JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2023
·Vol. 148
·期 6
·2401-2415
·
IF 4.4
Gao Wei,Li Yufeng,Zhao Jitao,Tang Weiwei,Zhang Zhe,Wang Jun,Wu Zhenyu,Li Minggang
The low crystallization rate and long molding time of poly(ethylene terephthalate) (PET) restricts its application in the field of engineering plastics. PET/graphene oxide (GO) composites were synthesized through in situ polymerization method with dimethyl terephthalate (DMT), ethylene glycol (EG) as reactants and GO as filler in order to overcome the above shortcomings. Influence of GO on the crystallization performance of PET was investigated. It was revealed GO raised the crystallization temperature and crystallization rate of PET, demonstrating the excellent nucleation capability of GO. The mechanism of PET nucleation induced by GO was investigated by Avrami equation and Hoffman-Lauritzen theory. It was obvious the crystallization behavior of PET was improved by reducing the free energy of nucleation and the fold surface free energy of PET caused by GO. Moreover, the non-isothermal kinetics of thermal decomposition of PET and PET/GO composites were studied by Friedman method. It was obvious that all of PET and PET/GO composites exhibited a fine thermal stability with no significant mass loss observed up to 370 °C (< 0.5%). The addition of GO improved the thermal stability of PET through raising the apparent activation energy, inhibiting the escape of volatile products and absorbing the degradation products in PET thermal decomposition procedure.
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CELLULOSE
·
2022
·Vol. 30
·期 3
·1841-1855
·
IF 6.123
Shuaib Suhaib Shuaib Adam,Niu Zixuan,Qian Zhiyi,Qi Shengyang,Yuan Weizhong
The development of phase change materials (PCMs)-based energy storage devices for both thermal and light energy has the potential to greatly enhance solar energy use efficiency, which is important in addressing the worldwide energy problem. Due to the environmentally friendly, good thermal and chemical stability, easy degradation, and good mechanical strength of ethyl cellulose, it was used to fabricate the shape-stabilized composite phase change material (ss-CPCM) with polyethylene glycol. The ss-CPCMs have a high latent enthalpy (174.33 J/g), high form stability, excellent thermal regulation abilities for both thermal energy storage and thermal insulation, and great cycle thermal performance. After adding long afterglow luminescence particles, the self-luminous ss-CPCMs were obtained. They can absorb and store visible and ultraviolet light, as well as emit green light in the dark for an extended period of time. The excellent properties of the self-luminous ss-CPCMs promise them great potential in applications, such as energy-saving, emergency lighting, furniture, smart building, and smart highway.
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Chinese Medicine
·
2022
·Vol. 17
·期 1
·1-12
·
IF 4.546
Wang Li,Shao Li,Chen Man-Yun,Wang Lin,Zhang Wei,Tan Feng-Bo,Huang Wei-Hua
Background Ginsenoside compound K (GC-K) potentially alleviates ulcerative colitis involved in gut microbiota, which is significantly associated with the occurrence and development of colitis. However, the effect and mechanism of GC-K on anti-colitis in relation to gut microbiota are not clear. This study focused on the prevention and mechanism of GC-K on Dextran sulfate sodium (DSS)-induced colitis of mice pertinent to gut microbiota. Methods DSS was used to establish a chronic colitis mouse model. Body weight analysis, colon length measurement, HE staining, and inflammatory factors levels were processed in animal experiments. Flow cytometry was employed to analyze Th17/Treg cells in the mouse spleen and blood. 16S rRNA sequencing was utilized to analyze gut microbiota. Fecal microbiota transplantation (FMT) experiment was employed to verify the anti-colitis efficacy of GC-K by reshaping gut microbiota. Results GC-K significantly relieved colitis-related symptoms due to decreased disease activity index (DAI) scores, spleen weight, and increased colon length. Additionally, the tight junction proteins were increased, and the pro-inflammatory cytokines, such as TNF-α, IL-6, IL-1β and IL-17, were decreased after GC-K treatment. Furthermore, Bacteroides spp. significantly increased after modeling. Moreover, FMT experiments confirmed that GC-K-driven gut microbiota greatly relieved DSS-induced colitis. Conclusion GC-K alleviated colitis via the modulation of gut microbiota. Graphical Abstract
