Effect of Bisphenol A Exposure on DNA Methylation is Associated with Decrease in Low-Frequency Power of Heart Rate Variability

Bao Dieu Linh Ngo(Bao Dieu Linh Ngo ),Yun-Chul Hong(Yun-Chul Hong),Jin Hee Kim(Jin Hee Kim) 한국환경보건학회 2021 한국환경보건학회 학술대회 자료집 Vol.2021 No.2

Analysis and Characterization of Glutathione Peroxidases in an Environmental Microbiome and Isolated Bacterial Microorganisms

( Yun-juan Bao ),( Qi Zhou ),( Xuejing Yu ),( Xiaolan Yu ),( Francis J ),( Castellino ) 한국미생물생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.3

Glutathione peroxidases (Gpx) are a group of antioxidant enzymes that protect cells or tissues against damage from reactive oxygen species (ROS). The Gpx proteins identified in mammals exhibit high catalytic activity toward glutathione (GSH). In contrast, a variety of non-mammalian Gpx proteins from diverse organisms, including fungi, plants, insects, and rodent parasites, show specificity for thioredoxin (TRX) rather than GSH and are designated as TRX-dependent peroxiredoxins. However, the study of the properties of Gpx in the environmental microbiome or isolated bacteria is limited. In this study, we analyzed the Gpx sequences, identified the characteristics of sequences and structures, and found that the environmental microbiome Gpx proteins should be classified as TRX-dependent, Gpx-like peroxiredoxins. This classification is based on the following three items of evidence: i) the conservation of the peroxidatic Cys residue; ii) the existence and conservation of the resolving Cys residue that forms the disulfide bond with the peroxidatic cysteine; and iii) the absence of dimeric and tetrameric interface domains. The conservation/divergence pattern of all known bacterial Gpx-like proteins in public databases shows that they share common characteristics with that from the environmental microbiome and are also TRX-dependent. Moreover, phylogenetic analysis shows that the bacterial Gpx-like proteins exhibit a star-like radiating phylogenetic structure forming a highly diverse genetic pool of TRX-dependent, Gpx-like peroxidases.

AI-Enabled Special Education : A Study on Factors Influencing Chinese Disabled College Students' Acceptance of AI-Assisted Mobile Foreign Language Vocabulary Learning

Bao, Tong,Bao, Xin Yun 중국지역학회 2024 중국지역연구 Vol.11 No.3

특수 교육 분야에서 인공지능 기술의 응용에 대한 관심이 점점 높아지고 있다. 모바일 학습 환경에서 스마트 기술은 장애 학생들에게 맞춤형 및 이용하기 용이한 언어 학습을 지원해 교육의 공정성을 높이고 학습 경험을 향상시킬 것으로 기대된다. 그러나 기존의 연구는 장애 학생들의 인공지능 보조 수단을 통한 모바일 언어 학습 수용에 영향을 미치는 요인 및 작용 메커니즘에 대한 관심이 부족했다. 본 연구는 장애 대학생 301명을 대상으로 최소자승법 구조방정식 모델(PLS-SEM)을 적용하여 인지적 태도와 감정적 태 도에 영향을 미치고 학생들의 수용도에 영향을 미치는 인지적 접근성, 인지적 유용성, 인지적 용이성 등과 같은 체계적인 특성을 분석하였다. 연구에 따르면 인지적 용이성과 인지적 유용성, 인지적 접근성은 차례로 학생들의 수용도에 영향을 미쳤다. 그중 인지적 용이성의 영향 정도가 가장 컸고 인지적 접근성의 영향 정도가 가장 낮은 것으로 나타났 다. 인지적 태도와 감정적 태도는 외부 자극 요인과 수용도 사이에서 이중매개 역할을 하였다. 그러나 인지적 접근성은 감정적 태도가 아닌 인지적 태도라는 단일 경로를 통해 수용도에 영향을 미친 것으로 나타났다. 이는 장애 학생들의 신기술 적용에 대한 심리적 요인 및 작용 메커니즘을 이해하는 데 도움이 되고 나아가 인지적 용이성, 감정적 경험 등의 요소의 중요성을 보여주고 있다. 뿐만 아니라 특수 교육 분야의 기술 수용 행위에 대한 연구를 풍부하게 하여 관련 학습 시스템의 최적화된 설계와 적용을 위한 실증적 근거와 실천적 시사점을 제공하고 있다. 본 연구의 결과는 특수 교육 분야에서 인공지능 기술의 심도 있는 적용과 혁신적 발전에 중요한 혁신적 가치가 있다. The application of artificial intelligence technology in special education is receiving increasing attention. In mobile learning environments, intelligent technology provides personalized and accessible language learning support for disabled students, potentially promoting educational equity and enhancing the learning experience. However, existing research has paid little attention to the factors influencing disabled students' acceptance of AI-assisted mobile foreign language vocabulary learning and the underlying mechanisms. This study targets 301 disabled college students, applying PLS-SEM to explore how system characteristics such as perceived accessibility, perceived usefulness, and perceived ease of use influence students' acceptance through cognitive and affective attitudes. The research finds that perceived ease of use, perceived usefulness, and perceived accessibility have decreasing levels of influence on students' acceptance, respectively. Cognitive and affective attitudes play a dual mediating role between external stimuli factors and acceptance, but perceived accessibility only influences acceptance through cognitive attitude rather than affective attitude. These findings reveal key psychological factors and mechanisms in disabled students' adoption of new technology, highlighting the importance of perceived ease of use and emotional experience. They enrich research on technology acceptance behavior in special education and provide empirical evidence and practical insights for optimizing the design and promotion of related learning systems. The results of this study have important reference value for the in-depth application and innovative development of artificial intelligence technology in special education.

