LncRNA HOTAIR accelerates free fatty acid-induced inflammatory response in HepG2 cells by recruiting SRSF1 to stabilize MLXIPL mRNA.

LncRNA HOTAIR has been reported to be associated with metabolic diseases of the liver. However, the effect of HOTAIR on non-alcoholic fatty liver disease (NAFLD) inflammation and its potential mechanism have not been reported. Genes and proteins expression were detected by qRT-PCR and Western blot respectively. The level of inflammatory cytokines was assessed by ELISA. HepG2 cell viability was detected by MTT assay. TG level and lipid accumulation were measured by Assay Kit and Oil red O staining, respectively. Direct binding relationship between HOTAIR and Serine/arginine splicing factor 1 (SRSF1), SRSF1 and MLX interacting protein like (MLXIPL) were confirmed by RNA-pull down and RIP assay. HOTAIR was highly expressed in free fatty acids (FFA)-treated HepG2 cells. HOTAIR knockdown alleviated FFA-induced inflammation of HepG2 cells. Then further analysis showed that HOTAIR and SRSF1 had a mutual binding relationship, and HOTAIR maintained MLXIPL mRNA stability via recruiting SRSF1 in HepG2 cells. Moreover, the inhibitory effect of HOTAIR knockdown on FFA-induced inflammation in HepG2 cells was reversed by MLXIPL overexpression. HOTAIR accelerates inflammation of FFA-induced HepG2 cells by recruiting SRSF1 to stabilize MLXIPL mRNA, which will help to find new effective strategies for NAFLD therapy. Supplementary Information: The online version contains supplementary material available at 10.1007/s10616-023-00614-x.

Improving Charge Storage of Biaxially-Oriented Polypropylene under Extreme Electric Fields by Excimer UV Irradiation.

Biaxially-oriented polypropylene (BOPP) is one of the most commonly used materials for film-based capacitors for power electronics and pulsed power systems. To address the pressing issue of performance-limiting loss under extreme electric-fields, here a one-step, high-throughput, and environment-friendly process based on very low-dose ultra-violet irradiation from KrCl (222 nm) and Xe2 (172 nm) excimer is demonstrated. The performance of commercial BOPP is boosted in terms of withstanding electric-field extremes (Weibull breakdown strength 694 to 811 V µm-1 by 17% at 25 °C and 428 to 651 V µm-1 by 52% at 120 °C), discharged energy density, and conduction losses. Importantly, the depth profile of space charge is precisely measured in situ with a high resolution of 500 nm by laser induced pressure pulse. Consequently, the space charge effect and electric-field distortion are reduced and related to the improved polymer films. It is demonstrated that energetic UV photons act as scissors for BOPP chains and dissociate oxygen molecules leading to the more thermally stable oxygen-containing structures, as deep traps to impede charge migration. This work provides a promising approach to produce polymers with customized microscopic characteristics that is compatible with the assembly lines of polymer-based capacitors.

Learning Cross-Domain Features With Dual-Path Signal Transformer.

The past decade has witnessed the rapid development of deep neural networks (DNNs) for automatic modulation classification (AMC). However, most of the available works learn signal features from only a single domain via DNNs, which is not reliable enough to work in uncertain and complex electromagnetic environments. In this brief, a new cross-domain signal transformer (CDSiT) is proposed for AMC, to explore the latent association between different domains of signals. By constructing a signal fusion bottleneck (SFB), CDSiT can implicitly fuse and classify signal features with complementary structures in different domains. Extensive experiments are performed on RadioML2016.10A and RadioML2018.01A, and the results show that CDSiT outperforms its counterparts, particularly for some modulation modes that are difficult to classify before. Through ablation experiences, we also verify the effectiveness of each module in CDSiT.

Mitotic Dysregulation at Tumor Initiation Creates a Therapeutic Vulnerability to Combination Anti-Mitotic and Pro-Apoptotic Agents for MYCN-Driven Neuroblastoma.

