Due to the surface inhomogeneity of the solid supports, direct growth of uniform bimetallic nanoparticles (NPs) with controllable structure and size thereon is particularly challenging. Herein, a ...surface‐confinement strategy is reported to directly prepare ultrafine bimetallic PtM NPs (MFe, Cu, and Co) with structure of core‐shell or intermetallic compounds on an N functionalized carbon support (NC). It is found that the N species of NC support can atomically disperse metal cations of precursors, which largely renders uniform nucleation and growth of bimetallic NPs and fine structure modulation of them. In another regard, metal transfer is confined to a narrow region on NC via N‐mediation, hence greatly favoring localized particle growth and formation of ultrafine bimetallic NPs. Remarkably, the ultrafine 3.1 ± 0.7 nm intermetallic Pt3Fe NPs on NC displayed excellent catalytic activity and durability toward electrochemical hydrogen evolution reaction.
A surface‐confinement growth mechanism is uncovered to selectively fabricate target structured ultrafine bimetallic nanoparticles such as the core‐shell and intermetallic PtM nanoparticles on the N functionalized carbon. Through structure manipulation, excellent catalytic performance toward electrochemical hydrogen evolution reaction is obtained over the supported intermetallic Pt3Fe nanoparticles.
The OH-initiated oxidation of vinyl alcohol (VA) produced by phototautomerization of acetaldehyde is thought to be a source of formic acid (FA) in the atmosphere. A recent theoretical study predicted ...that the VA + OH + O
reaction 1 proceeds by OH addition at α-C (66%) and β-C (33%) of VA and that FA is a main product of reaction 1. However, the metastable reactant ( anti-VA, ∼18% at 298 K, 1.42 kcal mol
higher than syn in energy) used in that study inspired us to reinvestigate reaction 1. Using the state-of-the-art quantum-chemical and kinetic calculations, we first found that a conformer of VA has a significant influence on the rate coefficient and branching ratio of reaction 1. Upon derivation, it is found that ∼84% of reaction 1 takes place through the β-C-addition channel and ∼16% of reaction 1 happens by the α-C-addition channel. The calculated total initial rate coefficient at 298 K is 1.48 × 10
cm
molecule
s
, which is in reasonable agreement with the experimental values of similar systems (vinyl ethers + OH reactions). The predicted main products of reaction 1 are glycolaldehyde and the HO
radical, whereas FA is just a byproduct.
Acetaminophen (APAP) abuse is a common public health problem which can cause severe liver damage. However, strategies for dealing with this situation safely and effectively are very limited. The goal ...of the current work was to evaluate the protection and potential molecular mechanisms of an ethanol extract from shoots of the wild vegetable shutou (Crateva unilocularis Buch.) (ECS) against APAP-induced liver damage in mice. Mice orally received ECS for seven days (300 or 600 mg/kg b.w. per day) before being intraperitoneally injected with APAP (250 mg/kg). Results exhibited that ECS obviously decreased the content of alkaline phosphatase, alanine aminotransferase, aspartate transaminase, and malondialdehyde (p < 0.05). Catalase and superoxide dismutase were notably restored (p < 0.05), and the content of reduced glutathione was obviously increased (p < 0.05). Moreover, ECS significantly inhibited the secretion of interleukin-1β and tumor necrosis factor-α (p < 0.05). Further analyses of the mechanisms showed that ECS may alleviate oxidative stress in the liver by increasing the expression of the nuclear factor erythroid-2-related factor 2 and NADH quinone oxidoreductase 1 proteins, and may suppress liver inflammation by inhibiting the expression of the phosphorylated-inhibitor kappa B alpha/inhibitor kappa B alpha, phosphorylated-nuclear factor κB/nuclear factor κB, and cyclooxygenase-2 proteins. Meanwhile, ECS inhibited hepatocyte apoptosis by enhancing B-cell lymphoma gene 2 and suppressing Bcl-2-associated X protein. In summary, ECS may be used as a dietary supplement to prevent the liver damage caused by APAP abuse.
