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The oxidative upgrading of renewable furfural (FUR) and ethanol is an important way to produce high-quality liquid fuel and value-added furanic derivatives. In this work, a series of supported Au catalysts were prepared using the colloid-immobilization technique, and further employed for catalytic oxidative condensation of FUR with ethanol in the presence of molecular oxygen. It is found that, with Au@CaO as the catalyst, 85.9% conversion of FUR and 81.8% selectivity of the product furan-2-acrolein were achieved in the absence of any homogeneous basic additive. The effects of different reactions such as reaction time, temperature and catalyst amount were explored in detail. Also, the influences of calcination temperature and amount of protective agent during the preparation of catalyst were investigated. According to the characterization results of catalyst, it is concluded that the synergistic effect of metallic Au and basic site of CaO support plays a significant role on the selective oxidative condensation. At last, a possible reaction mechanism is proposed based on the catalytic principle and experimental results.

Catalytic valorization of furfural (FUR) using a simple and low-cost metal catalyst has been considered as a hot topic in sustainable chemistry. In this work, a new Ni@R-Ca catalyst is prepared via the auto-combustion and in situ reduction method. When it is employed to promote the catalytic valorization of FUR in aliphatic alcohol, a nearly complete FUR conversion with excellent product selectivity is obtained under mild reaction conditions. Using methanol as reaction medium, the sole product is furfuryl alcohol (FA) in which ca. 99% yield of FA was attained. While, in ethanol, the obtained products mainly contain FA and furan-2-acrolein (FUA) in which a 94% conversion of FUR with a 91% total selectivity of FA and FUA was acquired. Based on the characterization of catalyst including XRD, SEM, XPS and H2-TPR techniques, it is concluded that the synergy effect of metal Ni and R-Ca crystal lattice plays a crucial role in the efficient conversion of FUR in aliphatic alcohol.

The reaction of coal char particles deposited on the molten slag surface in the entrained flow gasifier was of importance to the carbon conversion and slag discharge. In this study, the catalytic effect and migration behavior of the alkali metal (K) in molten slag during the gasification reaction of char particles on the molten slag surface were investigated and evaluated by using visualization and surface analytical techniques. The results showed the ionic K in the molten slag was not deactivated and accelerated the char gasification rate and carbon conversion of char particle on the molten slag surface as a catalytic effect. The complete conversion time of char particles on the molten slag with the addition of K was reduced by about 37%–67%, compared to the time of the char gasification without molten slag or the gasification on the slag with no addition of K. The carbon conversion of char particles was increased obviously with increasing the addition of K in the molten slag. From the analyses of scanning electron microscope (SEM) and energy dispersive spectrometry (EDS), the ionic K was found to gradually migrate and accumulate to the interface between the coal char particle and molten slag during the gasification process. The migrating and accumulating amount of K to the interface increased with the increases of both carbon conversion of the char particle and K addition of the slag. With a comparative experiment of the char combustion on the slag surface, a low temperature zone below the char particle during the gasification was key to cause a migration behavior of K with other elements (e.g. Si and Al) and further acted as a catalytic effect on the gasification reaction. Finally, a mechanism of the catalytic effect and migration behavior of ionic K in the slag during the char/molten slag interfacial gasification process was uncovered in this study.

