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ABSTRACT: The structural properties and the 4f →5d absorptions of Ce-doped LuAlO3 have been studied using the density functional theory-based generalized gradient approximation PBE + U (PBE: Perdew, Burke and Ernzerhof) and wavefunction-based embedded cluster calculations, respectively. The PBE or PBE + U calculations reveal that the substitution of Ce for Lu induces a strongly anisotropic distortion of the local atomic structure around the dopant site, which is largely insensitive to the value of U for the Ce 4f states. The calculated electronic structures depend explicitly on the value of U, and a value of U ≈ 6 eV is determined by comparison with experimental x-ray photoelectron data for CeAlO3. On the basis of the PBE-optimized structure, CASSCF/CASPT2 (complete-active-space self-consistent-field/second-order perturbation theory) embedded cluster calculations for the Ce3+ 4f→ 5d transitions yield energy and intensity patterns in fairly good agreement with those estimated from the experimental absorption spectrum. A Mulliken spin population analysis for the 5d1 states shows that the origins of the states are significantly different from being caused by the cubic crystal field, confirming an earlier conclusion as regards the origin of the 5d1 states based on semiempirical molecular orbital calculations. The importance of spin–orbit effects on the energies and wavefunctions of the Ce 5d1 states is highlighted.
Journal of Physics Condensed Matter 01/2012; 24(5):055502. · 2.55 Impact Factor
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ABSTRACT: A new line of outer root sheath (ORS) cells was established from hair follicles of Jining grey goat by using a mechanical separation combined with enzyme digestion. Cell morphology is described at different phases. The chromosome analysis of ORS cells, identification of the ORS cells and morphological reversion test were detected at the 4th and 40th passages. The ORS cells were healthy and the growth characteristics were stable with a population doubling time of 52 h. Chromosome analysis showed that >58% of cells were diploid. Test for ORS cell line CK19 expression was positive. This newly established ORS cell line not only lays the foundation for further studying on the growth, regeneration, development law of goat hair follicle but also provides a mirror for the research of human hair in medical field.
Biotechnology Letters 11/2011; 34(3):433-40. · 1.68 Impact Factor
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ABSTRACT: A mutant Saccharomyces cerevisiae CWY132 was isolated, producing 1.393 g L(-1) 2-phenylethanol (2-PE) in a batch process containing 5 g L(-1) L-phenylalanine (L-Phe), which is equivalent to an increase of 38.3% compared to the initial strain. In this study, biotransformation conditions of this strain were studied. We found glucose, KH2PO4, (NH4)2SO4, and amounts of inoculum cells had significant effects on the biotransformation process; in particular, the existence of (NH(4))(2)SO(4) in the medium strongly inhibited the yield of 2-PE, while an increase in the amount of inoculum had a positive correlation with the yield of 2-PE. The optimum condition for production of 2-PE was obtained using the following uniform design: glucose 34.16 g L(-1), yeast nitrogen base 0.17 g L(-1), MgSO4 0.5 g L(-1), KH2PO4 14.89 g L(-1), (NH4)2SO4 0 g L(-1), L-Phe 5 g L(-1), and an inoculum amount of 1.6 × 10(7) cells/mL. With the optimised conditions, the yield of 2-PE was further increased to 3.52 g L(-1) (an increase of 249.5%), which corresponds to a molar conversion rate of 95.19%.
Natural product research 04/2011; 25(7):754-9. · 1.01 Impact Factor
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ABSTRACT: To analyze the T-DNA integration pattern in the genome of grey mold Botrytis cinerea.
T-DNA (Transfer DNA) inserted mutant library of Botrytis cinerea was created by Agrobactirium tumfacience mediated transformation. By using TAIL-PCR (Thermal asymmetric interlaced polymerase chain reaction), we amplified and cloned the chromosomal regions flanking T-DNA insertions. The obtained T-DNA flanking sequences were subjected to alignment with standard T-DNA border sequence for identification and analysis of integration.
Up to 69% T-DNA inserted at noncoding regions and 30% inserted at exons. Recombination including deletion or addition of bases in T-DNA region was observed. The right borders of the T-DNA were frequently truncated, and by contrast the left borders were less prone to degradation and appeared to have been inserted in a relatively integrated manner. Extra sequence additions also occurred in T-DNA integration sites.
Analysis of T-DNA integration pattern in B. cinerea genome will stimulate the functional genomics study of this fungus.
ACTA MICROBIOLOGICA SINICA 02/2011; 51(2):203-7.
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ABSTRACT: Yeast two-hybrid system combined with the gateway technology will greatly facilitate the cloning of interested DNA fragment into yeast two-hybrid vectors and therefore increase the efficiency of yeast two-hybrid analysis. In this study, we constructed a pair of Gateway-compatible yeast two-hybrid vectors pBTM116GW and pVP16GW by introducing the gateway cassette (attR1-Cmr-ccdB-attR2) into the multiple cloning sites (MCS) of the previously described vectors pBTM116SS and pVP16S1, respectively. The applicability of newly generated vectors was tested by assaying the interaction between the kinase domain XA21K of rice (Oryza sativa) receptor like kinase XA21 and its interactor XB3. Since both Xa21K and Xb3 were cloned into a Gateway entry vector and then subcloned into pBTM116GW and pVP16GW by in vitro recombination with high efficiency, respectively, it demonstrated that the newly constructed gateway-compatible two-hybrid vectors will be useful in analysis of protein interactions in a high throughput way.
