Carbon nitride/polyimide porous film via an NIPS method with advanced dielectric and hydrophobicity properties

Herein, an ultra-low dielectric porous polyimide (PPI) composite film was fabricated by non-solvent induced phase separation (NIPS). High-performance carbon nitride nanosheets grafted by heptadecafluoro-1,1,2,2-tetradecyl-trimethoxysilane (CNNF) were incorporated into the PPI film to enhance thermomechanical and hydrophobic properties. The effects of non-solvent and filler content on the porous morphology, dielectric properties, hydrophobicity and thermomechanical properties of films were investigated. The porous morphology of the CNNF/PPI film changed from the coexistence of pipe-like and spongy structure via H2O, to a tightly-stacked porous structure via MeOH as non-solvent. The dielectric constants ε' of 0.5 wt%-CNNF/PPI(H2O) and 0.5 wt%-CNNF/PPI(MeOH) were 1.56 and 1.69 at 1 MHz, respectively, which were ∼50% lower than that of the original PI film (ε' = 3.33). With the introduction of CNNF, the water contact angle (WCA) of CNNF/PPI(H2O) increased from 66° to 107° and that of CNNF/PPI(MeOH) increased from 92° to 120°. Simultaneously, the storage modulus E' of 2 wt%-CNNF/PPI(MeOH) reached its highest value of ∼881 MPa, which was ∼350 MPa higher than that of PPI(MeOH), together with an enhancement in Tg. This method confirmed a promising prospect for the utilization of porous PI substrates in integrated circuits and microelectronic devices.

Ionic conductive konjac glucomannan/liquid crystal cellulose composite hydrogels with dual sensing of photo- and electro-signals capacities as wearable strain sensors

The ionic conductive hydrogel-based sensor exhibits wide applications in wearable electronic devices. However, the strength and ductility trade-off, multimodal requirements, and water-soluble polymer alternatives are significant challenges for the hydrogel-based sensor. Herein, a stretchable and conductive hydrogel is developed with a double network formed by incorporating polyacrylamide and ionic liquid into the konjac glucomannan network. The hydrogel displays significantly enhanced mechanical properties, and good tear/puncture resistance owing to the existence of covalent and non-covalent interactions. In addition, by the introduction of nematic liquid crystal hydroxypropyl cellulose, the hydrogel/cellulose-based strain sensor demonstrates excellent sensing performance in monitoring human motions and writing recognition ability with optical and electrical bimodal sensing response. This work provides new insights to further expand the options of hydrogel-based sensor matrix and to construct bimodal sensors.

MXene Clay (Ti2C)-Containing In Situ Polymerized Hollow Core-Shell Binder for Silicon-Based Anodes in Lithium-Ion Batteries

Silicon, an attractive anode material, suffers fast capacity fading due to the electrical isolation from massive volumetric expansion upon cycling. However, it holds a high theoretical capacity and low operation voltage in its practical application. In this study, a new water-based binder, MXene clay/hollow core-shell acrylate composite, was synthesized through an in situ emulsion polymerization technique to alleviate the fast capacity fading of the silicon anode efficiently. The efficient introduction of conductive MXene clay and the hollow core-shell structure, favorable to electron and ion transport in silicon-based electrodes, gives a novel conceptual design of the binder material. Such a strategy could alleviate electrical isolation after cycling and promises better electrochemical performance of the high-capacity anodes. The effect of the MXene introduction and hollow core-shell on the binder performance is thoroughly investigated using various characterization tools by comparison with no MXene-containing, core-shell acrylate, and commercial styrene-butadiene latex binders. Consequently, the silicon-based electrode containing the MXene clay/hollow core-shell acrylate binder exhibits a high capacity retention of 1351 mAh g-1 at 0.5C after 100 cycles and good rate capability of over 1100 mAh g-1 at 5C.

