Nanoscience and Nanotechnology Letters
·
2015
·Vol. 7
·期 11
·939-944
·
IF 1.431
Zhu Linhua,Zhu Qidong,Zhao Jie,Dai Chunyan
p-tert-Butylcalix[4]arene (PC4), de-tert-butyl calix[4]arene (DC4) and sulfonated calix[4]arene (SC4) were synthesized by means of acetalization, dealkylation and sulfonation. Their structures and morphologies were characterized with fourier transform infrared spectrometry (FTIR),
nuclear magnetic resonance spectroscopy (NMR) and scanning electron microscopy (SEM). The thermal properties of three calix[4]arenes were investigated with thermogravimetric analysis (TGA) and differential thermal gravity (DTG). TGA and DTG curves of calixarenes indicate that the thermal weight
loss process of calix[4]arenes includes 2 stages: the stage of inclusion complex loss and the stage of thermal decomposition. According to Kissinger method, the average apparent activation energies (E
a
) of thermal decomposition of PC4, DC4 and SC4 are 299.86 kJ/mol,
246.09 kJ/mol and 129.28 kJ/mol, respectively. Furthermore, according to the Phadnis-Deshpande model, the decomposition kinetic models of three calix[4]arene follow nucleation and nuclei growth mechanism, phase boundary mechanism and power law mechanism, respectively.
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COMBUSTION AND FLAME
·
2024
·
IF 5.8
Haikun Lang,Fangping Bin,Shuyao Chen,Xiaoli Zhang,Jiuzheng Yin,Jinzeng Pan,Zhandong Wang,Lixia Wei
Fischer–Tropsch synthesis is an important route for the productions of cleaner fuels from non-petroleum materials. Monomethylated alkanes are present in large quantities in Fischer–Tropsch synthetic fuels. However, side-chain position may make a difference in the combustion of the fuels. In this work, the 4-methylheptane (MH4) pyrolysis was investigated experimentally by using a jet-stirred reactor at 800–1125 K and at 760 Torr. Major pyrolysis products, including small molecules and aromatic products, were identified and measured by using the synchrotron ultra-violet photoionization method. Several species were detected and measured, including CH 4 , C 2 H 2 , C 2 H 4 , C 2 H 6 , C 3 H 4 , C 3 H 6 , C 3 H 8 , C 4 H 6 , IC 4 H 8 , C 5 H 6 , C 5 H 8 1-3, C 5 H 10 -2, benzene, naphthalene, indene and C 6 H 5 C 2 H, etc. A detailed kinetic model of MH4 pyrolysis was developed and validated against the experimental results in this work. Rate of production analysis of MH4 indicates that the most significant consumption pathways are H-abstractions. The unimolecular decomposition reactions by the breakages of C C bonds are also important pathways in MH4 consumption. The pyrolysis product distributions of 4-methylheptane, 3-methylheptane and 2-methylheptane were compared to demonstrate the effect of the methyl side chain position on the pyrolysis of those fuels. It is noted that the mole fraction distributions of the smaller species, including CH 4 , C 2 H 2 and C 2 H 6 , are not sensitive to the position of the methyl side-chain, while those of C3-C5 products, including PC 3 H 4 , C 3 H 6 , C 4 H 6 , IC 4 H 8 , C 5 H 8 1-3 and C 5 H 10 -2, are strongly affected. Novelty and significance statement The products of 4-methylheptane pyrolysis were identified and measured by using the synchrotron ultra-violet photoionization method. A detailed kinetic model of 4-methylheptane pyrolysis at atmospheric was constructed for the first time. The consumption pathways of 4-methylheptane pyrolysis were clarified. The effect of methyl side chain position on fuel pyrolysis was analysed. 4-Methylheptane is one of the important branched alkanes in Fischer–Tropsch synthetic diesel fuel. The present work extends the understanding of pyrolysis of long branched alkanes. The results of the study provide guidance in exploring ideal compositions for diesel alternative fuels.
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Journal of Materials Chemistry A
·
2025
·
IF 9.5
Xiaowen Wang,Dameng Gao,Xiao Liu,Xingyue He,Jian-Gong Ma,Peng Cheng
4-Nitrophenol (4-NP) is a common stuff involved in industrial production as well as a toxic pollutant which poses a threat to the environment and human health if not handled properly. Here, we have designed and synthesized two new metal-organic frameworks (MOFs), namely Ce-MOF-1 and Ce-MOF-2 with both fluorescent and electrochemical activities, which exhibite dual-mode sensing of 4-NP. The fluorescence emission spectra at 366 nm of both Ce-MOF-1 and Ce-MOF-2 displayed a significant turn-off signal affected by the competitive absorption and photoelectron transfer of 4-NP with the detection limits of 1.25 and 0.78 μM, respectively. Simutanously, in electrochemical sensing, 4-NP is irreversibly reduced to 4-hydroxylamine phenol under the catalysis of Ce-MOFs coating on electrode, which exhibit higher accuracy than fluorescence with detection limits of 0.36 and 0.41 μM, respectively, for the quantitatively sensing of 4-NP. Due to their complementary immunity to interference in electrochemical and fluorescence methods for 4-NP detection, Ce-MOFs exhibit more accurate 4-NP detection ability compared to other sensors. Finallly, both Ce-MOFs demonstrate excellent stability, reproducibility and selectivity in dual-mode sensing of 4-NP in tap water, that provides superior adaptability, reliability and accuracy compared to the traditional single-mode sensing method.
