ChemCatChem
·
2017
·Vol. 10
·期 2
·415-421
·
IF 4.803
Jianwei Ji,Haiwei Guo,Changzhi Li,Zaojuan Qi,Bo Zhang,Tao Dai,Min Jiang,Chuanqing Ren,Aiqin Wang,Tao Zhang
Graphical Chop up the wood : Tungsten-based bimetallic catalysts exhibit high activity and selectivity in the hydrogenolysis of typical model compounds of the α-O-4 linkage in lignin and deconstruction of lignin feedstock for the production of aromatic chemicals. High yields of C−O cleavage products are obtained without destroying the aromatic rings. Tungsten-based bimetallic catalysts M–W/AC (M=Ru, Pt, and Pd; AC=activated carbon) exhibited high activity and selectivity in the hydrogenolysis of typical α-O-4 model compounds and deconstruction of lignin feedstock for the production of aromatic chemicals. Synergy effect was observed between tungsten and noble-metal species, which on the one hand modulated the hydrogenolysis activity of tungsten and improved the activity of catalyst, and on the other hand suppressed overhydrogenation that avoided the formation of cycloalkanes. The conversion of α-O-4 model compounds with different substituents showed that electronic effects play an important role in stabilizing the reaction intermediates, and the electron-donating methoxy group on the aromatic ring accelerated the hydrogenolysis efficiency. Solvent effect was another factor that determined hydrogenolysis efficiency; dipolar aprotic solvents such as n -hexane provided the high yields of target aromatics. In the conversion of realistic lignins, the bimetallic catalyst showed excellent activity not only in α-O-4 cleavage but also in the hydrogenolysis of other major linkages such as β-O-4 and β−β between aromatic units, so that a high yield of liquid oil was obtained from lignin.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
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.
✓ 已验证
产品关联
DOI
高影响因子
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.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2016
·
IF 3.652
Shiliang Wu,Dekui Shen,Jun Hu,Huiyan Zhang,Rui Xiao
The pyrolytic characteristics of cellulose, cellobiose and glucose were examined by TG-FTIR combined with Py-GC–MS, in order to gain the effect of β -O-4 glycosidic bond on the pyrolysis process. In TG-FTIR analysis, two mass loss peaks were observed for cellobiose and glucose, indicating dehydration in low temperature stage and consequently intensive cracking of glycosidic bond and fragments for cellobiose. The samples were tested in Py-GC–MS at the temperature of 300, 500 and 900 °C according to their mass loss characteristics from TG-FTIR. Formation of furans from cellobiose, which involved the cracking of β -O-4 glycosidic bond, was prominent over other products, compared to that of cellulose and glucose. Four possible chemical pathways for the cleavage of β -O-4 glycosidic bond have been proposed with regard to the formation of furans and anhydrosugars from cellulose. Besides, another two reaction pathways leading to the formation of levoglucosan were also suggested.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION
·
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.
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
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
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 38
·30303-30309
·
IF 3.84
Yangling Li,Ying Tan,Kun Xu,Cuige Lu,Xuechen Liang,Pixin Wang
An in situ hydrogel based on oxidation cholesterol starch (OCS) and O-carboxymethyl chitosan (CMCT) that is completely devoid of potentially cytotoxic small molecule cross-linkers and does not require complex manoeuvres or catalysis has been formulated and characterized. The network structure was created by Schiff base formation. The mechanical properties, internal morphology and swelling ability of the injectable hydrogel were examined. Rheological measurements demonstrated that increasing the concentration of the monomer improved the storage modulus. SEM showed that the hydrogel possessed a well-defined porous structure. In addition, the Schiff base reaction was acid sensitive. Under acid conditions, the hydrogel could hydrolyse quickly compared with high pH conditions. Doxorubicin (DOX) was used as a model drug to investigate the control and release properties of the hydrogel. The cytotoxic potential of the hydrogel was determined using an in vitro viability assay with L929 cells as a model and the results revealed that the hydrogel was non-cytotoxic.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Functional Foods
·
2015
·
IF 3.574
Shang-Ta Wang,Ting-Fang Fang,Chen Hsu,Chia-Hao Chen,Chun-Jung Lin,Nan-Wei Su
Research has indicated the health beneficial effects of soyfoods. Genistein, one of the primary bioactive agents in soybeans, has a number of pharmacological and biological activities; however, its low water solubility and low intestinal permeability may lead to the depletion of genistein absorption from dietary intake and contribute to its poor oral bioavailability. Previous study revealed a water-soluble phosphate conjugate of genistein, genistein 7-O-phosphate (G7P), generated by biotransformation of Bacillus subtilis var. natto BCRC80517 with genistein. This study aimed to investigate the dissolution profile, intestinal permeability and oral bioavailability of genistein and G7P. G7P improved water solubility and also enhanced intestinal permeability in vitro and in situ , and greatly increased plasma exposure to genistein after oral administration in rats. The aqueous solubility of genistein is the absorption barrier to its oral bioavailability. G7P may be a promising and efficient alternative to genistein.
✓ 已验证
产品关联
DOI
高影响因子
BIOPOLYMERS
·
2017
·Vol. 107
·期 10
·e23038
·
IF 1.908
Yan Xiao,Jianqiang Wang,Jun Zhang,Andreas Heise,Meidong Lang
Copolypept(o)ides of polysarcosine (PSar) and poly( N -isopropyl-L-glutamine) (PIGA) with random and block sequence structures were synthesized by ring-opening polymerization (ROP) of sarcosine N -carboxyanhydrides (Sar-NCA) and γ-benzyl- l -glutamate N -carboxyanhydrides (BLG-NCA) and post modification. With different distribution of Sar along the main chain, H-bonding pattern and secondary structure of polypeptides were turned, as well as aggregation and gelation behavior. Both copolypept(o)ides formed hydrogels above their critical gelation concentrations (CGCs) without thermo-sensitivity, which was normally reserved for PEG copolypeptides (eg, PEG- b -PIGA). In particular, a different mechanism from previously reported micellar percolation or fibrillar entanglement was suggested for gelation of the random copolypept(o)ide. Therefore, hydrogels from copolymers of PSar and PIGA represented a new approach to construct easy-handling, biocompatible, biodegradable and thermo-stable gels that could potentially be applied in biomedical fields. Graphical
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）