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氧化石墨烯 2

Al-Cr203体系 1

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A mini review on chemical fixation of CO 2 : Absorption and catalytic conversion into cyclic carbonates

Weili DAI, Chaktong AU, Shenglian LUO, Shuangfeng YIN,

《化学科学与工程前沿(英文)》 2010年 第4卷 第2期   页码 163-171 doi: 10.1007/s11705-009-0235-0

摘要: In this article, we present our research results on chemical fixation of CO using organobismuth compounds. We fabricated bismuth biphenoate complex, Zn-Mg-Al composite oxides, and SBA-15 or Al-SBA-15 immobilized hydroxyl ionic liquid for CO cycloaddition onto epoxides. The hypervalent bismuth compounds show good ability for association and dissociation with CO. The bismuth biphenolate complexes are catalytically effective for the cycloaddition reaction. The heterogeneous catalysts, viz. Zn-Mg-Al oxides and SBA-15 or Al-SBA-15 immobilized ionic liquid, are efficient for the synthesis of cyclic carbonate from CO and epoxide. It is found that the presence of a trace amount of water can improve the catalytic activity of the immobilized ionic liquid.

关键词: SBA-15     CO cycloaddition     Al-SBA-15 immobilized     CO     dissociation    

Asymmetric transfer hydrogenation of prochiral ketone catalyzed over Fe-CS/SBA-15 catalyst

XUE Ping, WU Tao

《化学科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 251-255 doi: 10.1007/s11705-007-0045-1

摘要: A heterogeneous chiral catalyst Fe(III)-CS (chitosan) complex/mesoporous molecular sieve SBA-15 (Santa Barbara Amorphous) was prepared. The asymmetric transfer hydrogenations of prochiral acetophenone and 4-methyl-2-pentanone to corresponding chiral alcohols were carried out on Fe-CS/SBA-15 at atmosphere pressure using 2-propanol as hydrogen donor. Effects of Fe content in catalyst, reaction temperature, reaction time and promoter KOH concentration on the conversion of substrates and enantioselectivity were investigated. Fe-CS/SBA-15 with 2.2% mass fraction Fe exhibits considerable enantioselectivity and catalytic activity for the asymmetric transfer hydrogenations of aromatic ketone and aliphatic ketone. Under optimal reaction conditions: KOH concentration 0.03 mol/L, reaction temperature 70ºC and reaction time 4 h, enantiomer excess (ee) of ()-1-phenylethanol and conversion of acetophenone can reach 87.4% and 27.7%, respectively. Under the above KOH concentration and reaction temperature and reaction time of 8 h, the ee of ()-4-methyl-2-pentanol and conversion 4-methyl-2-pentanone amounted to 50.2% and 25.5%, respectively.

关键词: asymmetric transfer     enantioselectivity     Fe-CS/SBA-15     aliphatic     aromatic    

Enhanced desulfurization performance of hybrid membranes using embedded hierarchical porous SBA-15

Ye Zhang, Jian Song, Josue Quispe Mayta, Fusheng Pan, Xue Gao, Mei Li, Yimeng Song, Meidi Wang, Xingzhong Cao, Zhongyi Jiang

《化学科学与工程前沿(英文)》 2020年 第14卷 第4期   页码 661-672 doi: 10.1007/s11705-019-1830-3

摘要: The utilization of materials with a hierarchical porous structure as multi-functional additives is highly attractive in the preparation of hybrid membranes. In this study, novel hybrid membranes are designed by embedding hierarchical porous Santa Barbara Amorphous 15 (SBA-15) with a dual-pore architecture (micropores and mesopores) for pervaporation desulfurization. The SBA-15 with cylindrical mesopores provides molecular transport expressways to ensure improved permeability, while micropores on the wall have molecular sieving effects that are essential for the enhancement of permselectivity of thiophene molecules. Considering thiophene/ -octane mixture as a model system, the hybrid membrane with embedded 6 wt-% SBA-15 exhibits optimal pervaporation desulfurization performance with a permeation flux of 22.07 kg·m ·h and an enrichment factor of 6.76. Moreover, the detailed structure and properties of hybrid membranes are systematically characterized. This study demonstrates the immense potential of hierarchical porous materials as additives in membranes to simultaneously increase permeability and permselectivity.

