101 research outputs found

    Realization of broadband index-near-zero modes in nonreciprocal magneto-optical heterostructures

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    Epsilon-near-zero (ENZ) metamaterial with the relative permittivity approaching zero has been a hot research subject in the past decades. The wave in the ENZ region has infinite phase velocity (v=1/εμv=1/\sqrt{\varepsilon\mu}), whereas it cannot efficiently travel into the other devices or air due to the impedance mismatch or near-zero group velocity. In this paper, we demonstrate that the tunable index-near-zero (INZ) modes with vanishing wavenumbers (k=0k=0) and nonzero group velocities (vg0v_\mathrm{g} \neq 0) can be achieved in nonreciprocal magneto-optical systems. This kind of INZ modes has been experimentally demonstrated in the photonic crystals at Dirac point frequencies and that impedance-matching effect has been observed as well. Our theoretical analysis reveals that the INZ modes exhibit tunability when changing the parameter of the one-way (nonreciprocal) waveguides. Moreover, owing to the zero-phase-shift characteristic and decreasing vgv_\mathrm{g} of the INZ modes, several perfect optical buffers (POBs) are proposed in the microwave and terahertz regimes. The theoretical results are further verified by the numerical simulations performed by the finite element method. Our findings may open the new avenues for research in the areas of ultra -strong or -fast nonlinearity, perfect cloaking, high-resolution holographic imaging and wireless communications

    Immunoglobulin G Locus Events in Soft Tissue Sarcoma Cell Lines

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    Recently immunoglobulins (Igs) have been found to be expressed by cells other than B lymphocytes, including various human carcinoma cells. Sarcomas are derived from mesenchyme, and the knowledge about the occurrence of Ig production in sarcoma cells is very limited. Here we investigated the phenomenon of immunoglobulin G (IgG) expression and its molecular basis in 3 sarcoma cell lines. The mRNA transcripts of IgG heavy chain and kappa light chain were detected by RT-PCR. In addition, the expression of IgG proteins was confirmed by Western blot and immunofluorescence. Immuno-electron microscopy localized IgG to the cell membrane and rough endoplasmic reticulum. The essential enzymes required for gene rearrangement and class switch recombination, and IgG germ-line transcripts were also identified in these sarcoma cells. Chromatin immunoprecipitation results demonstrated histone H3 acetylation of both the recombination activating gene and Ig heavy chain regulatory elements. Collectively, these results confirmed IgG expression in sarcoma cells, the mechanism of which is very similar to that regulating IgG expression in B lymphocytes

    Bisphenol A and 17β-Estradiol Promote Arrhythmia in the Female Heart via Alteration of Calcium Handling

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    There is wide-spread human exposure to bisphenol A (BPA), a ubiquitous estrogenic endocrine disruptor that has been implicated as having potentially harmful effects on human heart health. Higher urine BPA concentrations have been shown to be associated with cardiovascular diseases in humans. However, neither the nature nor the mechanism(s) of BPA action on the heart are understood. leak suppressed estrogen-induced triggered activities. The rapid response of female myocytes to estrogens was abolished in an estrogen receptor (ER) β knockout mouse model. leak. Our study provides the first experimental evidence suggesting that exposure to estrogenic endocrine disrupting chemicals and the unique sensitivity of female hearts to estrogens may play a role in arrhythmogenesis in the female heart

    Cloud-Based Fault Tolerant Control for a DC Motor System

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    The fault tolerant control problem for a DC motor system is investigated in a cloud environment. Packet dropout phenomenon introduced by the limited-capacity communication channel is considered. Actuator faults are taken into consideration and fault diagnosis and fault tolerant control methods towards actuator faults are proposed to enhance the reliability of the whole cloud-based DC motor system. The fault diagnosis unit is then established with purpose of obtaining fault information. When the actuator fault is detected by comparing the residual signal with a predefined threshold, a residual matching approach is utilized to locate the fault. The fault can be further estimated by a least-squares filter. Based on the fault estimation, a fault tolerant controller is designed to guarantee the stability as well as the control performance of the DC motor system. Simulation result on a DC motor system shows the efficiency of the fault tolerant control method proposed in this paper

