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This study aimed to understand the dynamic changes in fibrosis and its relationship with the evaluation of post-treatment viral hepatitis using qFibrosis. A total of 158 paired pre- and post-treatment liver samples from patients with chronic hepatitis B (CHB; n = 100) and C (CHC; n = 58) were examined. qFibrosis was employed with artificial intelligence (AI) to analyze the fibrosis dynamics in the portal tract (PT), periportal (PP), midzonal, pericentral, and central vein (CV) regions. All patients with CHB achieved a virological response after 78 weeks of treatment, whereas patients with CHC achieved a sustained viral response after 24 weeks. For patients initially staged as F5/6 (Ishak system) at baseline, the post-treatment cases exhibited a significant reduction in the collagen proportionate area (CPA) (25–69%) and number of collagen strings (#string) (9–72%) across all regions. In contrast, those initially staged as F3/4 at baseline showed a similar CPA and #string trend at 24 weeks. For regression patients, 27 parameters (25 in the CV region) in patients staged as F3/4 and 15 parameters (three in the PT and 12 in the PP regions) in those staged as F5/6 showed significant differences between the CHB and CHC groups at baseline. Following successful antiviral treatment, the pre- and post-treatment liver samples provided quantitative evidence of the heterogeneity of fibrotic features. qFibrosis has the potential to provide new insights into the characteristics of fibrosis regression in both patients with CHB and CHC as early as 24 weeks after antiviral therapy. [ABSTRACT FROM AUTHOR]

This paper presents an in-depth analysis of the oscillation phenomenon occurring in multi-chip parallel automotive-grade power modules under short-circuit conditions and investigates three suppression methods. We tested and analyzed two commercial automotive-grade power modules, one containing two chips and the other containing a single chip, and found that short-circuit gate oscillations were more likely to occur in multi-chip parallel packaged modules than in single-chip packaged modules. Through experimental and simulation analyses, we observed that gate oscillations were mainly caused by the interaction between internal parasitic parameters of the module and the external drive circuit, and we found that high drive resistance and low common emitter inductance between parallel chips could effectively suppress gate voltage oscillations. We also analyzed the two mainstream suppression schemes, increasing the drive gate resistance and placing the drive capacitors in parallel. Unfortunately, we found that these suppression schemes were not ideal solutions because both schemes changed the switching characteristics of the power module. As an alternative, we propose a simple and effective solution that involves adding parallel connections between the parallel chips. Simulation calculations showed that this optimized method reduced the emitter inductance between parallel chips in the upper bridge arm by about 30% and in the lower bridge arm by 35%. Through short-circuit experiments conducted at different DC bus voltages, it has been verified that the new optimized solution effectively resolves gate oscillation issues without affecting the switching characteristics of the power module. [ABSTRACT FROM AUTHOR]

There is an increasing demand for the use of automotive sensors where complex working environments may easily lead to failure. Wire pull and shear test models based on finite-element analysis are established to evaluate their reliability by investigating the failure mode and mechanism of gold wire bonding. The effect of shear force position and pull force position on failure is also analyzed. The bonding failure was verified by experiments, which is consistent with the simulation result. The results show that: (1) The three-dimensional quantitative modeling reveals the process of bonding delamination and stress concentration. (2) The bonding–slip method (BSM) is adopted in the gold ball detaching process. The concept of three states, including deformation accumulation, cracking, and disengagement, was put forward to reveal the interface stress evolution trend according to the shear testing results. The results indicate that in the interface, the stress in the deformation accumulation state decreases from the tensile side (or compression side) to the center, and the stress in the cracking and disengagement states reduces gradually from the tensile side to the edge. When the interface is completely separated, the failed shear force concentrates on 42 g. The concept and theory proposed in this work can effectively reveal the failure mechanism of bonding interface and help to establish a new failure criterion. [ABSTRACT FROM AUTHOR]

Ag paste has been recognized as a promising substitute for Sn/Pb solder in SiC or GaN power electronic devices, owing to its ability to withstand high temperatures and facilitate low-temperature packing. The reliability of these high-power circuits is greatly influenced by the mechanical properties of sintered Ag paste. However, there exist substantial voids inside the sintered silver layer after sintering, and the conventional macroscopic constitutive models have certain limitation to describe the shear stress–strain relationship of sintered silver materials. To analyze the void evolution and microstructure of sintered silver, Ag composite pastes composed of micron flake silver and nano-silver particles were prepared. The mechanical behaviors were studied at different temperatures (0–125 °C) and strain rates (1 × 10−4–1 × 10−2) for Ag composite pastes. The crystal plastic finite element method (CPFEM) was developed to describe the microstructure evolution and shear behaviors of sintered silver at varied strain rates and ambient temperatures. The model parameters were obtained by fitting experimental shear test data to a representative volume element (RVE) model built on representative volume elements, also known as Voronoi tessellations. The numerical predictions were compared with the experimental data, which showed that the introduced crystal plasticity constitutive model can describe the shear constitutive behavior of a sintered silver specimen with reasonable accuracy. [ABSTRACT FROM AUTHOR]

