Electrochemical ageing study of mixed lanthanum/praseodymium nickelates La2-xPrxNiO4+δ as oxygen electrodes for solid oxide fuel or electrolysis cells

The chemical and electrochemical stability of lanthanide nickelates La2 NiO4+δ(LNO),Pr2 NiO4+δ(PNO)and their mixed compounds La(2-x)PrxNiO4+δ(LPNOs)with x=0.5,1 or 1.5 is reported.The aim is to promote these materials as efficient electrodes for solid oxide fuel cell(SOFC)and/or solid oxide electrolysis cell(SOEC).La2 NiO4+δand La1.5Pr0.5NiO4+δcompounds are chemically very stable as powders over one month in the temperature range 600-800℃,while the other materials rich in praseodymium progressively decompose into various perovskite-deriving components with additional Pr6 O11.Despite their uneven properties,all these materials are quite efficient and sustainable as electrodes on top of gadolinium doped ceria(GDCBL)//yttrium doped zirconia(8 YSZ)electrolyte,for one month at 700℃without polarization.Under polarization(300 mA·cm-2),the electrochemical performances of LNO,PNO and La1.5Pr0.5NiO4+δ(LP5 NO)quickly degrade in SOFC mode,i.e.for the oxygen reduction reaction,while they show durability in SOEC mode,i.e.for the oxide oxidation reaction.

Clarifying sub-genomic positions of QTLs for flowering habit and fruit quality in U.S. strawberry (Fragaria×ananassa) breeding populations using pedigree-based QTL analysis

The cultivated strawberry(Fragaria×ananassa)is consumed worldwide for its flavor and nutritional benefits.Genetic analysis of commercially important traits in strawberry are important for the development of breeding methods and tools for this species.Although several quantitative trait loci(QTL)have been previously detected for fruit quality and flowering traits using low-density genetic maps,clarity on the sub-genomic locations of these QTLs was missing.Recent discoveries in allo-octoploid strawberry genomics led to the development of the IStraw90 single-nucleotide polymorphism(SNP)array,enabling high-density genetic maps and finer resolution QTL analysis.In this study,breeder-specified traits were evaluated in the Eastern(Michigan)and Western(Oregon)United States for a common set of breeding populations during 2 years.Several QTLs were validated for soluble solids content(SSC),fruit weight(FWT),pH and titratable acidity(TA)using a pedigree-based QTL analysis approach.For fruit quality,a QTL for SSC on linkage group(LG)6A,a QTL for FWT on LG 2BII,a QTL for pH on LG 4CII and two QTLs for TA on LGs 2A and 5B were detected.In addition,a large-effect QTL for flowering was detected at the distal end of LG 4A,coinciding with the FaPFRU locus.Marker haplotype analysis in the FaPFRU region indicated that the homozygous recessive genotype was highly predictive of seasonal flowering.SNP probes in the FaPFRU region may help facilitate marker-assisted selection for this trait.

Magnetic resonance imaging under isoflurane anesthesia alters cortical cyclooxygenase-2 expression and glial cell morphology during sepsis-associated neurological dysfunction in rats

Background:Magnetic resonance imaging(MRI)of rodents combined with histol-ogy allows to determine what mechanisms underlie functional and structural brain changes during sepsis-associated encephalopathy.However,the effects of MRI per-formed in isoflurane-anesthetized rodents on modifications of the blood-brain bar-rier and the production of vasoactive prostaglandins and glia cells,which have been proposed to mediate sepsis-associated brain dysfunction,are unknown.Methods:This study addressed the effect of MRI under isoflurane anesthesia on blood-brain barrier integrity,cyclooxygenase-2 expression,and glial cell activation during cecal ligature and puncture-induced sepsis-associated brain dysfunction in rats.Results:Cecal ligature and puncture reduced food intake and the righting reflex.MRI under isoflurane anesthesia reduced blood-brain barrier breakdown,decreased cir-cularity of white matter astrocytes,and increased neuronal cyclooxygenase-2 immu-noreactivity in the cortex 24 hours after laparotomy.In addition,it annihilated cecal ligature and puncture-induced increased circularity of white matter microglia.MRI under isoflurane anesthesia,however,did not alter sepsis-associated perivascular cyclooxygenase-2 induction.Conclusion:These findings indicate that MRI under isoflurane anesthesia of rodents can modify neurovascular and glial responses and should,therefore,be interpreted with caution.

