An ethically guided preclinical device for phenotyping H_(2)production in laboratory rodents

Background:Dihydrogen(H_(2))is produced endogenously by the intestinal microbiota through the fermentation of diet carbohydrates.Over the past few years,numer-ous studies have demonstrated the significant therapeutic potential of H_(2)in various pathophysiological contexts,making the characterization of its production in labora-tory species of major preclinical importance.Methods:This study proposes an innovative solution to accurately monitor H_(2)pro-duction in free-moving rodents while respecting animal welfare standards.The devel-oped device consisted of a wire rodent cage placed inside an airtight chamber in which the air quality was maintained,and the H_(2)concentration was continuously analyzed.After the airtightness and efficiency of the systems used to control and maintain air quality in the chamber were checked,tests were carried out on rats and mice with different metabolic phenotypes,over 12 min to 1-h experiments and repeatedly.H_(2)production rates(HPR)were obtained using an easy calculation algorithm based on a first-order moving average.Results:HPR in hyperphagic Zucker rats was found to be twice as high as in control Wistar rats,respectively,2.64 and 1.27 nmol.s^(−1)per animal.In addition,the ingestion of inulin,a dietary fiber,stimulated H_(2)production in mice.HPRs were 0.46 nmol.s^(−1)for animals under control diet and 1.99 nmol.s^(−1)for animals under inulin diet.Conclusions:The proposed device coupled with our algorithm enables fine analysis of the metabolic phenotype of laboratory rats or mice with regard to their endogenous H_(2)production.

Dynamics of Low-Viscosity Liquids Interface in an Unevenly Rotating Vertical Layer

The behavior of two immiscible low-viscosity liquids differing in density and viscosity in a vertical flat layer undergoing modulated rotation is experimentally studied.The layer has a circular axisymmetric boundary.In the absence of modulation of the rotation speed,the interphase boundary has the shape of a short axisymmetric cylinder.A new effect has been discovered,under the influence of rotation speed modulation,the interface takes on a new dynamic equilibrium state.A more viscous liquid covers the end boundaries of the layer in the form of thin films,which have the shape of round spots of almost constant radius;with increasing amplitude of the velocity modulation,the wetting boundary expands.It is found that upon reaching the critical amplitude of oscillations,the film of a viscous liquid loses stability,and the outer edge of the wetting spot collapses and takes on a feathery structure.It is shown that this threshold is caused by the development of the Kelvin-Helmholtz oscillatory instability of the film.The spreading radius of a spot of light viscous liquid and its stability are studied depending on the rotation rate,amplitude,and frequency of rotation speed modulation.The discovered averaged effects are determined by different oscillatory interaction of fluids with the end-walls of the cell,due to different viscosities.The effect of films forming can find application in technological processes to intensify mass transfer at interphase boundaries.

Laser-induced plasma formation in water with up to 400 mJ double-pulse LIBS

Double-pulse LIBS is a promising technique for deep-sea applications.LIBS measurements in shallow water with up to 400 mJ each pulse were done to select laser parameters which promote optimized spectral line emission from plasma even at elevated pressures,where line broadening until loss of most of the spectral information can occur.Optical emission spectroscopy,using a Czerny-Turner spectrometer,has been applied to investigate the dependence of the emitted radiation on laser parameters and hydrostatic pressure.It has been found,that higher laser pulse energies,especially with short pulse delay as required in high water pressure,can also have an adverse effect on the measured spectrum.

Influence of manufacturing process-induced geometrical defects on the energy absorption capacity of polymer lattice structures

Modern additive manufacturing processes enable fabricating architected cellular materials of complex shape,which can be used for different purposes.Among them,lattice structures are increasingly used in applications requiring a compromise among lightness and suited mechanical properties,like improved energy absorption capacity and specific stiffness-to-weight and strength-to-weight ratios.A dedicated modeling strategy to assess the energy absorption capacity of lattice structures under uni-axial compression loading is presented in this work.The numerical model is developed in a non-linear framework accounting for the strain rate effect on the mechanical responses of the lattice structure.Four geometries,i.e.,cubic body centered cell,octet cell,rhombic-dodecahedron and truncated cuboctahedron 2+,are investigated.Specifically,the influence of the relative density of the representative volume element of each geometry,the strain-rate dependency of the bulk material and of the presence of the manufacturing process-induced geometrical imperfections on the energy absorption capacity of the lattice structure is investigated.The main outcome of this study points out the importance of correctly integrating geometrical imperfections into the modeling strategy when shock absorption applications are aimed for.