The oxidative upgrading of furfural (FUR) and aliphatic alcohols is an important way to produce desirable precursor of jet fuel or value-added furanic compound. Therein, developing a highly active catalytic system with switchable product selectivity still remains a challenge. In this work, we report a novel strategy on regulating the oxidative condensation and oxidative esterification of FUR with aliphatic alcohol in the presence of molecular oxygen. Firstly, Au@UiO-66 is prepared using different methods and employed as the catalyst for the oxidative valorization of FUR with methanol. It is found that the impregnation-reduction-H2 (I-H) method is the best where a 100% selectivity of methyl-2-furoate with a complete conversion was obtained using Au@UiO-66 as catalyst. Then, a series of metal-organic frameworks (MOFs) supported Au nanoparticles (Au@UiO-66-X) such as Au@UiO-66, Au@UiO-66-NH2, Au@UiO-66-NO2, Au@UiO-66-COOH and Au@UiO-66-NH3Cl have been prepared with I-H method and employed for oxidative valorization of furfural with ethanol. Experimental results showed that, in “FUR-ethanol-O2” system, the Au@UiO-66-X can efficiently regulate the oxidative condensation and oxidative esterification as two competitive reaction pathways. With Au@UiO-66-COOH as the catalyst, the oxidative condensation process is dominant in which 84.1% selectivity of furan-2-acrolein is attained; Meanwhile, the Au@UiO-66 is beneficial to the occurrence of oxidative esterification and generation of ethyl-2-furoate. At last, based on the catalyst characterization and the numerous control experiments, a possible catalytic reaction mechanism for conversion of FUR is proposed.

Background The efficacy of patent foramen ovale (PFO) closure for secondary stroke prevention in cryptogenic stroke (CS) patients with PFO is uncertain. This meta-analysis aims to assess whether PFO closure is superior to medical therapy. Methods Pooled estimates were calculated using Revman 5.3. The two primary endpoints were stroke and transient ischemic attack (TIA). Secondary outcomes included all-cause mortality, new-onset atrial fibrillation or flutter, major bleeding and any adverse event. Results Five randomized controlled trials were included. A total of 3440 patients were randomized to either PFO closure (n = 1829) or medical therapy group (n = 1611) and followed for average 2.0–5.9 years. PFO closure reduced the incidence of recurrent stroke in CS patients with PFO compared to medical therapy (Risk ratio (RR) 0.42, 95% confidence intervals (CI) 0.20–0.91, P = 0.03; hazard ratio (HR) 0.34, 95% CI 0.15–0.78, p = 0.01). There were no significant differences between the two groups in TIA (RR 0.78, 95% CI 0.53–1.15, P = 0.21; HR 0.73, 95% CI 0.49–1.09, p = 0.12), all-cause mortality (RR 0.76, 95% CI 0.35–1.63, P = 0.48), major bleeding (RR 0.96, 95% CI 0.42–2.20, P = 0.93) and any adverse event (RR 1.06, 95% CI 0.95–1.18, P = 0.29). Higher risk of new-onset atrial fibrillation or flutter was found in closure group (RR 4.69, 95% CI 2.17–10.12, P Conclusions PFO closure combined with medical therapy showed superiority over medical therapy alone for stroke prevention in carefully selected CS patients with PFO, but increased the risk of atrial fibrillation or flutter.

Background Depression is a common complication after stroke and has been associated with poor outcome. Thus, it is of great importance to identify potential biomarkers that can aid in predicting and detecting patients with stroke at high risk of poststroke depression (PSD) development. Previous studies showed that brain-derived neurotrophic factor (BDNF) had potential use as a biomarker for discriminating patients with stroke at high risk of PSD. However, the results were inconsistent. Methods A meta-analysis was performed to evaluate the correlation between the peripheral BDNF levels and the development of PSD in the acute stage of stroke. Results Data were obtained from 4 studies including 499 patients with stroke. Among them, 171 patients were diagnosed with PSD at follow-ups. Our results showed that patients with stroke who were predisposed to developing PSD had significantly lower serum BDNF concentrations at the early stage of stroke. Conclusions This study suggests a potential association between circulating BDNF concentrations at admission and subsequent PSD development, and provides additional support for the involvement of BDNF in the PSD development.

The formation of densely packed overlayer of iron phthalocyanine (FePc) molecules on single-layer graphene (SLG) epitaxially grown on Ru(0001) is studied by means of low temperature scanning tunneling microscopy. We show that the FePc molecules form single molecular arrays, ordered honeycomb lattice, Kagome lattice and square lattice with increasing molecular coverage. The densely packed square lattice of the molecular layer is modulated by the moire pattern of SLG/Ru(0001). The superposition of the square lattice of the molecular layer on the hexagonal lattice of SLG moire pattern leads to the formation of a larger strip moire pattern. This coverage-dependent self-assembling behavior of FePc on SLG/Ru(0001) is mainly driven by the inhomogeneous electronic structure of graphene moire pattern, due to spatial-dependent interfacial charge transfer between SLG and Ru(0001) substrate.

