54 research outputs found

    Nano-structured transmissive spectral filter matrix based on guided-mode resonances

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    Background: In this work, a nanostructured guided-mode resonance filter matrix with high transmission efficiency and narrow bandwidth is demonstrated. The developed nano-filter arrays have various usages, e.g., combined with the CMOS image sensors to realize compact spectrometers for biomedical sensing applications. Methods: In order to optimize the filter performance, the spectral responses of filters with different structural parameters are carefully studied based on the variable-controlling method. A quality factor is carried out for quantitative characterization. Results: In this case, a high fill factor of 0.9 can strongly suppress sidebands, while buffer layer thickness can be adjusted to mainly control the bandwidth. The transmission peaks shift from 386 nm to 1060 nm with good linearity when periods vary from 220 nm to 720 nm. The incident angle dependence is simulated to be ~ 1.1 nm/degree in ±30° range. The filters are then fabricated and characterized. The results obtained from both simulations and experiments agree well, where the filters with the period of 352 nm exhibit simulated and measured transmission peaks of 564 nm and 536 nm, the FWHM of 13 nm and 17 nm, respectively. In terms of metal material, besides aluminum, silver is also investigated towards optimization of the transmission efficiency. Conclusion: The transmission spectra of designed filters have high transmission and low sideband; its peaks cover the whole visible and near infrared range. These characteristics allow them to have the possibility to be integrated into image sensors for spectrometer applications

    Identification of hub genes associated with hepatitis B virus-related hepatocellular cancer using weighted gene co-expression network analysis and protein-protein interaction network analysis

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    Background. Chronic hepatitis B virus (HBV) infection is the main pathogen of hepatocellular carcinoma. However, the mechanisms of HBV-related hepatocellular carcinoma (HCC) progression are practically unknown. Materials and Methods. The results of RNA-sequence and clinical data for GSE121248 and GSE17548 were accessed from the Gene Expression Omnibus data library. We screened Sangerbox 3.0 for differentially expressed genes (DEGs). The weighted gene co-expression network analysis (WGCNA) was employed to select core modules and hub genes, and protein-protein interaction network module analysis also played a significant part in it. Validation was performed using RNA-sequence data of cancer and normal tissues of HBV-related HCC patients in the cancer genome atlas-liver hepatocellular cancer database (TCGA-LIHC). Results. 787 DEGs were identified from GSE121248 and 772 DEGs were identified from GSE17548. WGCNA analysis indicated that black modules (99 genes) and grey modules (105 genes) were significantly associated with HBV-related HCC. Gene ontology analysis found that there is a direct correlation between DEGs and the regulation of cell movement and adhesion; the internal components and external packaging structure of plasma membrane; signaling receptor binding, calcium ion binding, etc. Kyoto Encyclopedia of Genes and Genomes pathway analysis found out the association between cytokine receptors, cytokine-cytokine receptor interactions, and viral protein interactions with cytokines were important and HBV-related HCC. Finally, we further validated 6 key genes including C7, EGR1, EGR3, FOS, FOSB, and prostaglandin-endoperoxide synthase 2 by using the TCGALIHC. Conclusions. We identified 6 hub genes as candidate biomarkers for HBV-related HCC. These hub genes may act as an essential part of HBV-related HCC progression

    30 GHz surface acoustic wave transducers with extremely high mass sensitivity

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    A nano-patterning process is reported in this work, which can achieve surface acoustic wave (SAW) devices with an extremely high frequency and a super-high mass sensitivity. An integrated lift-off process with ion beam milling is used to minimize the short-circuiting problem and improve the quality of nanoscale interdigital transducers (IDTs). A specifically designed proximity-effect-correction algorithm is applied to mitigate the proximity effect occurring in the electron-beam lithography process. The IDTs with a period of 160 nm and a finger width of 35 nm are achieved, enabling a frequency of ∼30 GHz on lithium niobate based SAW devices. Both centrosymmetric type and axisymmetric type IDT structures are fabricated, and the results show that the centrosymmetric type tends to excite lower-order Rayleigh waves and the axisymmetric type tends to excite higher-order wave modes. A mass sensitivity of ∼388.2 MHz × mm2/μg is demonstrated, which is ∼109 times larger than that of a conventional quartz crystal balance and ∼50 times higher than a conventional SAW device with a wavelength of 4 μm

    The CMS High Level Trigger

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    At the Large Hadron Collider at CERN the proton bunches cross at a rate of 40MHz. At the Compact Muon Solenoid experiment the original collision rate is reduced by a factor of O (1000) using a Level-1 hardware trigger. A subsequent factor of O(1000) data reduction is obtained by a software-implemented High Level Trigger (HLT) selection that is executed on a multi-processor farm. In this review we present in detail prototype CMS HLT physics selection algorithms, expected trigger rates and trigger performance in terms of both physics efficiency and timing.Comment: accepted by EPJ Nov 200

    Future oxide-based resistive flash memories

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    DRAM, the type of memory cell widely used for high density high speed system memory, faces uncertainty in continued scaling for increased density and performance. Amongst emerging alternative technologies, Resistive Random Access Memory (RRAM) with its high speed and ability to scale further downwards presents itself as a possible candidate to replace DRAM. However the current best RRAM samples slightly fall short of the required endurance, and the device's behavior outside laboratory test setups still has many unknowns. This project looks at possible methods to increase to increase an RRAM device's endurance via external parameters, and to determine if an RRAM's behavior is suitable for use as DRAM's replacement.Bachelor of Engineerin

    Association of chronic hepatitis B with interferon-γ and interleukin-4

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    The pathogenesis of chronic hepatitis B (CHB) is mainly chronicity of hepatitis B virus infection caused by specific immune impairment. Modern studies have shown that activated specific inflammatory cells and the cytokines released by these cells such as interferon-γ (IFN-γ) and interleukin-4 (IL-4) play important roles in virus clearance and improvement of autoimmune function. With the constant development of traditional Chinese medicine, it has a widespread effect on the immune regulation system (especially IFN-γ and IL-4). This article reviews the research advances in immunologic mechanism if CHB in Chinese and Western medicine in recent years and provides new ideas and measures for traditional Chinese medicine to break the immune tolerance of CHB in terms of immune regulation

    Effect of Surface Texturing on Stresses during Rapid Changes in Temperature

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    Recently, there has been great interest in the application of the surface texturing method to enhance material surface performance. Material surfaces sometimes experience rapid temperature changes, and the local surface will obviously generate thermal stresses, which may be detrimental to the material structure. In order to understand the relationship between surface texturing and stresses, a numerical approach is used to investigate the effects of surface texturing on stresses. The results show that surface texturing can generate compressive stresses along the normal direction of the surface, and that strong tensional stresses can be formed in the center of a surface at the same time that are beneficial to material surface performance. However, a smooth surface cannot generate these beneficial stresses. In addition, there is an optimum design size with respect to textures, and the most desirable state of stress in a surface layer can be achieved at this size
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