Zhejiang California International NanoSystems Institute

Hangzhou, China

Zhejiang California International NanoSystems Institute

Hangzhou, China
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Tong J.,Jiaxing Glead Electronics Co. | Zhang B.,Jiaxing Glead Electronics Co. | Huang W.,Jiaxing Glead Electronics Co. | Yang H.,Zhejiang California International NanoSystems Institute
Materials Letters | Year: 2013

The effect of composition of Li2(Mg0.3Zn 0.7)Ti3O8-xTiO2 (-0.36≤x≤0.36, for short LMZT) on sinterability, crystalline phase, microstructure and microwave dielectric properties of the ZnO-B2O3-SiO 2 (for short ZBS) glass doped samples was systematically investigated. It shows that as x is over zero, rutile phase was detected and the crystalline grain size of LMZT ceramics decrease abruptly. It was also found that the bulk density and the quality factor (Q×f) gradually decreased, dielectric constant (εr) increased, the temperature coefficient of resonant frequency (τf) shifted to positive value with the increase of x value. When x=0.12, LMZT ceramics with 3 wt% ZBS sintered at 900 °C for 3 h show excellent dielectric properties: εr=25.1, Q×f=19,620 GHz, τf=-2.3 ppm/°C. It is compatible with Ag electrodes, which makes it a promising ceramic for low temperature co-fired ceramics technology application. © 2013 Elsevier B.V.

Xin C.-R.,Zhejiang University | Zhang J.,Zhejiang University | Liu Y.,University of Sheffield | Zhang Q.-L.,Zhejiang University | And 3 more authors.
Materials Research Bulletin | Year: 2013

Sc-doped barium titanate (BaTiO3) nanopowders and ceramics were prepared by a sol-gel method for the first time. The polymorphism, microstructure and dielectric properties were investigated. Pseudo-cubic Sc-doped BaTiO3 nanopowders with a particle size of 30-40 nm have been achieved at low temperature of 800 °C. A phase diagram for the solid solution system BaTi1-xScxO3-δ was obtained. The limit of pseudo-cubic Sc-doped BaTiO3 solid solution (BTss) and the stable hexagonal phase have a large dependence on temperatures. The dopant of Sc3+ can also dramatically refine the grain size of BaTiO3 to 300 nm when x = 0.10. For different Sc3+ content in BaTiO3 ceramics, two types of impedance response appeared, and the resistivity of ceramics was dominated by bulk resistance or grain boundary resistance. Curie temperature (TC) and dielectric constant decreased by increasing the Sc3+ content. Relaxor behaviour occurs below room temperature when x = 0.10. © 2013 Elsevier Ltd.

Tang Q.,Zhejiang California International Nanosystems Institute
Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences | Year: 2011

To investigate the effect of benzo(a)pyrene (BaP) on platelet aggregation and expression of P-selectin. Blood samples were collected from healthy volunteers and the platelets was washed. Platelet aggregation was monitored by aggregometer and the expression of P-seletin was detected by whole blood flow cytometry. BaP (10 μmol/L, 1 μmol/L and 0.1 μmol/L) did not induce platelet aggregation; however, preincubation with BaP (10 μmol/L) significantly enhanced ADP-induced platelet aggregation (P < 0.01) and platelet aggregation was (80 ± 10)%, while BaP-preincubation failed to enhance platelet aggregation under collagen and thrombin stimulation. Flow cytometry showed that preincubation with BaP increased ADP-induced, but not thrombin-induced P-selectin expression (P < 0.01). BaP can stimulate ADP-induced platelet aggregation and P-selectin expression, probably through the interaction with ADP-mediated signal pathway.

Li S.,Zhejiang University | Shen Q.,Zhejiang University | Shen Q.,Zhejiang California International NanoSystems Institute | Zong J.,Zhejiang California International NanoSystems Institute | And 2 more authors.
Journal of Alloys and Compounds | Year: 2010

Mesoporous anatase titania spheres with an average size of approx. 400 nm were facilely prepared at low temperature by treating the titanium glycolate precursor spheres with hot water (∼100 °C). The surface of the precursor particle became rough and the anatase phase began to form when it was treated with hot water for 1.5 h. With increasing treatment time, the crystallinity of the particles was improved, and the nanoporous structure further formed in the interior of the spheres. When the treatment time was prolonged to 6 h, the mesoporous anatase spheres were finally obtained, and they were composed of interconnected nanocrystals with the size less than 15 nm and pores with the mean size of 8.31 nm. The as-prepared mesoporous anatase titania spheres exhibited excellent adsorption capacity and better photocatalytic activity compared with the commercial photocatalyst P-25 due to the large specific surface area. Ostwald ripening and surface energy effects were presumed to play an important role in the formation of mesoporous structure and anatase nanocrystals. © 2010 Elsevier B.V. All rights reserved.