MYCN amplification occurs in approximately 20-30% of neuroblastoma patients and correlates with poor prognosis. The TH-MYCN transgenic mouse model mimics the development of human high-risk neuroblastoma and provides strong evidence for the oncogenic function of MYCN. In this study, we identified mitotic dysregulation as a hallmark of tumor initiation in the pre-cancerous ganglia from TH-MYCN mice that persists through tumor progression. Single-cell quantitative-PCR of coeliac ganglia from 10-day-old TH-MYCN mice revealed overexpression of mitotic genes in a subpopulation of premalignant neuroblasts at a level similar to single cells derived from established tumors. Prophylactic treatment using antimitotic agents barasertib and vincristine significantly delayed the onset of tumor formation, reduced pre-malignant neuroblast hyperplasia, and prolonged survival in TH-MYCN mice. Analysis of human neuroblastoma tumor cohorts showed a strong correlation between dysregulated mitosis and features of MYCN amplification, such as MYC(N) transcriptional activity, poor overall survival, and other clinical predictors of aggressive disease. To explore the therapeutic potential of targeting mitotic dysregulation, we showed that genetic and chemical inhibition of mitosis led to selective cell death in neuroblastoma cell lines with MYCN over-expression. Moreover, combination therapy with antimitotic compounds and BCL2 inhibitors exploited mitotic stress induced by antimitotics and was synergistically toxic to neuroblastoma cell lines. These results collectively suggest that mitotic dysregulation is a key component of tumorigenesis in early neuroblasts, which can be inhibited by the combination of antimitotic compounds and pro-apoptotic compounds in MYCN-driven neuroblastoma.

Slippery lubricant-infused silica nanoparticulate film processing for anti-biofouling applications.

Microbial biofilm build-up in water distribution systems can pose a risk to human health and pipe material integrity. The impact is more devastating in space stations and to astronauts due to the isolation from necessary replacement parts and medical resources. As a result, there is a need for coatings to be implemented onto the inner region of the pipe to minimize the adherence and growth of biofilms. Lubricant-infused surfaces has been one such interesting material for anti-biofouling applications in which their slippery property promotes repellence to many liquids and thus prevents bacterial adherence. Textured and porous films are suitable substrate candidates to infuse and contain the lubricant. However, there is little investigation in utilizing a nanoparticulate thin film as the substrate material for lubricant infusion. A nanoparticulate film has high porosity within the structure which can promote greater lubricant infusion and retention. The implementation as a thin film structure aids to reduce material consumption and cost. In our study, we utilized a well-studied nanoporous thin film fabricated via layer-by-layer assembly of polycations and colloid silica and then calcination for greater stability. The film was further functionalized to promote fluorinated groups and improve affinity with a fluorinated lubricant. The pristine nanoporous film was characterized to determine its morphology, thickness, wettability, and porosity. The lubricant-infused film was then tested for its lubricant layer stability upon various washing conditions and its performance against bacterial biofilm adherence as a result of its slippery property. Overall, the modified silica nanoparticulate thin film demonstrated potential as a base substrate for lubricant-infused surface fabrication that repelled against ambient aqueous solvents and as an anti-biofouling coating that demonstrated low biofilm coverage and colony forming unit values. Further optimization to improve lubricant retention or incorporation of a secondary function can aid in developing better coatings for biofilm mitigation.

Ultrathin Atomic Layer Deposited Al2O3 Overcoat Stabilizes Al2O3-Pt/Ni-Foam Hydrogenation Catalysts.

Galvanic exchange seeds the growth of Pt nanostructures on the Ni foam monolith. Subsequent atomic layer deposition of ultrathin Al2O3 followed by annealing under air affords supported Pt catalysts with ultralow loading (0.020 ppm). In addition to the expected enhancement of the stability of the Pt particles on the surface, the ∼2 nm Al2O3 overcoat appears to also play a crucial role in the overall structural integrity of the NiOx nanoplates that grow on the Ni foam surface as a result of the preparative route. The resulting material is physically robust toward repeated handling and showcases retention of catalytic activity over 10 standard catalyst recycling trials, standing in marked contrast to the uncoated samples. Catalyst activity was tested via the hydrogenation of various functionalized styrenes at low temperatures and low hydrogen pressure in ethanol as a solvent, with a TOF as high as 9.5 × 106 h-1 for unfunctionalized styrene. Notably, the catalysts show excellent tolerance toward F, Cl, and Br substituents and no hydrogenation of the aromatic ring.

