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Bin Deng

Publications and source records attributed to Bin Deng.

At least 19 recordsLinked to original sources
PubMed2006

Charge defects glowing in the dark.

We investigate the effects of local charge defects in HREM imaging, using electron densities calculated by density functional methods. As a model of a planar interface with a local charge defect we use the polar MgO square root (111)-3 x 3R30 degrees surface, which has an additional hole per surface unit cell. A complimentary example, the non-polar MgO (100) surface that has no local charge defect is simulated for comparison. We show that the contrast due to local charge defects is rather high, and suggest that they should be directly observable.

Journal Article↗
PubMed2006

Syntheses, structures, physical properties, and theoretical studies of CeMxOS (M = Cu, Ag; x approximately 0.8) and CeAgOS.

Black single crystals of the two nonstoichiometric cerium coinage-metal oxysulfide compounds CeCu(x)OS and CeAg(x)OS (x approximately 0.8) have been prepared by the reactions of Ce2S3 and CuO or Ag2O at 1223 or 1173 K, respectively. A black powder sample of CeAgOS has been prepared by the stoichiometric reaction of Ce2S3, CeO2, Ag2S, and Ag at 1073 K. These isostructural materials crystallize in the ZrSiCuAs structure type with two formula units in the tetragonal space group P4/nmm. Refined crystal structure results and chemical analyses provide evidence that the previously known anomalously small unit-cell volume of LnCuOS for Ln = Ce (Ln = rare-earth metal) is the result of Cu vacancies and the concomitant presence of both Ce3+ and Ce4+. Both CeCu(0.8)OS and CeAgOS are paramagnetic with mu(eff) values of 2.13(6) and 2.10(1) mu(B), respectively. CeCu(0.8)OS is a p-type semiconductor with a thermal activation energy Ea = 0.22 eV, sigma(electrical) = 9.8(1) 10(-3) S/cm at 298 K, and an optical band gap Eg < 0.73 eV. CeAgOS has conductivity sigma(conductivity) = 0.16(4) S/cm and an optical band gap Eg = 0.71 eV at 298 K. Theoretical calculations with an on-site Coulomb repulsion parameter indicate that the Ce 4f states are fully spin-polarized and are not localized in CeCuOS, CeCu(0.75)OS, or CeAgOS. Calculated band gaps for CeCu(0.75)OS and CeAgOS are 0.6 and 0.8 eV, respectively.

Journal Article↗
PubMed2006

Modification of host lipid raft proteome upon hepatitis C virus replication.

Hepatitis C virus (HCV) replication complex resides in detergent-insoluble subcellular domains or lipid rafts. We used two proteomics approaches to characterize the protein content of lipid rafts isolated from Huh7 cells and its modification upon HCV replication. Using two-dimensional electrophoresis and mass spectrometry, we identified approximately 100 protein spots in the isolated lipid rafts; among them, 39 were reproducibly modified in HCV replicon cell lines as compared with control cell lines. We also used stable isotope labeling by amino acids in cell culture (SILAC) combined with one-dimensional electrophoresis separation and mass spectrometry. Using this approach, we identified 1036 individual proteins based on peptides selected with at least 95% confidence; among them, 413 proteins were identified with at least two peptides. Quantification analysis identified 150 proteins modified by at least 2.5-fold (110 up-regulated and 40 down-regulated) in HCV-replicating cells compared with controls. Protein identifications and quantifications obtained by both proteomics approaches were largely concordant. Modulated proteins included a majority of proteins involved in vesicular and protein trafficking and in cell signaling. Remarkably for a large number of proteins, their up-regulation in lipid rafts of HCV replicon cells was due to their relocalization. By using small interfering RNAs directed to the modulated small GTPases Cdc42 and RhoA, we observed an increase in HCV replication, whereas reduction of syntaxin 7 expression resulted in decreased replication of HCV. Our findings indicate that protein subcellular relocalization occurs in HCV-containing cells that can directly affect HCV replication.

Cell Extracts↗
PubMed2006

Synthesis of copper-core/carbon-sheath nanocables by a surfactant-assisted hydrothermal reduction/carbonization process.

