Tetrabutylphosphonium amino acid ionic liquids as efficient catalysts for solvent-free Knoevenagel condensation reactions

Fan Ouyang,Duan-Jian Tao,Yan Zhou,Zhang-Min Li,Na Hu 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.8

Five tetrabutylphosphonium amino acid ionic liquids ([P4444][AA]) were prepared, characterized, and usedas catalysts for solvent-free Knoevenagel condensation reactions. The tetrabutylphosphonium prolinate ([P4444][Pro])showed excellent catalytic activity and selectivity in Knoevenagel condensation reactions of active methylene compoundswith various aromatic aldehydes, and all the yields of corresponding products were more than 85% under mildconditions. Furthermore, a plausible reaction mechanism for the excellent performance of [P4444][Pro] has been proposed,and [P4444][Pro] could be used repetitively at least six times without obvious decrease in activity and quantity.

One-Pot Synthesis of Platinum Nanodendrites with Enhanced Catalytic Performance for Methanol Oxidation Reaction

Shenshen Ouyang,Linfei Wang,Jing Cui,Haibo Shi,Tao Wang,Sheng Wang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.7

Controlling the synthesis of noble metal nanostructures with highly branched morphology to obtain specific physical and chemical properties has attracted much attention. This paper reports the synthesis of 3D Pt nanodendrites with controlled architectures (multibranched) by a simple one-pot hydrothermal reaction in the presence of fructose. At high reaction temperature, fructose not only acts as a reducing agent, but also forms a hydrothermal carbon, which, as a capping agent, is absorbed on the surface of metal nanocrystals and induces the anisotropic growth of Pt nanodendrites. The prepared Pt nanodendrites are highly porous, and have self-supported nanoarchitectures with a high surface area and a number of absorption sites for reactant molecules. The Pt nanodendrites exhibit a higher electrocatalytic activity and stability than commercial Pt/C for methanol oxidation reaction.

Improving the thermoelectric properties of carbon nanotubes through introducing graphene nanosprings

Xiaoyan Xu,Huaping Xiao,Tao Ouyang,Jianxin Zhong 한국물리학회 2020 Current Applied Physics Vol.20 No.1

Carbon nanotube (CNT) is a typical one-dimensional nanomaterial containing sp2 hybridization states. In this paper, we investigate the ballistic thermoelectric performance of CNTs incorporating graphene nanosprings by using non-equilibrium Green's function. The calculations reveal that the thermoelectric figure of merit could be obviously improved by introducing graphene nanosprings, which is about ten times of that of pristine CNTs at 700 K. Such enhancement is mainly attributed to the remarkable suppression of phononic and electronic thermal conductance and improvement of Seebeck coefficient. In addition, compared to the zigzag graphene nanospring, introducing of the armchair case possesses better thermoelectric performance. The results presented in this paper indicate that embedding graphene nanospring is a viable method to optimize the thermoelectric performance of CNTs and could provide useful theoretical guidance for design and fabrication of CNTs-based thermoelectric devices

Electron transport properties of Y-type zigzag branched carbon nanotubes

MaoSheng Ye,HangKong, OuYang,YiNi Lin,Quan Ynag,QingYang Xu,Tao Chen,LiNing Sun,Li Ma Techno-Press 2023 Advances in nano research Vol.15 No.3

The electron transport properties of Y-type zigzag branched carbon nanotubes (CNTs) are of great significance for micro and nano carbon-based electronic devices and their interconnection. Based on the semi-empirical method combining tight-binding density functional theory and non-equilibrium Green's function, the electron transport properties between the branches of Y-type zigzag branched CNT are studied. The results show that the drain-source current of semiconducting Y-type zigzag branched CNT (8, 0)-(4, 0)-(4, 0) is cut-off and not affected by the gate voltage in a bias voltage range [-0.5 V, 0.5 V]. The current presents a nonlinear change in a bias voltage range [-1.5 V, -0.5 V] and [0.5 V, 1.5 V]. The tangent slope of the current-voltage curve can be changed by the gate voltage to realize the regulation of the current. The regulation effect under negative bias voltage is more significant. For the larger diameter semiconducting Y-type zigzag branched CNT (10, 0)-(5, 0)-(5, 0), only the value of drain-source current increases due to the larger diameter. For metallic Y-type zigzag branched CNT (12, 0)-(6, 0)-(6, 0), the drain-source current presents a linear change in a bias voltage range [-1.5 V, 1.5 V] and is symmetrical about (0, 0). The slope of current-voltage line can be changed by the gate voltage to realize the regulation of the current. For three kinds of Y-type zigzag branched CNT with different diameters and different conductivity, the current-voltage curve trend changes from decline to rise when the branch of drain-source is exchanged. The current regulation effect of semiconducting Y-type zigzag branched CNT under negative bias voltage is also more significant.

