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•Both indirect oxidation and direct urea electro-oxidation paths exist on nickel.•Rate determining step depends on polarization potential and KOH concentration.•Nickel catalyst is ...poisoned by the CO2 intermediate.
Urea electro-oxidation reaction in alkaline medium is systematically analyzed by electrochemical impedance spectroscopy (EIS). The effects of polarization potential and KOH concentration on the impedance appearance are investigated. In the presence of urea, it is found that Nyquist plots exhibit two depressed semicircles, with one at higher frequencies stably locating in the first quadrant while the other’s location at lower frequencies varying between the first and second quadrant as the polarization potential changes. Results show both indirect and direct pathways proceed in urea electro-oxidation reaction. A mathematical model indicates the reverse loop in the Nyquist plots is attributed to CO2 poisoning on the catalyst, which is also validated by the followed chronoamperometric method. Moreover, the rate determining steps of urea electro-oxidation reaction is dependent on KOH concentration. The EIS technique gives a new sight to interpret the poor stability of urea electro-oxidation on nickel catalyst, and thus helps to explore a CO2-insensitive catalyst.
A highly sensitive sandwiched luminol electrochemiluminescence (ECL) immunosensor for sensitive detection of alpha-fetoprotein (AFP) was developed based on in situ generation of hydrogen peroxide ...working with platinum-gold alloy hybrid functionalized zinc oxide nanocomposites (Pt-Au@ZnONPs) as signal amplification.
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•The improved surface area and excellent biocompatibility of platinum-gold alloy hybrid functionalized zinc oxide nanocomposites (Pt-Au@ZnONPs) were used for binding the secondary antibody (Ab2) and glucose oxidase (GOD).•Pt-Au@ZnONPs and the loaded GOD amplified luminol ECL signals and promoted the luminal ECL response by efficiently catalyzing glucose to produce hydrogen peroxide (H2O2) in situ as a coreactant of luminol.•Pt-Au@ZnONPs catalyzed H2O2 to generate various reactive oxygen species that accelerated the ECL reaction of luminol, thus enhancing the ECL intensity of luminol and improving the sensitivity of the immunosensor.
A highly sensitive sandwiched luminol electrochemiluminescence (ECL) immunosensor has been constructed based on the double catalysis effect and multiamplification strategy of platinum-gold alloy hybrid functionalized zinc oxide nanocomposites (Pt-Au@ZnONPs). First, the improved surface area and excellent biocompatibility of Pt-Au@ZnONPs were used for binding the secondary antibody (Ab2) and glucose oxidase (GOD) to obtain the novel bioconjugate Pt-Au@ZnONPs-GOD-Ab2. Pt-Au@ZnONPs and the loaded GOD amplified luminol ECL signals and promoted the luminol ECL response by efficiently catalyzing glucose to produce hydrogen peroxide (H2O2) in situ as a coreactant of luminol. Then, Pt-Au@ZnONPs catalyzed H2O2 to generate various reactive oxygen species (ROSs) that accelerated the ECL reaction of luminol, thus enhanced the ECL intensity of luminol and improved the sensitivity of the immunosensor. Second, gold nanoparticles decorated reduced graphene sheets (AuNPs@GS) with large specific surface area, good biocompatibility, high conductivity, and high catalytic activity were prepared and used as substrate of the immunosensor to capture the primary antibody (Ab1). Experimental results demonstrated that the proposed ECL immunosensor showed a sensitive response for the detection of α-1-fetoprotein (AFP) from 0.1 pg mL−1 to 200 ng mL−1 with detection limit of 0.03 pg mL−1 (S/N = 3). The as-proposed luminol ECL immunosensor has excellent sensitivity, stability, and specificity, which makes it very promising for clinical applications.
Fabrication and performance of the castor oil (CO)‐based hyperbranched acrylate (C20AA) UV‐curable coatings are highlighted in this work. Herein, C20AA was obtained through a facile reaction of a ...castor oil‐based hyperbranched polyol (C20) with acrylic acid. FT‐IR and 1H NMR spectra confirmed the synthesis of the target C20AA. Subsequently, the as‐prepared C20AA was employed for crosslinking a commercialized linear polyurethane acrylate (PUA) UV‐curable oligomer. Specifically, by varying the content of C20AA over the range of 0, 20, 40, and 60 wt%, a series of UV‐curable coatings were prepared and coded as C20AA‐0, C20AA‐20, C20AA‐40, and C20AA‐60, respectively, which were further cured under UV irradiation. The effect of C20AA loadings on the UV‐curing efficiency and final polymer performance were investigated. Consequently, the tensile strength, Shore D hardness, pencil hardness, gel content, water resistance, and glass‐transition temperature of the UV‐cured coatings were greatly improved upon the addition of C20AA. Impressively, with the incorporation of 40 wt% C20AA, the resultant UV‐cured coating exhibited highest double bond conversion, superior chemical resistance, and good flexibility. Additionally, all of the coatings showed outstanding transparency and good surface microstructures.
