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Selective oxidation of 5-hydroxymethylfurfual (HMF) to 2,5-furandicarboxylic acid (FDCA) as a bioplastics monomer is efficiently promoted by a simple system without noble-metal and base additives. In this work, graphene oxide (GO) was first synthesised by an electrochemical method with flexible graphite paper (FGP) as start carbon material, then, nitrogen-doped graphene (NG) layers encapsulated Cu nanoparticles (NPs) was prepared by one-step thermal treatment of GO supported Cu2+ in flowing NH3 atmosphere. Compared with NG supported Cu NPs prepared by the traditional impregnation method, enhanced catalytic activity was achieved over Cu/NG and an FDCA yield of 95.2% was achieved under mild reaction conditions with tert-butylhydroperoxide (t-BuOOH) as the oxidant. Control experiments with different catalysts and different addition procedure of t-BuOOH showed the yield of HMF and various intermediates during reaction. From the changing of intermediates concentrations and reaction rates, a reaction pathway through HMF-DFF-FFCA-FDCA was proposed. This work gives a more convenient, more green, more economical and effective method in encapsulated metal NPs preparation and high selectivity in HMF oxidation to FDCA under mild conditions.

Development of viable cell estimation method without sacrificing proliferation and functions of cells cultured on regenerative biomaterials is essential for regenerative engineering. Cytotoxicity and depletion of resazurin are critical but often overlooked limitations that hindered applications of resazurin in viable cell estimation. The present work found that cytotoxicity and depletion of resazurin depended on cell concentration, resazurin concentration and resazurin incubation time. A simple strategy which only allowed cells to incubate with resazurin during each measurement was developed to eliminate negative effects of resazurin. This strategy was verified by monitoring proliferation of MC3T3-E1 preosteoblasts on poly(d,l-lactic acid) scaffold during a continuous 3D culture process for up to 21 days, comparing the accuracy with MTT assay which is a destructive assay with high sensitivity and accuracy and commonly used in regenerative engineering and comparing viability, proliferation and differentiation functions of MC3T3-E1, which were treated with/without this strategy for nondestructive evaluation. This method showed comparable linearity of standard curve and characteristics of growth curve to MTT assay. No major negative effects of this method on MC3T3-E1 viability and functions were found. Our work highlighted the importance of the concentration and incubation time of resazurin in designing application-specific nondestructive viability assay and would be helpful in improving the implanted medical devices as well as in regenerative engineering.

A multifunctional sensing platform based on bright blue-fluorescent nitrogen-doped carbon dots (N-CDs) has been ingeniously designed for the sensitive determination of Hg2+ and pH. The N-CDs were facilely fabricated via a one-step hydrothermal treatment of citric acid and folic acid with admirable merits including exceptional stability, low toxicity and distinguished biocompatibility. Intriguingly, the obtained N-CDs can be utilized to detect Hg2+ on the basis of the dynamic quenching effect, showing a linear range of 0 μM-400 μM as well as a detection limit of 0.124 μM. In addition, the obtained N-CDs revealed a significant emission enhancement with increasing pH from 4.0 to 10.0 and acquired a good linearity in the pH range of 6.8-7.8. Taking advantage of efficient analysis of Hg2+ and pH in aqueous solution, the as-synthesized N-CDs have been extended to the visualization biosensing platform to timely track Hg2+ and pH in living cells.

The Ni/SBA-15 and Ni/TiO2 catalysts with 20 wt% nickel with different metal–support interaction strength were designed using ordered mesoporous silica (SBA-15) and TiO2 (P25). The Ni/SBA-15 and Ni/TiO2 catalysts with 20 wt% nickel were investigated using various characterization techniques. It was found that the Ni/SBA-15 and Ni/TiO2 catalysts with 20 wt% nickel possess different nickel particle size and different reducibility because of the different strength between nickel and support interaction. Both Ni/SBA-15 and Ni/TiO2 catalysts were tested for the hydrodeoxygenation reaction of a model bio-oil using a fixed-bed reactor at different evaluation conditions. It was found that under high hydrogen pressure (≥7 bar), both Ni/SBA-15 and Ni/TiO2 catalysts are highly efficient because the organic oxygen compound could be converted completely. And the product selectivity is very sensitive to the hydrogen pressure. Under low hydrogen pressure (3–5 bar) Ni/TiO2 catalyst show rather higher selectivity toward aromatic hydrocarbon as compared with Ni/SBA-15 catalyst. Lower hydrogen pressure and reaction temperature will be beneficial to the aromatic hydrocarbon production. It is very important to reduction for the H2 consumption cost. TiO2 is a very potential candidate support for the catalyst design aiming to the sustainable aromatic hydrocarbon production.