Fully Integrated 3D Microelectrode Arrays with Polydopamine-Mediated Silicon Dioxide Insulation for Electrophysiological Interrogation of a Novel 3D Human, Neural Microphysiological Construct.

Advances within in vitro biological system complexity have enabled new possibilities for the "Organs-on-a-Chip" field. Microphysiological systems (MPS) as such incorporate sophisticated biological constructs with custom biological sensors. For microelectromechanical systems (MEMS) sensors, the dielectric layer is critical for device performance, where silicon dioxide (SiO2) represents an excellent candidate due to its biocompatibility and wide utility in MEMS devices. Yet, high temperatures traditionally preclude SiO2 from incorporation in polymer-based BioMEMS. Electron-beam deposition of SiO2 may provide a low-temperature, dielectric serving as a nanoporous MPS growth substrate. Herein, we enable improved adherence of nanoporous SiO2 to polycarbonate (PC) and 316L stainless steel (SS) via polydopamine (PDA)-mediated chemistry. The resulting stability of the combinatorial PDA-SiO2 film was interrogated, along with the nature of the intrafilm interactions. A custom polymer-metal three-dimensional (3D) microelectrode array (3D MEA) is then reported utilizing PDA-SiO2 insulation, for definition of novel dorsal root ganglion (DRG)/nociceptor and dorsal horn (DH) 3D neural constructs in excess of 6 months for the first time. Spontaneous/evoked compound action potentials (CAPs) are successfully reported. Finally, inhibitory drugs treatments showcase pharmacological responsiveness of the reported multipart biological activity. These results represent the initiation of a novel 3D MEA-integrated, 3D neural MPS for the long-term electrophysiological study.

Corrigendum: Loss of hepatic Surf4 depletes lipid droplets in the adrenal cortex but does not impair adrenal hormone production.

[This corrects the article DOI: 10.3389/fcvm.2021.764024.].

Surf4 (Surfeit Locus Protein 4) Deficiency Reduces Intestinal Lipid Absorption and Secretion and Decreases Metabolism in Mice.

BACKGROUND: Postprandial dyslipidemia is a causative risk factor for cardiovascular disease. The majority of absorbed dietary lipids are packaged into chylomicron and then delivered to circulation. Previous studies showed that Surf4 (surfeit locus protein 4) mediates very low-density lipoprotein secretion from hepatocytes. Silencing hepatic Surf4 markedly reduces the development of atherosclerosis in different mouse models of atherosclerosis without causing hepatic steatosis. However, the role of Surf4 in chylomicron secretion is unknown. METHODS: We developed inducible intestinal-specific Surf4 knockdown mice (Surf4IKO) using Vil1Cre-ERT2 and Surf4flox mice. Metabolic cages were used to monitor mouse metabolism. Enzymatic kits were employed to measure serum and tissue lipid levels. The expression of target genes was detected by qRT-PCR and Western Blot. Transmission electron microscopy and radiolabeled oleic acid were used to assess the structure of enterocytes and intestinal lipid absorption and secretion, respectively. Proteomics was performed to determine changes in protein expression in serum and jejunum. RESULTS: Surf4IKO mice, especially male Surf4IKO mice, displayed significant body weight loss, increased mortality, and reduced metabolism. Surf4IKO mice exhibited lipid accumulation in enterocytes and impaired fat absorption and secretion. Lipid droplets and small lipid vacuoles were accumulated in the cytosol and the endoplasmic reticulum lumen of the enterocytes of Surf4IKO mice, respectively. Surf4 colocalized with apoB and co-immunoprecipitated with apoB48 in differentiated Caco-2 cells. Intestinal Surf4 deficiency also significantly reduced serum triglyceride, cholesterol, and free fatty acid levels in mice. Proteomics data revealed that diverse pathways were altered in Surf4IKO mice. In addition, Surf4IKO mice had mild liver damage, decreased liver size and weight, and reduced hepatic triglyceride levels. CONCLUSIONS: Our findings demonstrate that intestinal Surf4 plays an essential role in lipid absorption and chylomicron secretion and suggest that the therapeutic use of Surf4 inhibition requires highly cell/tissue-specific targeting.

Kingella pumchi sp. nov., an organism isolated from human vertebral puncture tissue.

