• Journal of Ginseng Research
• /
• 제46권2호
• /
• pp.255-265
• /
• 2022

Background: Ginsenoside Rb1, a bioactive component isolated from the Panax ginseng, acts as a remedy to prevent myocardial injury. However, it is obscure whether the cardioprotective functions of Rb1 are related to the regulation of endogenous metabolites, and its potential molecular mechanism still needs further clarification, especially from a comprehensive metabolomics profiling perspective. Methods: The mice model of acute myocardial ischemia (AMI) and oxygen glucose deprivation (OGD)-induced cardiomyocytes injury were applied to explore the protective effect and mechanism of Rb1. Meanwhile, the comprehensive metabolomics profiling was conducted by high-performance liquid chromatography and quadrupole time-of-flight mass spectrometry (HPLC-Q/TOF-MS) and a tandem liquid chromatography and mass spectrometry (LC-MS). Results: Rb1 treatment profoundly reduced the infarct size and attenuated myocardial injury. The metabolic network map of 65 differential endogenous metabolites was constructed and provided a new inspiration for the treatment of AMI by Rb1, which was mainly associated with mitophagy. In vivo and in vitro experiments, Rb1 was found to improve mitochondrial morphology, mitochondrial function and promote mitophagy. Interestingly, the mitophagy inhibitor partly attenuated the cardioprotective effect of Rb1. Additionally, Rb1 markedly facilitated the phosphorylation of AMP-activated protein kinase α (AMPKα), and AMPK inhibition partially weakened the role of Rb1 in promoting mitophagy. Conclusions: Ginsenoside Rb1 protects acute myocardial ischemia injury through promoting mitophagy via AMPKα phosphorylation, which might lay the foundation for the further application of Rb1 in cardiovascular diseases.

• 분석과학
• /
• 제28권4호
• /
• pp.278-287
• /
• 2015

Phosphodiesterase type 5 inhibitors (PDE-5 inhibitors) are used in the treatment of erectile dysfunction. In recent years, a number of reports have been conducted on dietary supplements contaminated with PDE-5 analogues. In this study, 58 analogues of PDE-5 inhibitors were sorted into five groups: tadalafil, sildenafil, hongdenafil, vardenafil, and other analogues. These analogues were then evaluated using a liquid chromatography-quadrupole-time of flight mass spectrometry (LC-QTOF-MS) electrospray ionization mass method. Each compound has a unique fragmentation ion, which can be easily analyzed qualitatively. The fragmentation pathways of the analogues were elucidated based on the QTOF-MS and MS/MS data. Common ions were confirmed for each group by analyzing the structural characteristics and fragmentation pathways. Specifically, common ions were observed at m/z 169.08 and 135.04 (tadalafil analogues), m/z 311.15 and 283.12 (sildenafil analogues and hongdenafil analogues), and m/z 312.16 and 151.09 (vardenafil analogues). The advantage of this method is that the structure of unknown components can be determined by interpreting the product ions. Hence, the developed method can be used for the identification of unknown compounds. Fragmentation pathways may also aid in the detection and identification of PDE-5 inhibitor analogues.

• 한국산학기술학회논문지
• /
• 제13권1호
• /
• pp.87-98
• /
• 2012

교육과학기술부는 고등교육 프로그램 평가인증기관에 대한 정부 인정 사업을 추진해왔다. 이에 본 연구는 정부가 프로그램 평가인증기관을 인정하는 평가모형을 설정하고, 평가부문 및 평가항목, 평가지표를 개발하는데 목적이 있다. 이를 위해 본 연구는 프로그램 평가인증기관에 대한 정부인정의 개념을 설정하고, 프로그램 평가인증기관에 대한 정부인정 평가모형을 설계하였다. 평가 모형은 고등교육 프로그램 평가인증기관에 대한 정부인정사업의 절차를 반영하여 정부인정기관으로서의 기본적인 요건에 부합되는지 여부에 대한 적격성 검토를 수행하는 예비평가단계, 법령 및 관련 규정에 제시된 평가영역별 지정기준에 대한 충족 여부를 검증하는 본 평가단계의 과정으로 설정하였다. 아울러 평가영역에 따라 평가부문, 평가항목 및 평가지표들을 개발하였고, 심층적 검증을 위해 평가전문가들의 검토를 거쳐 2개 평가영역, 5개 평가부문, 24개 평가항목 및 33개 평가지표를 확정하였다.

• International Journal of Computer Science & Network Security
• /
• 제21권5호
• /
• pp.243-255
• /
• 2021

This study aimed to identify the effectiveness of the use of distance-evaluation tools and methods among students with learning difficulties from the teachers' point of view, to achieve this goal. A scale was built, and the psychometric characteristics were validated. It consisted, in its final form, of 17 items distributed on four axes, in addition to three open questions. It was applied to a random sample of (149) teachers of students with learning difficulties in Makkah Region. The results showed that teachers' keenness to encourage students with learning difficulties, so that they would not feel frustrated with the distance learning process. It was also evident that teachers did not use achievement portfolios in the evaluation process. In connection with the appropriate evaluation methods, the majority indicated the use of work sheets and visual evaluation methods that rely on audio and visual skills, such as presenting videos, pictures, audio and games, and applying short objective tests. Among the proposals to improve evaluation methods and tools: Individual evaluation, attention to individual treatment, obligating personal attendance of students to school, splitting the required tasks, and not increasing the skills required to be mastered. As for the obstacles that teachers face: Lack of time, difficulty in communicating with students with distance learning difficulties and problems related to the Internet such as interruption, weakness, or lack of availability.

