37 research outputs found

    Comparison of quantitative volumetric analysis and linear measurement for predicting the survival of Barcelona Clinic Liver Cancer 0- and A stage hepatocellular carcinoma after radiofrequency ablation

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    PURPOSEThe prognostic role of the tumor volume in patients with hepatocellular carcinoma (HCC) at the Barcelona Clinic Liver Cancer (BCLC) 0 and A stages remains unclear. This study aims to compare the volumetric measurement with linear measurement in early HCC burden profile and clarify the optimal cut-off value of the tumor volume.METHODSThe consecutive patients diagnosed with HCC who underwent initial and curative-intent radiofrequency ablation (RFA) were included retrospectively. The segmentation was performed semi-automatically, and enhanced tumor volume (ETV) as well as total tumor volume (TTV) were obtained. The patients were categorized into high- and low-tumor burden groups according to various cutoff values derived from commonly used diameter values, X-tile software, and decision-tree analysis. The inter- and intra-reviewer agreements were measured using the intra-class correlation coefficient. Univariate and multivariate time-to-event Cox regression analyses were performed to identify the prognostic factors of overall survival.RESULTSA total of 73 patients with 81 lesions were analyzed in the whole cohort with a median follow-up of 31.0 (interquartile range: 16.0–36.3). In tumor segmentation, excellent consistency was observed in intra- and inter-reviewer assessments. There was a strong correlation between diameter-derived spherical volume and ETV as well as ETV and TTV. As opposed to all linear candidates and 4,188 mm3 (sphere equivalent to 2 cm in diameter), ETV >14,137 mm3 (sphere equivalent to 3 cm in diameter) or 23,000 mm3 (sphere equivalent to 3.5 cm in diameter) was identified as an independent risk factor of survival. Considering the value of hazard ratio and convenience to use, when ETV was at 23,000 mm3, it was regarded as the optimal volumetric cut-off value in differentiating survival risk.CONCLUSIONThe volumetric measurement outperforms linear measurement on tumor burden evaluation for survival stratification in patients at BCLC 0 and A stages HCC after RFA

    Molecular characterization of SARS-CoV-2 nucleocapsid protein

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    Corona Virus Disease 2019 (COVID-19) is a highly prevalent and potent infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Until now, the world is still endeavoring to develop new ways to diagnose and treat COVID-19. At present, the clinical prevention and treatment of COVID-19 mainly targets the spike protein on the surface of SRAS-CoV-2. However, with the continuous emergence of SARS-CoV-2 Variants of concern (VOC), targeting the spike protein therapy shows a high degree of limitation. The Nucleocapsid Protein (N protein) of SARS-CoV-2 is highly conserved in virus evolution and is involved in the key process of viral infection and assembly. It is the most expressed viral structural protein after SARS-CoV-2 infection in humans and has high immunogenicity. Therefore, N protein as the key factor of virus infection and replication in basic research and clinical application has great potential research value. This article reviews the research progress on the structure and biological function of SARS-CoV-2 N protein, the diagnosis and drug research of targeting N protein, in order to promote researchers’ further understanding of SARS-CoV-2 N protein, and lay a theoretical foundation for the possible outbreak of new and sudden coronavirus infectious diseases in the future

    Advanced Processing Techniques and Impurity Management for High-Purity Quartz in Diverse Industrial Applications

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    While numerous studies have explored the mineralogical characteristics and purification techniques of high-purity quartz (HPQ), discussions on impurity control during various purification processes and their applications in photovoltaics, electronics, and optics remain limited. This review delves into the adverse effects of impurities such as aluminum, iron, and sodium in the manufacturing processes of these industries, emphasizing their critical role as these impurities can degrade material performance. This paper focuses on analyzing the types of impurities found in quartz and evaluates existing purification technologies such as acid washing, ultrasonic acid washing, chlorination roasting, and calcination quenching. It highlights the limitations of current technologies in processing quartz ore and discusses the advantages of different impurity types under various technological treatments. Moreover, it explores the environmental and economic impacts of these high-purity processes, underlining the necessity for more environmentally friendly and cost-effective purification techniques. The purpose of this review is to provide a comprehensive technical and strategic framework for the use of high-purity quartz in high-tech applications, supporting future research and industrial applications in this critical material field

