Rational designed strategy to dispel mutual interference of mercuric and ferric ions towards robust, pH-stable fluorescent carbon nanodots

Liu, Yang,Liu, Yanan,Lee, Jinpyo,Lee, Joong Hee,Park, Mira,Kim, Hak Yong The Royal Society of Chemistry 2017 The Analyst Vol.142 No.7

<P>As one of the most promising fluorometric nanosensors for metal ion sensing, carbon nanodots (C-dots) have developed rapidly in recent years. However, it is still a thorny problem to shield the mutual interference of two metal ions towards C-dots, <I>e.g.</I>, Hg<SUP>2+</SUP> and Fe<SUP>3+</SUP> ions. In the present work, we propose rational routes for the unique interaction between C-dots and Hg<SUP>2+</SUP> or Fe<SUP>3+</SUP>. The selectivity of the as-obtained label-free C-dots can be effectively switched by P3O10<SUP>5−</SUP> and SCN<SUP>−</SUP>. The resultant C-dots possess superior photoluminescence intensity stability in a wide pH range or in certain redox circumstances, which are highly preferred in terms of practical metal-ion detection. Moreover, the quenching-recovery-regeneration performances and quenching mechanisms were also investigated. Based on this stable and recoverable sensing platform, this in-depth study for dispelling interference from Hg<SUP>2+</SUP> and Fe<SUP>3+</SUP> ions may open up a new paradigm for developing potential detection of multi-metal ions using C-dots with switchable selectivity.</P>

Feasibility Study on Long-Term Continuous Ethanol Production from Cassava Supernatant by Immobilized Yeast Cells in Packed Bed Reactor

Liu Qingguo,Zhao Nan,Zou Yanan,Ying Hanjie,Dong Liu,Chen Yong 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.8

In this study, yeast cell immobilization was carried out in a packed bed reactor (PBR) to investigate the effects of the volumetric capacity of carriers as well as the different fermentation modes on fuel ethanol production. An optimal volumetric capacity of 10 g/l was found to obtain a high cell concentration. The productivity of immobilized cell fermentation was 16% higher than that of suspended-cell fermentation in batch and it reached a higher value of 4.28 g/l/h in repeated batches. Additionally, using this method, the ethanol yield (95.88%) was found to be higher than that of other tested methods due to low concentrations of residual sugars and free cells. Continuous ethanol production using four bioreactors showed a higher productivity (9.57 g/l/h) and yield (96.96%) with an ethanol concentration of 104.65 g/l obtained from 219.42 g/l of initial total sugar at a dilution rate of 0.092 h-1. Furthermore, we reversed the substrate-feed flow directions in the in-series bioreactors to keep the cells at their highest activity and to extend the length of continuous fermentation. Our study demonstrates an effective method of ethanol production with a new immobilized approach, and that by switching the flow directions, traditional continuous fermentation can be greatly improved, which could have practical and broad implications in industrial applications.

The effects of daily intake timing of almond on the body composition and blood lipid profile of healthy adults

Yanan Liu,Hyo-Jeong Hwang,Hyesook Ryu,You-Suk Lee,Hyun-Sook Kim,Hyunjin Park 한국영양학회 2017 Nutrition Research and Practice Vol.11 No.6

BACKGROUND/OBJECTIVES: Timing of almond intake during a day may result differently in the perspectives of body composition and changes of lipid profile. The current study was conducted to compare the effects of daily almond intake as a preload versus as a snack on body composition, blood lipid profile, and oxidative and inflammation indicators among young Korean adults aged 20-39 years old. SUBJECTS/METHODS: Participants were randomly assigned to one of three groups: a pre-meal almond group (PM), a snack almond group (SN) in which participants were instructed to consume 56 g of almonds either as a preload before meals or as a snack between meals, respectively, and a control group (CL) in which participants were provided high-carbohydrate iso-caloric control food. Measurements were performed at baseline, weeks 8 and 16. RESULTS: A total of 169 (M 77 / F 92) out of the 227 participants completed the study between June 2014 and June 2015 (n = 58 for PM; 55 for SN; and 56 for CL). A significant decrease in body fat mass was observed in the PM group at both weeks 8 and 16 compared with the CL. There were significant intervention effects on changes of body fat mass (P = 0.025), body fat percentages (P = 0.019), and visceral fat levels (P < 0.001). Consuming almonds as a daily snack reduced the levels of total cholesterol (P = 0.043) and low-density lipoprotein (LDL) cholesterol (P = 0.011) without changing high-density lipoprotein (HDL) cholesterol compared with the CL. CONCLUSION: Almond consumption as a preload modified body fat percentages, whereas snacking on almonds between meals improved blood lipid profiles. This trial was registered at ClinicalTrials.gov as NCT03014531.

