查找使用阿拉丁产品的科研文献

The synthesis of nano-sized TS-1 zeolites under rotational crystallisation conditions can inhibit anatase formation

Xing Wei,Yu-Jia Wang,Tie-Qiang Ren,Hai-Yan Wang,Min Wei

Hydrothermal synthesis is a typical method for the preparation of TS-1. In the current study, agitation was introduced during the crystallisation stage, and nano-sized TS-1 with little anatase TiO2 was successfully synthesised in a short time (1–8 h). Furthermore, under rotational crystallisation conditions, a series of TS-1 samples was prepared with different crystallisation times, and the products obtained were investigated as catalysts for the oxidative desulfurisation of thiophene from a model fuel. All samples were characterised utilising X-ray diffraction (XRD), scanning electron microscopy (SEM), N2-adsorption, ultraviolet-visible (UV-Vis) spectroscopy and Fourier-transform infrared (FT-IR) spectroscopy techniques. It was found that under rotational crystallisation conditions, nano-sized TS-1 could be synthesised in a short time that had improved efficiency for the oxidative desulfurisation reaction of thiophene in comparison with TS-1 synthesised by static crystallisation for 24 h.

Catalyst-Free Synthesis of Covalent Adaptable Network (CAN) Polyurethanes from Lignin with Editable Shape Memory Properties

Xiaozhen Ma,Shuqi Li,Fan Wang,Jialong Wu,Yeyan Chao,Xun Chen,Peng Chen,Jin Zhu,Ning Yan,Jing Chen

Graphical A catalyst-free dynamic covalently cross-linking polyurethane was successfully prepared by a one-step method using untreated lignin. And by adjusting the lignin content and the isocyanate index, the properties of LPUs could be adjusted. Mechanical properties of LPUs could be significantly improved by extrusion. In addition, it exhibited editable shape memory function. Therefore, this paper can provide new ideas for the structural design of lignin-based polyurethanes. Here a new strategy of catalyst-free direct synthesis of covalent adaptable network polyurethanes (LPUs) from lignin with editable shape memory effect is reported. Using unmodified lignin, PEG, and isocyanate under the condition of the isocyanate index less than 1.0 (NCO/OH<1.0), a variety of LPUs are obtained. When NCO/OH=0.8, a stable cross-linked network can be formed (ex. the gel content of LPU50-0.8 was 98±0.3 %). The activation energy ( E a ) value of LPUs is similar to that of polyhydroxyurethanes (PHUs), at around 110 kJ mol −1 . With an increase of lignin content, the LPUs show a transition from ductile fracture to brittle fracture mode. And the mechanical properties of LPUs are significantly enhanced after extrusion processing, with the maximum modulus reaching 649±26 MPa and the maximum toughness up to 9927±111 kJ m −3 . The improvement in mechanical properties is due to the homogenization of complex cross-linked network under the powerful external force of the extruder and the lignin that originally was free in the system participated in the exchange reactions. Moreover, LPUs can also be prepared continuously in one step by using an extruder as the reactor. In addition, LPU50-0.8 has an editable shape memory effect. This study develops a novel method for the synthesis of LPU from lignin with NCO/OH<1.0, showcasing new possibilities for value-added utilization of lignin, and expands the bio-based products portfolio from biomass feedstock to help meet future green manufacturing demands.

High-strength amphoteric hydrogel that can realize self-repairing of cement microcracks triggered by CO2 gas

Xiaona Huang,Yinchuan Wang,Xuguang Wang,Xiutian Yang,Hao Zhang,Fan Zhang,Chao Wang,Yungang Bai,Ying Liu,Jiarui Wang,Xinyue Wang,Hui Chi,Chao Zhou,Kun Xu,Pixin Wang

During the completion of a natural gas well , the annular gas migration of the cement paste significantly damages the cement quality. Thus, the cement with self-repairing property has great significance in oil well applications. In this work, chemically cross-linked hydrogels were synthesized by the solution polymerization of acrylamide , acrylic acid , and 2-(dimethylamino)ethyl methacrylate (DMAEMA) with NMBA as cross linker to plug the CO 2 -triggered microcracks in the cement paste. The mechanical strength of the hydrogel (Cu-PMAD) was significantly enhanced by complexation between Cu 2+ and the carboxyl group of the hydrogel network. As a self-healing plugging material, Cu-PMAD hydrogel powder was mixed with cement to prepare self-repairing cement slurry. The amphoteric structure of hydrogel was triggered by CO 2 due to the DMAEMA unit of the hydrogel was protonated, and the hydrogel can swell further by the anti-polyelectrolyte effect under CO 2 of nature gas and formation salt-bearing fluid. The good swelling ability and mechanical properties endowed the Cu-PMAD hydrogel with excellent plugging ability for cement microcracks triggered by CO 2 .

