JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A
·
2020
·Vol. 108
·期 12
·2435-2446
·
IF 3.525
Zhen Yu,Shisi Ma,Mengfan Wu,Huan Cui,Rong Wu,Sizhe Chen,Chenlin Xu,Xiaohe Lu,Songfu Feng
The vitreous substitute for proliferative vitreoretinopathy (PVR) surgery remains an unmet clinical need in ophthalmology. In our study, we developed an in situ formed hydrogel by crosslinking polyvinyl alcohol (PVA) and chitosan as a potential vitreous substitute. 5-fluorouracil (5-FU) Poly (lactic-co-glycolic acid) (PLGA) microspheres were developed and loaded onto the PVA/chitosan hydrogels to treat PVR. In vitro, PVA/chitosan hydrogels at four concentrations were subjected to morphological, physical, rheological analyses, and cytotoxicity was evaluated together with the characterization of 5-FU PLGA microspheres. In vivo, pharmacologically induce PVR rabbits were performed a vitrectomy. In the PVA group, 3% PVA/chitosan hydrogel was injected into the vitreous cavity. In the PVA/MS group, 3% PVA/chitosan hydrogel and 5-FU PLGA microspheres were injected. In the Control group, phosphate-buffered saline was injected. Therapeutic efficacy was evaluated with postoperative examinations and histological analyses. This study demonstrated that the 3% PVA/chitosan hydrogel showed properties similar to those of the human vitreous and could be a novel in situ crosslinked vitreous substitute for PVR. Loading 5-FU PLGA microspheres onto this hydrogel may represent an effective strategy to improve the prognosis of PVR.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ChemSusChem
·
2020
·Vol. 13
·期 12
·3127-3136
·
IF 7.962
Peter Kisszekelyi,Rifan Hardian,Hakkim Vovusha,Binglin Chen,Xianhai Zeng,Udo Schwingenschlögl,Jozsef Kupai,Gyorgy Szekely
Graphical Up the tempo : An efficient TEMPO-based electrocatalytic transformation of biomass-based C 6 -platform chemical 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) is reported. The molecular design and comparison of homogeneous (native, size-enlarged) and solid-supported (SiliaCAT, TurboBeads) TEMPOs is discussed for the oxidation in the ElectraSyn reactor with cost-effective electrodes and green solvents. Computational modeling reveals the synergistic effect of the catalyst/base system and facilitated the catalyst design. The catalytic transformation of bio-derived compounds, specifically 5-hydroxymethylfurfural (HMF), into value-added chemicals may provide sustainable alternatives to crude oil and natural gas-based products. HMF can be obtained from fructose and successfully converted to 2,5-diformylfuran (DFF) by an environmentally friendly organic electrosynthesis performed in an ElectraSyn reactor, using cost-effective and sustainable graphite (anode) and stainless-steel (cathode) electrodes in an undivided cell, eliminating the need for conventional precious metal electrodes. In this work, the electrocatalysis of HMF is performed by using green solvents such as acetonitrile, γ-valerolactone, as well as PolarClean, which is used in electrocatalysis for the first time. The reaction parameters and the synergistic effects of the TEMPO catalyst and 2,6-lutidine base are explored both experimentally and through computation modeling. The molecular design and synthesis of a size-enlarged C 3 -symmetric tris-TEMPO catalyst are also performed to facilitate a sustainable reaction work-up through nanofiltration. The obtained performance is then compared with those obtained by heterogeneous TEMPO alternatives recovered by using an external magnetic field and microfiltration. Results show that this new method of electrocatalytic oxidation of HMF to DFF can be achieved with excellent selectivity, good yield, and excellent catalyst recovery.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Tingwei Zhang,Wenzhi Li,Yongcan Jin,Wenhui Ou
A novel sulfonated chitosan-derived carbon-based catalyst was successfully prepared via isoamyl nitrite-assisted sulfanilic acid sulfonation , and its catalytic activity was examined using dehydration of fructose. The structural and chemical properties of sulfonated chitosan-derived carbon were characterized by SEM, FTIR, XRD, XPS , element analysis, N 2 adsorption-desorption experiment, and acid-base titration experiment. KOH was used as activating agent in the synthesizing of carbon supports, and it was found that properly increasing the dose of KOH during activation stage had a positive effect on the subsequent sulfonation of prepared activated carbon. 4KSCC, with the highest sulfonation degree (2.04 mmol/g), exhibited high performance for the conversion of fructose to HMF in various solvent, and an optimal HMF yield of 80.9% was obtained at 140 °C in 40 min. In addition, the reusability of 4KSCC for fructose dehydration was fairly good.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2020
