检索结果-南通市图书馆

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Therapeutic advances in neural regeneration for Huntington’s disease

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第9期19卷 1991-1997页

作者： Francesco d’Egidio Vanessa Castelli Giorgia Lombardozzi Fabrizio Ammannito Annamaria Cimini Michele d’Angelo department of Life Health and Environmental SciencesUniversity of L’AquilaL’AquilaItaly

Huntington’s disease is a neurodegenerative disease caused by the expansion mutation of a cytosine-adenine-guanine triplet in the exon 1 of the HTT gene which is responsible for the production of the huntingtin (Htt) protein. In physiological conditions, Htt is involved in many cellular processes such as cell signaling, transcriptional regulation, energy metabolism regulation, dNA maintenance, axonal trafficking, and antiapoptotic activity. When the genetic alteration is present, the production of a mutant version of Htt (mHtt) occurs, which is characterized by a plethora of pathogenic activities that, finally, lead to cell death. Among all the cells in which mHtt exerts its dangerous activity, the GABAergic Medium Spiny Neurons seem to be the most affected by the mHtt-induced excitotoxicity both in the cortex and in the striatum. However, as the neurodegeneration proceeds ahead the neuronal loss grows also in other brain areas such as the cerebellum, hypothalamus, thalamus, subthalamic nucleus, globus pallidus, and substantia nigra, determining the variety of symptoms that characterize Huntington’s disease. From a clinical point of view, Huntington’s disease is characterized by a wide spectrum of symptoms spanning from motor impairment to cognitive disorders and dementia. Huntington’s disease shows a prevalence of around 3.92 cases every 100,000 worldwide and an incidence of 0.48 new cases every 100,000/year. To date, there is no available cure for Huntington’s disease. Several treatments have been developed so far, aiming to reduce the severity of one or more symptoms to slow down the inexorable decline caused by the disease. In this context, the search for reliable strategies to target the different aspects of Huntington’s disease become of the utmost interest. In recent years, a variety of studies demonstrated the detrimental role of neuronal loss in Huntington’s disease condition highlighting how the replacement of lost cells would be a reasonable strategy to o

关键词： cell therapy exosomes extracellular vesicles Huntingtin Huntington’s disease medium spiny neurons neurodegenerative disease neurogenesis neuronal loss stem cells

Viscoelastic potential flow instability theory of Rivlin-Ericksen electrified fluids of cylindrical interface

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2024年第4期9卷 311-316页

作者： d.M.Mostafa department of Mathematics College of ScienceQassim UniversityPO Box 6644Buraidah 51452Saudi Arabia department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

A linear electrohydrodynamic Kelvin-Helmholtz instability of the interface between two viscoelastic Rivlin-Ericksen fluids enclosed by two concentric horizontal cylinders has been studied via the viscoelastic potential flow *** dispersion equation of complex coefficients for asymmetric disturbance has been obtained by using normal mode *** stability criteria are analyzed theoretically and illustrated *** imaginary part of growth rate is plotted versus the wave *** influences of dynamic viscoelastic,uniform velocities,Reynolds number,electric field,dynamic viscosity,density fluids ratio,dielectric constant ratio and inner fluid fraction on the stability of the system are *** study finds its significance in Ocean pipelines to transfer oil or gas such as Eastern Siberia-pacific Ocean oil pipeline.

关键词： Rivlin-Ericksen fluid Cylindrical flow Viscoelastic potential flow Electrohydrodynamics stability

Microscale shaping and rounding of ridge arrays and star pattern features on nickel mould via electrochemical polishing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第2期12卷 207-226页

作者： Sana Zaki Nan Zhang Michael d.Gilchrist School of Mechanical and Materials Engineering University College DublinBelfieldDublin 4Ireland

High quality micro mould tools are critical for ensuring defect-free production of micro injection moulded *** demoulding stage of the micro injection moulding can adversely affect the surface integrity due to friction,adhesion and thermal stresses between the metallic mould and polymeric replicated *** the present work,we propose the use of precision electropolishing(Ep)as a shaping and polishing process to control the draft angle and fillet radius of micro features in order to ease *** defects that occur in replicated polymer parts include cracks,burrs and distorted features.A nickel mould having multiple linear ridges and star shape patterns was designed for the present investigation to have characteristic dimensions ranging from 10μm to 150μm and with various aspect ratios to study the effect of electropolishing on modifying the shape of micro features and surface morphology.A transient 2d computational analysis has been conducted to anticipate the effect of shaping on the Ni mould after electrochemical polishing with non-uniform material removal rates,based on the distribution of current *** experimental results indicate that after shaping using Ep,the draft angle of star-patterns and linear patterns can be effectively increased by approximately 3.6°,while the fillet radius increases by up to 5.0μ*** controlling the electropolishing process,the surface roughness can be maintained under 50 *** work uses a green and environmental friendly nickel sulfamate electrolyte which can be effective for shaping of nickel micro features without causing any surface deposition.

