Pt and Pt-Ir porous ceramic electrodes for highly sensitive room temperature ammonia sensor

Dongxia WANG,Mengqiang WU,Wenlong LIU 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Antiarrhythmic effects of ginsenoside Rg2 on calcium chloride-induced arrhythmias without oral toxicity

Dongxia Gou,Xuejing Pei,Jiao Wang,Yue Wang,Chenxing Hu,Chengcheng Song,Sisi Cui,Yifa Zhou 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.5

Background: Malignant arrhythmias require drug therapy. However, most of the currently available antiarrhythmic drugs have significant side effects. Ginsenoside Rg2 exhibits excellent cardioprotective effects and appears to be a promising candidate for cardiovascular drug development. So far, the oral toxicity and antiarrhythmic effects of Rg2 have not been evaluated. Methods: Acute oral toxicity of Rg2 was assessed by the Limit Test method in mice. Subchronic oral toxicity was determined by repeated dose 28-day toxicity study in rats. Antiarrhythmic activities of Rg2 were evaluated in calcium chloride-induced arrhythmic rats. Antiarrhythmic mechanism of Rg2 was investigated in arrhythmic rats and H9c2 cardiomyocytes. Results: The results of toxicity studies indicated that Rg2 exhibited no single-dose (10 g/kg) acute oral toxicity. And 28-day repeated dose treatment with Rg2 (1.75, 3.5 and 5 g/kg/d) demonstrated minimal, if any, subchronic toxicity. Serum biochemical examination showed that total cholesterol in the high-dose cohort was dramatically decreased, whereas prothrombin time was increased at Day 28, suggesting that Rg2 might regulate lipid metabolism and have a potential anticoagulant effect. Moreover, pretreatment with Rg2 showed antiarrhythmic effects on the rat model of calcium chloride induced arrhythmia, in terms of the reduced duration time, mortality, and incidence of malignant arrhythmias. The antiarrhythmic mechanism of Rg2 might be the inhibition of calcium influx through L-type calcium channels by suppressing the phosphorylation of Ca<SUP>2+</SUP>/calmodulin-dependent protein kinase II. Conclusion: Our findings support the development of Rg2 as a promising antiarrhythmic drug with fewer side effects for clinical use.

Identification and Antimicrobial Activity Detection of Lactic Acid Bacteria Isolated from Corn Stover Silage

Dongxia Li,Kuikui Ni,Huili Pang,Yanping Wang,Yimin Cai,Qingsheng Jin 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.5

A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC 43971T, Micrococcus luteus ATCC 4698T and Escherichia coli ATCC 11775T were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at 100°C), but the antimicrobial activity was eliminated after treatment at 121°C for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.

Design of online damage images detection system for large-aperture mirrors of high power laser facility based on wavefront coding technology

Fang, Wang,Qinxiao, Liu,Dongxia, Hu,Hongjie, Liu,Tianran, Zheng Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.9

The laser transport system of the high power laser facility is mainly composed of large-aperture laser transport mirrors (TMs). Obtaining the high-resolution online damage images during the operation, which is of great significance for operating safely of the mirrors and the facility. Based on wavefront coding, pan-tilt scanning and image stitching technologies, an online laser-damage images detection system is designed, and it can achieve high-precision detection of surface characteristics of large-aperture laser transport mirrors. The preliminary simulation proves that the system can solve the depth of field matching problem caused by pan-tilt tilt imaging and achieve higher resolution.

Identification and Antimicrobial Activity Detection of Lactic Acid Bacteria Isolated from Corn Stover Silage

Li, Dongxia,Ni, Kuikui,Pang, Huili,Wang, Yanping,Cai, Yimin,Jin, Qingsheng Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.5

A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC $43971^T$, Micrococcus luteus ATCC $4698^T$ and Escherichia coli ATCC $11775^T$ were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at $100^{\circ}C$), but the antimicrobial activity was eliminated after treatment at $121^{\circ}C$ for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.

Research on Preparation Methods of Ultrafine Softwood Powder

Changsheng Fan,Dongxia Yang,Hongling Wang,Yan Sun,Hua lou,Hongru Yang 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.4

Pine wood sawdust is used as raw materials for experimental processing into ultrafine wood powder. Sizes of ultrafine wood powder particles serve as a standard for measuring ultrafine processing. The core part of the experimental processing equipment is the millstone which can exert great shear force and grinding force on strong fiber materials so as to ensure the successful preparation of ultrafine particles. The “equilibrium orbit” model is used to simulate processed superfine particles in calculating separation performance. Moreover, the CFD is chosen for simulating separation performance of wood powder particles with different sizes in the two-phase flow field, so as to ensure the successful separation and grading of wood powder particles with different sizes in the practical processing. Research is made on physical properties of collected wood powder as samples with different sizes and influence on composite material properties when ultrafine wood powder is taken as padding. Research on ultrafine wood powder provides meaningful experimental data and theoretical support for the future research on micro-nano fibrils.

microRNA-184 enhances the sensitivity of pheochromocytoma-12 cells to doxorubicin by targeting ADAM22

Zhao Nairui,Su Na,Wang Guangya,Fu Dongxia,Gao Fang,Zhang Yunna 대한독성 유전단백체 학회 2021 Molecular & cellular toxicology Vol.17 No.2