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JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Shu-Ting Zhang,Tao Li,Shi-Kai Deng,Jim C. Spain,Ning-Yi Zhou
Nitroanisoles are used widely as synthetic intermediates and explosives. Although bacteria have been reported to degrade 4-nitroanisole (4NA) under aerobic conditions , the key enzymes and the catalytic mechanism have remained elusive. Rhodococcus sp. strain JS3073 was isolated for its ability to grow on 4NA as the sole carbon and energy source. In this study, whole cell biotransformation experiments indicated that 4NA degradation is initiated by O -demethylation to form 4-nitrophenol (PNP), which undergoes subsequent degradation by a previously established pathway involving formation of 1,2,4-benzenetriol and release of nitrite. Based on comparative transcriptomics and heterologous expression, a novel three-component cytochrome P450 system encoded by pnaABC initiates the O -demethylation of 4NA to yield formaldehyde and PNP. The pnaABC genes encode a phthalate dioxygenase type reductase (PnaA), a cytochrome P450 monooxygenase (PnaB), and an EthD family protein (PnaC) with putative function similar to ferredoxins. This unusual P450 system also has a broad substrate specificity for nitroanisole derivatives. Sequence analysis of PnaAB revealed high identity with multiple self-sufficient P450s of the CYP116B subfamily. The findings revealed the molecular basis of the catabolic pathway for 4NA initiated by an unusual O -demethylase PnaABC and extends the understanding of the diversity among P450s and their electron transport chains.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 134
·期 8
·
IF 1.866
Defa Hou,Hanbing Ma,Xiuyun Li,Jie He,Huiwei Liao
A novel easily curing system of 2,2- bis (4-cyanatophenyl) propane(BACY) was prepared by employing 4,4′-(Hexafluoroisopropylidene) Diphenol (BPAF) as modifier. The curing efficiency of BPAF was evaluated by means of differential scanning calorimetry (DSC) and Fourier translation infrared spectroscopy analysis (FTIR). It was found that the exothermic peak temperature ( T p ) was 168 °C when the content of BPAF/BACY was 15/85 by weight, while the temperature of BACY was 215 °C under the same conditions when trace of cobalt(III) acetylacetonate(CoAt(III)) was added. Besides, BPAF/BACY system owned outstanding properties including excellent curing characteristics, high shear strength, remarkable dielectric properties and high thermal stability in contrast to BACY, 4,4′-(1-methylethylidene) bisphenol(BPA)/BACY, and nonylphenol(NoP)/BACY systems. Moreover, the properties of cured BPAF/BACY modified by different proportions of BPAF were studied in detail. It was shown that moderate BPAF was conducive to most properties of polycyanurate, and the optimal proportion of BPAF/BACY was 15/85 by weight. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44518.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2015
·Vol. 31
·期 6
·1051-1055
·
IF 0.875
Fang Xiaoting,Guo Hongyu,Yang Fafu,Bai Xiaoyan
By the Schiff-base condensation of formacyl calix[4]crown( 2 ) with raw chitosan, a novel calix[4]crown-grafted chitosan chelating polymer( 3 ) was conveniently prepared in good yield. The structure of polymer 3 was confirmed by elemental analysis, infrared(IR) spectrometry and X-ray diffraction(XRD) analysis. The elemental analysis suggests that the grafting degree of calixcrown unit was 22% on the amino groups of chitosan. The morphological characteristic of polymer 3 was studied by scanning electron microscopy(SEM). Polymer 3 possessed loose porous and smooth morphology of surface. The dyes adsorption abilities of polymer 3 for a series of organic dyes[Orange I(OI), Neutral red(NR), Victoria blue B(VB) and Brilliant green(BG)] were studied by solid-liquid adsorption experiments. The adsorption percentages increased from 45%―60%(raw chitosan for dyes) to 75%―90%(polymer 3 for dyes). The highest adsorption percentage reached 89% for VB. The saturated adsorption capacities for OI, NR, VB and BG were as high as 622, 564, 854 and 781 mg/g, respectively. The adsorption abilities kept stable at 70%―90% in the scope of pH=5―9. The adsorption abilities for anionic dye(OI) decreased gradually with the increase of pH and the opposite trend was observed for cationic dyes(NR, BG, VB). The adsorption percentages were 70%―90% after five times’ cycles for adsorption.
