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3D printed millireactors for process intensification

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Chinese Journal of Chemical Engineering 2020年第1期28卷 180-190页

作者： Harrson S.Santana Alan C.Rodrigues Mariana G.M.lopes Felipe N.Russo joao l.silva jr Osvaldir P.Taranto School of Chemical Engineering University of CampinasBrazil Federal Institute of Education Science and Technology of South of Minas GeraisBrazil

The scope of the present research aims at demonstrating the 3D printing use in the manufacturing of microchannels for chemical process applications. A comparison among digital model processing applications for 3D print(slicers) and a print layer thickness analysis were performed. The 3D print fidelity was verified in several devices, including the microchannels’ printing with and without micromixer zones. In order to highlight the 3D print potential in Chemical Engineering, the biodiesel synthesis was also carried out in a millireactor manufactured by 3D printing. The millireactor operated under laminar flow regime with a total flow rate of 75.25 ml·min^-1(increment of about 130 times over traditional microdevices used for biodiesel production).The printed millireactor provided a maximum yield of Ethyl Esters of 73.51% at 40 ℃, ethanol:oil molar ratio of7 and catalyst concentration of 1.25 wt% and residence time about 10 s. As a result of flow rate increment attained in the millireactor, the number of required units for scaling-up the chemical processes is reduced. Using the approach described in the present research, anyone could produce their own millireactor for chemical process in a simple way with the aid of a 3D printer.

关键词： Process intensification 3D printer Millireactors Micromixers Microdevices Biodiesel

Appropriateness of the study of iron deficiency anemia prior to referral for small bowel evaluation at a tertiary center

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World Journal of Gastroenterology 2017年第24期23卷 4444-4453页

作者： Jaime Pereira Rodrigues Rolando Pinho Joana silva Ana Ponte Mafalda Sousa joao Carlos silva joao Carvalho Department of Gastroenterology Centro Hospitalar Vila Nova de Gaia/EspinhoRua Conceicao FernandesVila Nova de Gaia

To evaluate the adequacy of the study of iron deficiency anemia (IDA) in real life practice prior to referral to a gastroenterology department for small bowel evaluation. METHODSAll consecutive patients referred to a gastroenterology department for small bowel investigation due to iron deficiency anemia, between January 2013 and December 2015 were included. Both patients referred from general practitioners or directly from different hospital departments were selected. Relevant clinical information regarding prior anemia workup was retrospectively collected from medical records. An appropriate pre-referral study was considered the execution of esophagogastroduodenoscopy (EGD) with Helicobacter pylori (H. pylori) investigation, colonoscopy with quality standards (recent, total and with adequate preparation) and celiac disease (CD) screening (through serologic testing and/or histopathological investigation). RESUlTSA total of 77 patients (58.4% female, mean age 67.1 ± 16.7 years) were included. Most (53.2%) patients were referred from general practitioners, 41.6% from other hospital specialties and 5.2% directly from the emergency department. The mean pre-referral hemoglobin concentration was 8.8 ± 2.0 g/dl and the majority of anemias had microcytic (71.4%) and hypochromic (72.7%) characteristics. 77.9% of patients presented with an incomplete pre-referral study: EGD in 97.4%, with H. pylori investigation in 58.3%, colonoscopy with quality criteria in 63.6%, and CD screening in 24.7%. Patients with an appropriate study at the time of referral were younger (48.7 ± 17.7 vs 72.3 ± 12.3 years, P ll bowel evaluation was ultimately undertaken in 72.7% of patients, with a more frequent evaluation in patients with a quality colonoscopy at referral (78.6% vs 23.8%); P likely cause of IDA was small bowel angioectasia (18.2%) but additional causes were also found in the upper and lower ga

关键词： Iron deficiency anemia Colonoscopy Celiac disease Esophagogastroduodenoscopy Helicobacter pylori Small bowel

MUlTIOBJECTIVE ROUTING IN MUlTISERVICE MPlS NETWORKS WITH TRAFFIC SPlITTING-A NETWORK FlOW APPROACH

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Journal of Systems Science and Systems Engineering 2015年第4期24卷 389-432页