·
IF 2.726
Yang Yunxia,Xia Shiying,Zhang Haixia,Niu Huihui,Dong Wenjing,Wu Xiangxiang
Two kinds of new complexes based on 3, 5-bis (triazol-1-yl) benzoic acid (HL) and 1, 3, 5-benzenetricarboxylic acid (H 3 bta), {[Zn 2 (μ 4 -L)(μ 3 -bta(3H 2 O)]∙H 2 O}n( 1 ) and {[Cd 2 (μ 4 -L)(μ 3 -bta(3H 2 O)]∙4H 2 O}n( 2 ), were prepared by solvothermal reactions and the structures were characterized by single-crystal X-ray diffraction. The experimental results showed that complexes 1 and 2 were isomorphic, in which metal ions were separately chelated with the ligands to form one mononuclear Cd 1 and another binuclear Cd 2 O 4 structure. Each metal center (M) can be considered as a three-connection, each M 2 O 4 as a six-connection, and the ligands of HL and H 3 bta can be used as three-junctions. Finally, complex 1 and 2 showed a (3, 6)-connection of {6 3 } 6 {6 6 ;8 6 ;10 2 ;12} topology. Solid-state fluorescence experiments showed that only complex 1 could selectively identify Fe 3+ (detection limit: 0.11 mM) and Cr 6+ (detection limit: 0.1 mM) in aqueous solution by a fluorescence quenching mechanism and the fluorescence quenching constant of Fe 3+ reached 10 4 . Dye adsorption experiments showed that the complexes could absorb different organic dyes and the adsorption capacity was 1 > 2 . Furthermore, the adsorption efficiency of 1 for methylene blue was as high as 97.64%.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Junzong Chen,Miaojuan Qiu,Shiqiang Zhang,Binbin Li,Dong Li,Xiuyu Huang,Zhirong Qian,Jing Zhao,Zhiyong Wang,Di Tang
Calcium based biomaterials were widely used for drug delivery application due to their biodegradability, biocompatibility, and high drug loading capacity. Herein, amino-capped polyamidoamine (PAMAM) dendrimer was applied as a macromolecular template to form amino-modified calcium phosphate hollow sphere (CaPO-NH 2 ). After loading with 5-fluorouracil (5Fu), this system performed synergistic cancer chemotherapy. In this study, the 5Fu/CaPO-NH 2 particles could be efficiently uptaken by cancer cells, and then decompose into Ca 2+ and release 5Fu drug in the cytoplasm; therefore calcium overload and reactive oxygen species (ROS) accumulation were found in PSN1 cells that could induce cell membrane damage and elicit cell apoptosis through a series of biochemical reactions including endoplasmic reticulum stress, lipid peroxidation and mitochondrial apoptosis. In the PSN1 pancreatic cancer xenograft model, the 5Fu/CaPO-NH 2 system performed high tumor inhibition via chemotherapy and calcium overload induced apoptosis. Comparingly, the normal cells and organs were insensitive to this synergistic therapy, which indicated the well biocompatibility of delivery system. Thus, this study provided a promising CaPO-NH 2 drug delivery platform for enhanced 5Fu chemotherapeutic effect.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2021
·
IF 3.171
Xing Zhang,Jingfeng Wu,Junhao Chen,Liang Lu,Lingjun Zhu,Shurong Wang
The catalytic cracking of bio-oil is important to produce aromatic hydrocarbons , which can partially replace gasoline or diesel to greatly reduce carbon emissions from transportation. To further promote the formation of aromatic hydrocarbons, this work studied the effects of the preparation method and the acid strength of Ga 2 O 3 /HZSM-5 on catalytic cracking of the bio-oil distilled fraction systematically. The preparation method of Ga 2 O 3 /HZSM-5 had an important effect on its catalytic activity: the Ga 2 O 3 /HZSM-5 prepared by physical mixing showed the low dispersion of active phases and poor pore structure, resulting in its insufficient activity and severe coke deposition; the Ga 2 O 3 /HZSM-5 prepared by precipitation exhibited the higher activity, while many polycyclic aromatic hydrocarbons unfavorable for the subsequent utilization were in the oil phase; the Ga 2 O 3 /HZSM-5 prepared by impregnation showed the highest activity and 35.5% (mass) selectivity of the oil phase, including 80.3% monocyclic aromatic hydrocarbons and 12.0% polycyclic aromatic hydrocarbons. The Brønsted acidity of Ga 2 O 3 /HZSM-5 decreased with Si/Al ratio, leading to the decline in reactant conversion, oil phase selectivity and quality. Meanwhile, the polymerization between monocyclic aromatic hydrocarbons and oxygenates was promoted to produce many polycyclic aromatic hydrocarbons and even coke, causing catalyst deactivation .
