The adsorption and electrooxidation of CO molecules at well‐defined Pt(hkl) single‐crystal electrode surfaces is a key step towards addressing catalyst poisoning mechanisms in fuel cells. Herein, we ...employed in situ electrochemical shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS) coupled with theoretical calculation to investigate CO electrooxidation on Pt(hkl) surfaces in acidic solution. We obtained the Raman signal of top‐ and bridge‐site adsorbed CO* molecules on Pt(111) and Pt(100). In contrast, on Pt(110) surfaces only top‐site adsorbed CO* was detected during the entire electrooxidation process. Direct spectroscopic evidence for OH* and COOH* species forming on Pt(100) and Pt(111) surfaces was afforded and confirmed subsequently via isotope substitution experiments and DFT calculations. In summary, the formation and adsorption of OH* and COOH* species plays a vital role in expediting the electrooxidation process, which relates with the pre‐oxidation peak of CO electrooxidation. This work deepens knowledge of the CO electrooxidation process and provides new perspectives for the design of anti‐poisoning and highly effective catalysts.
CO electrooxidation on Pt(hkl) surfaces in acidic solution has been investigated using in situ shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS). Direct spectroscopic evidence for OH* and COOH* species was observed and further confirmed by deuterium isotopic experiments and DFT calculations.
All molecules consist of chemical bonds, and much can be learned from mapping the spatiotemporal dynamics of these bonds. Since its invention a decade ago, stimulated Raman scattering (SRS) ...microscopy has become a powerful modality for imaging chemical bonds with high sensitivity, resolution, speed and specificity. We introduce the fundamentals of SRS microscopy and review innovations in SRS microscopes and imaging probes. We highlight examples of exciting biological applications, and share our vision for potential future breakthroughs for this technology.
Layered double hydroxides (LDHs) are a class of functional anionic clays, which consist of positively charged host layers (brucite‐like M(OH)6 octahedra) and interlayer anions. By virtue of their ...unique combination of structural features (including the tunability of both host layers and interlayer guest anion, exfoliation property, structure topological transformation, confinement effect), LDHs have many potential applications in heterogeneous catalysis—as catalysts themselves, catalyst supports, or catalyst precursors. In addition, the properties of LDH‐based catalysts can be tailored for specific purposes by facile modulation of their surface/interface defect structure (e.g., oxygen vacancy defects or metal defects), controlling the concentration/strength of surface acid/base sites, tuning the geometric/electronic structure of active sites, or by taking advantage of the confinement effect intrinsic to 2D materials. In addition, by utilizing the topological structural transformation of LDH precursors, supported metal catalysts can be obtained (as single metals, bimetallic alloys or heterostructures, and intermetallic compounds) with tunable particle size/morphology and intriguing electronic properties. The main focus of this review is on recent advances in structure design, preparation, and catalytic applications of LDH‐based heterogeneous catalysts. In addition, future challenges and development strategies are discussed from the viewpoints of modulation of intrinsic active sites and establishment of scalable fabrication processes.
By virtue of the unique structural merits of layered double hydroxides (LDHs) (e.g., tunability of both host layers and interlayer guest anion, exfoliation property, structure topological transformation, confinement effect), LDHs show extensive applications as catalysts, supports, or catalyst precursors (e.g., single‐metal, bimetallic alloy or heterostructure, and intermetallic compounds) in heterogeneous catalysis.
Breast cancer is an all too common disease in women, making how to effectively predict it an active research problem. A number of statistical and machine learning techniques have been employed to ...develop various breast cancer prediction models. Among them, support vector machines (SVM) have been shown to outperform many related techniques. To construct the SVM classifier, it is first necessary to decide the kernel function, and different kernel functions can result in different prediction performance. However, there have been very few studies focused on examining the prediction performances of SVM based on different kernel functions. Moreover, it is unknown whether SVM classifier ensembles which have been proposed to improve the performance of single classifiers can outperform single SVM classifiers in terms of breast cancer prediction. Therefore, the aim of this paper is to fully assess the prediction performance of SVM and SVM ensembles over small and large scale breast cancer datasets. The classification accuracy, ROC, F-measure, and computational times of training SVM and SVM ensembles are compared. The experimental results show that linear kernel based SVM ensembles based on the bagging method and RBF kernel based SVM ensembles with the boosting method can be the better choices for a small scale dataset, where feature selection should be performed in the data pre-processing stage. For a large scale dataset, RBF kernel based SVM ensembles based on boosting perform better than the other classifiers.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
1,2,3,5-Tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) is a typical donor-acceptor fluorophore, with carbazolyl as an electron donor and dicyanobenzene as an electron acceptor. It has emerged as ...a powerful organophotocatalyst since 2016. Excellent redox window, good chemical stability and broad applicability make 4CzIPN an attractive metal-free photocatalyst. In this review, the recent advances of the application of 4CzIPN as a photoredox catalyst in the past three years (2016-2018) for various organic reactions are summarized.
In this review, the recent advances of the application of 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) as a photoredox catalyst in the past three years (2016-2018) for various organic reactions are summarized.
