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Effects of a poly(hydroxyalkanoate)elastomer and kraft pulp fibres on biocomposite properties and three-dimensional(3d)printability of filaments for fused deposition modelling

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Journal of Bioresources and Bioproducts 2022年第3期7卷 161-172页

作者： Sandra rodríguez-Fabià Gary Chinga-Carrasco rISE PFI Høgskoleringen 6bTrondheim 7491Norway

Three-dimensional(3d)printing is a useful technique that allows the creation of objects with complex structures by deposition of successive layers of material.These materials are often from fossil origin.However,efforts are being made to produce environmentally friendly materials for 3d printing.The addition of lignocellulosic fibres to a polymer matrix is one of the alternatives to replace,for instance,glass fibres in composites as reinforcing materials.The fields of biocom-posites and 3d printing open innovative application areas for pulp fibres from the pulp and paper industry.In this work,biocomposites of poly(lactic acid)(PLA),poly(hydroxyalkanoate)(PHA)and kraft pulp fibres were prepared in order to find a suitable formulation for filaments for 3d printing.The effect of two different types of kraft fibres(bleached(B)and unbleached(U))and of PHA on the mechanical and thermal properties of the biocomposites was assessed.The addition of 30%kraft fibres to PLA resulted in an increase of the tensile modulus from 3074 to∼4800 MPa.In the case of biocomposites containing PHA(50%PLA/20%PHA/30%kraft)the increase in modulus was more moderate(PLA+PHA+U:3838 MPa,and PLA+PHA+B:3312 MPa).The tensile strength of PLA(66 MPa)increased to 77 MPa in PLA+kraft biocomposites,while a reduc-tion in strength was observed for PLA+PHA+U(43 MPa)and PLA+PHA+B(32 MPa).Filaments prepared with PLA,PHA and bleached and unbleached pulp fibres showed similar printability of complex geometries,demonstrating that unbleached pulp fibres could also be utilized in the preparation of biocomposites with good mechanical performance and 3d printing properties.

关键词： biocomposites 3d printing Poly(lactic acid) Kraft pulp

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Effect of La on the Corrosion Behavior and Mechanism of 3Ni Weathering Steel in a Simulated Marine Atmospheric Environment

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 308-324页

作者： Gang Niu rui Yuan r.d.K.Misra Na Gong Zhi-Hui Zhang Hao-Xiu Chen Hui-Bin Wu Cheng-Jia Shang Xin-Ping Mao Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China Laboratory for Excellence in Advanced Steel research Department of MetallurgicalMaterials and Biomedical EngineeringUniversity of Texas at El PasoEl PasoTX79968USA Institute of Materials research and Engineering Agency for ScienceTechnologyand ResearchSingapore138634Singapore department of Materials Science and Engineering University of TorontoTorontoONM5S 3E4Canada

The corrosion behavior and mechanism of 3Ni weathering steel in a simulated oceanic atmospheric environment are investigated in order to comprehend the impacts of La,as determined through electrochemical analysis and rust layer characterization.The results of this study demonstrate that the addition of La enhances the corrosion resistance of 3Ni weathering steel in the marine atmospheric environment,thereby reducing the corrosion rate and improving the protection of the rust layer.The influence of La on corrosion resistance can be attributed to two primary factors.Firstly,La functions as a grain refiner,minimizing the potential difference of the micro-regions on the substrate surface,thereby significantly reducing the corrosion of bare steel in the marine environment.Secondly,La inhibits the process of Fe_(3)O_(4) oxidation back toγ-FeOOH during corrosion at the local site,thus decreasing the formation ofγ-FeOOH and enhancing the charge transfer resistance.This research work may serve as a reference for expanding the application of rare earth elements in the field of weathering steel.

关键词： Weathering steel rare earth rust layer Corrosion behavior Corrosion resistance

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Treat to target in Crohn’s disease:A practical guide for clinicians

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World Journal of Gastroenterology 2024年第1期30卷 50-69页

作者： Ashish r Srinivasan department of Gastroenterology Austin HealthVictoriaMelbourne 3083Australia department of Gastroenterology Eastern HealthVictoriaMelbourne 3128Australia department of Medicine University of MelbourneVictoriaMelbourne 3052Australia

A treat-to-target(T2T)approach applies the principles of early intervention and tight disease control to optimise long-term outcomes in Crohn's disease.The Selecting Therapeutic Targets in Inflammatory Bowel disease(STrIdE)-II guidelines specify short,intermediate,and long-term treatment goals,documenting specific treatment targets to be achieved at each of these timepoints.Scheduled appraisal of Crohn’s disease activity against pre-defined treatment targets at these timepoints remains central to determining whether current therapy should be continued or modified.Consensus treatment targets in Crohn’s disease comprise combination clinical and patient-reported outcome remission,in conjunction with biomarker normalisation and endoscopic healing.Although the STrIdE-II guidelines endorse the pursuit of endoscopic healing,clinicians must consider that this may not always be appropriate,acceptable,or achievable in all patients.This underscores the need to engage patients at the outset in an effort to personalise care and individualise treatment targets.The use of non-invasive biomarkers such as faecal calprotectin in conjunction with cross-sectional imaging techniques,particularly intestinal ultrasound,holds great promise;as do emerging treatment targets such as transmural healing.Two randomised clinical trials,namely,CALM and STArdUST,have evaluated the efficacy of a T2T approach in achieving endoscopic endpoints in patients with Crohn’s disease.Findings from these studies reflect that patient subgroups and Crohn’s disease characteristics likely to benefit most from a T2T approach,remain to be clarified.Moreover,outside of clinical trials,data pertaining to the real-world effectiveness of a T2T approach remains scare,highlighting the need for pragmatic real-world studies.despite the obvious promise of a T2T approach,a lack of guidance to support its integration into real-world clinical practice has the potential to limit its uptake.This highlights the need to describe strategies,processes,and models of care capable of