The OH-initiated oxidation of vinyl alcohol (VA) produced by phototautomerization of acetaldehyde is thought to be a source of formic acid (FA) in the atmosphere. A recent theoretical study predicted ...that the VA + OH + O2 reaction 1 proceeds by OH addition at α-C (66%) and β-C (33%) of VA and that FA is a main product of reaction 1. However, the metastable reactant (anti-VA, ∼18% at 298 K, 1.42 kcal mol–1 higher than syn in energy) used in that study inspired us to reinvestigate reaction 1. Using the state-of-the-art quantum–chemical and kinetic calculations, we first found that a conformer of VA has a significant influence on the rate coefficient and branching ratio of reaction 1. Upon derivation, it is found that ∼84% of reaction 1 takes place through the β-C-addition channel and ∼16% of reaction 1 happens by the α-C-addition channel. The calculated total initial rate coefficient at 298 K is 1.48 × 10–11 cm3 molecule–1 s–1, which is in reasonable agreement with the experimental values of similar systems (vinyl ethers + OH reactions). The predicted main products of reaction 1 are glycolaldehyde and the HO2 radical, whereas FA is just a byproduct.
Mesoporous support-encapsulated fine-size metal nanoclusters hold great potential for catalytic applications by virtue of their high reactivity and fast mass transport kinetics but suffer greatly ...from particle aggregation and/or sintering, especially under high reaction temperatures. Here, we report an inner surface-confinement strategy to stabilize a variety of ultrafine metal nanoclusters (M = Pt, Pd, Ni, and Ag) inside mesoporous silica supports. The strategy is based on the selective N functionalization of the inner surface of mesopores, which not only assures the direct growth of ultrafine metal nanoclusters therein but also endows the active metal nanoclusters with excellent thermal stability via N-metal coordination. Remarkably, the mesopore-encapsulated N-coordinated Pt nanoclusters are particularly selective for making α,β-unsaturated alcohol, benefiting from their energetically favored reaction pathway for end-on binding α,β-unsaturated aldehyde reactants and heterolytic dissociation of hydrogen. The synthetic methodology is expected to provide new guidelines to improve the thermal stability of mesopore-encapsulated metal nanoclusters for superb catalysis.
Can a novel deep learning-based follicle volume biomarker using three-dimensional ultrasound (3D-US) be established to aid in the assessment of oocyte maturity, timing of HCG administration and the ...individual prediction of ovarian hyper-response?
A total of 515 IVF cases were enrolled, and 3D-US scanning was carried out on HCG administration day. A follicle volume biomarker established by means of a deep learning-based segmentation algorithm was used to calculate optimal leading follicle volume for predicting number of mature oocytes retrieved and optimizing HCG trigger timing. Performance of the novel biomarker cut-off value was compared with conventional two-dimensional ultrasound (2D-US) follicular diameter measurements in assessing oocyte retrieval outcome. Moreover, demographics, infertility work-up and ultrasound biomarkers were used to build models for predicting ovarian hyper-response.
On the basis of the deep learning method, the optimal cut-off value of the follicle volume biomarker was determined to be 0.5 cm3 for predicting number of mature oocytes retrieved; its performance was significantly better than the conventional method (two-dimensional diameter measurement ≥10 mm). The cut-off value for leading follicle volume to optimize HCG trigger timing was determined to be 3.0 cm3 and was significantly associated with a higher number of mature oocytes retrieved (P = 0.01). Accuracy of the multi-layer perceptron model was better than two-dimensional diameter measurement (0.890 versus 0.785) and other multivariate classifiers in predicting ovarian hyper-response (P < 0.001).
Deep learning segmentation methods and multivariate classifiers based on 3D-US were found to be potentially effective approaches for assessing mature oocyte retrieval outcome and individual prediction of ovarian hyper-response.
Recent research advances in bimetallic catalysts for carbon dioxide reduction reaction are comprehensively reviewed, covering their challenges, advantages, synthesis strategies, characterization ...techniques, applications, and mechanisms.
Display omitted
Carbon dioxide reduction reaction (CO2RR) represents an efficient approach to achieving carbon neutrality and simultaneously generating clean energy. However, the strong stability of CO2 molecules and the diversity of products pose significant challenges. As an emerging material, bimetallic catalysts have been widely reported for their unique advantages, such as tunable electronic structures, suitable adsorption/desorption of CO2 and intermediates, and optimizable d-band centers of active sites through bimetallic synergy. These catalysts provide a remarkable platform for converting CO2 into high value-added chemicals. This review comprehensively summarizes recent research advances in bimetallic catalysts for CO2RR. Firstly, the challenges associated with CO2RR, including activity and selectivity are analyzed, followed by a discussion on the unique advantages of bimetallic catalysts. Next, their synthesis strategies are categorized into dual-atom site catalysts (DACs), bimetallic nanoparticles and nanoclusters, binary metal semiconductors, and layered double hydroxides (LDHs). Additionally, advanced characterization techniques of bimetallic catalysts and their applications in CO2RR are thoroughly introduced. Finally, the prospects and challenges for the application of bimetallic materials are highlighted. This review aims to provide inspiration for CO2RR into high-value chemicals and shed light on the research of bimetallic materials.
