检索结果-南通市图书馆

Ebola virus disease model with a nonlinear incidence rate and density-dependent treatment

在线全文

学校读者我要写书评

暂无评论

Infectious Disease Modelling 2024年第3期9卷 775-804页

作者： Jacques ndéKengne calvin Tadmon committed Mathematics Team Research Unit in Mathematics and ApplicationsDepartment of Mathematics and Computer ScienceUniversity of DschangP.O.Box 67 DschangCameroon Institute of Mathematics University of MainzStaudingerweg 955128MainzGermany

This paper studies an Ebola epidemic model with an exponential nonlinear incidence function that considers the efficacy and the behaviour *** current model also incorporates a new density-dependent treatment that catches the impact of the disease transmission on the ***,we provide a theoretical study of the nonlinear differential equations model *** precisely,we derive the effective reproduction number and,under suitable conditions,prove the stability of ***,we show that the model exhibits the phenomenon of backward-bifurcation whenever the bifurcation parameter and the reproduction number are less than *** find that the bi-stability and backward-bifurcation are not automatically connected in epidemic *** fact,when a backward-bifurcation occurs,the disease-free equilibrium may be globally ***,we use well-known standard tools to fit the model to the data reported for the 2018–2020 Kivu Ebola outbreak,and perform the sensitivity *** control Ebola epidemics,our findings recommend a combination of a rapid behaviour change and the implementation of a proper treatment strategy with a high level of ***,we propose and analyze a fractional-order Ebola epidemic model,which is an extension of the first model *** use the caputo operator and construct the Grünwald-Letnikov nonstandard finite difference scheme,and show its advantages.

关键词： Ebola epidemic models Stability Bifurcation Density-dependent treatment Sensitivity analysis Fractional differential equations caputo fractional derivative Grünwald-letnikov nonstandard finite difference scheme

Encroachment drives facilitation at alpine shrublines

维普期刊数据库评论

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 62-72页

作者： Yafeng Wang Eryuan Liang J.julio camarero college of Ecology and Environment Nanjing Forestry UniversityNanjing210037China State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing100101China Instituto Pirenaico de Ecología(IPE-cSIc) Zaragoza50080Spain

Ongoing encroachment is driving recent alpine shrubline dynamics globally,but the role of shrub-shrub interactions in shaping shrublines and their relationships with stem density changes remain poorly ***,the size and age of shrubs from 26 Salix shrubline populations along a 900-km latitudinal gradient(30°-38°N)were measured and mapped across the eastern Tibetan *** pattern analyses were used to quantify the spatial distribution patterns of juveniles and adults,and to assess spatial associations between *** intensity of univariate and bivariate spatial patterns was related to biotic and abiotic *** mark correlation functions with a quantitative mark(shrub height,basal stem diameter,crown width)were also employed to investigate the spatial relationships between shrub traits of juveniles and *** equation models were used to explore the relationships among conspecific interactions,patterns,shrub traits and recruitment dynamics under climate *** shrublines showed clustered patterns,suggesting the existence of conspecific *** patterns of juveniles and conspecific interactions(potentially facilitation)tended to intensify with increasing soil moisture *** warming before 2010 triggered positive effects on population interactions and spatial patterns via increased shrub ***,summer warming after2010 triggered negative effects on interactions through reduced shrub ***,shrub recruitment shifts under rapid climate change could impact spatial patterns,alter conspecific interactions and modify the direction and degree of shrublines responses to *** changes would have profound implications for the stability of alpine woody ecosystems.

关键词： Alpine shrubline Positive interactions Facilitation Spatial clustering Point pattern analyses

Geochemistry and mineral chemistry of the armoor granitoids,eastern dharwar craton: implications for the redox conditions and tectono-magmatic environment

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第1期43卷 110-133页

作者： A.Ajay Kumar ch.Ashok Department of Geology Osmania UniversityHyderabad 500007India cSIR-National Geophysical Research Institute UppalHyderabad 500007India

