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Peng L, Zhang Y, Ke L, Kim TH, Zheng Q, Yan J, Zhang XG, Gao Y, Wang S, Cai J, Shen B, McQueeney RJ, Kaminski A, Kramer MJ, Zhou L. Relaxation Dynamics of Zero-Field Skyrmions over a Wide Temperature Range. NANO LETTERS 2018; 18:7777-7783. [PMID: 30499678 DOI: 10.1021/acs.nanolett.8b03553] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The promise of magnetic skyrmions in future spintronic devices hinges on their topologically enhanced stability and the ability to be manipulated by external fields. The technological advantages of nonvolatile zero-field skyrmion lattice (SkL) are significant if their stability and reliability can be demonstrated over a broad temperature range. Here, we study the relaxation dynamics including the evolution and lifetime of zero-field skyrmions generated from field cooling (FC) in an FeGe single-crystal plate via in situ Lorentz transmission electron microscopy (L-TEM). Three types of dynamic switching between zero-field skyrmions and stripes are identified and distinguished. Moreover, the generation and annihilation of these metastable skyrmions can be tailored during and after FC by varying the magnetic fields and the temperature. This dynamic relaxation behavior under the external fields provides a new understanding of zero-field skyrmions for their stability and reliability in spintronic applications and also raises new questions for theoretical models of skyrmion systems.
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Liu YT, Zhao FP, Miao HB, Fu SZ, Zhou S, Zhang XG, Qin G. [Expression of C-fos in nasopharyngeal carcinoma and the relationship with chemosensitivity and prognosis]. LIN CHUANG ER BI YAN HOU TOU JING WAI KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY, HEAD, AND NECK SURGERY 2018; 32:687-692. [PMID: 29771087 DOI: 10.13201/j.issn.1001-1781.2018.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Indexed: 11/12/2022]
Abstract
Objective:To investigate the expression of C-fos in patients with nasopharyngeal carcinoma(NPC), and analyze the relationship between the expression of C-fos and the clinical characteristics, chemosensitivity and prognosis. Method:Clinical and follow-up data of 75 NPC patients was analyzed retrospectively. The expression of C-fos was detected by immunohistochemical assay, and chemosensitivity was detected by ATP bioluminescent anticancer drug sensitivity detection technology. The relationship between them was studied.Result:The expression of C-fos in NPC was statistically higher than that in the control nasopharyngeal mucosa(P<0.001). It was found that C-fos had no statistical relationship with the gender, age, pathologic type, clinical stage of tumor classification, lymph node status, metastasis status and overall stage of NPC patients(P>0.05). NPC had different chemosensitivity with 8 anticancer drugs(P<0.001).There was a significant difference in chemosensitivity of paclitaxel between the high expression of C-fos group and the low expression of C-fos group(P=0.036). The rate of tumor progression was significantly higher in NPC patients with high expression of C-fos than in the low expression group(P=0.014).There was no significant difference in overall survival between the two groups(P=0.076). Conclusion:C-fos is highly expressed in NPC tissues, and the high expression of C-fos in NPC tissues may be related to tumor progression and resistance to paclitaxel.
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Ko W, Nguyen GD, Kim H, Kim JS, Zhang XG, Li AP. Accessing the Intrinsic Spin Transport in a Topological Insulator by Controlling the Crossover of Bulk-to-Surface Conductance. PHYSICAL REVIEW LETTERS 2018; 121:176801. [PMID: 30411944 DOI: 10.1103/physrevlett.121.176801] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Indexed: 06/08/2023]
Abstract
We report a method to control contributions of bulk and surface states in the topological insulator Bi_{2}Te_{2}Se that allows accessing the spin-polarized transport endowed by topological surface states. An intrinsic surface dominant transport is established when cooling the sample to low temperature or reducing the conduction channel length, both achieved in situ in the transport measurements with a four-probe scanning tunneling microscope without the need of further tailoring the sample. The topological surface states show characteristic transport behaviors with mobility about an order of magnitude higher than reported before, and a spin polarization approaching the theoretically predicted value. Our result demonstrates accessibility to the intrinsic high mobility spin transport of topological surface states, which paves a way to realizing topological spintronic devices.
