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Effect of Surface Modification on Corrosion Resistance of Pure *** in Vivo Observation

Chinese Journal of Biomedical Engineering(English Edition) 2006年第2期15卷 62-68页

作者： li xiao-mei guo tian-wen wang da-lin Stomatology of Changhai Hospital Second Military Medical UniversityShanghai 200433 Department of ProstheticsSchool of DentistryFourth Military Medical UniversityXi''an 710032 Stomatology of Changhai HospitalSecond Military Medical UniversityShanghai 200433

Objective: The aim of this experiment is to study the effect of three methods of surface modification on the corrosion resistance of commercial pure Titanium when used in oral environment for half a ***:48 specimens of pure titanium were made and divided into four groups randomly, one group was selected randomly as Group I (control group), the other three groups were treated by three methods of surface modification individually, GroupⅡ:heating oxidation in air(400℃,30min.), GroupⅢ:anodization (45 volts, 10 min.),GroupⅣ:TiN coating(firing temperature 200℃ , total coating time 62min.). Six edentulous volunteers with healthy oral mucosa participated in the in vivo study. One testing piece from each group was selected and fixed in the polished surface of upper complete dentures. Dynamic polarization curves were traced with electrochemical method after the specimens were placed either in oral cavity or in air for 6 months. Results: After all specimens were used, Ecorr altered in every group , Ecorr from high to low were in turn: TiN coating group>heating oxidation group> anodization group>control group, no obvious passive potential Ep and Ip was found in control group. Heating oxidation in air exhibited similar Ep to anodization, but Ip was remarkably lower than that of anodization; TiN coating showed obviously different polarization curves compared with heating-oxidation group and anodization group, Ecorr was positive, and no Ep and Ip was found. Conclusion: Under present experimental condition, all the three treatment methods could enhance corrosion resistance of pure titanium in oral environment, heating oxidation in air exhibited better resistance to corrode than anodization, TiN coating possessed the most excellent corrosion resistance, even after exposed in oral condition for 6 months, there was little change of corrosion resistance. Therefore TiN coating could be adopted to improve corrosion resistance of pure titanium in oral environment.

关键词： Surface modification,Pure Titanium,Corrosion,Heating oxidation,Anodization,TiN coating

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Carbide Precipitation in Ferrite in Nb–V-Bearing Low-Carbon Steel During Isothermal Quenching Process

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Acta Metallurgica Sinica(English Letters) 2017年第11期30卷 1067-1079页

作者： xiao-lin li Cheng-Shuai Lei Xiang-Tao Deng Yan-mei li Yong tian Zhao-Dong wang guo-Dong wang State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110819 China

The precipitation behavior of nanometer-sized carbides in ferrite in Nb-V-bearing low-carbon steel was studied by electron microscopy and nanoindentation hardness measurements. The results indicated that interphase precipitation and random precipitation could occur simultaneously for the specimen isothermally treated at 700 ℃ for 60 min, while in other specimens, only random precipitation was observed. This phenomenon might be explained by mass balance criterion during the diffusional phase transformation. Nanohardness result indicated that the average hardness of the specimens isothermally held at 600 ℃ for 20 min was 3.87 GPa. For the specimen isothermally holding at 650 ℃ for 20 min, the average hardness was 4.10 GPa and the distribution of the nanohardness was in a narrower range compared with that of the specimen isothermal holding at 600 ℃ for 20 min. These implied that the carbides in the specimens isothermal treated at 650℃ were more uniformly dispersed, and the number density of the carbides was greater than that treated at 600 ℃. Using Ashby-Orowan model, the contribution of precipitation strengthening to yield strength was estimated to be 110 MPa for the specimen isothermally treated at the temperature of 650 ℃ for 20 min.