    Cloud-Based Fault Tolerant Control for a DC Motor System

    Get PDF
    The fault tolerant control problem for a DC motor system is investigated in a cloud environment. Packet dropout phenomenon introduced by the limited-capacity communication channel is considered. Actuator faults are taken into consideration and fault diagnosis and fault tolerant control methods towards actuator faults are proposed to enhance the reliability of the whole cloud-based DC motor system. The fault diagnosis unit is then established with purpose of obtaining fault information. When the actuator fault is detected by comparing the residual signal with a predefined threshold, a residual matching approach is utilized to locate the fault. The fault can be further estimated by a least-squares filter. Based on the fault estimation, a fault tolerant controller is designed to guarantee the stability as well as the control performance of the DC motor system. Simulation result on a DC motor system shows the efficiency of the fault tolerant control method proposed in this paper

    Identification and analysis of senescence-related genes in caudal fin cells of triploid crucian carp

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    This research aims to identify the hub genes associated with the senescence of triploid caudal fin cells. Transcriptomic data are obtained from the high and low generation (P6, P60) of triploid crucian carp caudal fin cells by high-throughput sequencing technology. Initially, all differential genes between the high and low generations are screened, yielding 4140 significantly upregulated genes and 3724 significantly downregulated genes. Subsequently, an aging gene set containing 950 genes is downloaded from the CellAge database to extract the differentially expressed genes associated with caudal fin cell aging, totaling 29 genes. GO and KEGG enrichment analyses are performed on these 29 aging differential genes. The GO analysis shows enrichment mainly in cellular processes related to aging, such as regulation of cell division, chromatin organization, cell cycle regulation. KEGG analysis reveals that the 29 aging-related genes are primarily involved in cell cycle and cellular senescence pathways. A PPI network of aging-related genes is constructed using the STRING database and Cytoscape software. Top-ranked genes were identified by using Degree, MCC, MNC, and Closeness algorithms in the Cytohubba plugin in Cytoscape, resulting in hub genes EZH2, JUN, MYD88, RBL2, BMP4, CCND1, NFKB2, MMP9. Lastly, qRT-PCR validation of these eight hub genes further confirmed the involvement of four genes: EZH2, RBL2, BMP4, and CCND1. The hub gene screened in this study may become a potential biomarker of fish caudal fin cell senescence, which provides a valuable experimental basis for the senescence of fish caudal fin cells, especially the senescence of caudal fin cells in polyploid fish, and the reproduction and breeding improvement of polyploid fish. It also provides meaningful data for elucidating the molecular mechanism of polyploid formation in animals, as well as the formation of aging and tumour in human beings

    Dialysate Creatinine Response Patterns During Peritoneal Equilibration Test and the Association Between Cardiovascular Mortality: Findings from a Prospective Cohort Study

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    Background/Aims: During peritoneal equilibrium test (PET), intermediate measures of Dt/P (dialysate/plasma creatinine ratio), D0/P, D2/P and D4/P ratios might provide additional information regarding a patient’s cardiovascular mortality. We aimed to characterise heterogeneity of dialysate creatinine response patterns based on three ratios and compare cardiovascular mortality risks by response patterns. Methods: 3,477 patients initialising peritoneal dialysis (PD) between 2007-2015 were measured D0/P, D2/P and D4/P at baseline and 2-year cardiovascular mortality was defined as the primary outcome. Latent class mixed-effect models were fitted to identify distinct patterns of dialysate creatinine response. Multivariable Logistic regression model with adjustment of cardiometabolic factors were used to compare cardiovascular mortality by latent classes. Results: The 1st latent class including 36% of participants was characterised by consistently increasing and high Dt/P ratios both at 2-hour and 4-hour. The 2nd class including 61% of participants characterised by sharply increased ratio at 2-hour and slightly increased ratio at 4-hour. The 3rd class included 3% of participants with decreased ratio at 2-hour and increased ratio at 4-hour. Comparing the 1st class, the lower cardiovascular mortality risk was identified in the 2nd and 3rd class with adjusted odds ratio 0.65 (95% confidence interval: 0.62-0.69) and 0.48 (0.41-0.57), respectively. Conclusion: Patients with decreased Dt/P ratio between 0-hour and 2-hour and low ratios at 2-hour and 4-hour tend to have low cardiovascular mortality. Latent class analysis seems to be a promising method to reveal unidentified subgroups that do not fit into the risk category defined by Dt/P ratio at 4-hour
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