Eucommia ulmoides Leaf Polysaccharide in Conjugation with Ovalbumin Act as Delivery System Can Improve Immune Response

Haibo Feng,Jie Yang,Hui Zhi,Xin Hu,Yan Yang,Linzi Zhang,Qianqian Liu,Yangyang Feng,Daiyan Wu,Hangyu Li

In this investigation, to maximize the desired immunoenhancement effects of PsEUL and stimulate an efficient humoral and cellular immune response against an antigen, PsEUL and the model antigen ovalbumin (OVA) were coupled using the N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) reaction to yield a novel delivery system (PsEUL-OVA). The physicochemical characteristics and immune regulation effects of this new system were investigated. We found the yield of this EDC method to be 46.25%. In vitro, PsEUL-OVA (200 μg mL−1) could enhance macrophage proliferation and increase their phagocytic efficiency. In vivo, PsEUL-OVA could significantly increase the levels of OVA-specific antibody (IgG, IgG1, IgG2a, and IgG2b) titers and cytokine (IL-2, IL-4, IL-6, IFN-γ) levels. Additionally, it could activate T lymphocytes and facilitate the maturation of dendritic cells (DCs). These findings collectively suggested that PsEUL-OVA induced humoral and cellular immune responses by promoting the phagocytic activity of macrophages and DCs. Taken together, these results revealed that PsEUL-OVA had the potential to improve immune responses and provide a promising theoretical basis for the design of a novel delivery system.Keywords:polysaccharides fromEucommia ulmoides;adjuvant;delivery system;macrophage;dendritic cell

How can vanillin improve the performance of lignocellulosic biomass conversion in an immobilized laccase microreactor system?

Kai Lin,Ao Xia,Yun Huang,Xianqing Zhu,Xun Zhu,Kaiyong Cai,Zidong Wei,Qiang Liao

Gentle and effective pretreatment is necessary to produce clean lignocellulosic biomass-based fuels. Herein, inspired by the efficient lignin degradation in the foregut of termites, the microreactor system using immobilized laccase and recoverable vanillin was proposed. Firstly, the co-deposition coating of dopamine, hydrogen peroxide and copper sulfate was constructed for laccase immobilization and a high immobilization efficiency of 87.0% was obtained in 30 min. After storage for 10 days, 82.2% activity was maintained in the laccase-loaded microreactor, which is 210.0% higher than free laccase. In addition, 6% (w/w) vanillin can improve lignin degradation in the laccase-loaded microreactor without impairing laccase activity, leading to a 47.3% increment in cellulose accessibility. Finally, a high cellulose conversion rate of 88.1% can be achieved in 1 h with glucose productivity of 2.62 g L −1 h −1 . These demonstrated that the appropriate addition of vanillin can synergize with immobilized laccase to enhance the conversion of lignocellulosic biomass.

Can titanium dioxide nanoparticles modulate the effects of zinc oxide nanoparticles on aquatic leaf litter decomposition?

Jingjing Du,Xilin Wang,Yuyan Zhang,Gaozhong Pu,Baodan Jin,Wenrui Qv,Xia Cao

The potential impacts of metallic nanoparticles (NPs) at environmental levels on freshwater ecosystems cannot be ignored due to their frequent release. The most widely used metallic oxide, ZnO NPs and TiO 2 NPs (100 ng L −1 ) were applied to explore their single and combined effects on leaf litter decomposition. Although ZnO NPs and TiO 2 NPs alone or in combination increased 22.68%–41.17% of the leaf decomposition rate, they performed different toxic mechanisms in ecological processes. The microbial mass and enzyme activities significantly increased after acute exposure, but significantly decreased after chronic exposure to ZnO NPs. The activity of BG was the most sensitive factor that was decreased by 66.22%, 56.97%, and 39.39% after 21-day exposure to ZnO NPs, TiO 2 NPs, and in combination, respectively. In addition, the analysis of Fourier transform infrared spectroscopy suggested a novel perspective on understanding the promoting mechanism. The promotion effect of ZnO NPs relied on the enhanced decomposition of refractory organics and easily degradable substances due to the contribution of Anguillospora , Pyrenochaetopsis , and Bipolaris . The single exposure to TiO 2 NPs and combined exposure with ZnO NPs promoted microbial mass and hydrolase activities, with the stimulating effect attributed to the enhanced decomposition of soluble substances. Therefore, the results highlight the importance of chemical analysis of decomposed leaves to evaluate the potential threat of metallic NPs to the function of freshwater ecosystems.