Proton-conducting ceramic fuel cells (PCFCs) show unique advantages over oxygen-ionic-conducting counterparts at intermediate and low temperatures, which have attracted significant attention worldwide in recent years. A critical issue for world-spread applications is inadequate performance due to the lack of appropriate cathodes for PCFCs. Here, cubic perovskite BaCo0.4Fe0.5-xCe0.1RexO3-δ (Re Y, Gd x = 0, 0.1) materials are successfully synthesized and evaluated as the cathode in the PCFCs based on BaCe0.7Zr0.1Y0.1Yb0.1O3-δ as an electrolyte material. The Y- or Gd-doped perovskite BaCo0.4Fe0.4Ce0.1Y0.1O3-δ (BCFCeY), BaCo0.4Fe0.4Ce0.1Gd0.1O3-δ (BCFCeG) exhibit larger lattice parameters, and higher electrocatalytic activity comparing to their parent oxide BaCo0.4Fe0.5Ce0.1O3-δ (BCFCe). Among them, BCFCeG shows the best performance. The single cell with BCFCeG as the cathode material exhibits an interfacial polarization resistance as low as 0.12 Ω cm2 and delivers a promising peak power density of 504 mW cm−2 at 600 °C, while the BCFCe-based cell achieves only 437 mW cm−2 at 600 °C. The X-ray diffraction (XRD) results show good chemical compatibility for BCFCeG below 1050 °C. Moreover, it shows favorable stability in CO2-containing environment. This work confirms that BCFCeG could be a promising cathode for PCFCs.

We developed a fluorescent probe, named 2-(4-(acryloyloxy) phenyl)-4-(2-carboxyphenyl)-7-(diethylamino) chromenylium (PA-A), for detecting Cys using the –OH protection/deprotection strategy, which can react with Cys to form a red-emitting anthocyanidin derivative fluorophore. The probe has high selectivity to Cys over Hcy and GSH in phosphate buffer solution (PBS, 10 mM, pH = 7.4), high sensitivity, a low detection limit of 4.48 × 10−8 mol/L, and it can be recognized with the naked eye. Fluorescence imaging experiment of Cys with PA-A at the cellular successfully showed excellent tissue penetration.

Herein, we propose an eco-friendly synthesis of carbon dots (CDs) and ingeniously design a rapid and label-free “turn-off” sensing platform for ultrasensitive recognition of Fe3+ in vitro and in vivo. CDs with extraordinary advantages involving exceptional stability, ultra-low toxicity as well as admirable biocompatibility were simply prepared via one-step hydrothermal strategy of Caulis polygoni multiflora. Result indicated that as-acquired CDs not only exhibit excitation dependency, but also have a high quantum yield of (QY) up to 42%. Miraculously, the fluorescence of CDs can be extinguished sharply by Fe3+ because of static quenching effect with linear range of 0 µM–400 µM, yielding a detection limit of 0.025 μM. Benefiting from these characteristics, CDs have been extended for multicolourful imaging and tracking Fe3+ fluctuations in living cells. Bioimaging of zebrafish larvae exposed to CDs confirmed that it is smoothly circulated to other tissues and organs owing to their small size. Eventually, as-prepared CDs have been implemented for the real-time detection of Fe3+ in nude mice.

