CHEMISTRY & BIODIVERSITY
·
2025
·
IF 2.5
Qian Luo,Chen Sun,Xue Zhao,Er-Wei Li,Yu-Qing Yi,Yang Zhang,Shuai-Ming Zhu,Yu Yang,Rui Xu,Li-Xia Chen,You-Zhi Zhang,Chang-Wei Li
Two new cytochalasins ( 1 and 2 ) were isolated from the fermentation products of the fungus Xylaria necrophora SZSS1-2-2, along with nine known compounds: compound 3 , arbuschalasin B ( 4 ), cytochalasin C ( 5 ), cytochalasin D ( 6 ), 19,20-epoxycytochalasin C ( 7 ), 19,20-epoxycytochalasin D ( 8 ), cytochalasin R ( 9 ), cytochalasin D 13,14-epoxide ( 10 ), and arbuschalasin A ( 11 ). The structures and absolute configurations of these compounds were elucidated by spectroscopic analyses, electronic circular dichroism, and GIAO 13 C NMR computational methods. All isolated compounds were evaluated for their biological activities, and the results indicated that compounds 5 – 10 exhibited notable cytotoxic effects against the tested cell lines. However, none of the compounds showed antibacterial activity. Graphical
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DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2016
·Vol. 4
·期 7
·1361-1367
·
IF 4.872
Juanjuan Li,Xiaochun Hu,Shuo Shi,Yiwei Zhang,Tianming Yao
Early disease diagnosis is very important for the prevention or mitigation of metastasis. Effective and efficient methods are needed to improve the diagnosis and assessment of diseases. Thrombin is a biomarker for diagnosis of some diseases, such as pulmonary metastases and diseases associated with coagulation abnormalities. Lots of methods for detecting thrombin have been reported, however, most of them were based on a single aptamer and needed modification of aptamers, and label free sensors for thrombin detection based on an aptamer pair are challenging. In this work, we present three label free sensing platforms based on [Ru(bpy)2(o-mopip)]2+ (bpy = 2,2-bipyridine; o-mopip = 2-(2-methoxylphenyl)imidazo[4,5-f][1,10]phenanthroline) (OMO) and graphene oxide (GO) for thrombin detection. Thrombin detection using our three label free sensors is accomplished by specific target recognition based on aptamer pair TBA1/TBA2–thrombin, single aptamer TBA1–thrombin or TBA2–thrombin, respectively. Direct readouts of the target recognition is achieved by restoration of the fluorescence of OMO prequenched by GO. All of the three sensing platforms exhibited high sensitivity and selectivity. Furthermore, all sensing platforms were successfully applied to thrombin analysis in diluted bovine serum. According to the thrombin dependent response of the three platforms, the sensing platform based on aptamer pair TBA1 and TBA2 showed the highest sensitivity, widest linearity, best selectivity and recovery in diluted serum to thrombin. These results show that the sensing platform based on an aptamer pair have great potential for clinical diagnosis of disease-related biomarkers.
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高影响因子
Journal of the American Chemical Society
·
2020
·
IF 14.612
Hai-Fang Li,Wenbo Cao,Xiaoxiao Ma,Xiaobo Xie,Yu Xia,Zheng Ouyang
The [2 + 2] photocycloaddition of alkenes and carbonyls is of fundamental interest and practical importance, as this process is extensively involved in oxetane-ring constructions. Although individual carbonyl group or alkene moiety has been utilized as photoactive species for oxetane formations upon ultraviolet photoexcitation, direct excitation of the entire noncovalent complex involving alkene and carbonyl substrates to achieve [2 + 2] photocycloadditions is rarely addressed. Herein, complexes with noncovalent interactions between benzophenone and C═C bonds in unsaturated lipids have been successfully characterized, and for the first time a [2 + 2] cycloaddition leading to the formation of oxetanes has been identified under visible-light irradiation. The mechanism of this reaction is distinctly different from the well-studied Paternò–Büchi reaction. The entire complexes characterized as dimeric proton-bonded alkene and carbonyl substrates can be excited under visible light, leading to electron transfer from the alkene moiety in fatty acyls to the carbonyl group within the complex. These results provide new insight into utilizing noncovalent complexes for the synthesis of oxetanes in which the excitation wavelength becomes independent of each individual substrate.
