RUSSIAN JOURNAL OF ORGANIC CHEMISTRY
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2026
·Vol. 62
·期 7
·154
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IF 0.8
Zhai Le,Zhang Bomin,Wang Hongshe
A green and highly efficient protocol has been developed for the synthesis of 2,3-dihydroquinazolin-4(1 H )-ones via the cyclocondensation of 2-aminobenzamide with various aldehydes or ketones. The reactions proceed smoothly at room temperature in water, utilizing a catalytic amount of humic acid as an environmentally benign, cost-effective, and highly recyclable heterogeneous catalyst. This operational method offers several key advantages, including the use of an aqueous medium, mild operating conditions, excellent product yields, simple workup procedures, and seamless scalability to a gram scale.
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ELECTROCHIMICA ACTA
·
2010
·Vol. 55
·期 23
·7102-7108
·
IF 3.325
Huanshun Yin,Qiang Ma,Yunlei Zhou,Shiyun Ai,Lusheng Zhu
The graphene–chitosan composite film modified glassy carbon electrode (GCE) was fabricated and used to determine 4-aminophenol (4-AP). In 0.1 M pH 6.3 phosphate buffer solution , the redox peak currents of 4-AP increased significantly and the peak-to-peak separation decreased greatly at graphene–chitosan composite film modified GCE compared with bare GCE and chitosan modified GCE, indicating that graphene possessed electrocatalytic activity towards 4-AP. The experimental conditions were optimized and the kinetic parameters were investigated. The oxidation mechanism was discussed. Under the optimal experimental conditions, the oxidation peak current was proportional to 4-AP concentration in the range from 0.2 to 550 μM with the correlation coefficient of 0.9930. The detection limit was 0.057 μM (S/N = 3). Using the proposed method, 4-AP was successfully determined in water samples and paracetamol tablets with standard addition method, suggesting that this method can be applied to determine 4-AP in environments and pharmaceuticals.
研究领域:
电分析化学
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药物代谢
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环境监测
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生物传感器
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分子诊断
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转化医学
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Natural Product Communications
·
2023
·
IF 1.8
Wenjia Li,Qinggui Lei,Wenqing Li,Guoying Tan,Xingzhong Liu,Zhengming Qian
A high-performance liquid chromatography (HPLC) method for the determination of 4 nucleosides by one reference compound in Chinese cordyceps was developed. The sample of Chinese cordyceps was prepared by ultrasonic extraction with a 0.5% phosphoric acid aqueous solution. The separation of the sample was performed on a CORTECS T3 column (100 mm × 4.6 mm, 2.7 μm) by gradient elution with acetonitrile and water at a flow rate of 1.0 mL/min. The wavelengths were set as 258 nm (0-5 min), 252 nm (5-9.1 min), 258 nm (9.1-10.5 min), 249 nm (10.5-20 min) at which 4 nucleosides exhibited identical ultraviolet absorption. The accuracy, precision, reproducibility, and stability tests of the HPLC method were carried out, and the results indicated that the established HPLC method was suitable for the quantitative analysis of 4 nucleosides in Chinese cordyceps. This approach was compared to the traditional external standard method with 4 nucleoside reference compounds and the relative standard errors of the content determination results by the 2 methods were less than 3.5%. The HPLC method developed for quantitative measurement of 4 nucleosides in Chinese cordyceps is simple, lower cost, and time-saving, which provides a methodology alternative for quality control of Chinese cordyceps.
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CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Sehreish Abrar,Zhuang Ma,Ling Liu,Faisal Nazeer,Abdul Malik
In this work, novel equiatomic high entropy (Dy 1/4 Ho 1/4 Tm 1/4 Yb 1/4 ) 2 Si 2 O 7 or (4RE 1/4 ) 2 Si 2 O 7 ceramic pyrosilicate was fabricated through a single solid solution method to use as environmental barrier coating. The SEM analysis of high entropy powders shows the homogenous mixing and XRD proves the formation of single β-phase after milling and sintering. The coefficient of thermal expansion was reported as (2.3–4.8 × 10 −6 K −1 ) from 400 K −1 to 1723 K −1 . The ultra-low thermal diffusivity (0.4 mm 2 s −1 ) and thermal conductivity (0.8 W/m°C) were reported at 1500 °C for this novel HE ceramic disilicate. The as fabricated (4RE 1/4 ) 2 Si 2 O 7 pyrosilicate shows an excellent CMAS resistant for even up to 48 h and negligible amount of Ca is able to penetrate in the substrate. Rare earth disilicate species with intermediate radii such as Tm 3+ helps in maintaining phase stability along with passive element Yb 3+ of smaller radii which also protect the interface from severe CMAS attack. However, the rare earth species with larger radii such as Dy 3+ and Ho 3+ actively take part in apatite formation leading to reduced corrosion activity of CMAS melt by changing its composition. This result confirms the application of (4RE 1/4 ) 2 Si 2 O 7 as a potential candidate to be used as protecting coating material in harsh combustion environments.
