Solidified natural gas storage using gas hydrates is a promising technology for non-explosive, high capacity, and environmentally-friendly natural gas storage at mild storage conditions. Improvement ...in the kinetics of gas hydrate formation is essential for the further development of this novel technology. In this work, the use of graphite nanofluids for enhancing the CH4 hydrate formation was investigated. The experiments were conducted in a stirred tank reactor at 277.15 K and 6.0 MPa. The behavior of the CH4 hydrate nucleation and growth in graphite nanofluids was observed using a microscopy apparatus. The results indicate that compared to liquid water, the gas storage capacity obtained in graphite nanofluids increased by 3%, the induction time for the CH4 hydrate formation decreased by 89%, and the total time for hydrate formation decreased by 67%. Among the three graphite nanoparticles concentrations (0.2, 0.5, and 1.0 wt%) tested in this work, the concentration of 0.5 wt% was optimal for the enhancement of CH4 hydrate formation. The gas storage capacity obtained in the 0.5 wt% graphite nanofluids was higher than that obtained in other nanofluids such as the Fe3O4 and ZnO nanofluids. Thus, the use of graphite nanofluids is an effective approach to enhance hydrate formation for solidified natural gas storage, but the gas storage capacity should be further increased in future work.
•Graphite nanofluids was used to promote CH4 hydrate formation.•The effects of graphite nanoparticles on gas consumption and CH4 storage capacity were elucidated.•CH4 storage capacity obtained in graphite nanofluids was increased compared to other nanofluids.
BACKGROUND AND PURPOSE—Stroke is a major public health concern worldwide. Although clinical treatments have improved in the acute period after stroke, long-term therapeutics remain limited to ...physical rehabilitation in the delayed phase. This study is aimed to determine whether nNOS (neuronal NO synthase)-CAPON (carboxy-terminal postsynaptic density-95/discs large/zona occludens-1 ligand of nNOS) interaction may serve as a new therapeutic target in the delayed phase for stroke recovery.
METHODS—Photothrombotic stroke and transient middle cerebral artery occlusion were induced in mice. Adeno-associated virus (AAV)-cytomegalovirus (CMV)-CAPON-125C-GFP (green fluorescent protein)-3Flag and the other 2 drugs (Tat-CAPON-12C and ZLc-002) were microinjected into the peri-infarct cortex immediately and 4 to 10 days after photothrombotic stroke, respectively. ZLc-002 was also systemically injected 4 to 10 days after transient middle cerebral artery occlusion. Grid-walking task and cylinder task were conducted to assess motor function. Western blotting, immunohistochemistry, Golgi staining, and electrophysiology recordings were performed to uncover the mechanisms.
RESULTS—Stroke increased nNOS-CAPON association in the peri-infarct cortex in the delayed period. Inhibiting the ischemia-induced nNOS-CAPON association substantially decreased the number of foot faults in the grid-walking task and forelimb asymmetry in the cylinder task, suggesting the promotion of functional recovery from stroke. Moreover, dissociating nNOS-CAPON significantly facilitated dendritic remodeling and synaptic transmission, indicated by increased dendritic spine density, dendritic branching, and length and miniature excitatory postsynaptic current frequency but did not affect stroke-elicited neuronal loss, infarct size, or cerebral edema, suggesting that nNOS-CAPON interaction may function via regulating structural neuroplasticity, rather than neuroprotection. Furthermore, ZLc-002 reversed the transient middle cerebral artery occlusion–induced impairment of motor function.
CONCLUSIONS—Our results reveal that nNOS-CAPON coupling can serve as a novel pharmacological target for functional restoration after stroke.
The high viscosity and low fluidity of heavy crude oil hinder its sorption by conventional porous sorbents, so the efficient clean‐up of such heavy crude oil spills is challenging. Recently, Joule ...heating has been emerging as a new tool to reduce the viscosity of heavy crude oil dramatically. However, this direct‐contact heating approach presents a potential risk due to the high voltage applied. To develop a non‐contact recovery of viscous crude oil, here, a new approach for the fabrication of a series of ferrimagnetic sponges (FMSs) with hydrophobic porous channels is reported, whose surface can be remotely heated to 120 °C within 10 s under an alternating magnetic field (f = 274 kHz, H = 30 kA m−1). Compared with the solar‐driven superficial heating, the integral magnetic heating in FMSs can result in a higher internal temperature of the sponges because of the confinement of thermal transport in the porous channels, which contributes to a dramatic decrease in oil viscosity and a significant increase in oil flow into the pores of FMSs. Furthermore, FMSs assembled with a self‐priming pump can achieve continuous recovery of viscous crude oil (33.05 g h−1 cm−2) via remotely magnetic heating.