The mineralogical and geochemical characteristics of the K-rich granites from the Armoor granitic rocks in the northeastern portion of the Eastern Dharwar craton(EDc) are *** order to understand its physicochemical conditions,the petrogenesis of the granitoid was explained from biotite chemistry and geochemical *** of mineral chemistry expose that compositionally,K-feldspar and plagioclase in Armoor granite rocks range from An0,Ab_(3-5.9),Or_(94-96.9) and An_(5-29,-Ab71.9-94.9),Or_(0-1.5),*** mineral chemistry of biotite crystals exhibits composition that varies from primary to re-equilibrated primary *** biotites from the Armoor granites generally exhibit an I-type trend,with calc-alkaline parental magma in a subduction *** chemistry of granites displays magnetite(oxidized)series nature,which has oxygen fugacity(fO_(2))=-15.1 to-16.7(log_(10) bar),under high oxidizing *** and pressure estimates for the crystallization of Armoor granites based on biotite composition are T=612-716 ℃ and 1.0-0.4 kbar,***,these rocks are metaluminous to slightly peraluminous and magnesian,with calc-alkaline potassiumrich *** the chondrite normalized REE diagram,the granites have positive europium anomalies;rich Sr/Y,(Dy/Yb)_(N) ratios and reduced Mg#,Rb/Sr,Rb,Sr indicate that the melting of earlier rocks,crystal accumulation and residual garnet source formed at high *** examined granites show that they are produced from the melting of crustal ***,the extensive analyses of the described Armoor granite suggest that they were produced by crust sources and developed under oxidizing conditions in subduction setting.

关键词： Armoor granites Oxygen fugacity crystal accumulation Remelting Subduction

Bile acids,gut microbiota,and therapeutic insights in hepatocellular carcinoma

在线全文

学校读者我要写书评

暂无评论

cancer Biology & Medicine 2024年第2期21卷 144-162页

作者： Yang Song Harry ch Lau Xiang Zhang Jun Yu Institute of Digestive Disease and Department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesCUHK Shenzhen Research InstituteThe Chinese University of Hong KongHong KongChina Department of Gastroenterology Zhongshan Hospital Xiamen UniversityXiamen 361004China

Hepatocellular carcinoma(Hcc)is a prevalent and aggressive liver *** interplay between bile acids(BAs)and the gut microbiota has emerged as a critical factor in Hcc development and *** normal conditions,BA metabolism is tightly regulated through a bidirectional interplay between gut microorganisms and *** gut microbiota plays a critical role in BA metabolism,and BAs are endogenous signaling molecules that help maintain liver and intestinal *** note,dysbiotic changes in the gut microbiota during pathogenesis and cancer development can disrupt BA homeostasis,thereby leading to liver inflammation and fibrosis,and ultimately contributing to Hcc ***,understanding the intricate interplay between BAs and the gut microbiota is crucial for elucidating the mechanisms underlying *** this review,we comprehensively explore the roles and functions of BA metabolism,with a focus on the interactions between BAs and gut microorganisms in ***,therapeutic strategies targeting BA metabolism and the gut microbiota are discussed,including the use of BA agonists/antagonists,probiotic/prebiotic and dietary interventions,fecal microbiota transplantation,and engineered *** summary,understanding the complex BA-microbiota crosstalk can provide valuable insights into Hcc development and facilitate the development of innovative therapeutic approaches for liver malignancy.

关键词： Bile acid gut microbiota hepatocellular carcinoma therapeutics microbiota modulation

contemplative neuroaesthetics and architecture:A sensorimotor exploration

在线全文

学校读者我要写书评

暂无评论

Frontiers of Architectural Research 2024年第1期13卷 97-111页

作者： Zakaria Djebbara Juliet King Amir Ebadi Yoshio Nakamura julio Bermudez Department of Architecture DesignMediaand TechnologyAalborg UniversityAalborgDenmark Biopsychology und Neuroergonomy Technical University BerlinBerlinGermany Art Therapy Department The George Washington UniversityWashington DCUnited States Department of Neurology Indiana University School of MedicineIndianapolisUnited States Dellustration Washington DCUnited States Pain Research center Division of Pain MedicineDepartment of AnesthesiologyUniversity of Utah School of MedicineUtahUnited States School of Architecture and Planning The Catholic University of AmericaWashington DCUnited States

