AST to ALT ratio as a prospective risk predictor for liver cirrhosis in patients with chronic HBV infection.

BACKGROUND: Serum aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio (AAR) is one of the most frequent indicators to discriminate fibrosis and cirrhosis. However, the results remained controversial. The aim of this study was to evaluate the predictive effect of AAR on hepatitis B virus (HBV)-related cirrhosis development. METHOD: A retrospective cohort study was conducted based on 1754 chronic HBV-infected patients. Clinical variables at their initial visit and follow-up data were collected. Cox proportional hazards model was constructed to evaluate the predictive value of AAR on cirrhosis risk, and its discrimination accuracy was determined by receiver operating characteristic (ROC). The time-dependent effect was assessed by a Fine and Gray competing risk model. RESULTS: Compared to patients with lower AAR, those with elevated AAR level had higher risk of cirrhosis development by adjusting for host characteristics (dichotomized analyses: hazard ratio = 2.77, P = 8.25 × 10 -4 ; tertile analyses: hazard ratio = 2.95, P = 1.61 × 10 -3 ), with an increasing risk trend ( Ptrend = 4.56 × 10 -4 ). The effect remained prominent when ALT or AST was abnormal, while no significant risk was observed when AST and ALT were simultaneously normal. Time-dependent effect analysis demonstrated a persistently higher risk, with the average hazard ratio equivalent to 1.92. AAR level could improve the discrimination efficacy of host variables with area under the curve increased from 0.684 to 0.711 ( P  =  0.039 ). CONCLUSION: Higher AAR was significantly associated with increased risk of HBV-related cirrhosis, and might be a potential predictor of cirrhosis development.

Lead Selenide Thin Films and Uncooled Midinfrared Detectors by Vapor Phase Deposition.

The broad application of lead selenide (PbSe)-based uncooled midinfrared (MIR) detectors has been hindered by the nonuniformity of wafer-level films prepared by the conventional chemical bath deposition (CBD) method. Herein, using a vapor phase deposition (VPD) approach, we demonstrate the deposition of 3 in. wafer-scale uniform PbSe thin films with thicknesses of up to 1.5 µm. To trigger the MIR response, the as-grown films were sensitized at an elevated temperature in an oxygen-iodine atmosphere. We discovered that the key to spark off the MIR response of the PbSe detector originated from the self-assembled rodlike microstructures in the thin films, which can be controlled by the I2/PbSe flux ratio in the VPD process. At room temperature, the thin film detector exhibits an excellent optoelectronic performance, with detectivity up to 2.4 × 109 cm Hz1/2 W-1 achieved under optimized conditions. Our results show that the VPD method opens up a new avenue to the industrialization of uncooled lead-salt MIR detectors.

Enhanced performance in uncooled n-CdSe/p-PbSe photovoltaic detectors by high-temperature chloride passivation.

High-temperature chloride passivation (HTCP) was proposed to improve the crystalline quality and electrical properties of PbSe epitaxial films. The PL intensity of HTCP (111) PbSe epitaxial films exhibits a 14 times higher intensity than that of as-grown films, and a threefold increase in Hall mobility has been obtained after HTCP at 300 °C for 2 h. The improvement of optical and electrical properties is attributed to the high-temperature defect passivation induced by the HTCP process. The HTCP process of PbSe films was implemented in a CdSe/PbSe heterojunction PV detector, which exhibits a room temperature peak detectivity D* of 8.5 × 108 cm Hz1/2 W-1 in the mid-wavelength infrared region under blackbody radiation (227 °C), demonstrating potential applications in the fabrication of mid-infrared detectors and emitters.

Urine miR-93-5p is a promising biomarker for early detection of HBV-related hepatocellular carcinoma.

INTRODUCTION: The mortality rate of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC)continues to increase because sensitive, early and readily available diagnostic tools are lacking. To address this problem, we aimed to identify diagnosticbio markers to be used for early detection of HCC. MATERIALS AND METHODS: miR-93-5p was selected as a candidate biomarker based on the analyses of relevant Gene Expression Omnibus (GEO) datasets; it was validated using qPCR to quantify its expression levels in tissue, plasma and saliva sample sets. RESULTS: miR-93-5p was significantly upregulated in HBV-related HCC tissue. Notably, miR-93-5p in plasma and urine was also significantly increased in patients with early HBV-related HCC. The expression of miR-93-5p was significantly and positively correlated in pairwise comparisons of samples (tissue vs. plasma, tissue vs. urine, plasma vs. urine). Moreover, after curative hepatectomy,miR-93-5p in plasma and urine decreased significantly over one month after the curative hepatectomy and returned to normal levels. Furthermore, receiver operating characteristic (ROC) analysis indicated that both plasma and urine miR-39-5p could detect be used to early, advanced and overall HBV-related HCC cases with more than 85% sensitivities and 93% of specificities. Finally, urine miR-93-5p could be used to predict progress-free survival for early HCC patients who received curative hepatectomy and overall survival for advanced HCC patients without curative treatments. CONCLUSIONS: Plasma and urine miR-93-5p show great promise as potential novel biomarkers for early detection of HBV-related HCC. Moreover, urine miR-93-5p could be used to predict the prognosis of patients with HBV-related HCC.

