APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 34
·期 8
·e5707
·
IF 3.14
Laiyun Zhou,Mingliang Wang,Kaixuan Wang,Tiantian Wen,Lanzhi Wang
Fe 3 O 4 @SiO 2 -CeCl 3 catalyzed chemoselective synthesis of functionalized 3-substituted-1,5-benzodiazepines via one-pot multicomponent and domino reactions has been developed. During the one-pot synthesis process, one new cycle and four new bonds (one C–C, two C–N and one C=C) were constructed by the nucleophilic addition and eliminate reaction (dehydration etc.) process, intramolecular proton transfer and cyclization process. The major advantages of the present method are good to excellent yields, shorter reaction time, simple experimental procedure, easy work up, mild reaction conditions, recyclability of the catalyst and ability to tolerate a variety of functional groups which gives economical as well as ecological rewards.
研究领域:
有机化学
·
药物化学
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DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Bushra Naureen,A.S.M.A. Haseeb,W.J. Basirun,Farina Muhamad
Tissue degeneration due to diseases, accidents, and wars is a worldwide issue. One of the methods used by regenerative medicine (RM) to aid tissue repair is by using a biodegradable tissue engineering scaffold (TES). Different body tissues have variable regeneration abilities, and hence, they require TES with variable degradation rates. This paper focuses on synthesising four polyurethane foam scaffolds (PUFS) with variable degradation rates based on the concentration of incorporated chain extender (CE) poly[(R)-3-hydroxybutyrate] (P3HB). The polyol employed is poly (propylene fumarate) (PPF) along with aliphatic 1,6-hexamethylene diisocyanate (HDI). GPC provided the molecular weight (M n = 455.67 g mol −1 , M w = 587.15 g mol −1 ) and PDI (1.29) of the PPF. FTIR and 1 H and 13 C NMR confirmed the proposed structures (C C, COOR, and NHCOO) of the PUFS. The FESEM images revealed a bimodal pore structure , with random, irregular, interconnected pores (242–340 µm) and discrete void spaces (735–860 µm). The size of PUFS pores and void spaces (PU4 > PU3 > PU2 > PU1) is directly proportional to their respective degradation rates. The TGA/DTA curves show a decrease of an onset thermal decomposition temperature from PU1 to PU4 (267.17 ºC PU1, 267.28 ºC PU2, 256.01 ºC PU3 and 240.72 ºC PU4) due to the respective increase in CE concentration. The results of in-vitro degradation analysis at day 70, revealed significant difference between the weight loss (%) of each group (PU1 = 4.09 ± 0.18%, PU2 = 8.03 ± 0.17%, PU3 = 13.14 ± 0.12% and PU4 = 20.21 ± 0.19%). Thus, PUFS with a higher concentration of P3HB have a faster degradation rate due to the associated P3HB hydrolysable ester/-COOR functional group within the PUFS backbone. The chemical structure , bimodal morphology, and variable degradation rate of these PUFS could be employed for various RM applications.
研究领域:
生物材料学
·
再生医学
·
高分子化学
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DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 36
·18718-18726
·
IF 7.443
Gongzheng Yang,Huawei Song,Mingmei Wu,Chengxin Wang
Besides targeting low-voltage intercalation, NaTi2(PO4)3 (NTP) is a promising negative electrode material for non-aqueous sodium-ion batteries (SIBs). However, the low electronic conductivity of this material inhibits its potential applications. Herein, we report the controllable synthesis of four interesting porous NTP nanocubes via a one-pot solvothermal method. The as-synthesized products have shown excellent high-rate performance and cycling stability as SIB anodes. After 10 000 cycles at a 10C rate, 75.5% of the initial capacity is retained, which exceeds those of most of the reported SIB anode materials. Even at an extremely high rate of 100C, the NTP nanocubes can still deliver considerable reversible capacities after deep charging/discharging for 15 000 cycles. The superior electrochemical performances can be attributed to their unique nanostructures. We hope that such a finding of the new construction will enrich the NTP system and provide several possible candidates for SIB anodes.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
电池技术
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DOI
高影响因子
TALANTA
·
2011
·
IF 3.722
Ya-qin Wang,Wen-sheng Zou
New strategies for silica coating of inorganic nanoparticles became a research hotspot for enhancing the mechanical stability of colloidal particles and protecting colloidal particles against oxidation and agglomeration, and so on. In this paper, 3-aminopropyltriethoxysilane (APTES)-functionalized Mn doped (AF MnD) ZnS QDs was prepared to be firsyly through the use of silane coupling agents to form an active layer of silica, then sol–gel reaction of TEOS co-deposited with APTES on the surface of resultant active layer of silica. The emitted long lifetime room-temperature phosphorescence (RTP) of the resultant nanomaterials allows an appropriate delay time so that any fluorescent emission and scattering light can be easily avoided. The APTES anchored on the layer of silica can bind 2,4,6-trinitrotoluene (TNT) species to form TNT anion through acid–base pairing interaction, the TNT anion species may increase the charge-transfer pathways from the nanocrystals to nitroaromatic analytes, therefore further enhance the quenching efficiency of RTP. Moreover, APTES as capped reagents can enlarge the spectral sensitivity and enhance RTP response of nanocrystals to the electron-deficient nitroaromatic and nitrophenol species. Meanwhile, AF MnD ZnS QDs also exhibited a highly selective response toward TNT analyte through significant color change and quenching of 4 T 1 to 6 A 1 transition emission. This AF MnD ZnS QDs based sensor showed a very good linearity in the range of 0.05–1.8 μM with detection limit down to 50 nM (quenching percentage of phosphorescence intensity of 8%) and RSD of 3.5% ( n = 5). The reported QDs-based chemosensors here open up a promising prospect for the sensitive and convenient sensing of TNT explosive.