作者： Rita Girao-silva Jose Craveirinha joao Climaco M.Eugenia Captivo Department of Electrical and Computer Engineering University of Coimbra Polo ⅡPinhal de Marrocos P-3030-290 Coimbra Portugal Institute of Computers and Systems Engineering of Coimbra(INESC-Coimbra)R.Antero de Quental 199 P-3000-033 Coimbra Portugal Centro de Investigacao Operacional Faculdade de CienciasUniversidade de Lisboa Campo GrandeBloco C6Piso 4 P-1749-016 lisboa Portugal

A multiobjective routing model for Multiprotocol label Switching networks with multiple service types and traffic splitting is presented in this paper. The routing problem is formulated as a multiobjective mixed-integer program, where the considered objectives are the minimization of the bandwidth routing cost and the minimization of the load cost in the network links with a constraint on the maximal splitting of traffic trunks. Two different exact methods are developed for solving the formulated problem, one based on the classical constraint method and another based on a modified constraint method. A very extensive experimental study, with results on network performance measures in various reference test networks and in randomly generated networks, is also presented and its results are discussed.

关键词： Routing models multiobjective optimization telecommunication networks network flowapproach traffic splitting

Yet Another Intelligent Code-Generating System： A Flexible and low-Cost Solution

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Journal of Computer Science & Technology 2018年第5期33卷 940-965页

作者： joao Fabricio Filho luis Gustavo Araujo Rodriguez Anderson Faustino da silva Department of Informatics State University of Maringd Maringd-PR 87020-900 Brazil Federal University of Technology -- Parand Campo Mourao-PR 87301-899 Brazil

Modern compilers apply various code transformation algorithms to improve the quality of the target code. However, a complex problem is to determine which transformation algorithms must be utilized. This is difficult because of three reasons： a number of transformation algorithms, various combination possibilities, and several configuration possibil- ities. Over the last few years, various intelligent systems were presented in the literature. The goal of these systems is to search for transformation algorithms and thus apply them to a certain program. This paper proposes a flexible, low-cost and intelligent system capable of identifying transformation algorithms for an input program, considering the program＇s specific features. This system is flexible for parameterization selection and has a low-computational cost. In addition, it has the capability to maximize the exploration of available computational resources. The system was implemented under the low level Virtual Machine infrastructure and the results indicate that it is capable of exceeding, up to 21.36%, performance reached by other systems. In addition, it achieved an average improvement of up to 17.72% over the most aggressive compiler optimization level of the low level Virtual Machine infrastructure.

关键词： compiler code transformation iterative compilation knowledge representation machine learning

Indirect printing of hierarchical patient-specific scaffolds for meniscus tissue engineering

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Bio-Design and Manufacturing 2019年第4期2卷 225-241页

作者： joao BCosta Joana silva-Correia Sandra Pina Alain da silva Morais Sílvia Vieira Hélder Pereira joao Espregueira-Mendes Rui lReis Joaquim M.Oliveira B′s Research Group I3Bs-Research Institute on BiomaterialsBiodegradables and BiomimeticsUniversity of MinhoHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineAveParkZona Industrial da Gandra4805-017 Barco GmrPortugal ICVS/3B’s-PT Government Associate laboratory Braga/GuimaraesPortugal The Discoveries Centre for Regenerative and Precision Medicine Headquarters at University of MinhoAvepark4805-017 BarcoGuimar'sPortugal Ripoll y De Prado Sports Clinic:Murcia-Madrid FIFA Medical Centre of Excellence MurciaSpain Orthopedic Department Centro Hospitalar Póvoa de Varzim Vila do CondePortugal Clínica do Dragao Espregueira-Mendes Sports CentreFIFA Medical Centre of ExcellencePortoPortugal Dom Henrique Research Centre PortoPortugal Orthopedic Department University of MinhoBragaPortugal