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Pei YH, He YZ, Zhang XG, Sun BS. [Experimental study scavenging effect of paraquat by hemoperfusion]. ZHONGHUA LAO DONG WEI SHENG ZHI YE BING ZA ZHI = ZHONGHUA LAODONG WEISHENG ZHIYEBING ZAZHI = CHINESE JOURNAL OF INDUSTRIAL HYGIENE AND OCCUPATIONAL DISEASES 2018; 35:523-525. [PMID: 29081105 DOI: 10.3760/cma.j.issn.1001-9391.2017.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To determine the scavenging effect and the change of metabolism of paraquat (PQ) using hemoperfusion (HP) once and twice within 12 hours after intoxication and explore the better scheme of HP. Methods: 18 beagles were randomly divided into 3 groups. Single HP group, Double HP group and Control group. Peripheral veins blood was collected at different times within 48 hours after exposure in each group. Toxin concentration was measured, analyzed and compared among 3 groups. Results: 6 hours after exposure, Single HP group and Double HP group has finished the first HP treatment, and the concentration of PQ was lower than that of the control group, the difference was statistically significant (P<0.05) . 10 hours after exposure, there was no statistical difference of toxin concentration among 3 groups (P>0.05) . 12 hours after exposure, Double HP group has finished the second HP treatment, the concentration of PQ was significantly lower than that of Single HP group and Control group (P<0.05) . 24 hours and 48 hours after exposure, there was no statistical difference of toxin concentration among 3 groups (P>0.05) . Statistical difference were not observed in toxicokinetical parameters among 3 groups (P>0.05) . Conclusion: HP treatment once and twice within 12 hours after intoxication could effectively reduce the toxin concentration in the peripheral veins blood after HP for about 4 hours, then the toxin concentration would return to the same level as Control group quickly. It was suggested that at the beginning of poisoning, HP treatment once or twice could not significantly change the metabolism of paraquat.
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Wu YN, Zhang XG, Pantelides ST. Wu, Zhang, and Pantelides Reply. PHYSICAL REVIEW LETTERS 2018; 120:039602. [PMID: 29400530 DOI: 10.1103/physrevlett.120.039602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Indexed: 06/07/2023]
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Wu YN, Zhang XG, Pantelides ST. Wu, Zhang, and Pantelides Reply. PHYSICAL REVIEW LETTERS 2018; 120:039604. [PMID: 29400504 DOI: 10.1103/physrevlett.120.039604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Indexed: 06/07/2023]
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Peng L, Zhang Y, Wang W, He M, Li L, Ding B, Li J, Sun Y, Zhang XG, Cai J, Wang S, Wu G, Shen B. Real-Space Observation of Nonvolatile Zero-Field Biskyrmion Lattice Generation in MnNiGa Magnet. NANO LETTERS 2017; 17:7075-7079. [PMID: 28990787 DOI: 10.1021/acs.nanolett.7b03792] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Magnetic skyrmions, particular those without the support of external magnetic fields over a wide temperature region, are promising as alternative spintronic units to overcome the fundamental size limitation of conventional magnetic bits. In this study, we use in situ Lorentz microscope to directly demonstrate the generation and sustainability of robust biskyrmion lattice at zero magnetic field over a wide temperature range of 16-338 K in MnNiGa alloy. This procedure includes a simple field-cooling manipulation from 360 K (higher than Curie temperature TC ∼ 350 K), where topological transition easily occurs by adapting the short-range magnetic clusters under a certain magnetic field. The biskyrmion phase is favored upon cooling below TC. Once they are generated, the robust high-density biskyrmions persist even after removing the external magnetic field due to the topological protection and the increased energy barrier.
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Hus SM, Zhang XG, Nguyen GD, Ko W, Baddorf AP, Chen YP, Li AP. Detection of the Spin-Chemical Potential in Topological Insulators Using Spin-Polarized Four-Probe STM. PHYSICAL REVIEW LETTERS 2017; 119:137202. [PMID: 29341679 DOI: 10.1103/physrevlett.119.137202] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Indexed: 06/07/2023]
Abstract
We demonstrate a new method for the detection of the spin-chemical potential in topological insulators using spin-polarized four-probe scanning tunneling microscopy on in situ cleaved Bi_{2}Te_{2}Se surfaces. Two-dimensional (2D) surface and 3D bulk conductions are separated quantitatively via variable probe-spacing measurements, enabling the isolation of the nonvanishing spin-dependent electrochemical potential from the Ohmic contribution. This component is identified as the spin-chemical potential arising from the 2D charge current through the spin momentum locked topological surface states (TSS). This method provides a direct measurement of spin current generation efficiency and opens a new avenue to access the intrinsic spin transport associated with pristine TSS.