A review of processing of Cu/C base plate composites for interfacial control and improved properties

The increase in both power and packing densities in power electronic devices has led to an increase in the market demand for effective heat-dissipating materials with a high thermal conductivity and thermal expansion coefficient compatible with chip materials while still ensuring the reliability of the power modules.Metal matrix composites,especially copper matrix composites,containing carbon fibers,carbon nanofibers,or diamond are considered very promising as the next generation of thermalmanagement materials in power electronic packages.These composites exhibit enhanced thermal properties,as compared to pure copper,combined with lower density.This paper presents powder metallurgy and hot uniaxial pressing fabrication techniques for copper/carbon composite materials which promise to be efficient heat-dissipation materials for power electronic modules.Thermal analyses clearly indicate that interfacial treatments are required in these composites to achieve high thermal and thermomechanical properties.Control of interfaces(through a novel reinforcement surface treatment,the addition of a carbide-forming element inside the copper powders,and processing methods),when selected carefully and processed properly,will form the right chemical/mechanical bonding between copper and carbon,enhancing all of the desired thermal and thermomechanical properties while minimizing the deleterious effects.This paper outlines a variety of methods and interfacial materials that achieve these goals.

Growth, Duplication and Lateral Mutual Compressive Deformation of Akouemma hemisphaeria on the Seafloor of Okondja Basin at 2.2 Ga (Gabon)

A colony of macro-fossils Akouemma hemisphaeria has been described in the Paleoproterozoic sedimentary basin of Okondja, Gabon. These fossils are classified into two groups according to their spheroidal or elongated forms. The spheroidal shapes are similar, have a tripartite structure with two hemispheres and a median disc and gradually pass to the elongated forms. These elongated forms have a pronounced bipartite tendency to two “hemispheres” separated by a median surface, and often have several ovoid “pieces” attached. The elongated specimens show both lateral growth marks and signs of fission. Growth marks are characterized by unidirectional homogeneous side elongations and lateral bud-like protuberances. The signs of fission are marked by circular furrows perpendicular to the direction of elongation, called “constriction furrows” with varying depths depending on the degree of fission of the specimen and internal vertical “division planes”. All of these ovoid and elongated specimens have undergone significant initial deformations due mainly to mutual lateral compressions in tabular beds. The Akouemma hemisphaeria macro-organisms, which were primitive probably sessile organisms, lived on the seafloor. They provide the oldest known record of macro-organisms on Earth having vegetative growth and asexual reproduction by budding, lateral elongation and fission. Their mutual lateral deformations would result from their growth.

QTL analysis for ascorbic acid content in strawberry fruit reveals a complex genetic architecture and association with GDP-L-galactose phosphorylase

Strawberry(Fragaria×ananassa)fruits are an excellent source of L-ascorbic acid(AsA),a powerful antioxidant for plants and humans.Identifying the genetic components underlying AsA accumulation is crucial for enhancing strawberry nutritional quality.Here,we unravel the genetic architecture of AsA accumulation using an F1 population derived from parental lines‘Candonga’and‘Senga Sengana’,adapted to distinct Southern and Northern European areas.To account for environmental effects,the F1 and parental lines were grown and phenotyped in five locations across Europe(France,Germany,Italy,Poland and Spain).Fruit AsA content displayed normal distribution typical of quantitative traits and ranged five-fold,with significant differences among genotypes and environments.AsA content in each country and the average in all of them was used in combination with 6,974 markers for quantitative trait locus(QTL)analysis.Environmentally stable QTLs for AsA content were detected in linkage group(LG)3A,LG 5A,LG 5B,LG 6B and LG 7C.Candidate genes were identified within stable QTL intervals and expression analysis in lines with contrasting AsA content suggested that GDP-L-Galactose Phosphorylase FaGGP(3A),and the chloroplast-located AsA transporter gene FaPHT4;4(7C)might be the underlying genetic factors for QTLs on LG 3A and 7C,respectively.We show that recessive alleles of FaGGP(3A)inherited from both parental lines increase fruit AsA content.Furthermore,expression of FaGGP(3A)was two-fold higher in lines with high AsA.Markers here identified represent a useful resource for efficient selection of new strawberry cultivars with increased AsA content.

Preparation of a ε-caprolactonic diterpenoid derivate by unexpected oxidative cleavage/lactonization of 2-oxoaustroeupatol

From aerial parts of Austroeupatorium inulifolium was isolated the ent-nor-furano triol labdane austroeupatol 1.The compound 1 was treated with IBX showing an unexpected selectivity at the potentially oxidizable sites of the sub-strate yielding the 2-oxoaustroeupatol(2)and 2,19-dioxoaustroeupatol(3).The treatment of 2 with sodium periodate yields a heterocyclic derivative(ε-caprolactone derivate 4)formed by oxidative cleavage and unexpected intramo-lecular attack of the hydroxymethylene(C-19)oxygen to the ketonic carbon(C-2).A plausible mechanistic pathway for the obtention of compound 4 is proposed.