A Gram-negative, non-motile rod and strictly aerobic bacterium, designated as 18B16333T, was isolated from vertebral puncture tissue of a patient at Peking union medical college hospital in China. Growth occurred in NaCl concentrations of 0-1% (w/v) (optimum growth at 0% NaCl), at temperatures of 25-40 °C (optimum growth at 37 °C) and at pH 6.0-9.0 (optimum growth at pH 8.0). Diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine were the predominant polar lipids, and the major fatty acids were C16:0, C18:1 ω7c/C18:1 ω6c and C16:1 ω7c/C16:1 ω6c. Phylogenetic analysis based on 16S rRNA gene sequence comparisons indicated that strain 18B16333T was most closely related to Kingella potus CCUG 49773 T (97.3%, 16S rRNA gene sequence identity) and Neisseria bacilliformis CCUG 50858 T (96.8%). The ANI values between strain 18B16333T and the type strains K. potus CCUG 49773 T, N. bacilliformis CCUG 50858 T, Kingella kingae CCUG 352 T and Neisseria gonorrhoeae CCUG 26876 T were 77.3%, 79.1%, 72.1% and 75.4%, respectively. The dDDH values between strain 18B16333T and the four reference strains mentioned above were 24.8%, 26.9%, 24.2% and 20.7%. Further core gene analysis distinctively clustered strain 18B16333T with four Kingella species but not with Neisseria species. Based on the phenotypic, chemotaxonomic, and phylogenetic properties, strain 18B16333T represents a novel species of the genus Kingella, for which the name Kingella pumchi sp. nov. is proposed. The type strain is Kingella pumchi 18B16333T (= CICC 24913 T = CCUG 75125 T).

Macromolecules Absorbed from Influenza Infection-Based Sera Modulate the Cellular Uptake of Polymeric Nanoparticles.

Optimizing the biological identity of nanoparticles (NPs) for efficient tumor uptake remains challenging. The controlled formation of a protein corona on NPs through protein absorption from biofluids could favor a biological identity that enables tumor accumulation. To increase the diversity of proteins absorbed by NPs, sera derived from Influenza A virus (IAV)-infected mice were used to pre-coat NPs formed using a hyperbranched polyester polymer (HBPE-NPs). HBPE-NPs, encapsulating a tracking dye or cancer drug, were treated with sera from days 3-6 of IAV infection (VS3-6), and uptake of HBPE-NPs by breast cancer cells was examined. Cancer cells demonstrated better uptake of HBPE-NPs pre-treated with VS3-6 over polyethylene glycol (PEG)-HBPE-NPs, a standard NP surface modification. The uptake of VS5 pre-treated HBPE-NPs by monocytic cells (THP-1) was decreased over PEG-HBPE-NPs. VS5-treated HBPE-NPs delivered a cancer drug more efficiently and displayed better in vivo distribution over controls, remaining stable even after interacting with endothelial cells. Using a proteomics approach, proteins absorbed from sera-treated HBPE-NPs were identified, such as thrombospondin-1 (TSP-1), that could bind multiple cancer cell receptors. Our findings indicate that serum collected during an immune response to infection is a rich source of macromolecules that are absorbed by NPs and modulate their biological identity, achieving rationally designed uptake by targeted cell types.

Polydopamine surface functionalization of 3D printed resin material for enhanced polystyrene adhesion towards insulation layers for 3D microelectrode arrays (3D MEAs).

