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稳定同位素在药物代谢动力学研究中的应用

国外医学.药学分册 1982年第2期 116-117页

作者： murphy p j 魏湘

气相层析-质谱测定(GC/MS)与稳定同位素相结合,使这类同位素在药物代谢动力学研究中的应用获得很大的发展。气相层析和高效液相层析的高分辨力,加上定量质谱片图法(Quantitative mass fragmentography)的特异性和敏感性,已形成一种高度... 详细信息

气相层析-质谱测定(GC/MS)与稳定同位素相结合,使这类同位素在药物代谢动力学研究中的应用获得很大的发展。气相层析和高效液相层析的高分辨力,加上定量质谱片图法(Quantitative mass fragmentography)的特异性和敏感性,已形成一种高度敏感的分析方法。本法已用于测定下列药物,其敏感度为:氯压定,0.15ng/ml;环磷酰胺20.0ng/ml;哌替啶,100.0ng/ml;睾酮,0.2ng/ml;奎尼丁,1.0μg/ml;利多卡因,1.0μg/ml;苯妥英钠,1.0 μg/ml;丙咪嗪,10.0 ng/ml;甲苯磺丁脲,200.0ng/ml;非那西丁,10.0ng/ml;东莨菪碱,2.0ng/ml等。稳定同位素在药物代谢动力学研究中可应

关键词：稳定同位素 MS 质谱仪分析仪器美散酮药物学药物代谢动力学

Selection of digital fabrication technique in the construction industry--A multi-criteria decision-making approach

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Frontiers of Structural and Civil Engineering 2024年第7期18卷 977-997页

作者： M.p.SALAIMANIMAGUDAM j.jAYApRAKASH Department of Structural and Geotechnical Engineering School of Civil EngineeringVellore Institute of TechnologyVellore 632014India

Digital fabrication techniques,in recent decades,have provided the basis of a sustainable revolution in the construction ***,selecting the digital fabrication method in terms of manufacturability and functionality requirements is a complex *** paper presents alternatives and criteria for selection of digital fabrication techniques by adopting the multi-criteria decision-making *** alternatives considered in the study are concrete three-dimensional(3D)printing,shotcrete,smart dynamic casting,material intrusion,mesh molding,injection concrete 3D printing,and thin forming *** criteria include formwork utilization,reinforcement incorporation,geometrical complexity,material enhancement,assembly complexity,surface finish,and build *** demonstrates different multi-criteria decision-making techniques,with both subjective and objective weighting *** given ranking is based on the current condition of digital fabrication in the construction *** study reveals that in the selection of digital fabrication techniques,the criteria including reinforcement incorporation,build area,and geometrical complexity play a pivotal role,collectively accounting for nearly 70% of the overall *** the evaluated techniques,concrete 3D printing emerged as the best performer,however the shotcrete and mesh molding techniques in the second and third positions.

关键词： digital fabrication multicriteria decision-making concrete 3D printing

proteins as nanomagnets and magnetoreceptors

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Zoological Research 2024年第4期45卷 831-832页

作者： p.j.Hore Department of Chemistry University of OxfordUK

It is an appealing notion that a protein molecule could act as a nanomagnet.A genetically encodable biomolecule with a permanent magnetic moment at room temperature could have a range of applications:a magnetogenetic actuator,a magnetic tag for purifying and immobilizing enzymes,a contrast agent for magnetic resonance imaging,and a basis for a biomimetic magnetic sensing device,to name just a few.A magnetic protein could perhaps also function as the sensor in the magnetic compass that enables small songbirds to navigate the huge distances between their breeding and wintering *** though such possibilities may be,how realistic are they?

关键词： magnetic magnets enable

Wettability,reactivity,and interface structure in Mg/Ni system

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journal of Magnesium and Alloys 2024年第2期12卷 659-672页

作者： S.Terlicka N.Sobczak Ł.Maj p.Darłak j.j.Sobczak Institute of Metallurgy and Materials Science Polish Academy of Sciences25 Reymonta Str.KrakowPoland Faculty of Foundry Engineering AGH University23 Reymonta Str.KrakowPoland