Some Views on the Contribution of Design Theory to Engineering Education

This paper aims at presenting the organisation,the findings and the lessons learnt of a design casestudy workshop organized in the context of UB1-HIT joint master programme.After presenting the content and the evolution of this workshop over the years,findings and lessons learnt are discussed and final conclusions and perspectives are being proposed at the end of the paper.

GrapevineXL reliably predicts multi-annual dynamics of vine water status, berry growth, and sugar accumulation in vineyards

Climate and water availability greatly affect each season’s grape yield and quality.Using models to accurately predict environment impacts on fruit productivity and quality is a huge challenge.We calibrated and validated the functional-structural model,GrapevineXL,with a data set including grapevine seasonal midday stem water potential(�xylem),berry dry weight(DW),fresh weight(FW),and sugar concentration per volume([Sugar])for a wine grape cultivar(Vitis vinifera cv.Cabernet Franc)in field conditions over 13 years in Bordeaux,France.Our results showed that the model could make a fair prediction of seasonal�xylem and good-to-excellent predictions of berry DW,FW,[Sugar]and leaf gas exchange responses to predawn and midday leaf water potentials under diverse environmental conditions with 14 key parameters.By running virtual experiments to mimic climate change,an advanced veraison(i.e.the onset of ripening)of 14 and 28 days led to significant decreases of berry FW by 2.70%and 3.22%,clear increases of berry[Sugar]by 2.90%and 4.29%,and shortened ripening duration in 8 out of 13 simulated years,respectively.Moreover,the impact of the advanced veraison varied with seasonal patterns of climate and soil water availability.Overall,the results showed that the GrapevineXL model can predict plant water use and berry growth in field conditions and could serve as a valuable tool for designing sustainable vineyard management strategies to cope with climate change.

New Scenarios for a Shift towards Agroecology in Viticulture

In the light of its negative impacts on the environment and human health, conventional agriculture is currently facing new challenges;for example, reducing pesticide reliance, improving biodiversity, adapting to climate change and reconciling winegrowers with consumers, which require changes to be made to vineyard management. A shift towards more sustainable agriculture via the development of agroecological systems may be key to meeting these environmental, economic and social challenges. This study aimed to evaluate the performance of existing viticultural systems, as well as that of three new scenarios that we built to change conventional vine production systems and their related practices. The end aim is to adopt the principles of agroecology, and more virtuously, to ensure that vine production remains in line with societal expectations. First, thirty-eight different viticultural systems were chosen. Three realistic scenarios for changing these production systems were then built by working with stakeholders and incorporating the best practices that had been identified in the vineyard. Conventional practices were optimised in the first scenario and an agroecological approach was adopted for the other two scenarios: an Agroecological scenario (using synthetic chemicals) and an Agroecological-Bio scenario (organic system). All three scenarios were based on a combination of good practices which contribute to enhancing vineyard biodiversity, and which thus restore biological regulation and in turn reduce pesticides. The viticultural systems performances have been evaluated with a methodology involving multicriteria decision aid using ELECTRE Tri-C and ELECTRE III methods. Seven evaluation criteria were selected which covered socio-economic performance (economic profitability, workload and system complexity) and environmental performance (pesticide pressure, pesticide ecotoxicity, agroecological practices and pesticide drift). The best performances were achieved by the two agroecological scenarios, and this methodology can be adaptable to different production systems everywhere in different viticultural regions.

Characterizing microlensing planetary system OGLE-2014-BLG-0676Lb with adaptive optics imaging

We constrain the host-star flux of the microlensing planet OGLE-2014-BLG-0676 Lb using adaptive optics(AO)images taken by the Magellan and Keck telescopes.We measure the flux of the light blended with the microlensed source to be K=16.79±0.04 mag and J=17.76±0.03 mag.Assuming that the blend is the lens star,we find that the host is a 0.73_(-0.29)^(+0.14)M_(⊙)star at a distance of2.67_(-1.41)^(+0.77)kpc,where the relatively large uncertainty in angular Einstein radius measurement is the major source of uncertainty.With mass of M_(p)=3.68_(-1.44)^(+0.69)M_J,the planet is likely a"super Jupiter"at a projected separation of r_(⊥)=4.53_(-2.50)^(+1.49)AU,and a degenerate model yields a similar M_p=3.73_(-1.47)^(+0.73)M_(J)at a closer separation of r_(⊥)=2.56_(-1.41)^(+0.84)AU.Our estimates are consistent with the previous Bayesian analysis based on a Galactic model.OGLE-2014-BLG-0676 Lb belongs to a sample of planets discovered in a"secondgeneration"planetary microlensing survey and we attempt to systematically constrain host properties of this sample with high-resolution imaging to study the distribution of planets.

