The manufacture of bionic materials to simulate the natural counterparts has attracted extensive attention. As one of the subcategories of biomimetic materials, the development of artificial enzyme is intensive pursuing. As a kind of artificial enzyme, nanozymes are dedicated to solve the limitations of natural enzymes. In recent years, attributed to the explosive development of nanotechnology, biotechnology, catalysis science, computational design and theory calculation, research on nanozymes has made great progress. To highlight these achievements and help researchers to understand the current investigation status of nanozyme, the state‐of‐the‐art development in nanozymes from fabrication materials to bioapplications are summarized. First different raw materials are summarized, including metal‐based, metal‐free, metal‐organic frameworks‐based, and some other novel matters, which are applied to fabricate nanozymes. The different types of enzymes‐like catalytic activities of nanozymes are briefly discussed. Subsequently, the wide applications of nanozymes such as anti‐oxidation, curing diseases, anti‐bacteria, biosensing, and bioimaging are discussed. Finally, the current challenges faced by nanozymes are outlined and the future directions for advancing nanozyme research are outlooked. The authors hope this review can inspire research in the fields of nanotechnology, chemistry, biology, materials science, and theoretical computing, and can contribute to the development of nanozymes.

A nonaqueous capillary electrophoresis (NACE) method was developed for simultaneous assay of three bioactive components (1: cryptotanshinone; 2: tanshinone IIA, and 3: tanshinone I) in Radix Salviae miltiorrhizae and in its herbal preparations for the first time. After optimization of separation conditions, a buffer of 250 mmol L(-1) ammonium acetate containing 30% acetonitrile and 1.0% acetic acid (V:V) in methanol was selected for separating the three analytes, but baseline separation of tanshinon I and tanshinone IIA was not obtained. Therefore second-order derivative electropherograms were applied for resolving overlapping peaks. Regression equations revealed good linear relationships (correlation coefficients 0.9943-0.9991) between peak heights in second-order derivative electropherograms and concentrations of the three analytes. The relative standard deviations (RSD) of the migration times and the peak height of the three constituents were in the range of 0.81 -0.88% and 0.34-1.13% (intra-day), 1.57-1.86% and 3.05-5.52% (inter-day), respectively. The recoveries of three constituents ranged from 90.2 to 108.5%. The results indicated that baseline separation of the analytes was sometimes hard to obtain and second-order derivative electropherograms were applicable for the resolving and analysis of overlapping peaks.

Cyclooxygenase-2 (COX-2) participates in cancer invasion and metastasis by decreasing the expression of E-cadherin. However, the molecular mechanisms through which COX-2 regulates E-cadherin expression and function have not yet been fully elucidated. The aim of this study was to investigate the possible molecular mechanisms through which COX-2 regulates E-cadherin expression in gastric cancer. The mRNA and protein expression of COX-2, nuclear factor-κB (NF-κB), Snail and E-cadherin was detected in gastric cancer cells by quantitative PCR and western blot analysis, respectively. The expression of these genes was also detected in healthy gastric mucosa and gastric cancer tissues by immunohistochemistry. We detected various levels of COX-2, nuclear factor-κB (NF-κB), Snail and E-cadherin expression in the normal gastric mucosa and cancer tissues; however, the expression patterns differed: the increased expression of COX-2, NF-κB and Snail was observed in the gastric cancer tissues, whereas there was a considerable reduction in E-cadherin expression in the cancer tissues compared to the normal gastric mucosa. The expression patterns of COX-2, NF-κB and Snail were similar. The increased expression of COX-2 in the gastric cancer tissues closely correlated with the increased expression of NF-κB and Snail, but inversely correlated with the expression of E-cadherin. Treatment of the SGC7901 cells (which express high levels of COX-2) with celecoxib, a COX-2 inhibitor, not only led to a marked dose- and time-dependent decrease in the expression of COX-2, NF-κB and Snail, but also led to a significant increase in the expression of E-cadherin, and this was associated with a reduction in cell invasion. By contrast, the same treatment did not alter the expression of these genes in another gastric cancer cell line, MGC803 (which barely expresses COX-2). These data suggest that COX-2 regulates the expression of E-cadherin through the NF-κB and Snail signaling pathway in gastric cancer.

