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Characterization of the Topography and Wettability of English Weed Leaves and Biomimetic Replicas

Journal of Bionic Engineering 2014年第3期11卷 346-359页

作者： Pedro miguel Matos Pereira Ana Sofia Moita Gabriel Amaro Monteiro Duarte miguel Franca Prazeres IBB - Institute for Biotechnology and Bioengineering Centre for Biological and Chemical Engineering Department of Bioengineering Instituto Superior Tecnico Universidade de Lisboa Av. Rovisco Pals 1049-001 Lisboa Portugal IN+ - Center for Innovation Technology and Policy Research Instituto Superior T~cnico Universidade de Lisboa Av. Rovisco Pais 1049-001 Lisboa Portugal

The topography and wettability of the underside of English weed （Oxalis pes-caprae） leaves and of their biomimetic replicas are investigated. Polyvinyl siloxane molds were cast from the leaves and then filled with an epoxy pre-polymer to produce replicas. The particular topographical structures of leaves and replicas were evaluated by optical microscopy and Scanning Electron Microscopy （SEM） analysis. The static wettability of leaves and replicas was assessed by contact angle measurements, while the dynamic wettability was characterized by estimating contact angle hysteresis and studying the dynamic behavior of impacting water droplets. A smooth glass slip and its replica were used as control surfaces. The replica moulding method used was able to transfer the characteristic pattern of irregular 100 μm - 200 μm × 60 μm convex papillae interspersed with stomata of the original leaf to the epoxy replicas. The static contact angle of 143°± 3° and the contact angle hysteresis of 2~ indicate that the underside of the English weed leaf is close to superhydrophobic. The lower contact angles （130° ± 4°） and higher hysteresis （31°） observed for the replica when compared with the original leaves were associated to an inaccurate replication of the chemistry and structures of the three-dimensional wax projections covering the plant surface. Also, trichomes in the original leaves could not be accurately reproduced due to their flexibility and fragility. Differences in wetting behavior were also evident from droplet impact experiments, with rebound regimes prevailing in the original leaves and regimes characterized by higher adhesion and larger dissipation predominating in the replicas. Nevertheless, the morphological features of the leaf transferred to the replica were sufficient to promote a clear hydrophobic behavior of the replica when compared with the smooth epoxy reference surface.

关键词： biomimetic surfaces oxalis pes-caprae English weed replica molding wettability micro-topography

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Plumbing System of Hunga Tonga Hunga Ha'apai Volcano

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Journal of Earth Science 2023年第3期34卷 706-716页

作者： Román Alvarez miguel Camacho Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas(IIMAS) Universidad Nacional Autónoma de MéxicoCoyoacán CDMX 04510Mexico Posgrado en Ciencias de la Tierra Universidad Nacional Autónoma de MéxicoCoyoacán CDMX 04510Mexico

The Hunga Tonga Hunga Ha’apai submarine volcano has experienced repeated eruptions in the latest *** recent one,in January 2022,released an enormous amount of energy inducing global perturbations,as tsunamis and atmospheric *** structure of the volcano is poorly understood,especially its internal ***-seated magmatic connections are difficult to define or *** use a high-resolution gravity data set obtained via satellite to calculate the Bouguer anomaly over its structure,to perform a preliminary exploration of its *** 3D gravity inversions,we find a complex plumbing system with various exhaust trajectories and multiple surface pockets of low-density material within the volcanic edifice;some appear to be associated with ring *** is in line with the report of the 2009 eruption,described as beginning from multiple *** found no signs of a magma chamber within 6 km depth,although several volcanic conduits are identified from such depth to the *** variations occur within a plumbing conduit or may vary from one conduit to another in the same *** models yield quantitative estimates for areas of magma-water interaction,constituting a baseline to compare with structural changes to be induced in future eruptions.

关键词： Hunga Tonga Hunga Ha'apai satellite gravity data 3D inversions volcano Tofua Island

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Science Letters:Blind spot detection using vision for automotive applications

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第10期9卷 1369-1372页

作者： miguel ngel SOTELO José BARRIGA Department of Electronics University of Alcalá Alcalá de Henares 28871 Spain

This paper describes a vision-based system for blind spot detection (BSD) in intelligent vehicle applications. A camera is mounted in the lateral mirror of a car with the intention of visually detecting cars that are located in the so-called blind spot and cannot be perceived by the vehicle driver. The detection of cars in the blind spot is carried out using computer vision techniques, based on optical flow and a double-stage data clustering technique for robust vehicle detection.

