MACROMOLECULAR RESEARCH
·
2017
·Vol. 25
·期 11
·1070-1075
·
IF 1.405
Wu Dan,Lv Yin,Guo Rui,Li Jiahui,Habadati Aerman,Lu Bowen,Wang Heyun,Wei Zhong
To evaluate the effects of different alcohols (primary, secondary, and two different tertiary alcohols) as initiators on the structure of polycaprolactone (PCL) in ring-opening polymerization (ROP), four experiments were conducted in toluene with tin(II) 2-ethylhexanoate (Sn(Oct) 2 ) as the catalyst. The kinetics of ε -caprolactone ( ε -CL) ROP at different temperatures and monomer concentrations were studied with n -butanol as the initiator and Sn(Oct) 2 as the catalyst. The kinetic plot of ln(M 0 /M t ) vs. time ( t ) seems a linear, which indicates that the propagation rate is in the first order with respect to monomer concentration. When the reaction temperature increased, the reaction rate and the final relative maximum monomer conversions also increased. The molecular weight of PCL initially increased and then decreased as monomer conversion increased. This behavior can be attributed to the high viscosity of the system, which affected monomer diffusion and polymer chain propagation. In addition, prolonging reaction time caused inter-/intramolecular transesterification. However, when monomer concentration decreased, the reaction rate decreased. The actual activation energy of Sn(Oct) 2 -catalyzed ROP of ε -CL in toluene was -75 kJ/mol.
研究领域:
高分子化学
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材料科学
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有机催化
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化学反应工程
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DOI
高影响因子
BioScience Trends
·
2014
·Vol. 7
·期 3
·144-151
·
IF 1.213
Xiaoying Zhou,Yazhou Cui,Jing Luan,Xiaoyan Zhou,Genglin Zhang,Xiumei Zhang,Jinxiang Han
Matrix vesicles (MVs) involved in the initiation of mineralization by deposition of hydroxyapatite (HA) in their lumen are released by the budding of mineralization-competent cells during skeletogenesis and bone development. To identify additional mineralization-related proteins, MVs were isolated from non-stimulated and stimulated Saos-2 cells in culture via an ExoquickTM approach and the corresponding proteomes were identified and quantified with label-free quantitative proteome technology. The isolated MVs were confirmed by electron microscopy, alkaline phosphatase activity (ALP), biomarkers, and mineral formation analyses. Label-free quantitative proteome analysis revealed that 19 calcium binding proteins (CaBPs), including Grp94, calnexin, calreticulin, calmodulin, and S100A4/A10, were up-regulated in MVs of Saos-2 cells upon stimulation of mineralization. This result provides new clues to study the mechanism of the initiation of MV-mediated mineralization.
研究领域:
蛋白质组学
·
骨生物学
·
细胞生物化学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Yeyin Tao,Xingyun Chen,Shusen Peng,Yongcun Ma
Self-assembled organothiol is a well-known process to endow specific protective properties and usually involves passive incubation. Researchers have recently confirmed that the potential-assisted method is more selective and faster than the passive method. This paper provides an original and promising approach for Cu protection by 2-mercaptobenzobthiazole (MBT) assembled film prepared from an aqueous solution within minutes under potential control. Electrochemical studies, salt spray tests, and XPS highlight and confirm the benefits of this method to result in film features, organic solvent-free, and considerable savings of preparation time. Experimental results also demonstrate that the substrate potential exerts a significant effect on the quality of MBT film. The effectiveness of negative potential in MBT film formation can be attributed to two aspects: first, it can inhibit the oxidation of Cu metal to Cu(II) in the aqueous solution, and second, it can make MBT molecule bond to Cu mainly through forming thiolate Cu-S bond with its exocyclic S atom.