The complex meniscus tissue plays a critical role in the knee. The high susceptibility to injury has led to an intense pursuit for better tissue engineering regenerative strategies, where scaffolds play a major role. In this study, indirect printed hierarchical multilayered sca ffolds composed by a silk fibroin (SF) upper layer and an 80/20 (w/w) ratio of SF/ionic-doped β-tricalcium phosphate (TCP) bottom layer were developed. Furthermore, a comparative analysis between two types of sca ffolds pro- duced using di fferent SF concentrations, i.e., 8% (w/v) (Hi8) and 16% (w/v) (Hi16) was performed. In terms of architecture and morphology, the produced sca ffolds presented homogeneous porosity in both layers and no di fferences were observed when comparing both sca ffolds. A decrease in terms of mechanical performance of the sca ffolds was observed when SF concentration decreased from 16 to 8% (w/v). Hi16 revealed a static compressive modulus of 0.66 ± 0.05 MPa and dynamical mechanical properties ranging from 2.17 ± 0.25 to 3.19 ± 0.38 MPa. By its turn, Hi8 presented a compressive modulus of 0.27 ± 0.08 MPa and dynamical mechanical properties ranging from 1.03 ± 0.08 MPa to 1.56 ± 0.13 MPa. In vitro bioactivity studies showed formation of apatite crystals onto the surface of Hi8 and Hi16 bottom layers. Human meniscus cells (hMCs) and human primary osteoblasts were cultured separately onto the top layer (SF8 and SF16) and bottom layer (SF8/TCP and SF16/TCP) of the hierarchical sca ffolds Hi8 and Hi16, respectively. Both cell types showed good adhesion and proliferation as denoted by the live/dead staining, Alamar Blue assay and DNA quanti fication analysis. Subcutaneous implantation in mice revealed weak in flammation and sca ffold’s integrity. The hierarchical indirect printed SF sca ffolds can be promising candidate for meniscus TE sca ffolding applications due their suitable mechanical properties, good biological performance and possibility of being applied in a patie

关键词： Patient-specific Indirect printing Hierarchical Silk fibroin Enzymatic-cross-linking Meniscus

Induced pluripotent stem cells, a giant leap for mankind therapeutic applications

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World Journal of Stem Cells 2019年第7期11卷 421-430页

作者： JoséBraganca joao Andrélopes leonardo Mendes-silva joao Miguel Almeida Santos Department of Biomedical Sciences and Medicine University of AlgarveFaro 8005-139Portugal Centre for Biomedical Research(CBMR) University of AlgarveFaro 8005-139Portugal

Induced pluripotent stem cells(iPSC)technology has propelled the field of stem cells biology,providing new cells to explore the molecular mechanisms of pluripotency,cancer biology and aging.A major advantage of human iPSC,compared to the pluripotent embryonic stem cells,is that they can be generated from virtually any embryonic or adult somatic cell type without destruction of human *** addition,iPSC can be generated from somatic cells harvested from normal individuals or patients,and used as a cellular tool to unravel mechanisms of human development and to model diseases in a manner not possible *** these fundamental aspects of human biology and physiology that are revealed using iPSC or iPSC-derived cells,these cells hold an immense potential for cell-based therapies,and for the discovery of new or personalized pharmacological treatments for many ***,we review some of the current challenges and concerns about iPSC *** introduce the potential held by iPSC for research and development of novel health-related *** briefly present the efforts made by the scientific and clinical communities to create the necessary guidelines and regulations to achieve the highest quality standards in the procedures for iPSC generation,characterization and long-term ***,we present some of the audacious and pioneer clinical trials in progress with iPSC-derived cells.

关键词： Induced pluripotent stem cells Reprogramming Cell-based therapy Stem cell banking Disease modelling

Current advances in solid free-form techniques for osteochondral tissue engineering

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Bio-Design and Manufacturing 2018年第3期1卷 171-181页

作者： joao Bebiano Costa Joana silva-Correia Rui luis Reis Joaquim Miguel Oliveira B's Research Group I3Bs - Research Institute onBiomaterials Biodegradables and Biomimetics University ofMinho Headquarters of the European Institute of Excellenceon Tissue Engineering and Regenerative Medicine AveParkParque de Ciencia e Tecnologia Zona Industrial da Gandra4805-017 Barco Guimaraes Portugal ICVS/3B's-PT Government Associate laboratory Braga Guimarfies Portugal The Discoveries Centre for Regenerative and PrecisionMedicine Headquarters at University of MinhoAvepark 4805-017 Barco Guimaraes Portugal

Osteochondral （OC） lesions are characterized by defects in two different zones, the cartilage region and subchondral bone region. These lesions are frequently associated with mechanical instability, as well as osteoarthritic degenerative changes in the knee. The lack of spontaneous healing and the drawbacks of the current treatments have increased the attention from the scientific community to this issue. Different tissue engineering approaches have been attempted using different polymers and different scaffolds＇ processing. However, the current conventional techniques do not allow the full control over scaffold fabrication, and in this type of approaches, the tuning ability is the key to success in tissue regeneration. In this sense, the researchers have placed their efforts in the development of solid free-form （SFF） techniques. These techniques allow tuning different properties at the micro-macro scale, creating scaffolds with appropriate features for OC tissue engineering. In this review, it is discussed the current SFF techniques used in OC tissue engineering and presented their promising results and current challenges.