Bioinformatics analysis and verification of m6A related genes based on the construction of keloid diagnostic model

Keloids are formed due to abnormal hyperplasia of the skin connective tissue. We explored the relationship between N6-methyladenosine (m6A)-related genes and keloids. The transcriptomic datasets (GSE44270 and GSE185309) of keloid and normal skin tissues samples were obtained from the Gene Expression Omnibus database. We constructed the m6A landscape and verified the corresponding genes using immunohistochemistry. We extracted hub genes for unsupervised clustering analysis using protein-protein interaction (PPI) network; gene ontology enrichment analysis was performed to determine the biological processes or functions affected by the differentially expressed genes (DEGs). We performed immune infiltration analysis to determine the relationship between keloids and the immune microenvironment using single-sample gene set enrichment analysis and CIBERSORT. Differential expression of several m6A genes was observed between the two groups; insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) was significantly upregulated in keloid patients. PPI analysis elucidated six genes with significant differences between the two keloid sample groups. Enrichment analysis revealed that the DEGs were mainly enriched in cell division, proliferation, and metabolism. Moreover, significant differences in immunity-related pathways were observed. Therefore, the results of this study will provide a reference for the elucidation of the pathogenesis and therapeutic targets of keloids.

Multifunctional AIE Nanosphere-Based "Nanobomb" for Trimodal Imaging-Guided Photothermal/Photodynamic/Pharmacological Therapy of Drug-Resistant Bacterial Infections

Injudicious or inappropriate use of antibiotics has led to the prevalence of drug-resistant bacteria, posing a huge menace to global health. Here, a self-assembled aggregation-induced emission (AIE) nanosphere (AIE-PEG₁₀₀₀ NPs) that simultaneously possesses near-infrared region II (NIR-II) fluorescence emissive, photothermal, and photodynamic properties is prepared using a multifunctional AIE luminogen (AIE-4COOH). The AIE-PEG₁₀₀₀ NPs were encapsulated with teicoplanin (Tei) and ammonium bicarbonate (AB) into lipid nanovesicles to form a laser-activated "nanobomb" (AIE-Tei@AB NVs) for the multimodal theranostics of drug-resistant bacterial infections. In vivo experiments validate that the "nanobomb" enables high-performance NIR-II fluorescence, infrared thermal, and ultrasound (AB decomposition during the photothermal process to produce numerous CO₂/NH₃ bubbles, which is an efficient ultrasound contrast agent) imaging of multidrug-resistant bacteria-infected foci after intravenous administration of AIE-Tei@AB NVs followed by 660 nm laser stimulation. The highly efficient photothermal and photodynamic features of AIE-Tei@AB NVs, combined with the excellent pharmacological property of rapidly released Tei during bubble generation and NV disintegration, collectively promote broad-spectrum eradication of three clinically isolated multidrug-resistant bacteria strains and rapid healing of infected wounds. This multimodal imaging-guided synergistic therapeutic strategy can be extended for the theranostics of superbugs.

Visualization study of perturbations induced by plasma actuators and its effect on shock wave/boundary-layer interaction

Abstract

Surface arc plasma actuator array is used to control the shock wave/boundary-layer interaction in a Ma = 2 flow. Two types of interaction are examined. The flow topology of Surface arc plasma actuator array operating at high-frequency is firstly visualized via particle laser scattering (PLS) technique. The results show that two typical flow structures are observed in the discharging process: the thermal gas bubble and the trailing vortices. The high-frame low-exposure schlieren results for flow visualization indicate a significant separation inhibition in both experiments due to an improvement in the mixture upstream of the interaction region and promoting more turbulent structure into the boundary layer. In the baseline, the separation shock oscillates in a low-frequency mode. When plasma actuation is turned on, the spectra change dramatically when compared to the baseline condition without control. There is an apparent frequency shift for separation shock.

Graphical abstract

A deep learning based multimodal fusion model for skin lesion diagnosis using smartphone collected clinical images and metadata

Introduction

Skin cancer is one of the most common types of cancer. An accessible tool to the public can help screening for malign lesion. We aimed to develop a deep learning model to classify skin lesion using clinical images and meta information collected from smartphones.

Methods

A deep neural network was developed with two encoders for extracting information from image data and metadata. A multimodal fusion module with intra-modality self-attention and inter-modality cross-attention was proposed to effectively combine image features and meta features. The model was trained on tested on a public dataset and compared with other state-of-the-art methods using five-fold cross-validation.

Results

Including metadata is shown to significantly improve a model's performance. Our model outperformed other metadata fusion methods in terms of accuracy, balanced accuracy and area under the receiver-operating characteristic curve, with an averaged value of 0.768±0.022, 0.775±0.022 and 0.947±0.007.

