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Developing highly active and selective catalysts for the hydrogenation of nitroarenes, an environmentally benign process to produce industrially important aniline intermediates, is highly desirable...

Diabetic cardiomyopathy is characterized by diabetes‐induced myocardial abnormalities, accompanied by inflammatory response and alterations in inflammation‐related signalling pathways. Kirenol, isolated from Herba Siegesbeckiae, has potent anti‐inflammatory properties. In this study, we aimed to investigate the cardioprotective effect of kirenol against DCM and underlying the potential mechanisms in a type 2 diabetes mellitus model. Kirenol treatment significantly decreased high glucose‐induced cardiofibroblasts proliferation and increased the cardiomyocytes viability, prevented the loss of mitochondrial membrane potential and further attenuated cardiomyocytes apoptosis, accompanied by a reduction in apoptosis‐related protein expression. Kirenol gavage could affect the expression of pro‐inflammatory cytokines in a dose‐dependent manner but not lower lipid profiles, and only decrease fasting plasma glucose, fasting plasma insulin and mean HbA1c levels in high‐dose kirenol‐treated group at some time‐points. Left ventricular dysfunction, hypertrophy, fibrosis and cell apoptosis, as structural and functional abnormalities, were ameliorated by kirenol administration. Moreover, in diabetic hearts, oral kirenol significantly attenuated activation of mitogen‐activated protein kinase subfamily and nuclear translocation of NF‐κB and Smad2/3 and decreased phosphorylation of IκBα and both fibrosis‐related and apoptosis‐related proteins. In an Electrophoretic mobility shift assay, the binding activities of NF‐κB, Smad3/4, SP1 and AP‐1 in the nucleus of diabetic myocardium were significantly down‐regulated by kirenol treatment. Additionally, high dose significantly enhanced myocardial Akt phosphorylation without intraperitoneal injection of insulin. Kirenol may have potent cardioprotective effects on treating for the established diabetic cardiomyopathy, which involves the inhibition of inflammation and fibrosis‐related signalling pathways and is independent of lowering hyperglycaemia, hyperinsulinemia and lipid profiles.

We report a real-space imaging of formaldehyde (HCHO) adsorption on a TiO2(110) surface probed by high-resolution scanning tunnelling microscopy (STM). Density functional theory calculations (DFT) ...

The influence of the magnetism of transition metal oxide, nickel(II) oxide (NiO), on its surface reactivity and the dependence of surface reactivity on surface orientation and reactant magnetism were studied by density functional theory plus U calculations. We considered five different antiferromagnetically ordered structures and one ferromagnetically ordered structure, NiO(001) and Ni(011) surfaces, paramagnetic molecule NO, and nonparamagnetic molecule CO. The calculations showed that the dependence of surface energies on magnetism was modest, ranging from 49 to 54 meV/A2 for NiO(001) and from 162 to 172 meV/A2 for NiO(011). On NiO(001), both molecules preferred the top site of the Ni cation exclusively for all NiO magnetic structures considered, and calculated adsorption energies ranged from –0.33 to –0.37 eV for CO and from –0.42 to –0.46 eV for NO. On NiO(011), both molecules preferred the bridge site of two Ni cations irrespective of the NiO magnetism. It was found that rather than the long-range magnetism of bulk NiO, the local magnetic order of two coordinated Ni cations binding to the adsorbed molecule had a pronounced influence on adsorption. The calculated NO adsorption energy at the (↑↓) bridge sites ranged from –0.99 to –1.05 eV, and become stronger at the (↑↑) bridge sites with values of –1.21 to –1.30 eV. For CO, although the calculated adsorption energies at the (↑↓) bridge sites (–0.73 to –0.75 eV) were very close to those at the (↑↑) bridge sites (–0.71 to –0.72 eV), their electron hybridizations were very different. The present work highlights the importance of the local magnetic order of transition metal oxides on molecular adsorption at multi-fold sites.

Co-based nanomaterials have been intensively explored as promising noble metal free oxygen evolution reaction (OER) electrocatalysts. Herein, we first report phase selective synthesis of novel hierarchical CoTe2 and CoTe nanofleeces for efficient OER catalyst. The CoTe2 nanofleeces exhibited excellent electrocatalytic activity and stablity for OER in alkaline media. It has been discovered that the CoTe2 catalyst exhibited superior OER activity to the CoTe catalyst and comparable to the state-of-the-art RuO2 catalyst. Density functional theory calculations showed that the binding strength and lateral interaction of the reaction intermediates on CoTe2 and CoTe are essential for the order of their overpotential and the trend variation at different condition. This study provides value insights for rational design of noble metal free OER catalysts with high performance and low cost by use of Co-based chalcogenides.