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Chinese Journal of Natural Medicines
·
2014
·
IF 0
De-Biao YAN,Dong-Ping ZHANG,Ming LI,Wen-Yuan LIU,Feng FENG,Bin DI,Qing-Long GUO,Ning XIE
To synthesize a series of 3-, 4-, and/or 11-trihydroxy modified bergenin derivatives and evaluated their cytotoxic activity in vitro . The phenolic hydroxyl groups of bergenin were protected by benzyl groups with benzyl bromide. Treatment of dibenzyl bergenin with the corresponding acid in the presence of EDC·HCl and DMAP in CH 2 Cl 2 , followed by hydrogenation over Pd/C catalysts, afforded derivatives of bergenin esters. All of the target compounds were identified by IR, MS, and 1 H NMR. Twenty-six novel and three known derivatives of bergenin esters were synthesized. Their cytotoxicity values were evaluated by the MTT assay on the inhibition of DU-145 and BGC-823 cells in vitro . Several triply-substituted ( 3a, 4a, 5a, 6a, 7a ) and doubly-substituted ( 8b, 9b ) bergenin derivatives exhibited higher cytotoxic activity than bergenin. The result showed that the size of substituents and the lipophilicity of the bergenin esters displayed an important role on their cytotoxic activity.
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HYDROMETALLURGY
·
2016
·
IF 2.29
Zhang Peng,Dong Linfei,Zhang Dongxiang,Lei Shi,Hongmei Yang,Jinying Li,Wang Yaling,V.V. Tarasov
Calix[4]arene derivatives including diethyl phosphite groups were used for the first time for separating Nd(III) from nitrate media. Calix[4]arene derivatives were synthesized and characterized by infrared spectroscopy (IR), mass spectroscopy (MS), and 1 H NMR. Four calix[4]arene derivatives, CalixF (①), DCalixF (②), PCalixF (⑤), and POCalixF (⑥), were used in a solvent extraction method. The effects of aqueous acidity, diluent, temperature, shaking time, and Nd(III) concentration were investigated. The results showed that the extraction ability of ⑤ and ⑥ with a phosphate functional group at the upper rim were best for the extraction of Nd(III). Derivative ⑥ had better complexing capacities than ⑤ for the generation of a phenolic hydroxyl group at the lower rim. The enthalpy (∆ H O ), Gibbs free energy (∆ G O ), and entropy (∆ S O ) changes for the extraction were obtained from a thermodynamic study. The results showed that the extraction of Nd(III) from a nitric acid system might be an endothermic reaction since the process was naturally spontaneous and increasing the temperature during extraction was determined to be thermodynamically feasible. The extraction of Nd(III) was governed by a two-stage chemical reaction and diffusion process. In the first stage, the process was controlled by a fast chemical reaction at the liquid-liquid interface. The composition of the Nd(III)-calix[4]arene derivative complex was determined to be [Nd(NO 3 ) 3 ] 2 [L]. The second stage was the diffusion of extracted products towards equilibrium. Calix[4]arene derivative ⑥ was found to be an efficient extractant for the separation of Nd(III) and would be a potential extractant for the disposal of radioactive waste in spent fuel .
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ANALYTICAL CHEMISTRY
·
2018
·
IF 6.042
Jian Sun,Jiahui Zhao,Xingfu Bao,Qifeng Wang,Xiurong Yang
Diethanolamine (DEA) has been extensively utilized as an alkaline buffer in current assays of alkaline phosphatase (ALP) activity in the past decades. While playing the role of a buffer, the chemical reactivity of DEA has been widely ignored in such assays. Herein, we report an interesting chromogenic interaction between DEA and 4-aminophenol (AP) in the presence of H2O for the first time, which inspires us to develop a novel DEA-participated ALP activity assay by using 4-aminophenyl phosphate (APP) as a substrate. This APP/DEA-based colorimetric approach has been proved to be comparable and even superior to the conventional p-nitrophenyl phosphate (pNPP)-based one, especially in the low ALP activity region, due to its higher sensitivity. The clear response mechanism and excellent sensing performance ensure that it can be further applied to determining ALP activity in real biological samples, screening potential ALP inhibitors in vitro, establishing ALP-enabled ELISA, and even fluorophore-assisted fluorescent ALP activity assay. It is demonstrated that this strategy not only possesses a good feasibility, but also exhibits a promising outlook for a series of ALP-related and -extended detections.
