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The role of mechanotransduction versus hypoxia during simulated orthodontic compressive strain——an in vitro study of human periodontal ligament fibroblasts

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International Journal of Oral Science 2019年第4期11卷 315-324页

作者： Niklas Ullrich Agnes Schroder Jonathan Jantsch Gerrit Spanier Peter Proff Christian Kirschneck University Medical centre of regensburg Franz-Josef-Strauβ-Allee 11D-93053 RegensburgGermany department of Orthodontics University Medical Centre of RegensburgFranz-Josef-Strauβ-Allee 11D-93053 RegensburgGermany department of Medical Microbiology and Hygiene University Medical Centre of RegensburgFranz-Josef-Strauβ-Allee 11D-93053 RegensburgGermany department of Cranio-Maxillo-Facial Surgery University Medical Centre of RegensburgFranz-Josef-Strauβ-Allee 11D-93053 RegensburgGermany

during orthodontic tooth movement(OTM)mechanical forces trigger pseudo-inflammatory,osteoclastogenic and remodelling processes in the periodontal ligament(PdL)that are mediated by PdL fibroblasts via the expression of various signalling *** far,it is unknown whether these processes are mainly induced by mechanical cellular deformation(mechanotransduction)or by concomitant hypoxic conditions via the compression of periodontal blood *** primary PdL fibroblasts were randomly seeded in conventional six-well cell culture plates with O2-impermeable polystyrene membranes and in special plates with gas-permeable membranes(Lumox?,Sarstedt),enabling the experimental separation of mechanotransducive and hypoxic effects that occur concomitantly during *** simulate physiological orthodontic compressive forces,PdL fibroblasts were stimulated mechanically at 2 g·cm?2 for 48 h after 24 h of *** quantified the cell viability by MTT assay,gene expression by quantitative real-time polymerase chain reaction(rT-qPCr)and protein expression by western blot/enzyme-linked immunosorbent assays(ELISA).In addition,PdL-fibroblast-mediated osteoclastogenesis(TrAP+cells)was measured in a 72-h coculture with rAW264.7 *** expression of HIF-1α,COX-2,PGE2,VEGF,COL1A2,collagen and ALPL,and the rANKL/OPG ratios at the mrNA/protein levels during PdL-fibroblast-mediated osteoclastogenesis were significantly elevated by mechanical loading irrespective of the oxygen supply,whereas hypoxic conditions had no significant additional *** cellular–molecular mediation of OTM by PdL fibroblasts via the expression of various signalling molecules is expected to be predominantly controlled by the application of force(mechanotransduction),whereas hypoxic effects seem to play only a minor *** the context of OTM,the hypoxic marker HIF-1αdoes not appear to be primarily stabilized by a reduced O2 supply but is rather stabilised mechanically.

关键词： rAW264.7 periodontal mec

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Authigenic gypsum found in gas hydrate-associated sediments from Hydrate ridge, the eastern North Pacific

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Science China Earth Sciences 2004年第3期47卷 280-288页

作者： Erwin Suess dirk rickert department of Marine Environmental Geology Research Centre of Marine Geology University of Kiel Kiel D-24148 Germany Department of Marine Environmental Geology Research Centre of Marine Geology University of Kiel Kiel D-24148 Germany

Characteristic gypsum micro-sphere and granular mass were discovered by bin-ocular microscope in the gas hydrate-associated sediments at cores SO143-221 and SO143/TVG40-2A respectively on Hydrate ridge of Cascadia margin, the eastern North Pacific. Xrd patterns and EPA analyses show both micro-sphere and granular mass of the crystals have the typical peaks and the typical main chemical compositions of gypsum, although their weight percents are slightly less than the others in the non-gas hydrate-associated marine regions. SEM pictures show that the gypsum crystals have clear crystal boundaries, planes, edges and cleav-ages of gypsum in form either of single crystal or of twin crystals. In view of the fact that there are meanwhile gas hydrate-associated authigenic carbonates and SO42--rich pore water in the same sediment cores, it could be inferred reasonably that the gypsums formed also authigenically in the gas hydrate-associated environment too, most probably at the interface between the down-ward advecting sulfate-rich seawater and the below gas hydrate, which spilled calcium during its formation on Hydrate ridge. The two distinct forms of crystal intergrowth, which are the granular mass of series single gypsum crystals at core SO143/TVG40-2A and the microsphere of gypsum crystals accompanied with detrital components at core SO143-221 respectively, indicate that they precipitated most likely in different interstitial water dynamic environments. So, the distinct authigenic gypsums found in gas hydrate-associated sediments on Hydrate ridge could also be believed as one of the parameters which could be used to indicate the presence of gas hydrate in an unknown marine sediment cores.

