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Neural Regeneration Research 2025年第3期20卷 819-820页

作者： Rayudu Gopalakrishna jennifer Aguilar Emily Lee william j.Mack Department of Integrative Anatomical Sciences Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCAUSA Department of Neurological Surgery Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCAUSA

The dietary polyphenolic compounds resveratrol and quercetin prevent neurodegenerative diseases in experimental models;however, they reach the brain only in nanomolar concentrations in the glucuronidated and sulfated ... 详细信息

关键词： resveratrol molar dated

Microstructure and tensile properties of magnesium nanocomposites fabricated using magnesium chips and carbon black

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journal of Magnesium and Alloys 2020年第3期8卷 860-872页

作者： T.j.Lee w.j.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

In this study,carbon black(0,0.01,0.03 and 0.08 wt%)and AZ31(Mg-3Al-lZn)magnesium chips were used to fabricate carbon black-reinforced magnesium matrix composites with extrusion or a combination of extrusion and high-ratio differential speed *** hot pressing at 693 K and extrusion at 623 K with an extrusion ratio of 22,the magnesium chips coated with carbon black were soundly bonded into a bulk composite *** grain sizes of the extruded materials were similar with a size of 48.2-51.5|im despite the difference in the amount of carbon *** yield strength and ultimate tensile strength increased from 177 to 191 MPa and from 240 to 265 MPa,respectively,as a result of the addition of 0.01%carbon black;however,a further increase in the strength was marginal with additional carbon *** same trend was observed in the strain hardening *** tensile elongation increased by to the addition of 0.01%carbon black(from 15.8%to 17.4%)due to the increased work hardening effect,but decreased with additional carbon black due to its agglomeration and poor dispersion at higher *** high-ratio differential speed rolling(HRDSR)on the extruded materials and subsequent annealing,the AZ31 and AZ31 composites had a similar fine grain size of 16.3-17.9 *** annealed HRDSR composites showed the best mechanical properties at a higher content of carbon black(0.03%)compared to that(0.01%)for the extruded *** resulted from the enhanced dispersion effect of the carbon black due to the high shear flow induced during the HRDSR *** extruded composites exhibited the three distinct hardening stages(stage II,stage III and stage IV),while the annealed HRDSR composites mainly displayed the stage III *** addition of carbon black increased the strain hardening rate at all the strain hardening stages in both of the extruded and annealed HRDSR *** the initial hardening stage,the strain hardening rates of the extruded comp

关键词： Recycling Magnesium alloys chips Carbon black Nanocomposites Extrusion Differential speed rolling

Postoperative Crohn’s disease recurrence: A practical approach

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world journal of Gastroenterology 2008年第36期14卷 5540-5548页

作者： Pilar nos Eugeni Domènech Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd) Spain

Crohn's disease is a chronic inflammatory condition that may involve any segment of the gastrointestinal tract. Although several drugs have proven efficacy in inducing and maintaining disease in remission, resectional surgery remains as a cornerstone in the management of the disease, mainly for the treatment of its stenosing and penetrating complications. However, the occurrence of new mucosal (endoscopic) lesions in the neoterminal ileum early after surgery is almost constant, it is followed in the mid-term by clinical symptoms and, in a proportion of patients, repeated intestinal resections are required. Pathogenesis of postoperative recurrence (POR) is not fully understood, but luminal factors (commensal microbes, dietary antigens) seem to play an important role, and environmental and genetic factors may also have a relevant influence. Many studies tried to identify clinical predictors for POR with heterogeneous results, and only smoking has repeatedly been associated with a higher risk of POR. Ileocolonoscopy remains as the gold standard for the assessment of appearance and severity of POR, although the real usefulness of the available endoscopic score needs to be revisited and alternative techniques are emerging. Several drugs have been evaluated to prevent POR with limited success. Smoking cessation seems to be one of the more beneficial therapeutic measures. Aminosalicylates have only proved to be of marginal benefit, and they are only used in low-risk patients. Nitroimidazolic antibiotics, although efficient, are associated with a high rate of intolerance and might induce irreversible side effects when used for a long-term. Thiopurines are not widely used after ileocecal resection, maybe because some concerns in giving immunomodulators in asymptomatic patients still remain. In the era of biological agents and genetic testing, a well-established preventive strategy for POR is still lacking, and larger studies to identify good clinical, serological, and geneti

关键词： Crohn's disease Postoperative recurrence Smoking Aminosalicylates Nitroimidazolic antibiotics Thiopurines