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Journal of Extracellular Vesicles
·
2023
·Vol. 12
·期 9
·12364
·
IF 16
Jie He,Hengyu Li,John Mai,Yuqing Ke,Chunhui Zhai,Jiao Jiao Li,Lai Jiang,Guangxia Shen,Xianting Ding
Extracellular vesicle (EV) surface proteins, expressed by primary tumours, are important biomarkers for early cancer diagnosis. However, the detection of these EV proteins is complicated by their low abundance and interference from non-EV components in clinical samples. Herein, we present a MEmbrane-Specific Separation and two-step Cascade AmpLificatioN (MESS2CAN) strategy for direct detection of EV surface proteins within 4 h. MESS2CAN utilises novel lipid probes (long chains linked by PEG2K with biotin at one end, and DSPE at the other end) and streptavidin-coated magnetic beads, permitting a 49.6% EV recovery rate within 1 h. A dual amplification strategy with a primer exchange reaction (PER) cascaded by the Cas12a system then allows sensitive detection of the target protein at 10 EV particles per microliter. Using 4 cell lines and 90 clinical test samples, we demonstrate MESS2CAN for analysing HER2, EpCAM and EGFR expression on EVs derived from cells and patient plasma. MESS2CAN reports the desired specificity and sensitivity of EGFR (AUC = 0.98) and of HER2 (AUC = 1) for discriminating between HER2-positive breast cancer, triple-negative breast cancer and healthy donors. MESS2CAN is a pioneering method for highly sensitive in vitro EV diagnostics, applicable to clinical samples with trace amounts of EVs.
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高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 31
·10509-10519
·
IF 6.4
Chengcheng Zhou,Ding Shen,Xingpeng Chai,Boyang Shi,Wenya Zhu,Guowei Wang
The rapid development of the semiconductor industry puts forward higher requirements on the properties of insulating dielectrics. As a supramolecular compound, calix[4]arene has a unique cavity structure, showing potential for a low-k material. We herein reported a novel strategy to functionalize the 4-tert-butylcalix[4]arene with different numbers of benzocyclobutene (BCB) units (2 or 4) and spacers (–(CH2)3– or –(CH2)6–) by sequential substitution and hydrosilylation reactions. These precursors can be cured under heating to form a crosslinked film. The optimized curation condition was screened by differential scanning calorimetry (DSC) measurement. Combining with a comparison experiment using a precursor with calix[4]arene but without BCB units, the wide-angle X-ray scattering (WAXS) pattern and thermal analysis provided solid evidence that the high thermal stability of the film (glass transition temperature (Tg) > 110 °C, 5 wt% loss temperature >367 °C, and the coefficient of the thermal expansion < 87.88 ppm °C−1) was majorly contributed by calix[4]arene, while the excellent dielectric properties (the lowest dielectric constant Dk = 2.23 and the average dielectric loss Df < 1.5 × 10−3) were synergistically affected by both calix[4]arene and BCB units. The static water contact angle was mostly higher than 100° and high hydrophobicity was confirmed, which can meet the additional requirements in practical application. The low dielectric constant synergized by calix[4]arene and the BCB unit is hoped to aid in developing a novel strategy for low-k materials.
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JOURNAL OF TOXICOLOGICAL SCIENCES
·
2016
·Vol. 41
·期 3
·371-381
·
IF 1.224
Wei-Feng Xu,Yan-Sen Li,Peng-Yuan Dai,Chun-Mei Li
4-nitrophenol (PNP) is generally regarded as a diesel exhaust particle (DEP). Arginine plays an important role as a new feed additive, possessing highly efficient antioxidant activities. Here we investigated the effects of dietary supplementation with arginine against ovarian damage induced by PNP in rats. A total of thirty-two female rats postnatal day 28 (PND 28) were randomly divided into four groups. Two groups were fed with basal diet or 13 g/kg arginine in diet for 4 weeks, respectively; the other two groups were given PNP (100 mg/kg b.w.) daily by subcutaneous injection for 2 weeks following pretreatment with either basal diet or arginine diet for 2 weeks. The values of body weight gain (BWG), average daily gain (ADG) and percentage weight gain (PWG) upon PNP treatment were significantly reduced than those in other groups. The relative liver weight in the PNP group was significantly decreased compared with the control group. Treatment with PNP significant reduced the number of corpora lutea, although serum 17β-estradiol (E2) and progesterone (P4) concentrations were unchanged. The morphology of the ovaries in PNP-treated rats displayed necrosis, follicular deformation and granulosa cells irregular arrangement. Moreover, exposure to PNP enhanced production of malondialdehyde (MDA) and hydrogen peroxide (H2O2), and decreased the activities of total superoxide dismutase (T-SOD) and catalase (CAT), and the co-administration of arginine can attenuate the oxidative stress caused by PNP. These results suggest that arginine may have a protective effect against ovarian damage induced by PNP owing to its antioxidant capacity effect.
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