关键词: hybrid membranes     hierarchical porous SBA-15     sieving effect     pervaporation     desulfurization    

Oxidation-extraction desulfurization of model oil over Zr-ZSM-5/SBA-15 and kinetic study

Chuanzhu LU,Hui FU,Huipeng LI,Hua ZHAO,Tianfeng CAI

《化学科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 203-211 doi: 10.1007/s11705-014-1420-3

摘要: ZSM-5/SBA-15 composite molecular sieves were synthesized using post-synthesis method and characterized by X-ray diffraction and N adsorption-desorption. The oxidative-extration desulfurization of model oil was investigated by using hydrogen peroxide as the oxidant, tetrabutyl ammonium bromide as phase transfer catalyst, dimethyl sulfoxide as extractant, and Zr-ZSM-5/SBA-15, Ag-ZSM-5/SBA-15, Ce-ZSM-5/SBA-15 as catalyst. Under the optimal conditions, the desulfurization rate decreases in the order: Zr-ZSM-5/SBA-15>Ce-ZSM-5/SBA-15>Ag-ZSM-5/SBA-15. The highest desulfurization rate is 84.53% under the catalysis of Zr-ZSM-5/SBA-15. Kinetics analysis shows that the reaction is pseudo-first-order with the activation energy of 44.23 kJ/mol.

关键词: composite molecular sieve     oxidation desulfuration     extraction     kinetic    

Covalent triazine framework with efficient photocatalytic activity in aqueous and solid media

Cyrine Ayed, Wei Huang, Kai A. I. Zhang

《化学科学与工程前沿(英文)》 2020年 第14卷 第3期   页码 397-404 doi: 10.1007/s11705-019-1884-2

摘要: Covalent triazine frameworks (CTFs) have been recently employed for visible light-driven photocatalysis due to their unique optical and electronic properties. However, the usually highly hydrophobic nature of CTFs, which originates from their overall aromatic backbone, leads to limitations of CTFs for applications in aqueous media. In this study, we aim to extend the range of the application media of CTFs and design hybrid material of a CTF and mesoporous silica (SBA-15) for efficient photocatalysis in aqueous medium. A thiophene-containing CTF was directly synthesized in mesopores of SBA-15. Due to the high surface area and the added hydrophilic properties by silica, the hybrid material demonstrated excellent adsorption of organic molecules in water. This leads not only to high photocatalytic performance of the hybrid material for the degradation of organic dyes in water, but also for efficient photocatalysis in solvent-free and solid state. Furthermore, the reusability, stability and easy recovery of the hybrid material offers promising metal-free heterogeneous photocatalyst for broader applications in different reaction media.

关键词: photocatalysis     covalent triazine framework     aqueous medium     SBA-15     solid state    

Immobilized

Pei MA, Dan ZHANG

《环境科学与工程前沿(英文)》 2012年 第6卷 第4期   页码 498-508 doi: 10.1007/s11783-012-0429-4

摘要: To investigate the potential use of ( ) residue for Cd adsorption, poly alcohol Na alginate (PVA) was applied to immobilize it. The parameters including contact time, pH, adsorbent dosages, and coexisting metal ions were studied. The suitable pH for immobilized was 4–7 wider than that for raw (pH 6–7). In the presence of Pb concentration varying from 0 to 30 mg·L , the Cd adsorption ratios declined by 6.71% and 47.45% for immobilized and raw , respectively. While, with the coexisting ion Cu concentration varied from 0 to 30 mg·L , the Cd adsorption ratios declined by 12.97% and 50.56% for immobilized and raw , respectively. The Cd adsorption isotherms in single–metal and dual-metal solutions were analyzed by using Langmuir, Freundlich, and Dubinin–Radushkevich models. The Cd adsorption capacities ( ) in single-metal solution were 6.448 mg·L and 2.832 mg·L for immobilized and raw , respectively. The of immobilized were 1.850 mg Cd·g in Cd + Pb solution and 3.961 mg Cd·g in Cd + Cu solution, respectively. The Cd adsorption processes subjected to both adsorbents follow pseudo-second-order model. Mechanism study showed the functional group of was –OH, –NH, –CO, and PVA played an important role in metal adsorbing. Mining wastewater treatment test showed that PVA–SA-immobilized was effective in mixed pollutant treatment even for wastewater containing metal ions in very low concentration.