Background Pheochromocytoma (PCC) is a catecholamine-producing and neuroendocrine tumor with the 5-year overall survival of advanced stage PCC lower than 40%. Increasing evidence has shown that aberrant expression of microRNAs (miRNAs) plays important roles in the development and chemotherapy resistance of cancers including PCC. Objective The tumor-suppressive function of miR-184 has been identified in several types of cancers. The aim of this study is to explore the function and the underlying mechanism of miR-184 in the chemo-resistance of PCC. Results miR-184 expression was significantly lower in doxorubicin (Dox)-resistant pheochromocytoma-12 (PC-12) cells and PCC patients. Consistently, in vitro analysis showed that overexpression of miR-184 obviously improved the sensitivity of PC-12/Dox cells, while knockdown of miR-184 sensitised PC-12/Dox cells to chemotherapeutics. To further understand the possible functional mechanism of miR184 in the chemo-resistance of PCC, the targets of miR-184 were predicted. The results of miRDB database suggested A disintegrin and metalloproteinase 22 (ADAM22) carrying the potential complementary binding sites of miR-184 within its 3′-untranslated region (UTR). Further experiments confirmed that miR-184 bound the 3′-UTR of ADAM22 mRNA and down-regulated the expression of ADAM22 in PC-12/Dox cells. Moreover, ADAM22 was overexpressed in Dox-resistant PC-12 cells and PCC patients. Additionally, overexpression of ADAM22 attenuated miR-184-mediated chemo-sensitivity of PC-12/Dox cells. Conclusion miR-184 played a role in the chemo-sensitivity of PC-12/Dox cells at least partially via negatively regulating ADAM22. These results suggested miR-184 as a possible novel target to attenuate the chemo-resistance of PCC. Background Pheochromocytoma (PCC) is a catecholamine-producing and neuroendocrine tumor with the 5-year overall survival of advanced stage PCC lower than 40%. Increasing evidence has shown that aberrant expression of microRNAs (miRNAs) plays important roles in the development and chemotherapy resistance of cancers including PCC. Objective The tumor-suppressive function of miR-184 has been identified in several types of cancers. The aim of this study is to explore the function and the underlying mechanism of miR-184 in the chemo-resistance of PCC. Results miR-184 expression was significantly lower in doxorubicin (Dox)-resistant pheochromocytoma-12 (PC-12) cells and PCC patients. Consistently, in vitro analysis showed that overexpression of miR-184 obviously improved the sensitivity of PC-12/Dox cells, while knockdown of miR-184 sensitised PC-12/Dox cells to chemotherapeutics. To further understand the possible functional mechanism of miR184 in the chemo-resistance of PCC, the targets of miR-184 were predicted. The results of miRDB database suggested A disintegrin and metalloproteinase 22 (ADAM22) carrying the potential complementary binding sites of miR-184 within its 3′-untranslated region (UTR). Further experiments confirmed that miR-184 bound the 3′-UTR of ADAM22 mRNA and down-regulated the expression of ADAM22 in PC-12/Dox cells. Moreover, ADAM22 was overexpressed in Dox-resistant PC-12 cells and PCC patients. Additionally, overexpression of ADAM22 attenuated miR-184-mediated chemo-sensitivity of PC-12/Dox cells. Conclusion miR-184 played a role in the chemo-sensitivity of PC-12/Dox cells at least partially via negatively regulating ADAM22. These results suggested miR-184 as a possible novel target to attenuate the chemo-resistance of PCC.

A Novel Method for Survivability Test Based on End Nodes in Large Scale Network

( Ming Liang ),( Zhao Gang ),( Wang Dongxia ),( Huang Minhuan ),( Li Xiang ),( Miao Qing ),( Xu Fei ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.2

Survivability is a necessary property of network system in disturbed environment. Recovery ability is a key actor of survivability. This paper concludes network survivability into a novel composite metric, i.e. Network Recovery Degree (NRD). In order to measure this metric in quantity, a concept of Source-Destination Pair (SD Pair), is created to abstract end-to-end activity based on end nodes in network, and the quality of SD Pair is also used to describe network performance, such as connectivity, quality of service, link degree, and so on. After that, a Survivability Test method in large scale Network based on SD pairs, called STNSD, is provided. How to select SD Pairs effectively in large scale network is also provided. We set up simulation environment to validate the test method in a severe destroy scenario and evaluate the method scalability in different large scale network scenarios. Experiment and analysis shows that the metric NRD correctly reflects the effort of different survivability strategy, and the proposed test method STNSD has good scalability and can be used to test and evaluate quantitative survivability in large scale network.

Hydrothermal Synthesis of Hierarchical Hollow Li(Ni0.8Co0.15Al0.05)O2 Microspheres for Lithium Ion Batteries

Liu Wenlong,Jiang Weiwei,Yan Chenran,Feng Wei,Wang Dongxia,Zhao Liming,Feng Tingting,Gong Feng 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.11

Li(Ni0.8Co0.15Al0.05)O2 (NCA) cathode material for lithium ion batteries is synthesized by calcining Ni–Co–Al hydroxide or carbonate hydroxide hydrate precursor, which is obtained by hydrothermal method, and the NCA cathode material is hierarchical hollow microspheres with the diameter in the range of 3–5 µm and composed of nanoflakes and/or nanowires. The effect of hydrothermal reaction time on the morphologies and the crystalline quality of the NCA cathode material is investigated on the basis of scanning electron microscopy, X-ray diffraction, and tunneling electron microscopy. The NCA cathode material shows smooth and monotonous charge/discharge characteristics, delivers a reversible capacity as 144.4 mAh/g and retains 90.4% after 50 cycles at a current density of 0.1 C between 2.5 and 4.3 V.