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WATER RESEARCH
·
2023
·
IF 12.8
Wei-Ran Han,Wen-Long Wang,Tie-Jun Qiao,Wei Wang,Hang Su,Chen-Xin Xu,Qian-Yuan Wu
Micro-bubble aeration is an efficient way to promote ozonation performance, but the technology is challenged by extensive energy cost. Here, a ceramic ultrafiltration membrane was used to achieve ozone micro-bubble (0–80 µm) aeration in a simple way at gaseous pressures of 0.14–0.19 MPa. Compared with milli-bubble aeration, micro-bubble aeration increased the equilibrium aquatic O 3 concentrations by 1.53–3.25 times and apparent O 3 transfer rates by 3.12–3.35 times at pH 5.0–8.0. Consequently, the • OH yield was 2.67–3.54 times via faster O 3 transfer to the aquatic solution followed by decomposition rather than interfacial reaction. Ozone micro-bubble aeration outperformed milli-bubble aeration, with the degradation kinetics of 2,4-D being 3.08–4.36 times higher. Both O 3 -oxidation and • OH oxidation were important to the promotion with the contributions being 35.8%-45.9% and 54.1%-64.2%, respectively. The operational and water matric conditions influenced the oxidation performance via both O 3 oxidation and • OH oxidation, which is reported for the first time. In general, the ceramic membrane offered a low-energy approach of ozone micro-bubble aeration for efficient pollutant degradation. The O 3 oxidation and • OH oxidation were proportionally promoted by ozone micro-bubble due to O 3 transfer enhancement. Thus, the promotive mechanism can be interpreted as the synchronous enchantment on ozone exposure and • OH exposure for the first time.
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CHEMICO-BIOLOGICAL INTERACTIONS
·
2022
·
IF 5.168
Yudong Yin,Li Sun,Lixin Sheng,Liqiong Zhang,Jingjing Liu,Xiaoan Wen,Weibin Mo,Quande Wang,Keguang Cheng
In order to discover more effective and less toxic drugs in the field of anti-tumor, the backbone structure of 17 β -estradiol was modified, and 11 target compounds were synthesized. Compounds 5 and 10 , which exhibited better anti-tumor activity and higher selectivity (more than 10-fold), were chosen for further biological investigation. Flow cytometry results indicated that 5 and 10 could arrest MCF-7 cells in the G2 phase and induce apoptosis . Immunohistochemical analysis revealed that 5 and 10 could bind to the estradiol receptor alpha in MCF-7 cells. Western blotting and real-time PCR assays were performed to detect the effects of compounds on apoptosis-related targets at the protein and gene levels. These results showed that both 5 and 10 could dosed-dependently increase the expression of Apaf-1, Bax, caspase-3,8,9 and reduce the expression levels of the anti-apoptotic factors Bcl-2 and Bcl-xL. Besides, the Human apoptosis array assay demonstrated the expression level of death receptor Trail R2/DR5 was upregulated obviously while the expression of TNF R1, IAPs and Hsp27/60/70 were downregulated. On the whole, 5 induced MCF-7 cell death through the endogenous pathway in mitochondria and the exogenous pathway with death receptor Trail R2/DR5.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Lingjun Bu,Xiaojun Chen,Yangtao Wu,Shiqing Zhou
Halonitrophenols (HNPs) are emerging aromatic nitrogenous disinfection by-products ( N -DBPs) with high cyto- and genotoxicity. However, limited information is available regarding the formation mechanism of HNP during chlorination after the UV/chlorine process. In the past, dissolved organic nitrogen (DON) constitutes a vast array of N -DBP precursors due to its heterogeneous nature. Amino acids (AAs) are an important class of DON in water, where combined AAs (i.e., peptides and proteins) make up a larger identifiable section. In this study, three AAs including free tyrosine (Tyr) and two oligopeptides (i.e., tyrosine-alanine (Tyr-Ala) and tyrosine-tyrosine-tyrosine (Tyr-Tyr-Tyr)) were selected as model AAs to evaluate the effect of the UV/chlorine process on the formation of 2,6-dichloro-4-nitrophenol (DCNP). We found an enhanced formation of DCNP after the UV/chlorine process in comparison with direct chlorination, which indicated the nitrogen sources in AAs can contribute to the formation of HNPs. The presence of NO • in the UV/chlorine process was demonstrated by electron spin-resonance spectroscopy (ESR) test. The effects of three typical factors (i.e., UV fluence, pH, and Cl 2 /AA) on the formation of DCNP in the UV/chlorine process were investigated to optimize parameters to minimize the formation of HNPs. Furthermore, it was observed that oligopeptides exhibited higher yields of DCNP than free Tyr. Based on this, we propose a possible formation pathway of DCNP from 2 oligopeptides to elucidate the formation mechanisms more intuitively. We observed and confirmed a convertible tendency from HNPs to aliphatic DBPs (e.g., trichloronitromethane). Overall, this study provided a reliable theoretical basis for a comprehensive understanding of the precursors, formation mechanisms and control methods of HNPs.