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Wu YN, Zhang XG, Pantelides ST. Fundamental Resolution of Difficulties in the Theory of Charged Point Defects in Semiconductors. PHYSICAL REVIEW LETTERS 2017; 119:105501. [PMID: 28949192 DOI: 10.1103/physrevlett.119.105501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Indexed: 06/07/2023]
Abstract
A defect's formation energy is a key theoretical quantity that allows the calculation of equilibrium defect concentrations in solids and aids in the identification of defects that control the properties of materials and device performance, efficiency, and reliability. The theory of formation energies is rigorous only for neutral defects, but the Coulomb potentials of charged defects require additional ad hoc numerical procedures. Here we invoke statistical mechanics to derive a revised theory of charged-defect formation energies, which eliminates the need for ad hoc numerical procedures. Calculations become straightforward and transparent. We present calculations demonstrating the significance of the revised theory for defect formation energies and thermodynamic transition levels.
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Zhang XG, Li H, Hu JH. Effects of various cryoprotectants on the quality of frozen-thawed immature bovine (Qinchuan cattle) calf testicular tissue. Andrologia 2017; 49. [PMID: 28295478 DOI: 10.1111/and.12743] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2016] [Indexed: 01/09/2023] Open
Abstract
To investigate the effects of different concentrations of various cryoprotectants (CPs) on the cell viability as well as expression of spermatogenesis-related genes, such as CREM, Stra8 and HSP70-2 in frozen-thawed bovine calf testicular tissue, immature bovine (Qinchuan cattle) calf testicular tissue was collected and cryopreserved in the cryomedia containing different concentrations (5%, 10%, 15% and 20%) of the following three CPs: glycerol, ethylene glycol (EG) and dimethyl sulphoxide (DMSO) respectively. After 1 month cryopreservation in liquid nitrogen, cell viability was evaluated using Trypan blue exclusion under a bright-field microscope. The mRNA expression of the three genes was also evaluated using qRT-PCR. The results indicated that different concentrations of glycerol, EG and DMSO in cryomedia during cryopreservation could protect bovine calf testicular tissue in various ways to avoid freezing or cryopreservation-induced expression changes in spermatogenesis-related genes. The highest cell viability and the three spermatogenesis-related genes (CREM, Stra8 and HSP70-2) expression level came from the cryomedia containing glycerol, EG and DMSO at 10% concentration respectively (p < .05). Meanwhile, compared with the other CPs, the frozen-thawed bovine calf testicular tissue treated with 10% DMSO exhibited the highest cell viability and mRNA expression level of the spermatogenesis-related genes (CREM, Stra8 and HSP70-2).
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Pan YL, Pan Y, Qu CM, Su CG, Li JH, Zhang XG. Identification and cloning of GOLDEN2-LIKE1 (GLK1), a transcription factor associated with chloroplast development in Brassica napus L. GENETICS AND MOLECULAR RESEARCH 2017; 16:gmr-16-01-gmr.16018942. [PMID: 28218778 DOI: 10.4238/gmr16018942] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Photosynthesis is the process by which dry matter accumulates, which affects rapeseed yield. In this study, we identified GOLDEN2-LIKE1 (GLK1), located on chromosome A07 and 59.2 kb away from the single nucleotide polymorphism marker SNP16353A07, which encodes a transcription factor associated with the rate of photosynthesis in leaves. We then identified 96 GLK1 family members from 53 species using a hidden Markov model (HMM) search and found 24 of these genes, which were derived from 17 Brassicaceae species. Phylogenetic analysis showed that 24 Brassicaceae proteins were classified into three subgroups, named the Brassica family, Adenium arabicum, and Arabidopsis. Using homologous cloning methods, we identified four BnaGLK1 copies; however, the coding sequences were shorter than the putative sequences from the reference genome, probably due to splicing errors among the reference genome sequence or different gene copies being present in the different B. napus lines. In addition, we found that BnaGLK1 genes were expressed at higher levels in leaves with more chloroplasts than were present in other leaves. Overexpression of BnaGLK1a resulted in darker leaves and siliques than observed in the control, suggesting that BnaGLK1 might promote chloroplast development to affect the rate of photosynthesis in leaves. These results will help to elucidate the mechanism of chloroplast biogenesis by GLK1 in B. napus.