Effect of compressibility on the hypervelocity penetration

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Acta Mechanica Sinica 2018年第1期34卷 82-98页

作者： w.j.Song X.w.Chen P.Chen Department of Mechanics and Engineering Science College of Engineering Peking University Advanced Research Institute for Multidisciplinary Science Beijing Institute of Technology The State Key Lab of Explosion Science and Technology Beijing Institute of Technology Centre for Applied Physics and Technology (CAPT) Peking University

we further consider the effect of rod strength by employing the compressible penetration model to study the effect of compressibility on hypervelocity ***, we define different instances of penetration efficiency in various modified models and compare these penetration efficiencies to identify the effects of different factors in the compressible model. To systematically discuss the effect of compressibility in different metallic rod-target combinations, we construct three cases, i.e., the penetrations by the more compressible rod into the less compressible target, rod into the analogously compressible target, and the less compressible rod into the more compressible target. The effects of volumetric strain, internal energy, and strength on the penetration efficiency are analyzed simultaneously. It indicates that the compressibility of the rod and target increases the pressure at the rod/target interface. The more compressible rod/target has larger volumetric strain and higher internal energy. Both the larger volumetric strain and higher strength enhance the penetration or anti-penetration ability. On the other hand, the higher internal energy weakens the penetration or anti-penetration ability. The two trends conflict, but the volumetric strain dominates in the variation of the penetration efficiency, which would not approach the hydrodynamic limit if the rod and target are not analogously compressible. However, if the compressibility of the rod and target is analogous, it has little effect on the penetration efficiency.

关键词： Compressibility Hypervelocity penetration Equation of state(EOS) Shockwave Bernoulli equation

Glass-forming Ability and Corrosion Resistance of Zr—Cu—Al—Co Bulk Metallic Glass

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journal of Materials Science & Technology 2016年第4期32卷 349-354页

作者： w.Zhou w.P.weng j.X.Hou Shagang School of Iron and Steel Soochow University

Investigations were carried out to examine the effects of Co addition on the glass-forming ability （GFA） and corrosion resistance of Zr46Cu46AI8 bulk metallic glass in chloride-containing solution. It is found that the GFA of （Zr46Cu46Al8）100-xCox （x = 0, 1, 2, and 4 at.%） alloys reduces with the increase in Co content and correlates well with the parameters, such as the supercooled liquid region width ATx, the reduced glass transition temperature Trg and γ. The corrosion resistance is however found to be enhanced with the in- crease in Co concentration. The addition of Co causes the enrichment of Zr and Al, but depletes Cu in the surface films, which effectively enhances the corrosion potential and lowers the corrosion current density.

关键词： Bulk metallic glassCo-additionGlass-forming abilityCorrosion resistance

Effect of environments and normal loads on tribological properties of nitrided Ni(45)(FeCoCr)(40)(AlTi)(15)high-entropy alloys

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journal of Materials Science & Technology 2020年第7期42卷 85-96页

作者： L.w.Lan X.j.wang R.P.Guo H.j.Yang j.w.Qiao Research Center for High-Entropy Alloys College of Materials Science and EngineeringTaiyuan University of TechnologyTaiyuan030024China

The tribological properties of nitrided Ni(45)(FeCoCr)(40)(AlTi)(15)high-entropy alloys(HEAs)were investigated in air and simulated acid rain under different normal loads(5,7,10,and 12 N)at ambient *** results revealed that as-cast HEAs were only composed of FCC phase,while the volume fraction of FCC phase in the nitrided alloys was significantly ***,the hard phases of AIN,CrN,Fe4 N,and TiN phases were formed in the nitrided *** thickness of the nitriding layer was about 8.4μ*** hardness increased from 8.7 GPa in as-cast alloys to 14.5 GPa in the nitrided *** addition,under the same conditions,the friction coefficient of the nitrided alloys was higher than that of as-cast alloys,but the wear rate was generally lower than that of as-cast ***,the wear rate of the nitrided alloys was the lowest in acid rain due to the lubrication,cleaning,and cooling in the liquid *** air,dominating wear mechanisms in as-cast and nitrided alloys were abrasive,delamination,and adhesive ***,the wear mechanism of as-cast and nitrided alloys in acid rain was mainly abrasive and corrosion wears.