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Yu Dong,Tiantian Ping,Xiaoqin Shi,Shufeng Shen
Nonaqueous amine-based blends have great potential for energy-efficient CO 2 absorbent. In this work, densities and viscosities were measured for liquid binary mixtures of 2-(ethylamino)ethanol (EAE) and 2-(butylamino)ethanol (BAE) with 2-butoxyethanol (EGBE) at temperatures of (293.15–353.15)K over the entire concentration range and atmospheric pressure. Intermolecular interactions between EGBE and two secondary amines with different carbon chain length were discussed. The excess molar volume ( V E ), viscosity deviations ( ∆η ) and excess Gibbs free energy ( ∆G ⁎ E ) were calculated from the experimental data and also correlated with the Redlich-Kister equation to estimate the binary interaction parameters. The experimental data and the calculated from the proposed correlations for the studied binary mixtures matched well each other, with AADs within 0.01% and 1.45% for density and viscosity respectively. The variation of excess properties was also discussed in terms of intermolecular interactions. Weak interactions on mixing these binary mixtures with different mass fractions were observed from the FTIR spectra analysis.
研究领域:
化学工程
·
热力学
·
流体物理化学
·
气体吸收
·
分离科学
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高影响因子
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY
·
2024
·Vol. 60
·期 10
·1999-2003
·
IF 0.8
Li C. L.,Wang S. Y.,Zhan M. R.,Chen C. C.,Wang Z. X.
Chiral monosubstituted cyclohexanediamine catalyst, namely (1 R ,2 R )-2-(piperidin-1-yl)cyclohexan-1-amine ( Cat1 ) has been efficiently synthesized and used to catalyze the aldol reaction of cyclohexanone and 2-(trifluoromethyl)benzaldehyde to obtain ( R )-2-{( S )-hydroxy[2-(trifluoromethyl)phenyl]methyl}cyclohexan-1-one. The catalyst (20 mol %) provided high yield (up to 85%) and excellent enantioselectivity (95.6% ee ) in water solution in three parallel tests.
研究领域:
有机化学
·
催化化学
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高影响因子
Atmosphere
·
2018
·Vol. 9
·期 10
·401
·
IF 1.704
Chen Lv,Lin Du,Narcisse T. Tsona,Xiaotong Jiang,Wenxing Wang
Rate coefficients at ambient temperature and atmospheric pressure for the reaction of ozone with 2-methoxypropene (2-MPE) and 2-ethoxypropene (2-EPE) were determined in an evacuable 100 L Teflon reaction chamber using absolute and relative rate methods. The product experiments were carried out using a 50 L Teflon reaction chamber in conjunction with FTIR as the detection technique. The rate coefficients (kin units of cm3molecule−1s−1) obtained are 1.18 ± 0.13 × 10−17and 1.89 ± 0.23 × 10−17for reactions with 2-MPE and 2-EPE, respectively. The effects of the alkoxy group on the gas-phase reactivity of alkyl vinyl ethers toward ozone are compared and discussed. The major ozonolysis products are methyl acetate, formaldehyde and CO2for 2-MPE, and ethyl acetate, formaldehyde and CO2for 2-EPE. Possible mechanisms for the two vinyl ethers are proposed based on the observed reaction products. Additionally, atmospheric lifetimes of 32 h and 21 h for 2-MPE and 2-EPE were estimated based on the measured rate constants and the ambient tropospheric concentration of ozone, respectively. The obtained values of the lifetimes indicate that the reaction with ozone is an important loss process for these vinyl ethers in the atmosphere, especially in polluted areas.Keywords:vinyl ethers;rate coefficient;absolute and relative kinetics;mechanism;atmospheric implications
研究领域:
大气化学
·
环境科学
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高影响因子
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
·
2022
·Vol. 119
·期 51
·e2211193119
·
IF 12.779
Jieming Sheng,Le Wang,Andrea Candini,Wenrui Jiang,Lianglong Huang,Bin Xi,Jize Zhao,Han Ge,Nan Zhao,Ying Fu,Jun Ren,Jiong Yang,Ping Miao,Xin Tong,Dapeng Yu,Shanmin Wang,Qihang Liu,Maiko Kofu,Richard Mole,Giorgio Biasiol,Dehong Yu,Igor A. Zaliznyak,Jia-Wei Mei,Liusuo Wu
