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ABSTRCTThe α-fetoprotein (AFP) and soluble intercellular adhesion molecule-1 (sICAM-1) have certain diagnostic value, but their potential value in prognosis prediction, especially immunotherapy response prediction, remains unclear in liver cancer. Through the tumour-free survival (TFS) and overall survival (OS) rates analyses of serum AFP and sICAM-1 levels in 87 patients with primary hepatocellular carcinoma (HCC), the patients whose AFP and sICAM-1 levels were normal (AFP < 20 μg/L or sICAM-1 < 1000 μg/L) before surgery or recovered to normal after surgery exhibited a lower tumour recurrence rate and better OS than patients with elevated serum levels of the two markers. Combined analysis showed that patients with synchronously elevated levels of AFP and sICAM-1 showed the lowest TFS and OS. In addition, the RNA-seq data and clinical information of The Cancer Genome Atlas Liver Hepatocellular Carcinoma were collected to analyse the predictive values of AFP and ICAM-1 in the diagnosis, prognosis and immunotherapy of HCC. The results indicated that the combined application of the two indicators had higher accuracy in both the diagnosis and prognostic prediction of HCC by receiver operating characteristic curves. AFP and ICAM-1 were significantly correlated with multiple immune cells in HCC samples but not in normal samples. The patients with low expression of the two indicators were most likely to benefit from the immune checkpoint blockade therapy. In conclusion, AFP and ICAM-1 play vital roles in the diagnosis, prognostic prediction, and immunotherapy of HCC, suggesting that they are considered as prognostic predictors in clinical practice.

Purpose Recent studies have illustrated that the peritumoral regions of medical images have value for clinical diagnosis. However, the existing approaches using peritumoral regions mainly focus on the diagnostic capability of the single region and ignore the advantages of effectively fusing the intratumoral and peritumoral regions. In addition, these methods need accurate segmentation masks in the testing stage, which are tedious and inconvenient in clinical applications. To address these issues, we construct a deep convolutional neural network that can adaptively fuse the information of multiple tumoral-regions (FMRNet) for breast tumor classification using ultrasound (US) images without segmentation masks in the testing stage. Methods To sufficiently excavate the potential relationship, we design a fused network and two independent modules to extract and fuse features of multiple regions simultaneously. First, we introduce two enhanced combined-tumoral (EC) region modules, aiming to enhance the combined-tumoral features gradually. Then we further design a three-branch module for extracting and fusing the features of intratumoral, peritumoral, and combined-tumoral regions, denoted as the IPC module. Especially, we design a novel fusion module by introducing a channel attention module to adaptively fuse the features of three regions. The model is evaluated on two public datasets including UDIAT and BUSI with breast tumor ultrasound images. Two independent groups of experiments are performed on two respective datasets using the five-fold stratified cross-validation strategy. Finally, we conduct ablation experiments on two datasets, in which BUSI is used as the training set and UDIAT is used as the testing set. Results We conduct detailed ablation experiments about the proposed two modules and comparative experiments with other existing representative methods. The experimental results show that the proposed method yields state-of-the-art performance on both two datasets. Especially, in the UDIAT dataset, the proposed FMRNet achieves a high accuracy of 0.945 and a specificity of 0.945 respectively. Moreover, the precision (PRE = 0.909) even dramatically improves by 21.6% on the BUSI dataset compared with the existing method of the best result. Conclusion The proposed FMRNet shows good performance in breast tumor classification with US images, and proves its capability of exploiting and fusing the information of multiple tumoral-regions. Furthermore, the FMRNet has potential value in classifying other types of cancers using multiple tumoral-regions of other kinds of medical images. This article is protected by copyright. All rights reserved.

A Finite Element Method (FEM) to establish the model of CAT resistive anode and Square resistive anode is proposed. The characteristics of electrode charge signal are analyzed. The factors that affect the position reconstruction linearity of resistive anode are analyzed, including the geometric parameters and sheet resistance of the surface resistive layer, by calculating the amount of electrode charge from a simulated photon hit. It has been concluded that signal development time should be greater than 8R'C' ( R'C' =RC / μ2 ) seconds in order to ensure the root mean square (RMS) nonlinearity (%) of position reconstruction is less than 3% for these two resistive anodes, with capacitance C , and sheet resistance R of sensitive region.