关键词: immobilization     Lentinus edodes residue     competitive adsorption     isotherm    

Characterization and catalytic properties of mesoporous CuO/SBA-16 prepared by different impregnation

DONG Yongli, YUAN Fulong, ZHU Yujun, ZHAO Lina, CAI Zhicheng

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 150-154 doi: 10.1007/s11705-008-0036-x

摘要: CuO/SBA-16 catalysts were prepared by two different routes – the conventional impregnation method and the modified impregnation method with pH adjustment. These catalysts were characterized by X-ray diffraction (XRD), atomic absorption spectrometry (AAS), N physisorption and hydrogen temperature programmed reduction (H-TPR) measurements which reveal that the cubic cage-like () pore structure of the parent SBA-16 molecule sieves was well maintained throughout the synthesis. After introduction of Cu, a different CuO dispersion exists on these catalysts. The CuO/SBA-16 prepared by modified impregnation method has a single highly dispersed CuO which is considered as a highly efficient species for hydroxylation of phenol with HO. CuO/SBA-16 prepared by the conventional impregnation method shows the presence of bulk CuO species which is undesirable for this reaction.

关键词: different     CuO/SBA-16     temperature     physisorption     introduction    

Degradation of bisphenol A by microorganisms immobilized on polyvinyl alcohol microspheres

Xue BAI, Hanchang SHI, Zhengfang YE, Qiujin SUN, Qing WANG, Zhongyou WANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第6期   页码 844-850 doi: 10.1007/s11783-013-0487-2

摘要: In this study, microorganisms (named B111) were immobilized on polyvinyl alcohol microspheres prepared by the inverse suspension crosslinked method. The biodegradation of bisphenol A (BPA) and 4-hydroxybenzaldehyde, a degradation product of BPA, by free and immobilized B111 was investigated. The BPA degradation studies were carried out at initial BPA concentrations ranging from 25 to 150 mg·L . The affinity constant K and maximum degradation rate were 98.3 mg·L and 19.7 mg·mg VSS·d for free B111, as well as 87.2 mg·L and 21.1 mg·mg VSS·d for immobilized B111, respectively. 16S rDNA gene sequence analyses confirmed that the dominant genera were and for BPA biodegradation in microorganisms B111.

关键词: bisphenol A     polyvinyl alcohol     immobilized microorganisms     4-hydroxybenzaldehyde    

Mercury removal and recovery by immobilized

Meifang CHIEN, Ryo NAKAHATA, Tetsuya ONO, Keisuke MIYAUCHI, Ginro ENDO

《化学科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 192-197 doi: 10.1007/s11705-012-1284-3

摘要: From several mercury removing microorganisms, we selected MB1, which is non-pathogenic, broad-spectrum mercury resistant, mercuric ion reducing, heat tolerant, and spore-forming, as a useful bacterium for bioremediation of mercury pollution. In this study, mercury removal performance of the immobilized MB1 was investigated to develop safe, efficient and stable catalytic bio-agent for mercury bioremediation. The results showed that the alginate gel immobilized MB1 cells efficiently removed 80% of mercury from the solution containing 10 mg/L mercuric chloride within 24 h. These cells still had high activity of mercury removal even after mercuric ion loading was repeated for nine times. The analysis of mercury contents of the alginate beads with and without immobilized MB1 suggested that a large portion of reduced metallic mercury was trapped in the gel beads. It was concluded that the alginate gel immobilized MB1 cells have potential to remove and recover mercury from mercury-containing water.