An interplay of geometrical frustration and strong quantum fluctuations in a spin-1/2 triangular-lattice antiferromagnet (TAF) can lead to exotic quantum states. Here, we report the neutron-scattering, magnetization, specific heat, and magnetocaloric studies of the recently discovered spin-1/2 TAF Na2BaCo(PO4)2, which can be described by a spin-1/2 easy axis XXZ model. The zero-field neutron diffraction experiment reveals an incommensurate antiferromagnetic ground state with a significantly reduced ordered moment of about 0.54(2) μB/Co. Different magnetic phase diagrams with magnetic fields in the ab plane and along the easy c-axis were extracted based on the magnetic susceptibility, specific heat, and elastic neutron-scattering results. In addition, two-dimensional (2D) spin dispersion in the triangular plane was observed in the high-field polarized state, and microscopic exchange parameters of the spin Hamiltonian have been determined through the linear spin wave theory. Consistently, quantum critical behaviors with the universality class of d = 2 and νz = 1 were established in the vicinity of the saturation field, where a Bose–Einstein condensation (BEC) of diluted magnons occurs. The newly discovered quantum criticality and fractional magnetization phase in this ideal spin-1/2 TAF present exciting opportunities for exploring exotic quantum phenomena.
研究领域:
凝聚态物理
·
量子磁性
·
强关联电子系统
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低维量子系统
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中子散射
·
量子相变
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高影响因子
RSC Advances
·
2026
·Vol. 16
·期 18
·16748-16755
·
IF 6.1
Yuqi Zhang,Yuan Yao,Peihao Dou,Qing Cheng,Yanqiang Zhang
An ionic liquid (IL)-H2O2 propellant offers a green alternative to the traditional hydrazine-N2O4 system. Due to the weak oxidizing ability of H2O2, typical ILs cannot be spontaneously ignited. To address this issue, catalytic ignition was proposed, and a series of metal complex catalysts with the formula M(vim)2(DCA)2 (M = Mn, Fe, Co, and Cu) were synthesized. Single-crystal X-ray diffraction analysis shows that the Mn, Fe and Co complexes adopt an octahedral geometry, while the Cu complex exhibits a planar quadrilateral geometry. The physicochemical properties (Td, ΔHc, ΔHf, and Isp) of the fuels (10 wt% M(vim)2(DCA)2 + 90 wt% [BMIM]DCA) were evaluated. Dynamic light scattering and UV-vis spectroscopy analyses confirm that the four complexes disperse well in [BMIM]DCA. Ignition tests reveal that Cu(vim)2(DCA)2 exhibits the best catalytic performance for the ignition of [BMIM]DCA with H2O2, achieving tid as short as 21 ms. EPR studies indicate that Cu(vim)2(DCA)2 catalyzes H2O2 to generate reactive oxygen species (·OH, ·O2−, and 1O2), which subsequently induce the spontaneous ignition of [BMIM]DCA. DFT calculations reveal that the zero-dimensional geometry of Cu(vim)2(DCA)2 features an unsaturated Cu center and electron-rich ligand framework. This typical structure enables efficient electron transfer to activate H2O2, boosting ROS generation and ignition. This work clarifies the crucial role of the metal center in the IL-H2O2 system and provides an important insight into the catalytic ignition of the “double-green” propellants.
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高影响因子
Petroleum Science
·
2022
·
IF 4.757
Tian-Ci Zhang,Ji-Jiang Ge,Hao Wu,Hong-Bin Guo,Bao-Lei Jiao,Zhen Qian
The BST oilfield in the northwestern Taklamakan Desert is a fractured carbonate reservoir, but issues of water breakthrough are becoming increasingly severe with the development of water flooding. Unfortunately, the high-temperature and high-salt conditions (130 °C, 71695 mg/L) of the BST oilfield pose challenges for the development of plugging agents. In this study, the effects of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) content on AM/AMPS copolymers and gels were studied through viscosity measurements, nuclear magnetic resonance (NMR), and cryo-scanning electron microscope (Cryo-SEM). Moreover, the AMPS stabilization mechanism of the polymers and gels was explained. Heat-resistant and salt-tolerant gel systems were developed, and their gelation properties, thermal stability, injection capacity, and plugging ability were evaluated. Experimental results showed inconsistencies between the effects of AMPS content on the polymers and gels. For the polymers, the thermal stability increased with increased AMPS content in the polymer. However, excessive AMPS content resulted in poor gelation and low strength. The developed gel systems with S30 polymer (AMPS content is approximately 26%) exhibited excellent thermal stability, controllable gelation time, good injection capacity, and plugging ability. The field application results indicated that most production wells had a positive response, with reduced water-cut and increased daily oil production.
