Owing to the unique structural,electronic,and physico-chemical properties,molybdenum clusters are expected to play an important role in future nanotechnologies.However,their ground states are still under debate.In thi...Owing to the unique structural,electronic,and physico-chemical properties,molybdenum clusters are expected to play an important role in future nanotechnologies.However,their ground states are still under debate.In this study,the crystal structure analysis by particle swarm optimization(CALYPSO)approach is used for the global minimum search,which is followed by first-principles calculations,to detect an obvious dimerization tendency in Mo_(n)(n=2-18)clusters when the 4s and 4p semicore states are not regarded as the valence states.Further,the clusters with even number of atoms are usually magic clusters with high stability.However,after including the4 s and 4 p electrons as valence electrons,the dimerization tendency exhibits a drastic reduction because the average hybridization indices H_(sp),H_(sd),and H_(pd) are reduced significantly.Overall,this work reports new ground states of Mo_(n)(n=11,14,15)clusters and proves that semicore states are essential for Mo_(n) clusters.展开更多
A series of clusters Ni4P are designed to simulate the amorphous alloy Ni80P20. After the cluster models are computed by DFT, several stable structures are gained. Their geometric, electronic and catalytic properties ...A series of clusters Ni4P are designed to simulate the amorphous alloy Ni80P20. After the cluster models are computed by DFT, several stable structures are gained. Their geometric, electronic and catalytic properties have been analyzed and discussed. It is proved that cluster Ni4P can reflect the amorphous alloy Ni80P20 very well from the geometry parameters. We find the deformed triangle dipyramid with quadruplet state （configuration 1^（4）） is the most stable structure for cluster Ni4P, which is the most possible local structure in amorphous alloy Ni80P20. And the transition energy between two isomers with the same multiple state is higher than the one with the different. Bond Ni-P plays a very important role in offering the system stability for cluster Ni4E P is the electron donor, and Ni is the accepter in cluster Ni4P, which is in accordance with the experiment results. The 3d orbital populations and Fermi levels of clusters Ni4 have been decreased with the addition of atom E Based on the research of Fermi levels of clusters Ni4P to approach the Fermi level of H2 and their density of state （DOS）, the highest catalytic active property in cluster Ni4P is owned to configuration 1^（4）.展开更多
Aim: In the field of neuroinflammation, identifying specific effects of pharmacological agents and other factors is problematic given the relative difficulty and expense in obtaining and culturing primary microglia. I...Aim: In the field of neuroinflammation, identifying specific effects of pharmacological agents and other factors is problematic given the relative difficulty and expense in obtaining and culturing primary microglia. Immortalized microglial cell lines are very useful, but only a limited number have been characterized for inflammatory signaling. Therefore, characterization of lipopolysaccharide (LPS)-induced toll-like receptor 4 (TLR4) signaling in CHME-5, a microglial cell line, is expected to be of value as an experimental model of inflammatory signaling in the central nervous system (CNS). Methods: It was recently suggested that CHME-5 cells are of rat origin, not human, hence, verification of this claim using short tandem repeat genotype sequencing, along with immunoblotting, reverse transcription-polymerase chain reaction, and immunocytochemistry techniques to validate that CHME-5 retain morphological, phenotypical, and functional characteristics of primary microglia were undertaken. Results: LPS induced inhibitor kappa B-alpha and nuclear factor-kappa B (NF-κB) p65 activation, NF-κB p65 binding activity, and tumor necrosis factor alpha gene expression.Additionally, results also confirmed the maintenance of microglial phenotype as seen with increased cluster of differentiation 68 gene and protein expression, immunofluorescence, and the absence of glial fibrillary acidic protein-immunoreactivity.TLR4 gene expression and immunofluorescence were significantly increased after LPS treatment. Conclusion: These data demonstrate that CHME-5 cells are not human, but are indeed a beneficial tool for studying microglial inflammatory signaling.展开更多
Title compound,Mr=1273.16,was synthesized by a substitution reaction and its crystal' is triclinic belonging to space group P1 with cell parameters:a=13.944(2),b=14.143(7),c=14.233(3), A,a=77.35(3)°,β=69.94(...Title compound,Mr=1273.16,was synthesized by a substitution reaction and its crystal' is triclinic belonging to space group P1 with cell parameters:a=13.944(2),b=14.143(7),c=14.233(3), A,a=77.35(3)°,β=69.94(2)°,γ=63.50(3)°,V=2351(1)A^3,Z=2,D_c=1.799g cm^(-3).Room tem- perature,graphite-filtered Mo K_α,radiation(λ=0.71073A)was used for data collection.μ=14.988 cm^(-1),F(000)=1280,R=0.051 for 7025 observed reflections.The crystal consists of decrete cluster molecules containing a duster core[Mo_3(μ_3-S)]^(10+)with three μ-S,one μ-dtp(dtp=[S_2P(OC_2H_5)]^(2-), three x-dtp and one allylthioureo to form a local six-coordinated sphere around each Mo atom.The bónds of cluster skeleton[Mo_3(μ_3-S)(μ-S)_3]^(4+),Mo—Mo 2.744～2.766,Mo—(μ_3-S)2.340～2.342 and Mo—(μ-S)2.272～2.296 A,are comparable with those found in the related analogues.展开更多
基金supported by the National Natural Science Foundation of China (No.11404098 and No.11604082)the Student Research Training Program of Henan University of Science and Technology(WLSRTP201911)
文摘Owing to the unique structural,electronic,and physico-chemical properties,molybdenum clusters are expected to play an important role in future nanotechnologies.However,their ground states are still under debate.In this study,the crystal structure analysis by particle swarm optimization(CALYPSO)approach is used for the global minimum search,which is followed by first-principles calculations,to detect an obvious dimerization tendency in Mo_(n)(n=2-18)clusters when the 4s and 4p semicore states are not regarded as the valence states.Further,the clusters with even number of atoms are usually magic clusters with high stability.However,after including the4 s and 4 p electrons as valence electrons,the dimerization tendency exhibits a drastic reduction because the average hybridization indices H_(sp),H_(sd),and H_(pd) are reduced significantly.Overall,this work reports new ground states of Mo_(n)(n=11,14,15)clusters and proves that semicore states are essential for Mo_(n) clusters.