关键词: mercury removal     immobilized bacteria     alginate gel     bioremediation    

GDF15 negatively regulates chemosensitivity via TGFBR2-AKT pathway-dependent metabolism in esophageal

《医学前沿(英文)》 2023年 第17卷 第1期   页码 119-131 doi: 10.1007/s11684-022-0949-7

摘要: Treating patients with esophageal squamous cell carcinoma (ESCC) is challenging due to the high chemoresistance. Growth differentiation factor 15 (GDF15) is crucial in the development of various types of tumors and negatively related to the prognosis of ESCC patients according to our previous research. In this study, the link between GDF15 and chemotherapy resistance in ESCC was further explored. The relationship between GDF15 and the chemotherapy response was investigated through in vitro and in vivo studies. ESCC patients with high levels of GDF15 expression showed an inferior chemotherapeutic response. GDF15 improved the tolerance of ESCC cell lines to low-dose cisplatin by regulating AKT phosphorylation via TGFBR2. Through an in vivo study, we further validated that the anti-GDF15 antibody improved the tumor inhibition effect of cisplatin. Metabolomics showed that GDF15 could alter cellular metabolism and enhance the expression of UGT1A. AKT and TGFBR2 inhibition resulted in the reversal of the GDF15-induced expression of UGT1A, indicating that TGFBR2-AKT pathway-dependent metabolic pathways were involved in the resistance of ESCC cells to cisplatin. The present investigation suggests that a high level of GDF15 expression leads to ESCC chemoresistance and that GDF15 can be targeted during chemotherapy, resulting in beneficial therapeutic outcomes.

关键词: GDF15     esophageal squamous cell carcinoma     chemoresistance     cellular metabolism     TGFBR2     AKT    

Enhanced methane production during long-term UASB operation at high organic loads as enabled by the immobilized

《环境科学与工程前沿(英文)》 2022年 第16卷 第6期 doi: 10.1007/s11783-021-1505-4

摘要:

• Fungi enable the constant UASB operation even at OLR of 25.0 kg/(m3×d).

关键词: Anaerobic digestion     Fungi     Methane production     High OLR     Microbial community    

Beneficial metabolic activities of inflammatory cytokine interleukin 15 in obesity and type 2 diabetes

null

《医学前沿(英文)》 2015年 第9卷 第2期   页码 139-145 doi: 10.1007/s11684-015-0377-z

摘要:

In obesity, chronic inflammation is believed to induce insulin resistance and impairs adipose tissue function. Although this view is supported by a large body of literature, it has been challenged by growing evidence that pro-inflammatory cytokines may favor insulin sensitivity through induction of energy expenditure. In this review article, interleukin 15 (IL-15) is used as a new example to explain the beneficial effects of the pro-inflammatory cytokines. IL-15 is secreted by multiple types of cells including macrophages, neutrophils and skeletal muscle cells. IL-15 expression is induced in immune cells by endotoxin and in muscle cells by physical exercise. Its transcription is induced by transcription factor NF-κB. IL-15 binds to its receptor that contains three different subunits (α, β and γ) to activate JAK/STAT, PI3K/Akt, IKK/NF-κB and JNK/AP1 pathways in cells. In the regulation of metabolism, IL-15 reduces weight gain without inhibiting food intake in rodents. IL-15 suppresses lipogenesis, stimulates brown fat function, improves insulin sensitivity through weight loss and energy expenditure. In human, circulating IL-15 is negatively associated with body weight. In the immune system, IL-15 stimulates proliferation and differentiation of T cells, NK cells, monocytes and neutrophils. In the anti-obesity effects of IL-15, T cells and NK cells are not required, but leptin receptor is required. In summary, evidence from human and rodents supports that the pro-inflammatory cytokine IL-15 may enhance energy expenditure to protect the body from obesity and type 2 diabetes. The mechanism of IL-15 action remains to be fully uncovered in the regulation of energy expenditure.

