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Now showing items 97 - 112 of 213

  • Creeping Motion of Self Interstitial Atom Clusters in Tungsten

    Zhou, Wang Huai   Zhang, Chuan Guo   Li, Yong Gang   Zeng, Zhi  

    The formation and motion features of self interstitial atom (SIA) clusters in tungsten are studied by molecular dynamics (MD) simulations. The static calculations show that the SIA clusters are stable with binding energy over 2 eV. The SIA clusters exhibit a fast one dimensional (1D) motion along < 111 >. Through analysis of the change of relative distance between SIAs, we find that SIAs jump in small displacements we call creeping motion, which is a new collective diffusion process different from that of iron. The potential energy surface of SIAs implicates that the creeping motion is due to the strong interaction between SIAs. These imply that several diffusion mechanism for SIA clusters can operate in BCC metals and could help us explore deep insight into the performance of materials under irradiation.
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  • High expression of EZH2 as a marker for the differential diagnosis of malignant and benign myogenic tumors.

    Zhang, Ning   Zeng, Zhi   Li, Shaobo   Wang, Fei   Huang, Peng  

    Overlap in morphologic features between malignant and benign myogenic tumors, such as leiomyosarcoma (LMS) vs. leiomyoma as well as rhabdomyosarcoma (RMS) vs. rhabdomyoma, often makes differential diagnosis difficult and challenging. Here the expressions of Enhancer of Zeste Homolog 2 (EZH2), Suppressor of Zeste 12 (SUZ12), retinoblastoma protein associated protein 46 (RbAp46), Embryonic Ectoderm Development (EED) and ki-67 protein were detected by immunohistochemistry to evaluate their values in differential diagnosis. The expression of EZH2 mRNA was investigated by analyzing the Gene Expression Omnibus Datasets. The results demonstrated that EZH2 protein was detected in 81.25% (26/32) of LMS and 70.58% (36/51) of RMS, whereas none of leiomyoma (n=3D16), rhabdomyoma (n=3D15) and normal tissues (n=3D31) showed positive immunostaining (p<0.05). EZH2 protein was found to have a sensitivity of 91.30% and specificity of 100% in distinguishing well-differentiated LMS from cellular leiomyoma, and a sensitivity of 92.86% and specificity of 100% in distinguishing well-differentiated embryonal rhabdomyosarcoma (ERMS) from fetal rhabdomyoma. Besides, the expression of EZH2 mRNA was higher in LMS and RMS than in benign tumors (p<0.05). The expressions of SUZ12 and RbAp46 protein were higher in RMS than in rhabdomyoma (p<0.05). Conclusively, the high expression of EZH2 is a promising marker in distinguishing well-differentiated LMS from cellular leiomyoma, or well-differentiated ERMS from fetal rhabdomyoma, and the upregulation of EZH2 protein expression may occur at transcriptional level.=20
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  • Electronic structure and magnetism of La4Ni3O8 from first principles

    Liu, Ting   Zhang, Guoren   Zhang, Xiaoli   Jia, Ting   Zeng, Zhi   Lin, H. Q.  

    The magnetic and electronic properties of La4Ni3O8 are investigated by performing the full-potential linearized augmented plane wave method. The C-type antiferromagnetic spin ordering is preferred and a molecular correlated insulating state with high-spin Ni ions is found. Our results have proved that this insulating state is caused by a correlation effect and the strong interlayer interaction. Such strong interlayer coupling results from the high-spin occupation of Ni ions.
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  • The strong quasi-one-dimensional antiferromagnetism in a charge-transfer insulator: AgSO4

    Zhang, Xiaoli   Jia, Ting   Liu, Ting   Zeng, Zhi   Lin, H. Q.  

    The strong quasi-one-dimensional antiferromagnetism and the electronic structure of AgSO4 are investigated by performing the first-principles density functional calculations. The results show that the strong quasi-one-dimensional antiferromagnetic coupling in AgSO4 is along [1<(1over bar>1] diagonal of the unit cell. The superexchange interaction between the Ag1 4d(x12-y12) and the Ag2 4d(x22-22) orbitals gives rise to the unusual strong quasi-one-dimensional antiferromagnetic behavior. We also found that AgSO4 is a charge-transfer insulator. (C) 2012 American Institute of Physics. [doi:10.1063/1.3677796]
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  • Osteopontin promotes collagen I synthesis in hepatic stellate cells by miRNA-129-5p inhibition (vol 362,pg 343,2018)

    Chen, Yinghua   Ou, Yitao   Dong, Jiale   Yang, Guizhi   Zeng, Zhi   Liu, Ying   Liu, Bing   Li, Weidong   He, Xiaoshun   Lan, Tian  

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  • Absorption spectra and electronic structures of AumAgn (m+n=8) clusters