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Zhang XG, Zhang H, Liang XL, Liu Q, Wang HY, Cao B, Cao J, Liu S, Long YJ, Xie WY, Peng DZ. Epigenetic mechanism of maternal post-traumatic stress disorder in delayed rat offspring development: dysregulation of methylation and gene expression. GENETICS AND MOLECULAR RESEARCH 2016; 15:gmr9009. [PMID: 27706597 DOI: 10.4238/gmr.15039009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Maternal post-traumatic stress disorder (PTSD) increases the risk of adverse neurodevelopmental outcomes in the child. Epigenetic alternations may play an essential role in the negative effects of PTSD. This study was aimed to investigate the possible epigenetic alterations of maternal PTSD, which underpins the developmental and behavioral impact. 24 pregnant Sprague-Dawley (SD) rats were randomly grouped into PTSD and control groups. Open-field tests (OFTs), elevated pull maze (EPM) assays, gene expression profile chip tests, and methylated DNA immunoprecipitation sequencing (MeDIP-Seq) were performed on the offsprings 30 days after birth. The results showed that PTSD offsprings had lower body weights and OFT scores than control offsprings. Enzyme-linked immunosorbent assays showed that serotonin receptor (5-HT) and dopamine levels were significantly lower in PTSD offsprings than in control offsprings. In contrast, corticosterone levels were higher in the PTSD group than in the control group. In a comparison of the PTSD group versus the control group, 4,160 significantly differentially methylated loci containing 30,657 CpGs were identified; 2,487 genes, including 13 dysmethylated genes, were validated by gene expression profiling, showing a negative correlation between methylation and gene expression (R = -0.617, P = 0.043). In conclusion, maternal PTSD could delay the physical and behavioral development of offsprings, and the underlying mechanism could contribute to changes in neurotransmitters and gene expression, owing to dysregulation of whole-genome methylation. These findings could support further clinical research on appropriate interventions for maternal PTSD to prevent methylation dysregulation and developmental retardation.
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Zhang H, Li X, Chen Y, Durand C, Li AP, Zhang XG. Conductivity map from scanning tunneling potentiometry. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:083702. [PMID: 27587126 DOI: 10.1063/1.4960081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present a novel method for extracting two-dimensional (2D) conductivity profiles from large electrochemical potential datasets acquired by scanning tunneling potentiometry of a 2D conductor. The method consists of a data preprocessing procedure to reduce/eliminate noise and a numerical conductivity reconstruction. The preprocessing procedure employs an inverse consistent image registration method to align the forward and backward scans of the same line for each image line followed by a total variation (TV) based image restoration method to obtain a (nearly) noise-free potential from the aligned scans. The preprocessed potential is then used for numerical conductivity reconstruction, based on a TV model solved by accelerated alternating direction method of multiplier. The method is demonstrated on a measurement of the grain boundary of a monolayer graphene, yielding a nearly 10:1 ratio for the grain boundary resistivity over bulk resistivity.