The ability to manipulate the genome in a programmable manner has illuminated biology and shown promise in plant breeding. Prime editing, a versatile gene-editing approach that directly writes new genetic information into a specified DNA site without requiring double-strand DNA breaks, suffers from low efficiency in plants

A multifunctional sensing platform based on bright blue-fluorescent nitrogen-doped carbon dots (N-CDs) has been ingeniously designed for the sensitive determination of Hg2+ and pH. The N-CDs were facilely fabricated via a one-step hydrothermal treatment of citric acid and folic acid with admirable merits including exceptional stability, low toxicity and distinguished biocompatibility. Intriguingly, the obtained N-CDs can be utilized to detect Hg2+ on the basis of the dynamic quenching effect, showing a linear range of 0 μM-400 μM as well as a detection limit of 0.124 μM. In addition, the obtained N-CDs revealed a significant emission enhancement with increasing pH from 4.0 to 10.0 and acquired a good linearity in the pH range of 6.8-7.8. Taking advantage of efficient analysis of Hg2+ and pH in aqueous solution, the as-synthesized N-CDs have been extended to the visualization biosensing platform to timely track Hg2+ and pH in living cells.

In present work, ordered mesoporous material SBA-15 was synthesized by using poly (alkylene oxide) block copolymer (Pluronic P123) as template and ethylsilicate as silica source in weak acid environment in a wide range of temperature. The focus of synthesis research was high hydrothermal temperature. The obtained products were characterized by various techniques, including XRD, N2 sorption isotherms, FTIR spectroscopy and thermogravimetric. The effect of hydrothermal temperature on the specific surface area, pore volume and pore size of SBA-15 products was investigated systematically. As the hydrothermal temperature increases from the 100–120 °C, the specific surface area and the pore volume of the mesoporous molecular sieve increase greatly. When the hydrothermal temperature increase further, the pore volume of the mesoporous molecular sieve increase continually. But the specific surface area decrease significantly. When the hydrothermal temperature is too high (over 140 °C), the order degree begins to decrease, So the specific surface area and pore volume decrease significantly because the pores structure have significant destruction and collapse. Mechanism and structural characteristics of P123 block copolymer could explain in detail the effect of hydrothermal temperature on the property and structure of mesoporous molecular sieve SBA-15., Materials chemistry, Theoretical chemistry; SBA-15; Synthesis; Hydrothermal; Mesopore

Graphene oxide (GO), prepared by the modified Hummers method, was applied as a highly active and selective solid acid catalyst for oxidative transformation of furfural (FAL) into succinic acid (SA)...

In this work, pyridinic-nitrogen-dominated nitrogen doped graphene with Cu incorporation (Cu/NG) are prepared via a facile and effective process. In prepared nitrogen doped graphene (NG), high nitrogen content up to 13.5 wt% was achieved and pyridinic-nitrogen dopant enriched to 11.9 at.%. Cu nanoparticles can be highly stabilized by NG materials and the stabilized Cu loading is linearly correlated with the pyridinic nitrogen content in NG. With Cu/NG as the catalyst and 2,2,6,6-tetramethyl-piperidin-1-oxyl (TEMPO) as co-catalyst, 5-hydroxymethylfurfural (HMF) was oxidized to 2,5-diformylfuran (DFF) in the new developed catalytic system under relative mild conditions (70 °C, 8 h) with high HMF conversion (99.8%) and DFF yield (99.2%). By various characterization and experimental data, Cu-N-C nano-centers were speculated to be the actives sites in catalytic oxidation of HMF. Comparison of high-resolution XPS spectra of N 1s between NG and Cu/NG material indicates the existence of strong interaction between Cu nanoparticles and pyridinic N. The developed catalytic system showed high efficiency in HMF oxidation and Cu/NG can be recycled for eight times without any obvious Cu leaching and catalytic activity loss.

Graphene oxide (GO) sheets are emerging as a new class of carbocatalyst, and also a perfect platform for metal-oxide catalyst assembling. The oxygen groups on either side of GO basal plane can be functioned as the anchor by employing GO as scaffolds. Vanadium-oxo nanosheets (VON) were assembled onto the surface of GO material from homogeneously dissolved VO(acac)2 solution via a facile route. Control experiments with different methods prepared graphene materials illustrate the nucleation and fabrication process of VON on GO surface with detailed TEM and XPS investigation. The evolution of oxygen groups in graphene material was also investigated. Hydroxyl/epoxy in GO sheets was considered to be important and favorable for the fabrication of VON on GO surface. The developed material was shown to be an efficient and recyclable heterogeneous catalyst for aerobic oxidation of 5-hydroxymethyfurfural (HMF) and furfural into maleic anhydride. Up to 90.9% yield of maleic anhydride from HMF and 59.9% from furfural were achieved under optimized reaction conditions, the reaction rate difference between HMF and FAL was studied on the basis of oxidation mechanism and their molecular structures.