DOX-loaded mesoporous hydroxyapatite modified by hyaluronic acid can achieve efficient targeted therapy for lung cancer

Yanjie Hu,Jisong Zhang,Liangliang Dong,Li Xu,Enguo Chen

Dimethylglycine Can Enhance the Cryopreservation of Red Blood Cells by Reducing Ice Formation and Oxidative Damage

Yuying Hu,Xiangjian Liu,Marlene Davis Ekpo,Jiangming Chen,Xiaoxiao Chen,Wenqian Zhang,Rui Zhao,Jingxian Xie,Yongju He,Songwen Tan

The cryopreservation of red blood cells (RBCs) holds great potential for ensuring timely blood transfusions and maintaining an adequate RBC inventory. The conventional cryoprotectants (CPAs) have a lot of limitations, and there is an obvious need for novel, efficient, and biocompatible CPAs. Here, it is shown for the first time that the addition of dimethylglycine (DMG) improved the thawed RBC recovery from 11.55 ± 1.40% to 72.15 ± 1.22%. We found that DMG could reduce the mechanical damage by inhibiting ice formation and recrystallization during cryopreservation. DMG can also scavenge reactive oxygen species (ROS) and maintain endogenous antioxidant enzyme activities to decrease oxidative damage during cryopreservation. Furthermore, the properties of thawed RBCs were found to be similar to the fresh RBCs in the control. Finally, the technique for order performance by similarity to ideal solution (TOPSIS) was used to compare the performance of glycerol (Gly), hydroxyethyl starch (HES), and DMG in cryopreservation, and DMG exhibited the best efficiency. This work confirms the use of DMG as a novel CPA for cryopreservation of RBCs and may promote clinical transfusion therapy.Keywords:cryopreservation;dimethylglycine;red blood cells;cryoprotectant

Can the mix-charged NF membrane directly obtained by the interfacial polymerization of PIP and TMC?

Qiu-Yu Zhu,Zi-Yun Xu,Jie-Han Fu,Jie Huang,Zhen-Liang Xu,Min Tong,En-Chao Li,Yong-Jian Tang

Currently, most nanofiltration membranes exhibit satisfactory separation performance on the anions or cations, and few membranes could concurrently separate anion and cation . Therefore, preparing nanofiltration membranes with excellent separation performance for both anionic and cationic ions remains a challenge. Herein, we have developed a series of nanofiltration membranes using conventional interfacial polymerization with different ratios of trimesoyl chloride (TMC) and piperazine (PIP) concentrations. In the interface polymerization process, the amine groups carried by PIP imparted a positive charge, while the hydrolysis of acyl chloride groups resulted in the generation of carboxylic acid groups that introduced a negative charge. The mix-charged nanofiltration membrane could be fabricated by varying PIP/TMC concentration ratios. The optimized membrane exhibited high rejection rates for bivalent ions (Na 2 SO 4 rejection of 96.6 %, MgCl 2 rejection of 93.0 %), and its selectivity for Mg 2+ /Li + mixed solution was improved significantly. This work provides a novel approach for the development of nanofiltration membranes capable of effectively separating mono-/divalent ions.

Can the heptapeptide ASSIVSF of the β2-adrenoceptor recognize ephedrine and pseudoephedrine epimers in a complex system?

Jiatai Yin,Yiheng Gou,Yiheng Wang,Qingyuan Ma,Rui Wang,Jing Yu,Yajun Zhang,Jing Wang,Qian Li,Xinfeng Zhao

