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Hierarchical ZSM-5 zeolite with radial mesopores: Preparation, formation mechanism and application for benzene alkylation

Darui Wang, Hongmin Sun, Wei Liu, Zhenhao Shen, Weimin Yang

《化学科学与工程前沿（英文）》 2020年第14卷第2期页码 248-257 doi: 10.1007/s11705-019-1853-9

摘要： Hierarchical ZSM-5 zeolite with radial mesopores is controllably synthesized using piperidine in a NaOH solution. The piperidine molecules enter the zeolite micropores and protect the zeolite framework from extensive desilication. The areas containing fewer aluminum atoms contain fewer piperidine protectant molecules and so they dissolve first. Small amounts of mesopores are then gradually generated in areas with more aluminum atoms and more piperidine protectant. In this manner, radial mesopores are formed in the ZSM-5 zeolite with a maximal preservation of the micropores and active sites. The optimal hierarchical ZSM-5 zeolite, prepared with a molar ratio of piperidine to zeolite of 0.03, had a mesopore surface area of 136 m ·g and a solid yield of 80%. The incorporation of the radial mesopores results in micropores that are interconnected which shortened the average diffusion path length. Compared to the parent zeolite, the hierarchical ZSM-5 zeolite possesses more accessible acid sites and has a higher catalytic activity and a longer lifetime for the alkylation of benzene.

关键词： hierarchical ZSM-5 zeolite protective desilication piperidine radial mesopores benzene alkylation

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Enhancing thermostability of -mannanase by protective additives

LIU Zhaohui, QI Wei, WU Weina, LIU Yue, HE Zhimin

《化学科学与工程前沿（英文）》 2008年第2卷第4期页码 439-442 doi: 10.1007/s11705-008-0062-8

摘要： The effects of some sugars (glucose, mannose, fructose, sucrose and chitosan) and polyols (glycol, glycerol and sorbitol) as protective additive on the thermostability of -mannanase were studied. The optimal reaction temperatures of -mannanase and the thermodynamics and the deactivation kinetics with or without additives were also investigated. The experimental results show that sucrose, chitosan and sorbitol could apparently improve the thermal stability of -mannanase when their concentration was kept at 2 g/L. The optimal combination additive proportion was sucrose: chitosan : sorbitol = 1 : 2 : 2 (molar ratio) using the orthogonal experimental design. The sucrose, chitosan, glycerol, sorbitol and the combination additive might increase the optimal reaction temperature from 50°C to about 60°C due to their good protection effect. The thermal deactivation curves of -mannanase accorded with the kinetic rules of first order reaction, and the corresponding kinetic and thermodynamic parameters were calculated. Meanwhile, the protective mechanism of the additives against deactivation of enzyme was also discussed.

关键词： protective additive g/L orthogonal experimental combination additive corresponding

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The influence of brain death on donor liver and the potential mechanisms of protective intervention

null

《医学前沿（英文）》 2011年第5卷第1期页码 8-14 doi: 10.1007/s11684-011-0109-y

摘要：

Brain-dead donors have become one of the main sources of organs for transplantation in Western countries. The quality of donor organs is closely related to the outcome of the transplantation. Experimental studies have confirmed the inferior graft survival of livers from brain-dead donors compared with those from living donors. Studies conducted in the past 10 years have shown that brain death is associated with effects on the decreased donor organ quality. However, whether the decrease in the viability of donor organs is caused by brain death or by the events before and after brain death remains uncertain. The purpose of this review is to introduce the advances and controversies regarding the influence of brain death on the viability of donor livers and to summarize the mechanisms of the different protective interventions for donor livers.

关键词： brain death donor liver

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Dealumination and desilication for Al-rich HZSM-5 zeolite via steam-alkaline treatment and its application

