MOLECULES
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2017
·Vol. 22
·期 1
·150
·
IF 2.861
Dongjun Lv,Mingjie Zhang
Two polymer catalysts (Pd-OCMCS and Ni-OCMCS) with good reusability were synthesized by coordinating Pd and Ni ontoO-carboxymethyl chitosan (OCMCS). The chemical structure and thermal stability of prepared catalysts were determined by Fourier transform infrared (FT-IR) spectra, Energy Dispersive Spectrometer (EDS)analysis, X-ray diffraction (XRD), and thermogravimetric analyzer (TG-DTG), and the analysis results showed that the Pd and Ni ions coordinated onto the OCMCS and formed a ligand with the –COOH group, amino groups, and –OH group on the OCMCS, and the EDS and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) analysis results showed that the loading amounts of Pd and Ni were approximately 8.3% and 8.9%, respectively. In the Heck reaction between aryl halides andn-butyl acrylate catalyzed by the prepared catalyst, the test results showed that the product yield followed the order of aryl iodide > aryl bromide > aryl chloride. Additionally, the product yield for the aryl iodide and aryl bromide could reach up to 99% and 96%, respectively. Moreover, the electron-withdrawing and electron-donating property of the group on the aryl also affected the product yield, and the product yield for aryl halides with electron-withdrawing groupp-NO2,p-CH3CO, andp-CHO was higher than that with electron-donating groupp-CH3.Keywords:O-carboxymethyl chitosan;biopolymer-supported catalyst;Pd-OCMCS;Ni-OCMCS;heck reaction
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JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION
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2017
·Vol. 38
·期 1
·30-36
·
IF 0.938
Sun W. Z.,Cheng J. G.,Huang Z. K.,Jiang Y.,Wu L. E.,Liu L. M.
The present work determined the phase relations in Si-Al-M-O-C (M = Zr, Mg) systems, involving SiC-Al 2 O 3 -ZrO 2 , SiC-Al 2 O 3 -MgO, SiC-SiO 2 -Al 2 O 3 -ZrO 2 and SiC-SiO 2 -Al 2 O 3 -MgO systems by XRD phase analyses of the solid-state reacted samples from powder mixtures of SiC, Al 2 O 3 , ZrO 2 , MgO and SiO 2 . Within these systems, SiC was respectively compatible with other neighboring phases, forming a set of four-phase compatibility tetrahedrons. The subsolidus phase diagrams of the SiC-SiO 2 -Al 2 O 3 -ZrO 2 and SiC-SiO 2 -Al 2 O 3 -MgO quaternary systems were presented.
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Nature Communications
·
2024
·Vol. 15
·期 1
·1-11
·
IF 14.7
Pei An,Wang Peng,Zhang Shiyi,Zhang Qinghua,Jiang Xiaoyi,Chen Zhaoxi,Zhou Weiwei,Qin Qizhen,Liu Renfeng,Du Ruian,Li Zhengjian,Qiu Yongcai,Yan Keyou,Gu Lin,Ye Jinyu,Waterhouse Geoffrey I. N.,Huang Wei-Hsiang,Chen Chi-Liang,Zhao Yun,Chen Guangxu
Challenges in direct catalytic oxidation of biomass-derived aldehyde and alcohol into acid with high activity and selectivity hinder the widespread biomass application. Herein, we demonstrate that a Pd/Ni(OH) 2 catalyst with abundant Ni 2+ -O-Pd interfaces allows electrooxidation of 5-hydroxymethylfurfural to 2, 5-furandicarboxylic acid with a selectivity near 100 % and 2, 5-furandicarboxylic acid yield of 97.3% at 0.6 volts (versus a reversible hydrogen electrode) in 1 M KOH electrolyte under ambient conditions. The rate-determining step of the intermediate oxidation of 5-hydroxymethyl-2-furancarboxylic acid is promoted by the increased OH species and low C–H activation energy barrier at Ni 2+ -O-Pd interfaces. Further, the Ni 2+ -O-Pd interfaces prevent the agglomeration of Pd nanoparticles during the reaction, greatly improving the stability of the catalyst. In this work, Pd/Ni(OH) 2 catalyst can achieve 100% 5-hydroxymethylfurfural conversion and >90% 2, 5-furandicarboxylic acid selectivity in a flow-cell and work stably over 200 h under a fixed cell voltage of 0.85 V.
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JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2017
·Vol. 164
·期 13
·A3303
·
IF 3.259
Qianqing Zhao,Mingqi Li
To develop high-capacity and low-cost carbon material, a novel high-content N, O-codoped C anode material is synthesized using melamine and glucose as starting materials. The as-prepared sample is composed of hierarchical meso-macroporous carbon bulks and graphene-like carbon sheets with 23.5 wt% N and 13.8 wt% O. The high-content N, O-codoped C exhibits high lithium storage capacity, long cycle life and excellent rate capability. At 200 mA g−1 over a voltage window of 0–3.0 V at 25°C, a discharge of about 670 mAh g−1 can be obtained after 500 cycles. Even at 1600 mA g−1, the high-content N, O-codoped C still exhibits a stable discharge capacity of 330 mAh g−1. Compared with the O-doped C and non-doped C materials, the high-content N, O-codoped C shows significant advantages in lithium storage performance, which are attributed to its high surface area, abundant porosity, graphene-like structure and rich heteroatom doping. With the rise of temperature, the lithium storage capacity of the high-content N, O-codoped C increases. With the decrease of delithation cutoff voltage, the reversible capacity of the high-content N, O-codoped C decreases. When assembled a full cell with the LiNi0.5Co0.2Mn0.3O2 cathode, a relatively stable cycling performance can be obtained.