Conclusion

A deep learning model using smartphone collected images and metadata for skin lesion diagnosis was successfully developed. The proposed model showed promising performance and could be a potential tool for skin cancer screening.

Therapeutic potential of exosomes from adipose-derived stem cells in chronic wound healing

Chronic wound healing remains a challenging medical problem affecting society, which urgently requires anatomical and functional solutions. Adipose-derived stem cells (ADSCs), mesenchymal stem cells with self-renewal and multiple differentiation ability, play essential roles in wound healing and tissue regeneration. The exosomes from ADSCs (ADSC-EXOs) are extracellular vesicles that are essential for communication between cells. ADSC-EXOs release various bioactive molecules and subsequently restore tissue homeostasis and accelerate wound healing, by promoting various stages of wound repair, including regulating the inflammatory response, promoting wound angiogenesis, accelerating cell proliferation, and modulating wound remodeling. Compared with ADSCs, ADSC-EXOs have the advantages of avoiding ethical issues, being easily stored, and having high stability. In this review, a literature search of PubMed, Medline, and Google Scholar was performed for articles before August 1, 2022 focusing on exosomes from ADSCs, chronic wound repair, and therapeutic potential. This review aimed to provide new therapeutic strategies to help investigators explore how ADSC-EXOs regulate intercellular communication in chronic wounds.

Enhanced Electromagnetic Interference Shielding Properties of Immiscible Polyblends with Selective Localization of Reduced Graphene Oxide Networks

Herein, an effective technique of curing reaction-induced phase separation (CRIPS) was used to construct a reduced graphene oxide (RGO) network in the immiscible diglycidyl ether of the bisphenol A/polyetherimide (DGEBA/PEI) polyblend system. The unique chemical reduction of RGO facilitated the reduction of oxygenated groups and simultaneously appended amino groups that stimulate the curing process. The selective interfacial localization of RGO was predicted numerically by the harmonic and geometric mean technique and further confirmed by field emission transmission electron microscopy (FETEM) analysis. Due to interfacial localization, the electrical conductivity was increased to 366 S/m with 3 wt.% RGO reinforcement. The thermomechanical properties of nanocomposites were determined by dynamic mechanical analysis (DMA). The storage modulus of 3 wt.% RGO-reinforced polyblend exhibited an improvement of ~15%, and glass transition temperature (T_g) was 10.1 °C higher over neat DGEBA. Furthermore, the total shielding effectiveness (SE_T) was increased to 25.8 dB in the X-band region, with only 3 wt.% RGO, which represents ~99.9% shielding efficiency. These phase separation-controlled nanocomposites with selective localization of electrically conductive nanofiller at a low concentration will extend the applicability of polyblends to multifunctional structural nanocomposite applications.

Construction and Mechanism Analysis of a Self-Assembled Conductive Network in DGEBA/PEI/HRGO Nanocomposites by Controlling Filler Selective Localization

Herein, a feasible and effective approach is developed to build an electrically conductive and double percolation network-like structure via the incorporation of highly reduced graphene oxide (HRGO) into a polymer blend of diglycidyl ether of bisphenol A/polyetherimide (DGEBA/PEI). With the assistance of the curing reaction-induced phase separation (CRIPS) technique, an interconnected network of HRGO is formed in the phase-separated structure of the DGEBA/PEI polymer blend due to selective localization behavior. In this study, HRGO was prepared from a unique chemical reduction technique. The DGEBA/PEI/HRGO nanocomposite was analyzed in terms of phase structure by content of PEI and low weight fractions of HRGO (0.5 wt.%). The HRGO delivered a high electrical conductivity in DGEBA/PEI polyblends, wherein the value increased from 5.03 × 10⁻¹⁶ S/m to 5.88 S/m at a low content of HRGO (0.5 wt.%). Furthermore, the HRGO accelerated the curing reaction process of CRIPS due to its amino group. Finally, dynamic mechanical analyses (DMA) were performed to understand the CRIPS phenomenon and selective localization of HRGO reinforcement. The storage modulus increased monotonically from 1536 MPa to 1660 MPa for the 25 phr (parts per hundred in the DGEBA) PEI polyblend and reached 1915 MPa with 0.5 wt.% HRGO reinforcement. These simultaneous improvements in electrical conductivity and dynamic mechanical properties clearly demonstrate the potential of this conductive polyblend for various engineering applications.