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Yanqing Xue,Bo Li,Xinliang Wang,Xinlei Li,Han Zhang,Qitang Hao
Agglomeration behavior of TiB 2 particles in 5%TiB 2 /Al-4.5%Cu composites (all compositions are in wt.% unless otherwise specified) is studied by adding different content of Mg to improve its strength and ductility, a widely used in-situ molten salt reaction process is used to produce the composites. The results show that addition of Mg could not only significantly segregate TiB 2 particles but also further refine the α-Al grains and then improve the mechanical properties of the composites on the basis of TiB 2 particles. Here, 0.5% Mg is considered the optimum mass fraction for dispersion, refinement, and modification of particles based on the results of investigation. The yield strength (YS), ultimate tensile strength (UTS), elastic Young’s modulus (EM), and Vicker’s hardness (VHN) of the composites in T6 heat treatment are increased to 375 MPa, 486 MPa, 88 GPa, and 167 HV - an improvement of 21.8%, 16.5%, 20.9%, and 9.4%, respectively, versus the original TiB 2 /Al-4.5%Cu composite (308 MPa, 417 MPa, 63 GPa, and 153 HV). The elongation of the composite is improved by 20.9%. These merits are mainly attributed to addition of Mg, which increases the surface-spread coefficient of TiB 2 particles by reducing the surface tension of the Al melt, thereby improving the wettability .
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2021
·
IF 5.541
Jianjun Xiao,Minjiao Yang,Qingfeng Che,Yingquan Chen,Xu Chen,Haiping Yang,Pietro Bartocci,Francesco Fantozzi,Hanping Chen
The effect of potassium in biomass on the catalytic activity of ZSM-5 zeolite in the fast pyrolysis of biomass was investigated using 2-methylfuran (2-MF) as the typical model compound. The mechanism of action of potassium was explored in detail, along with the physicochemical properties of ZSM-5, including crystallinity, pore structure, and surface acidity. The physicochemical properties of ZSM-5 deteriorated to varying degrees after being tainted with different potassium sources (KOH, K 2 CO 3 , KAc, and KCl). Compared with neutral KCl and strong alkali KOH, K 2 CO 3 , and KAc, with weaker alkalinity but larger crystal structure, exerted a larger influence on ZSM-5. Changes in ZSM-5 tainted with K 2 CO 3 were the greatest, and crystallinity, surface area, acidity, and the corresponding yields of valuable aromatic hydrocarbons and gas products, all declined significantly, compared with raw ZSM-5. When the amount of K(CO 3 2− ) on ZSM-5 was less than 0.5 wt%, only minor (<10 %) changes were observed in crystallinity and surface area, but total acidity decreased by over 30 percent. The conversion of 2-MF was increased using ZSM-5 tainted with less than 0.5 wt% K(CO 3 2- ) and less liquid oxygenated compounds and more CO 2 were produced. Appropriate total acidity, adjusted by a tiny amount of K 2 CO 3 , could promote deoxygenation to CO 2. However, the decarbonylation reaction was inhibited, causing a negative effect on monocyclic aromatic hydrocarbons, which was attributed to the large-scale loss of both acidity and physical structure of ZSM-5 caused by more than 1.0 wt% K(CO 3 2- ).