关键词： Computer vision Optical flow Blind spot detection (BSD) Intelligent vehicles

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Natural variation of ncHLAII molecules:challenges and perspectives

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Cellular & Molecular Immunology 2022年第12期19卷 1432-1434页

作者： miguelÁlvaro-Benito Protein Biochemistry Institute for BiochemistryFreie Universität BerlinBerlinGermany

Identifying causal genetic variants for a given phenotype improves diagnosis and provides insights for designing ***,defining the link and/or contribution to a phenotype of rare variants or those with an indirect cont... 详细信息

关键词： diagnosis insight designing

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Role of gene polymorphisms in gastric cancer and its precursor lesions:Current knowledge and perspectives in Latin American countries

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World Journal of Gastroenterology 2014年第16期20卷 4503-4515页

作者： miguel Angel Chiurillo Laboratorio de Genética Molecular "Dr.Jorge Yunis-Turbay" Decanato de Ciencias de la SaludUniversidad Centroccidental Lisandro AlvaradoBarquisimeto 3001Venezuela

Latin America shows one of the highest incidence rates of gastric cancer in the world,with variations in mortality rates among nations or even within countries belonging to this *** cancer is the result of a multifactorial complex process,for which a multistep model of carcinogenesis is currently *** to the infection with Helicobacter pylori,that plays a major role,environmental factors as well as genetic susceptibility factors are significant players at different stages in the gastric cancer *** differences in population origin,demographic structure,socio-economic development,and the impact of globalization lifestyles experienced in Latin America in the last decades,all together offer opportunities for studying in this context the influence of genetic polymorphisms in the susceptibility to gastric *** aim of this article is to discuss current trends on gastric cancer in Latin American countries and to review the available published information about studies of association of gene polymorphisms involved in gastric cancer susceptibility from this region of the world.A total of 40 genes or genomic regions and69 genetic variants,58%representing markers involved in inflammatory response,have been used in a number of studies in which predominates a low number of individuals(cases and controls)*** of IL-1B(-511 C/T,14 studies;-31 T/C,10 studies)and IL-1RN(variable number of tandem repeats,17 studies)are the most represented ones in the reviewed *** genetic variants recently evaluated in large metaanalyses and associated with gastric cancer risk were also analyzed in a few studies[e.g.,prostate stem cell antigen(PSCA),CDH1,Survivin].Further and better analysis centered in gene polymorphisms linked to other covariates,epidemiological studies and the information provided by meta-analyses and genome-wide association studies should help to improve our understanding of gastric cancer etiology in order to d

关键词： Latin America Gastric cancer Precancerous lesions Gene polymorphisms Single nucleotide polymorphisms

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An integrated assessment of a group with complex systematics: the Iberomaghrebian lizard genus Podarcis (Squamata, Lacertidae)

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Integrative Zoology 2008年第4期3卷 247-266页

作者： miguel A.CARRETERO CIBIO Reseach Center in Biodiversity and Genetic ResourcesCampus Agrário de Vair鉶4485-661VairaoPortugal

A critical review of the evolutionary biology of Iberian and North African lizard members of the genus Podarcis(Lacertidae)based on phylogeny,phylogeography,morphometrics,behavior,ecology and physiology is *** Iberomaghrebian region is inhabited by at least 12 different evolutionary lineages that group into a monophyl-etic clade(except Podarcis muralis).In contrast to the current taxonomy,the saxicolous‘Podarcis hispanica’is paraphyletic with respect to Podarcis bocagei and Podarcis carbonelli,two currently recognized *** in the phylogenetic tree are deep,resulting from old divergences,clearly preceding the ***,more recent range changes as a result of glaciations are also *** most plausible evolutionary scenario for this group indicates both vicariant and dispersal *** parapatry between lineages is the rule,sympatry and even syntopy are frequent,but usually between ground-dwelling and saxicolous *** between forms with similar habitat use are rare and *** distinctiveness between lineages has been demonstrated,indicating historical ***,other characters have repeatedly evolved under similar environmental pressures independently of the evolutionary *** sexual dimorphism derives from sexual selection and is attained before sexual maturity,although developmental restrictions *** between popu-lations is also important and derives from local variation in both natural(habitat,climate)and sexual(density)selective *** for short-term changes has already been found,particularly in insular *** isolation between syntopic forms and partner recognition are based on male–male competition and on visual and chemical recognition of females by conspecific *** this ancient diversification,most forms maintain a degree of reproductive *** may occur,but is limited,and there is evidence of selection

关键词： Morphometrics Mediterranean basin phylogeny Podarcis reproductive isolation speciation.