Roles of microRNA-206 in Osteosarcoma Pathogenesis and Progression

Bao, Yun-Ping,Yi, Yang,Peng, Li-Lin,Fang, Jing,Liu, Ke-Bin,Li, Wu-Zhou,Luo, Hua-Song Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

Backgroud and Aims: MicroRNA-206 has proven to be down-regulated in many human malignancies in correlation with tumour progression. Our study aimed to characterize miR-206 contributions to initiation and malignant progression of human osteosarcoma. Methods: MiR-206 expression was detected in human osteosarcoma cell 1ine MG63, human normal osteoblastic cell line hFOB 1.19, and paired osteosarcoma and normal adjacent tissues from 65 patients using quantitative RT-PCR. Relationships of miR-206 levels to clinicopathological characteristics were also investigated. Moreover, miR-206 mimics and negative control siRNA were transfected into MG63 cells to observe effects on cell viability, apoptosis, invasion and migration. Results: We found that miR-206 was down-regulated in the osteosarcoma cell line MG63 and primary tumor samples, and decreased miR-206 expression was significantly associated with advanced clinical stage, T classification, metastasis and poor histological differentiation. Additionally, transfection of miR-206 mimics could reduce MG-63 cell viability, promote cell apoptosis, and inhibit cell invasion and migration. Conclusions: These findings indicate that miR-206 may have a key role in osteosarcoma pathogenesis and development. It could serve as a useful biomarker for prediction of osteosarcoma progression, and provide a potential target for gene therapy.

Nonlinear dynamic analysis of an external gear system with meshing beyond pitch point

He-yun Bao,Guang-hu Jin,Feng-xia Lu 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.12

A two-dimensional non-linear dynamics model of a gear with meshing beyond pitch point with six degrees has been established, considering time-varying meshing stiffness, time-varying bearing stiffness, time-varying friction, backlash and bearing clearance. Timevarying meshing stiffness is computed by using material mechanics method. The friction coefficient of Coulomb model and the friction coefficient of EHL theory are analyzed and compared in dynamic response. The global bifurcation characteristics caused by input speed, backlash, bearing clearance and damping are investigated. The maximum Lyapunov exponent which leads to chaos characters effect of changing parameters is analyzed. The verification experiment is carried out on the CL-100 test rig. Meshing frequency has main impact on vibration acceleration of ordinary spur gear and double meshing frequency has main impact on vibration acceleration of gear with meshing beyond pitch point. The results show that the gear with meshing beyond is better than ordinary spur gear whether in bifurcation characteristics or in vibration acceleration response.

