23 research outputs found

    Improved Ferroelectric and Leakage Properties of Ce Doped in BiFeO 3

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    Ce doped BiFeO3 thin films with a perovskite structure were prepared using solution-gelation method. It shows that the ferroelectric properties have been enhanced after doping Ce. The enhanced ferroelectric properties are attributed to the structural transformation and the reduced leakage current after doping rare metal of Ce. It has been found that the phase structures of the films transfer from rhombohedral symmetry structure to the coexistence of the tetragonal and orthorhombic symmetry structure. And Fe2+ ions have been reduced, which leads to the decreased leakage for Ce doped BiFeO3 thin films. The present work can provide an available way to improve the ferroelectric and leakage properties for multiferroic BiFeO3 based thin films

    Accurate segmentation algorithm of acoustic neuroma in the cerebellopontine angle based on ACP-TransUNet

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    Acoustic neuroma is one of the most common tumors in the cerebellopontine angle area. Patients with acoustic neuroma have clinical manifestations of the cerebellopontine angle occupying syndrome, such as tinnitus, hearing impairment and even hearing loss. Acoustic neuromas often grow in the internal auditory canal. Neurosurgeons need to observe the lesion contour with the help of MRI images, which not only takes a lot of time, but also is easily affected by subjective factors. Therefore, the automatic and accurate segmentation of acoustic neuroma in cerebellopontine angle on MRI is of great significance for surgical treatment and expected rehabilitation. In this paper, an automatic segmentation method based on Transformer is proposed, using TransUNet as the core model. As some acoustic neuromas are irregular in shape and grow into the internal auditory canal, larger receptive fields are thus needed to synthesize the features. Therefore, we added Atrous Spatial Pyramid Pooling to CNN, which can obtain a larger receptive field without losing too much resolution. Since acoustic neuromas often occur in the cerebellopontine angle area with relatively fixed position, we combined channel attention with pixel attention in the up-sampling stage so as to make our model automatically learn different weights by adding the attention mechanism. In addition, we collected 300 MRI sequence nuclear resonance images of patients with acoustic neuromas in Tianjin Huanhu hospital for training and verification. The ablation experimental results show that the proposed method is reasonable and effective. The comparative experimental results show that the Dice and Hausdorff 95 metrics of the proposed method reach 95.74% and 1.9476 mm respectively, indicating that it is not only superior to the classical models such as UNet, PANet, PSPNet, UNet++, and DeepLabv3, but also show better performance than the newly-proposed SOTA (state-of-the-art) models such as CCNet, MANet, BiseNetv2, Swin-Unet, MedT, TransUNet, and UCTransNet

    Single-loop foldable 8R mechanisms with multiple modes

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    Maresin-1 inhibits high glucose induced ferroptosis in ARPE-19 cells by activating the Nrf2/HO-1/GPX4 pathway

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    Abstract Background Maresin-1 plays an important role in diabetic illnesses and ferroptosis is associated with pathogenic processes of diabetic retinopathy (DR). The goal of this study is to explore the influence of maresin-1 on ferroptosis and its molecular mechanism in DR. Methods ARPE-19 cells were exposed to high glucose (HG) condition for developing a cellular model of DR. The CCK-8 assay and flow cytometry were used to assess ARPE-19 cell proliferation and apoptosis, respectively. Furthermore, the GSH content, MDA content, ROS level, and Fe2+ level were measured by using a colorimetric GSH test kit, a Lipid Peroxidation MDA Assay Kit, a DCFH-DA assay and the phirozine technique, respectively. Immunofluorescence labelling was used to detect protein levels of ACSL4 and PTGS2. Messenger RNA and protein expression of HO-1, GPX4 and Nrf2 was evaluated through western blotting and quantitative real time-polymerase chain reaction (qRT-PCR). To establish a diabetic mouse model, mice were intraperitoneally injected 150 mg/kg streptozotocin. The MDA content, ROS level and the iron level were detected by using corresponding commercial kits. Results Maresin-1 promoted cell proliferation while reducing the apoptotic process in HG-induced ARPE-19 cells. Maresin-1 significantly reduced ferroptosis induced by HG in ARPE-19 cells, as demonstrated as a result of decreased MDA content, ROS level, Fe2+ level, PTGS2 expression, ACSL4 expression and increased GSH content. With respect to mechanisms, maresin-1 treatment up-regulated the mRNA expression and protein expression of HO-1, GPX4 and Nrf2 in HG-induced ARPE-19 cells. Nrf2 inhibitor reversed the inhibitory effects of maresin-1 on ferroptosis in HG-induced ARPE-19 cells. In vivo experiments, we found that Maresin-1 evidently repressed ferroptosis a mouse model of DR, as evidenced by the decreased MDA content, ROS level and iron level in retinal tissues of mice. Conclusion Maresin-1 protects ARPE cells from HG-induced ferroptosis via activating the Nrf2/HO-1/GPX4 pathway, suggesting that maresin-1 prevents DR development