SBA-15 supported nickel phosphide particles with high dispersion were successfully synthesized by using deposition-precipitation method to introduce the Ni source. Strong interaction between the Ni precursor and SBA-15 support could form and prevent the precursor migration. So the deposition-precipitation method could lead to the infiltration within the pore walls of SBA-15 and thus very uniform dispersion of Ni source over the SBA-15 support. After temperature-programmed reduction (TPR) of the phosphate precursor, the nickel phosphide particles with high dispersion were obtained. The pore channel of the SBA-15 support could stabilize the Ni2P particles, preventing sintering after the high reduction temperature and shaping their morphology. The total sulfur capacity over Ni2P/SBA-15 is approximately 1 times higher than over the reference sample. Differences in selectivity to sulfur compound were observed for Ni2P/SBA-15 adsorbents with different loading. The selectivity to sulfur compound for Ni2P/SBA-15 adsorbent is correlated with the particle size of Ni2P crystallites. The synthesis of small Ni2P crystallite is promising for novel Ni2P-based adsorbent.

Ceria nanorods arrays (HT-CeO2) were successfully synthesized by using mesostructured silica SBA-15 as hard template. The pore channel of the hard template SBA-15 could stabilize the CeO2 particles, prevent sintering during the calcination process by the high temperature and shape their rodlike morphology. HT-CeO2 was obtained by removing the silica matrix with diluted HF washing. Consequently, HT-CeO2 nanorods have a significant improvement in the textural properties with a higher surface area and total pore volume than the reference sample synthesized in the absence of template. X-ray diffraction (XRD) revealed that the only crystalline phase present in this material was CeO2 with fluorite structure. Transmission electron microscopy (TEM) shows that the HT-CeO2 is mainly constituted by agglomerates of nanorods. EDX microanalysis confirms the efficient removal of silicon template. The Ni/HT-CeO2 is more selective to the thiophene (aromatic sulfur compounds) as large amount of olefin coexisting as compared with Ni/SBA-15. The adsorption capacity of 5 wt% Ni/HT-CeO2 is decreased only by 4% due to 10 vol.% olefin addition.

Mesoporous silica-included heteropolyacids materials were synthesized and characterized by nitrogen sorption, XRD, FT-IR, TEM and NH3-TPD. Characterization results show that silica included heteropolyacids is a kind of Bronsted acid catalyst possessing large surface area, suitable pore structure, appropriate acid strength and high acid density. These materials are used as solid catalysts for the alkylation of phenol with cyclohexene. The mesoporous channel facilitates not only the dispersion of Bronsted acidity centers but also the transport of reactant and product molecules, thus leading to a significantly improved catalytic performance. Through adjusting the interaction between the support pore channel surface and heteropolyacid acive species, different acidity amount and strength can be obtained, leading to the tunable selectivity to the alkylation of phenol with cyclohexene. The improvement of reusability of silica-included HPA catalyst was related to the uniform dispersion of HPA and the enhanced interaction between HPA and the support. In six cycles of the catalyst, a stable activity could be mainttained.

This paper proposes a heterogeneous parallel processor for high-speed vision chip. It contains four levels of processors with different parallelisms and complexities: processing element (PE) array processor, patch processing unit (PPU) array processor, self-organizing map (SOM) neural network processor, and dual-core microprocessor unit (MPU). The fine-grained PE array processor, middle-grained PPU array processor, and SOM neural network processor carry out image processing in pixel-parallel, patch-parallel, and distributed-parallel fashions, respectively. The MPU controls the overall system and executes some serial algorithms. The processor can improve the total system performance from low-level to high-level image processing significantly. A prototype is implemented with $64 \times 64$ PE array, $8 \times 8$ PPU array, $16 \times 24$ SOM network, and a dual-core MPU. The proposed heterogeneous parallel processor introduces a new degree of parallelism, namely, patch parallel, which is for parallel local-feature extraction and feature detection. It can flexibly perform the state-of-the-art computer vision as well as various image processing algorithms at high speed. Various complicated applications, including feature extraction, face detection, and high-speed tracking, are demonstrated.