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高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 149
·期 11
·2994-2999
·
IF 2.372
Zhang Shengnan,Wang Hongmei,Cang Ruibai,Lu Bin,Zhao Jingxiang,Cai Qinghai
Abstract A composite material (FeSIL) prepared by FeCl 3 -imidazolium ionic liquid grafted on SBA-15 exhibited effective catalytic activity for solvent-free oxidation of styrene into benzaldehyde with high selectivity using H 2 O 2 oxidant and it presented easy recovery and reusability. In situ DRIFTS spectra for styrene and H 2 O 2 adsorption showed that an intermediate Fe 3+ –π surface complex on the catalyst surface was responsible for the activation of styrene and its reaction with H 2 O 2 molecules on the surface or in the bulk phase. Graphic Abstract Iron-chloride immobilized ionic liquid (FeSIL) was prepared by N -methylimidazole reacting with chloropropylsilane grafted on SBA-15 and coordinating of FeCl 3 to the imidazolium on the surface. The higher catalytic activity of the catalyst for effective oxidation of styrene under solvent-free condition were achieved The catalyst can be easily recovered and effectively reused without a significant loss in its activity.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-10
·
IF 5.479
Qin Dan,Wang Jiangtao,Ge Changzi,Lian Ziru
A straightforward method has been developed for selective separation of chloramphenicol (CAP) from marine sediment samples. Magnetic molecularly imprinted nanoparticles (NPs) of type Fe 3 O 4 @SiO 2 were prepared via surface imprinting with CAP. The NPs were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and thermogravimetric analysis. They have perfect core-shell structure, excellent thermal stability, high affinity and selectivity to CAP. The imprinting factor and Scatchard analysis also reveal good specific recognition to the template. The imprinted NPs were applied as sorbents for fast and selective extraction of CAP from marine sediment samples. The experimental parameters affecting separation efficiency were optimized. Three marine sediment samples were analyzed. Following desorption with methanol/water (90/10, v /v), CAP was quantified by HPLC with DAD detection. The limit of detection is 0.1 μg L −1 with a good linear response between 0.1–20 mg L −1 of CAP concentration (R 2 = 0.999, n = 3). The method exhibits satisfactory recoveries from spiked samples (77.9–102.5%) and has low relative standard deviations (<6.3%). The magnetic material can be used at least 5 times by the regeneration without any loss of selectivity and adsorption capability.
Schematic presentation of magnetic molecularly imprinted nanoparticles (MMIPs) as sorbent for fast extraction and chromatographic analysis of chloramphenicol (CAP) from marine sediments. CAP-MMIPs are synthesized by surface imprinting method using 3-methacryloxy propyl trimethoxy silane (MPS) as the silane coupling agent.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-10
·
IF 5.479
Shi Bingfang,Su Yubin,Duan Yan,Chen Shengyu,Zuo Weiyuan
Nitrogen-doped graphene quantum dots (N-GQD) were employed along with Cu(II) ions under alkaline conditions and room temperature to synthesize nanocomposites of type Cu(II)/Cu 2 O/N-GQDs. These nanocomposites exhibit excellent stability and dispersity, and also display a peroxidase-like activity that is superior to pure Cu 2 O nanoparticles and natural peroxidase (POx). A chemiluminescence (CL) method was designed that is based on the use of uricase which oxidizes uric acid under formation of H 2 O 2 . The nanocomposites were used as a POx mimic in the luminol-H 2 O 2 CL system. Under optimized conditions, a linear relationship between CL intensity and the uric acid (UA) concentration in the range of 0.16—4.0 μM, and a detection limit of 0.041 μM (at S/ N = 3) were obtained. The CL method was applied to the determination of UA in spiked serum and urine, and recoveries ranged from 85.0 to 121.3%.
Schematic presentation of synthesis strategy of Cu(II)/Cu 2 O/N-GQDs and the CL method based Cu(II)/Cu 2 O/N-GQDs for H 2 O 2 -meidated uric acid detection. The method can be used for the determination of uric acid (UA) with the detection limit of 0.041 μM.
