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High Value Materials from the Forests

Advances in Materials Physics and Chemistry 2016年第3期6卷 54-60页

作者： Geoffrey R. Mitchell Sara Biscaia Vidhura Subash Mahendra Artur Mateus centre for rapid and sustainable product development Polytechnic Institute of Leiria Marinha Grande Portugal

The design, process and synthesis of high value composite materials from forests in scientific research has been widely discussed in recent times ensuring greater awareness and accessibility to its associated communities and the economy in general. Raw materials obtained from the forests can be multi-folded in its use as a virgin source of an energy provider such as wooden blocks to more complex processed material development. In this paper, we will be focusing on the latter related to sustainable development of rosins. Rosins are exudates of pine resins which consist of hydrophobic characteristics that are widely used as a precursor for many applications without significant alterations. We discuss the nature, process and its support in composite material. The composite material has been tailored with related to chemical and physical properties. Chemically rosins contain free carboxyl acid functional group and carbon-carbon double bonds which are potent to react with other reactive species to facilitate various intermediates. Here we have looked at its reaction intermediates and subsequent products for composite material of high value using environmentally friendly methodologies, such as solvent free methods. Biodegradable polymer incorporated composite scaffolds using rosins are studied to tailor the bioactivity. We treat the eco-friendly pine resins which is biocompatible to complement the biopolymers as the process of extracting rosin from pine resin is a particular green process, involving only a natural product (pine resin) and producing no waste. The paper discusses the preparation of composite scaffolds for use in tissue engineering applications.

关键词： Biopolymers Composites Tissue Engineering Scaffolds Biomanufacturing

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Constrained Fractional Variational Problems of Variable Order

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IEEE/CAA Journal of Automatica Sinica 2017年第1期4卷 80-88页

作者： Dina Tavares Ricardo Almeida Delfim F.M.Torres Department of Mathematics Polytechnic Institute of Leiria Department of Mathematics University of Aveiro

Isoperimetric problems consist in minimizing or maximizing a cost functional subject to an integral *** this work, we present two fractional isoperimetric problems where the Lagrangian depends on a combined Caputo derivative of variable fractional order and we present a new variational problem subject to a holonomic constraint. We establish necessary optimality conditions in order to determine the minimizers of the fractional problems. The terminal point in the cost integral,as well as the terminal state, are considered to be free, and we obtain corresponding natural boundary conditions.

关键词： Fractional calculus fractional calculus of variations holonomic constraints isoperimetric constraints optimization variable fractional order

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Wear behavior of Ti6Al4V biomedical alloys processed by selective laser melting, hot pressing and conventional casting

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Transactions of Nonferrous Metals Society of China 2017年第4期27卷 829-838页

作者： F.BARTOLOMEU M.BUCIUMEANU E.PINTO N.ALVES F.S.SILVA O.CARVALHO G.MIRANDA Center for Micro-Electro Mechanical Systems (CMEMS-UMinho) University of Minho Azurem 4800-058 Guimaraes Portugal Cross-Border Faculty of Humanities Economics and Engineering"Dunarea de Jos" University of Galati Domneasca 47 800008 Galati Romania centre for rapid and sustainable product development polytechnic institute of leiria Rua General Norton de Matos Apartado 4133 2411-901 Leiria Portugal

The aim of this work was to study the influence of the processing route on the microstructural constituents,hardness andtribological(wear and friction)behavior of Ti6Al4V biomedical *** this sense,three different processing routes were studied:conventional casting,hot pressing and selective laser melting.A comprehensive metallurgical,mechanical and tribologicalcharacterization was performed by X-ray diffraction analysis,Vickers hardness tests and reciprocating ball-on-plate wear tests ofTi6Al4V/Al2O3sliding *** results showed a great influence of the processing route on the microstructural constituents andconsequent differences on hardness and wear *** highest hardness and wear resistance were obtained for Ti6Al4Valloy produced by selective laser melting,due to a markedly different cooling rate that leads to significantly different microstructurewhen compared to hot pressing and *** study assesses and confirms that selective laser melting is potential to producecustomized Ti6Al4V implants with improved wear performance.