Yuehua Fang, Fan Yang, Xuan He, Xuedong Zhu

《化学科学与工程前沿（英文）》 2019年第13卷第3期页码 543-553 doi: 10.1007/s11705-018-1778-8

摘要： The hierarchical HZSM-5 was prepared via dealumination and desilication of commercial Al-rich HZSM-5, and characterized by X-ray diffraction, Al magic-angle spinning nuclear magnetic resonance, inductively coupled plasma mass spectrometry, scanning electron microscope, transmission electron microscope, N adsorption-desorption, NH temperature-programmed desorption, performed thermogravimetric and Raman spectrum. The results showed that partial framework of HZSM-5 was removed after steam treatment at 0.15 MPa, 500°C for 3 h. HZSM-5 with high specific surface area and much mesoporosity was obtained by the subsequent alkaline treatment. The regulation of acid quantity was achieved by altering the concentration of alkaline. Dealumination and desilication of Al-rich HZSM-5 zeolites became more effective using a combination of steam and alkaline treatments than using alkaline treatment alone. Methanol aromatization reaction was employed to evaluate the catalytic performance of treated HZSM-5 at 0.15 MPa, 450°C and MHSV of 1.5 h . The results indicated that after steam treatment, HZSM-5 further treated with 0.2 mol/L NaOH exhibits the best catalytic performance: the selectivity of aromatics reached 42.1% and the lifetime of catalyst attained 212 h, which are much better than untreated HZSM-5.

关键词： steam treatment alkaline treatment hierarchical ZSM-5 methanol aromatization

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PAK1 is a novel cardiac protective signaling molecule

null

《医学前沿（英文）》 2014年第8卷第4期页码 399-403 doi: 10.1007/s11684-014-0380-9

摘要：

We review here the novel cardiac protective effects of the multifunctional enzyme, p21-activated kinase 1 (PAK1), a member of a serine/threonine protein kinase family. Despite the large body of evidence from studies in noncardiac tissue indicating that PAK1 activity is key in the regulation of a number of cellular functions, the role of PAK1 in the heart has only been revealed over the past few years. In this review, we assemble an overview of the recent findings on PAK1 signaling in the heart, particularly its cardiac protective effects. We present a model for PAK1 signaling that provides a mechanism for specifically affecting cardiac cellular processes in which regulation of protein phosphorylation states by protein phosphatase 2A (PP2A) predominates. We discuss the anti-adrenergic and antihypertrophic cardiac protective effects of PAK1, as well as its role in maintaining ventricular Ca²⁺ homeostasis and electrophysiological stability under physiological, β-adrenergic and hypertrophic stress conditions.

关键词： p21-activated kinase 1 (PAK1) heart

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Antioxidative potential of metformin: Possible protective mechanism against generating OH radicals

Huibin Guo, Ning Wang, Xiang Li

《环境科学与工程前沿（英文）》 2021年第15卷第2期 doi: 10.1007/s11783-020-1313-2

摘要： Abstract • Metformin consumes O2−• and OH• induced by PM are proposed. • OH• dominated the oxidation of metformin compared with O2−• • Metformin can prevent the harm of ROS induced by PM to human health. • Antioxidative potential of metformin was first proposed to provide measures. Exposure to particulate matter (PM) can lead to the excessive accumulation of reactive oxygen species (ROS), which causes oxidative stress and endangers human health. In this study, the effects of metformin on PM-induced radicals were investigated, and the antioxidation reaction mechanism of metformin was analyzed by the density functional theory (DFT) method. The corresponding results revealed that the consumption rate of dithiothreitol (DTT) increased as the metformin concentration (0–40 mmol/L) increased under exposure to PM active components. Moreover, the OH radical content decreased as the metformin concentration increased. This result may be related to the consumption of PM-induced OH radicals by metformin, which promotes the DTT consumption rate. Additionally, because the initiation reaction has a high barrier, the oxidation reaction rate between metformin and •O2− is not very fast, although various catalysts may be present in the human environment. Importantly, we found that the barrier of metformin induced by OH radicals is only 9.6 kcal/mol while the barrier of metformin induced by oxygen is 57.9 kcal/mol, which shows that the rate of the •OH-initiated oxidative reaction of metformin is much faster and that this reaction path occurs more easily. By sample analysis, the mean OH radical generation was 55 nmol/min/g (ranging from 5 to 105 nmol/min/g) on haze days and 30 nmol/min/g (ranging from 10 to 50 nmol/min/g) on non-haze days. Moreover, OH radical generation was higher on haze days than on neighboring non-haze days. Taken together, all data suggest that metformin could consume the PM-induced radicals, such as OH radicals and •O2−, thereby providing health protection.

关键词： Antioxidative potential Metformin Mechanism OH radical Health protection.

