Study on the Influence of Ultrasonic Vibration on the Specific Energy of Sawing Ceramic

AbstractThe hard as well as brittle constituents are typically difficult-to-machined materials, and this character upsurges the machining cost. Many non-traditional machining methods were developed to improve its cost-effectiveness. Ultrasonic vibration assisted grinding has been improved the processing performance of a variety of brittle materials, and achieved good results in processing application. In this study, engineering ceramic was precisely sawn using a thin diamond blade with or without ultrasonic vibration conditions. During the sawing process, the specific sawing energy was investigated with the measurement of sawing forces to explore the influence of ultrasonic vibration. The results showed that the ultrasonic vibration made a significant reduction in specific sawing energy. The specific sawing energy decreased with the increase of the maximum undeformed chip thickness in both the sawing conditions; however ultrasonic vibration changed the trend of specific sawing energy in normal cutting mode from exponentially decreasing to a good linear decreasing. Under the ultrasonic vibration assisted sawing condition, the impact of the diamond grain on the engineering ceramic caused to much more material removal in brittle fracture mode. The reducing of the plastic transformation also reduced the energy consumption during the engineering ceramic sawing process

Biocompatibility and safety evaluation of a silk fibroin-doped calcium polyphosphate scaffold copolymer in vitro and in vivo

For the reconstruction of cartilage and bone defects, bone repair scaffolds with porous network structures have been extensively studied. In our previous study, CPP-type bioceramics showed higher compressive strength and enhanced degradation after silk fibroin doping, and SF/CPP could be considered a suitable bioceramic for bone tissue-engineering. The aim of this study was to evaluate the biocompatibility and safety of SF/CPP in vitro and in vivo. The cell biocompatibility was evaluated with regard to the cytotoxicity of the scaffolds using co-culture and MTT tests in vitro. The in vivo biocompatibility of SF/CPP was evaluated by implanting the scaffolds in the subcutaneous and intramuscular regions of experimental animals. We established an experimental animal model to prepare critical-sized cranial defects and evaluated the biodegradability and osteoconductivity of the scaffolds in vivo. The results indicated that the SF/CPP scaffold yielded better biocompatibility and safety performance than the CPP scaffold in vitro and in vivo. Immunohistochemistry staining in vivo for OPN and OCN also indicated that SF/CPP has potential to promote the regeneration of critical-sized cranial defects. The SF/CPP scaffold has good biocompatibility and safety for experimental animals and could also serve as a potential effective bioceramic for a range of bone regeneration applications

INT: Towards Infinite-frames 3D Detection with An Efficient Framework

It is natural to construct a multi-frame instead of a single-frame 3D detector for a continuous-time stream. Although increasing the number of frames might improve performance, previous multi-frame studies only used very limited frames to build their systems due to the dramatically increased computational and memory cost. To address these issues, we propose a novel on-stream training and prediction framework that, in theory, can employ an infinite number of frames while keeping the same amount of computation as a single-frame detector. This infinite framework (INT), which can be used with most existing detectors, is utilized, for example, on the popular CenterPoint, with significant latency reductions and performance improvements. We've also conducted extensive experiments on two large-scale datasets, nuScenes and Waymo Open Dataset, to demonstrate the scheme's effectiveness and efficiency. By employing INT on CenterPoint, we can get around 7% (Waymo) and 15% (nuScenes) performance boost with only 2~4ms latency overhead, and currently SOTA on the Waymo 3D Detection leaderboard.Comment: accepted by ECCV202

Protective Effect of a Combined Glutamine and Curcumin Formulation on Alcoholic Gastric Mucosal Damage