关键词： Treat to target Inflammatory bowel disease Crohn’s disease Treatment targets Endoscopic remission Transmural healing Time to response Intestinal ultrasound

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Therapeutic advances in neural regeneration for Huntington’s disease

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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 overcome the neurodegeneration. In this view, num

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

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

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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 residues.However,clay-based sorption strategies for mixtures of GLP and AMPA in soil,plants and garden produce have been very limited.In 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 growth.Effects 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 studied.The time course results showed a continuous GLP degradation to AMPA.The 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 dissociation.Plants 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 leaves.results 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

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Kinematic analysis of flexible bipedal robotic systems

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 795-818页

作者： r.FazEL A.M.SHAFEI S.r.NEKOO department of Mechanical Engineering Shahid Bahonar University of KermanKerman ***Iran departamento de Ingenieria de Sistemas y Automatica Escuela Técnica Superior de IngenieriaUniversidad de SevillaSeville 41092Spain

In spite of its intrinsic complexities,the passive gait of bipedal robots on a sloping ramp is a subject of interest for numerous researchers.What distinguishes the present research from similar works is the consideration of flexibility in the constituent links of this type of robotic systems.This is not a far-fetched assumption because in the transient(impact)phase,due to the impulsive forces which are applied to the system,the likelihood of exciting the vibration modes increases considerably.Moreover,the human leg bones that are involved in walking are supported by viscoelastic muscles and ligaments.Therefore,for achieving more exact results,it is essential to model the robot links with viscoelastic properties.To this end,the Gibbs-Appell formulation and Newton's kinematic impact law are used to derive the most general form of the system's dynamic equations in the swing and transient phases of motion.The most important issue in the passive walking motion of bipedal robots is the determination of the initial robot configuration with which the system could accomplish a periodic and stable gait solely under the effect of gravitational force.The extremely unstable nature of the system studied in this paper and the vibrations caused by the impulsive forces induced by the impact of robot feet with the inclined surface are some of the very serious challenges encountered for achieving the above-mentioned goal.To overcome such challenges,an innovative method that uses a combination of the linearized equations of motion in the swing phase and the algebraic motion equations in the transition phase is presented in this paper to obtain an eigenvalue problem.By solving this problem,the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are determined.The effects of the characteristic parameters of elastic links including the modulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of robotic systems are also studied.The findings o

关键词： bipedal robot flexible link swing phase transient phase eigenvalue problem Kelvin-Voigt coefficient

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Evaluation of vaccine rollout strategies for emerging infectious diseases:A model-based approach including protection attitudes

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Infectious disease Modelling 2023年第4期8卷 1032-1049页

作者： Mauricio Paton Juan M.Acuna Jorge rodríguez department of Chemical Engineering College of EngineeringKhalifa UniversitySAN Campus PO Box 127788Abu DhabiUnited Arab Emirates department of Epidemiology and Public Health College of Medicine.Khalifa UniversityPO Box 127788Abu DhabiUnited Arab Emirates

Vaccine allocation strategies become crucial during vaccine shortages,especially in the face of potential outbreaks of new infectious diseases,as witnessed during the COVId-19 pandemic.To address this,a specialized compartmental model is created,which simulates an emerging infectious disease similar to COVId-19.This model divides the population into different age groups and is used to compare various vaccine prioritisation approaches,aiming to minimize the total number of fatalities.The model is an improvement upon previous ones as it incorporates essential behavioural factors and is adapted to account for the protective effects of vaccination against both disease infection and transmission.It takes into account human behaviors such as mask-wearing and social distancing by utilizing specific parameters related to self-protection,awareness levels,and the frequency of daily person-to-person interactions within each age group.Furthermore,a novel method for dynamic vaccine prioritisation was introduced in this study.This approach is model-independent and relies on the dynamic r number.It is the first time such a method has been developed,offering a decision-making approach that is not tied to any specific model.This innovation provides a flexible and adaptable strategy for determining vaccine priorities based on real-time data and the current state of the outbreak.Our findings reveal crucial insights into vaccine allocation strategies.When the daily rollout rates are fast(0.75%or higher)and children are eligible for vaccination,prioritising groups with high daily person-to-person interactions can lead to substantial reductions in total fatalities(up to approximately 40%lower).On the other hand,if rollout rates are slower and overall vaccination coverage is high,focusing on vaccinating elders emerges as the most effective strategy,resulting in up to approximately 10%fewer fatalities.However,the scenario changes significantly when children are not eligible for vaccination,as they constitute a highly interactive populat