Epimer separation is crucial in the field of analytical chemistry, separation science, and the pharmaceutical industry. No reported methods could separate simultaneously epimers or even isomers and remove other unwanted, co-existing, interfering substances from complex systems like herbal extracts. Herein, we prepared a heptapeptide-modified stationary phase for the separation of 1R,2S -(-)-ephedrine [(-)-Ephe] and 1S,2S -(+)-pseudoephedrine [(+)-Pse] epimers from Ephedra sinica Stapf extract and blood samples. The heptapeptide stationary phase was comprehensively characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The separation efficiency of the heptapeptide column was compared with an affinity column packed with full-length β 2 -AR functionalized silica gel (β 2 -AR column). The binding affinity of the heptapeptide with (+)-Pse was 3-fold greater than that with (-)-Ephe. Their binding mechanisms were extensively characterized by chromatographic analysis, ultraviolet spectra, circular dichroism analysis, isothermal titration calorimetry, and molecule docking. An enhanced hydrogen bonding was clearly observed in the heptapeptide-(+)-Pse complex. Such results demonstrated that the heptapeptide can recognize (+)-Pse and (-)-Ephe epimers in a complex system. This work, we believe, was the first report to simultaneously separate epimers and remove non-specific interfering substances from complex samples. The method was potentially applicable to more challenging sample separation, such as chiral separation from complex systems.

Can lignin nanosphere be used as a recycled sacrificed template for constructing high performance loose nanofiltration membranes?

Jinsong He,Wenjie Liu,Fan Ni,Dong Tian,Yongjia Lei,Jianmei Zou,Yanzong Zhang,Fei Shen,Xiaochan An

Sacrificed template strategy has become a promising pathway to construct high performance loose nanofiltration (LNF) membranes for dye-containing wastewater treatment. However, few studies have been conducted on the recycling of templates in the LNF membrane preparation. In this study, lignin nanoparticles (LNPs) with abundant biomass sources, low cost, renewable ability, were attempted to be used as a recycled sacrificed template for the first time. The LNPs were easily renewed by concentration and NaOH dialysis with smaller nano-size and more hydrophilic surface. The optimized P-LNF-50 membrane prepared by pristine LNPs templates exhibited high water permeability of 146.24 LMH·bar −1 , excellent separation of dye/salt (i.e. rejection: 97.79 % for CR, 0.48 % for Na 2 SO 4 , 0.25 % for NaCl), and superior long-term stability. Interestingly, the R1-LNF-70 membrane prepared by 1 st recycled LNPs templates can still maintain high water permeability of 132.97 LMH·bar −1 and excellent separation of dye/salt (i.e. rejection rate: 98.31 % for CR, and 1.27 % for Na 2 SO 4 ). While the 2 nd recycled LNPs can not produce satisfied LNF membranes due to its poor figuration and easy aggregation. The inherent relationships between LNPs templates and selective layers were deeply explored. Importantly, the Sankey chart of recycling LNPs template technique and cost analysis indicated that the LNPs could be used as green templates for two cycles with comparable permeability and selectivity of dye/salts. Overall, our study paves the way for recycling of sacrificed templates for the scalable fabrication of high performance LNF membranes.

Synthesis of a BiOIO3/Bi2O4 heterojunction that can efficiently degrade rhodamine B and ciprofloxacin under visible light

Hao Hu,Chengdong Xu,Jiacheng Jin,Mingchen Xu,Yue Cheng,Weiwei Ji,Zhencen Ding,Min Shao,Yushan Wan

In this paper, BiOIO 3 and Bi 2 O 4 nanosheet monomers were synthesized and used to prepare several BiOIO 3 /Bi 2 O 4 composites by an ultrasonic impregnation method. The resulting photocatalytic materials were characterized by XRD , SEM, TEM, XPS , FTIR, PL , UV–Visible diffuse reflectance spectroscopy (DRS), and BET. The photocatalytic activity of the BiOIO 3 /Bi 2 O 4 composites was evaluated by the degradation of rhodamine B (RhB) and ciprofloxacin (CIP) under simulated sunlight and compared to the activities of BiOIO 3 and Bi 2 O 4 operating alone. The results showed that Bi 2 O 4 was closely attached to the surface of BiOIO 3 , and the composite had a good degradation effect on RhB and CIP, with the best performing material being a 0.9-BiOIO 3 /Bi 2 O 4 composite, which achieved 97.6% degradation of RhB within 60 min and 85.6% degradation of CIP within 120 min. The observed degradation performance was considerably higher than that of other composite samples and monomers due to the good energy level matching of the BiOIO 3 /Bi 2 O 4 composite, which broadened the light response interval, improved the electron transfer rate and enhanced the photocatalytic activity. Free radical capture experiments showed that the ·O 2 - $\stackrel{-}{2}$ and h + free radicals significantly contributed to the degradation of pollutants. Cyclic tests showed that the composite also had good stability. The results of this study showed that bismuth-based photocatalysts might be used for environmental remediation.