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Sample records for biomimetic strategies based

  1. BIOMIMETIC STRATEGIES IN ORGANIC SYNTHESIS. TERPENES

    Directory of Open Access Journals (Sweden)

    V. Kulcitki

    2012-12-01

    Full Text Available The current paper represents an outline of the selected contributions to the biomimetic procedures and approaches for the synthesis of terpenes with complex structure and diverse functionalisation pattern. These include homologation strategies, cyclisations, rearrangements, as well as biomimetic remote functionalisations.

  2. Biomimetic Cilia Based on MEMS Technology

    Institute of Scientific and Technical Information of China (English)

    Zhi-guo Zhou; Zhi-wen Liu

    2008-01-01

    A review on the research of Micro Electromechanical Systems (MEMS) technology based biomimetic cilia is presented. Biomimetic cilia, enabled by the advancement of MEMS technology, have been under dynamic development for the past decade. After a brief description of the background of cilia and MEMS technology, different biomimetic cilia applications are reviewed. Biomimetic cilia micro-actuators, including micromachined polyimide bimorph biomimetic cilia micro-actuator, electro-statically actuated polymer biomimetic cilia micro-actuator, and magnetically actuated nanorod array biomimetic cilia micro-actuator, are presented. Subsequently micromachined underwater flow biomimetic cilia micro-sensor is studied, followed by acoustic flow micro-sensor. The fabrication of these MEMS-based biomimetic cilia devices, characterization of their physical properties, and the results of their application experiments are discussed.

  3. Biomimetic Strategies for Sensing Biological Species

    Directory of Open Access Journals (Sweden)

    Munawar Hussain

    2013-02-01

    Full Text Available The starting point of modern biosensing was the application of actual biological species for recognition. Increasing understanding of the principles underlying such recognition (and biofunctionality in general, however, has triggered a dynamic field in chemistry and materials sciences that aims at joining the best of two worlds by combining concepts derived from nature with the processability of manmade materials, e.g., sensitivity and ruggedness. This review covers different biomimetic strategies leading to highly selective (biochemical sensors: the first section covers molecularly imprinted polymers (MIP that attempt to generate a fully artificial, macromolecular mold of a species in order to detect it selectively. A different strategy comprises of devising polymer coatings to change the biocompatibility of surfaces that can also be used to immobilized natural receptors/ligands and thus stabilize them. Rationally speaking, this leads to self-assembled monolayers closely resembling cell membranes, sometimes also including bioreceptors. Finally, this review will highlight some approaches to generate artificial analogs of natural recognition materials and biomimetic approaches in nanotechnology. It mainly focuses on the literature published since 2005.

  4. Synergistic intrafibrillar/extrafibrillar mineralization of collagen scaffolds based on a biomimetic strategy to promote the regeneration of bone defects

    Directory of Open Access Journals (Sweden)

    Wang Y

    2016-05-01

    Full Text Available Yao Wang,1 Ngo Van Manh,1,2 Haorong Wang,1 Xue Zhong,1 Xu Zhang,1 Changyi Li1 1School of Dentistry, Hospital of Stomatology, Tianjin Medical University, Tianjin, People’s Republic of China; 2Thaibinh University of Medicine and Pharmacy, Thaibinh, Vietnam Abstract: The mineralization of collagen scaffolds can improve their mechanical properties and biocompatibility, thereby providing an appropriate microenvironment for bone regeneration. The primary purpose of the present study is to fabricate a synergistically intra- and extrafibrillar mineralized collagen scaffold, which has many advantages in terms of biocompatibility, biomechanical properties, and further osteogenic potential. In this study, mineralized collagen scaffolds were fabricated using a traditional mineralization method (ie, immersed in simulated body fluid as a control group and using a biomimetic method based on the polymer-induced liquid precursor process as an experimental group. In the polymer-induced liquid precursor process, a negatively charged polymer, carboxymethyl chitosan (CMC, was used to stabilize amorphous calcium phosphate (ACP to form nanocomplexes of CMC/ACP. Collagen scaffolds mineralized based on the polymer-induced liquid precursor process were in gel form such that nanocomplexes of CMC/ACP can easily be drawn into the interstices of the collagen fibrils. Scanning electron microscopy and transmission electron microscopy were used to examine the porous micromorphology and synergistic mineralization pattern of the collagen scaffolds. Compared with simulated body fluid, nanocomplexes of CMC/ACP significantly increased the modulus of the collagen scaffolds. The results of in vitro experiments showed that the cell count and differentiated degrees in the experimental group were higher than those in the control group. Histological staining and micro-computed tomography showed that the amount of new bone regenerated in the experimental group was larger than that in the

  5. Biomimetics

    Indian Academy of Sciences (India)

    P Ramachandra Rao

    2003-06-01

    The well-organised multifunctional structures, systems and biogenic materials found in nature have attracted the interest of scientists working in many disciplines. The efforts have resulted in the development of a new and rapidly growing field of scientific effort called biomimetics. In this article we present a few natural materials and systems and explore how ideas from nature are being interpreted and modified to suit efforts aimed at designing better machines and synthesising newer materials.

  6. Biomimetic material strategies for cardiac tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Molamma P., E-mail: nnimpp@nus.edu.sg [Health Care and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Venugopal, J. [Health Care and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Kai, Dan [NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (Singapore); Ramakrishna, Seeram [Health Care and Energy Materials Laboratory, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore)

    2011-04-08

    Cardiovascular disease precedes many serious complications including myocardial infarction (MI) and it remains a major problem for the global community. Adult mammalian heart has limited ability to regenerate and compensate for the loss of cardiomyocytes. Restoration of cardiac function by replacement of diseased myocardium with functional cardiomyocytes is an intriguing strategy because it offers a potential cure for MI. Biomaterials are fabricated in nanometer scale dimensions by combining the chemical, biological, mechanical and electrical aspects of material for potential tissue engineering (TE) applications. Synthetic polymers offer advantageous in their ability to tailor the mechanical properties, and natural polymers offer cell recognition sites necessary for cell, adhesion and proliferation. Cardiac tissue engineering (TE) aim for the development of a bioengineered construct that can provide physical support to the damaged cardiac tissue by replacing certain functions of the damaged extracellular matrix and prevent adverse cardiac remodeling and dysfunction after MI. Electrospun nanofibers are applied as heart muscle patches, while hydrogels serve as a platform for controlled delivery of growth factors, prevent mechanical complications and assist in cell recruitment. This article reviews the applications of different natural and synthetic polymeric materials utilized as cardiac patches, injectables or 3D constructs for cardiac TE. Smart organization of nanoscale assemblies with synergistic approaches of utilizing nanofibers and hydrogels could further advance the field of cardiac tissue engineering. Rapid innovations in biomedical engineering and cell biology will bring about new insights in the development of optimal scaffolds and methods to create tissue constructs with relevant contractile properties and electrical integration to replace or substitute the diseased myocardium.

  7. Biomimetic visual detection based on insect neurobiology

    Science.gov (United States)

    O'Carroll, David C.

    2001-11-01

    With a visual system that accounts for as much as 30% of the lifted mass, flying insects such as dragonflies and hoverflies invest more in vision than any other animal. Impressive visual performance is subserved by a surprisingly simple visual system. In a typical insect eye, between 2,000 and 30,000 pixels in the image are analyzed by fewer than 200,000 neurons in underlying neural circuits. The combination of sophisticated visual processing with an approachable level of complexity has made the insect visual system a leading model for biomimetic approaches to computer vision. Much neurobiological research has focused on neural circuits used for detection of moving patterns (e.g. optical flow during flight) and moving targets (e.g. prey). Research from several labs has led to great advances in our understanding of the neural mechanisms involved, and has spawned neuromorphic hardware based on key processes identified in neurobiological experiments. Despite its attractions, the highly non-linear nature of several key stages in insect visual processing presents a challenge to understanding. I will describe examples of adaptive elements of neural circuits in the fly visual system which analyze the direction and velocity of wide-field optical flow patterns and the result of experiments that suggest that these non-linearities may contribute to robust responses to natural image motion.

  8. Ionic Colloidal Molding as a Biomimetic Scaffolding Strategy for Uniform Bone Tissue Regeneration.

    Science.gov (United States)

    Zhang, Jian; Jia, Jinpeng; Kim, Jimin P; Shen, Hong; Yang, Fei; Zhang, Qiang; Xu, Meng; Bi, Wenzhi; Wang, Xing; Yang, Jian; Wu, Decheng

    2017-02-21

    Inspired by the highly ordered nanostructure of bone, nanodopant composite biomaterials are gaining special attention for their ability to guide bone tissue regeneration through structural and biological cues. However, bone malformation in orthopedic surgery is a lingering issue, partly due to the high surface energy of traditional nanoparticles contributing to aggregation and inhomogeneity. Recently, carboxyl-functionalized synthetic polymers have been shown to mimic the carboxyl-rich surface motifs of non-collagenous proteins in stabilizing hydroxyapatite and directing intrafibrillar mineralization in-vitro. Based on this biomimetic approach, it is herein demonstrated that carboxyl functionalization of poly(lactic-co-glycolic acid) can achieve great material homogeneity in nanocomposites. This ionic colloidal molding method stabilizes hydroxyapatite precursors to confer even nanodopant packing, improving therapeutic outcomes in bone repair by remarkably improving mechanical properties of nanocomposites and optimizing controlled drug release, resulting in better cell in-growth and osteogenic differentiation. Lastly, better controlled biomaterial degradation significantly improved osteointegration, translating to highly regular bone formation with minimal fibrous tissue and increased bone density in rabbit radial defect models. Ionic colloidal molding is a simple yet effective approach of achieving materials homogeneity and modulating crystal nucleation, serving as an excellent biomimetic scaffolding strategy to rebuild natural bone integrity.

  9. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    Directory of Open Access Journals (Sweden)

    Catia Algieri

    2014-07-01

    Full Text Available An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported.

  10. A biomimetic tactile sensing system based on polyvinylidene fluoride film

    Science.gov (United States)

    Xin, Yi; Tian, Hongying; Guo, Chao; Li, Xiang; Sun, Hongshuai; Wang, Peiyuan; Qian, Chenghui; Wang, Shuhong; Wang, Cheng

    2016-02-01

    Polyvinylidene fluoride (PVDF) film has been widely investigated as a sensing material due to its outstanding properties such as biocompatibility, high thermal stability, good chemical resistance, high piezo-, pyro- and ferro-electric properties. This paper reports on the design, test, and analysis of a biomimetic tactile sensor based on PVDF film. This sensor consists of a PVDF film with aluminum electrodes, a pair of insulating layers, and a "handprint" friction layer with a copper foil. It is designed for easy fabrication and high reliability in outputting signals. In bionics, the fingerprint of the glabrous skin plays an important role during object handling. Therefore, in order to enhance friction and to provide better manipulation, the ridges of the fingertips were introduced into the design of the proposed tactile sensor. And, a basic experimental study on the selection of the high sensitivity fingerprint type for the biomimetic sensor was performed. In addition, we proposed a texture distinguish experiment to verify the sensor sensitivity. The experiment's results show that the novel biomimetic sensor is effective in discriminating object surface characteristics. Furthermore, an efficient visual application program (LabVIEW) and a quantitative evaluation method were proposed for the verification of the biomimetic sensor. The proposed tactile sensor shows great potential for contact force and slip measurements.

  11. Design of biomimetic camouflage materials based on angiosperm leaf organs

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The micro structures and reflectance spectra of angiosperm leaves were compared with those of angiosperm petals. The study indicated that angiosperm leaf organs had identical micro structures and reflectance characteristics in the wave band of near infrared. Micro structures and compositions of leaf organs were the crucial factors influencing their reflectance spectra. The model of biomimetic materials based on angiosperm leaf organs was introduced and verified. From 300 to 2600 nm, the similarity coefficients of reflectance spectra of the foam containing water and Platanus Orientalis Linn. leaves were all above 0.969. The biomimetic camou- flage material exhibited almost the same reflectance spectra with those of green leaves in ultraviolet, visible and near infrared wave bands. And its "concolor and conspectrum" effect might take on reconnaissance of hyperspectral and ultra hy- perspectral imaging.

  12. Design of biomimetic camouflage materials based on angiosperm leaf organs

    Institute of Scientific and Technical Information of China (English)

    LIU ZhiMing; WU WenJian; HU BiRu

    2008-01-01

    The micro structures and reflectance spectra of angiosperm leaves were compared with those of angiosperm petals. The study indicated that angiosperm leaf organs had identical micro structures and reflectance characteristics in the wave band of near infrared. Micro structures and compositions of leaf organs were the crucial factors influencing their reflectance spectra. The model of biomimetic materials based on angiosperm leaf organs was introduced and verified. From 300 to 2600 nm, the similarity coefficients of reflectance spectra of the foam containing water and Platanus Orientalis Linn. leaves were all above 0.969. The biomimetic camou-flage material exhibited almost the same reflectance spectra with those of green leaves in ultraviolet, visible and near infrared wave bands, And its "concolor and conspectrum" effect might take on reconnaissance of hyperspectral and ultra hyperspectral imaging.

  13. Research on cooperative ball-pushing for multiple biomimetic robotic-fish based on dynamic role assignment strategy%基于动态角色的多机器鱼协作顶球研究

    Institute of Scientific and Technical Information of China (English)

    肖权; 孔峰; 谢广明

    2012-01-01

    机器鱼水球比赛是进行多机器鱼协作研究的标准平台.考虑在机器鱼水球比赛中的协作顶球策略问题,以行为机制理论为基础,根据机器鱼与球之间的距离及机器鱼的方向,通过引入进攻与防守函数来确定各机器鱼的动态角色分配.进一步将多机器鱼协作顶球任务划分为4个子任务层,分别对4个子任务层的行为机制与算法加以规划.最后,通过实验验证了多机器鱼协作顶球策略的可行性和有效性.%Water polo game performs as one standard platform for the study on multiple biomimetic robotic-fish cooperation these days. Consider the ball-pushing task, in which the dynamic roles of robotic-fish are determined by attack and defense functions which are based on the distances between the robotic-fish and the center of ball and the directions of the robotic-fish. Further, the ball-pushing task is plotted into four subtask levels, whose behaviors and algo-rithm are plotted separately. Finally, it is verified through test that it is effective and feasible for the multiple biomimetic robotic-fish to cooperative push ball on multiple biomimetic robotic-fish coopera-tive control platforms.

  14. Aquaporin-Based Biomimetic Polymeric Membranes: Approaches and Challenges

    Directory of Open Access Journals (Sweden)

    Joachim Habel

    2015-07-01

    Full Text Available In recent years, aquaporin biomimetic membranes (ABMs for water separation have gained considerable interest. Although the first ABMs are commercially available, there are still many challenges associated with further ABM development. Here, we discuss the interplay of the main components of ABMs: aquaporin proteins (AQPs, block copolymers for AQP reconstitution, and polymer-based supporting structures. First, we briefly cover challenges and review recent developments in understanding the interplay between AQP and block copolymers. Second, we review some experimental characterization methods for investigating AQP incorporation including freeze-fracture transmission electron microscopy, fluorescence correlation spectroscopy, stopped-flow light scattering, and small-angle X-ray scattering. Third, we focus on recent efforts in embedding reconstituted AQPs in membrane designs that are based on conventional thin film interfacial polymerization techniques. Finally, we describe some new developments in interfacial polymerization using polyhedral oligomeric silsesquioxane cages for increasing the physical and chemical durability of thin film composite membranes.

  15. A biomimetic projector with high subwavelength directivity based on dolphin biosonar

    Science.gov (United States)

    Zhang, Yu; Gao, Xiaowei; Zhang, Sai; Cao, Wenwu; Tang, Liguo; Wang, Ding; Li, Yan

    2014-09-01

    Based on computed tomography of a Yangtze finless porpoise's biosonar system, a biomimetic structure was designed to include air cavity, gradient-index material, and steel outer-structure mimicking air sacs, melon, and skull, respectively. The mainlobe pressure was about three times higher, the angular resolution was one order of magnitude higher, and the effective source size was orders of magnitude larger than those of the subwavelength source without the biomimetic structure. The superior subwavelength directivity over a broad bandwidth suggests potential applications of this biomimetic projector in underwater sonar, medical ultrasonography, and other related applications.

  16. 基于神经步进激励机制的蛇形机器人环境自适应仿生控制策略%Self-adaptable Biomimetic Control Strategy for Snake Robots Based on Neural Stepping Stimulation Mechanism

    Institute of Scientific and Technical Information of China (English)

    唐超权; 马书根; 李斌; 王明辉

    2013-01-01

    Current gaits modification strategy for snake robots to adapt to environment is complex and needs long time to adjust control parameters. By introducing neural stepping stimulation mechanism, a simple and fast biomimetic control strategy is proposed based on the multi-phase central pattern generator (CPG). The multi-phase CPG which produces various snake robots gaits is built. Based on biological study, the neural stepping stimulation mechanism is proposed. Through the kinematic analysis of three major snake robots gaits, the relationship between control parameters and motion performance is obtained. Combined with snake robots locomotion characteristics, the complete snake robots adaptable biomimetic control strategy is built with the neural stepping stimulation mechanism. There is a simulation comparing the performance of this strategy with traditional control method for snake robots and a experiment verifying the control strategy.%针对已有的蛇形机器人在环境适应过程中步态调整策略复杂,参数调整时间长的问题,引入神经步进激励机制,提出一种基于多模态中枢模式发生器模型的简单快速的仿生控制策略.构建能够产生蛇形机器人多种步态的多模态中枢模式发生器模型,并基于仿生学原理提出神经步进激励机制.通过对蛇形机器人三种主要步态的运动学分析,得出其运动性能与控制参数之间的关系,利用神经步进激励机制并结合蛇形机器人自身的运动特性建立蛇形机器人环境自适应仿生控制策略.通过仿真将该策略与传统蛇形机器人控制方法进行对比,并利用试验验证了该策略的有效性.

  17. Aquaporin-Based Biomimetic Polymeric Membranes: Approaches and Challenges

    DEFF Research Database (Denmark)

    Habel, Joachim Erich Otto; Hansen, Michael; Kynde, Søren;

    2015-01-01

    In recent years, aquaporin biomimetic membranes (ABMs) for water separation have gained considerable interest. Although the first ABMs are commercially available, there are still many challenges associated with further ABM development. Here, we discuss the interplay of the main components of ABMs...... thin film interfacial polymerization techniques. Finally, we describe some new developments in interfacial polymerization using polyhedral oligomeric silsesquioxane cages for increasing the physical and chemical durability of thin film composite membranes....

  18. Biomimetic Nanotubes Based on Cyclodextrins for Ion-Channel Applications.

    Science.gov (United States)

    Mamad-Hemouch, Hajar; Ramoul, Hassen; Abou Taha, Mohammad; Bacri, Laurent; Huin, Cécile; Przybylski, Cédric; Oukhaled, Abdelghani; Thiébot, Bénédicte; Patriarche, Gilles; Jarroux, Nathalie; Pelta, Juan

    2015-11-11

    Biomimetic membrane channels offer a great potential for fundamental studies and applications. Here, we report the fabrication and characterization of short cyclodextrin nanotubes, their insertion into membranes, and cytotoxicity assay. Mass spectrometry and high-resolution transmission electron microscopy were used to confirm the synthesis pathway leading to the formation of short nanotubes and to describe their structural parameters in terms of length, diameter, and number of cyclodextrins. Our results show the control of the number of cyclodextrins threaded on the polyrotaxane leading to nanotube synthesis. Structural parameters obtained by electron microscopy are consistent with the distribution of the number of cyclodextrins evaluated by mass spectrometry from the initial polymer distribution. An electrophysiological study at single molecule level demonstrates the ion channel formation into lipid bilayers, and the energy penalty for the entry of ions into the confined nanotube. In the presence of nanotubes, the cell physiology is not altered.

  19. The progress of olfactory transduction and biomimetic olfactory-based biosensors

    Institute of Scientific and Technical Information of China (English)

    WU ChunSheng; WANG LiJiang; ZHOU Jun; ZHAO LuHang; WANG Ping

    2007-01-01

    Olfaction is a very important sensation for all animals. Recently great progress has been made in the research of olfactory transduction. Especially the novel finding of the gene superfamily encoding olfactory receptors has led to rapid advances in olfactory transduction. These advances also promoted the research of biomimetic olfactory-based biosensors and some obvious achievements have been obtained due to their potential commercial prospects and promising industrial applications. This paper briefly introduces the biological basis of olfaction, summarizes the progress of olfactory signal transduction in the olfactory neuron, the olfactory bulb and the olfactory cortex, outlines the latest developments and applications of biomimetic olfactory-based biosensors. Finally, the olfactory biosensor based on light addressable potentiometric sensor (LAPS) is addressed in detail based on our recent work and the research trends of olfactory biosensors in future are discussed.

  20. Biomimetic Mineralization on a Macroporous Cellulose-Based Matrix for Bone Regeneration

    OpenAIRE

    2013-01-01

    The aim of this study is to investigate the biomimetic mineralization on a cellulose-based porous matrix with an improved biological profile. The cellulose matrix was precalcified using three methods: (i) cellulose samples were treated with a solution of calcium chloride and diammonium hydrogen phosphate; (ii) the carboxymethylated cellulose matrix was stored in a saturated calcium hydroxide solution; (iii) the cellulose matrix was mixed with a calcium silicate solution in order to introduce ...

  1. Biomimetic apatite-based composite materials obtained by spark plasma sintering (SPS): physicochemical and mechanical characterizations.

    Science.gov (United States)

    Brouillet, Fabien; Laurencin, Danielle; Grossin, David; Drouet, Christophe; Estournes, Claude; Chevallier, Geoffroy; Rey, Christian

    2015-08-01

    Nanocrystalline calcium phosphate apatites are biomimetic compounds analogous to bone mineral and are at the origin of the bioactivity of most biomaterials used as bone substitutes. Their unique surface reactivity originates from the presence of a hydrated layer containing labile ions (mostly divalent ones). So the setup of 3D biocompatible apatite-based bioceramics exhibiting a high reactivity requests the development of «low» temperature consolidation processes such as spark plasma sintering (SPS), in order to preserve the characteristics of the hydrated nanocrystals. However, mechanical performances may still need to be improved for such nanocrystalline apatite bioceramics, especially in view of load-bearing applications. The reinforcement by association with biopolymers represents an appealing approach, while preserving the advantageous biological properties of biomimetic apatites. Herein, we report the preparation of composites based on biomimetic apatite associated with various quantities of microcrystalline cellulose (MCC, 1-20 wt%), a natural fibrous polymer. The SPS-consolidated composites were analyzed from both physicochemical (X-ray diffraction, Fourier transform infrared, solid state NMR) and mechanical (Brazilian test) viewpoints. The preservation of the physicochemical characteristics of apatite and cellulose in the final material was observed. Mechanical properties of the composite materials were found to be directly related to the polymer/apatite ratios and a maximum crushing strength was reached for 10 wt% of MCC.

  2. Biomimetic sensing layer based on electrospun conductive polymer webs.

    Science.gov (United States)

    Zampetti, E; Pantalei, S; Scalese, S; Bearzotti, A; De Cesare, F; Spinella, C; Macagnano, A

    2011-01-15

    The aim of the present study is to combine a bio-inspired nanofibrous artificial epithelium to the electronic nose (e-nose) principles. The sensing device set up was an electronic nose consisting of an array of 9 micro-chemoresistors (Cr-Au, 3×3) coated with electrospun nanofibrous structures. These were comprised of doped polyemeraldine base blended with 3 different polymers: polyethylene oxide, polyvinilpyrrolidone and polystyrene, which acted as carriers for the conducting polymer and were the major responsible of the features of each fibrous overlay (electrical parameters, selectivity and sensitivity ranges). The two sensing strategies here adopted and compared consisted in the use of 2 different textural coatings: a single- and a double-overlay, where the double-overlay resulting from overdeposition of 2 different polymer blends. Such e-nose included a plurality of nanofibres whose electrical parameters were at the same time depending on each polymer exposure to analytes (NO(2), NH(3)) and on the spatial distribution of the interlacing fibres. The morphology of the coating arrangements of this novel e-nose was investigated by scanning electron microscopy (SEM) and its sensor responses were processed by multicomponent data analyses (PCA and PLS) reporting encouraging results for detection and recognition of analytes at ppb levels.

  3. Biomimetics: process, tools and practice.

    Science.gov (United States)

    Fayemi, P E; Wanieck, K; Zollfrank, C; Maranzana, N; Aoussat, A

    2017-01-23

    Biomimetics applies principles and strategies abstracted from biological systems to engineering and technological design. With a huge potential for innovation, biomimetics could evolve into a key process in businesses. Yet challenges remain within the process of biomimetics, especially from the perspective of potential users. We work to clarify the understanding of the process of biomimetics. Therefore, we briefly summarize the terminology of biomimetics and bioinspiration. The implementation of biomimetics requires a stated process. Therefore, we present a model of the problem-driven process of biomimetics that can be used for problem-solving activity. The process of biomimetics can be facilitated by existing tools and creative methods. We mapped a set of tools to the biomimetic process model and set up assessment sheets to evaluate the theoretical and practical value of these tools. We analyzed the tools in interdisciplinary research workshops and present the characteristics of the tools. We also present the attempt of a utility tree which, once finalized, could be used to guide users through the process by choosing appropriate tools respective to their own expertize. The aim of this paper is to foster the dialogue and facilitate a closer collaboration within the field of biomimetics.

  4. Calcifying tissue regeneration via biomimetic materials chemistry.

    Science.gov (United States)

    Green, David W; Goto, Tazuko K; Kim, Kye-Seong; Jung, Han-Sung

    2014-12-06

    Materials chemistry is making a fundamental impact in regenerative sciences providing many platforms for tissue development. However, there is a surprising paucity of replacements that accurately mimic the structure and function of the structural fabric of tissues or promote faithful tissue reconstruction. Methodologies in biomimetic materials chemistry have shown promise in replicating morphologies, architectures and functional building blocks of acellular mineralized tissues dentine, enamel and bone or that can be used to fully regenerate them with integrated cell populations. Biomimetic materials chemistry encompasses the two processes of crystal formation and mineralization of crystals into inorganic formations on organic templates. This review will revisit the successes of biomimetics materials chemistry in regenerative medicine, including coccolithophore simulants able to promote in vivo bone formation. In-depth knowledge of biomineralization throughout evolution informs the biomimetic materials chemist of the most effective techniques for regenerative framework construction exemplified via exploitation of liquid crystals (LCs) and complex self-organizing media. Therefore, a new innovative direction would be to create chemical environments that perform reaction-diffusion exchanges as the basis for building complex biomimetic inorganic structures. This has evolved widely in biology, as have LCs, serving as self-organizing templates in pattern formation of structural biomaterials. For instance, a study is highlighted in which artificially fabricated chiral LCs, made from bacteriophages are transformed into a faithful copy of enamel. While chemical-based strategies are highly promising at creating new biomimetic structures there are limits to the degree of complexity that can be generated. Thus, there may be good reason to implement living or artificial cells in 'morphosynthesis' of complex inorganic constructs. In the future, cellular construction is probably

  5. Biomimetic interfaces based on S-layer proteins, lipid membranes and functional biomolecules.

    Science.gov (United States)

    Schuster, Bernhard; Sleytr, Uwe B

    2014-07-06

    Designing and utilization of biomimetic membrane systems generated by bottom-up processes is a rapidly growing scientific and engineering field. Elucidation of the supramolecular construction principle of archaeal cell envelopes composed of S-layer stabilized lipid membranes led to new strategies for generating highly stable functional lipid membranes at meso- and macroscopic scale. In this review, we provide a state-of-the-art survey of how S-layer proteins, lipids and polymers may be used as basic building blocks for the assembly of S-layer-supported lipid membranes. These biomimetic membrane systems are distinguished by a nanopatterned fluidity, enhanced stability and longevity and, thus, provide a dedicated reconstitution matrix for membrane-active peptides and transmembrane proteins. Exciting areas in the (lab-on-a-) biochip technology are combining composite S-layer membrane systems involving specific membrane functions with the silicon world. Thus, it might become possible to create artificial noses or tongues, where many receptor proteins have to be exposed and read out simultaneously. Moreover, S-layer-coated liposomes and emulsomes copying virus envelopes constitute promising nanoformulations for the production of novel targeting, delivery, encapsulation and imaging systems.

  6. Enhanced Neural Cell Adhesion and Neurite Outgrowth on Graphene-Based Biomimetic Substrates

    Directory of Open Access Journals (Sweden)

    Suck Won Hong

    2014-01-01

    Full Text Available Neural cell adhesion and neurite outgrowth were examined on graphene-based biomimetic substrates. The biocompatibility of carbon nanomaterials such as graphene and carbon nanotubes (CNTs, that is, single-walled and multiwalled CNTs, against pheochromocytoma-derived PC-12 neural cells was also evaluated by quantifying metabolic activity (with WST-8 assay, intracellular oxidative stress (with ROS assay, and membrane integrity (with LDH assay. Graphene films were grown by using chemical vapor deposition and were then coated onto glass coverslips by using the scooping method. Graphene sheets were patterned on SiO2/Si substrates by using photolithography and were then covered with serum for a neural cell culture. Both types of CNTs induced significant dose-dependent decreases in the viability of PC-12 cells, whereas graphene exerted adverse effects on the neural cells just at over 62.5 ppm. This result implies that graphene and CNTs, even though they were the same carbon-based nanomaterials, show differential influences on neural cells. Furthermore, graphene-coated or graphene-patterned substrates were shown to substantially enhance the adhesion and neurite outgrowth of PC-12 cells. These results suggest that graphene-based substrates as biomimetic cues have good biocompatibility as well as a unique surface property that can enhance the neural cells, which would open up enormous opportunities in neural regeneration and nanomedicine.

  7. Enhanced neural cell adhesion and neurite outgrowth on graphene-based biomimetic substrates.

    Science.gov (United States)

    Hong, Suck Won; Lee, Jong Ho; Kang, Seok Hee; Hwang, Eun Young; Hwang, Yu-Shik; Lee, Mi Hee; Han, Dong-Wook; Park, Jong-Chul

    2014-01-01

    Neural cell adhesion and neurite outgrowth were examined on graphene-based biomimetic substrates. The biocompatibility of carbon nanomaterials such as graphene and carbon nanotubes (CNTs), that is, single-walled and multiwalled CNTs, against pheochromocytoma-derived PC-12 neural cells was also evaluated by quantifying metabolic activity (with WST-8 assay), intracellular oxidative stress (with ROS assay), and membrane integrity (with LDH assay). Graphene films were grown by using chemical vapor deposition and were then coated onto glass coverslips by using the scooping method. Graphene sheets were patterned on SiO2/Si substrates by using photolithography and were then covered with serum for a neural cell culture. Both types of CNTs induced significant dose-dependent decreases in the viability of PC-12 cells, whereas graphene exerted adverse effects on the neural cells just at over 62.5 ppm. This result implies that graphene and CNTs, even though they were the same carbon-based nanomaterials, show differential influences on neural cells. Furthermore, graphene-coated or graphene-patterned substrates were shown to substantially enhance the adhesion and neurite outgrowth of PC-12 cells. These results suggest that graphene-based substrates as biomimetic cues have good biocompatibility as well as a unique surface property that can enhance the neural cells, which would open up enormous opportunities in neural regeneration and nanomedicine.

  8. Synthesis and Characterization of a Chondroitin Sulfate Based Hybrid Bio/Synthetic Biomimetic Aggrecan Macromolecule

    Science.gov (United States)

    Sarkar, Sumona

    Lower back pain resulting from intervertebral disc degeneration is one of the leading musculoskeletal disorders confronting our health system. In order to mechanically stabilize the disc early in the degenerative cascade and prevent the need for spinal fusion surgeries, we have proposed the development of a hybrid-bio/synthetic biomimetic proteoglycan macromolecule for injection into the disc in the early stages of degeneration. The goal of this thesis was to incorporate natural chondroitin sulfate (CS) chains into bottle brush polymer synthesis strategies for the fabrication of CS-macromolecules which mimic the proteoglycan structure and function while resisting enzymatic degradation. Both the "grafting-to" and "grafting-through" techniques of bottle brush synthesis were explored. CS was immobilized via a terminal primary amine onto a model polymeric backbone (polyacrylic acid) for investigation of the "grafting-to" strategy and an epoxy-amine step-growth polymerization technique was utilized for the "grafting-through" synthesis of CS-macromolecules with polyethylene glycol backbone segments. Incorporation of a synthetic polymeric backbone at the terminal amine of CS was confirmed via biochemical assays, 1H-NMR and FTIR spectroscopy, and CS-macromolecule size was demonstrated to be higher than that of natural CS via gel permeation chromatography, transmission electron microscopy and viscosity measurements. Further analysis of CS-macromolecule functionality indicated maintenance of natural CS properties such as high fixed charge density, high osmotic potential and low cytotoxicity with nucleus pulposus cells. These studies are the first attempt at the incorporation of natural CS into biomimetic bottle brush structures. CS-macromolecules synthesized via the methods developed in these studies may be utilized in the treatment and prevention of debilitating back pain as well as act as mimetics for other proteoglycans implicated in cartilage, heart valve, and nervous

  9. Solid-supported biomimetic membranes based on amphiphilic block copolymers

    OpenAIRE

    Kowal, Justyna

    2015-01-01

    Planar artificial membranes based on amphiphilic block copolymers are of high interest due to their potential applications in catalysis, drug screening, sensing, etc. Such polymeric membranes can successfully mimic biological membranes, providing high robustness and stability, which makes them good candidates to be developed in direction of applications. Even though solid-supported polymer membranes have been already investigated to a certain extent, it is still an emerging area. This thesis ...

  10. Molecular recognition in homogeneous transition metal catalysis: a biomimetic strategy for high selectivity.

    Science.gov (United States)

    Das, Siddartha; Brudvig, Gary W; Crabtree, Robert H

    2008-01-28

    Traditional methods for selectivity control in homogeneous transition metal catalysis either employ steric effects in a binding pocket or chelate control. In a supramolecular strategy, encapsulation of the substrate can provide useful shape and size selectivity. A fully developed molecular recognition strategy involving hydrogen bonding or solvophobic forces has given almost completely regioselective functionalization of remote, unactivated C-H bonds.

  11. A biomimetic strategy to form calcium phosphate crystals on type I collagen substrate

    Energy Technology Data Exchange (ETDEWEB)

    Xu Zhang [Department of Restorative Dentistry, Faculty of Dentistry, National University of Singapore, 5 Lower Kent Ridge Road 119074, Singapore (Singapore); Neoh, Koon Gee [Department of Chemical and Biomolecular Engineering, National University of Singapore, Kent Ridge 119260, Singapore (Singapore); Kishen, Anil, E-mail: anil.kishen@utoronto.ca [Discipline of Endodontics, Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON (Canada)

    2010-07-20

    Objective: The aim of this study is to induce mineralization of collagen by introducing phosphate groups onto type I collagen from eggshell membrane (ESM) by treating with sodium trimetaphosphate (STMP). This strategy is based on the hypothesis that phosphate groups introduced on collagen can mimic the nucleating role of phosphorylated non-collagenous proteins bound to collagen for inducing mineralization in natural hard tissue. Method: The collagen membrane was phosphorylated by treating it with a solution of STMP and saturated calcium hydroxide. The phosphorylated collagen was subsequently exposed to a mineralization solution and the pattern of mineralization on the surface of phosphorylated collagen substrate was analyzed. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), field emission electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and microhardness test were used to characterize the collagen substrate and the pattern of minerals formed on the collagen surface. Results: The FTIR and EDX results indicated that the phosphate groups were incorporated onto the collagen surface by treatment with STMP. During the mineralization process, the plate-like mineral, octacalcium phosphate (OCP), which was initially formed on the surface of ESM, was later transformed into needle-like hydroxyapatite (HAP) as indicated by the SEM, FESEM, EDX and XRD findings. The microhardness test displayed significant increase in the Knoop hardness number of the mineralized collagen. Conclusions: Phosphate groups can be introduced onto type I collagen surface by treating it with STMP and such phosphorylated collagen can induce the mineralization of type I collagen.

  12. Enhancing Osteoconduction of PLLA-Based Nanocomposite Scaffolds for Bone Regeneration Using Different Biomimetic Signals to MSCs

    Directory of Open Access Journals (Sweden)

    Nicola Baldini

    2012-02-01

    Full Text Available In bone engineering, the adhesion, proliferation and differentiation of mesenchymal stromal cells rely on signaling from chemico-physical structure of the substrate, therefore prompting the design of mimetic “extracellular matrix”-like scaffolds. In this study, three-dimensional porous poly-L-lactic acid (PLLA-based scaffolds have been mixed with different components, including single walled carbon nanotubes (CNT, micro-hydroxyapatite particles (HA, and BMP2, and treated with plasma (PT, to obtain four different nanocomposites: PLLA + CNT, PLLA + CNTHA, PLLA + CNT + HA + BMP2 and PLLA + CNT + HA + PT. Adult bone marrow mesenchymal stromal cells (MSCs were derived from the femur of orthopaedic patients, seeded on the scaffolds and cultured under osteogenic induction up to differentiation and mineralization. The release of specific metabolites and temporal gene expression profiles of marrow-derived osteoprogenitors were analyzed at definite time points, relevant to in vitro culture as well as in vivo differentiation. As a result, the role of the different biomimetic components added to the PLLA matrix was deciphered, with BMP2-added scaffolds showing the highest biomimetic activity on cells differentiating to mature osteoblasts. The modification of a polymeric scaffold with reinforcing components which also work as biomimetic cues for cells can effectively direct osteoprogenitor cells differentiation, so as to shorten the time required for mineralization.

  13. Large-Deformation Curling Actuators Based on Carbon Nanotube Composite: Advanced-Structure Design and Biomimetic Application.

    Science.gov (United States)

    Chen, Luzhuo; Weng, Mingcen; Zhou, Zhiwei; Zhou, Yi; Zhang, Lingling; Li, Jiaxin; Huang, Zhigao; Zhang, Wei; Liu, Changhong; Fan, Shoushan

    2015-12-22

    In recent years, electroactive polymers have been developed as actuator materials. As an important branch of electroactive polymers, electrothermal actuators (ETAs) demonstrate potential applications in the fields of artificial muscles, biomimetic devices, robotics, and so on. Large-shape deformation, low-voltage-driven actuation, and ultrafast fabrication are critical to the development of ETA. However, a simultaneous optimization of all of these advantages has not been realized yet. Practical biomimetic applications are also rare. In this work, we introduce an ultrafast approach to fabricate a curling actuator based on a newly designed carbon nanotube and polymer composite, which completely realizes all of the above required advantages. The actuator shows an ultralarge curling actuation with a curvature greater than 1.0 cm(-1) and bending angle larger than 360°, even curling into a tubular structure. The driving voltage is down to a low voltage of 5 V. The remarkable actuation is attributed not only to the mismatch in the coefficients of thermal expansion but also to the mechanical property changes of materials during temperature change. We also construct an S-shape actuator to show the possibility of building advanced-structure actuators. A weightlifting walking robot is further designed that exhibits a fast-moving motion while lifting a sample heavier than itself, demonstrating promising biomimetic applications.

  14. Biomimetic synthesis of cellular SiC based ceramics from plant precursor

    Indian Academy of Sciences (India)

    O P Chakrabarti; H S Maiti; R Majumdar

    2004-10-01

    A novel biomimetic approach in designing and fabricating engineering ceramic materials has gained much interest in recent times. Following this approach, synthesis has been made of dense Si–SiC duplex ceramic composites and highly porous SiC ceramics in the image of the morphological features inherent in the caudex stem of a local monocotyledonous plant. The process route involves making of a carbonaceous biopreform and its subsequent reaction with an infiltrating silicon melt to yield the biomorphic Si–SiC ceramic composites with flexural strength and Young’s modulus of 264 MPa and 247 Gpa, respectively and loss in weight of only ∼ 9% during oxidative heating up to 1200°C in flowing air. The Si–SiC composites were transformed into porous (49 vol.%) SiC ceramics with complete preservation of microcellular anatomy of the parent plant, by depleting residual silicon phase in channel pores through reaction with carbon. SiC based materials so derived can be used in structural applications and in designing high temperature filters and catalyst supports.

  15. Biomimetic Mineralization on a Macroporous Cellulose-Based Matrix for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Odeta Petrauskaite

    2013-01-01

    Full Text Available The aim of this study is to investigate the biomimetic mineralization on a cellulose-based porous matrix with an improved biological profile. The cellulose matrix was precalcified using three methods: (i cellulose samples were treated with a solution of calcium chloride and diammonium hydrogen phosphate; (ii the carboxymethylated cellulose matrix was stored in a saturated calcium hydroxide solution; (iii the cellulose matrix was mixed with a calcium silicate solution in order to introduce silanol groups and to combine them with calcium ions. All the methods resulted in a mineralization of the cellulose surfaces after immersion in a simulated body fluid solution. Over a period of 14 days, the matrix was completely covered with hydroxyapatite crystals. Hydroxyapatite formation depended on functional groups on the matrix surface as well as on the precalcification method. The largest hydroxyapatite crystals were obtained on the carboxymethylated cellulose matrix treated with calcium hydroxide solution. The porous cellulose matrix was not cytotoxic, allowing the adhesion and proliferation of human osteoblastic cells. Comparatively, improved cell adhesion and growth rate were achieved on the mineralized cellulose matrices.

  16. Biomimetic-Based Output Feedback for Attitude Stabilization of Rigid Bodies: Real-Time Experimentation on a Quadrotor

    Directory of Open Access Journals (Sweden)

    José Fermi Guerrero-Castellanos

    2015-08-01

    Full Text Available The present paper deals with the development of bounded feedback control laws mimicking the strategy adopted by flapping flyers to stabilize the attitude of systems falling within the framework of rigid bodies. Flapping flyers are able to orient their trajectory without any knowledge of their current attitude and without any attitude computation. They rely on the measurements of some sensitive organs: halteres, leg sensilla and magnetic sense, which give information about their angular velocity and the orientation of gravity and magnetic field vectors. Therefore, the proposed feedback laws are computed using direct inertial sensors measurements, that is vector observations with/without angular velocity measurements. Hence, the attitude is not explicitly required. This biomimetic approach is very simple, requires little computational power and is suitable for embedded applications on small control units. The boundedness of the control signal is taken into consideration through the design of the control laws by saturation of the actuators’ input. The asymptotic stability of the closed loop system is proven by Lyapunov analysis. Real-time experiments are carried out on a quadrotor using MEMS inertial sensors in order to emphasize the efficiency of this biomimetic strategy by showing the convergence of the body’s states in hovering mode, as well as the robustness with respect to external disturbances.

  17. Biomimetic Receptors and Sensors

    Directory of Open Access Journals (Sweden)

    Franz L. Dickert

    2014-11-01

    Full Text Available In biomimetics, living systems are imitated to develop receptors for ions, molecules and bioparticles. The most pertinent idea is self-organization in analogy to evolution in nature, which created the key-lock principle. Today, modern science has been developing host-guest chemistry, a strategy of supramolecular chemistry for designing interactions of analytes with synthetic receptors. This can be realized, e.g., by self-assembled monolayers (SAMs or molecular imprinting. The strategies are used for solid phase extraction (SPE, but preferably in developing recognition layers of chemical sensors.

  18. Biomimetic surface modification of polypropylene by surface chain transfer reaction based on mussel-inspired adhesion technology and thiol chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Zhijun; Zhao, Yang; Sun, Wei; Shi, Suqing, E-mail: shisq@nwu.edu.cn; Gong, Yongkuan

    2016-11-15

    Highlights: • Biomimetic surface modification of PP was successfully conducted by integrating mussel-inspired technology, thiol chemistry and cell outer membranes-like structures. • The resultant biomimetic surface exhibits good interface and surface stability. • The obvious suppression of protein adsorption and platelet adhesion is also achieved. • The residue thoil groups on the surface could be further functionalized. - Abstract: Biomimetic surface modification of polypropylene (PP) is conducted by surface chain transfer reaction based on the mussel-inspired versatile adhesion technology and thiol chemistry, using 2-methacryloyloxyethylphosphorylcholine (MPC) as a hydrophilic monomer mimicking the cell outer membrane structure and 2,2-azobisisobutyronitrile (AIBN) as initiator in ethanol. A layer of polydopamine (PDA) is firstly deposited onto PP surface, which not only offers good interfacial adhesion with PP, but also supplies secondary reaction sites (-NH{sub 2}) to covalently anchor thiol groups onto PP surface. Then the radical chain transfer to surface-bonded thiol groups and surface re-initiated polymerization of MPC lead to the formation of a thin layer of polymer brush (PMPC) with cell outer membrane mimetic structure on PP surface. X-ray photoelectron spectrophotometer (XPS), atomic force microscopy (AFM) and water contact angle measurements are used to characterize the PP surfaces before and after modification. The protein adsorption and platelet adhesion experiments are also employed to evaluate the interactions of PP surface with biomolecules. The results show that PMPC is successfully grafted onto PP surface. In comparison with bare PP, the resultant PP-PMPC surface exhibits greatly improved protein and platelet resistance performance, which is the contribution of both increased surface hydrophilicity and zwitterionic structure. More importantly, the residue thiol groups on PP-PMPC surface create a new pathway to further functionalize such

  19. Dopamine modulated ionic permeability in mesoporous silica sphere based biomimetic compartment.

    Science.gov (United States)

    Liu, Wei; Yang, Xiaohai; He, Dinggeng; He, Leiliang; Li, Li; Liu, Yu; Liu, Jianbo; Wang, Kemin

    2016-06-01

    The building of artificial systems with similar structure and function as cellular compartments will expand our understanding of compartmentalization related biological process and facilitate the construction of biomimetic highly functional structures. Herein, surface phenylboronic acid functionalized mesoporous silica sphere was developed as a biomimetic dopamine gated compartment, in which the ionic permeability can be well modulated through the dopamine-binding induced charge reversal. As the phenylboronic acid is negatively charged, the negatively charged 1, 3, 6, 8-pyrenetetrasulfonic acid (TPSA) was hindered from permeation into the biomimetic compartment. However, the presence of dopamine and its binding with phenylboronic acid reversed the gatekeeper shell from negative to positive charged and gated the permeation of TPSA into the interior. The dopamine gated permeation phenomenon resembles that in biological system, and thus the phenylboronic acid functionalized mesoporous silica sphere was taken as a simple model for dopamine gated ion channel decorated biological compartment. It will also contribute to the development of artificial cell and responsive nanoreactor.

  20. Biomimetic magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Michael T. Klem

    2005-09-01

    Full Text Available Magnetic nanoparticles are of considerable interest because of their potential use in high-density memory devices, spintronics, and applications in diagnostic medicine. The conditions for synthesis of these materials are often complicated by their high reaction temperatures, costly reagents, and post-processing requirements. Practical applications of magnetic nanoparticles will require the development of alternate synthetic strategies that can overcome these impediments. Biomimetic approaches to materials chemistry have provided a new avenue for the synthesis and assembly of magnetic nanomaterials that has great potential for overcoming these obstacles.

  1. A biomimetic vision-based hovercraft accounts for bees' complex behaviour in various corridors.

    Science.gov (United States)

    Roubieu, Frédéric L; Serres, Julien R; Colonnier, Fabien; Franceschini, Nicolas; Viollet, Stéphane; Ruffier, Franck

    2014-09-01

    Here we present the first systematic comparison between the visual guidance behaviour of a biomimetic robot and those of honeybees flying in similar environments. We built a miniature hovercraft which can travel safely along corridors with various configurations. For the first time, we implemented on a real physical robot the 'lateral optic flow regulation autopilot', which we previously studied computer simulations. This autopilot inspired by the results of experiments on various species of hymenoptera consists of two intertwined feedback loops, the speed and lateral control loops, each of which has its own optic flow (OF) set-point. A heading-lock system makes the robot move straight ahead as fast as 69 cm s(-1) with a clearance from one wall as small as 31 cm, giving an unusually high translational OF value (125° s(-1)). Our biomimetic robot was found to navigate safely along straight, tapered and bent corridors, and to react appropriately to perturbations such as the lack of texture on one wall, the presence of a tapering or non-stationary section of the corridor and even a sloping terrain equivalent to a wind disturbance. The front end of the visual system consists of only two local motion sensors (LMS), one on each side. This minimalistic visual system measuring the lateral OF suffices to control both the robot's forward speed and its clearance from the walls without ever measuring any speeds or distances. We added two additional LMSs oriented at +/-45° to improve the robot's performances in stiffly tapered corridors. The simple control system accounts for worker bees' ability to navigate safely in six challenging environments: straight corridors, single walls, tapered corridors, straight corridors with part of one wall moving or missing, as well as in the presence of wind.

  2. Biomimetic Mineralization of Recombinamer-Based Hydrogels toward Controlled Morphologies and High Mineral Density.

    Science.gov (United States)

    Li, Yuping; Chen, Xi; Fok, Alex; Rodriguez-Cabello, Jose Carlos; Aparicio, Conrado

    2015-11-25

    The use of insoluble organic matrices as a structural template for the bottom-up fabrication of organic-inorganic nanocomposites is a powerful way to build a variety of advanced materials with defined and controlled morphologies and superior mechanical properties. Calcium phosphate mineralization in polymeric hydrogels is receiving significant attention in terms of obtaining biomimetic hierarchical structures with unique mechanical properties and understanding the mechanisms of the biomineralization process. However, integration of organic matrices with hydroxyapatite nanocrystals, different in morphology and composition, has not been well-achieved yet at nanoscale. In this study, we synthesized thermoresponsive hydrogels, composed of elastin-like recombinamers (ELRs), to template mineralization of hydroxyapatite nanocrystals using a biomimetic polymer-induced liquid-precursor (PILP) mineralization process. Different from conventional mineralization where minerals were deposited on the surface of organic matrices, they were infiltrated into the frameworks of ELR matrices, preserving their microporous structure. After 14 days of mineralization, an average of 78 μm mineralization depth was achieved. Mineral density up to 1.9 g/cm(3) was found after 28 days of mineralization, which is comparable to natural bone and dentin. In the dry state, the elastic modulus and hardness of the mineralized hydrogels were 20.3 ± 1.7 and 0.93 ± 0.07 GPa, respectively. After hydration, they were reduced to 4.50 ± 0.55 and 0.10 ± 0.03 GPa, respectively. These values were lower but still on the same order of magnitude as those of natural hard tissues. The results indicated that inorganic-organic hybrid biomaterials with controlled morphologies can be achieved using organic templates of ELRs. Notably, the chemical and physical properties of ELRs can be tuned, which might help elucidate the mechanisms by which living organisms regulate the mineralization process.

  3. Biomimetic graphene films and their properties

    Science.gov (United States)

    Zhang, Yong-Lai; Chen, Qi-Dai; Jin, Zhi; Kim, Eunkyoung; Sun, Hong-Bo

    2012-07-01

    Biomimetic fabrication has long been considered a short cut to the rational design and production of artificial materials or devices that possess fascinating properties, just like natural creatures. Considering the fact that graphene exhibits a lot of exceptional properties in a wide range of scientific fields, biomimetic fabrication of graphene multiscale structures, denoted as biomimetic graphene, is of great interest in both fundamental research and industrial applications. Especially, the combination of graphene with biomimetic structures would realize structural and functional integrity, and thus bring a new opportunity of developing novel graphene-based devices with remarkable performance. In this feature article, we highlight the recent advances in biomimetic graphene films and their structure-defined properties. Functionalized graphene films with multiscale structures inspired from a wide range of biomaterials including rose petals, butterfly wings, nacre and honeycomb have been collected and presented. Moreover, both current challenges and future perspectives of biomimetic graphene are discussed. Although research of the so-called ``biomimetic graphene'' is still at an early stage, it might become a ``hot topic'' in the near future.