We aim to investigate the impact of different clinical phases' definitions of chronic hepatitis B (CHB) infection on the profiles of grey zone, based on HBV guidelines set by the Chinese Society of Hepatology and Chinese Society of Infectious Diseases (CSH/CSID, 2022 version) and guidelines set by the American Association for the Study of Liver Diseases (AASLD, 2018 version). We retrospectively examined untreated CHB patients enrolled in the China Registry of Hepatitis B database. Patients' clinical phases were determined as per CSH/CSID and AASLD. Liver fibrosis was estimated by FIB-4 and/or APRI. Among 3462 CHB patients, 56.9% and 41.7% fell into the grey zone based on AASLD and CSH/CSID. Compared with grey zone patients as per AASLD, those under CSH/CSID guidelines showed lower levels of median ALT (26.0 vs. 37.0 U/L, p < 0.001), AST (25.0 vs. 29.4 U/L, p < 0.001) and APRI (0.3 vs. 0.4, p < 0.001), and lower rates of advanced fibrosis estimated by APRI (7.9% vs. 11.4% p = 0.001), but comparable rates by FIB-4 (13.0% vs. 14.1%, p = 0.389). With the stepwise lowering of ALT upper limits of normal (ULN) values from 50/40 U/L for males/females to 40/40 U/L, 35/25 U/L and 30/19 U/L, the proportions of grey zone patients as per CSH/CSID declined from 46.7% to 41.7%, 34.3% and 28.8%, respectively, whereas they remained stable (55.7%, 56.2%, 56.9% and 57.0%) as per AASLD. Compared with the AASLD guidelines, CSH/CSID guidelines leave fewer and less severe patients in the grey zone. Lowering ALT ULN values reduces the number of grey zone patients as per CSH/CSID, but not under AASLD guidelines. [ABSTRACT FROM AUTHOR]

The efficient separation of ilmenite is a difficult problem in minerals flotation. For this issue, α-aminooctyl phosphinic acid (APA) was developed as a selective collector to separate ilmenite. The flotation test result showed that APA was more efficient for improving ilmenite recovery compared with octylphosphonic acid (OPA). Adsorption, ZETA and FTIR measurements proved that the chemical interaction between collector APA and the surface of ilmenite was stronger than OPA, while the result is completely opposite in the case of titanaugite. Moreover, XPS test and DFT calculations indicated that the collector APA was coordinated with the surface of ilmenite through P-O-Fe and P-O-Ti bonding. The amine group in the α-site of the phosphonyl group facilitated APA to be a stable zwitterion in the solution, which greatly enhanced the nucleophilicity of the phosphonic acid group. On the other hand, more appropriate coordination energy was another reason for the superior collecting selectivity of APA than OPA. [ABSTRACT FROM AUTHOR]

Optically clear adhesive (OCA) has been widely used in flexible devices, where wavy stripes that cause troublesome long-term reliability problems often occur. The complex mechanical behavior of OCA should be studied, as it is related to the aforementioned problems. Therefore, it is necessary to establish reasonable mechanical constitutive models for deformation and stress control. In this work, hyperelastic and viscoelastic mechanical tests were carried out systematically and relative constitutive models of OCA material were established. We found that temperature has a great influence on OCA's mechanical properties. The stress and modulus both decreased rapidly as the temperature increased. In the static viscoelasticity test, the initial stress at 85 °C was only 12.6 kPa, 57.4% lower than the initial stress at 30 °C. However, in the dynamic test, the storage modulus monotonically decreased from 1666.3 MPa to 0.6628 MPa as the temperature rose, and the decline rate reached the maximum near the glass transition temperature (Tg = 0 °C). The test data and constitutive models can be used as design references in the manufacturing process, as well as for product reliability evaluation. [ABSTRACT FROM AUTHOR]

Excessive TiO2 in titanomagnetite concentrates (TC) causes unavoidable problems in subsequent smelting. At present, this issue cannot be addressed using traditional mineral processing technology. Herein, a strategy of metallurgy-beneficiation combination to decrease the TiO2 grade in TC before smelting was proposed. Roasting TC with calcium carbonate (CaCO3) together with magnetic separation proved to be a viable strategy. Under optimal conditions (roasting temperature = 1400 °C, CaCO3 ratio = 20%, and magnetic intensity = 0.18 T), iron and titanium was separated efficiently (Fe grade: 56.6 wt.%; Fe recovery: 70 wt.%; TiO2 grade 3 wt.%; TiO2 removal: 84.1 wt.%). X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy analysis were used to study the mechanisms. The results showed that Ti in TC could react with CaO to form CaTiO3, and thermodynamic calculations provided a relevant theoretical basis. In sum, the metallurgy-beneficiation combination strategy was proven as an effective method to decrease unwanted TiO2 in TC. [ABSTRACT FROM AUTHOR]