Sequential learning algorithms are a good choice for learning data one-by-one or chunk-by-chunk. Liang et al. has proposed OS-ELM algorithm based on the ordinary ELM algorithm, which produces better generalization performance than other famous sequential learning algorithms. One of the deficiencies of OS-ELM is that all the observations are weighted equally regardless of the acquisition time. However, the training data often have timeliness in many real industrial applications. In this paper, we propose a modified online sequential learning algorithm with the forgetting factor (named WOS-ELM algorithm) that weights the new observations more. Then a convergence analysis is presented to make sure the estimation of output weights tend to converge at the exponential speed with the arriving of new observations. For the determination of the value of forgetting factor, it would change with the forecast error automatically and get rid of excessive human interference. We employ several applications in the simulation part including time-series predication, time-variant system identification and the weather forecast problem. The simulation results show that WOS-ELM is more accurate and robust than other sequential learning algorithms.

This note proposes a modified ELM algorithm named P-ELM subject to how to get rid of the multicollinear problem in calculation based on PCA technique. By reducing the dimension of hidden layer output matrix (H) without loss major information through PCA theory, the proposed P-ELM algorithm can not only ensure the full column rank of newly generated hidden layer output matrix ( H ' ), but also improve the training speed. In order to verify the effectiveness of P-ELM algorithm, this paper establishes a soft measurement model for hot metal temperature in the blast furnace (BF). Some comparative simulation results with other famous feedforward neural network and the ordinary ELM algorithm with its variants illustrate the better generalization performance and stability of the proposed P-ELM algorithm.

A selective reductive amination of aliphatic aldehydes and cycloaliphatic ketones is achieved with tetragonal zirconium dioxide (t-ZrO2) as the catalyst. With N, N-dimethyl formamide (DMF) as the solvent, low-molecular-weight amine source and reductant, a more than 99 % yield of N, N-dimethylpentan-1-amine or N, N-dimethyl cyclohexanamine was obtained when n-pentanal or cyclohexanone was used as the substrate. Particularly, the crystallographic structures exhibit a significant effect on catalytic performance where the tetragonal crystalline was preferable to monoclinic one during the reductive amination reaction. In addition, the recycling experiments of catalysts indicate that t-ZrO2 still kept a high catalytic activity even after being reused five times. From the result of DFT calculations, it is concluded that the crystalline of zirconium dioxide is closely related to the charge transferring rate between the catalyst and the adsorbed reactant. Finally, based on the experiment phenomena and simulation result, a possible reaction mechanism is proposed for the reductive amination of cyclohexanone.

A pyridinyl-functionalized ionic liquid, N-butyl-N′-(4-pyridylheptyl)imidazolium bromide ([BuPyIm]Br), is synthesized and applied as an additive for dye-sensitized solar cells (DSSCs). Compared with the volatile organic additive, 4-tert-butyl pyridine (TBP) (generally 0.5 M in the electrolyte), [BuPyIm]Br can be used at a very low concentration (0.1 M in the electrolyte) for high overall power conversion efficiency DSSCs, which shows an overall power conversion efficiency of 5.67% under the simulated air mass 1.5 solar spectrum illumination at 100 mW cm−2 and 6.69% at 15 mW cm−2, respectively. Furthermore, [BuPyIm]Br-based DSSCs show better long-term stability than that of TBP-based devices. These results indicate that the DSSC devices based on the pyridinyl-functionalized ionic liquid additive can overcome the drawbacks of the volatile organic additive, and offer a feasible method to fabricate DSSCs in future practical applications.

Myocardial fibrosis functions as an independent risk factor involved in various cardiac diseases such as hypertension, left ventricular diastolic dysfunction and myocardial infarction. Our previous study indicated triptolide (TP), a diterpenoid isolated from Tripterygium wilfordii , attenuated