研究领域:
材料科学
·
电化学
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2020
·
IF 2.888
Jinyi Chen,Hongxing Wang
Density and viscosity data of pure 3-chloro-4-fluoronitrobenzene and 3-chloro-2-fluoronitrobenzene were obtained in temperature range from 318.15 K to 348.15 K at the local atmospheric pressure of 99.7 kPa. The value of corresponding saturated vapour pressure of two isomers were determined in the temperature range of 409 K to 517 K. The relationship between temperature and density can be well correlated by the linear equation. The viscosity data was well described by the Litovitz, Ghatee, VFT, and Andrade equations, and the calculated value by the VFT equation is consistent with the measured data. Both the Antoine and Riedel equations can accurately describe the relationship between saturated vapour pressure and temperature of 3-chloro-4-fluoronitrobenzene and 3-chloro-2-fluoronitrobenzene, which can meet the requirements for chemical design. In addition, the thermal expansion coefficient was determined based on the density data, and the molar vaporisation enthalpy of two isomers was evaluated using the Clausius-Clapeyron equation.
研究领域:
化学工程
·
物理化学
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DOI
高影响因子
JOURNAL OF COORDINATION CHEMISTRY
·
2014
·
IF 2.212
Xiao-Li Tang,Ai-Qing Ma,Guo-Qiang Cai,Long-Guan Zhu
Three complexes with same components, PdII, 2-sulfobenzoate and 1,10-phenanthroline, [Pd(phen)2]⋅2(2-Hsb) (1), [Pd(phen)2](2-Hsb)⋅(2-Hsb)⋅2H2O (2), and [Pd(phen)2]⋅[Pd(phen)(2-sb)2]⋅6H2O (3), where 2-H2sb is 2-sulfobenzoic acid and phen is 1,10-phenanthroline, were synthesized and characterized by IR spectra, elemental analyses, thermogravimetric analyses, UV–vis absorption spectra and powder X-ray analysis. Single X-ray crystal structural analyses showed that 1 and 2 are ionic species, while 3 is a dimer through weak bonding interactions. In 1 and 2, 2-Hsb− ligands are partly deprotonated and it is fully deprotonated in 3. In 2 and 3 there are hydrogen bonds and π–π interactions. Extended hydrogen bonding structures for 2 and 3 are 1-D and 3-D architectures, respectively. The oxidation of methyl phenyl sulfide by 1-3 as homogeneous catalysts gave high conversion and selectivity in methanol. The addition of 2-sulfobenzoic acid in the catalytic reaction further promotes the conversion.
研究领域:
化学
·
材料科学
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Tingting Luo,Yiqi Li,Yanxue Xu,Shiting Zhang,Yujue Wang,Xingming Kou,Dan Xiao
In this article, a hyperfluorescence 2-pyridone derivative (D-TPCA) has been synthesized within 5 min by the microwave-assistant heat treatment of the aqueous mixture of citric acid and 2-aminoethanethiol hydrochloride. The as-prepared D-TPCA exhibited good aqueous solubility and excellent fluorescent property with a quantum yield of 89.9%. Because the fluorescence of D-TPCA could be effectively quenched by picric acid (PA), D-TPCA could be served as a “turn-off” fluorescence sensor for PA in aqueous solution. The proposed sensing method permitted a selective and sensitive detection of PA in a linear range of 0–45 μM with a detection limit of 56.0 nM. The determination results of PA in real water samples with a recovery range of 95.4–107.3% confirmed a good analytical performance of this sensor. In addition, the possible sensing mechanism has been discussed in detail.
研究领域:
分析化学
·
材料科学
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DOI
高影响因子
Scientific Reports
·
2026
·
IF 4.9
Ren Yanrong,Zhu Wenhui,He Yueyue,Ye Songlin,Lv Jie,Liu Jianqiao,Li Anqi,Yuan Ziliang
2-Arylpropionic acids, exemplified by ibuprofen, are important structural motifs widely found in bioactive molecules and pharmaceutical agents, and their industrial synthesis is therefore of considerable significance. Herein, we report a systematic study of the photo-Favorskii rearrangement synthesis of 2-arylpropionic acids using zinc acetate as a cost-effective, readily available, and environmentally benign acid scavenger. Under mild visible-light irradiation conditions, this protocol enables efficient conversion of α-chloroketones into the corresponding 2-arylpropionic acids, delivering moderate to good yields across a broad range of more than 11 substrates. This work demonstrates the potential of zinc acetate for sustainable organic synthesis and provides an environmentally benign, efficient strategy for the preparation of valuable carboxylic acid derivatives.
