Delaminated Ni-Al layered double hydroxide (LDH) was incorporated between graphene nanosheets to form a layered structure as a new generation of supercapacitor electrode material. First, Ni-Al ...layered double hydroxide (LDH) was grown hydrothermally, then delaminated by ultrasonication, and combined with a graphene oxide suspension prepared by a modified Hummers method. Subsequently, the graphene oxide in this mixture was reduced to graphene. It is the first time to prepare such layered hybrid structure from these two pre-prepared layered materials: graphene oxide and delaminated Ni-Al LDH in aqueous medium—instead of the in-situ growth of Ni-Al LDH on graphene oxide nanosheets. Using both materials in their layered form provided more contact between electrochemically active areas which resulted in two favourable conditions to realize their electrochemical energy storage capacity: graphene has enhanced the conductivity of Ni–Al LDH and eliminated the need of conducting additives; the Ni-Al LDH has prevented the restacking of graphene sheets. The layer structured hybrid material demonstrated a superior electrochemical performance due to the synergistic effect from the pseudocapacitance of Ni-Al LDH and the electrical double layer capacitance of graphene. The graphene/Ni-Al LDH–based electrodes provided a specific capacitance of 915F/g at a current density of 2A/g based on the total mass of active materials in the absence of conductive additives. After 1500 cycles at a current density of 10A/g, 95% of the initial capacitance was retained. The high electrochemical performance and facile aqueous-based synthesis route demonstrated that the G/Ni-Al LDH composite can be a promising electrode material for supercapacitor applications.
Redox-active polyimide materials hold a great promise for electrochemical energy storage applications, especially for flexible energy storage devices. However, the low utilization efficiency due to ...poor electrical conductivity of the materials remains one of the greatest challenges. In this work, we designed and prepared polyimide–graphene composite materials and tested their electrochemical properties in sodium-ion capacitors. By manipulating the interfacial chemistry and interactions between the polyimide and graphene, composite electrode materials with different polyimide particle sizes and morphologies were obtained. Sodium-ion storage capacity was significantly improved, from ∼50 mAh g–1 for pure polyimide to 225 mAh g–1 for a polyimide–graphene composite. A hybrid sodium-ion capacitor fabricated with freestanding polyimide–graphene composite as the negative electrode and reduced graphene oxide as the positive electrode delivered energy densities of 55.5 and 21.5 Wh kg–1 at power densities of 395 and 3400 W kg–1, respectively. A flexible sodium-ion capacitor with outstanding mechanical properties was also demonstrated.
The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This ...work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2
/
years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.
Summary
Porcine deltacoronavirus (PDCoV) is a recently identified coronavirus in the genus Deltacoronavirus that can cause enteric disease with clinical signs including diarrhoea, vomiting, ...dehydration and mortality in neonatal piglets. Although evidence of the prevalence of PDCoV in China is accumulating, little published information about Chinese PDCoV isolates is available. In this study, we investigated the presence of PDCoV in 49 faecal/intestinal samples from piglets with diarrhoea on different farms in Hebei province. Five samples (10.2%) were positive for PDCoV, but no coinfection of PDCoV with other enteropathogens was observed. A PDCoV strain named HB‐BD was successfully isolated from the intestinal contents of a diarrhoeic piglet and serially propagated in swine testicular (ST) cells for >40 passages. The complete genome of the HB‐BD strain was sequenced and analysed. Genomic analysis showed that the HB‐BD strain had a closer relationship with Chinese strains than those from other countries and was grouped within the Chinese PDCoV cluster. The results of this study will be valuable for further research of PDCoV genetic evolution and development of effective diagnostic reagents, assays and potential vaccines against newly emerged PDCoV strains.
Located at the important tumor suppressor locus, 3p22, PLCD1 encodes an enzyme that mediates regulatory signaling of energy metabolism, calcium homeostasis and intracellular movements. We identified ...PLCD1 as a downregulated gene in aerodigestive carcinomas through expression profiling and epigenetic characterization. We found that PLCD1 was expressed in all normal adult tissues but low or silenced in 84% (16/19) gastric cancer cell lines, well correlated with its CpG island (CGI) methylation status. Methylation was further detected in 62% (61/98) gastric primary tumors, but none of normal gastric mucosa tissues. PLCD1 methylation was significantly correlated with tumor high stage. Detailed methylation analysis of 37 CpG sites at the PLCD1 CGI by bisulfite genomic sequencing confirmed its methylation. PLCD1 silencing could be reversed by pharmacological demethylation with 5-aza-2'-deoxycytidine, indicating a direct epigenetic silencing. Ectopic expression of PLCD1 in silenced gastric tumor cells dramatically inhibited their clonogenicity and migration, possibly through downregulating MMP7 expression and hampering the reorganization of cytoskeleton through cofilin inactivation by phosphorylation. Thus, epigenetic inactivation of PLCD1 is common and tumor-specific in gastric cancer, and PLCD1 acts as a functional tumor suppressor involved in gastric carcinogenesis.