3D printing involves the use of photopolymerizable resins, which are toxic and typically have incompatible properties with materials such as polystyrene (PS), which present limitations for biomedical applications. We present a method to dramatically improve the poor adhesion between the PS insulative layer on 3D printed Microelectrode Array (MEA) substrates by functionalizing the resin surface with polydopamine (PDA), a mussel-inspired surface chemistry derivative. A commercial 3D printing prepolymer resin, FormLabs Clear (FLC), was printed using a digital light processing (DLP) printer and then surface functionalized with PDA by alkali-induced aqueous immersion deposition and self-polymerization. It was observed that the adhesion of the PS to FLC was improved due to the precision emanating from the DLP method and further improved after the functionalization of DLP printed substrates with PDA at 1, 12, and 24 h time intervals. The adhesion of PS was evaluated through scotch tape peel testing and instron measurements of planar substrates and incubation testing with qualitative analysis of printed culture wells. The composition and topology of the samples were studied to understand how the properties of the surface change after PDA functionalization and how this contributes to the overall improvement in PS adhesion. Furthermore, the surface energies at each PDA deposition time were calculated from contact angle studies as it related to adhesion. Finally, biocompatibility assays of the newly modified surfaces were performed using mouse cardiac cells (HL-1) to demonstrate the biocompatibility of the PDA functionalization process. PDA surface functionalization of 3D DLP printed FLC resin resulted in a dramatic improvement of thin film PS adhesion and proved to be a biocompatible solution for improving additive manufacturing processes to realize biosensors such as in vitro MEAs.

Cost-effective screen-printed carbon electrode biosensors for rapid detection of microcystin-LR in surface waters for early warning of harmful algal blooms.

Microcystins (MCs) are toxins produced by cyanobacteria commonly found in harmful algal blooms (HABs). Due to their toxicity to humans and other organisms, the World Health Organization (WHO) sets a guideline of 1 µg L-1 for microcystin-leucine-arginine (MC-LR) in drinking water. However, current analytical techniques for the detection of MC-LR such as liquid chromatography-mass spectrometry (LC-MS) and ELISA are costly, bulky, time-consuming, and mostly conducted in a laboratory, requiring highly trained personnel. An analytical method that can be used in the field for rapid determination is essential. In this study, an anti-MC-LR/MC-LR/cysteamine-coated screen-printed carbon electrode (SPCE) biosensor was newly developed to detect MC-LR, bioelectrochemically, in water. The functionalization of the electrode surface was confirmed with surface characterization methods. The sensor performance was evaluated by electrochemical impedance spectroscopy (EIS), obtaining a linear working range of MC-LR concentrations between 0.1 and 100 µg L-1 with a limit of detection (LOD) of 0.69 ng L-1. Natural water samples experiencing HABs were collected and analyzed using the developed biosensor, demonstrating the excellent performance of the biosensor with a relative standard deviation (RSD) of 0.65%. The interference tests showed minimal error and RSD values against other common MCs and possible coexisting ions found in water. The biosensor showed acceptable functionality with a shelf life of up to 12 weeks. Overall, the anti-MC-LR/MC-LR/cysteamine/SPCE biosensors can be an innovative solution with characteristics that allow for in situ, low-cost, and easy-to-use capabilities which are essential for developing an overarching and integrated "smart" environmental management system.

[Effect of invisible appliance without bracket and self-locking bracket appliance on periodontal and subgingival flora in patients with periodontitis].

PURPOSE: To observe the effect of non-bracket invisible appliance and self-locking bracket appliance on periodontal health and subgingival flora in patients with periodontitis. METHODS: One hundred and ten patients with periodontitis who received orthodontic treatment were divided into invisible group and self-locking bracket group. The periodontal index including probing depth (PD), gingival index (GI), sulcular bleeding index (SBI) and plaque index (PLI) ，and the levels of inflammatory factors in the gingival crevicular fluid were examined. Visual analogue scale (VAS) was used to evaluate periodontal pain before and after correction, and the curative effect was evaluated. The status of common pathogenic bacteria in the subgingival plaque of patients after correction was detected by PCR. The data were analyzed with SPSS19.0 software package. RESULTS: Twelve months after treatment and at the end of treatment, PLI of the self-locking bracket group was significantly higher than the invisible group(P＜0.05), but PD, GI and SBI between the two groups had no significant difference. After correction, the inflammatory factors in the invisible group were significantly lower than those in the self-locking bracket group(P＜0.05). At 1d after treatment, pain index in the invisible group was significantly lower than the self-locking group(P＜0.05). The clinical total effective rate of the invisible group was significantly higher than the self-locking group (89.10% vs 76.36%). After treatment, the detection rate and the content of subgingival pathogenic bacteria in the self-locking bracket group were significantly higher than the invisible group(P＜0.05). CONCLUSIONS: During orthodontic treatment of periodontitis, wearing non-bracket invisible appliance can effectively inhibit inflammatory response and proliferation of subgingival pathogens, which is more conducive to the maintenance of periodontal health and oral hygiene.