The product selectivity in catalytic hydrogenation of nitriles is strongly correlated with the structure of the catalyst. In this work, two types of atomically dispersed Pd species stabilized on the defect-rich nanodiamond-graphene (ND@G) hybrid support: single Pd atoms (Pd1/ND@G) and fully exposed Pd clusters with average three Pd atoms (Pdn/ND@G), were fabricated. The two catalysts show distinct difference in the catalytic transfer hydrogenation of nitriles. The Pd1/ND@G catalyst preferentially generates secondary amines (Turnover frequency (TOF@333 K 709 h−1, selectivity >98%), while the Pdn/ND@G catalyst exhibits high selectivity towards primary amines (TOF@313 K 543 h−1, selectivity >98%) under mild reaction conditions. Detailed characterizations and density functional theory (DFT) calculations show that the structure of atomically dispersed Pd catalysts governs the dissociative adsorption pattern of H2 and also the hydrogenation pathway of the benzylideneimine (BI) intermediate, resulting in different product selectivity over Pd1/ND@G and Pdn/ND@G, respectively. The structure-performance relationship established over atomically dispersed Pd catalysts provides valuable insights for designing catalysts with tunable selectivity.

Objectives To evaluate the prevalence of Helicobacter pylori infection and risk factors and to serotype the strains in Wuwei, located in north‐western China, which has a high incidence of gastric cancer. Methods Helicobacter pylori infection was analysed in 21 291 adults by 14C‐urea breath test, and H. pylori antibody were detected in 9183 serum samples by latex immunoturbidimetric method. The correlation of H. pylori infection with demographic–economic, lifestyle factors and medical history among the participants was determined by questionnaire. The antibodies against H. pylori urease, VacA and CagA in serum were determined by dot immunobinding assay. Results The infection rate of H. pylori was 53.0%, and 90.1% of strains were type I strains. The H. pylori infection rate was higher among farmers (OR = 1.34, 95% CI: 1.19–1.50) and individuals who had a junior high school or higher education level (OR = 1.10, 95% CI: 1.06–1.15), and was lower in older individuals (OR = 0.86, 95% CI: 0.83–0.90), individuals with high income (OR = 0.93, 95% CI: 0.90–0.95), individuals with a habit of eating quickly (OR = 0.93, 95% CI: 0.87–0.99) and individuals who consumed more fruit and vegetables (OR = 0.90, 95% CI: 0.85–0.95). Individuals with history of cholecystitis/cholecystolithiasis, hypertension and asthma were negatively correlated with H. pylori infection (P < 0.05). Conclusion The prevalence of H. pylori infection is high in Wuwei. The major prevalent strain is type I strain. Age, education, occupation, household income, consumption of fruit and vegetables, and habit of eating quickly are independent risk factors for H. pylori infection, which is also associated with individuals with a history of extragastric diseases.

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Fabricating efficient and stable nanocatalysts for chemoselective hydrogenation of nitroaromatics is highly desirable because the amines hold tremendous promise for the synthesis of nitrogen containing chemicals. Here, a highly reactive and stable porous carbon nitride encapsulated magnetically hollow platinum nanocage is developed with subnanometer thick walls (Fe 3 O 4 @ sn Pt@PCN) for this transformation. This well‐controlled nanoreactor is prepared via the following procedures: the preparation of core template, the deposition of platinum nanocage with subnanometer thick walls, oxidative etching, and calcination. This highly integrated catalyst demonstrates excellent performance for the catalytic transfer hydrogenation of various nitroaromatics and the reaction can reach >99% conversion and >99% selectivity. With the ultrathin wall structure, the atom utilization of platinum atoms is highly efficient. The X‐ray photoelectron spectroscopy results indicate that partial electrons transfer from the iron oxides to Pt nanowalls, and this increases the electron density of sn Pt nanoparticles, thus promoting the catalytic activity for the transfer hydrogenation of nitroaromatics. For the reduction of 4‐nitrophenol, the reaction rate constant K app is 0.23 min −1 and the turnover frequency (TOF) is up to 3062 h −1 . Additional reaction results illustrate that this magnetic nanoreactor can be reused more than eight times and it is a promising catalytic nanoplatform in heterogeneous catalysis.

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