Search

In this paper, a deep learning based time-domain inversion method is proposed to reconstruct high-contrast scatterers from the measured electromagnetic fields. The scatterers investigated in this study include four kinds of geometry shapes, which cover the arbitrary geometrical shapes, handwritings and lossy medium. After being well trained, the performance of the proposed method is evaluated from the perspective of accuracy, noise interference, and computational acceleration. It can be proven that the proposed framework can realize high-precision inversion in several milliseconds. Compared with typical reconstruction methods, it avoids the iterative calculation by utilizing the parallel computing ability of GPU and thus significantly reduce the computing time. Besides, the proposed method has shown the potential to be applied in practical scenarios with experimental results. Herein, it is confident that the proposed method has the potential to serve as a new path for real-time quantitative microwave imaging for various practical scenarios. In the end, the limitation of the method is also discussed. [ABSTRACT FROM AUTHOR]

The borehole induced polarization method has been widely used in deep mineral exploration, oil and gas resource exploration, and water resource exploration because of its high efficiency and good exploration effect. At present, the related research on the cross-well induced polarization method assumes that the underground medium is isotropic, but the electrical characteristics of the actual earth medium are anisotropic. To analyze the influence of the anisotropic characteristics on the cross-well induced polarization method, in this paper, the anisotropic forward algorithm of conductivity and polarizability in different principal axis directions based on the finite element method is studied. A three-dimensional forward simulation of the cross-well induced polarization method in anisotropic media is realized. The effectiveness and correctness of the algorithm are verified by testing and comparing complex 3-D isotropic and anisotropic models. Anisotropic geological models of the horizontal plate and inclined plate are constructed to analyze the anisotropic influences of conductivity and polarizability in different principal axis directions on the cross-well induced polarization response. The results show that the emitter sources with different depths in the well have different influences on the electrical response of the plates. Anisotropic conductivity and polarizability in horizontal plates exhibit most pronounced characteristics in the x-direction, significantly influencing the apparent polarizability curves. However, when the resistivity and polarizability are both anisotropic, the change in the z-direction is the most complicated. When the plate is inclined, the amplitude of the electrical response curve decreases to a certain extent, and the position where the amplitude appears shifts to different degrees. Notably, the response curves of the y-direction anisotropy are basically consistent with the response curves of the isotropy, regardless of the anisotropy of the conductivity and polarizability or anomalous body tilts. The results of this study improve our understanding of the influence of anisotropy on cross-well induced polarization and provide theoretical support for the interpretation of cross-well induced polarization data considering anisotropy. [ABSTRACT FROM AUTHOR]

The sonodynamic activities of gold nanoparticles (GNPs) with different morphologies, gold nanospheres (GNSs), gold nanoflowers (GNFs) and gold nanorods (GNRs), were explored by multi‐spectroscopic methods, in which the lesion degree of human serum albumin (HSA) was used as assessment index. The results revealed that three GNPs all had certain sonosensitivity but varying from different morphologies. It was also found that GNPs concentration and ultrasonic parameters were all critical influencing factors of sonodynamic injury HSA. Investigating the physical damage mechanism, the results indicated that the secondary and tertiary structure of HSA were compromised by ultrasound (US) combined with GNPs, so that the conformation of HSA was altered and the function was variously disturbed due to GNPs different morphologies. Studying the chemical damage mechanism, the results discovered that the yield of singlet oxygen (1O2) produced by GNPs with various morphologies combined with US was significant difference. Therefore, comprehensively analyzing the research results under different factors, the order of sonodynamic activities of GNPs was GNSs≈GNFs>GNRs. These findings may provide reference for the application of GNPs as sonosensitizers in sonodynamic therapy. [ABSTRACT FROM AUTHOR]

Background: The optimal occlusion and reperfusion time to balance blood loss and ischemia–reperfusion injury to the remnant liver remains unclear. The aim was to explore the clinical impact of prolonging the hepatic hilum occlusion time from 15 to 20 min using the intermittent Pringle maneuver (IPM) combined with controlled low central venous pressure (CLCVP). Methods: A total of 151 patients were included and divided into an experimental group (Group 20,75 cases) and a control group (Group 15,76 cases). In both groups, the hepatic hilum was blocked by the IPM combined with CLCVP to control intraoperative hepatic cross-sectional bleeding. The preoperative, intraoperative and postoperative parameters and safety were compared between the two groups. Results: There were no significant differences between the two groups in the postoperative aminotransferase serum levels (p > 0.05). However, the operation time in Group 20 was significantly lower than that in Group 15 (222.4 ± 87.8 vs. 250.7 ± 94.5 min, p < 0.05). The procalcitonin at 1 day after operation in Group 20 was lower than that at 1 day after operation in Group 15 (0.78 ± 0.66 vs. 1.45 ± 1.33 ng/mL, p < 0.05). There was no significant difference in the incidence of postoperative bleeding, postoperative bile leakage and postoperative infection between the two groups (p > 0.05). Conclusions: For patients with hepatocellular carcinoma after hepatitis B cirrhosis, it is feasible and safe to prolong the hepatic hilum occlusion time from 15 to 20 min using the IPM combined with CLCVP. [ABSTRACT FROM AUTHOR]

FADD is a common adaptor shared by several death receptors for signalling apoptosis through recruitment and activation of caspase 8 (refs 1-3). Death receptors are essential for immune homeostasis, but [...]

The effects of imeglimin, a novel antidiabetes agent, on β-cell function remain unclear. Here, we unveiled the impact of imeglimin on β-cell survival. Treatment with imeglimin augmented mitochondrial function, enhanced insulin secretion, promoted β-cell proliferation, and improved β-cell survival in mouse islets. Imeglimin upregulated the expression of endoplasmic reticulum (ER)-related molecules, including Chop (Ddit3), Gadd34 (Ppp1r15a), Atf3, and Sdf2l1, and decreased eIF2α phosphorylation after treatment with thapsigargin and restored global protein synthesis in β-cells under ER stress. Imeglimin failed to protect against ER stress-induced β-cell apoptosis in CHOP-deficient islets or in the presence of GADD34 inhibitor. Treatment with imeglimin showed a significant decrease in the number of apoptotic β-cells and increased β-cell mass in Akita mice. Imeglimin also protected against β-cell apoptosis in both human islets and human pluripotent stem cell-derived β-like cells. Taken together, imeglimin modulates the ER homeostasis pathway, which results in the prevention of β-cell apoptosis both in vitro and in vivo. [ABSTRACT FROM AUTHOR]