关键词： authigenic gypsum, gas hydrate-associated sediment, Hydrate ridge, eastern North Pacific.

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A NEW STATIC MECHANICS MOdEL TO SOLVE CONTACT PrOBLEMS IN MECHANICAL SYSTEMS

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Applied Mathematics and Mechanics(English Edition) 2004年第11期25卷 1314-1322页

作者：陆志华叶庆泰 r & d centre Shanghai Mitsubishi Elevator CO. LTD Shanghai 200245 P.R.China .School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 P.R.China School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 P.R.China

The coupling of the local contact problems between the components and the deformation of the components in the mechanical system were discovered.A series of coordinate systems have been founded to describe the mechanical system with the contact *** method of isolating the boundary of contact body from others has been used to describe the constraint between the contacting points.A more generalized static mechanics model of the mechanical system with the contact problems has been founded through the principle of virtual *** an application,the model was used to study the multi_teeth engagement problems in the inner meshed planet gear *** stress distribution of contact gears was got.A test has verified that the static contact model and the computational method are right.

关键词： mechanical system contact problem planet gear drive

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Preliminary Mapping and Characterisation of Soils in the Pirin Mountains (Bulgaria)

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Journal of Mountain Science 2008年第2期5卷 122-129页

作者： Maika Lβiger Jrg Scheithauer Karsten Grunewald University of Technology dresden D-01062 Dresden Germany Landscape research centre dresden Am Ende 14 D-01277 Dresden Germany

Soil types, humus types and vegetation as well as their hypsometric variation were analysed in terms of sequences in the northern part of the high mountains of the Pirin National Park at altitudes between looo and 2400 m a.s.1. The study area is characterised by a large variety of natural parameters like petrology （mainly marble and granite）, morphology （different slope deposits, exposition） and the orographic climate gradient. Statistical analyses using these parameters provided a basis for the soil group classification of the sites. Based on a digital Terrain Model （dTM） and a geological map of the Pirin National Park, the results of these statistical analyses were used to generate a ＂map of potential soil groups＂（regionalisation using GIS）. Six potential soil groups could be determined. The resulting map exhibits a confidence level of 68 % on 74.4 % of the covered area. rendzic Leptosols, in combination with Folic Histosols and Histi-lithic Leptosols occur in the alpine and subalpine regions on calcareous substrates. With decreasing altitude they are replaced by a mosaic of rendzic Leptosols, Phaeozems and an increasing occurrence of Cambic Umbrisols. Umbrisols found on silicatic substrates in the alpine region are replaced by Cambic Umbrisols with decreasing altitude as well. Hence, pedogenesis is characterised by increasing browning and depth of the soil profiles with decreasing altitude. The pH-level is slightly acidic to neutral in lower zones and on calcareous rocky bases. Acidification increases in the subalpine zone. Soil pH decreases down to 4 on silicate subtrates. Typical humic values in mineral topsoils are 10 to 12 %, and in organic layers of the soils above 2000 m a.s.1, they are even more. The C：N ratio closely ranges around 20 （median）.

关键词： Cluster analysis soil mapping hypsometric soil differentiation Southeast Europe

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The role of dietary fibre in pig production,with a particular emphasis on reproduction

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Journal of Animal Science and Biotechnology 2018年第4期9卷 783-793页

作者： Selene Jarrett Cheryl J.Ashworth The roslin Institute and r(d)SVS University of Edinburgh

Fibres from a variety of sources are a common constituent of pig feeds. They provide a means to utilise locallyproduced plant materials which are often a by-product of the food or drink industry. The value of a high fibre diet in terms of producing satiety has long been recognised. However the addition of fibre can reduce feed intake, which is clearly detrimental during stages of the production cycle when nutrient needs are high, for example in growing piglets and during lactation. More recently, fibre has been found to promote novel benefits to pig production systems,particularly given the reduction in antimicrobial use world-wide, concern for the welfare of animals fed a restricted diet and the need to ensure that such systems are more environmentally friendly. For example, inclusion of dietary fibre can alter the gut microbiota in ways that could reduce the need for antibiotics, while controlled addition of certain fibre types may reduce nitrogen losses into the environment and so reduce the environmental cost of pig *** particular potential value is the opportunity to use crude fibre concentrates as ’functional’ feed additives to improve young pig growth and welfare. Perhaps the greatest opportunity for the use of high fibre diets is to improve the reproductive efficiency of pigs. Increased dietary fibre before mating improves oocyte maturation, prenatal survival and litter size; providing a consumer-acceptable means of increasing the amount of saleable meat produced per sow. The mechanisms responsible for these beneficial effects remain to be elucidated. However, changes in plasma and follicular fluid concentrations of key hormones and metabolites, as well as effects of the hypothalamic satiety centre on gonadotrophin secretion and epigenetic effects are strong candidates.