FDTD simulation of the optical properties for a gold nanoparticle-overnanosheet hybrid structure

Yu Chen,Jie Wang,Tao Xu,Min Liu,Jinxin Liu,Han Huang,Fangping Ouyang 한국물리학회 2020 Current Applied Physics Vol.20 No.3

The optical properties of a two-dimensional gold nanoparticle-over-nanosheet (2D-AuNP/NS) have been studied using Finite-Difference Time-Domain (FDTD) method. 2D-AuNP/NS hybrid structure exhibits three typical localized surface plasmon (LSP) resonances, which occur in nanogaps between NP-NP, NP-NS and coupled upper and lower surface of NS respectively. Thus, the influence of AuNP-size, surface AuNP-coverage, NP-NP-spacing and NS-thickness on the localized electric field was analyzed in details. The LSP resonance between NP-NS has been predicted to be the most important effect on SERS, which is dominant, stable and can maintain the SERS intensity even at a relatively low NP-coverage. If a slight deviation of AuNPs away from their original periodic positions was permitted, a disordered model was then constructed which would more closely approximate the real AuNP/NS hybrid structure and was able to calculate the influence of disorder on LSP resonance. A blue shift (rather than red shift) of the resonance peak was observed and its peak intensity would increase first and decrease then with the increase of NP-NP-spacing. FDTD simulations have finally illustrated that NP-coverage should be controlled ranging from 80.0 % to 87.0% or just equal to 100%, if both AuNP-size and NP-thickness is controlled to 10 nm. The FDTD simulation results are qualitative agreement with the existing experimental data and are very useful in the future materials designs for AuNS-based nanocomposite.

p-Anisaldehyde Exerts Its Antifungal Activity Against Penicillium digitatum and Penicillium italicum by Disrupting the Cell Wall Integrity and Membrane Permeability

Jinxin Che,Xiumei Chen,Qiuli Ouyang,Nengguo Tao 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.6

Penicillium digitatum and P. italicum are the two important postharvest pathogens in citrus, causing about 90% of the total loss of citrus fruit during storage and transportation. Natural fungicides such as essential oils have been widely used instead of chemical fungicides for preventing and controlling postharvest diseases. In this research, p-anisaldehyde exhibited a strong inhibitory effect on P. digitatum and P. italicum, with the minimum inhibitory concentration and minimum fungicidal concentration values of both being 2.00 μl/ml. Additionally, p-anisaldehyde visibly inhibited both the green mold and blue mold development of citrus fruits inoculated with P. digitatum and P. italicum. The mycelia morphologies of these pathogens were greatly altered, and the membrane permeability and cell wall integrity of mycelia were severely disrupted under p-anisaldehyde treatment. These results suggest that the antifungal activity of p-anisaldehyde against P. digitatum and P. italicum can be attributed to the disruption of the cell wall integrity.

Isolation and Characterization of a Mesophilic Arthrospira maxima Strain Capable of Producing Docosahexaenoic Acid

( Hong Jun Hu ),( Ye Guang Li ),( Chun Tao Yin ),( Ye Xin Ouyang ) 한국미생물 · 생명공학회 2011 Journal of microbiology and biotechnology Vol.21 No.7

A strain of the cyanobacterium Arthrospira was isolated from Lake Chahannaoer in northern China and was characterized according to microscopic morphology, photosynthetic oxygen-evolving activity, growth rate, and nutritional profile. Compared with thermophilic Arthrospira species occurring naturally in tropical and subtropical lakes, this isolate is mesophilic and grows optimally at ~20°C. The total protein, fatty acid, phycocyanin, carotenoid, and chlorophyll a contents were 67.6, 6.1, 4.32, 0.29, and 0.76 grams per 100 grams of dry weight, respectively. The strain is rich in polyunsaturated fatty acids (PUFAs). An essential omega-3 fatty acid, docosahexaenoic acid (DHA), was detected, and γ-linolenic acid (GLA) and DHA accounted for 28.3% of the total fatty acid content. These features of this newly isolated strain make it potentially useful in commercial mass culture in local areas or as a biofuel feedstock. It is also an alternative resource for studying the metabolic PUFA pathways and mechanisms of cold stress tolerance in cyanobacteria.