关键词： biomedical alloy Ti6Al4V alloy wear behavior microstructure selective laser melting hot pressing casting

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Metal alginates for polyphenol delivery systems: Studies on crosslinking ions and easy-to-use patches for release of protective flavonoids in skin

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Bioactive Materials 2020年第3期5卷 447-457页

作者： João Silva Pavlo Vanat Dorinda Marques-da-Silva Joaquim Rui Rodrigues Ricardo Lagoa School of Technology and Management Polytechnic Institute of LeiriaPortugal Laboratório Associado LSRE-LCM School of Technology and ManagementPolytechnic Institute of LeiriaPortugal UCIBIO-Faculty of Science and Technology NOVA University of LisbonPortugal

Incorporation of bioactive natural compounds like polyphenols is an attractive approach for enhanced functionalities of *** particular flavonoids have important pharmacological activities,and controlled release systems may be instrumental to realize the full potential of these *** presents interesting attributes for dermal and other biomaterial applications,and studies were carried here to support the development of polyphenol-loaded alginate *** of capillary viscosity indicated that ionic medium is an effective strategy to modulate the polyelectrolyte effect and viscosity properties of *** gelation,considerable differences were observed between alginate gels produced with Ca^2+,Ba^2+,Cu^2+,Fe^2+,Fe^3+and Zn^2+as crosslinkers,especially concerning shrinkage and morphological *** assays with different polyphenols in the presence of alginate-gelling cations pointed to the choice of calcium,barium and zinc as safer ***-based films loaded with epicatechin were prepared and the kinetics of release of the flavonoid *** results with calcium,barium and zinc alginate matrices indicated that the release dynamics is dependent on film thicknesses,but also on the crosslinking metal *** these grounds,an alginate-based system of convenient use was devised,so that flavonoids can be easily loaded at simple point-of-care conditions before dermal *** epicatechin-loaded patch was tested on an ex-vivo skin model and demonstrated capacity to deliver therapeutically relevant concentrations on skin ***,the flavonoid released was not modified and retained full antioxidant *** alginate-based system proposed offers a multifunctional approach for flavonoid controllable delivery and protection of skin injured or under risk.

关键词： Topical drug delivery Intrinsic viscosity Biopolymer Epigallocatechin-gallate Antioxidant dressing

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Mechanical properties characterization of different types of masonry infill walls

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Frontiers of Structural and Civil Engineering 2020年第2期14卷 411-434页

作者： Andre FURTADO Hugo RODRIGUES Antonio AREDE Humberto VARUM CONSTRUCT-LESE Department of Civil EngineeringFaculty of EngineeringUniversity of PortoPorto 4200-465Portugal R1SCO School of Technology and ManagementPolytechnic Institute of LeiriaLeiria 2411-901Portugal

It is remarkable,the recent advances concerning the development of numerical modeling frameworks to simulate the infill panels'seismic ***,there is a lack of experimental data of their mechanical properties,which are of full importance to calibrate the numerical *** primary objective of this paper is to present an extensive experimental campaign of mechanical characterization tests of infill masonry walls made with three different types of masonry units:lightweight vertical hollow concrete blocks and hollow clay *** different types of experimental tests were carried out,namely:compression strength tests,diagonal tensile strength tests,and flexural strength tests parallel and perpendicular to the horizontal bed joints.A total amount of 80 tests were carried out and are reported in the present *** second objective of this study was to compare the mechanical properties of as-built and existing infill *** results presented and discussed herein,will be in terms of strain-stress curves and damages observed within the *** was observed a fragile behavior in the panels made with hollow clay horizontal bricks,without propagation of *** plaster increased the flexural strength by 57%.

关键词： masonry infill walls experimental characterization compression strength shear diagonal strength flexural strength

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Understanding Tremor in rapid Upper Limb Movements Using 3D Accelerometers Data

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Neuroscience & Medicine 2014年第5期5卷 205-213页

作者： Paula Pascoal-Faria Miguel Patrício Adriana Leal Francisco Caramelo António Freire Cristina Januário Miguel Castelo-Branco Center for rapid and sustainable product development (CDRSP) School of Technology and Management (ESTG) of the Polytechnic Institute of Leiria (IPLeiria) Leiria Portugal IBILI Faculty of Medicine University of Coimbra Coimbra Portugal Laboratory of Biostatistics and Medical Informatics IBILI Faculty of Medicine University of Coimbra Coimbra Portugal Neurology Department Coimbra University Hospital Centre (CHUC) Coimbra Portugal

