungal activity and mechanism of action of betaine derivatives have not yet been fully understood. In this study, we investigated the antifungal activity of six betaine derivatives against Malassezia restricta, which is the most frequently isolated fungus from the human skin and is implicated in the development of dandruff. We found that, among the six betaine derivatives, lauryl betaine showed the most potent antifungal activity. The mechanism of action of lauryl betaine was studied mainly using another phylogenetically close model fungal organism, Cryptococcus neoformans, because of a lack of available genetic manipulation and functional genomics tools for M. restricta. Our genome-wide reverse genetic screening method using the C. neoformans gene deletion mutant library showed that the mutants with mutations in genes for cell membrane synthesis and integrity, particularly ergosterol synthesis, are highly sensitive to lauryl betaine. Furthermore, transcriptome changes in both C. neoformans and M. restricta cells grown in the presence of lauryl betaine were analyzed and the results indicated that the compound mainly affected cell membrane synthesis, particularly ergosterol synthesis. Overall, our data demonstrated that lauryl betaine influences ergosterol synthesis in C. neoformans and that the compound exerts a similar mechanism of action on M. restricta.

• Nuclear Engineering and Technology
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• 제48권2호
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• pp.318-329
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• 2016

Reducing critical boron concentration in a commercial pressurized water reactor core offers many advantages in view of safety and economics. This paper presents a preliminary investigation of a reduced-boron pressurized water reactor core to achieve a clearly negative moderator temperature coefficient at hot zero power using the newly-proposed "Burnable absorber-Integrated Guide Thimble" (BigT) absorbers. The reference core is based on a commercial OPR1000 equilibrium configuration. The reduced-boron ORP1000 configuration was determined by simply replacing commercial gadolinia-based burnable absorbers with the optimized BigT-loaded design. The equilibrium cores in this study were directly searched via repetitive Monte Carlo depletion calculations until convergence. The results demonstrate that, with the same fuel management scheme as in the reference core, application of the BigT absorbers can effectively reduce the critical boron concentration at the beginning of cycle by about 65 ppm. More crucially, the analyses indicate promising potential of the reduced-boron OPR1000 core with the BigT absorbers, as its moderator temperature coefficient at the beginning of cycle is clearly more negative and all other vital neutronic parameters are within practical safety limits. All simulations were completed using the Monte Carlo Serpent code with the ENDF/B-VII.0 library.

• 한방안이비인후피부과학회지
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• 제32권4호
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• pp.90-100
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• 2019

Objectives : The purpose of this study is to determine the safety and efficacy of low level laser. Methods : We searched 11 electronic databases(Pubmed, CAJ, EMBASE, Medline, Cochrane Library, KMBASE, KISS, KISTI, NDSL, RISS, Oasis) up to March 2019. We included randomized controlled trials(RCTs) using low level laser for alopecia. The methodological quality of each RCT was assessed by the Cochrane risk of bias tool. Results : 8 RCT studies were eligible in our review. The meta-analysis of 2 studies showed favorable results for the use of low level laser with minoxidil 5% than minoxidil 5% and 6 studies showed favorable results for the use of low level laser than placebo light. The results of meta-analysis showed that low-level laser has an efficacy on alopecia. There were no serious side effects or adverse effects. High risk of bias were observed in all studies. Conclusion : Now limited evidence is available to support low level laser for alopecia and further well-designed RCTs should be encouraged.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2454-2463
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• 2021

The objective of this research is to the use of americium (AmO₂) as a burnable absorber effectively instead of conventional gadolinium (Gd₂O₃) for VVER-1200 reactor by analyzing its impacts on reactivity, power peaking factor (PPF), safety factor, and quality of the spent fuel. The assembly is burned to 60 GWd/t by using SRAC-2006 code and JENDL-4.0 data library for finding the optimum amount and effective way of using AmO₂ as a burnable absorber. From these studies, it is found that AmO₂ can decrease the excess reactivity like Gd₂O₃ without changing the criticality life span and enrichment of ²³⁵U. A homogeneous mixture of the 0.20% AmO₂+ 4.95% enriched UO₂ fuel rod (model MF-4) decreases the PPF than the reference assembly. The use of AmO₂+UO₂ in the integral burnable absorber (IBA) rod or the outer layer could also decrease the PPF up to 10 GWd/t but increases rapidly after 30 GWd/t, which could be a safety threat. The fuel temperature coefficient and void coefficient of the model MF-4 are the same as the reference assembly. In addition, 22% of initially loaded Am are burning effectively and contributing to the power production.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2445-2453
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• 2021

