Impact of Cu2O doping on high dielectric properties of CuO ceramics

Dan-Dan Wang,Feng-Zi Zhou,Jing-Xiao Cao,Li-Ben Li,Guo-Ling Li 한국물리학회 2017 Current Applied Physics Vol.17 No.5

Single-phase CuO ceramic samples were prepared with the starting nano powders of CuO þ xCu2O (x ¼ 0, 1, 3, 7% in mole ratio) via solid state reaction method, and characterized by X-ray diffraction, Raman scattering and scanning electron microscopy. For all the samples, the temperature dependences of dielectric constants and losses were measured at the frequencies of 102, 103, 104, 105 and 106 Hz, respectively. With increasing doping content of Cu2O, a strong correlation is demonstrated at given temperature and frequency between the measured dielectric constants and the unit-cell volumes of CuO. The strong correlation is argued in terms of the change in densities of Cu]O defects (e.g. Cu/O vacancies and/or interstitial Cu impurities) due to Cu2O doping, which is supported by the formation energies of Cu]O defects and the corresponding unit-cell volume from first-principles calculations. The high dielectric constant (~103e105) of CuO ceramic is therefore attributed to the reduction in resistance due to Cu/O defects in the grain by Maxwell-Wagner mechanism.

Assessment of Esophageal Motor Disorders Using High-resolution Manometry in Esophageal Dysphagia With Normal Endoscopy

Dan Wang,Xiu Wang,Yao Yu,Xiaowen Xu,Jing Wang,Yuting Jia,Hong Xu 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.1

Background/Aims The distribution and esophageal motor characteristics of Chinese patients with esophageal dysphagia who exhibit no structural abnormalities on esophagogastroduodenoscopy remain unclear. Our aim is to assess the esophageal motor patterns using high-resolution manometry (HRM) and classify them according to the Chicago classification version 3.0 (CC v3.0). Furthermore, we compared the CC v3.0 and the previous version 2.0 (CC v2.0) for diagnosis of motor disorders. Methods Two hundred thirty-six (mean age 48.4 ± 12.2 years, 61.9% female) patients with esophageal dysphagia were included for analysis of motor function using HRM. All participants were administered a questionnaire to determine Eckardt scores before HRM. Results According to the CC v3.0, 57 (24.2%) patients showed evidence of esophagogastric junction outflow obstruction and were classified as Group 1. Eighteen (7.6%) patients with major disorders of peristalsis were classified as Group 2. Minor disorders of peristalsis (Group 3) were much more frequent (129 [54.7%] patients). Thirty-two (13.6%) patients had normal esophageal manometry were classified as Group 4. All patients with abnormal pH or pH impedance monitoring (n = 44) had minor motor disorders (ineffective esophageal motility [IEM] = 34, fragmented peristalsis = 10). Based on motor category, the Eckardt score was 4.7 ± 0.1 in Group 1, 4.5 ± 0.3 in Group 2, 3.5 ± 0.1 in Group 3, and 3.9 ± 0.1 in Group 4. Conclusions IEM was the most common esophageal motor disorder in patients with esophageal dysphagia who showed no structural abnormality on endoscopy. While a high Eckardt score suggests outflow obstruction or a major motor disorder, a low score suggests IEM.

An Autonomous Driving Approach Based on Trajectory Learning Using Deep Neural Networks

Wang Dan,Wang Canye,Wang Yulong,Wang Hang,Pei Feng 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.6

Autonomous driving approaches today are mainly based on perception-planning-action modular pipelines and the End2End paradigm respectively. The End2End paradigm is a strategy that directly maps raw sensor data to vehicle control actions. This strategy is very promising and appealing because complex module design and cumbersome data labeling are avoided. Since this approach lacks a degree of interpretability, safety and practicability. we propose an autonomous driving approach based on trajectory learning using deep neural networks in this paper. In comparison to End2End algorithm, it is found that the trajectory learning algorithm performs better in autonomous driving. As for trajectory learning algorithm, the CNN_Raw-RNN network structure is established, which is verified to be more effective than the original CNN_LSTM network structure. Besides, we propose an autonomous driving architecture of a pilot and copilot combination. The pilot is responsible for trajectory prediction via imitation learning with labeled driving trajectories, while the copilot is a safety module that is employed to verify the effectiveness of the vehicle trajectory by the results of the semantic segmentation auxiliary task. The proposed autonomous driving architecture is verified with a real car on urban roads without manual intervention within 40 km.