关键词： Micro feature shaping and electropolishing Micro mould tools Green electrolyte demoulding micro patterns

Kinetics of glyphosate and aminomethylphosphonic acid sorption onto montmorillonite clays in soil and their translocation to genetically modified corn

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第1期135卷 669-680页

作者： Meichen Wang Kelly J Rivenbark Timothy d phillips Veterinary physiology and pharmacology College of Veterinary Medicine and Biomedical SciencesTexas A&M UniversityTX 77845USA

The co-occurrence of glyphosate(GLp)and aminomethylphosphonic acid(AMpA)in contaminated water,soil,sediment and plants is a cause for concern due to potential threats to the ecosystem and human health.A major route of exposure is through contact with contaminated soil and consumption of crops containing GLp and AMpA ***,clay-based sorption strategies for mixtures of GLp and AMpA in soil,plants and garden produce have been very *** this study,in vitro soil and in vivo genetically modified corn models were used to establish the proof of concept that the inclusion of clay sorbents in contaminated soils will reduce the bioavailability of GLp and AMpA in soils and their adverse effects on plant *** of chemical concentration(1–10 mg/kg),sorbent dose(0.5%-3%in soil and 0.5%-1%in plants)and duration(up to 28 days)on sorption kinetics were *** time course results showed a continuous GLp degradation to *** inclusion of calcium montmorillonite(CM)and acid processed montmorillonite(ApM)clays at all doses significantly and consistently reduced the bioavailability of both chemicals from soils to plant roots and leaves in a dose-and time-dependent manner without detectable *** treated with 0.5%and 1%ApM inclusion showed the highest growth rate(p≤0.05)and lowest chemical bioavailability with up to 76%reduction in roots and57%reduction in *** indicated that montmorillonite clays could be added as soil supplements to reduce hazardous mixtures of GLp and AMpA in soils and plants.

关键词： Glyphosate AMpA Adsorption Soil remediation plant Hydroponic system

Wind energy feasibility and wind turbine selection studies for the city Surat,India

在线全文

学校读者我要写书评

暂无评论

Clean Energy 2024年第3期8卷 166-173页

作者： Arshi Banu p S Maanat Bhadani Hindustan Institute of Technology and Science ChennaiIndia The doon School UttarakhandDehradunIndia

Wind energy represents a clean,abundant and cost-effective power source,fostering job growth and environmental *** wind energy harnesses several gigawatts today,its availability hinges on diverse factors,with geographical location standing *** turbines,with varying capacity ranges,saturate the *** site-specific suitability and matching the appropriate turbine to meet specific requirements are of paramount *** study aims to assess the feasibility of wind energy in Surat,Gujarat,India and select an optimal small commercial turbine for residential *** research involves Rayleigh and Weibull probability distribution functions based on yearlong velocity *** distributions are fitted with actual data,revealing the most probable velocity(v_(mf)=3 m/s)and velocity at maximum power(v_(pmax)=5 m/s).The power availability of the site has been assessed as 42.6 W/m^(2)using both graphical and analytical *** commercial turbines have been shortlisted based on on-site power criteria and their specifications are evaluated against site power availability.A comparative analysis culminates in identifying the most suitable turbine for the *** best suitable turbine for the site with an annual energy yield of 8 MW has been suggested amongst selected turbines for small-scale residential applications.

关键词： site feasibility wind energy commercial wind turbine probability distribution function rated power

Stress granules: friend or foe in neurodegenerative disorders?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第2期19卷 403-404页

作者： Shanshan Xu Nico p.dantuma department of Cell and Molecular Biology(CMB) Karolinska InstitutetSolnavägen 9S-17165 StockholmSweden

Neurodegenerative diseases,such as Alzheimer’s disease,parkinson’s disease,and amyotrophic lateral sclerosis,despite the diversity in clinical symptoms,share a striking feature at the cellular level:the accumulation of insoluble aggregates of misfolded proteins that are sequestered in intraneuronal inclusion *** mutations in disease-associated proteins that render them aggregation-prone,the decline of protein homeostasis(***)with aging is also believed to be a contributing factor to the accumulation of protein aggregates.

关键词： degenerative homeostasis clinical

Chebyshev polynomial-based Ritz method for thermal buckling and free vibration behaviors of metal foam beams

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 891-910页

作者： N.d.NGUYEN T.N.NGUYEN Faculty of Civil Engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City 71309Viet Nam Faculty of Engineering and Technology Kien Giang UniversityChau Thanh 92000Viet Nam

This study presents the Chebyshev polynomials-based Ritz method to examine the thermal buckling and free vibration characteristics of metal foam *** analyses include three models for porosity distribution and two scenarios for thermal *** material properties are assessed under two conditions,i.e.,temperature dependence and temperature *** theoretical framework for the beams is based on the higher-order shear deformation theory,which incorporates shear deformations with higher-order *** governing equations are established from the Lagrange equations,and the beam displacement fields are approximated by the Chebyshev *** simulations are performed to evaluate the effects of thermal load,slenderness,boundary condition(BC),and porosity distribution on the buckling and vibration behaviors of metal foam *** findings highlight the significant influence of temperature-dependent(Td)material properties on metal foam beams'buckling and vibration responses.

关键词： Ritz method Chebyshev function buckling vibration metal foam beam higher-order beam theory(HOBT)

Unveiling the culprit:the fusobacterium lineage that populates colorectal cancer

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2024年第6期9卷 2349-2350页

作者： Johannes Betge Matthias p.Ebert department of Medicine Ⅱ Medical Faculty MannheimHeidelberg UniversityMannheimGermany Junior Clinical Cooperation Unit Translational Gastrointestinal Oncology and preclinical Models German Cancer Research Center(DKFZ)HeidelbergGermany dKFZ Hector Cancer Institute at University Medical Center MannheimGermany MMpU Microbiota drug Metabolism and Cancer Therapy European Molecular Biology LaboratoryHeidelbergGermany

In a recent study published in Nature,Zepeda-Rivera et al.1 discovered that one distinct clade of Fusobacterium nucleatum animalis(Fna)dominates the colorectal cancer(CRC)tumor *** work unravels a more precise understanding of a major bacterial species associated with CRC progression,thereby establishing a new focus for future studies,which may aid to develop improved microbiome-based diagnostics and treatments(Fig.1).

关键词： colorectal al. cancer