Method of soft metal (Cu) strengthening of Ti
SiC
was conducted to increase the hardness and improve the wear resistance of Ti
SiC
. Ti
SiC
/Cu composites containing 15 vol.% Cu were fabricated by ...Spark Plasma Sintering (SPS) in a vacuum. The effect of the sintering temperature on the phase composition, microstructure and mechanical properties of the composites was investigated in detail. The as-synthesized composites were thoroughly characterized by scanning electron micrography (SEM), optical micrography (OM) and X-ray diffractometry (XRD), respectively. The results indicated that the constituent of the Ti
SiC
/Cu composites sintered at different temperatures included Ti
SiC
, Cu
Si and TiC. The formation of Cu
Si and TiC originated from the reaction between Ti
SiC
and Cu, which was induced by the presence of Cu and the de-intercalation of Si atoms Ti
SiC
. OM analysis showed that with the increase in the sintering temperature, the reaction between Ti
SiC
and Cu was severe, leading to the Ti
SiC
getting smaller and smaller. SEM measurements illustrated that the uniformity of the microstructure distribution of the composites was restricted by the agglomeration of Cu, controlling the mechanical behaviors of the composites. At 1000 °C, the distribution of Cu in the composites was relatively even; thus, the composites exhibited the highest density, relatively high hardness and compressive strength. The relationships of the temperature, the current and the axial dimension with the time during the sintering process were further discussed. Additionally, a schematic illustration was proposed to explain the related sintering characteristic of the composites sintered by SPS. The as-synthesized Ti
SiC
/Cu composites were expected to improve the wear resistance of polycrystalline Ti
SiC
.
Novel porous Co
3
O
4
nanosheets (NSs) were synthesized on the flexible carbon cloth (CC) substrate by a facile hydrothermal method and applied to construct a non-enzymatic sensor for glucose ...detection. The sensor is based on the electro-catalytic oxidation of glucose on the surface of Co
3
O
4
NSs. Since this particular nanostructure can provide large surface area and more active sites, the Co
3
O
4
NSs non-enzymatic sensor exhibits excellent analytical performance, such as a high sensitivity (8506 μA mM
−1
cm
−2
), a fast response time (less than 6 s), low detection limit of 1 μM, good selectivity, and long-term stability. The results suggest that the porous Co
3
O
4
NSs have great potential applications in the development of sensors for enzyme-free detection of glucose.
Goldfish have been subjected to over 1,000 y of intensive domestication and selective breeding. In this report, we describe a highquality goldfish genome (2n = 100), anchoring 95.75% of contigs into ...50 pseudochromosomes. Comparative genomics enabled us to disentangle the two subgenomes that resulted from an ancient hybridization event. Resequencing 185 representative goldfish variants and 16 wild crucian carp revealed the origin of goldfish and identified genomic regions that have been shaped by selective sweeps linked to its domestication. Our comprehensive collection of goldfish varieties enabled us to associate genetic variations with a number of well-known anatomical features, including features that distinguish traditional goldfish clades. Additionally, we identified a tyrosine-protein kinase receptor as a candidate causal gene for the first well-known case of Mendelian inheritance in goldfish—the transparent mutant. The goldfish genome and diversity data offer unique resources to make goldfish a promising model for functional genomics, as well as domestication.
Herein, the nanosized MOR zeolites were applied for selective catalytic reduction of NO x with NH3, and the effect of particle size on catalytic performance was studied in detail. Accordingly, three ...kinds of Cu-MOR with different particle sizes (0.23, 0.96, and 2.20 μm) were prepared and used for removing NO x from diesel exhaust. Our results demonstrated that Cu-MOR-0.23 with the minimal particle size had the best catalytic performance. Decreasing the particle size can effectively shorten the length of the C axis (12-MR channel), which is beneficial for the diffusion of substrates and products. This advantage was also verified by the Weisz–Prater criterion that the Cu-MOR with the smallest particle size has the least hindered diffusion of the mass transportation. Our work provides a new approach for promoting the catalytic performance of conventional cheaper catalysts used in the removal of NO x from diesel exhaust.