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Liu YH, Yi Q, Hou XB, Zhang XG, Zhang JJ, Liu HM, Hu YF, Huang YB. Comparative quantitative trait locus mapping of maize flowering-related traits in an F2:3 and recombinant inbred line population. GENETICS AND MOLECULAR RESEARCH 2016; 15:gmr8465. [PMID: 27420987 DOI: 10.4238/gmr.15028465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Flowering-related traits in maize are affected by complex factors and are important for the improvement of cropping systems in the maize zone. Quantitative trait loci (QTLs) detected using different materials and methods usually vary. In the present study, 266 maize (Zea mays) F2:3 families and 301 recombinant inbred lines (RIL) derived from a cross between 08-641 (founding parent from southeast China) and Ye478 (founding parent from China) were evaluated for four flowering-related traits, including days to tasseling (DTT), days to pollen shedding (DPS), days to silking (DTS), and anthesis-silking interval. Sixty-six QTLs controlling the target traits were detected in the F2:3 and RIL populations via single environment analysis and joint analysis across all environments (JAAE). The QTLs explained 0.8-13.47% of the phenotypic variation, with 12 QTLs explaining more than 10%. The results of meta-QTL (MQTL) analysis indicated that 41 QTLs could be integrated into 14 MQTLs. One MQTL included 2.9 QTLs, ranging from two to ten QTLs for one to three traits. QTLs, including MQTL1-1 and MQTL9-1, were detected across the F2:3 and RIL populations via SAE and JAAE. Among the MQTLs, nine QTLs were integrated into MQTL9-1 and affected DTT, DPS, and DTS, with the favored allele being derived from 08-641. MQTL3-2 showed high phenotypic variation and was suitable for fine mapping to determine the genetic mechanisms of flowering. MQTL3-2 could be applied to improve inbred lines using marker-assisted selection.
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Li X, Zhang BL, Zhang XG, Su XL. Correlation between PPARg2 gene Pro12Ala polymorphism and cerebral infarction in an Inner Mongolian Han Chinese population. GENETICS AND MOLECULAR RESEARCH 2016; 15:gmr7332. [PMID: 27420933 DOI: 10.4238/gmr.15027332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The variant of PPAR-g2 has been shown to promote the increase of carotid IMT in patients suffering from cerebral infarction and the Pro12Ala polymorphism in the peroxisome proliferator-activated receptorg2 (PPARg2) gene may be associated with cerebral infarction. However, due to the different genetic background, race, and regional variations of cerebral infarction patient, the results of investigations into this subject differ. The aim of this study was to investigate this polymorphism in relation to cerebral infarction among the Inner Mongolian Han Chinese population. A total of 574 Han Chinese individuals from Inner Mongolian were selected randomly, including 302 patients with cerebral infarction and 272 healthy controls. Polymerase chain reaction-restriction fragment length polymorphism was used to determine genotypes of the PPARg2 Pro12Ala variant and results were confirmed by direct sequencing. Genotype frequencies were found to be 90.7 and 91.9% for P/P, 8.6 and 7.7% for P/A, and 0.7 and 0.4 for A/A in the cerebral infarction and control groups, respectively. No statistically significant differences in genotype distribution were observed between the two groups (P > 0.05). Moreover, PPARg2 Pro12Ala genotype was not significantly associated with altered fasting blood glucose, blood pressure, or serum lipid profiles. After adjustment for gender, body mass index, and smoking habit, logistic regression was used to analyze the relationship between the Pro12Ala polymorphism and cerebral infarction (odds ratio = 0.888, 95% confidence interval = 0.106-7.460, P > 0.05), revealing that this variant was not the main pathogenic factor involved. Therefore, the Pro12Ala mutation of PPARg2 may not be associated with cerebral infarction in the Inner Mongolian Han Chinese population.
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Zhang HH, Shen YH, Xiong XM, Han MJ, Qi DW, Zhang XG. Evidence for horizontal transfer of a recently active Academ transposon. INSECT MOLECULAR BIOLOGY 2016; 25:338-346. [PMID: 26959720 DOI: 10.1111/imb.12225] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Horizontal transfer (HT), the exchange of genetic material between species, plays important roles in transposon biology and genome evolution. In this study, we provide the first documented example of a new Academ transposon involved in recent and distant HTs into the genomes of species belonging to seven different orders of insects: Lepidoptera, Hymenoptera, Neuroptera, Embioptera, Dermaptera, Trichoptera and Zoraptera. These results suggest that HT of DNA transposons amongst insects has occurred on a broader scale than previously appreciated. The Academ transposon discovered in the Lepidoptera and parasitic wasps is of particular interest because the intimate association between wasps and their lepidopteran hosts might provide an opportunity for HT of transposons.