A ferrimagnetic sponge with the skeletons coated with poly(dimethylsiloxane) and iron oxide nanoparticles is developed to achieve continuous recovery of viscous crude oil. Under the exposure of an alternating magnetic field, the viscosity of the viscous oil around the sponge decreases sharply, thus accelerating its absorption.
Synthetic polymeric scaffolds are commonly used in bone tissue engineering (BTE) due to their biocompatibility and adequate mechanical properties. However, their hydrophobicity and the lack of ...specific cell recognition sites confined their practical application. In this study, to improve the cell seeding efficiency and osteoinductivity, an injectable thermo-sensitive chitosan hydrogel (CSG) was incorporated into a 3D-printed poly(ε-caprolactone) (PCL) scaffold to form a hybrid scaffold. To demonstrate the feasibility of this hybrid system for BTE application, rabbit bone marrow mesenchymal stem cells (BMMSCs) and bone morphogenetic protein-2 (BMP-2) were encapsulated in CSG. Pure PCL scaffolds were used as controls. Cell proliferation and viability were investigated. Osteogenic gene expressions of BMMSCs in various scaffolds were determined with reverse transcription polymerase chain reaction (RT-PCR). Growth factor releasing profile and mechanical tests were performed. CCK-8 assay confirmed greater cell retention and proliferation in chitosan and hybrid groups. Confocal microscopy showed even distribution of cells in the hybrid system. After 2-week osteogenic culture in vitro, BMMSCs in hybrid and chitosan scaffolds showed stronger osteogenesis and bone-matrix formation. To conclude, chitosan/PCL hybrid scaffolds are a favorable platform for BTE due to its capacity to carry cells and drugs, and excellent mechanical strength.
Although the key metabolic regulatory functions of mammalian peroxisome proliferator-activated receptor α (PPARα) have been thoroughly studied, the molecular mechanisms and metabolic regulation of ...PPARα activation in fish are less known. In the first part of the present study, Nile tilapia (Nt)PPARα was cloned and identified, and high mRNA expression levels were detected in the brain, liver, and heart. NtPPARα was activated by an agonist (fenofibrate) and by fasting and was verified in primary hepatocytes and living fish by decreased phosphorylation of NtPPARα and/or increased NtPPARα mRNA and protein expression. In the second part of the present work, fenofibrate was fed to fish or fish were fasted for 4weeks to investigate the metabolic regulatory effects of NtPPARα. A transcriptomic study was also performed. The results indicated that fenofibrate decreased hepatic triglyceride and 18C-series fatty acid contents but increased the catabolic rate of intraperitoneally injected 1-14C palmitate in vivo, hepatic mitochondrial β-oxidation efficiency, the quantity of cytochrome b DNA, and carnitine palmitoyltransferase-1a mRNA expression. Fenofibrate also increased serum glucose, insulin, and lactate concentrations. Fasting had stronger hypolipidemic and gene regulatory effects than those of fenofibrate. Taken together, we conclude that: 1) liver is one of the main target tissues of the metabolic regulation of NtPPARα activation; 2) dephosphorylation is the basal NtPPARα activation mechanism rather than enhanced mRNA and protein expression; 3) activated NtPPARα has a hypolipidemic effect by increasing activity and the number of hepatic mitochondria; and 4) PPARα activation affects carbohydrate metabolism by altering energy homeostasis among nutrients.
•PPARα was activated in response to fenofibrate and fasting in Nile tilapia.•Liver is one of the main target tissues of NtPPARα activation.•Dephosphorylation is the basal mechanism of NtPPARα activation.•NtPPARα activation increased activity and the number of hepatic mitochondria.•PPARα activation affects carbohydrate metabolism.
A room‐temperature, visible‐light‐driven N‐centered iminyl radical‐mediated and redox‐neutral C−C single bond cleavage/radical addition cascade reaction of oxime esters and unsaturated systems has ...been accomplished. The strategy tolerates a wide range of O‐acyl oximes and unsaturated systems, such as alkenes, silyl enol ethers, alkynes, and isonitrile, enabling highly selective formation of various chemical bonds. This method thus provides an efficient approach to various diversely substituted cyano‐containing alkenes, ketones, carbocycles, and heterocycles.
A visible‐light‐driven room‐temperature N‐centered iminyl radical‐mediated and redox‐neutral C−C single bond cleavage/radical addition cascade reaction of oxime esters and unsaturated systems has been accomplished. The strategy tolerates a wide range of O‐acyl oximes and alkenes, silyl enol ethers, alkynes, and isonitrile. This method allows access to various cyano‐containing alkenes, ketones, carbocycles, and heterocycles.