Background/Aims: This study was to investigate the influence of scoparone on pancreatic fibrosis in vitro and in vivo. Methods: Pancreatic stellate cells (PSCs) were isolated from pancreas tissue ...blocks, and cultured for 3-5 generations for the experiment. PSCs were treated with scoparone in different doses as experimental groups, salvianolic acid B as a positive control and PBS as a blank group. We measured the effects of scoparone on cellular proliferation, oxidative stress, epithelial-mesenchymal transition (EMT), and pancreatic fibrosis. Cellular oxidative stress was detected by using commercially available kits. The impact of scoparone on EMT and fibrosis was detected through immunofluorescence or western blotting. Results: Compared with the control group, scoparone significantly inhibited stellate cell proliferation, and reduced MDA, the expression of mesenchymal makers, and increased the levels of SOD and the expression of E-cadherin (P < 0.05). Western blot analysis showed that scoparone downregulated the expression of TGF-β and p-smad2/3, and upregultated the expression of smad7 (P < 0.05). Conclusion: Scoparone can reduce the levels of oxidative stress, repress pancreatic stellate cells activation, and alleviate fibrosis by regulating TGF-β/Smad pathway.
Patients with inflammatory bowel disease, which includes ulcerative colitis and Crohn's disease, are at a significantly increased risk of developing colorectal cancer, and aberrant interleukin ...(IL)-6/STAT3 signaling pathway exists in both inflammatory bowel disease and inflammation-related gastrointestinal cancers. We have previously found that oroxylin A inhibited the NF-κB signaling in human colon tumor HCT-116 cells. However, whether oroxylin A could inhibit the colitis-associated carcinogenesis remains to be determined.
HCT-116 cells were treated with various concentrations of oroxylin A. Expression of relative proteins of IL-6/STAT3 signaling pathway was assayed by Western blot and immunofluorescence analysis. Mouse model for colitis-associated colorectal cancer was induced by a combined treatment with 10 mg/kg azoxymethane (AOM) followed by 3 cycles of 2.5% dextran sodium sulfate in C57BL/6 mice. IL-6 and IL-1β gene expression were analyzed by quantitative real-time PCR. Expression of relative proteins was examined by immunohistochemistry and Western blot.
Oroxylin A effectively inhibited IL-6/STAT3 pathway in human HCT-116 cells, and the effect of oroxylin A was reversible. Dietary administration of oroxylin A throughout the experimental period significantly reduced the tumor burden, inhibited cell proliferation, and induced apoptosis in colon carcinomas. The expression of inflammatory cytokines IL-6 and IL-1β decreased in tumors in oroxylin A-treated mice. The IL-6/STAT3 signaling pathway was attenuated in oroxylin A-treated mice.
Our results demonstrated that oroxylin A inhibits colitis-associated carcinogenesis through modulating IL-6/STAT3 pathway in AOM/dextran sodium sulfate mouse model and in HCT-116 cells.
Nowadays, the demand for high-speed information transmission is increasing rapidly. Visible light communication (VLC) based on light-emitting diodes (LEDs) is supposed as a potential candidate for ...future 6G communication networks. However, as an emerging field of optical communications, the data rate of VLC systems is restricted to the extremely limited modulation bandwidth and nonlinear characteristics of optoelectronic devices. In this paper, we outline the state of art and challenges of VLC, and introduce the key technologies for high-speed Silicon (Si) -substrate LED-based VLC systems. Based on an optimized integrated 4×4 8-wavelength LED array and advanced digital signal processing (DSP) methods, we demonstrate an ultrahigh-speed VLC system. Digital Zobel network (DZN) pre-equalization and transfer learning bidirectional gate recurrent unit (TL-Bi-GRU) based post-equalization are proposed to mitigate linear and nonlinear impairment. The yellow and green LEDs are especially enhanced in high-efficacy, and achieve the impressive data rates of 3.45 Gbit/s, and 3.83 Gbit/s respectively, which is a remarkable improvement. The achievable overall data rate of the device is 28.93 Gbit/s. As far as we know, it's the highest data rate achieved by a single-chip Si-substrate LED array.
PDF
