Atomic Force Microscopy of Asymmetric Membranes from Turtle Erythrocytes

Yongmei Tian,Mingjun Cai,Haijiao Xu,Bohua Ding,Xian Hao,Junguang Jiang,Yingchun Sun,Hongda Wang 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.8

The cell membrane provides critical cellular functions that rely on its elaborate structure and organization. The structure of turtle membranes is an important part of an ongoing study of erythrocyte membranes. Using a combination of atomic force microscopy and single-molecule force spectroscopy, we characterized the turtle erythrocyte membrane structure with molecular resolution in a quasi-native state. High-resolution images both leaflets of turtle erythrocyte membranes revealed a smooth outer membrane leaflet and a protein covered inner membrane leaflet. This asymmetry was verified by single-molecule force spectroscopy, which detects numerous exposed amino groups of membrane proteins in the inner membrane leaflet but much fewer in the outer leaflet. The asymmetric membrane structure of turtle erythrocytes is consistent with the semi-mosaic model of human, chicken and fish erythrocyte membrane structure, making the semi-mosaic model more widely applicable. From the perspective of biological evolution, this result may support the universality of the semi-mosaic model.

Fabrication of Novel n-SrTiO3/p-BiOI Heterojunction for Degradation of Crystal Violet Under Simulated Solar Light Irradiation

Yongmei Xia,Zuming He,Jiangbin Su,Ya Liu,Bin Tang,Xiaoping Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.6

Novel n-SrTiO3/p-BiOI heterojunction composites were successfully fabricated by loading SrTiO3 particles onto the surface of BiOI nanoflakes via a two-step method. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), energy-disperse X-ray spectroscopy (EDS), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), diffuse reflectance spectroscopy (DRS) and electrochemical measurements. The results show that the n-SrTiO3/p-BiOI heterojunction composites are composed of perovskite structure SrTiO3 and tetragonal phase BiOI. The composites exhibit excellent photocatalytic performance for the degradation of crystal violet (CV) solution under simulated solar light irradiation, which is superior to that of pristine BiOI and SrTiO3. The 30 wt.% SrTiO3/BiOI composite is found to be the optimal composite, over which the dye degradation reaches 92.5% for 30 min of photocatalysis. The photocatalytic activity of the 30 wt.% SrTiO3/BiOI composite is found to be 3.94 times and 28.2 times higher than that of bare BiOI and SrTiO3, respectively. The reactive species trapping experiments suggest that · O-2 and holes are the main active species responsible for the CV degradation. In addition, the electrochemical measurements elucidate the effective separation of photoinduced electron–hole pairs. Moreover, on the basis of experimental and theoretical results, a possible mechanism for the enhanced photocatalytic performance of the SrTiO3/BiOI heterojunction composites is also proposed.

LINC00662 Promotes Oral Squamous Cell Carcinoma Cell Growth and Metastasis through miR-144-3p/EZH2 Axis

Yongmei Yao,Yang Liu,Fengqin Jin,Zhaohua Meng 연세대학교의과대학 2021 Yonsei medical journal Vol.62 No.7

Purpose: Long non-coding RNA (lncRNA) is identified as an important regulator involved in oral squamous cell carcinoma(OSCC) tumorigenesis. This study aimed to investigate the functional role and underlying mechanism of LINC00662 in OSCC. Materials and Methods: The expression levels of LINC00662, miR-144-3p, and enhancer of zeste homolog 2 (EZH2) mRNA werequantified with quantitative real-time polymerase chain reaction in OSCC tissues and cell lines. Western blot analysis was used toassay the expression levels of E-cadherin, Vimentin, and EZH2. Cell proliferation, migration, and invasion were monitored by cellcounting kit-8 and Transwell assays. Dual-luciferase reporter and RNA immunoprecipitation assays were employed to verify theregulatory relationship between LINC00662 and miR-144-3p. Results: The expression of LINC00662, positively associated with the increased TNM stage and lymph node metastasis of the patients,was up-regulated in OSCC tissues and cells. The overexpression of LINC00662 facilitated the proliferation, migration, andinvasion of OSCC cells. MiR-144-3p could bind to LINC00662, and the promoting effect of LINC00662 overexpression was counteractedby miR-144-3p mimic. Moreover, EZH2 expression was negatively regulated by miR-144-3p and positively regulated byLINC00662. The silencing of EZH2 attenuated the promoting effects of overexpression of LINC00662 on cell proliferation, migration,invasion, and epithelial-mesenchymal transition. Conclusion: LINC00662, as an oncogenic lncRNA of OSCC, accelerates OSCC progression by repressing miR-144-3p expressionand increasing EZH2 expression.