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Durand C, Zhang XG, Hus SM, Ma C, McGuire MA, Xu Y, Cao H, Miotkowski I, Chen YP, Li AP. Differentiation of Surface and Bulk Conductivities in Topological Insulators via Four-Probe Spectroscopy. NANO LETTERS 2016; 16:2213-2220. [PMID: 26954427 DOI: 10.1021/acs.nanolett.5b04425] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We show a new method to differentiate conductivities from the surface states and the coexisting bulk states in topological insulators using a four-probe transport spectroscopy in a multiprobe scanning tunneling microscopy system. We derive a scaling relation of measured resistance with respect to varying interprobe spacing for two interconnected conduction channels to allow quantitative determination of conductivities from both channels. Using this method, we demonstrate the separation of 2D and 3D conduction in topological insulators by comparing the conductance scaling of Bi2Se3, Bi2Te2Se, and Sb-doped Bi2Se3 against a pure 2D conductance of graphene on SiC substrate. We also quantitatively show the effect of surface doping carriers on the 2D conductance enhancement in topological insulators. The method offers a means to understanding not just the topological insulators but also the 2D to 3D crossover of conductance in other complex systems.
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Teng ZW, Zhu Y, Na Q, Zhang XG, Zhao H, Wei GJ, Zhao J, Zhang XW, Wang GZ, Liang J, Zhang ZJ, Liu YG. Regulatory effect of miRNA on multi-directional differentiation ability of mesenchymal stem cell in treatment of osteoporosis. J BIOL REG HOMEOS AG 2016; 30:345-352. [PMID: 27358120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This study was designed to evaluate the effect of miRNA acting in regulating multi-directional differentiation ability of mesenchymal stem cell in treatment of osteoporosis (OP), with the aim of finding a new idea and approach for clinical treatment of OP. Estrogen deficiency-induced OP mice model was established by means of ovariectomy (OVX). Additionally, a sham group was set up for control. Bone Marrow Mesenchymal Stem Cells (BMMSCs) of OVX group (O/BMMSCs) and BMMSCs of sham group (S/BMMSCs) were separately cultured. Then surface markers of BMMSCs were detected. Multi-directional differentiation ability was identified in the two groups by giving cells targeted induced stimulation. It was found that the bone trabecula, bone density and bone volume fraction of distal femoral metaphysis in the OVX group were much lower than those of the sham group. Moreover, trabecular bone space in the OVX group became larger; O/BMMSCs and S/BMMSCs both had normal expression of surface markers as well as potentials of osteogenic and adipogenic differentiation; O/BMMSCs had a weaker osteogenic capability but a stronger adipogenic capability than S/BMMSCs. All the findings suggest that the regulatory effect of miRNA on multi-directional differentiation ability plays a vital role in the treatment of OP, and there is a close correlation between them; deficiency or functional defect of BMMSCs can result in the occurrence of OP.
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Wang Q, Ye T, Chen HL, Zhang XG, Zhang LZ. Correlation between intensity modulated radiotherapy and bone marrow suppression in breast cancer. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2016; 20:75-81. [PMID: 26813456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
OBJECTIVE To study the correlation factors of bone marrow suppression in breast cancer radiotherapy and find out the method to guide the target area, dose limitation for breast cancer to reduce the risk of bone marrow suppression. PATIENTS AND METHODS 72 cases of breast cancer patients were collected through retrospective, clinical control study. For patients with Grade 0-3, bone marrow suppression in the course of radiotherapy, the dose-volume parameters (V5, V10, V20, V30, V50, D20, D40, D60, D80, D100, Min, Max, Dmean) of the chest and rib of each patient were collected and analyzed from multiple points including tumor stage, age, lesion location, surgical approach, chemotherapy regimen and the number of cycles, bone dose-volume parameters. RESULTS The relative parameters of the rib in the middle and severe bone marrow suppression group were significantly higher than those in the mild bone marrow depression group and the p values of V5, V10, V20, V30, Dmean, D40, D60, D80, D100 were less than 0.05. The difference of V50 in the two groups was statistically significant (p <0.05). For chemotherapy regimens containing doxorubicin, epirubicin, cyclophosphamide, the differences between bone marrow suppression group and non-bone marrow suppression were statistically significant (p =0.002). CONCLUSIONS The dose-volume parameters of the rib radiation is one of the main factors causing the suppression of bone marrow in radiotherapy, and the volume of the 50Gy irradiation is also a contribution to the bone marrow. For patients accepted chemotherapy with doxorubicin, epirubicin, cyclophosphamide before radiotherapy, bone marrow suppression is more likely to occur during radiotherapy. After radical mastectomy or the volume of thoracic rib is increased because of the small breast, the occurrence of bone marrow suppression is increased. The effects of radiation on the bone marrow suppression were small, while its effect on the ribs was more evident, especially on the ribs V20 and Dmean and the difference was statically significant.