A simple hydrothermal method has been developed for the one-step synthesis of copper-core/carbon-sheath nanocables in solution. The obtained nanostructures were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM), Raman, and UV-vis spectrum analysis. These copper@carbon nanocables formed through the hydrothermal reduction/carbonization in the presence of surfactant cetyltrimethylammonium bromide (CTAB) acting as the structure-directing agent by hydrothermal treatment. HRTEM and selected-area electron diffraction (SAED) indicate that the resulted Cu nanowires had the preferred [110] growth direction. The influence of the reaction temperature, reaction time, and pH on the final products was investigated in detail. The possible formation mechanism for copper-core/carbon-sheath nanocables was also proposed. Amorphous carbon nanotubes can be obtained by etching the copper core in the nanocables.

Journal Article↗
PubMed2006

Fitting valence charge densities at a crystal surface.

A procedure is reported for obtaining a much better initial parameterization of the charge density than that possible from a neutral atom model. This procedure involves the parameterization of a bulk charge density model in terms of simple variables such as bond lengths, which can then be transferred to the problem of interest, for instance a surface. Parameterization is accomplished through the fitting of density functional theory calculations for a variety of crystal distortions. The details of the parameterization are discussed for the specific case of silicon. This parameterized model can then be applied to surfaces or to other problems where an initial higher-order model is needed without the addition of any extra fitted parameters. The non-convexity of the charge density problem is also discussed.

Journal Article↗
PubMed2006

Polymer-controlled crystallization of zinc oxide hexagonal nanorings and disks.

In this study, we have developed a novel route to the synthesis of ZnO nanorings, disks, and diskoidlike crystals on a large scale by a facile solution-based method by using polymers as crystal growth modifiers. The crystals precipitated with polyacrylamide (PAM) as the additive show ringlike morphology. A possible growth mechanism of the ZnO nanostructures based on typical polymer-crystals interactions in a mild aqueous solution is given. The polymer contains in the side chain a large number of amide ligands that are able to coordinate with Zn(2+) ions, that is, the otherwise just weakly exposed (001) face, leading to a lowering of surface energy and inhibition of growth along this direction and the formation of ringlike morphologies. While in the presence of carboxyl-functionalized polyacrylamide (PAM-COOH), nearly monodispersed disklike crystals were observed and finally evolved into diskoidlike microstructures with the reaction time prolonged. Polymer-directed crystal growth and mediated self-assembly of nanocrystals may provide promising routes to rational synthesis of various ordered inorganic and inorganic-organic hybrid materials with complex form and structural specialization.

Journal Article↗
PubMed2006

[Rhizosphere effects of Pinus sylvestris var. mongolica on soil phosphorus transformation].

To understand the phosphorus (P) mobilization mechanism of Mongolian pine (Pinus sylvestris var. mongolica) on a P-deficient semi-arid sandy soil of northern China, this paper compared the P fractions and acid phosphomonoesterase (AP) activity in the bulk and rhizosphere soils under different age Mongolian pine plantations. The results showed that when compared with the bulk soil, the organic C, labile organic P, and organic C/P ratio increased significantly, microbial and AP activities improved, and organic P mineralization accelerated in the rhizosphere soil. Root activity of the Mongolian pine significantly increased the bioavailability of soil P, and accelerated the shift of organic P and Ca-P to Fe-P and Al-P. The rhizosphere effects on soil P in different forms enhanced with stand age, whereas in adverse on AP activity. The bulk and rhizosphere soil had the similar trend in the dynamics of its P fractions with stand age. Soil total P pool reduced gradually while labile P pool increased with stand age. It should be essential to protect forest floor to replenish soil P pool and guarantee a long-term soil P supply.

Ecosystem↗
PubMed2005

Novel multilamellar mesostructured molybdenum oxide nanofibers and nanobelts: synthesis and characterization.