研究领域:
石油工程
·
材料科学
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高影响因子
ENERGY
·
2017
·
IF 4.52
J. Yan,C.Y. Zhao,Z.H. Pan
Cyclic stability is a key factor in the design of thermochemical heat storage systems . Because carbon dioxide (CO 2 ) may react with heat storage materials and lead to a decrease in energy storage efficiency, the effect of CO 2 on Ca(OH) 2 /CaO and Mg(OH) 2 /MgO systems is investigated in this study. The experimental results show that CO 2 reacts with CaO in the water vapor that appears during the heat release process. Therefore, in the design of Ca(OH) 2 /CaO systems, CO 2 should be cleared from the system. The results from Mg(OH) 2 /MgO systems show that CO 2 only slightly reacts with MgO and Mg(OH) 2 during heat storage and release processes. This study indicates that carbonic acid (H 2 CO 3 ) could easily react with CaO/Ca(OH) 2 to form CaCO 3 during heat release processes. Generally, the remaining CO 2 reduces the reversibility of Ca(OH) 2 /CaO systems but has only a slight influence on Mg(OH) 2 /MgO systems. In addition, the experimental results show that carbonate shell does not exist in rehydration for both of the CaO/MgO samples, but the influence of CO 2 on the entire process increases after each cycle.
研究领域:
材料科学
·
能源工程
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高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2022
·Vol. 101
·期 7
·3813-3820
·
IF 2.5
Rong Xu,Qingming Song,Chuang Li,Junfeng Li,Hongjun Yang,Jian Chen,Zhipeng Mao
2-Chloro-2-methylbutane is an important organic compound widely used as a starting material in organic synthesis. It is mainly produced by the addition reaction of isoamylene and hydrochloric acid. As a raw material, isoamylene has a low boiling point and an extremely low flash point, making it a high-risk material in large-scale industrial productions. In this paper, a highly efficient production of 2-Chloro-2-methylbutane was realized using a continuous flow micro-channel reactor. Through the back pressure system of the reactor, the fluid pressure was increased, which elevated the reaction temperature, and enhanced the rate of reaction. The obtained optimal reaction conditions for the process were a reaction temperature of 90°C, pressure of 0.67 MPa, residence time of reactants of 15 min, n (hydrochloric acid): n (isoamylene) = 2.80:1.00, and v (hydrochloric acid): v (isoamylene) = 4.40:1.76. Compared with a batch process, the micro-channel process significantly shortened the reaction time and conversion a continuous and an efficient production. Computational analysis using computational fluid dynamics (CFD) simulation software was used to simulate the two-phase flow in the micro-channel reactor, and the results were consistent with the experimental results.
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高影响因子
JOURNAL OF POLYMER SCIENCE
·
2022
·Vol. 60
·期 9
·1468-1479
·
IF 3.046
Ming Duan,Gang Wu,Tianbin Gu,Xiaohui Jiang,Lei Zhao,Limei Zhou,Yunwen Liao,Qiang Pu
Present work reports a new type of poly( N -alkyl-2-[4-hydroxybut-2-ynyl] pyridinium bromides) (designated as Po-n, n = 8, 12, 16 of carbon atoms in the alkyl chain). Po-n were synthesized and characterized by FTIR, GPC, and NMR analysis. The possible polymerization mechanism was proposed and supported by theoretic calculation. A preliminary probe was performed on the conductivity and anticorrosive ability of the conjugated polymer. The results showed that these polymers demonstrated poor conductivity, however the conductivity was enhanced by graphene doping. Po-n are good inhibitors for X70 steel corrosion in HCl solution. So, the conjugated polymers may play important roles in the fields of optoelectronic devices and steel corrosion inhibition. Graphical
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高影响因子
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