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Yu SC, Xu YY, Li Y, Xu B, Sun Q, Li F, Zhang XG. Construction of tissue engineered skin with human amniotic mesenchymal stem cells and human amniotic epithelial cells. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2015; 19:4627-4635. [PMID: 26698261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
OBJECTIVE To establish a new model for construction of tissue engineered skin with human amniotic mesenchymal stem cells (hAMSCs) and human amniotic epithelial cells (hAECs). MATERIALS AND METHODS hAMSCs and hAECs were isolated from amniotic membrane. The morphology and phenotype of hAMSCs and hAECs were confirmed by microscope and flow cytometry, respectively. Then, we performed RT-PCR and immunofluorescence staining to assess the expression of stem cells and keratinocyte markers. Moreover, cell co-culture was performed to observe the growth and phenotype characteristics of hAMSCs and hAECs in vitro. In addition, tissue engineered skin with hAMSCs and hAECs was constructed and assessed with histological methods. RESULTS hAMSCs and hAECs were successfully isolated, exhibiting fibroblast-like morphous and cobblestone-shape epithelial morphous, respectively. The surface biomarker analysis showed that hAMSCs and hAECs were both positive for CD73, CD90 and CD105, and negative for CD34 and HLA-DR. The RT-PCR showed that hAMSCs expressed stem cell marker Nanog and c-MYC, and keratinocyte marker K19, β1 integrin and K8, whereas hAECs expressed stem cell marker KLF4 and c-MYC, and keratinocyte marker K19, β1 integrin, K5 and K8. The expression of keratinocyte proliferation antigen K14 was also found on hAECs. Furthermore, we found co-culture has no impact on the phenotype of hAMSCs and hAECs, but increased the proliferation activity of hAECs and decreased the proliferation activity of hAMSCs. Finally, the histological analysis showed that the tissue engineered skin exhibited similar structure as normal skin. CONCLUSIONS Tissue engineered skin with hAMSCs and hAECs was successfully constructed and shown a similar feature as a skin equivalent. The tissue engineered skin might have good application prospects in regenerative medicine.
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Zhao P, Wang Y, Zhang Y, Guo T, Zhang Z, Zhang WJ, Zhang XG, Ashraf MA. The extraction of different proteins in selenium enriched peanuts and their antioxidant properties. Saudi J Biol Sci 2015; 23:353-7. [PMID: 27081360 PMCID: PMC4818322 DOI: 10.1016/j.sjbs.2015.08.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/13/2015] [Accepted: 08/16/2015] [Indexed: 11/30/2022] Open
Abstract
In this study, the selenium enriched peanuts and the different solubility proteins extracted from them were investigated. The dried defatted selenium enriched peanuts (SeP) powder (0.3147 μg/g) had a 2.5-fold higher mean total selenium concentration than general peanuts (GP) power (0.1233 μg/g). The SeP had higher concentration of selenium, manganese and zinc than that of GP, but less calcium. The rate of extraction of protein was 23.39% for peanuts and alkali soluble protein was the main component of protein in SeP, which accounted for 92.82% of total soluble protein and combined selenium was 77.33% of total selenium protein. In different forms of proteins from SeP, the WSePr due to higher concentration of selenium had higher DPPH free-radical scavenging activity, higher reducing activity and longer induction time than other proteins.