This study was to investigate the expression correlation between long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1), miR-200a-3p and programmed death-ligand 1 ...(PD-L1) in non-small cell lung cancer (NSCLC), and their roles in NSCLC. Real-time polymerase chain reaction (PCR) was performed to detect the expressions of MALAT1, miR-200a-3p and PD-L1 in NSCLC tissues and cells for the correlation analysis. The starBase and Targetscan databases were used to predict the binding sites between MALAT1 and miR-200a-3p, and miR-200a-3p and PD-L1, respectively. The targeting relationship between MALAT1 and miR-200a-3p, and miR-200a-3p and PD-L1 were further verified by real-time PCR and dual luciferase reporter gene assay. Cell proliferation was monitored by CCK8 and colony formation assays. The apoptosis was detected using flow cytometry. Wound healing assay and transwell assay were conducted to determine cell migration and invasion. In this study, we demonstrated that in NSCLC tissues, the expression level of MALAT1 was negatively correlated with that of miR-200a-3p, while positively correlated with PD-L1. Besides, MALAT1 promoted proliferation, mobility, migration, and invasion of NSCLC cells via sponging miR-200a-3p. PD-L1 was validated as a target of miR-200a-3p, and indirectly modulated by MALAT1. In conclusion, LncRNA MALAT1 facilitates the progression of NSCLC by modulating miR-200a-3p/PDL1 axis.
This study aimed to investigate ADRB2 gene expression and further understand the effects of dexmedetomidine on cardiac output and oxygen metabolism in tissues and organs by comparing the changes in ...hemodynamics after the patient has been sedated with dexmedetomidine and propofol after abdominal surgery. A total of 84 patients were randomly divided into the Dexmedetomidine Group (DEX Group with 40 cases) and Propofol Group (PRO Group with 44 cases). For the DEX Group, dexmedetomidine was used for sedation (loading dose: 1 ug/kg, infused for 10min; maintenance dose: 0.3ug/kg/h ~); for the PRO Group, propofol was used for sedation (loading dose: 0.5mg/kg, infused for 10min; maintenance dose: 0.5mg/kg/h ~), and the dosage of sedation drug was according to the sedation target (BIS value 60-80). Before the sedation and 5min, 10min, 30min, 1h, 2h, 4h and 6h after the loading dose, the Mindray and Vigileo monitors were used to record the BIS values and hemodynamics indices of the patients in both groups. Both DEX and PRO groups could reach the target BIS value (P> 0.05). The CI decreases before and after the administration in both groups were significant (P <0.01). The SV level of DEX group after administration was higher than before administration, while the SV level of the PRO Group after administration was lower than before administration (P <0.01). The lactate clearance rate (6h) of DEX Group was higher than that of PRO Group (P <0.05). The incidence of postoperative delirium in the Dexmedetomidine Group was lower than in the Propofol Group (P <0.05). Compared with propofol, dexmedetomidine for sedation can reduce the heart rate and increase the cardiac stroke output. Cell analysis of the ADRB2 gene showed that this gene is more expressed in the cytosol. Also, its expression in the respiratory system is more than in other organs. Considering that this gene plays a role in stimulating the sympathetic nervous system and the cardiovascular system, it can be used in the safety regulation of clinical prognosis and treatment resistance along with Dexmedetomidine and Propofol.
T-cell immunoglobulin mucin-1 (TIM-1) has been reported to be associated with the biological behavior of several malignant tumors; however, it is not clear whether it has a role in cervical cancer ...(CC).
TIM-1 expression in cervical epithelial tumor tissues and cells was detected by immunohistochemistry or real-time quantitative-PCR and western blotting. CC cells from cell lines expressing low levels of TIM-1 were infected with lentiviral vectors encoding TIM-1. Changes in the malignant behavior of CC cells were assessed by CCK-8, wound healing, Transwell migration and invasion assays, and flow cytometry in vitro; while a xenograft tumor model was established to analyze the effects of TIM-1 on tumor growth in vivo. Changes in the levels of proteins related to the cell cycle, apoptosis, and Epithelial-mesenchymal transition (EMT) were determined by western blotting.
TIM-1 expression was higher in CC tissues, than in high grade squamous intraepithelial lesion, low grade squamous intraepithelial lesion, or normal cervical tissues, and was also expressed in three CC cell lines. In HeLa and SiHa cells overexpressing TIM-1, proliferation, invasion, and migration increased, while whereas apoptosis was inhibited. Furthermore, TIM-1 downregulated the expression of p53, BAX, and E-cadherin, and increased cyclin D1, Bcl-2, Snail1, N-cadherin, vimentin, MMP-2, and VEGF. PI3K, p-AKT, and mTOR protein levels also increased, while total AKT protein levels remained unchanged.