Liu X.,Zhejiang University | Jiang J.,Zhejiang University | Shao J.,Zhejiang California International Nanosystems Institute | Yin Y.,Zhejiang University | Ma Z.,Zhejiang University
Applied Microbiology and Biotechnology | Year: 2010

Using a deep serial analysis of gene expression (DeepSAGE) sequencing approach, we profiled the transcriptional response of Fusarium graminearum to tebuconazole, a most widely used azole fungicide. By comparing the expression of genes in F. graminearum treated and untreated with tebuconazole, we identified 324 and 155 genes showing more than a 5-fold increase and decrease, respectively, in expression upon tebuconazole treatment. These genes are involved in a variety of cell functions including egrosterol biosynthesis, transcription, and cellular metabolism. The validity of DeepSAGE results were confirmed by real-time PCR analysis of expression of 20 genes with different expression levels in the DeepSAGE analysis. The results from this study provide useful information in understanding the mechanisms for the responses of F. graminearum to azole fungicides. © 2009 Springer-Verlag.

Li S.,Zhejiang University | Shen Q.,Zhejiang University | Shen Q.,Zhejiang California International NanoSystems Institute | Zong J.,Zhejiang University | And 2 more authors.
Materials Research Bulletin | Year: 2010

A facile route was presented to fabricate mesoporous anatase titania spheres at low temperature; the titania precursor sphere was prepared through a template-free process and then treated by the boiling water. X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM) were adopted to characterize the morphology and crystal structure of the products. The adsorption properties and photocatalytic activities were also investigated. The results indicated that the porous structure and anatase nanocrystals were gradually formed from the surface to the interior of the titania precursor spheres with increasing treatment time. Moreover, there was little change in the size of the spheres during boiling water treatment, thus the size of the mesoporous anatase titania spheres could be easily tailored by controlling the diameter of precursor spheres. The as-prepared product showed excellent adsorption capacity and photocatalytic activity than the commercial P25 due to its high specific surface area. © 2010 Elsevier Ltd. All rights reserved.

Chen J.,Zhejiang University | Chen Q.,Zhejiang University | Jiang L.,Zhejiang University | Cheng C.,Zhejiang University | And 4 more authors.
BMC Microbiology | Year: 2010

Background: Ecological, biochemical and genetic resemblance as well as clear differences of virulence between L. monocytogenes and L. innocua make this bacterial clade attractive as a model to examine evolution of pathogenicity. This study was attempted to examine the population structure of L. innocua and the microevolution in the L. innocua-L. monocytogenes clade via profiling of 37 internalin genes and multilocus sequence typing based on the sequences of 9 unlinked genes gyrB, sigB, dapE, hisJ, ribC, purM, gap, tuf and betL. Results: L. innocua was genetically monophyletic compared to L. monocytogenes, and comprised four subgroups. Subgroups A and B correlated with internalin types 1 and 3 (except the strain 0063 belonging to subgroup C) and internalin types 2 and 4 respectively. The majority of L. innocua strains belonged to these two subgroups. Subgroup A harbored a whole set of L. monocytogenes-L. innocua common and L. innocua-specific internalin genes, and displayed higher recombination rates than those of subgroup B, including the relative frequency of occurrence of recombination versus mutation (ρ/θ) and the relative effect of recombination versus point mutation (r/m). Subgroup A also exhibited a significantly smaller exterior/interior branch length ratio than expected under the coalescent model, suggesting a recent expansion of its population size. The phylogram based on the analysis with correction for recombination revealed that the time to the most recent common ancestor (TMRCA) of L. innocua subgroups A and B were similar. Additionally, subgroup D, which correlated with internalin type 5, branched off from the other three subgroups. All L. innocua strains lacked seventeen virulence genes found in L. monocytogenes (except for the subgroup D strain L43 harboring inlJ and two subgroup B strains bearing bsh) and were nonpathogenic to mice. Conclusions: L. innocua represents a young species descending from L. monocytogenes and comprises four subgroups: two major subgroups A and B, and one atypical subgroup D serving as a link between L. monocytogenes and L. innocua in the evolutionary chain. Although subgroups A and B appeared at approximately the same time, subgroup A seems to have experienced a recent expansion of the population size with higher recombination frequency and effect than those of subgroup B, and might represent the possible evolutionary direction towards adaptation to enviroments. The evolutionary history in the L. monocytogenes-L. innocua clade represents a rare example of evolution towards reduced virulence of pathogens. © 2010 Chen et al; licensee BioMed Central Ltd.

