Effect of Discharge Voltage on the Microstructure of Graphene/PEKK Composite Samples by Electromagnetic Powder Molding.

The light weight, electrical conductivity, environmental friendliness, and high mechanical properties of graphene/PEKK composites make them popular in biomedical, electronic component and aerospace fields. However, the compaction density and carbonization of the specimen influence the microstructure and conductivity of the graphene/PEKK composite prepared by in situ polymerization, so electromagnetic-assisted molding was used to manufacture products to avoid carbonization and enhance the compaction density. The effects of different discharge voltages on the microstructure of the formed graphene/PEKK specimens were compared. Increasing the discharge voltage will lead to a closer distribution of flake graphene in the matrix to improve the compaction density, mechanical performance and conductivity. At the same time, the numerical analysis model was validated by comparison with the compaction density of the experimental results. Based on this research, the stress/strain distribution on the specimen was obtained with increasing discharge voltages.

Prognostic signatures of sphingolipids: Understanding the immune landscape and predictive role in immunotherapy response and outcomes of hepatocellular carcinoma.

Background: Hepatocellular carcinoma (HCC) is a complex disease with a poor outlook for patients in advanced stages. Immune cells play an important role in the progression of HCC. The metabolism of sphingolipids functions in both tumor growth and immune infiltration. However, little research has focused on using sphingolipid factors to predict HCC prognosis. This study aimed to identify the key sphingolipids genes (SPGs) in HCC and develop a reliable prognostic model based on these genes. Methods: The TCGA, GEO, and ICGC datasets were grouped using SPGs obtained from the InnateDB portal. A prognostic gene signature was created by applying LASSO-Cox analysis and evaluating it with Cox regression. The validity of the signature was verified using ICGC and GEO datasets. The tumor microenvironment (TME) was examined using ESTIMATE and CIBERSORT, and potential therapeutic targets were identified through machine learning. Single-cell sequencing was used to examine the distribution of signature genes in cells within the TME. Cell viability and migration were tested to confirm the role of the key SPGs. Results: We identified 28 SPGs that have an impact on survival. Using clinicopathological features and 6 genes, we developed a nomogram for HCC. The high- and low-risk groups were found to have distinct immune characteristics and response to drugs. Unlike CD8 T cells, M0 and M2 macrophages were found to be highly infiltrated in the TME of the high-risk subgroup. High levels of SPGs were found to be a good indicator of response to immunotherapy. In cell function experiments, SMPD2 and CSTA were found to enhance survival and migration of Huh7 cells, while silencing these genes increased the sensitivity of Huh7 cells to lapatinib. Conclusion: The study presents a six-gene signature and a nomogram that can aid clinicians in choosing personalized treatments for HCC patients. Furthermore, it uncovers the connection between sphingolipid-related genes and the immune microenvironment, offering a novel approach for immunotherapy. By focusing on crucial sphingolipid genes like SMPD2 and CSTA, the efficacy of anti-tumor therapy can be increased in HCC cells.

Circ_0000595 knockdown alleviates CoCl2-mediated effects in VSMCs by regulating the miR-582-3p/ADAM10 axis.

BACKGROUND: Thoracic aortic aneurysm (TAA) is a serious vascular disease causing the death of elder people. Accumulating studies have reported that circular RNAs (circRNAs) are implicated in the regulation of aortic aneurysms. However, the role of circ_0000595 in the progression of TAA is still unclear. METHODS: Quantitative real-time PCR (qRT-PCR) and western blotting were implemented to assess circ_0000595, microRNA (miR)-582-3p, guanine nucleotide-binding protein alpha subunit (ADAM10), PCNA, Bax, and Bcl-2 expression. The proliferation of vascular smooth muscle cells was determined using cell counting kit 8 (CCK-8) and 5-ethynyl-2-deoxyuridine (EdU). Cell apoptosis was measured using flow cytometry, and caspase-3 activity was analyzed using a commercial kit. After bioinformatics analysis, the interaction between miR-582-3p and circ_0000595 or ADAM10 was validated using a dual-luciferase reporter and RNA immunoprecipitation. RESULTS: As compared with controls, TAA tissues and CoCl2-induced VSMCs displayed high expression of circ_0000595 and ADAM10, and low expression of miR-582-3p. CoCl2 treatment evidently suppressed VSMC proliferation and promoted VSMCs apoptosis, and these impacts were reverted by circ_0000595 knockdown. Circ_0000595 acted as a molecular sponge for miR-582-3p, and circ_0000595 silencing-mediated influences in CoCl2-induced VSMCs were overturned by miR-582-3p inhibitor. ADAM10 was confirmed as a target gene of miR-582-3p, and miR-582-3p overexpression-induced influence was almost restored by overexpressed ADAM10 in CoCl2-induced VSMCs. Besides, circ_0000595 contributed to ADAM10 protein expression by sponging miR-582-3p. CONCLUSION: Our data verified that circ_0000595 silencing might attenuate CoCl2-mediated impacts in VSMCs by regulating the miR-582-3p/ADAM10 axis, providing new potential roads for treating TAA.