  4. Biomimetic thin film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

    1995-09-01

    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  5. Towards the LIVING envelope: Biomimetics for building envelope adaptation

    NARCIS (Netherlands)

    Badarnah Kadri, L.

    2012-01-01

    Several biomimetic design strategies are available for various applications, though the research on biomimetics as a design tool in architecture is still challenging. This is due to a lack of systematic design tools required for identifying relevant organisms, or natural systems, and abstracting the

  6. Artificial Muscles Based on Electroactive Polymers as an Enabling Tool in Biomimetics

    Science.gov (United States)

    Bar-Cohen, Y.

    2007-01-01

    Evolution has resolved many of nature's challenges leading to working and lasting solutions that employ principles of physics, chemistry, mechanical engineering, materials science, and many other fields of science and engineering. Nature's inventions have always inspired human achievements leading to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems, and many other benefits. Some of the technologies that have emerged include artificial intelligence, artificial vision, and artificial muscles, where the latter is the moniker for electroactive polymers (EAPs). To take advantage of these materials and make them practical actuators, efforts are made worldwide to develop capabilities that are critical to the field infrastructure. Researchers are developing analytical model and comprehensive understanding of EAP materials response mechanism as well as effective processing and characterization techniques. The field is still in its emerging state and robust materials are still not readily available; however, in recent years, significant progress has been made and commercial products have already started to appear. In the current paper, the state-of-the-art and challenges to artificial muscles as well as their potential application to biomimetic mechanisms and devices are described and discussed.

  7. Biomimetic control based on a model of chemotaxis in Escherichia coli.

    Science.gov (United States)

    Tsuji, Toshio; Suzuki, Michiyo; Takiguchi, Noboru; Ohtake, Hisao

    2010-01-01

    In the field of molecular biology, extending now to the more comprehensive area of systems biology, the development of computer models for synthetic cell simulation has accelerated extensively and has begun to be used for various purposes, such as biochemical analysis. These models, describing the highly efficient environmental searching mechanisms and adaptability of living organisms, can be used as machine-control algorithms in the field of systems engineering. To realize this biomimetic intelligent control, we require a stripped-down model that expresses a series of information-processing tasks from stimulation input to movement. Here we selected the bacterium Escherichia coli as a target organism because it has a relatively simple molecular and organizational structure, which can be characterized using biochemical and genetic analyses. We particularly focused on a motility response known as chemotaxis and developed a computer model that includes not only intracellular information processing but also motor control. After confirming the effectiveness and validity of the proposed model by a series of computer simulations, we applied it to a mobile robot control problem. This is probably the first study showing that a bacterial model can be used as an autonomous control algorithm. Our results suggest that many excellent models proposed thus far for biochemical purposes can be applied to problems in other fields.

  8. Biomimetic sensor based on molecularly imprinted polymer with nitroreductase-like activity for metronidazole detection.

    Science.gov (United States)

    Gu, Yue; Yan, Xiaoyi; Li, Cong; Zheng, Bo; Li, Yaru; Liu, Weilu; Zhang, Zhiquan; Yang, Ming

    2016-03-15

    The utility of molecularly imprinted polymer (MIP) as electrochemical sensor often suffers from its limited catalytic efficiency. Here, we proposed an alternative approach by combining the concept of MIP with the use of mimetic enzyme. A metronidazole imprinted polymer with nitroreductase-like activity was successfully achieved via an electrochemical method, where melamine served two purposes: functional monomer of MIP and component of mimetic enzyme. During the imprinting process, the redox-active center, which is responsible for catalysis, was introduced into the imprinted cavities. Accordingly, the imprinted polymer, having both catalysis centers and recognition sites, exhibited enhanced electrocatalytic activity and selectivity. The sensing performances of this metronidazole imprinted biomimetic sensor were evaluated in detail. Results revealed that the response to metronidazole was linear in the concentration range of 0.5-1000 μM, and the detection limit was 0.12 μM (S/N=3). In addition, we applied the proposed sensor to detect metronidazole in an injection solution and the results implied its feasibility for practical application.

  9. Synthesis of robust and high-performance aquaporin-based biomimetic membranes by interfacial polymerization-membrane preparation and RO performance characterization

    DEFF Research Database (Denmark)

    Zhao, Yang; Qiu, Changquan; Li, Xuesong;

    2012-01-01

    %) at an applied pressure of 5bar. Its permeability was ∼40% higher compared to a commercial brackish water RO membrane (BW30) and an order of magnitude higher compared to a seawater RO membrane (SW30HR), which clearly demonstrates the great potential of the TFC ABM for desalination applications.......Aquaporins are water channel proteins with excellent water permeability and solute rejection, which makes them promising for preparing high-performance biomimetic membranes. Despite the growing interest in aquaporin-based biomimetic membranes (ABMs), it is challenging to produce robust and defect...... or with inactive (mutant) aquaporins, were also similarly prepared. The separation performance of these membranes was evaluated by cross-flow reverse osmosis (RO) tests. Compared to the controls, the active ABM achieved significantly higher water permeability (∼4L/m2hbar) with comparable NaCl rejection (∼97...

  10. A MIP-based biomimetic sensor for the impedimetric detection of histamine in different pH environments

    Energy Technology Data Exchange (ETDEWEB)

    Bongaers, E.; Alenus, J.; Horemans, F.; Weustenraed, A.; Cleij, T.J. [Institute for Materials Research, Hasselt University, Diepenbeek (Belgium); Lutsen, L. [IMEC, Division IMOMEC, Diepenbeek (Belgium); Vanderzande, D.; Wagner, P. [Institute for Materials Research, Hasselt University, Diepenbeek (Belgium); IMEC, Division IMOMEC, Diepenbeek (Belgium); Troost, F.J.; Brummer, R.J. [Gastroenterology and Hepatology, Department of Internal Medicine, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, Maastricht (Netherlands)

    2010-04-15

    The development of novel biosensors is a rapidly growing field. Substituting the biological receptor layer from the biosensor with a synthetic receptor opens the door for the development of biomimetic sensors that are chemically and physically inert, as opposed to the sensors containing biological recognition elements. Using molecularly imprinted polymers (MIPs) the specificity and affinity of biological receptors can be mimicked. In addition, a MIP-based sensor can measure in harsh environments. Histamine occurs in harsh environments in food and bodily fluids and is chosen as the target molecule for impedimetric detection. When 10 nM histamine is present in pH neutral environments, the impedance increases 45% with respect to the impedance of the sensor without histamine. Specificity is tested with respect to histidine. The influence of the pH on the performance of the sensor is tested. In a pH range of pH 5-12 the MIPs are stable, although they exhibit a varying degree of protonation. The same holds true for the target molecule of which the protonation also varies with the pH of the solution. It is shown that the pH dependent degree of protonation of both the MIP and the histamine has a large impact on the binding of histamine to the nanocavity in the MIP. Hence, the detection of histamine by a MIP-based sensor is affected by the pH of the solution. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  11. Molecularly imprinted polymer based on MWCNT-QDs as fluorescent biomimetic sensor for specific recognition of target protein

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Zhaoqiang [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Annie Bligh, S.W. [Department of Life Sciences, Faculty of Science and Technology, University of Westminster, 115 New Cavendish Street, London W1W 6UW (United Kingdom); Tao, Lei; Quan, Jing [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Nie, Huali, E-mail: niehuali@dhu.edu.cn [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Zhu, Limin, E-mail: lzhu@dhu.edu.cn [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Gong, Xiao [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China)

    2015-03-01

    A novel molecularly imprinted optosensing material based on multi-walled carbon nanotube-quantum dots (MWCNT-QDs) has been designed and synthesized for its high selectivity, sensitivity and specificity in the recognition of a target protein bovine serum albumin (BSA). Molecularly imprinted polymer coated MWCNT-QDs using BSA as the template (BMIP-coated MWCNT-QDs) exhibits a fast mass-transfer speed with a response time of 25 min. It is found that the BSA as a target protein can significantly quench the luminescence of BMIP-coated MWCNT-QDs in a concentration-dependent manner that is best described by a Stern–Volmer equation. The K{sub SV} for BSA is much higher than bovine hemoglobin and lysozyme, implying a highly selective recognition of the BMIP-coated MWCNT-QDs to BSA. Under optimal conditions, the relative fluorescence intensity of BMIP-coated MWCNT-QDs decreases linearly with the increasing target protein BSA in the concentration range of 5.0 × 10{sup −7}–35.0 × 10{sup −7} M with a detection limit of 80 nM. - Highlights: • A novel fluorescent biomimetic sensor based on MWCNT-QDs was designed. • The sensor exhibited a fast mass-transfer speed with a response time of 25 min. • The sensor possessed a highly selective recognition to BSA.

  12. Biomimetic membranes for sensor and separation applications

    CERN Document Server

    2012-01-01

    This book addresses the possibilities and challenges in mimicking biological membranes and creating membrane-based sensor and separation devices. It covers recent advances in developing biomimetic membranes for technological applications with a focus on the use of integral membrane protein mediated transport. It describes the fundamentals of biosensing as well as separation and shows how the two processes work together in biological systems. The book provides an overview of the current state of the art, points to areas that need further investigation and anticipates future directions in the field. Biomimetics is a truly cross-disciplinary approach and this is exemplified by the challenges in mimicking osmotic processes as they occur in nature using aquaporin protein water channels as central building blocks. In the development of a biomimetic sensor/separation technology, both channel and carrier proteins are important and examples of how these may be reconstituted and controlled in biomimetic membranes are ...

  13. Biomimetic Flow Sensors

    NARCIS (Netherlands)

    Casas, J.; Liu, Chang; Krijnen, G.J.M.

    2012-01-01

    Biomimetic flow sensors are biologically inspired devices that measure the speed and direction of fluids. This survey starts by describing the role and functioning of airflow-sensing hairs in arthropods and in fishes, carries on with the biomimetic MEMS implementations, both for air and water flow s

  14. Biomimetic surface modification of polypropylene by surface chain transfer reaction based on mussel-inspired adhesion technology and thiol chemistry

    Science.gov (United States)

    Niu, Zhijun; Zhao, Yang; Sun, Wei; Shi, Suqing; Gong, Yongkuan

    2016-11-01

    Biomimetic surface modification of polypropylene (PP) is conducted by surface chain transfer reaction based on the mussel-inspired versatile adhesion technology and thiol chemistry, using 2-methacryloyloxyethylphosphorylcholine (MPC) as a hydrophilic monomer mimicking the cell outer membrane structure and 2,2-azobisisobutyronitrile (AIBN) as initiator in ethanol. A layer of polydopamine (PDA) is firstly deposited onto PP surface, which not only offers good interfacial adhesion with PP, but also supplies secondary reaction sites (-NH2) to covalently anchor thiol groups onto PP surface. Then the radical chain transfer to surface-bonded thiol groups and surface re-initiated polymerization of MPC lead to the formation of a thin layer of polymer brush (PMPC) with cell outer membrane mimetic structure on PP surface. X-ray photoelectron spectrophotometer (XPS), atomic force microscopy (AFM) and water contact angle measurements are used to characterize the PP surfaces before and after modification. The protein adsorption and platelet adhesion experiments are also employed to evaluate the interactions of PP surface with biomolecules. The results show that PMPC is successfully grafted onto PP surface. In comparison with bare PP, the resultant PP-PMPC surface exhibits greatly improved protein and platelet resistance performance, which is the contribution of both increased surface hydrophilicity and zwitterionic structure. More importantly, the residue thiol groups on PP-PMPC surface create a new pathway to further functionalize such zwitterion modified PP surface.

  15. Bio-replicated forming of the biomimetic drag-reducing surfaces in large area based on shark skin

    Institute of Scientific and Technical Information of China (English)

    HAN Xin; ZHANG DeYuan; LI Xiang; LI YuanYue

    2008-01-01

    On the investigation of biomimetic drag-reducing surface, direct replication of the firm scarfskins on low-resistance creatures to form biomimetic drag-reducing surfaces with relatively vivid morphology relative to the living prototype is a new attempt of the bio-replicated forming technology. Taking shark skin as the bio-replication template, the hot embossing method was applied to the micro-replication of its outward morphology. Furthermore, the skins were jointed together to form the drag-reducing sur-face in large area. The results of the resistance measurements in a water tunnel according to the flat-plate sample pieces have shown that the biomimetic shark-skin coating fabricated by the bio-replicated forming method has significant drag reduction effect, and that the drag reduction effi-ciency reached 8.25% in the test conditions.

  16. 基于胸鳍辅助推进的仿生机器鱼%Biomimetic Robotic Fish Based on Pectoral Fins Auxiliary Propulsion

    Institute of Scientific and Technical Information of China (English)

    王梅娟; 王楠; 瞿逸洲; 韦典成

    2016-01-01

    为提高仿生机器鱼游动的机动性能并完善传统尾鳍推进模式,设计一种基于胸鳍辅助推进的仿生机器鱼。将胸鳍与尾鳍推进模式相结合,采用正弦信号对仿生机器鱼的尾鳍进行控制,通过胸鳍来调整鱼体方向,从而实现上升及下降的动力提供。对机器鱼整体、主控系统、执行模块和通信模块进行设计,并通过实验验证。实验结果表明:该仿生机器鱼能够更灵活、更精确地实现浅水中前进、上升下潜以及盘旋、回转和制动,并通过人机交互对仿生鱼进行控制,结合其自主避障、图像传输等辅助功能,实现对海洋环境的实时监测。%For improving biomimetic robotic fish swimming flexibility and traditional tail fin propulsion, design biomimetic robotic fish based on pectoral fins auxiliary propulsion. Combine pectoral fins auxiliary propulsion mode with tail fin propulsion, use sine signal to control tail of biomimetic robotic fish, change fish swimming direction by pectoral fins, then realize power supply of ascending and descending. Design biomimetic robotic fish, main control system, execution module and communication module, verify it by test. The test results show: the biomimetic robotic fish can be more flexible and precise to realize advancing in shallow water, floating, diving circle flight, rotating and braking, then control fish by human-computer interaction, realize real time monitoring on ocean environment by combining auxiliary functions such as autonomous obstacle negotiation function, and image transmission.

  17. Sensing in nature: using biomimetics for design of sensors

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Cheong, Hyunmin; Shu, Li

    2008-01-01

    Purpose – The purpose of this paper is to illustrate how biomimetics can be applied in sensor design. Biomimetics is an engineering discipline that uses nature as an inspiration source for generating ideas for how to solve engineering problems. The paper reviews a number of biomimetic studies...... of sense organs in animals and illustrates how a formal search method developed at University of Toronto can be applied to sensor design. Design/methodology/approach – Using biomimetics involves a search for relevant cases, a proper analysis of the biological solutions, identification of design principles...... or the search gives too many results. This is handled by a more advanced search strategy where the search is either widened or it is focused further mainly using biological synonyms. Findings – A major problem in biomimetic design is finding the relevant analogies to actual design tasks in nature. Research...

  18. Biomimetic materials design for cardiac tissue regeneration.

    Science.gov (United States)

    Dunn, David A; Hodge, Alexander J; Lipke, Elizabeth A

    2014-01-01

    Cardiovascular disease is the leading cause of death worldwide. In the absence of sufficient numbers of organs for heart transplant, alternate approaches for healing or replacing diseased heart tissue are under investigation. Designing biomimetic materials to support these approaches will be essential to their overall success. Strategies for cardiac tissue engineering include injection of cells, implantation of three-dimensional tissue constructs or patches, injection of acellular materials, and replacement of valves. To replicate physiological function and facilitate engraftment into native tissue, materials used in these approaches should have properties that mimic those of the natural cardiac environment. Multiple aspects of the cardiac microenvironment have been emulated using biomimetic materials including delivery of bioactive factors, presentation of cell-specific adhesion sites, design of surface topography to guide tissue alignment and dictate cell shape, modulation of mechanical stiffness and electrical conductivity, and fabrication of three-dimensional structures to guide tissue formation and function. Biomaterials can be engineered to assist in stem cell expansion and differentiation, to protect cells during injection and facilitate their retention and survival in vivo, and to provide mechanical support and guidance for engineered tissue formation. Numerous studies have investigated the use of biomimetic materials for cardiac regeneration. Biomimetic material design will continue to exploit advances in nanotechnology to better recreate the cellular environment and advance cardiac regeneration. Overall, biomimetic materials are moving the field of cardiac regenerative medicine forward and promise to deliver new therapies in combating heart disease.

  19. Biomimetic thin film synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Graff, G.L.; Campbell, A.A.; Gordon, N.R.

    1995-05-01

    The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

  20. Biomimetic Production of Hydrogen

    Science.gov (United States)

    Gust, Devens

    2004-03-01

    The basic reaction for hydrogen generation is formation of molecular hydrogen from two electrons and two protons. Although there are many possible sources for the protons and electrons, and a variety of mechanisms for providing the requisite energy for hydrogen synthesis, the most abundant and readily available source of protons and electrons is water, and the most attractive source of energy for powering the process is sunlight. Not surprisingly, living systems have evolved to take advantage of these sources for materials and energy. Thus, biology provides paradigms for carrying out the reactions necessary for hydrogen production. Photosynthesis in green plants uses sunlight as the source of energy for the oxidation of water to give molecular oxygen, protons, and reduction potential. Some photosynthetic organisms are capable of using this reduction potential, in the form of the reduced redox protein ferredoxin, to reduce protons and produce molecular hydrogen via the action of an hydrogenase enzyme. A variety of other organisms metabolize the reduced carbon compounds that are ultimately the major products of photosynthesis to produce molecular hydrogen. These facts suggest that it might be possible to use light energy to make molecular hydrogen via biomimetic constructs that employ principles similar to those used by natural organisms, or perhaps with hybrid "bionic" systems that combine biomimetic materials with natural enzymes. It is now possible to construct artificial photosynthetic systems that mimic some of the major steps in the natural process.(1) Artificial antennas based on porphyrins, carotenoids and other chromophores absorb light at various wavelengths in the solar spectrum and transfer the harvested excitation energy to artificial photosynthetic reaction centers.(2) In these centers, photoinduced electron transfer uses the energy from light to move an electron from a donor to an acceptor moiety, generating a high-energy charge-separated state

  1. Anomalously augmented charge transport capabilities of biomimetically transformed collagen intercalated nano graphene based biocolloids

    CERN Document Server

    Dhar, Purbarun; Nayar, Suprabha; Das, Sarit K

    2015-01-01

    Collagen micro fibrils bio mimetically intercalate graphitic structures in aqueous media to form graphene nano platelets collagen complex (G Cl). Synthesized G Cl based stable, aqueous bio nanocolloids exhibit anomalously augmented charge transportation capabilities over simple collagen or graphene based colloids. The concentration tunable electrical transport properties of synthesized aqueous G Cl bio nanocolloids has been experimentally observed, theoretically analyzed and mathematically modeled. A comprehensive approach to mathematically predict the electrical transport properties of simple graphene and collagen based colloids has been presented. A theoretical formulation to explain the augmented transport characteristics of the G Cl bio nanocolloids based on the physico chemical interactions among the two entities, as revealed from extensive characterizations of the G Cl bio complex, has also been proposed. Physical interactions between the zwitterionic amino acid molecules within the collagen triple heli...

  2. Biomimetic peptide-based models of [FeFe]-hydrogenases: utilization of phosphine-containing peptides.

    Science.gov (United States)

    Roy, Souvik; Nguyen, Thuy-Ai D; Gan, Lu; Jones, Anne K

    2015-09-07

    Two synthetic strategies for incorporating diiron analogues of [FeFe]-hydrogenases into short peptides via phosphine functional groups are described. First, utilizing the amine side chain of lysine as an anchor, phosphine carboxylic acids can be coupled via amide formation to resin-bound peptides. Second, artificial, phosphine-containing amino acids can be directly incorporated into peptides via solution phase peptide synthesis. The second approach is demonstrated using three amino acids each with a different phosphine substituent (diphenyl, diisopropyl, and diethyl phosphine). In total, five distinct monophosphine-substituted, diiron model complexes were prepared by reaction of the phosphine-peptides with diiron hexacarbonyl precursors, either (μ-pdt)Fe2(CO)6 or (μ-bdt)Fe2(CO)6 (pdt = propane-1,3-dithiolate, bdt = benzene-1,2-dithiolate). Formation of the complexes was confirmed by UV/Vis, FTIR and (31)P NMR spectroscopy. Electrocatalysis by these complexes is reported in the presence of acetic acid in mixed aqueous-organic solutions. Addition of water results in enhancement of the catalytic rates.

  3. Laser technology in biomimetics basics and applications

    CERN Document Server

    Belegratis, Maria

    2013-01-01

    Lasers are progressively more used as versatile tools for fabrication purposes. The wide range of available powers, wavelengths, operation modes, repetition rates etc. facilitate the processing of a large spectrum of materials at exceptional precision and quality. Hence, manifold methods were established in the past and novel methods are continuously under development. Biomimetics, the translation from nature-inspired principles to technical applications, is strongly multidisciplinary. This field offers intrinsically a wide scope of applications for laser based methods regarding structuring and modification of materials. This book is dedicated to laser fabrication methods in biomimetics. It introduces both, a laser technology as well as an application focused approach.  The book covers the most important laser lithographic methods and various biomimetics application scenarios ranging from coatings and biotechnology to construction, medical applications and photonics.

  4. Biomimetic membranes for sensor and separation applications

    DEFF Research Database (Denmark)

    Helix Nielsen, Claus

    2009-01-01

    massive transport of matter in and out the cell. Nature has elegantly met this challenge by developing membranes in the form of lipid bilayers in which specialized and highly efficient transport proteins are incorporated. This raises the question: is it possible to mimic biological membranes and create...... membrane-based sensor and/or separation devices? In the development of biomimetic sensor/separation technology, both channels (ion and water channels) and carriers (transporters) are important. Generally, each class of transport proteins conducts specific molecular species in and out of the cell while...... generally have a lower turnover but are capable of transport against gradients. For both classes of proteins, their unique flux-properties make them interesting as candidates in biomimetic sensor/separation devices. An ideal sensor/separation device requires the supporting biomimetic matrix to be virtually...

  5. Biomimetic agent based modelling using male Frog calling behaviour as a case study

    DEFF Research Database (Denmark)

    Jørgensen, Søren V.; Demazeau, Yves; Christensen-Dalsgaard, Jakob;

    2014-01-01

    A new agent-based modelling tool has been developed to allow the modelling of populations of individuals whose interactions are characterised by tightly timed dynamics. The tool was developed to model male frog calling dynamics, to facilitate research into what local rules may be employed...... Frog, E. coqui, is implemented as a case study for the presentation and discussion of the tool, and results from this model are presented. RANA, in its present stage of development, is shown to be able to handle the problem of modelling calling frogs, and several fruitful extensions are proposed...

  6. Biomimetic microsensors inspired by marine life

    CERN Document Server

    Kottapalli, Ajay Giri Prakash; Miao, Jianmin; Triantafyllou, Michael S

    2017-01-01

    This book narrates the development of various biomimetic microelectromechanical systems (MEMS) sensors, such as pressure, flow, acceleration, chemical, and tactile sensors, that are inspired by sensing phenomenon that exist in marine life. The research described in this book is multi-faceted and combines the expertise and understanding from diverse fields, including biomimetics, microfabrication, sensor engineering, MEMS design, nanotechnology, and material science. A series of chapters examine the design and fabrication of MEMS sensors that function on piezoresistive, piezoelectric, strain gauge, and chemical sensing principles. By translating nature-based engineering solutions to artificial manmade technology, we could find innovative solutions to critical problems.

  7. Molecularly imprinted polymers as biomimetic receptors for fluorescence-based optical sensors

    Science.gov (United States)

    Moreno-Bondi, María C.; Urraca, Javier L.; Benito-Peña, Elena; Navarro-Villoslada, Fernando; Martins, Sofía A.; Orellana, Guillermo; Sellergren, Börje

    2007-07-01

    Molecularly imprinted polymers (MIPs), human-made polymers capable of recognizing a particular molecule in the presence of others due to the selective cavities of the material, have been successfully applied to the development of chromatographic and solid phase extraction methods. They have also been applied to the development of electrochemical, piezoelectrical and optical sensors. In parallel with the classification of biosensors, MIP-based devices can work according to two different detection schemes: (1) affinity sensors ("plastic-bodies") and, (2) catalytic sensors ("plastic-enzymes"). In the first case the change in a characteristic optical property, most frequently fluorescence, of the analyte or of the polymer is monitored, upon their mutual interaction. Alternatively, a fluorescent analogue of the target analyte can also be used to develop sensors based on competitive assays (MIAs). Optimization of the polymer composition and, in particular, a proper choice of the nature of the functional monomers involved in the polymerization process, is critical to prepare materials able to selectively interact with the analyte in aqueous media and with the fast kinetics required for analytical applications. Moreover, a rational design of fluorescent analogues of non-naturally fluorescent templates or of fluorescent monomers able to change its property upon interaction with the analyte, is also a bottle neck for wide application of this recognition elements in optical sensing. In this paper we present several approaches to address these issues namely the optimization of MIP composition and the design and synthesis of novel fluorophores for the analysis of antibiotics and mycotoxins in real samples.

  8. Knowledge Based Strategies for Knowledge Based Organizations

    OpenAIRE

    2012-01-01

    In the present, we can observe that a new economy is arising. It is an economy based on knowledge and ideas, in which the key factor for prosperity and for creation of the new jobs is the knowledge capitalization. Knowledge capitalization, intellectual capital, obtaining prosperity in the market economy imposes a new terminology, new managerial methods and techniques, new technologies and also new strategies. In other words, knowledge based economy, as a new type of economy; impose a new type...

  9. Biomimetic myocardial patches fabricated with poly(ɛ-caprolactone) and polyethylene glycol-based polyurethanes.

    Science.gov (United States)

    Silvestri, Antonella; Sartori, Susanna; Boffito, Monica; Mattu, Clara; Di Rienzo, Anna M; Boccafoschi, Francesca; Ciardelli, Gianluca

    2014-07-01

    The production of efficient heart patches for myocardium repair requires the use of biomaterials with high elastomeric properties and controllable biodegradability. To fulfil these design criteria we propose biodegradable poly(ester urethanes) and poly(ether ester urethanes) from poly(ɛ-caprolactone) (PCL) and poly(ethylene glycol) (PEG) as macrodiols, 1,4-diisocyanatobutane as diisocyanate, l-Lysine Ethyl Ester and Alanine-Alanine-Lysine (AAK) as chain extenders. This peptide was used to tune biodegradability properties, since the Alanine-Alanine sequence is a target for the elastase enzyme. Enzymatic degradation tests demonstrated the feasibility of tuning biodegradability properties due to the introduction of AAK peptide in polyurethane backbone. Two formulations have been processed into porous scaffolds by Thermally-Induced Phase Separation (TIPS). Scanning Electron Microscopy micrographs revealed promising microstructures, which were characterized by stretched and unidirectional pores and mimicked the striated muscle tissue. Tensile tests showed that, although scaffolds are characterized by lower mechanical properties than films, these substrates have suitable elastomeric behaviors and elastic moduli for contractile and soft tissue regeneration. Viability tests on cardiomyocytes revealed the best cell response for dense film and porous scaffold obtained from PCL and Lysine Ethyl Ester-based polyurethane, with an increased viability for the porous substrate, which is ascribable to the morphological features of its microstructure. Future works will be addressed to study the in vivo behavior of these constructs and to confirm their applicability for myocardial tissue engineering.

  10. Biomimetics materials, structures and processes : examples, ideas and case studies

    CERN Document Server

    Bruckner, Dietmar; Hellmich, Christian; Schmiedmayer, Heinz-Bodo; Stachelberger, Herbert; Gebeshuber, Ille

    2011-01-01

    The book presents an outline of current activities in the field of biomimetics and integrates a variety of applications comprising biophysics, surface sciences, architecture and medicine. Biomimetics as innovation method is characterised by interdisciplinary information transfer from the life sciences to technical application fields aiming at increased performance, functionality and energy efficiency. The contributions of the book relate to the research areas: - Materials and structures in nanotechnology and biomaterials - Biomimetic approaches to develop new forms, construction principles and design methods in architecture - Information and dynamics in automation, neuroinformatics and biomechanics Readers will be informed about the latest research approaches and results in biomimetics with examples ranging from bionic nano-membranes to function-targeted design of tribological surfaces and the translation of natural auditory coding strategies.

  11. A belief-based evolutionarily stable strategy.

    Science.gov (United States)

    Deng, Xinyang; Wang, Zhen; Liu, Qi; Deng, Yong; Mahadevan, Sankaran

    2014-11-21

    As an equilibrium refinement of the Nash equilibrium, evolutionarily stable strategy (ESS) is a key concept in evolutionary game theory and has attracted growing interest. An ESS can be either a pure strategy or a mixed strategy. Even though the randomness is allowed in mixed strategy, the selection probability of pure strategy in a mixed strategy may fluctuate due to the impact of many factors. The fluctuation can lead to more uncertainty. In this paper, such uncertainty involved in mixed strategy has been further taken into consideration: a belief strategy is proposed in terms of Dempster-Shafer evidence theory. Furthermore, based on the proposed belief strategy, a belief-based ESS has been developed. The belief strategy and belief-based ESS can reduce to the mixed strategy and mixed ESS, which provide more realistic and powerful tools to describe interactions among agents.

  12. Biomimetic microenvironments for regenerative endodontics.

    Science.gov (United States)

    Kaushik, Sagar N; Kim, Bogeun; Walma, Alexander M Cruz; Choi, Sung Chul; Wu, Hui; Mao, Jeremy J; Jun, Ho-Wook; Cheon, Kyounga

    2016-01-01

    Regenerative endodontics has been proposed to replace damaged and underdeveloped tooth structures with normal pulp-dentin tissue by providing a natural extracellular matrix (ECM) mimicking environment; stem cells, signaling molecules, and scaffolds. In addition, clinical success of the regenerative endodontic treatments can be evidenced by absence of signs and symptoms; no bony pathology, a disinfected pulp, and the maturation of root dentin in length and thickness. In spite of the various approaches of regenerative endodontics, there are several major challenges that remain to be improved: a) the endodontic root canal is a strong harbor of the endodontic bacterial biofilm and the fundamental etiologic factors of recurrent endodontic diseases, (b) tooth discolorations are caused by antibiotics and filling materials, (c) cervical root fractures are caused by endodontic medicaments, (d) pulp tissue is not vascularized nor innervated, and (e) the dentin matrix is not developed with adequate root thickness and length. Generally, current clinical protocols and recent studies have shown a limited success of the pulp-dentin tissue regeneration. Throughout the various approaches, the construction of biomimetic microenvironments of pulp-dentin tissue is a key concept of the tissue engineering based regenerative endodontics. The biomimetic microenvironments are composed of a synthetic nano-scaled polymeric fiber structure that mimics native pulp ECM and functions as a scaffold of the pulp-dentin tissue complex. They will provide a framework of the pulp ECM, can deliver selective bioactive molecules, and may recruit pluripotent stem cells from the vicinity of the pulp apex. The polymeric nanofibers are produced by methods of self-assembly, electrospinning, and phase separation. In order to be applied to biomedical use, the polymeric nanofibers require biocompatibility, stability, and biodegradability. Therefore, this review focuses on the development and application of the

  13. Biomimetics of human movement: functional or aesthetic?

    Science.gov (United States)

    Harris, Christopher M

    2009-09-01

    How should robotic or prosthetic arms be programmed to move? Copying human smooth movements is popular in synthetic systems, but what does this really achieve? We cannot address these biomimetic issues without a deep understanding of why natural movements are so stereotyped. In this article, we distinguish between 'functional' and 'aesthetic' biomimetics. Functional biomimetics requires insight into the problem that nature has solved and recognition that a similar problem exists in the synthetic system. In aesthetic biomimetics, nature is copied for its own sake and no insight is needed. We examine the popular minimum jerk (MJ) model that has often been used to generate smooth human-like point-to-point movements in synthetic arms. The MJ model was originally justified as maximizing 'smoothness'; however, it is also the limiting optimal trajectory for a wide range of cost functions for brief movements, including the minimum variance (MV) model, where smoothness is a by-product of optimizing the speed-accuracy trade-off imposed by proportional noise (PN: signal-dependent noise with the standard deviation proportional to mean). PN is unlikely to be dominant in synthetic systems, and the control objectives of natural movements (speed and accuracy) would not be optimized in synthetic systems by human-like movements. Thus, employing MJ or MV controllers in robotic arms is just aesthetic biomimetics. For prosthetic arms, the goal is aesthetic by definition, but it is still crucial to recognize that MV trajectories and PN are deeply embedded in the human motor system. Thus, PN arises at the neural level, as a recruitment strategy of motor units and probably optimizes motor neuron noise. Human reaching is under continuous adaptive control. For prosthetic devices that do not have this natural architecture, natural plasticity would drive the system towards unnatural movements. We propose that a truly neuromorphic system with parallel force generators (muscle fibres) and noisy

  14. Biomimetic Coacervate Environments for Protein Analysis

    Science.gov (United States)

    Perry, Sarah; McCall, Patrick; Srivastava, Samavayan; Kovar, David; Gardel, Margaret; Tirrell, Matthew

    2015-03-01

    Living cells have evolved sophisticated intracellular organization strategies that are challenging to reproduce synthetically. Biomolecular function depends on both the structure of the molecule itself and the properties of the surrounding medium. The ability to simulate the in vivo environment and isolate biological networks for study in an artificial milieu without sacrificing the crowding, structure, and compartmentalization of a cellular environment, represent engineering challenges with tremendous potential to impact both biological studies and biomedical applications. Emerging experience has shown that polypeptide-based complex coacervation (electrostatically-driven liquid-liquid phase separation) produces a biomimetic microenvironment capable of tuning protein biochemical activity. We have investigated the effect of polypeptide-based coacervates on the dynamic self-assembly of cytoskeletal actin filaments. Coacervate materials are able to directly affect the nucleation and assembly dynamics. We observe effects that can be attributed to the length and chemical specificity of the encapsulating polypeptides, as well as the overall crowded nature of a polymer-rich coacervate phase. Coacervate-based systems are particularly attractive for use in biochemical assays because the compartmentalization afforded by liquid-liquid phase separation does not necessarily inhibit the transport of molecules across the compartmental barrier.

  15. Biomimetic sensor based on hemin/carbon nanotubes/chitosan modified microelectrode for nitric oxide measurement in the brain.

    Science.gov (United States)

    Santos, Ricardo M; Rodrigues, Marcelo S; Laranjinha, João; Barbosa, Rui M

    2013-06-15

    A novel biomimetic microsensor for measuring nitric oxide (NO) in the brain in vivo was developed. The sensor consists of hemin and functionalized multi-wall carbon nanotubes covalently attached to chitosan via the carbodiimide crosslinker EDC followed by chitosan electrodeposition on the surface of carbon fiber microelectrodes. Cyclic voltammetry supported direct electron transfer from the Fe(III)/Fe(II) couple of hemin to the carbon surface at -0.370 V and -0.305 V vs. Ag/AgCl for cathodic and anodic peaks, respectively. Square wave voltammetry revealed a NO reduction peak at -0.762 V vs. Ag/AgCl that increased linearly with NO concentration between 0.25 and 1 μM. The average sensitivity of the microsensors was 1.72 nA/μM and the limit of detection was 25 nM. Oxygen and hydrogen peroxide reduction peaks were observed at -0.269 V and -0.332 V vs. Ag/AgCl, respectively and no response was observed for other relevant interferents, namely ascorbate, nitrite and dopamine. The microsensor was successfully applied to the measurement of exogenously applied NO in the rat brain in vivo.

  16. Motion Control Algorithms for a Free-swimming Biomimetic Robot Fish

    Institute of Scientific and Technical Information of China (English)

    YUJun-Zhi; CHENEr-Kui; WANGShuo; TANMin

    2005-01-01

    A practical motion control strategy for a radio-controlled, 4-1ink and free-swimming biomimetic robot fish is presented. Based on control performance of the fish the fish's motion control task is decomposed into on-line speed control and orientation control. The speed control algorithm is implemented by using piecewise control, and orientation control is realized by fuzzy logic. Combining with step control and fuzzy control, a point-to-point (PTP) control algorithm is proposed and applied to the closed-loop experimental system that uses a vision-based position sensing subsystem to provide feedback. Experiments confirm the reliability and effectiveness of the presented algorithms.

  17. Fabrication and characterization of biomimetic multichanneled crosslinked-urethane-doped polyester tissue engineered nerve guides.

    Science.gov (United States)

    Tran, Richard T; Choy, Wai Man; Cao, Hung; Qattan, Ibrahim; Chiao, Jung-Chih; Ip, Wing Yuk; Yeung, Kelvin Wai Kwok; Yang, Jian

    2014-08-01

    Biomimetic scaffolds that replicate the native architecture and mechanical properties of target tissues have been recently shown to be a very promising strategy to guide cellular growth and facilitate tissue regeneration. In this study, porous, soft, and elastic crosslinked urethane-doped polyester (CUPE) tissue engineered nerve guides were fabricated with multiple longitudinally oriented channels and an external non-porous sheath to mimic the native endoneurial microtubular and epineurium structure, respectively. The fabrication technique described herein is highly adaptable and allows for fine control over the resulting nerve guide architecture in terms of channel number, channel diameter, porosity, and mechanical properties. Biomimetic multichanneled CUPE guides were fabricated with various channel numbers and displayed an ultimate peak stress of 1.38 ± 0.22 MPa with a corresponding elongation at break of 122.76 ± 42.17%, which were comparable to that of native nerve tissue. The CUPE nerve guides were also evaluated in vivo for the repair of a 1 cm rat sciatic nerve defect. Although histological evaluations revealed collapse of the inner structure from CUPE TENGs, the CUPE nerve guides displayed fiber populations and densities comparable with nerve autograft controls after 8 weeks of implantation. These studies are the first report of a CUPE-based biomimetic multichanneled nerve guide and warrant future studies towards optimization of the channel geometry for use in neural tissue engineering.

  18. Microfluidic devices for investigation of biomimetic membranes for sensor and separation applications

    DEFF Research Database (Denmark)

    Pszon-Bartosz, Kamila Justyna

    drug candidates and in separation technologies, where an exciting example is water purification device based on biomimetic membranes containing aquaporins (highly water selective proteins). However, there are many challenges that must be overcome in order to build biomimetic membrane-based devices...

  19. Cell Interactions within Biomimetic Apatite Microenvironments

    OpenAIRE

    Tsang, Eric

    2014-01-01

    Bioactive ceramics, such as calcium phosphate-based materials, have been studied extensively for the regeneration of bone tissue. Accelerated apatite coatings prepared from biomimetic methods is one approach that has had a history of success in both in vitro and in vivo studies for bone regeneration [1]-[4]. However, how cells interact within the apatite microenvironment remains largely unclear, despite the vast literature available today. In response, this thesis evaluates the in vitro i...

  20. Flexible fabrication of biomimetic bamboo-like hybrid microfibers.

    Science.gov (United States)

    Yu, Yue; Wen, Hui; Ma, Jingyun; Lykkemark, Simon; Xu, Hui; Qin, Jianhua

    2014-04-23

    Biomimetic and flexible bamboo-like hybrid fibers are produced using a novel one-step strategy. By combining a droplet microfluidic technique with a wet-spinning process, biocompatible microfibers are incorporated with polymer spheres or multicellular spheroids. As a result of the controllability of this approach, it has potential applications in materials science and tissue engineering.

  1. Biomimetic Membrane Arrays on Cast Hydrogel Supports

    DEFF Research Database (Denmark)

    Roerdink-Lander, Monique; Ibragimova, Sania; Rein Hansen, Christian;

    2011-01-01

    Lipid bilayers are intrinsically fragile and require mechanical support in technical applications based on biomimetic membranes. Tethering the lipid bilayer membranes to solid substrates, either directly through covalent or ionic substrate−lipid links or indirectly on substrate-supported cushions......, provides mechanical support but at the cost of small molecule transport through the membrane−support sandwich. To stabilize biomimetic membranes while allowing transport through a membrane−support sandwich, we have investigated the feasibility of using an ethylene tetrafluoroethylene (ETFE......)/hydrogel sandwich as the support. The sandwich is realized as a perforated surface-treated ETFE film onto which a hydrogel composite support structure is cast. We report a simple method to prepare arrays of lipid bilayer membranes with low intrinsic electrical conductance on the highly permeable, self...

  2. Biomaterial Scaffolds with Biomimetic Fluidic Channels for Hepatocyte Culture

    Institute of Scientific and Technical Information of China (English)

    Xiao Li; Jiankang He; Yaxiong Liu; Qian Zhao; Wanquan Wu; Dichen Li; Zhongmin Jin

    2013-01-01

    Biomaterial scaffolds play an important role in maintaining the viability and biological functions of highly metabolic hepatocytes in liver tissue engineering.One of the major challenges involves building a complex microchannel network inside three-dimensional (3D) scaffolds for efficient mass transportation.Here we presented a biomimetic strategy to generate a microchannel network within porous biomaterial scaffolds by mimicking the vascular tree of rat liver.The typical parameters of the blood vessels were incorporated into the biomimetic design of the microchannel network such as branching angle and diameter.Silk fibroin-gelatin scaffolds with biomimetic vascular tree were fabricated by combining micromolding,freeze drying and 3D rolling techniques.The relationship between the micro-channeled design and flow pattern was revealed by a flow experiment,which indicated that the scaffolds with biomimetic vascular tree exhibited unique capability in improving mass transportation inside the 3D scaffold.The 3D scaffolds,preseeded with primary hepatocytes,were dynamically cultured in a bioreactor system.The results confirmed that the pre-designed biomimetic microchannel network facilitated the generation and expansion of hepatocytes.

  3. Biomimetic nanoparticles: preparation, characterization and biomedical applications

    Directory of Open Access Journals (Sweden)

    Ana Maria Carmona-Ribeiro

    2010-04-01

    Full Text Available Ana Maria Carmona-RibeiroBiocolloids Lab, Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, BrazilAbstract: Mimicking nature is a powerful approach for developing novel lipid-based devices for drug and vaccine delivery. In this review, biomimetic assemblies based on natural or synthetic lipids by themselves or associated to silica, latex or drug particles will be discussed. In water, self-assembly of lipid molecules into supramolecular structures is fairly well understood. However, their self-assembly on a solid surface or at an interface remains poorly understood. In certain cases, hydrophobic drug granules can be dispersed in aqueous solution via lipid adsorption surrounding the drug particles as nanocapsules. In other instances, hydrophobic drug molecules attach as monomers to borders of lipid bilayer fragments providing drug formulations that are effective in vivo at low drug-to-lipid-molar ratio. Cationic biomimetic particles offer suitable interfacial environment for adsorption, presentation and targeting of biomolecules in vivo. Thereby antigens can effectively be presented by tailored biomimetic particles for development of vaccines over a range of defined and controllable particle sizes. Biomolecular recognition between receptor and ligand can be reconstituted by means of receptor immobilization into supported lipidic bilayers allowing isolation and characterization of signal transduction steps.Keywords: cationic lipid, phospholipids, bilayer fragments, vesicles, silica, polymeric particles, antigens, novel cationic immunoadjuvants, drugs

  4. Biomimetic synthesis and characterization of semiconducting hybrid organic–inorganic composite materials based on polyaniline–polyethylene glycol–CdS system

    Indian Academy of Sciences (India)

    A Singh; N P Singh; R A Singh

    2011-07-01

    Triple hybrid materials based on polyaniline-polyethylene glycol and cadmium sulphide have been prepared by the duffusion–limited biomimetic route and characterized by a number of spectroscopic, XRD, SEM, thermal and electrical measurements. These hybrid materials have been prepared by controlled precipitation of cadmium sulphide by passing H2S gas and mixing the resultant colloid with the acidic solution of aniline. in situ polymerization of adsorbed anilinium ions on anionic surface of CdS resulted in hybrids. Water–soluble polyethylene glycol led to diffusion–limited growth of polyaniline and CdS resulting in a nanosized hybrid material as indicated by UV-visible spectra, X-ray diffraction (XRD) and scanning electron microscopy (SEM). AC impedance spectroscopic studies on binary and ternary nanocomposites of polyaniline with polyethylene glycol and cadmium sulphide separately and triple hybrid system have been reported. Equivalent circuits were determined and discussed in the light of contributions made from different sources such as grain, grain boundary and electrode.

  5. Molecular recognition and self-assembly special feature: Self-assembled biomimetic [2Fe2S]-hydrogenase-based photocatalyst for molecular hydrogen evolution.

    Science.gov (United States)

    Kluwer, A M; Kapre, R; Hartl, F; Lutz, M; Spek, A L; Brouwer, A M; van Leeuwen, P W N M; Reek, J N H

    2009-06-30

    The large-scale production of clean energy is one of the major challenges society is currently facing. Molecular hydrogen is envisaged as a key green fuel for the future, but it becomes a sustainable alternative for classical fuels only if it is also produced in a clean fashion. Here, we report a supramolecular biomimetic approach to form a catalyst that produces molecular hydrogen using light as the energy source. It is composed of an assembly of chromophores to a bis(thiolate)-bridged diiron ([2Fe2S]) based hydrogenase catalyst. The supramolecular building block approach introduced in this article enabled the easy formation of a series of complexes, which are all thoroughly characterized, revealing that the photoactivity of the catalyst assembly strongly depends on its nature. The active species, formed from different complexes, appears to be the [Fe(2)(micro-pdt)(CO)(4){PPh(2)(4-py)}(2)] (3) with 2 different types of porphyrins (5a and 5b) coordinated to it. The modular supramolecular approach was important in this study as with a limited number of building blocks several different complexes were generated.

  6. Biomimetic Synthesis of Insulin Enabled by Oxime Ligation and Traceless "C-Peptide" Chemical Excision.

    Science.gov (United States)

    Thalluri, Kishore; Kou, Binbin; Gelfanov, Vasily; Mayer, John P; Liu, Fa; DiMarchi, Richard D

    2017-02-03

    For decades, insulin has represented a preeminent synthetic target. Recently introduced "biomimetic" strategies based on convertible single-chain precursors require incorporation of a chemical linker or a unique proteolytic site, which limits their practicality. In this approach the A- and B-chains are linked by two sequential oxime ligations followed by disulfide bond formation under redox conditions and linker excision by diketopiperazine (DKP) formation and ester hydrolysis, yielding native two-chain insulin. The method is expected to be applicable to any member of the insulin superfamily.

  7. Evidence-Based Classroom Behaviour Management Strategies

    Science.gov (United States)

    Parsonson, Barry S.

    2012-01-01

    This paper reviews a range of evidence-based strategies for application by teachers to reduce disruptive and challenging behaviours in their classrooms. These include a number of antecedent strategies intended to help minimise the emergence of problematic behaviours and a range of those which provide positive consequences for appropriate student…

  8. Desalination by biomimetic aquaporin membranes: Review of status and prospects

    DEFF Research Database (Denmark)

    Tang, C.Y.; Zhao, Y.; Wang, R.;

    2013-01-01

    Based on their unique combination of offering high water permeability and high solute rejection aquaporin proteins have attracted considerable interest over the last years as functional building blocks of biomimetic membranes for water desalination and reuse. The purpose of this review is to prov......Based on their unique combination of offering high water permeability and high solute rejection aquaporin proteins have attracted considerable interest over the last years as functional building blocks of biomimetic membranes for water desalination and reuse. The purpose of this review...... is to provide an overview of the properties of aquaporins, their preparation and characterization. We discuss the challenges in exploiting the remarkable properties of aquaporin proteins for membrane separation processes and we present various attempts to construct aquaporin in membranes for desalination......; including an overview of our own recent developments in aquaporin-based membranes. Finally we outline future prospects of aquaporin based biomimetic membrane for desalination and water reuse....

  9. MARKETING STRATEGIES BASED ON THE BUYING PROCESS

    Directory of Open Access Journals (Sweden)

    LIVIU NEAMŢU

    2016-04-01

    Full Text Available In marketing, due to dynamic, rapid and permanent changes known on the market, we will talk more about politics than about strategy, the time horizon covered is much lower than that contained in a classic strategy, with a risk that elements and criteria to which we refer are no longer current. Sales growth strategies are, in fact, combination strategies and consist in the company applying, in its different units, different strategies, according to the requirement of appropriate strategies applied to different environments of action. A business strategy must be based on knowledge of customer purchasing behavior. To contact customers, a company may use one or more specific strategies. Every marketing strategy serves the interest of increasing competitiveness, and of stabilizing and improving the companys position in the market in a highly competitive environment. In the age of transformation into market economy, rapid technological development, and confrontation between economic and ecological factors, every single manager is compelled to elaborate an attitude, and to take a stand concerning research and development, technological transfer, the technological level of products, and the quality of services, because these are the factors determining the future development, the chances of survival, and in a wider sense the objectives of marketing strategy.

  10. BatSLAM: Simultaneous localization and mapping using biomimetic sonar.

    Science.gov (United States)

    Steckel, Jan; Peremans, Herbert

    2013-01-01

    We propose to combine a biomimetic navigation model which solves a simultaneous localization and mapping task with a biomimetic sonar mounted on a mobile robot to address two related questions. First, can robotic sonar sensing lead to intelligent interactions with complex environments? Second, can we model sonar based spatial orientation and the construction of spatial maps by bats? To address these questions we adapt the mapping module of RatSLAM, a previously published navigation system based on computational models of the rodent hippocampus. We analyze the performance of the proposed robotic implementation operating in the real world. We conclude that the biomimetic navigation model operating on the information from the biomimetic sonar allows an autonomous agent to map unmodified (office) environments efficiently and consistently. Furthermore, these results also show that successful navigation does not require the readings of the biomimetic sonar to be interpreted in terms of individual objects/landmarks in the environment. We argue that the system has applications in robotics as well as in the field of biology as a simple, first order, model for sonar based spatial orientation and map building.

  11. BatSLAM: Simultaneous localization and mapping using biomimetic sonar.

    Directory of Open Access Journals (Sweden)

    Jan Steckel

    Full Text Available We propose to combine a biomimetic navigation model which solves a simultaneous localization and mapping task with a biomimetic sonar mounted on a mobile robot to address two related questions. First, can robotic sonar sensing lead to intelligent interactions with complex environments? Second, can we model sonar based spatial orientation and the construction of spatial maps by bats? To address these questions we adapt the mapping module of RatSLAM, a previously published navigation system based on computational models of the rodent hippocampus. We analyze the performance of the proposed robotic implementation operating in the real world. We conclude that the biomimetic navigation model operating on the information from the biomimetic sonar allows an autonomous agent to map unmodified (office environments efficiently and consistently. Furthermore, these results also show that successful navigation does not require the readings of the biomimetic sonar to be interpreted in terms of individual objects/landmarks in the environment. We argue that the system has applications in robotics as well as in the field of biology as a simple, first order, model for sonar based spatial orientation and map building.