关键词: inflammation     obesity     cytokine     energy expenditure     insulin resistance    

of dilution rate on dynamic and steady-state biofilm characteristics during phenol biodegradation by immobilized

Veena Bangalore Rangappa, Vidya Shetty Kodialbail, Saidutta Malur Bharthaiyengar

《环境科学与工程前沿(英文)》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0863-9

摘要: Continuous pulsed plate bioreactor (PPBR) was used for phenol biodegradation. cells immobilized on granular activated carbon was used. Dynamic and steady state biofilm characteristics depend on dilution rate (DR). Lower DR favour phenol degradation and uniform, thick biofilm formation. Exo polymeric substance production in biofilm are favoured at lower dilution rates. Pulsed plate bioreactor (PPBR) is a biofilm reactor which has been proven to be very efficient in phenol biodegradation. The present paper reports the studies on the effect of dilution rate on the physical, chemical and morphological characteristics of biofilms formed by the cells of Pseudomonas desmolyticum on granular activated carbon (GAC) in PPBR during biodegradation of phenol. The percentage degradation of phenol decreased from 99% to 73% with an increase in dilution rate from 0.33 h?1 to 0.99 h?1 showing that residence time in the reactor governs the phenol removal efficiency rather than the external mass transfer limitations. Lower dilution rates favor higher production of biomass, extracellular polymeric substances (EPS) as well as the protein, carbohydrate and humic substances content of EPS. Increase in dilution rate leads to decrease in biofilm thickness, biofilm dry density, and attached dry biomass, transforming the biofilm from dense, smooth compact structure to a rough and patchy structure. Thus, the performance of PPBR in terms of dynamic and steady-state biofilm characteristics associated with phenol biodegradation is a strong function of dilution rate. Operation of PPBR at lower dilution rates is recommended for continuous biologic treatment of wastewaters for phenol removal.

关键词: Biofilm     Exopolymeric substances     Phenol     Dilution rate     Pulsed plate bioreactor    

Regioselective acylation of pyridoxine catalyzed by immobilized lipase in ionic liquid

BAI Shu, REN Mengyuan, WANG Lele, SUN Yan

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 301-307 doi: 10.1007/s11705-008-0060-x

摘要: The regioselective acylation of pyridoxine catalyzed by immobilized lipase () in 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF) has been investigated, and compared with that in acetonitrile (ACN). The acetylation of pyridoxine using acetic anhydride in [BMIM]PF gave comparable conversion of pyridoxine to 5-monoacetyl pyridoxine with considerably higher regioselectivity (93%–95%) than that in ACN (70%–73%). Among the tested parameters, water activity () and temperature have profound effects on the reaction performances in either [BMIM]PF or ACN. For the reaction in [BMIM]PF, higher temperature (50°C–55°C) and lower (<0.01) are preferable conditions to obtain better conversion and regioselectivity. Mass transfer limitation and intrinsic kinetic from the ionic nature of ionic liquids (ILs) may account for a different rate-temperature profile and a lower velocity at lower temperature in [BMIM]PF-mediated reaction. Moreover, consecutive batch reactions for enzyme reuse also show that lipase exhibited a much higher thermal stability and better reusability in [BMIM]PF than in ACN, which represents another advantage of ILs as an alternative to traditional solvents beyond green technology.

关键词: ACN     stability     1-butyl-3-methylimidazolium hexafluorophosphate     different rate-temperature     alternative    

Molecular aspects of MERS-CoV

null

《医学前沿(英文)》 2017年 第11卷 第3期   页码 365-377 doi: 10.1007/s11684-017-0521-z

摘要:

Middle East respiratory syndrome coronavirus (MERS-CoV) is a betacoronavirus which can cause acute respiratory distress in humans and is associated with a relatively high mortality rate. Since it was first identified in a patient who died in a Jeddah hospital in 2012, the World Health Organization has been notified of 1735 laboratory-confirmed cases from 27 countries, including 628 deaths. Most cases have occurred in Saudi Arabia. MERS-CoV ancestors may be found in Old World bats of the Vespertilionidae family. After a proposed bat to camel switching event, transmission of MERS-CoV to humans is likely to have been the result of multiple zoonotic transfers from dromedary camels. Human-to-human transmission appears to require close contact with infected persons, with outbreaks mainly occurring in hospital environments. Outbreaks have been associated with inadequate infection prevention and control implementation, resulting in recommendations on basic and more advanced infection prevention and control measures by the World Health Organization, and issuing of government guidelines based on these recommendations in affected countries including Saudi Arabia. Evolutionary changes in the virus, particularly in the viral spike protein which mediates virus-host cell contact may potentially increase transmission of this virus. Efforts are on-going to identify specific evidence-based therapies or vaccines. The broad-spectrum antiviral nitazoxanide has been shown to have in vitro activity against MERS-CoV. Synthetic peptides and candidate vaccines based on regions of the spike protein have shown promise in rodent and non-human primate models. GLS-5300, a prophylactic DNA-plasmid vaccine encoding S protein, is the first MERS-CoV vaccine to be tested in humans, while monoclonal antibody, m336 has given promising results in animal models and has potential for use in outbreak situations.

关键词: MERS-CoV     Saudi Arabia     spike protein     transmission     evolution     vaccine    

标题 作者 时间 类型 操作

A mini review on chemical fixation of CO 2 : Absorption and catalytic conversion into cyclic carbonates

Weili DAI, Chaktong AU, Shenglian LUO, Shuangfeng YIN,

期刊论文

Asymmetric transfer hydrogenation of prochiral ketone catalyzed over Fe-CS/SBA-15 catalyst

XUE Ping, WU Tao

期刊论文

Enhanced desulfurization performance of hybrid membranes using embedded hierarchical porous SBA-15

Ye Zhang, Jian Song, Josue Quispe Mayta, Fusheng Pan, Xue Gao, Mei Li, Yimeng Song, Meidi Wang, Xingzhong Cao, Zhongyi Jiang

期刊论文

Oxidation-extraction desulfurization of model oil over Zr-ZSM-5/SBA-15 and kinetic study

Chuanzhu LU,Hui FU,Huipeng LI,Hua ZHAO,Tianfeng CAI

期刊论文

Covalent triazine framework with efficient photocatalytic activity in aqueous and solid media

Cyrine Ayed, Wei Huang, Kai A. I. Zhang

期刊论文

Immobilized

Pei MA, Dan ZHANG

期刊论文

Characterization and catalytic properties of mesoporous CuO/SBA-16 prepared by different impregnation

DONG Yongli, YUAN Fulong, ZHU Yujun, ZHAO Lina, CAI Zhicheng

期刊论文

Degradation of bisphenol A by microorganisms immobilized on polyvinyl alcohol microspheres

Xue BAI, Hanchang SHI, Zhengfang YE, Qiujin SUN, Qing WANG, Zhongyou WANG

期刊论文

Mercury removal and recovery by immobilized

Meifang CHIEN, Ryo NAKAHATA, Tetsuya ONO, Keisuke MIYAUCHI, Ginro ENDO

期刊论文

GDF15 negatively regulates chemosensitivity via TGFBR2-AKT pathway-dependent metabolism in esophageal

期刊论文

Enhanced methane production during long-term UASB operation at high organic loads as enabled by the immobilized

期刊论文

Beneficial metabolic activities of inflammatory cytokine interleukin 15 in obesity and type 2 diabetes

null

期刊论文

of dilution rate on dynamic and steady-state biofilm characteristics during phenol biodegradation by immobilized

Veena Bangalore Rangappa, Vidya Shetty Kodialbail, Saidutta Malur Bharthaiyengar

期刊论文

Regioselective acylation of pyridoxine catalyzed by immobilized lipase in ionic liquid

BAI Shu, REN Mengyuan, WANG Lele, SUN Yan

期刊论文

Molecular aspects of MERS-CoV

null

期刊论文