Alpha-alumina (α-Al 2 O 3 ) materials has a wide range of applications because of its excellent properties at high temperature. Tabular α-Al 2 O 3 was unexpectedly synthesized by etching mullite from Si x Al y O z composites since our original intention was highly porous α-Al 2 O 3 . Silica-alumina xerogels with different Al/Si molar ratio as 3, 6, 9 and ∞ (pure alumina) were prepared via sol-gel route, followed by calcination at 1400 °C to obtain Si x Al y O z composites. XRD results showed that the composite existed as mullite when the Al/Si ratio equaled to 3 and as the combination of mullite and corundum (α-alumina) when the Al/Si ratio equaled to 6 and 9, while pure α-Al 2 O 3 was obtained when Al/Si ratio equaled to ∞ signed as sol-gel α-Al 2 O 3 . The mullite phase in Si x Al y O z composites could be etched completely by hydrofluoric acid under room temperature in terms of the treating time was long enough and left tabular α-Al 2 O 3 for the samples with Al/Si molar ratio as 6 and 9. The interaction between mullite and α-Al 2 O 3 during the thermo process may direct the formation of tabular morphology. Structural and property characterizations show the tabular morphology, low surface area, perfect crystallinity and weak acidity of α-Al 2 O 3 . Furthermore, the adsorption of dibenzothiophene, a molecular with planar morphology, on tabular α-Al 2 O 3 , sol-gel α-Al 2 O 3 as well as γ-Al 2 O 3 was investigated at room temperature in comparison. Tabular α-Al 2 O 3 exhibited the highest adsorption capacity and best regeneration ability than other two.

Rapid, reliable, and convenient fluorescent probes are of great importance for specifically identifying permanganate and pH in biological systems. In this work, raw materials were provided by malic acid and neutral red for the preparation of red emission carbon dots (RCDs) using a hydrothermal carbonization approach. Superior features of RCDs including good stability, exceptional biocompatibility, and prominent water solubility were found, which enables them to favorably track permanganate and pH. Upon the introduction of permanganate, as-acquired RCDs presented a notable emission enhancement owing to aggregation induced emission (AIE) mechanism. Results indicated that they can act as “turn-on” fluorescent sensor for quantitative analysis of permanganate in the scope of 0–115 μM with a detection limit of 14.5 nM. Most importantly, this probe exhibited a special responsive functionality towards pH, in which a good linearity in the pH range of 6.2–8.2 could be readily realized. Besides, evident color changes of RCDs solution under sunlight can be visualized at different pH, which is more desirable for the fluorescent and colorimetric bimodal sensing of pH. Intriguingly, it was observed that RCDs can successfully target lysosome in living cells. Finally, as-developed RCDs were performed for the label-free, real-time visualization of permanganate and pH fluctuations in vivo and in vitro.

Because of spinel's suitable redox properties, this article focuses on its application as a candidate of thermochemical energy storage materials. Pechini method was used to synthesize of the copper and manganese mixed metal oxides with spinel structure. X-ray diffraction (XRD) was used to determine the crystal structure of the sample. The thermochemical energy storage of the samples was measured by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). It was found that sample with Cu mole ratio 1/3 showed suitable cycle stability and more flexible temperature range. It is a potential candidate for thermal energy storage material. Through the comparison of air and nitrogen-air redox cycle, it is revealed that the reduction is more thorough in inert atmosphere than in air atmosphere.

In this work, a colorimetric and fluorescent dual mode sensor based on lysosome-targeted CDs has been desirably implemented to identify Fe3+ fluctuations in vitro and in vivo. By simple one-pot hydrothermal carbonization of dried field mint, yellow-fluorescent CDs were directly fabricated without the assistance of other reagents and hold exceptional stability, superior biocompatibility as well as ultra-low cytotoxicity. Results indicated that as-prepared CDs can provide a rapid, reliable, and highly selective recognition of Fe3+ with a linear range of 0 μM–400 μM and a detection limit of 0.037 μM. Impressively, it was found that as-developed CDs can successfully target lysosome with high colocalization coefficient (0.85) and responds to fluctuations of Fe3+ in living cells. Further, acquired CDs was ingeniously devoted to Escherichia coli imaging. Besides, obtained CDs was eventually utilized to track the variation of Fe3+ in vivo system. A preliminary research expresses that as-synthesized CDs can function as an effective tool to detect Fe3+ in vitro and in vivo and thus indicates the promising applicability for disease detection in physiology and pathology in the future.