Manufacturing Technologies of Polymer Composites-A Review.

Polymer composites have been widely used in the aviation, aerospace, automotive, military, medical, agricultural and industrial fields due to their excellent mechanical properties, heat resistance, flame retardant, impact resistance and corrosion resistance. In general, their manufacturing process is one of the key factors affecting the life cycle of polymer composites. This article provides an overview of typical manufacturing technologies, including surface coating, additive manufacturing and magnetic pulse powder compaction, which are normally used to reduce the failure behaviour of polymer composites in service so that the quality of composite products can be improved. Advanced polymer composite powder manufacturing processes, the processing mechanism and experimental methods are described, and the influence of different manufacturing processes on the moulding quality is revealed. This investigation can provide suitable methods for the selection of manufacturing technology to improve the quality of polymer composite products.

Community centered public safety resilience under public emergencies: A case study of COVID-19.

During public emergencies, the level of public safety will be resilient and follow a process from decline to rise. Regarding the concept and influencing factors of public safety resilience, a three-level public safety resilience framework that includes personal, community, and government levels was proposed in this study. It provided the overall metrics that used the resistance and recovery ability to describe the dynamic characteristics of public safety resilience as well as the resilience assessment indexes on three levels. In the context of the Coronavirus Disease 2019 (COVID-19) pandemic, this study applied the proposed framework in a case study on public safety resilience at the Beihang community, Beijing, China through descriptive statistics, structural equation model, and principal component regression analysis of questionnaire data. The data analysis results showed that community resilience was the most important of the three levels of public safety resilience. In addition, community resilience could improve personal resilience, and government resilience had a positive effect on community and personal resilience. Compared with the resistance ability, the recovery ability was influenced more by the operation and improvement of the community. This study is conducive to understanding and improving public safety resilience on the personal, community, and government levels and can help relevant parties improve their ability to respond to the COVID-19 pandemic. Furthermore, the methods used in this study can be extended to other studies on public emergencies.

Long non-coding RNA placenta­specific protein 2 regulates the chemosensitivity of cancer cells to cisplatin in hepatocellular carcinoma (HCC) by sponging microRNA-96 to upregulate X-linked inhibitor of apoptosis protein.

This study was conducted to investigate the roles of lncRNA PLAC2 and XiaP in hepatocellular carcinoma (HCC). HCC and paired non-tumor tissues were collected from 62 HCC patients who received cisplatin-based treatment. At 0, 2, and 4 months of post-cisplatin-based therapy, blood samples (5 ml) were collected from all patients and prepared plasma samples. LncRNA PLAC2 expression in tissue and plasma samples was determined by RT-qPCR. The interactions between lncRNA PLAC2 and XiaP in HCC cell lines were assessed by overexpression experiments. Cell viability and apoptosis under cisplatin treatment were analyzed by MTT assay and cell apoptosis assay, respectively. The direct interaction between lncRNA PLAC2 and miR-96, which can target XiaP, was analyzed by performing RNA-RNA pulldown assay. It was observed that lncRNA PLAC2 was upregulated in HCC tissues than in non-tumor tissues. LncRNA PLAC2 expression in HCC tissues was not affected by HBV and HCV but upregulated after cisplatin-based treatment. Similarly, cisplatin treatment of HCC cells increased PLAC2 expression. LncRNA PLAC2 and XiaP overexpression increased viability and decreased apoptosis of cisplatin-treated HCC cells, while lncRNA PLAC2 knockdown decreased viability and increased apoptosis of cisplatin-treated HCC cells. Western blot analysis showed that lncRNA PLAC2 increased XiaP protein accumulation, while lncRNA PLAC2 siRNA silencing decreased XiaP expression in HCC cells. LncRNA PLAC2 and miR-96 directly interacted with each other, while they failed to regulate the expression of each other. In conclusion, lncRNA PLAC2 negatively regulates the chemosensitivity of HCC cells to cisplatin, possibly by sponging miR-96 to upregulate miR-96.

A Density-Dependent Modified Doraivelu Model for the Cold Compaction of Poly (Ether Ketone Ketone) Powders.

The cold compaction of poly (ether ketone ketone) (PEKK) powder was studied by experiments and simulations based on the modified Doraivelu model. Although this model can successfully predict the compaction behavior of metal powders, discussion of the prediction of polymer powders is lacking. Based on the mechanical theory of metal plasticity, the modified Doraivelu model was established by introducing the material parameters m and n. The modified model can predict the compaction density of PEKK powder during cold compaction. A sub-increment method for this constitutive model was then established and implemented into a finite-element model by using the user-defined material subroutine UMAT in ABAQUS/Standard. Consequently, the material parameters of the modified Doraivelu model were identified by an inverse method using the experimental data and simulation results. It was found that when m = 0, n = 4, and the initial relative density was 0.4485, the simulation results were the closest to the experimental ones.

Smoking induces the occurrence of colorectal cancer via changing the intestinal permeability.

