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Methylcyclopentenyl cation mediated reaction route in methanol-to-olefins reaction over H-RUB-50 with small cavity

Journal of Energy Chemistry 2020年第6期29卷 25-30,I0002页

作者： Wenna Zhang Shutao Xu Yuchun Zhi Yingxu Wei Zhongmin Liu National Engineering Laboratory for Methanol to Olefins State Energy Low Carbon Catalysis and Engineering R&D CenterDalian National Laboratory for Clean EnergyiChEM(Collaborative Innovation Center of Chemistry for Energy Materials)Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

Methylcyclopentenyl cations(MCP+)have been regarded as active intermediates during methanol conversion,however,their function mode in the reaction are still uncertain.In our recent report,trimethylcyclopentenyl cation(triMCP+)and its deprotonated counterpart(trimethylcyclopentadiene,tri MCP)were directly captured on H-RUB-50 catalyst with small cavity by the aid of in situ 13C MAS NMR spectroscopy,and their higher catalytic reactivity were clarified by 12C/13C-CH3OH isotopic switch experiment.In this contribution,an alternative route-cyclopentadienes-based cycle was applied on methanol conversion catalyzed on the H-RUB-50,in which ethene was produced with the participation of tri MCP+as critical intermediate.Then the cyclopentadienes-based cycle was predicted to be energetically favorable for ethene formation by density functional theory(DFT)calculations.The energetic comparison of paring mechanism in the aromatics-based cycle and cyclopentadienes-based cycle with the involvements of trimethylcyclopentadienyl(tri MCPdi+)and tri MCP+as the corresponding active intermediates suggests that cyclopentadienes-based cycle is a feasible route for ethene formation.Furthermore,this work highlights the importance of the steric constraint and the host-guest interaction induced by the zeolite with cavity structure in the formation of intermediates and reaction pathway.

关键词： Methanol to olefins H-RUB-50 Methylcyclopentenyl cation Cyclopentadienes-based cycle

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An in vitro study on interaction of anisodine and monocrotaline with organic cation transporters of the SLC22 and SLC47 families

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Chinese Journal of Natural Medicines 2019年第7期17卷 490-497页

作者： CHEN Jia-Yin Jürgen Brockmoller Mladen V.Tzvetkov WANG Li-Jun CHEN Xi-Jing Department of Pharmacy Peking University Shenzhen Hospital Shenzhen 518036 China Institute for Clinical Pharmacology University Medical Center Gottingen Georg-August University Gottingen 37075 Germany Clinical Pharmacokinetics Lab China Pharmaceutical University Nanjing 211198 China

Current study systematically investigated the interaction of two alkaloids, anisodine and monocrotaline, with organic cation transporter OCT1, 2, 3, MATE1 and MATE2-K by using in vitro stably transfected HEK293 cells. Both anisodine and monocrotaline inhibited the OCTs and MATE transporters. The lowest IC50 was 12.9 μmol·L-1 of anisodine on OCT1 and the highest was 1.8 mmol·L-1 of monocrotaline on OCT2. Anisodine was a substrate of OCT2(Km = 13.3 ± 2.6 μmol·L-1 and Vmax = 286.8 ± 53.6 pmol/mg protein/min). Monocrotaline was determined to be a substrate of both OCT1(Km = 109.1 ± 17.8 μmol·L^-1, Vmax = 576.5 ± 87.5 pmol/mg protein/min) and OCT2(Km = 64.7 ± 14.8 μmol·L^-1, Vmax = 180.7 ± 22.0 pmol/mg protein/min), other than OCT3 and MATE transporters. The results indicated that OCT2 may be important for renal elimination of anisodine and OCT1 was responsible for monocrotaline uptake into liver. However neither MATE1 nor MATE2-K could facilitate transcellular transport of anisodine and monocrotaline. Accumulation of these drugs in the organs with high OCT1 expression(liver) and OCT2 expression(kidney) may be expected.