    Zhao, Gao-Feng   Sun, Jian-Min   Zeng, Zhi  

    The electronic structures and absorption spectra of AumAgn (m + n = 8) clusters have been investigated using time-dependent density functional response theory. We have discovered that the vertical ionization potentials, highest occupied molecular orbital level, lowest unoccupied molecular orbital level and binding energies of the most stable binary AumAgn are intermediate between those of Ag-8 and Au-8 clusters. The analysis of the low-energy absorption spectra shows that the dominant excitation energies and the corresponding oscillator strengths exhibit an obvious odd-even oscillation with the variation of the number of An atoms. The odd-even oscillation character indicates that the optical properties of AumAgn can be tuned by changing the stoichiometries. The excitation of electrons to exterior atoms plays a key role in optical responses of AumAgn clusters. (c) 2007 Elsevier B.V. All rights reserved.
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  • The structural and electronic properties of Ag-adsorbed (SiO(2))(n) (n=1-7) clusters

    Zhao, Gao-feng   Zhi, Li-li   Guo, Ling-ju   Zeng, Zhi  

    Equilibrium geometries, charge distributions, stabilities, and electronic properties of the Ag-adsorbed (SiO(2))(n) (n=1-7) clusters have been investigated using density functional theory with generalized gradient approximation for exchange-correlation functional. The results show that the Ag atom preferably binds to silicon atom with dangling bond in nearly a fixed direction, and the incoming Ag atoms tend to cluster on the existing Ag cluster leading to the formation of Ag islands. The adsorbed Ag atom only causes charge redistributions of the atoms near itself. The effect of the adsorbed Ag atom on the bonding natures and structural features of the silica clusters is minor, attributing to the tendency of stability order of Ag(SiO(2))(n) (n=1-7) clusters in consistent with silica clusters. In addition, the energy gaps between the highest occupied and lowest unoccupied molecular orbitals remarkably decrease compared with the pure (SiO(2))(n) (n=1-7) clusters, eventually approaching the near infrared radiation region. This suggests that these small clusters may be an alternative material which has a similar functionality in treating cancer to the large gold-coated silica nanoshells and the small Au(3)(SiO(2))(3) cluster. (c) 2007 American Institute of Physics.
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  • Hydrogen storage in Li-doped charged single-walled carbon nanotubes RID G-5770-2010

    Ni, Meiyan   Huang, Liangfeng   Guo, Lingju   Zeng, Zhi  

    Density functional calculations have been carried out to investigate the interaction of hydrogen molecules with Li-doped charged single-walled carbon nanotubes (SWNTs). The results show that binding of H(2) on positively charged Li-doped SWNTs is enhanced compared with that on uncharged systems. As the charge of the Li-doped SWNTs increases, the binding energy of H(2) increases with the largest binding energy of 0.26 eV. The reason for the increase in H(2) binding energy is that the positively charged tube improves the charge transfer from Li atom to the tube and make the Li atom more ionized, which strengthens the polarization interaction between H(2) and Li atom. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
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  • Comparison of direct DNA strand breaks induced by low energy electrons with different inelastic cross sections

    Li, Jun-Li   Li, Chun-Yan   Qiu, Rui   Yan, Cong-Chong   Xie, Wen-Zhang   Zeng, Zhi   Tung, Chuan-Jong  

    In order to study the influence of inelastic cross sections on the simulation of direct DNA strand breaks induced by low energy electrons, six different sets of inelastic cross section data were calculated and loaded into the Geant4-DNA code to calculate the DNA strand break yields under the same conditions. The six sets of the inelastic cross sections were calculated by applying the dielectric function method of Emfietzoglou's optical-data treatments, with two different optical datasets and three different dispersion models, using the same Born corrections. Results show that the inelastic cross sections have a notable influence on the direct DNA strand break yields. The yields simulated with the inelastic cross sections based on Hayashi's optical data are greater than those based on Heller's optical data. The discrepancies are about 30-45% for the single strand break yields and 45-80% for the double strand break yields. Among the yields simulated with cross sections of the three different dispersion models, generally the greatest are those of the extended-Drude dispersion model, the second are those of the extended-oscillator-Drude dispersion model, and the last are those of the Ashley's delta-oscillator dispersion model. For the single strand break yields, the differences between the first two are very little and the differences between the last two are about 6-57%. For the double strand break yields, the biggest difference between the first two can be about 90% and the differences between the last two are about 17-70%. (C) 2013 Elsevier B.V. All rights reserved.
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  • Hetero-metal encapsulation induced ratiometric recognition of fluoride

    Yu, Aiwen   Zhang, Yitong   Liu, Wanqiang   Gao, Jinwei   Zhang, Lingbo   Zeng, Zhi   Zheng, Yuhui  

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  • A National Cross-Sectional Survey on Work Environment Associated With Psychological Well-Being and Job Satisfaction Among Chinese Employees

    Zeng, Zhi   Liu, Jun   Xie, Qiong   Wu, Yali   Wang, Hua   Lu, Liming  

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  • Overexpression of pyruvate kinase M2 predicts a poor prognosis for patients with osteosarcoma

    Liu, Zheng-xuan   Hong, Liang   Fang, Song-qing   Tan, Guang-hua   Huang, Pei-guan   Zeng, Zhi   Xia, Xue   Wang, Xiao-xu  