Deterministic and probabilistic analysis of great-depth braced excavations:A 32 m excavation case study in Paris

The Fort d’Issy-Vanves-Clamart(FIVC)braced excavation in France is analyzed to provide insights into the geotechnical serviceability assessment of excavations at great depth within deterministic and probabilistic frameworks.The FIVC excavation is excavated at 32 m below the ground surface in Parisian sedimentary basin and a plane-strain finite element analysis is implemented to examine the wall deflections and ground surface settlements.A stochastic finite element method based on the polynomial chaos Kriging metamodel(MSFEM)is then proposed for the probabilistic analyses.Comparisons with field measurements and former studies are carried out.Several academic cases are then conducted to investigate the great-depth excavation stability regarding the maximum horizontal wall deflection and maximum ground surface settlement.The results indicate that the proposed MSFEM is effective for probabilistic analyses and can provide useful insights for the excavation design and construction.A sensitivity analysis for seven considered random parameters is then implemented.The soil friction angle at the excavation bottom layer is the most significant one for design.The soil-wall interaction effects on the excavation stability are also given.

Systematic Review on Ground-Based Cloud Tracking Methods for Photovoltaics Nowcasting

Renewable energies are highly dependent on local weather conditions, with photovoltaic energy being particularly affected by intermittent clouds. Anticipating the impact of cloud shadows on power plants is crucial, as clouds can cause partial shading, excessive irradiation, and operational issues. This study focuses on analyzing cloud tracking methods for short-term forecasts, aiming to mitigate such impacts. We conducted a systematic literature review, highlighting the most significant articles on cloud tracking from ground-based observations. We explore both traditional image processing techniques and advances in deep learning models. Additionally, we discuss current challenges and future research directions in this rapidly evolving field, aiming to provide a comprehensive overview of the state of the art and identify opportunities for significant advancements in the next generation of cloud tracking systems based on computer vision and deep learning.

The Role of the Size Effect on the Drying of Refractory Castables—How Its Under-standing Could Narrow the Gap between Laboratory Studies and Industrial Reality

Refractories have unique capabilities such as sustaining their shape and properties at extreme conditions such as the combination of high temperatures and thermal shock,contact with molten metals and slags and in some circumstances resistance to erosion from abrasive particles.Given the large processing output of the heavy industries such as the cement and steel ones which both require high temperature processes,the refractories structures span various meters and weight of several tons.As the water removal stage of hydraulic bonded castables in industrial sites takes hours(10-60 h)due to the risk of explosive spalling,efforts to mitigate it are commonly studied.This has provided theoretical understanding of the general aspects of drying and important tools,such as the thermogravimetry analysis(TGA),for the design of refractory compositions with higher explosive spalling resistance.However,the optimization of this process is still far from the industrial reality especially because the actual linings that require the drying are orders of magnitude larger than the samples considered in the laboratory tests.Therefore,this study proposed the analysis of the sample volume effect on the water removal dynamics through TGA of high alumina castables with calcium aluminate cement.Conventionalφ5 cm×5 cm cylindrical samples were assessed in a laboratory scale equipment whereas macro TGA were carried out considering 20 cm×20 cm×20 cm and 30 cm×30 cm×30 cm cubic samples.Additionally,the effect of polymeric fibers was also considered.It was found out that the different thermal gradients within the macro TGA samples resulted in an inflection on the sample’s heating rate and that the mass loss was affected by the volume considered,especially for the composition without additives.These findings highlight the requirement of carefully taking into consideration the different dimensional sizes and thermal gradients in the samples when analyzing and interpreting the laboratory studies,and especially when trying to extrapolate such results to the industrial reality.

Droughts in Homogeneous Areas of South America and Associated Processes during the Months of Austral Spring and Summer

Droughts that occurred in selected areas located in homogeneous regions of South America during the austral springs(SON)and summers(DJF)from 1982 to 2019 are identified using the Standard Precipitation Index(SPI).Four areas were analyzed for droughts in SON,and three areas were analyzed for droughts in DJF.The areas in the Amazon suffered from the majority of their droughts during El Niño years,while most of the droughts in the areas of southern Brazil,Uruguay,and North Argentina occurred during La Niña years.In southeastern and central-western parts of Brazil,droughts occurred during both phases of El Nino-Southern Oscillation(ENSO)and also during neutral years.Thus,other processes besides ENSO are likely related to the observed droughts.The droughts were investigated for each area and month,and composites of atmospheric and oceanic variables during both seasons were analyzed for the selected cases.Regional and large-scale field composites were examined to identify the main processes associated with dry conditions in the different areas.Regional features were related to the influence of high pressure over southern and southeastern areas and the divergence of moisture flux in all areas.Meridional circulations contributed to subsidence over the dry regions.The large-scale influential features include SST anomalies,wavetrains over the South Pacific Ocean with centers of action over South America that produced subsidence in the study areas,and convection anomalies in the Maritime continent and surrounding areas.Therefore,the droughts were associated with a combination of regional and large-scale features that produced subsidence over the analyzed regions.