关键词： Abrasive wear Hardness Corrosive wear Microstructure wear mechanism

Evaluation of microvascular reactivity with laser Doppler flowmetry in chronic kidney disease

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world journal of Nephrology 2013年第3期2卷 77-83页

作者： Levente Babos Zoltán járai jános Nemcsik Department of Family Medicine Semmelweis University1125 BudapestHungary Department of Cardiology St.Imre Teaching Hospital1115 BudapestHungary

Cardiovascular diseases are the major causes of mortality in patients with chronic kidney disease(CKD).The complex process of accelerated athero- and arteriosclerosis in CKD is associated with this phenomenon,where endothelial dysfunction(ED) is one of the initial steps. Hence, the early diagnosis of ED can potentially lead to early interventions which could result in a better outcome for these patients. Several methodologies have been developed for the diagnosis of ED. Laser Doppler flowmetry(LDF) enables us to study the microcirculation continuously in a non-invasive manner. In our review we would like to focus on different tests developed for LDF, like postocclusive reactive hyperaemia,local heating, iontophoresis, microdialysis or analysis of flowmotion. we would also like to summarize the available data in CKD with these methodologies to enlighten their perspectives in the clinical use on this patient population.

关键词： Chronic kidney disease Laser Doppler fowmetry Endothelial dysfunction Iontophoresis Postoc clusive reactive hyperaemia Local heating Microdialysis Flowmotion

Microstructure and mechanical optimization of probeless friction stir spot welded joint of an Al-Li alloy

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journal of Materials Science & Technology 2018年第10期34卷 1739-1746页

作者： Q. Chu w.Y. Li X.w. Yang j.j. Shen A. Vairis w.Y. Feng w.B. wang State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding Technologies Northwestern Polytechnical University Xi'an710072 China Helmholtz-Zentrum Geesthacht Institute of Materials Research Materials Mechanics Geesthacht 21502 Germany Mechanical Engineering Department TEl of Crete Heraklion Crete 71004 Greece China PSw Center Beijing 100024 China

In this work, a third generation AI-Li alloy has been successfully spot welded with probeless friction stir spot welding （P-FSSw）, which is a variant of conventional friction stir welding. The Box-Behnken exper-imental design in response surface methodology （RSM） was applied to optimize the P-FSSw parameters to attain maximum tensile/shear strength of the spot joints. Results show that an optimal failure load of 7.83 kN was obtained under a dwell time of 7.2 s, rotation speed of 950 rpm and plunge rate of 30 mm/rain. Sufficient dwell time is essential for heat conduction, material flow and expansion of the stir zone to form a sound joint. Two fracture modes were observed, which were significantly affected by hook defect. In addition to mechanical testing, electron backscattering diffraction （EBSD） and differential scanning calorimetry （DSC） were used for microstructure evolution and property analysis. The precipitation of GP zone and AI3Li as well as the ultrafine grains were responsible for the high microhardness in the stir zone.

关键词： Probeless friction stir spot welding Precipitation Mechanical property Fracture mechanism

Extending the Relational Model to Deal withProbabilistic Data

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journal of Computer Science & Technology 2000年第3期15卷 230-240页

作者：马宗民 ZHANG w.j MA w.Y CityUniversityofHongKong KowloonHongKongP.R.China

According to the soundness and completeness of information in databases, the expressive form and the semantics of incomplete information are discussed in this paper. On the basis of the discussion, the current studies on incomplete data in relational databases are reviewed. In order to represent stochastic uncertainty in most general sense in the real world, probabilistic data are introduced into relational databases. An extended relational data model is presented to express and manipulate probabilistic data and the operations in relational algebra based on the extended model are defined in this paper.

关键词： incomplete information uncertain information extended relational model probabilistic data relational algebra

Optimum operation conditions of nitrogen and phosphorus removal by a biofilm-activated-sludge system

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journal of Environmental Sciences 2003年第1期15卷 25-30页

作者： LIUjun－xin j．w．vanGroenestijin ResearchCentreforEco－EnviromentalSciences ChineseAcademyofSciencesBeijing100085China DepartmentofEnvironmentalBiotechnoloty TNOInstituteofEnviromentalSciencesEnergyReseachandProc

In the biofilm and activated sludge combined system, denitrifying bacteria attached on the fibrous carriers in the anoxic tank, while the sludge containing nitrifying and phosphorus removal bacteria was only recirculated between the aerobic and anaerobic tanks. Therefore, the factors affected and restricted nitrification, denitrification and phosphorus removal in a traditional A/A/O process were resolved. This paper describes the optimum operation conditions for nitrogen and phosphorus removal using this system.

关键词： nitrification denitrification phosphorus removal biofilm activated sludge