Preparation of NiO and CoO nanoparticles using M2+-oleate (M = NiCo) as precursor

Zhongping Chen,Aiqun Xu,Yu Zhang,Ning Gu 한국물리학회 2010 Current Applied Physics Vol.10 No.3

The preparation of NiO and CoO nanoparticles was reported. The dot-like NiO and flower-like CoO nanoparticles were obtained using M2+-oleate (M = Ni, Co) as precursor via thermal decomposition method. Transmission electron microscopic (TEM) images monitored the growth of NiO and CoO nanoparticles. When the reaction complex including M2+-oleate (M = Ni, Co) precursor, oleic acid and 1-octadecene was heated to the refluxing temperature (320 ℃), the formed NiO and CoO nanoparticles were needlelike and very small, indicating low growth speed. However, when the reaction complex was kept refluxing for 30 min, dot-like NiO and flower-like CoO nanoparticles were observed, suggesting the accelerated growth at this refluxing stage. The difference of the morphology of the resultant NiO and CoO nanoparticles resulted from the difference of their growth mode. Selected-area electron diffraction (SAED) patterns showed the face-centered cubic structures of NiO and CoO nanoparticles. The magnetic property of the nanoparticles was studied using vibrating sample magnetometer (VSM).

Growth and Triterpenic Acid Accumulation of Cyclocarya paliurus Cell Suspension Cultures

Zhongping Yin,Xinchen Shangguan,Jiguang Chen,Qiang Zhao,Dongming Li 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.3

Cyclocarya paliurus is a unique plant growing in central China with hypoglycaemic and hypolipaemia effects. To make better use of this functional food resource,cell suspension cultures and triterpenic acid accumulation were studied. Stable and uniform cell suspension cultures were established in liquid basal Murashige and Skoog medium supplemented with 2,4-dichlorophenoxy acetic acid (0.5 mg/L), naphthalene acetic acid (0.3 mg/L) and cytokinin (1.0 mg/L). According to the growth curve and triterpenic acid accumulation curve, the 8 ~ 10th day postinoculation was the optimum time for subculture, and the 14th day was the optimum time for harvest. Murashige and Skoog medium and woody plant medium were suitable for both cell growth and triterpenic acid accumulation. 3%sucrose (w/v), 60 mM total nitrogen (NO3-/NH4+ = 2/1),1.25 mM KH2PO4, 2 mM CaCl2, and 2 mM MgSO4 were all found to be fit for cell growth and triterpenic acid accumulation in a cell suspension culture of Cyclocarya paliurus. Total triterpenic acid, ursolic acid and oleanolic acid content in suspended cultured cells were all significantly higher than that of leaves and calluses (P 0.01), with levels up to 6.24, 2.28, and 0.94% (of dry weight), respectively. The betulinic acid content of suspended cultured cells also reached 0.82%, which was significantly higher than that of calluses. These results suggest that suspended cultured cells of Cyclocarya paliurus were rich in triterpenic acids and could be used for the production of total triterpenic acid, ursolic acid, oleanolic acid and betulinic acid.

THE EXISTENCE OF SOLUTIONS AND WELL-POSEDNESS FOR BILEVEL MIXED EQUILIBRIUM PROBLEMS IN BANACH SPACES

Chen, Jia-wei,Cho, Yeol Je,Wan, Zhongping The Mathematical Society of the Republic of China 2013 Taiwanese journal of mathematics Vol.17 No.2

Graphene Quantum Dots Enhanced Photocatalytic Activity of Sb2WO6 Under Ultraviolet- and Visible-Light Irradiation

Shan Li,Zhongping Chen,Datong Wu,Yong Qin,Yong Kong 대한화학회 2020 Bulletin of the Korean Chemical Society Vol.41 No.5

A novel composite of graphene quantum dots functionalized Sb2WO6 (GQDs/Sb2WO6) was prepared by an electrostatic self-assembly method and used as a photocatalyst for the degradation of an organic pollutant. The resulting GQDs/Sb2WO6 was characterized by electron microscopy and optical measurements. The photocatalytic activity of GQDs/Sb2WO6 was investigated by degrading methyl orange (MO) under UV-light and visible-light irradiation. Compared with pure Sb2WO6, enhancement of the photocatalytic performance of GQDs/Sb2WO6 was achieved, and the degradation efficiency for MO was almost 100% within 3 h under UV-light irradiation and 71.4% within 3 h under visible-light irradiation. The photocatalytic degradation mechanism of GQDs/Sb2WO6 was illustrated by free radical and hole scavenging experiments, and the main active species were confirmed to be holes (h+) and superoxide anion radicals (O2·?). Moreover, the GQDs/Sb2WO6 composites exhibited high recyclability and stability and had potential application for decomposing other organic contaminants in water.

Multimodal intravascular photoacoustic and ultrasound imaging

Yan Li,Zhongping Chen 대한의용생체공학회 2018 Biomedical Engineering Letters (BMEL) Vol.8 No.2

The rupture of atherosclerotic plaques is the leading cause of death in developed countries. Early identification ofvulnerable plaque is the essential step in preventing acute coronary events. Intravascular photoacoustic (IVPA) technologyis able to visualize chemical composition of atherosclerotic plaque with high specificity and sensitivity. Integrated withintravascular ultrasound (IVUS) imaging, this multimodal intravascular IVPA/IVUS imaging technology is able to provideboth structural and chemical compositions of arterial walls for detecting and characterizing atherosclerotic plaques. In thispaper, we present representative multimodal IVPA/IVUS imaging systems and discuss current scientific innovations,potential limitations, and prospective improvements for characterization of coronary atherosclerosis.