AFRICAN JOURNAL OF BIOTECHNOLOGY 04/2010; 9:1392-1396. · 0.57 Impact Factor
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ABSTRACT: Construction of Botrytis cinerea T-DNA insertion mutant library through Agrobacterium-mediated transformation and for further understanding of the molecular mechanisms underlying the pathogenicity of Botrytis cinerea.
Agrobacterium containing the binary vector pCMBIA1390 was used for transformation of Botrytis cinerea. Hygromycin resistant transformants were screened out and subjected to biological and morphological observation, Detached tomato leaves were used for pathogenicity assay. The flanking sequence of T-DNA inserted in mutant genome was cloned and analyzed by using TAIL-PCR.
A variety of mutants were obtained and important phenotypes including reduction in growth rate, loss or reduction in conidiation and loss of pathogenicity were screened out. The T-DNA flanking sequence of one of the mutants was successfully amplified with TAIL-PCR.
Agrobacterium-mediated transformation system of Botrytis cinerea was established and a T-DNA insertion mutants library was constructed. TAIL-PCR was an effective method for isolating the flanking sequence of T-DNA inserted in genome.
ACTA MICROBIOLOGICA SINICA 02/2010; 50(2):169-73.
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ABSTRACT: The structural and electronic properties of lutecia (C-type Lu(2)O(3)) have been investigated using the projected augmented wave (PAW) method based on the periodic density functional theory (DFT). Two models for the localized Lu 4f electrons have been employed, in which the f electrons are treated as a part of the inner core and as valence electrons, respectively. With the former model, the Perdew-Burke-Ernzerhof (PBE) calculations yield a crystal structure in good agreement with experiments, while with the latter model, the PBE+U results show that the optimum U(eff) parameter value is dependent on the property investigated. The variation of structural properties with respect to the model used and the U(eff) value chosen has been rationalized in terms of the repulsive interaction between Lu 4f and O 2p electrons owing to the insufficient self-interaction cancelation associated with the localized f electrons in the DFT functional. Based on the calculated results, a practical scheme is proposed for the calculation of Lu(2)O(3) and the related materials in cases where the f electronic properties are relevant.
Journal of Physics Condensed Matter 11/2009; 21(45):455601. · 2.55 Impact Factor
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ABSTRACT: Cell-wall chitin biosynthesis in the phytopathogenic fungus Botrytis cinerea involves 7 classes of chitin synthases. In this study, we disrupted a gene encoding a chitin synthase with a myosin-like motor domain (BcchsV) through Agrobacterium tumefaciens mediated transformation. The resulting mutant was not significantly affected in either growth characteristics or pathogenicity on tomato leaves. Surprisingly, the BcchsV mutant exhibited a 31% (m/m) increase in its chitin content compared with the wild-type strain. In addition, the BcchsV mutant showed increased sensitivity to Calcofluor White and slightly enhanced tolerance to cell-wall disturbing substances and osmosis regulators, including SDS, sorbitol, and NaCl. These results suggest that Bcchs does not play an essential role in the synthesis of cell-wall chitin in B. cinerea. However, disruption of this gene provoked a compensatory mechanism regulating the cellular response to cell-wall damage.
Canadian Journal of Microbiology 11/2009; 55(11):1267-74. · 1.36 Impact Factor
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ABSTRACT: We report the construction of two Gateway fungal expression vectors pCBGW and pGWBF. The pCBGW was generated by introducing an expression cassette, which consists of a Gateway recombinant cassette (attR1-Cmr-ccdB-attR2) under the control of fungal promoter PgpdA and a terminator TtrpC, into the multiple cloning site of fungal vector pCB1004. The pGWBF is a binary vector, which was generated from the plant expression vector pGWB2 by replacing the CaMV35S promoter with PgpdA. The pGWBF can be transformed into fungi efficiently with Agrobacterium-mediated transformation. The applicability of two newly constructed vectors was tested by generating the destination vectors pGWBF-GFP and pCBGW-GFP and examining the expression of GFP gene in Trichoderma viride and Gibberella fujikuroi, respectively. Combining with the advantage of Gateway cloning technology, pCBGW and pGWBF will be useful in fungi for large-scale investigation of gene functions by constructing the interested gene destination/expression vectors in a high-throughput way.
Plasmid 07/2009; 62(2):128-33. · 1.52 Impact Factor
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ABSTRACT: The first three-dimensional interaction potential energy surface of the Xe-CO complex is developed using the single and double excitation coupled cluster theory with noniterative treatment of triple excitations. Mixed basis sets, aug-cc-pVQZ for the C and O atoms and aug-cc-pVQZ-PP for the Xe atom, including an additional (3s3p2d2f1g) set of midbond functions are used. The calculated single point energies at five fixed r(co) values are fitted to an analytic two-dimensional potential model, and further the five model potentials are used to construct the three-dimensional potential energy surface by interpolating along (r-r(e)). Dynamical calculations with the vibrationally averaged potentials are performed to determine the energy levels and the frequencies of various rovibrational transitions. Our results agree well with the experiment. For example, the IR transitions of 508 lines are precisely reproduced with only a total rms error of 0.105 cm(-1).