As a key component of electron multiplier device, a microchannel plate (MCP) can be applied in many scientific fields. Pure aluminum oxide (Al2O3) as secondary electron emission (SEE) layer were deposited in the pores of MCP via atomic layer deposition (ALD) to overcome problems such as high dark current and low lifetime which often occur on traditional MCP. In this paper, we systematically investigate the morphology, element distribution, and structure of samples by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS), respectively. Output current of different thickness of Al2O3 was studied and an optimal thickness was found. Experimental tests show that the average gain of ALD-MCP was nearly five times better than that of traditional MCP, and the ALD-MCP showed better sensitivity and longer lifetime.

In this paper, we propose a hermetically sealed X-ray microchannel plate imager as a more effective and stable alternative to the traditional open-structured imager. With two microstrip photocathodes of 100 nm Au and 100 nm CsI , respectively, the proposed imager has a measured exposure time of 65 ps when applied with a 200 ps width gate pulse. The static response test shows that the image intensity of the CsI microstrip photocathode is 3.4 times that of the Au microstrip photocathode when illuminated by a non-monochromatic portable X-ray source with high energy photons. The sealed imager not only enhances the sensitivity and stability of the framing camera, but also has the potential to reduce crosstalks and artifacts, thus further improves the precision of measurement in practice.

Low-Level Light Imaging(LLLI) devices are now been widely used in military, astronomy, scientific, and even in surveillance for our daily uses. The traditional devices like ICCD, EBCCD, EMCCD, which either complicated in structure or require extra cooling system. However, a novel device called Electron Bombarded Active Pixel Sensor(EBAPS) has been developed, it is a proximity focused device which lead photoelectrons produced by photocathode hitting directly towards back illuminated CMOS and cause the semiconductor bombard phenomenon to amplification and then being readout. EBAPS is relatively small in size, less weight, with high sensitivity, and can be used to detect single photon event, etc. Although it has been proven to have excellent sensitivity in the field of LLLI, the performance today is still considered far from its maximum potential. Here, we modeled the structure of EBAPS and studied the factors influencing the performance of the device. By selecting proper parameters like proximity distance, acceleration voltage, photocathode quantum efficiency, etc., we achieved the single photon image mode with a satisfactory sensitivity. Besides, we simulated the electron scattering trajectories among the semiconducting multiplication area by using Monte Carlo method, we compared the simulation results in different conditions and successfully in finding the optimum parameter, which achieved a relatively high sensitivity. The simulation results in this paper could have a profound theoretical foundation in developing higher gain EBAPS.

To realize a high-performance solid-state photon-enhanced thermionic emission (SPETE) solar energy converter, in this study, a graded bandgap window layer is therefore adopted, throughout which the bandgap gradation is generated via the variation of Al composition in the A l x G a 1 − x As layer in the SPETE converter with a GaAs absorber. Based on one-dimension steady-state equation, an analytical model is formed in analyzing performance of the proposed device in our study. Theoretical simulation results indicate that not only are the losses of contact surface recombination being decreased via the bandgap-gradation-induced build-in electric field of the window layer, but also the photon-generated electrons are effectively collected, thereby improving the conversion efficiency. Moreover, the effect of bandgap energy of the contact surface and the width of the window layer on device performance is discussed. A trade-off of high-efficient SPETE converters is therefore realized between large contact surface bandgap and thin window layer width, to which the rationale lies in the improved process of electron collection facilitated by the enhanced build-in electric field rather than reducing the photon absorption in the window layer. Threshold values for barrier height at the emitting interface are presented to guarantee the ideal voltage-current characteristic. It is found that the threshold values of barrier increase with the increase in temperatures.

Graded bandgap AlxGa1-xAs/GaAs photocathode with enhanced quantum efficiency is analyzed in this study. We present the relevant quantum efficiency equations by solving onedimensional continuity equations for transmission-mode graded bandgap AlxGa1-xAs/GaAs and standard AlGaAs/GaAs photocathodes. The results show that the built-in electrical field from bandgap gradation efficiently collects photogenerated electrons in the buffer layer such that quantum efficiencies in the short regions are improved in transmission-mode AlxGa1-xAs/GaAs photocathode. The results also show that a thinner buffer layer improves the short-wavelength response of transmission-mode photocathode. Increasing the active layer thickness improves long-wavelength responses but reduces short-wavelength responses. The method presented in this work may provide better estimate of performance and guide the optimum design of graded bandgap AlxGa1-xAs/GaAs photocathode.

