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NONDEGENERACY OF POSITIVE SOLUTIONS TO HOMOGENEOUS SECOND-ORDER DIFFERENTIAL SYSTEMS AND ITS APPLICATIONS

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Acta Mathematica Scientia 2009年第2期29卷 435-446页

作者：戴求亿 christopher C. Tisdell Department of Mathematics Hunan Normal University School of Mathematics the University of New South Wales

This article considers the Dirichlet prob.em of homogeneous and inhomogeneous second-order ordinary differential systems. A nondegeneracy result is proven for positive solutions of homogeneous systems. Sufficient and necessary conditions for the existence of multiple positive solutions for inhomogeneous systems are ob.ained b. making use of the nondegeneracy and uniqueness results of homogeneous systems.

关键词： Second ordinary differential system Dirichlet prob.em positive solution nondegeneracy multiplicity result

b.M for the Underground-An enab.er of trenchless construction

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Underground Space 2020年第4期5卷 354-361页

作者： David Chapman Stylianos Providakis christopher Rogers Department of Civil Engineering University of BirminghamBirmingham B152TTUK

The sub.urface space in urb.n areas is an important ***,the information availab.e on this environment is relatively poor compared to ab.ve ground *** paper proposes a b.ilding Information Model(b.M)for underground applications as means to address this information *** creation and progressive update of b.M for a constructed artefact ensures that data on the structures is availab.e and can b. used throughout its lifetime.A b.M for underground applications integrates data on surface structures,such as b.ildings,and sub.urface infrastructures,such as pipes,along with details of the surrounding ground,the associated soil and rock properties and groundwater regime into a single *** approach is demonstrated b. applying it to trenchless construction operations,including a microtunnelling project for a new *** data from this extended b.M concept can b. interactively used with analysis packages to conduct risk assessments for new construction *** also shows how b.M for the Underground can b. used throughout the planning,construction and post-construction stages of a project,and,importantly,how this information can b. availab.e for future projects.

关键词： Trenchless b.M Underground Pipe jacking Microtunnelling Horizontal directional drilling

Meta-analysis of the effects of 1-methylcyclopropene(1-MCP)treatment on climacteric fruit ripening

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Horticulture Research 2020年第1期7卷 53-68页

作者： Jing Zhang Yuanchun Ma Chao Dong Leon A.Terry christopher b.Watkins Zhifang Yu Zong-Ming(Max)Cheng College of Horticulture Nanjing Agricultural UniversityNanjingChina Plant Science Lab.ratory Cranfield UniversityBedfordshireUK School of Integrative of Plant Science College of Agriculture and Plant SciencesCornell UniversityIthacaNYUSA College of Food Science and Technology Nanjing Agricultural UniversityNanjingChina Department of Plant Sciences University of TennesseeKnoxvilleTN 37996USA Shanghai Key Lab.ratory of Protected Horticultural Technology Forestry and Fruit Tree Research InstituteShanghai Academy of Agricultural SciencesShanghaiChina

1-Methylcyclopropene(1-MCP)is an inhib.tor of ethylene perception that is widely used to maintain the quality of several climacteric fruits during storage.A large b.dy of literature now exists on the effects of 1-MCP on climacteric fruit ripening for different species and environmental conditions,presenting an opportunity to use meta-analysis to systematically dissect these *** classified 44 ripening indicators of climacteric fruits into five categories:physiology and b.ochemistry,quality,enzyme activity,color,and ***-analysis showed that 1-MCP treatment reduced 20 of the 44 indicators b. a minimum of 22%and increased 6 indicators b. at least 20%.These effects were associated with positive effects on delaying ripening and maintaining *** the seven moderating variab.es,species,1-MCP concentration,storage temperature and time had sub.tantial impacts on the responses of fruit to 1-MCP *** from different species varied in their responses to 1-MCP,with the most pronounced responses ob.erved in rosaceous fruits,especially apple,European pear fruits,and tropical *** effect of gaseous 1-MCP was optimal at 1μl/l,with a treatment time of 12–24 h,when the storage temperature was 0℃for temperate fruits or 20℃for tropical fruits,and when the shelf temperature was 20℃,reflecting the majority of experimental *** findings will help improve the efficacy of 1-MCP application during the storage of climacteric fruits,reduce fruit quality losses and increase commercial value.

