Scientific Reports
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2014
·Vol. 4
·期 1
·1-7
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IF 5.078
Parhira Supawadee,Zhu Guo-Yuan,Jiang Ren-Wang,Liu Liang,Bai Li-Ping,Jiang Zhi-Hong
Two stereoisomeric cardenolides, uscharin (1) and a new compound, 2′- epi -uscharin (2), were isolated from the latex of Calotropis gigantea (Asclepiadaceae). Their structures were fully elucidated based on their spectroscopic data, X-ray crystallographic data and chemical evidences. Both epimers (1 and 2) exhibited strong inhibitory effects on HIF-1 activity with different magnitudes. Compound 1 showed much more potent activity than 2 and digoxin, a well-known HIF-1 inhibitor. Discrepancy in potencies between 1 and 2 revealed the contribution of a β-configuration of 2′ hydroxyl moiety for HIF-1 inhibitory activity. This is a first report of the activity of HIF-1 inhibition of thiazoline ring-containing cardenolides.
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JOURNAL OF MOLECULAR LIQUIDS
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2014
·
IF 2.083
Jiayi Chen,Lingxiao Chen,Yueqing Lu,Yingjie Xu
Densities ( ρ ) and viscosities ( η ) of 1-methylimidazolium acetate ([Mim]Ac) protic ionic liquid + water mixture were measured at T = (293.15, 298.15, 303.15, 308.15 and 313.15) K under atmospheric pressure. Refractive indices ( n D ) and electrical conductivities ( κ ) of the above-mentioned system over the entire composition range were measured at 298.15 K. Excess molar volumes ( V E ), viscosity deviations (Δ η ) and refractive index deviations (Δ n D ) were obtained from the experimental data and fitted to the Redlich–Kister equation with satisfactory results. The results show that V E values of the system are negative over the whole composition range, whereas Δ η and Δ n D values are positive. Other volumetric properties such as apparent molar volumes ( V ϕi ), partial molar volumes ( V ¯ m , i ) and excess partial molar volumes ( V ¯ m , i E ) of the system were calculated from the density data. The concentration dependence of κ was fitted according to the empirical Casteel–Amis equation. The measured and derived properties were employed to investigate the intermolecular interactions of the system.
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FLUID PHASE EQUILIBRIA
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2015
·
IF 2.2
Yanni Du,Haiyang Wang,Shichao Du,Yan Wang,Cui Huang,Yujia Qin,Junbo Gong
In this study, the liquid–liquid phase separation and crystallization of vanillin from 1-propanol/water solution were investigated. It was found that water could contribute to the improvement of vanillin solubility in 1-propanol/water solution, but the solubility of vanillin decreased with the increasing water/1-propanol ratios, when the water content was over 30 wt.%. High water fraction in 1-propanol/water solvents will result in the liquid–liquid phase separation in the crystallization process , and the liquid–liquid phase separation dominated the process before the nucleation of crystals during the crystallization of vanillin. A ternary phase diagram (vanillin/1-propanol/water) including the solubility curves and the liquid–liquid phase separation curves was measured and could, in certain cases, clearly illustrate the liquid–liquid phase separation and crystallization process of vanillin in 1-propanol/water solutions. As shown in the ternary phase diagram, liquid–liquid phase separation under high initial vanillin concentration results in low purity of vanillin crystals due to the inhibited crystallization process by liquid–liquid phase separation. Partial phase immiscibility was a function of temperature and the range of immiscibility decreased with increasing temperature. Moreover, nucleation and crystal growth of vanillin in the presence of liquid–liquid phase separation were investigated; process parameters such as the composition of solvent, cooling profiles and seeding were optimized to avoid liquid–liquid phase separation and thus increase the purity of crystallization products.