The sessile drop method was applied to the experimental investigation of the wetting and spreading behaviors of liquid Mg drops on pure Ni *** comparison,the experiments were performed in two variants:(1)using the Capillary purification(Cp)procedure,which allows the non-contact heating and squeezing of a pure oxide-free Mg drop;(2)by classical Contact Heating(CH)*** high-temperature tests were performed under isothermal conditions(Cp:760℃for 30 s;CH:715℃for 300 s)using Ar+5 wt%H_(2) *** the sessile drop tests,images of the Mg/Ni couples were recorded by CCD cameras(57 fps),which were then applied to calculate the contact angles of metal/substrate *** and transmission electron microscopy analyses,both coupled with energy-dispersive X-ray spectroscopy,were used for detailed structural characterization of the solidified *** was found that an oxide-free Mg drop obtained by the Cp procedure showed a wetting phenomenon on the Ni substrate(an average contact angleθpreading and good wetting over the Ni substrate(θ_((Cp))~20°in 5 s)to form a final contact angle ofθ_(f(Cp))~18°.In contrast,a different wetting behavior was observed for the CH procedure,where the unavoidable primary oxide film on the Mg surface blocked the spreading of liquid Mg showing apparently non-wetting behavior after 300 s contact at the test ***,in both cases,the deep craters formed in the Ni substrates under the Mg drops and significant change in the structure of initially pure Mg drops to Mg-Ni alloys suggest a strong dissolution of Ni in liquid Mg and apparent values of the final contact angles measured for the Mg/Ni system.

关键词： Magnesium-based alloys Sessile drop tests Capillary purification procedure Wettability Reactivity Contact angle

On the analytical solution of transient friction in channel flows

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： F.j.GARCíA-GARCíA p.FARINAS-ALVARINO Department of Naval&Industrial Engineering Polytechnic School of EngineeringUniversity of A CorunaCampus Industrial de FerrolFerrol 15403A CorunaSpain Integraciones Técnicas de Seguridad S.A.Pol.Ind.Espiritu SantoC/Nobel15Cambre 15650A CorunaSpain

The transient friction in channel mean flows is the sum of two contributions,i.e.,the underlying laminar flow(ULF)and the purely turbulent component(pTC),and the contributions are analyzed separately by theoretical *** is found that,the transient friction may be higher or remarkably lower than that in equal-Reynolds number steady-state *** universal time constant for plane-parallel laminar flows is reported,and the role of the time constant in a turbulent mean flow is *** is shown that the time constant is related to the turbulence's frozen ***,a study of the logarithmic layer during the transient flow is accomplished,which shows that the logarithmic layer is destroyed.

关键词： transient friction transient flow unsteady channel flow

Drought events influence nutrient canopy exchanges and green leaf partitioning during senescence in a deciduous forest

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Forest Ecosystems 2024年第1期11卷 110-119页

作者： j.Touche C.Calvaruso p.De Donato M.-p.Turpault INRAE BEFF-54000NancyFrance UMR 7359 GeoRessourcesFaculte des Sciences-Campus des Aiguillettes54506Vandoeuvre Les NancyFrance EcoSustain Environmental Engineering OfficeResearch and DevelopmentKanfen57330France

The increase in the frequency and intensity of drought events expected in the coming decades in Western Europe may disturb forest biogeochemical cycles and create nutrient deficiencies in *** possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced ***,the effects of drought events on this partitioning and the consequences for the maintenance of tree nutrition are poorly *** experiment in a beech forest in Meuse(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence *** aim was to identify potential nutritional consequences of droughts for *** nutrient dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by almost a third of the potassium(K)partitioning to resorption(*** efficiency),thus reducing the K reserve in trees for the next growing *** result suggests that with the increased drought frequency and intensity expected for the coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same study *** foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(p)were also *** addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is more likely to improve tree *** calcium(Ca)negative resorption decreased,with no apparent consequence in our study *** results show that nutrient exchanges in the canopy and the partitioning of the green leaf

关键词： Natural drought Beech forest Canopy Resorption Foliar leaching Senesced leaves Nutrition

CO oxidation under lean and stoichiometric conditions over ceriazirconia with very low metal contents(Cu,Co,Ag and pt)

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journal of Rare Earths 2024年第9期42卷 1669-1681,I0002页

作者： j.C.Martínez-Munuera M.p.Yeste A.García-García MCMA Group Department of Inorganic Chemistry and Institute of MaterialsUniversity of AlicanteCarretera de San Vicente del Raspeig s/n03690San Vicente del RaspeigAlicanteSpain Solid Chemistry and Catalysis Group Department of Materials ScienceMetallurgic Engineering and Inorganic ChemistryInstitute of Electronic Microscopy and Materials ResearchUniversity of CádizAp.40E-11510Puerto RealCádizSpain