One-Step Hydrothermal Synthesis of Bi2S3-TiO2-RGO Composites with Enhanced Visible Light Photocatalytic Activities

Yanan Li,Zhongmin Liu,Yaru Li,Yongchuan Wu,Jitao Chen,Yanjun Liu,Ping Na 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.5

The Bi2S3-TiO2-RGO composites were synthesized by a facile one-step hydrothermal method and applied for the photocatalytic degradation of Rhodamine B (Rh B) under the visible light. The Bi2S3-TiO2-RGO composites were characterized by transmission electron microscopy, X-ray diffraction, Raman and Fourier transform infrared spectrometer. The results indicated that the Bi2S3-TiO2-RGO composites were successfully prepared, and Ti-O-C and S-C bonds were existing among Bi2S3, TiO2 as well as RGO. Furthermore, the photocatalytic ability of Bi2S3-TiO2-RGO composites was excellent under visible light due to its responding to the whole visible light region, low recombination rate of photogenerated electron–hole pairs and relatively negative conduction band. Rh B photocatalytic degradation rate was 99.5% after 50 min and still could reach 98.4% after five cycles. Finally, a formation mechanism as well as a photocatalytic mechanism of Bi2S3-TiO2-RGO composites were proposed based on the experimental results.

The effect of the HRB linker of Newcastle disease virus fusion protein on the fusogenic activity

Liu Yaqing,Liu Ying,Huang Yanan,Wen Hongling,Zhao Li,Song Yanyan,Wang Zhiyu 한국미생물학회 2021 The journal of microbiology Vol.59 No.5

Newcastle disease, designated a class A disease of poultry by the Office international des epizooties (OIE), is an acute infection caused by Newcastle disease virus (NDV). The merging of the envelope of NDV with the membrane of a target host cell is the key step in the infection pathway, which is driven by the concerted action of two glycoproteins: haemagglutinin- neuraminidase (HN) and fusion (F) protein. When the HN protein binds to the host cell surface receptor, the F protein is activated to mediate fusion. The three-dimensional structure of the F protein has been reported to have low electron density between the DIII domain and the HRB domain, and this electron-poor region is defined as the HRB linker. To clarify the contributing role of the HRB linker in the NDV F protein-mediated fusion process, 6 single amino acid mutants were obtained by site-directed mutagenesis of the HRB linker. The expression of the mutants and their abilities to mediate fusion were analysed, and the key amino acids in the HRB linker were identified as L436, E439, I450, and S453, as they can modulate the fusion ability or expression of the active form to a certain extent. The data shed light on the crucial role of the F protein HRB linker in the acquisition of a normal fusogenic phenotype.

Green synthesis of fluorescent carbon dots from carrot juice for in vitro cellular imaging

Yang Liu,Yanan Liu,Mira Park,Soo-Jin Park,Yifan Zhang,Md Rashedunnabi Akanda,Byung-Yong Park,Hak Yong Kim 한국탄소학회 2017 Carbon Letters Vol.21 No.-

We report the use of carrot, a new and inexpensive biomaterial source, for preparing high quality carbon dots (CDs) instead of semi-conductive quantum dots for bioimaging application. The as-derived CDs possessing down and up-conversion photoluminescence features were obtained from carrot juice by commonly used hydrothermal treatment. The corresponding physiochemical and optical properties were investigated by electron microscopy, fluorescent spectrometry, and other spectroscopic methods. The surfaces of obtained CDs were highly covered with hydroxyl groups and nitrogen groups without further modification. The quantum yield of as-obtained CDs was as high as 5.16%. The cell viability of HaCaT cells against a purified CD aqueous solution was higher than 85% even at higher concentration (700 μg mL−1) after 24 h incubation. Finally, CD cultured cells exhibited distinguished blue, green, and red colors, respectively, during in vitro imaging when excited by three wavelength lasers under a confocal microscope. Offering excellent optical properties, biocompatibility, low cytotoxicity, and good cellular imaging capability, the carrot juice derived CDs are a promising candidate for biomedical applications.