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Nano-copper ions assembled cellulose-based composite with antibacterial activity for biodegradable personal protective

《化学科学与工程前沿（英文）》 2023年第17卷第10期页码 1544-1554 doi: 10.1007/s11705-022-2288-2

摘要： The current SARS-CoV-2 pandemic has resulted in the widespread use of personal protective equipment, particularly face masks. However, the use of commercial disposable face masks puts great pressure on the environment. In this study, nano-copper ions assembled cotton fabric used in face masks to impart antibacterial activity has been discussed. To produce the nanocomposite, the cotton fabric was modified by sodium chloroacetate after its mercerization, and assembled with bactericidal nano-copper ions (about 10.61 mg·g^–1) through electrostatic adsorption. It demonstrated excellent antibacterial activity against Staphylococcus aureus and Escherichia coli because the gaps between fibers in the cotton fabric allow the nano-copper ions to be fully released. Moreover, the antibacterial efficiency was maintained even after 50 washing cycles. Furthermore, the face mask constructed with this novel nanocomposite upper layer exhibited a high particle filtration efficiency (96.08% ± 0.91%) without compromising the air permeability (28.9 min·L^–1). This green, economical, facile, and scalable process of depositing nano-copper ions onto modified cotton fibric has great potential to reduce disease transmission, resource consumption, and environmental impact of waste, while also expanding the range of protective fabrics.

关键词： cellulose-based nanocomposite biodegradable antibacterial fabric nano-copper ions face masks

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Effect of hyperlipidemia on endothelial VCAM-1 expression and the protective role of fenofibrate

WU Jun, LIN Jinchao, HE Zhaochu, OU Biru, GUO Haisen

《医学前沿（英文）》 2007年第1卷第4期页码 356-358 doi: 10.1007/s11684-007-0068-5

摘要： The effect of hyperlipidemia and inflammation on endothelial functions was studied. The enrolled included control (basic chow), hyperlipidemia and fenofibrate-treated groups (high fat diet). The hyperlipidemia model was set up by four-week atherogenic diet, followed by a 16-week treatment in the fenofibrate-treated group (fenofibrate 40 mg/kg every day) and without treatment in the hyperlipidemia group, respectively. In the 20th week, serum lipid level and NO levels were measured, and the expression of vascular cell adhesion molecule-1 (VCAM-1) and cell adhesiveness in aortic endothelia observed by computer-aided system. Compared with the control group, hyperlipidemia rats showed lower levels of NO and ncreases in leukocyte accumulation on the endothelial surface, also stronger and more extensive endothelial expression of VCAM-1. In fenofibrate-treated group, the expression of VCAM-1 and leukocyte accumulation on the endothelial surface was decreased, while serum levels of NO were increased as compared with hyperli pidemia group. Hyperlipidemia can inhibit the NO activity and promote the damage of VACA-1 to aortic endothelia. Fenofibrate can effectively prevent the pathogenesis of atherosclerosis by restoring NO levels and down-regulating the VCAM-1 expression.

关键词： endothelial 16-week treatment leukocyte accumulation mg/kg NO

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Immunogenicity and protective immunity against otitis media caused by pneumococcus in mice of Hib conjugate

null

《医学前沿（英文）》 2016年第10卷第4期页码 490-498 doi: 10.1007/s11684-016-0470-y

摘要：

This study evaluated the immunogenicity and protective immunity of a Hemophilus influenzae b (Hib) polysaccharide conjugate vaccine with the pneumococcal surface adhesin A (PsaA) protein carrier in young mice. The Hib polysaccharide was conjugated with the rPsaA protein carrier, which was produced using recombinant DNA technology. A total of 15 young mice aged 3 weeks to 5 weeks were immunized with the conjugate vaccine, and another 15 young mice of the same age were immunized with the licensed Hib-tetanus toxoid (TT) vaccine. Furthermore, the third group of 15 young mice was inoculated with phosphate buffer saline as control. The immunized mice were inoculated with pneumococcus in the middle ear. Results showed that IgG antibody responses against both the PsaA protein and Hib polysaccharide were observed in the Hib-PsaA group. However, no statistical difference was observed in the titer of IgG against the Hib polysaccharide between Hib-PsaA and Hib-TT groups. The elimination rate of pneumococcus and the inflammation of the middle ear showed the effectiveness of protective immunity against otitis media caused by pneumococcus. Our results suggest that the Hib polysaccharide can be successfully conjugated with rPsaA via amide condensation. This new Hib-PsaA conjugate vaccine can induce both anti-PsaA and anti-Hib immune responses in young mice and elicit effective protection against acute otitis media caused by pneumococcus.