Preclinical and clinical evidence of the association of colibactinproducing Escherichia coli with anxiety and depression in colon cancer

BACKGROUND The association between the intestinal microbiota and psychiatric disorders is becoming increasingly apparent.The gut microbiota contributes to colorectal carcinogenesis(CRC),as demonstrated with colibactin-producing Escherichia coli(CoPEC).AIM To evaluate the association between CoPEC prevalence and anxiety-and depressive-like behaviors with both preclinical and clinical approaches.METHODS Patients followed after a CRC surgery and for whom the prevalence of CoPEC has been investigated underwent a psychiatric interview.Results were compared according to the CoPEC colonization.In parallel C57BL6/J wild type mice and mice with a CRC susceptibility were chronically infected with a CoPEC strain.Their behavior was assessed using the Elevated Plus Maze test,the Forced Swimming Test and the Behavior recognition system PhenoTyper®.RESULTS In a limited cohort,all patients with CoPEC colonization presented with psychiatric disorders several years before cancer diagnosis,whereas only one patient(17%)without CoPEC did.This result was confirmed in C57BL6/J wildtype mice and in a CRC susceptibility mouse model(adenomatous polyposis colimultiple intestinal neoplasia/+).Mice exhibited a significant increase in anxiety-and depressive-like behaviors after chronic infection with a CoPEC strain.CONCLUSION This finding provides the first evidence that CoPEC infection can induce microbiota-gut-brain axis disturbances in addition to its procarcinogenic properties.

Projected Changes in the Climate Zoning of Côte d’Ivoire

This study assesses the projected changes in the climate zoning of Côte d’Ivoire using the hierarchical classification of principal components (HCPC) method applied to the daily precipitation data of an ensemble of 14 CORDEX-AFRICA simulations under RCP4.5 and RCP8.5 scenarios. The results indicate the existence of three climate zones in Côte d’Ivoire (the coastal, the centre and the north) over the historical period (1981-2005). Moreover, CORDEX simulations project an extension of the surface area of drier climatic zones while a reduction of wetter zones, associated with the appearance of an intermediate climate zone with surface area varying from 77,560 km2 to 134,960 km2 depending on the period and the scenario. These results highlight the potential impacts of climate change on the delimitation of the climate zones of Côte d’Ivoire under the greenhouse gas emission scenarios. Thus, there is a reduction in the surface areas suitable for the production of cash crops such as cocoa and coffee. This could hinder the country’s economy and development, mainly based on these cash crops.

Influence of Continental Atmospheric Forcing on the Decadal Variability of the West African Monsoon

The West African Monsoon (WAM) is characterized by strong decadal and multi-decadal variability and the impacts can be catastrophic for the local populations. One of the factors put forward to explain this variability involves the role of atmospheric dynamics, linked in particular to the Saharan Heat Low (SHL). This article addresses this question by comparing the sets of preindustrial control and historical simulation data from climate models carried out in the framework of the CMIP5 project and observations data over the 20th century. Through multivariate statistical analyses, it was established that decadal modes of ocean variability and decadal variability of Saharan atmospheric dynamics significantly influence decadal variability of monsoon precipitation. These results also suggest the existence of external anthropogenic forcing, which is superimposed on the decadal natural variability inducing an intensification of the signal in the historical simulations compared to preindustrial control simulations. We have also shown that decadal rainfall variability in the Sahel, once the influence of oceanic modes has been eliminated, appears to be driven mainly by the activity of the Arabian Heat Low (AHL) in the central Sahel, and by the structure of the meridional temperature gradient over the inter-tropical Atlantic in the western Sahel.

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.