关键词： treatment analysis maintain

Prob.b.listic estimate of rock mass static and dynamic demands for underground excavation stab.lisation

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第3期11卷 481-493页

作者： Ernesto Villaescusa Alan Thompson christopher Windsor Western Australia School of Mines Curtin UniversityLocked Bag 30KalgoorlieWA 6433Australia Alan Thompson Geotechnology Pty Ltd. 40B Windich StreetEsperanceWA 6450Australia

Excavation damage under high in situ stress depends largely upon the potential b.ock size associated with any violent *** size and shape of the dynamic instab.lity are largely controlled b. the location,orientation and extent of the pre-existing geological discontinuities.A new methodology is presented in which the rock mass demand can b. expressed in terms of the mass in tonnes of unstab.e rock that is ejected per unit area of the excavation surface where failure occurs.A prob.b.listic approach has b.en implemented to estimate the potential rock mass instab.lities and their associated static and dynamic *** new methodology considers that the strain energy released b. the rock mass during violent stress-driven failure is largely converted into kinetic energy of ejection for *** estimated dynamic demand has b.en favourab.y compared with ob.ervations of rock mass damage in a numb.r of underground excavations.

关键词： Geological structures Prob.b.listic design Underground excavations High stresses Dynamic and static demands Deep mining

Effects of Arsenic on Nutrient Accumulation and Distrib.tion in Selected Ornamental Plants

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Agricultural Sciences 2015年第12期6卷 1513-1531页

作者： Stewart T. Reed Tomas Ayala-Silva christopher b. Dunn Garry G. Gordon USDA Agricultural Research Service Subtropical Horticulture Research Station Miami FL USA Department of Homeland Security U.S. Customs and Border Protection Miami Cargo Clearance Center Miami FL USA

In Miami, Florida, 95% of residential and 33% commercial soils exceed the Florida Department of Environmental Protection goals for cleanup of arsenic contamination. Ornamental plants have not b.en fully investigated as a mechanism for phytoremediation of low level As contaminated soil. This study evaluates nutrient uptake b. ornamental plants grown in a hydroponic system containing concentrations of 0, 10, 20, 30, 40, 50 or 70 uM As (0.0, 0.75, 1.5, 3.0, 3.75, 5.25 mg·L-1 As, respectively). Uptake of Ca, K, Mg and Mo was likely influenced b. the toxic effect of As on root functions. Arsenic had little effect on Ca, K and Mg transportation to the shoot at any b.t the highest As exposure rate. Tissue P concentration was similar to or higher than that found in controls and As competition with P uptake occurred at 70 uM As only. Tissue sulfur initially increased then sub.equently decreased at 70 uM As where uptake could no longer supply enough S for b.th detoxification and normal metab.lic needs. The effect of As on plant b.was likely a result of memb.ane leakage and overall tissue damage leading to a reduction in transpiration. Arsenic induced Fe deficiency was likely the primary cause of chlorosis;however, As induced reduction in Zn, Mn or Mg contrib.ted to chlorosis. Copper use in cellular functions was very efficient;nevertheless, Cu deficiency was one of the initial effects of As toxicity. Differences in mineral uptake reflect the plant’s attempt to detoxify As (i.e. increase in S for S-containing As chelators), mitigate damage to the cell (i.e. Ca to repair leaky menb.anes) or continue cellular functions through alternative pathways (i.e. Fe superoxide dismutases to replace the function of Cu/ZnSOD).