Yan C.,Zhejiang University | Wu W.,Zhejiang University | Li H.,Zhejiang University | Li H.,Huzhou Maternity and Child Care Hospital | And 5 more authors.
Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis | Year: 2010

Benzo[a]pyrene (BaP) is a potent pro-carcinogen generated from the combustion of fossil fuel and cigarette smoke. Previously, using a proteomic approach, we have shown that BaP can induce changes in the expression of many cellular proteins, including transcription regulators. In the present study, using a similar approach, we examined the nuclear protein response to BaP in HeLa cells and found that BaP treatment caused expression changes in many nuclear proteins. Twenty-four of these proteins were successfully identified, several of which are involved in the alternative splicing of mRNA, DNA replication, recombination, and repair. The changed expression levels were further confirmed by immunoblot analysis using specific antibodies for two proteins, Lamin A and mitotic checkpoint protein Bub3. The nuclear localization of these two proteins was also confirmed by confocal microscopy. To determine whether alternative splicing was activated following BaP treatment, we examined Fas and CD44, two genes previously shown to be targets of alternative splicing in respond to DNA damage. While no significant activation of alternative splicing was observed for Fas, CD44 splicing variants were found after BaP treatment. Together, these data show that DNA damage induces dramatic changes in nuclear protein expression, and that alternative splicing might be involved in the cellular response to DNA damage. © 2010 Elsevier B.V. All rights reserved.

Li D.,Zhejiang University | Li D.,Zhejiang California International NanoSystems Institute | Ye C.,Zhejiang University | Zhu Y.,Zhejiang University | And 2 more authors.
Journal of Biomedical Materials Research - Part B Applied Biomaterials | Year: 2012

The bone mesenchymal stem cells (BMSCs) were seeded on [poly(lactide-co- glycolide) scaffolds with hydroxyapatite (HA) coating, and "s" stands for surface] (PLGA/HA-S), PLGA/HA-M (containing the same HA amount in the matrix as that of the PLGA/HA-S and "m" stands for matrix), and PLGA scaffolds, which were then cultured in a medium-containing Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2). In vitro culture of rat BMSCs found no different cell morphology in all the scaffolds, but the alkaline phosphatase activity and osteogenic gene expression of type I collagen (COL I) and osteocalcin (OCN) in the PLGA/HA-S scaffolds were always highest and were significantly improved in comparison with those in the PLGA scaffolds. In a rat calvarial defect model, new bone formation was enhanced in the PLGA/HA-S/ErhBMP-2 implants at 4 and 8 weeks after implantation too. Therefore, the PLGA/HA-S scaffold can better enhance the ErhBMP-2-induced osteogenic differentiation of BMSCs in vitro and osteogenesis in vivo. © 2012 WILEY PERIODICALS, INC.

Li D.,Zhejiang University | Li D.,Zhejiang California International NanoSystems Institute | Ye C.,Zhejiang University | Zhu Y.,Zhejiang University | And 3 more authors.
Polymers for Advanced Technologies | Year: 2012

Poly(lactide-co-glycolide) (PLGA) scaffolds embedded spatially with hydroxyapatite (HA) particles on the pore walls (PLGA/HA-S) were fabricated by using HA-coated paraffin spheres as porogens, which were prepared by Pickering emulsion. For comparisons, PLGA scaffolds loaded with same amount of HA particles (2%) in the matrix (PLGA/HA-M) and pure PLGA scaffolds were prepared by using pure paraffin spheres as porogens. Although the three types of scaffolds had same pore size (450-600μm) and similar porosity (90%-93%), the PLGA/HA-S showed the highest compression modulus. The embedment of the HA particles on the pore walls endow the PLGA/HA-S scaffold with a stronger ability of protein adsorption and mineralization as well as a larger mechanical strength against compression. In vitro culture of rat bone marrow stem cells revealed that cell morphology and proliferation ability were similar on all the scaffolds. However, the alkaline phosphatase activity was significantly improved for the cells cultured on the PLGA/HA-S scaffolds. Therefore, the method for fabricating scaffolds with spatially embedded nanoparticles provides a new way to obtain the bioactive scaffolds for tissue engineering. © 2011 John Wiley & Sons, Ltd.

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