Krüppel-like factors (KLFs) regulate a wide variety of cellular functions and modulate pathological processes. In the present study, a post‑translational mechanism of microRNAs (miRs) was ...investigated in H2O2-induced human cardiomyocyte (HCM) injury. In H2O2‑cultured HCM cells, reactive oxygen species and apoptotic cells were measured via flow cytometry. miR‑506/‑124 mimics and inhibitors were transfected to induce gain or loss of miR‑506/‑124 function. Cell proliferation was analyzed by an MTT assay. The targeted genes were predicted by a bioinformatics algorithm and confirmed by a dual luciferase reporter assay. The mRNA and protein expression levels were measured by reverse transcription‑polymerse chain reaction analysis and western blotting, respectively. The results indicated that H2O2 induced significant apoptosis and increased the concentration of reactive oxygen species (ROS) in HCMs. H2O2 markedly upregulated the expression levels of KLF4 and KLF5, and downregulated the expression levels of miR‑506 and miR‑124 in the HCMs. In addition, bioinformatics analysis showed the potential miR‑506 and miR‑124 binding sites within the 3'‑untranslated region of KLF4 and KLF5 in the HCMs. The overexpression of miR‑506 and miR‑124 inhibited the H2O2‑induced upregulation of KLF4 and KLF5 in the HCMs. The overexpression of miR‑506 and miR‑214 reversed the H2O2‑induced apoptosis and increase of ROS in the HCMs. In conclusion, the overexpression of miR‑506 and miR‑214 were confirmed to have a protective effect against H2O2‑induced HCM injury by suppressing the expression of KLF4 and KLF5.
Abstract
Ti
3
C
2
layers with a layered two-dimensional structure are synthesized by immersing a precursor Ti
3
AlC
2
with hydrofluoric acid solution. The microstructure of Ti
3
C
2
layers is ...analyzed by SEM, XRD, Raman and AFM. Additionally, the tribological behavior of Ti
3
C
2
layers is investigated at various loads and sliding speeds by sliding against Si
3
N
4
balls on a UMT-2 tribometer. In comparison, the tribological behavior of Ti
3
AlC
2
at various loads is tested under identical condition. The results indicate that the Ti
3
C
2
layers have been successfully prepared and their thickness mainly distributes in the range of 2.3–3.1 nm. Moreover, the Ti
3
C
2
layers exhibit better tribological behavior than its precursor -Ti
3
AlC
2
in dry sliding. It is expected that the Ti
3
C
2
layers will be applied as a solid lubricant additive for other materials.
Astragalus membranaceus and Curcuma zedoaria, two traditional Chinese medicines, are widely used together in colorectal cancer adjuvant treatment. Many different mechanisms should be involved in the ...benefit effect of Astragalus membranaceus and Curcuma zedoaria. In this study, we established that the combined extract from Astragalus membranaceus and Curcuma zedoaria (HQEZ) decreased the metastasis ability in colorectal cancer cells (HCT116, a cell line of colorectal carcinoma established from Homo sapiens) in vitro, and the treatment induced the downregulation of EMT signal and decreased CXCR4 expression and the level of β-catenin. Overexpression of CXCR4 and the administration of the agonist and inhibitor to β-catenin signal pathway were used to explore the mechanism of Astragalus membranaceus and Curcuma zedoaria in colorectal cancer treatment. The data demonstrated that HQEZ increased the phosphorylation of β-catenin which related to the degradation of β-catenin, and it induced the downregulation of EMT signal and CXCR4. It meant that the influence of β-catenin should be a key event in the antimetastasis effects of Astragalus membranaceus-Curcuma zedoaria in colorectal cancer model. These findings revealed the potential effect and mechanism of Astragalus membranaceus-Curcuma zedoaria in colorectal cancer treatment and provided insight for optimization of the usage.
Here we developed a highly efficient solvent-free, one-pot procedure for synthesizing α-ketoamides from ethylarenes and amines, by oxidizing a C–H bond sp 3 center. A copper catalyst was employed, ...and the reactions proceeded smoothly at ambient temperatures. Most of the tested ethylarenes and amines were successfully converted to their corresponding α-ketoamides in moderate to excellent yields of up to 93% with three equivalents of the oxidant tert -butyl hydroperoxide.
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