Rare ginsenoside Ia synthesized from F1 by cloning and overexpression of the UDP-glycosyltransferase gene from Bacillus subtilis: synthesis, characterization, and in vitro melanogenesis inhibition activity in BL6B16 cells

Wang, Dan-Dan,Jin, Yan,Wang, Chao,Kim, Yeon-Ju,Perez, Zuly Elizabeth Jimenez,Baek, Nam In,Mathiyalagan, Ramya,Markus, Josua,Yang, Deok-Chun The Korean Society of Ginseng 2018 Journal of Ginseng Research Vol.42 No.1

Background: Ginsenoside F1 has been described to possess skin-whitening effects on humans. We aimed to synthesize a new ginsenoside derivative from F1 and investigate its cytotoxicity and melanogenesis inhibitory activity in B16BL6 cells using recombinant glycosyltransferase enzyme. Glycosylation has the advantage of synthesizing rare chemical compounds from common compounds with great ease. Methods: UDP-glycosyltransferase (BSGT1) gene from Bacillus subtilis was selected for cloning. The recombinant glycosyltransferase enzyme was purified, characterized, and utilized to enzymatically transform F1 into its derivative. The new product was characterized by NMR techniques and evaluated by MTT, melanin count, and tyrosinase inhibition assay. Results: The new derivative was identified as (20S)-$3{\beta},6{\alpha},12{\beta}$,20-tetrahydroxydammar-24-ene-20-O-${\beta}$-D-glucopyranosyl-3-O-${\beta}$-D-glucopyranoside(ginsenoside Ia), which possesses an additional glucose linked into the C-3 position of substrate F1. Ia had been previously reported; however, no in vitro biological activity was further examined. This study focused on the mass production of arduous ginsenoside Ia from accessible F1 and its inhibitory effect of melanogenesis in B16BL6 cells. Ia showed greater inhibition of melanin and tyrosinase at $100{\mu}mol/L$ than F1 and arbutin. These results suggested that Ia decreased cellular melanin synthesis in B16BL6 cells through downregulation of tyrosinase activity. Conclusion: To our knowledge, this is the first study to report on the mass production of rare ginsenoside Ia from F1 using recombinant UDP-glycosyltransferase isolated from B. subtillis and its superior melanogenesis inhibitory activity in B16BL6 cells as compared to its precursor. In brief, ginsenoside Ia can be applied for further study in cosmetics.

Glycosyltransformation of ginsenoside Rh2 into two novel ginsenosides using recombinant glycosyltransferase from Lactobacillus rhamnosus and its in vitro applications

Dan-Dan Wang,Yeon-Ju Kim,Nam In Baek,Ramya Mathiyalagan,Chao Wang,Yan Jin,Xing Yue Xu,Deok-Chun Yang 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.1