    It is stated that high expression of pyruvate kinase (PKM2) emerges as a significant player in the metabolism and progression of various human malignancies. However, the expression of PKM2 and its association with the prognosis of osteosarcoma had not yet been studied. In the present study, the expression and biological significance of PKM2 in osteosarcoma were investigated. We found that PKM2 expression was elevated in the cancerous tissues and it was more abundant than the adjacent normal tissues (60.2 vs 26.1 %, p < 0.001). Moreover, we showed that high PKM2 expression was positively correlated with Enneking stage (p = 0.006) and distant metastasis (p = 0.007) but not with the age, gender, tumor site, tumor size, histologic grade, alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and local pain of the patients. Furthermore, Kaplan-Meier analysis revealed that the overall survival (OS) for patients with high PKM2 expression was significantly lower than those with low PKM2 expression (p < 0.001). Finally, multivariate analysis revealed that high PKM2 expression was an independent prognostic factor for osteosarcoma patients (p = 0.004). Collectively, these data indicated that elevated PKM2 might serve as a novel target for the treatment of osteosarcoma.
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  • Pulmonary artery perforation caused by a left atrial appendage closure device

    Lu, Cong   Zeng, Jie   Meng, Qingguo   Zeng, Zhi  

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  • Design of Chalcopyrite-type CuFeSe2 Nanocrystals: Microstructure, Magnetism, Photoluminescence and Sensing performances

    Wu, Nengtao   Li, Ye   Zeng, Min   Gao, Jinwei   Tang, Yiping   Zeng, Zhi   Zheng, Yuhui  

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  • Analysis of Volatile Components of Adenosma indianum (Lour.) Merr. by Steam Distillation and Headspace Solid-Phase Microextraction

    Zeng, Zhi   Meng, Chunyan   Ye, Xuening   Zeng, Zhuo  

    The essential oil of Adenosma indianum (Lour.) Merr. plays an important role in its antibacterial and antiphlogistic activities. In this work, the volatile components were extracted by steam distillation (SD) and headspace solid-phase microextraction (HS-SPME) and analysed by gas chromatography-mass spectrometry (GC-MS). A total of 49 volatile components were identified by GC-MS, and the major volatile components were alpha-limonene (20.59-35.07%), fenchone (15.79-31.81%), alpha-caryophyllene (6.98-10.32%), beta-caryophyllene (6.98-10.19%), and piperitenone oxide (1.96-11.63%). The comparison of the volatile components from A. indianum (Lour.) Merr. grown in two regions of China was reported. Also, the comparison of the volatile components by SD and HS-SPME was discussed. The results showed that the major volatile components of A. indianum(Lour.) Merr. from two regions of China were similar but varied with different extraction methods. These results were indicative of the suitability of HS-SPME method for simple, rapid, and solvent-free analysis of the volatile components of the medicinal plants.
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  • Decreased left atrial myocardial strain in patients with suboptimal blood pressure control

    Chen, Xiao-Jing   Chen, Chen   Liang, Yu-Jia   Gao, Xi-Lian   Jiang, Jing   Kang, Yu   Chen, Yu-Cheng   Zeng, Zhi  

    Background: Suboptimal blood pressure (BP) control is commonly observed in patients receiving antihypertensive agents, but the relationship between uncontrolled BP and left atrial (LA) impairment remains unknown. Methods: This study enrolled 279 hypertensive patients who had been medicated, as well as 85 matched normal controls. The BP of systolic <140 mmHg and diastolic<90 mmHg was defined as optimal (HT1 group, n=3D146), otherwise as suboptimal BP control (HT2 group, n =3D 133). LA myocardial function was assessed by the systolic (S-Sa), early diastolic (S-Ea), and late diastolic (S-Aa) LA strains. Results: Both the HT1 group and HT2 group had higher BP reading, thicker interventricular septum, larger LA volume index, and enhanced active atrial emptying fraction than the control group (all <0.05). When compared with normal subjects, hypertensive patients displayed obvious reduction in the S-Sa (50.0 +/- 10.9 vs. 35.9 +/- 8.0%), S-Ea (30.1 +/- 7.7 vs. 18.5 +/- 7.1%) and S-Aa (19.9 +/- 6.4 vs. 17.8 +/- 4.2%) (all p < 0.001). In addition to a further impaired S-Ea found in the HT2 group than in the HT1 group (17.2 +/- 5.3 vs. 19.8 +/- 8.3%, p =3D 0.002), the treated BP of >140/90 mmHg appeared an independent risk factor associated with the abnormal S-Ea (odds ratio, 2.957; interval of confidence, 1.614-5.415; p =3D 0.001). Conclusions: Suboptimal BP control status in hypertensive patients is related to a further reduction of LA myocardial function assessed by the novel 2DSTI free strain, and suboptimal BP might be regarded as a composite risk factor and therefore a simplified treatment target. However, the prognostic value of LA free strain in patients with inability to achieve the BP target needs to be evaluated in future prospective studies.
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