  12. A Biomimetic Haptic Sensor

    Directory of Open Access Journals (Sweden)

    Ben Mitchinson

    2008-11-01

    Full Text Available The design and implementation of the periphery of an artificial whisker sensory system is presented. It has been developed by adopting a biomimetic approach to model the structure and function of rodent facial vibrissae. The artificial vibrissae have been formed using composite materials and have the ability to be actively moved or whisked. The sensory structures at the root of real vibrissae has been modelled and implemented using micro strain gauges and Digital Signal Processors. The primary afferents and vibrissal trigeminal ganglion have been modelled using empirical data taken from electrophysiological measurements, and implemented in real-time using a Field Programmable Gate Array. Pipelining techniques were employed to maximise the utility of the FPGA hardware. The system is to be integrated into a more complete whisker sensory model, including neural structures within the central nervous system, which can be used to orient a mobile robot.

  13. Joystick-based Control for a Biomimetic Biped Climbing Robot%双手爪式仿生攀爬机器人的摇杆控制

    Institute of Scientific and Technical Information of China (English)

    蔡传武; 管贻生; 周雪峰; 江励; 朱海飞; 吴文强; 张宪民; 张宏

    2012-01-01

    探讨一种新型双手爪式5自由度仿生攀爬机器人(Climbot)的摇杆控制方法.首先,对机器人的运动学和可夹持空间问题进行了分析.然后,针对其双手爪交替夹持攀爬的特点,提出了直观的摇杆操作模式,包括对不同的攀爬步态设计了不同的操作坐标系,并利用建立变换矩阵的方法将交替夹持端前后的机器人描述在同一坐标系中.最后,通过尺蠖、扭转和翻转3种步态的路灯杆攀爬和应用示范实验结果证明了该摇杆控制方法的有效性.%A joystick-based control method is studied for Climbot, which is a novel 5-DoF (degree of freedom) biomimetic biped climbing robot. The kinematics and the available grasping area of the robot are analyzed firstly. And then, according to the characteristics of the robot biped climbing by switching its fixed-gripper, an intuitional joystick-based operating mode is proposed, in which different operating coordinates are defined for corresponding climbing gaits, and a matrix transform algorithm is presented to keep the robot coordinate system unchanging after switching its fixed-gripper. Finally, road-pole climbing experiments with three gaits (including inchworm-like, turning-around and turning-over gaits) and an application demonstration are carried out to verify the effectiveness of the presented joystick-based control method.

  14. 3D Perception of Biomimetic Eye Based on Motion Vision and Stereo Vision%仿生眼运动视觉与立体视觉3维感知

    Institute of Scientific and Technical Information of China (English)

    王庆滨; 邹伟; 徐德; 张峰

    2015-01-01

    In order to overcome the narrow visual field of binocular vision and the low precision of monocular vision, a binocular biomimetic eye platform with 4 rotational degrees of freedom is designed based on the structural characteristics of human eyes, so that the robot can achieve human-like environment perception with binocular stereo vision and monoc-ular motion vision. Initial location and parameters calibration of the biomimetic eye platform are accomplished based on the vision alignment strategy and hand-eye calibration. The methods of binocular stereo perception and monocular motion stereo perception are given based on the dynamically changing external parameters. The former perceives the 3D information through the two images obtained by two cameras in real-time and their relative posture, and the latter perceives the 3D infor-mation by synthesize multiple images obtained by one camera and its corresponding postures at multiple adjacent moments. Experimental results shows that the relative perception accuracy of binocular vision is 0.38% and the relative perception accuracy of monocular motion vision is 0.82%. In conclusion, the method proposed can broaden the field of binocular vision, and ensure the accuracy of binocular perception and monocular motion perception.%为使机器人同时具备双目立体视觉和单目运动视觉的仿人化环境感知能力,克服双目视场狭窄、单目深度感知精度低的缺陷,本文基于人眼结构特点,设计了一个具有4个旋转自由度的双目仿生眼平台,并分别基于视觉对准策略和手眼标定技术实现了该平台的初始定位和参数标定.给出了基于外部参数动态变化的双目立体感知方法和单目运动立体感知方法,前者通过两架摄像机实时获取的图像信息以及摄像机相对位姿信息进行3维感知,后者综合利用单个摄像机在多个相邻时刻获取的多个图像及其对应姿态进行3维感知.实验结果中的双目

  15. Effective Length Design of Humanoid Robot Fingers Using Biomimetic Optimization

    Directory of Open Access Journals (Sweden)

    Byoung-Ho Kim

    2015-10-01

    Full Text Available In this study, we propose an effective design method for the phalangeal parameters and the total size of humanoid robot fingers based on a biomimetic optimization. For the optimization, an interphalangeal joint coordination parameter and the length constraints inherent in human fingers are considered from a biomimetic perspective. A reasonable grasp formulation is also taken into account from the viewpoint of power grasping, where the grasp space of a humanoid robot finger is importantly considered to determine the phalangeal length parameters. The usefulness of the devised biomimetic optimization method is shown through the design examples of various humanoid robot fingers. In fact, the optimization-based finger design method enables us to determine effectively the proper phalangeal size of humanoid robot fingers for human-like object handling tasks. In addition, we discuss its contribution to the structural configuration and coordinated motion of a humanoid robot finger, and address its practical availability in terms of effective finger design.

  16. Conventional vs Biomimetic Approaches to the Exploration of Mars

    Science.gov (United States)

    Ellery, A.

    It is not usual to refer to convention in planetary exploration missions by virtue of the innovation required for such projects. The term conventional refers to the methodologies, tools and approaches typically adopted in engineering that are applied to such missions. Presented is a "conventional" Mars rover mission in which the author was involved - ExoMars - into which is interspersed references to examples where biomimetic approaches may yield superior capabilities. Biomimetics is a relatively recently active area of research which seeks to examine how biological systems solve the problem of survival in the natural environment. Biological organisms are autonomous entities that must survive in a hostile world adapting both adaptivity and robustness. It is not then surprising that biomimetics is particularly useful when applied to robotic elements of a Mars exploration mission. I present a number of areas in which biomimetics may yield new solutions to the problem of Mars exploration - optic flow navigation, potential field navigation, genetically-evolved neuro-controllers, legged locomotion, electric motors implementing muscular behaviour, and a biomimetic drill based on the wood wasp ovipositor. Each of these techniques offers an alternative approach to conventional ones. However, the perceptive hurdles are likely to dwarf the technical hurdles in implementing many of these methods in the near future.

  17. Numerical Analysis of Erosion Caused by Biomimetic Axial Fan Blade

    Directory of Open Access Journals (Sweden)

    Jun-Qiu Zhang

    2013-01-01

    Full Text Available Damage caused by erosion has been reported in several industries for a wide range of situations. In the present work, a new method is presented to improve the erosion resistance of machine components by biomimetic method. A numerical investigation of solid particle erosion in the standard and biomimetic configuration blade of axial fan is presented. The analysis consists in the application of the discrete phase model, for modeling the solid particles flow, and the Eulerian conservation equations to the continuous phase. The numerical study employs computational fluid dynamics (CFD software, based on a finite volume method. User-defined function was used to define wear equation. Gas/solid flow axial fan was simulated to calculate the erosion rate of the particles on the fan blades and comparatively analyzed the erosive wear of the smooth surface, the groove-shaped, and convex hull-shaped biomimetic surface axial flow fan blade. The results show that the groove-shaped biomimetic blade antierosion ability is better than that of the other two fan blades. Thoroughly analyze of antierosion mechanism of the biomimetic blade from many factors including the flow velocity contours and flow path lines, impact velocity, impact angle, particle trajectories, and the number of collisions.

  18. Sustainability assessment of a lightweight biomimetic ceiling structure.

    Science.gov (United States)

    Antony, Florian; Grießhammer, Rainer; Speck, Thomas; Speck, Olga

    2014-03-01

    An intensive and continuous debate centres on the question of whether biomimetics has a specific potential to contribute to sustainability. In the context of a case study, the objective of this paper is to contribute to this debate by presenting the first systematic approach to assess the sustainability of a complex biomimetic product. The object of inquiry is a lecture hall's ribbed slab. Based on criteria suggested by the Association of German Engineers (VDI), it has been verified that the slab has been correctly defined as biomimetic. Moreover, a systematic comparative product sustainability assessment has been carefully carried out. For purposes of comparison, estimated static calculations have been performed for conceivable current state-of-the-art lightweight ceiling structures. Alternative options are a hollow article slab and a pre-stressed flat slab. Besides a detailed benefit analysis and a discussion of social effects, their costs have also been compared. A particularly detailed life cycle assessment on the respective environmental impacts has also been performed. Results show that the biomimetic ribbed slab built in the 1960s is able to keep up with the current state-of-the-art lightweight solutions in terms of sustainability. These promising results encourage a systematic search for a broad range of sustainable biomimetic solutions.

  19. A future of living machines?: International trends and prospects in biomimetic and biohybrid systems

    Science.gov (United States)

    Prescott, Tony J.; Lepora, Nathan; Vershure, Paul F. M. J.

    2014-03-01

    Research in the fields of biomimetic and biohybrid systems is developing at an accelerating rate. Biomimetics can be understood as the development of new technologies using principles abstracted from the study of biological systems, however, biomimetics can also be viewed from an alternate perspective as an important methodology for improving our understanding of the world we live in and of ourselves as biological organisms. A biohybrid entity comprises at least one artificial (engineered) component combined with a biological one. With technologies such as microscale mobile computing, prosthetics and implants, humankind is moving towards a more biohybrid future in which biomimetics helps us to engineer biocompatible technologies. This paper reviews recent progress in the development of biomimetic and biohybrid systems focusing particularly on technologies that emulate living organisms—living machines. Based on our recent bibliographic analysis [1] we examine how biomimetics is already creating life-like robots and identify some key unresolved challenges that constitute bottlenecks for the field. Drawing on our recent research in biomimetic mammalian robots, including humanoids, we review the future prospects for such machines and consider some of their likely impacts on society, including the existential risk of creating artifacts with significant autonomy that could come to match or exceed humankind in intelligence. We conclude that living machines are more likely to be a benefit than a threat but that we should also ensure that progress in biomimetics and biohybrid systems is made with broad societal consent.

  20. Biomimetics in materials science self-healing, self-lubricating, and self-cleaning materials

    CERN Document Server

    Nosonovsky, Michael

    2012-01-01

    Biomimetics in Materials Science provides a comprehensive theoretical and practical review of biomimetic materials with self-healing, self-lubricating and self-cleaning properties. These three topics are closely related and constitute rapidly developing areas of study. The field of self-healing materials requires a new conceptual understanding of this biomimetic technology, which is in contrast to traditional  engineering processes such as wear and fatigue.  Biomimetics in Materials Science is the first monograph to be devoted to these materials. A new theoretical framework for these processes is presented based on the concept of multi-scale structure of entropy and non-equilibrium thermodynamics, together with a detailed review of the available technology. The latter includes experimental, modeling, and simulation results obtained on self-healing/lubricating/cleaning materials since their emergence in the past decade. Describes smart, biomimetic materials in the context of nanotechnology, biotechnology, an...

  1. The preosteoblast response of electrospinning PLGA/PCL nanofibers: effects of biomimetic architecture and collagen I

    Directory of Open Access Journals (Sweden)

    Qian YZ

    2016-08-01

    Full Text Available Yunzhu Qian,1,2 Hanbang Chen,1 Yang Xu,1 Jianxin Yang,2 Xuefeng Zhou,3 Feimin Zhang,1 Ning Gu3 1Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 2Center of Stomatology, The Second Affiliated Hospital of Soochow University, Suzhou, 3School of Biological Science and Medical Engineering, Southeast University, Nanjing, People’s Republic of China Abstract: Constructing biomimetic structure and incorporating bioactive molecules is an effective strategy to achieve a more favorable cell response. To explore the effect of electrospinning (ES nanofibrous architecture and collagen I (COL I-incorporated modification on tuning osteoblast response, a resorbable membrane composed of poly(lactic-co-glycolic acid/poly(caprolactone (PLGA/PCL; 7:3 w/w was developed via ES. COL I was blended into PLGA/PCL solution to prepare composite ES membrane. Notably, relatively better cell response was delivered by the bioactive ES-based membrane which was fabricated by modification of 3,4-dihydroxyphenylalanine and COL I. After investigation by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, contact angle measurement, and mechanical test, polyporous three-dimensional nanofibrous structure with low tensile force and the successful integration of COL I was obtained by the ES method. Compared with traditional PLGA/PCL membrane, the surface hydrophilicity of collagen-incorporated membranes was largely enhanced. The behavior of mouse preosteoblast MC3T3-E1 cell infiltration and proliferation on membranes was studied at 24 and 48 hours. The negative control was fabricated by solvent casting. Evaluation of cell adhesion and morphology demonstrated that all the ES membranes were more favorable for promoting the cell adhesion and spreading than the casting membrane. Cell Counting Kit-8 assays revealed that biomimetic architecture, surface topography, and bioactive properties of membranes were favorable for cell

  2. Imprinting Technology in Electrochemical Biomimetic Sensors.

    Science.gov (United States)

    Frasco, Manuela F; Truta, Liliana A A N A; Sales, M Goreti F; Moreira, Felismina T C

    2017-03-06

    Biosensors are a promising tool offering the possibility of low cost and fast analytical screening in point-of-care diagnostics and for on-site detection in the field. Most biosensors in routine use ensure their selectivity/specificity by including natural receptors as biorecognition element. These materials are however too expensive and hard to obtain for every biochemical molecule of interest in environmental and clinical practice. Molecularly imprinted polymers have emerged through time as an alternative to natural antibodies in biosensors. In theory, these materials are stable and robust, presenting much higher capacity to resist to harsher conditions of pH, temperature, pressure or organic solvents. In addition, these synthetic materials are much cheaper than their natural counterparts while offering equivalent affinity and sensitivity in the molecular recognition of the target analyte. Imprinting technology and biosensors have met quite recently, relying mostly on electrochemical detection and enabling a direct reading of different analytes, while promoting significant advances in various fields of use. Thus, this review encompasses such developments and describes a general overview for building promising biomimetic materials as biorecognition elements in electrochemical sensors. It includes different molecular imprinting strategies such as the choice of polymer material, imprinting methodology and assembly on the transduction platform. Their interface with the most recent nanostructured supports acting as standard conductive materials within electrochemical biomimetic sensors is pointed out.

  3. Imprinting Technology in Electrochemical Biomimetic Sensors

    Directory of Open Access Journals (Sweden)

    Manuela F. Frasco

    2017-03-01

    Full Text Available Biosensors are a promising tool offering the possibility of low cost and fast analytical screening in point-of-care diagnostics and for on-site detection in the field. Most biosensors in routine use ensure their selectivity/specificity by including natural receptors as biorecognition element. These materials are however too expensive and hard to obtain for every biochemical molecule of interest in environmental and clinical practice. Molecularly imprinted polymers have emerged through time as an alternative to natural antibodies in biosensors. In theory, these materials are stable and robust, presenting much higher capacity to resist to harsher conditions of pH, temperature, pressure or organic solvents. In addition, these synthetic materials are much cheaper than their natural counterparts while offering equivalent affinity and sensitivity in the molecular recognition of the target analyte. Imprinting technology and biosensors have met quite recently, relying mostly on electrochemical detection and enabling a direct reading of different analytes, while promoting significant advances in various fields of use. Thus, this review encompasses such developments and describes a general overview for building promising biomimetic materials as biorecognition elements in electrochemical sensors. It includes different molecular imprinting strategies such as the choice of polymer material, imprinting methodology and assembly on the transduction platform. Their interface with the most recent nanostructured supports acting as standard conductive materials within electrochemical biomimetic sensors is pointed out.

  4. Biomimetic cilia arrays generate simultaneous pumping and mixing regimes.

    Science.gov (United States)

    Shields, A R; Fiser, B L; Evans, B A; Falvo, M R; Washburn, S; Superfine, R

    2010-09-07

    Living systems employ cilia to control and to sense the flow of fluids for many purposes, such as pumping, locomotion, feeding, and tissue morphogenesis. Beyond their use in biology, functional arrays of artificial cilia have been envisaged as a potential biomimetic strategy for inducing fluid flow and mixing in lab-on-a-chip devices. Here we report on fluid transport produced by magnetically actuated arrays of biomimetic cilia whose size approaches that of their biological counterparts, a scale at which advection and diffusion compete to determine mass transport. Our biomimetic cilia recreate the beat shape of embryonic nodal cilia, simultaneously generating two sharply segregated regimes of fluid flow: Above the cilia tips their motion causes directed, long-range fluid transport, whereas below the tips we show that the cilia beat generates an enhanced diffusivity capable of producing increased mixing rates. These two distinct types of flow occur simultaneously and are separated in space by less than 5 microm, approximately 20% of the biomimetic cilium length. While this suggests that our system may have applications as a versatile microfluidics device, we also focus on the biological implications of our findings. Our statistical analysis of particle transport identifying an enhanced diffusion regime provides novel evidence for the existence of mixing in ciliated systems, and we demonstrate that the directed transport regime is Poiseuille-Couette flow, the first analytical model consistent with biological measurements of fluid flow in the embryonic node.

  5. Tailored antireflective biomimetic nanostructures for UV applications

    Energy Technology Data Exchange (ETDEWEB)

    Morhard, Christoph; Pacholski, Claudia; Spatz, Joachim P [Department of New Materials and Biosystems, Max Planck Institute for Metals Research, Heisenbergstrasse 3, D-70569 Stuttgart (Germany); Lehr, Dennis; Brunner, Robert; Helgert, Michael [Carl Zeiss Jena GmbH, Technology Center, Carl-Zeiss-Promenade 10, D-07745 Jena (Germany); Sundermann, Michael, E-mail: Pacholski@mf.mpg.de [Carl Zeiss Jena GmbH, Technology Center, Carl-Zeiss-Strasse 56, D-73447 Oberkochen (Germany)

    2010-10-22

    Antireflective surfaces composed of biomimetic sub-wavelength structures that employ the 'moth eye principle' for reflectance reduction are highly desirable in many optical applications such as solar cells, photodetectors and laser optics. We report an efficient approach for the fabrication of antireflective surfaces based on a two-step process consisting of gold nanoparticle mask generation by micellar block copolymer nanolithography and a multi-step reactive ion etching process. Depending on the RIE process parameters nanostructured surfaces with tailored antireflective properties can easily be fabricated that show optimum performance for specific applications.

  6. Sustaining an Acquisition-based Growth Strategy

    DEFF Research Database (Denmark)

    Henningsson, Stefan; Toppenberg, Gustav; Shanks, Graeme

    complementarity, c) directing and governing the integration process, and d) post-acquisition evaluation of the achieved integration and proposing ways forward. Using the EA capability in the acquisition process improves Cisco’s ability to rapidly capture value from its acquisitions and to sustain its acquisition......-based growth strategy over time....

  7. Strategies for reward-based crowdfunding campaigns

    DEFF Research Database (Denmark)

    Kraus, Sascha; Richter, Christian; Brem, Alexander

    2016-01-01

    Crowdfunding represents an alternative way of funding entrepreneurial ventures – and is attracting a high amount of interest in research as well as practice. Against this back- ground, this paper analyzes reward-based crowdfunding campaign strategies and their communication tools. To do this, 446...... crowdfunding projects were gathered and empirically analyzed. Three different paths of successful crowdfunding projects could be identified and are described in detail. Practical implications of crowdfunding strategies are derived, and are dependent on the required sales effort and the project added value....... The terms communicator, networker and self-runner are created for this crowdfunding strategy and filled with practi- cal examples. This paper contributes to the literature in different ways: first, it sheds more light on the developing concept of crowdfunding, with an overview of current academic dis...

  8. Biomimetic wet-stable fibres via wet spinning and diacid-based crosslinking of collagen triple helices

    CERN Document Server

    Arafat, M Tarik; Yin, Jie; Wood, David J; Russell, Stephen J

    2015-01-01

    One of the limitations of electrospun collagen as bone-like fibrous structure is the potential collagen triple helix denaturation in the fibre state and the corresponding inadequate wet stability even after crosslinking. Here, we have demonstrated the feasibility of accomplishing wet-stable fibres by wet spinning and diacid-based crosslinking of collagen triple helices, whereby fibre ability to act as bone-mimicking mineralisation system has also been explored. Circular dichroism (CD) demonstrated nearly complete triple helix retention in resulting wet-spun fibres, and the corresponding chemically crosslinked fibres successfully preserved their fibrous morphology following 1-week incubation in phosphate buffer solution (PBS). The presented novel diacid-based crosslinking route imparted superior tensile modulus and strength to the resulting fibres indicating that covalent functionalization of distant collagen molecules is unlikely to be accomplished by current state-of-the-art carbodiimide-based crosslinking. ...

  9. Advances in biomimetic regeneration of elastic matrix structures.

    Science.gov (United States)

    Sivaraman, Balakrishnan; Bashur, Chris A; Ramamurthi, Anand

    2012-10-01

    Elastin is a vital component of the extracellular matrix, providing soft connective tissues with the property of elastic recoil following deformation and regulating the cellular response via biomechanical transduction to maintain tissue homeostasis. The limited ability of most adult cells to synthesize elastin precursors and assemble them into mature crosslinked structures has hindered the development of functional tissue-engineered constructs that exhibit the structure and biomechanics of normal native elastic tissues in the body. In diseased tissues, the chronic overexpression of proteolytic enzymes can cause significant matrix degradation, to further limit the accumulation and quality (e.g., fiber formation) of newly deposited elastic matrix. This review provides an overview of the role and importance of elastin and elastic matrix in soft tissues, the challenges to elastic matrix generation in vitro and to regenerative elastic matrix repair in vivo, current biomolecular strategies to enhance elastin deposition and matrix assembly, and the need to concurrently inhibit proteolytic matrix disruption for improving the quantity and quality of elastogenesis. The review further presents biomaterial-based options using scaffolds and nanocarriers for spatio-temporal control over the presentation and release of these biomolecules, to enable biomimetic assembly of clinically relevant native elastic matrix-like superstructures. Finally, this review provides an overview of recent advances and prospects for the application of these strategies to regenerating tissue-type specific elastic matrix structures and superstructures.

  10. Engineering Tough Materials: Biomimetic Eggshell

    Science.gov (United States)

    2016-08-29

    Engineering Tough Materials: Biomimetic Eggshell Final Report, 29 August 2016 Dr. Michelle L. Oyen, with PhD student H. Burak Caliskan and Research...Fellow Dr. David Labonte Cambridge University Engineering Dept., Trumpington Street, Cambridge CB2 1PZ, UK ~ Approved for public release; distribution

  11. Colorimetric biomimetic sensor systems based on molecularly imprinted polymer membranes for highly-selective detection of phenol in environmental samples

    Directory of Open Access Journals (Sweden)

    Sergeyeva T. A.

    2014-05-01

    Full Text Available Aim. Development of an easy-to-use colorimetric sensor system for fast and accurate detection of phenol in envi- ronmental samples. Methods. Technique of molecular imprinting, method of in situ polymerization of molecularly imprinted polymer membranes. Results. The proposed sensor is based on free-standing molecularly imprinted polymer (MIP membranes, synthesized by in situ polymerization, and having in their structure artificial binding sites capable of selective phenol recognition. The quantitative detection of phenol, selectively adsorbed by the MIP membranes, is based on its reaction with 4-aminoantipyrine, which gives a pink-colored product. The intensity of staining of the MIP membrane is proportional to phenol concentration in the analyzed sample. Phenol can be detected within the range 50 nM–10 mM with limit of detection 50 nM, which corresponds to the concentrations that have to be detected in natural and waste waters in accordance with environmental protection standards. Stability of the MIP-membrane-based sensors was assessed during 12 months storage at room temperature. Conclusions. The sensor system provides highly-selective and sensitive detection of phenol in both mo- del and real (drinking, natural, and waste water samples. As compared to traditional methods of phenol detection, the proposed system is characterized by simplicity of operation and can be used in non-laboratory conditions.

  12. Face recognition based on dyadic wavelet transform and biomimetic pattern recognition%基于二进小波变换和仿生模式识别的人脸识别

    Institute of Scientific and Technical Information of China (English)

    陈勇; 王宪保

    2013-01-01

      针对人脸图像易受光线和表情影响的特点,提出了一种基于二进小波变换和仿生模式识别的人脸识别方法。应用样条二进小波对人脸图像进行处理,对得到的细节子图进行融合。在FFT和PCA处理与降维后,用仿生模式识别进行学习和识别。实验结果表明,该方法比传统方法具有更高的识别率。%Aiming at robustness of face recognition under the condition of illumination perturbations and facial variety, a face recognition method based on dyadic wavelet transform and biomimetic pattern recognition is proposed in this paper. The spline dyadic wavelet is applied to face images. The detail subbands are merged by concatenation. The facial images are treated and reduced dimension respectively by FFT(Fast Fourier Transform)and PCA(Principal Component Analysis). The feature vectors are learned and recognized by biomimetic pattern recognition. The experimental results prove that the correct recognition rate of the method in this paper is higher than traditional recognition method.

  13. Preparation, anti-biofouling and drag-reduction properties of a biomimetic shark skin surface

    Directory of Open Access Journals (Sweden)

    Xia Pu

    2016-04-01

    Full Text Available Shark skin surfaces show non-smoothness characteristics due to the presence of a riblet structure. In this study, biomimetic shark skin was prepared by using the polydimethylsiloxane (PDMS-embedded elastomeric stamping (PEES method. Scanning electron microscopy (SEM was used to examine the surface microstructure and fine structure of shark skin and biomimetic shark skin. To analyse the hydrophobic mechanism of the shark skin surface microstructure, the effect of biomimetic shark skin surface microstructure on surface wettability was evaluated by recording water contact angle. Additionally, protein adhesion experiments and anti-algae adhesion performance testing experiments were used to investigate and evaluate the anti-biofouling properties of the surface microstructure of biomimetic shark skin. The recorded values of the water contact angle of differently microstructured surfaces revealed that specific microstructures have certain effects on surface wettability. The anti-biofouling properties of the biomimetic shark skin surface with microstructures were superior to a smooth surface using the same polymers as substrates. Moreover, the air layer fixed on the surface of the biomimetic shark skin was found to play a key role in their antibiont adhesion property. An experiment into drag reduction was also conducted. Based on the experimental results, the microstructured surface of the prepared biomimetic shark skin played a significant role in reducing drag. The maximum of drag reduction rate is 12.5%, which is higher than the corresponding maximum drag reduction rate of membrane material with a smooth surface.

  14. 3D Modelling of Biological Systems for Biomimetics

    Institute of Scientific and Technical Information of China (English)

    Shujun Zhang; Kevin Hapeshi; Ashok K. Bhattacharya

    2004-01-01

    With the advanced development of computer-based enabling technologies, many engineering, medical, biology,chemistry, physics and food science etc have developed to the unprecedented levels, which lead to many research and development interests in various multi-discipline areas. Among them, biomimetics is one of the most promising and attractive branches of study. Biomimetics is a branch of study that uses biological systems as a model to develop synthetic systems.To learn from nature, one of the fundamental issues is to understand the natural systems such animals, insects, plants and human beings etc. The geometrical characterization and representation of natural systems is an important fundamental work for biomimetics research. 3D modeling plays a key role in the geometrical characterization and representation, especially in computer graphical visualization. This paper firstly presents the typical procedure of 3D modelling methods and then reviews the previous work of 3D geometrical modelling techniques and systems developed for industrial, medical and animation applications. Especially the paper discusses the problems associated with the existing techniques and systems when they are applied to 3D modelling of biological systems. Based upon the discussions, the paper proposes some areas of research interests in 3D modelling of biological systems and for Biomimetics.

  15. Strategy-based listening and pragmatic comprehension

    Directory of Open Access Journals (Sweden)

    Corsetti, Cristiane Ruzicki

    2014-01-01

    Full Text Available This article addresses the role of strategy-based listening as an alternative methodological approach to develop pragmatic comprehension in L2 contexts. Pragmatic comprehension refers to the understanding of speech acts and conversational implicatures. Listening comprehension comprises both bottom-up and top-down processes. Strategy-based listening encompasses the activation of pragmatic knowledge through pre-listening activities and the development of specific listening micro-skills. An empirical project which included a classroom project carried out with a group of eight learners preparing for the IELTS examination in 2009 corroborated the following assumptions: in order to achieve listening proficiency, learners need practice in making inferences as semantic and pragmatic inferences are embedded in verbal communication; semantic and pragmatic aspects affecting the meaning of utterances can be highlighted via comprehension activities focusing on specific listening subskills. The results of the classroom project suggested that strategy-based listening is potentially capable of directly enhancing pragmatic comprehension but were inconclusive with regards to pragmatic production

  16. A model for μ-biomimetic thermal infrared sensors based on the infrared receptors of Melanophila acuminata.

    Science.gov (United States)

    Siebke, Georg; Holik, Peter; Schmitz, Sam; Schmitz, Helmut; Lacher, Manfred; Steltenkamp, Siegfried

    2014-09-01

    Beetles of the genus Melanophila acuminata detect forest fires from distances as far as 130 km with infrared-sensing organs. Inspired by this extremely sensitive biological device, we are developing an IR sensor that operates at ambient temperature using MEMS technology. The sensor consists of two liquid-filled chambers that are connected by a micro-fluidic system. Absorption of IR radiation by one of these chambers leads to heating and expansion of a liquid. The increasing pressure deflects a membrane covered by one electrode of a plate capacitor. The micro-fluidic system and the second chamber represent a fluidic low-pass filter, preventing slow, but large pressure changes. However, the strong frequency dependence of the filter demands a precise characterization of its properties. Here, we present a theoretical model that describes the frequency-dependent response of the sensor based on material properties and geometrical dimensions. Our model is divided into four distinct parts that address different aspects of the sensor. The model describes the frequency-dependent behaviour of the fluidic filter and a thermal low-pass filter as well as saturation effects at low frequencies. This model allows the calculation of optimal design parameters, and thereby provides the foundation for the development of such a sensor.

  17. Biomimetic membranes and methods of making biomimetic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Rempe, Susan; Brinker, Jeffrey C.; Rogers, David Michael; Jiang, Ying-Bing; Yang, Shaorong

    2016-11-08

    The present disclosure is directed to biomimetic membranes and methods of manufacturing such membranes that include structural features that mimic the structures of cellular membrane channels and produce membrane designs capable of high selectivity and high permeability or adsorptivity. The membrane structure, material and chemistry can be selected to perform liquid separations, gas separation and capture, ion transport and adsorption for a variety of applications.

  18. Additive Manufacturing of Biomedical Constructs with Biomimetic Structural Organizations

    Directory of Open Access Journals (Sweden)

    Xiao Li

    2016-11-01

    Full Text Available Additive manufacturing (AM, sometimes called three-dimensional (3D printing, has attracted a lot of research interest and is presenting unprecedented opportunities in biomedical fields, because this technology enables the fabrication of biomedical constructs with great freedom and in high precision. An important strategy in AM of biomedical constructs is to mimic the structural organizations of natural biological organisms. This can be done by directly depositing cells and biomaterials, depositing biomaterial structures before seeding cells, or fabricating molds before casting biomaterials and cells. This review organizes the research advances of AM-based biomimetic biomedical constructs into three major directions: 3D constructs that mimic tubular and branched networks of vasculatures; 3D constructs that contains gradient interfaces between different tissues; and 3D constructs that have different cells positioned to create multicellular systems. Other recent advances are also highlighted, regarding the applications of AM for organs-on-chips, AM-based micro/nanostructures, and functional nanomaterials. Under this theme, multiple aspects of AM including imaging/characterization, material selection, design, and printing techniques are discussed. The outlook at the end of this review points out several possible research directions for the future.

  19. Biological and Biomimetic Comb Polyelectrolytes

    Directory of Open Access Journals (Sweden)

    Aristeidis Papagiannopoulos

    2010-05-01

    Full Text Available Some new phenomena involved in the physical properties of comb polyelectrolyte solutions are reviewed. Special emphasis is given to synthetic biomimetic materials, and the structures formed by these molecules are compared with those of naturally occurring glycoprotein and proteoglycan solutions. Developments in the determination of the structure and dynamics (viscoelasticity of comb polymers in solution are also covered. Specifically the appearance of multi-globular structures, helical instabilities, liquid crystalline phases, and the self-assembly of the materials to produce hierarchical comb morphologies is examined. Comb polyelectrolytes are surface active and a short review is made of some recent experiments in this area that relate to their morphology when suspended in solution. We hope to emphasize the wide variety of phenomena demonstrated by the vast range of naturally occurring comb polyelectrolytes and the challenges presented to synthetic chemists designing biomimetic materials.

  20. Therapeutic Strategies Based on Polymeric Microparticles

    Directory of Open Access Journals (Sweden)

    C. Vilos

    2012-01-01

    Full Text Available The development of the field of materials science, the ability to perform multidisciplinary scientific work, and the need for novel administration technologies that maximize therapeutic effects and minimize adverse reactions to readily available drugs have led to the development of delivery systems based on microencapsulation, which has taken one step closer to the target of personalized medicine. Drug delivery systems based on polymeric microparticles are generating a strong impact on preclinical and clinical drug development and have reached a broad development in different fields supporting a critical role in the near future of medical practice. This paper presents the foundations of polymeric microparticles based on their formulation, mechanisms of drug release and some of their innovative therapeutic strategies to board multiple diseases.

  1. A low-cost, high-yield fabrication method for producing optimized biomimetic dry adhesives

    Science.gov (United States)

    Sameoto, D.; Menon, C.

    2009-11-01

    We present a low-cost, large-scale method of fabricating biomimetic dry adhesives. This process is useful because it uses all photosensitive polymers with minimum fabrication costs or complexity to produce molds for silicone-based dry adhesives. A thick-film lift-off process is used to define molds using AZ 9260 photoresist, with a slow acting, deep UV sensitive material, PMGI, used as both an adhesion promoter for the AZ 9260 photoresist and as an undercutting material to produce mushroom-shaped fibers. The benefits to this process are ease of fabrication, wide range of potential layer thicknesses, no special surface treatment requirements to demold silicone adhesives and easy stripping of the full mold if process failure does occur. Sylgard® 184 silicone is used to cast full sheets of biomimetic dry adhesives off 4" diameter wafers, and different fiber geometries are tested for normal adhesion properties. Additionally, failure modes of the adhesive during fabrication are noted and strategies for avoiding these failures are discussed. We use this fabrication method to produce different fiber geometries with varying cap diameters and test them for normal adhesion strengths. The results indicate that the cap diameters relative to post diameters for mushroom-shaped fibers dominate the adhesion properties.

  2. Base-of-the-pyramid global strategy

    Directory of Open Access Journals (Sweden)

    Boşcor, D.

    2010-12-01

    Full Text Available Global strategies for MNCs should focus on customers in emerging and developing markets instead of customers in developed economies. The “base-of-the-pyramid segment” comprises 4 billion people in the world. In order to be successful, companies will be required to form unconventional partnerships- with entities ranging from local governments to non-profit organizations - to gain the community’s trust and understand the environmental, infrastructure and political issues that may affect business. Being able to provide affordable, high-quality products and services in this market segment often means new approaches to marketing- new packaging and pricing structures, and using unfamiliar distribution structures.

  3. Engineering Tough Materials: Biomimetic Eggshell

    Science.gov (United States)

    2015-01-30

    at 300 oC indicates the intra-crystalline protein degradation conditions. Figure 4.6, shows the TGA analysis of pure calcite crystals that were...synthesized using the same parameters with that of BSA-entrapped calcites. Comparison of TGA analysis of eggshell crystals and biomimetic synthesis of BSA...powder and analysed using TGA under the same experimental conditions. The result of the TGA analysis of eggshell powder is shown in Figure 4.6. Similar

  4. Biomimetic design processes in architecture: morphogenetic and evolutionary computational design.

    Science.gov (United States)

    Menges, Achim

    2012-03-01

    Design computation has profound impact on architectural design methods. This paper explains how computational design enables the development of biomimetic design processes specific to architecture, and how they need to be significantly different from established biomimetic processes in engineering disciplines. The paper first explains the fundamental difference between computer-aided and computational design in architecture, as the understanding of this distinction is of critical importance for the research presented. Thereafter, the conceptual relation and possible transfer of principles from natural morphogenesis to design computation are introduced and the related developments of generative, feature-based, constraint-based, process-based and feedback-based computational design methods are presented. This morphogenetic design research is then related to exploratory evolutionary computation, followed by the presentation of two case studies focusing on the exemplary development of spatial envelope morphologies and urban block morphologies.

  5. New software rejuvenation strategy based on measurement and time

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Operational software systems often experience an "aging" phenomenon, characterized by progressive performance degradation and a sudden hang/crash failure. Software rejuvenation is a proactive fault-tolerance strategy aimed to prevent unexpected outages due to aging. A new rejuvenation strategy based on measurement and time, and constructs a SRN model to evaluate this strategy. Numerical results show that this strategy outweighs either the purely measurementbased or the purely time-based strategy and can effectively improve system performance.

  6. Biomimetic Microelectronics for Regenerative Neuronal Cuff Implants.

    Science.gov (United States)

    Karnaushenko, Daniil; Münzenrieder, Niko; Karnaushenko, Dmitriy D; Koch, Britta; Meyer, Anne K; Baunack, Stefan; Petti, Luisa; Tröster, Gerhard; Makarov, Denys; Schmidt, Oliver G

    2015-11-18

    Smart biomimetics, a unique class of devices combining the mechanical adaptivity of soft actuators with the imperceptibility of microelectronics, is introduced. Due to their inherent ability to self-assemble, biomimetic microelectronics can firmly yet gently attach to an inorganic or biological tissue enabling enclosure of, for example, nervous fibers, or guide the growth of neuronal cells during regeneration.

  7. Bottom-Up Synthesis and Sensor Applications of Biomimetic Nanostructures

    Directory of Open Access Journals (Sweden)

    Li Wang

    2016-01-01

    Full Text Available The combination of nanotechnology, biology, and bioengineering greatly improved the developments of nanomaterials with unique functions and properties. Biomolecules as the nanoscale building blocks play very important roles for the final formation of functional nanostructures. Many kinds of novel nanostructures have been created by using the bioinspired self-assembly and subsequent binding with various nanoparticles. In this review, we summarized the studies on the fabrications and sensor applications of biomimetic nanostructures. The strategies for creating different bottom-up nanostructures by using biomolecules like DNA, protein, peptide, and virus, as well as microorganisms like bacteria and plant leaf are introduced. In addition, the potential applications of the synthesized biomimetic nanostructures for colorimetry, fluorescence, surface plasmon resonance, surface-enhanced Raman scattering, electrical resistance, electrochemistry, and quartz crystal microbalance sensors are presented. This review will promote the understanding of relationships between biomolecules/microorganisms and functional nanomaterials in one way, and in another way it will guide the design and synthesis of biomimetic nanomaterials with unique properties in the future.

  8. Iris Localization Based on Edge Searching Strategies

    Institute of Scientific and Technical Information of China (English)

    Wang Yong; Han Jiuqiang

    2005-01-01

    An iris localization scheme based on edge searching strategies is presented. First, the edge detection operator Laplacian-ofGaussian (LoG) is used to iris original image to search its inner boundary. Then, a circle detection operator is introduced to locate the outer boundary and its center, which is invariant of translation, rotation and scale. Finally, the method of curve fitting is developed in localization of eyelid. The performance of the proposed method is tested with 756 iris images from 108 different classes in CASIA Iris Database and compared with the conventional Hough transform method. The experimental results show that without loss of localization accuracy, the proposed iris localization algorithm is apparently faster than Hough transform.

  9. Motion Control Algorithms for a Free-swimming Biomimetic Robot Fish%仿生机器鱼运动控制算法研究

    Institute of Scientific and Technical Information of China (English)

    喻俊志; 陈尔奎; 王硕; 谭民

    2005-01-01

    A practical motion control strategy for a radio-controlled, 4-link and free-swimming biomimetic robot fish is presented. Based on control performance of the fish the fish's motion control task is decomposed into on-line speed control and orientation control. The speed control algorithm is implemented by using piecewise control, and orientation control is realized by fuzzy logic. Combining with step control and fuzzy control, a point-to-point (PTP) control algorithm is proposed and applied to the closed-loop experimental system that uses a vision-based position sensing subsystem to provide feedback. Experiments confirm the reliability and effectiveness of the presented algorithms.

  10. Biomimetic microchannels of planar reactors for optimized photocatalytic efficiency of water purification

    Science.gov (United States)

    Liao, Wuxia; Wang, Ning; Wang, Taisheng; Xu, Jia; Han, Xudong; Liu, Zhenyu; Yu, Weixing

    2016-01-01

    This paper reports a biomimetic design of microchannels in the planar reactors with the aim to optimize the photocatalytic efficiency of water purification. Inspired from biology, a bifurcated microchannel has been designed based on the Murray's law to connect to the reaction chamber for photocatalytic reaction. The microchannels are designed to have a constant depth of 50 μm but variable aspect ratios ranging from 0.015 to 0.125. To prove its effectiveness for photocatalytic water purification, the biomimetic planar reactors have been tested and compared with the non-biomimetic ones, showing an improvement of the degradation efficiency by 68%. By employing the finite element method, the flow process of the designed microchannel reactors has been simulated and analyzed. It is found that the biomimetic design owns a larger flow velocity fluctuation than that of the non-biomimetic one, which in turn results in a faster photocatalytic reaction speed. Such a biomimetic design paves the way for the design of more efficient planar reactors and may also find applications in other microfluidic systems that involve the use of microchannels. PMID:26958102

  11. Biomimetic oral mucin from polymer micelle networks

    Science.gov (United States)

    Authimoolam, Sundar Prasanth

    Mucin networks are formed by the complexation of bottlebrush-like mucin glycoprotein with other small molecule glycoproteins. These glycoproteins create nanoscale strands that then arrange into a nanoporous mesh. These networks play an important role in ensuring surface hydration, lubricity and barrier protection. In order to understand the functional behavior in mucin networks, it is important to decouple their chemical and physical effects responsible for generating the fundamental property-function relationship. To achieve this goal, we propose to develop a synthetic biomimetic mucin using a layer-by-layer (LBL) deposition approach. In this work, a hierarchical 3-dimensional structures resembling natural mucin networks was generated using affinity-based interactions on synthetic and biological surfaces. Unlike conventional polyelectrolyte-based LBL methods, pre-assembled biotin-functionalized filamentous (worm-like) micelles was utilized as the network building block, which from complementary additions of streptavidin generated synthetic networks of desired thickness. The biomimetic nature in those synthetic networks are studied by evaluating its structural and bio-functional properties. Structurally, synthetic networks formed a nanoporous mesh. The networks demonstrated excellent surface hydration property and were able capable of microbial capture. Those functional properties are akin to that of natural mucin networks. Further, the role of synthetic mucin as a drug delivery vehicle, capable of providing localized and tunable release was demonstrated. By incorporating antibacterial curcumin drug loading within synthetic networks, bacterial growth inhibition was also demonstrated. Thus, such bioactive interfaces can serve as a model for independently characterizing mucin network properties and through its role as a drug carrier vehicle it presents exciting future opportunities for localized drug delivery, in regenerative applications and as bio

  12. Biomimetic Crawling Motion of Soft and Slender Gel-worm

    Institute of Scientific and Technical Information of China (English)

    Song Miao LIANG; Jian XU; Li Na ZHANG

    2006-01-01

    Inspired by the locomotion of terrestrial limbless animals, the present work attempt to study the motion of biomimetic system based on poly(vinyl alcohol)/dimethylsulfoxide gel. The system was operated in air by employing a non-contacted DC electric field. The results showed that the gel exhibited a long-range snail-like motion and had a very fast response rate.

  13. Monterey Strategy Seminar: Day 1: Capabilities Based Planning.

    OpenAIRE

    Russell, James A; Pulsipher, Lashley; Zellen, Barry; Lavoy, Peter R.; Clary, Christopher

    2004-01-01

    Monterey Strategy Seminar: Day 1: Capabilities Based Planning. Day 2: Dissuasion in the U.S. Defense Strategy. Day 3: Global Strike Warfare Naval Postgraduate School Center for Contemporary Conflict (CCC)

  14. Biomimetic artificial sphincter muscles: status and challenges

    Science.gov (United States)

    Leung, Vanessa; Fattorini, Elisa; Karapetkova, Maria; Osmani, Bekim; Töpper, Tino; Weiss, Florian; Müller, Bert

    2016-04-01

    Fecal incontinence is the involuntary loss of bowel content and affects more than 12% of the adult population, including 45% of retirement home residents. Severe fecal incontinence is often treated by implanting an artificial sphincter. Currently available implants, however, have long-term reoperation rates of 95% and definitive explantation rates of 40%. These statistics show that the implants fail to reproduce the capabilities of the natural sphincter and that the development of an adaptive, biologically inspired implant is required. Dielectric elastomer actuators (DEA) are being developed as artificial muscles for a biomimetic sphincter, due to their suitable response time, reaction forces, and energy consumption. However, at present the operation voltage of DEAs is too high for artificial muscles implanted in the human body. To reduce the operating voltage to tens of volts, we are using microfabrication to reduce the thickness of the elastomer layer to the nanometer level. Two microfabrication methods are being investigated: molecular beam deposition and electrospray deposition. This communication covers the current status and a perspective on the way forward, including the long-term prospects of constructing a smart sphincter from low-voltage sensors and actuators based on nanometer-thin dielectric elastomer films. As DEA can also provide sensory feedback, a biomimetic sphincter can be designed in accordance with the geometrical and mechanical parameters of its natural counterpart. The availability of such technology will enable fast pressure adaption comparable to the natural feedback mechanism, so that tissue atrophy and erosion can be avoided while maintaining continence du ring daily activities.

  15. Performance-based inspection and maintenance strategies

    Energy Technology Data Exchange (ETDEWEB)

    Vesely, W.E.

    1995-04-01

    Performance-based inspection and maintenance strategies utilize measures of equipment performance to help guide inspection and maintenance activities. A relevant measure of performance for safety system components is component unavailability. The component unavailability can also be input into a plant risk model such as a Probabilistic Risk Assessment (PRA) to determine the associated plant risk performance. Based on the present and projected unavailability performance, or the present and projected risk performance, the effectiveness of current maintenance activities can be evaluated and this information can be used to plan future maintenance activities. A significant amount of information other than downtimes or failure times is collected or can be collected when an inspection or maintenance is conducted which can be used to estimate the component unavailability. This information generally involves observations on the condition or state of the component or component piecepart. The information can be detailed such as the amount of corrosion buildup or can be general such as the general state of the component described as {open_quotes}high degradation{close_quotes}, {open_quotes}moderate degradation{close_quotes}, or {open_quotes}low degradation{close_quotes}. Much of the information collected in maintenance logs is qualitative and fuzzy. As part of an NRC Research program on performance-based engineering modeling, approaches have been developed to apply Fuzzy Set Theory to information collected on the state of the component to determine the implied component or component piecepart unavailability. Demonstrations of the applications of Fuzzy Set Theory are presented utilizing information from plant maintenance logs. The demonstrations show the power of Fuzzy Set Theory in translating engineering information to reliability and risk implications.

  16. Challenges in Commercializing Biomimetic Membranes

    Directory of Open Access Journals (Sweden)

    Mark Perry

    2015-11-01

    Full Text Available The discovery of selective water channel proteins—aquaporins—has prompted growing interest in using these proteins, as the building blocks for designing new types of membranes. However, as with any other new and potentially disruptive technology, barriers for successful market entry exist. One category includes customer-related barriers, which can be influenced to some extent. Another category includes market-technical-related barriers, which can be very difficult to overcome by an organization/company aiming at successfully introducing their innovation on the market—in particular if both the organization and the technology are at early stages. Often, one faces barriers from both these categories at the same time, which makes it necessary to gain insight of the particular market when introducing a new innovative product. In this review we present the basic concepts and discuss some of these barriers and challenges associated with introducing biomimetic aquaporin membranes. These include technical issues in membrane production and product testing. Then we discuss possible business models for introducing new technologies in general, followed by a presentation of beach-head market segments relevant for biomimetic aquaporin membranes.

  17. Biomimetics for next generation materials.

    Science.gov (United States)

    Barthelat, Francois

    2007-12-15

    Billions of years of evolution have produced extremely efficient natural materials, which are increasingly becoming a source of inspiration for engineers. Biomimetics-the science of imitating nature-is a growing multidisciplinary field which is now leading to the fabrication of novel materials with remarkable mechanical properties. This article discusses the mechanics of hard biological materials, and more specifically of nacre and bone. These high-performance natural composites are made up of relatively weak components (brittle minerals and soft proteins) arranged in intricate ways to achieve specific combinations of stiffness, strength and toughness (resistance to cracking). Determining which features control the performance of these materials is the first step in biomimetics. These 'key features' can then be implemented into artificial bio-inspired synthetic materials, using innovative techniques such as layer-by-layer assembly or ice-templated crystallization. The most promising approaches, however, are self-assembly and biomineralization because they will enable tight control of structures at the nanoscale. In this 'bottom-up' fabrication, also inspired from nature, molecular structures and crystals are assembled with a little or no external intervention. The resulting materials will offer new combinations of low weight, stiffness and toughness, with added functionalities such as self-healing. Only tight collaborations between engineers, chemists, materials scientists and biologists will make these 'next-generation' materials a reality.

  18. Researches and developments of biomimetics in tribology

    Institute of Scientific and Technical Information of China (English)

    DAI Zhendong; TONG Jin; REN Luquan

    2006-01-01

    Animals and plants have developed optimal geometric structures, smart topological materials and multi-functional surface textures with excellent tribological characteristics through the evolution of thousand millions of years and become models for tribological design. This paper puts forward the definition and fundament of biomimetic tribology, investigates the status of self-cleaning of liquid-solid interface, adhesion between animals' feet and solid surface, wear characteristics of biological surfaces and biomimetic design, as well as the friction and bionic design on liquid-solid interface. The further developments of the tribological biomimetics are discussed.

  19. Biomimetic, Catalytic Oxidation in Organic Synthesis

    Institute of Scientific and Technical Information of China (English)

    Shun-lchi Murahashi

    2005-01-01

    @@ 1Introduction Oxidation is one of the most fundamental reactions in organic synthesis. Owing to the current need to develop forward-looking technology that is environmentally acceptable with respect many aspects. The most attractive approaches are biomimetic oxidation reactions that are closely related to the metabolism of living things. The metabolisms are governed by a variety of enzymes such as cytochrome P-450 and flavoenzyme.Simulation of the function of these enzymes with simple transition metal complex catalyst or organic catalysts led to the discovery of biomimetic, catalytic oxidations with peroxides[1]. We extended such biomimetic methods to the oxidation with molecular oxygen under mild conditions.

  20. Food Security Strategy Based on Computer Innovation

    Directory of Open Access Journals (Sweden)

    Ruihui Mu

    2015-04-01

    Full Text Available Case analysis to identify innovative strategies for food security occurred in the Oriental Hotel, voluntarily implement food safety control. Food security strategy investigation and the reasons for their use of multiple data sources, including accommodation and catering industry to implement and document interviews with key decision makers in the hotel performed to observe the business environment were examined. This finding suggests that addressing food security, not only is the food control strategy, when the issue of marketing and business strategy is very important. The results of this study also demonstrated the relationship between reward and food security strategies. Interview analysis showed that the attitude of senior management in the hotel's food security policy, the company's ability to significantly dependent on the corporate image.

  1. Development of biomimetic catalytic oxidation methods and non-salt methods using transition metal-based acid and base ambiphilic catalysts.