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高影响因子
ACTA PHARMACOLOGICA SINICA
·
2019
·Vol. 40
·期 10
·1334-1342
·
IF 4.01
Lu Bin,Chen Xiao-bing,Hong Yu-cai,Zhu Hong,He Qiao-jun,Yang Bo,Ying Mei-dan,Cao Ji
Ferroptosis is a newly characterized iron-dependent form of nonapoptotic regulated cell death triggered by lipid reactive oxygen species (LOOH). The dysregulation of ferroptosis is highly related to cancer, and the induction of ferroptosis is also proposed as a potential strategy for cancer therapy. Although several key regulators have been identified that are involved in ferroptosis, the molecular mechanism underlying this process remains largely unknown. Here, we report that Peroxiredoxin-6 (PRDX6) is a bona fide negative regulator of ferroptotic cell death. The knockdown of intracellular PRDX6 significantly enhances LOOH and ferroptotic cell death triggered by ferroptosis inducers (Erastin and RSL-3), which is correlated with the transcriptional activation of heme oxygenase-1. Moreover, overexpression of heme oxygenase-1 enhances both Erastin- and RSL-3-triggered LOOH, suggesting that heme oxygenase-1 mediates PRDX6 silencing-enhanced ferroptosis. More importantly, the application of a specific PRDX6 phospholipase A2 (iPLA2) inhibitor, MJ-33, synergistically enhances the ferroptosis induced by Erastin, suggesting that PRDX6 removes LOOH through its iPLA2 activity. Thus, our findings reveal an essential role of PRDX6 in protecting cells against ferroptosis and provide a potential target to improve the antitumor activity of ferroptosis-based chemotherapy.
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高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 13
·2971-2979
·
IF 3.286
Wang Jiaqi,Wang Chen,Fan Li,Zhao Liang,Tan Wen-Song
Chinese hamster ovary (CHO) cells are predominant in the production of therapeutic proteins to treat various diseases. Characterization and investigation of CHO cell metabolism in a quick and simple way could boost process and cell line development. Therefore, a method to simultaneously detect seven redox- and energy-related metabolites in CHO cells by capillary electrophoresis has been developed. An on-line focusing technique was applied to improve the peak shape and resolution by using a 50 μm × 44 cm uncoated fused silica capillary. Key parameters and their interactions were investigated by design of experiments (DoE) and optimized conditions were determined by desirability function as follows: 24 °C, 95 mM, and pH 9.4 of BGE. The method was validated to ensure sensitivity, linearity, and reproducibility. The limits of detection (LODs) ranged from 0.050 to 0.688 mg/L for seven metabolites, and correlation coefficients of linearity were all greater than 0.996. The relative standard deviations (RSD) of migration time and peak area were smaller than 0.872% and 5.5%, respectively, except for NADPH, and the recoveries were between 97.5 and 101.2%. The method was successfully applied to analyze the extracts from CHO cells under two different culture conditions.
Graphical abstract
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高影响因子
WATER AIR AND SOIL POLLUTION
·
2019
·Vol. 230
·期 4
·1-13
·
IF 1.774
Liu Yong,Wang Gui,Yang Wenning,Yang Jie,Li Jia
Biotemplating method is a promising way to obtain hierarchical materials with unique morphology and property. In the current work, a novel hierarchically porous ZnAl-CLDH (calcined layered double hydroxides)/FeWO 4 had been successfully synthesized by a facile biotemplated method. The obtained samples were characterized in detail via FESEM-EDX, TEM, XRD, IR, TGA, and BET techniques. The as-synthesized ZnAl-CLDH/FeWO 4 hierarchical microspheres were composed of ZnAl-CLDH nanosheets and FeWO 4 nanoparticles. The obtained sample exhibited both high adsorption and visible-light photocatalytic activity toward Congo Red (CR) in water. It was found that the adsorption process was well described by the pseudo-second-order kinetic model and the Langmuir isotherm model, while the photocatalytic degradation process was well fitted to the first-order kinetics model. The enhanced photocatalytic performance was mainly due to the hierarchically porous structure that could offer more exposed active sites, as well as the unique energy band structure of heterostructures, that facilitated the efficient separation and transfer of photoinduced carriers and enhanced light harvesting. In addition, the as-prepared sample had quickly magnetic response and could be easily separated from water under an external magnetic field after wastewater treatment.