This paper mainly explores the influence of different experiment factors on the angelica lactone self-aggregation process to synthesize C 10 , C 15 and C 20 self-aggregation products through Michael addition by base catalysis. Various experiment factors including types of catalysts, temperature, time and catalyst amounts are investigated in the angelica lactone self-aggregation process. And the possible mechanism of angelica lactone self-aggregation process catalyzed by carbonate is proposed. The results show that anhydrous potassium carbonate exhibits the higher efficiency and milder application conditions than other base catalysts. The different dominating products could be obtained by using anhydrous potassium carbonate under different experiment conditions. The optimal conditions for the angelica lactone dimer (C 10 ) are 10 wt% catalyst, 343 K and 30 min, and the maximal yield of dimer is 69.26%; the optimal conditions for the angelica lactone trimer (C 15 ) are 12 wt% catalyst, 333 K and 20 min, and the maximal yield of trimer is 49.89%; the optimal conditions for the angelica lactone tretramer (C 20 ) are 12 wt% catalyst, 343 K and 60 min and the maximal yield of tretramer is 62.46%.

Commercial adsorbents were tested for removing the dibenzothiophene sulfone (DBTO) from a model diesel fuel and organosulfur oxidized products (sulfones) from a real diesel fuel under ambient conditions. Activated carbons treated by concentrated H2SO4 at high temperature showed increasing adsorption capacity and affinity towards DBTO. On the basis of adsorption tests and the characterization by BET, base titration, SEM, XPS, Visible-Raman and FTIR, the acidic-oxygenated groups incorporated to the surface act as adsorption sites for selective adsorption of sulfone. The specific interaction may be formed through the acid-base interaction involving the SO group. Activated carbon treated by steam at 900 °C and followed by concentrated H2SO4 at 250 °C displayed significantly enhanced DBTO adsorption performance and a sulfur capacity of 5.8 mg S/g adsorbent for removing organosulfur compound from a real diesel to less than 10 ppmw.

Activated carbons chemically treated by steam and concentrated H2SO4, were used as adsorbents for removing organic sulfur compounds from a model diesel. The modified activated carbon was characterized by N2 sorption, base titration and FTIR spectroscopy. As compared with the untreated activated carbon, the treatment by a steam at 900 °C increased the mesoporous volumes from 0.248 to 0.856 cm3/g and sulfur adsorption capacity for dibenzothiophene from 10.9 to 20.6 mg/g and the treatment by a concentrated H2SO4 at 250 °C increased the amount of surface acidic-oxygenated groups from 0.05 to 1.95 mmol/g, and total adsorption capacity for dibenzothiophene from 10.9 to 33.3 mg/g. The total adsorption capacity for dibenzothiophene is found to be proportional to the mesoporous volume and the amount of surface oxygen-containing groups. It is proposed that direct interaction between the sulfur atom and surface oxygen-containing groups plays an important role in the adsorption of organic sulfur compound.

Visual target tracking has made significant advances in past decades. However, fast and robust vision target tracking systems are still greatly demanded. This paper proposes a novel high-speed target tracking system based on hierarchical parallel vision processor architecture. This system contains three main parts: 1) a CMOS image sensor; 2) a vision processor; and 3) an actuator with two degrees of freedom. The vision processor integrates a pixel-parallel processing element (PE) array, a row-parallel row processor (RP) array, dual-core microprocessor unit (MPU) and motor controller. The PE array and RP array can speed up low-level and middle-level image processing operations by ${O(M^{2})}$ and ${O}$ ( ${M}$ ), respectively. The MPU is responsible for the high-level image processing and the overall chip management. A novel tracking algorithm based on a gray-level local binary pattern descriptor is proposed. The descriptor describes not only local texture feature but also distribution of luminance. The algorithm increases the robustness of the tracking system under low resolution scenery and complex background. It can be carried out by the vision processor with very high efficiency. Experiment results demonstrate that the system can track a fast moving target under complex conditions and the vision processor can achieve over 2000 frames/s processing speed of the target tracking algorithm with $ {750\times 480}$ image resolution.