Malnutrition worsens fluorosis-induced damage in hypothalamic-pituitary-ovarian axis of rats

Yongmei Liu,Ling Li,Jingfeng Xu,Siwen Yu,Shijun Wang,Maojuan Yu,Wenbing Zou,Mingliang Cheng,Shuhua Xia 대한독성 유전단백체 학회 2019 Molecular & cellular toxicology Vol.15 No.2

Backgrounds: This study aimed to evaluate the effects of malnutrition on the hypothalamic-pituitary-ovarian axis (HPOA) sex hormones in female rats with coal burning-type fluorosis. Methods: Female rats were divided into four groups: control, malnutrition, fluorosis, and fluorosis with malnutrition. Rats in the control and malnutrition groups were fed pollution-free corn with either regular or low protein content. Rats in the fluorosis and fluorosis with malnutrition groups were fed corn roasted with coals from the fluorosis endemic areas of Zhijin, China,with either regular or low protein content. Results: Results revealed that the body weight of rats with protein malnutrition was significantly reduced compared with that of the control and fluorosis rats. Urinary fluoride was significantly decreased and bone fluoride was significantly increased in the fluorosis with malnutrition group compared to the fluorosis group. Moreover, protein malnutrition significantly enhanced the effect of fluoride on gonadotropin-releasing hormone, follicle-stimulating hormone, luteinizing hormone, and testosterone. Histological and ultrastructural analyses revealed that protein malnutrition intensified fluoride-induced ovary damage. Conclusion: Malnourishment could promote the abnormal secretion of HPOA sex hormones in females with fluorosis.

Prognostic value of Nrf2/HO-1 expression and its correlation with occurrence in esophageal squamous cell carcinoma

Gao Yongmei,Li Mengyan,Wang Bo,Ma Yuqing 한국유전학회 2023 Genes & Genomics Vol.45 No.6

Background Esophageal squamous cell carcinoma (ESCC) is thought to be started and developed by genes associated with inflammation. A cancer's ability to spread and grow can be aided by nuclear factor erythroid-2 related factor 2 (Nrf2) hyperactivation, which can also make a tumor more resistant to chemotherapy and radiation treatment. However, it is still unknown how Nrf2 gene expression affects ESCC prognosis and controls function throughout ESCC advancement. Objective The expression of Nrf2 and HO-1 in ESCC and precancerous esophageal precancerous lesions was analyzed, and their relationship with esophageal squamous cell carcinoma was analyzed. Methods Immunohistochemistry (IHC) was used to confirm the expression of Nrf2 and heme oxygenase-1 (HO-1) proteins in tissue microarrays from Chinese populations with ESCC. We looked at the connections between Nrf2/HO-1 expression and invading immune cells using the TIMER database. Results Ethnicity and N stage are associated with Nrf2 overexpression. Differentiation, N stage, vascular invasion, distant metastasis, and American Joint Committee on Cancer (AJCC) staging are all associated with HO-1 overexpression. The expression of Nrf2 and HO-1 had a favorable correlation. Patients with elevated Nrf2 and HO-1 expression had lower progression-free survival (PFS) and overall survival (OS). In high-grade intraepithelial neoplasia, Nrf2 and HO-1 expression generally occurred, partially in low-grade intraepithelial neoplasia specimens, and rarely in normal mucosa. We further show that Nrf2 suppression is linked to higher immunological marker expression and lower immune cell infiltration. Conclusion The prognosis of ESCC may be improved by inhibiting the expression of Nrf2 and HO-1. A lack of immune cells was seen in ESCC with Nrf2 impairment.

Atomic Force Microscopy of Asymmetric Membranes from Turtle Erythrocytes

Tian, Yongmei,Cai, Mingjun,Xu, Haijiao,Ding, Bohua,Hao, Xian,Jiang, Junguang,Sun, Yingchun,Wang, Hongda Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.8

The cell membrane provides critical cellular functions that rely on its elaborate structure and organization. The structure of turtle membranes is an important part of an ongoing study of erythrocyte membranes. Using a combination of atomic force microscopy and single-molecule force spectroscopy, we characterized the turtle erythrocyte membrane structure with molecular resolution in a quasi-native state. High-resolution images both leaflets of turtle erythrocyte membranes revealed a smooth outer membrane leaflet and a protein covered inner membrane leaflet. This asymmetry was verified by single-molecule force spectroscopy, which detects numerous exposed amino groups of membrane proteins in the inner membrane leaflet but much fewer in the outer leaflet. The asymmetric membrane structure of turtle erythrocytes is consistent with the semi-mosaic model of human, chicken and fish erythrocyte membrane structure, making the semi-mosaic model more widely applicable. From the perspective of biological evolution, this result may support the universality of the semi-mosaic model.