    Science.gov (United States)

    Murahashi, Shun-Ichi

    2011-01-01

    This review focuses on the development of ruthenium and flavin catalysts for environmentally benign oxidation reactions based on mimicking the functions of cytochrome P-450 and flavoenzymes, and low valent transition-metal catalysts that replace conventional acids and bases. Several new concepts and new types of catalytic reactions based on these concepts are described. (Communicated by Ryoji Noyori, M.J.A.).

  2. A new titanium based alloy Ti-27Nb-13Zr produced by powder metallurgy with biomimetic coating for use as a biomaterial.

    Science.gov (United States)

    Mendes, Marcio W D; Ágreda, Carola G; Bressiani, Ana H A; Bressiani, José C

    2016-06-01

    Titanium alloys are widely used in biomedical applications due to their excellent properties such as high strength, good corrosion resistance and biocompatibility. Titanium alloys with alloying elements such as Nb and Zr are biocompatible and have Young's modulus close to that of human bone. To increase the bioactivity of titanium alloy surfaces is used chemical treatment with NaOH followed by immersion in simulated body fluid (SBF). The purpose of this study was to produce the alloy Ti-27Nb-13Zr with low Young's modulus by powder metallurgy using powders produced by the HDH process. The formation of biomimetic coatings on samples immersed in SBF for 3, 7, 11 and 15 days was evaluated. Characterization of the coating was performed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and scanning electron microscope. The microstructure and composition of the alloy were determined using SEM and XRD, while the mechanical properties were evaluated by determining the elastic modulus and the Vickers microhardness. The sintered alloys were composed of α and β phases, equiaxed grains and with density around 97.8% of its theoretical density. The Vickers microhardness and elasticity modulus of the alloy were determined and their values indicate that this alloy can be used as a biomaterial. Analysis of the coating revealed the presence of calcium phosphate layers on samples immersed for >3 days in the SBF solution.

  3. Study on Equipment Selective Maintenance Strategy Based on Performance

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, an equipment selective maintenance strategy based on performance is brought forward according to the situation in China, in which reliability, computer technology,condition monitoring and management theory is applied. The theory points of the strategy are put forward. The maintenance strategy has been applied in.mine hoist system.

  4. Linear Strategy for Boolean Ring Based Theorem Proving

    Institute of Scientific and Technical Information of China (English)

    WU Jinzhao; LIU Zhuojun

    2000-01-01

    Two inference rules are discussed in boolean ring based theorem proving, and linear strategy is developed. It is shown that both of them are complete for linear strategy. Moreover, by introducing a partial ordering on atoms, pseudo O-linear and O-linear strategies are presented. The former is complete, the latter, however, is complete for clausal theorem proving.

  5. A multi-electrode biomimetic electrolocation sensor

    Science.gov (United States)

    Mayekar, K.; Damalla, D.; Gottwald, M.; Bousack, H.; von der Emde, G.

    2012-04-01

    We present the concept of an active multi-electrode catheter inspired by the electroreceptive system of the weakly electric fish, Gnathonemus petersii. The skin of this fish exhibits numerous electroreceptor organs which are capable of sensing a self induced electrical field. Our sensor is composed of a sending electrode and sixteen receiving electrodes. The electrical field produced by the sending electrode was measured by the receiving electrodes and objects were detected by the perturbation of the electrical field they induce. The intended application of such a sensor is in coronary diagnostics, in particular in distinguishing various types of plaques, which are major causes of heart attack. For calibration of the sensor system, finite element modeling (FEM) was performed. To validate the model, experimental measurements were carried out with two different systems. The physical system was glass tubing with metal and plastic wall insertions as targets. For the control of the experiment and for data acquisition, the software LabView designed for 17 electrodes was used. Different parameters of the electric images were analyzed for the prediction of the electrical properties and size of the inserted targets in the tube. Comparisons of the voltage modulations predicted from the FEM model and the experiments showed a good correspondence. It can be concluded that this novel biomimetic method can be further developed for detailed investigations of atherosclerotic lesions. Finally, we discuss various design strategies to optimize the output of the sensor using different simulated models to enhance target recognition.

  6. Molecular motor assembly of a biomimetic system

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.

  7. Biomimetic design method for innovation and sustainability

    CERN Document Server

    Helfman Cohen, Yael

    2017-01-01

    Presenting a novel biomimetic design method for transferring design solutions from nature to technology, this book focuses on structure-function patterns in nature and advanced modeling tools derived from TRIZ, the theory of inventive problem-solving. The book includes an extensive literature review on biomimicry as an engine of both innovation and sustainability, and discusses in detail the biomimetic design process, current biomimetic design methods and tools. The structural biomimetic design method for innovation and sustainability put forward in this text encompasses (1) the research method and rationale used to develop and validate this new design method; (2) the suggested design algorithm and tools including the Findstructure database, structure-function patterns and ideality patterns; and (3) analyses of four case studies describing how to use the proposed method. This book offers an essential resource for designers who wish to use nature as a source of inspiration and knowledge, innovators and sustain...

  8. Development of a Molecularly Imprinted Biomimetic Electrode

    Directory of Open Access Journals (Sweden)

    Evangelyn C. Alocilja

    2007-08-01

    Full Text Available The technique of molecular imprinting produces artificial receptor sites in apolymer that can be used in a biomimetic sensor. This research extends previous studies ofa molecularly imprinted polymer (MIP biomimetic sensor for the small drug theophylline.The presence of theophylline in the biomimetic sensor was monitored by analyzing thepeak currents from cyclic voltammetry experiments. The functional working range of theMIP modified electrode was 2 - 4 mM theophylline. The concentration of theophyllinethat resulted in the best signal was 3 mM. The MIP sensor showed no response to thestructurally related molecule caffeine, and therefore was selective to the target analytetheophylline. This research will provide the foundation for future studies that will result indurable biomimetic sensors that can offer a viable alternative to current sensors.

  9. The Catalog Management Strategy of Distributed Data Base Systems

    Institute of Scientific and Technical Information of China (English)

    周龙骧; 秦箕英

    1994-01-01

    In this paper the catalog management strategy of the successfully integrating and running DDBMS C-POREL is summarized.The new catalog management strategy and its implementation scheme are based on the analysis of the catalog management methods of the pioneer DDBMS.The goal of the new strategy is to improve the system efficiency.Analysis and practice show that this strategy is successful.

  10. Food Security Strategy Based on Computer Innovation

    OpenAIRE

    Ruihui Mu

    2015-01-01

    Case analysis to identify innovative strategies for food security occurred in the Oriental Hotel, voluntarily implement food safety control. Food security strategy investigation and the reasons for their use of multiple data sources, including accommodation and catering industry to implement and document interviews with key decision makers in the hotel performed to observe the business environment were examined. This finding suggests that addressing food security, not only is the food control...

  11. Biomimetic mechanism for micro aircraft

    Science.gov (United States)

    Pines, Darryll J. (Inventor); Bohorquez, Felipe A. (Inventor); Sirohi, Jayant (Inventor)

    2005-01-01

    A biomimetic pitching and flapping mechanism including a support member, at least two blade joints for holding blades and operatively connected to the support member. An outer shaft member is concentric with the support member, and an inner shaft member is concentric with the outer shaft member. The mechanism allows the blades of a small-scale rotor to be actuated in the flap and pitch degrees of freedom. The pitching and the flapping are completely independent from and uncoupled to each other. As such, the rotor can independently flap, or independently pitch, or flap and pitch simultaneously with different amplitudes and/or frequencies. The mechanism can also be used in a non-rotary wing configuration, such as an ornithopter, in which case the rotational degree of freedom would be suppressed.

  12. Biomimetic use of genetic algorithms

    CERN Document Server

    Dessalles, Jean-Louis

    2011-01-01

    Genetic algorithms are considered as an original way to solve problems, probably because of their generality and of their "blind" nature. But GAs are also unusual since the features of many implementations (among all that could be thought of) are principally led by the biological metaphor, while efficiency measurements intervene only afterwards. We propose here to examine the relevance of these biomimetic aspects, by pointing out some fundamental similarities and divergences between GAs and the genome of living beings shaped by natural selection. One of the main differences comes from the fact that GAs rely principally on the so-called implicit parallelism, while giving to the mutation/selection mechanism the second role. Such differences could suggest new ways of employing GAs on complex problems, using complex codings and starting from nearly homogeneous populations.

  13. Biomimetic and Bioinspired Synthesis of Nanomaterials/Nanostructures.

    Science.gov (United States)

    Zan, Guangtao; Wu, Qingsheng

    2016-03-16

    In recent years, due to its unparalleled advantages, the biomimetic and bioinspired synthesis of nanomaterials/nanostructures has drawn increasing interest and attention. Generally, biomimetic synthesis can be conducted either by mimicking the functions of natural materials/structures or by mimicking the biological processes that organisms employ to produce substances or materials. Biomimetic synthesis is therefore divided here into "functional biomimetic synthesis" and "process biomimetic synthesis". Process biomimetic synthesis is the focus of this review. First, the above two terms are defined and their relationship is discussed. Next different levels of biological processes that can be used for process biomimetic synthesis are compiled. Then the current progress of process biomimetic synthesis is systematically summarized and reviewed from the following five perspectives: i) elementary biomimetic system via biomass templates, ii) high-level biomimetic system via soft/hard-combined films, iii) intelligent biomimetic systems via liquid membranes, iv) living-organism biomimetic systems, and v) macromolecular bioinspired systems. Moreover, for these five biomimetic systems, the synthesis procedures, basic principles, and relationships are discussed, and the challenges that are encountered and directions for further development are considered.

  14. EXPORT STRATEGY BASED ON MARKET RESEARCH

    Directory of Open Access Journals (Sweden)

    Octavian-Liviu OLARU

    2014-05-01

    Full Text Available A strategy is a general plan aimed to develop a business. Even export firm that wants to develop and prosper needs some form of strategy. A company's strategic fit with the trading environment has to be continuously reconsidered because it is likely to erode. Managers should be well informed in order to develop their judgment and understanding of the driving forces that shape the business environment. The greatest mistakes are made by exporters who think they know a foreign market as well as they know their local one, only to find after an ill-fated export launch, that they do not.

  15. 基于局部相位量化与仿生模式的伪装人脸识别算法%Disguised Face Recognition Algorithm Based On Local Phase Quantization and Biomimetic Pattern

    Institute of Scientific and Technical Information of China (English)

    翟懿奎; 甘俊英; 徐颖

    2012-01-01

    Disguised face recognition (FR) is considered as one of the difficult and important problems in FR field. Rather than disguised modeling, a disguised face recognition algorithm based on local phase quantization (LPQ) feature and biomimetic pattern recognition (BPR) theory is presented in this paper. The LPQ method is applied to extract the phase statistics feature which is robust to the disguised mode and the biomimetic hyper sausage neuron is adopted to construct high dimensional geometry coverage of different classes, which makes full use of continuous characteristics of different class face features while avoids the interruption of the disguised mode. Experiments on the AR database and the disguised face recognition database established by police face combination software show that, compared with the state-of-the-art method, the proposed recognition algorithm can achieve high recognition rate under disguised conditions.%伪装条件下的鲁棒人脸识别,目前在人脸识别领域被日益重视,并认为是难点问题之一.本文采用非伪装建模方法,提出了一种基于局部相位量化特征提取与仿生模式识别理论的伪装人脸识别算法.该算法采用了局部相位量化方法进行对伪装模式下具有较好鲁棒性的相位统计特征提取,进而采用仿生神经元构建高维几何覆盖形体,有效利用了不同类别人脸特征的连续性,从而避免了伪装模式的干扰.在AR数据库及采用警用面部复合软件设计建立的伪装数据库上的仿真实验均表明,与现有主流算法相比较而言,本文所提识别算法在伪装条件下取得了较高的识别性能.

  16. 激光直写法制备仿刚毛微纳阵列的研究%Fabrication of Hierarchical Bio-mimetic Gecko Hair Arrays Based on Laser Direct Writing

    Institute of Scientific and Technical Information of China (English)

    耿路峰; 于敏; 浦东林; 陈林森; 戴振东

    2011-01-01

    Inspired by gecko attachment system, a new method was proposed to fabricate hierarchical bio-mimetic gecko hair arrays by adopting laser direct writing. The fabrication process was controlled on computer. Single-layer pillars of different radial dimensions and axial dimension were fabricated. Based on the laser direct writing, three fabricating schemes of hierarchical structure were developed. Among them,top-down method made the second level structure buried in the structure of the first level by the regulation and control of the exposure time and development time, which effectively improve the connection strength between two arrays. Relationships of exposure depth and exposure time, development depth and development time were also established. This method of fabricating bio-mimetic ecko hair arrays has advantages of low cost and quantity production.%提出一种采用激光直写技术制备微纳阵列的新方法来制备仿壁虎刚毛二级结构微阵列。该制备过程由计算机控制完成。实验制备出具有不同几何尺寸的一级结构阵列,并在此基础上探索制备二级结构微阵列的三种方案,其中,“自上而下”的方案通过对曝光时间和显影时间的控制使第二级结构扎根于第一级结构中,有效提高了两级结构间的连接强度。制备实验的同时,分析了曝光时间、显影时间等参数对阵列制备的影响。激光直写制备微纳阵列的方法具有高效率、低成本的优点。

  17. Blind Equalization Based on Evolution Strategies

    Institute of Scientific and Technical Information of China (English)

    SongYu; ZhangXianda; 等

    1997-01-01

    Conventional blind equalization algorithms suffer from ill convergence to local minima and slow convergence speed.This paper proposes a novel blind equalization algorithm.using random search methods-evolution strategies and existing cost functions,Simulation results verify the fast and global convergence of the proposed algorithm.

  18. Sound-Based Strategy Training in Multiplication

    Science.gov (United States)

    Askeland, Margit

    2012-01-01

    The main purpose of the present study was to examine the long-term effects of a previous quasi-experiment that used inner speech as a tool to promote appropriate strategies in multiplication. Results one year after the intervention were published by Ostad and Askeland. This is a follow-up study. The 50-week intervention program was conducted in…

  19. Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration.

    Science.gov (United States)

    Green, David W; Lee, Jung-Seok; Jung, Han-Sung

    2016-01-01

    The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a "water-tight" barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachment complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia, and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organizing cell-cell connections, cell-matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption, and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis.

  20. Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration

    Directory of Open Access Journals (Sweden)

    David William Green

    2016-02-01

    Full Text Available The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a water-tight barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachement complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement.. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organising cell-cell connections, cell-matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis.

  1. Oriented and Ordered Biomimetic Remineralization of the Surface of Demineralized Dental Enamel Using HAP@ACP Nanoparticles Guided by Glycine

    Science.gov (United States)

    Wang, Haorong; Xiao, Zuohui; Yang, Jie; Lu, Danyang; Kishen, Anil; Li, Yanqiu; Chen, Zhen; Que, Kehua; Zhang, Qian; Deng, Xuliang; Yang, Xiaoping; Cai, Qing; Chen, Ning; Cong, Changhong; Guan, Binbin; Li, Ting; Zhang, Xu

    2017-01-01

    Achieving oriented and ordered remineralization on the surface of demineralized dental enamel, thereby restoring the satisfactory mechanical properties approaching those of sound enamel, is still a challenge for dentists. To mimic the natural biomineralization approach for enamel remineralization, the biological process of enamel development proteins, such as amelogenin, was simulated in this study. In this work, carboxymethyl chitosan (CMC) conjugated with alendronate (ALN) was applied to stabilize amorphous calcium phosphate (ACP) to form CMC/ACP nanoparticles. Sodium hypochlorite (NaClO) functioned as the protease which decompose amelogenin in vivo to degrade the CMC-ALN matrix and generate HAP@ACP core-shell nanoparticles. Finally, when guided by 10 mM glycine (Gly), HAP@ACP nanoparticles can arrange orderly and subsequently transform from an amorphous phase to well-ordered rod-like apatite crystals to achieve oriented and ordered biomimetic remineralization on acid-etched enamel surfaces. This biomimetic remineralization process is achieved through the oriented attachment (OA) of nanoparticles based on non-classical crystallization theory. These results indicate that finding and developing analogues of natural proteins such as amelogenin involved in the biomineralization by natural macromolecular polymers and imitating the process of biomineralization would be an effective strategy for enamel remineralization. Furthermore, this method represents a promising method for the management of early caries in minimal invasive dentistry (MID).

  2. Oriented and Ordered Biomimetic Remineralization of the Surface of Demineralized Dental Enamel Using HAP@ACP Nanoparticles Guided by Glycine

    Science.gov (United States)

    Wang, Haorong; Xiao, Zuohui; Yang, Jie; Lu, Danyang; Kishen, Anil; Li, Yanqiu; Chen, Zhen; Que, Kehua; Zhang, Qian; Deng, Xuliang; Yang, Xiaoping; Cai, Qing; Chen, Ning; Cong, Changhong; Guan, Binbin; Li, Ting; Zhang, Xu

    2017-01-01

    Achieving oriented and ordered remineralization on the surface of demineralized dental enamel, thereby restoring the satisfactory mechanical properties approaching those of sound enamel, is still a challenge for dentists. To mimic the natural biomineralization approach for enamel remineralization, the biological process of enamel development proteins, such as amelogenin, was simulated in this study. In this work, carboxymethyl chitosan (CMC) conjugated with alendronate (ALN) was applied to stabilize amorphous calcium phosphate (ACP) to form CMC/ACP nanoparticles. Sodium hypochlorite (NaClO) functioned as the protease which decompose amelogenin in vivo to degrade the CMC-ALN matrix and generate HAP@ACP core-shell nanoparticles. Finally, when guided by 10 mM glycine (Gly), HAP@ACP nanoparticles can arrange orderly and subsequently transform from an amorphous phase to well-ordered rod-like apatite crystals to achieve oriented and ordered biomimetic remineralization on acid-etched enamel surfaces. This biomimetic remineralization process is achieved through the oriented attachment (OA) of nanoparticles based on non-classical crystallization theory. These results indicate that finding and developing analogues of natural proteins such as amelogenin involved in the biomineralization by natural macromolecular polymers and imitating the process of biomineralization would be an effective strategy for enamel remineralization. Furthermore, this method represents a promising method for the management of early caries in minimal invasive dentistry (MID). PMID:28079165

  3. STRATEGI PEMBELAJARAN DENGAN FOCUSED BASED EDUCATION

    OpenAIRE

    2006-01-01

    Tujuan penulisan ini untuk memberikan masukan bagi penyelenggara program studi keteknikan atau program vokasi dan okupasi agar keluaran yang di hasilkan cepat memperoleh pekerjaan sesuai bidangnya. Pendekatan yang diusulkan adalah strategi pembelajaran yang terfokus, mendasar dan mendalam. Manfaat yang ingin di capai adalah keluaran yang dihasilkan siap pakai, siap kerja dan siap latih, artinya setiap lulusan yang di hasilkan lembaga pendidikan dapat terserap dan mampu diterima di pasar ker...

  4. An Immunization Strategy Based on Propagation Mechanism

    Directory of Open Access Journals (Sweden)

    Yixin Zhu

    2014-01-01

    Full Text Available With the ubiquity of smart phones, wearable equipment, and wireless sensors, the topologies of networks composed by them change along with time. The immunization strategies in which network immune nodes are chosen by analyzing the static aggregation network topologies have been challenged. The studies about interaction propagations between two pathogens show that the interaction can change propagation threshold and the final epidemic size of each other, which provides a new thinking of immunization method. The eradication or inhibition of the virus can be achieved through the spread of its opposite party. Here, we put forward an immunization strategy whose implementation does not depend on the analysis of network topology. The immunization agents are randomly placed on a few of individuals of network and spread out from these individuals on network in a propagation method. The immunization agents prevent virus infecting their habitat nodes with certain immune success rate. The analysis and simulation of evolution equation of the model show that immune propagation has a significant impact on the spread threshold and steady-state density of virus on a finite size of BA networks. Simulations on some real-world networks also suggest that the immunization strategy is feasible and effective.

  5. Affordance Learning Based on Subtask's Optimal Strategy

    Directory of Open Access Journals (Sweden)

    Huaqing Min

    2015-08-01

    Full Text Available Affordances define the relationships between the robot and environment, in terms of actions that the robot is able to perform. Prior work is mainly about predicting the possibility of a reactive action, and the object's affordance is invariable. However, in the domain of dynamic programming, a robot’s task could often be decomposed into several subtasks, and each subtask could limit the search space. As a result, the robot only needs to replan its sub strategy when an unexpected situation happens, and an object’s affordance might change over time depending on the robot’s state and current subtask. In this paper, we propose a novel affordance model linking the subtask, object, robot state and optimal action. An affordance represents the first action of the optimal strategy under the current subtask when detecting an object, and its influence is promoted from a primitive action to the subtask strategy. Furthermore, hierarchical reinforcement learning and state abstraction mechanism are introduced to learn the task graph and reduce state space. In the navigation experiment, the robot equipped with a camera could learn the objects’ crucial characteristics, and gain their affordances in different subtasks.

  6. Biomimetic catalysts responsive to specific chemical signals

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yan [Iowa State Univ., Ames, IA (United States)

    2015-03-04

    Part 1. Design of Biomimetic Catalysts Based on Amphiphilic Systems The overall objective of our research is to create biomimetic catalysts from amphiphilic molecules. More specifically, we aim to create supramolecular systems that can be used to control the microenvironment around a catalytic center in a biomimetic fashion and apply the learning to construct supramolecular catalysts with novel functions found in enzymatic catalysts. We have prepared synthetic molecules (i.e., foldamers) that could fold into helical structures with nanometer-sized internal hydrophilic cavities. Cavities of this size are typically observed only in the tertiary and quaternary structures of proteins but were formed in our foldamer prepared in just a few steps from the monomer. Similar to many proteins, our foldamers displayed cooperativity in the folding/unfolding equilibrium and followed a two-state conformational transition. In addition, their conformational change could be triggered by solvent polarity, pH, or presence of metal ions and certain organic molecules. We studied their environmentally dependent conformational changes in solutions, surfactant micelles, and lipid bilayer membranes. Unlike conventional rigid supramolecular host, a foldamer undergoes conformational change during guest binding. Our study in the molecular recognition of an oligocholate host yielded some extremely exciting results. Cooperativity between host conformation and host–guest interactions was found to “magnify” weak binding interactions. In other words, since binding affinity is determined by the overall change of free energy during the binding, guest-induced conformational change of the host, whether near or far from the binding site, affects the binding. This study has strong implications in catalysis because enzymes have been hypothesized to harvest similar intramolecular forces to strengthen their binding with the transition state of an enzyme-catalyzed reaction. The supramolecular and

  7. Sensing in nature: using biomimetics for design of sensors

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Cheong, Hyunmin; Shu, Li

    2010-01-01

    The paper illustrates how biomimetics can be applied in sensor design. Biomimetics is an engineering discipline that uses nature as an inspiration source for generating ideas for how to solve engineering problems. Using biomimetics involves a search for relevant cases, a proper analysis...

  8. STRATEGI PEMBELAJARAN DENGAN FOCUSED BASED EDUCATION

    Directory of Open Access Journals (Sweden)

    Suranto Suranto

    2006-04-01

    Full Text Available Tujuan penulisan ini untuk memberikan masukan bagi penyelenggara program studi keteknikan atau program vokasi dan okupasi agar keluaran yang di hasilkan cepat memperoleh pekerjaan sesuai bidangnya. Pendekatan yang diusulkan adalah strategi pembelajaran yang terfokus, mendasar dan mendalam. Manfaat yang ingin di capai adalah keluaran yang dihasilkan siap pakai, siap kerja dan siap latih, artinya setiap lulusan yang di hasilkan lembaga pendidikan dapat terserap dan mampu diterima di pasar kerja, serta mampu mengaktualisasikan dirinya sendiri menjadi kreator dan inovator. Pendidikan siap pakai tersebut harus di bekali materi enterpreneur dan penggalian potensi diri dengan perpaduan pendidikan vokasi yang di dasari kurikulum berbasis life skill. Link and match yang didengungkan selama ini tidak optimal, maka istilah ini diganti dengan we serve the real world. Hal ini berdasarkan analisis bahwa pendidikan vokasi yang siap kerja ke depan mempunyai ciri penguasaan terhadap teknologi, mampu mengedepankan life skiil, berkreasi, berinovasi, menghasilkan produk nyata, keluaran yang siap kerja, mampu berwira usaha, dominasi praktek, bekerja sama dengan dunia industri, untuk meraih cita-cita tersebut dibutuhkan asesmen strategi pembelajaran yang tepat.

  9. Beyond products: services-based strategy.

    Science.gov (United States)

    Quinn, J B; Doorley, T L; Paquette, P C

    1990-01-01

    Services technologies are changing the way companies in every industry--manufacturers and service providers alike--compete. Vertical integration, physical facilities, even a seemingly superior product can no longer assure a competitive edge. Instead, sustainable advantage is more and more likely to come from developing superior capabilities in a few core service skills--and out-sourcing as much of the rest as possible. Within companies, technology is increasing the leverage of service activities: today, more value added comes from design innovations, product image, or other attributes that services create than from the production process. New technologies also let independent enterprises provide world-class services at lower costs than customers could achieve if they performed the activities themselves. These changes have far-reaching implications for how managers structure their organizations and define strategic focus. Companies like Apple, Honda, and Merck show that a less integrated but more focused organization is key to competitive success. They build their strategies around a few highly developed capabilities. And they outsource as many of the other activities in their value chain as possible. To help managers develop an activity-focused strategy, the authors offer a new way to approach competitive analyses, guidelines for determining which activities to outsource and which to retain, and an overview of the risks and rewards of strategic outsourcing. Throughout, they draw on the findings of their three-year study of the major impacts technology has had in the service sector.

  10. Web-Based Learning: Cognitive Styles and Instructional Strategies

    Science.gov (United States)

    Alomyan, Hesham Raji

    2016-01-01

    This paper reports a study, which investigated whether different instructional strategies might interact with individual's cognitive style in learning. A web-based learning package was designed employing three strategies, Interactive Concept Maps, Illustration with Embedded Text and Text-Only. Group Embedded Figure Test was administered to 178…

  11. The Resource-Based Horizontal Acquisition Strategy of JBS

    OpenAIRE

    Ronald Jean Degen

    2012-01-01

    This paper examines the resource-based horizontal acquisition strategy of JBS. This strategy transformed a relatively small business that was founded in 1953 (comprising a butcher shop and small abattoir located in a small town in the interior of Brazil) into the world?s biggest meat producer by 2010.

  12. Toward a Common Understanding of Research-Based Instructional Strategies

    Science.gov (United States)

    Goodwin, Deborah; Webb, Mary Ann

    2014-01-01

    A review of available books, articles and on-line resources which deal with "Research-Based Instructional Strategies" will produce a plethora of materials which promote the effectiveness of these strategies on student achievement. Also, a perusal of classroom instruction and teacher evaluation instruments will reveal that many of the…

  13. Positive versus Negative Communication Strategies in Task-Based Learning

    Science.gov (United States)

    Rohani, Siti

    2013-01-01

    This study aimed at describing how the implementation of Task-Based Learning (TBL) would shape or change students' use of oral communication strategies. Students' problems and strategies to solve the problems during the implementation of TBL were also explored. The study was a mixed method, employing both quantitative and qualitative analysis…

  14. Optimization of Equipment Maintenance Strategy Based on Availability

    Institute of Scientific and Technical Information of China (English)

    张友诚

    2001-01-01

    It is very important to optimize maintenance strategy in maintenance plan. Proper parameters play a decisive role for the optimization. In the opinion of writer, availability is a basic parameter, failure consequence cost and failure characteristic are also important parameters. Maintenance strategy can be optimized on the base by means of quantitative analysis and diagram.

  15. Biomimetic optical sensor for aerospace applications

    Science.gov (United States)

    Frost, Susan A.; Gorospe, George E.; Wright, Cameron H. G.; Barrett, Steven F.

    2015-05-01

    We report on a fiber optic sensor based on the physiological aspects of the eye and vision-related neural layers of the common housefly (Musca domestica) that has been developed and built for aerospace applications. The intent of the research is to reproduce select features from the fly's vision system that are desirable in image processing, including high functionality in low-light and low-contrast environments, sensitivity to motion, compact size, lightweight, and low power and computation requirements. The fly uses a combination of overlapping photoreceptor responses that are well approximated by Gaussian distributions and neural superposition to detect image features, such as object motion, to a much higher degree than just the photoreceptor density would imply. The Gaussian overlap in the biomimetic sensor comes from the front-end optical design, and the neural superposition is accomplished by subsequently combining the signals using analog electronics. The fly eye sensor is being developed to perform real-time tracking of a target on a flexible aircraft wing experiencing bending and torsion loads during flight. We report on results of laboratory experiments using the fly eye sensor to sense a target moving across its field of view.

  16. Mineralization of Zein Films by Biomimetic Process

    Institute of Scientific and Technical Information of China (English)

    JIN; Xiaoning; ZHANG; Yanxiang; MA; Ying; ZENG; Sheng; WANG; Shaozhen; MA; Yalu

    2015-01-01

    The transparent or opaque zein film was prepared by a phase separation method with a zein ethanol aqueous solution.The circular zein film was self-assembled on the air-water interface.According to the images by scanning electron microscopy,the upper surface of film is flat and smooth and the downward surface presents a complex reticulation structure of corn protein fiber.Zein film as a biomimetic mineralization template is used to synthesize calcium phosphate crystals by a bioinspired mineralization process.Randomly oriented apatite crystals appear on the both surfaces of zein film after immersion in lOxsimulated body fluid,and the phase composition and morphology of the deposited calcium apatite are also distinguished from deposited location and immersion time.The phase transformation process from dicalcium phosphate dihydrate into hydroxyapatite(HAp) phase was investigated by X-ray powder diffraction,transmission electron microscopy and Fourier transform infrared spectroscopy,respectively.Based on the results by energy dispersive X-ray spectroscopy,the Ca/P ratio of the deposited apatite increases with the transformation from DCPD to HAp.The HAp/Zein films possess the excellent biodegradable structural features,and the coating of HAp crystallites has some potential applications for bone repair and regeneration.

  17. Mineralization of Zein Films by Biomimetic Process

    Institute of Scientific and Technical Information of China (English)

    JIN Xiaoning; ZHANG Yanxiang; MA Ying; ZENG Sheng; WANG Shaozhen; MA Yalu

    2015-01-01

    The transparent or opaque zein film was prepared by a phase separation method with a zein ethanol aqueous solution. The circular zein film was self-assembled on the air-water interface. According to the images by scanning elec-tron microscopy, the upper surface of film is flat and smooth and the downward surface presents a complex reticulation structure of corn protein fiber. Zein film as a biomimetic mineralization template is used to synthesize calcium phosphate crystals by a bioinspired mineralization process. Randomly oriented apatite crystals appear on the both surfaces of zein film after immersion in 10´simulated body fluid, and the phase composition and morphology of the deposited calcium apatite are also distinguished from deposited location and immersion time. The phase transformation process from dical-cium phosphate dihydrate into hydroxyapatite (HAp) phase was investigated by X-ray powder diffraction, transmission electron microscopy and Fourier transform infrared spectroscopy, respectively. Based on the results by energy dispersive X-ray spectroscopy, the Ca/P ratio of the deposited apatite increases with the transformation from DCPD to HAp. The HAp/Zein films possess the excellent biodegradable structural features, and the coating of HAp crystallites has some potential applications for bone repair and regeneration.

  18. Characterization of antiseptic apatite powders prepared at biomimetics temperature and pH

    Directory of Open Access Journals (Sweden)

    Soumia Belouafa

    2008-03-01

    Full Text Available Antiseptic apatite-based calcium phosphates were prepared as the single-phase powders. Phosphocalcic oxygenated apatites were synthesized from calcium salts and orthophosphate dissolved in oxygenated water solution at 30%, under the biomimetic conditions of 37 °C and pH 7.4. The characterization and chemical analysis of the synthesized biomimetic apatite powders were performed by scanning electron microscopy (SEM, powder X ray diffraction (XRD, Fourier-transformed infrared spectroscopy (FT-IR and chemical analysis. The obtained materials are a calcium deficient apatites with different morphologies.

  19. Biomimetics, color, and the arts

    Science.gov (United States)

    Schenk, Franziska

    2015-03-01

    Color as dramatic, dynamic and dazzling as the iridescent hues on the wings of certain butterflies has never been encountered in the art world. Unlike and unmatched by the chemical pigments of the artists' palette, this changeable color is created by transparent, colorless nanostructures that, as with prisms, diffract and reflect light to render spectral color visible. Until now, iridescent colors, by their very nature, have defied artists' best efforts to fully capture these rainbow hues. Now, for the first time, the artist and researcher Franziska Schenk employs latest nature-inspired color-shift technology to actually simulate the iridescence of butterflies and beetles on canvas. Crucially, studying the ingenious ways in which a range of such displays are created by insects has provided the artist with vital clues on how to adapt and adopt these challenging optical nano-materials for painting. And indeed, after years of meticulous and painstaking research both in the lab and studio, the desired effect is achieved. The resulting paintings, like an iridescent insect, do in fact fluctuate in perceived color - depending on the light and viewing angle. In tracing the artist's respective biomimetic approach, the paper not only provides an insight into the new color technology's evolution and innovative artistic possibilities, but also suggests what artists can learn from nature.

  20. Evolutionary Algorithm Based on Immune Strategy

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; JIAO Licheng

    2001-01-01

    A novel evolutionary algorithm,evolution-immunity strategies(EIS), is proposed with reference to the immune theory in biology, which constructs an immune operator accomplished by two steps, a vaccination and an immune selection. The aim of introducing the immune concepts and methods into ES is for finding the ways and means obtaining the optimal solution of difficult problems with locally characteristic information. The detail processes of realizing EIS are presented which contain 6 steps. EIS is analyzed with Markovian theory and it is approved to be convergent with probability 1. In EIS, an immune operator is an aggregation of specific operations and procedures, and methods of selecting vaccines and constructing an immune operator are given in this paper. It is shown with an example of the 442-city TSP that the EIS can restrain the degenerate phenomenon during the evolutionary process by simulated calculating result, improve the searching capability and efficiency, and therefore, increase the convergent speed greatly.

  1. Special section on biomimetics of movement.

    Science.gov (United States)

    Carpi, Federico; Erb, Rainer; Jeronimidis, George

    2011-12-01

    Movement in biology is an essential aspect of survival for many organisms, animals and plants. Implementing movement efficiently to meet specific needs is a key attribute of natural living systems, and can provide ideas for man-made developments. If we had to find a subtitle able to essentially convey the aim of this special section, it could read as follows: 'taking inspiration from nature for new materials, actuators, structures and controls for systems that move'. Our world is characterized by a huge variety of technical, engineering systems that move. They surround us in countless products that integrate actuators for different kinds of purposes. Basically, any kind of mechatronic system, such as those used for consumer products, machines, vehicles, industrial systems, robots, etc, is based on one or more devices that move, according to different implementations and motion ranges, often in response to external and internal stimuli. Despite this, technical solutions to develop systems that move do not evolve very quickly as they rely on traditional and well consolidated actuation technologies, which are implemented according to known architectures and with established materials. This fact limits our capability to overcome challenges related to the needs continuously raised by new fields of application, either at small or at large scales. Biomimetics-based approaches may provide innovative thinking and technologies in the field, taking inspiration from nature for smart and effective solutions. In an effort to disseminate current advances in this field, this special section collects some papers that cover different topics. A brief synopsis of the content of each contribution is presented below. The first paper, by Lienhard et al [1], deals with bioinspiration for the realization of structural parts in systems that passively move. It presents a bioinspired hingeless flapping mechanism, considered as a solution to the kinematics of deployable systems for

  2. A multi-channel biomimetic neuroprosthesis to support treadmill gait training in stroke patients.

    Science.gov (United States)

    Chia, Noelia; Ambrosini, Emilia; Baccinelli, Walter; Nardone, Antonio; Monticone, Marco; Ferrigno, Giancarlo; Pedrocchi, Alessandra; Ferrante, Simona

    2015-01-01

    This study presents an innovative multi-channel neuroprosthesis that induces a biomimetic activation of the main lower-limb muscles during treadmill gait training to be used in the rehabilitation of stroke patients. The electrostimulation strategy replicates the physiological muscle synergies used by healthy subjects to walk on a treadmill at their self-selected speed. This strategy is mapped to the current gait sub-phases, which are identified in real time by a custom algorithm. This algorithm divides the gait cycle into six sub-phases, based on two inertial sensors placed laterally on the shanks. Therefore, the pre-defined stimulation profiles are expanded or stretched based on the actual gait pattern of each single subject. A preliminary experimental protocol, involving 10 healthy volunteers, was carried out to extract the muscle synergies and validate the gait-detection algorithm, which were afterwards used in the development of the neuroprosthesis. The feasibility of the neuroprosthesis was tested on one healthy subject who simulated different gait patterns, and a chronic stroke patient. The results showed the correct functioning of the system. A pilot study of the neurorehabilitation treatment for stroke patients is currently being carried out.

  3. Biomimetic Receptors for Bioanalyte Detection by Quartz Crystal Microbalances — From Molecules to Cells

    Directory of Open Access Journals (Sweden)

    Usman Latif

    2014-12-01

    Full Text Available A universal label-free detection of bioanalytes can be performed with biomimetic quartz crystal microbalance (QCM coatings prepared by imprinting strategies. Bulk imprinting was used to detect the endocrine disrupting chemicals (EDCs known as estradiols. The estrogen 17β-estradiol is one of the most potent EDCs, even at very low concentrations. A highly sensitive, selective and robust QCM sensor was fabricated for real time monitoring of 17β-estradiol in water samples by using molecular imprinted polyurethane. Optimization of porogen (pyrene and cross-linker (phloroglucinol levels leads to improved sensitivity, selectivity and response time of the estradiol sensor. Surface imprinting of polyurethane as sensor coating also allowed us to generate interaction sites for the selective recognition of bacteria, even in a very complex mixture of interfering compounds, while they were growing from their spores in nutrient solution. A double molecular imprinting approach was followed to transfer the geometrical features of natural bacteria onto the synthetic polymer to generate biomimetic bacteria. The use of biomimetic bacteria as template makes it possible to prepare multiple sensor coatings with similar sensitivity and selectivity. Thus, cell typing, e.g., differentiation of bacteria strains, bacteria growth profile and extent of their nutrition, can be monitored by biomimetic mass sensors. Obviously, this leads to controlled cell growth in bioreactors.

  4. 3-D Locomotion control for a biomimetic robot fish

    Institute of Scientific and Technical Information of China (English)

    Zhigang ZHANG; Shuo WANG; Min TAN

    2004-01-01

    This paper concerns with 3-D locomotion control methods for a biomimetic robot fish. The system architecture of the fish is firstly presented based on a physical model of carangiform fish. The robot fish has a flexible body, a rigid caudal fin and a pair of pectoral fins, driven by several servomotors. The motion control of the robot fish are then divided into speed control, orientation control, submerge control and transient motion control, corresponding algorithms are detailed respectively.Finally, experiments and analyses on a 4-1ink, radio-controlled robot fish prototype with 3-D locomotion show its good performance.

  5. Automated sampling and data processing derived from biomimetic membranes

    DEFF Research Database (Denmark)

    Perry, Mark; Vissing, Thomas; Boesen, P.;

    2009-01-01

    Recent advances in biomimetic membrane systems have resulted in an increase in membrane lifetimes from hours to days and months. Long-lived membrane systems demand the development of both new automated monitoring equipment capable of measuring electrophysiological membrane characteristics and new...... data processing software to analyze and organize the large amounts of data generated. In this work, we developed an automated instrumental voltage clamp solution based on a custom-designed software controller application (the WaveManager), which enables automated on-line voltage clamp data acquisition...

  6. Strategies for searching and managing evidence-based practice resources.

    Science.gov (United States)

    Robb, Meigan; Shellenbarger, Teresa

    2014-10-01

    Evidence-based nursing practice requires the use of effective search strategies to locate relevant resources to guide practice change. Continuing education and staff development professionals can assist nurses to conduct effective literature searches. This article provides suggestions for strategies to aid in identifying search terms. Strategies also are recommended for refining searches by using controlled vocabulary, truncation, Boolean operators, PICOT (Population/Patient Problem, Intervention, Comparison, Outcome, Time) searching, and search limits. Suggestions for methods of managing resources also are identified. Using these approaches will assist in more effective literature searches and may help evidence-based practice decisions.

  7. Minimally invasive restorative dentistry: a biomimetic approach.

    Science.gov (United States)

    Malterud, Mark I

    2006-08-01

    When providing dental treatment for a given patient, the practitioner should use a minimally invasive technique that conserves sound tooth structure as a clinical imperative. Biomimetics is a tenet that guides the author's practice and is generally described as the mimicking of natural life. This can be accomplished in many cases using contemporary composite resins and adhesive dental procedures. Both provide clinical benefits and support the biomimetic philosophy for treatment. This article illustrates a minimally invasive approach for the restoration of carious cervical defects created by poor hygiene exacerbated by the presence of orthodontic brackets.

  8. Tissue bionics: examples in biomimetic tissue engineering.

    Science.gov (United States)

    Green, David W

    2008-09-01

    Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed 'tissue bionics'. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic.

  9. Degree-based attacks and defense strategies in complex networks

    Science.gov (United States)

    Yehezkel, Aviv; Cohen, Reuven

    2012-12-01

    We study the stability of random scale-free networks to degree-dependent attacks. We present analytical and numerical results to compute the critical fraction pc of nodes that need to be removed for destroying the network under this attack for different attack parameters. We study the effect of different defense strategies, based on the addition of a constant number of links on network robustness. We test defense strategies based on adding links to either low degree, middegree or high degree nodes. We find using analytical results and simulations that the middegree nodes defense strategy leads to the largest improvement to the network robustness against degree-based attacks. We also test these defense strategies on an internet autonomous systems map and obtain similar results.

  10. NCLEX-RN success: evidence-based strategies.

    Science.gov (United States)

    Thomas, Marie H; Baker, Susan Scott

    2011-01-01

    Evidence-based nursing requires that students think reflectively and use clinical inquiry to develop clinical reasoning and decision-making skills. Likewise, nursing students need a strategy to be successful in passing the NCLEX-RN. The authors identify strategies based on nursing research to facilitate student success. While learning the evidence-based nursing process, the student must begin to think like a nurse while answering clinical practice questions. Using the skills taught for evidence-based nursing can be a powerful tool to approach the NCLEX-RN and succeed.

  11. Cell-Based Strategies for Meniscus Tissue Engineering

    Science.gov (United States)

    Niu, Wei; Guo, Weimin; Han, Shufeng; Zhu, Yun; Liu, Shuyun; Guo, Quanyi

    2016-01-01

    Meniscus injuries remain a significant challenge due to the poor healing potential of the inner avascular zone. Following a series of studies and clinical trials, tissue engineering is considered a promising prospect for meniscus repair and regeneration. As one of the key factors in tissue engineering, cells are believed to be highly beneficial in generating bionic meniscus structures to replace injured ones in patients. Therefore, cell-based strategies for meniscus tissue engineering play a fundamental role in meniscal regeneration. According to current studies, the main cell-based strategies for meniscus tissue engineering are single cell type strategies; cell coculture strategies also were applied to meniscus tissue engineering. Likewise, on the one side, the zonal recapitulation strategies based on mimicking meniscal differing cells and internal architectures have received wide attentions. On the other side, cell self-assembling strategies without any scaffolds may be a better way to build a bionic meniscus. In this review, we primarily discuss cell seeds for meniscus tissue engineering and their application strategies. We also discuss recent advances and achievements in meniscus repair experiments that further improve our understanding of meniscus tissue engineering. PMID:27274735

  12. Cell-Based Strategies for Meniscus Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Wei Niu

    2016-01-01

    Full Text Available Meniscus injuries remain a significant challenge due to the poor healing potential of the inner avascular zone. Following a series of studies and clinical trials, tissue engineering is considered a promising prospect for meniscus repair and regeneration. As one of the key factors in tissue engineering, cells are believed to be highly beneficial in generating bionic meniscus structures to replace injured ones in patients. Therefore, cell-based strategies for meniscus tissue engineering play a fundamental role in meniscal regeneration. According to current studies, the main cell-based strategies for meniscus tissue engineering are single cell type strategies; cell coculture strategies also were applied to meniscus tissue engineering. Likewise, on the one side, the zonal recapitulation strategies based on mimicking meniscal differing cells and internal architectures have received wide attentions. On the other side, cell self-assembling strategies without any scaffolds may be a better way to build a bionic meniscus. In this review, we primarily discuss cell seeds for meniscus tissue engineering and their application strategies. We also discuss recent advances and achievements in meniscus repair experiments that further improve our understanding of meniscus tissue engineering.

  13. Design and fabrication of a biomimetic gyroscope inspired by the fly's haltere

    NARCIS (Netherlands)

    Droogendijk, H.; Brookhuis, R.A.; Boer, de M.J.; Sanders, R.G.P.; Krijnen, G.J.M.

    2012-01-01

    We report on the design and fabrication of a MEMS-based gyroscopic system inspired by the fly's haltere system. Two types of so-called biomimetic gyroscopes have been designed, fabricated and their drive mode has been characterized. First measurements indicate excitable gyropscopes with natural freq

  14. Design and fabrication of a biomimetic gyroscope inspired by the fly’s haltere

    NARCIS (Netherlands)

    Droogendijk, H.; Brookhuis, R.A.; Boer, de M.J.; Sanders, R.G.P.; Krijnen, G.J.M.

    2013-01-01

    We report on the design and fabrication of a MEMS-based gyroscopic system inspired by the fly’s haltere system. Two types of so-called biomimetic gyroscopes have been designed, fabricated and partially characterized. First measurements indicate excitable gyropscopes with natural frequencies in the o

  15. Towards a biomimetic gyroscope inspired by the fly's haltere using microelectromechanical systems technology

    NARCIS (Netherlands)

    Droogendijk, H.; Brookhuis, R.A.; Boer, de M.J.; Sanders, R.G.P.; Krijnen, G.J.M.

    2014-01-01

    Flies use so-called halteres to sense body rotation based on Coriolis forces for supporting equilibrium reflexes. Inspired by these halteres, a biomimetic gimbal-suspended gyroscope has been developed using microelectromechanical systems (MEMS) technology. Design rules for this type of gyroscope are

  16. Non-degenerate parametric amplification and filtering in biomimetic hair flow sensors

    NARCIS (Netherlands)

    Droogendijk, H.; Bruinink, C.M.; Sanders, R.G.P.; Krijnen, G.J.M.

    2011-01-01

    We report non-degenerate parametric amplification in our biomimetic MEMS hair-based flow-sensors with improved responsivity and sharp filtering through AC-biasing. To the best of our knowledge, this is the first flow sensor with tunable filtering by non-degenerate electromechanical parametric amplif

  17. Biomimetic nanoassemblies of 1-O-octodecyl-2-conjugated linoleoyl-sn-glycero-3-phosphatidyl gemcitabine with phospholipase A2-triggered degradation for the treatment of cancer.

    Science.gov (United States)

    Zuo, Jing; Tong, Li; Du, Lina; Yang, Ming; Jin, Yiguang

    2017-04-01

    Phospholipids are important biomolecules with strong self-assembling ability to form biomembranes or liposomes. However, biomimetic prodrugs of phospholipids are not well known, including their self-assembling behavior at the air/water interface or in aqueous media. Here we design and prepare a biomimetic phospholipid-like amphiphilic prodrug, 1-O-octodecyl-2-conjugated linoleoyl-sn-glycero-3-phosphatidyl gemcitabine (OLGPG). After spreading at the air/water interface, it formed Langmuir monolayers. Stable nanoassemblies were obtained based on molecular self-assembly after OLGPG was injected in water. An amphiphilic long-chained lipid, cholesteryl hemisuccinate polyethylene glycol 1500 (CHS-PEG) was mixed in the OLGPG Langmuir monolayers and nanoassemblies with the optimal proportion. The OLGPG and OLGPG/CHS-PEG nanoassemblies were spherical vesicles due to the hydrophobic interaction of lipid moieties with the small sizes of 50.33nm and 64.76nm, respectively. Phospholipase A2 (PLA2) is highly expressed in tumor tissues to specifically degrade the 2-acyl of phospholipid to lysophospholipid. OLGPG showed PLA2-sensitive degradation. The nanoassemblies showed higher in vitro anticancer effect on HepG2 cells than the parent drug gemcitabine. In the in vivo studies on the hepatocellular tumor-bearing mouse model, the OLGPG/CHS-PEG nanoassemblies group (eq. to 1/5 dose of the Gem group) showed the highest antitumor and tumor targeting effects compared to the other groups. The long-circulating phospholipid-like prodrug nanoassemblies are the promising anticancer nanomedicines based on the biomimetic strategy and specific tumor microenvironment.

  18. Touch stimulated pulse generation in biomimetic single-layer graphene

    Science.gov (United States)

    Sul, Onejae; Chun, Hyunsuk; Choi, Eunseok; Choi, Jungbong; Cho, Kyeongwon; Jang, Dongpyo; Chun, Sungwoo; Park, Wanjun; Lee, Seung-Beck

    2016-02-01

    Detecting variation in contact pressure is a separate sensing mode in the human somatosensory system that differs from the detection of pressure magnitude. If pressure magnitude and variation sensing can be achieved simultaneously, an advanced biomimetic tactile system that better emulates human senses may be developed. We report on a novel single-layer graphene based artificial mechanoreceptor that generates a resistance pulse as the contact stimulus passes a specific threshold pressure, mimicking the generation of action potentials in a biological fast-adapting mechanoreceptor. The electric field from a flexible membrane gate electrode placed above a graphene channel raises the Fermi level from the valence band as pressure deflects the membrane. The threshold pressure is reached when the Fermi level crosses the Dirac point in the graphene energy band, which generates a sharp peak in the measured resistance. We found that by changing the gate potential it was possible to modulate the threshold pressure and using a series of graphene channels, a train of pulses were generated during a transient pressurizing stimulus demonstrating biomimetic behaviour.Detecting variation in contact pressure is a separate sensing mode in the human somatosensory system that differs from the detection of pressure magnitude. If pressure magnitude and variation sensing can be achieved simultaneously, an advanced biomimetic tactile system that better emulates human senses may be developed. We report on a novel single-layer graphene based artificial mechanoreceptor that generates a resistance pulse as the contact stimulus passes a specific threshold pressure, mimicking the generation of action potentials in a biological fast-adapting mechanoreceptor. The electric field from a flexible membrane gate electrode placed above a graphene channel raises the Fermi level from the valence band as pressure deflects the membrane. The threshold pressure is reached when the Fermi level crosses the Dirac

  19. PREFACE: Symposium 13: Ceramics for Medicine, Biotechnology and Biomimetics

    Science.gov (United States)

    Ohtsuki, Chikara

    2011-10-01

    Preface to Symposium 13 (Ceramics for Medicine, Biotechnology and Biomimetics) of the International Congress on Ceramics III, 14-18 November 2010, Osaka, Japan Ceramic materials are now widely used in biomedical fields, such as applications of artificial bones, joints and teeth. The high potential of ceramics to exhibit biological functionality is expected to produce novel materials supporting biotechnology. These applications are governed by the interactions of materials and biological molecules. So far, 'bioceramics' is a type of biomaterial used for repairing damaged tissues. The orthopaedic application of bioceramics has advanced rapidly since the invention of Bioglass® that was found to encourage direct bonding with living bone. Hydroxyapatite and calcium phosphate ceramics are now popular bioceramics for use in artificial bones. While the bone-bonding behavior of materials was understood phenomenologically, very little has been known about the mechanism of either hard or soft tissue attachment or tissue growth on ceramic-based materials, such as glasses, glass-ceramics, ceramic composites and organic-inorganic hybrids. This symposium discussed the scientific understanding of the interface between biomedical materials and soft/hard tissues, and the design and construction of nanoscopic interfaces. It also involved establishment of biomimetic structures, characterization of natural life-related hard and soft tissues, and their formation mechanisms for a wide range of applications in biotechnology through 45 oral presentations including 5 invited lectures and 45 posters. I wish to express my sincere appreciation to the organizers of this symposium in the ICC3 conference. I am also grateful to the invited speakers, all the participants and organizing committee of the ICC3. It is my great pleasure that this proceedings could be published as the fruit of this symposium's achievement, which includes the contributions in all aspect of scientific understanding and

  20. A water-forming NADH oxidase from Lactobacillus pentosus suitable for the regeneration of synthetic biomimetic cofactors.