3D bioprinted breast cancer model reveals stroma-mediated modulation of extracellular matrix and radiosensitivity

Deciphering breast cancer treatment resistance remains hindered by the lack of models that can successfully capture the four-dimensional dynamics of the tumor microenvironment.Here,we show that microextrusion bioprinting can reproducibly generate distinct cancer and stromal compartments integrating cells relevant to human pathology.Our findings unveil the functional maturation of this millimeter-sized model,showcasing the development of a hypoxic cancer core and an increased surface proliferation.Maturation was also driven by the presence of cancer-associated fibroblasts(CAF)that induced elevated microvascular-like structures complexity.Such modulation was concomitant to extracellular matrix remodeling,with high levels of collagen and matricellular proteins deposition by CAF,simultaneously increasing tumor stiffness and recapitulating breast cancer fibrotic development.Importantly,our bioprinted model faithfully reproduced response to treatment,further modulated by CAF.Notably,CAF played a protective role for cancer cells against radiotherapy,facilitating increased paracrine communications.This model holds promise as a platform to decipher interactions within the microenvironment and evaluate stroma-targeted drugs in a context relevant to human pathology.

A COVID-19 epidemic model with latency period

At the beginning of a COVID-19 infection,there is a period of time known as the exposed or latency period,before an infected person is capable of transmitting the infection to another person.We develop two differential equations models to account for this period.The first is a model that incorporates infected persons in the exposed class,before transmission is possible.The second is a model that incorporates a time delay in infected persons,before transmission is possible.We apply both models to the COVID-19 epidemic in China.We estimate the epidemiological parameters in the models,such as the transmission rate and the basic reproductive number,using data of reported cases.We thus evaluate the role of the exposed or latency period in the dynamics of a COVID-19 epidemic.

Ultrafine Ru nanoparticles anchored on core-shell structured zeolite-carbon for efficient catalysis of hydrogen generation

As a promising route to hydrogen production,hydrolysis of ammonia borane(AB)aqueous solution requires efficient and stable catalysts.In this paper,a carbon-coated zeolite is prepared by high temperature calcination using glucose as carbon source.Ultrafine Ru nanoparticles are anchored on the composite support with core-shell structure using a simple in situ reduction method.The prepared catalyst expressed outstanding catalytic activity in the hydrolytic dehydrogenation of AB.The effects of support prepared by different synthesis parameters on the performance of catalyst are investigated.The Ru/S-1@C(RSC-2)catalyst exhibited the highest catalytic activity for hydrolytic dehydrogenation of AB with a turnover frequency of 892 min^(-1)at room temperature.This performance is superior to that of many catalysts previously reported.The excellent catalytic activity is attributed to the carbon layer on catalyst surface effectively limiting the aggregation of Ru nanoparticles in the hydrolysis reaction.The zeolite also plays a role in preactivation of water.This pre-activation accelerates the ratelimiting step of water dissociation in the reaction.The kinetic studies for determining the activation energy(E_(a)=36.8 kJ·mol^(-1))were based on reaction temperature.The effects of catalyst concentration,AB concentration and NaOH concentration on hydrolysis rate of AB were further investigated.The high-performance catalysts and the preparation method in this study have wide application prospects in the field of clean energy.

Self-assembly of colloidal polymers from two-patch silica nanoparticles

We report the formation of colloidal polymers consisting of disk-like silica nanoparticles(NPs)with polystyrene(PS)chains at the bottom of their two cavities assembled through reduction of the solvent quality for the PS chains and linked by hydrophobic associations.We show that this NPs assembly exhibits a two-stage process involving reaction-controlled polymerization and diffusion-controlled polymerization.Colloidal polymer networks are produced by the incorporation of three-patch NPs,which serve as branching points between the colloidal chains.By co-assembling preformed homopolymers composed of patchy NPs of different sizes or surface chemical groups,block copolymers are also achieved.This study provides insight into the process of self-assembly of two-patch NPs by precisely designing the components to generate colloidal analogues of linear macromolecular chains.