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 54
·33969-33979
·
IF 3.361
Luxin Zhang,Yuting Liu,Ruijun Sun,Simin Yi
5-Ethoxymethylfurfural (EMF) has been identified as a potential biofuel and fuel additive, for which the production from glucose (the most abundant and inexpensive monosaccharide) in a one-step process would be highly desirable. Here, the synthesis of sulfonic acid-functionalized porous coordination polymers (PCPs) and their application as catalysts for EMF synthesis are reported. PCP(Cr)-BA (PCP material with Cr3+ ions and H2BDC-SO3H linkers) and PCP(Cr)-NA (PCP material with Cr3+ ions and H2NDC(SO3H)2 linkers) materials containing both Cr3+ sites and Brønsted-acidic –SO3H sites were prepared. The morphology, pore structure, acidity, chemical composition, and thermal stability of the two functionalized PCP(Cr) catalysts were analyzed by systematic characterization. The catalysts featured a porous morphology and dual Cr3+ and –SO3H sites, which enabled the cascade conversion of glucose to EMF. PCP(Cr)-BA exhibited higher performance than PCP(Cr)-NA with an EMF yield of 23.1% in the conversion of glucose at 140 °C after 22 h in an ethanol/water system. In addition, the as-prepared catalyst exhibited a high stability in the current catalytic system for EMF production from glucose with a constant catalytic activity in a four-run recycling test without an intermediate regeneration step.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Siqian Zhang,Cheng Zhang,Qiang Wang,Wha-Seung Ahn
A series of ZSM-5 catalysts were synthesized using fly ash from power plants and red mud from aluminum production in different weight ratios. The ZSM-5 was subsequently coimpregnated with Co and Mn and tested for the low-temperature selective catalytic reduction of NOx by NH3 (NH3-SCR). These catalysts were characterized by XRD, N2-adsorption isotherms, SEM, XPS, and H2-TPR. Among all the prepared catalysts, 5 wt % Co 10 wt % Mn/ZSM-5 had shown the best catalytic activity, with 98.8% conversion of NOx and 90.7% selectivity toward N2 at 150 °C. This is comparable to the performance of a similar ZSM-5 catalyst prepared using chemical reagents. The high ratio of Mn4+/(Mn4+ + Mn3+ + Mn2+) in the catalyst improved the NOx conversion, whereas the moderate redox property imparted by Co3+ led to high N2 selectivity. This catalyst also showed strong resistance against poisoning in 100 ppm SO2 and 5% H2O. This work demonstrates that effective NOx removal treatment with high N2 selectivity and sufficient stability for either cement plants or incinerators can be achieved by using a porous catalyst/support material produced from industrial solid wastes.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Qian Yao,Ying Zhang,Yao Fu
We report on catalytic fast pyrolysis microalgae under ammonia atmosphere into acetonitrile over Ga/HZSM-5, which provides a long-term sustainable option for acetonitrile production and microalgae valorization. The effect of various catalysts, reaction conditions and species of microalgae on acetonitrile production was explored systematically. Under the optimized conditions, the maximum carbon yield of acetonitrile from Chlorella vulgaris was 23.4%, and the selectivity of acetonitrile in bio-oil was up to 77.2%. The possible reaction pathways were proposed according to the comprehensive experimental investigation on the conversion of model compounds and intermediates (proteins, carbohydrates, lipids, amino acids, carboxylic acids, furans, and amines). High-resolution transmission electron microscopy (TEM) analysis showed that Ga was present mainly at the outer surface of zeolite crystals, and a small amount of Ga was doped into the zeolite crystals.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Jiashi Wang,Qinhong Wei,Qingxiang Ma,Zhongya Guo,Fangfang Qin,Zinfer R. Ismagilov,Wenzhong Shen
At present, the increasing consumption of fossil fuels as well as the expanding of more effective avenues to prepare carbon materials have inspired scholars' confidence to seek for alternative carbon sources. To address this issue, a N-doped graphene shell encapsulated metallic Co (Co@NGs) catalyst was fabricated using glucose and melamine as carbon source and nitrogen source via carbonization and employed for 5-hydroxylmethylfurfural (HMF) hydrogenation to produce 2,5-dimethylfuran (DMF) biofuel. Here, the prepared Co@NGs catalyst which possessed striking Mott-Schottky effect presented strong electronic interaction at the interface of surface metallic Co and doped N, leading to the electron transfer from metallic Co to doped N on carbon substrate. Experimental results indicated that the decreased electron density of metallic Co was more conductive to selective catalytic hydrogenation of HMF to form DMF. More importantly, the catalytic activity of the Mott-Schottky-type Co@NGs catalyst could be regulated by adjusting the nitrogen content. That is, the high nitrogen content increased the work function of Co@NGs and thus the enhanced rectifying response at the interface by which to enhance the catalytic performance. The best Co@NGs catalyst exhibited both high HMF conversion (close to 100 %) and DMF selectivity (94.7 %), much better than those of conventional N-doped carbon supported Co catalysts.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）