Search

Supplemental Digital Content is available in the text, Introduction: The incidence of hepatocellular carcinoma (HCC) ranks sixth in the world, but its mortality is the third highest due to the lack of early diagnostic markers. Nowadays, the increase of autoantibody levels has been found in many cancers, and many studies have begun to pay attention to the detection of anti-p53 antibodies in HCC. The purpose of this study is to quantitatively and comprehensively analyze the potential diagnostic value of anti-p53 autoantibodies in HCC Methods: English articles up to November 2019 were collected. The overall sensitivity and specificity were calculated. Besides, the positive likelihood ratio, negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and summary receiver operating characteristic curves of the overall diagnostic accuracy of anti-p53 antibody were calculated by STATA software. Finally, according to the heterogeneity of the results, the subgroup analysis, and the publication bias were performed. Results: A total of 16 eligible studies were incorporated into this meta-analysis, including 1323 patients with HCC and 1896 control. The pooled sensitivity was 0.28(0.17–0.41) and specificity was 0.98 (0.95–0.99). The pooled DOR was 10.44 (6.31–17.29) and the pooled NLR was 0.74 (0.63–0.86). The area under ROC curve of symmetrical ROC was 0.840. Conclusions: The anti-p53 antibody has a high specificity for HCC, but the low sensitivity is not perfect and would limit the clinical application. The anti-p53 antibody would help rule out HCC but not help rule in HCC for early diagnosis. Whether combined as a diagnostic panel with other biomarkers or laboratory tests may prove useful requires further study.

The dark current characterization of In x Ga 1-x As with x =0.78 have been investigated. Meanwhile, the dark current related deep level trap with E t = 0.26 eV is detected by using Deep-Level Transient Spectroscopy (DLTS). 2D simulation of dark current shows that SRH recombination, trap-assisted tunneling and band-to-band tunneling currents are the main contributors to the dark current of In x Ga 1-x As( x=0.78) detector. To further improve the dark current characteristic, we need to improve the material growth.

The dynamic characteristics of an accelerometer’s shell is analyzed. To avoid resonance and subsequent failure, the shell’s natural frequencies and harmonic response are important considerations in structure optimization, for they significantly influence the performance of the sensors. The finite element analysis software ANSYS was applied to get the vibration characteristics of the shell based on the theory of dynamic analysis. The natural frequencies and mode shapes of the shell’s first six modes were calculated by modal analysis. Also, harmonic response analysis of the shell was carried out by the simulation. Thus, the interaction between the shell’s behavior and outside excitation can be predicted, and various design options of the shell can be evaluated in the design period.

Low surface leakage current is one of the prerequistites to reach the low leakage and high efficiencies of mesa type photodiodes. In this paper, we have studied the surface leakage of 2.6 µm mesa InGaAs p–i–n photodetectors by using two different passivation technologies: inductive coupled plasma chemical vapor deposition (ICPCVD) and plasma enhanced chemical vapor deposition (PECVD). It is found that the total leakage current of the detector with ICPCVD technology is significantly reduced compared to that with PECVD technology due to the decrease of the device's surface leakage current. A TCAD-based dark current model further reveals that the reduction of the surface leakage current at the low reverse voltage is about two orders of magnitude. As a result, ICPCVD is the promising deposition technology for SiNx passivation layer on mesa InGaAs photodetectors.

We fabricate 2.6 μm InGaAs photodetectors by MBE technology and study its dark current mechanisms. Deep-level transient spectroscopy (DLTS) demonstrates a deep-level trap located at Ec - 0.25 eV in the absorption layer. Using the trap parameters, a dark current model is constructed and the device simulation generates the dark current characteristic which agrees well with the experimental data. The model suggests that the dark current at low reverse voltage is dominated by the Shockley-Read-Hall (SRH) and trap-assisted tunneling (TAT). Furthermore, it predicts some basic rules for suppressing the dark current in 2.6 μm InGaAs detectors.

The dark current mechanism of extended wavelength InxGa1−xAs photo-detectors is still a debated issue. In this paper, the deep-level transient spectroscopy (DLTS) and dark current characteristics of InxGa1−xAs/InP detectors are investigated. Using trap parameters obtained from DLTS measurement, the device simulations of current-voltage characteristics are carried out by Silvaco Altas. The results reveal that the dark current at the low reverse bias voltage is associated with deep level trap induced trap assisted tunneling and Shockley-Read-Hall generation mechanism. The reduction of the deep level trap concentration in InxGa1−xAs absorption layer could dramatically suppress the dark current near zero bias in extended wavelength InxGa1−xAs/InP detectors.