The role of hepatic Surf4 in lipoprotein metabolism and the development of atherosclerosis in apoE-/- mice.

Elevated plasma levels of low-density lipoprotein-C (LDL-C) increase the risk of atherosclerotic cardiovascular disease. Circulating LDL is derived from very low-density lipoprotein (VLDL) metabolism and cleared by LDL receptor (LDLR). We have previously demonstrated that cargo receptor Surfeit 4 (Surf4) mediates VLDL secretion. Inhibition of hepatic Surf4 impairs VLDL secretion, significantly reduces plasma LDL-C levels, and markedly mitigates the development of atherosclerosis in LDLR knockout (Ldlr-/-) mice. Here, we investigated the role of Surf4 in lipoprotein metabolism and the development of atherosclerosis in another commonly used mouse model of atherosclerosis, apolipoprotein E knockout (apoE-/-) mice. Adeno-associated viral shRNA was used to silence Surf4 expression mainly in the liver of apoE-/- mice. In apoE-/- mice fed a regular chow diet, knockdown of Surf4 expression significantly reduced triglyceride secretion and plasma levels of non-HDL cholesterol and triglycerides without causing hepatic lipid accumulation or liver damage. When Surf4 was knocked down in apoE-/- mice fed the Western-type diet, we observed a significant reduction in plasma levels of non-HDL cholesterol, but not triglycerides. Knockdown of Surf4 did not increase hepatic cholesterol and triglyceride levels or cause liver damage, but significantly diminished atherosclerosis lesions. Therefore, our findings indicate the potential of hepatic Surf4 inhibition as a novel therapeutic strategy to reduce the risk of atherosclerotic cardiovascular disease.

Genome-Based Analysis of Aspergillus niger Aggregate Species from China and Their Potential for Fumonisin B2 and Ochratoxin A Production.

Based on entire genome sequencing, this study focused on the classification of Aspergillus niger aggregation species and investigated their potential for fumonisin B2 (FB2) and ochratoxin A (OTA) production. In the current study, 22 strains were used, namely 17 A. niger strains, four A. welwitschiae strains, and one A. lacticoffeatus (a synonym of A. niger) strain. Traditional multigene phylogenetic analysis, average nucleotide identity analysis (ANI), and the whole-genome single-nucleotide polymorphism (SNP) analyses were used to reconfirm the taxonomic status of A. niger, A. welwitschiae, and A. lacticoffeatus. The ability of A. niger to produce FB2 and OTA on five culture substrates was determined, and the association between FB2 and OTA gene clusters and toxin-producing abilities was explored. The results revealed that the ANI method could distinguish A. niger from A. welwitschiae, with an ANI value of < 98%. The SNP-based phylogenetic analysis suggested that A. niger and A. welwitschiae were two independent phylogenetic species. The ANI, SNP, and multigene phylogenetic analysis supported previous findings that A. lacticoffeatus was a synonymous species of A. niger. Aspergillus niger strains exhibited the varied potential of producing FB2 and OTA on different culture media. The A. niger genome sequence analysis revealed no significant difference in fumonisin gene clusters between FB2-nonproducing isolates and FB2-producing isolates, and the integrity of the ochratoxin biosynthesis genes cluster was clearly associated with OTA production. In conclusion, gene sequencing can be useful in assessing A. niger's ability to produce OTA, but it cannot reliably predict its ability to produce FB2.

In-situ microplastic egestion efficiency of the eastern oyster Crassostrea virginica.

Microplastics (MP) are a pervasive environmental pollutant that enter coastal water bodies, posing an ingestion risk to marine biota. This study quantified the ability of the Eastern oyster (Crassostrea virginica) to egest MP in-situ in their biodeposits - feces and pseudofeces. Oysters of all sizes were able to egest environmental MP at a mean rate of 1 MP per 1 h through feces, and 1 MP per 2 h through pseudofeces. Smaller C. virginica were more efficient at egesting MP, and efficiency decreased by 0.8% per 1-g increase in tissue weight, with C. virginica of harvestable size being much less efficient. These findings are of relevance to resource managers for C. virginica populations as it further contributes to our understanding of MP accumulation in wild populations and has implications for not just C. virginica but also for their consumers.