关键词： High-strength low-alloy(HSLA) Interphase precipitation Carbides Nanoindentation hardness High-resolution transmission electronic microscopy(HRTEM)

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Asymptotic Normality of Nonparametric Estimate for Zero-Utility Premiums

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Acta Mathematicae Applicatae Sinica 2019年第3期35卷 607-619页

作者： li-min wen xiao-hong ZHUANG guo-ping mei Yi ZHANG Department of Statistics Jiangxi Normal UniversityNanchang 330022China Department of Economics and Business Management Shangrao Normal UniversityShangrao 334001China School of Statistics Jiangxi University of Finance and EconomicsNanchang 330013China

Zero-utility principle is one of the main premium pricing principles,which has been widely used in insurance *** this paper,the nonparametric estimation of zero-utility premium is *** addition,the consistency and asymptotic normality of the estimation are *** special cases including linear,exponential and quadratic utility are ***,the Monte Carlo method is used to show the convergence rate of premium ***,the histogram and Normal-Probability-Plot are given to investigate the asymptotic normality of the *** results show that our estimations are good enough to use in practice.

关键词： zero-utility premiums nonparametric estimation consistency asymptotic normality

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The effects of Trichoderma on preventing cucumber fusarium wilt and regulating cucumber physiology

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Journal of Integrative Agriculture 2019年第3期18卷 607-617页

作者： li mei MA Guang-shu liAN Hua SU xiao-lin tian Ying HUANG wen-kun mei Jie JIANG Xi-liang Institute of Plant Protection Chinese Academy of Agricultural Sciences College of Agronomy Heilongjiang Bayi Agricultural University

In our previous studies, we identified 3 Trichoderma strains with anti-Fusarium oxysporum activity, including T. asperellum 525, T. harzianum 610, and T. pseudokoningii 886. Here, we evaluated the effects of these 3 Trichoderma strains on preventing cucumber fusarium wilt through pot culture and greenhouse culture experiments. All 3 Trichoderma strains demonstrated higher control effects toward cucumber fusarium wilt than previous studies, with efficacies over 78%. Additionally, inoculation with the 3 Trichoderma strains significantly promoted the quality and yield of cucumbers. Among the 3 strains, Trichoderma 866 was the most effective, with disease control efficacy of 78.64% and a cucumber yield increase of 33%. Furthermore, seedlings inoculated with Trichoderma exhibited significantly increased measures of plant height, stem diameter, leaf area, aboveground fresh weight, underground fresh weight, chlorophyll content, and nitric nitrogen content, as well as the activities of several stress-resistance enzymes, including superoxide dismutase(SOD), peroxidase(POD), catalase(CAT), polyphenol oxidase(PPO), and ascorbate oxidase(AAO). In addition, the plants inoculated with Trichoderma showed decreased cell membrane permeability and malondialdehyde(Mda) content in the leaves. Together, our results suggest that T. asperellum 525, T. harzianum 610, and T. pseudokoningii 886 inoculations inhibit F. oxysporum infection, stimulate the metabolism in cucumbers, and enhance the activities of stress-resistance enzymes, which consequently promote the growth of cucumber plants, prevent cucumber fusarium wilt, and improve the yield and quality of cucumbers. T. harzianum is a commonly used biocontrol fungus, while few studies have focused on T. asperellum or T. koningense. In this study, strains of T. asperellum and T. pseudokoningii showed excellent plant disease prevention and growth promoting effects on cucumber, indicating that they also have great potential as biocontrol fungi

关键词： Trichoderma cucumber fusarium wilt physicochemical features control effect Fusarium oxysporum f. sp. cucumerinum Owen

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Development of A Fiber-Packed In-Tube Extraction Device and Its Application for BTEX Analysis

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分析化学 2021年

作者： ZHU Bo guo xiao-Yang wang Xi-Yue liAN li-li ZHANG Hao GAO wen-Xiu tian Yuan-Yuan ZHANG xiao-Yu LOU da-Wei Department of Analytical Chemistry Jilin Institute of Chemical Technology Shuangliao Rural Energy Agriculture Environmental Protection Center Department of Analytical Chemistry Jilin University