One-dimensional molybdenum oxide nanostructures with layered mesostructures were prepared directly from commercial bulk MoO3 crystals by a surfactant-templated hydrothermal process. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, infrared spectra, and thermal analyses have been used to characterize the obtained molybdenum oxide nanomaterials. By use of cetyltrimethylammonium bromide as the structure-directing template, novel molybdenum oxide nanofibers with triple interlayer distances of 2.84, 2.66, and 2.46 nm have been obtained. The nanofibers have diameters of 20-100 nm and length up to 20 microm. The growth of multilamellar molybdenum oxide nanofibers can be interpreted by the combination of surfactant/inorganic self-assembly process and host/guest intercalation chemistry. On the basis of the X-ray diffraction and infrared results, a possible arrangement of surfactant in the interlayer space of molybdenum oxide by bilayer micelles with different tilt angles has been proposed. In addition, the thermal stability of surfactant has been improved by intercalation. Moreover, molybdenum oxide nanobelts with two kinds of interlayered structures were also produced in the presence of n-alkylamines (n = 12, 14, 16, and 18) following a similar method, these nanobelts show length up to more than 10 microm, width ranging between 200 and 600 microm, and width-to-thickness ratios of about 3-12. A linear relationship is observed between the interlayer distance and the number of carbon atoms in n-alkyl chains.

Journal Article↗
PubMed2005

Synthesis and structural characterization of some selenoruthenates and telluroruthenates.

The reaction of solid [RuClCp(PPh(3))(2)] with TeSe(3)(2-) or Se(n)(2-) in DMF leads to the formation of [RuCp(PPh(3))(mu(2)-Se(2))](2) (1). In the structure of this compound the two bridging Se(2) groups lead to a six-membered Ru(2)Se(4) ring in a chair conformation. Attached to each Ru center is a PPh(3) ligand in an equatorial position and a Cp ring in an axial position. The compound is diamagnetic. The compound [Ru(2)Cp(2)(mu(3)-Se(2))(mu(3)-Se)](2) (2) is obtained under similar conditions in the presence of air. This structure comprises a centrosymmetric Ru(4)Se(6) dimer formed from the two bridging Se groups and the two bridging Se(2) groups. Each Ru center is pi-bonded to a Cp ring. The reaction of solid [RuClCp(PPh(3))(2)] with a Te(n)(2-) polytelluride solution in DMF leads to the diamagnetic compound [(RuCp(PPh(3)))(2)(mu(2)-(1,4-eta:3,6-eta)Te(6))] (3). Here the Ru centers are bound to a bridging Te(6) chain at the 1, 4, 3, and 6 positions, leading to a bicyclic Ru(2)Te(6) ring. Each Ru atom is bound to a Cp ring and a PPh(3) group. This dimer possesses a center of symmetry. The structure of 3 is the first example of a bicyclic complex where fusion occurs along a Te-Te bond. If the same reaction is carried out in DMF/CH(2)Cl(2), rather than DMF, then [(RuCp(PPh(3)))(2)(mu(2)-(1,4-eta:3,6-eta)Te(6))].CH(2)Cl(2) (4) is obtained. In the solid state it possesses the same Ru(2)Te(6) structural unit as does 3, but the unit lacks a crystallographically imposed center of symmetry. The electronic structures of 3 and 4 have been analyzed with the use of first principles density functional theory. Bond order analysis indicates that the Te-Te bond where fusion occurs has a shared bonding charge of about (2)/(3) of that found for Te-Te single bonds.

Journal Article↗
PubMed2005

A wide range of protein isoforms in serum and plasma uncovered by a quantitative intact protein analysis system.

We have implemented an orthogonal 3-D intact protein analysis system (IPAS) to quantitatively profile protein differences between human serum and plasma. Reference specimens consisting of pooled Caucasian-American serum, citrate-anticoagulated plasma, and EDTA-anticoagulated plasma were each depleted of six highly abundant proteins, concentrated, and labeled with a different Cy dye (Cy5, Cy3, or Cy2). A mixture consisting of each of the labeled samples was subjected to three dimensions of separation based on charge, hydrophobicity, and molecular mass. Differences in the abundance of proteins between each of the three samples were determined. More than 5000 bands were found to have greater than two-fold difference in intensity between any pair of labeled specimens by quantitative imaging. As expected, some of the differences in band intensities between serum and plasma were attributable to proteins related to coagulation. Interestingly, many proteins were identified in multiple fractions, each exhibiting different pI, hydrophobicity, or molecular mass. This is likely reflective of the expression of different protein isoforms or specific protein cleavage products, as illustrated by complement component 3 precursor and clusterin. IPAS provides a high resolution, high sensitivity, and quantitative approach for the analysis of serum and plasma proteins, and allows assessment of PTMs as a potential source of biomarkers.