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产品关联
DOI
高影响因子
IONICS
·
2017
·Vol. 23
·期 9
·2377-2385
·
IF 2.062
Pan Guangxing,Song Yonghai,Miao Longfei,Wang Li
A novel ascorbic acid (AA) electrochemical biosensor based on ferrocene dicarboxylic acid (Fc(COOH) 2 )/zeolitic imidazolate framework-8 (ZIF-8)/three-dimensional (3D) kenaf stem-derived macroporous carbon (3D-KSCs) was proposed for the first time. The formation and properties of Fc(COOH) 2 /ZIF-8/3D-KCSs nanocomposites were characterized by scanning electron microscopy, Fourier transform-infrared spectroscopy, N 2 adsorption/desorption isotherms, X-ray powder diffraction, and energy dispersive X-ray spectroscopy. The results showed that a large number of short rod-like ZIF-8/Fc(COOH) 2 was arrayed on the 3D-KSCs surface via a simple one-step hydrothermal method. Fc(COOH) 2 was firmly encapsulated into the pores of ZIF-8 simultaneously during the synthesis process of ZIF-8. The Fc(COOH) 2 /ZIF-8/3D-KCSs nanocomposites were employed to prepare integrated Fc(COOH) 2 /ZIF-8/3D-KSCs electrode directly for electrochemical AA sensing, and the integrated electrode showed better performance for AA detection than traditional enzyme-based biosensors and nonenzymatic sensors. A wide detection range of 0.06 μM~5.01 mM and a low detection limit of 0.017 μM were obtained with good stability and selectivity. The work also sheds new light on developing ZIF-8-based nanocomposites for electrochemical sensing.
ᅟ
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产品关联
DOI
高影响因子
JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
·
2024
·
IF 5.6
Cong Wu,Qi Jiang,Hui Zhong,Xudong Zhou,Leping Liu,Tong Pan,Chao Liu,Wei Wang,Wenbing Sheng
An oxidising and substituting one-pot reaction strategy has been developed to synthesise dihydromyricetin derivatives with the aim of enhancing the inhibitory activity of dihydromyricetin against SARS-CoV-2. Different ω-methoxy-ω-oxeylkyl was introduced in C7-OH site and yielded eight analogs, all of them showed good inhibitory activity against SARS-CoV-2 3CLpro with IC50 values ranging from 0.72 to 2.36 μM. In the Vero E6-cell, compound 3 has a good activity of anti-SARS-CoV-2 virus (Omicron virus BA.5) in the prevention model, with an EC50 of 15.84 μM, and so do compound 10 in the therapeutic model, with an EC50 of 11.52 μM. The results suggest that the introduction of long chain ω-oxeylkyl at C7-OH facilitate the inhibition of viral replication in the therapeutic model, which is consistent with the binding energies predicted from molecular docking conclusions. It implies that dihydromyricetin derivatives have the potential to become effective inhibitors of SARS-CoV-2 Omicron and other viruses.
研究领域:
药物化学
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病毒学
·
生物信息学
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DOI
PubMed
高影响因子
Journal of Energy Chemistry
·
2024
·
IF 14
Xuejun Xu,Rutao Meng,Yue Liu,Han Xu,Jianpeng Li,Yi Zhang
Solution-processed chalcopyrite solar cells are widely regarded as a promising alternative method in reducing the cost compared with vacuum-based techniques. It is noted that the absorber layer usually needs to be prepared under a high insert pressure (∼1.6 atm) to suppress element loss or under a mild pressure but additional surface etching is needed for fabricating high efficient solar cell. Herein, a copper gradient structured precursor is proposed to prepare CuIn(S,Se) 2 (CISSe) film under a mild pressure (1.1 atm). The designed gradient Cu not only promotes crystal grain growth and tailors the defects, but also avoids the surface etching of the formed CISSe film for the fabrication of high efficient solar cells. Further, Cu gradient design decreases the conduction band offset of heterojunction, boosting the carriers transport across the p-n heterojunction. Accordingly, a 13.35% efficient CISSe solar cell, comparable to the high efficient CISSe solar cell prepared by this method under high pressure or with film surface etching, is fabricated. This work provides a facile pathway to fabricate high efficient solution-processed chalcopyrite solar cell, avoiding high selenization pressure and film etching, and shows huge potential for solution-processed copper-based solar cells.