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Defence Technology
·
2023
·
IF 5.1
Er-hai An,Xiao-xia Li,Cun-juan Yu,Ying-xin Tan,Zi-jun Fan,Qing-xia Li,Peng Deng,Xiong Cao
Fe/N-based biomass porous carbon composite (Fe/N-pCarbon) was prepared by a facile high-temperature carbonization method from biomass, and the effect of Fe/N-pCarbon on the thermal decomposition of energetic molecular perovskite-based material DAP-4 was studied. Biomass porous carbonaceous materials was considered as the micro/nano support layers for in situ deposition of Fe/N precursors. Fe/N-pCarbon was prepared simply by the high-temperature carbonization method. It was found that it showed the inherent catalysis properties for thermal decomposition of DAP-4. The heat release of DAP-4/Fe/N-pCarbon by DSC curves tested had increased slightly, compared from DAP-4/Fe/N-pCarbon-0. The decomposition temperature peak of DAP-4 at the presence of Fe/N-pCarbon had reduced by 79°C from 384.4°C (pure DAP-4) to 305.4°C (DAP-4/Fe/N-pCarbon-3). The apparent activation energy of DAP-4 thermal decomposition also had decreased by 29.1 J/mol. The possible catalytic decomposition mechanism of DAP-4 with Fe/N-pCarbon was proposed.
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JOURNAL OF POLYMER RESEARCH
·
2023
·Vol. 30
·期 2
·1-15
·
IF 2.8
Qin Y. X.,Wang C.,Li K. Y.,Jin B. R.,Chen Y. R.,Ren L.,Zhang M. Y.,Zhang H. X.
Considering the current research background of environmental problems and shortages of petroleum resources aiming at proposing the “green” polymer blend with good degradability and properties similar to oil-based merchandise currently on the market, in the present study, two series of fully biodegradable blends consisting of PBS/P34HB (PBP) and PBS-g-GMA/P34HB (PGP) have been successfully fabricated by a simple and environmental-friendly processing methodology. In this work, the resulting biodegradable blends are in detail studied from the mechanical, thermal, crystallization, and morphology points of view. To improve the miscibility and enhance the interfacial adhesion between both phases of poly(butylene succinate) (PBS) as the matrix and poly (3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) as the modifier, with consequent improvement in material mechanical properties, glycidyl methacrylate (GMA) is grafted on PBS via reactive blending in the process. The incorporation of 10wt% P34HB into the blend promotes a dramatic increase of 614% in the Izod impact strength. The crystallization temperature (Tc) of PGP is 87.78℃ when 30wt% P34HB is added, which is 25% higher than that of pure PBS and 11% higher than that of the PBP blend. Meanwhile, the crystallinity of PGP is 30.12%, 47%, and 37% decline compared to pure PBS and PBP, respectively. Rheological results show that storage modulus, loss modulus, and complex viscosity improve significantly with the increase of P34HB amount, indicating that the enhancement of melt strength is beneficial to the processing and forming of the materials.