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CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
Jiale Huang,Cheng Liu,Daohua Sun,Yingling Hong,Mingming Du,Tareque Odoom-Wubah,Weiping Fang,Qingbiao Li
Au/TS-1 catalysts prepared by an eco-friendly and economical bioreduction method were used for the liquid phase epoxidation of styrene to styrene oxide (SO) using aqueous hydrogen peroxide (H 2 O 2 ) as oxidant. The catalysts were characterized by a variety of techniques including FT-IR, DRUV–Vis, UV–Vis, N 2 physisorption, XRD, XPS, TG–DTG and TEM. The influence of various parameters (Au loading, calcination, solvents, oxidants, reaction temperature, reaction time and catalyst amount) on the catalytic performance was systematically investigated. The results showed that both the conversion of styrene and selectivity to SO were improved and enhanced when catalyzed by biosynthesized gold nanoparticles (GNPs) supported on TS-1. However, decomposing the Cacumen Platycladi ( CP ) biomass properly through calcinations can enhance the catalytic performance though it acted as reductant and protective agents during the catalysts preparation. Besides, the optimum catalytic activity and stability of bioreduction Au/TS-1 catalysts were obtained under operational conditions of Au loading of 1.0 wt.%, CP extract (10 g L −1 ) as reductant, calcined at 723 K for 2 h, reaction time of 10 h, reaction temperature of 333 K, catalyst amount of 500 mg, aqueous H 2 O 2 (30 wt.%) as oxidant and N,N-dimethylformamide as solvent. Under the optimal condition, styrene conversion of 92.7% and SO selectivity of 90.4% was achieved, which were comparable or even superior to those reported in the literatures. The catalyst was reused five times, without significant decrease in both the styrene conversion and SO selectivity.
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CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
C. Shen,Y.J. Wang,C. Dong,G.S. Luo
In this work, porous glass beads supported with TS-1 particles have been successfully prepared through in situ crystallization. TS-1 particles with uniform size and high crystallization are well dispersed on the surface of porous glass beads. As the support, porous glass beads exhibit the advantages of more manageable surface chemistry, better chemical and thermal stability, and larger specific surface area compared to that of conventional TS-1 films on flat or tubular supports. The experimental results show that the surface chemistry has profound influence on the morphology of TS-1 particles. The catalytic performance of the material was characterized with the reaction of ammoximation of cyclohexanone. Complete conversion was reached after 20 min in a stirred tank reactor with the selectivity of 100%. Compared with the commercial catalyst, the reaction rate was increased by 54 times. The prepared catalysts were packed in a bed reactor, and the effects of space time, content of catalyst, temperature and pressure were investigated. The conversion of 48.1% was reached by the catalyst with TS-1 loading of 0.183 wt.% at 353 K and the space time of only 1.57 min, and 100% recovery in catalytic activity after 5 cycles was demonstrated.
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JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2015
·Vol. 308
·期 3
·865-875
·
IF 1.034
Zhang Hui,Xue Jinhua,Hu Nan,Sun Jing,Ding Dexin,Wang Yongdong,Li Le
The adsorption of U(VI) from low concentration solution by HKUST-1@H 3 PW 12 O 40 was studied as a function of various experimental parameters including pH, interfering ions, contact time, initial uranium concentration and temperature by batch experiments. Equilibrium data were found to fit with Langmuir isotherm model better than Freundlich isotherm model. The kinetic adsorption was fitted by the pseudo-second-order model well. Thermodynamic data from the adsorption experiments indicate that adsorption process is spontaneous and endothermic. HKUST-1@H 3 PW 12 O 40 can selectively adsorb U(VI) from multi-metal ion solutions and the adsorption capacity of HKUST-1@H 3 PW 12 O 40 don’t decrease significantly after three cycles of desorption-reuse. The results show that HKUST-1@H 3 PW 12 O 40 is suitable for removal of U(VI) from low concentration solutions.