This paper takes initial steps towards developing a theoretical framework of contemplative neuroaesthetics through sensorimotor *** first argue that this new area has been largely omitted from the contemporary research agenda in neuroaesthetics and thus remains a domain of untapped *** seek to define this domain to foster a clear and focused investigation of the capacity of the arts and architecture to induce phenomenological states of a contemplative *** proposing a sensorimotor account of the experience of architecture,we operationalize how being attuned to architecture can lead to contemplative *** contrasting the externally-induced methods with internally-induced methods for eliciting a contemplative state of mind,we argue that architecture may spontaneously and effortlessly lead to such states as certain built features naturally resonate with our sensorimotor *** suggest that becoming sensible of the resonance and attunement process between internal and external states is what creates an occasion for an externallyinduced contemplative ***,we review neuroscientific studies of architecture,elaborate on the brain regions involved in such aesthetic contemplative responses,provide architectural examples,and point at the contributions that this new area of inquiry may have in fields such as the evidence-based design movement in architecture.

关键词： Neuropheno menology Neuroaesthetics contemplative states Architectural experience Well-being

Photosynthetic Gas Exchange and Nitrogen Assimilation in Green Bean Plants Supplied with Two Sources of Silicon

在线全文

学校读者我要写书评

暂无评论

Phyton-International Journal of Experimental Botany 2024年第5期93卷 963-980页

作者： julio c.Anchondo-Páez Esteban Sánchez carlos A.Ramírez-Estrada Alondra Salcido-Martínez Erick H.Ochoa-chaparro Department of Plant Physiology Centro de Investigación en Alimentación y DesarrolloCiudad Delicias33089México

Beans contain a wide range of vitamins,proteins,calcium,and zinc which make them an important food source for many *** meet the demand for bean production worldwide,large amounts of fertilizers and pesticides are ***,the cost of production and environmental impact *** produce food sustainably,the use of beneficial nutrients such as silicon as a biostimulant has been ***,information about the effect of different sources of silicon on the metabolism of bean plants is *** plants *** were grown in pots for 60 days and the effect of foliar application of silicon nanoparticles and the silicon-based biostimulant codasilat 4 concentrations(0,1,2,and 4 mM)on total biomass,yield,photosynthetic pigment concentration,photosynthetic activity,stomatal conductance,transpiration rate,chlorophyll fluorescence,and nitrogen assimilation were *** results obtained showed that the supply of silicon at a dose of 1 mM functioned as a biostimulant,favoring gas exchange and nitrogen assimilation within the plant,which stimulated growth and *** results of this research work allowed a better comprehension of the effects of silicon application through silicon nanoparticles and the biostimulant codasilon the physiology of green bean plants.

关键词： Nanoparticles silicon Phaseolus vulgaris L.

Phosphine/Benzocyclone-based Neutral Nickel catalysts for Ethylene Polymerization and copolymerization with Polar Monomers

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

chinese Journal of Polymer Science 2024年第2期42卷 202-212,I0007页

作者： Fei Wang Li Pan Vladislav A.Tuskaev Svetlana ch.Gagieva Yue-Sheng Li Tianjin Key Lab of composite&Functional Materials School of Material Science and EngineeringTianjin UniversityTianjin300072China Department of chemistry Lomonosov Moscow State UniversityRussian Federation InstitutionLeninskie Gory 1Moscow119991Russian Federation A N Nesmeyanov Institute of Organoelement compounds Russian Academy of SciencesVavilova st.28Moscow119991Russian Federation

The efficient copolymerization of olefin with polar monomers using nickel-based catalysts presents a longstanding challenge. In this contribution, three phosphine-benzocyclone ligands and corresponding neutral nickel catalysts(Ni1: Ar = Ph;Ni2: Ar = 2-(c_(6)H_(5))c_(6)H_(4);Ni3: Ar = 2-[2',6'-(Me O)_(2)-c_(6)H3]c_(6)H_(4)) were prepared and applied for the ethylene polymerization and copolymerization with polar monomers without any cocatalyst. The bulky substituent groups in complexes Ni2 and Ni3 contributed to high catalytic activities(up to 7.24×10^(6) and 9.04×10^(6)g·mol Ni^(-1)·h^(-1), respectively), and produced high-molecular-weight polyethylene(Mw up to 545.7 k Da). complex Ni3 exhibited high activities for ethylene polymerization at the level of 10^(6) g·mol Ni^(-1)·h^(-1) across a wide range from 30 ℃ to 120 ℃, exhibiting excellent high temperature tolerance. These nickel complexes were also effectively employed in the copolymerization of ethylene with methyl acrylate, ethyl acrylate, butyl acrylate and lauryl acrylate, producing copolymers with high molecular weights(Mw up to 80.5 k Da) and high polar monomer incorporation(up to 8.2 mol%). Microstructure analyses revealed that the introduction of large sterically hindered substituents facilitated the incorporation of polar functional units into the polymer backbone. This study demonstrates the potential of these nickel-based catalysts for efficient copolymerization of olefin with polar monomers.