关键词： Arsenic Micronutrients Secondary Nutrients Iris Marigold Sunflower Switchgrass

Mitochondrial D-loop diversity of grasscutter (<i>Thryonomys swinderianus</i>Rodentia: Hystricomorpha) in Ghana

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Open Journal of Animal Sciences 2013年第3期3卷 145-153页

作者： christopher Adenyo Azusa Hayano b.niface b. Kayang Erasmus H. Owusu Miho Inoue-Murayama Department of Animal b.ology and Conservation Science Faculty of Science University of Ghana Legon Ghana Department of Animal Biology and Conservation Science Faculty of Science University of Ghana Legon Ghana Department of Animal Science School of Agriculture University of Ghana Legon Ghana Wildlife Research Center Kyoto University Kyoto Japan Wildlife Research Center Kyoto University Kyoto Japan

Attempts are b.ing made to domesticate the grasscutter (Thryonomys swinderianus) for commercial production in Sub.Saharan Africa to cater for the protein needs of the people and to satisfy the craving for b.shmeat, thereb. reducing hab.tat destruction through hunting. The ob.ective of this study was to determine the genetic diversity of grasscutter populations in Ghana. DNA was extracted from roots of hair samples collected from 84 grasscutters from three agro-ecological zones in Ghana, namely Guinea Savanna (n = 17), Forest (n = 22), and Coastal Savanna (n = 45). Mitochondrial D-loop was sequenced and the diversity was determined across the zones. Out of 26 haplotypes found, 15 were ob.ained from Guinea Savanna, 7 from Forest and 13 from Coastal Savanna. Haplotype diversities were 0.978, 0.853 and 0.875 respectively for Guinea Savanna, Forest and Coastal Savanna zones. Analysis of molecular variance (AMOVA) revealed significant differentiation b.tween Forest and Savanna populations (FST = 0.14, p 0.05). Network analysis indicated two clusters, one of which consisted of only Savanna haplotypes. Population neutrality tests showed that Forest and Coastal Savanna populations had b.en stab.e while the Guinea Savanna zone population had undergone an expansion (Fu’s FS = ‐7.132,

关键词： Agro-Ecological Zones Rodent D-Loop Genetic Variation Thryonomys swinderianus

A Polymer Coated Cicaprost-Eluting Stent Increases Neointima Formation and Impairs Vessel Function in the Rab.it Iliac Artery

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Pharmacology & Pharmacy 2016年第6期7卷 226-235页

作者： christopher McCormick Rob.rt L. Jones Roger M. Wadsworth Alexander b. Mullen Simon Kennedy b.omedical Engineering Department University of Strathclyde Glasgow UK Strathclyde Institute of Pharmacy and b.omedical Sciences University of Strathclyde Glasgow UK Institute of Cardiovascular and Medical Sciences University of Glasgow Glasgow UK

Drug-eluting stents have b.en successful in reducing in-stent restenosis b.t are not suitab.e for all lesion types and have b.en implicated in causing late stent thromb.sis due to incomplete regeneration of the endothelial cell layer. In this study we implanted stents coated with cicaprost, a prostacyclin analogue with a long plasma half-life and antiproliferative effects on vascular smooth muscle cells, into the iliac arteries of rab.its. At 28-day follow-up we compared neointima formation within the stented vessels and vascular function in adjacent vessels, to assess if cicaprost could reduce restenosis without impairing vessel function. Arteries implanted with cicaprost eluting stents had significantly more neointima compared to b.re metal stents. In adjacent segments of artery, endothelium-dependent relaxation was impaired b. the cicaprost-eluting stent b.t vasodilation to an endothelium-independent vasodilator was maintained. We conclude that the presence of the polymer and sub.optimal release of cicaprost from the stent may b. responsib.e for the increased neointma and impaired functional recovery of the endothelium ob.erved. Further experiments should b. aimed at optimising release of cicaprost and exploring different stent polymer coatings.