Pharmacogenetic considerations for optimizing tacrolimus dosing in liver and kidney transplant patients

The introduction of tacrolimus in clinical practice has improved patient survival after organ transplant.However,despite the long use of tacrolimus in clinical practice,the best way to use this agent is still a matter of intense debate.The start of the genomic era has generated new research areas,such as pharmacogenetics,which studies the variability of drug response in relation to the genetic factors involved in the processes responsible for the pharmacokinetics and/or the action mechanism of a drug in the body.This variability seems to be correlated with the presence of genetic polymorphisms.Genotyping is an attractive option especially for the initiation of the dosing of tacrolimus;also,unlike phenotypic tests,the genotype is a stable characteristic that needs to be determined only once for any given gene.However,prospective clinical studies must show that genotype determination before transplantation allows for better use of a given drug and improves the safety and clinical efficacy of that medication.At present,research has been able to reliably show that the CYP3A5 genotype,but not the CYP3A4 or ABCB1 ones,can modify the pharmacokinetics of tacrolimus.However,it has not been possible to incontrovertibly show that the corresponding changes in the pharmacokinetic profile are linked with different patient outcomes regarding tacrolimus efficacy and toxicity.For these reasons,pharmacogenetics and individualized medicine remain a fascinating area for further study and may ultimately become the face of future medical practice and drug dosing.

Stability of highly supersaturated vanadium electrolyte solution and characterization of precipitated phases for vanadium redox flow battery

The vanadium redox flow battery(VRFB)has been receiving great attention in recent years as one of the most viable energy storage technologies for large-scale applications.However,higher concentrations of vanadium species are required in the H_(2)O-H_(2)SO_(4) electrolyte in order to improve the VRFB energy density.This might lead to unwanted precipitation of vanadium compounds,whose nature has not been accurately characterized yet.For this purpose,this study reports the preparation ofⅤ^((Ⅱ)),ⅤV^((Ⅲ)),Ⅴ^((Ⅳ))andⅤ^((Ⅴ))supersaturated solutions in a 5 M H_(2)SO_(4)-H_(2)O electrolyte by an electrolytic method,from the only vanadium sulfate compound commercially available(VOSO_(4)).The precipitates obtained by ageing of the stirred solutions are representative of the solids that may form in a VRFB operated with such supersaturated solutions.The solid phases are identified using thermogravimetric analysis,X-ray diffraction and SEM.We report that dissolvedⅤ^((Ⅱ)),Ⅴ^((Ⅲ))andⅤ^((Ⅳ))species precipitate as crystals of VSO_(4),V_(2)(SO_(4))3 and VOSO_(4) hydrates and not in their anhydrous form;conversely V^((Ⅴ))precipitates as an amorphous V_(2) O_(5) oxide partially hydrated.The measured hydration degrees(respectively 1.5,9,3 and 0.26 mol of H_(2)O per mol of compound)might significantly affect the overall engineering of VRFB operating with high vanadium concentrations.

Recent Extremes of Drought and Flooding in Amazonia: Vulnerabilities and Human Adaptation

The present study focuses on the impacts of extreme drought and flooding situations in Amazonia, using level/discharge data from some rivers in the Amazon region as indicators of impacts. The last 10 years have featured various “once in a century” droughts and floods in the Amazon basin, which have affected human and natural systems in the region. We assess a history of such hazards based on river data, and discuss some of the observed impacts in terms of vulnerability of human and natural systems, as well as some of adaptation strategies implemented by regional and local governments to cope with them. A critical perspective of mitigation of drought and flood policies in Amazonia suggests that they have been mostly ineffective in reducing vulnerability for the majority of the population, constituting, perhaps, examples of maladaptation via the undermining of resilience.

Investigation of a CO2 Switching Arc Using Spectroscopic Diagnostics and Computational Fluid Dynamics Simulations

A deep understanding of the physical processes coming along with the current interruption in high voltage circuit breakers is essential for the optimization of today’s switching technologies.Therefore a switching arc in a model circuit breaker is studied by means of computational fluid dynamics(CFD)simulations and optical emission spectroscopy(OES)in this contribution.Experimental investigations are performed in carbon dioxide(CO2)at absolute filling pressures of 0.1 and 0.5 MPa.CFD simulations are carried out based on a model of the arcing zone including a consistent treatment of the radiation transport and the wall ablation.Carbon ion line radiation is analysed in the experiment using an optical path in the heating channel between the electrodes inside the nozzle system.The pressure value in the arc is estimated based on the line width-intensity dependence.Obtained values correspond to the measured pressure outside the arc.For the temperature profiles,a good agreement within the accuracy of the approaches is observed between the CFD simulations and the results of OES.

