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Controllable synthesis of zone-distributed Pd over CeO₂-ZrO₂/Al₂O₃ as advanced three-way catalyst

JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY 2018年 58卷 246-257页

作者： Lan, Li Chen, Shanhu Li, Hongmei Li, Hanmei Wu, Wanxia Deng, Jie Chen, Yaoqiang Chengdu Univ Coll Pharm & Biol Engn Chengdu 610106 Sichuan Peoples R China Sinocat Environm Technol Co Ltd Chengdu 611731 Sichuan Peoples R China Sichuan Univ Coll Chem Minist Educ Key Lab Green Chem & Technol Chengdu 610064 Sichuan Peoples R China

Two optimally designed catalysts (Ce0.7Zr0.3O2/Pd/Al2O3, Pd/Ce0.7Zr0.3O2/Pd/Al2O3) were synthesized and compared with conventional Pd/Ce0.7Zr0.3O2/Pd/Al2O3. The characterization results reveal that for Pd/Ce0.7Zr0.3O2/Pd/Al2O3, Pd species undergo severe agglomeration and encapsulation during thermal aging process, leading to dramatic catalyst deactivation. While for the two optimized catalysts, some Pd species initially distributed on Al2O3 would migrate to the surface of CexZr1-xO2(CZ) grains upon aging treatment, resulting in enhanced Pd-CZ interaction, thus the two aged samples possess higher dispersion, larger amount of oxidized Pd2+ species and more oxygen vacancies compared with conventional Pd/Ce0.7Zr0.3O2/Pd/Al2O3-a. Consequently, modified reducibility and improved three-way catalytic performance are obtained, especially for Pd/Ce0.7Zr0.3O2/Pd/Al2O3-a. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

关键词： Optimally designed catalysts Pd-CZ interaction Dispersion Oxidation state Three-way catalytic performance

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Apparent magnitude calculation method for complex shaped space objects

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ADVANCES IN SPACE research 2018年第11期62卷 2988-2997页

作者： Wang, Yang Du, Xiaoping Zhao, Jiguang Gou, Ruixin Space Engn Univ Beijing 101416 Peoples R China 63611 Troops Korla 841000 Peoples R China

The apparent magnitude of a complex shaped space object is difficult to calculate since its visible triangular facets are hard to be determined. The most common-used visible facets determination method is to judge the incident and emergent angle, but this method does not apply to a space object which is a combination of convex bodies or has a concave surface. In this paper, a new quadtree-based hidden vertex removal method is presented, and it is composed of four steps: coordinate transformation, hidden vertex removal, quadtree decompositions and visible triangular facets determination. This method can determine visible triangular facets of a space object of any shapes. Once a space object triangular facet model, the observed direction of a telescope and the incident direction of the sunlight are given, the visible triangular facets of the space object can be obtained. Two experiments are carried out to verify the visible triangular facet determination performance of this method qualitatively and quantitatively. Experiment results show the visible triangular facet calculated by the proposed method is accurate and reasonable. (C) 2018 COSPAR. Published by Elsevier Ltd. All rights reserved.

关键词： Apparent magnitude Space object Complex shape Visible facet

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Fibroblast growth factor 21 prolongs lifespan and improves stress tolerance in the silkworm,Bombyx mori

Fibroblast growth factor 21 prolongs lifespan and improves s...

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中国蚕学会2021年学术年会

作者： Jiang-Bo Song Kai-Ge Hao Xin Chen Yan-Hua Zhang Zi-Lin Cheng Shuang Mao Yong-Xi Tang Xiao-Ling Tong Fang-Yin Dai State Key Laboratory of Silkworm Genome Biology Key Laboratory for Sericulture Biology and Genetic BreedingMinistry of Agriculture and Rural AffairsCollege of BiotechnologySouthwest University

Background:Fibroblast growth factor 21(FGF21),an FGF family member,is an atypical hormone and pro-longevity ***:To better understand of the effects of exogenous administration of FGF21 on lifespan and stress tolerance,and the underlying molecular basis,we used the silkworm,Bombyx mori,as an experimental animal model to evaluate FGF21's pharmaceutical ***:Lifespan was significantly prolonged in female silkworms with FGF21 replenishment,whereas no effect was observed in the male ***21 replenishment also significantly improved the activity of antioxidant systems such as glutathione-S-transferase(GST) and superoxide dismutase(SOD) and significantly decreased malondialdehyde(MDA) ***,FGF21 was found to play a critical role in enhancing stress resistance,including ultraviolet(UV) irradiation tolerance and ***,AMPK,Fox O,and sirtuins were activated by FGF21 and may be responsible for the prolonged lifespan and enhanced antioxidant activity observed in ***:Collectively,the results suggest the molecular pathways underlying of FGF21-induced longevity and stress tolerance,and support the use of silkworms as a promising experimental animal model for evaluating the pharmaceutical effects of small molecules.