An Energy Harvester Coupled with a Triboelectric Mechanism and Electrostatic Mechanism for Biomechanical Energy Harvesting.

Energy-harvesting devices based on a single energy conversion mechanism generally have a low output and low conversion efficiency. To solve this problem, an energy harvester coupled with a triboelectric mechanism and electrostatic mechanism for biomechanical energy harvesting is presented. The output performances of the device coupled with a triboelectric mechanism and electrostatic mechanism were systematically studied through principle analysis, simulation, and experimental demonstration. Experiments showed that the output performance of the device was greatly improved by coupling the electrostatic induction mechanisms, and a sustainable and enhanced peak power of approximately 289 µW was produced when the external impedance was 100 MΩ, which gave over a 46-fold enhancement to the conventional single triboelectric conversion mechanism. Moreover, it showed higher resolution for motion states compared with the conventional triboelectric nanogenerator, and can precisely and constantly monitor and distinguish various motion states, including stepping, walking, running, and jumping. Furthermore, it can charge a capacitor of 10 µF to 3 V within 2 min and light up 16 LEDs. On this basis, a self-powered access control system, based on gait recognition, was successfully demonstrated. This work proposes a novel and cost-effective method for biomechanical energy harvesting, which provides a more convenient choice for human motion status monitoring and can be widely used in personnel identification systems.

A novel ultrasound-mediated nanodroplet-based gene delivery system for osteoporosis treatment.

This project aimed to develop, optimize, and test an ultrasound-responsive targeted nanodroplet system for the delivery of osteoporosis-related silencing gene Cathepsin K small interfering RNA (CTSK siRNA) for osteoporosis treatment. The nanodroplet (ND) is composed of a gas core made from perfluorocarbon, stabilized with albumin, encapsulated with CTSK siRNA, and embedded with alendronate (AL) for bone targeting (CTSK siRNA-ND-AL). Following the development, the responsiveness of CTSK siRNA-ND-AL to a therapeutic ultrasound probe was examined. The results of biocompatibility tests with human bone marrow-derived mesenchymal stem cells proved no significant cell death (P > 0.05). When the CTSK siRNA-ND-AL was supplemented with human osteoclast precursors, they suppressed osteoclastogenesis. Thus, this project establishes the potential of nanotechnology and ultrasound to deliver genes into the osteoclasts. This research also presents a novel ultrasound responsive and targeted nanodroplet platform that can be used as a gene and drug delivery system for various diseases including cancer.

Nanoparticle-embedded hydrogel synthesized electrodes for electrochemical oxidation of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).

In this study, sliver (Ag) and gold (Au) nanoparticles (NPs) were embedded on poly (acrylic acid) (PAA)/poly (allylamine) hydrochloride (PAH) hydrogel fibers for improved electrochemical oxidation (EO) of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) removal. The NPs-loaded PAA/PAHs shows the better charge transport compared to the ceramic nanofiber membranes (CNM) electrodes. At 10 mA cm-2 of current density, the Ag-PAA/PAH electrodes showed a faster removal of PFAS compared to the Ag-CNM electrode probably due to large surface area-volume ratio and high porosity from the hydrogel. Among NPs-loaded PAA/PAH electrodes, the Ag/Au-PAA/PAH electrodes showed the highest removal of PFOA (72%) and PFOS (91%) in 2 h with the maximum removal rate of PFOA (0.0046 min-1) and PFOS (0.0093 min-1). The rapid PFOS removal is possibly due to the high activity of electron transfer with a higher redox potential of SO4•- than •OH. The highly stable F- generation was obtained from each electrode during reproducibility (n = 3). The net energy consumption from Ag/Au-PAA/PAH electrode was 164.9 kWh m-3 for 72% PFOA removal and 90 kWh m-3 for 91% PFOS removal, respectively. The developed Au-PAA/PAH electrodes were applied to lake water samples and showed acceptable PFOS removal (65%) with relative standard deviations (RSD) of 10.2% (n = 3) at 10 mA cm-2 of current density. Overall, the NP-embedded hydrogel nanofibers were proven to be a promising sustainable catalyst for the electrochemical PFAS oxidation in water.