• Biomolecules & Therapeutics
• /
• 제25권3호
• /
• pp.288-295
• /
• 2017

The incidence of polypharmacy-which can result in drug-drug interactions-has increased in recent years. Drug-metabolizing enzymes and drug transporters are important polypharmacy modulators. In this study, the effects of bosentan and rifampin on the expression and activities of organic anion-transporting peptide (OATP) and cytochrome P450 (CYP450) 2C9 and CYP3A4 were investigated in vitro. HEK293 cells and primary human hepatocytes overexpressing the target genes were treated with bosentan and various concentrations of rifampin, which decreased the uptake activities of OATP transporters in a dose-dependent manner. In primary human hepatocytes, CYP2C9 and CYP3A4 gene expression and activities decreased upon treatment with $20{\mu}M$ $bosentan+200{\mu}M$ rifampin. Rifampin also reduced gene expression of OATP1B1, OATP1B3, and OATP2B1 transporter, and inhibited bosentan influx in human hepatocytes at increasing concentrations. These results confirm rifampin- and bosentan-induced interactions between OATP transporters and CYP450.

• Geomechanics and Engineering
• /
• 제12권1호
• /
• pp.35-52
• /
• 2017

In order to evaluate the grouting effects of water-rich fault in tunnels systematically, a feasible and scientific method is introduced based on the extension theory. First, eight main influencing factors are chosen as evaluation indexes by analyzing the changes of permeability, mechanical properties and deformation of surrounding rocks. The model of evaluating grouting effects based on the extension theory is established following this. According to four quality grades of grouting effects, normalization of evaluation indexes is carried out, aiming to meet the requirement of extension theory on data format. The index weight is allocated by adopting the entropy method. Finally, the model is applied to the grouting effects evaluation in water-rich fault F4-4 of Qingdao Jiaozhou Bay Subsea Tunnel, China. The evaluation results are in good agreement with the test results on the site, which shows that the evaluation model is feasible in this field, providing a powerful tool for systematically evaluating the grouting effects of water-rich fault in tunnels.

• 경영과학
• /
• 제14권1호
• /
• pp.177-203
• /
• 1997

This study concerns performance evaluation of the research-funding agencies focused on Korea Science and Engineering Foundation(KOSEF). On the basis of the constituents approach and the systems approach of organizational effectiveness theory, the evaluation items are derived reflecting generic characteristics of the research-funding agencies, and their priorities are determined using analytic hierarchy process(AHP). Three groups of constituents with differing interest and expections are identified, and their perceptions on the importance of the evaluation items are measured through questionnaire survey. Analyses show that the evaluation items perceived important by each constituency are significant different from one another. The implications of the result to the Government and KOSEF are discussed.

• ETRI Journal
• /
• 제27권4호
• /
• pp.465-468
• /
• 2005

This paper presents a new trust evaluation scheme in an ad hoc network. To overcome the limited information about unfamiliar nodes and to reduce the required memory space, we propose a cluster-based trust evaluation scheme, in which neighboring nodes form a cluster and select one node as a cluster head. The head issues a trust value certificate that can be referred to by its non-neighbor nodes. In this way, an evaluation of an unfamiliar node's trust can be done very efficiently and precisely. In this paper, we present a trust evaluation metric using this scheme and some operations for forming and managing a cluster. An analysis of the proposed scheme over some security problems is also presented.

• 분석과학
• /
• 제16권1호
• /
• pp.90-93
• /
• 2003

The standard uncertainties of two different approaches using the same data set are compared and evaluated using an example of gravimetric standard gas preparation. It is shown that the correlation between input quantities should be taken into account for the proper evaluation of uncertainty resulting from random effects.

• International Journal of Advanced Culture Technology
• /
• 제6권4호
• /
• pp.131-142
• /
• 2018

This research examines the impact of teachers' self-evaluation on their classroom interactions with students. Changes in class behavior were analyzed by following two experienced middle school teachers for one semester of self-evaluation, comparing their classes at the beginning and end of the semester. A qualitative research method was adopted to take, a deeper look at the effect of changes in the teachers' in class actions. Both of the teachers reported positive effects of implementing self-evaluation on their teaching pedagogy, focusing specifically on their interactions with students when asking question and giving feedback. By the end of semester, they were asking broader questions that encouraged their students to engage in deeper thought and, when giving feedback, the class atmosphere was much brighter with better communication due to the positive reinforcement provided. This research supports research into ways to enhance teachers' expertise and improve their teaching via self-evaluation, centering on teachers' actions in the classroom.