Understanding the underlying molecular mechanisms of liver fibrosis is important to develop effective therapy. Herein, we show that focal-adhesion-kinse (FAK) plays a key role in promoting hepatic ...stellate cells (HSCs) activation in vitro and liver fibrosis progression in vivo. FAK activation is associated with increased expression of α-smooth muscle actin (α-SMA) and collagen in fibrotic live tissues. Transforming growth factor beta-1 (TGF-β1) induces FAK activation in a time and dose dependent manner. FAK activation precedes the α-SMA expression in HSCs. Inhibition of FAK activation blocks the α-SMA and collagen expression, and inhibits the formation of stress fibers in TGF-β1 treated HSCs. Furthermore, inhibition of FAK activation significantly reduces HSC migration and small GTPase activation, and induces apoptotic signaling in TGF-β1 treated HSCs. Importantly, FAK inhibitor attenuates liver fibrosis in vivo and significantly reduces collagen and α-SMA expression in an animal model of liver fibrosis. These data demonstrate that FAK plays an essential role in HSC activation and liver fibrosis progression, and FAK signaling pathway could be a potential target for liver fibrosis.
Sodium‐ion batteries (SIBs) show practical applications in large‐scale energy storage systems. But, their power density is limited by the sluggish Na+ diffusion into the cathode and anode materials. ...Herein, the authors demonstrate a prototype of ultrahigh power SIB, consisting of the high‐rate Na3V2(PO4)3 (NVP) cathode, graphite‐type mesocarbon microbeads (MCMB) anode, and Na+‐diglyme electrolyte. It is found that the overpotential of the NVP cathode obeys the Ohmic rule. Thus, the as‐synthesized NVP@C@carbon nanotubes (CNTs) cathode with the high conductive CNTs networks displays high electronic conductivity, reducing the overpotential and charge transfer resistances and leading to the remarkable rate capability over 1000C. For the MCMB anode, the initial Na‐diglyme+ co‐intercalation step is pseudocapacitive dominated, and then the expanded graphite's layers ensure the subsequent fast ions diffusion. The rapid (de)intercalation kinetics in between the cathode and anode are well‐matched. Thus, the assembled MCMB|1 m NaPF6 in diglyme|NVP@C@CNTs full‐cell SIB delivers the energy density of 88 Wh kg−1 at the high power density of ≈10 kW kg−1. Even at the ultrahigh power density of 23 kW kg−1, an energy density of 58 Wh kg−1 is obtained. The encouraging results of the full cell will promote the development of high‐power SIB for large‐scale applications in the future.
A prototype of ultrahigh power sodium ion battery (SIB), mesocarbon microbeads|Na+‐diglyme|Na3V2(PO4)3, is assembled. The as‐synthesized Na3V2(PO4)3@C@CNTs cathode and mesocarbon microbeads anode display the well‐matched rate capability. The assembled full‐cell delivers an energy density of 88 Wh kg−1 at ultrahigh power density of ≈10 kW kg−1.
A novel two‐stage profile maximum likelihood estimator is proposed to estimate the source location and the systematic errors jointly, with the aim of addressing the problem of source localisation ...using angle‐only measurements from a single sensor with unknown sensor altitude and systematic measurement errors. The proposed two‐stage profile maximum likelihood estimator algorithm is capable of decoupling the azimuth and elevation angle measurements while transforming the original maximum likelihood optimisation problem into two sub‐problems, that is, two‐dimensional‐projected maximum likelihood estimator and relative altitude maximum likelihood estimator. In terms of the two‐dimensional‐projected maximum likelihood estimator, an algorithm combining pseudo‐linear estimating and Kalman filtering is proposed to generate an initial estimate. Subsequently, a Gauss–Newton iterative method is developed to estimate the two‐dimensional‐projected target location and the azimuth systematic error jointly. The relative height maximum likelihood estimator is initialised using a pseudo‐linear estimator. Next, a Gauss–Newton iterative algorithm is adopted to estimate the elevation systematic error and the relative height. As indicated by the result of the simulation studies, the proposed algorithm exhibits an estimation performance close to the Cramér–Rao lower bound with unknown sensor altitude and systematic measurement errors.
A novel 2S‐PMLE algorithm is proposed to address the problem of SPAOSL with unknown sensor altitude and systematic measurement errors by jointly estimating the source position and the systematic errors. The CRLB is derived and simulation studies are done by comparing the proposed algorithms with other angle‐only source localisation algorithms.
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