    Science.gov (United States)

    Nowak, Claudia; Beer, Barbara; Pick, André; Roth, Teresa; Lommes, Petra; Sieber, Volker

    2015-01-01

    The cell-free biocatalytic production of fine chemicals by oxidoreductases has continuously grown over the past years. Since especially dehydrogenases depend on the stoichiometric use of nicotinamide pyridine cofactors, an integrated efficient recycling system is crucial to allow process operation under economic conditions. Lately, the variety of cofactors for biocatalysis was broadened by the utilization of totally synthetic and cheap biomimetics. Though, to date the regeneration has been limited to chemical or electrochemical methods. Here, we report an enzymatic recycling by the flavoprotein NADH-oxidase from Lactobacillus pentosus (LpNox). Since this enzyme has not been described before, we first characterized it in regard to its optimal reaction parameters. We found that the heterologously overexpressed enzyme only contained 13% FAD. In vitro loading of the enzyme with FAD, resulted in a higher specific activity towards its natural cofactor NADH as well as different nicotinamide derived biomimetics. Apart from the enzymatic recycling, which gives water as a by-product by transferring four electrons onto oxygen, unbound FAD can also catalyze the oxidation of biomimetic cofactors. Here a two electron process takes place yielding H2O2 instead. The enzymatic and chemical recycling was compared in regard to reaction kinetics for the natural and biomimetic cofactors. With LpNox and FAD, two recycling strategies for biomimetic cofactors are described with either water or hydrogen peroxide as by-product.

  1. A water-forming NADH oxidase from Lactobacillus pentosus and its potential application in the regeneration of synthetic biomimetic cofactors

    Directory of Open Access Journals (Sweden)

    Claudia eNowak

    2015-09-01

    Full Text Available The cell-free biocatalytic production of fine chemicals by oxidoreductases has continuously grown over the past years. Since especially dehydrogenases depend on the stoichiometric use of nicotinamide pyridine cofactors, an integrated efficient recycling system is crucial to allow process operation under economic conditions. Lately, the variety of cofactors for biocatalysis was broadened by the utilization of totally synthetic and cheap biomimetics. Though, to date the regeneration has been limited to chemical or electrochemical methods. Here, we report an enzymatic recycling by the flavoprotein NADH-oxidase from Lactobacillus pentosus (LpNox. Since this enzyme has not been described before, we first characterized it in regard to its optimal reaction parameters. We found that the heterologously overexpressed enzyme only contained 13 % FAD. In vitro loading of the enzyme with FAD, resulted in a higher specific activity towards its natural cofactor NADH as well as different nicotinamide derived biomimetics. Apart from the enzymatic recycling, which gives water as a by-product by transferring four electrons onto oxygen, unbound FAD can also catalyse the oxidation of biomimetic cofactors. Here a two electron process takes place yielding H2O2 instead. The enzymatic and chemical recycling was compared in regard to reaction kinetics for the natural and biomimetic cofactors. With LpNox and FAD, two recycling strategies for biomimetic cofactors are described with either water or hydrogen peroxide as a by-product.

  2. Calcifying tissue regeneration via biomimetic materials chemistry

    OpenAIRE

    Green, David W.; Goto, Tazuko K.; Kim, Kye-Seong; Jung, Han-Sung

    2014-01-01

    Materials chemistry is making a fundamental impact in regenerative sciences providing many platforms for tissue development. However, there is a surprising paucity of replacements that accurately mimic the structure and function of the structural fabric of tissues or promote faithful tissue reconstruction. Methodologies in biomimetic materials chemistry have shown promise in replicating morphologies, architectures and functional building blocks of acellular mineralized tissues dentine, enamel...

  3. Proteins and Peptides in Biomimetic Polymeric Membranes

    DEFF Research Database (Denmark)

    Perez, Alfredo Gonzalez

    2013-01-01

    This chapter discusses recent advances and the main advantages of block copolymers for functional membrane protein reconstitution in biomimetic polymeric membranes. A rational approach to the reconstitution of membrane proteins in a functional form can be addressed by a more holistic view by usin...

  4. Activity-Based Information Integrating the operations strategy

    Directory of Open Access Journals (Sweden)

    José Augusto da Rocha de Araujo

    2005-12-01

    Full Text Available In the globalized world, companies seek for new operations strategies to ensure world corporate success. This article analyzes how the cost management models – both traditional and activity-based, aid the planning and management of corporate globalized operations. The efficacy of the models application depends on their alignment with the competitive strategy. Companies must evaluate the nature of the competition and its competitive priorities; they should then define the necessary and sufficient dependence level on costs information. In this article, three dependence levels are presented: operational, decision support and strategic control. The result of the research shows the importance of alignment between the cost management model and the competitive strategy for corporate success, and confirms the adequacy of the activity-based costing model as a supporting tool for decision taking in a global strategy. Case studies in world class companies in Brazil are presented.

  5. Control Strategies for the DAB Based PV Interface System

    Science.gov (United States)

    El-Helw, Hadi M.; Al-Hasheem, Mohamed; Marei, Mostafa I.

    2016-01-01

    This paper presents an interface system based on the Dual Active Bridge (DAB) converter for Photovoltaic (PV) arrays. Two control strategies are proposed for the DAB converter to harvest the maximum power from the PV array. The first strategy is based on a simple PI controller to regulate the terminal PV voltage through the phase shift angle of the DAB converter. The Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) technique is utilized to set the reference of the PV terminal voltage. The second strategy presented in this paper employs the Artificial Neural Network (ANN) to directly set the phase shift angle of the DAB converter that results in harvesting maximum power. This feed-forward strategy overcomes the stability issues of the feedback strategy. The proposed PV interface systems are modeled and simulated using MATLAB/SIMULINK and the EMTDC/PSCAD software packages. The simulation results reveal accurate and fast response of the proposed systems. The dynamic performance of the proposed feed-forward strategy outdoes that of the feedback strategy in terms of accuracy and response time. Moreover, an experimental prototype is built to test and validate the proposed PV interface system. PMID:27560138

  6. Control Strategies for the DAB Based PV Interface System.

    Science.gov (United States)

    El-Helw, Hadi M; Al-Hasheem, Mohamed; Marei, Mostafa I

    2016-01-01

    This paper presents an interface system based on the Dual Active Bridge (DAB) converter for Photovoltaic (PV) arrays. Two control strategies are proposed for the DAB converter to harvest the maximum power from the PV array. The first strategy is based on a simple PI controller to regulate the terminal PV voltage through the phase shift angle of the DAB converter. The Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) technique is utilized to set the reference of the PV terminal voltage. The second strategy presented in this paper employs the Artificial Neural Network (ANN) to directly set the phase shift angle of the DAB converter that results in harvesting maximum power. This feed-forward strategy overcomes the stability issues of the feedback strategy. The proposed PV interface systems are modeled and simulated using MATLAB/SIMULINK and the EMTDC/PSCAD software packages. The simulation results reveal accurate and fast response of the proposed systems. The dynamic performance of the proposed feed-forward strategy outdoes that of the feedback strategy in terms of accuracy and response time. Moreover, an experimental prototype is built to test and validate the proposed PV interface system.

  7. Operator scheduling strategy for LBS-based intelligent transportation system

    Institute of Scientific and Technical Information of China (English)

    WU Jing-jing; XIA Ying; GE Jun-wei; Dong-wook Lee; Hae-young Bae

    2007-01-01

    With the development of location technologies, advanced LBS-based ITS increasingly requires the capability of database technologies to manage the continuously arrived vehicles' location, traffic jam and other interrelated information of large amounts of traffic in the following years. And some burst arrival stream data will challenge the real-time performance and the allocation of limited resource. However, choosing a desirable database operator scheduling strategy can significantly improve the performance of the system. The path capability strategy was chosen and improved as ITS' operator scheduling strategy to meet the real-time response and the minimal memory requirement of the system.

  8. [Global brain metastases management strategy: a multidisciplinary-based approach].

    Science.gov (United States)

    Métellus, P; Tallet, A; Dhermain, F; Reyns, N; Carpentier, A; Spano, J-P; Azria, D; Noël, G; Barlési, F; Taillibert, S; Le Rhun, É

    2015-02-01

    Brain metastases management has evolved over the last fifteen years and may use varying strategies, including more or less aggressive treatments, sometimes combined, leading to an improvement in patient's survival and quality of life. The therapeutic decision is subject to a multidisciplinary analysis, taking into account established prognostic factors including patient's general condition, extracerebral disease status and clinical and radiological presentation of lesions. In this article, we propose a management strategy based on the state of current knowledge and available therapeutic resources.

  9. UAV Robust Strategy Control Based on MAS

    Directory of Open Access Journals (Sweden)

    Jian Han

    2014-01-01

    Full Text Available A novel multiagent system (MAS has been proposed to integrate individual UAV (unmanned aerial vehicle to form a UAV team which can accomplish complex missions with better efficiency and effect. The MAS based UAV team control is more able to conquer dynamic situations and enhance the performance of any single UAV. In this paper, the MAS proposed and established combines the reacting and thinking abilities to be an initiative and autonomous hybrid system which can solve missions involving coordinated flight and cooperative operation. The MAS uses BDI model to support its logical perception and to classify the different missions; then the missions will be allocated by utilizing auction mechanism after analyzing dynamic parameters. Prim potential algorithm, particle swarm algorithm, and reallocation mechanism are proposed to realize the rational decomposing and optimal allocation in order to reach the maximum profit. After simulation, the MAS has been proved to be able to promote the success ratio and raise the robustness, while realizing feasibility of coordinated flight and optimality of cooperative mission.

  10. Nanotechnology-based water treatment strategies.

    Science.gov (United States)

    Kumar, Sandeep; Ahlawat, Wandit; Bhanjana, Gaurav; Heydarifard, Solmaz; Nazhad, Mousa M; Dilbaghi, Neeraj

    2014-02-01

    The most important component for living beings on the earth is access to clean and safe drinking water. Globally, water scarcity is pervasive even in water-rich areas as immense pressure has been created by the burgeoning human population, industrialization, civilization, environmental changes and agricultural activities. The problem of access to safe water is inevitable and requires tremendous research to devise new, cheaper technologies for purification of water, while taking into account energy requirements and environmental impact. This review highlights nanotechnology-based water treatment technologies being developed and used to improve desalination of sea and brackish water, safe reuse of wastewater, disinfection and decontamination of water, i.e., biosorption and nanoadsorption for contaminant removal, nanophotocatalysis for chemical degradation of contaminants, nanosensors for contaminant detection, different membrane technologies including reverse osmosis, nanofiltration, ultrafiltration, electro-dialysis etc. This review also deals with the fate and transport of engineered nanomaterials in water and wastewater treatment systems along with the risks associated with nanomaterials.

  11. Engineering nanomaterials with a combined electrochemical and molecular biomimetic approach

    Science.gov (United States)

    Dai, Haixia

    Biocomposite materials, such as bones, teeth, and shells, are created using mild aqueous solution-based processes near room temperature. Proteins add flexibility to these processes by facilitating the nucleation, growth, and ordering of specific inorganic materials into hierarchical structures. We aim to develop a biomimetic strategy for engineering technologically relevant inorganic materials with controlled compositions and structures, as Nature does, using proteins to orchestrate material formation and assembly. This approach involves three basic steps: (i) preparation of inorganic substrates compatible with combinatorial polypeptide screening; (ii) identification of inorganic-binding polypeptides and their engineering into inorganic-binding proteins; and (iii) protein-mediated inorganic nucleation and organization. Cuprous oxide (Cu2O), a p-type semiconductor, has been used to demonstrate all three steps. Zinc oxide (ZnO), an n-type semiconductor, has been used to show the generality of selected steps. Step (i), preparation of high quality inorganic substrates to select inorganic-binding polypeptides, was accomplished using electrochemical microfabrication to grow and pattern Cu2O and ZnO. Raman spectroscopy and x-ray photoelectron spectroscopy were used to verify phase purity and compositional stability of these surfaces during polypeptide screening. Step (ii), accomplished in collaboration with personnel in Prof Baneyx' lab at the University of Washington, involved incubating the inorganic substrates with the FliTrx(TM) random peptide library to identify cysteine-constrained dodecapeptides that bind the targeted inorganic. Insertion of a Cu2O-binding dodecapeptide into the DNA-binding protein TraI endowed the engineered TraI with strong affinity for Cu2O (Kd ≈ 10 -8 M). Finally, step (iii) involved nonequilibrium synthesis and organization of Cu2O nanoparticles, taking advantage of the inorganic and DNA recognition properties of the engineered TraI. The

  12. Research trends in biomimetic medical materials for tissue engineering: 3D bioprinting, surface modification, nano/micro-technology and clinical aspects in tissue engineering of cartilage and bone.

    Science.gov (United States)

    Chen, Cen; Bang, Sumi; Cho, Younghak; Lee, Sahnghoon; Lee, Inseop; Zhang, ShengMin; Noh, Insup

    2016-01-01

    This review discusses about biomimetic medical materials for tissue engineering of bone and cartilage, after previous scientific commentary of the invitation-based, Korea-China joint symposium on biomimetic medical materials, which was held in Seoul, Korea, from October 22 to 26, 2015. The contents of this review were evolved from the presentations of that symposium. Four topics of biomimetic medical materials were discussed from different research groups here: 1) 3D bioprinting medical materials, 2) nano/micro-technology, 3) surface modification of biomaterials for their interactions with cells and 4) clinical aspects of biomaterials for cartilage focusing on cells, scaffolds and cytokines.

  13. Braking Performance of a Biomimetic Squid-Like Underwater Robot

    Institute of Scientific and Technical Information of China (English)

    Md.Mahbubar Rahman; Sinpei Sugimori; Hiroshi Miki; Risa Yamamoto; Yugo Sanada; Yasuyuki Toda

    2013-01-01

    In this study,the braking performance of the undulating fin propulsion system ofa biomimetic squid-like underwater robot was investigated through free run experiment and simulation of the quasi-steady mathematical model.The quasi-steady equations of motion were solved using the measured and calculated hydrodynamic forces and compared with free-run test results.Various braking strategies were tested and discussed in terms of stopping ability and the forces acting on the stopping stage.The stopping performance of the undulating fin propulsion system tured out to be excellent considering the short stopping time and short stopping distance.This is because of the large negative thrust produced by progressive wave in opposite direction.It was confirmed that the undulating fin propulsion system can effectively perform braking even in complex underwater explorations.

  14. Plasmonic nanoparticles tuned thermal sensitive photonic polymer for biomimetic chameleon

    Science.gov (United States)

    Yan, Yang; Liu, Lin; Cai, Zihe; Xu, Jiwen; Xu, Zhou; Zhang, Di; Hu, Xiaobin

    2016-08-01

    Among many thermo-photochromic materials, the color-changing behavior caused by temperature and light is usually lack of a full color response. And the study on visible light-stimuli chromic response is rarely reported. Here, we proposed a strategy to design a thermo-photochromic chameleon biomimetic material consisting of photonic poly(N-isopropylacrylamide-co-methacrylic acid) copolymer and plasmonic nanoparticles which has a vivid color change triggered by temperature and light like chameleons. We make use of the plasmonic nanoparticles like gold nanoparticles and silver nanoparticles to increase the sensitivity of the responsive behavior and control the lower critical solution temperature of the thermosensitive films by tuning the polymer chain conformation transition. Finally, it is possible that this film would have colorimetric responses to the entire VIS spectrum by the addition of different plasmonic nanoparticles to tune the plasmonic excitation wavelength. As a result, this method provides a potential use in new biosensors, military and many other aspects.

  15. Computation of Unsteady Flow Past a Biomimetic Fin

    Institute of Scientific and Technical Information of China (English)

    Hao Liu; Naomi Kato

    2004-01-01

    The unsteady hydrodynamics of a biomimetic fin attached to a cylindrical body has been studied numerically using a computational fluid dynamic (CFD) simulator based on an in-house solver of the Navier-Stokes equations, combined with a recently developed multi-block, overset grid method. The fin-body CFD model is based on a mechanical pectoral fin device, which consists of a cylindrical body and an asymmetric fin and can mimic flapping, rowing and feathering motions of the pectoral fins in fishes. First the multi-block, overset grid method incorporated into the NS solver was verified through an extensive study of unsteady flows past a single fin undergoing rowing and feathering motion. Then unsteady flows past the biomimetic fin-body model undergoing the same motions were computed and compared with the measurements of forces of the mechanical pectoral fin, which shows good agreement in both time-varying and time-averaged hydrodynamic forces. The relationship between force generation and vortex dynamics points to the importance of the match in fin kinematics between power and recovery strokes and implies that an optimal selection of parameters of phase lags between and amplitudes of rowing and feathering motions can improve the performance of labriform propulsion in terms of either maximum force generation or minimum mechanical power.

  16. Developing a biomimetic tooth bud model.

    Science.gov (United States)

    Smith, Elizabeth E; Zhang, Weibo; Schiele, Nathan R; Khademhosseini, Ali; Kuo, Catherine K; Yelick, Pamela C

    2017-01-08

    A long-term goal is to bioengineer, fully functional, living teeth for regenerative medicine and dentistry applications. Biologically based replacement teeth would avoid insufficiencies of the currently used dental implants. Using natural tooth development as a guide, a model was fabricated using post-natal porcine dental epithelial (pDE), porcine dental mesenchymal (pDM) progenitor cells, and human umbilical vein endothelial cells (HUVEC) encapsulated within gelatin methacrylate (GelMA) hydrogels. Previous publications have shown that post-natal DE and DM cells seeded onto synthetic scaffolds exhibited mineralized tooth crowns composed of dentin and enamel. However, these tooth structures were small and formed within the pores of the scaffolds. The present study shows that dental cell-encapsulated GelMA constructs can support mineralized dental tissue formation of predictable size and shape. Individually encapsulated pDE or pDM cell GelMA constructs were analysed to identify formulas that supported pDE and pDM cell attachment, spreading, metabolic activity, and neo-vasculature formation with co-seeded endothelial cells (HUVECs). GelMa constructs consisting of pDE-HUVECS in 3% GelMA and pDM-HUVECs within 5% GelMA supported dental cell differentiation and vascular mineralized dental tissue formation in vivo. These studies are the first to demonstrate the use of GelMA hydrogels to support the formation of post-natal dental progenitor cell-derived mineralized and functionally vascularized tissues of specified size and shape. These results introduce a novel three-dimensional biomimetic tooth bud model for eventual bioengineered tooth replacement teeth in humans. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Biomimetics on seed dispersal: survey and insights for space exploration.

    Science.gov (United States)

    Pandolfi, Camilla; Izzo, Dario

    2013-06-01

    Seeds provide the vital genetic link and dispersal agent between successive generations of plants. Without seed dispersal as a means of reproduction, many plants would quickly die out. Because plants lack any sort of mobility and remain in the same spot for their entire lives, they rely on seed dispersal to transport their offspring throughout the environment. This can be accomplished either collectively or individually; in any case as seeds ultimately abdicate their movement, they are at the mercy of environmental factors. Thus, seed dispersal strategies are characterized by robustness, adaptability, intelligence (both behavioral and morphological), and mass and energy efficiency (including the ability to utilize environmental sources of energy available): all qualities that advanced engineering systems aim at in general, and in particular those that need to enable complex endeavors such as space exploration. Plants evolved and adapted their strategy according to their environment, and taken together, they enclose many desirable characteristics that a space mission needs to have. Understanding in detail how plants control the development of seeds, fabricate structural components for their dispersal, build molecular machineries to keep seeds dormant up to the right moment and monitor the environment to release them at the right time could provide several solutions impacting current space mission design practices. It can lead to miniaturization, higher integration and packing efficiency, energy efficiency and higher autonomy and robustness. Consequently, there would appear to be good reasons for considering biomimetic solutions from plant kingdom when designing space missions, especially to other celestial bodies, where solid and liquid surfaces, atmosphere, etc constitute and are obviously parallel with the terrestrial environment where plants evolved. In this paper, we review the current state of biomimetics on seed dispersal to improve space mission design.

  18. ROBUST INTERNAL MODEL CONTROL STRATEGY BASED PID CONTROLLER FOR BLDCM

    Directory of Open Access Journals (Sweden)

    A.PURNA CHANDRA RAO

    2010-11-01

    Full Text Available All the closed loop control system requires the controller for improvement of transient response of the error signal. Though the tuning of PID controller in real time is bit difficult and moreover it lacks the disturbance rejection capability. This paper presents a tuning of PID parameters based on internal model strategy. The advantageous of the proposed control strategy is well described in the paper. To test the validity of the proposed control, it is implemented in brushless dc motor drive. The mathematical model of brushless dc motor (BLDC is presented for control design. In addition the robustness of the control strategy is discussed. The proposed control strategy possesses good transient responses and good load disturbance response. In addition, the proposed control strategy possesses good tracking ability. To test the effectiveness of the proposed strategy, the BLDC is represented in transfer function model and later implemented in test system. The results are presented to validate the proposed control strategy for BLDC drive.

  19. Human elastin-based recombinant biopolymers improve mesenchymal stem cell differentiation.

    Science.gov (United States)

    Çelebi, Betül; Cloutier, Maxime; Rabelo, Rodrigo B; Balloni, Rodrigo; Mantovani, Diego; Bandiera, Antonella

    2012-11-01

    Elastin-based polypeptides are a class of smart biopolymers representing an important model in the design of biomaterials. The combination of biomimetic materials with cells that have great plasticity provides a promising strategy for the realization of highly engineered cell-based constructs for regenerative medicine and tissue repair applications. Two recombinant biopolymers inspired by human elastin are assessed as coating agents to prepare biomimetic surfaces for cell culture. These substrates are assayed for hBM MSC culture. The coated surfaces are also characterized with AFM to evaluate the topographical features of the deposited biopolymers. The results suggest that the elastin-derived biomimetic surfaces play a stimulatory role on osteogenic differentiation of MSCs.

  20. Storage Management Strategy of Flash-Based Platform

    Institute of Scientific and Technical Information of China (English)

    WANG Taiyong; ZHAO Li; HU Shiguang; WANG Tao

    2009-01-01

    Storage management strategy can be expressed by a file system. Commercial file system for embedded application is generally complicated and resource wasted. In this paper, a specified file system adapted to embedded system with flash-based memory is developed. To guarantee the average usage of flash storage sectors, the strategy of wear leveling and adaptive damage management is introduced, in which a dynamic storage space management mode and the strategy of first in first out (FIFO) are adopted. Moreover, the strategy of redundancy design and fast-calculation and tracing is also adopted to extend the life of kernel sector, which can guarantee the reliable ser-vice of system booting. The practical application in an embedded CNC (computerized numerical control) platform proves that the file system has effective performance. Furthermore, the flash file system can be transplanted to dif-ferent embedded platforms by changing a few bottom hardware parameters with universality.

  1. POSITIVE VERSUS NEGATIVE COMMUNICATION STRATEGIES IN TASK-BASED LEARNING

    Directory of Open Access Journals (Sweden)

    Siti Rohani

    2013-07-01

    Full Text Available This study aimed at describing how the implementation of Task Based Learning (TBL would shape or change students’ use of oral communication strategies. Students’ problems and strategies to solve the problems during the implementation of TBL were also explored. The study was a mixed method, employing both quantitative and qualitative analysis throughmulti-methods of questionnaire, interviews, focus group discussion, learning journals, and classroom observation. Participants were 26 second year students of the State Polytechnic of Malang. Data collection was conducted for one semester. Findingsshow linguistic and non-linguistic problems encountered by students during one-semester implementation of TBL. Students also performedincreased use of positive strategies but reduced use of negative strategies after the implementation of TBL.

  2. Control strategies for VSC-based HVDC transmission system

    DEFF Research Database (Denmark)

    Stan, Ana-Irina; Stroe, Daniel Ioan; Silva, Rodrigo Da

    2011-01-01

    Throughout this paper the modeling and control of the VSC-based HVDC systems are investigated and described. Two different control methods capable of controlling such systems are proposed. Both developed control strategies are implemented in the dq synchronous reference frame. In order to analyze...... the behavior of the developed VSC-based HVDC transmission system two study cases are carried out using MATLAB/Simulink. The results obtained from simulations show acceptable performances, of the proposed strategies, when changes in the reference parameters are considered. The active power flow between...... the converters is succesfully achieved while, the independent control of active and reactive power is also verified....

  3. An approximation based global optimization strategy for structural synthesis

    Science.gov (United States)

    Sepulveda, A. E.; Schmit, L. A.

    1991-01-01

    A global optimization strategy for structural synthesis based on approximation concepts is presented. The methodology involves the solution of a sequence of highly accurate approximate problems using a global optimization algorithm. The global optimization algorithm implemented consists of a branch and bound strategy based on the interval evaluation of the objective function and constraint functions, combined with a local feasible directions algorithm. The approximate design optimization problems are constructed using first order approximations of selected intermediate response quantities in terms of intermediate design variables. Some numerical results for example problems are presented to illustrate the efficacy of the design procedure setforth.

  4. Biomimetic Olfactory Sensing System Based on Brain-Machine Interface and Olfactory Decoding%基于脑-机接口和嗅觉解码的仿生气味识别系统

    Institute of Scientific and Technical Information of China (English)

    董琪; 秦臻; 胡靓; 庄柳静; 张斌; 王平

    2015-01-01

    Mammalian olfactory systems have merits of higher sensitivity, selectivity and faster response than current electronic nose systems based on chemical sensor array in odor recognition. The purpose of this study is to develop a biomimetic olfactory sensing system based on brain-machine interface technology for odor detection in vivo electrophysiological measurements of olfactory bulb. In this work, extracellular potentials of mitral/tufted cells in olfactory bulb were recorded by implanted 16-channel microwire electrode arrays. The odor-evoked response signals were analyzed. We found that neural activities of different neurons showed visible different firing patterns in both temporal features and rate features when stimulated by different small molecular odorants. Odors were classified by an algorithm based on population vector similarity and support vector machine. The results suggest that the novel bioelectonic nose is sensitive to odorant stimuli. With the development of BMI and olfactory decoding methods, we believe that this system will represent emerging and promising platforms for wide applications in medical diagnosis and security fields.%为了探讨利用生物嗅觉传感系统进行气味识别的可行性,提出了一种基于脑-机接口的仿生气味识别系统。该系统利用大鼠嗅觉感受细胞作为气味敏感传感单元,使用16通道植入式微丝电极记录和分析具有气味刺激特征的嗅球僧帽细胞电位响应信号。实验结果显示,该系统对气味具有高度敏感性,通过一定模式识别处理算法,不同的气味刺激具有较好的区分性,证明了该系统有望应用于气味的检测和识别。

  5. Formation of Biomimetic Hydroxyapatite Coating on Titanium Plates

    Directory of Open Access Journals (Sweden)

    Ievgen Volodymyrovych PYLYPCHUK

    2014-09-01

    Full Text Available Hydroxyapatite (HA has long been used as a coating material in the implant industry for orthopedic implant applications. HA is the natural inorganic constituent of bone and teeth. By coating titanium (base material of implant engineering because of its lightness and durability with hydroxyapatite, we can provide higher biocompatibility of titanium implants, according to HA ability to form a direct biochemical bond with living tissues. This article reports a biomimetic approach for coating hydroxyapatite with titanium A method of modifying the surface of titanium by organic modifiers (for creating functional groups on the surface, followed by formation "self-assembled" layer of biomimetic hydroxyapatite in simulated body fluid (SBF. FTIR and XPS confirmed the formation of hydroxyapatite coatings on titanium surface. Comparative study of the formation of HA on the surface of titanium plates modified by different functional groups: Ti(≡OH, Ti/(≡Si-OH and Ti/(≡COOH is conducted. It was found that the closest to natural stoichiometric hydroxyapatite Ca/P ratio was obtained on Ti/(≡COOH samples. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4974

  6. Biomimetic nanocrystalline apatites: Emerging perspectives in cancer diagnosis and treatment.

    Science.gov (United States)

    Al-Kattan, Ahmed; Girod-Fullana, Sophie; Charvillat, Cédric; Ternet-Fontebasso, Hélène; Dufour, Pascal; Dexpert-Ghys, Jeannette; Santran, Véronique; Bordère, Julie; Pipy, Bernard; Bernad, José; Drouet, Christophe

    2012-02-14

    Nanocrystalline calcium phosphate apatites constitute the mineral part of hard tissues, and the synthesis of biomimetic analogs is now well-mastered at the lab-scale. Recent advances in the fine physico-chemical characterization of these phases enable one to envision original applications in the medical field along with a better understanding of the underlying chemistry and related pharmacological features. In this contribution, we specifically focused on applications of biomimetic apatites in the field of cancer diagnosis or treatment. We first report on the production and first biological evaluations (cytotoxicity, pro-inflammatory potential, internalization by ZR-75-1 breast cancer cells) of individualized luminescent nanoparticles based on Eu-doped apatites, eventually associated with folic acid, for medical imaging purposes. We then detail, in a first approach, the preparation of tridimensional constructs associating nanocrystalline apatite aqueous gels and drug-loaded pectin microspheres. Sustained releases of a fluorescein analog (erythrosin) used as model molecule were obtained over 7 days, in comparison with the ceramic or microsphere reference compounds. Such systems could constitute original bone-filling materials for in situ delivery of anticancer drugs.

  7. Biomimetic Drag Reduction Study on Herringbone Riblets of Bird Feather

    Institute of Scientific and Technical Information of China (English)

    Huawei Chen; Fugang Rao; Xiaopeng Shang; Deyuan Zhang; Ichiro Hagiwara

    2013-01-01

    Birds have gradually formed various excellent structures such as streamlined shape and hollow shaft of feather to improve their flying performance by millions of years of natural selection.As typical property of bird feather,herringbone riblets align along the shaft of each feather,which is caused by perfect link of barbs,especially for the primary and secondary feathers of wings.Such herringbone riblets of feather are assumed to have great impact on drag reduction.In this paper,microstructures of secondary feathers of adult pigeons are investigated by SEM,and their structural parameters are statistically obtained.Based on quantitative analysis of feather structure,novel biomimetic herringbone riblets with narrow smooth edge are proposed to reduce surface drag.In comparison with traditional microgroove riblets and other drag reduction structures,the drag reduction rate of the proposed biomimetic herringbone riblets is experimentally clarified up to 16%,much higher than others.Moreover,the drag reduction mechanism of herringbone riblets are also confirmed and exploited by CFD.

  8. Fault Diagnosis Strategies for SOFC-Based Power Generation Plants

    Directory of Open Access Journals (Sweden)

    Paola Costamagna

    2016-08-01

    Full Text Available The success of distributed power generation by plants based on solid oxide fuel cells (SOFCs is hindered by reliability problems that can be mitigated through an effective fault detection and isolation (FDI system. However, the numerous operating conditions under which such plants can operate and the random size of the possible faults make identifying damaged plant components starting from the physical variables measured in the plant very difficult. In this context, we assess two classical FDI strategies (model-based with fault signature matrix and data-driven with statistical classification and the combination of them. For this assessment, a quantitative model of the SOFC-based plant, which is able to simulate regular and faulty conditions, is used. Moreover, a hybrid approach based on the random forest (RF classification method is introduced to address the discrimination of regular and faulty situations due to its practical advantages. Working with a common dataset, the FDI performances obtained using the aforementioned strategies, with different sets of monitored variables, are observed and compared. We conclude that the hybrid FDI strategy, realized by combining a model-based scheme with a statistical classifier, outperforms the other strategies. In addition, the inclusion of two physical variables that should be measured inside the SOFCs can significantly improve the FDI performance, despite the actual difficulty in performing such measurements.

  9. Fault Diagnosis Strategies for SOFC-Based Power Generation Plants.

    Science.gov (United States)

    Costamagna, Paola; De Giorgi, Andrea; Gotelli, Alberto; Magistri, Loredana; Moser, Gabriele; Sciaccaluga, Emanuele; Trucco, Andrea

    2016-08-22

    The success of distributed power generation by plants based on solid oxide fuel cells (SOFCs) is hindered by reliability problems that can be mitigated through an effective fault detection and isolation (FDI) system. However, the numerous operating conditions under which such plants can operate and the random size of the possible faults make identifying damaged plant components starting from the physical variables measured in the plant very difficult. In this context, we assess two classical FDI strategies (model-based with fault signature matrix and data-driven with statistical classification) and the combination of them. For this assessment, a quantitative model of the SOFC-based plant, which is able to simulate regular and faulty conditions, is used. Moreover, a hybrid approach based on the random forest (RF) classification method is introduced to address the discrimination of regular and faulty situations due to its practical advantages. Working with a common dataset, the FDI performances obtained using the aforementioned strategies, with different sets of monitored variables, are observed and compared. We conclude that the hybrid FDI strategy, realized by combining a model-based scheme with a statistical classifier, outperforms the other strategies. In addition, the inclusion of two physical variables that should be measured inside the SOFCs can significantly improve the FDI performance, despite the actual difficulty in performing such measurements.

  10. Biomimetic catalysts responsive to specific chemical signals

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yan [Iowa State Univ., Ames, IA (United States)

    2015-03-04

    Part 1. Design of Biomimetic Catalysts Based on Amphiphilic Systems The overall objective of our research is to create biomimetic catalysts from amphiphilic molecules. More specifically, we aim to create supramolecular systems that can be used to control the microenvironment around a catalytic center in a biomimetic fashion and apply the learning to construct supramolecular catalysts with novel functions found in enzymatic catalysts. We have prepared synthetic molecules (i.e., foldamers) that could fold into helical structures with nanometer-sized internal hydrophilic cavities. Cavities of this size are typically observed only in the tertiary and quaternary structures of proteins but were formed in our foldamer prepared in just a few steps from the monomer. Similar to many proteins, our foldamers displayed cooperativity in the folding/unfolding equilibrium and followed a two-state conformational transition. In addition, their conformational change could be triggered by solvent polarity, pH, or presence of metal ions and certain organic molecules. We studied their environmentally dependent conformational changes in solutions, surfactant micelles, and lipid bilayer membranes. Unlike conventional rigid supramolecular host, a foldamer undergoes conformational change during guest binding. Our study in the molecular recognition of an oligocholate host yielded some extremely exciting results. Cooperativity between host conformation and host–guest interactions was found to “magnify” weak binding interactions. In other words, since binding affinity is determined by the overall change of free energy during the binding, guest-induced conformational change of the host, whether near or far from the binding site, affects the binding. This study has strong implications in catalysis because enzymes have been hypothesized to harvest similar intramolecular forces to strengthen their binding with the transition state of an enzyme-catalyzed reaction. The supramolecular and

  11. Efficient learning strategy of Chinese characters based on network approach

    CERN Document Server

    Yan, Xiao-Yong; Di, Zengru; Havlin, Shlomo; Wu, Jinshan

    2013-01-01

    Based on network analysis of hierarchical structural relations among Chinese characters, we develop an efficient learning strategy of Chinese characters. We regard a more efficient learning method if one learns the same number of useful Chinese characters in less effort or time. We construct a node-weighted network of Chinese characters, where character usage frequencies are used as node weights. Using this hierarchical node-weighted network, we propose a new learning method, the distributed node weight (DNW) strategy, which is based on a new measure of nodes' importance that takes into account both the weight of the nodes and the hierarchical structure of the network. Chinese character learning strategies, particularly their learning order, are analyzed as dynamical processes over the network. We compare the efficiency of three theoretical learning methods and two commonly used methods from mainstream Chinese textbooks, one for Chinese elementary school students and the other for students learning Chinese as...

  12. Design and implementation of a biomimetic turtle hydrofoil for an autonomous underwater vehicle.

    Science.gov (United States)

    Font, Davinia; Tresanchez, Marcel; Siegentahler, Cedric; Pallejà, Tomàs; Teixidó, Mercè; Pradalier, Cedric; Palacin, Jordi

    2011-01-01

    This paper presents the design and implementation of a turtle hydrofoil for an Autonomous Underwater Vehicle (AUV). The final design of the AUV must have navigation performance like a turtle, which has also been the biomimetic inspiration for the design of the hydrofoil and propulsion system. The hydrofoil design is based on a National Advisory Committee for Aeronautics (NACA) 0014 hydrodynamic profile. During the design stage, four different propulsion systems were compared in terms of propulsion path, compactness, sealing and required power. The final implementation is based on a ball-and-socket mechanism because it is very compact and provides three degrees of freedom (DoF) to the hydrofoil with very few restrictions on the propulsion path. The propulsion obtained with the final implementation of the hydrofoil has been empirically evaluated in a water channel comparing different motion strategies. The results obtained have confirmed that the proposed turtle hydrofoil controlled with a mechanism with three DoF generates can be used in the future implementation of the planned AUV.

  13. Design and Implementation of a Biomimetic Turtle Hydrofoil for an Autonomous Underwater Vehicle

    Science.gov (United States)

    Font, Davinia; Tresanchez, Marcel; Siegentahler, Cedric; Pallejà, Tomàs; Teixidó, Mercè; Pradalier, Cedric; Palacin, Jordi

    2011-01-01

    This paper presents the design and implementation of a turtle hydrofoil for an Autonomous Underwater Vehicle (AUV). The final design of the AUV must have navigation performance like a turtle, which has also been the biomimetic inspiration for the design of the hydrofoil and propulsion system. The hydrofoil design is based on a National Advisory Committee for Aeronautics (NACA) 0014 hydrodynamic profile. During the design stage, four different propulsion systems were compared in terms of propulsion path, compactness, sealing and required power. The final implementation is based on a ball-and-socket mechanism because it is very compact and provides three degrees of freedom (DoF) to the hydrofoil with very few restrictions on the propulsion path. The propulsion obtained with the final implementation of the hydrofoil has been empirically evaluated in a water channel comparing different motion strategies. The results obtained have confirmed that the proposed turtle hydrofoil controlled with a mechanism with three DoF generates can be used in the future implementation of the planned AUV. PMID:22247660

  14. Design and Implementation of a Biomimetic Turtle Hydrofoil for an Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Jordi Palacin

    2011-11-01

    Full Text Available This paper presents the design and implementation of a turtle hydrofoil for an Autonomous Underwater Vehicle (AUV. The final design of the AUV must have navigation performance like a turtle, which has also been the biomimetic inspiration for the design of the hydrofoil and propulsion system. The hydrofoil design is based on a National Advisory Committee for Aeronautics (NACA 0014 hydrodynamic profile. During the design stage, four different propulsion systems were compared in terms of propulsion path, compactness, sealing and required power. The final implementation is based on a ball-and-socket mechanism because it is very compact and provides three degrees of freedom (DoF to the hydrofoil with very few restrictions on the propulsion path. The propulsion obtained with the final implementation of the hydrofoil has been empirically evaluated in a water channel comparing different motion strategies. The results obtained have confirmed that the proposed turtle hydrofoil controlled with a mechanism with three DoF generates can be used in the future implementation of the planned AUV.

  15. A Social Marketing Based Strategy For Planning Diversity Events

    Directory of Open Access Journals (Sweden)

    Sambhavi Lakshminarayanan

    2011-07-01

    Full Text Available Organizations are both enriched and challenged by diversity. Organizational diversity management is based on several factors such as strategy, competitive positioning and internal culture. Most organizations hold events of various kinds as part of their diversity strategy. Although participation in events is often mandated, such as in training programs, providing opportunities for voluntary participation is also important. In particular, organizing events in which participation is voluntary signals that management is willing to be responsive and flexible. Events, in general, are a highly visible aspect of diversity programs and serve many purposes, such as providing information, building awareness and creating social capital. On the other hand, there are associated costs. Consequently, organizations need to plan events carefully in order to obtain their full benefit. This paper presents a comprehensive strategy for planning, publicising and organizing diversity related events. The strategy addresses the interests and needs of all individuals in the organization with a goal of maximizing voluntary participation.  A simple yet powerful method from (social marketing is used in constructing the comprehensive strategy: that of market segmentation. In this paper, individuals in an organization are classified into four segments. Events, too, are classified into four types – support, celebratory, educational and training. Each segment responds best to a specific type of event. This link between segments and events is used to formulate the strategy that recommends organizing all four types of events, during a planning period, as part of the diversity management effort. 

  16. Biodegradable and biomimetic elastomeric scaffolds for tissue-engineered heart valves.

    Science.gov (United States)

    Xue, Yingfei; Sant, Vinayak; Phillippi, Julie; Sant, Shilpa

    2017-01-15

    Valvular heart diseases are the third leading cause of cardiovascular disease, resulting in more than 25,000 deaths annually in the United States. Heart valve tissue engineering (HVTE) has emerged as a putative treatment strategy such that the designed construct would ideally withstand native dynamic mechanical environment, guide regeneration of the diseased tissue and more importantly, have the ability to grow with the patient. These desired functions could be achieved by biomimetic design of tissue-engineered constructs that recapitulate in vivo heart valve microenvironment with biomimetic architecture, optimal mechanical properties and possess suitable biodegradability and biocompatibility. Synthetic biodegradable elastomers have gained interest in HVTE due to their excellent mechanical compliance, controllable chemical structure and tunable degradability. This review focuses on the state-of-art strategies to engineer biomimetic elastomeric scaffolds for HVTE. We first discuss the various types of biodegradable synthetic elastomers and their key properties. We then highlight tissue engineering approaches to recreate some of the features in the heart valve microenvironment such as anisotropic and hierarchical tri-layered architecture, mechanical anisotropy and biocompatibility.

  17. Marking Strategies in Metacognition-Evaluated Computer-Based Testing

    Science.gov (United States)

    Chen, Li-Ju; Ho, Rong-Guey; Yen, Yung-Chin

    2010-01-01

    This study aimed to explore the effects of marking and metacognition-evaluated feedback (MEF) in computer-based testing (CBT) on student performance and review behavior. Marking is a strategy, in which students place a question mark next to a test item to indicate an uncertain answer. The MEF provided students with feedback on test results…

  18. Constructing Breaker Sequence based System Restoration Strategy with Graph Theory

    OpenAIRE

    Peng, C.; Qin, Z.; Wang, C.; Hou, Y

    2014-01-01

    This paper has proposed a mapping approach to serve as an interface between the branch-bus model and the breaker-based model. In order to find the specific optimal operation for breakers in substations according to the restoration strategies, firstly, the paper has established the breaker-based model for the substation by using graphic theory, and then the optimal operation sequence for breakers has been figured out by adopting Dijkstra algorithm. Finally, a case study for a realistic power s...

  19. Forward osmosis biomimetic membranes in industrial and environmental applications

    DEFF Research Database (Denmark)

    Bajraktari, Niada; Madsen, Henrik Tækker; Nielsen, K. H.;

    in increasing costs and fouling/scaling problems. In an attempt to overcome these problems, attention has recently turned to the use of forward osmosis, where a solution with a high osmotic pressure is used to draw water from the solution that is to be filtered. This technology promises to reduce the energy....... In this work we have investigated two potential uses of this technology: Peptide up-concentration and pesticide removal. We have developed a new method for up-concentration of small molecular compounds based on gentle water removal from the sample by forward osmosis. The technology is based on two units; 1......) a single use filtration module containing a sample reservoir and a biomimetic aquaporin based forward osmosis membrane. 2) a multi-use desktop forward osmosis system containing draw solution mixing, and monitoring devices. The sample is placed in the single use module and the module is then mounted...

  20. Green Tribology Biomimetics, Energy Conservation and Sustainability

    CERN Document Server

    Bhushan, Bharat

    2012-01-01

    Tribology is the study of friction, wear and lubrication. Recently, the concept of “green tribology” as “the science and technology of the tribological aspects of ecological balance and of environmental and biological impacts” was introduced. The field of green tribology includes tribological technology that mimics living nature (biomimetic surfaces) and thus is expected to be environmentally friendly, the control of friction and wear that is of importance for energy conservation and conversion, environmental aspects of lubrication and surface modification techniques, and tribological aspects of green applications such as wind-power turbines or solar panels. This book is the first comprehensive volume on green tribology. The chapters are prepared by leading experts in their fields and cover such topics as biomimetics, environmentally friendly lubrication, tribology of wind turbines and renewable sources of energy, and ecological impact of new technologies of surface treatment.

  1. Green tribology. Biomimetics, energy conservation and sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Nosonovsky, Michael [Wisconsin Univ., Milwaukee, WI (United States). Dept. of Mechanical Engineering; Bhushan, Bharat (eds.) [Ohio State Univ., Columbus, OH (US). Nanoprobe Lab. for Bio- and Nanotechnology and Biomimetics (NLB2)

    2012-07-01

    Tribology is the study of friction, wear and lubrication. Recently, the concept of ''green tribology'' as ''the science and technology of the tribological aspects of ecological balance and of environmental and biological impacts'' was introduced. The field of green tribology includes tribological technology that mimics living nature (biomimetic surfaces) and thus is expected to be environmentally friendly, the control of friction and wear that is of importance for energy conservation and conversion, environmental aspects of lubrication and surface modification techniques, and tribological aspects of green applications such as wind-power turbines or solar panels. This book is the first comprehensive volume on green tribology. The chapters are prepared by leading experts in their fields and cover such topics as biomimetics, environmentally friendly lubrication, tribology of wind turbines and renewable sources of energy, and ecological impact of new technologies of surface treatment. (orig.)

  2. The Top of the Biomimetic Triangle

    Institute of Scientific and Technical Information of China (English)

    Andrei P. Sommer; Dan Zhu; Matthias Wiora; Hans-Joerg Fecht

    2008-01-01

    There is increasing observational evidence indicating that crystalline interfacial water layers play a central role in evolution and biology. For instance in cellular recognition processes, in particular during first contact events, where cells decide upon survival or entering apoptosis. Understanding water layers is thus crucial in biomedical engineering, specifically in the design of biomaterials inspired by biomimetic principles. Whereas there is ample experimental evidence for crystalline interfacial water layers on surfaces in air, their subaquatic presence could not be verified directly, so far. Analysing a polarity dependent asym- metry in the surface conductivity on hydrogenated nanocrystalline diamond, we show that crystalline interfacial water layers persist subaquatically. Nanoscopic interfacial water layers with an order different from that of bulk water have been identified at room temperature on both hydrophilic and hydrophobic model surfaces - in air and subaquatically. Their generalization and systematic inclusion into the catalogue of physical and chemical determinants of biocompatibility complete the biomimetic triangle.

  3. Mobile Robot Navigation Algorithm of Biomimetic Conditioned Reflex Based on Biological Antennas%基于生物触角的仿生条件反射机器人导航算法

    Institute of Scientific and Technical Information of China (English)

    江济良; 屠大维; 许烁; 赵其杰

    2013-01-01

    运用神经行为学原理提出一种模拟生物条件反射活动的机器人导航算法.对于环境感知,提出生物触角模型,因仅对特定区域信息进行处理,大大减小了计算量;对于运动控制,提出一种实用的改进Bug算法,机器人依靠生物触角感知环境刺激,实时激励触发相应的行走行为.最后在多种障碍物分布情形下进行算法对比验证.结果表明,机器人可以利用该算法实现未知环境下定目标点自主导航,具有转向次数少、绕行障碍物距离小及运动路径平滑等优点.该算法在自主移动机器人和自主牵引车辆中具有潜在应用价值.%This paper proposes a navigation algorithm of biomimetic conditioned reflex for mobile robots based on neu-roethology principles.For environment perception,a biological antenna model is proposed to delineate the interested sensing areas, and thus decrease the computational burden. For motion planning and control, according to a practical Bug algorithm proposed in this paper, the obtained environment stimulation is responded to generate the corresponding walking behavior. Experiments have been carried out in different conditions of obstacle distribution for algorithm verification. The results present its practicability,fewer turning number, smaller route length and smooth motion path. It can be expected that this algorithm will be of potential application in automated mobile robot(AMR)and automated guided vehicle(AGV).

  4. Theory of Networked Minority Games based on Strategy Pattern Dynamics

    OpenAIRE

    Lo, T. S.; H.Y. Chan; P.M. Hui; Johnson, N F

    2004-01-01

    We formulate a theory of agent-based models in which agents compete to be in a winning group. The agents may be part of a network or not, and the winning group may be a minority group or not. The novel feature of the present formalism is its focus on the dynamical pattern of strategy rankings, and its careful treatment of the strategy ties which arise during the system's temporal evolution. We apply it to the Minority Game (MG) with connected populations. Expressions for the mean success rate...

  5. Kirigami design and fabrication for biomimetic robotics

    Science.gov (United States)

    Rossiter, Jonathan; Sareh, Sina

    2014-03-01

    Biomimetics faces a continual challenge of how to bridge the gap between what Nature has so effectively evolved and the current tools and materials that engineers and scientists can exploit. Kirigami, from the Japanese `cut' and `paper', is a method of design where laminar materials are cut and then forced out-of-plane to yield 3D structures. Kirimimetic design provides a convenient and relatively closed design space within which to replicate some of the most interesting niche biological mechanisms. These include complex flexing organelles such as cilia in algae, energy storage and buckled structures in plants, and organic appendages that actuate out-of-plane such as the myoneme of the Vorticella protozoa. Where traditional kirigami employs passive materials which must be forced to transition to higher dimensions, we can exploit planar smart actuators and artificial muscles to create self-actuating kirigami structures. Here we review biomimetics with respect to the kirigami design and fabrication methods and examine how smart materials, including electroactive polymers and shape memory polymers, can be used to realise effective biomimetic components for robotic, deployable structures and engineering systems. One-way actuation, for example using shape memory polymers, can yield complete self-deploying structures. Bi-directional actuation, in contrast, can be exploited to mimic fundamental biological mechanisms such as thrust generation and fluid control. We present recent examples of kirigami robotic mechanisms and actuators and discuss planar fabrication methods, including rapid prototyping and 3D printing, and how current technologies, and their limitations, affect Kirigami robotics.

  6. Biomimetic Composite Structural T-joints

    Institute of Scientific and Technical Information of China (English)

    Vimal Kumar Thummalapalli; Steven L.Donaldson

    2012-01-01

    Biological structural fixed joints exhibit unique attributes,including highly optimized fiber paths which minimize stress concentrations.In addition,since the joints consist of continuous,uncut fiber architectures,the joints enable the organism to transport information and chemicals from one part of the body to the other.To the contrary,sections of man-made composite material structures are often joined using bolted or bonded joints,which involve low strength and high stress concentrations.These methods are also expensive to achieve.Additional functions such as fluid transport,electrical signal delivery,and thermal conductivity across the joints typically require parasitic tubes,wires,and attachment clips.By using the biomimetic methods,we seek to overcome the limitations which are present in the conventional methods. In the present work,biomimetic co-cured composite sandwich T-joints were constructed using unidirectional glass fiber,epoxy resin,and structural foam.The joints were fabricated using the wet lay-up vacuum bag resin infusion method.Foam sandwich T-joints with multiple continuous fiber architectures and sandwich foam thickness were prepared.The designs were tested in quasi-static bending using a mechanical load frame.The significantweight savings using the biomimetic approaches is discussed,as well as a comparison of failure modes versus architecture is described.