A fiber-packed in-tube extraction device was developed with heat-resistant fibers coated with molecularly imprinted polymer as adsorbent for concentration of the volatile organic compounds（VOCs）. The coated fibers were longitudinally packed into a filling chamber. The inner diameter of the filling chamber was 3 mm and its length was 2.5 cm. The filling chamber was connected to gas chromatography port by a stainless needle. The device was heated by an external heater consisting of the heating wire surrounded outside of the filling chamber to gasify the analytes in the adsorbent. The prepared fiber-packed in-tube extraction device was used to analyze benzene, toluene, ethylbenzene and o-xylene in gas sample coupled with gas chromatography. The result shows that the device has better permeability. The extraction time for 150 mL gas sample was 1.2 min. The range of linear detection, recovery, limit of detection（LOD） and limit of quantification（LOQ） were also evaluated for the promising method. The calibration plots for benzene, toluene, ethylbenzene, and o-xylene were linear in the concentration range of 1-300 μg·L;, and the corresponding correlation coefficients exceeded 0.9936. The LODs and LOQs of the analytes were in the range of 0.02-0.03 μg·L;and 0.03-0.05 μg·L;, respectively. The recoveries of benzene, toluene, ethylbenzene, and o-xylene were 90.3%, 94.3%, 98.7%, and 103.3%, respectively.

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A new phenanthraquinone from the roots of Peucedanum praeruptorum

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Chinese Chemical Letters 2010年第7期21卷 816-817页

作者： Cun Zhang li li Yong Qing xiao wen li xiao Jie Yin guo Fang tian Dong Dong Chen Yun wang Institute of Chinese Materia Madica China Academy of Traditional Chinese MedicineBeijing 100700China

A new compound,9,10-dihydrophenanthrinic acid,9,10-dione-3,4-methylenedioxy-8-methoxy（1） was isolated from the roots of Peucedanum praeruptorum Dunn on the basis of spectral evidences.

关键词： Peucedanum praeruptorum 9 10-Phenanthraquinone 9 10-Dihydrophenanthrinic acid 9 10-Dione-3 4-methylenedioxy-8-methoxy

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ATP6AP2,a regulator of LRP6/β-catenin protein trafficking,promotes Wnt/β-catenin signaling and bone formation in a cell type dependent manner

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Bone Research 2024年第2期12卷 453-468页

作者： Lei Xiong Hao-Han guo Jin-Xiu Pan xiao Ren daehoon Lee li Chen lin mei wen-Cheng Xiong Department of Neurosciences School of MedicineCase Western Reserve UniversityClevelandOH 44106USA Louis Stoke VA Medical Center ClevelandOH 44106USA

Wnt/β-catenin signaling is critical for various cellular processes in multiple cell types,including osteoblast(OB)differentiation and *** how Wnt/β-catenin signaling is regulated in OBs remain ***6AP2,an accessory subunit of V-ATPase,plays important roles in multiple cell types/organs and multiple signaling ***,little is known whether and how ATP6AP2 in OBs regulates Wnt/β-catenin signaling and bone *** we provide evidence for ATP6AP2 in the OB-lineage cells to promote OB-mediated bone formation and bone homeostasis selectively in the trabecular bone *** knocking out(CKO)ATP6AP2 in the OB-lineage cells(Atp6ap2^(Ocn-Cre))reduced trabecular,but not cortical,bone formation and bone *** and cellular biochemical studies revealed that LRP6 and N-cadherin were reduced in ATP6AP2-KO BMSCs and OBs,but not *** in vitro and in vivo studies revealed impairedβ-catenin signaling in ATP6AP2-KO BMSCs and OBs,but not osteocytes,under both basal and Wnt stimulated conditions,although LRP5 was decreased in ATP6AP2-KO osteocytes,but not *** cell biological studies uncovered that osteoblastic ATP6AP2 is not required for Wnt3a suppression ofβ-catenin phosphorylation,but necessary for LRP6/β-catenin and N-cadherin/β-catenin protein complex distribution at the cell membrane,thus preventing their *** of activeβ-catenin diminished the OB differentiation deficit in ATP6AP2-KO *** together,these results support the view for ATP6AP2 as a critical regulator of both LRP6 and N-cadherin protein trafficking and stability,and thus regulatingβ-catenin levels,demonstrating an un-recognized function of osteoblastic ATP6AP2 in promoting Wnt/LRP6/β-catenin signaling and trabecular bone formation.