关键词： Anisodine Monocrotaline Organic cation transporter OCT MATE

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Adsorption equilibrium, kinetics, and dynamic separation of Ca2+ and Mg2+ ions from phosphoric acid–nitric acid aqueous solution by strong acid cation resin

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Chinese Journal of Chemical Engineering 2019年第12期27卷 2930-2936页

作者： Rui Lü Qing Xi Tan Li Rui Li Xiaochao Zhang Jianxin Liu Caimei Fan Junqiang Feng Lingyun Zhang ZhihuaWang College of Chemistry and Chemical Engineering Taiyuan University of TechnologyTaiyuan 030024China Shenzhen Batian Ecological Engineering Co.Ltd. Shenzhen 518057China Tianji Coal Chemical Group Co.Ltd. Changzhi 047507China

The separation of Ca2+and Mg2+ions from phosphoric acid-nitric acid aqueous solution is very significant for the neutralization process of nitrophosphate fertilizer.This paper studied the adsorption equilibrium,kinetics,and dynamic separation of Ca2+and Mg2+ions by strong acid cation resin,and the effects of phosphoric acid and nitric acid on the adsorption process were investigated.The results reveal that the adsorption process of Ca2+and Mg2+ions in pure water on resin is in good agreement with the Langmuir isotherm model and their maximal adsorption capacities are 1.86 mmol·g-1 and 1.83 mmol·g-1,respectively.The adsorption kinetics of Ca2+and Mg2+ions on resin fits better with the pseudo-first-order model,and the adsorption equilibrium in pure water is reached within 10 min contact time,while at the present of phosphoric acid,the adsorption rate of Ca2+and Mg2+ions on resin will go down.The dynamic separation experiments demonstrate that the designed column adsorption is able to undertake the separation of metal ions from the mix acids aqueous solution,but the dynamic operation should control the flow rate of mix acid solution.Besides nitric acid solution was proved to be effective to completely regenerate the spent resin and achieve the recyclable operation of separation process.

关键词： Ca2+and Mg2+ions Strong acid cation resin Adsorption equilibrium Kinetics Dynamic separation

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Mechanism and kinetics study on removal of Iron from phosphoric acid by cation exchange resin

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Chinese Journal of Chemical Engineering 2019年第5期27卷 1050-1057页

作者： Xinke Leng Yanjun Zhong Dehua Xu Xinlong Wang Lin Yang School of Chemical Engineering Sichuan University

Iron element is one of the main impurities in wet-process phosphoric acid and it has a significant impact on the subsequent phosphorus chemical products. This paper studied the feasibility of using Sinco-430 cation exchange resin for iron removal from phosphoric acid. The specific surface area and the total exchange capacity of resin were 8.91 m2·g-1 and 5.18 mmol·g-1, respectively. The sorption mechanism was determined by FTIR and XPS and the results indicated that iron was combined with-SO3 H in resin. The removal process was studied as a function of temperature, H3 PO4 content and mass ratio between resin and solution. The unit mass of resin to remove iron was 0.058 g·g-1 resin when the operating parameters were T = 50 ℃, H3 PO4 content = 27.61 wt%and S/L = 0.1, respectively. Kinetics study demonstrated that pseudo-second-order reaction model fits this study best and the calculated activation energy of overall reaction is 29.10 kJ·mol-1. The overall reaction process was mainly controlled by pore diffusion.

关键词： Purification of wet-process phosphoric acid cation exchange resin Kinetics models Diffusion models

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Radical cation Diels-Alder Reactions of Non-Conjugated Alkenes as Dienophiles by Electrocatalysis

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Chinese Journal of Chemistry 2019年第6期37卷 561-564页

作者： Atsushi Ozaki Yusuke Yamaguchi Yohei Okada Kazuhiro Chiba Department of Applied Biological Science Tokyo University of Agriculture and Technology3-5-8 Saiwai-choFuchuTokyo 183-8509Japan Department of Chemical Engineering Tokyo University of Agriculture and Technology2-24-16 Naka-choKoganeiTokyo 184-8588Japan

Radical cation Diels-Alder reactions provide a powerful method for the construction of six-membered ring systems between both electron-rich dienes and dienophiles. However, the most recent examples of this class have been limited to β-methylstyrenes as dienophiles;the use of non-conjugated alkenes remains challenging. The present study describes the serendipitous development of novel radical cation Diels-Alder reactions by electrocatalysis that use non-conjugated alkenes as dienophiles. The key to successful transformation involves highly substituted cyclohexenyl radical cations that are stable enough to be reduced by intermolecular single electron transfer.