关键词： Fibre Pig Pregnancy Production reproduction

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The influence of terrain age and altitude on the arthropod communities found on recently deglaciated terrain

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Current Zoology 2014年第2期60卷 203-220页

作者： Markus FrANZEN Petra dIEKEr UFZ Helmholtz-Centre for Environmental Research Department of Community Ecology Theodor-Lieser-Strasse 4 D-06120Halle (Saale) Germany centre for Methods Leuphana University Lfineburg Scharnhorststrage 1 D-21335 Liineburg Germany

Climate warming has been more pronounced in the Arctic than elsewhere, resulting in a recent rapid glacial retreat. Over 85% of the Almajallojekna glacier has disappeared over the last 115 years and it is one of the fastest retreating glaciers in Sweden. In 2011 and 2012, at 18 sites in the vicinity of the remaining glacier network, we sampled arthropods and related the species richness, abundance and proportion of herbivores to altitude （ranging from 824 to 1,524 m.a.s.1.） and the age of the site （ranging from 0 to 〉 115 years）. Temperature was measured at six sites and the average annual air temperature ranged from -3.7℃ to 1.1℃. In total, we recorded 3,705 arthropods from 117 species in nine different taxonomic groups. The most abundant and species-rich group was Coleoptera （1,381 individuals, 41 species） followed by Araneae （1,050 individuals, 15 species） and Macrolepidoptera （732 individuals, 17 species）. Only at lower altitudes did the abundance and species richness of arthropods increase with increasing age of the site. The results were consistent among the studied taxonomic groups and when controlling for sam- piing intensity using two different approaches. The proportion of herbivores decreased with increasing age of the site and with increasing altitude. Clearly, altitude appears more important than the age of the site and, at higher altitudes, abundance, species richness and herbivory are low [Current Zoology 60 （2）： 203-220, 2014].

关键词： Climate change Glacier foreland Emerging communities Insects and arachnids Subarctic environment Speciesrichness

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Selective leaching and recovery of V as iron vanadate from industrially generated Mo-V residue

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Transactions of Nonferrous Metals Society of China 2018年第11期28卷 2369-2375页

作者： P.C.rOUT G.K.MISHrA d.MOHAPATrA B.PAdH B.r.rEddY Technology centre R＆D DepartmentRubamin Ltd.Halol-389350Indi

A commercial process was developed to treat a Ca-based Mo-V residue generated in Mo processing plant. Vanadium wasselectively leached using acetic acid and recovered as iron vanadate by hydro process. Process conditions for selective V leachingand iron vanadate precipitation were investigated. V recovery efficiency of 90.3% was achieved with a V content of 26.5% and an Fecontent of 29% in the iron vanadate cake suitable for ferrovanadium industry. The overall Mo recovery in the whole process was98.6%. The obtained leach residue containing 14.3% Mo with negligible impurities can be used as a feed material for the Moproduction process or ferromolybdenum industry. This simple and economical process generates two product streams from a singleoperation and has the potential to solve a long standing problem of handling such a mixed Mo？V residue.

关键词： iron vanadate leaching acetic acid precipitation ferrovanadium

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China＇s Foreign Trade： A ＂New Normal＂

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China & World Economy 2017年第2期25卷 1-21页

作者： Francoise Lemoine deniz Unal centre d'Etudes Prospectives et d'Informations Intemationales France.

Since the global financial crisis of 2007/2008, China＇s foreign trade has continued to grow faster than international trade, but its drivers are now different from those prevailing before. The participation of the Chinese economy in the global production chains through processing activities is no longer the main driver of its trade performance. The new driving force of change is ordinary trade, based mainly on local inputs and domestic demand. China, which played a major role in the globalization process as an export base for multinational companies, is now shifting to having a ＂＇normal＇foreign trade system, which is more closely integrated into the domestic economy.