Objective: This study aimed to investigate the protective effect and underlying mechanism of a combined glutamine and curcumin formulation on ethanol-induced gastric mucosal damage in rats. Method: A total of fifty SPF-grade healthy SD male rats were randomly partitioned into five groups: A normal group, a model control group, a cimetidine group, a high-dose treatment group, and a low-dose treatment group. After a period of 30 days marked by oral gavage administration, all groups, with the exception of the normal group, were euthanized post anhydrous ethanol-induced modeling. The histopathological alterations in the gastric mucosa were observed via hematoxylin & eosin (H&E) staining. Furthermore, serum levels of malondialdehyde (MDA), nitric oxide (NO), and glutathione peroxidase (GSH-PX) were ascertained using a specific reagent kit. Concurrently, the concentration of prostaglandin E2 (PGE2) within the tissue and the expression levels of heme oxygenase-1 (HO-1), NADPH quinone oxidoreductase (NQO1), the antioxidant-related nuclear factor-E2-related factor 2 (Nrf2) gene, and glycogen synthase kinase-3β (GSK-3β) were evaluated. Results: In the cimetidine and high-dose treatment groups, the incidence of gastric mucosal bleeding and other forms of injury were noticeably mitigated (P<0.05) compared to the model control group, with the high-dose treatment group demonstrating a more pronounced effect. Moreover, the model control group exhibited a significant elevation in MDA content and GSH-PX activity and a concurrent decline in NO and PGE2 levels (P<0.05). The expression of antioxidant-related genes, namely, HO-1, NQO1, and Nrf2, was significantly suppressed (P<0.05), whereas GSK-3β expression was markedly increased. In contrast, in comparison to the model control group, the cimetidine and high-dose treatment groups manifested a significant reduction in MDA content and GSH-PX activity, while NO and PGE2 levels notably increased (P<0.05). The expression of the antioxidant-related genes HO-1, NQO1, and Nrf2 was significantly returned to normal (P<0.05), and GSK-3β expression was suppressed (P<0.05). Conclusion: The combined formulation appears to exert an inhibitory effect on ethanol-induced acute gastric mucosal damage. This effect is hypothesized to be associated with the Keap1-Nrf2-ARE oxidative stress signaling pathway

Ankyrin Repeats of ANKRA2 Recognize a PxLPxL Motif on the 3M Syndrome Protein CCDC8

SummaryPeptide motifs are often used for protein-protein interactions. We have recently demonstrated that ankyrin repeats of ANKRA2 and the paralogous bare lymphocyte syndrome transcription factor RFXANK recognize PxLPxL/I motifs shared by megalin, three histone deacetylases, and RFX5. We show here that that CCDC8 is a major partner of ANKRA2 but not RFXANK in cells. The CCDC8 gene is mutated in 3M syndrome, a short-stature disorder with additional facial and skeletal abnormalities. Two other genes mutated in this syndrome encode CUL7 and OBSL1. While CUL7 is a ubiquitin ligase and OBSL1 associates with the cytoskeleton, little is known about CCDC8. Binding and structural analyses reveal that the ankyrin repeats of ANKRA2 recognize a PxLPxL motif at the C-terminal region of CCDC8. The N-terminal part interacts with OBSL1 to form a CUL7 ligase complex. These results link ANKRA2 unexpectedly to 3M syndrome and suggest novel regulatory mechanisms for histone deacetylases and RFX7

FusionFormer: A Multi-sensory Fusion in Bird's-Eye-View and Temporal Consistent Transformer for 3D Objection

Multi-sensor modal fusion has demonstrated strong advantages in 3D object detection tasks. However, existing methods that fuse multi-modal features through a simple channel concatenation require transformation features into bird's eye view space and may lose the information on Z-axis thus leads to inferior performance. To this end, we propose FusionFormer, an end-to-end multi-modal fusion framework that leverages transformers to fuse multi-modal features and obtain fused BEV features. And based on the flexible adaptability of FusionFormer to the input modality representation, we propose a depth prediction branch that can be added to the framework to improve detection performance in camera-based detection tasks. In addition, we propose a plug-and-play temporal fusion module based on transformers that can fuse historical frame BEV features for more stable and reliable detection results. We evaluate our method on the nuScenes dataset and achieve 72.6% mAP and 75.1% NDS for 3D object detection tasks, outperforming state-of-the-art methods

Cardiac Sca-1+ cells are not intrinsic stem cells for myocardial development, renewal and repair

Background: For over a decade, Sca-1+ cells within the mouse heart have been widely recognized as a stem cell population with multipotency that can give rise to cardiomyocytes, endothelial cells and smooth muscle cells in vitro and after cardiac grafting. However, the developmental origin and authentic nature of these cells remain elusive. Methods: Here, we used a series of high-fidelity genetic mouse models to characterize the identity and regenerative potential of cardiac resident Sca-1+ cells. Results: With these novel genetic mouse models, we found that Sca-1 does not label cardiac precursor cells during early embryonic heart formation. Postnatal cardiac resident Sca-1+ cells are in fact a pure endothelial cell population. They retain endothelial properties and exhibit minimal cardiomyogenic potential during development, normal aging and upon ischemic injury. Conclusions: Our study provides definitive insights into the nature of cardiac resident Sca-1+ cells. The observations challenge the current dogma that cardiac resident Sca-1+ cells are intrinsic stem cells for myocardial development, renewal and repair and suggest that the mechanisms of transplanted Sca-1+ cells in heart repair need to be reassessed