The Journal of chemical physics 04/2009; 130(12):124311. · 3.09 Impact Factor
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ABSTRACT: The magnetic properties of the Gd(12)O(18) cluster cut from the bulk Gd(2)O(3) crystal are investigated using the spin-polarized density functional theory within the broken-symmetry approach. Our work reveals that in the ground state of the cluster the antiferromagnetic coupling between adjacent Gd (4f(7)) spins is preferred energetically. This result is in contrast to a recent prediction made by Pedersen and Ojamae (Pedersen, H.; Ojamae, L. Nano Lett. 2006, 6, 2004) but is consistent with recent experimental observations. The optimized structures of the cluster in the lowest-energy broken-symmetry state and the highest-spin ferromagnetic state are almost identical. The latter state is 71.5 cm(-1) higher in energy than the former one, giving a value of about -0.24 cm(-1) for the magnetic coupling constant, which is comparable to that estimated from experiments on the bulk crystal. The relative energies of various 4f(7) spin patterns of the cluster are calculated, and certain characteristics of the cluster in the lowest-energy broken-symmetry state are discussed.
The Journal of Physical Chemistry A 01/2009; 112(51):13650-4. · 2.95 Impact Factor
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ABSTRACT: An accurate three-dimensional potential energy surface (PES) for the He-Na2 van der Waals complex was calculated at the coupled cluster singles-and-doubles with noniterative inclusion of connected
triple (CCSD(T)) level of theory. A mixed basis set, aug-cc-pVQZ for the He atom and cc-pCVQZ for the sodium atom, and an
additional (3s3p2d1f) set of midbond functions were used. The computed interaction energies in 819 configurations were fitted
to a 96-parameter analytic potential model by least squares fitting. The PES has two shallow wells corresponding to the T-shaped
structure and the linear configuration, which are located at 12.5a
0 and 14 a
0 with depths of 1.769 and 1.684 cm−1, respectively. The who potential energy surface exhibits weak anisotropy. Based on the fitted PES, state-to-state differential
cross sections were calculated.
Science in China Series B Chemistry 05/2008; 51(6):539-544. · 1.20 Impact Factor
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ABSTRACT: The first two-dimensional potential energy surface for the Xe-CO van der Waals interaction is calculated by the single and double excitation coupled-cluster theory with noniterative treatment of triple excitations. Mixed basis sets, aug-cc-pVQZ for the C and O atoms, and aug-cc-pVQZ-PP for the Xe atom, with an additional (3s3p2d2f1g) set of midbond functions, are used. Our potential energy surface has a single, nearly T-shaped minimum of -131.87 cm(-1) at R(e)=7.80a(0) and theta(e)=102.5 degrees. Based on the potential, the bound state energies are calculated for seven isotopomers of the Xe-(12)C(16)O complex, seven isotopomers of the Xe-(13)C(16)O complex, and three isotopomers of the Xe-(13)C(18)O complex. Compared with available experimental data, the predicted transition frequencies and spectroscopic constants are in good agreement with the experimental results.
The Journal of Chemical Physics 02/2008; 128(4):044309. · 3.33 Impact Factor
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ABSTRACT: The first ab initio potential energy surface of the Kr-CO complex is developed using single and double excitation coupled-cluster theory with noniterative treatment of triple excitations. Mixed basis sets, aug-cc-pVQZ for the C and O atoms and aug-cc-pVQZ-PP for the Kr atom, with an additional (3s3p2d2f1g) set of midbond functions are used. The computed interaction energies in 336 configurations are analytically fitted to a two-dimensional potential model by a least squares fit. The potential has a minimum of -119.68 cm(-1) with Re=7.35a 0 at an approximate T-shaped geometry (theta e=98.5 degrees ). Bound state energies are calculated up to J=12, thus enabling a comprehensive comparison between theory and available experimental data as well as providing detailed guidance for future spectroscopic investigations of higher-lying states. The predicted transition frequencies and spectroscopic constants are in good agreement with the experimental results.
The Journal of Chemical Physics 12/2007; 127(17):174301. · 3.33 Impact Factor
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ABSTRACT: The close coupling calculation of rotationally inelastic collision of Ne with LiH is first performed by employing a recently computed ab initio potential energy surface [Chem. Phys. Lett. 327 (2000) 305]. State-to-state differential, partial and integral cross-sections are calculated. Differential cross-sections show the feature of forward scattering for low Δj inelastic transitions and backward scattering for high Δj transitions. Two maxima exist in the curve of partial cross-sections and they are originated from different mechanism. The dependence of the integral cross-sections on j′ for initial states j=0,1 displays a pronounced oscillatory structure rather than a monotonic one, and dependence on low collision energy presents resonance feature. These features are related to the anisotropic interaction potential.
Chemical Physics. 303(3):309-316.