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Food Chemistry-X
·
2024
·
IF 6.5
Qian Zhang,Yu-Qiao Wang,Lin Li,Hao-Lin Song,Hai-Tao Wu,Bei-Wei Zhu
Salidroside (Sal), the main bioactive substance in Rhodiola rosea , is a promising functional food component with a wide range of pharmacological effects, but its biological activity is challenging to sustain due to its short half-life, low oral bioavailability, and susceptibility to environmental factors. The aim of this study was to investigate the effect of sodium alginate (SA) concentration on the construction of W/O/W emulsion in the protection of Sal. With the escalation of SA concentrations, the range of droplet size distribution was smaller and the droplets were more uniform. When the concentration of SA was 2 %, the average droplet size reached 9.1 ± 0.1 μm, and the encapsulation efficiency of Sal was 77.8 ± 1.8 %. Moreover, the double emulsion with 2 % SA was the most stable for 28 days at 4 °C since the oil droplets were embedded in the network structure of SA.
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JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 40
·19075-19087
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IF 3.5
Tong Yifan,Liu Linxiang,Chen Zehong,Zhong Linxin
Hydrophobic, elastic, and conductive (HEC) aerogels have significant potential in electronic devices. Herein, we propose a new method to fabricate an HEC aerogel with excellent mechanical and sensing performances from TEMPO-oxidized bacterial cellulose (O-BC) and conductive MXene nanosheets via directional freeze-drying and silanization modification. O-BC with a high aspect ratio can interweave with each other to form continuous layers, while MXene can induce a regular and flat structure and provide good conductivity. The silanization modification ensures high hydrophobicity and high elasticity, which can prevent the aerogel from structural collapse by avoiding adhesion among lamellae. The resulting aerogel can withstand compressive strain high up to 90% and long-term compression for 10,000 cycles at 50% strain due to the elastic and hydrophobic lamellar structure. It also offers a precise electrical response to stress signals in a broad detection range of 0–40 kPa and can accurately detect biological signals from humans. These structural and mechanical performance benefits make the HEC aerogel valuable in the field of pressure sensing.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yu Ding,Xuebin Jiang,Hanjun Liu,Huanyu Liu,Guoyun Liu,Wentao Ma,Zhoucheng Li,Baiyun Jin,Yuanzhu Mi,Xuemin Yan
The separation of water-in-oil (W/O) emulsion causes a major problem in the process of crude oil extraction. To address this challenge, amphipathic hyperbranched polymer demulsifiers were developed, incorporating dendritic polyamide-amine as the hydrophilic core and alkyl glycidyl ether as hydrophobic branch. This structure allows for switching the amphiphilicity of demulsifiers by regulating the length of hydrophobic branch, thereby achieving the demulsification of W/O emulsion. Specifically, the demulsification experiments showed that at a concentration of 500 mg/L, TEM 8 demulsifier achieved a demulsification efficiency (DE) of 100 % within 150 min at 45 ℃. Moreover, it also had superior DE across a wide pH value from 4 to 12. Interfacial characteristic experiments −including three-phase contact angle (TCA), surface tension (SFT), dynamic interfacial tension (IFT) and viscoelasticity modulus (VM)- were performed to elucidate the demulsification mechanism. In summary, TEM 8 effectively reduces interfacial tension and substitutes the natural surfactants at oil–water interface. This causes the rupture of interfacial film and coalescence of droplets, which facilitates demulsification. These findings highlight the potential of the hyperbranched polymer demulsifier for the effective separation of W/O emulsions at low temperature, suggesting its promising applications in advanced water–oil separation.
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ACTA PHARMACOLOGICA SINICA
·
2024
·
IF 6.9
Zhang Chen-chun,Li Yuan,Jiang Chang-you,Le Qiu-min,Liu Xing,Ma Lan,Wang Fei-fei
The O-linked-β-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation) is a critical post-translational modification that couples the external stimuli to intracellular signal transduction networks. However, the critical protein targets of O-GlcNAcylation in oxidative stress-induced apoptosis remain to be elucidated. Here, we show that treatment with H 2 O 2 inhibited O-GlcNAcylation, impaired cell viability, increased the cleaved caspase 3 and accelerated apoptosis of neuroblastoma N2a cells. The O-GlcNAc transferase (OGT) inhibitor OSMI-1 or the O-GlcNAcase (OGA) inhibitor Thiamet-G enhanced or inhibited H 2 O 2 -induced apoptosis, respectively. The total and phosphorylated protein levels, as well as the promoter activities of signal transducer and activator of transcription factor 3 (STAT3) and Forkhead box protein O 1 (FOXO1) were suppressed by OSMI-1. In contrast, overexpressing OGT or treating with Thiamet-G increased the total protein levels of STAT3 and FOXO1. Overexpression of STAT3 or FOXO1 abolished OSMI-1-induced apoptosis. Whereas the anti-apoptotic effect of OGT and Thiamet-G in H 2 O 2 -treated cells was abolished by either downregulating the expression or activity of endogenous STAT3 or FOXO1. These results suggest that STAT3 or FOXO1 are the potential targets of O-GlcNAcylation involved in the H 2 O 2 -induced apoptosis of N2a cells.