Tremor is a manifestation of a variety of human neurodegenerative diseases, notably Parkinson’s disease (PD) and Essential Tremor (ET), both affecting millions worldwide. PD is primarily caused by a progressive loss of dopamine neurons in the nigrostriatal system that leads to widespread motor symptoms such as bradykinesia, rigidity, tremor and postural instability. ET typically involves a tremor of the arms, hands or fingers. No definitive test or biomarker is yet available for PD or ET, so the rate of misdiagnosis is relatively high. As tremor is a very common feature at the onset of both diseases, it is crucial to be able to characterize it. This is made possible using acce?lerometers to quantify the tremor amplitude and frequency. In this work we aim to find tasks involving upper limb movements that are suitable to modulate both types of tremor. Four tasks were tested, differing on whether the arms moved together or alternatingly and whether loads were added. Significant differences in tremor measures were found when patients were asked to perform simultaneous rapid arms movements with loads placed on their wrists. These results may allow the design of an efficient fMRI protocol for identifying the cortical circuits responsible for the modulation of tremor.

关键词： Disease Essential Tremor Tremor Quantification Tremor Modulation Accelerometers

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Controlling and Evaluating the Structure and Morphology of Polymers on Multiple Scales

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Journal of Materials Science and Chemical Engineering 2015年第12期3卷 48-60页

作者： Geoffrey R. Mitchell Ana Tojeira Thomas Gkourmpis James J. Holt Peter Harris Marilena Pezzuto centre for rapid and sustainable product development Institute Polytechnic of Leiria Marinha Grande Portugal Innovation & Technology Borealis AB Stenungsund Sweden Department of Physics University of Reading Whiteknghts Reading UK centre for Advanced Microscopy University of Reading Whiteknights Reading UK CNR-Istituto di Chimica e Tecnologia dei Polimeri Pozzuoli Italy

Crystalline polymers spontaneously form hierarchical structures although the precise manner in which these scales of structure are interconnected especially terms of the formation and evolution of the complete structure remains unclear. We have set out to control these scales of structure by introducing additional components which self-assemble in to nano-scale units which then direct the crystallisation of the polymer matrix. In other words, we first assemble a low concentration top-level structure which is designed to template or direct the sub-sequent crystallisation of the matrix polymer. This top level structure takes on the role of controlling the structure. We have set out to both establish the design principles of such structures and to develop experimental procedures which allow us to follow the formation of such complex hierarchical polymer structures. In particular we focus of the relationships between these different levels of structure and time sequence of events required for the structure to evolve in the targeted manner. In this programme, we have exploited time-resolving small-angle X-ray scattering and electron microscopy together with neutron scattering to probe and quantify the different scales of structure and their evolution. We highlight new neutron scattering instrumentation which we believe have great potential in the growing field of hierarchical structures in polymers. The addition of small quantities of nanoparticles to conventional and sustainable thermoplastics leads to property enhancements with considerable potential in a number of areas Most engineered nano-particles are highly stable and these exist as nano-particles prior to compounding with the polymer resin, they remain as nano- particles during the active use as well as in the subsequent waste and recycling streams. In this work we also explore the potential for constructing nano-particles within the polymer matrix during processing from organic compounds selected to provide nano

关键词： Component Semi-Crystalline Polymers Morphology Texture Nucleation Growth Shear Flow

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Corrosion behaviour of PEEK or β-TCP-impregnated Ti6Al4V SLM structures targeting biomedical applications

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Transactions of Nonferrous Metals Society of China 2019年第12期29卷 2523-2533页

作者： M.M.COSTA T.A.DANTAS F.BARTOLOMEU N.ALVES F.S.SILVA G.MIRANDA F.TOPTAN Center for Micro Electro Mechanical Systems(CMEMS) University of Minho(UMinho)4800-058 GuimarãesPortugal MIT Portugal Program School of EngineeringUniversity of MinhoGuimarãesPortugal centre for rapid and sustainable product development polytechnic institute of leiria Rua General Norton de MatosApartado 4133LeiriaPortugal IBTN/Br–Brazilian Branch of the institute of Biomaterials Tribocorrosion and NanomedicineUNESPCampus de BauruAv.Eng.Luiz Edmundo Carrijo Coube14-0117033-360BauruSPBrazil

Ti6Al4V cellular structures were produced by selective laser melting(SLM)and then filled either with beta-tricalcium phosphate(β-TCP)or PEEK(poly-ether-ether-ketone)through powder metallurgy techniques,to improve osteoconductivity and wear *** corrosion behavior of these structures was explored considering its importance for the long-term performance of *** revealed that the incorporation of open cellular pores induced higher electrochemical kinetics when being compared with dense *** impregnation ofβ-TCP and PEEK led to the creation of voids or gaps between the metallic matrix and the impregnated material which also influenced the corrosion behavior of the cellular structures.