  7. Molecular docking and structure-based drug design strategies.

    Science.gov (United States)

    Ferreira, Leonardo G; Dos Santos, Ricardo N; Oliva, Glaucius; Andricopulo, Adriano D

    2015-07-22

    Pharmaceutical research has successfully incorporated a wealth of molecular modeling methods, within a variety of drug discovery programs, to study complex biological and chemical systems. The integration of computational and experimental strategies has been of great value in the identification and development of novel promising compounds. Broadly used in modern drug design, molecular docking methods explore the ligand conformations adopted within the binding sites of macromolecular targets. This approach also estimates the ligand-receptor binding free energy by evaluating critical phenomena involved in the intermolecular recognition process. Today, as a variety of docking algorithms are available, an understanding of the advantages and limitations of each method is of fundamental importance in the development of effective strategies and the generation of relevant results. The purpose of this review is to examine current molecular docking strategies used in drug discovery and medicinal chemistry, exploring the advances in the field and the role played by the integration of structure- and ligand-based methods.

  8. Investment Strategy Based on Aviation Accidents: Are there abnormal returns?

    Directory of Open Access Journals (Sweden)

    Marcos Rosa Costa

    2013-06-01

    Full Text Available This article investigates whether an investment strategy based on aviation accidents can generate abnormal returns. We performed an event study considering all the aviation accidents with more than 10 fatalities in the period from 1998 to 2009 and the stock market performance of the respective airlines and aircraft manufacturers in the days after the event. The tests performed were based on the model of Campbell, Lo & MacKinlay (1997 for definition of abnormal returns, by means of linear regression between the firms’ stock returns and the return of a market portfolio used as a benchmark. This enabled projecting the expected future returns of the airlines and aircraft makers, for comparison with the observed returns after each event. The result obtained suggests that an investment strategy based on aviation accidents is feasible because abnormal returns can be obtained in the period immediately following an aviation disaster.

  9. Engineering anisotropic biomimetic fibrocartilage microenvironment by bioprinting mesenchymal stem cells in nanoliter gel droplets.

    Science.gov (United States)

    Gurkan, Umut A; El Assal, Rami; Yildiz, Simin E; Sung, Yuree; Trachtenberg, Alexander J; Kuo, Winston P; Demirci, Utkan

    2014-07-07

    Over the past decade, bioprinting has emerged as a promising patterning strategy to organize cells and extracellular components both in two and three dimensions (2D and 3D) to engineer functional tissue mimicking constructs. So far, tissue printing has neither been used for 3D patterning of mesenchymal stem cells (MSCs) in multiphase growth factor embedded 3D hydrogels nor been investigated phenotypically in terms of simultaneous differentiation into different cell types within the same micropatterned 3D tissue constructs. Accordingly, we demonstrated a biochemical gradient by bioprinting nanoliter droplets encapsulating human MSCs, bone morphogenetic protein 2 (BMP-2), and transforming growth factor β1 (TGF- β1), engineering an anisotropic biomimetic fibrocartilage microenvironment. Assessment of the model tissue construct displayed multiphasic anisotropy of the incorporated biochemical factors after patterning. Quantitative real time polymerase chain reaction (qRT-PCR) results suggested genomic expression patterns leading to simultaneous differentiation of MSC populations into osteogenic and chondrogenic phenotype within the multiphasic construct, evidenced by upregulation of osteogenesis and condrogenesis related genes during in vitro culture. Comprehensive phenotypic network and pathway analysis results, which were based on genomic expression data, indicated activation of differentiation related mechanisms, via signaling pathways, including TGF, BMP, and vascular endothelial growth factor.

  10. Teaching strategies to support evidence-based practice.

    Science.gov (United States)

    Winters, Charlene A; Echeverri, Rebecca

    2012-06-01

    Evidence-based practice is an expected core competency of all health care clinicians regardless of discipline. Use of evidence-based practice means integrating the best research with clinical expertise and patient values to achieve optimal health outcomes. Evidence-based practice requires nurses to access and appraise evidence rapidly before integrating it into clinical practice. Role modeling and integrating the skills necessary to develop evidence-based practice into clinical and nonclinical courses is an important part in developing positive attitudes toward evidence-based practice, an essential first step to using evidence to guide practice decisions. The step-by-step approach to evidence-based practice proposed by Melnyk and colleagues provides an excellent organizing framework for teaching strategies specifically designed to facilitate nurses' knowledge and skill development in evidence-based practice.

  11. Efficient learning strategy of Chinese characters based on network approach.

    Science.gov (United States)

    Yan, Xiaoyong; Fan, Ying; Di, Zengru; Havlin, Shlomo; Wu, Jinshan

    2013-01-01

    We develop an efficient learning strategy of Chinese characters based on the network of the hierarchical structural relations between Chinese characters. A more efficient strategy is that of learning the same number of useful Chinese characters in less effort or time. We construct a node-weighted network of Chinese characters, where character usage frequencies are used as node weights. Using this hierarchical node-weighted network, we propose a new learning method, the distributed node weight (DNW) strategy, which is based on a new measure of nodes' importance that considers both the weight of the nodes and its location in the network hierarchical structure. Chinese character learning strategies, particularly their learning order, are analyzed as dynamical processes over the network. We compare the efficiency of three theoretical learning methods and two commonly used methods from mainstream Chinese textbooks, one for Chinese elementary school students and the other for students learning Chinese as a second language. We find that the DNW method significantly outperforms the others, implying that the efficiency of current learning methods of major textbooks can be greatly improved.

  12. Efficient Plant Supervision Strategy Using NN Based Techniques

    Science.gov (United States)

    Garcia, Ramon Ferreiro; Rolle, Jose Luis Calvo; Castelo, Francisco Javier Perez

    Most of non-linear type one and type two control systems suffers from lack of detectability when model based techniques are applied on FDI (fault detection and isolation) tasks. In general, all types of processes suffer from lack of detectability also due to the ambiguity to discriminate the process, sensors and actuators in order to isolate any given fault. This work deals with a strategy to detect and isolate faults which include massive neural networks based functional approximation procedures associated to recursive rule based techniques applied to a parity space approach.

  13. Healthy Aging Promotion through Neuroscientific Information-Based Strategies.

    Science.gov (United States)

    Seinfeld, Sofia; Sanchez-Vives, Maria V

    2015-09-28

    To ensure the well-being of a rapidly growing elderly population, it is fundamental to find strategies to foster healthy brain aging. With this intention, we designed a program of scientific-based lectures aimed at dissemination by established neuroscientists about brain function, brain plasticity and how lifestyle influences the brain. We also carried out a pilot study on the impact of the lectures on attendees. The objective was to provide information to elderly people in order to encourage them to identify unhealthy and healthy daily habits, and more importantly, to promote behavioral changes towards healthy brain aging. Here we report on our experience. In order to determine the impact of the lectures in the daily routine of the attendees, we asked them to fill out questionnaires. Preliminary results indicate that neuroscientific information-based strategies can be a useful method to have a positive impact on the lives of elderly, increase their awareness on how to improve brain function and promote positive lifestyle modifications. Furthermore, based on self-reported data, we also found that through this strategy it is possible to promote behavioral changes related to nutrition, sleep, and realization of physical and cognitively stimulating activities. Finally, based on the results obtained, the importance of promoting self-efficacy and the empowerment of the older populations is highlighted.

  14. Biomimetic chemical sensors using bioengineered olfactory and taste cells

    OpenAIRE

    Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping; Wu, Chunsheng

    2014-01-01

    Biological olfactory and taste systems are natural chemical sensing systems with unique performances for the detection of environmental chemical signals. With the advances in olfactory and taste transduction mechanisms, biomimetic chemical sensors have achieved significant progress due to their promising prospects and potential applications. Biomimetic chemical sensors exploit the unique capability of biological functional components for chemical sensing, which are often sourced from sensing ...

  15. Rule-based semantic web services matching strategy

    Science.gov (United States)

    Fan, Hong; Wang, Zhihua

    2011-12-01

    With the development of Web services technology, the number of service increases rapidly, and it becomes a challenge task that how to efficiently discovery the services that exactly match the user's requirements from the large scale of services library. Many semantic Web services discovery technologies proposed by the recent literatures only focus on the keyword-based or primary semantic based service's matching. This paper studies the rules and rule reasoning based service matching algorithm in the background of large scale services library. Firstly, the formal descriptions of semantic web services and service matching is presented. The services' matching are divided into four levels: Exact, Plugin, Subsume and Fail and their formal descriptions are also presented. Then, the service matching is regarded as rule-based reasoning issues. A set of match rules are firstly given and the related services set is retrieved from services ontology base through rule-based reasoning, and their matching levels are determined by distinguishing the relationships between service's I/O and user's request I/O. Finally, the experiment based on two services sets show that the proposed services matching strategy can easily implement the smart service discovery and obtains the high service discovery efficiency in comparison with the traditional global traversal strategy.

  16. Research Strategies in Science-based Start-ups

    DEFF Research Database (Denmark)

    Valentin, Finn; Dahlgren, Johan Henrich; Lund Jensen, Rasmus

    instead the attention to the quality of their science, or the roles of boards, management, and collaborative networks etc. Using a unique comprehensive dataset on Danish and Swedish biotech start-ups in drug discovery this paper analyzes their research strategies. Adopting a Simonean point of departure we......Although biotech start-ups fail or succeed based on their research few attempts have been made to examine if and how they strategize in this core of their activity. Popular views on Dedicated Biotech Firms (DBFs) see the inherent uncertainty of research as defying notions of strategizing, directing...... that Shonhoovens classical argument that "strategy matters" is valid not only for the larger high-tech firms covered by her study, but also for small research-based start-ups operating at the very well springs of knowledge where science directly interacts with technologies. Even though a lot more research...

  17. Improving Adenovirus Based Gene Transfer: Strategies to Accomplish Immune Evasion

    Directory of Open Access Journals (Sweden)

    Andrea Amalfitano

    2010-09-01

    Full Text Available Adenovirus (Ad based gene transfer vectors continue to be the platform of choice for an increasing number of clinical trials worldwide. In fact, within the last five years, the number of clinical trials that utilize Ad based vectors has doubled, indicating growing enthusiasm for the numerous positive characteristics of this gene transfer platform. For example, Ad vectors can be easily and relatively inexpensively produced to high titers in a cGMP compliant manner, can be stably stored and transported, and have a broad applicability for a wide range of clinical conditions, including both gene therapy and vaccine applications. Ad vector based gene transfer will become more useful as strategies to counteract innate and/or pre-existing adaptive immune responses to Ads are developed and confirmed to be efficacious. The approaches attempting to overcome these limitations can be divided into two broad categories: pre-emptive immune modulation of the host, and selective modification of the Ad vector itself. The first category of methods includes the use of immunosuppressive drugs or specific compounds to block important immune pathways, which are known to be induced by Ads. The second category comprises several innovative strategies inclusive of: (1 Ad-capsid-display of specific inhibitors or ligands; (2 covalent modifications of the entire Ad vector capsid moiety; (3 the use of tissue specific promoters and local administration routes; (4 the use of genome modified Ads; and (5 the development of chimeric or alternative serotype Ads. This review article will focus on both the promise and the limitations of each of these immune evasion strategies, and in the process delineate future directions in developing safer and more efficacious Ad-based gene transfer strategies.

  18. The Result Integration Algorithm Based on Matching Strategy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The following paper provides a new algorithm: a result integration algorithm based on matching strategy. The algorithm extracts the title and the abstract of Web pages, calculates the relevance between the query string and the Web pages, decides the Web pages accepted, rejected and sorts them out in user interfaces. The experiment results indicate obviously that the new algorithms improve the precision of meta-search engine. This technique is very useful to meta-search engine.

  19. A Novel Marketing Strategy based on Information Technology

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiao

    2012-01-01

    Marketing, electronic data interchange, internet data center, electric ordering system Abstract:Marketing is the process of performing market research, selling products and/or services to customers and promoting them via advertising to further enhance sales. It generates the strategy that underlies sales techniques, business communication, and business developments. Information technology is the acquisition, processing, storage and dissemination of vocal, pictorial, textual and numerical information by a microelectronics-based combination of computing and telecommunications.

  20. Biomimetics: forecasting the future of science, engineering, and medicine.

    Science.gov (United States)

    Hwang, Jangsun; Jeong, Yoon; Park, Jeong Min; Lee, Kwan Hong; Hong, Jong Wook; Choi, Jonghoon

    2015-01-01

    Biomimetics is the study of nature and natural phenomena to understand the principles of underlying mechanisms, to obtain ideas from nature, and to apply concepts that may benefit science, engineering, and medicine. Examples of biomimetic studies include fluid-drag reduction swimsuits inspired by the structure of shark's skin, velcro fasteners modeled on burrs, shape of airplanes developed from the look of birds, and stable building structures copied from the backbone of turban shells. In this article, we focus on the current research topics in biomimetics and discuss the potential of biomimetics in science, engineering, and medicine. Our report proposes to become a blueprint for accomplishments that can stem from biomimetics in the next 5 years as well as providing insight into their unseen limitations.

  1. The Impact of a Strategies-Based Instruction on Iranian EAP Students’ Reading Strategy Use: Developing Strategic EAP Readers

    Directory of Open Access Journals (Sweden)

    Seyyed Hossein Kashef

    2014-01-01

    Full Text Available Underperformance of students in EAP reading comprehension has been an issue of concern for teachers, syllabus designers, and curriculum developers in general and for EAP practitioners in particular. In spite of the fact that considerable efforts have been made to improve reading comprehension of students through strategies instruction over past decades, EAP students however have not benefited much from learning strategies. Thus, this study intended to investigate the impact of a Strategies-Based Instruction (SBI on undergraduate students’ reading strategy use in an EAP context. Taking an instructional model from strategies taxonomy of Oxford (1990; 2001, it was assumed that in contrast to conventional EAP reading methods, SBI would be more effective in encouraging reading strategy use and as a result developing reading comprehension of EAP students through encouraging the use of effective strategies and skills. To do so, 80 freshman undergraduate students were chosen as the participants of this study who were in two intact classes. After administration of a pre-test, treatment (22 sessions, 2 sessions per week, and a post-test, the collected data was analyzed using t-test to examine the effect of the proposed method of instruction. The results of the analysis showed that the teaching intervention had a significant effect on students’ reading strategy use. The findings have implications for teachers encouraging effective reading comprehension instruction through the use of strategies in EAP teaching contexts. Keywords: Strategies-based instruction; EAP; learning strategies; reading strategies; reading comprehension

  2. A gait planning method applied to hexapod biomimetic robot locomotion

    Institute of Scientific and Technical Information of China (English)

    Chen Fu; Yan Jihong; Zang Xizhe; Zhao Jie

    2009-01-01

    In order to fulfill the goal of autonomous walking on rough terrain, a distributed gait planning method applied to hexapod biomimetic robot locomotion is proposed based on the research effort of gait coordination mechanism of stick insect. The mathematical relation of walking velocity and gait pattern was depicted, a set of local rules operating between adjacent legs were put forward, and a distributed network of local rules for gait control was constructed. With the interaction of adjacent legs, adaptive adjustment of phase sequence fluctuation of walking legs resulting from change of terrain conditions or variety of walking speed was implemented to generate statically stable gait. In the simulation experiments, adaptive adjustment of inter-leg phase sequence and smooth transition of velocity and gait pattern were realized, and static stableness was ensured simultaneously, which provided the hexapod robot with the capability of walking on rough terrain stably and expeditiously.

  3. Efficient Enzyme-Free Biomimetic Sensors for Natural Phenol Detection.

    Science.gov (United States)

    Ferreira Garcia, Luane; Ribeiro Souza, Aparecido; Sanz Lobón, Germán; Dos Santos, Wallans Torres Pio; Alecrim, Morgana Fernandes; Fontes Santiago, Mariângela; de Sotomayor, Rafael Luque Álvarez; de Souza Gil, Eric

    2016-08-13

    The development of sensors and biosensors based on copper enzymes and/or copper oxides for phenol sensing is disclosed in this work. The electrochemical properties were studied by cyclic and differential pulse voltammetry using standard solutions of potassium ferrocyanide, phosphate/acetate buffers and representative natural phenols in a wide pH range (3.0 to 9.0). Among the natural phenols herein investigated, the highest sensitivity was observed for rutin, a powerful antioxidant widespread in functional foods and ubiquitous in the plant kingdom. The calibration curve for rutin performed at optimum pH (7.0) was linear in a broad concentration range, 1 to 120 µM (r = 0.99), showing detection limits of 0.4 µM. The optimized biomimetic sensor was also applied in total phenol determination in natural samples, exhibiting higher stability and sensitivity as well as distinct selectivity for antioxidant compounds.

  4. Biomimetic Yeast Cell Typing—Application of QCMs

    Directory of Open Access Journals (Sweden)

    Franz L. Dickert

    2009-10-01

    Full Text Available Artificial antibodies represent a key factor in the generation of sensing systems for the selective detection of bioanalytes of variable sizes. With biomimetic surfaces, the important model organism Saccharomyces cerevisiae and several of its growth stages may be detected. Quartz crystal microbalances (QCM with 10 MHz fundamental frequency and coated with polymers imprinted with synchronized yeast cells are presented, which are able to detect duplex cells with high selectivity. Furthermore, a multichannel quartz crystal microbalance (MQCM was designed and optimized for the measurement in liquids. This one-chip system based on four-electrode geometry allows the simultaneous detection of four analytes and, thus, provides a monitoring system for biotechnology and process control. For further standardization of the method, synthetic stamps containing plastic yeast cells in different growth stages were produced and utilized for imprinting. Mass-sensitive measurements with such MIPs resulted in the same sensor characteristics as obtained for those imprinted with native yeast cells.

  5. Transport of Carbon Dioxide through a Biomimetic Membrane

    Directory of Open Access Journals (Sweden)

    Efstathios Matsaridis

    2011-01-01

    Full Text Available Biomimetic membranes (BMM based on polymer filters impregnated with lipids or their analogues are widely applied in numerous areas of physics, biology, and medicine. In this paper we report the design and testing of an electrochemical system, which allows the investigation of CO2 transport through natural membranes such as alveoli barrier membrane system and also can be applied for solid-state measurements. The experimental setup comprises a specially designed two-compartment cell with BMM connected with an electrochemical workstation placed in a Faraday cage, two PH meters, and a nondispersive infrared gas analyzer. We prove, experimentally, that the CO2 transport through the natural membranes under different conditions depends on pH and displays a similar behavior as natural membranes. The influence of different drugs on the CO2 transport process through such membranes is discussed.

  6. A Novel Bio-mimetic Wireless Micro Robot for Endoscope

    Institute of Scientific and Technical Information of China (English)

    YE Dong-dong; YAN Guo-zheng; WANG Kua-dong; MA Guan-ying

    2008-01-01

    A novel bio-mimetic wireless micro robot for endoscope is developed. Its autonomous manner is earthworm-like and driven by linear actuators based on DC motor. It is different from the conventional micro robot endoscope that wireless module is used for communicating and power transfer. The fabricated micro robot system is detailedly described, including structure, micro robot locomotion principle, communication control module and wireless power transfer module. The experimental results show that the driving force of the lineaar actuator can reach to 2.55 N and supplying power is up to 480 mW DC power for receiving coil in the proposed system, which all fulfill the need of the micro robot system. The micro robot can creep reliably in the large intestine of pig and other contact environments.

  7. Proposing an Evidence-Based Strategy for Software Requirements Engineering.

    Science.gov (United States)

    Lindoerfer, Doris; Mansmann, Ulrich

    2016-01-01

    This paper discusses an evidence-based approach to software requirements engineering. The approach is called evidence-based, since it uses publications on the specific problem as a surrogate for stakeholder interests, to formulate risks and testing experiences. This complements the idea that agile software development models are more relevant, in which requirements and solutions evolve through collaboration between self-organizing cross-functional teams. The strategy is exemplified and applied to the development of a Software Requirements list used to develop software systems for patient registries.

  8. A Comparative Evaluation of Computer Based and Non-Computer Based Instructional Strategies.

    Science.gov (United States)

    Emerson, Ian

    1988-01-01

    Compares the computer assisted instruction (CAI) tutorial with its non-computerized pedagogical roots: the Socratic Dialog with Skinner's Programmed Instruction. Tests the effectiveness of a CAI tutorial on diffusion and osmosis against four other interactive and non-interactive instructional strategies. Notes computer based strategies were…

  9. Community based rehabilitation: a strategy for peace-building

    Directory of Open Access Journals (Sweden)

    Hodgson Jennifer

    2002-11-01

    Full Text Available Abstract Background Certain features of peace-building distinguish it from peacekeeping, and make it an appropriate strategy in dealing with vertical conflict and low intensity conflict. However, some theorists suggest that attempts, through peace-building, to impose liberal values upon non-democratic cultures are misguided and lack an ethical basis. Discussion We have been investigating the peace-building properties of community based approaches to disability in a number of countries. This paper describes the practice and impact of peace-building through Community Based Rehabilitation (CBR strategies in the context of armed conflict. The ethical basis for peace-building through practical community initiatives is explored. A number of benefits and challenges to using CBR strategies for peace-building purposes are identified. Summary During post-conflict reconstruction, disability is a powerful emotive lever that can be used to mobilize cooperation between factions. We suggest that civil society, in contrast to state-level intervention, has a valuable role in reducing the risks of conflict through community initiatives.

  10. Robust High Performance Aquaporin based Biomimetic Membranes

    DEFF Research Database (Denmark)

    Helix Nielsen, Claus; Zhao, Yichun; Qiu, C.;

    2013-01-01

    on top of a support membrane. Control membranes, either without aquaporins or with the inactive AqpZ R189A mutant aquaporin served as controls. The separation performance of the membranes was evaluated by cross-flow forward osmosis (FO) and reverse osmosis (RO) tests. In RO the ABM achieved a water...

  11. Catechol-based biomimetic functional materials

    OpenAIRE

    Sedó, Josep; Saiz-Poseu, Javier; Busqué, Félix; Ruiz Molina, Daniel

    2013-01-01

    Catechols are found in nature taking part in a remarkably broad scope of biochemical processes and functions. Though not exclusively, such versatility may be traced back to several properties uniquely found together in the o-dihydroxyaryl chemical function; namely, its ability to establish reversible equilibria at moderate redox potentials and pHs and to irreversibly cross-link through complex oxidation mechanisms; its excellent chelating properties, greatly exemplified by, but by no means ex...

  12. Biomimetic virus-based colourimetric sensors

    Science.gov (United States)

    Oh, Jin-Woo; Chung, Woo-Jae; Heo, Kwang; Jin, Hyo-Eon; Lee, Byung Yang; Wang, Eddie; Zueger, Chris; Wong, Winnie; Meyer, Joel; Kim, Chuntae; Lee, So-Young; Kim, Won-Geun; Zemla, Marcin; Auer, Manfred; Hexemer, Alexander; Lee, Seung-Wuk

    2014-01-01

    Many materials in nature change colours in response to stimuli, making them attractive for use as sensor platform. However, both natural materials and their synthetic analogues lack selectivity towards specific chemicals, and introducing such selectivity remains a challenge. Here we report the self-assembly of genetically engineered viruses (M13 phage) into target-specific, colourimetric biosensors. The sensors are composed of phage-bundle nanostructures and exhibit viewing-angle independent colour, similar to collagen structures in turkey skin. On exposure to various volatile organic chemicals, the structures rapidly swell and undergo distinct colour changes. Furthermore, sensors composed of phage displaying trinitrotoluene (TNT)-binding peptide motifs identified from a phage display selectively distinguish TNT down to 300 p.p.b. over similarly structured chemicals. Our tunable, colourimetric sensors can be useful for the detection of a variety of harmful toxicants and pathogens to protect human health and national security.

  13. Bacterial Cellulose-based Biomimetic Composites

    OpenAIRE

    2010-01-01

    Microbial cellulose has proven to be a remarkably versatile biomaterial and can be used in a wide variety of fields, to produce for instance paper products, electronics, acoustics, and biomedical devices. Various biodegradable and biocompatible polymeric materials have recently been investigated to fabricate inorganic-organic hybrid composites by mimicking the mineralization system of natural bone, with some successful outcomes. However, the search for an ideal biomaterial with properties and...

  14. Towards a biomimetic gyroscope inspired by the fly's haltere using microelectromechanical systems technology.

    Science.gov (United States)

    Droogendijk, H; Brookhuis, R A; de Boer, M J; Sanders, R G P; Krijnen, G J M

    2014-10-06

    Flies use so-called halteres to sense body rotation based on Coriolis forces for supporting equilibrium reflexes. Inspired by these halteres, a biomimetic gimbal-suspended gyroscope has been developed using microelectromechanical systems (MEMS) technology. Design rules for this type of gyroscope are derived, in which the haltere-inspired MEMS gyroscope is geared towards a large measurement bandwidth and a fast response, rather than towards a high responsivity. Measurements for the biomimetic gyroscope indicate a (drive mode) resonance frequency of about 550 Hz and a damping ratio of 0.9. Further, the theoretical performance of the fly's gyroscopic system and the developed MEMS haltere-based gyroscope is assessed and the potential of this MEMS gyroscope is discussed.

  15. Long-term, high frequency in situ measurements of intertidal mussel bed temperatures using biomimetic sensors

    Science.gov (United States)

    Helmuth, Brian; Choi, Francis; Matzelle, Allison; Torossian, Jessica L.; Morello, Scott L.; Mislan, K. A. S.; Yamane, Lauren; Strickland, Denise; Szathmary, P. Lauren; Gilman, Sarah E.; Tockstein, Alyson; Hilbish, Thomas J.; Burrows, Michael T.; Power, Anne Marie; Gosling, Elizabeth; Mieszkowska, Nova; Harley, Christopher D. G.; Nishizaki, Michael; Carrington, Emily; Menge, Bruce; Petes, Laura; Foley, Melissa M.; Johnson, Angela; Poole, Megan; Noble, Mae M.; Richmond, Erin L.; Robart, Matt; Robinson, Jonathan; Sapp, Jerod; Sones, Jackie; Broitman, Bernardo R.; Denny, Mark W.; Mach, Katharine J.; Miller, Luke P.; O'Donnell, Michael; Ross, Philip; Hofmann, Gretchen E.; Zippay, Mackenzie; Blanchette, Carol; Macfarlan, J. A.; Carpizo-Ituarte, Eugenio; Ruttenberg, Benjamin; Peña Mejía, Carlos E.; McQuaid, Christopher D.; Lathlean, Justin; Monaco, Cristián J.; Nicastro, Katy R.; Zardi, Gerardo

    2016-10-01

    At a proximal level, the physiological impacts of global climate change on ectothermic organisms are manifest as changes in body temperatures. Especially for plants and animals exposed to direct solar radiation, body temperatures can be substantially different from air temperatures. We deployed biomimetic sensors that approximate the thermal characteristics of intertidal mussels at 71 sites worldwide, from 1998-present. Loggers recorded temperatures at 10-30 min intervals nearly continuously at multiple intertidal elevations. Comparisons against direct measurements of mussel tissue temperature indicated errors of ~2.0-2.5 °C, during daily fluctuations that often exceeded 15°-20 °C. Geographic patterns in thermal stress based on biomimetic logger measurements were generally far more complex than anticipated based only on ‘habitat-level’ measurements of air or sea surface temperature. This unique data set provides an opportunity to link physiological measurements with spatially- and temporally-explicit field observations of body temperature.

  16. Biomimetic Experimental Research on Hexapod Robot's Locomotion Planning

    Institute of Scientific and Technical Information of China (English)

    HUANG Lin; HAN Bao-ling; LUO Qing-sheng; ZHANG Chun-lin; XU Jia

    2009-01-01

    To provide hexapod robots with strategies of locomotion planning,observation experiments were operated on a kind of ant with the use of high speed digital photography and computer assistant analysis.Through digitalization of original analog video,locomotion characters of ants were obtained,the biomimetic foundation was laid for polynomial trajectory planning of multi-legged robots,which was deduced with mathematics method.In addition,five rules were concluded,which apply to hexapod robots marching locomotion planning.The first one is the fundamental strategy of multi-legged robots' leg trajectory planning.The second one helps to enhance the static and dynamic stability of multi-legged robots.The third one can improve the validity and feasibility of legs' falling points.The last two give criterions of multi-legged robots' toe trajectory figures and practical recommendatory constraints.These five rules give a good method for marching locomotion planning of multi-legged robots,and can be expended to turning planning and any other special locomotion.

  17. An adaptive fusion strategy of polarization image based on NSCT

    Science.gov (United States)

    Zhao, Chang-xia; Duan, Jin; Mo, Chun-he; Chen, Guang-qiu; Fu, Qiang

    2015-03-01

    An improved image fusion algorithm based on the NSCT is proposed in this paper. After decomposition NSCT method of multi-scale and multiple directions, polarization image was decomposed into two parts: low frequency sub-band and high frequency band-pass images. The fusion strategy of combining local regional energy and gradient structure similarity were used in low-frequency coefficients. While in the high-frequency band-pass coefficients part, the fusion strategy of the location spatial frequency as the correlation coefficient was used. The intensity image and polarization degree image are fused for improving the sharpness and contrast of the image. The experiments show that the algorithm is effective to improve the imaging quality in the turbid medium.

  18. A multipronged, nutritional-based strategy for managing Alzheimer's disease.

    Science.gov (United States)

    Glick, J Leslie; McMillan, Philip A

    2016-06-01

    A nutritional-based strategy has been proposed in order to improve cognitive performance of Alzheimer's disease (AD) patients. The strategy requires daily dietary supplementation with magnesium (Mg), folic acid, and vitamins B6 and B12, daily consumption of silicic acid-rich mineral water in order to lower the body burden of Al, and several plasma exchange procedures in order to replace Aβ-bound albumin with fresh albumin. Evidence suggests that the deteriorating cognitive performance associated with AD may be improved by supplementation with either Mg alone or with the combination of the above three B vitamins (B vitamin combo), or by drinking silicic acid-rich mineral water, or by undergoing plasma exchange. However, for the following reasons the combination of all four therapeutic approaches may have a synergistic effect on improving cognitive performance of AD patients.

  19. Available Bandwidth Estimation Strategy Based on the Network Allocation Vector

    Directory of Open Access Journals (Sweden)

    Hongtao Liu

    2012-12-01

    Full Text Available Available bandwidth is of great importance to network Quality of Service assurance, network load balancing, streaming media rate control, routing, and congestion control, etc.. In this paper, the available bandwidth estimation strategy based on the Network Allocation Vector for Wireless Sensor Networks is proposed. According to the size of the average contention window, network nodes predict the probability of collision in process of frame transmission, and then estimate the number of retransmission. Through the collection of Hello packets periodically sent by neighbors, nodes obtain their Network Allocation Vector, and then estimate the available bandwidth. The simulation results show that the strategy is simple and effective, can accurately estimate the collision of data frames as well as the available bandwidth of Wireless Sensor Networks.

  20. Congestion Control Strategy for Opportunistic Network Based on Message Values

    Directory of Open Access Journals (Sweden)

    Deng-yin Zhang

    2014-05-01

    Full Text Available To solve the congestion problem in opportunistic networks, a congestion control strategy based on message deleting and transferring(DATM is proposed. The congested node calculates the storage value of each message according to the forwarding probability and TTL of message, then deletes the message with the minimum storage value and transfers the message with the minimum forwarding probability to neighboring nodes. The neighboring nodes calculate the receiving value of the message according to the forwarding probability and free buffer capacity of this message. The congested node transfers the message to the neighboring node with the maximum receiving value. The message will be deleted when there is no neighboring node to receive it. The algorithm is more targeted at deleting messages. Besides, it combines the strategy of transferring message. Therefore, it can deal with the congestion more efficiently. The message arrival rate is improved significantly and the end-to-end delay is also reduced to some extent.

  1. Treatment-resistant schizophrenia: Evidence-based strategies

    Directory of Open Access Journals (Sweden)

    Susanne Englisch

    2012-01-01

    Full Text Available Treatment-resistant symptoms complicate the clinical course of schizophrenia, and a large proportion of patients do not reach functional recovery. In consequence, polypharmacy is frequently used in treatment-refractory cases, addressing psychotic positive, negative and cognitive symptoms, treatment-emergent side effects caused by antipsychotics and comorbid depressive or obsessive-compulsive symptoms. To a large extent, such strategies are not covered by pharmacological guidelines which strongly suggest antipsychotic monotherapy. Add-on strategies comprise combinations of several antipsychotic agents and augmentations with mood stabilizers; moreover, antidepressants and experimental substances are applied. Based on the accumulated evidence of clinical trials and meta-analyses, combinations of clozapine with certain second-generation antipsychotic agents and the augmentation of antipsychotics with antidepressants seem recommendable, while the augmentation with mood stabilizers cannot be considered superior to placebo. Forthcoming investigations will have to focus on innovative pharmacological agents, the clinical spectrum of cognitive deficits and the implementation of cognitive behavioral therapy.

  2. Multiobjective Optimization Based Vessel Collision Avoidance Strategy Optimization

    Directory of Open Access Journals (Sweden)

    Qingyang Xu

    2014-01-01

    Full Text Available The vessel collision accidents cause a great loss of lives and property. In order to reduce the human fault and greatly improve the safety of marine traffic, collision avoidance strategy optimization is proposed to achieve this. In the paper, a multiobjective optimization algorithm NSGA-II is adopted to search for the optimal collision avoidance strategy considering the safety as well as economy elements of collision avoidance. Ship domain and Arena are used to evaluate the collision risk in the simulation. Based on the optimization, an optimal rudder angle is recommended to navigator for collision avoidance. In the simulation example, a crossing encounter situation is simulated, and the NSGA-II searches for the optimal collision avoidance operation under the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS. The simulation studies exhibit the validity of the method.

  3. SEU mitigation strategies for SRAM-based FPGA

    Science.gov (United States)

    Luo, Pei; Zhang, Jian

    2011-08-01

    The type of Field Programmable Gate Arrays (FPGAs) technology and device family used in a design is a key factor for system reliability. Though antifuse-based FPGAs are widely used in aerospace because of their high reliability, current antifuse-based FPGA devices are expensive and leave no room for mistakes or changes since they are not reprogrammable. The substitute for antifuse-based FPGAs are needed in aerospace design, they should be both reprogrammable and highly reliable to Single Event Upset effects (SEUs). SRAM-based FPGAs are widely and systematically used in complex embedding digital systems both in a single chip industry and commercial applications. They are reprogrammable and high in density because of the smaller SRAM cells and logic structures. But the SRAM-based FPGAs are especially sensitive to cosmic radiation because the configuration information is stored in SRAM memory. The ideal FPGA for aerospace use should be high-density SRAM-based which is also insensitive to cosmic radiation induced SEUs. Therefore, in order to enable the use of SRAM-based FPGAs in safety critical applications, new techniques and strategies are essential to mitigate the SEU errors in such devices. In order to improve the reliability of SRAM-based FPGAs which are very sensitive to SEU errors, techniques such as reconfiguration and Triple Module Redundancy (TMR) are widely used in the aerospace electronic systems to mitigate the SEU and Single Event Functional Interrupt (SEFI) errors. Compared to reconfiguration and triplication, scrubbing and partial reconfiguration will utilize fewer or even no internal resources of FPGA. What's more, the detection and repair process can detect and correct SEU errors in configuration memories of the FPGA without affecting or interrupting the proper working of the system while reconfiguration would terminate the operation of the FPGA. This paper presents a payload system realized on Xilinx Virtex-4 FPGA which mitigates SEU effects in the

  4. Biotechnologies and biomimetics for civil engineering

    CERN Document Server

    Labrincha, J; Diamanti, M; Yu, C-P; Lee, H

    2015-01-01

    Putting forward an innovative approach to solving current technological problems faced by human society, this book encompasses a holistic way of perceiving the potential of natural systems. Nature has developed several materials and processes which both maintain an optimal performance and are also totally biodegradable, properties which can be used in civil engineering. Delivering the latest research findings to building industry professionals and other practitioners, as well as containing information useful to the public, ‘Biotechnologies and Biomimetics for Civil Engineering’ serves as an important tool to tackle the challenges of a more sustainable construction industry and the future of buildings.

  5. Erythrocentaurin, Biosynthesis Postulation and Biomimetic Synthesis

    Institute of Scientific and Technical Information of China (English)

    LEI,Jun; YUAN,Xiang-Hui; LIU,Zhu-Lan; LIU,Jian-Li

    2004-01-01

    @@ Erythrocentaurin is a relatively simple nature product isolated from the root of Gentiana macrophylla Pall.[1] The co-existed of gentiopicroside from the same species led to speculation that erythrocentaurin is a biosynthesis product of gentiopicroside. The transformation of secologanin to carbocyclic aglycone under biomimetic condition has already known (Scheme 1).[2,3] The postulated biosynthesis pathway of erythrocentaurin may be in the same way. In the process the cyclic hemiacetal of the aglycone opened to the dialdehyde which then undergoes a vinylogous aldol reaction, and then dehydroxylation and double bond migration to the title compound (Scheme 2).

  6. Biomimetic magnetic nanocomposite for smart skins

    KAUST Repository

    Alfadhel, Ahmed

    2015-11-01

    We report a biomimetic tactile sensor consisting of magnetic nanocomposite artificial cilia and magnetic sensors. The nanocomposite is fashioned from polydimethylsiloxane and iron nanowires and exhibits a permanent magnetic behavior. This enables remote operation without an additional magnetic field to magnetize the nanowires, which simplifies device integration. Moreover, the highly elastic and easy patternable nanocomposite is corrosion resistant and thermally stable. The highly sensitive and power efficient tactile sensors can detect vertical and shear forces from interactions with objects. The sensors can operate in dry and wet environment with the ability to measure different properties such as the texture and the movement or stability of objects, with easily adjustable performance.

  7. Synthesis of the Biomimetic Polymer: Aliphatic Diamine and RGDS Modified Poly(d,l-lactic acid)

    Institute of Scientific and Technical Information of China (English)

    Xu Feng NIU; Yuan Liang WANG; Yan Feng LUO; Jun PAN; Juan Fang SHANG; Li Xia GUO

    2005-01-01

    A novel poly(d,l-lactic acid) (PDLLA) based biomimetic polymer was synthesized by grafting maleic anhydride, butanediamine and arg-gly-asp-ser (RGDS) peptides onto the backbone of PDLLA, aiming to overcome the acidity and auto-accelerating degradation of PDLLA during degradation and to improve its biospecificity and biocompatibility. The synthetic copolymer was characterized by FTIR, 13C NMR and amino acid analyzer (AAA).

  8. Water-Soluble Cellulose Derivatives Are Sustainable Additives for Biomimetic Calcium Phosphate Mineralization

    OpenAIRE

    2016-01-01

    The effect of cellulose-based polyelectrolytes on biomimetic calcium phosphate mineralization is described. Three cellulose derivatives, a polyanion, a polycation, and a polyzwitterion were used as additives. Scanning electron microscopy, X-ray diffraction, IR and Raman spectroscopy show that, depending on the composition of the starting solution, hydroxyapatite or brushite precipitates form. Infrared and Raman spectroscopy also show that significant amounts of nitrate ions are incorporated i...

  9. Design and Implementation of a Biomimetic Turtle Hydrofoil for an Autonomous Underwater Vehicle

    OpenAIRE

    Jordi Palacin; Cedric Pradalier; Mercè Teixidó; Tomàs Pallejà; Cedric Siegentahler; Marcel Tresanchez; Davinia Font

    2011-01-01

    This paper presents the design and implementation of a turtle hydrofoil for an Autonomous Underwater Vehicle (AUV). The final design of the AUV must have navigation performance like a turtle, which has also been the biomimetic inspiration for the design of the hydrofoil and propulsion system. The hydrofoil design is based on a National Advisory Committee for Aeronautics (NACA) 0014 hydrodynamic profile. During the design stage, four different propulsion systems were compared in terms of propu...

  10. Improved Offline Connected Script Recognition Based on Hybrid Strategy

    Directory of Open Access Journals (Sweden)

    Tanzila Saba

    2010-06-01

    Full Text Available In domain of analytic cursive word recognition, there are two main approaches: explicit segmentation based and implicit segmentation based. However, both approaches have their own shortcomings. To overcome individual weaknesses, this paper presents a hybrid strategy for recognition of strings of characters (words or numerals. In a two stage dynamic programming based, lexicon driven approach, first an explicit segmentation is applied to segment either cursive andwritten words or numeric strings. However, at this stage, segmentation points are not finalized. In the second verification stage, statistical features are extracted from each segmented area to recognize characters using a trained neural network. To enhance segmentation and recognition accuracy, lexicon is consulted using existing dynamic programming matching techniques. Accordingly, segmentation points are altered to decide true character boundaries byusing lexicon feedback. A rigorous experimental protocol shows high performance of the proposed method for cursive handwritten words and numeral strings.

  11. Molecular Docking and Structure-Based Drug Design Strategies

    Directory of Open Access Journals (Sweden)

    Leonardo G. Ferreira

    2015-07-01

    Full Text Available Pharmaceutical research has successfully incorporated a wealth of molecular modeling methods, within a variety of drug discovery programs, to study complex biological and chemical systems. The integration of computational and experimental strategies has been of great value in the identification and development of novel promising compounds. Broadly used in modern drug design, molecular docking methods explore the ligand conformations adopted within the binding sites of macromolecular targets. This approach also estimates the ligand-receptor binding free energy by evaluating critical phenomena involved in the intermolecular recognition process. Today, as a variety of docking algorithms are available, an understanding of the advantages and limitations of each method is of fundamental importance in the development of effective strategies and the generation of relevant results. The purpose of this review is to examine current molecular docking strategies used in drug discovery and medicinal chemistry, exploring the advances in the field and the role played by the integration of structure- and ligand-based methods.

  12. An Ethernet LAN based distributed generation system load shedding strategy

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    2011-01-01

    This paper firstly analyzes and compares various communication technologies, and proposes a communication system for a distributed generation system (DGS) with wind turbines. Then the paper presents a novel simulation method of considering the interactions between the communication system and power...... system, by using two software platforms: OPNET and EMTDC/PSCAD. A control method based on the communication technique has been designed to stabilize the DG system during power system disturbances. A case study is presented to demonstrate the effectiveness of the proposed communication system, simulation...... method and control strategy....

  13. Biomimetic Spider Leg Joints: A Review from Biomechanical Research to Compliant Robotic Actuators

    Directory of Open Access Journals (Sweden)

    Stefan Landkammer

    2016-07-01

    Full Text Available Due to their inherent compliance, soft actuated joints are becoming increasingly important for robotic applications, especially when human-robot-interactions are expected. Several of these flexible actuators are inspired by biological models. One perfect showpiece for biomimetic robots is the spider leg, because it combines lightweight design and graceful movements with powerful and dynamic actuation. Building on this motivation, the review article focuses on compliant robotic joints inspired by the function principle of the spider leg. The mechanism is introduced by an overview of existing biological and biomechanical research. Thereupon a classification of robots that are bio-inspired by spider joints is presented. Based on this, the biomimetic robot applications referring to the spider principle are identified and discussed.

  14. A new three dimensional biomimetic hydrogel to deliver factors secreted by human mesenchymal stem cells in spinal cord injury.

    Science.gov (United States)

    Caron, Ilaria; Rossi, Filippo; Papa, Simonetta; Aloe, Rossella; Sculco, Marika; Mauri, Emanuele; Sacchetti, Alessandro; Erba, Eugenio; Panini, Nicolò; Parazzi, Valentina; Barilani, Mario; Forloni, Gianluigi; Perale, Giuseppe; Lazzari, Lorenza; Veglianese, Pietro

    2016-01-01

    Stem cell therapy with human mesenchymal stem cells (hMSCs) represents a promising strategy in spinal cord injury (SCI). However, both systemic and parenchymal hMSCs administrations show significant drawbacks as a limited number and viability of stem cells in situ. Biomaterials able to encapsulate and sustain hMSCs represent a viable approach to overcome these limitations potentially improving the stem cell therapy. In this study, we evaluate a new agarose/carbomer based hydrogel which combines different strategies to optimize hMSCs viability, density and delivery of paracrine factors. Specifically, we evaluate a new loading procedure on a lyophilized scaffold (soaked up effect) that reduces mechanical stress in encapsulating hMSCs into the hydrogel. In addition, we combine arginine-glycine-aspartic acid (RGD) tripeptide and 3D extracellular matrix deposition to increase the capacity to attach and maintain healthy hMSCs within the hydrogel over time. Furthermore, the fluidic diffusion from the hydrogel toward the injury site is improved by using a cling film that oriented efficaciously the delivery of paracrine factors in vivo. Finally, we demonstrate that an improved combination as here proposed of hMSCs and biomimetic hydrogel is able to immunomodulate significantly the pro-inflammatory environment in a SCI mouse model, increasing M2 macrophagic population and promoting a pro-regenerative environment in situ.

  15. Biomimetics as a design methodology – possibilities and challenges

    DEFF Research Database (Denmark)

    Lenau, Torben Anker

    2009-01-01

    Biomimetics – or bionik as it is called in parts of Europe – offer a number of promising opportunities and challenges for the designer. The paper investigates how biomimetics as a design methodology is used in engineering design by looking at examples of biological searches and highlight...... the possibilities and challenges. Biomimetics for engineering design is explored through an experiment involving 12 design engineering students. For 7 selected problem areas they searched biology literature available at a university library and identified a number of biological solutions. Central solution...

  16. Biomimetics applied to centering in micro-assembly

    DEFF Research Database (Denmark)

    Shu, L.H.; Lenau, Torben Anker; Hansen, Hans Nørgaard;

    2003-01-01

    This paper describes the application of a biomimetic search method to develop ideas for centering objects in micro-assembly. Biomimetics involves the imitation of biological phenomena to solve problems. An obstacle to the use of biomimetics in engineering is knowledge of biological phenomena...... that is relevant to the problem at hand. The method described here starts with an engineering problem, and then systematically searches for analogous biological phenomena using functional keywords. This method is illustrated by finding and using analogies for the problem of positioning and centering objects during...

  17. The Effect of Strategy Instruction Based on the Cognitive Academic Language Learning Approach over Reading Comprehension and Strategy Use

    Science.gov (United States)

    Gurses, Meral Ozkan; Adiguzel, Oktay Cem

    2013-01-01

    This study investigates the effects of reading strategies instruction based on the Cognitive Academic Language Learning Approach over students' skill to comprehend what they read in French and their use of reading strategies. It has an action research design. Eighteen students studying at French Preparatory Program at Eskisehir Osmangazi…

  18. Nature-Based Strategies for Improving Urban Health and Safety.

    Science.gov (United States)

    Kondo, Michelle C; South, Eugenia C; Branas, Charles C

    2015-10-01

    Place-based programs are being noticed as key opportunities to prevent disease and promote public health and safety for populations at-large. As one key type of place-based intervention, nature-based and green space strategies can play an especially large role in improving health and safety for dwellers in urban environments such as US legacy cities that lack nature and greenery. In this paper, we describe the current understanding of place-based influences on public health and safety. We focus on nonchemical environmental factors, many of which are related to urban abandonment and blight. We then review findings from studies of nature-based interventions regarding impacts on health, perceptions of safety, and crime. Based on our findings, we suggest that further research in this area will require (1) refined measures of green space, nature, and health and safety for cities, (2) interdisciplinary science and cross-sector policy collaboration, (3) observational studies as well as randomized controlled experiments and natural experiments using appropriate spatial counterfactuals and mixed methods, and (4) return-on-investment calculations of potential economic, social, and health costs and benefits of urban greening initiatives.

  19. Research of information classification and strategy intelligence extract algorithm based on military strategy hall

    Science.gov (United States)

    Chen, Lei; Li, Dehua; Yang, Jie

    2007-12-01

    Constructing virtual international strategy environment needs many kinds of information, such as economy, politic, military, diploma, culture, science, etc. So it is very important to build an information auto-extract, classification, recombination and analysis management system with high efficiency as the foundation and component of military strategy hall. This paper firstly use improved Boost algorithm to classify obtained initial information, then use a strategy intelligence extract algorithm to extract strategy intelligence from initial information to help strategist to analysis information.

  20. Cloud Task Scheduling for Load Balancing based on Intelligent Strategy

    Directory of Open Access Journals (Sweden)

    Arabi E. keshk

    2014-04-01

    Full Text Available Cloud computing is a type of parallel and distributed system consisting of a collection of interconnected and virtual computers. With the increasing demand and benefits of cloud computing infrastructure, different computing can be performed on cloud environment. One of the fundamental issues in this environment is related to task scheduling. Cloud task scheduling is an NP-hard optimization problem, and many meta-heuristic algorithms have been proposed to solve it. A good task scheduler should adapt its scheduling strategy to the changing environment and the types of tasks. In this paper a cloud task scheduling policy based on ant colony optimization algorithm for load balancing compared with different scheduling algorithms has been proposed. Ant Colony Optimization (ACO is random optimization search approach that will be used for allocating the incoming jobs to the virtual machines. The main contribution of our work is to balance the system load while trying to minimizing the make span of a given tasks set. The load balancing factor, related to the job finishing rate, is proposed to make the job finishing rate at different resource being similar and the ability of the load balancing will be improved. The proposed scheduling strategy was simulated using Cloudsim toolkit package. Experimental results showed that, the proposed algorithm outperformed scheduling algorithms that are based on the basic ACO or Modified Ant Colony Optimization (MACO.

  1. Die Face Engineering based Springback Compensation Strategy and Implementation

    Science.gov (United States)

    Tang, Arthur; Lee, Wing; He, Jeanne; Xu, Jinbo; Liu, Kesu; Chen, Chin Chun

    2005-08-01

    Springback or shape change has been one of the major challenges in sheet metal fabrication, particularly with increase application of high strength steel (HSS) and aluminum alloys in automotive stamping. Springback, an elastic material recovery after the unloading of stamping tools, causes variations and inconsistencies of final part dimensions. Minor or mild springback usually can be corrected in the re-strike process. Excessive springback must be corrected so the part will be produced within the given design tolerance and dimension. The commonly used Spring Forward approaches and shape compensations such as over-crown and over-bending are proven effective to alleviate excessive springback. To enhance these approaches, a new strategy of Die Face Engineering (DFE) based processing is proposed to quickly and easily to achieve the maximum allowable compensation using the under cut (or die lock) as the primary criteria. The implementation of the die face compensation through iterative FEA calculation, automatic surface mapping, projection and manual morphing are crucial to meet production environment requirements in terms of generating NC quality CAD surfaces of the compensated or morphed die face. In this paper, the strategy of the die face compensation with the consideration of the under cut criteria is presented. The implementation of various processes to enable user to perform the die face compensation task in a production environment is also discussed. Finally, two examples are shown to demonstrate the implementation of the proposed springback compensation scheme based on the combined CAE/CAD methodology.