关键词： China domestic market growth model foreign direct investment foreign trade

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development of Human in vitro Brain-blood Barrier Model from Induced Pluripotent Stem Cell-derived Endothelial Cells to Predict the in vivo Permeability of drugs

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Neuroscience Bulletin 2019年第6期35卷 996-1010页

作者： Yuan Li Xueying Sun Houfu Liu Liang Huang Guofeng Meng Yu ding Wenji Su Jiaqi Lu Sophie Gong Georg C.Terstappen ru Zhang Wandong Zhang Shanghai Key Laboratory of Signaling and disease research Laboratory of Receptor-Based Bio-medicineCollaborative Innovation Center for Brain ScienceSchool of Life Sciences and TechnologyTongji UniversityShanghai 200092China Platform Technology&Sciences GlaxoSmithKline China R&D CentreShanghai 201203China Neurosciences Therapeutic Area Unit GlaxoSmithKline China R&D CentreShanghai 201203China Human Health Therapeutics research centre National Research Council of Canada Faculty of Medicine University of OttawaOttawa K1A0R6Canada

An in vitro blood-brain barrier(BBB) model is critical for enabling rapid screening of the BBB permeability of the drugs targeting on the central nervous *** many models have been developed, their reproducibility and renewability remain a challenge. Furthermore, drug transport data from many of the models do not correlate well with the data for in vivo BBB drug ***-pluripotent stem cell(i PSC) technology provides reproducible cell resources for in vitro BBB ***, we generated a human in vitro BBB model by differentiating the human i PSC(hi PSC) line GM25256 into brain endothelial-type cells. The model displayed BBB characteristics including tight junction proteins(ZO-1,claudin-5, and occludin) and endothelial markers(von Willebrand factor and Ulex), as well as high transendothelial electrical resistance(TEEr)(1560 ***2±230 ***2) and c-GTPase activity. Co-culture with primary rat astrocytes significantly increased the TEEr of the model(2970 ***2 to 4185 ***2). rNAseq analysis confirmed the expression of key BBB-related genes in the hi PSC-derived endothelial cells in comparison with primary human brain microvascular endothelial cells,including P-glycoprotein(Pgp) and breast cancer resistant protein(BCrP). drug transport assays for nine CNS compounds showed that the permeability of non-Pgp/BCrP and Pgp/BCrP substrates across the model was strongly correlated with rodent in situ brain perfusion data for these compounds(r2= 0.982 and r2= 0.9973,respectively), demonstrating the functionality of the drug transporters in the model. Thus, this model may be used to rapidly screen CNS compounds, to predict the in vivo BBB permeability of these compounds and to study the biology of the BBB.

关键词： Blood-brain barrier drug transport Induced pluripotent stem cell Cell differentiation Prediction of in vivo permeability

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Constructing 2d bismuth-based heterostructure for highly efficient photocatalytic CO2 reduction

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Tungsten 2025年第1期 71-79页

作者： ruo-Hang Xu Hao-Yu Jiang dan-dan Cui Kun-rong du Hong-run Zhang Sheng-Jie Xu Ya-Qi Li Zhi-Zhen ren Liang Wang Wei-Chang Hao Yi du School of Physics and BUAA-UOW Joint research centre Beihang University Shenzhen Institute of Beihang University centre for Catalysis and Clean Energy School of Environment and Science Griffith University

reforming carbon dioxide（CO2） into fuels and valuable chemicals using solar energy holds significant potential for emission reduction and addressing energy supply *** recombination of photocarriers remains a major obstacle,however,to enhancing solar energy conversion efficiency in the photocatalytic reaction *** two-dimensional materials,constructing heterogeneous structures has emerged as an effective strategy to enhance the separation of photoexcited carriers by leveraging the internal electric field at the heterogeneous ***,we present a facile strategy for preparing Bi4NbO8Br/Bi2WO6plate-on-plate Z-scheme junctions with a strong internal electric field by in situ *** unique heterostructure facilitates efficient separation and transport of photoexcited charges by harnessing the internal electric field induced by chemical bonding at the lateral ***,the Bi4NbO8Br/Bi2WO6heterostructure exhibits enhanced CO2photoreduction properties,along with a CO yield rate of approximately 35 μmol·g-1·h-1under full light *** work offers novel insights into the synthesis of unique hetero structures intended to enhance the efficiency of photocatalytic CO2reduction.

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