Supported single-atom catalysts have attracted increasing interest due to their high atomic efficiencies and simple structures used to establish the structure–activity relations in catalysis. In this contribution, we present a density functional theory study of ZnO supported single transition metal (TM: Mn, Fe, Co, and Ni) atoms for the water gas shift reaction (WGSR). We find that these single TM1 atoms prefer to substitute in the surface Zn lattice and exhibit promising activity for stabilizing the intermediates (i.e. CO, OH, and COOH) involved in WGSR. Meanwhile, the surface lattice O coordinated with the TM1 atoms is responsible for the hydrogen abstraction process. The formation of COOH via the association between CO and OH is the rate-limiting step in the catalytic cycle. Microkinetic modeling analysis is used to determine the activity trend, and a volcano-like plot between the calculated rates and the binding energies of COOH is obtained, suggesting that the COOH binding energy might be a good activity descriptor for catalyst screening. Among these single atoms, the single Ni1 atom exhibits the highest activity and is promising for WGSR.

Photocatalysis of a single methanol molecule on the TiO2(110) surface was investigated using a high-resolution scanning tunneling microscopy (STM) technique. Three different types of elementary methanol photocatalytic processes, methanol photodissociation, photoinduced migration of formaldehyde, and formaldehyde photodesorption, were clearly observed. Detailed chemical structures of the intermediates were obtained through careful comparisons between experimental STM images and theoretical simulations based on density functional theory (DFT) calculations. This work demonstrates that elementary photocatalytic processes of a single methanol molecule on the surface can be followed step by step using advanced STM imaging techniques. Such a study can provide unprecedented insights into the surface photocatalytic processes and will greatly help us to understand photocatalysis at the most fundamental level.

Background Guang-Pheretima, which is originated from Pheretima aspergillum, has been documented in academic Chinese herbal studies for nearly 2000 years for its prominent treating effects of various inflammatory diseases such as asthma, cough and fever. However, the anti-inflammatory activity and mechanism of Guang-Pheretima has been rarely reported. Hence, we investigated the inhibitory effect and the underlying mechanism of Guang-Pheretima aqueous extracts on inflammatory response in RAW 264.7 cells. Method RAW 264.7 macrophages were pretreated with various concentrations of Guang-Pheretima decoction (GPD) or protein-free Guang-Pheretima decoction (PF-GPD) and subsequently stimulated with lipopolysaccharide (LPS) to trigger the inflammatory response. Productions of nitric oxide (NO) were determined by Griess reaction, and prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 were measured by enzyme-linked immunosorbent assays (ELISA). The protein expressions and messenger ribonucleic acid (mRNA) amounts of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 were analyzed by Western Blot and Real-Time polymerase chain reaction (PCR), respectively. Finally, the translocation of nuclear factor (NF)-κB was observed by Western Blot. Results GPD of the experimental concentrations showed no anti-inflammatory activity. In contrast, PF-GPD at concentrations of 40–320 μg/mL significantly inhibited NF-κB activation and reduced the production of inflammatory mediators, such as NO, PGE2, TNF-α, as well as the related key synthases including iNOS and COX-2. Moreover, PF-GPD markedly suppressed the release of inflammatory cytokines, such as IL-1β and IL-6. Conclusion These results demonstrate the excellent anti-inflammatory properties of PF-GPD, and suggest that Guang-Pheretima may be used to treat and prevent certain inflammatory diseases.

The single Pt1 and Au1 atoms stabilized by lattice oxygen on ZnO{1010} surface for methanol steam reforming is reported. Density functional theory calculations reveal that the catalysis of the single precious metal atoms together with coordinated lattice oxygen stems from its stronger binding toward the intermediates, lowering reaction barriers, changing on the reaction pathway, enhancing greatly the activity. The measured turnover frequency of single Pt1 sites was more than 1000 times higher than the pristine ZnO. The results provide valuable insights for the catalysis of the atomically dispersed precious metals on oxide supports.