研究领域:
材料科学
·
分析化学
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DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2018
·
IF 3.974
Shi-Weng Li,Xiao-Ying Zeng,Yan Leng,Lin Feng,Xiao-Hu Kang
In vitro experiments were performed to determine whether auxin can mediate the formation of adventitious roots in response to heavy metal and drought stresses using a model rooting plant, mung bean [ Vigna radiata (L.) Wilczek]. The treatments with CdCl 2 or mannitol alone significantly inhibited the formation and growth of adventitious roots in mung bean seedlings. In contrast, when CdCl 2 or mannitol was applied together with indole-3-butyric acid (IBA), IBA considerably cancelled the inhibition of adventitious rooting by stresses. Treatment with CdCl 2 or mannitol alone significantly increased the soluble protein and malondialdehyde (MDA) contents. CdCl 2 and mannitol stress each induced differentially significant changes in the activities of antioxidative enzyme and antioxidant levels during adventitious rooting. Notably, both CdCl 2 and mannitol stress strongly reduced the peroxidase (POD) and ascorbate peroxidase (APX) activities and glutathione (GSH) and phenols levels. Catalase and superoxide dismutase (SOD) activity were enhanced by CdCl 2 but reduced by mannitol. CdCl 2 increased the ascorbate acid (ASA) level, which was decreased by mannitol. Furthermore, when CdCl 2 or mannitol was applied together with IBA, IBA counteracted the CdCl 2 - or mannitol-induced increase or decrease in certain antioxidants, MDA, and antioxidative enzymes. These results suggest that Cd and mannitol stress inhibition of adventitious rooting is associated with the regulation of antioxidative enzymes and antioxidants in cells to defense the oxidative stress . Moreover, IBA alleviates the effects of Cd and mannitol stress on the rooting process partially through the regulation of antioxidative defense systems.
研究领域:
植物学
·
环境科学
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DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2019
·Vol. 48
·期 28
·10537-10546
·
IF 4.052
Guofeng Liu,Yeqing Chen,Mochen Jia,Zhen Sun,Binbin Ding,Shuai Shao,Fan Jiang,Zuoling Fu,Ping'an Ma,Jun Lin
Rare earth ion-doped fluoride upconversion nanoparticles (UCNPs), emerging as a novel class of probes and drug carriers, exhibit superior promise for bio-applications in diagnostics and treatment on account of their strong luminescence, fine biocompatibility, and high drug loading. However, the fine control and manipulation of particle size and the distribution of rare earth ion-doped oxides has remained an insurmountable challenge to date. In this work, we construct and synthesize silica-coated Gd2(WO4)3:Yb3+/Ho3+ nanoparticles by one-pot co-precipitation, with uniform distribution (∼130 nm) and enhanced yellow fluorescence. Particularly, the nanoparticles not only possess outstanding temperature sensing performance at biological temperatures in water by utilizing the fluorescence intensity ratio (FIR) method, but also allow a further serviceable contrast effect in vitro and in vivo based on the prominent T1-weighted magnetic resonance (MR) signal of Gd3+. Compared with cisplatin and platinum(IV) (DSP), the Gd2(WO4)3@SiO2 nanoparticles functionalized with DSP (Gd2(WO4)3@SiO2-Pt-PEG) exert higher lethality against CT26 cells and significantly inhibit the growth of tumors at the same concentration of Pt. This effect occurs through the greater level of cell endocytosis. The lethality value of the latter is 10 times higher than the former after the same length of time according to inductively coupled plasma-mass spectrometry (ICP-MS) results. In short, the monodisperse and strongly fluorescent Gd2(WO4)3@SiO2-Pt-PEG nanoparticles are endowed with dual-mode imaging, temperature sensing and anticancer functions, which provide a significant guide for synthesis and bio-application of lanthanide ion-doped oxides.