Anticoagulants↗
PubMed2005

Separation of tissue proteins of human lung carcinomas by partial-filling capillary electrophoresis.

Tissue proteins from human squamous cell lung carcinomas (SQCLC) and small cell lung carcinomas (SCLC) were separated in 0.01% hydroxypylmethyl cellulose (HPMC) linear polymer sieving solutions in the inlet portion of the capillary and next to the outlet of the capillary, followed by capillary zone electrophoresis (CZE) in 40 mM phosphate buffer, pH 2.5. A proper HPMC concentration could cause a molecular sieving effect through the formation of an entangled polymer network. The migration time of the analyte in this matrix depended on the size and electrophoretic mobility of the analyte, the mesh size, and the electric field strength. In the CZE separation, the electroosmotic flow and the charge-to-size ratio of the analyte were important parameters. HPMC concentration and zone length were examined to optimize the separation. Applying this partial-filling technique to the separation of water-soluble proteins from human lung tissues, we found a greatly improved resolution and increased peak intensity. The capillary electrophoresis patterns of normal, SQCLC, and SCLC were obtained and compared for their molecular classifications.

Carcinoma, Small Cell↗
PubMed2005

Proteomics analysis of stage-specific proteins expressed in human squamous cell lung carcinoma tissues.

There is a growing interest in applying proteomics to gain insight into the mechanism of tumorigenesis, develop new markers for molecular diagnosis and accelerate drug development. In an attempt to find new stage-specific tumor markers, patients suffering from squamous cell lung carcinomas (SQCLC) at different pathologic stages have been selected to achieve differential protein expression patterns. Two-dimensional polyacrylamide gel electrophoresis (2-DE) profiles of human SQCLC and normal tissue were compared. Differential protein spots were identified with peptide mass fingerprinting (PMF) based on matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and database searching. A total of 63 unique proteins were identified in this experiment. Among them, peroxiredoxin 1 (PRDX1) expression level was significantly increased from stage I to III, and had a slight decrease at stage IV; whereas, a lasting decrease in the expression level of tropomyosins 3 (TPM3), was observed with the malignant progression from I stage to IV stage. These results provide further insight into malignant transformation in SQCLC and proteins may serve as new biomarkers for early diagnosis.

Biomarkers, Tumor↗
PubMed2004

Syntheses, structure, some band gaps, and electronic structures of CsLnZnTe3 (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Y).

Eleven new quaternary rare-earth tellurides, CsLnZnTe3 (Ln=La, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Y), were prepared from solid-state reactions at 1123 K. These isostructural materials crystallize in the layered KZrCuS3 structure type in the orthorhombic space group Cmcm. The structure is composed of LnTe6 octahedra and ZnTe4 tetrahedra that share edges to form [LnZnTe3] layers. These layers stack perpendicular to [010] and are separated by layers of face- and edge-sharing CsTe8 bicapped trigonal prisms. There are no Te-Te bonds in the structure of these CsLnZnTe3 compounds so the formal oxidation states of Cs/Ln/Zn/Te are 1+/3+/2+/2-. Optical band gaps of 2.13 eV for CsGdZnTe3 and 2.12 eV for CsTbZnTe3 were deduced from single-crystal optical absorption measurements. A first-principles calculation of the density of states and the frequency-dependent optical properties was performed on CsGdZnTe3. The calculated band gap of 2.1 eV is in good agreement with the experimental value. A quadratic fit for the lanthanide contraction of the Ln-Te distance is superior to a linear one if the closed-shell atom is included.

Journal Article↗
PubMed2004

Dicerium orthosilicate selenide and dicerium orthosilicate telluride, Ce2(SiO4)Q (Q = Se or Te).

The crystal structures of two new quaternary compounds, viz. dicerium orthosilicate selenide and dicerium orthosilicate telluride, Ce(2)(SiO(4))Q (Q = Se or Te), have been determined from single-crystal X-ray diffraction data. Each structure comprises infinite chains of SiO(4) tetrahedra separated by Ce and Q atoms. The site symmetries are Ce m and 2, Si 2 and Q m. The O atoms are in general positions.