Research on Domain-independent Opinion Target Extraction

Sun Yongmei,Huo Hua 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.1

Opinion Target Extraction is one of the important tasks for text sentiment analysis, which has attracted much attention from many researchers. For this task, we proposed an M-Score algorithm utilized in the model which realized the domain-independent opinion target extraction function. This algorithm is derived from the Pointwise Mutual Information algorithm, but the difference is that it doesn’t need any manual seeds collection or any web searching engines, which reduces the manual participation and easy to be transplanted. This model starts with document preprocessing, effective opinion sentences extraction and candidate opinion target extraction by employing Conditional Random Fields Model with feature templates. Next, the M-Score algorithm is employed to extract seed set, and the bootstrapping approach is invoked to process the candidate opinion targets. Finally, the model uses word frequency and the Noun pruning algorithm to filter the opinion targets, and then obtains the final opinion targets for output. The experimental results show that the M-score method performs better than Pointwise Mutual Information algorithm in precision and recall.

The Research on Measure Method of Association Rules Mining

Gao Yongmei,Bao Fuguang 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.2

Data mining receives much attention from artificial intelligence and databases, and the association rule is one of the most important research fields of data mining. In this paper, the advantages and disadvantages of the specific indicators of objective measure, subjective measure, and association rule based on statistical perspective are discussed. Some indicators of statistical perspective are adopted to measure the association rules, which can effectively solve the problems of association rules. Next, a further verification of the advantage and disadvantages of the indicators is made by the combination of the theory and application, a new measure frame is put forward as well. Then, the dynamic association rules are analyzed through making a comparative analysis in the following four aspects: the traditional association analysis without the life cycle, the association rules with the life cycle, the weighted dynamic association rules and the weighted dynamic association rules weighted by the consumption amount, showing the influence of timeliness on association rules analysis, and thus effectively mining some rules with low support in global period but high support in a certain period.

A QoS-aware Adaptive Coloring Scheduling Algorithm for Co-located WBANs

( Jingxian Wang ),( Yongmei Sun ),( Shuyun Luo ),( Yuefeng Ji ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.12

Interference may occur when several co-located wireless body area networks (WBANs) share the same channel simultaneously, which is compressed by resource scheduling generally. In this paper, a QoS-aware Adaptive Coloring (QAC) scheduling algorithm is proposed, which contains two components: interference sets determination and time slots assignment. The highlight of QAC is to determine the interference graph based on the relay scheme and adapted to the network QoS by multi-coloring approach. However, the frequent resource assignment brings in extra energy consumption and packet loss. Thus we come up with a launch condition for the QAC scheduling algorithm, that is if the interference duration is longer than a threshold predetermined, time slots rescheduling is activated. Furthermore, based on the relative distance and moving speed between WBANs, a prediction model for interference duration is proposed. The simulation results show that compared with the state-of-the-art approaches, the QAC scheduling algorithm has better performance in terms of network capacity, average delay and resource utility.

Credit Risk Measurement Study of Commercial Banks Based on the Innovation Discrete Hopfield Neural Network Model

Yawen Zhao,Yongmei Sun 한국무역연구원 2021 The International Academy of Global Business and T Vol.17 No.2

Purpose – Credit risk is always the major risk in the banking industry, and the main target of regulatory authorities. Based on modern financial theory and new credit instruments, modern risk measurement models have played a great role in the measurement of credit risk. However, most of these models assume normal distribution, which will lead to a deviation between the analysis results and the actual distribution of credit risk, c ause the “ thick tail” phenomenon, a nd reduce the accuracy of measurement results. In this context, the development of modern information technology makes it possible to introduce artificial intelligence technology into credit risk measurement, s uch as an artificial neural network, d ecision tree, g enetic programming, and support vector machine. Design/Methodology/Approach – Firstly, we use the commonly used an expert survey method and the research results and experience of previous scholars for reference to realize the transformation of regulatory indicators f rom qualitative t o quantitative. T hen, a c redit r isk measurement model based on t he Hopfield network was constructed in order to evaluate credit risk. Finally, the simulation experiment was carried out using real data from a commercial bank. Findings – The results show that a credit risk measurement model based on Hopfield neural network can accurately reflect the credit risk state of banking institutions. This shows that the credit risk measurement model proposed in this paper not only has the function of supporting decision-making for commercial bank managers, it is also an effective way for financial regulators to grasp the risk change trend in time. Research Implications – A credit risk measurement model of commercial banks based on a discrete Hopfield neural network is proposed. Because an artificial neural network has the advantages of strong “robustness”, high prediction accuracy, and is unstructured, this paper uses the associative memory function of DHNN to construct a credit risk measurement model based on a discrete Hopfield neural network. Simulation results show that the model can accurately reflect the credit risk status of banks.