Small RNA sequencing reveals miRNAs important for hypoxic adaptation in the Tibetan chicken

1. The Tibetan chicken, which is an indigenous breed living on the Tibetan Plateau, exhibits hypoxic adaptations to its high-altitude environment. However, the molecular mechanism behind this hypoxic adaptation is still unclear. This study aimed to investigate differentially expressed miRNAs involved in hypoxic adaptation through high-throughput RNA sequencing. 2. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to verify the differentially expressed miRNAs and their target genes in chicken embryonic heart tissues and fibroblasts. Luciferase reporter assays were performed to confirm the relationship between miRNAs and target genes. 3. The study identified 37 differentially expressed miRNAs in Tibetan chicken embryonic heart tissues, including 20 up- and 17 down-regulated miRNAs, compared to those found in lowland chickens. Differentially expressed miRNAs were mainly involved in biological processes, such as cell cycle arrest, toll-like receptor signalling pathways, and I-kappa B kinase/NF-kappa B signalling. The data showed that gga-miR-34 c-5p was significantly upregulated in Tibetan chicken tissues and hypoxic fibroblasts, while EHHADH, a target gene of gga-miR-34 c-5p, was downregulated. Moreover, gga-miR-34 c-5p dramatically decreased the luciferase activity of the wild EHHADH, whereas no effect on the mutational EHHADH was found. 4. This study identified miRNA expression profiles in the Tibetan chicken and suggested that miR-34 c-5p acts as a novel miRNA associated with hypoxic adaptation. This facilitates the understanding of molecular mechanisms that underlie long-term exposure to hypoxia.

P6231Iron status and risk of cardio-metabolic diseases in European adults: a Mendelian randomization study

Background

Observational studies have reported conflicting results about the associations of iron status with risk of cardio-metabolic diseases but such studies are constrained by confounding and reverse causality.

Purpose

To assess the causal relevance of iron status biomarkers (transferrin, serum iron, and ferritin) for risk of coronary artery diseases (CAD), ischaemic stroke (IS), and type 2 diabetes (T2D), using Mendelian randomization (MR).

Methods

Effect size estimates for genetic variants associated with iron status biomarkers were obtained from the Genetics of Iron Status consortium (transferrin saturation, serum iron, and ferritin: n=48,972). The corresponding effects of these variants on the risk of CAD, IS and T2D were obtained from a meta-analysis of unrelated participants of European ancestry in the UK Biobank (UKB), together with previously recruited participants in CARDIOGRAMplusC4D (total n=90,377 CAD cases), MEGASTROKE (total n=43,381 IS cases) and DIAGRAM (total n=74,124 T2D cases), respectively. The main analysis used a two-sample inverse-variance weighted MR, while the sensitivity analyses used weighted-median, weighted-mode, MR-PRESSO, and MR-Egger approaches.

Results

MR analysis demonstrated significant inverse association of each of the three genetically-instrumented iron status biomarker with risk of CAD (transferrin saturation OR=0.96 [95% CI: 0.92–0.99], p=0.02; serum iron OR=0.93 [0.89–0.97], p=0.001; and ferritin OR=0.86 (0.79–0.94), p=0.001, per 1 SD higher level). In contrast, these iron status biomarkers showed positive associations with risk of T2D (transferrin saturation OR=1.06 [1.01–1.11], p=0.01; serum iron OR=1.06 [0.99–1.13], p=0.07; and ferritin OR=1.12 [0.99–1.26], p=0.06, per 1 SD higher level). There was positive, but non-significant, association of IS with each of the iron status biomarker analysed. Sensitivity analyses using several different MR approaches yielded concordant results.

Conclusions

Among European adults, iron status appeared to have causal associations, but in opposite directions, with the risk of CHD and T2D. Our findings highlight the need for caution about strategies for advocating iron supplementation in individuals with normal haemoglobin levels for prevention of CAD.