In this work,several ceria-zirconia based catalysts with very lo w(and equimolar) metal contents were prepared,characterised and tested for the CO oxidatio n reaction(under lean and stoichiometric conditions),trying to emulate those conditions found in a diesel oxidation catalyst(DOC) system from a diesel engine and those encountered under gasoline exhaust(λ=1).The metals chosen are Cu,Co,Ag and pt(as a reliable benchmark).The results reveal enormous differences among reducibility and catalytic activity despite quite similar structural and textural properties of the catalysts,showing differences among dispersion(Ag-catalyst seems to present a low level of dispersion).This catalyst seems to be characterised,as well,by a strong electronic interaction between Ce and Ag centres which is suggested to yield an improved reducibility under H_(2)-TpR ***,the order in catalytic activity(Cu>Ag>Co≈pt>>support) seems not to follow the order found in reducibility and the Cu-catalyst seems to be the most active independently on the reaction conditions,yielding nearly overlapped CO oxidation catalytic *** restingly,a stro ng correlation between the catalytic activity under the two conditions tested and the OSC values of the Ce_(0.8)Zr_(0.2)O_(2)-supported metal catalysts is ***,OSC parameter measured at 150℃ can be used as a relevant descriptor to evaluate the CO oxidation activity at low and medium conversions for the investigated catalysts,much better than the H_(2)-TpR measurements.

关键词： CO oxidation Low metal content Ceria-zirconia Copper species OSC parameter Rare earths

performance of unique and secure routing protocol(USRp)in flying Adhoc Networks for healthcare applications

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High-Confidence Computing 2024年第1期4卷 24-31页

作者： j.Vijitha Ananthi p.Subha Hency jose Department of Biomedical Engineering Karunya Institute of Technology and SciencesCoimbatoreIndia

Nowadays,Flying Adhoc Networks play a vital role due to its high efficiency in fast *** aerial vehicles transmit data much faster than other networks and are useful in all aspects of *** healthcare applications,wireless body area network transmits the data,whereas the security,which is the most important concern to be focused in a flying adhoc network is not *** intruders tamper the network,degrading the overall network *** avoid security issues,a unique and secure routing protocol that provides a single solution for five different types of attacks such as,black hole attacks,grey hole attacks,yoyo attacks,conjoint attack and jamming attacks,is *** simulation results analyses the network performance by using the proposed routing *** comparison to the other solutions rendered to resolve the affected network,this proposed routing protocol has a higher throughput,higher delivery rate,and lower *** Unique and Secure Routing protocol(USRp)provides an integrated solution for an efficient and secure communication in a flying adhoc network.

关键词： Secure routing protocol Flying Adhoc Networks Unmanned aerial vehicles Mobile Adhoc network Attackers Denial of service attacks

Laser-induced graphene-coated wearable smart textile electrodes for biopotentials signal monitoring

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Frontiers of Materials Science 2024年第1期18卷 95-111页

作者： C.M.Vidhya Yogita Maithani Sakshi Kapoor j.p.Singh Department of physics Indian Institute of Technology DelhiHauz KhasNew Delhi 110016India

This paper describes how to produce a wearable dry electrode at a reasonable cost and how to use it for the monitoring of biopotentials in *** textiles in wearable technologies have made a great advancement in the health care management and living standards of *** was manufactured using the low-cost single-step process,laser ablation of polyimide,a commercial *** dispersions were made using solvent isopropyl alcohol which has low boiling point,nontoxicity,and environmental *** successive coating of the graphene dispersion on the cotton fabric to make it conductive,the sheet resistance of the resulting fabric dropped to 3% of its initial *** laser-induced graphene(LIG)cotton dry electrodes thus manufactured are comparable to Ag/AgCl wet electrodes in terms of the skin-to-electrode impedance,measuring between 78.0 and 7.2 kΩ for the frequency between 40 Hz and 1 *** LIG cotton electrode displayed a signal-to-noise ratio of 20.17 *** to its comfort,simplicity,and good performance over a longer period of time,the textile electrode appears suited for medical applications.

关键词： biopotential electrocardiogram electromyogram flexible electrode textile porous graphene