关键词： Bombyx mori fibroblast growth factor 21 (FGF21) lifespan oxidation resistance stress tolerance

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Resveratrol elongates the lifespan and improves antioxidant activity in the silkworm,Bombyx mori

Resveratrol elongates the lifespan and improves antioxidant ...

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中国蚕学会2021年学术年会

作者： Jiangbo Song Lian Liu Kaige Hao Shuang Mao Yongxi Tang Xiaoling Tong Fangyin Dai State Key Laboratory of Silkworm Genome Biology Key Laboratory for Sericulture Biology and Genetic BreedingMinistry of Agriculture and Rural AffairsCollege of BiotechnologySouthwest University

A large body of research has shown that the plant polyphenol resveratrol,one of the most prominent small molecules,has beneficial protective effects in multiple organisms,including worms,flies,and *** understand the effects of resveratrol on lifespan,we evaluated its effects in the silkworm Bombyx *** this study,we found that lifespan was significantly prolonged in both female and male silkworms treated with *** larval weight was significantly increased from day 3 of the 5th larval instar(L5D3) to day 7 of the 5th larval instar(L5D7).However,the weight of the pupa,cocoon,and total cocoon were not significantly different in female silkworms with resveratrol treatment than in ***,resveratrol significantly improved the thermotolerance of the silkworm,which enhanced their survival ***,antioxidant activity was increased by resveratrol in both female and male ***,an antioxidant-related signalling pathway,SIRT7-FoxO-GST,was activated in silkworms under resveratrol ***,these results aid our understanding of the molecular pathways underlying resveratrol induced pro-longevity effects and indicate that the silkworm is a promising animal model for evaluating the effects of lifespan-extending drugs.

关键词： Resveratrol Bombyx mori Lifespan antioxidant activity SIRT7-FoxO-GST pathway

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Lensless Wiener–Khinchin telescope based on second-order spatial autocorrelation of thermal light

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Chinese Optics Letters 2019年第9期17卷 43-49页

作者： Zhentao Liu Xia Shen Honglin Liu Hong Yu Shensheng Han Key Laboratory for Quantum Optics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences

The resolution of a conventional imaging system based on first-order field correlation can be directly obtained from the optical transfer function. However, it is challenging to determine the resolution of an imaging system through random media, including imaging through scattering media and imaging through randomly inhomogeneous media, since the point-to-point correspondence between the object and the image plane in these systems cannot be established by the first-order field correlation anymore. In this Letter, from the perspective of ghost imaging, we demonstrate for the first time, to the best of our knowledge, that the point-to-point correspondence in these imaging systems can be quantitatively recovered from the second-order correlation of light fields, and the imaging capability, such as resolution, of such imaging schemes can thus be derived by analyzing second-order autocorrelation of the optical transfer function. Based on this theoretical analysis, we propose a lensless Wiener–Khinchin telescope based on second-order spatial autocorrelation of thermal light, which can acquire the image of an object by a snapshot via using a spatial random phase modulator. As an incoherent imaging approach illuminated by thermal light, the lensless Wiener–Khinchin telescope can be applied in many fields such as X-ray astronomical observations.

关键词： optical snapshot random object can X-ray be our

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Semi-rationally engineered variants of S-adenosylmethionine synthetase from Escherichia coli with reduced product inhibition and improved catalytic activity

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ENZYME AND MICROBIAL techNOLOGY 2019年 129卷 109355页

作者： Wang, Xiu Jiang, Yiqi Wu, Mianbin Zhu, Li Yang, Lirong Lin, Jianping Zhejiang Univ Coll Chem & Biol Engn Key Lab Biomass Chem Engn Minist Educ Hangzhou 310027 Zhejiang Peoples R China