Acknowledgement/Funding

British Heart Found, Medical Research Council, Wellcome Trust, NIHR Biomedical Research Centre, Oxford

Sodium butyrate alleviates high-glucose-induced renal glomerular endothelial cells damage via inhibiting pyroptosis

We recently found that Sodium butyrate (NaB) possesses anti-inflammatory effects in diabetic nephropathy (DN) mouse model and in high-glucose induced mouse glomerular mesangial cells. Pyroptosis is a programmed cell death accompanied with the release of pro-inflammatory factors. Gasdermin D (GSDMD) is a novel discovered pivotal executive protein of pyroptosis, which can be cleaved by inflammatory caspases. The aim of our study is to verify if NaB have some effects against high-glucose induces pyroptosis in renal Glomerular endothelial cells (GECs). For this aim, human GECs were cultured and exposed to high-glucose. Exogenous NaB, caspase 1 inhibitor Ac-YVAD-CMK (A-Y-C) or knockdown GSDMD by siRNA were used. We found high glucose could increase Propidium Iodide (PI) positive cells and elevate release of lactate dehydrogenase (LDH), Interleukin 1 beta (IL-1β) and Interleukin 18 (IL-18); protein levels of GSDMD, GSDMD N-terminal domain (GSDMD-N) and cleaved-caspase-1 were also elevated. Effect of NaB on LDH release and PI positive cells was further enhanced by inhibiting caspase 1-GSDMD. In addition, high glucose-induced nuclear factor kappa-B (NF-κB)/NF-κB inhibitor α (IκB-α) signaling pathway was reversed by NaB or A-Y-C administration. In conclusion, NaB could ameliorate high-glucose induced GECs via caspase1-GSDMD canonical pyroptosis pathway; and NF-κB/IκB-α signaling pathway was involved in it.

Synthesis of poly(acrylic acid) coated magnetic nanospheres via a multiple polymerization route

Magnetic nanospheres are versatile candidates for both fundamental and practical applications. Before they are applied in more complicated fields, their surface must be modified by several functionalities. However, the surface modification can be affected by the magnetic nanoparticles (MNP) embedded in the polymer matrix. Herein, the synthesis of poly(acrylic acid) coated magnetic nanospheres via a multiple polymerization route is described. During the synthesis process, seed emulsion polymerization was applied to redistribute the MNP in the polymer matrix, and the relationship between the structure of magnetic nanospheres and the thickness of the grafted poly(acrylic acid) layer was investigated. The development of size, morphology and magnetic properties of the nanospheres were characterized by transmission electron microscopy, dynamic light scattering, thermogravimetric analysis, X-ray diffraction and vibrating sample magnetometry. This work would pave the way to design and preparation of new structure of functional magnetic nanospheres with precise surface modification.

Cannabis use and risk of schizophrenia: a Mendelian randomization study

Cannabis use is observationally associated with an increased risk of schizophrenia, but whether the relationship is causal is not known. Using a genetic approach, we took 10 independent genetic variants previously identified to associate with cannabis use in 32 330 individuals to determine the nature of the association between cannabis use and risk of schizophrenia. Genetic variants were employed as instruments to recapitulate a randomized controlled trial involving two groups (cannabis users vs nonusers) to estimate the causal effect of cannabis use on risk of schizophrenia in 34 241 cases and 45 604 controls from predominantly European descent. Genetically-derived estimates were compared with a meta-analysis of observational studies reporting ever use of cannabis and risk of schizophrenia or related disorders. Based on the genetic approach, use of cannabis was associated with increased risk of schizophrenia (odds ratio (OR) of schizophrenia for users vs nonusers of cannabis: 1.37; 95% confidence interval (CI), 1.09-1.67; P-value=0.007). The corresponding estimate from observational analysis was 1.43 (95% CI, 1.19-1.67; P-value for heterogeneity =0.76). The genetic markers did not show evidence of pleiotropic effects and accounting for tobacco exposure did not alter the association (OR of schizophrenia for users vs nonusers of cannabis, adjusted for ever vs never smoker: 1.41; 95% CI, 1.09-1.83). This adds to the substantial evidence base that has previously identified cannabis use to associate with increased risk of schizophrenia, by suggesting that the relationship is causal. Such robust evidence may inform public health messages about cannabis use, especially regarding its potential mental health consequences.

The fabrication and application of magnetite coated N-doped carbon microtubes hybrid nanomaterials with sandwich structures

Triple-walled Fe₃O₄@N-doped carbon@Fe₃O₄ microtubes were synthesized using N-doped carbon microtubes as templates.