Background: Ginsenoside Rh2 is well known for many pharmacological activities, such as anticancer, antidiabetes, antiinflammatory, and antiobesity properties. Glycosyltransferases (GTs) are ubiquitous enzymes present in nature and are widely used for the synthesis of oligosaccharides, polysaccharides, glycoconjugates, and novel derivatives. We aimed to synthesize new ginsenosides from Rh2 using the recombinant GT enzyme and investigate its cytotoxicity with diverse cell lines. Methods: We have used a GT gene with 1,224-bp gene sequence cloned from Lactobacillus rhamnosus (LRGT) and then expressed in Escherichia coli BL21 (DE3). The recombinant GT protein was purified and demonstrated to transform Rh2 into two novel ginsenosides, and they were characterized by nuclear magnetic resonance (NMR) techniques and evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assay. Results: Two novel ginsenosides with an additional glucopyranosyl (6/1) and two additional glucopyranosyl (6/1) linked with the C-3 position of the substrate Rh2 were synthesized, respectively. Cell viability assay in the lung cancer (A549) cell line showed that glucosyl ginsenoside Rh2 inhibited cell viability more potently than ginsenoside Rg3 and Rh2 at a concentration of 10 μM. Furthermore, glucosyl ginsenoside Rh2 did not exhibit any cytotoxic effect in murine macrophage cells (RAW264.7), mouse embryo fibroblasts cells (3T3-L1), and skin cells (B16BL6) at a concentration of 10 μM compared with ginsenoside Rh2 and Rg3. Conclusion: This is the first report on the synthesis of two novel ginsenosides, namely, glucosyl ginsenoside Rh2 and diglucosyl ginsenoside Rh2 from Rh2 by using recombinant GT isolated from L. rhamnosus. Moreover, diglucosyl ginsenoside Rh2 might be a new candidate for treatment of inflammation, obesity, and skin whiting, and especially for anticancer.

Preparation and Characterization of A Semi-interpenetrating Network Alkaline Anion Exchange Membrane

Yifu Wang,Heting Wan,Dan Wang,Jilin Wang,Lulu Wang,Ruijiang Feng 한국섬유공학회 2018 Fibers and polymers Vol.19 No.1

A series of semi-interpenetrating network (semi-IPN) anion exchange membranes (QCS/St-G8-2-8, Quaternized chitosan/styrene-[maleic alkylene group diethyl bis (octyl dimethyl chloro/bromide), abbreviated as G8-2-8] were prepared via in-situ polymerization by Styrene (St) and G8-2-8 in QCS casting solution. During the process of in-situ polymerization, linearblock polymers (St-G8-2-8) of Styrene and G8-2-8 was constructed, then was mixed with QCS casting solution, followed crosslinking the QCS by glutaraldehyde (GA). With the increasing content of linear block polymer, water uptake and swelling ratio of the composite membrane decreased; This kind of linear structure makes an order arrangement of quaternaryammonium groups which improves the OH− migration efficiency. At 70 oC, the M-30 composite membrane performs a high OH− conductivity of 8.20×10-2 S·cm-1, the methanol permeability is 3.23×10-6 cm-2·s-1 which is still lower than Nafion 115 of 2.42×10-6 cm-2·s-1, but M-30 shows a higher selectivity of 25.3 than Nafion 115 of 11.6. Furthermore, the membranes exhibited excellent thermal stability (≥150 oC), the tensile strength of the composite membrane is in the range of 14-25 MPa and elongation at break is in the range of 16-37 % at room temperature, as well as superior chemical stability in 1.0 M KOH solution for 250 h.

Enantioselective Esterification of Ibuprofen by a Novel Thermophilic Biocatalyst: APE1547

Zhao Dan-tong,Xun Er-na,Wang Jia-xin,Wang Ren,Wei Xiao-fei,Wang Lei,Wang Zhi 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.4

The enantioselective esterification of ibuprofen catalyzed by a novel thermophilic esterase (APE1547)from the archaeon Aeropyrum pernix K1 was successfully conducted in organic solvents. The effects of acyl acceptor,substrate ratio, organic solvent, temperature, and water activity were investigated. Under optimum conditions, the highest enantioselectivity (E = 38.1) was obtained with a higher enzyme activity (216.5 μmol/g/h). Celites were added into the reaction mixture to remove the water produced in the esterification. The reaction achieved its equilibrium in approximately 96 h with a conversion of 57 and 99%(ee) of the un-reacted (S)-ibuprofen obtained.