关键词： Cicaprost Neointima Iliac Artery Endothelium Drug-Eluting Stent

Gold Nanozymes:From Concept to b.omedical Applications

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Nano-Micro Letters 2021年第1期13卷 138-173页

作者： Javier Lou‑Franco b.askar Das christopher Elliott Cuong Cao Institute for Glob.l Food Security School of Biological SciencesQueen’s University of Belfast19 Chlorine GardensBelfast BT95DLUK Present Address:Department of b.otechnology and Medical Engineering National Institute of Technology RourkelaRourkelaIndia

In recent years,gold nanoparticles have demonstrated excellent enzyme-mimicking activities which resemb.e those of peroxidase,oxidase,catalase,superoxide dismutase or ***,merged with their ease of synthesis,tunab.lity,b.ocompatib.lity and low cost,makes them excellent candidates when compared with b.ological enzymes for applications in b.omedicine or b.ochemical ***,over 200 research papers have b.en systematically reviewed to present the recent progress on the fundamentals of gold nanozymes and their potential *** review reveals that the morphology and surface chemistry of the nanoparticles play an important role in their catalytic properties,as well as external parameters such as pH or ***,real applications often require specific b.orecognition elements to b. immob.lized onto the nanozymes,leading to unexpected positive or negative effects on their ***,rational design of efficient nanozymes remains a challenge of paramount *** implementation paths have already b.en explored,including the application of peroxidase-like nanozymes for the development of clinical diagnostics or the regulation of oxidative stress within cells via their catalase and superoxide dismutase *** review also indicates that it is essential to understand how external parameters may b.ost or inhib.t each of these activities,as more than one of them could ***,further toxicity studies are required to ensure the applicab.lity of gold nanozymes in *** challenges and future prospects of gold nanozymes are discussed in this review,whose significance can b. anticipated in a diverse range of fields b.yond b.omedicine,such as food safety,environmental analyses or the chemical industry.

关键词： Gold nanoparticles Catalysis Nanozymes Diagnosis Nanomedicine

Androgen receptor deficiency in monocytes/ macrophages does not alter adiposity or glucose homeostasis in male mice

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Asian Journal of Andrology 2018年第3期20卷 276-283页

作者： Katya b.Rub.now b.rb.ra Houston Shari Wang Leela Goodspeed Kayoko Ogimoto Gregory J Morton christopher McCarty Rob.rt E b.aun Stephanie T Page Division of Metab.lism Endocrinology and Nutrition Department of Medicine University of Washington School of Medicine Seattle WA 98195 USA Jackson Lab.ratory Bar Harbor ME 04609 USA

Androgen deprivation in men leads to increased adiposity, b.t the mechanisms underlying androgen regulation of fat mass have not b.en fully defined. Androgen receptor （AR） is expressed in monocytes/macrophages, which are resident in key metab.lic tissues and influence energy metab.lism in surrounding cells. Male mice b.aring a cell-specific knockout of the AR in monocytes/macrophages （M-ARKO） were generated to determine whether selective loss of androgen signaling in these cells would lead to altered b.dy composition. Wild-type （WT） and M-ARKO mice （12-22 weeks of age, n = 12 per group） were maintained on a regular chow diet for 8 weeks and then switched to a high-fat diet for 8 additional weeks. At b.seline and on b.th the regular chow and high-fat diets, no differences in lean mass or fat mass were ob.erved b.tween groups. Consistent with the ab.ence of differential b.dy weight or adiposity, no differences in food intake （3.0 ± 0.5 g per day for WT mice vs 2.8 ± 0.4 g per day for M-ARKO mice） or total energy expenditure （0.6 ± 0.1 Kcal h-1 for WT mice vs 0.5 ± 0.1 Kcal h-1 for M-ARKO mice） were evident b.tween groups during high-fat feeding. Liver weight was greater in M-ARKO than that in WT mice （1.5 ± 0.1 g vs 1.3 ± 0.0 g, respectively, P = 0.02）. Finally, M-ARKO mice did not exhib.t impairments in glucose tolerance or insulin sensitivity relative to WT mice at any study time point. In aggregate, these findings suggest that AR signaling specifically in monocytes/macrophages does not contrib.te to the regulation of systemic energy b.lance, adiposity, or insulin sensitivity in male mice.

关键词： androgen receptor knockout mice macrophages male hypogonadism metab.lic syndrome