To explore the processing mechanism of Aurantii Fructus decoction pieces used in Guangdong province and Hong Kong by analysing the chemical variation between raw and processed Aurantii Fructus with different methods based on UHPLC-Q-TOF-MS. The total ion chromatograms detected in positive and negative ion modes, and ion peak area ratio before and after processing were taken as variation indexes in the comparison. The results indicated that fermented Aurantii Fructus could produce three new ingredients, namely eriodictyol-7-glucoside, hesperetin-7-O-glucoside and 5-demethylnobiletin. At the same time, it could significantly increase the content of naringenin and hesperetin components, and could increase the content of such limonin derivatives as sudachinoid A, obacunoic acid and limoninand nomilinic acid. This suggests that the fermentation processing method of Aurantii Fructus decoction pieces used in Guangdong province and Hong Kong is of important significance for enhancing biological activity and bioavailability, and improving the clinical efficacy of Aurantii Fructus decoction pieces, and so is worth further protection and promotion.

Utilizing ambient pressure X-ray photoelectron spectroscopy (AP-XPS), the surface segregation and oxidation of Pt3Ni(1 1 1) alloys are investigated as a function of temperature and oxygen pressure. The in situ AP-XPS measurements of oxygen oxidation process show that the Pt “skin” surface is not stable under the exposure of oxygen pressure of 100 mTorr at room temperature. As the temperature and pressure are elevated, the formations of Ni2O3, NiOx, and NiO are observed on surface while Pt atom starts to reduce its adsorbed oxygen, which is a clear sign of surface segregation of Ni to surface. Upon the evacuation of oxygen gas, i.e. ultrahigh vacuum condition, both of NiOx and NiO oxide get reduced and Ni2O3 remains on the surface. The DFT calculation is employed to explain the formation of surface oxides under oxidation condition.

Ethnopharmacological relevance and aim of the study Guang-Pheretima, the live form of the earthworm Pheretima aspergillum , is a traditional Chinese medicine commonly used for the treatment of asthma, cough, stroke, epilepsy and other diseases due to its anti-inflammatory, anti-asthmatic, anti-seizure, thrombolytic and diuretic properties. Although Guang-Pheretima is effective in the relief of asthma, its pharmacological activity and the underlying molecular mechanisms are not fully understood. Hence, we investigated the effects of a Pheretima aspergillum decoction (PAD) against inflammation in a model of ovalbumin (OVA)-induced asthma in BALB/c mice, as well as the nuclear factor-κB (NF-κB) pathway involved in this process. Materials and methods OVA was used to sensitize and challenge the airway of the mice, and PAD was administrated by gavage. We measured airway hyperresponsiveness (AHR) in the mice 24 h following a final methacholine challenge with whole-body plethysmography. The bronchoalveolar lavage fluid (BALF), serum and pulmonary tissues were collected 48 h after the last challenge. The levels of inflammatory factors and the related mRNAs were determined by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR), respectively. The number of differential inflammatory cells in the BALF was counted. Serum total and OVA-specific IgE levels were measured with ELISA. The activation of NF-κB signaling in the lung was detected by western blotting. In addition, the lung tissues were stained with hematoxylin and eosin or periodic acid Schiff stain for histopathological examination. Results PAD treatment significantly alleviated AHR in the asthmatic mice, decreased the mRNA and protein levels of IL-4, IL-5 and IL-13 and downregulated IgE. In addition, PAD treatment attenuated mucus secretion and infiltration of inflammatory cells in the lung while inhibiting the activation of NF-κB signaling. Conclusions PAD effectively inhibited the activation of NF-κB signaling in the lungs of mice with OVA-induced asthma, and mitigated AHR and Th2 type inflammatory reactions. Therefore, PAD may serve as a drug candidate for asthma treatment.

To analyze the volatile components of Platycladus orientalis extracted by headspace solid phase microextraction (HS-SPME) and steam distillation-extraction (DSE).The volatile components which were extracted by DSE and analyzed by GC-MS; The HS-SPME conditions was optimized, and the volatile components were analyzed by GC-MS.Sixty-two kinds of volatile components extracted by DSE were isolated and 50 of them were identified; Sixty-eight kinds of volatile components extracted by HS-SPME were isolated and 67 of them were identified.Compared with DSE,HS-SPME has higher retrieval matching and sensitivity, which is more suitable for the analysis of the volatile components of P. orientalis.

Correction for ‘First-principles study of single transition metal atoms on ZnO for the water gas shift reaction’ by Xiang-Kui Gu et al., Catal. Sci. Technol., 2017, DOI: 10.1039/c7cy00704c.