研究领域:
生物医学工程
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纳米医学
·
材料科学
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DOI
PubMed
高影响因子
JOURNAL OF PORPHYRINS AND PHTHALOCYANINES
·
2021
·
IF 1.811
Safi Ullah,Keisuke Ogumi,Xuelin Zhen,Huan Wang,Yutaka Matsuo
A Suzuki–Miyaura coupling reaction was performed to synthesize 5,15- meso -bis(2-chlorothiophen-3-yl)porphyrins in order to obtain a building block for further functional porphyrins. Photophysical and electrochemical properties were investigated to understand the effect of 2-chloro substituted thiophenes which are connected at their 3-position to the meso -position of the porphyrin. A computational calculation with counterpoise method was demonstrated to estimate the relative intermolecular interaction in order to compare solubility. Installed chloro atoms at the 2-position of thiophen-3-yl decreased in intermolecular interaction which caused an increase in solubility.
研究领域:
有机化学
·
材料科学
·
计算化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Yini Liu,Debao Wang,Zhilan Sun,Fang Liu,Lihui Du,Daoying Wang
In this study, antibacterial nanofiber films were prepared by electrospinning gelatin, chitosan, and 3-phenyllactic acid (PLA). The addition of PLA improved the microstructures of the nanofibers, and the nanofiber films (GCP-1 and GCP-2) had uniform and continuous structures with a diameter range of 40‐–70 nm when the PLA concentrations in the polymers were 1% and 2%. Under acidic conditions, chitosan and PLA interacted and formed hydrogen bonds , which decreased the crystallinity of the nanofiber films. The GCP-2 nanofiber film had the best thermal stability , water stability, and water vapor permeability. Compared with the control GCP-0 film, the four nanofiber films with PLA (GCP-1, GCP-2, GCP-3, and GCP-4) had more effective antibacterial effects, and GCP-2 film reduced approximately 4 log CFU/mL of Salmonella enterica Enteritidis and Staphylococcus aureus in 30 min. Results suggested that the GCP-2 nanofiber film mat can be used as an active food packaging.
研究领域:
材料科学
·
食品科学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ORGANOMETALLIC CHEMISTRY
·
2016
·
IF 2.336
Kun Liu,Kai-Kai Liu,Mu-Jeng Cheng,Ming-Han Han
A combined experimental and theoretical study was conducted to investigate the isomerization of 2-methyl-3-butenenitrile (2M3BN) to 3-pentenenitrile (3PN) and to 2-methyl-2-butenenitrile (2M2BN) catalyzed by nickel diphosphine complexes. Ni(1,4-bis(diphenylphosphino)butane) (dppb) was identified as the most reactive catalyst among the complexes that we examined experimentally. Quantum mechanics (density functional theory) was then used to study the two isomerization mechanisms catalyzed by this complex. We find that for the 2M3BN → 3PN isomerization, the reaction is initiated with C CN bond cleavage, followed by an allyl direct rotation and C CN bond reformation. For the 2M3BN → 2M2BN isomerization, the most energetically favorable pathway begins with C H bond activation, followed by a π-σ-σ-π allyl rearrangement and C H bond reformation. Our proposed mechanism for the 2M3BN → 2M2BN isomerization is slightly different (yet energetically more favorable) than that described in previous studies, where it has been suggested that 2M2BN is obtained through a π-σ-σ allyl rearrangement rather than a π-σ-σ-π type rearrangement. Additionally, we investigated the effect of Lewis acids in the 2M3BN → 3PN isomerization, which has been shown in most experiments to attenuate the reaction. Notably, our calculations indicated that ZnCl 2 , which is used as a model Lewis acid, actually reduces the barriers for all elementary steps. However, the effective kinetic barrier for the isomerization increases from 23.7 (without ZnCl 2 ) to 24.0 kcal/mol because of the formation of a very stable Ni(π-allyl) (CN ZnCl 2 ) intermediate, causing a decrease in the reaction rate. This theoretical result was further confirmed by our own experiments.