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CHEMOSPHERE
·
2023
·
IF 8.8
Hao Cheng,Liwen Zhang,Jun Feng,Tingfan Tang,Danfeng Qin
A novel, sensitive Ti 3 C 2 MXene/Co 3 O 4 /carbon nanofibers (Ti 3 C 2 MXene/Co 3 O 4 /CNFs) composite was synthesized via a HF exfoliating Ti 3 AlC 2 strategy, followed by doping Co 3 O 4 and Ti 3 C 2 MXene into the CNFs via a combination electrospinning and thermal annealing process. Ti 3 C 2 MXene/Co 3 O 4 /CNFs composite exhibits higher catalytic effect, conductivity, chemical stability, and electrochemical performance than Co 3 O 4 and Ti 3 C 2 MXene in electrochemical impedance, differential pulse stripping voltammetry, chronocoulometry, and cyclic voltammetry tests. This Ti 3 C 2 MXene/Co 3 O 4 /CNFs hybrid modified electrode provides fast analysis of 4-aminophenol (4-AP) with ultrahigh sensitivity, enhanced reproducibility and strong anti-interference capability. Furthermore, the level of 4-AP was quantified by this electrode with a wide linear range from 0.5 to 150 μM (R 2 > 0.99) and a low detection limit about 0.018 μM was achieved. Finally, the fabricated electrode was used for fast and sensitive analysis of 4-AP spiked in tap water and blood serum samples. This work presents the new Ti 3 C 2 MXene/Co 3 O 4 /CNFs electrode provides a platform for 4-AP monitoring and has the advantages of high selectivity , accuracy, simplicity, and rapid analysis.
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Soft Matter
·
2023
·Vol. 19
·期 30
·5711-5722
·
IF 3.4
Yanrong Cheng,Wenlin Xu,Yaqiong Wang,Xia Guo
The PEG/salt aqueous two-phase system (ATPS) is the most common ATPS, but its application is still limited due to the restricted polarity difference between the two phases and the poor enhancement effect of adjuvants on ATPS performance so far. Unlike the adjuvants used so far, calixarenes can bind ions and molecules via multiple noncovalent interactions. In the present study, a water-soluble calixarene, p-sulfonatocalix[4]arene (SC[4]), was used for the first time as the adjuvant to improve the performance of the PEG 600/(NH4)2SO4 ATPS through multiple interactions. It is found that when the SC[4] and the SC[4]/imidazole ionic liquid ([Cnmim]Br) complex were used as the adjuvants, the formation of PEG 600/(NH4)2SO4 ATPS was enhanced, and the transfer of the extracts (including S-mandelic acid, L-tryptophan, and L-phenylalanine) into the PEG phase was promoted. Moreover, although the single [Cnmim]Br, a commonly used adjuvant, does not promote the migration of the target molecules into the polymer phase, the SC[4]/[Cnmim]Br complex is superior to SC[4] in enhancing the performance of the ATPS because the SC[4]/[Cnmim]Br aggregates enable more binding sites to combine with the extract. Besides, the partition coefficient of SC[4] in the PEG/trisodium citrate ATPS is much smaller than that in the PEG/(NH4)2SO4 ATPS, which is helpful for the recovery of extracts into the citrate phase.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Shuang Xiao,Peng Zhang,Guowen Zhang,Wenwen Li,Haowen Lin,Xing Hu
The activation of toll-like receptor 4 (TLR4) signaling is crucial for initiating and coordinating the immune response against infections, and is proved as a vital target for inflammatory diseases. Herein, TLR4 with sufficient amount and functional activity was generated by heterologous expression and used to investigate the mechanism of apigenin (Api)/chrysin (Chr) inhibition of TLR4 activation. The results demonstrated that Api/Chr exhibited a strong fluorescence quenching effect through a static quenching and a high binding affinity ( K a > 10 5 L·mol −1 ) with TLR4, indicating the potential of Api/Chr as a TLR4 inhibitor. Additionally, the binding of Api/Chr induced a loose and unstable conformation of TLR4 with evidence like the decreased hydrophobicity of the tryptophan microenvironment, decreased α-helix content and increased free sulfhydryl content, resulting in reduced stability of the TLR4. The computer simulations revealed that Api/Chr occupied the myeloid differentiation factor 2 (MD-2) binding region, preventing MD-2 from binding to TLR4. Furthermore, the accuracy of the binding site between Api/Chr and TLR4 was confirmed through genetic mutations . Overall, the mechanism by which Api/Chr inhibited TLR4 activation was elucidated at the macroscopic and molecular levels, providing the worthful information concerning the future therapeutic application of Api/Chr as a natural TLR4 inhibitor.
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