Summary
Aims
Baicalin (BAI), a flavonoid compound isolated from the root of Scutellaria baicalensis Georgi, has been established to have potent anti‐inflammation and neuroprotective properties; ...however, its effects during Alzheimer's disease (AD) treatment have not been well studied. This study aimed to investigate the effects of BAI pretreatment on cognitive impairment and neuronal protection against microglia‐induced neuroinflammation and to explore the mechanisms underlying its anti‐inflammation effects.
Methods
To determine whether BAI plays a positive role in ameliorating the memory and cognition deficits in APP (amyloid beta precursor protein)/PS1 (presenilin‐1) mice, behavioral experiments were conducted. We assessed the effects of BAI on microglial activation, the production of proinflammatory cytokines, and neuroinflammation‐mediated neuron apoptosis in vivo and in vitro using Western blot, RT‐PCR, ELISA, immunohistochemistry, and immunofluorescence. Finally, to elucidate the anti‐inflammation mechanisms underlying the effects of BAI, the protein expression of NLRP3 inflammasomes and the expression of proteins involved in the TLR4/NF‐κB signaling pathway were measured using Western blot and immunofluorescence.
Results
The results indicated that BAI treatment attenuated spatial memory dysfunction in APP/PS1 mice, as assessed by the passive avoidance test and the Morris water maze test. Additionally, BAI administration effectively decreased the number of activated microglia and proinflammatory cytokines, as well as neuroinflammation‐mediated neuron apoptosis, in APP/PS1 mice and LPS (lipopolysaccharides)/Aβ‐stimulated BV2 microglial cells. Lastly, the molecular mechanistic study revealed that BAI inhibited microglia‐induced neuroinflammation via suppression of the activation of NLRP3 inflammasomes and the TLR4/NF‐κB signaling pathway.
Conclusion
Overall, the results of the present study indicated that BAI is a promising neuroprotective compound for use in the prevention and treatment of microglia‐mediated neuroinflammation during AD progression.
Background Invasion and metastasis are the main causes of unfavourable prognosis in patients diagnosed with bladder cancer. The efficacy of immunotherapy in bladder cancer remains suboptimal due to ...the presence of an immunosuppressive microenvironment. The novel protein family with sequence similarity 171B (FAM171B) has been identified, but its precise role and mechanism in bladder cancer remain unclear. Methods In this study, we conducted an analysis to investigate the associations between FAM171B expression and the prognosis and clinicopathological stage of bladder cancer. To this end, we utilized RNA sequencing data from the TCGA and GEO databases, as well as tumor tissue specimens obtained from our clinical centre. RNA sequencing analysis allowed us to examine the biological function of FAM171B at the transcriptional level in bladder cancer cells. Additionally, we used immunoprecipitation and mass spectrometry to identify the protein that interacts with FAM171B in bladder cancer cells. The effects of FAM171B on modulating tumor-associated macrophages (TAMs) and vimentin-mediated tumor progression, as well as the underlying mechanisms, were clarified by phalloidin staining, immunofluorescence staining, ELISA, RNA immunoprecipitation, flow cytometry and a bladder cancer graft model. Results FAM171B expression exhibits strong positive correlation with poor survival outcomes and advanced clinicopathological stages in patients with bladder cancer. FAM171B significantly promoted bladder cancer growth and metastasis, accompanied by TAM accumulation in the microenvironment, in vivo and in vitro. Through studies of the molecular mechanism, we found that FAM171B contributes to tumor progression by stabilizing vimentin in the cytoplasm. Additionally, our research revealed that FAM171B enhances the splicing of CCL2 mRNA by interacting with heterogeneous nuclear ribonucleoprotein U (HNRNPU), ultimately leading to increased recruitment and M2 polarization of TAMs. Conclusions In this study, we identified FAM171B as a potent factor that promotes the progression of bladder cancer. These findings establish a solid theoretical foundation for considering FAM171B as a potential diagnostic and therapeutic biomarker for bladder cancer. Keywords: Bladder cancer, CCL2, Macrophage, Vimentin
Inorganic cesium lead iodide perovskite CsPbI3 is attracting great attention as a light absorber for single or multi‐junction photovoltaics due to its outstanding thermal stability and proper band ...gap. However, the device performance of CsPbI3‐based perovskite solar cells (PSCs) is limited by the unsatisfactory crystal quality and thus severe non‐radiative recombination. Here, vacuum‐assisted thermal annealing (VATA) is demonstrated as an effective approach for controlling the morphology and crystallinity of the CsPbI3 perovskite films formed from the precursors of PbI2, CsI, and dimethylammonium iodide (DMAI). By this method, a large‐area and high‐quality CsPbI3 film is obtained, exhibiting a much reduced trap‐state density with prolonged charge lifetime. Consequently, the solar cell efficiency is raised from 17.26 to 20.06 %, along with enhanced stability. The VATA would be an effective approach for fabricating high‐performance thin‐film CsPbI3 perovskite optoelectronics.
A vacuum‐assisted thermal annealing approach is employed for the fabrication of CsPbI3 perovskite films with full surface coverage and enhanced crystallization. The resultant CsPbI3 perovskite solar cells exhibit a power conversion efficiency (PCE) as high as 20.06 %, along with enhanced long‐term stability.
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