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An approach of the internal friction-dependent temperature changes for conventional and pure biogenic lubricating greases

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Friction 2024年第4期12卷 780-795页

作者： Leif AHME Erik KUHN miguelÁngel DELGADO Department of Mechanical Engineering and Production Management Hamburg University of Applied SciencesHamburg 20099Germany Department of Chemical Engineering Research in Product Technology and Chemical Processes(Pro2TecS)University of HuelvaHuelva 21071Spain

This work investigated the temperature changes inside the bulk of lubricating greases under controlled high-shear stress conditions(250-500 s-1).For this purpose,a newly developed temperature-measuring cell called Calidus was successfully *** temperature changes(ΔT)have been related to the greases'components(thickener,base oil-type,and composition)and the structural degradation of the lubricating ***,a theoretical approach was proposed for calculating the internal temperature change of lubricating greases during shear *** greases showed an internal temperature profile characterised by a sudden rise inΔT within the first 4 h from starting the test and subsequentΔT decay until it reaches the steady state ***,it was found that greases C1 and C5,formulated with lithium and calcium soap,respectively,with different soap content(16.1 wt%and 9.7 wt%,respectively),but the same base castor oil,showed the highest value of the maximumΔT,c.a.3.2 K,and the most drastic drop ofΔ*** greases showed both the highest specific densities and heat *** addition,they showed the lowest ratio of expended energies(Rtee),which means more structural degradation in the stressed *** the contrary,the grease C3,with 13 wt%of Li-soap but the lowest base oil's viscosity,showed the lowest maximumΔT and the temperature profile was characterised by a moderate variation ofΔT along the *** biogenic grease B3 developed a low-temperature change in the group of pure bio-genic greases close to grease C3.

关键词： shear-induced structural degradation rheology temperature measurements lubricating greases density lubricating greases specific heat capacities

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Capsule endoscopy

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World Journal of Gastroenterology 2009年第13期15卷 1584-1586页

作者： miguel Muoz-Navas Gastroenterology Department University Clinic of Navarra

Capsule endoscopy(CE) is a simple,safe,non-invasive,reliable technique,well accepted and tolerated by the patients,which allows complete exploration of the small *** advent of CE in 2000 has dramatically changed the diagnosis and management of many diseases of the small intestine,such as obscure gastrointestinal bleeding,Crohn's disease,small bowel tumors,polyposis syndromes,*** has become the gold standard for the diagnosis of most diseases of the small *** this technique has also been used for esophageal and colonic diseases.

关键词： Capsule endoscopy Small intestine Gastrointestinal hemorrhage Crohn's disease Gastro-intestinal neoplasms Intestinal polyposis

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Brain-machine-brain interfaces as the foundation for the next generation of neuroprostheses

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National Science Review 2022年第10期9卷 8-10页

作者： miguel A.L.Nicolelis Department of Neurobiology Duke University International Institute of Neuroscience Edmond and Lily Safra

Back in 2011,my laboratory at the Duke University Center for Neuroengineering proposed a new variation on the already-classic paradigm known as brain-machine interfaces (BMIs)[1].In a series of experiments [2],we showed that monkeys could not only learn to employ electrical signals from large neuronal ensembles (300-700 neurons)located in the primary motor cortex(M1) to control the movements of an avatar arm and hand—*** a typical BMI paradigm—but that they could also interpret in real time,streams of electrical signals delivered directly to their primary somatosensory cortex (S1) via cortical *** strategy was created to allow these monkeys to perform a tactile discrimination task,without any interference from their physical ***,instead of using their real finger tips to perform such a task,this approach allowed our monkeys to use their brain activity to directly control the movements of’virtual finger tips to scan the texture of a series of virtual *** receiving,via cortical microstimulation,electrical signals directly into their S1 that were proportional to the virtual surface textures of these objects,the monkeys learned to quickly select the correct object that they needed to identify to receive a ***,

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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

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