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MICROPOROUS AND MESOPOROUS MATERIALS
·
2018
·
IF 3.649
Mingqiang Liu,Lishu Shao,Jianhan Huang,You-Nian Liu
The O-containing hyper-cross-linked polymers were synthesized from phenol (2-naphthol) and formaldehyde dimethyl acetal by a simple one-step Friedel-Crafts reaction, they were subsequently carbonized using KOH as the activating agent, and their adsorption to CO 2 was carefully tested. The results indicated that these samples had a high Brunauer-Emmett-Teller surface area (up to 2241 m 2 /g), pore volume (up to 1.20 cm 3 /g), CO 2 uptake (up to 6.3 mmol/g at 273 K and 1.0 bar), and CO 2 /N 2 selectivity (up to 96 for the HCPs, and 22.5 for the porous carbon). In particular, the CO 2 adsorption was highly dependent on the ultramicropore volume (pore width<0.7 nm), while the CO 2 /N 2 selectivity mainly relied on the oxygen content and the ultramicropore structure.
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Small
·
2025
·
IF 12.1
Shaojie Mo,Ang Xu,Mo Li,Zhongyang Zheng,Youwei Yan,Xinyun Wang,Heping Li
Hydrogen embrittlement in metals seriously threatens the safe and durable operation of hydrogen energy. Developing efficient and robust hydrogen barriers is a viable solution to solve this issue but remains a significant challenge. An amorphous (ErAlCrZrTi)O high-entropy nanofilm is successfully fabricated via sol-gel on steel and identified as highly efficient and robust hydrogen barrier. At 270 nm thickness, the nanofilm achieves ultra-low hydrogen permeability of 1.35 × 10 −15 mol m −1 s −1 Pa −0.5 , enhancing hydrogen resistance by 2738 times at 500 °C compared with that of bare steel. Compared to Er 2 O 3 , Al 2 O 3 , Cr 2 O 3 , and ZrO 2 , it improves hydrogen resistance by 5, 11, 26, and 90 times, respectively. Moreover, such a high hydrogen resistance can be satisfyingly retained even after the (ErAlCrZrTi)O nanofilm suffering 10 dpa irradiation. The nanofilm exhibits 37 MPa bonding strength and exceptional thermal shock resistance, attributed to the formation of Cr₂O₃ transition layer via precipitation and oxidation of Cr from the substrate during annealing. It strengthens adhesion and alleviates thermal expansion mismatch with the substrate. The mechanism for the high barrier efficiency is further revealed by this theoretical calculations. These results provide tremendous insights on the understanding and future design of high-performance hydrogen barriers for hydrogen embrittlement prevention.
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CARBOHYDRATE RESEARCH
·
2012
·
IF 2.332
Liqiang Wu,Zhikui Yin
A simple and clean synthesis of per- O -acetylation carbohydrate derivatives has been accomplished by treatment of sugars with a stoichiometric quantity of acetic anhydride under solvent-free conditions in the presence of sulfonic acid functionalized nano γ-Al 2 O 3 as an efficient and environmentally benign catalyst.
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Nature Communications
·
2024
·Vol. 15
·期 1
·1-16
·
IF 14.7
Cao Shiyang,Wang Tong,Ren Yifan,Wu Gengshan,Zhang Yuan,Tan Yafang,Zhou Yazhou,Chen Hongyan,Zhang Yu,Song Yajun,Yang Ruifu,Du Zongmin
Post-translational addition of O-linked N-acetylglucosamine (O-GlcNAc) to proteins is commonly associated with a variety of stress responses and cellular processes in eukaryotes, but its potential roles in bacteria are unclear. Here, we show that protein HmwC acts as an O-GlcNAc transferase (OGT) responsible for O-GlcNAcylation of multiple proteins in Yersinia pestis , a flea-borne pathogen responsible for plague. We identify 64 O-GlcNAcylated proteins (comprising 65 sites) with differential abundance under conditions mimicking the mammalian host (Mh) and flea vector (Fv) environments. Deletion of hmwC , encoding a putative OGT, structurally distinct from any existing member of the GT41 family, results in reduced O-GlcNAcylation, reduced growth, and alterations in virulence properties and survival under stress. Purified HmwC can modify target proteins in vitro using UDP-GlcNAc as sugar donor. One of the target proteins, OsdY, promotes Y. pestis survival under oxidative stress conditions. Thus, our results support that regulation of antioxidative responses through O-GlcNAcylation may be a conserved process shared by prokaryotes and eukaryotes.
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危险品化学品经营许可证（带存储）