The combination of benzoic acid and 2,2,6,6-teramethylpiperidin-1-oxyl (TEMPO) afforded an efficient catalytic system for the aerobic oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-diformylfuran (DFF) under certain conditions. The maximum conversion of 86.7 % for HMF was obtained with a nearly 77.8 % DFF yield at 1 mmol benzoic acid and 0.4 MPa oxygen pressure in acetonitrile. The aerobic oxidation ability of HMF into DFF depended on the electron density of the organic acid skeletal structure with the carboxyl group. Meanwhile, the catalyst system of benzoic acid/TEMPO also exhibited good performance for aerobic oxidation of other alcohols. Based on experimental results, we propose that the benzoic acid acted as the primary catalyst and TEMPO was the key co-catalyst, oxidized into oxoammonium cation through electron transport and then regenerated by a superoxide radical during the reaction.

The dehydration of fructose in aqueous and biphasic system was studied using heteropolyacids, immobilized in silica, as catalyst. The catalysts were characterized by ICP-AES, nitrogen sorption, NH3-TPD, TEM, FT-IR, XRD, and TGA. The effect of different parameters, such as reaction temperature, reaction time, catalyst loading and volume ratio of water with methyl isobutyl ketone (MIBK) was studied. Silica included tungstosilisic acid (HSiW) was found to function as an efficient catalyst for the transformation of fructose into 5-hydroxymethylfurfural in aqueous phase. Addition of MIBK into the reaction system can increase both of fructose conversion and HMF selectivity. Besides, MIBK showed a positive effect in increasing the stability of the catalyst by suppressing the formation and deposition of humins over catalyst surface. After the third catalysis cycles, a stabilization of the catalytic activity was observed.

Ce-containing SBA-15 materials with Ce/Si molar ratio ranging from 0 to 0.08 were prepared by mixing an acidic suspension of colloidal CeO 2 particles along with the surfactant during the synthesis of mesostructured silica. The obtained solids were characterized by powder X-ray diffraction (XRD), N 2 sorption isotherms, TEM, UV–vis, and Raman spectroscopy. Structural analyses confirmed that all the samples present a well-ordered hexagonal mesoporous structure, with larger pore diameter and volume than unmodified SBA-15 due to the incorporation of the lanthanide promoter. According to the characterization results different cerium species, namely dispersed Ce species and CeO 2 crystallites, are formed depending on the Ce/Si ratio of the Ce-SBA-15 materials. On the other hand, Ni/Ce-SBA-15 catalysts were prepared by wet impregnation of the mesoporous supports and the comparison of the different samples showed that the incorporation of Ce progressively enhances Ni dispersion. These catalysts were assayed for hydrotreating of anisole at temperatures in the 270–290 °C range and moderate hydrogen pressure (7 bar). Such process is relevant for the upgrading of bio-oils derived from the pyrolysis of lignocellulosic biomass. Catalytic activity tests reveal that conversion of anisole progressively improves with increasing Ce/Si ratio and exceeds 30% at 290 °C for the catalyst with Ce/Si = 0.08. In these conditions the main product is methoxycyclohexane in all cases. However, almost a two-fold increment of benzene yields can be obtained with Ce-promoted catalysts when compared to Ni/SBA-15. This enhancement of the selectivity towards aromatic is very promising for the development of a green route for the production of those chemicals.

2,5-hexanedione, a valuable platform chemical which is being broadly used in biofuel, medicinal chemistry and drug discovery, was synthesized from biomass derived dimethyl furane using a highly efficient biphasic system. In this biphasic systems, mineral acids (HCl, H2SO4 and H3PO4) dissolved in aqueous phase were used as hydrolysis catalysts. The hydrolysis reaction is suggested to take place at the interface between the aqueous and the organic phase. But more importantly, water-immiscible organic phase could continuously extract the in-situ produced 2,5-hexanedione from the interface to prevent the extended contact between the 2,5-hexanedione and the acids, thereby avoiding the oligomerization side reactions A yield of 99 % could be obtained when methyl isobutyl ketone (MIBK) was the organic phase in the biphasic system.