研究领域:
材料科学
·
可再生能源
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DOI
高影响因子
ENVIRONMENTAL TOXICOLOGY
·
2018
·Vol. 34
·期 2
·141-149
·
IF 2.491
Xia Wang,Baida Kong,Bingnan He,Lai Wei,Jianbo Zhu,Yuanxiang Jin,Yudong Shan,Weitao Wang,Chunqiang Pan,Zhengwei Fu
8:2 Fluorotelomer alcohol (8:2 FTOH) is widely used in houseware and industrial goods and is ubiquitous in the surrounding environment. 8:2 FTOH has been linked to hepatoxicity, nephrotoxicity, and reproductive toxicity, as well as endocrine-disrupting effects. However, as of yet, the research regarding immunotoxicity of 8:2 FTOH remains largely limited. In the present study, adult male C57BL/6 mice were administered with 10, 30, and 100 mg/kg/d 8:2 FTOH by gavage for 28 days to investigate its immunotoxicity in vivo. The results showed that exposure to 8:2 FTOH caused increases in liver weight and histological changes in the liver, including vacuolation, cell swelling, immune cell infiltration, karyopyknosis and nuclear swelling. No histological change in either the spleen or the thymus was observed after administration of 8:2 FTOH. In addition, exposure to 8:2 FTOH reduced the concentration of IL-1β in serum, and mRNA levels of IL-1β, IL-6 , and TNF-α in both the thymus and spleen. CXCL-1 mRNA expression was downregulated in both the liver and thymus after 8:2 FTOH administration, while only IL-1β mRNA expression was upregulated in the liver. Moreover, the exposure of primary cultured splenocytes to 8:2 FTOH inhibited the ConA-stimulated proliferation of splenocytes at concentrations of 30 and 100 μM, and the LPS-stimulated proliferation of splenocytes at 100 μM. Furthermore, 8:2 FTOH inhibited the level of secreted IFN-γ in ConA-stimulated splenocytes. The results obtained in the study demonstrated that 8:2 FTOH posed potential immunotoxicity and liver injury in mice. Our findings will provide novel data for the health risk assessment of 8:2 FTOH.
研究领域:
毒理学
·
免疫学
·
环境健康
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DOI
PubMed
高影响因子
JOURNAL OF RARE EARTHS
·
2018
·
IF 2.524
Yaqian Chen,Huanping Wang,Xiaoting Zhang,Zhen Xiao,Qinghua Yang,Ruoshan Lei,Degang Deng,Lihui Huang,Shiqing Xu
(Y 0.87 La 0.1 Zr 0.03 ) 2 O 3 nanopowders doped with various concentrations of Tm 3+ and Ho 3+ were prepared by the citrate method. The standard cubic Y 2 O 3 phase can be matched in the Tm 3+ /Ho 3+ co-doped (Y 0.87 La 0.1 Zr 0.03 ) 2 O 3 nanopowders. The nanopowders exhibit average particle sizes of 40, 60, 80 and 100 nm after calcinated at 900, 1000, 1100 and 1200 °C, respectively. The energy transfer from Tm 3+ to Ho 3+ and the optimum fluorescence emission around 2 μm were investigated. Results indicate that the emission bands at around 1.86 and 1.95 μm correspond to 3 F 4 → 3 H 6 transition of Tm 3+ and 5 I 7 → 5 I 8 transition of Ho 3+ , respectively. Better spectral properties were achieved in Tm 3+ /Ho 3+ co-doped (Y 0.87 La 0.1 Zr 0.03 ) 2 O 3 nanopowders with the average size of 100 nm obtained at the conditions of the treatment of precursors calcinated at 1200 °C for 2 h doped with 1.5 mol% Tm 3+ and 1 mol% Ho 3+ .
研究领域:
材料科学
·
光学
·
纳米技术
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DOI
高影响因子
危险品化学品经营许可证（带存储）