Our study indicated that TIM-1 overexpression promoted cell migration and invasion, and inhibited cell apoptosis in CC through modulation of the PI3K/AKT/p53 and PI3K/AKT/mTOR signaling pathways, and may be a candidate diagnostic biomarker of this disease.
In this research, a new Mg-air battery based on Mg–14Li–1Al–0.1Ce was prepared and the battery performance was investigated by constant current discharge test. The corrosion behavior of Mg, AZ31 and ...Mg–Li–Al–Ce were studied by self-corrosion rate measurement and potentiodynamic polarization measurement. The characteristics of Mg–Li–Al–Ce after discharge were investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that Mg–Li–Al–Ce is more active than Mg and AZ31. The self-corrosion rate is found to be in the order: Mg–Li–Al–Ce
<
Mg
<
AZ31. It has been observed that the Mg-air battery based on Mg–Li–Al–Ce offers higher operating voltage, anodic efficiency and capacity than those with Mg and AZ31. SEM and EIS results show that the discharge product of Mg–Li–Al–Ce is loosely adhered to the alloy surface, and thus Mg–Li–Al–Ce could keep high discharge activity during discharge.
In this study, five three-dimensional angle-interlock fabrics with different warp and weft densities were fabricated using 1000D Kevlar filaments. The Kevlar/EP composites were prepared by ...vacuum-assisted molding techniques. The low-velocity impact property of the composite was tested, focusing on the effects of the warp and weft densities, impact energy, impactor shape, and impactor diameter. The damage area, dent depth, and crack lengths in the warp and weft direction were used to evaluate the impact performance, and the specimens were compared with plain-weave composites with similar areal densities. The dominant failure mode of the conical impactor was fiber fracture, while the dominant failure mode of the hemispherical impactor was fiber-resin debonding. The cylindrical impactor showed only minor resin fragmentation. The residual flexural strength of the composite after impact was tested to provide insights into its mechanical properties. The study findings will provide a theoretical basis for the optimization of the design of impact-resistant structures using such materials and facilitate their engineering applications.
Abstract Purpose To evaluate the value of CT-based radiomics signature for differentiating Borrmann type IV gastric cancer (GC) from primary gastric lymphoma (PGL). Materials and methods 40 patients ...with Borrmann type IV GC and 30 patients with PGL were retrospectively recruited. 485 radiomics features were extracted and selected from the portal venous CT images to build a radiomics signature. Subjective CT findings, including gastric wall peristalsis, perigastric fat infiltration, lymphadenopathy below the renal hila and enhancement pattern, were assessed to construct a subjective findings model. The radiomics signature, subjective CT findings, age and gender were integrated into a combined model by multivariate analysis. The diagnostic performance of these three models was assessed with receiver operating characteristics curves (ROC) and were compared using DeLong test. Results The subjective findings model, the radiomics signature and the combined model showed a diagnostic accuracy of 81.43% (AUC area under the curve, 0.806; 95%CI confidence interval: 0.696-0.917; sensitivity, 63.33%; specificity, 95.00%), 84.29% (AUC, 0.886 95%CI: 0.809-0.963; sensitivity, 86.67%; specificity, 82.50%), 87.14% (AUC, 0.903 95%CI: 0.831-0.975; sensitivity, 70.00%; specificity, 100%), respectively. There were no significant differences in AUC among these three models (P = 0.051-0.422). Conclusion Radiomics analysis has the potential to accurately differentiate Borrmann type IV GC from PGL.
Graphene and its derivatives have exhibited wide potential applications in electronics, structural engineering and medicine. However, over utilization and untreated discharge may cause its ...distribution into environmental as well as biological chain, which raised the concerns of potential health risk as a potential hazard. Accumulating evidence has demonstrated that graphene derivatives induce lung fibrosis in vivo, so overall goal of this study was to explore the molecular mechanisms underlying the pulmonary fibrotic responses of reduced graphene oxide (rGO), using in vitro assays. Epithelial-mesenchymal transition (EMT) has profound effect on development of pulmonary fibrosis. Herein, we evaluated the EMT effect of rGO samples on A549 cells. Firstly, rGO penetrated through the A549 cells membrane into the cytosol by endocytosis and located in late endosome and/or lysosomes observed via transmission electron microscopy (TEM), and were well tolerant by cells. Secondly, rGO promoted the cell migration and invasion capacities at lower doses (below 10 μg/ml), but significantly inhibited the capacities at 20 μg/ml. Moreover, rGO-induced EMT were evidenced by decreased expression of epithelial marker like E-cadherin, β-catenin, Smad4 and increased expression of mesenchymal markers like Vimentin, VEGF-B, TWIST1. Based on our findings, it is supposed that rGO can effectively induce EMT through altering epithelial-mesenchymal transition markers in A549 cells.
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