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•Highly dispersed CNTs grafted by –SO3- groups covalently.•Improved hydrate formation in SCNTs nanofluid.•Great recycling performances of SCNTs used in the repetitive hydrate ...formations.
The hydrate-based technology has been viewed as a great potential approach for the natural gas storage and transportation, whose commercialization however is challenged by the limited energy storage efficiency and slow formation kinetics. In this work, we used carbon nanotubes (CNTs) as carriers and covalently grafted functional group of -SO3- (similar to the hydrophilic group contained in sodium dodecyl sulfate) onto the nano-carriers surface to prepare a novel promoter, sulfonated carbon nanotubes (SCNTs). The SCNTs nanofluid showed higher dispersity and stability than the pristine CNTs (PCNTs). In the methane hydrate formations, the high methane storage capacity of 142 v/v in the SCNTs nanofluid was achieved, whereas 50–65 v/v was obtained with the oxidized CNTs (OCNTs) or PCNTs as promoter. Interestingly, the larger number of sulfonate groups grafted on CNTs, the shorter hydrate formation period and the smaller hydrate reaction stochasticity were obtained. The formation rate was enhanced from 0.237 mmol/(mol water·min) to 0.413 mmol/(mol water·min) when SCNTs concentration grew from 25 mg/L to 150 mg/L. Additionally, the SCNTs kept excellent recycling performance at ten reuses in the methane hydrate formations, which was meaningful to the actual hydrate-based gas storage and transportation.
A new, efficient Cu-catalyzed intramolecular C−H oxidation/acylation method has been developed for the synthesis of substituted indoline-2,3-diones (isatins). In the presence of CuCl2 and O2, a ...variety of formyl-N-arylformamides underwent the tandem reaction to afford the corresponding indoline-2,3-diones in moderate to good yields. It is noteworthy that the reaction serves as the first example of transition-metal-catalyzed transformation for the preparation of indoline-2,3-diones.
A flexible nickel foam (NF) based reduced Holey Graphene Oxide (rHGO) wrapping on NiO@NF hybrid supercapacitor electrode is fabricated using facile hydrothermal reaction followed by HGO dispersion ...dipping to achieve an efficient, bendable and scalable supercapacitor with high capacitance for wearable smart device usage. The sample electrode reveals a typical wrapping morphology of porous rHGO spreading on uniform nickel oxide crystal layer while exposing crystals through recurrent rHGO slits. Benefiting from this morphology and optimization of fabrication parameters, the sample electrode gains better electrochemical performance from higher electric double layer capacitance incorporation and more efficient electrolyte ion transportation, with less than 0.1 Ω equivalent series resistance (ESR), 752.9 F/g of capacitance, and 90% capacitance retention under 10 A/g current density. The sample electrode is then made into an all-solid-state supercapacitor device possessing 0.267 Wh/m2 energy density at a power density of 8.14 W/m2, and the bendable fact of the device endows it 97% capacitance retention after 500 times of curving, making it especially suitable as flexible energy provider. This simple fabrication method should shed light on flexible hybrid supercapacitor development.
AIM:To investigate the role of pre-B-cell leukemia homeobox(PBX)3 in migration and invasion of colorectal cancer(CRC)cells.METHODS:We detected PBX3 expression in five cell lines and surgical ...specimens from 111 patients with CRC using real-time reverse transcription-polymerase chain reaction.We forced expression of PBX3 in low metastatic HT-29 and SW480 cells and knocked down expression of PBX3 in highly metastatic LOVO and HCT-8 cells.Wound healing and Boyden chamber assays were used to detect cell migration and invasionafter altered expression of PBX3.Western blot was performed to detect the change of signaling molecule ERK1/2 following PBX3 overexpression.RESULTS:High level of PBX3 expression was correlated with the invasive potential of CRC cells,and significantly associated with lymph node invasion(P=0.02),distant metastasis(P=0.04),advanced TNM stage(P=0.03)and poor overall survival of patients(P<0.05).Ectopic expression of PBX3 in low metastatic cells was shown to promote migration and invasion,while inhibited PBX3 expression in highly metastatic cells suppressed migration and invasion.Furthermore,upregulation of phosphorylated extracellular signal-regulated kinase(ERK)1/2 was found to be one of the targeted molecules responsible for PBX3-induced CRC cell migration and invasion.CONCLUSION:PBX3 induces invasion and metastasis of CRC cells partially through activation of the MAPK/ERK signaling pathway.
This paper presents an optimal weighted least squares (WLS) method for designing low-complexity all-pass variable fractional-delay (VFD) digital filters. Instead of using a fixed range for the VFD ...parameter p and same-order constant-coefficient filters (subfilters), both the VFD parameter range p isin p Min , p Max and subfilter orders are optimized such that a low-complexity all-pass VFD filter can be achieved for the LS design. To suppress the peak errors of variable frequency response, weighting functions are adopted and optimized such that the boundary peak errors can be further reduced but without noticeably increasing the total error energy (integral of squared error) of variable frequency response. After optimizing the variable range of the VFD parameter, weighting functions, and subfilter orders, an all-pass VFD filter can be designed by using a generalized noniterative WLS method, which yields a closed-form solution. Design examples are given to illustrate that utilizing different-order subfilters, along with the optimal range and optimal weighting functions, can yield an all-pass VFD filter with significantly reduced complexity and design errors as compared with existing ones.