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Iberi V, Vlassiouk I, Zhang XG, Matola B, Linn A, Joy DC, Rondinone AJ. Maskless Lithography and in situ Visualization of Conductivity of Graphene using Helium Ion Microscopy. Sci Rep 2015; 5:11952. [PMID: 26150202 PMCID: PMC4493665 DOI: 10.1038/srep11952] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 06/10/2015] [Indexed: 11/30/2022] Open
Abstract
The remarkable mechanical and electronic properties of graphene make it an ideal candidate for next generation nanoelectronics. With the recent development of commercial-level single-crystal graphene layers, the potential for manufacturing household graphene-based devices has improved, but significant challenges still remain with regards to patterning the graphene into devices. In the case of graphene supported on a substrate, traditional nanofabrication techniques such as e-beam lithography (EBL) are often used in fabricating graphene nanoribbons but the multi-step processes they require can result in contamination of the graphene with resists and solvents. In this letter, we report the utility of scanning helium ion lithography for fabricating functional graphene nanoconductors that are supported directly on a silicon dioxide layer, and we measure the minimum feature size achievable due to limitations imposed by thermal fluctuations and ion scattering during the milling process. Further we demonstrate that ion beams, due to their positive charging nature, may be used to observe and test the conductivity of graphene-based nanoelectronic devices in situ.
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Cao G, Singh DJ, Zhang XG, Samolyuk G, Qiao L, Parish C, Jin K, Zhang Y, Guo H, Tang S, Wang W, Yi J, Cantoni C, Siemons W, Payzant EA, Biegalski M, Ward TZ, Mandrus D, Stocks GM, Gai Z. Ferromagnetism and nonmetallic transport of thin-film α-FeSi(2): a stabilized metastable material. PHYSICAL REVIEW LETTERS 2015; 114:147202. [PMID: 25910157 DOI: 10.1103/physrevlett.114.147202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Indexed: 06/04/2023]
Abstract
A metastable phase α-FeSi_{2} was epitaxially stabilized on a silicon substrate using pulsed laser deposition. Nonmetallic and ferromagnetic behaviors are tailored on α-FeSi_{2} (111) thin films, while the bulk material of α-FeSi_{2} is metallic and nonmagnetic. The transport property of the films renders two different conducting states with a strong crossover at 50 K, which is accompanied by the onset of a ferromagnetic transition as well as a substantial magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of α-FeSi_{2} obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our finding sheds light on achieving ferromagnetic semiconductors through both their structure and doping tailoring, and provides an example of a tailored material with rich functionalities for both basic research and practical applications.
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Zhang XG, Yan GJ, Hong JY, Su ZZ, Yang GS, Li QW, Hu JH. Effects of bovine serum albumin on boar sperm quality during liquid storage at 17°C. Reprod Domest Anim 2015; 50:263-269. [PMID: 25622981 DOI: 10.1111/rda.12481] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 12/14/2014] [Indexed: 11/28/2022]
Abstract
This study aimed to investigate the effects of bovine serum albumin (BSA) on boar sperm quality during liquid storage at 17°C. Boar semen samples were collected and diluted with Modena containing different concentrations (0, 1, 2, 3, 4, 5 and 6 g/l) of BSA, and sperm motility, plasma membrane integrity, acrosome integrity, total antioxidative capacity (T-AOC) activity and malondialdehyde (MDA) content were measured and analysed. The results showed that Modena supplemented with 3, 4 and 5 g/l BSA could improve boar sperm motility, effective survival time and plasma membrane integrity (p < 0.05), decrease MDA content (p < 0.05), while no statistical difference was observed for sperm acrosome integrity and T-AOC activity among these three groups (p > 0.05). The semen sample diluted with Modena containing 4 g/l BSA could achieve optimum effect, and sperm survival time was 7.5 days. After 7 days preservation, sperm motility, plasma membrane integrity and acrosome integrity were 54%, 49% and 78%, respectively. T-AOC activity and MDA content were 1.03 U/ml and 17.5 nmol/ml, respectively. In conclusion, Modena supplemented with BSA reduced the oxidative stress and improved the sperm quality of boar semen during liquid storage at 17°C, and 4 g/l BSA was the optimum concentration. Further studies are required to obtain more concrete results on the determination of antioxidant capacities of BSA in liquid preserved boar semen.
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Zhang XG, Yang L. Does Blood Lipid Screening is Cost-Effectiveness Among Chinese Adults Aged 45 And Above? VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2014; 17:A762. [PMID: 27202789 DOI: 10.1016/j.jval.2014.08.264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
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