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JOURNAL OF CHEMICAL THERMODYNAMICS
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2015
·
IF 2.679
Hengde Li,Yongtao Han,Cheng Huang,Chufen Yang
On this paper, experimental (liquid + liquid) equilibrium (LLE) results are presented for systems composed of β-citronellol and aqueous 1-propanol or acetone. To evaluate the phase separation properties of β-citronellol in aqueous mixtures, LLE values for the ternary systems (water + 1-propanol + β-citronellol) and (water + acetone + β-citronellol) were determined with a tie-line method at T = (283.15, 298.15, and 313.15 ± 0.02) K and atmospheric pressure. The reliability of the experimental tie-lines was verified by the Hand and Bachman equations. Ternary phase diagrams, distribution ratios of 1-propanol and acetone in the mixtures are shown. The effect of the temperature on the ternary (liquid + liquid) equilibria was examined and discussed. The experimental LLE values were satisfactorily correlated by extended UNIQUAC and modified UNIQUAC models.
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RSC Advances
·
2015
·Vol. 5
·期 41
·32416-32420
·
IF 3.84
Kang Qin,Kai Wang,Yang Li,Fanhe Kong,Tao Wang
The phase behavior of the 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]) and carbon dioxide (CO2) system from atmospheric to supercritical state was investigated at 0.1–15.0 MPa and 308.15–343.15 K. The solubility data of CO2 in [emim][BF4] and the volumetric expansion ratios of CO2-saturated [emim][BF4] were provided. Experimental results indicated that although CO2 dissolved significantly in [emim][BF4] (from 0 to 62 mol%), the ionic liquid phase only had an expansion ratio less than 17 vol%. The density difference between CO2-saturated [emim][BF4] and pure [emim][BF4] was obvious at high pressure and low temperature, with a maximum of 16.11% at 308.15 K and 15.0 MPa. Based on the experimental results, a fitting equation applicable to precise data interpolation was proposed for the CO2-saturated [emim][BF4] density in this study.
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Metals
·
2025
·Vol. 15
·期 3
·299
·
IF 2.5
Feng Jiang,Shuai He,Wei Sun,Yuanjia Luo,Honghu Tang
The effective and environmental separation of chalcopyrite and molybdenite has long presented a challenge in mineral processing due to their similar floatability and close association at room temperature. This study explores the non-toxic 1-thioglycerol (1-TG) as a selective depressant for chalcopyrite–molybdenite flotation separation. An impressive separation effect was realized through single-mineral and mixed-mineral flotation experiments when using 1-TG as a depressant and kerosene as a collector. Contact angle measurements, zeta potential tests, and Fourier transform infrared spectroscopy (FT-IR) confirm the selective adsorption of 1-TG on the chalcopyrite surface, leading to enhanced surface hydrophilicity and the inhibition of collector adsorption. The depression mechanism is further elucidated through X-ray photoelectron spectroscopy (XPS), which demonstrates that it occurs via chemosorption between the thiol group in 1-TG and active iron sites on the chalcopyrite surface. These findings provide a potential efficient depressant for chalcopyrite–molybdenite flotation separation with low dosage, environmental friendliness, and human harmlessness.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Qiang Ma,Fan Li,Xianglong Zhang,Bowen Yang,Yingjie Zhang,Qingyuan Wang,Qihong Wu,Jin Huang,Jiming Hao
With the rapid development of ore refining, coal power plants, and mining, aqueous thallium pollution in natural waters has been reported over the past few decades. However, few thallium control technologies have been put into practice. In this study, a modified MOF adsorbent, MnO 2 @HKUST-1(MOH), was fabricated. Its chemical component shift, thermal stability, and microstructure changes during thallium adsorption were analyzed using TGA, XRD, XPS, and TEM-EDS techniques. The results showed a promising Tl + removal rate of over 90 %, and an adsorption capacity of 178.8 mg/g was obtained at a pH of 5 and a temperature of 293 K. The dynamic behavior of Tl + adsorption on MOH was simulated using power rate law expression (PRL), pseudo-first-order model (PFO), and pseudo-second-order model (PSO), which revealed a superior selection of Tl + among other competing heavy metal ions (Cr 3+ , Fe 3+ , Ca 2+ , Zn 2+ , and Cu 2+ ). The Tl + removal mechanism was further studied, which was mainly forced by surface adsorption/desorption. Based on its efficient Tl + removal rate, high adsorption capacity, promising regeneration property, and economical price, the MOH adsorbent has the potential to be a feasible option for smelting, ore refining, packaging, and testing wastewater treatment.