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Science China-Chemistry
·
2019
·Vol. 62
·期 6
·767-774
·
IF 6.085
Li Erpeng,Li Wenqin,Li Linchang,Zhang Hao,Shen Chao,Wu Zihua,Zhang Weiwei,Xu Xiaojia,Tian He,Zhu Wei-Hong,Wu Yongzhen
The development of p-i-n structured perovskite solar cells (PSCs) requires more extensive explorations on seeking efficient, low cost and stable hole transporting materials (HTMs). Small molecular HTMs are superior to polymeric ones in terms of synthetic reproducibility as well as purity. However, thin films composed of small molecules are usually labile during the solution-based perovskite deposition. Herein, we propose a molecular engineering strategy of incorporating oligothiophene as conjugation bridge to develop robust oligomer HTMs for p-i-n type PSCs. Upon increasing the oligothiophene chain length from α-bithiophene to α-quaterthiophene and α-hexathiophene, their HOMO energy levels remain unchanged, but their solubility in common organic solvents decreased remarkably, thus greatly enhancing their tolerance to the perovskite deposition. The rational design of oligothiophene chain length can effectively tune their optoelectronic properties as well as thin film stability under polar solvent soaking. The best performance is achieved by an α-quaterthiophene based HTM (QT), showing a high efficiency of 17.69% with fill factor of 0.81, which are comparable to those of a commercially available benchmark polymer HTM (poly[bis (4-phenyl)(2,4-dimethylphenyl) amine], PTAA) based devices fabricated under the same conditions. Our developed oligomer system not only provides the definite molecular structures like small molecule-type HTMs, but also exhibits the excellent film-forming like polymer-type HTMs, thus achieving the well-balanced parameters among solvent tolerance, thin film conductivity, and interfacial charge transfer efficiency, especially building up a platform to develop low cost and reproducible efficient HTMs in p-i-n structured perovskite solar cells.
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JOURNAL OF SOLUTION CHEMISTRY
·
2019
·Vol. 48
·期 1
·82-103
·
IF 1.039
Jin Jing,Shao Fangjun,Dong Hong,Wu Chuan
Densities and refractive indices are investigated for four binary mixture systems of dimethylvinylethoxysilane with n -heptane, n -octane, n -nonane and n -decane at different temperatures (298.15, 303.15, 308.15, 313.15 and 318.15 K) and atmospheric pressure. From these experimental data, the excess molar volume, isobaric coefficient of thermal expansion, deviation in refractive index, molar refraction, and deviation in the molar refraction have been calculated. The computed quantities have been fitted with the Redlich–Kister equation to derive the coefficients and estimate the standard deviations. The values of the partial excess volume at infinite dilution were calculated using the coefficients of the Redlich–Kister smoothing equation. The effects of composition and temperature on these properties are discussed.
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CATALYSIS LETTERS
·
2019
·Vol. 149
·期 2
·361-372
·
IF 2.372
Liu Yanan,Yang Zhao,Zhang Xinyi,He Yufei,Feng Junting,Li Dianqing
Abstract A series of CeO 2 with the morphology of nanocube (NC), nanopolyhedron (NP) and nanorod (NR) were synthesized by hydrothermal method as substrates to support monometallic Au catalysts. Insight into support morphology-dependent the property of active component and catalytic behavior for the selective hydrogenation of phenylacetylene has been performed. Specifically, nanocube ceria could disperse monometallic Au nanoparticles due to a large amount of low coordinated sites that readily generated the strong interaction for anchoring active metal, whereas the polyhedron and rod-like ceria supported Au nanoparticles possessed large size and wide particle distribution. As expected, well-dispersed and stable Au/CeO 2 nanocube demonstrated 83% of selectivity towards styrene when the conversion of phenylacetylene reached 90%, which was much higher than that of others. Preferable activity was mainly ascribed to small size of Au nanoparticles, which facilitated the adsorption/dissociation of hydrogen considered as the rate-determining step. Enhanced selectivity was due to the electronic effect that caused by strong interaction between Au and cubic CeO 2 , which also contributed to good stability. This work not only provides a facile method for the preparation of highly dispersed and efficient Au/CeO 2 catalysts by modulating the morphology of support, but also offers a novel idea for the fabrication of other highly dispersed supported metal catalysts with enhanced behavior in heterogeneous catalysis. Graphical Abstract
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