In this article, we have investigated the equations of motion of the photons coupled to Weyl tensor by the geometric optics approximation and the corresponding shadow in a Brane-World black hole ...spacetime. It is shown that there exists a double shadow for a black hole since the coupling photons with different polarization directions propagate along different paths in the spacetime. Furthermore, we discuss the effects of the metric parameter
α
related to the cosmological constant, X-cold dark matter parameter
β
and the coupling parameter
λ
on the umbra (the overlap region of the double shadow) and the penumbra. We also obtain the finite-distance corrections to the deflection angle of light in the Brane-World black hole spacetime as the photons coupled to Weyl tensor by using a recent geometric method.
The natural compound Zerumbone (hereinafter referred to as ZER), a monocyclic sesquiterpenoid, has been reported to possess many pharmacological properties, including antioxidant and ...anti-inflammatory properties. This study aimed to investigate the underlying mechanism of ZER against acute liver injury (ALI) in CCl
-induced mice models. ICR mice were pretreated intraperitoneally with ZER for five days, then received a CCl
injection two hours after the last ZER administration and were sacrificed 24 h later. Examination of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and the histopathological analysis confirmed the hepatoprotective effect of ZER. Biochemical assays revealed that ZER pretreatment recovered the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), restored the glutathione (GSH) reservoir, and reduced the production of malondialdehyde (MDA), all in a dose-dependent manner. Furthermore, administration of ZER in vivo reduced the release amounts of pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) and inhibited the increased protein levels of Toll-like receptor 4 (TLR4), nuclear factor-kappaB (NF-κB) p-p65, and cyclooxygenase (COX-2). Further studies in lipopolysaccharide (LPS)-induced Raw264.7 inflammatory cellular models verified that ZER could inhibit inflammation via inactivating the TLR4/NF-κB/COX-2 pathway. Thus, our study indicated that ZER exhibited a hepatoprotective effect against ALI through its antioxidant and anti-inflammatory activities and the possible mechanism might be mediated by the TLR4/NF-κB/COX-2 pathway. Collectively, our studies indicate ZER could be a potential candidate for chemical liver injury treatment.
Influences of magnetic field on microscopic structures and macroscopic properties of water are studied by the spectrum techniques of infrared, Raman, visible, ultraviolet lights and X-ray. From these ...investigations, we know that the magnetic fields change the distribution of molecules and electrons, cause displacements and polarization of molecules and atoms, result in changes of dipole-moment transition and vibrational states of molecules and variation of transition probability of electrons, but does not alter the constitution of molecules and atoms. These are helpful in seeking the mechanism of magnetization of water. Meanwhile, we also measure the changed rules of the surface tension force, soaking effect or angle of contact, viscosity, rheology features, refraction index, dielectric constant and electric conductivity of magnetized water relative to that of pure water. The results show that the magnetic fields increase the soaking degree and hydrophobicity of water to materials, depress its surface-tension force, diminish the viscosity of war, enhance the feature of plastic flowing of water, and increase the refraction index, dielectric constant and electric conductivity of water after magnetization. These changes are caused by the above changes of microscopic structures under the action of magnetic field. Therefore, our studies are significant in science and has practical value of applications.
Lightweight ECC (LWECC) has been extensively concerned due to its superior tensile performance, durability and low self-weight. However, the high environmental impact and material cost of ECC impede ...its broader engineering applications. The objective of this research is to develop a novel sustainable and cost-effective ultra-lightweight engineered cementitious composite (ULECC) under the micro-mechanical design theory. Five lightweight ECCs were designed using different lightweight fillers (LF) and replacement ratios with three mixtures being categorized as ULECC. The impacts of LF content and curing regimes (standard or hot-water curing) on the density, mechanical, and microstructural properties were investigated. The proposed ULECC exhibited impressive tensile behavior and a low density of 950–1260 kg/m3. The specific tensile strengths (strength-to-density ratio) and strain capacities of ULECC were 110% and 70% higher than conventional M45-ECC. Compared to the conventional LWECC, ULECC offered the competitive strength and ductility with a substantial increase in sustainability and reduction of material cost. Hot-water curing played a vital role in improving ductility-related performance. The micro-mechanical design theory and SEM analysis of ULECC well explained the test results. This research lays the groundwork for developing the sustainable and economical ULECC for future structural application.
We reported a novel and effective strategy to achieve higher continuity at a lower volume fraction of interphase by using compatibilizers in ternary blend consisting of PVDF, PS and HDPE. PVDF-g-PS ...was synthesized by electron beam radiation induced free radical graft copolymerization reaction and PVDF-g-PS was characterized by FTIR, DSC and 1H NMR. PVDF-g-PS showed effective compatibilization in PVDF/PS binary blend. The phase size of PVDF/PS binary blend was decreased at addition of PVDF-g-PS. For phase morphology development, morphology of uncompatibilized PVDF/PS/HDPE (52/6/42 vol%) ternary blend revealed a part of PS droplets situated in PVDF/HDPE interface, the other part was located inside HDPE phase. Whereas, compatibilized blend showed more and more PS migrate to PVDF/HDPE interface. When adding 7% PVDF-g-PS, PS droplets formed into uniform layer self-assembly arrayed at interface, then tri-continuous morphology was formed and continuity of PS phase increased by 32%, ultralow percolation threshold ternary blend was successfully achieved.
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•PVDF-g-PS is synthesized by electron beam radiation induced free radical graft copolymerization reaction.•PS droplets migrate to interface of PVDF/HDPE self-assembly when adding PVDF-g-PS.•Tri-continuous morphology in PVDF/PS/HDPE ternary blend is achieved at effect of PVDF-g-PS when PS phase is as low as 6%.
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