PURPOSE: Colorectal cancer (CRC) is the third most frequent cancer. Its occurrence is closely linked to lifestyle and diet habits, such as excessive intake of high-fat food, but their impact on CRC, however, remain unclear. METHODS: Eligible CRC patients were retrospectively analyzed. Overall survival (OS) and recurrence-free survival (RFS) in smokers and non-smokers of CRC patients were assessed. APCmin/+ mice were exposed to cigarette smoking, followed by detection of CRC growth and intestinal permeability. RESULTS: A total of 416 eligible CRC patients were recruited, involving 218 (52.4%) smokers and 198 (47.6%) non-smokers. OS was shorter in CRC smokers than in non-smokers (p=0.005), whereas smoking did not affect RFS in CRC patients (p=0.251). Cigarette smoking increased CRC tumor numbers of CRC in APCmin/+ mice. Proliferation and apoptosis of colorectal epithelial cells, and inflammatory response in mice were changed following smoking. Notably, the treatment of probiotics mixture VSL#3 decreased the number of CRC tissues and intestinal permeability in APCmin/+ mice exposed to cigarette smoking. CONCLUSIONS: Smoking increases the susceptibility to CRC through damaging the intestinal permeability. Protecting the intestinal permeability significantly protects intestinal tracts.

Investigation of Electromagnetic Pulse Compaction on Conducting Graphene/PEKK Composite Powder.

Polymer-composite materials have the characteristics of light weight, high load, corrosion resistance, heat resistance, and high oil resistance. In particular, graphene composite has better electrical conductivity and mechanical performance. However, the raw materials of graphene composite are processed into semi-finished products, directly affecting their performance and service life. The electromagnetic pulse compaction was initially studied to get the product Graphene/PEKK composite powder. Simultaneously, spark plasma sintering was used to get the bars to determine the electrical conductivity of Graphene/PEKK composite. On the basis of this result, conducting Graphene/PEKK composite powder can be processed by electromagnetic pulse compaction. Finite element numerical analysis was used to obtain process parameters during the electromagnetic pulse compaction. The results show that discharge voltage and discharge capacitance influence on the magnetic force, which is a main moulding factor affecting stress, strain and density distribution on the specimen during electromagnetic pulse compaction in a few microseconds.

Structure-based discovery and redesign of TGF-ß1 Elbow epitope recognition by its type-II receptor in hypertrophic scarring biotherapy.

Transforming growth factor-ß1 (TGF-ß1) signaling pathway has been implicated in the fibroblast activation of hypertrophic scarring (HS). Previously, we proposed a new biotherapeutic strategy to combat HS by disrupting the intermolecular interaction of TGF-ß1 with its cognate type-II receptor (TßR-II). Here, we further demonstrate that the binding site of TGF-ß1 to TßR-II is not overlapped with the conformational wrist epitope and linear knuckle epitope that are traditionally recognized as the functional binding sites of bone morphogenetic protein-2 (BMP-2) to its type-II receptor (BMPR-II), which can thus be regarded as a new functional site we called elbow epitope. Structural, energetic, and dynamic investigations reveal that the elbow epitope consists of two sequentially discontinuous, spatially vicinal segments Loop30-34 and Turn90-95 ; they cannot work effectively to independently interact with TßR-II. Rational redesign of the epitope is performed using an integrated in silio-in vitro method based on crystal and modeled structure data. In the procedure, the two epitope segments are split from the interface of TGF-ß1-TßR-II complex and then connected with each other in a head-to-tail manner by adding a flexible poly-(Gly)n linker between them, thus resulting in a series of combined peptides. We found that the peptide affinity reaches maximum at n = 2, which shares a consistent binding mode with the elbow epitope at native complex interface. The linker of either too long (n > 2) or too short (n < 2) cannot properly place the gap space between the two segments, thus impairing the binding compatibility of designed peptides with TßR-II active site.

Resilience of and recovery strategies for weighted networks.

The robustness and resilience of complex networks have been widely studied and discussed in both research and industry because today, the diversity of system components and the complexity of the connection between units are increasingly influencing the reliability of complex systems. Previous studies have focused on node failure in networks, proposing several performance indicators. However, a single performance indicator cannot comprehensively measure all the performance aspects; thus, the selected performance indicators and recovery strategies lack consistency with respect to the targeted complex systems. This paper introduces a novel stress-strength-balanced weighted network model based on two network transmission hypotheses. Then, with respect to different concerns of the complex network, we propose two modified network performance measurement indicators and compare these indicators in terms of their trends in the attack process. In addition, we introduce several network recovery strategies and compare their efficiencies. Our findings are as follows: (1) The evaluation and judgment of the network performance depend on the performance measurement indicators we use. (2) Different recovery strategies exhibit distinct efficiencies in recovering different aspects of network performance, and no strategy exists that can improve all the network performance aspects simultaneously. (3) The timing of the recovery is proved to have a deep influence on the cost and efficiency of network recovery; thus, the optimal recovery strategy for a damaged network varies with the extent of the damage. From the results of the simulation of the attack-recovery process, we conclude that while defining and analyzing complex network models, we should adjust our network topology, weight assignment, and performance indicators in accordance with the focal characteristics of complex systems so that we can use the network model to build robust complex systems and efficient logistics and maintenance strategies.