Co-containing catalysts supported on super-microporous Al2O3–ZrO2 (denoted as Co/AZ(X)) with different Al/Zr molar ratio (X) were prepared by impregnation method, and they were applied to the dehydrogenation of ethylbenzene with CO2 as soft oxidant. It was found that textural and chemical properties of Co/AZ(X) materials were strongly influenced by Al/Zr molar ratio. The catalytic performance of these materials highly depended on their physicochemical properties, and the 2.5Co/AZ(0.7) catalyst with an intermediate acidity, high surface area and high metal dispersion exhibited the best catalytic performance in the dehydrogenation of ethylbenzene with CO2.

The oxidation of 5-hydroxylmethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is a sustainable and promising method for the preparation of bio-derived aromatic polyesters. Nitrogen doped carbon material is an effective catalyst support in preparing supported nanoparticle metal catalysts in heterogeneous reactions. In this work, by pyrolysis of bio-waste carbon material, pomelo peel, under 800 °C flowing NH3, high nitrogen (up to 11.4 wt%) doped porous carbon material (NC) was facilely obtained. Pt nanoparticles (NPs) can be uniformly dispersed on NC surface and stabilized by the doped nitrogen dopant. Supported Pt NPs by NC-800 (Pt/NC-800) was proved to be an efficient catalyst in aerobic oxidation of HMF into FDCA. Control experiments show that the oxidation of 5-hydrox-ymethyl-2-furancarboxylic acid (HMFCA) to 5-formyl-2-furancarboxylic acid (FFCA) by supported Pt NPs was the key step to determine the oxidation rate of HMF to FDCA. With controlled experiment results and previous reports, a catalytic mechanism involving water, molecular O2, hydroxyl ions and Pt NPs was given and explained well of the phenomenon of high HMFCA concentration accumulation during reaction.

Additional file 1:Figure S1. Base editing results of SpCas9-pBE system. Genes, target sequences and sequencing results of six editing targets were showed in SpCas9-pBE system. PAM sequence was highlighted in green, the C to T conversion bases were highlighted in blue. Red arrow indicated the mutation peak. The results were from 15 positive calli. Figure S2. Base editing results of SpCas9-rBE system.Genes, target sequences and sequencing results of four editing targets were showed in SpCas9-rBE system. PAM sequence was highlighted in green, the C to T conversion bases were highlighted in blue. Red arrow indicated the mutation peak. The results were from 15 positive calli. Figure S3. On-target activities of high fidelity SpCas9 variants guided by wild-type sgRNA.a C-T substitution frequency of SpCas9-pBE and high fidelity Cas9 pBEs at three genomic targets. b Random mutation frequency of SpCas9 and three variants at three genomic targets. All the frequencies were calculated among 15 positive calli. Figure S4. C-T substitution and random mutation occurred at NRT1.1B site in pBE system. Three samples with random mutations were selected from the calli of SpCas9-pBE and eSpCas9(1.1)-pBE complexed with the modified sgRNA each to detect the actual mutation types. PCR product were cloned to pEASY-B vetor and 27 positive clones were sent for sequencing. Arrows indicated the substitution base. Figure S5. Random mutation frequency at NRT1.1B site in pBE system. Three samples with random mutations were selected from the calli of SpCas9-pBE and eSpCas9(1.1)-pBE complexed with the modified sgRNA each. Proportions of C-T substitution (SNP), random mutation (Indel), and substitution mixed with random mutation (SNP + Indel) were shown from 27 positive B-vector cloing above. Figure S6. Schematic diagram for the constructions of base editors. Fragments, backbones and related restriction enzymes used in the construction of SpCas9-pBE (a) and SpCas9-rBE (b) base editors. Figure S7. Essential sequences used in this study.

Mesoporous rod-like SiC has been prepared by using SBA-15 as hard template and sucrose as carbon source through a vapor-solid mechanism. The material was characterized by X-ray diffraction (XRD), high resolution transmission electronmicroscopy (HRTEM) and thermalgravimetric (TG) analysis. The obtained material exhibits different morphologies, and consists of a rod-like SiC core and amorphous silica shell which is due to the excessive silica during the reaction between silica and carbon to form SiC. The diameter of the SiC nanorods are ranged from 8 to 60 nm, and the silica shell has a thickness of about 4 nm. The silica coating SiC nanorods possess more porous structure than pure SiC and in turn make it more useful in catalytic fields.