  2. An Enhanced Differential Evolution Algorithm Based on Multiple Mutation Strategies

    Directory of Open Access Journals (Sweden)

    Wan-li Xiang

    2015-01-01

    Full Text Available Differential evolution algorithm is a simple yet efficient metaheuristic for global optimization over continuous spaces. However, there is a shortcoming of premature convergence in standard DE, especially in DE/best/1/bin. In order to take advantage of direction guidance information of the best individual of DE/best/1/bin and avoid getting into local trap, based on multiple mutation strategies, an enhanced differential evolution algorithm, named EDE, is proposed in this paper. In the EDE algorithm, an initialization technique, opposition-based learning initialization for improving the initial solution quality, and a new combined mutation strategy composed of DE/current/1/bin together with DE/pbest/bin/1 for the sake of accelerating standard DE and preventing DE from clustering around the global best individual, as well as a perturbation scheme for further avoiding premature convergence, are integrated. In addition, we also introduce two linear time-varying functions, which are used to decide which solution search equation is chosen at the phases of mutation and perturbation, respectively. Experimental results tested on twenty-five benchmark functions show that EDE is far better than the standard DE. In further comparisons, EDE is compared with other five state-of-the-art approaches and related results show that EDE is still superior to or at least equal to these methods on most of benchmark functions.

  3. Occasion Based Promotional Strategies of Consumer Durable Segment in Kerala

    Directory of Open Access Journals (Sweden)

    George Stanley

    2012-06-01

    Full Text Available Occasion Based Marketing is an approach to connect when and why consumers use the product with how they shop for the product. Companies need to realize that their customers are not only different from each other, but are also different from themselves at different times. People have different needs when they are at work and when they are at home or socializing. They act differently during holiday seasons and at regular days. Kerala is highly developed market for consumer products. National as well as International brands have been trying to have a fair share of this market. The study is focused mainly on the promotional strategies of consumer durable companies and retailers during festival season. The high frequency of promotional campaigns by entire consumer durable companies and retailers during festival seasons clearly shows the importance of Occasion Based Marketing in Kerala market. The results of this study would mean that the consumer durable companies and retailers are adapting various promotional strategies to attract deal prone, promotion liking customers.

  4. Clonal Strategy Algorithm Based on the Immune Memory

    Institute of Scientific and Technical Information of China (English)

    Ruo-Chen Liu; Li-Cheng Jiao; Hai-Feng Du

    2005-01-01

    Based on the clonal selection theory and immune memory mechanism in the natural immune system, a novel artificial immune system algorithm, Clonal Strategy Algorithm based on the Immune Memory (CSAIM), is proposed in this paper. The algorithm realizes the evolution of antibody population and the evolution of memory unit at the same time, and by using clonal selection operator, the global optimal computation can be combined with the local searching. According to antibody-antibody (Ab-Ab) affinity and antibody-antigen (Ab-Ag) affinity, the algorithm can allot adaptively the scales of memory unit and antibody population. It is proved theoretically that CSAIM is convergent with probability 1. And with the computer simulations of eight benchmark functions and one instance of traveling salesman problem (TSP), it is shown that CSAIM has strong abilities in having high convergence speed, enhancing the diversity of the population and avoiding the premature convergence to some extent.

  5. Evaluating Personal Archiving Strategies for Internet-based Information

    CERN Document Server

    Marshall, Catherine C; Nelson, Michael L

    2007-01-01

    Internet-based personal digital belongings present different vulnerabilities than locally stored materials. We use responses to a survey of people who have recovered lost websites, in combination with supplementary interviews, to paint a fuller picture of current curatorial strategies and practices. We examine the types of personal, topical, and commercial websites that respondents have lost and the reasons they have lost this potentially valuable material. We further explore what they have tried to recover and how the loss influences their subsequent practices. We found that curation of personal digital materials in online stores bears some striking similarities to the curation of similar materials stored locally in that study participants continue to archive personal assets by relying on a combination of benign neglect, sporadic backups, and unsystematic file replication. However, we have also identified issues specific to Internet-based material: how risk is spread by distributing the files among multiple ...

  6. Design of a wireless biomimetic fish-like robot based on ICPF actuator%基于ICPF驱动器无线仿生鱼型机器人设计

    Institute of Scientific and Technical Information of China (English)

    樊成; 魏祥; 冯磊; 郭健; 郭书祥

    2014-01-01

    In this paper, a wireless intelligent biomimetic fish-like robot has been developed. We choose the ICPF(Ionic Conducting Polymer Film) material as the actuator for the fish-like robot, to choose the 3-way infrared ob-stacle avoidance sensor embedded in fish eyes and fish mouth as the navigation system of the fish-like robot,to choose the Arduino Mini Pro as the main controller. Due to the characteristics of low power consumption of the ICPF material, the biomimetic fish-like robot can realize forward motion, turning motion and obstacle avoidance mo-tion without noise in water. In addition, the biomimetic fish-like robot can live with other real fish without interfer-ence in the same environment, the battery of the developed fish-like robot can last 3 hours, and it can realize on-line programming and can be charged in real-time. The experimental results indicated that the developed fish-like robot can move smoothly in water, the maximum velocity of the biomimetic fish-like robot can be obtained at 10.02 mm/s when the driving voltage is 9 V and the driving frequency is 1 Hz, the developed fish-like robot will be used to the field of military detection and ocean exploitation.%本文设计了一个无线智能仿生鱼型机器人.采用离子导电聚合物薄膜材料ICPF (Ionic conducting polymer film)作为机器人驱动器,在鱼眼和鱼嘴处内嵌3路红外避障传感器作为仿生鱼型机器人的导航系统,在机器人体内嵌入Arduino Mini Pro作为机器人的主控制器.由于选用低功耗的ICPF材料,该鱼型机器人续航时间长达3 h,该仿生鱼型机器人可实现在水中无噪声前进、转弯和避障等运动模式,且可以实现在线编程和实时充电.实验测试结果表明,该仿生鱼型机器人系统稳定,在水中运动如真实的鱼,可以同其他鱼类生物在同一环境中无干扰的交互生存,在9V、1 Hz电压信号的驱动下,最大游动速度为10.02 mm/s,该仿生鱼型机

  7. CHAPTER 6. Biomimetic Materials for Efficient Atmospheric Water Collection

    KAUST Repository

    Zhang, Lianbin

    2016-02-23

    Water scarcity is a severe problem in semi-arid desert regions, land-scarce countries and in countries with high levels of economic activity. In these regions, the collection of atmospheric water - for example, fog - is recognized as an important method of providing water. In nature, through millions of year evolution, some animals and plants in many of the arid regions have developed unique and highly efficient systems with delicate microstructures and composition for the purpose of fog collection to survive the harsh conditions. With the unique ability of fog collection, these creatures could readily cope with insufficient access to fresh water or lack of precipitation. These natural examples have inspired the design and fabrication of artificial fog collection materials and devices. In this chapter, we will first introduce some natural examples for their unique fog collection capability, and then give some examples of the bioinspired materials and devices that are fabricated artificially to mimic these natural creatures for the purpose of fog collection. We believe that the biomimetic strategy is one of the most promising routes for the design and fabrication of functional materials and devices for the solution of the global water crisis.

  8. Age-based differences in strategy use in choice tasks

    Directory of Open Access Journals (Sweden)

    Darrell A. Worthy

    2012-01-01

    Full Text Available We incorporated behavioral and computational modeling techniques to examine age-based differences in strategy use in two four-choice decision-making tasks. Healthy older (aged 60-82 years and younger adults (aged 18-23 years performed one of two decision-making tasks that differed in the degree to which rewards for each option depended on the choices made on previous trials. In the choice-independent task rewards for each choice were not affected by the sequence of previous choices that had been made. In contrast, in the choice-dependent task rewards for each option were based on how often each option had been chosen in the past. We compared the fits of a model that assumes the use of a win-stay-lose-shift (WSLS heuristic to make decisions, to the fits of a reinforcement-learning (RL model that compared expected reward values for each option to make decisions. Younger adults were best fit by the RL model, while older adults showed significantly more evidence of being best fit by the WSLS heuristic model. This led older adults to perform worse than younger adults in the choice-independent task, but better in the choice-dependent task. These results coincide with previous work in our labs that also found better performance for older adults in choice-dependent tasks (Worthy et al., 2011, and the present results suggest that qualitative age-based differences in the strategies used in choice tasks may underlie older adults’ advantage in choice-dependent tasks. We discuss possible factors behind these differences such as neurobiological changes associated with aging, and increased use of heuristics by older adults.

  9. Energy Optimal Control Strategy of PHEV Based on PMP Algorithm

    Directory of Open Access Journals (Sweden)

    Tiezhou Wu

    2017-01-01

    Full Text Available Under the global voice of “energy saving” and the current boom in the development of energy storage technology at home and abroad, energy optimal control of the whole hybrid electric vehicle power system, as one of the core technologies of electric vehicles, is bound to become a hot target of “clean energy” vehicle development and research. This paper considers the constraints to the performance of energy storage system in Parallel Hybrid Electric Vehicle (PHEV, from which lithium-ion battery frequently charges/discharges, PHEV largely consumes energy of fuel, and their are difficulty in energy recovery and other issues in a single cycle; the research uses lithium-ion battery combined with super-capacitor (SC, which is hybrid energy storage system (Li-SC HESS, working together with internal combustion engine (ICE to drive PHEV. Combined with PSO-PI controller and Li-SC HESS internal power limited management approach, the research proposes the PHEV energy optimal control strategy. It is based on revised Pontryagin’s minimum principle (PMP algorithm, which establishes the PHEV vehicle simulation model through ADVISOR software and verifies the effectiveness and feasibility. Finally, the results show that the energy optimization control strategy can improve the instantaneity of tracking PHEV minimum fuel consumption track, implement energy saving, and prolong the life of lithium-ion batteries and thereby can improve hybrid energy storage system performance.

  10. Function-based integration strategy for an agile manufacturing testbed

    Science.gov (United States)

    Park, Hisup

    1997-01-01

    This paper describes an integration strategy for plug-and- play software based on functional descriptions of the software modules. The functional descriptions identify explicitly the role of each module with respect to the overall systems. They define the critical dependencies that affect the individual modules and thus affect the behavior of the system. The specified roles, dependencies and behavioral constraints are then incorporated in a group of shared objects that are distributed over a network. These objects may be interchanged with others without disrupting the system so long as the replacements meet the interface and functional requirements. In this paper, we propose a framework for modeling the behavior of plug-and-play software modules that will be used to (1) design and predict the outcome of the integration, (2) generate the interface and functional requirements of individual modules, and (3) form a dynamic foundation for applying interchangeable software modules. I describe this strategy in the context of the development of an agile manufacturing testbed. The testbed represents a collection of production cells for machining operations, supported by a network of software modules or agents for planning, fabrication, and inspection. A process definition layer holds the functional description of the software modules. A network of distributed objects interact with one another over the Internet and comprise the plug-compatible software nodes that execute these functions. This paper will explore the technical and operational ramifications of using the functional description framework to organize and coordinate the distributed object modules.

  11. Design of a biomimetic polymer-composite hip prosthesis.

    Science.gov (United States)

    Bougherara, Habiba; Bureau, Martin; Campbell, Melissa; Vadean, Aurelian; Yahia, L'Hocine

    2007-07-01

    A new biomimetic composite hip prosthesis (stem) was designed to obtain properties similar to those of the contiguous bone, in particular stiffness, to allow normal loading of the surrounding femoral bone. This normal loading would reduce excessive stress shielding, known to result in bone loss, and micromotions at the bone-implant interface, leading to aseptic prosthetic loosening. The design proposed is based on a hollow substructure made of hydroxyapatite-coated, continuous carbon fiber (CF) reinforced polyamide 12 (PA12) composite with an internal soft polymer-based core. Different composite configurations were studied to match the properties of host tissue. Nonlinear three-dimensional analysis of the hip prosthesis was carried out using a three-dimensional finite element bone model based on the composite femur. The performance of composite-based hip and titanium alloy-based (Ti-6Al-4V) stems embedded into femoral bone was compared. The effect of core stiffness and ply configuration was also analyzed. Results show that stresses in composite stem are lower than those in Ti stem, and that the femoral bone implanted with composite structure sustains more load than the one implanted with Ti stem. Micromotions in the composite stem are significantly smaller than those in Ti stem over the entire bone-implant surface because of the favorable interfacial stress distribution.

  12. Biomimetic mineral coatings in dental and orthopaedic implantology

    Institute of Scientific and Technical Information of China (English)

    Yue-lian LIU; Klaas de GROOT; Ernst B.HUNZIKER

    2009-01-01

    Biomimetic techniques are used to deposit coatings of calcium phosphate upon medical devices. The procedure is conducted under near-physiological, or "biomimetic", conditions of temperature and pH primarily to improve their biocompatibility and biodegradability of the materials. The inorganic layers genelated by biomi-metic methods resemble bone mineral, and can be degraded within a biological milieu.The biomimetic coating technique involves the nuclea-tion and growth of bone-like crystals upon a pretreated substrate by immersing this in a supersaturated solution of calcium phosphate under physiological conditions of temperature (37~C) and pH (7.4). The method, originally developed by Kokubo in 1990, has since undergone improvement and refinement by several groups of investigators.Biomimetic coatings are valuable in that they can serve as a vehicle for the slow and sustained release of osteogenic agents at the site of implantation. This attribute is rendered possible by the near-physiological conditions under which these coatings are prepared, which permits an incorporation of binactive agents into the inorganic crystal latticework rather than their nlere superficial adsorption onto preformed layers. In addition, the biomimetic coating technique can be applied to implants of an organic as well as of an inorganic nature and to those with irregular surface geometries, which is not possible using conventional methodologies.

  13. Proteinuria: The diagnostic strategy based on urine proteins differentiation

    Directory of Open Access Journals (Sweden)

    Stojimirović Biljana B.

    2004-01-01

    Full Text Available Basal glomerular membrane represents mechanical and electrical barrier for passing of the plasma proteins. Mechanical barrier is composed of cylindrical pores and filtration fissure, and negative layer charge in exterior and interior side of basal glomerular membrane, made of heparan sulphate and sialoglicoproteine, provides certain electrical barrier. Diagnostic strategy based on different serum and urine proteins enables the differentiation of various types of proteinuria. Depending on etiology of proteinuria it can be prerenal, renal and postrenal. By analyzing albumin, armicroglobulin, immunoglobulin G and armacroglobulin, together with total protein in urine, it is possible to detect and differentiate causes of prerenal, renal (glomerular, tubular, glomerulo-tubular and postrenal proteinuria. The adequate and early differentiation of proteinuria type is of an immense diagnostic and therapeutic importance.

  14. Tissue-engineering-based strategies for regenerative endodontics.

    Science.gov (United States)

    Albuquerque, M T P; Valera, M C; Nakashima, M; Nör, J E; Bottino, M C

    2014-12-01

    Stemming from in vitro and in vivo pre-clinical and human models, tissue-engineering-based strategies continue to demonstrate great potential for the regeneration of the pulp-dentin complex, particularly in necrotic, immature permanent teeth. Nanofibrous scaffolds, which closely resemble the native extracellular matrix, have been successfully synthesized by various techniques, including but not limited to electrospinning. A common goal in scaffold synthesis has been the notion of promoting cell guidance through the careful design and use of a collection of biochemical and physical cues capable of governing and stimulating specific events at the cellular and tissue levels. The latest advances in processing technologies allow for the fabrication of scaffolds where selected bioactive molecules can be delivered locally, thus increasing the possibilities for clinical success. Though electrospun scaffolds have not yet been tested in vivo in either human or animal pulpless models in immature permanent teeth, recent studies have highlighted their regenerative potential both from an in vitro and in vivo (i.e., subcutaneous model) standpoint. Possible applications for these bioactive scaffolds continue to evolve, with significant prospects related to the regeneration of both dentin and pulp tissue and, more recently, to root canal disinfection. Nonetheless, no single implantable scaffold can consistently guide the coordinated growth and development of the multiple tissue types involved in the functional regeneration of the pulp-dentin complex. The purpose of this review is to provide a comprehensive perspective on the latest discoveries related to the use of scaffolds and/or stem cells in regenerative endodontics. The authors focused this review on bioactive nanofibrous scaffolds, injectable scaffolds and stem cells, and pre-clinical findings using stem-cell-based strategies. These topics are discussed in detail in an attempt to provide future direction and to shed light on

  15. Biomimetics for architecture & design nature, analogies, technology

    CERN Document Server

    Pohl, Göran

    2015-01-01

    This book provides the readers with a timely guide to the application of biomimetic principles in architecture and engineering design. As a result of a combined effort by two internationally recognized authorities, the biologist Werner Nachtigall and the architect Göran Pohl, the book describes the principles which can be used to compare nature and technology, and at the same time it presents detailed explanations and examples showing how biology can be used as a source of inspiration and “translated” in building and architectural solutions (biomimicry). Even though nature cannot be directly copied, the living world can provide architects and engineers with a wealth of analogues and inspirations for their own creative designs. But how can analysis of natural entities give rise to advanced and sustainable design? By reporting on the latest bionic design methods and using extensive artwork, the book guides readers through the field of nature-inspired architecture, offering an extraordinary resource for pro...

  16. Clues for biomimetics from natural composite materials

    Science.gov (United States)

    Lapidot, Shaul; Meirovitch, Sigal; Sharon, Sigal; Heyman, Arnon; Kaplan, David L; Shoseyov, Oded

    2013-01-01

    Bio-inspired material systems are derived from different living organisms such as plants, arthropods, mammals and marine organisms. These biomaterial systems from nature are always present in the form of composites, with molecular-scale interactions optimized to direct functional features. With interest in replacing synthetic materials with natural materials due to biocompatibility, sustainability and green chemistry issues, it is important to understand the molecular structure and chemistry of the raw component materials to also learn from their natural engineering, interfaces and interactions leading to durable and highly functional material architectures. This review will focus on applications of biomaterials in single material forms, as well as biomimetic composites inspired by natural organizational features. Examples of different natural composite systems will be described, followed by implementation of the principles underlying their composite organization into artificial bio-inspired systems for materials with new functional features for future medicine. PMID:22994958

  17. Electrochemical characterization of hydrogels for biomimetic applications

    DEFF Research Database (Denmark)

    Peláez, L.; Romero, V.; Escalera, S.

    2011-01-01

    ) or a photoinitiator (P) to encapsulate and stabilize biomimetic membranes for novel separation technologies or biosensor applications. In this paper, we have investigated the electrochemical properties of the hydrogels used for membrane encapsulation. Specifically, we studied the crosslinked hydrogels by using...... electrochemical impedance spectroscopy (EIS), and we demonstrated that chemically crosslinked hydrogels had lower values for the effective electrical resistance and higher values for the electrical capacitance compared with hydrogels with photoinitiated crosslinking. Transport numbers were obtained using......〉 and 〈Pw〉 values than PEG‐1000‐DMA‐P and PEG‐400‐DA‐P hydrogels. In conclusion, our results show that hydrogel electrochemical properties can be controlled by the choice of polymer and type of crosslinking used and that their water and salt permeability properties are congruent with the use of hydrogels...

  18. Progress of Biomimetic Artificial Nose and Tongue

    Science.gov (United States)

    Wang, Ping; Liu, Qingjun

    2009-05-01

    As two of the basic senses of human beings, olfaction and gustation play a very important role in daily life. These two types of chemical sensors are important for recognizing environmental conditions. Electronic nose and electronic tongue, which mimics animals' olfaction and gustation to detect odors and chemical components, have been carried out due to their potential commercial applications for biomedicine, food industry and environmental protection. In this report, the biomimetic artificial nose and tongue is presented. Firstly, the smell and taste sensors mimicking the mammalian olfaction and gustation was described, and then, some mimetic design of electronic nose and tongue for odorants and tastants detection are developed. Finally, olfactory and gustatory biosensors are presented as the developing trends of this field.

  19. A Biomimetic Approach to Lubricate Engineering Materials

    DEFF Research Database (Denmark)

    Røn, Troels

    This PhD thesis consists of studies on biomimetic aqueous boundary lubrication by applying amphihilic copolymers and hydrophobin proteins as lubricant addtives. Studies on the temperature dependency of neat water and hydrogel lubrication were also conducted. Amphiphilic diblock, triblock and graft...... copolymers were applied as synthetic boundary lubricant additives in water in relation to test the hypothesis that adsorbed polyelectrolyte brushes can displays the same superior lubricity over neutral brushes as has been observed for covalently anchored brushes. In the case of diblock copolymers......-b-PMEA-b-PMAA was also studied. After adsorption onto a nonpolar hydrophobic surface from aqueous solution, an equal and homogeneous mixture of neutral PEG and charged PMAA chains is formed on the surface, with an adsorbed polymer mass comparable to its fully neutral counterpart, PEG-b-PMEA-b-PEG. The lubricity of PEG...

  20. Challenges in biomimetic design and innovation

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Barfoed, Michael; Shu, Li

    challenge is illustrated by the beetle project which analyse photonic nanostructures in beetle shells in order to synthesise surface coatings. It shows that understanding the complexity in nature is far from being a trivial task. It involves the understanding of knowledge from different scientific domains...... including the terminology and knowledge organisation. It is often easy to recognise the splendour of a biological solution, but it can be much more difficult to understand the underlying mechanisms. Another challenge in biomimetic design is the search and identification of relevant solutions in nature....... This is a key issue in design and innovation work where problem identification and systematic search for suitable solution principle are major activities. One way to deal with this challenge is to use a biology search method. The use of such a method is illustrated with a case story describing the design...

  1. Biomimetic gyroid nanostructures exceeding their natural origins

    Science.gov (United States)

    Gan, Zongsong; Turner, Mark D.; Gu, Min

    2016-01-01

    Using optical two-beam lithography with improved resolution and enhanced mechanical strength, we demonstrate the replication of gyroid photonic nanostructures found in the butterfly Callophrys rubi. These artificial structures are shown to have size, controllability, and uniformity that are superior to those of their biological counterparts. In particular, the elastic Young’s modulus of fabricated nanowires is enhanced by up to 20%. As such, the circular dichroism enabled by the gyroid nanostructures can operate in the near-ultraviolet wavelength region, shorter than that supported by the natural butterfly wings of C. rubi. This fabrication technique provides a unique tool for extracting three-dimensional photonic designs from nature and will aid the investigation of biomimetic nanostructures. PMID:27386542

  2. Biomimetic gyroid nanostructures exceeding their natural origins.

    Science.gov (United States)

    Gan, Zongsong; Turner, Mark D; Gu, Min

    2016-05-01

    Using optical two-beam lithography with improved resolution and enhanced mechanical strength, we demonstrate the replication of gyroid photonic nanostructures found in the butterfly Callophrys rubi. These artificial structures are shown to have size, controllability, and uniformity that are superior to those of their biological counterparts. In particular, the elastic Young's modulus of fabricated nanowires is enhanced by up to 20%. As such, the circular dichroism enabled by the gyroid nanostructures can operate in the near-ultraviolet wavelength region, shorter than that supported by the natural butterfly wings of C. rubi. This fabrication technique provides a unique tool for extracting three-dimensional photonic designs from nature and will aid the investigation of biomimetic nanostructures.

  3. Development of a Biomimetic Quadruped Robot

    Institute of Scientific and Technical Information of China (English)

    Thanhtam Ho; Sunghac Choi; Sangyoon Lee

    2007-01-01

    This paper presents the design and prototype of a small quadruped robot whose walking motion is realized by two piezocomposite actuators. In the design, biomimetic ideas are employed to obtain the agility of motions and sustainability of a heavy load. The design of the robot legs is inspired by the leg configuration of insects, two joints (hip and knee) of the leg enable two basic motions, lifting and stepping. The robot frame is designed to have a slope relative to the horizontal plane, which makes the robot move forward. In addition, the bounding locomotion of quadruped animals is implemented in the robot. Experiments show that the robot can carry an additional load of about 100 g and run with a fairly high velocity. The quadruped prototype can be an important step towards the goal of building an autonomous mobile robot actuated by piezocomposite actuators.

  4. Computer-based learning: games as an instructional strategy.

    Science.gov (United States)

    Blake, J; Goodman, J

    1999-01-01

    Games are a creative teaching strategy that enhances learning and problem solving. Gaming strategies are being used by the authors to make learning interesting, stimulating and fun. This article focuses on the development and implementation of computer games as an instructional strategy. Positive outcomes have resulted from the use of games in the classroom.

  5. Bio-microfluidics: biomaterials and biomimetic designs.

    Science.gov (United States)

    Domachuk, Peter; Tsioris, Konstantinos; Omenetto, Fiorenzo G; Kaplan, David L

    2010-01-12

    Bio-microfluidics applies biomaterials and biologically inspired structural designs (biomimetics) to microfluidic devices. Microfluidics, the techniques for constraining fluids on the micrometer and sub-micrometer scale, offer applications ranging from lab-on-a-chip to optofluidics. Despite this wealth of applications, the design of typical microfluidic devices imparts relatively simple, laminar behavior on fluids and is realized using materials and techniques from silicon planar fabrication. On the other hand, highly complex microfluidic behavior is commonplace in nature, where fluids with nonlinear rheology flow through chaotic vasculature composed from a range of biopolymers. In this Review, the current state of bio-microfluidic materials, designs and applications are examined. Biopolymers enable bio-microfluidic devices with versatile functionalization chemistries, flexibility in fabrication, and biocompatibility in vitro and in vivo. Polymeric materials such as alginate, collagen, chitosan, and silk are being explored as bulk and film materials for bio-microfluidics. Hydrogels offer options for mechanically functional devices for microfluidic systems such as self-regulating valves, microlens arrays and drug release systems, vital for integrated bio-microfluidic devices. These devices including growth factor gradients to study cell responses, blood analysis, biomimetic capillary designs, and blood vessel tissue culture systems, as some recent examples of inroads in the field that should lead the way in a new generation of microfluidic devices for bio-related needs and applications. Perhaps one of the most intriguing directions for the future will be fully implantable microfluidic devices that will also integrate with existing vasculature and slowly degrade to fully recapitulate native tissue structure and function, yet serve critical interim functions, such as tissue maintenance, drug release, mechanical support, and cell delivery.

  6. User-oriented design strategies for a Lunar base

    Science.gov (United States)

    Jukola, Paivi

    'Form follows function can be translated, among other, to communicate a desire to prioritize functional objectives for a particular design task. Thus it is less likely that a design program for a multi-functional habitat, for an all-purpose vehicle, or for a general community, will lead to most optimal, cost-effective and sustainable solutions. A power plant, a factory, a farm and a research center have over centuries had different logistical and functional requirements, despite of the local culture on various parts around the planet Earth. 'The same size fits all' concept is likely to lead to less user-friendly solutions. The paper proposes to rethink and to investigate alternative strategies to formulate objectives for a Lunar base. Diverse scientific experiments and potential future research programs for the Moon have a number of functional requirements that differ from each other. A crew of 4-6 may not be optimal for the most innovative research. The discussion is based on research of Human Factors and Design for visiting professor lectures for a Lunar base project with Howard University and NASA Marshall Space Center 2009-2010.

  7. Rethinking Strategy Instruction: Direct Reading Strategy Instruction versus Computer-Based Guided Practice

    Science.gov (United States)

    Lenhard, Wolfgang; Baier, Herbert; Endlich, Darius; Schneider, Wolfgang; Hoffmann, Joachim

    2013-01-01

    There are many established reading strategy training programmes, which explicitly teach strategic and meta-cognitive knowledge to improve reading comprehension. Although instruction in strategy knowledge leads to improvements in meta-cognitive skills, the effects do not always transfer to reading comprehension. Therefore, to investigate…

  8. Instruction of Research-Based Comprehension Strategies in Basal Reading Programs

    Science.gov (United States)

    Pilonieta, Paola

    2010-01-01

    Research supports using research-based comprehension strategies; however, comprehension strategy instruction is not highly visible in basal reading programs or classroom instruction, resulting in many students who struggle with comprehension. A content analysis examined which research-based comprehension strategies were presented in five…

  9. Biomimetic synthesis and biocompatibility evaluation of carbonated apatites template-mediated by heparin

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Yi [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Sun, Yuhua [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Chen, Xiaofang [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhu, Peizhi, E-mail: pzzhu@umich.edu [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Wei, Shicheng, E-mail: sc-wei@pku.edu.cn [Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China)

    2013-07-01

    Biomimetic synthesis of carbonated apatites with good biocompatibility is a promising strategy for the broadening application of apatites for bone tissue engineering. Most researchers were interested in collagen or gelatin-based templates for synthesis of apatite minerals. Inspired by recent findings about the important role of polysaccharides in bone biomineralization, here we reported that heparin, a mucopolysaccharide, was used to synthesize carbonated apatites in vitro. The results indicated that the Ca/P ratio, carbon content, crystallinity and morphology of the apatites varied depending on the heparin concentration and the initial pH value. The morphology of apatite changed from flake-shaped to needle-shaped, and the degree of crystallinity decreased with the increasing of heparin concentration. Biocompatibility of the apatites was tested by proliferation and alkaline phosphatase activity of MC3T3-E1 cells. The results suggested that carbonated apatites synthesized in the presence of heparin were more favorable to the proliferation and differentiation of MC3T3-E1 cells compared with traditional method. In summary, the heparin concentration and the initial pH value play a key role in the chemical constitution and morphology, as well as biological properties of apatites. These biocompatible nano-apatite crystals hold great potential to be applied as bioactive materials for bone tissue engineering. - Highlights: • Heparin was used as a template to synthesize needle-shaped nano-apatite. • Changing the pH value and concentration led to different properties of apatite. • Apatite prepared by heparin was more favorable to the osteogenic differentiation. • Possible synthesis mechanism of apatite templated by heparin was described.

  10. A Swarm Optimization Based Power Aware Clustering Strategy for WSNs

    Directory of Open Access Journals (Sweden)

    Harendra S. Jangwan

    2017-02-01

    Full Text Available The technique of division of a wireless sensor network (WSN into clusters has proved to most suitable for the reliable data communication inside the network. This approach also improves the throughput of the system along with other attributes such as rate of delivering data packet to the base station (BS and overall energy dissipation of the sensor nodes in the network. This in turn results in the increased network lifetime. As the sensor nodes are operated by battery or some other source, this introduces a constraint in energy resource. Therefore, there is a strong need to develop a novel approach to overcome this constraint, since this phenomenon leads to the degradation of the network. The swarm intelligence approach is able to cope with all such pitfalls of WSNs. In this paper, we have presented a cluster-head (CH selection technique which is based on swarm optimization with the main aim to increase the overall network lifetime. The proposed approach gives higher effects with regards to power utilization of nodes, data packets received at BS and stability period, and for this reason serves to be a higher performer as compared to Stable Election Protocol (SEP and Enhance Threshold Sensitive Stable Election Protocol(ETSSEP. MATLAB simulation outcomes exhibit that the proposed clustering strategy outperforms the SEP and ETSSEP with regards to the above noted attributes.

  11. A Region-Based Strategy for Collaborative Roadmap Construction

    KAUST Repository

    Denny, Jory

    2015-01-01

    © Springer International Publishing Switzerland 2015. Motion planning has seen much attention over the past two decades. A great deal of progress has been made in sampling-based planning, whereby a planner builds an approximate representation of the planning space. While these planners have demonstrated success inmany scenarios, there are still difficult problems where they lack robustness or efficiency, e.g., certain types of narrow spaces. Conversely, human intuition can often determine an approximate solution to these problems quite effectively, but humans lack the speed and precision necessary to perform the corresponding low-level tasks (such as collision checking) in a timely manner. In this work, we introduce a novel strategy called Region Steering in which the user and a PRM planner work cooperatively to map the space while maintaining the probabilistic completeness property of the PRMplanner. Region Steering utilizes two-way communication to integrate the strengths of both the user and the planner, thereby overcoming the weaknesses inherent to relying on either one alone. In one communication direction, a user can input regions, or bounding volumes in the workspace, to bias sampling towards or away from these areas. In the other direction, the planner displays its progress to the user and colors the regions based on their perceived usefulness.We demonstrate that Region Steering provides roadmap customizability, reduced mapping time, and smaller roadmap sizes compared with fully automated PRMs, e.g., Gaussian PRM.

  12. Therapists' attitudes towards psychotherapeutic strategies in community-based psychotherapy with children with disruptive behavior problems.

    Science.gov (United States)

    Brookman-Frazee, Lauren; Garland, Ann F; Taylor, Robin; Zoffness, Rachel

    2009-01-01

    Little is known about what individual treatment strategies therapists providing usual care psychotherapy consider the most valuable to their practice. The Therapeutic Strategies Survey (TSS) assesses therapists' attitudes about the value of 27 individual treatment strategies in their practice with children with disruptive behavior problems in community-based outpatient psychotherapy. Findings indicate that therapists from multiple professional disciplines highly value many individual psychotherapeutic strategies, and consider strategies common to a majority of evidence-based practices (EBPs) for this population at least as important as strategies not emphasized in EBPs. Implications for developing therapist training and implementation of EBPs are discussed.

  13. Electroactive biomimetic collagen-silver nanowire composite scaffolds

    Science.gov (United States)

    Wickham, Abeni; Vagin, Mikhail; Khalaf, Hazem; Bertazzo, Sergio; Hodder, Peter; Dånmark, Staffan; Bengtsson, Torbjörn; Altimiras, Jordi; Aili, Daniel

    2016-07-01

    Electroactive biomaterials are widely explored as bioelectrodes and as scaffolds for neural and cardiac regeneration. Most electrodes and conductive scaffolds for tissue regeneration are based on synthetic materials that have limited biocompatibility and often display large discrepancies in mechanical properties with the surrounding tissue causing problems during tissue integration and regeneration. This work shows the development of a biomimetic nanocomposite material prepared from self-assembled collagen fibrils and silver nanowires (AgNW). Despite consisting of mostly type I collagen fibrils, the homogeneously embedded AgNWs provide these materials with a charge storage capacity of about 2.3 mC cm-2 and a charge injection capacity of 0.3 mC cm-2, which is on par with bioelectrodes used in the clinic. The mechanical properties of the materials are similar to soft tissues with a dynamic elastic modulus within the lower kPa range. The nanocomposites also support proliferation of embryonic cardiomyocytes while inhibiting the growth of both Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis. The developed collagen/AgNW composites thus represent a highly attractive bioelectrode and scaffold material for a wide range of biomedical applications.Electroactive biomaterials are widely explored as bioelectrodes and as scaffolds for neural and cardiac regeneration. Most electrodes and conductive scaffolds for tissue regeneration are based on synthetic materials that have limited biocompatibility and often display large discrepancies in mechanical properties with the surrounding tissue causing problems during tissue integration and regeneration. This work shows the development of a biomimetic nanocomposite material prepared from self-assembled collagen fibrils and silver nanowires (AgNW). Despite consisting of mostly type I collagen fibrils, the homogeneously embedded AgNWs provide these materials with a charge storage capacity of about 2.3 mC cm-2

  14. Domain-based Teaching Strategy for Intelligent Tutoring System Based on Generic Rules

    Science.gov (United States)

    Kseibat, Dawod; Mansour, Ali; Adjei, Osei; Phillips, Paul

    In this paper we present a framework for selecting the proper instructional strategy for a given teaching material based on its attributes. The new approach is based on a flexible design by means of generic rules. The framework was adapted in an Intelligent Tutoring System to teach Modern Standard Arabic language to adult English-speaking learners with no pre-knowledge of Arabic language is required.

  15. Optimal design and motion control of biomimetic robotic fish

    Institute of Scientific and Technical Information of China (English)

    YU JunZhi; WANG Long; ZHAO Wei; TAN Min

    2008-01-01

    This paper is concerned with the design, optimization, and motion control of a radio-controlled, multi-link, free-swimming biomimetic robotic fish based on an opti-mized kinematic and dynamic model of fish swimming. The performance of the robotic fish is determined by both the fish's morphological characteristics and ki-nematic parameters. By applying ichthyologic theories of propulsion, a design framework that takes into consideration both mechatronic constraints in physical realization and feasibility of control methods is presented, under which a multiple linked robotic fish that integrates both the carangiform and anguilliform swimming modes can be easily developed. Taking account of both theoretic hydrodynamic issues and practical problems in engineering realization, the optimal link-length-ratios are numerically calculated by an improved constrained cyclic variable method, which are successfully applied to a series of real robotic fishes. The rhythmic movements of swimming are driven by a central pattern generator (CPG) based on nonlinear oscillations, and up-and-down motion by regulating the rotating angle of pectoral fins. The experimental results verify that the presented scheme and method are effective in design and implementation.

  16. Biomimetic MEMS sensor array for navigation and water detection

    Science.gov (United States)

    Futterknecht, Oliver; Macqueen, Mark O.; Karman, Salmah; Diah, S. Zaleha M.; Gebeshuber, Ille C.

    2013-05-01

    The focus of this study is biomimetic concept development for a MEMS sensor array for navigation and water detection. The MEMS sensor array is inspired by abstractions of the respective biological functions: polarized skylight-based navigation sensors in honeybees (Apis mellifera) and the ability of African elephants (Loxodonta africana) to detect water. The focus lies on how to navigate to and how to detect water sources in desert-like or remote areas. The goal is to develop a sensor that can provide both, navigation clues and help in detecting nearby water sources. We basically use the information provided by the natural polarization pattern produced by the sunbeams scattered within the atmosphere combined with the capability of the honeybee's compound eye to extrapolate the navigation information. The detection device uses light beam reactive MEMS, which are capable to detect the skylight polarization based on the Rayleigh sky model. For water detection we present various possible approaches to realize the sensor. In the first approach, polarization is used: moisture saturated areas near ground have a small but distinctively different effect on scattering and polarizing light than less moist ones. Modified skylight polarization sensors (Karman, Diah and Gebeshuber, 2012) are used to visualize this small change in scattering. The second approach is inspired by the ability of elephants to detect infrasound produced by underground water reservoirs, and shall be used to determine the location of underground rivers and visualize their exact routes.

  17. Cuttlebone: Characterisation, Application and Development of Biomimetic Materials

    Institute of Scientific and Technical Information of China (English)

    Joseph Cadman; Shiwei Zhou; Yuhang Chen; Qing Li

    2012-01-01

    Cuttlebone signifies a special class of ultra-lightweight cellular natural material possessing unique chemical,mechanical and structural properties,which have drawn considerable attention in the literature.The aim of this paper is to better understand the mechanical and biological roles of cuttlebone.First,the existing literature concerning the characterisation and potential applications inspired by this remarkable biomaterial is critiqued.Second,the finite element-based homogenisation method is used to verify that morphological variations within individual cuttlebone samples have minimal impact on the effective mechanical properties.This finding agrees with existing literature,which suggests that cuttlebone strength is dictated by the cuttlefish habitation depth.Subsequently,this homogenisation approach is further developed to characterise the effective mechanical bulk modulus and biofluidic permeability that cuttlebone provides,thereby quantifying its mechanical and transporting functionalities to inspire bionic design of structures and materials for more extensive applications.Finally,a brief rationale for the need to design a biomimetic material inspired by the cuttlebone microstructure is provided,based on the preceding investigation.

  18. Mixed ligand Cu(II)N2O2 complexes: biomimetic synthesis, activities in vitro and biological models, theoretical calculations.

    Science.gov (United States)

    Li, Chen; Yin, Bing; Kang, Yifan; Liu, Ping; Chen, Liang; Wang, Yaoyu; Li, Jianli

    2014-12-15

    Three new mixed ligand Cu(II)N2O2 complexes, namely, [Cu(II)(2-A-6-MBT)2(m-NB)2] (1), [Cu(II)(2-ABT)2(m-NB)2] (2), and [Cu(II)(2-ABT)2(o-NB)2] (3), (2-A-6-MBT = 2-amino-6-methoxybenzothiazole, m-NB = m-nitrobenzoate, 2-ABT = 2-aminobenzothiazole, and o-NB = o-nitrobenzoate), have been prepared by the biomimetic synthesis strategy, and their structures were determined by X-ray crystallography studies and spectral methods. These complexes exhibited the effective superoxide dismutase (SOD) activity and catecholase activity. On the basis of the experimental data and computational studies, the structure-activity relationship for these complexes was investigated. The results reveal that electron-accepting abilities of these complexes and coordination geometries have significant effects on the SOD activity and catecholase activity. Then, we found that 1 and 2 exerted potent intracellular antioxidant capacity in the model of H2O2-induced oxidative stress based on HeLa cervical cancer cells, which were screened out by the cytotoxicity assays of different kinds of cells. Furthermore, 1-3 showed the favorable biocompatibility in two different biological models: Saccharomyces cerevisiae and human vascular endothelial cells. These biological experimental data are indicative of the promising application potential of these complexes in biology and pharmacology.

  19. Integrating biologically inspired nanomaterials and table-top stereolithography for 3D printed biomimetic osteochondral scaffolds.

    Science.gov (United States)

    Castro, Nathan J; O'Brien, Joseph; Zhang, Lijie Grace

    2015-09-01

    The osteochondral interface of an arthritic joint is notoriously difficult to regenerate due to its extremely poor regenerative capacity and complex stratified architecture. Native osteochondral tissue extracellular matrix is composed of numerous nanoscale organic and inorganic constituents. Although various tissue engineering strategies exist in addressing osteochondral defects, limitations persist with regards to tissue scaffolding which exhibit biomimetic cues at the nano to micro scale. In an effort to address this, the current work focused on 3D printing biomimetic nanocomposite scaffolds for improved osteochondral tissue regeneration. For this purpose, two biologically-inspired nanomaterials have been synthesized consisting of (1) osteoconductive nanocrystalline hydroxyapatite (nHA) (primary inorganic component of bone) and (2) core-shell poly(lactic-co-glycolic) acid (PLGA) nanospheres encapsulated with chondrogenic transforming growth-factor β1 (TGF-β1) for sustained delivery. Then, a novel table-top stereolithography 3D printer and the nano-ink (i.e., nHA + nanosphere + hydrogel) were employed to fabricate a porous and highly interconnected osteochondral scaffold with hierarchical nano-to-micro structure and spatiotemporal bioactive factor gradients. Our results showed that human bone marrow-derived mesenchymal stem cell adhesion, proliferation, and osteochondral differentiation were greatly improved in the biomimetic graded 3D printed osteochondral construct in vitro. The current work served to illustrate the efficacy of the nano-ink and current 3D printing technology for efficient fabrication of a novel nanocomposite hydrogel scaffold. In addition, tissue-specific growth factors illustrated a synergistic effect leading to increased cell adhesion and directed stem cell differentiation.

  20. Integrating biologically inspired nanomaterials and table-top stereolithography for 3D printed biomimetic osteochondral scaffolds

    Science.gov (United States)

    Castro, Nathan J.; O'Brien, Joseph; Zhang, Lijie Grace

    2015-08-01

    The osteochondral interface of an arthritic joint is notoriously difficult to regenerate due to its extremely poor regenerative capacity and complex stratified architecture. Native osteochondral tissue extracellular matrix is composed of numerous nanoscale organic and inorganic constituents. Although various tissue engineering strategies exist in addressing osteochondral defects, limitations persist with regards to tissue scaffolding which exhibit biomimetic cues at the nano to micro scale. In an effort to address this, the current work focused on 3D printing biomimetic nanocomposite scaffolds for improved osteochondral tissue regeneration. For this purpose, two biologically-inspired nanomaterials have been synthesized consisting of (1) osteoconductive nanocrystalline hydroxyapatite (nHA) (primary inorganic component of bone) and (2) core-shell poly(lactic-co-glycolic) acid (PLGA) nanospheres encapsulated with chondrogenic transforming growth-factor β1 (TGF-β1) for sustained delivery. Then, a novel table-top stereolithography 3D printer and the nano-ink (i.e., nHA + nanosphere + hydrogel) were employed to fabricate a porous and highly interconnected osteochondral scaffold with hierarchical nano-to-micro structure and spatiotemporal bioactive factor gradients. Our results showed that human bone marrow-derived mesenchymal stem cell adhesion, proliferation, and osteochondral differentiation were greatly improved in the biomimetic graded 3D printed osteochondral construct in vitro. The current work served to illustrate the efficacy of the nano-ink and current 3D printing technology for efficient fabrication of a novel nanocomposite hydrogel scaffold. In addition, tissue-specific growth factors illustrated a synergistic effect leading to increased cell adhesion and directed stem cell differentiation.

  1. Plant Surfaces: Structures and Functions for Biomimetic Innovations

    Science.gov (United States)

    Barthlott, Wilhelm; Mail, Matthias; Bhushan, Bharat; Koch, Kerstin

    2017-04-01

    An overview of plant surface structures and their evolution is presented. It combines surface chemistry and architecture with their functions and refers to possible biomimetic applications. Within some 3.5 billion years biological species evolved highly complex multifunctional surfaces for interacting with their environments: some 10 million living prototypes (i.e., estimated number of existing plants and animals) for engineers. The complexity of the hierarchical structures and their functionality in biological organisms surpasses all abiotic natural surfaces: even superhydrophobicity is restricted in nature to living organisms and was probably a key evolutionary step with the invasion of terrestrial habitats some 350-450 million years ago in plants and insects. Special attention should be paid to the fact that global environmental change implies a dramatic loss of species and with it the biological role models. Plants, the dominating group of organisms on our planet, are sessile organisms with large multifunctional surfaces and thus exhibit particular intriguing features. Superhydrophilicity and superhydrophobicity are focal points in this work. We estimate that superhydrophobic plant leaves (e.g., grasses) comprise in total an area of around 250 million km2, which is about 50% of the total surface of our planet. A survey of structures and functions based on own examinations of almost 20,000 species is provided, for further references we refer to Barthlott et al. (Philos. Trans. R. Soc. A 374: 20160191, 1). A basic difference exists between aquatic non-vascular and land-living vascular plants; the latter exhibit a particular intriguing surface chemistry and architecture. The diversity of features is described in detail according to their hierarchical structural order. The first underlying and essential feature is the polymer cuticle superimposed by epicuticular wax and the curvature of single cells up to complex multicellular structures. A descriptive terminology

  2. Patterns of Growth—Biomimetics and Architectural Design

    Directory of Open Access Journals (Sweden)

    Petra Gruber

    2017-04-01

    Full Text Available This paper discusses the approach of biomimetic design in architecture applied to the theme of growth in biology by taking two exemplary research projects at the intersection of arts and sciences. The first project, ‘Biornametics’, dealt with patterns from nature; the second project ‘Growing as Building (GrAB’ took on biological growth as a specific theme for the transfer to architecture and the arts. Within a timeframe of five years (2011–2015, the research was conducted under the Program for Arts-based Research PEEK (Programm zur Entwicklung und Erschliessung der Künste of the Austrian Science Fund FWF (Fonds zur Förderung der wissenschaftlichen Forschung. The underlying hypothesis was that growth processes in nature have not been studied for transfer into technology and architecture yet and that, with advanced software tools, promising applications could be found. To ensure a high degree of innovation, this research was done with an interdisciplinary team of architects, engineers, and scientists (mainly biologists to lay the groundwork for future product-oriented technological solutions. Growth, as one of the important characteristics of living organisms, is used as a frame for research into systems and principles that shall deliver innovative and sustainable solutions in architecture and the arts. Biomimetics as a methodology was used to create and guide information transfer from the life sciences to innovative proto-architectural solutions. The research aimed at transferring qualities present in biological growth; for example, adaptiveness, exploration, or local resource harvesting into technical design and production processes. In contrast to our current building construction, implementing principles of growth could potentially transform building towards a more integrated and sustainable setting, a new living architecture. Tools and methods, especially Quality Function Deployment (QFD for matching biological role models with

  3. Biomimetically Ornamented Rapid Prototyping Fabrication of an Apatite-Collagen-Polycaprolactone Composite Construct with Nano-Micro-Macro Hierarchical Structure for Large Bone Defect Treatment.

    Science.gov (United States)

    Wang, Jinbing; Wu, Dingyu; Zhang, Zhanzhao; Li, Jun; Shen, Yi; Wang, Zhenxing; Li, Yu; Zhang, Zhi-Yong; Sun, Jian

    2015-12-01

    Biomaterial-based bone graft substitute with favorable mechanical and biological properties could be used as an alternative to autograft for large defect treatment. Here, an apatite-collagen-polycaprolactone (Ap-Col-PCL) composite construct was developed with unique nano-micro-macro hierarchical architectures by combining rapid prototyping (RP) fabrication technology and a 3D functionalization strategy. Macroporous PCL framework was fabricated using RP technology, then functionalized by collagen incorporation and biomimetic deposition. Ap-Col-PCL composite construct was characterized with hierarchical architectures of a nanoscale (∼100 nm thickness and ∼1 μm length) platelike apatite coating on the microporous (126 ± 18 μm) collagen networks, which homogeneously filled the macroporous (∼1000 μm) PCL frameworks and possessed a favorable hydrophilic property and compressive modulus (68.75 ± 3.39 MPa) similar to that of cancellous bone. Moreover, in vitro cell culture assay and in vivo critical-sized bone defect implantation demonstrated that the Ap-Col-PCL construct could not only significantly increase the cell adhesion capability (2.0-fold) and promote faster cell proliferation but also successfully bridge the segmental long bone defect within 12 weeks with much more bone regeneration (5.2-fold), better osteointegration (7.2-fold), and a faster new bone deposition rate (2.9-fold). Our study demonstrated that biomimetically ornamented Ap-Col-PCL constructs exhibit a favorable mechanical property, more bone tissue ingrowth, and better osteointegration capability as an effective bone graft substitute for critical-sized bone defect treatment; meanwhile, it can also harness the advantages of RP technology, in particular, facilitating the customization of the shape and size of implants according to medical images during clinical application.

  4. Antibody-Based Strategies to Prevent and Treat Influenza

    Directory of Open Access Journals (Sweden)

    Ram eSasisekharan

    2015-07-01

    Full Text Available Passive immunization using antibodies has been suggested to offer several benefits in comparison to other antiviral treatment options. The potential for seasonal protection arising from a single injection of antibodies is appealing and has been pursued for a number of infectious agents. However, until recently, antibody-based strategies to combat infectious agents has been hampered due to the fact that typical antibodies have been found to be strain-specific, with the virus evolving resistance in many cases. The discovery of broadly neutralizing antibodies (bNAbs in, for example, influenza, dengue virus, and HIV, which bind to multiple, structurally-diverse strains has provided renewed interest in this area. This review will focus on new technologies that enable the discovery of bNAbs, the challenges and opportunities of immunotherapies as an important addition to existing antiviral therapy, and the role of antibody discovery in informing rational vaccine discovery – with agents targeting influenza specifically addressed. Multiple agents have entered the clinic and raise the possibility that a single antibody or small combination of antibodies can effectively neutralize a wide variety of strains. However, challenges remain - including combating escape variants, pharmacodynamics of antibody distribution, and development of efficacy biomarkers beyond virologic endpoints.

  5. [Optimal allocation of irrigation water resources based on systematical strategy].

    Science.gov (United States)

    Cheng, Shuai; Zhang, Shu-qing

    2015-01-01

    With the development of the society and economy, as well as the rapid increase of population, more and more water is needed by human, which intensified the shortage of water resources. The scarcity of water resources and growing competition of water in different water use sectors reduce water availability for irrigation, so it is significant to plan and manage irrigation water resources scientifically and reasonably for improving water use efficiency (WUE) and ensuring food security. Many investigations indicate that WUE can be increased by optimization of water use. However, present studies focused primarily on a particular aspect or scale, which lack systematic analysis on the problem of irrigation water allocation. By summarizing previous related studies, especially those based on intelligent algorithms, this article proposed a multi-level, multi-scale framework for allocating irrigation water, and illustrated the basic theory of each component of the framework. Systematical strategy of optimal irrigation water allocation can not only control the total volume of irrigation water on the time scale, but also reduce water loss on the spatial scale. It could provide scientific basis and technical support for improving the irrigation water management level and ensuring the food security.