关键词： Neutral nickel catalyst Ethylene polymerization copolymerization Polar acrylate monomers

Polyoxidovanadates a new therapeutic alternative for neurodegenerative and aging diseases

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第3期19卷 571-577页

作者： Sonia Irais Gonzalez-cano Gonzalo Flores Jorge Guevara julio cesar Morales-Medina Samuel Treviño Alfonso Diaz Faculty of chemical Sciences Benemerita Autonomous University of PueblaPueblaMexico Institute of Physiology Benemerita Autonomous University of PueblaPueblaMexico Department of Biochemistry Faculty of MedicineNational Autonomous University of MexicoMexico CityMexico Animal Reproduction Research center CINVESTAV-Autonomous University of TlaxcalaTlaxcalaMexico

Aging is a natural phenomenon characterized by a progressive decline in physiological integrity,leading to a deterioration of cognitive function and increasing the risk of suffering from chronic-degenerative diseases,including cardiovascular diseases,osteoporosis,cancer,diabetes,and *** is considered the major risk factor for Parkinson’s and Alzheimer’s disease ***,diabetes and insulin resistance constitute additional risk factors for developing neurodegenerative ***,no treatment can effectively reverse these neurodegenerative ***,some antidiabetic drugs have opened the possibility of being used against neurodegenerative *** the previous framework,Vanadium species have demonstrated a notable antidiabetic *** research group evaluated polyoxidovanadates such as decavanadate and metforminium-decavanadate with preventive and corrective activity on neurodegeneration in brain-specific areas from rats with metabolic *** results suggest that these polyoxidovanadates induce neuronal and cognitive restoration *** review aims to describe the therapeutic potential of polyoxidovanadates as insulin-enhancer agents in the brain,constituting a therapeutic alternative for aging and neurodegenerative diseases.

关键词： Alzheimer’s disease antidiabetic brain cognition diabetes insulin neurodegeneration neuroinflammation oxidative stress Vanadium species

The effect of electrical current on lubricant film thickness in boundary and mixed lubrication contacts measured with ultrasound

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第8期12卷 1882-1896页

作者： julio A.cAO-ROMERO-GALLEGOS Saeid TAGHIZADEH Oscar A.AGUILAR-ROSAS R.S.DWYER-JOYcE Leonardo I.FARFAN-cABRERA Tecnologico de Monterrey Escuela de Ingeniería y CienciasAve.Eugenio Garza Sada 2501MonterreyN.L.64849México Department of Mechanical Engineering Leonardo Centre for TribologyUniversity of SheffieldSheffield S13JDUK

This work explores experimentally the effects of Dc electrical currents on lubricant film thickness alteration in lubricated sliding steel contacts in the boundary and mixed regime as measured by *** experiments were performed in a two-electrode cell-based pin-on-disk tester instrumented with ultrasonic *** and electrified tribological tests were conducted on steel flat-on-flat contacts under various speeds and loads using both a mineral base oil and a gear *** thickness,coefficient of friction(coF),and electrical contact resistance(EcR)were measured during short experiments(30 s)in unelectrified and electrified(1.5 and 3 A)*** results suggest that film thickness,coF,and all EcR are altered by passing Dc currents through the *** particular,film thickness increased and decreased,respectively,by applying electricity at the different speeds and loads *** alterations were majorly ascribed to oil viscosity decrease by local heat and surface oxidation caused by electrical discharge and break down at the interface.

关键词： electrified sliding ultrasonic measurement electric vehicles pin-on-disk