研究领域:
有机化学
·
理论化学
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DOI
高影响因子
Materials
·
2020
·Vol. 13
·期 24
·5733
·
IF 3.057
Tiancheng He,Caihuan Lv,Wenhao Li,Guohua Huang,Zhihui Hu,Jianmei Xu
The electronics related to the fifth generation mobile communication technology (5G) are projected to possess significant market potential. High dielectric constant microwave ceramics used as filters and resonators in 5G have thus attracted great attention. The Ba6−3x(Sm1−yNdy)8+2xTi18O54(x =2/3) ceramic system has aroused people’s interest due to its underlying excellent microwave dielectric properties. In this paper, the relationships between the dielectric constant, Nd-doped content, sintering temperature and the density of Ba6−3x(Sm1−yNdy)8+2xTi18O54(x =2/3) ceramics were studied. The linear regression equation was established by statistical product and service solution (SPSS) data analysis software, and the factors affecting the dielectric constant have been analyzed by using the enter and stepwise methods, respectively. It is found that the model established by the stepwise method is practically significant withY= −71.168 + 6.946x1+ 25.799x3, whereY,x1andx3represent the dielectric constant, Nd content and the density, respectively. According to this model, the influence of density on the dielectric constant is greater than that of Nd doping concentration. We bring the linear regression analysis method into the research field of microwave dielectric ceramics, hoping to provide an instructive for the optimization of ceramic technology.Keywords:microwave dielectric ceramics;Ba6−3x(Sm1−yNdy)8+2xTi18O54(x =2/3) system;dielectric constant;linear regression analysis
研究领域:
材料科学
·
电子工程
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DOI
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2024
·
IF 3.4
Dingyu Guo,Zhengchao Wang,Wanqing Wei,Wei Song,Jing Wu,Jian Wen,Guipeng Hu,Xiaomin Li,Cong Gao,Xiulai Chen,Liming Liu
D-allulose is a naturally occurring rare sugar and beneficial to human health. However, the efficient biosynthesis of D-allulose remains a challenge. Here, we mined a new D-tagatose 3-epimerase from Kroppenstedtia eburnean (KeDt3e) with high catalytic efficiency . Initially, crucial factors contributing to the low conversion of KeDt3e were identified through crystal structure analysis, density functional theory calculations (DFT), and molecular dynamics (MD) simulations. Subsequently, based on the mechanism, combining restructuring the flexible region, proline substitution based onconsensus sequence analysis, introducing disulfide bonds , and grafting properties, and reshaping the active center, the optimal mutant M5 of KeDt3e was obtained with enhanced thermostability and activity. The optimal mutant M5 exhibited an enzyme activity of 130.8 U/mg, representing a 1.2-fold increase; T m value increased from 52.7 °C to 71.2 °C; and half-life at 55 °C extended to 273.7 min, representing a 58.2-fold improvement, and the detailed mechanism of performance improvement was analyzed. Finally, by screening the ribosome-binding site (RBS) of the optimal mutant M5 recombinant bacterium (G01), the engineered strain G08 with higher expression levels was obtained. The engineered strain G08 catalyzed 500 g/L D-fructose to produce 172.4 g/L D-allulose, with a conversion of 34.4% in 0.5 h and productivity of 344.8 g/L/h on a 1 L scale. This study presents a promising approach for industrial-scale production of D-allulose.
研究领域:
生物化学
·
食品科学
·
酶工程
✓ 已验证
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2026
·Vol. 156
·期 9
·242
·
IF 2.5
Shi Guopu,Shi Fangxu,Liang Fuxin,Wei Yulin,Li Yuanguang,Han Yubing,Wu Junyan,Huang Sai,Wang Honglei,Ji Jun,Wu Chao
Ethyl 3-piperidine-carboxylate is an important intermediate in the pharmaceutical field. To break through the limitations of poor mechanical strength and thermal stability of catalysts and low catalytic efficiency of foam ceramic carriers due to the lack of active sites in traditional synthesis, this study used the hydrogenation synthesis of ethyl nicotinate to produce this intermediate as the probe reaction. Pd-Ni/Ru-Al 2 O 3 -SiO 2 foam ceramic catalysts were prepared by the sol-gel method and the impregnation method. Relying on the bimetallic differentiated synergistic effect of Ni, Ru, and Pd, the above technical bottlenecks were overcome. A variety of characterization techniques reveal its core mechanism of action: Pd serves as the catalytic core, and Ni can optimize the electronic structure, enabling the Pd-Ni alloy to obtain the optimal d-band center and adsorption energy, laying an electronic foundation for efficient catalysis. Ru can precisely control the particle size of Pd-Ru alloy, which is 4.5 nm smaller than that of single-metal Pd, significantly improving the metal dispersion and the utilization rate of active sites. The three-dimensional network structure of foam ceramics enhances mass transfer efficiency. The γ-Al 2 O 3 -SiO 2 coating provides abundant active sites and excellent stability. The catalytic performance of this system has been significantly enhanced. Among them, the yield of the corresponding product of the Pd-Ni bimetallic catalyst reached 92.57%, and it still remained above 80% after five cycles of use, providing new prospects for the green and efficient synthesis of ethyl 3-piperidine-carboxylic acid esters and the development of low-cost hydrogenation catalysts. Graphical
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高影响因子
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