Electron bombarded Active Pixel Sensor (EBAPS) is well known for its low noise in low-light level imaging, high mechanical integration, and a relatively low cost. It plays an important role in areas of the industrial process as well as the fundamental scientific research. However, the performance of EBAPS is intensively influenced by the structural parameters (i.e. the acceleration voltage between cathode and anode, thickness of the passivation layer, etc.). Due to the influence of these factors mentioned above, the performance of EBAPS is restricted to achieve its best condition. Herein, a model based on the optimized Monte Carlo method was proposed for effectively analyzing the scattering behavior of electrons within the electron multiplier layer. Unlike traditional simulation, which only deals with the electron scattering in longitudinal, in this paper, we simulate the electron scattering character not only in horizontal but also vertical among the multiplier layer, which would react to the influence induced by structural parameters more complete and more precise. Based on the proposed model, an experimental prototype of EBAPS is built and its detection sensitivity achieves [Formula: see text] lux under spectral response of ultraviolet (UV) spectroscopy, which improved a lot from our former design. The proposed model can be used for analyzing the influence induced by structural parameters, which exhibit enormous potential for exploring the high-gain EBAPS.

Delay line anode detector has high spatial resolution and high count rate. It has been an important technical means for single photon imaging from near earth space to deep space. A two dimensional delay line anode is designed using multilayer circuit board technology. A complete set of PCB delay line anode single photon detection system is established. The spatial resolution of the detector is theoretically analyzed. Moreover, the signal transmission characteristic of PCB delay line and the dark count rate of the detector are tested. Theoretical analysis and experimental results show that the detector spatial resolution is about 100um and the overall dark count rate is 4counts/cm2 at 2.3KV.

The structural models of micro-channel plate (MCP) and fluorescent screen of the framing camera were established. By combining the finite element integration and Monte Carlo method, software Simion and Lorenz were respectively used to simulate the effects of different voltages loaded on the fluorescent screen, different closed distance between fluorescent screen and MCP, and electrode immersion depth at MCP output on the spatial resolution, in order to obtain an axisymmetric distribution curve. Results showed that the closed distance between MCP and fluorescent screen had the largest impact on the framing camera’s spatial resolution. In addition, higher fluorescent screen voltage did not necessarily result in better spatial resolution, as it was influenced by the light-emitting mechanism of the fluorescent screen. At the framing camera’s current closed distance of 0.8mm, a fluorescent screen voltage of 5000V could achieve the best spatial resolution.

A new method to get a X-ray framing camera with picoseconds time resolution was proposed based on time amplification. Its principle comes from that we use high voltage electrical pulse to get speed dispersion of the photoelectrons pulse first, and then the photoelectrons pulse will be stretched in axial direction by drift area, at the end the photoelectrons pulse after stretched will be framing imaged by a traditional MCP（microchannel plate）gated framing camera. A model of the camera was built according to this method. Time amplification of the system is about 30, and image magnification of the system is about 0.4. Parameters for designing the camera system were presented after theoretical deriving and model simulation. At last, theoretical time resolution and spatial resolution of the camera were given.

Tuberculosis (TB) caused by Mycobacterium tuberculosis (MTB) leads to serious health problems as a chronic respiratory infectious disease. Here we established a real-time fluorescence loop-mediated isothermal amplification assay (RealAmp) using a portable ESE Quant tube scanner as a convenient rapid detection method for MTB. The method efficacy from sputum samples was further investigated, and the reaction time was only 20 min with the detection limit low to 10 2 CFU/ml concentration of MTB. We assessed a total of 1067 samples by the RealAmp assay, comparing the results with smear microscopy and conventional culture methods. To examine whether the failure to detect TB by culturing is due to low sensitivity or true absence, we examined the culture negative samples by commercial real time PCR MTB detection kit, and the results were compared with RealAmp. The data showed that RealAmp assay had a higher positive rate than that of sputum smear and culture methods. RealAmp had a sensitivity of 96.70% and a specificity of 91.55% when compared with culture. In addition, its sensitivity and specificity were 95.29% and 86.88% respectively compared with examination of smear samples using light microscopy. The sensitivity of RealAmp in comparison to real time PCR was 98.25% and specificity was 99.11% in validation of culture negative samples. The present study revealed the newly established RealAmp assay as a convenient, efficient, sensitive and specific method that could be an alternative for rapid detection of MTB and a tool to validate culture and smear negative samples. Furthermore, the portability of the ESE Quant tube scanner also contributed to the promising application for grassroots and field detection of MTB.