关键词： conjugate vaccine pneumococcal surface adhesin A Hemophilus influenzae b immunogenicity otitis media

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PROTECTIVE ROLES OF D1 PROTEIN TURNOVER AND THE XANTHOPHYLL CYCLE IN TOMATO (

Tao LU, Jiazhi LU, Mingfang QI, Zhouping SUN, Yufeng LIU, Tianlai LI

《农业科学与工程前沿（英文）》页码 262-279 doi: 10.15302/J-FASE-2021383

摘要： D1 protein turnover and the xanthophyll cycle (XC) are important photoprotective mechanisms in plants that operate under adverse conditions. Here, streptomycin sulfate (SM) and dithiothreitol (DTT) were used in tomato plants as inhibitors of D1 protein turnover and XC to elucidate their photoprotective impacts under sub-high temperature and high light conditions (HH, 35°C, 1000 µmol·m ·s ). SM and DTT treatments significantly reduced the net photosynthetic rate, apparent quantum efficiency, maximum photochemical efficiency, and potential activity of photosystem II, leading to photoinhibition and a decline in plant biomass under HH. The increase in reactive oxygen species levels resulted in thylakoid membrane lipid peroxidation. In addition, there were increased non-photochemical quenching and decreased chlorophyll pigments in SM and DTT application, causing an inhibition of D1 protein production at both transcriptional and translational levels. Overall, inhibition of D1 turnover caused greater photoinhibition than XC inhibition. Additionally, the recovery levels of most photosynthesis indicators in DTT-treated plants were higher than in SM-treated plants. These findings support the view that D1 turnover has a more important role than XC in photoprotection in tomato under HH conditions.

关键词： D1 turnover photoinhibition photoprotection photosynthesis tomato xanthophyll cycle

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Glucagon-like peptide-2 exhibits protective effect on hepatic ischemia-reperfusion injury in rats

null

《医学前沿（英文）》 2015年第9卷第3期页码 368-373 doi: 10.1007/s11684-015-0403-1

摘要：

Glucagon-like peptide-2 (GLP-2) has potent anti-inflammatory effects and protects against experimental ischemia/reperfusion (I/R) injury in pulmonary, intestinal, and myocardial tissue. However, its protective abilities against I/R injury in the liver are unknown. We investigated the potential role of GLP-2 pretreatment on hepatic I/R injury in rats. A total of 24 rats were randomly divided into three groups (n = 8). The first group was the control group; the second group was the vehicle-treated hepatic ischemia/reperfusion (HIR, vehicle saline-treated) group; and the third group was the GLP-2 pretreated I/R (GLP2-IR) group. Each rat in the third group was intraperitoneally administered 5 μg GLP-2 for 5 d before the procedure. A portal triad was created to induce ischemia with a vascular atraumatic clamp. After 40 min, the clamp was released to initiate hepatic reperfusion for 6 h. Blood samples and tissue specimens from the liver were obtained. Alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels significantly increased in the saline-treated HIR group (P<0.001), whereas GLP-2 pretreatment significantly decreased their levels (P<0.01). Our data suggested that GLP-2 pretreatment may have a protective effect on liver I/R injury. However, dose-response studies are necessary to determine the most effective dose.

关键词： ischemia/reperfusion liver glucagon-like peptide-2 alanine aminotransferase

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钻地武器的毁伤效应及深地下防护工程关键科学问题

范鹏贤,钱七虎,王明洋

《中国工程科学》 2013年第15卷第5期页码 47-58

摘要：

防护工程是国防威慑力量的重要组成部分，具有重要的战略地位。美俄等军事大国大力发展的深钻地（核）武器已经对我国重要防护工程的生存造成了严重的威胁。本文总结了外军现役钻地（核）武器的性能指标与发展前景，对钻地武器的毁伤效应进行了评估和分析，综述了侵彻效应、爆炸成坑效应、爆炸地冲击效应等方面的研究成果。针对新时期的主要威胁，简述了提高防护工程防护能力的主要措施和技术途径，提出了主被动结合的综合防护体系、深部非线性岩体力学、摆型波与超低摩擦现象、多弹聚集打击效应等目前亟需开展研究的关键科学问题。