Temperature impact analysis of star gear bearing inner ring based on under-race lubrication passage

He-yun Bao,Chun-lei Wang,Feng-xia Lu 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.12

In order to reduce the inner ring temperature and the oil consumption, temperature impact of star gear bearing inner ring based on under-race lubrication passage is analyzed, the flow and temperature fields of the inner ring are simulated using the realizable k-ɛ turbulence model based on the computational fluid dynamics (CFD) method, and experimental verification is performed. The results indicate that adding annular grooves to the star gear cylindrical roller bearing has a significant impact in reducing the temperature of the inner ring, and annular grooves with different cross-sectional sizes have different impacts in reducing the temperature of the inner ring. When the cross-sectional area of the annular grooves is 5 × 1.5 mm, the temperatures of the inner raceway of the left and right bearing decrease from 123.95 and 111.98 °C to 104.3 and 101.4 °C, respectively.

Analysis on temperature field of friction pair of aviation friction clutch based on different groove shapes of friction disk

He-yun Bao,Weidi Kong,Xiaonan Hou,Rupeng Zhu 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.8

To examine the influence of the groove shape of a friction disk on the transient temperature field in the engagement process of aviation wet friction clutch, a transient thermal analysis model of friction clutch was established, and the application method of thermal boundary conditions, including the calculation of convective heat transfer coefficient and heat flux density, was studied. The transient heat loading process was established by the partition method of friction disk and steel disk. The temperature characteristics of wet clutch friction pairs with different groove shapes during the engagement process were analyzed and tested on an SAE#2 testing machine. Results show that when the clutch is engaged, the temperature of the friction pair composed of two-way parallel groove, three-way parallel groove, and waffle groove friction disk increases continuously at first and finally decreases slightly; the highest temperature of the friction disk and steel disk is at the ring near the outer ring of the friction disk;and the waffle groove friction disk is more suitable for aviation wet friction clutch.

Calculation method of radial displacement in the engaging process of wet friction clutch

He-yun Bao,Xiang Li,Wei Huang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.9

The radial vibration of the wet friction clutch has a certain influence on the engagement characteristics during the engagement process, and this influence cannot be ignored. This paper takes a variable speed configuration as the research object, establishing a six-degree-of-freedom equivalent bending-torsional vibration model of the variable speed transmission system, and studies the calculation method of the meridional displacement during the engagement process of the clutch. The Runge-Kutta method is used in this paper to solve the dynamic model and analyzes the relationship between the joint state and the radial vibration amplitude. The verified experiment is then conducted. Simulation and test results show the following: the clutch eccentric distance and the radial vibration amplitude, as well as the mass of the driven disc of the clutch and the radial vibration amplitude, all increase. The supporting rigidity of the clutch becomes large, the amplitude of radial vibration becomes small.

Novel DNAH1 Mutation Loci Lead to Multiple Morphological Abnormalities of the Sperm Flagella and Literature Review

Zhuang Bao-Jun,Xu Su-Yun,Dong Liang,Zhang Pei-Hai,Zhuang Bao-Lin,Huang Xiao-Peng,Li Guang-Sen,You Yao-Dong,Chen Di'Ang,Yu Xu-Jun,Chang De-Gui 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.4

The protein encoded by dynein axonemal heavy chain 1 (DNAH1) is a part of dynein, which regulates the function of cilia and sperm flagella. The mutant of DNAH1 causes the deletion of inner dynein arm 3 in the flagellum, leading to multiple morphological abnormalities of the sperm flagella (MMAF) and severe asthenozoospermia. However, instead of asthenozoospermia and MMAF, the result caused by the mutation of DNAH1 remains unknown. Here we report a male infertility patient with severe asthenozoospermia and teratozoospermia. We found two heterozygous mutations in DNAH1 (c.6912C>A and c.7076G>T) and which were reported to be associated with MMAF for the first time. We next collected and analyzed 65 cases of DNAH1 mutation and found that the proportion of short flagella is the largest, while the bent flagella account for the smallest, and the incidence of head deformity is not high in the sperm of these patients. Finally, we also analyzed 31 DNAH1 mutation patients who were treated with intracytoplasmic sperm injection (ICSI) and achieved beneficial outcomes. We hope our research will be helpful in the diagnosis and treatment of male infertility caused by DNAH1 mutation.