文摘A series of clusters Ni4P are designed to simulate the amorphous alloy Ni80P20. After the cluster models are computed by DFT, several stable structures are gained. Their geometric, electronic and catalytic properties have been analyzed and discussed. It is proved that cluster Ni4P can reflect the amorphous alloy Ni80P20 very well from the geometry parameters. We find the deformed triangle dipyramid with quadruplet state （configuration 1^（4）） is the most stable structure for cluster Ni4P, which is the most possible local structure in amorphous alloy Ni80P20. And the transition energy between two isomers with the same multiple state is higher than the one with the different. Bond Ni-P plays a very important role in offering the system stability for cluster Ni4E P is the electron donor, and Ni is the accepter in cluster Ni4P, which is in accordance with the experiment results. The 3d orbital populations and Fermi levels of clusters Ni4 have been decreased with the addition of atom E Based on the research of Fermi levels of clusters Ni4P to approach the Fermi level of H2 and their density of state （DOS）, the highest catalytic active property in cluster Ni4P is owned to configuration 1^（4）.
文摘Aim: In the field of neuroinflammation, identifying specific effects of pharmacological agents and other factors is problematic given the relative difficulty and expense in obtaining and culturing primary microglia. Immortalized microglial cell lines are very useful, but only a limited number have been characterized for inflammatory signaling. Therefore, characterization of lipopolysaccharide (LPS)-induced toll-like receptor 4 (TLR4) signaling in CHME-5, a microglial cell line, is expected to be of value as an experimental model of inflammatory signaling in the central nervous system (CNS). Methods: It was recently suggested that CHME-5 cells are of rat origin, not human, hence, verification of this claim using short tandem repeat genotype sequencing, along with immunoblotting, reverse transcription-polymerase chain reaction, and immunocytochemistry techniques to validate that CHME-5 retain morphological, phenotypical, and functional characteristics of primary microglia were undertaken. Results: LPS induced inhibitor kappa B-alpha and nuclear factor-kappa B (NF-κB) p65 activation, NF-κB p65 binding activity, and tumor necrosis factor alpha gene expression.Additionally, results also confirmed the maintenance of microglial phenotype as seen with increased cluster of differentiation 68 gene and protein expression, immunofluorescence, and the absence of glial fibrillary acidic protein-immunoreactivity.TLR4 gene expression and immunofluorescence were significantly increased after LPS treatment. Conclusion: These data demonstrate that CHME-5 cells are not human, but are indeed a beneficial tool for studying microglial inflammatory signaling.
文摘Title compound,Mr=1273.16,was synthesized by a substitution reaction and its crystal' is triclinic belonging to space group P1 with cell parameters:a=13.944(2),b=14.143(7),c=14.233(3), A,a=77.35(3)°,β=69.94(2)°,γ=63.50(3)°,V=2351(1)A^3,Z=2,D_c=1.799g cm^(-3).Room tem- perature,graphite-filtered Mo K_α,radiation(λ=0.71073A)was used for data collection.μ=14.988 cm^(-1),F(000)=1280,R=0.051 for 7025 observed reflections.The crystal consists of decrete cluster molecules containing a duster core[Mo_3(μ_3-S)]^(10+)with three μ-S,one μ-dtp(dtp=[S_2P(OC_2H_5)]^(2-), three x-dtp and one allylthioureo to form a local six-coordinated sphere around each Mo atom.The bónds of cluster skeleton[Mo_3(μ_3-S)(μ-S)_3]^(4+),Mo—Mo 2.744～2.766,Mo—(μ_3-S)2.340～2.342 and Mo—(μ-S)2.272～2.296 A,are comparable with those found in the related analogues.