인센티브관광 참가자들의 관광수용태세와 사후행동에 대한 차이에 관한 연구

유아남(Liu, Yanan),김대관(Kim, Dae Kawn) 한국관광레저학회 2014 관광레저연구 Vol.26 No.1

Protocadherin alpha 3 inhibits lung squamous cell carcinoma metastasis and epithelial-mesenchymal transition

Tao Yu,Fei Liu,Chang Liu,Yongyu Liu,Jianhui Jia,Yanan Liu,Yi Ren 한국유전학회 2022 Genes & Genomics Vol.44 No.2

Background: Lung squamous cell carcinoma (LUSC) is associated with poor clinical prognosis and lacks available targeted therapy. Given that the major threat of cancer is metastasis, delineation of the molecular mechanism underlying it would help devise therapeutic strategies. Objective: To investigate the functional role of protocadherin alpha 3 (PCDHA3) in LUSC, as well as investigate the underlying molecular mechanism. Methods: Data for PCDHA3 expression and clinical information in The Cancer Genome Atlas (TCGA) were extracted and analyzed in the UALCAN platform. Expression levels of PCDHA3 in LUSC cell lines were analyzed via RT-PCR and western blot. Overexpression of PCDHA3 was conducted via plasmid transfection. CCK-8 and cell cycle assays were utilized to investigate effect of PCDHA3 on cell proliferation. Transwell assay was used to detect migration and invasion. The underlying mechanism was demonstrated via western blot analysis. Results: Our data indicate that PCDHA3 was low expressed in three kinds of LUSC cell lines and best in H520 cells. Furthermore, overexpression of PCDHA3 could significantly impair LUSC cells proliferation, invasion and migration. Moreover, PCHDA3 repressed the biomarkers of mesenchymal (N-cadherin, fibronectin and vimentin) and increased expression of epithelial markers (E-cadherin and α-catenin). On the other hand, PCDHA3 overexpression partially blocked epithelial-mesenchymal transition. Conclusions: PCDHA3 suppressed the LUSC cells proliferation, invasion and migration via inhibiting the expression of EMT signatures, suggesting that PCDHA3 could serve as a valuable therapeutic target for LUSC therapy.

鲁菜文化的传承与发展研究

刘,亚,男(Yanan Liu),陈,尘,(Chen Chen) 동북아경상학회 2021 동북아경상연구 Vol.2 No.2

餐饮业作为与人民生活密切相关的产业, 在整个消费中所占比例已超过10%, 对消费有着明显的拉动作用。在整个菜系中, 鲁菜作为其中之一对带动餐饮业发展、推动消费市场升级有着至关重要的作用。鲁菜不仅是一种菜系, 同时象征着齐鲁文化。因此, 本文从鲁菜文化的传承与发展的现状入手, 通过研究鲁菜发展过程中所面临的问题, 对鲁菜文化挖掘与传承提出建设意见, 丰富鲁菜文化相关研究, 有助于促进鲁菜甚至中国餐饮产业的发展。 Purpose – Dig deeply into Shandong cuisine culture, explore the cultural deposits and historical background in the development of Shandong cuisine, and tell the story of Shandong cuisine; Combining the opportunities and challenges faced by the development of Shandong cuisine, we should break the development bottleneck of Shandong cuisine with innovative thinking and seek effective countermeasures for the development and inheritance of Shandong cuisine industry. Design/Methodology/Approach – Through interviews and documents, through cooperation with social organizations and catering institutions, and through oral history , Shandong cuisine masters and experts in Shandong cuisine management industry were interviewed to collect their views and grasp of the future development direction of Shandong cuisine industry and organize the cost articles. Findings – The revitalization of Shandong cuisine culture needs the joint efforts of the government, enterprises, universities and industries to seize the opportunity, continuously develop and summarize. Research Implications – In this article, in the hope that Shandong cuisine industry to industry and education integration, culture and the integration of tourism, rural revitalization, and digital age new marketing ways to promote the image of Shandong cuisine, better promote the Shandong cuisine culture and realize the long-term development of the industry of Shandong cuisine, let more people know the Shandong cuisine.

Research on the explosion release method and damage mechanism of titanium alloy fan blade

Yanan Zhang,Zekan He,Chuang Liu,Meng Wang,Haijun Xuan,Mingmin Qu,Zehui Fang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.8

The current advanced aero-engine fan rotors are usually integrally-bladed rotor discs, and the root of the fan blade has irregular curved surface, which brings technical difficulties and challenges to achieve the blade releasing. In this paper, the dynamic response and energy dissipation process of the titanium alloy blade under shaped charge jet explosion were analyzed by numerical model, and the explosion damage mechanism of titanium alloy fan blades was clarified. Finally, a FBO test was conducted to verify the blade explosion release method in rotating state. Through the energy dissipation analysis of the whole explosion process, it can be seen that the overall residual kinetic energy of the blade is about 15.7 J, which is only 0.02 % of the initial kinetic energy of the releasing blade in rotating. It is indicated that the explosion separation method will not generate additional kinetic energy to the released blade.