关键词： Solid free-form Osteochondral Tissue engineering Scaffolds

Abiotic stress on seed germination and plant growth of Zeyheria tuberculosa

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Journal of Forestry Research 2023年第5期34卷 1511-1522页

作者： Robson luis silva de Medeiros Rinaldo Cesar de Paula joao Vitor Oliveira de Souza joao Pedro Peixoto Fernandes Department of Agricultural Sciences School of Agricultural and Veterinarian SciencesSao Paulo State University(Unesp)14884-900JaboticabalSao PauloBrazil

Zeyheria tuberculosa(Vell.)Bureau ex *** among the Brazilian flora threatened with *** has high-quality wood and can be used to recover herbicidecontaminated ***,abiotic stresses can harm seed germination and seedling development under adverse conditions and need to be understood to improve autochthonous or indigenous biodiversity conservation and strengthen reforestation *** study evaluated the effects of temperature,water and saline stress on *** seed germination and water stress on seedling *** laboratory experiments evaluated germination under:(1)different temperatures(20,25,30,35 and 40℃);(2)different water potentials simulated with polyethylene glycol(PEG6000)at 25 and 30℃;and,(3)different osmotic potentials simulated with NaCl at 25 and 30℃.In addition,a greenhouse experiment subjected seedlings to five water regimes(20%,35%,50%,65%and 80%of maximum substrate water holding capacity).In the laboratory,seedling biometry and germination were evaluated,while physiological and morphological parameters were assessed in the *** potential of seeds increased at 25 and 30℃.Germination and vigor decreased as water and saline stresses *** tolerance thresholds for water and salt stresses were-0.6 and-0.4 MPa,*** the greenhouse,the most restrictive water regimes reduced seedling physiological and morphological *** development was compromised at moisture levels below50%field capacity.

关键词： Bignoniaceae Climate change Ipê-felpudo Ipê-preto Water stress

Dynamic Instability of Straight Bars Subjected to Impulsive Axial loads Using the DEM

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Computer Modeling in Engineering & Sciences 2015年第2期104卷 87-104页

作者： leticia Fleck Fadel Miguel leandro Fleck Fadel Miguel joao Kaminski jr. Department of Mechanical Engineering UFRGSPorto AlegreRSBrazil Department of Civil Engineering UFSCFlorianopolisSCBrazil Department of Structures and Civil Construction UFSMSanta MariaRSBrazil

Since the half of the XX century,attention was given to the instability of structures under parametric excitation,especially under periodic *** the other hand,the instability of bars subjected to axial loads of impulsive type has been little studied,in spite of the practical importance of the ***,in Engineering Design it is frequently supposed,without tests or additional verifications,that an axial load of short duration can exceed the Euler critical load of the bar without inducing damage in the *** this context,this paper proposes the use of the truss-like Discrete Element Method(DEM)for determining the dynamic response of elastic straight bars subjected to axial loads defined by pulses of short *** proposed approach allows the consideration of initial imperfections,as well as large displacements and other non-linear *** influence of the pulse duration and other effects in the response of the bar are also ***,the performance of the proposed methodology is verified in static and dynamic instability problems of homogeneous bars without geometrical imperfections,by comparing the DEM results with analytical solutions available in the *** that,the DEM is employed to analyze more complex cases,including bars with initial imperfections and non-homogeneous bars,in which material properties,as Young’s modulus and mass density,are assumed to be correlated Gaussian random *** proposed methodology has proven to be a useful and easy tool for analysis of dynamic instability of bars and could therefore be used by designers for estimating the dynamic buckling load.

关键词： Dynamic Instability Critical Buckling load Discrete Element Method Impulsive load Stochastic Fields Mesh Imperfections