关键词： radical cation Diels-Alder reaction non-conjugated alkene electrochemistry single electron transfer

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Equilibria between the K^+ binding and cation vacancy conformations of potassium channels

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Protein & Cell 2019年第7期10卷 533-537页

作者： Yao He Bo Zhang Hao Dong Penglin Xu Xiaoying Cai Ting Zhou Mu Yu Jun Liang Xiao Zheng Changlin Tian Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences University of Science and Technology of China Hefei 230027 China Kuang Yaming Honors School and Institute for Brain Sciences Nanjing University Nanjing 210023 China Hefei National Laboratory for Physical Sciences at the Microscale and School of Chemistry and Material Sciences University of Science and Technology of China Hefei 230026 China

Dear Editor, Potassium channels are integral membrane proteins that selectively con duct K^+ ions across cell membra ne (Hille, 2001). They play essential roles in maintaining cellular ionic homoeostasis and generating action membrane potentials in excitable cells. The mechanism of K^+ selectivity has been evaluated in many biophysical and physiological studies (Zhou et al., 2001;Liu et al., 2015;Schewe et al., 2016). A highly con served signature seque nee, TVGYG, in the selectivity filter of potassium channels (e.g., KcsA) is known to coordinate K^+ ions (Zhou et al., 2001). Carbonyls of these residues point toward the pore, forming four continuous ion binding sites (S1-S4) and resulting in higher selectivity for K^+ over Na^+(Zhou et al., 2001). The NaK channel from Bacillus cereus is a norvselective cation channel that shares high structural homology with KcsA (Shi et al., 2006). Owing to a distinctive primary sequenee of 63TVGDG67, the selectivity filter of NaK preserves only two ion binding sites, allocated similarly as S3 and S4 in KcsA (Alam and Jiang, 2009a, b). Remarkably, the D66Y and N68D double mutations of NaK channel (Fig. S1) transform it into a K^+ selective channel (termed as NaK2K)(Sauer et al., 2013). Crystal structure of NaK and NaK2K have revealed distinet binding coordination of Na^+ and K^+ ions in their selectivity filter (Figs. S2 and S3)(Alam and Jiang, 2009a, b;Sauer et al., 2013). However, dynamics of the NaK and NaK2K selectivity filter with the bind泊g of Na+ or K^+ are still elusive. Especially, it has been known that the membrane environment is highly diverse from deterge nt micelles, which was con sidered to in flue nee the structure and functi on of membrane protei ns dramatically (Cross et al., 2011). Thus, it is necessary to study the cation and binding properties of NaK NaK2K channels in lipid bilayers.

关键词： Equilibria K^+binding cation vacancy conformations

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Monovalent cation perm-selective membranes(MCPMs)"New developments and perspectives

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Chinese Journal of Chemical Engineering 2017年第11期25卷 1606-1615页

作者： Liang Ge Bin Wu Dongbo Yu Abhishek N.Mondal Linxiao Hou Noor U1 Afsar Qiuhua Li Tingting Xu Jibin Miao Tongwen Xu CAS Key Laboratory of Soft Matter Chemistry Collaborative Innovation Center of Chemistry for Energy MaterialsSchool of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026China

As one of the most typical and promising membrane processes, electrodialysis(ED) technique plays a more and more significant role in industrial separation. Especially, the separation of monovalent cations and multivalent cations is currently a hot topic, which is not only desirable for many industries but also challenging for academic explorations. The main aim of the present contribution is to view the advances of a wide variety of monovalent cation perm-selective membranes(MCPMs) and their preparation technologies including(1) covalent crosslinking,(2) surface modification,(3) polymer blending,(4) electrospinning,(5) nanofiltration alike membrane,and(6) organic–inorganic hybrid. The relevant advantages and disadvantages with respect to some specific cases have been discussed and compared in detail. Furthermore, we elaborately discuss the opportunities and challenges of MCPMs, the fabricating strategies to take and the future perspectives.

关键词： Ion exchange membranes Monovalrnt cation perm-selective membranes Electrodialysis Ion separation Electro- nanofiltr ation

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Challenges in Cardiovascular Risk Prediction and Stratifi cation in Women

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Cardiovascular Innovations and Applications 2019年第B02期3卷 329-348页

作者： Sonia Henry,MD Rachel Bond,MD Stacey Rosen,MD Cindy Grines,MD Jennifer Mieres,MD Northwell Health Department of CardiologyNorthshore University HospitalHofstra School of Medicine300 Community DriveManhassetNY 11030USA Northwell Health Department of CardiologyHofstra North Shore-LIJ School of MedicineLenox Hill Hospital110 E.59th StreetSuite 8ANew YorkNY 10022USA Northwell Health Department of CardiologyHofstra School of MedicineThe Katz Institute for Women’s Health1981 Marcus AvenueSuite E110Lake SuccessNY 11042USA Hofstra School of Medicine Northwell Health1979 Marcus Avenue Suite 236Lake SuccessNY 11042USA