关键词： behaviour slower utilizing

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Neurogenic potential of NG2 in neurotrauma:a systematic review

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Neural regeneration research 2024年第12期19卷 2673-2683页

作者： Yuri r.rigo radharani Benvenutti Luis V.Portela Nathan r.Strogulski departamento de Bioquímica Instituto de Ciências Básicas da SaúdeUniversidade Federal do Rio Grande do Sul(UFRGS)Porto AlegreBrazil School of Pharmacy and Biomolecular Sciences RCSI University of Medicine and Health SciencesDublinIreland School of Biochemistry and Immunology Trinity Biomedical Sciences InstituteTrinity College DublinUniversity of DublinDublinIreland

regenerative approaches towards neuronal loss following traumatic brain or spinal cord injury have long been considered a dogma in neuroscience and remain a cutting-edge area of research.This is reflected in a large disparity between the number of studies investigating primary and secondary injury as therapeutic to rgets in spinal co rd and traumatic brain injuries.Significant advances in biotechnology may have the potential to reshape the current state-of-the-art and bring focus to primary injury neurotrauma research.recent studies using neural-glial factor/antigen 2(NG2)cells indicate that they may differentiate into neurons even in the developed brain.As these cells show great potential to play a regenerative role,studies have been conducted to test various manipulations in neurotrauma models aimed at eliciting a neurogenic response from them.In the present study,we systematically reviewed the experimental protocols and findings described in the scientific literature,which were peer-reviewed original research articles(1)describing preclinical experimental studies,(2)investigating NG2 cells,(3)associated with neurogenesis and neurotrauma,and(4)in vitro and/or in vivo,available in PubMed/MEdLINE,Web of Science or SCOPUS,from 1998 to 2022.Here,we have reviewed a total of 1504 papers,and summarized findings that ultimately suggest that NG2 cells possess an inducible neurogenic potential in animal models and in vitro.We also discriminate findings of NG2 neurogenesis promoted by different pharmacological and genetic approaches over functional and biochemical outcomes of traumatic brain injury and spinal co rd injury models,and provide mounting evidence for the potential benefits of manipulated NG2 cell ex vivo transplantation in primary injury treatment.These findings indicate the feasibility of NG2 cell neurogenesis strategies and add new players in the development of therapeutic alternatives for neurotrauma.

关键词： neural-glial antigen 2 neural-glial factor 2 neuron differentiation NG2 cell regeneration spinal cord injury(SCI) traumatic brain injury(TBI)

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Phylogenetic endemism of the orchids of Megamexico reveals complementary areas for conservation

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Plant diversity 2022年第4期44卷 351-359页

作者： Brandon E.Gutierrez-rodríguez Marilyn Vasquez-Cruz Victoria Sosa Instituto de Ecología AC Carretera Antigua a Coatepec 351El Haya91073 XalapaVeracruzMexico Unidad de Genomica Avanzada Laboratorio Nacional de Genomica para La BiodiversidadCentro de Investigaciony Estudios Avanzados IrapuatoLibramiento Norte Carretera Leon Km.9.636821 IrapuatoGuanajuatoMexico

Orchid diversity provides a unique opportunity to further our understanding of biotic and abiotic factors linked to patterns of richness,endemism,and phylogenetic endemism in many regions.However,orchid diversity is consistently threatened by illegal trade and habitat transformation.Here,we identified areas critical for orchid conservation in the biogeographic province of Megamexico.For this purpose,we evaluated orchid endemism,phylogenetic diversity,and phylogenetic endemism within Megamexico and characterized orchid life forms.Our results indicate that the majority of the regions with the highest estimates of endemism and phylogenetic endemism are in southern Mexico and northern Central America,mostly located on the Pacific side of Megamexico.Among the most important orchid lineages,several belong to epiphytic lineages such as Pleurothallidinae,Laeliinae and Oncidiinae.We also found that species from diverse and distantly related lineages converge in montane forests where suitable substrates for epiphytes abound.Furthermore,the southernmost areas of phylogenetic diversity and endemism of Megamexico are in unprotected areas.Thus,we conclude that the most critical areas for orchid conservation in Megamexico are located in southern Mexico and northern Central America.We recommend that these areas should be given priority by the Mexican system of natural protected areas as complementary conservation areas.

关键词： Epiphytes Geophytes Orchids Phylogenetic endemism Weighted endemism

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role of pituitary adenylate cyclase-activating polypeptide in peripheral nerve regeneration:a cellular and molecular perspective

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Neural regeneration research 2024年第7期19卷 1429-1430页

作者： Grazia Maugeri Velia d’Agata Section of Anatomy Histology and Movement SciencesDepartment of Biomedical and Biotechnological SciencesUniversity of CataniaCataniaItaly

Neuro regeneration is a very complex phenomenon characterized by the generation of new neurons and synapses,involving connections between adjacent cells and axonal projections.Neuroregeneration supplies additional lon... 详细信息

关键词： replace functional regeneration

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