Parkinson’s Disease with Fatigue: Clinical Characteristics and Potential Mechanisms Relevant to α-Synuclein Oligomer

Li-Jun Zuo,Shu-Yang Yu,Fang Wang,Yanghui Xia,Ying-Shan Piao,Yang Du,Teng-Hong Lian,Rui-Dan Wang,Qiu-Jin Yu,Ya-Jie Wang,Xiao-Min Wang,Piu Chan,Sheng-Di Chen,Yongjun Wang,Wei Zhang 대한신경과학회 2016 Journal of Clinical Neurology Vol.12 No.2

Background and Purpose The aim of this study was to identify the clinical characteristics and potential mechanisms relevant to pathological proteins in Parkinson’s disease (PD) patients who experience fatigue. Methods PD patients (n=102) were evaluated using a fatigue severity scale and scales for motor and nonmotor symptoms. The levels of three pathological proteins—α-synuclein oligomer, β-amyloid (Aβ)1-42, and tau—were measured in 102 cerebrospinal fluid (CSF) samples from these PD patients. Linear regression analyses were performed between fatigue score and the CSF levels of the above-listed pathological proteins in PD patients. Results The frequency of fatigue in the PD patients was 62.75%. The fatigue group had worse motor symptoms and anxiety, depression, and autonomic dysfunction. The CSF level of α-synuclein oligomer was higher and that of Aβ1-42 was lower in the fatigue group than in the non-fatigue group. In multiple linear regression analyses, fatigue severity was significantly and positively correlated with the α-synuclein oligomer level in the CSF of PD patients, after adjusting for confounders. Conclusions PD patients experience a high frequency of fatigue. PD patients with fatigue have worse motor and part nonmotor symptoms. Fatigue in PD patients is associated with an increased α-synuclein oligomer level in the CSF

Molecular characterization and expression of suppressor of cytokine signaling (SOCS) 1, 2 and 3 under acute hypoxia and reoxygenation in pufferfish, Takifugu fasciatus

Dan Wang,Xin Wen,Xinyu Zhang,Yadong Hu,Xinru Li,Wenxu Zhu,Tao Wang,Shaowu Yin 한국유전학회 2018 Genes & Genomics Vol.40 No.11

Hypoxia seriously affects the innate immune system of fish. However, the roles of suppressor of cytokine signaling (SOCS), pivotal anti-inflammatory genes, in response to hypoxia/reoxygenation remain largely unexplored. The primary objective of this study was to elucidate the function of SOCS genes under acute hypoxia and reoxygenation in pufferfish (Takifugu fasciatus). In the present study, SOCS1, 2 and 3 were identified in T. fasciatus referred to as TfSOCS1, 2 and 3. Then, qRTPCR and western blot analysis were employed to assess their expressions at both the mRNA and protein levels. Tissue distribution demonstrated that the three SOCS genes were predominantly distributed in gill, brain and liver. Under hypoxia challenge (1.63 ± 0.2 mg/L DO for 2, 4, 6 and 8 h), the expressions of TfSOCS1 and 3 in brain and liver at the mRNA and protein levels were significantly decreased, while their expressions showed an opposite trend in gill. Different from the expressions of TfSOCS1 and 3, the expression of TfSOCS2 was inhibited in gill, along with its increased expression in brain and liver. After normoxic recovery (7.0 ± 0.3 mg/L of DO for 4 and 12 h), most of TfSOCS genes were significantly altered at R4 (reoxygenation for 4 h) and returned to the normal level at R12 (reoxygenation for 12 h). SOCS genes played vital roles in response to hypoxia/reoxygenation challenge. Our findings greatly strengthened the relation between innate immune and hypoxia stress in T. fasciatus.

Hazard of Plastics

Wang Dan 한국콘텐츠학회 2019 ICCC International Digital Design Invitation Exhib Vol.2019 No.12