Journal Article↗
PubMed2004

Isolation and identification of a new thymic peptide from calf thymus.

Various thymic peptides (including thymulin, thymic humoral factor, thymopoietin, etc.) play important roles in the process of T cell maturation and development. We isolated a new peptide from calf thymus and named it thymus activity factor II (TAF-II). A yield of 0.92 mg of TAF-II was purified from 500 g calf thymus. Analysis by LC/MSD-Trap showed the amino acid sequence of this hexapeptide to be Glu-Ala-Lys-Ser-Gln-Gly-OH with molecular weight 618.5 daltons. We have also begun to investigate the influence of TAF-II.

Adult↗
PubMed2004

[Effect of jianxin pinglu pill on arrhythmia and aquaporin 4 expression in rats with myocardial ischemia/reperfusion injury].

OBJECTIVE: To explore the effect of jianxin pinglu pill (JPP) on arrhythmia and aquaporin 4 (AQP4) in rats with myocardial ischemia/reperfusion (I/R) injury. METHODS: The effects of JPP on arrhythmia, mortality and AQP4 on I/R injured rats model induced by blocking left coronary artery were observed using II lead of ECG, HE stain and AQP4 immunohistochemical stain. RESULTS: JPP showed significant effect in lowering the arrhythmia occurrence and mortality, reducing myocardial ischemic edema and injury, strengthening AQP4 expression in myocardial tissue. CONCLUSION: JPP has the effect of preventing I/R induced arrhythmia, it might be related with its action in up-regulating AQP4 expression level in myocardium and reducing the intracellular edema.

Animals↗
PubMed2003

[Effect of cell cycle on telomerase activity of hepatoma cells and its relationship with replication of hepatitis B virus].

BACKGROUND & OBJECTIVE: Previous studies have shown that the expression of telomerase activity is closely correlated with the formation and development of tumor cells. Furthermore, the cell cycle is associated with hepatitis B virus (HBV) replication level and telomerase activity. For further study their relationship, this experiment was designed to investigate the effect of serum deprivation or all-trans-retinoic acid(RA)on cell cycle of human hepatoma cells transfected by HBV DNA (HepG2 cell line) and the associations of cell cycle with telomerase activity and HBV replication. METHODS: Human hepatoma HepG2 cells were respectively treated with serum deprivation or RA. Cell cycle was analyzed using flow cytometry. Telomerase activity was determined quantitatively by TRAP-PCR-ELISA. HBV-DNA in culture media was determined using quantitative PCR and semiquantitative dot blot hybridization assay. HBsAg and HBeAg in cell culture media were measured using quantitative ELISA. RESULTS: RA treatment or serum deprivation inhibited the proliferation of HepG2 cells and the cells were arrested at G(0)/G(1) phase. The percentages of G(0)/G(1) phase of RA group and serum deprivation were 68.3% and 65.2%, respectively, while that of control group was 43.1% (P< 0.01). The levels of telomerase activity also significantly decreased. The absorbance values that represented the telomerase activity of RA group and serum deprivation group were 0.32 and 0.41, respectively, while that of control group was 1.34(P< 0.01). In addition,HBV replication of HepG2 cells remarkably increased, which was shown as high products of HBV-DNA, HBsAg and HBeAg in culture media of RA group and serum deprivation group. The contents of HBV DNAs were 4.4x10(6), 5.1x10(6), and 1.2x10(6) copies/ml in RA group, serum deprivation group, and control group, respectively(P< 0.01). The values of P/N of HBsAg were 3.5, 3.7, and 1.3 in RA group, serum deprivation group, and control group, respectively (P< 0.01). The values of P/N of HBeAg were 19.8, 22.5, and 13.4 in RA group, serum deprivation group, and control group, respectively (P< 0.01). CONCLUSION: Telomerase expression was associated with cell cycle in HepG2 cells. Telomerase was mainly expressed in S phase of cell cycle. HBV replication was also closely correlated with cell cycle, which increased in quiescent hepatocytes and decreased in proliferating hepatocytes.

Carcinoma, Hepatocellular↗