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Redox Biology
·
2024
·
IF 10.7
Liyong Huang,Xue Wang,Yanning Zheng,Dongcen Lang,Jian Wang,Shuaiguo Yan,Ying Chen
Subarachnoid hemorrhage (SAH), a devastating disease with a high mortality rate and poor outcomes, tightly associated with the dysregulation of iron metabolism and ferroptosis. (-)-Epigallocatechin-3-gallate (EGCG) is one of major bioactive compounds of tea catechin because of its well-known iron-chelating and antioxidative activities. However, the findings of iron-induced cell injuries after SAH remain controversial and the underlying therapeutic mechanisms of EGCG in ferroptosis is limited. Here, the ability of EGCG to inhibit iron-induced cell death following the alleviation of neurological function deficits was investigated by using in vivo SAH models. As expected, EGCG inhibited oxyhemoglobin (OxyHb)-induced the over-expression of HO-1, which mainly distributed in astrocytes and microglial cells. Subsequently, EGCG blocked ferrous iron accumulation through HO-1-mediated iron metabolic reprogramming. Therefore, oxidative stress and mitochondrial dysfunction was rescued by EGCG, which resulted in the downregulation of ferroptosis and ferritinophagy rather than apoptosis after SAH. As a result, EGCG exerted the superior therapeutic effects in the maintenance of iron homeostasis in glial cells, such as astrocytes and microglial cells, as well as in the improvement of functional outcomes after SAH. These findings highlighted that glial cells were not only the iron-rich cells in the brain but also susceptible to ferroptosis and ferritinophagy after SAH. The detrimental role of HO-1-mediated ferroptosis in glial cells can be regarded as an effective therapeutic target of EGCG in the prevention and treatment of SAH.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Rui Li,Shuangjun Li,Luyang Zuo,Xiangping Xiao,Huitao Fan,Bo Li,Liya Wang
The spatial segmentation of photogenerated carriers is crucial for achieving efficient photocatalytic H 2 production (PHP) rates in photocatalyst. Design studies of crystalline catalyst facets and selective morphology control can facilitate the development of catalysts that expose more advantageous active facets. Herein, Cu 2 WS 4 /ZnIn 2 S 4 composites are constructed by growing ZnIn 2 S 4 nanosheets in situ on Cu 2 WS 4 with largely exposed {0 0 1} surface. Experiments and density functional theory calculations demonstrate that the electrons of ZnIn 2 S 4 flowed to the {0 0 1} surface of Cu 2 WS 4 , and the holes vectorially migrated to the {1 0 1} surface, during the reaction process, resulting in efficient spatial separation of the photogenerated carriers. The Cu 2 WS 4 /ZnIn 2 S 4 achieves a PHP rate of 23.67 mmol g −1 h −1 , 13.44-fold increase compared with pure ZnIn 2 S 4 . This report combines the advantages of the high-energy activity of the Cu 2 WS 4 {0 0 1} surface to morphologically control the ratio of the {0 0 1}/{1 0 1} surfaces so that ZnIn 2 S 4 can contact a larger area of the {0 0 1} surface. Furthermore, under the influence of crystallographic effects on the {0 0 1} and {1 0 1} surfaces, electrons and holes of ZnIn 2 S 4 are transferred to different crystalline facets, promoting the redox reaction. This paper provides effective ideas for the rational design of photocatalysts with efficient carrier space separation.
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