There has been an appropriate focus,since the turn of the 21 st century,on sex-and gender-specifi c cardiovascular disease(CVD)as increasing evidence suggests that there are substantial differences in the risk factor profi le,social and environmental factors,clinical presentation,diagnosis,and treatment of ischemic heart disease in women compared with men.As a result of increased awareness,detection,and treatment of ischemic heart disease in women,there has been signifi cant reduction(greater than 30%)in cardiovascular mortality,and in 2013,more US men than US women died of CVD.Nevertheless,continued efforts are required as CVD remains the leading cause of cardiovascular morbidity and death of women in the Western world,and in women younger than 55 years there has been a rise in cardiovascular mortality.In this article,we review several of the contributing factors that continue to cause challenges in accurate risk prediction and risk stratifi cation in women.

关键词： sex and gender disparity risk prediction risk stratifi cation ischemic heart disease

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Effect of ivabradine on hyperpolarization activated cation current in canine pulmonary vein sleeve cardiomyocytes with atrial fibrillation

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Journal of Geriatric Cardiology 2008年第1期5卷 39-42页

作者： Yang Li Yan Huang Zongbin Li Hao Wang Jianguo Song Yuqi Liu Lei Gao Shiwen Wang Institute of Geriatric Cardiology Chinese PLA General HospitalBeijing 100853china Institute ofCardiologythe First affilated HospitalXinjiang Medical UniversityUrumqi 830054china Institute of Geriatric CardiologyChinese PLA General HospitalBeijing 100853china Institute of Geriatric CardiologyChinese PLA General HospitalBeijing 100853china Institute ofCardiologythe First affilated HospitalXinjiang Medical UniversityUrumqi 830054china Institute of Geriatric CardiologyChinese PLA General HospitalBeijing 100853china Institute of Geriatric CardiologyChinese PLA General HospitalBeijing 100853china Institute of Geriatric CardiologyChinese PLA General HospitalBeijing 100853china

Objective To study the effect of ivabradine on hyperpolarization activated cation current in canine pulmonary vein(PY) sleeve cardiomyocytes with atrial fibrillation.Methods Dissociation of PVs yielded single cardiomyocytes from a Landengorff column without or with pacemaker activity from long-term rapidly atrial pacing (RAP) canines.If current was measured with the whole-cell patch-clamp technique.Results Compared with the control group,the rapidly atrial pacing canine PV cardiomyocytes had spontaneous diastolic depolarization and had larger If densities.Ivabradine (Iva,1 μM),a selective inhibitor of the If current,markedly reduced If currents in the RAP from -2.66±0.4 pA/pF to -1.58±0.1 pA/pF at the test potential of-120 mV (P＜0.01,n=12).Inhibition effect of Iva of If current showed concentration-dependent range from 0.1 to 10.0μM,with IC50 of 2.2 μ M ( 1.8-2.9 μM,95% CL).Furthermore,V1/ of steady-state activated curve was shifted from -84.3±4.9 mV to -106.9±3.4 mV and k value of steady-state activated curve was changed from 12.1+2.6 mV to 9.9±3.4 mV by the application of.1.0 μM Iva ( P＜0.01,n=12).Conclusions Our study revealed that Ivarbadine may significantly decrease If of rapidly atrial pacing pulmonary vein sleeve ceUs with atrial fibdllation.(J Geriatr Cardiol 2008;5:39-42)

关键词： ivarbadine hyperpolarization activated cation anine pulmonary vein sleeves atrial fibrillation

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Separation of Clay Minerals from Host Sediments Using cation Exchange Resins

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Chinese Journal Of Geochemistry 2003年第4期22卷 337-344页

作者： I.S.Ismael H.M.Baioumy Faculty of Education Suez Canal UniversityCentral Metallurgical Research and Development Institute Suez Egypt 87Helwan Cairo Egypt

Classic physical and chemical treatments applied to separating clay minerals from the host sediments are often difficult or aggressive for clay minerals. A technique using cation exchange resins (amberlite IRC\|50H and amberlite IR\|120) is used to separate clay minerals from the host sediments. The technique is based on the exchange of cations in the minerals that may be associated clay minerals in sediments, such as Ca and Mg from dolomite; Ca from calcite, gypsum and francolite with cations carried by resin radicals. The associated minerals such as gypsum, calcite, dolomite and francolite are removed in descending order. Separation of clay minerals using cation exchange resins is less aggressive than that by other classic treatments. The efficiency of amberlite IRC\|50H in the removal of associated minerals is greater than that of amberlite IR\|120.

关键词： clay mineral host sediment cation exchange resin Experimental technique separate

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