Since the nuclear data forms a vital component in reactor physics computations, the nuclear community needs processing codes as tools for translating the Evaluated Nuclear Data Files (ENDF) to simulate nuclear-related problems such as an ACE format that is used for MCNP. Errors, inaccuracies or discrepancies in library processing may lead to a calculation that disagrees with the experimentally measured benchmark. This paper provides an overview of the processing and preparation of ENDF/B-VIII.0 incident neutron data with NECP-Atlas and NJOY codes for implementation in the MCNP code. The resulting libraries are statistically inter-compared and tested by conducting benchmark calculations, as the mutualcomparison is a source of strong feedback for further improvements in processing procedures. The database of the benchmark experiments is based on a selection taken from the International Handbook of Evaluated Criticality Safety Benchmark Experiments (ICSBEP handbook) and those proposed by Russell D. Mosteller. In general, there is quite good agreement between the NECP-Atlas1.2 and NJOY21^(1.0.0.json) results with no substantial differences, if the correct input parameters are used.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2095-2103
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• 2021

A small power ADS design using thorium oxide and diluent matrix reprocessed fuel is proposed for a high transmutation rate, small reactivity swing, and strong safety features. Two fuel matrices (CERCER and CERMET) and different recycled fuel compositions recovered from UO₂ spent fuels with 45 GWd/tU and 60 GWd/tU burnup were investigated to determine the suitable fuel for the ADS. It was found that the transmutation of each isotope depends on TRU initial loading amount. After examining the cores, the results show that CERCER fueled ADS has a negative coolant void reactivity (CVR) and a smaller radiotoxicity at discharge compared to that of CERMET core. It implies that CERCER fuel has enhanced safety features and more flavor in terms of radiotoxicity management. To increase fuel utilization and core operation efficiency, a simple assembly shuffling pattern for the CERCER fueled ADS is also proposed. Eigenvalue and burnup calculations were conducted using Serpent 2 with ENDF/B-VII.0 library in both kcode and external source modes, and it indicates that the results of transmutation analyses obtained by kcode only is reliable to discuss the transmutation potential of ADS. Burnup calculation with the fixed-source mode is essential to be used for more practical results of the transmutation by ADS.

• 대한한의학회지
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• 제42권4호
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• pp.75-101
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• 2021

Objectives: ncluding stroke. The aim of this study was to systematically review the clinical evidence of CT for stroke. Methods: To identify randomized controlled trials (RCTs) reporting the effectiveness and/or safety of CT, seven databases including PubMed, EMBASE, and Cochrane Library were searched for articles published from January 2000 to February 2021 without language restrictions. Meta-analysis was performed using Review Manager 5.4 software and the results were presented as mean difference (MD) or standard mean difference (SMD) for continuous variables and odds ratio (OR) for diverse variables with 95% confidence intervals (CIs). Assessment of the methodological quality of the eligible trials was conducted using the Cochrane Collaboration tool for risk of bias in RCTs. Results: Twenty-two RCTs with 1653 participants were included in the final analysis. CT provided additional benefit in improving upper limb motor function (Fugl-Meyer assessment for upper limb motor function, MD 6.91, 95% CI 4.64 to 1.67, P<0.00001) and spasticity (response rate, OR 3.28, 95% CI 1.31 to 8.22, P=0.08) in stroke survivors receiving conventional medical treatment. These findings were supported with a moderate level of evidence. CT did not significantly increase the occurrence of adverse events. Conclusions: This study demonstrated the potential of CT to be beneficial in managing a variety of complications in stroke survivors. However, to compensate for the shortcomings of the existing evidence, rigorously designed large-scale RCTs are warranted in the future.