关键词：钻地武器毁伤效应深地下防护工程

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防护工程设备自动化系统一体化集成方法研究

缪小平,彭福胜,耿世彬,范良凯,江丰

《中国工程科学》 2013年第15卷第5期页码 84-94

摘要：

本文指出我国设备自动化系统存在的主要问题是将系统的集成作为弱电集成，导致自动化系统和设备系统相脱节。分析了设备自动化系统集成的目标、阶段划分及其评价标准。提出防护工程自动化系统与设备系统一体化集成的方法：瞄准设备自动化系统预期目标，在设计、施工、编程调试各个环节，甚至产品开发阶段，必须密切加强自动化系统与设备系统配合。

关键词：防护工程设备自动化系统集成

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一种构件化的坑道工程动荷段实体模型设计质量判决方法

袁辉,王凤山,许继恒,付成群

《中国工程科学》 2013年第15卷第5期页码 106-112

摘要：

为有效表示坑道工程空间对象，并有效支持动荷段实体的各种拓扑操作和毁伤分析等军事应用，提出了坑道工程动荷段实体模型构件化设计解决方案和设计质量的直觉模糊判决方法。适应坑道工程动荷段实体模型构件化设计的多样性特征和有效性验证约束，确定直觉模糊的正负理想构件化设计事件，比较构件化设计事件与正负理想事件的距离，建立坑道工程动荷段实体模型构件化设计事件的优势度计算模型，进而得到构件化设计事件集合的序列。案例表明，方法有效解决了坑道工程动荷段实体模型构件化设计质量判决问题，为科学的坑道工程动荷段实体模型设计实践提供了一种理论和方法。

关键词：坑道工程构件设计质量实体模型直觉模糊集优势度

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Protective roles of heat stress on the neurons in hippocampal CA1 region of mice

WANG Chunxu, WANG Hanxing

《医学前沿（英文）》 2007年第1卷第4期页码 418-422 doi: 10.1007/s11684-007-0082-7

摘要： The effects of heat stress on the neurons in hippocampal CA1 region of brain ischemia/reperfusion were explored. The mice were pretreated with heat stress followed by ischemia/reperfusion by clipping bilateral cervical commo n arteries for 7 min. Mice were divided randomly into four groups as follows: (1) normal control group; (2) heat stress pretreated subsequent to ischemia/reperfusion group (HS/IR); (3) ischemia/reperfusion group (IR); and (4) heat stress group (HS). Animals in the last three groups were subdivided into three subgroups: 1 d, 4 d, 14 d respectively. The Morris water maze was used to test the ability of learning and memorizing, Nissl staining was used to count the average number of survived neurons in hippocampal CA1 region, and immunohistochemistry combined with image analysis system to detect the changes of Microtubule associated protein 2 (MAP-2) expression. The results showed that mice in IR group exhibited increased escape latency when compared with that of normal, HS and HS/IR groups (<0.01), and the mice in IR group adopted an inefficient search strategy, major in circling and restricted searching manners. Nissl staining results showed a significant reduction in the number of pyramidal neurons in hippocampal CA1 regions in HS/IR and IR groups, with a decrease in IR group (<0.01). Compared with normal group, the expression of MAP-2 in hippocampal CA1 region obviously decreased in IR group (<0.05). The present results indicate that heat stress pretreatment can improve the spatial learning and memorizing function through protection to hippocampal neurons.

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标题作者时间类型操作

Hierarchical ZSM-5 zeolite with radial mesopores: Preparation, formation mechanism and application for benzene alkylation

Darui Wang, Hongmin Sun, Wei Liu, Zhenhao Shen, Weimin Yang

期刊论文

Enhancing thermostability of -mannanase by protective additives

LIU Zhaohui, QI Wei, WU Weina, LIU Yue, HE Zhimin

期刊论文

The influence of brain death on donor liver and the potential mechanisms of protective intervention

null

期刊论文

Dealumination and desilication for Al-rich HZSM-5 zeolite via steam-alkaline treatment and its application