Clarifying predictions for COVID-19 from testing data: The example of New York State

With the spread of COVID-19 across the world,a large amount of data on reported cases has become available.We are studying here a potential bias induced by the daily number of tests which may be insufficient or vary over time.Indeed,tests are hard to produce at the early stage of the epidemic and can therefore be a limiting factor in the detection of cases.Such a limitation may have a strong impact on the reported cases data.Indeed,some cases may be missing from the official count because the number of tests was not sufficient on a given day.In this work,we propose a new differential equation epidemic model which uses the daily number of tests as an input.We obtain a good agreement between the model simulations and the reported cases data coming from the state of New York.We also explore the relationship between the dynamic of the number of tests and the dynamics of the cases.We obtain a good match between the data and the outcome of the model.Finally,by multiplying the number of tests by 2,5,10,and 100 we explore the consequences for the number of reported cases.

Interfacial active sites on Co-Co_(2)C@carbon heterostructure for enhanced catalytic hydrogen generation

Designing catalysts with capable dual-active sites to drive catalytic hydrogen generation is necessary for the future hydrogen economy.Herein,the interfacial active sites consisting of Co and Co-C on Co-Co_(2)C@carbon heterostructure are designed through annealing and highpressure carbonization.The operating temperature during the high-pressure carbonization under a CO-reducing environment is responsible for the construction and regulation of Co-Co_(2)C@C heterostructure.The optimal catalyst has a high turnover frequency(TOF) of33.1 min^(-1) and low activation energy(E_a) of27.3 kJ-mol^(-1) during the hydrolysis of NH_(3)BH_(3).The catalytic stability of Co-Co_(2)C@C has no dramatic deterioration even after 5 cyclic usages.The interfacial active sites and the carbon on the catalyst surface enhance hydrogen generation kinetics and catalytic stability.The construction of interfacial active sites in Co-Co_(2)C@C prompts the dissociation of reactants(NH_(3)BH_(3) and H_(2)O molecules),leading to an enhanced catalytic hydrogen generation from NH_(3)BH_(3) hydrolysis(Co activates NH_(3)BH_(3) and Co-C activates H_(2)O).The construction of hetero-structural catalysts provides theoretical direction for the rational design of advanced transition metal carbide materials in the field of energy catalysis and conversion.

A Multi-Material CCALE-MOF Approach in Cylindrical Geometry

In this paper we present recent developments concerning a Cell-Centered Arbitrary Lagrangian Eulerian(CCALE)strategy using the Moment Of Fluid(MOF)interface reconstruction for the numerical simulation of multi-material compressible fluid flows on unstructured grids in cylindrical geometries.Especially,our attention is focused here on the following points.First,we propose a new formulation of the scheme used during the Lagrangian phase in the particular case of axisymmetric geometries.Then,the MOF method is considered for multi-interface reconstruction in cylindrical geometry.Subsequently,a method devoted to the rezoning of polar meshes is detailed.Finally,a generalization of the hybrid remapping to cylindrical geometries is presented.These explorations are validated by mean of several test cases using unstructured grid that clearly illustrate the robustness and accuracy of the new method.

Anionic Polymerization of Butadiene Using Lithium/Potassium Multi-metallic Systems:Influence on Polymerization Control and Polybutadiene Microstructure

Thermal,mechanical,and viscoelastic properties of polybutadiene-based rubber materials are highly dependent on polybutadiene microstructure.The use of polar modifier in association with alkyllithium is a well-known method to obtain polybutadiene with a high vinyl con tent.Another approach is to use bimetallic initiating species such as alkyllithium combined to heavier alkali metal alkoxide(RONa,ROK...).The polymerization control is n evertheless not achieved and several parameters were found to influe nee it.Using bimetallic in itiating systems based on alkyllithium and a potassium alkoxide,alkyllithium structure,initiator preformation time,and initiator composition were identified as parameters influencing the anionic polymerization process of butadiene and/or polybutadiene microstructure.In addition,the use of trimetallic systems based on alkyllithium,potassium alkoxide,and alkylaluminum was investigated in order to prevent side reactions regardless of the[K]/[Li]ratio and of the initiator preformation time.

Migration of a red blood cell in a permeable microvessel

One of the important features of the microvessels is with permeable vessels.The hyperpermeablility is especially prounounced due to the fast grow of the microvessel in the tumor tissues.Flow field induced by leakage often presents a different figure compared to that of the health vessel.Non-uniform velocity and pressure distribution are found in the simulation by using Lattice Boltzmann Method combined with Starling law.This non-uniform flow field has significant influence on the mass transport in permeable mocrovessel,such as the motion of red blood cell.Using 2D spring network model to express the red blood cell and immersed boundary method to implement the coupling of fluid and structure,numerical simulations were carried out to study the migration of a red blood cell in a straight permeable channel.The results show that the staying time of red blood cell in the leakage region increases with the intensity of leakage.We also found that the leakage can weaken the lateral migration of the red blood cell from the wall to the channel center,and even tune the migration towards the wall when the leakage is reasonably strong.