关键词： LRP6 impaired organs

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Identification and Detection of Actinobacillus pleuropneumoniae in Infected and Subclinically Infected Pigs by Multiplex PCR Based on the Genes ApxIVA and OmlA

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Agricultural Sciences in China 2006年第2期5卷 146-154页

作者： xiao guo-sheng CAO San-jie DUAN li-li wen Xin-tian MA xiao-ping CHEN Hua-mei Laboratory of Animal Infectious Disease and Microarray/Key Laboratory of Animal Disease and Human Health of Sichuan Province College of Animal Science and Veterinary Medicine Sichuan Agricultural University Ya＇an 625014 P.R.China

PCRs based on different genes of Actinobacillus pleuropneumoniae have been developed for detecting and identifying A. pleuropneumoniae. Some of them could amplify positive fragments from the phylogenetically closely related species bacteria. To improve veracity and specificity of PCR, a species-specific multiplex PCR assay was developed to identify and detect A. pleuropneumoniae, based on the 3＇-terminus of the species-specific apxlVA gene and the already existing species-specific primers in the omlA gene. Both 346-bp and 950-bp fragments could be simultaneously amplified from all A. pleuropneumoniae reference strains and isolates, and the species specificity of the assay was evaluated with a collection of ten strains representing eight different species bacteria including species normally found in the respiratory tracts of swine. All of these strains turned out negative in the multiplex PCR. All sequences of products of multiplex PCR randomly sampled were also correct. The sensitivity of the multiplex PCR was determined to be 10 pg of A. pleuropneumoniae DNA. The multiplex PCR and bacterial isolation were compared to determine their sensitivities by using experimentally infected pigs and clinical disease pigs. The multiplex PCR was more sensitive than bacterial isolation. The multiplex PCR was also evaluated on mixed bacterial cultures from clinical healthy pigs. 26/100 （26%） of the subclinically infected pigs were detected from clinical healthy pigs. The results indicate that the multiplex PCR assay is a sensitive, highly specific, and effective diagnostic tool for identification and detection of A. pleuropneumoniae.

关键词： multiplex PCR Actinobacillus pleuropneumoniae pig bacteria apxIVA and omlA genes

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Differential volatile organic compounds in royal jelly associated with different nectar plants

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Journal of Integrative Agriculture 2016年第5期15卷 1157-1165页

作者： ZHAO Ya-zhou li Zhi-guo tian wen-li FANG xiao-ming SU Song-kun PENG wen-jun Institute of Apicultural Research Chinese Academy of Agricultural Sciences College of Bee Sciences Fujian Agriculture and Forestry University

The aim of this work was to distinguish volatile organic compound（VOC） profiles of royal jelly（RJ） from different nectar plants. Headspace solid-phase microextraction（HS-SPME） was used to extract VOCs from raw RJ harvested from 10 nectar plants in flowering seasons. Qualitative and semi-quantitative analysis of VOCs extracts were performed by gas chromatography-mass spectrometry（GC-MS）. Results showed that VOC profiles of RJ from the samples were rich in acid, ester and aldehyde compound classes, however, contents of them were differential, exemplified by the data from acetic acid, benzoic acid methyl ester, hexanoic acid and octanoic acid. As a conclusion, these four VOCs can be used for distinguishing RJ harvested in the seasons of different nectar plants.

关键词： royal jelly volatile organic compounds nectar plant headspace solid-phase microextraction gas chromatography-mass spectrometry

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Three-dimensional topological insulators:case of quaternary Heusler compounds

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Rare Metals 2021年第5期40卷 1219-1223页

作者： xiao-tian wang Xue-Fang dai Hong-Ying Jia li-Ying wang guo-Dong liu Xi-Feng liu wen Yuan Yu-Ting Cui School of Material Sciences and Engineering Hebei University of TechnologyTianjin 300130China College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082China Department of Chemistry Michigan State UniversityEast LansingMichigan 48824USA School of Physics and Electronic Engineering Chongqing Normal UniversityChongqing 400044China

The feasibility of converting quaternary Heusler compounds XX’MZ(X=Sc,La;X’=Sc,Y;M=Ru,Fe;Z=Pb)into three-dimensional topological insulators was investigated by first-principle *** is found that the topological insulating state can be achieved in these quaternary Heusler compounds by the proper strain engineering or the substitution of *** of these compounds investigated in this paper have a negative formation energy,which implies that they are possible to be synthesized in reality.

关键词： Topological insulator Heusler compound Electronic structure

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