S-adenosylmethionine synthetase (MAT) catalyzes the synthesis of S-adenosylmethionine (SAM) from ATP and L-methionine. SAM is the major methyl donor for more than 100 transmethylation reactions. It is also a common cosubstrate involved in transsulfuration and aminopropylation. However, product inhibition largely restrains the activity of MAT and limits the enzymatic synthesis of SAM. In this research, the product inhibition of MAT from Escherichia coli was reduced via semi-rational modification. A triple variant (Variant III, I303 V/I65 V/L186 V) showed a 42-fold increase in K-i,K-ATP and a 2.08-fold increase in specific activity when compared to wild-type MAT. Its K-i,K-ATP was 0.42 mM and specific acitivity was 3.78 +/- 0.19 U/mg. Increased K-i,K-ATP means reduced product inhibition which enhances SAM accumulation. The SAM produced by Variant III could reach to 3.27 mM while SAM produced by wild-type MAT was 1.62 mM in the presence of 10 mM substrates. When the residue in 104th of Variant III was further optimized by site-saturated mutagenesis, the specific activity of Variant IV (I303 V/I65 V/L186 V/N104 K) reached to 6.02 +/- 0.22 U/mg at 37 degrees C, though the SAM concentration decreased to 2.68 mM with 10 mM substrates. Analysis of protein 3D structure suggests that changes in hydrogen bonds or other ligand interactions around active site may account for the variety of product inhibition and enzyme activity. The Variant III and Variant IV with reduced inhibition and improved enzyme activity in the study would be more suitable candidates for SAM production in the future.

关键词： S-adenosylmethionine synthetase Product inhibition Enzyme activity Semi-rational modification Saturated mutagenesis

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Sorption of Pb (II) onto < 1 μm effective diameter clay minerals extracted from different soils of the Loess Plateau, china

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GEODERMA 2019年 337卷 1058-1066页

作者： Yin, Xianqiang Yu, Lin Luo, Xiuhua Zhang, Zhe Sun, Huimin Mosa, Ahmed Ali Wang, Nong Northwest A&F Univ Coll Nat Resources & Environm Yangling 712100 Shaanxi Peoples R China Suzhou Wetland Protect & Management Stn Suzhou 215107 Peoples R China Mansoura Univ Soils Dept Fac Agr Mansoura 35516 Egypt Minist Agr Peoples Republ China Agroenvironm Protect Inst Tianjin 300191 Peoples R China

Fine clay particles in the soil, especially for " DL (476.19 mg g(-1)) > ML (416.67 mg g(-1)) > AS (263.16 mg g(-1)) based on their grain size, surface area, organo-mineral composition and active functional... 详细信息

Fine clay particles in the soil, especially for "< 1 mu m effective diameter clay minerals" (< 1 mu m EDCM) are the most important sink of heavy metals immobilization. However, heavy metal-loaded < 1 mu m EDCM still pose a threat to the environment based on their high accessibility in various ecosystems. < 1 mu m EDCM of different loessial soils (i.e. aeolian sandy (AS), manual loessial (ML), cultivated loessial (CL), and dark loessial (DL)) were extracted to identify their binding capacity of Pb(II) ions. Physiochemical characterization of < 1 mu m EDCM was performed using atomic force microscopy (AFM), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). The micro-aggregates features of < 1 mu m EDCM were further investigated using AFM. Nano morphological features of CL and ML exhibited a roughness shape with higher aggregates formation. However, DL and AS showed a less-aggregated shape with higher potential for accessibility to various ecosystems. Sorption equilibrium time varied greatly among different < 1 mu m EDCM (4 h with AS, 9 h with ML and DL, and 16 h with CL). Sorption process was mainly controlled by intraparticle diffusion and dominated by chemisorption. The maximum sorption capacity of Pb (II) onto < 1 mu m EDCM showed the rank as: CL (588.24 mg g(-1)) > DL (476.19 mg g(-1)) > ML (416.67 mg g(-1)) > AS (263.16 mg g(-1)) based on their grain size, surface area, organo-mineral composition and active functional groups. Data of sorption isotherm showed a high fitting with Temkin model assuming that electrostatic interaction is an important mechanism controlling Pb (II) sorption onto < 1 mu m EDCM. Finding of this study will provide insights about the vital roles < 1 mu m EDCM and their aggregates in controlling the bioavailability of heavy metals in aquatic and terrestrial ecosystems.

关键词： Characterization Lead Sorption < 1 mu m effective diameter clay minerals Loess plateau

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De novo generation of specific human IgGs by in vitro immunization using autologous proteins containing immunogenic p-nitrophenylalanine

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MABS 2019年第2期11卷 401-410页

作者： Tong, Yue Fang, Xu Tian, Hong Zhong, Shengwei Jin, Liang Gao, Xiangdong Yao, Wenbing China Pharmaceut Univ Jiangsu Key Lab Druggabil Biopharmaceut State Key Lab Nat Med Sch Life Sci & Technol Nanjing 210009 Jiangsu Peoples R China