    Robust Switching Gain-Based Fractional-Order Sliding Mode Control for Wind-Powered Microgrids

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    This study proposes a novel fractional-order sliding-mode control strategy with robust switching gain to achieve reliable and high quality of wind-powered microgrid systems. Three fractional-order sliding mode controllers are designed to generate continuous control signals and regulate the outer DC-link voltage loop and inner current loop in the grid-side inverters. High robustness and stability of the grid-side inverter can be guaranteed even in the presence of parameter variations and external disturbances. Owing to the fractional-order sliding manifold and fractional-order integral control law, the chattering is attenuated. The fractional-order robust adaptive switching gain is designed to avoid overestimating the upper bound of matched/unmatched uncertainties, save the control energy, and guarantee the rapidity and robustness of the convergence. Simulations validate the proposed method

    Temperature-Dependent and Threshold Behavior of Sm3+ Ions on Fluorescence Properties of Lithium Niobate Single Crystals

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    Temperature-dependent and threshold behavior of Sm3+ ions on fluorescence properties of lithium niobate (LiNbO3, LN) single crystals were systematically investigated. The test materials, congruent LiNbO3 single crystals (Sm:LN), with various concentrations of doped Sm3+ ions from 0.2 to 2.0 mol.%, were grown using the Czochralski technique. Absorption spectra were obtained at room temperature, and photoluminescence spectra were measured at various temperatures in the range from 73 K to 423 K. Judd–Ofelt theory was applied to calculate the intensity parameters Ωt (t = 2, 4, 6) for 1.0 mol.% Sm3+-doped LiNbO3, as well as the radiative transition rate, Ar, branching ratio, β, and radiative lifetime, τr, of the fluorescent 4G5/2 level. Under 409 nm laser excitation, the photoluminescence spectra of the visible fluorescence of Sm3+ mainly contains 568, 610, and 651 nm emission spectra, corresponding to the energy level transitions of 4G5/2→6H5/2, 4G5/2→6H7/2, and 4G5/2→6H9/2, respectively. The concentration of Sm3+ ions has great impact on the fluorescence intensity. The luminescence intensity of Sm (1.0 mol.%):LN is about ten times as against Sm (0.2 mol.%):LN at 610 nm. The intensity of the fluorescence spectra were found to be highly depend on temperature, as well as the concentration of Sm3+ ions in LiNbO3 single crystals, as predicted; however, the lifetime changed little with the temperature, indicating that the temperature has little effect on it, in Sm:LN single crystals. Sm:LN single crystals, with orange-red emission spectra, can be used as the active material in new light sources, fluorescent display devices, UV-sensors, and visible lasers

    Rate Control for Scalable Video Model

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    Scalable video coding (SVC) has become more and more important with the enrichment of multimedia data and the diversification of network and terminal devices. In current MPEG SVC activities, a scalable extension of H.264/AVC, called scalable video model (SVM) 1-4, is proposed by HHI and has shown further coding efficiency improvement and scalability functionality. However, the SVM model doesn’t provide an efficient rate control scheme now, and rate control is achieved through a full search for selecting a suitable quantization parameter (QP). That is very inefficient and much time-consuming. In this paper, an efficient rate control scheme is proposed for the SVM, which is derived from the state-of-the-art hybrid rate control schemes of JVT 5,6 with some considerations for scalable video coding. In the proposed rate control scheme, the rate distortion optimization (RDO) involved in the step of encoding temporal subband pictures is only implemented on the low-pass subband pictures, and rate control is independently applied to each spatial layer. For each spatial layer, the rate control is implemented at GOP, picture and basic unit levels. Furthermore, for the temporal subband pictures obtained from the motion compensation temporal filtering 7-11 (MCTF), the target bit allocation and quantization parameter selection inside a GOP could make full use of the hierarchical relations inherent from the MCTF. The proposed rate control scheme has been implemented into SVM3.0 1 and experiment results show that the proposed algorithm can achieve the target bit rate with little bit rate fluctuation and keep fine image quality at the same time, but the computation complexity is reduced heavily
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