关键词： Ti6Al4V cellular structures corrosion multimaterial design poly-ether-ether-ketone(PEEK) beta-tricalcium phosphate(β-TCP)

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Open Source Tool for Networks Management Communication

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Journal of Electrical Engineering 2017年第1期5卷 35-46页

作者： Nuno Tiago Louro Simoes Carlos Manuel da Silva Rabadao School of Technology and Management Polytechnic Institute of Leiria Leiria Portugal Research Center for Informatics and Communications Polytechnic Institute of Leiria Leiria Portugal

Considering the complexity of the networks and the need for telecommunication operators （Telco） to present innovations to their clients, the quickest possible, one of the solutions for this complexity could be to centralize its configuration. Thus the SDN （software-defmed networking） concept may be an important solution. This paper suggests the implementation of a tool to support the development and testing of networks and services before they are put into production. The use of a tool that simplifies the configuration of a network service makes the networks and services to be less susceptible to errors and failures by those who set them up, thus allowing telecom operators, among others, to be able to create new services, improve the monitorization of their human resources and, above all, improve their fmancial results. In the end, success will be achieved because with a simple interaction and basic knowledge we are able to manage network services.

关键词： SDN network services network programming NSO.

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Usefulness of serum C-reactive protein and calprotectin for the early detection of colorectal anastomotic leakage:A prospective observational study

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World Journal of Gastroenterology 2022年第24期28卷 2758-2774页

作者： Nuno J G Rama Marlene C C Lages Maria Pedro S Guarino Óscar Lourenço Patrícia C Motta Lima Diana Parente Cândida S G Silva Ricardo Castro Ana Bento Anabela Rocha Fernando Castro-Pocas João Pimente Colorectal Surgical Division Leiria Hospital CentreLeiria 2410-021Portugal Abel Salazar Biomedical institute(ICBAS) University of OportoOporto 4099-002Portugal Center for Innovative Care and Health Technology(ciTechCare) Polytechnic of LeiriaLeiria 2410-541Portugal Faculty of Economics CeBERUniversity of CoimbraCoimbra 3000-137Portugal Clinical Pathology Division Leiria Hospital CentreLeiria 2410-541Portugal Surgical Division Oporto Hospital CentreOporto 4099-001Portugal Department of Gastroenterology Santo António HospitalPorto Hospital CenterPorto 4099-001Portugal institute of Biomedical Sciences Abel Salazar University of PortoPorto 4099-001Portugal Faculty of Medicine University of CoimbraCoimbra 3004-531Portugal Surgical Division Montes Claros HospitalCoimbra 3030-320Portugal

BACKGROUND Colorectal anastomotic leakage(CAL)is one of the most dreaded complications after colorectal surgery,with an incidence that can be as high as 27%.This event is associated with increased morbidity and mortality;therefore,its early diagnosis is crucial to reduce clinical consequences and *** biomarkers have been suggested as laboratory tools for the diagnosis of *** To assess the usefulness of plasma C-reactive protein(CRP)and calprotectin(CLP)as early predictors of *** A prospective monocentric observational study was conducted including patients who underwent colorectal resection with anastomosis,from March 2017 to August *** were divided into three groups:G1–no complications;G2–complications not related to CAL;and G3–*** biomarkers were measured and analyzed in the first 5 postoperative days(PODs),namely white blood cell(WBC)count,eosinophil cell count(ECC),CRP,CLP,and procalcitonin(PCT).Clinical criteria,such as abdominal pain and clinical condition,were also *** correlation between biomarkers and CAL was *** operating characteristic(ROC)curve analysis was used to compare the accuracy of these biomarkers as predictors of CAL,and the area under the ROC curve(AUROC),specificity,sensitivity,positive predictive value,and negative predictive value(NPV)during this period were *** In total,25 of 396 patients developed CAL(6.3%),and the mean time for this diagnosis was 9.0±6.8 *** operative characteristics,such as surgical approach,blood loss,intraoperative complications,and duration of the procedure,were notably related to the development of *** length of hospital stay was markedly higher in the group that developed CAL compared with the group with complications other than CAL and the group with no complications(median of 21 d vs 13 d and 7 d respectively;P<0.001).For abdominal pain,the best predictive performance was on POD4 and POD5,with the largest AUROC of 0.84 on ***

关键词： Anastomotic leakage Colorectal Surgery Biomarkers C-reactive protein Calprotectin

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