In vitro immunization can to used to produce monoclonal antibodies(mAbs), but this technology is limited by poor reproducibility and the requirement of pre-immunized lymphocytes. To improve this approach, we recently developed a method for rapid generation of antigen-specific B cells. Here, we report the application of this system to the production of human IgGs against tumor necrosis factor (TNF). We expressed mutant proteins with site-specific incorporated p-nitrophenylalanine (pNO(2)Phe), which stimulated an in vitro immune response in human immune cells. After constructing an antigen-specific antibody library from in vitro immunized B cells identified by fluorescence-activated cell sorting, we demonstrated that many point mutation events of the variable region occurred in our step-by-step co-cultivation system for affinity maturation in vitro. To mimic the class switching, we panned for high-affinity antigen-binding fragments by the phage display method, assembled them and identified hTNF-neutralizing human IgGs. This approach may provide a general method for raising high-affinity monoclonal antibodies against self-proteins. Furthermore, it supports mechanistic understanding in breaking human self-tolerance with pNO(2)Phe.

关键词： In vitro immunization full human monoclonal antibodies immunological tolerance IgGs p-nitrophenylalanine

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Co-transport of graphene oxide and heavy metal ions in surface-modified porous media

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CHEMOSPHERE 2019年 218卷 1-13页

作者： Yin, Xianqiang Jiang, Yanji Tan, Yuehui Meng, Xiangmin Sun, Huimin Wang, Nong Northwest A&F Univ Coll Nat Resources & Environm Yangling 712100 Shaanxi Peoples R China Minist Agr Key Lab Plant Nutr & Agrienvironm Northwest China Yangling 712100 Shaanxi Peoples R China Minist Agr Peoples Republ China Tianjin Agroenvironm Protect Inst Tianjin 300191 Peoples R China

The ability to predict the transport of heavy metal ions in porous media with different surface characteristics is crucial to protect groundwater quality and public health. In this study, the effects of graphene oxide (GO) on co-transport and remobilization of Pb2+ and Cd2+ in humic acid (HA), smectite, kaolinite, and ferrihydrite-coated sand media were evaluated via laboratory packed-column experiments. Scanning electron microscope and energy dispersive X-ray analysis showed that the surface morphology of the coated sands was quite different and that similar to 56.7-89.9% of the surface was covered by the coating and the major elemental components were C, O, Si, Al, and Fe. GO exhibited high mobility in HA, kaolinite, and smectite-coated sand, but showed high retention in ferrihydrite-coated sand. While GO reduced the transport of Pb2+ and Cd2+, both metal ions also reduced the mobility of GO in coated-sand columns. Elution experiments revealed that GO led to the remobilization and release of the previously sorbed Pb(2+)and Cd2+ from the coated sand. However, GO could not release Pb(2+)and Cd2+ from smectite-coated sand columns, probably because smectite has stronger adsorption affinity to the heavy metals than GO. Derjaguin-Landau-Verwey-Overbeek calculations were employed and explained the GO transport behavior in the columns well. Furthermore, the advection-dispersion-reaction equation simulated the cotransport of Pb2+ and Cd2+ with GO in the coated sand well. These results are expected to provide insight into the potential impact of coexisting nanomaterials with contaminants in vulnerable soil and groundwater systems. (C) 2018 Elsevier Ltd. All rights reserved.

关键词： Transport Graphene oxide Pb2+ Cd2+ Coated sand DLVO theory

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Evaluation of the silkworm lemon mutant as an invertebrate animal model for human sepiapterin reductase deficiency

Evaluation of the silkworm lemon mutant as an invertebrate a...

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中国蚕学会2021年学术年会

作者： Guihua Jiang Jiangbo Song Hai Hu Xiaoling Tong Fangyin Dai State Key Laboratory of Silkworm Genome Biology Key Laboratory of Sericulture Biology and Genetic BreedingMinistry of Agriculture and Rural AffairsCollege of BiotechnologySouthwest University

Human sepiapterin reductase(SR) deficiency is an inherited disease caused by SPR gene mutations and is a monoamine neurotransmitter ***,we investigated whether the silkworm lemon mutant could serve as a model of SR deficiency.A point mutation in the BmSPR gene led to a five amino acid deletion at the carboxyl terminus in the lemon *** addition,classical phenotypes seen in SR deficient patients were observed in the lemon mutant,including a normal phenylalanine level,a decreased dopamine and serotonin content,and an increased neopterin level.A recovery test showed that the replenishment of L-dopa significantly increased the dopamine level in the lemon *** silkworm lemon mutant also showed negative behavioural *** results suggest that the silkworm lemon mutant has an appropriate genetic basis and meets the biochemical requirements to be a model of SR ***,the silkworm lemon mutant can serve as a candidate animal model of SR deficiency,which may be helpful in facilitating accurate diagnosis and effective treatment options of SR deficiency.

关键词： Bombyx mori lemon mutant BmSPR sepiapterin reductase deficiency animal model of human diseases

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