PbI2 3D network transporting model for the charge separation mechanism of PbSe detectors.

PbSe films deposited by chemical bath deposition (CBD) technology were sensitized in various atmospheres to distinguish the role of iodine and oxygen in the sensitization process. No infrared (IR) photo response was observed in samples sensitized in pure oxygen, showing the O element cannot trigger the infrared response of PbSe. However, a high detectivity of 1 × 1010 was achieved in the sample sensitized in a N2/I2 atmosphere, which demonstrates iodine is a key element for inducing an IR response. The role of iodine was analyzed from the morphological evolution, phase composition transformation and resistance change during the sensitization process. The XRD and FESEM results show a PbI2 3D network forming around the PbSe grains in the sensitization process, playing the role of photo-generated electron transporting channels, which is key to inducing the IR response of PbSe detectors. The 3D network conducting model can explain well the charge separation mechanism of PbSe IR photoconductive detection.

Modified vapor phase deposition technology for high-performance uncooled MIR PbSe detectors.

The low performance of middle infrared (MIR) PbSe detectors fabricated from vapor phase deposition (VPD) technology restricts the rapid development of VPD technology and detector commercialization. A modified VPD process was proposed to duplicate the microstructural features of high-performance CBD-PbSe detectors for a breakthrough in the VPD technology. A peak detectivity D* of 1.6 × 1010 cm Hz1/2 W-1 at 298 K was achieved under the optimized sensitization, approaching the best performance of CBD-PbSe detectors. Through the contrasting various microstructures obtained from diverse methods, the nanoparticle self-assembly structure in VPD-PbSe oriented rod-like crystals is an important factor for the IR sensitivity. The microstructural evolution demonstrated that there is a large space to grow for VPD-PbSe detectivity D* via eliminating the voids formed in the iodine-sensitization process. The increased performance indicates that the modified VPD technology can provide technical support for the manufacturing of the megapixel uncooled lead-salt FPA imager and accelerate its industrialization.

Self-powered SBD solar-blind photodetector fabricated on the single crystal of ß-Ga2O3.

A Schottky barrier diode (SBD) solar-blind photodetector was fabricated based on the single crystal ß-Ga2O3. Cu and Ti/Au were deposited on the top and bottom surface of Ga2O3 as Schottky and ohmic contacts, respectively. The SBD exhibits a higher rectification ratio of up to 5 × 107 at ±2 V. The photoresponse spectra show a maximum responsivity at 241 nm and a cutoff wavelength of 256 nm. The solar-blind/ultraviolet and solar-blind/visible rejection ratio can reach a high level of up to 200 and 1000, respectively. It is interesting that the device has a clear response to the solar-blind wavelength at zero bias, which confirms it can be used as a self-powered solar-blind photodetector.

The light-induced pyro-phototronic effect improving a ZnO/NiO/Si heterojunction photodetector for selectively detecting ultraviolet or visible illumination.

In this work, we fabricate a ZnO/NiO/Si heterojunction photodetector, which successfully realizes selective detection of UV or visible light in a single photodetector. In addition, the pyro-phototronic effect has been confirmed as an effective approach for enhancing the performance of photodetectors based on ZnO. The pyro-phototronic effect is carefully studied by comparing with a ZnO/Si heterojunction photodetector under UV and visible illumination at different bias voltages. To enhance the photodetector's wavelength selectivity, the parameters and structure are further optimized for the ZnO/NiO/SiO2/Si heterojunction photodetector. The newly designed photodetector may be used to selectively detect and distinguish UV and visible illumination in a single photodetector.

Low Al-composition p-GaN/Mg-doped Al0.25Ga0.75N/n+-GaN polarization-induced backward tunneling junction grown by metal-organic chemical vapor deposition on sapphire substrate.

Low Al-composition p-GaN/Mg-doped Al0.25Ga0.75N/n(+)-GaN polarization-induced backward tunneling junction (PIBTJ) was grown by metal-organic chemical vapor deposition on sapphire substrate. A self-consistent solution of Poisson-Schrödinger equations combined with polarization-induced theory was used to model PIBTJ structure, energy band diagrams and free carrier concentrations distribution. The PIBTJ displays reliable and reproducible backward tunneling with a current density of 3 A/cm(2) at the reverse bias of -1 V. The absence of negative differential resistance behavior of PIBTJ at forward bias can mainly be attributed to the hole compensation centers, including C, H and O impurities, accumulated at the p-GaN/Mg-doped AlGaN heterointerface.