Screening for Metastatic Osteosarcoma Biomarkers with a DNA Microarray

Diao, Chun-Yu,Guo, Hong-Bing,Ouyang, Yu-Rong,Zhang, Han-Cong,Liu, Li-Hong,Bu, Jie,Wang, Zhi-Hua,Xiao, Tao Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Objective: The aim of this study was to screen for possible biomarkers of metastatic osteosarcoma (OS) using a DNA microarray. Methods: We downloaded the gene expression profile GSE49003 from Gene Expression Omnibus database, which included 6 gene chips from metastatic and 6 from non-metastatic OS patients. The R package was used to screen and identify differentially expressed genes (DEGs) between metastatic and non-metastatic OS patients. Then we compared the expression of DEGs in the two groups and sub-grouped into up-regulated and down-regulated, followed by functional enrichment analysis using the DAVID system. Subsequently, we constructed an miRNA-DEG regulatory network with the help of WebGestalt software. Results: A total of 323 DEGs, including 134 up-regulated and 189 down-regulated, were screened out. The up-regulated DEGs were enriched in 14 subcategories and most significantly in cytoskeleton organization, while the down-regulated DEGs were prevalent in 13 subcategories, especially wound healing. In addition, we identified two important miRNAs (miR-202 and miR-9) pivotal for OS metastasis, and their relevant genes, CALD1 and STX1A. Conclusions: MiR-202 and miR-9 are potential key factors affecting the metastasis of OS and CALD1 and STX1A may be possible targets beneficial for the treatment of metastatic OS. However, further experimental studies are needed to confirm our results.

Prescription Patterns for Bipolar Disorder in Asian Countries: Findings from Research on Asian Prescription Pattern-Bipolar Disorder

Shih-Ku Lin,Shu-Yu Yang,Seon-Cheol Park,Ok-Jin Jang,Xiaomin Zhu,Yu-Tao Xiang,Wen-Chen Ouyang,Afzal Javed,M. Nasar Sayeed Khan,Sandeep Grover,Ajit Avasthi,Roy Abraham Kallivayalil,Kok Yoon Chee,Norliza 대한정신약물학회 2022 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.20 No.1

Objective: Pharmacotherapy including mood stabilizers and antipsychotics are frequently used in bipolar disorder (BD); however, the lack of consensus regarding the definition of polypharmacy hinders conducting comparative studies across different settings and countries. Research on Asian Prescription Pattern (REAP) is the largest and the longest lasting international collaborative research in psychiatry in Asia. The objective of REAP BD was to investigate the prescription patterns of psychotropic medications across Asian countries. The rates of polypharmacy and psychotropic drug load were also analyzed. Methods: The data collection was web-based. Prescription patterns were categorized as (1) mood stabilizer monotherapy: one mood stabilizer; (2) antipsychotic monotherapy: one antipsychotic; (3) simple polypharmacy: one mood stabilizer and one antipsychotic; and (4) complex polypharmacy: ≥ 2 mood stabilizers or/and antipsychotics. The psychotropic drug load in each patient was calculated using the defined daily dose method. Results: Among 2003 patients with BD (52.1% female, 42.4 years) from 12 countries, 1,619 (80.8%) patients received mood stabilizers, 1,644 (82.14%) received antipsychotics, and 424 (21.2%) received antidepressants, with 14.7% mood stabilizer monotherapy, 13.4% antipsychotic monotherapy, 48.9% simple polypharmacy, 20.3% complex polypharmacy, and 2.6% other therapy. The average psychotropic drug load was 2.05 ± 1.40. Results varied widely between countries. Conclusion: Over 70% of psychotropic regimens involved polypharmacy, which accords with the high prevalence of polypharmacy in BD under a permissive criterion (2 or more core psychotropic drugs) worldwide. Notably, ≥ 80% of our sample received antipsychotics, which may indicate an increasing trend in antipsychotic use for BD treatment.

Component Prototyping for the China Spallation Neutron Source Project

Jie Wei,Yanwei Chen,Yunlong Chi,Changdong Deng,Haiyi Dong,Shinian Fu,Wei He,Kaixi Huang,Wen Kang,Jian Li,Huafu Ouyang,Huamin Qu,Caitu Shi,Hong Sun,Jingyu Tang,Juzhou Tao,Sheng Wang,Zhongxiong Xu,Xueju 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.5

The China Spallation Neutron Source (CSNS) complex consists of an H- linear accelerator, a rapid cycling synchrotron accelerating the beam to 1.6 GeV, a solid tungsten target station and instruments for spallation neutron applications. The facility operates at a 25-Hz repetition rate with an initial design beam power of 120 kW and is upgradeable to 500 kW. The primary challenge is to build a robust and reliable user-friendly facility with upgrade potential at a fraction of the \world standard" cost. Success of the project relies on the results of prototyping research & development (R&D) of key technical systems and components. This paper discusses the prototyping experiences of the past two and a half years. The China Spallation Neutron Source (CSNS) complex consists of an H- linear accelerator, a rapid cycling synchrotron accelerating the beam to 1.6 GeV, a solid tungsten target station and instruments for spallation neutron applications. The facility operates at a 25-Hz repetition rate with an initial design beam power of 120 kW and is upgradeable to 500 kW. The primary challenge is to build a robust and reliable user-friendly facility with upgrade potential at a fraction of the \world standard" cost. Success of the project relies on the results of prototyping research & development (R&D) of key technical systems and components. This paper discusses the prototyping experiences of the past two and a half years.