아편전쟁을 바라보는 조선의 다중 시선 - 19세기 중후반 조선 조정, 지식층, 서민층의 대청인식 연구 -

장보운 ( Zhang Bao Yun ) 한국사상사학회 2017 韓國思想史學 Vol.0 No.56

본 연구는 제1차·제2차 아편전쟁에 대한 조선 조정, 지식층 그리고 서민층의 반응을 중심으로 당시 조선 사회 각 계층의 대청인식에 대해 고찰하였다. 제1차 아편전쟁에 대해 당시 조선에서는 유신환(兪莘煥), 이항로(李恒老) 등 극소수의 지식인을 제외하고는 조선 조정 내부나 지식층, 서민층에서 모두 큰 위기로 인식하지 않았고 무덤덤하거나 낙관적인 반응을 보였다. 이는 서민층이나 일부 지식인들이 전쟁 소식을 신속하게 접하지 못했던 것도 한 원인이었을 것으로 파악된다. 또한 청이 제1차 아편전쟁에 대해 보여준 상황에 대한 인식이 낙관적이었기 때문에 조선사회에서도 청의 패전에 대해 큰 관심을 가지지 않았다고 분석된다. 한편 제1차 아편전쟁에서 청의 패배를 충격이나 위기로 받아들인 일부 지식인들 간에도 사상적 균열을 보이며, 청의 멸망을 기대하는 부류와 청과의 공동운명 관계를 강조하는 부류가 나뉘는가 하면 서민층에서는 대청(對淸)복수의식이 여전히 상당부분 남아 있었다. 이는 서세(西勢)의 위협이 각 계층 조선인들에게 동일한 위기감으로 인식되지 않았기 때문으로 사료된다. 그러나 제2차 아편전쟁은 조선 조정이나 지식층, 서민층에서 모두 순망치한의 위기감을 느끼게 했다. 이러한 위기에 대한 대응 및 청에 대한 태도에서 당시 각 계층은 다양한 견해를 보였다. 조선 조정이나 지식층 중 일부 관료적 지식인은 청을 연합세력으로 이해했다. 반면, 재야지식인이나 서민들 가운데에는 청이 약해짐에 따라 대청(對淸)복수론을 펼치는 사람이 있는가 하면, 청을 객관적으로 파악하거나 청의 위기에 대해 관망적 자세를 취한 사람도 있었다. 이는 각 계층의 서로 다른 서세인식, 그리고 조선에 대한 정치적, 문화적 자신감 등 조선의 주체성에 대한 태도의 차이와 관련된다고 생각된다. This article considers how the different society strata of the Joseon Dynasty`s perceptions of the Qing Dynasty were affected by the First and Second Opium Wars with attention to the reactions of the Joseon Dynasty, intellectuals, and commoners at that time. As regards the First Opium War, except a few intellectuals, such as Yu Shin-hwan(兪莘煥, 1801~1859) and Yi Hang-no(李恒老, 1792~ 1868), the Joseon government, the intellectuals and the commoners did not recognize it as a serious crisis and reacted with a calm, even optimistic, attitude. The fact that the commoners and some intellectuals did not receive the latest news about the war in a timely manner contributed to this perception. Additionally, Qing Dynasty`s own attitude to the First Opium War reduced concerns about the Qing`s defeat in Joseon society. In contrast, even those intellectuals who viewed the Qing defeat as a threat still had different viewpoints. Firstly, some of them expected the destruction of the Qing Dynasty; while others emphasized the common destiny between the two countries. Further, commoners retained a significant amount of revenge consciousness regarding the Qing Dynasty. That the Western powers were not viewed with the same sense of crisis by Koreans of different class influenced the diversity of opinion. However, the Second Opium War induced in all Joseon social strata an extreme sense of crisis. Still, opinions about the crisis and attitudes toward the Qing Dynasty varied among the classes. On one hand, the rulers of government and some intellectuals who participated in realpolitik understood the Qing as an allied force. On the other hand, due to the weakness of the Qing Dynasty, the commoners and some intellectuals who were out of power expanded calls for revenge against the Qing; finally, some also looked at the Qing Dynasty objectively, and took a wait-and-see attitude to the Qing`s crisis. Different social strata`s perceptions of Western powers and their own attitudes toward the identity of the Joseon Dynasty, such as the level of self-confidence in the realms of policy, culture, and so on, directly affected their perceptions of the Qing and its level of crisis in the aftermath of both Opium Wars.