Multimodal photoacoustic imaging: systems, applications, and agents

Kim, Chulhong,Chen, Zhongping Springer-Verlag 2018 Biomedical Engineering Letters (BMEL) Vol.8 No.2

Enhancement of α-ketoglutarate Production in Torulopsis glabrata: Redistribution of Carbon Flux from Pyruvate to α-ketoglutarate

Dandan Zhang,Nan Liang,Zhongping Shi,Liming Liu,Jian Chen,Guocheng Du 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.2

This manuscript aimed at increasing the production of α-ketoglutarate by the multi-vitamin auxotrophic yeast Torulpsis glabrata CCTCC M202019. The carbon flux was redistributed from pyruvate to α-ketoglutarate node by manipulating the specific activity of pyruvate dehydrogenase complex (PDH), pyruvate carboxylase (PC), pyruvate decarboxylase (PDC), and α-ketoglutarate dehydrogenase complex (KGDH). By proper increase of PDH, PC, and PDC activities, α-ketoglutarate in fermentation broth could be accumulated to the levels of 17.1 g/L, 21.6 g/L, and 31.2 g/L, respectively. In addition, decrease in the specific activity of KGDH also resulted in an enhanced α-ketoglutarate synthesis. With a proposed combinational enzymes regulation strategy, the highest α-ketoglutarate concentration of 37.7 g/L was achieved This manuscript aimed at increasing the production of α-ketoglutarate by the multi-vitamin auxotrophic yeast Torulpsis glabrata CCTCC M202019. The carbon flux was redistributed from pyruvate to α-ketoglutarate node by manipulating the specific activity of pyruvate dehydrogenase complex (PDH), pyruvate carboxylase (PC), pyruvate decarboxylase (PDC), and α-ketoglutarate dehydrogenase complex (KGDH). By proper increase of PDH, PC, and PDC activities, α-ketoglutarate in fermentation broth could be accumulated to the levels of 17.1 g/L, 21.6 g/L, and 31.2 g/L, respectively. In addition, decrease in the specific activity of KGDH also resulted in an enhanced α-ketoglutarate synthesis. With a proposed combinational enzymes regulation strategy, the highest α-ketoglutarate concentration of 37.7 g/L was achieved

Multidimensional culture system for SH-SY5Y cells on microwell patterns regulated by the ROCK signaling pathway

Donghuo Zhong,Xingnuan Li,Zhongping Wang,Shikai Qi,Mengxi Chen,Chengjin Li,Shan He 한국고분자학회 2024 Macromolecular Research Vol.32 No.4

This study presents the fabrication of polylactic acid microwell patterns using a lithography-based replica molding method for the development of three-dimensional (3D) neural cell-based assays. SH-SY5Y human neuroblastoma cells interfaced with these patterns, and cell growth and morphological characteristics were evaluated with and without an inhibitor of the rho-associated coiled-coil kinase (ROCK) signaling pathway. The results revealed that the culture systems of SH-SY5Y cells on the microwell patterns could be categorized as two-dimensional (2D), 3D, and near-two-dimensional (N2D), according to their location within a dynamic multidimensional culture system. Furthermore, the geometric features of the patterns significantly impact the efficiency of the conversion model, which was characterized by the proliferation and percentage of cells in different culture systems. The rearrangement of the microfilament cytoskeleton and morphological spreading of cells on the patterns were suppressed by the downregulation of the ROCK signaling pathway. The inhibition of the ROCK signaling pathway had a time-dependent effect on the proliferation and migration of cells on the patterned substrate, where topographical cues, cell morphology, and density played pivotal roles. Consequently, the proposed system serves as a practical model for studying the functional behaviors of neural cells by dynamically assembling multidimensional culture systems on the same platform, facilitating the development of cell-based assays.

Double common-path interferometer for flexible optical probe of optical coherence tomography

Park, Jae Seok,Chen, Zhongping,Jeong, Myung Yung,Kim, Chang-Seok Optical Society of America 2012 Optics express Vol.20 No.2

<P>A flexible curled optical cord is useful for a common-path optical coherence tomography (OCT) system because a bending-insensitive arbitrary length can be chosen for the endoscopic imaging probe. However, there has been a critical problem that the partial reflector needs to be placed in between the sample and the objective lens. It limits the structure design of optical probe and leads to a low transverse resolution OCT imaging. Instead of a conventional single common-path interferometer, we propose a novel double common-path interferometer configuration in order to generate an interference signal that is independent of the optical distance between the partial reflector and sample. Due to the limitless tuning of the objective distance, an objective lens with a high numerical aperture (NA) up to 0.85 can be successfully used for phase-sensitive optical coherence tomography to achieve a 3-dimensional profile image of a transverse resolution of 0.7 <I>μ</I>m. The intensity and phase terms of the interference signal can be obtained simultaneously from a Fourier-domain mode locked swept laser source for fast data acquisition with a phase stability of 979 pm.</P>

Q-switched Erbium-doped fiber laser at 1600 nm for photoacoustic imaging application

Piao, Zhonglie,Zeng, Lvming,Chen, Zhongping,Kim, Chang-Seok American Institute of Physics 2016 Applied Physics Letters Vol.108 No.14