75 research outputs found

    Magnetic Interaction Reversal in Watermelon Nanostructured Cr-Doped Fe Nanoclusters

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    Cr-doped core-shell Fe/Fe-oxide nanoclusters (NCs) were synthesized at varied atomic percentages of Cr from 0 at. % to 8 at. %. The low concentrations of Cr (%) were selected in order to inhibit the complete conversion of the Fe-oxide shell to Cr2O3 and the Fe core to FeCr alloy. The magnetic interaction in Fe/Fe-oxide NCs (~25 nm) can be controlled by antiferromagnetic Cr-dopant. We report the origin of σ-FeCr phase at very low Cr concentration (2 at. %) unlike in previous studies, and the interaction reversal from dipolar to exchange interaction in watermelon-like Cr-doped core-shell NCs

    Copper-doped nano laponite coating on poly(butylene succinate) scaffold with antibacterial properties and cytocompatibility for biomedical application

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    An ideal artificial bone will likely be multifunctional, combining different technologies to simultaneously promote bone regeneration while inhibiting microbial infection. In this study, copper- (Cu-) doped nano laponite (cnLAP) was prepared by a cation-exchanged method, and the cnLAP coating on poly(butylene succinate) (PBSu) scaffold was fabricated by poly(dopamine) modification. The results showed that incorporation of Cu ions into nano laponite (nLAP) did not have obvious effects on the morphology and surface area of cnLAP (compared with nLAP), which could be coated easily on macroporous PBSu scaffolds. In addition, the cnLAP-coated PBSu scaffolds could inhibit the growth of both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), indicating good antibacterial activity. Moreover, the cnLAP-coated PBSu scaffolds significantly promoted proliferation and improved alkaline phosphatase (ALP) activity of bone mesenchymal stem cells (BMSCs) compared with PBSu scaffolds. Furthermore, no obvious differences in cell responses to cnLAP- and nLAP-coated PBSu scaffolds were found, indicating that incorporation of Cu into nLAP had no negative effects on its cytocompatibility. The results suggested that the cnLAP-coated PBSu scaffolds exhibited excellent cytocompatibility and antimicrobial activity, which might offer promising opportunities for promoting bone regeneration and prevention of infectious from bacteria and effective treatment of bone defects.National Natural Science Foundation of China [51772194, 81771990]; Key Medical Program of Science and Technology Development of Shanghai [17441900600, 15441902500]; Ministry of Education, Youth and Sports of the Czech Republic Program NPU I [LO1504

    Evaluation and revision of long-range single-site lightning location accuracy considering the time delay of ground wave

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    Detecting the distance and orientation of long-distance thunderstorms has very important practical significance. The multi-station lightning location system relies on a high-precision time module and good network communication capabilities, but in some cases these conditions cannot be met, but there is still a need for lightning activity monitoring, and it is very important to establish a single-site lightning location system. In this paper, we have established a long-distance single-site lightning location station, and in order to improve the accuracy of distance estimation, a numerical algorithm is used to obtain the relationship between the ground wave arrival time delay and the propagation distance, and it is used to revise the time difference between the peak value of the skywave and ground wave. Moreover, we used multi-station lightning location data to revise the site-error in magnetic direction finder method to improve the accuracy of the direction calculation. The results show that the effective detection range of the single-site we have been established is 200 km–2000 km, and the revised average direction deviation dropped from 12.3° to 8.6°. The verification results of thunderstorms within the effective detection range show that the relative error of single-site lightning location is 8.4%–18.6% after the revision

    Genetic Polymorphisms in Enzymes Involved in One-Carbon Metabolism and Anti-epileptic Drug Monotherapy on Homocysteine Metabolism in Patients With Epilepsy

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    Aims: To investigate the effects of single nucleotide polymorphisms (SNPs) in genes of one-carbon metabolism (OCM) related enzymes and anti-epileptic drug (AED) monotherapy on homocysteine (Hcy) metabolism in patients with epilepsy, and to further explore specific SNPs that may increase patients' susceptibility to the effects of AEDs on the Hcy imbalance.Method: This case-control study analyzed 279 patients with epilepsy, including patients receiving monotherapy with valproate (VPA) (n = 53), oxcarbazepine (OXC) (n = 71), lamotrigine (LTG) (n = 55), or levetiracetam (LEV) (n = 35) and patients who had not taken any AEDs (controls, n = 65) for at least 6 months. Serum levels of vitamin B12 (vit B12), folate (FA) and Hcy were measured, and 23 SNPs in 13 genes of OCM-related enzymes were genotyped in all patients.Results: Methylenetetrahydrofolate reductase (MTHFR) rs1801133 was associated with elevated serum Hcy levels in patients with epilepsy (P < 0.001), and patients presenting the TT genotype exhibited higher serum Hcy levels than patients with the CC (P < 0.001) or CT (P < 0.001) genotype. A subsequent multiple linear regression analysis showed that AED monotherapy with VPA (vs. control: P = 0.023) or OXC (vs. control: P = 0.041), and genotypes of MTHFR rs1801133 TT (vs. CC: P < 0.001; vs. CT: P < 0.001), transcobalamin 2 (TCN2) rs1801198 CC (vs. GC: P = 0.039) and folate receptor 1 (FOLR1) rs2071010 AA (vs. GA: P = 0.031) were independent risk factors for higher Hcy levels. In the subgroup analysis of patients taking OXC, we found that patients with genotypes of MTHFR rs1801133 TT (vs. CC: P = 0.001; vs. CT: P < 0.001) and TCN2 rs1801198 CC (vs. GC: P = 0.021; vs. GG: P = 0.018) exhibited higher serum Hcy levels.Conclusions: VPA, OXC, and genotypes of MTHFR rs1801133 TT, TCN2 rs1801198 CC, and FOLR1 rs2071010 AA are all independent risk factors for elevated Hcy levels in patients with epilepsy. Moreover, genotypes of MTHFR rs1801133 TT and TCN2 rs1801198 CC may increase patients' susceptibility to the effect of OXC on disrupting Hcy homeostasis

    The Measurement and Elimination of Mode Splitting: From the Perspective of the Partly Ensemble Empirical Mode Decomposition

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    The problems of mode mixing, mode splitting, and pseudocomponents caused by intermittence or white noise signals during empirical mode decomposition (EMD) are difficult to resolve. The partly ensemble EMD (PEEMD) method is introduced first. The PEEMD method can eliminate mode mixing via the permutation entropy (PE) of the intrinsic mode functions (IMFs). Then, bilateral permutation entropy (BPE) of the IMFs is proposed as a means to detect and eliminate mode splitting by means of the reconstructed signals in the PEEMD. Moreover, known ingredient component signals are comparatively designed to verify that the PEEMD method can effectively detect and progressively address the problem of mode splitting to some degree and generate IMFs with better performance. The microseismic signal is applied to prove, by means of spectral analysis, that this method is effective

    Analysis on the Characteristics of Mt. Emei Basalt Rock and Fiber-Used Basalt Deposit in E’bian Area, Sichuan Province

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    The Permian Emeishan basalt formations exposed in the E’bian area are mostly overflow facies, and the rocks are dark gray to gray-green. According to their genesis and structural composition characteristics, the Emeishan basalts in the E’bian area can be divided into porphyry There are four rock types: compactbasalt, porphyriticbasalt, stomata-almond basalt, and tuffaceous basalt. Research on the rock and chemical characteristics of basalt has been carried out, and the research shows that there is fiber-used basalt in the area that is suitable for drawing, which has a good development and utilization prospect
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