    Mechanism for generating and promoting manufacturing project portfolio synergy

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    To explore the mechanism for generating and promoting project portfolio (PP) synergy, a model applying the causal loop diagram (CLD) is established. The efforts have been done include four parts. First, a sustainable objective system is determined through the improved balanced scorecard. Second, three categories of manufacturing projects are identified to illustrate the characteristics and objectives. Third, a CLD model is constructed based on the objective achievement process of PPs. Fourth, suggestions are made to promote the objective realization by synergy. The major result is that the generation and promotion mechanism are portrayed through the causal loops and feedbacks of CLD. CLD is adopted as the analytical approach for superiority in visualizing complex relationships. The main findings are: (1) The synergy generation mechanism is specified that PP synergy generates from the collaborative behaviors among PPs. (2) PP synergy promotes objective realization through additional effects arise from complex feedbacks among behaviors

    The Variation Analysis of DNA Methylation in Wheat Carrying Gametocidal Chromosome 3C from Aegilops triuncialis

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    Gametocidal (Gc) chromosomes can ensure their preferential transmission by killing the gametes without themselves through causing chromosome breakage and therefore have been exploited as an effective tool for genetic breeding. However, to date very little is known about the molecular mechanism of Gc action. In this study, we used methylation-sensitive amplified polymorphism (MSAP) technique to assess the extent and pattern of cytosine methylation alterations at the whole genome level between two lines of wheat Gc addition line and their common wheat parent. The results indicated that the overall levels of cytosine methylation of two studied Gc addition lines (CS–3C and CS–3C3C, 48.68% and 48.65%, respectively) were significantly increased when compared to common wheat CS (41.31%) and no matter fully methylated or hemimethylated rates enhanced in Gc addition lines. A set of 30 isolated fragments that showed different DNA methylation or demethylation patterns between the three lines were sequenced and the results indicated that 8 fragments showed significant homology to known sequences, of which three were homologous to MITE transposon (Miniature inverted–repeat transposable elements), LTR-retrotransposon WIS-1p and retrotransposon Gypsy, respectively. Overall, our results showed that DNA methylation could play a role in the Gc action

    Experimental and Numerical Simulations of the Solidification Process in Continuous Casting of Slab

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    Thermal simulation equipment (TSE) was recently developed to simulate the solidification process in the industrial continuous casting of slab. The grain growth, solid-liquid interface movement, and columnar-to-equiaxed transition (CET) in the continuous casting process can be reproduced using this equipment. The current study is focused on the effects of different cooling rates and superheat conditions on the grain growth in the solidification process of chromium-saving ferritic stainless steel (B425). The temperature distribution and microstructure evolution are simulated by a Cellular Automaton-Finite Element (CAFE) model. The experimental results demonstrate that the temperature gradient and the grain growth rate of the sample can be effectively controlled by the equipment. It is observed from optical micrographs of the microstructure that the average equiaxed grain ratio increases when the superheat temperature decreases. The average equiaxed grain ratio is approximately 26% and 42% under superheat conditions of 40 °C and 30 °C, respectively, and no apparent columnar grain generation in the samples occurs under superheat conditions of 10 °C and 20 °C, as the result of a large thermal resistance at the copper-sample interface and low superheat inside the sample. A lower cooling rate results in a higher equiaxed crystal ratio in the sample. As the cooling rate decreases, the equiaxed crystal ratio becomes 14%, 23%, and 42%. Comparing the simulation results with the experimental observations, a reasonable qualitative agreement is achieved for the chilled layer thickness, grain morphology, and CET in the sample. Thus, the CAFE model in the current study can accurately predict the grain growth under different superheating and cooling rate conditions

    Comparison of efficacy and complications of endoscopic and percutaneous biliary drainage in malignant obstructive jaundice: a systematic review and meta-analysis

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    Abstract Background Malignant obstructive jaundice is a common problem in the clinic. Currently, the generally applied treatment methods are percutaneous transhepatic biliary drainage (PTBD) and endoscopic biliary drainage (EBD). Nevertheless, there has not been a uniform conclusion published on either efficacy of the two types of drainage or the incidence rate of complications. Therefore, we conducted a systematic review and meta-analysis of studies comparing endoscopic versus percutaneous biliary drainage in malignant obstructive jaundice, to determine whether there is any difference between percutaneous and endoscopic biliary drainage, with respect to efficacy and incidence rate of overall complications. Methods The enrolled studies contain a total of three randomized controlled trials and eleven retrospective studies, which together encompass 2246 patients with PTBD and 8100 patients with EBD. Results Our analysis indicates that there is no difference between PTBD and EBD with regard to therapeutic success rate (%), overall complication (%), intraperitoneal bile leak, 30-day mortality, sepsis, or duodenal perforation (%). Cholangitis and pancreatitis after PTBD were lower than after EBD, with odds ratios (OR) of 0.48 (95% confidence interval (CI), 0.31 to 0.74) and 0.16 (95% CI, 0.05 to 0.52), respectively. Incidences of bleeding and tube dislocation for PTBD were higher than EBD, OR of 1.81 (95% CI, 1.35 to 2.44) and 3.41 (95% CI, 1.10 to 10.60). Conclusions This meta-analysis indicates certain advantages for both PTBD and EBD. In the clinical practice, it is advised to choose specifically either PTBD or EBD, based on location of obstruction, purpose of drainage (as a preoperative procedure or a palliative treatment) and level of experience in biliary drainage at individual treatment centers
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