Influence of extrusion temperature on microstructure and mechanical properties of Mg-4Y-4Sm-0.5Zr alloy

The solution-treated Mg-4Y-4Sm-0.5Zr alloy was extruded at temperatures from 325℃ to 500℃.Dynamic recrystallization(DRX) completely occurs when the alloy is extruded at 350℃and above.The grains of the extruded alloy are obviously refined by the occurrence of DRX.The average grain size of the extruded alloy increases with increasing the extrusion temperature,leading to a slight decrease of the ultimate tensile strength(UTS) and the yield strength(YS) .On the contrary,the UTS and YS of the extruded and aged alloy increase with increasing the extrusion temperature.Values of UTS of 400 MPa,YS larger than 300 MPa and elongation(EL) of 7%are achieved after extrusion at 400℃ and ageing at 200℃ for 16 h.Both grain refinement and precipitation are efficient strengthening mechanisms for the Mg-4Y-4Sm-0.5Zr alloy.

Preparation and Properties of Cellulose Nanomaterials

Cellulose is the most abundant biomass material in nature and it is mainly extracted from natural or lignocellulosic fibers.After purification,cellulose fibers exhibit two interesting features for their further transformation into nanomaterials:a hierarchical and multi-level strcture,and a semicrystalline microstructure.Different forms of cellulose nanomaterials,resulting from a top-down deconstructing strategy(cellulose nanocrystals(CNCs),cellulose nanofibrils(CNFs))or bottom-up strategy(bacterial cellulose(BC))can be prepared.Multiple mechanical shearing actions applied to cellulosic fibers release more or less the nanofibrils individually.A controlled strong acid hydrolysis treatment can be applied to cellulosic fibers allowing dissolution of non-crystalline domains.Such cellulose nanomaterials have been the focus of an exponentially increasing number of works or reviews devoted to understand such materials and their applications.They have a high potential for an emerging industry.In the nanoscale,cellulose exhibits specific properties broadening the applications of this naturally occurring polymer.An overview of existing methods for the preparation of cellulose nanomaterials and their specific properties that outperform and contrast with cellulose in the microscale is proposed.

Projections of the impacts of climate change on the water deficit and on the precipitation erosive indexes in Mantaro River Basin, Peru

Projections of climate change are essential to guide sustainable development plans in the tropical Andean countries such as Peru. This study assessed the projections of precipitation and potential evaporation, rain erosive potential, and precipitation concentration in the Mantaro River Basin, in the Peruvian Andes, which is important for agriculture and energy production in Peru. We assumed the Intergovernmental Panel on Climate Change （IPCC） AIB greenhouse gas emission scenario and simulated the global climate change by the HadCM3 global climate model. Due to the steepness of the mountain slopes and the narrowness of the river valley, this study uses the downscaling of the global model simulations by the regional Eta model down to 2o-km resolution. The downscaling projections show decrease in the monthly precipitation with respect to the baseline period, especially during the rainy season, between February and April, until the end of the 21st century. Meanwhile, a progressive increase in the monthly evaporation from the baseline period is projected. The Modified Fournier Index （MFI） shows a statistically significant downward trend in the Mantaro River Basin, whieh suggests a possible reduction in the rain erosive potential. The Precipitation Concentration Index （PCI） shows a statistically significant increasing trend, which indicates increasingly more irregular temporal distribution of precipitation towards the end of the century. The results of this study allow us to conclude that there should be a gradual increase in water deficit and precipitation concentration. Both changes can be negative for agriculture, power generation, and water supply in the Mantaro River Basin in Peru.

Time-dependent behaviour of the Callovo-Oxfordian claystone-concrete interface

In the context of the Cigeo project,the French National Radioactive Waste Management Agency(Andra)is studying the behaviour of a deep geological facility for radioactive waste deposit in the CallovoOxfordian(COx)claystone.The assessment of durability of this project requires the prediction of irreversible strain over a large time scale.The mechanical interaction of the host rock and the concrete support of tunnels must be investigated to ensure the long-term sustainability of the structure.The instantaneous and time-dependent behaviour of the claystone-concrete interface is experimentally investigated with direct shear tests and long-duration shear tests of a few months.The mechanical and structural state of the claystone which is affected after interaction with concrete reflects to the response of the claystone-concrete interface,and thus different types of COx claystone-concrete interfaces are tested.The delayed deformation of the interface is found to be linked to the level of the normal loading and the loading history while a different response of the interface was observed from the short-and long-duration tests,indicating a possible progressive modification of interface under long-duration loadings.