Abstract
A theoretical study on the interplay of frustrated skyrmion and magnons should reveal new physics and future experiment designs. In this study, we investigate the magnon-driven dynamics of ...frustrated skyrmion in synthetic antiferromagnets based on micromagnetic simulations, focusing on the effect of skyrmion helicity oscillation. The oscillation speed and Hall angle of the frustrated skyrmion depending on the magnon intensity and damping constant are simulated, which demonstrates that the skyrmion helicity oscillation effectively suppresses Hall motion. The elastic scattering theory reveals that the helicity oscillation affects the scattering cross-section of injected magnons, which in turn effectively modulates the skyrmion Hall motion. This study provides a comprehensive understanding of magnon-skyrmion scattering in frustrated magnets, thus benefiting future spintronic and magnonic applications.
To evaluate different features between benign and malignant pulmonary focal ground-glass opacity (fGGO) on multidetector CT (MDCT).
82 pathologically or clinically confirmed fGGOs were ...retrospectively analysed with regard to demographic data, lesion size and location, attenuation value and MDCT features including shape, margin, interface, internal characteristics and adjacent structure. Differences between benign and malignant fGGOs were analysed using a χ(2) test, Fisher's exact test or Mann-Whitney U-test. Morphological characteristics were analysed by binary logistic regression analysis to estimate the likelihood of malignancy.
There were 21 benign and 61 malignant lesions. No statistical differences were found between benign and malignant fGGOs in terms of demographic data, size, location and attenuation value. The frequency of lobulation (p=0.000), spiculation (p=0.008), spine-like process (p=0.004), well-defined but coarse interface (p=0.000), bronchus cut-off (p=0.003), other air-containing space (p=0.000), pleural indentation (p=0.000) and vascular convergence (p=0.006) was significantly higher in malignant fGGOs than that in benign fGGOs. Binary logistic regression analysis showed that lobulation, interface and pleural indentation were important indicators for malignant diagnosis of fGGO, with the corresponding odds ratios of 8.122, 3.139 and 9.076, respectively. In addition, a well-defined but coarse interface was the most important indicator of malignancy among all interface types. With all three important indicators considered, the diagnostic sensitivity, specificity and accuracy were 93.4%, 66.7% and 86.6%, respectively.
An fGGO with lobulation, a well-defined but coarse interface and pleural indentation gives a greater than average likelihood of being malignant.
Polyamines, small aliphatic polycations, have been suggested to play key roles in a number of biological processes. In this paper, attempts were made to investigate the possibility of improving ...dehydration tolerance of citrus in vitro plants by exogenous application of spermine (Spm). ‘Red Tangerine’ (Citrus reticulata Blanco) in vitro plants pretreated with 1 mM Spm exhibited less wilted phenotype and lower water loss and electrolyte leakage than the control under dehydration. Spm-pretreated plants contained higher endogenous polyamine content during the course of the experiment relative to the control, particularly at the end of dehydration, coupled with higher expression levels of ADC and SPMS. Histochemical staining showed that the Spm-pretreated leaves were stained to a lower extent than those without Spm pretreatment, implying generation of less reactive oxygen species (ROS). On the contrary, activities of peroxidase (POD) and superoxide dismutase (SOD) in the Spm-pretreated samples were higher than the control at a given time point or during the whole experiment, suggesting that Spm exerted a positive effect on antioxidant systems. In addition, significantly smaller stomatal aperture size was observed in Spm-pretreated epidermal peels, which showed that stomatal closure was promoted by polyamines. All of these data suggest that Spm pretreatment causes accumulation of higher endogenous polyamines and accordingly leads to more effective ROS scavenging (less tissue damage) and stimulated stomatal closure (lower water loss) upon dehydration, which may function collectively to enhance dehydration tolerance.
Abstract
Powders surface precipitate has strong relations with the microstructure and properties of powder metallurgy components. Morphology, element distribution and crystal structure of the ...precipitate at gas atomized Ni-base superalloy powders surface were investigated. Results show that the precipitate is lamelliform and prefers to form at grain boundaries and interdendrite regions than dendrite arms. With powders size decreasing, the precipitate shape observed from surface varies from strip to rectangular and to nearly round, and the precipitate density increases, measured 17.75 μm
−2
, 21.42 μm
−2
, 26.50 μm
−2
at nearly 45μm, 30μm and 10μm powders surface respectively, but the precipitate average size changes conversely, that is 228nm, 193nm, 77nm respectively. The precipitate enriches in high melting point elements Ti, Nb, Mo, W, Zr and poor in low melting point elements Ni, Cr, Co, Al. Crystal structure analysis reveals that the precipitate is MC, M
23
C
6
or M
6
C carbide.
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