  6. A Novel Diversity-Based Replacement Strategy for Evolutionary Algorithms.

    Science.gov (United States)

    Segura, Carlos; Coello Coello, Carlos A; Segredo, Eduardo; Aguirre, Arturo Hernandez

    2016-12-01

    Premature convergence is one of the best-known drawbacks that affects the performance of evolutionary algorithms. An alternative for dealing with this problem is to explicitly try to maintain proper diversity. In this paper, a new replacement strategy that preserves useful diversity is presented. The novelty of our method is that it combines the idea of transforming a single-objective problem into a multiobjective one, by considering diversity as an explicit objective, with the idea of adapting the balance induced between exploration and exploitation to the various optimization stages. Specifically, in the initial phases, larger amounts of diversity are accepted. The diversity measure considered in this paper is based on calculating distances to the closest surviving individual. Analyses with a multimodal function better justify the design decisions and provide greater insight into the working operation of the proposal. Computational results with a packing problem that was proposed in a popular contest illustrate the usefulness of the proposal. The new method significantly improves on the best results known to date for this problem and compares favorably against a large number of state-of-the-art schemes.

  7. Evidence-based post-exercise recovery strategies in basketball.

    Science.gov (United States)

    Calleja-González, Julio; Terrados, Nicolás; Mielgo-Ayuso, Juan; Delextrat, Anne; Jukic, Igor; Vaquera, Alejandro; Torres, Lorena; Schelling, Xavier; Stojanovic, Marko; Ostojic, Sergej M

    2016-01-01

    Basketball can be described as a moderate-to-long duration exercise including repeated bouts of high-intensity activity interspersed with periods of low to moderate active recovery or passive rest. A match is characterized by repeated explosive activities, such as sprints, jumps, shuffles and rapid changes in direction. In top-level modern basketball, players are frequently required to play consecutive matches with limited time to recover. To ensure adequate recovery after any basketball activity (i.e., match or training), it is necessary to know the type of fatigue induced and, if possible, its underlying mechanisms. Despite limited scientific evidence to support their effectiveness in facilitating optimal recovery, certain recovery strategies are commonly utilized in basketball. It is particularly important to optimize recovery because players spend a much greater proportion of their time recovering than they do in training. Therefore, the main aim of this report is to facilitate useful information that may lead to practical application, based on the scientific evidence and applied knowledge specifically in basketball.

  8. Teaching strategies based on Celestin Freinet for health education

    Directory of Open Access Journals (Sweden)

    Silvia Padilla Loredo

    2012-08-01

    Full Text Available This article reflects on the strategies of Celestin Freinet, which can be adapted to health education in primary care. The purpose of these strategies is to contribute to the effectiveness of social and sanitary actions in Mexico, especially with regards to self-help groups.

  9. Developing Hydrogeological Site Characterization Strategies based on Human Health Risk

    Science.gov (United States)

    de Barros, F.; Rubin, Y.; Maxwell, R. M.

    2013-12-01

    In order to provide better sustainable groundwater quality management and minimize the impact of contamination in humans, improved understanding and quantification of the interaction between hydrogeological models, geological site information and human health are needed. Considering the joint influence of these components in the overall human health risk assessment and the corresponding sources of uncertainty aid decision makers to better allocate resources in data acquisition campaigns. This is important to (1) achieve remediation goals in a cost-effective manner, (2) protect human health and (3) keep water supplies clean in order to keep with quality standards. Such task is challenging since a full characterization of the subsurface is unfeasible due to financial and technological constraints. In addition, human exposure and physiological response to contamination are subject to uncertainty and variability. Normally, sampling strategies are developed with the goal of reducing uncertainty, but less often they are developed in the context of their impacts on the overall system uncertainty. Therefore, quantifying the impact from each of these components (hydrogeological, behavioral and physiological) in final human health risk prediction can provide guidance for decision makers to best allocate resources towards minimal prediction uncertainty. In this presentation, a multi-component human health risk-based framework is presented which allows decision makers to set priorities through an information entropy-based visualization tool. Results highlight the role of characteristic length-scales characterizing flow and transport in determining data needs within an integrated hydrogeological-health framework. Conditions where uncertainty reduction in human health risk predictions may benefit from better understanding of the health component, as opposed to a more detailed hydrogeological characterization, are also discussed. Finally, results illustrate how different dose

  10. Tubular inverse opal scaffolds for biomimetic vessels

    Science.gov (United States)

    Zhao, Ze; Wang, Jie; Lu, Jie; Yu, Yunru; Fu, Fanfan; Wang, Huan; Liu, Yuxiao; Zhao, Yuanjin; Gu, Zhongze

    2016-07-01

    There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially oriented elliptical pattern microstructures on their surfaces. It is demonstrated that these tailored tubular scaffolds can effectively make endothelial cells to form an integrated hollow tubular structure on their inner surface and induce smooth muscle cells to form a circumferential orientation on their outer surface. These features of our tubular scaffolds make them highly promising for the construction of biomimetic blood vessels.There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially

  11. Distance-Based Routing Strategy for Traffic Transport in Spatial Networks

    Directory of Open Access Journals (Sweden)

    Wei Huang

    2013-01-01

    Full Text Available It is well known that routing strategies based on global topological information is not a good choice for the enhancement of traffic throughput in large-scale networks due to the heavy communication cost. On the contrary, acquiring spatial information, such as spatial distances among nodes, is more feasible. In this paper, we propose a novel distance-based routing strategy in spatial scale-free networks, called LDistance strategy. The probability of establishing links among nodes obeys the power-law in the spatial network under study. Compared with the LDegree strategy (Wang et al., 2006 and the mixed strategy (a strategy combining both greedy routing strategy and random routing strategy, results show that our proposed LDistance strategy can further enhance traffic capacity. Besides, the LDistance strategy can also achieve a much shorter delivering time than the LDegree strategy. Analyses reveal that the superiority of our strategy is mainly due to the interdependent relationship between topological and spatial characteristics in spatial scale-free networks. Furthermore, along transporting path in the LDistance strategy, the spatial distance to destination decays more rapidly, and the degrees of routers are higher than those in the LDegree strategy.

  12. Biomimetics: forecasting the future of science, engineering, and medicine

    Directory of Open Access Journals (Sweden)

    Hwang J

    2015-09-01

    Full Text Available Jangsun Hwang,1 Yoon Jeong,1,2 Jeong Min Park,3 Kwan Hong Lee,1,2,4 Jong Wook Hong,1,2 Jonghoon Choi1,2 1Department of Bionano Technology, Graduate School, Hanyang University, Seoul, 2Department of Bionano Engineering, Hanyang University ERICA, Ansan, Korea; 3Department of Biomedical Engineering, Boston University, 4OpenView Venture Partners, Boston, MA, USA Abstract: Biomimetics is the study of nature and natural phenomena to understand the principles of underlying mechanisms, to obtain ideas from nature, and to apply concepts that may benefit science, engineering, and medicine. Examples of biomimetic studies include fluid-drag reduction swimsuits inspired by the structure of shark’s skin, velcro fasteners modeled on burrs, shape of airplanes developed from the look of birds, and stable building structures copied from the backbone of turban shells. In this article, we focus on the current research topics in biomimetics and discuss the potential of biomimetics in science, engineering, and medicine. Our report proposes to become a blueprint for accomplishments that can stem from biomimetics in the next 5 years as well as providing insight into their unseen limitations. Keywords: biomimicry, tissue engineering, biomaterials, nature, nanotechnology, nanomedicine

  13. Biomimetic chemical sensors using bioengineered olfactory and taste cells

    Science.gov (United States)

    Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping; Wu, Chunsheng

    2014-01-01

    Biological olfactory and taste systems are natural chemical sensing systems with unique performances for the detection of environmental chemical signals. With the advances in olfactory and taste transduction mechanisms, biomimetic chemical sensors have achieved significant progress due to their promising prospects and potential applications. Biomimetic chemical sensors exploit the unique capability of biological functional components for chemical sensing, which are often sourced from sensing units of biological olfactory or taste systems at the tissue level, cellular level, or molecular level. Specifically, at the cellular level, there are mainly two categories of cells have been employed for the development of biomimetic chemical sensors, which are natural cells and bioengineered cells, respectively. Natural cells are directly isolated from biological olfactory and taste systems, which are convenient to achieve. However, natural cells often suffer from the undefined sensing properties and limited amount of identical cells. On the other hand, bioengineered cells have shown decisive advantages to be applied in the development of biomimetic chemical sensors due to the powerful biotechnology for the reconstruction of the cell sensing properties. Here, we briefly summarized the most recent advances of biomimetic chemical sensors using bioengineered olfactory and taste cells. The development challenges and future trends are discussed as well. PMID:25482234

  14. Listening Strategy Use and Influential Factors in Web-Based Computer Assisted Language Learning

    Science.gov (United States)

    Chen, L.; Zhang, R.; Liu, C.

    2014-01-01

    This study investigates second and foreign language (L2) learners' listening strategy use and factors that influence their strategy use in a Web-based computer assisted language learning (CALL) system. A strategy inventory, a factor questionnaire and a standardized listening test were used to collect data from a group of 82 Chinese students…

  15. Review of current strategies to induce self-healing behaviour in fibre reinforced polymer based composites

    NARCIS (Netherlands)

    Zwaag, van der S.; Grande, A.M.; Post, W.; Garcia, S.J.; Bor, T.C.

    2014-01-01

    This paper addresses the various strategies to induce self-healing behaviour in fibre reinforced polymer based composites. A distinction is made between the extrinsic and intrinsic healing strategies. These strategies can be applied at the level of the fibre, the fibre/matrix interface or at the lev

  16. Therapists' Attitudes Towards Psychotherapeutic Strategies in Community-Based Psychotherapy with Children with Disruptive Behavior Problems

    OpenAIRE

    Brookman-Frazee, Lauren; Garland, Ann F.; Taylor, Robin; Zoffness, Rachel

    2008-01-01

    Little is known about what individual treatment strategies therapists providing usual care psychotherapy consider the most valuable to their practice. The Therapeutic Strategies Survey (TSS) assesses therapists' attitudes about the value of 27 individual treatment strategies in their practice with children with disruptive behavior problems in community-based outpatient psychotherapy. Findings indicate that therapists from multiple professional disciplines highly value many individual psychoth...

  17. Multi-agent coordination strategy estimation method based on control domain

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    For estimation group competition and multiagent coordination strategy, this paper introduces a notion based on multiagent group. According to the control domain, it analyzes the multiagent strategy during competi tion in the macroscopic. It has been adopted in robot soccer and result enunciates that our method does not de pend on competition result. It can objectively quantitatively estimate coordination strategy.

  18. Strategy selection in cue-based decision making.

    Science.gov (United States)

    Bryant, David J

    2014-06-01

    People can make use of a range of heuristic and rational, compensatory strategies to perform a multiple-cue judgment task. It has been proposed that people are sensitive to the amount of cognitive effort required to employ decision strategies. Experiment 1 employed a dual-task methodology to investigate whether participants' preference for heuristic versus compensatory decision strategies can be altered by increasing the cognitive demands of the task. As indicated by participants' decision times, a secondary task interfered more with the performance of a heuristic than compensatory decision strategy but did not affect the proportions of participants using either type of strategy. A stimulus set effect suggested that the conjunction of cue salience and cue validity might play a determining role in strategy selection. The results of Experiment 2 indicated that when a perceptually salient cue was also the most valid, the majority of participants preferred a single-cue heuristic strategy. Overall, the results contradict the view that heuristics are more likely to be adopted when a task is made more cognitively demanding. It is argued that people employ 2 learning processes during training, one an associative learning process in which cue-outcome associations are developed by sampling multiple cues, and another that involves the sequential examination of single cues to serve as a basis for a single-cue heuristic.

  19. Biomimetic solution against dewetting in a highly hydrophobic nanopore.

    Science.gov (United States)

    Picaud, Fabien; Paris, Guillaume; Gharbi, Tijani; Balme, Sébastien; Lepoitevin, Mathilde; Tangaraj, Vidhyadevi; Bechelany, Mikhael; Janot, Jean Marc; Balanzat, Emmanuel; Henn, François

    2016-06-14

    A water molecule is the foundation of life and is the primary compound in every living system. While many of its properties are understood in a bulk solvent, its behavior in a small hydrophobic nanopore still raises fundamental questions. For instance, a wetting/dewetting transition in a hydrophobic solid-state or a polymer nanopore occurs stochastically and can only be prevented by external physical stimuli. Controlling these transitions would be a primary requirement to improve many applications. Some biological channels, such as gramicidin A (gA) proteins, show a high rate of water and ion diffusion in their central subnanochannel while their external surface is highly hydrophobic. The diameter of this channel is significantly smaller than the inner size of the lowest artificial nanopore in which water drying occurs (i.e. 1.4 nm). In this paper, we propose an innovative idea to generate nanopore wetting as a result of which the application of an external field is no longer required. In a nanopore, the drying or wetting of the inner walls occurs randomly (in experiments and in simulations). However, we have shown how the confinement of gA, in a dried hydrophobic nanopore, rapidly generates a stable wetting of the latter. We believe that this simple idea, based on biomimetism, could represent a real breakthrough that could help to improve and develop new nanoscale applications.

  20. Dopamine-melanin nanofilms for biomimetic structural coloration.

    Science.gov (United States)

    Wu, Tong-Fei; Hong, Jong-Dal

    2015-02-09

    This article describes the formation of dopamine-melanin thin films (50-200 nm thick) at an air/dopamine solution interface under static conditions. Beneath these films, spherical melanin granules formed in bulk liquid phase. The thickness of dopamine-melanin films at the interface relied mainly on the concentration of dopamine solution and the reaction time. A plausible mechanism underlining dopamine-melanin thin film formation was proposed based on the hydrophobicity of dopamine-melanin aggregates and the mass transport of the aggregates to the air/solution interface as a result of convective flow. The thickness of the interfacial films increased linearly with the dopamine concentration and the reaction time. The dopamine-melanin thin film and granules (formed in bulk liquid phase) with a double-layered structure were transferred onto a solid substrate to mimic the (keratin layer)/(melanin granules) structure present in bird plumage, thereby preparing full dopamine-melanin thin-film reflectors. The reflected color of the thin-film reflectors depended on the film thickness, which could be adjusted according to the dopamine concentration. The reflectance of the resulted reflectors exhibited a maximal reflectance value of 8-11%, comparable to that of bird plumage (∼11%). This study provides a useful, simple, and low-cost approach to the fabrication of biomimetic thin-film reflectors using full dopamine-melanin materials.

  1. Silaffins in Silica Biomineralization and Biomimetic Silica Precipitation

    Directory of Open Access Journals (Sweden)

    Carolin C. Lechner

    2015-08-01

    Full Text Available Biomineralization processes leading to complex solid structures of inorganic material in biological systems are constantly gaining attention in biotechnology and biomedical research. An outstanding example for biomineral morphogenesis is the formation of highly elaborate, nano-patterned silica shells by diatoms. Among the organic macromolecules that have been closely linked to the tightly controlled precipitation of silica in diatoms, silaffins play an extraordinary role. These peptides typically occur as complex posttranslationally modified variants and are directly involved in the silica deposition process in diatoms. However, even in vitro silaffin-based peptides alone, with and without posttranslational modifications, can efficiently mediate biomimetic silica precipitation leading to silica material with different properties as well as with encapsulated cargo molecules of a large size range. In this review, the biomineralization process of silica in diatoms is summarized with a specific focus on silaffins and their in vitro silica precipitation properties. Applications in the area of bio- and nanotechnology as well as in diagnostics and therapy are discussed.

  2. Nanoviscosity Measurements Revealing Domain Formation in Biomimetic Membranes.

    Science.gov (United States)

    Hasan, Imad Younus; Mechler, Adam

    2017-02-07

    Partitioning of lipid molecules in biomimetic membranes is a model system for the study of naturally occurring domains, such as rafts, in biological membranes. The existence of nanometer scale membrane domains in binary lipid mixtures has been shown with microscopy methods; however, the nature of these domains has not been established unequivocally. A common notion is to ascribe domain separation to thermodynamic phase equilibria. However, characterizing thermodynamic phases of single bilayer membranes has not been possible due to their extreme dimensions: the size of the domains falls to the order of tens to hundreds of nanometers whereas the membrane thickness is only a few nanometers. Here, we present direct measurements of phase transitions in single bilayers of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)/1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) phospholipid mixtures using quartz crystal microbalance-based nanoviscosity measurements. Coexisting thermodynamic phases have been successfully identified, and a phase diagram was constructed for the single bilayer binary lipid system. It was demonstrated that domain separation only takes place in planar membranes, and thus, it is absent in liposomes and not detectable in calorimetric measurements on liposome suspensions. On the basis of energetic analysis, the main transition was identified as the breaking of van der Waals interactions between the acyl chains.

  3. Piezoelectric Templates - New Views on Biomineralization and Biomimetics.

    Science.gov (United States)

    Stitz, Nina; Eiben, Sabine; Atanasova, Petia; Domingo, Neus; Leineweber, Andreas; Burghard, Zaklina; Bill, Joachim

    2016-05-23

    Biomineralization in general is based on electrostatic interactions and molecular recognition of organic and inorganic phases. These principles of biomineralization have also been utilized and transferred to bio-inspired synthesis of functional materials during the past decades. Proteins involved in both, biomineralization and bio-inspired processes, are often piezoelectric due to their dipolar character hinting to the impact of a template's piezoelectricity on mineralization processes. However, the piezoelectric contribution on the mineralization process and especially the interaction of organic and inorganic phases is hardly considered so far. We herein report the successful use of the intrinsic piezoelectric properties of tobacco mosaic virus (TMV) to synthesize piezoelectric ZnO. Such films show a two-fold increase of the piezoelectric coefficient up to 7.2 pm V(-1) compared to films synthesized on non-piezoelectric templates. By utilizing the intrinsic piezoelectricity of a biotemplate, we thus established a novel synthesis pathway towards functional materials, which sheds light on the whole field of biomimetics. The obtained results are of even broader and general interest since they are providing a new, more comprehensive insight into the mechanisms involved into biomineralization in living nature.

  4. Biomimetic antimicrobial cloak by graphene-oxide agar hydrogel.

    Science.gov (United States)

    Papi, Massimiliano; Palmieri, Valentina; Bugli, Francesca; De Spirito, Marco; Sanguinetti, Maurizio; Ciancico, Carlotta; Braidotti, Maria Chiara; Gentilini, Silvia; Angelani, Luca; Conti, Claudio

    2016-12-01

    Antibacterial surfaces have an enormous economic and social impact on the worldwide technological fight against diseases. However, bacteria develop resistance and coatings are often not uniform and not stable in time. The challenge is finding an antibacterial coating that is biocompatible, cost-effective, not toxic, and spreadable over large and irregular surfaces. Here we demonstrate an antibacterial cloak by laser printing of graphene oxide hydrogels mimicking the Cancer Pagurus carapace. We observe up to 90% reduction of bacteria cells. This cloak exploits natural surface patterns evolved to resist to microorganisms infection, and the antimicrobial efficacy of graphene oxide. Cell integrity analysis by scanning electron microscopy and nucleic acids release show bacteriostatic and bactericidal effect. Nucleic acids release demonstrates microorganism cutting, and microscopy reveals cells wrapped by the laser treated gel. A theoretical active matter model confirms our findings. The employment of biomimetic graphene oxide gels opens unique possibilities to decrease infections in biomedical applications and chirurgical equipment; our antibiotic-free approach, based on the geometric reduction of microbial adhesion and the mechanical action of Graphene Oxide sheets, is potentially not affected by bacterial resistance.

  5. Biomimetically Enhanced Demineralized Bone Matrix for Bone Regenerative Applications

    Directory of Open Access Journals (Sweden)

    Sriram eRavindran

    2015-10-01

    Full Text Available Demineralized bone matrix (DBM is one of the most widely used bone graft materials in dentistry. However, the ability of DBM to reliably and predictably induce bone regeneration has always been a cause for concern. The quality of DBM varies greatly depending on several donor dependent factors and also manufacturing techniques. In order to standardize the quality and to enable reliable and predictable bone regeneration, we have generated a biomimetically-enhanced version of DBM (BE-DBM using clinical grade commercial DBM as a control. We have generated the BE-DBM by incorporating a cell-derived pro-osteogenic extracellular matrix (ECM within clinical grade DBM. In the present study, we have characterized the BE-DBM and evaluated its ability to induce osteogenic differentiation of human marrow derived stromal cells (HMSCs with respect to clinical grade commercial DBM. Our results indicate that the BE-DBM contains significantly more pro-osteogenic factors than DBM and enhances HMSC differentiation and mineralized matrix formation in vitro and in vivo. Based on our results, we envision that the BE-DBM has the potential to replace DBM as the bone graft material of choice.

  6. Conducting IPN actuator/sensor for biomimetic vibrissa system

    Science.gov (United States)

    Festin, N.; Plesse, C.; Pirim, P.; Chevrot, C.; Vidal, F.

    2014-03-01

    Electroactive polymers, or EAPs, are polymers that exhibit a change in size or shape when stimulated by an electric field. The most common applications of this type of material are in actuators and sensors. One promising technology is the elaboration of electronic conducting polymers based actuators with Interpenetrating Polymer Networks (IPNs) architecture. Their many advantageous properties as low working voltage, light weight and high lifetime make them very attractive for various applications including robotics. Conducting IPNs were fabricated by oxidative polymerization of 3,4-ethylenedioxythiophene within a flexible Solid Polymer Electrolytes (SPE) combining poly(ethylene oxide) and Nitrile Butadiene Rubber. SPE mechanical properties and ionic conductivities in the presence of 1-ethyl-3- methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMITFSI) have been characterized. The presence of the elastomer within the SPE greatly improves the actuator performances. The free strain as well as the blocking force was characterized as a function of the actuator length. The sensing properties of those conducting IPNs allow their integration into a biomimetic perception prototype: a system mimicking the tactile perception of rat vibrissae.

  7. Biomimetic polymers of plant cutin: an approach from molecular modeling.

    Science.gov (United States)

    San-Miguel, Miguel A; Oviedo, Jaime; Heredia-Guerrero, Jose Alejandro; Heredia, Antonio; Benitez, Jose Jesus

    2014-07-01

    Biomimetics of materials is based on adopting and reproducing a model in nature with a well-defined functionality optimized through evolution. An example is barrier polymers that protect living tissues from the environment. The protecting layer of fruits, leaves, and non-lignified stems is the plant cuticle. The cuticle is a complex system in which the cutin is the main component. Cutin is a biopolyester made of polyhydroxylated carboxylic acids of 16 and 18 carbon atoms. The biosynthesis of cutin in plants is not well understood yet, but a direct chemical route involving the self-assembly of either molecules or molecular aggregates has been proposed. In this work, we present a combined study using experimental and simulation techniques on self-assembled layers of monomers selectively functionalized with hydroxyl groups. Our results demonstrate that the number and position of the hydroxyl groups are critical for the interaction between single molecules and the further rearrangement. Also, the presence of lateral hydroxyl groups reinforces lateral interactions and favors the bi-dimensional growth (2D), while terminal hydroxyl groups facilitate the formation of a second layer caused by head-tail interactions. The balance of 2D/3D growth is fundamental for the plant to create a protecting layer both large enough in 2D and thick enough in 3D.

  8. Biomimetic self-cleaning surfaces: synthesis, mechanism and applications.

    Science.gov (United States)

    Xu, Quan; Zhang, Wenwen; Dong, Chenbo; Sreeprasad, Theruvakkattil Sreenivasan; Xia, Zhenhai

    2016-09-01

    With millions of years of natural evolution, organisms have achieved sophisticated structures, patterns or textures with complex, spontaneous multifunctionality. Among all the fascinating characteristics observed in biosystems, self-cleaning ability is regarded as one of the most interesting topics in biomimicry because of its potential applications in various fields such as aerospace, energy conversion and biomedical and environmental protection. Recently, in-depth studies have been carried out on various compelling biostructures including lotus leaves, shark skins, butterfly wings and gecko feet. To understand and mimic their self-cleaning mechanisms in artificial structures, in this article, recent progress in self-cleaning techniques is discussed and summarized. Based on the underlying self-cleaning mechanisms, the methods are classified into two categories: self-cleaning with water and without water. The review gives a succinct account of the detailed mechanisms and biomimetic processes applied to create artificial self-cleaning materials and surfaces, and provides some examples of cutting-edge applications such as anti-reflection, water repellence, self-healing, anti-fogging and micro-manipulators. The prospectives and directions of future development are also briefly proposed.

  9. A functional assay-based strategy for nanomaterial risk forecasting

    Energy Technology Data Exchange (ETDEWEB)

    Hendren, Christine Ogilvie, E-mail: christine.hendren@duke.edu [Center for the Environmental Implications of NanoTechnology, Duke University, Durham, NC 27708 (United States); Lowry, Gregory V., E-mail: glowry@andrew.cmu.edu [Center for the Environmental Implications of NanoTechnology, Duke University, Durham, NC 27708 (United States); Department of Civil and Environmental Engineering, Carnegie Mellon University, 119 Porter Hall, Pittsburgh, PA 15213 (United States); Unrine, Jason M., E-mail: jason.unrine@uky.edu [Center for the Environmental Implications of NanoTechnology, Duke University, Durham, NC 27708 (United States); Department of Plant and Soil Sciences, University of Kentucky, Agricultural Science Center, Lexington, KY 40546 (United States); Wiesner, Mark R., E-mail: wiesner@duke.edu [Center for the Environmental Implications of NanoTechnology, Duke University, Durham, NC 27708 (United States); Department of Civil and Environmental Engineering, Duke University, 121 Hudson Hall PO Box 90287, Durham, NC 27708 (United States)

    2015-12-01

    The study of nanomaterial impacts on environment, health and safety (nanoEHS) has been largely predicated on the assumption that exposure and hazard can be predicted from physical–chemical properties of nanomaterials. This approach is rooted in the view that nanoöbjects essentially resemble chemicals with additional particle-based attributes that must be included among their intrinsic physical–chemical descriptors. With the exception of the trivial case of nanomaterials made from toxic or highly reactive materials, this approach has yielded few actionable guidelines for predicting nanomaterial risk. This article addresses inherent problems in structuring a nanoEHS research strategy based on the goal of predicting outcomes directly from nanomaterial properties, and proposes a framework for organizing data and designing integrated experiments based on functional assays (FAs). FAs are intermediary, semi-empirical measures of processes or functions within a specified system that bridge the gap between nanomaterial properties and potential outcomes in complex systems. The three components of a functional assay are standardized protocols for parameter determination and reporting, a theoretical context for parameter application and reference systems. We propose the identification and adoption of reference systems where FAs may be applied to provide parameter estimates for environmental fate and effects models, as well as benchmarks for comparing the results of FAs and experiments conducted in more complex and varied systems. Surface affinity and dissolution rate are identified as two critical FAs for characterizing nanomaterial behavior in a variety of important systems. The use of these FAs to predict bioaccumulation and toxicity for initial and aged nanomaterials is illustrated for the case of silver nanoparticles and Caenorhabditis elegans. - Highlights: • Approaches to predict risk directly from nanomaterial (NM) properties are problematic. • We propose

  10. Flight Control of Biomimetic Air Vehicles Using Vibrational Control and Averaging

    Science.gov (United States)

    Tahmasian, Sevak; Woolsey, Craig A.

    2016-09-01

    A combination of vibrational inputs and state feedback is applied to control the flight of a biomimetic air vehicle. First, a control strategy is developed for longitudinal flight, using a quasi-steady aerodynamic model and neglecting wing inertial effects. Vertical and forward motion is controlled by modulating the wings' stroke and feather angles, respectively. Stabilizing control parameter values are determined using the time-averaged dynamic model. Simulations of a system resembling a hawkmoth show that the proposed controller can overcome modeling error associated with the wing inertia and small parameter uncertainties when following a prescribed trajectory. After introducing the approach through an application to longitudinal flight, the control strategy is extended to address flight in three-dimensional space.

  11. Not Just Fun, But Serious Strategies: Using Meta-Cognitive Strategies in Game-Based Learning

    Science.gov (United States)

    Kim, Bokyeong; Park, Hyungsung; Baek, Youngkyun

    2009-01-01

    The purpose of this study is to explore the effects of the meta-cognitive strategies on the academic and gaming achievements. Exploring the effects of those achievements on the social problem solving of students is also of interest. For this purpose, the MMORPG [Massively Multiple Online Role Playing Game] "Gersang" was used. The…

  12. Parallel Representation of Value-Based and Finite State-Based Strategies in the Ventral and Dorsal Striatum.

    Directory of Open Access Journals (Sweden)

    Makoto Ito

    2015-11-01

    Full Text Available Previous theoretical studies of animal and human behavioral learning have focused on the dichotomy of the value-based strategy using action value functions to predict rewards and the model-based strategy using internal models to predict environmental states. However, animals and humans often take simple procedural behaviors, such as the "win-stay, lose-switch" strategy without explicit prediction of rewards or states. Here we consider another strategy, the finite state-based strategy, in which a subject selects an action depending on its discrete internal state and updates the state depending on the action chosen and the reward outcome. By analyzing choice behavior of rats in a free-choice task, we found that the finite state-based strategy fitted their behavioral choices more accurately than value-based and model-based strategies did. When fitted models were run autonomously with the same task, only the finite state-based strategy could reproduce the key feature of choice sequences. Analyses of neural activity recorded from the dorsolateral striatum (DLS, the dorsomedial striatum (DMS, and the ventral striatum (VS identified significant fractions of neurons in all three subareas for which activities were correlated with individual states of the finite state-based strategy. The signal of internal states at the time of choice was found in DMS, and for clusters of states was found in VS. In addition, action values and state values of the value-based strategy were encoded in DMS and VS, respectively. These results suggest that both the value-based strategy and the finite state-based strategy are implemented in the striatum.

  13. Software architecture of biomimetic underwater vehicle

    Science.gov (United States)

    Praczyk, Tomasz; Szymak, Piotr

    2016-05-01

    Autonomous underwater vehicles are vehicles that are entirely or partly independent of human decisions. In order to obtain operational independence, the vehicles have to be equipped with a specialized software. The main task of the software is to move the vehicle along a trajectory with collision avoidance. Moreover, the software has also to manage different devices installed on the vehicle board, e.g. to start and stop cameras, sonars etc. In addition to the software embedded on the vehicle board, the software responsible for managing the vehicle by the operator is also necessary. Its task is to define mission of the vehicle, to start, to stop the mission, to send emergency commands, to monitor vehicle parameters, and to control the vehicle in remotely operated mode. An important objective of the software is also to support development and tests of other software components. To this end, a simulation environment is necessary, i.e. simulation model of the vehicle and all its key devices, the model of the sea environment, and the software to visualize behavior of the vehicle. The paper presents architecture of the software designed for biomimetic autonomous underwater vehicle (BAUV) that is being constructed within the framework of the scientific project financed by Polish National Center of Research and Development.

  14. Stable isotope labeling strategy based on coding theory

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Takuma; Koshiba, Seizo; Yokoyama, Jun; Kigawa, Takanori, E-mail: kigawa@riken.jp [RIKEN Quantitative Biology Center (QBiC), Laboratory for Biomolecular Structure and Dynamics (Japan)

    2015-10-15

    We describe a strategy for stable isotope-aided protein nuclear magnetic resonance (NMR) analysis, called stable isotope encoding. The basic idea of this strategy is that amino-acid selective labeling can be considered as “encoding and decoding” processes, in which the information of amino acid type is encoded by the stable isotope labeling ratio of the corresponding residue and it is decoded by analyzing NMR spectra. According to the idea, the strategy can diminish the required number of labelled samples by increasing information content per sample, enabling discrimination of 19 kinds of non-proline amino acids with only three labeled samples. The idea also enables this strategy to combine with information technologies, such as error detection by check digit, to improve the robustness of analyses with low quality data. Stable isotope encoding will facilitate NMR analyses of proteins under non-ideal conditions, such as those in large complex systems, with low-solubility, and in living cells.

  15. Biomimetic Nanotechnology: A Powerful Means to address Global Challenges

    CERN Document Server

    Gebeshuber, Ille C

    2010-01-01

    Biomimetic nanotechnology is a prominent research area at the meeting place of life sciences with engineering and physics: it is a continuously growing field that deals with knowledge transfer from biology to nanotechnology. Biomimetic nanotechnology is a field that has the potential to substantially support successful mastering of major global challenges. The Millennium Project was commissioned by the United Nations Secretary-General in 2002 to develop a concrete action plan for the world to reverse the grinding poverty, hunger and disease affecting billions of people. It states 15 Global Challenges: sustainable development, water, population and resources, democratization, long-term perspectives, information technology, the rich-poor gap, health, capacity to decide, peace and conflict, status of women, transnational crime, energy, science and technology and global ethics. The possible contributions to master these challenges with the help of biomimetic nanotechnology will be discussed in detail.

  16. Tribological and electrochemical studies on biomimetic synovial fluids

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this study, tribological and electrochemical performances of the new biomimetic synovial fluids were studied according to different composition concentrations, including hyaluronic acid, albumin and alendronic acid sodium. By using Taguchi method, the composition contents of the biomimetic synovial fluids were designed. Items such as friction coefficient, mean scar diameter and viscosity were investigated via a four-ball tribo-tester, viscosity meter and optical microscope. Polarization studies were carried out to analyze the electrochemical behaviour of the fluids. Results showed that hyaluronic acid dominates the viscosity of the fluids. High albumin concentration will reduce friction, while increasing wear rate due to the electro-chemical effect. Alendronic acid sodium is found to reduce the biocorrosion of CoCrMo as well as provide better lubricating. In conclusion, biomimetic synovial fluids partially recover the functions of natural synovial fluids and provide good lubricating property.

  17. PEM Fuel Cells Redesign Using Biomimetic and TRIZ Design Methodologies

    Science.gov (United States)

    Fung, Keith Kin Kei

    Two formal design methodologies, biomimetic design and the Theory of Inventive Problem Solving, TRIZ, were applied to the redesign of a Proton Exchange Membrane (PEM) fuel cell. Proof of concept prototyping was performed on two of the concepts for water management. The liquid water collection with strategically placed wicks concept demonstrated the potential benefits for a fuel cell. Conversely, the periodic flow direction reversal concepts might cause a potential reduction water removal from a fuel cell. The causes of this water removal reduction remain unclear. In additional, three of the concepts generated with biomimetic design were further studied and demonstrated to stimulate more creative ideas in the thermal and water management of fuel cells. The biomimetic design and the TRIZ methodologies were successfully applied to fuel cells and provided different perspectives to the redesign of fuel cells. The methodologies should continue to be used to improve fuel cells.

  18. Superhydrophobic surfaces: from natural to biomimetic to functional.

    Science.gov (United States)

    Guo, Zhiguang; Liu, Weimin; Su, Bao-Lian

    2011-01-15

    Nature is the creation of aesthetic functional systems, in which many natural materials have vagarious structures. Inspired from nature, such as lotus leaf, butterfly' wings, showing excellent superhydrophobicity, scientists have recently fabricated a lot of biomimetic superhydrophobic surfaces by virtue of various smart and easy routes. Whilst, many examples, such as lotus effect, clearly tell us that biomimicry is dissimilar to a simple copying or duplicating of biological structures. In this feature article, we review the recent studies in both natural superhydrophobic surfaces and biomimetic superhydrophobic surfaces, and highlight some of the recent advances in the last four years, including the various smart routes to construct rough surfaces, and a lot of chemical modifications which lead to superhydrophobicity. We also review their functions and applications to date. Finally, the promising routes from biomimetic superhydrophobic surfaces in the next are proposed.

  19. Controlling the Biomimetic Implant Interface: Modulating Antimicrobial Activity by Spacer Design

    Science.gov (United States)

    Wisdom, Cate; Vanoosten, Sarah Kay; Boone, Kyle W.; Khvostenko, Dmytro; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

    2016-08-01

    Surgical site infection is a common cause of post-operative morbidity, often leading to implant loosening, ultimately requiring revision surgery, increased costs and worse surgical outcomes. Since implant failure starts at the implant surface, creating and controlling the bio-material interface will play a critical role in reducing infection while improving host cell-to-implant interaction. Here, we engineered a biomimetic interface based upon a chimeric peptide that incorporates a titanium binding peptide (TiBP) with an antimicrobial peptide (AMP) into a single molecule to direct binding to the implant surface and deliver an antimicrobial activity against S. mutans and S. epidermidis, two bacteria which are linked with clinical implant infections. To optimize antimicrobial activity, we investigated the design of the spacer domain separating the two functional domains of the chimeric peptide. Lengthening and changing the amino acid composition of the spacer resulted in an improvement of minimum inhibitory concentration by a three-fold against S. mutans. Surfaces coated with the chimeric peptide reduced dramatically the number of bacteria, with up to a nine-fold reduction for S. mutans and a 48-fold reduction for S. epidermidis. Ab initio predictions of antimicrobial activity based on structural features were confirmed. Host cell attachment and viability at the biomimetic interface were also improved compared to the untreated implant surface. Biomimetic interfaces formed with this chimeric peptide offer interminable potential by coupling antimicrobial and improved host cell responses to implantable titanium materials, and this peptide based approach can be extended to various biomaterials surfaces.

  20. 模仿蛇怪蜥蜴的仿生推进装置结构研究%Research on the structure of a biomimetic propulsion based on basilisk lizard

    Institute of Scientific and Technical Information of China (English)

    高飞; 吕建刚; 张晓涛; 白向华

    2012-01-01

    通过模仿蛇怪蜥蜴在水上行走时腿部的运动姿态,设计了一种轮-叶复合式仿生推进装置.为了在结构设计阶段评估叶片数对推进装置动力性能的影响,利用三维造型软件建立了不同叶片数的推进装置的物理模型,通过计算流体力学软件对推进装置进行了数值计算,获得了三种设计方案的水动力学特性.仿真结果表明:随着叶片数的增加,推进力呈减小趋势,升力呈增大趋势,推进装置受力周期性波动的幅值随之减小.最后,根据物理模型制作了试验样机,入水测试表明仿生推进装置能够实现滑行状态.%Simulated the move status of a basilisk lizard running on the water to develop a wheel-blade compound propulsion unit. In order to optimize the structure of biomimetic propulsion during its conceptual design phase, a physical model was developed by Pro/E, CFD software was used to simulate the movement of the bionic propulsion unit, obtained the hydrodynamic performance of the three options. The simulation results indicate that increase the number of leaves, thrust is decreasing and lift is increasing, propulsion can provide a more stable thrust and lift. At last, made an experimental prototype and used it to do a test. The test shows that propulsion can bring about itself moving on the water.

  1. Biomimetic/Bioinspired Design of Enzyme@capsule Nano/Microsystems.

    Science.gov (United States)

    Shi, J; Jiang, Y; Zhang, S; Yang, D; Jiang, Z

    2016-01-01

    Enzyme@capsule nano/microsystems, which refer to the enzyme-immobilized capsules, have received tremendous interest owing to the combination of the high catalytic activities of encapsulated enzymes and the hierarchical structure of the capsule. The preparation of capsules and simultaneous encapsulation of enzymes is recognized as the core process for the rational design and construction of enzyme@capsule nano/microsystems. The strategy used has three major steps: (a) generation of the templates, (b) surface coating on the templates, and (c) removal of the templates, and it has been proven to be effective and versatile for the construction of enzyme@capsule nano/microsystems. Several conventional methods, including layer-by-layer assembly of polyelectrolytes, liquid crystalline templating method, etc., were used to design and construct enzyme@capsule nano/microsystems, but these have two major drawbacks. One is the low mechanical stability of the systems and the second is the harsh conditions used in the construction process. Learning from nature, several biomimetic/bioinspired methods such as biomineralization, biomimetic/bioinspired adhesion, and their combination have been exploited for the construction of enzyme@capsule nano/microsystems. In this chapter, we will present a general protocol for the construction of enzyme@capsule nano/microsystems using the latter approach. Some suggestions for improved design, construction, and characterization will also be presented with detailed procedures for specific examples.

  2. Biomimetic Nanofibrillation in Two-Component Biopolymer Blends with Structural Analogs to Spider Silk

    Science.gov (United States)

    Xie, Lan; Xu, Huan; Li, Liang-Bin; Hsiao, Benjamin S.; Zhong, Gan-Ji; Li, Zhong-Ming

    2016-10-01

    Despite the enormous potential in bioinspired fabrication of high-strength structure by mimicking the spinning process of spider silk, currently accessible routes (e.g., microfluidic and electrospinning approaches) still have substantial function gaps in providing precision control over the nanofibrillar superstructure, crystalline morphology or molecular orientation. Here the concept of biomimetic nanofibrillation, by copying the spiders’ spinning principles, was conceived to build silk-mimicking hierarchies in two-phase biodegradable blends, strategically involving the stepwise integration of elongational shear and high-pressure shear. Phase separation confined on nanoscale, together with deformation of discrete phases and pre-alignment of polymer chains, was triggered in the elongational shear, conferring the readiness for direct nanofibrillation in the latter shearing stage. The orderly aligned nanofibrils, featuring an ultralow diameter of around 100 nm and the “rigid-soft” system crosslinked by nanocrystal domains like silk protein dopes, were secreted by fine nanochannels. The incorporation of multiscale silk-mimicking structures afforded exceptional combination of strength, ductility and toughness for the nanofibrillar polymer composites. The proposed spider spinning-mimicking strategy, offering the biomimetic function integration unattainable with current approaches, may prompt materials scientists to pursue biopolymer mimics of silk with high performance yet light weight.

  3. Design specifications of the Human Robotic interface for the biomimetic underwater robot "yellow submarine project"

    CERN Document Server

    Bheemaiah, Anil

    2010-01-01

    This paper describes the design of a web based multi agent design for a collision avoidance auto navigation biomimetic submarine for submarine hydroelectricity. The paper describes the nature of the map - topology interface for river bodies and the design of interactive agents for the control of the robotic submarine. The agents are migratory on the web and are designed in XML/html interface with both interactive capabilities and visibility on a map. The paper describes mathematically the user interface and the map definition languages used for the multi agent description

  4. Biomimetic Intrafibrillar Mineralization of Type I Collagen with Intermediate Precursors-loaded Mesoporous Carriers

    Science.gov (United States)

    Zhang, Wei; Luo, Xiao-juan; Niu, Li-na; Yang, Hong-ye; Yiu, Cynthia K.Y.; Wang, Tian-da; Zhou, Li-qun; Mao, Jing; Huang, Cui; Pashley, David H.; Tay, Franklin R.

    2015-01-01

    Limited continuous replenishment of the mineralization medium is a restriction for in-situ solution-based remineralization of hypomineralized body tissues. Here, we report a process that generated amine-functionalized mesoporous silica nanoparticles for sustained release of biomimetic analog-stabilized amorphous calcium phosphate precursors. Both two-dimensional and three-dimensional collagen models can be intrafibrillarly mineralized with these released fluidic intermediate precursors. This represents an important advance in the translation of biomineralization concepts into regimes for in-situ remineralization of bone and teeth. PMID:26053330

  5. Biomimetic actuators using electroactive polymers (EAP) as artificial muscles

    Science.gov (United States)

    Bar-Cohen, Yoseph

    2006-01-01

    Evolution has resolved many of nature's challenges leading to lasting solutions with maximal performance and effective use of resources. Nature's inventions have always inspired human achievements leading to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems and many other benefits. The field of mimicking nature is known as Biomimetics and one of its topics includes electroactive polymers that gain the moniker artificial muscles. Integrating EAP with embedded sensors, self-repair and many other capabilities that are used in composite materials can add greatly to the capability of smart biomimetic systems. Such development would enable fascinating possibilities potentially turning science fiction ideas into engineering reality.

  6. A Handover Strategy in the LEO Satellite-Based Constellation Networks with ISLs

    Institute of Scientific and Technical Information of China (English)

    LIU Gang; GOU Dingyong; WU Shiqi

    2003-01-01

    A new handover strategy named minimal-hops handover(MHH) strategy for the low earth orbit(LEO) satellite constellations networks equipped with inter-satellite links(ISLs) is proposed.MHH strategy, which is based on the hops of the end-to-end connection paths and makes good use of the regularity of the constellation network topology, can appropriately combine the handover procedure with routing and efficiently solve the inter-satellite handover issue. Moreover, MHH strategy can provide quality of services( QoS) guarantees to some extent. The system performances of the MHH strategy, such as time propagation delay and handover frequency, are evaluated and compared with that of other previous strategies. The simulation results show that MHH strategy performs better than other previous handover strategies.

  7. Identifying Multiple Levels of Discussion-Based Teaching Strategies for Constructing Scientific Models

    Science.gov (United States)

    Williams, Grant; Clement, John

    2015-01-01

    This study sought to identify specific types of discussion-based strategies that two successful high school physics teachers using a model-based approach utilized in attempting to foster students' construction of explanatory models for scientific concepts. We found evidence that, in addition to previously documented dialogical strategies that teachers utilize to engage students in effectively communicating their scientific ideas in class, there is a second level of more cognitively focused model-construction-supporting strategies that these teachers utilized in attempting to foster students' learning. A further distinction between macro and micro strategy levels within the set of cognitive strategies is proposed. The relationships between the resulting three levels of strategies are portrayed in a diagramming system that tracks discussions over time. The study attempts to contribute to a clearer understanding of how discussion-leading strategies may be used to scaffold the development of conceptual understanding.

  8. Operations Strategy Development in Project-based Production – a building contractor implements Lean

    DEFF Research Database (Denmark)

    Koch, Christian; Friis, Ole Uhrskov

    2015-01-01

    Purpose: To study how operations strategy innovation occurs in project-based production and organisation. Design/methodology/approach: A longitudinal case study encompassing the processes at the company headquarters and in two projects using Lean. Findings: The operations strategy development...... commences at a middle level in the organisation, is underpinned and embedded in production projects, and only after several years becomes embedded in the corporate operations strategy. The projects use Lean principles in a differentiated manner. Research limitations/implications: A qualitative case study...... operations strategy development. Originality/value: The present study contributes to the small body of studies of operations strategy development processes by providing insight into how project-based companies renew their operations strategy. Key words: Lean, Construction, Operations Strategy, Political...

  9. Web-based training of metacognitive strategies for text comprehension: Focus on poor comprehenders

    NARCIS (Netherlands)

    Johnson, M.C.

    2005-01-01

    Metacognitive reading strategies were trained and practiced using interactive Web-based tools. Twenty middle school poor reading comprehenders were trained in two metacognitive strategies using a Web-based application called 3D-Readers. The training texts were science-oriented and merged the narrati

  10. Optimal Electricity Charge Strategy Based on Price Elasticity of Demand for Users

    Science.gov (United States)

    Li, Xin; Xu, Daidai; Zang, Chuanzhi

    The price elasticity is very important for the prediction of electricity demand. This paper mainly establishes the price elasticity coefficient for electricity in single period and inter-temporal. Then, a charging strategy is established based on these coefficients. To evaluate the strategy proposed, simulations of the two elastic coefficients are carried out based on the history data of a certain region.

  11. Biomimetic photo-actuation: progress and challenges

    Science.gov (United States)

    Dicker, Michael P. M.; Weaver, Paul M.; Rossiter, Jonathan M.; Bond, Ian P.; Faul, Charl F. J.

    2016-04-01

    Photo-actuation, such as that observed in the reversible sun-tracking movements of heliotropic plants, is produced by a complex, yet elegant series of processes. In the heliotropic leaf movements of the Cornish Mallow, photo-actuation involves the generation, transport and manipulation of chemical signals from a distributed network of sensors in the leaf veins to a specialized osmosis driven actuation region in the leaf stem. It is theorized that such an arrangement is both efficient in terms of materials use and operational energy conversion, as well as being highly robust. We concern ourselves with understanding and mimicking these light driven, chemically controlled actuating systems with the aim of generating intelligent structures which share the properties of efficiency and robustness that are so important to survival in Nature. In this work we present recent progress in mimicking these photo-actuating systems through remote light exposure of a metastable state photoacid and the resulting signal and energy transfer through solution to a pH-responsive hydrogel actuator. Reversible actuation strains of 20% were achieved from this arrangement, with modelling then employed to reveal the critical influence hydrogel pKa has on this result. Although the strong actuation achieved highlights the progress that has been made in replicating the principles of biomimetic photo-actuation, challenges such as photoacid degradation were also revealed. It is anticipated that current work can directly lead to the development of high-performance and low-cost solartrackers for increased photovoltaic energy capture and to the creation of new types of intelligent structures employing chemical control systems.

  12. Biomimetic processing of oriented crystalline ceramic layers

    Energy Technology Data Exchange (ETDEWEB)

    Cesarano, J.; Shelnutt, J.A.

    1997-10-01

    The aim of this project was to develop the capabilities for Sandia to fabricate self assembled Langmuir-Blodgett (LB) films of various materials and to exploit their two-dimensional crystalline structure to promote the growth of oriented thin films of inorganic materials at room temperature. This includes the design and synthesis of Langmuir-active (amphiphilic) organic molecules with end groups offering high nucleation potential for various ceramics. A longer range goal is that of understanding the underlying principles, making it feasible to use the techniques presented in this report to fabricate unique oriented films of various materials for electronic, sensor, and membrane applications. Therefore, whenever possible, work completed in this report was completed with the intention of addressing the fundamental phenomena underlying the growth of crystalline, inorganic films on template layers of highly organized organic molecules. This problem was inspired by biological processes, which often produce exquisitely engineered structures via templated growth on polymeric layers. Seashells, for example, exhibit great toughness owing to their fine brick-and-mortar structure that results from templated growth of calcium carbonate on top of layers of ordered organic proteins. A key goal in this work, therefore, is to demonstrate a positive correlation between the order and orientation of the template layer and that of the crystalline ceramic material grown upon it. The work completed was comprised of several parallel efforts that encompassed the entire spectrum of biomimetic growth from solution. Studies were completed on seashells and the mechanisms of growth for calcium carbonate. Studies were completed on the characterization of LB films and the capability developed for the in-house fabrication of these films. Standard films of fatty acids were studied as well as novel polypeptides and porphyrins that were synthesized.

  13. Mobile English Vocabulary Learning Based on Concept-Mapping Strategy

    Science.gov (United States)

    Liu, Pei-Lin

    2016-01-01

    Numerous researchers in education recognize that vocabulary is essential in foreign language learning. However, students often encounter vocabulary that is difficult to remember. Providing effective vocabulary learning strategies is therefore more valuable than teaching students a large amount of vocabulary. The purpose of this study was to…

  14. An Organization-based View of Strategy and an Integrative Framework of Strategic Management

    DEFF Research Database (Denmark)

    Li, Xin

    Just like scholars distinguish two types of firm’s external environment, i.e., competitive and institutional, we make a distinction between two types of firm’s internal environment, i.e., resources and organization. Based on this distinction, we propose an organization-based view of strategy (OBV......), not only as a label to unite various organization-related issues within the strategy field, but also as a fourth research paradigm to supplement to three existing paradigms, i.e., industry- or competition-based view (CBV), resource-based view (RBV), and institution-based view (IBV). Bringing the four...... paradigms together, we transform Mike Peng’s ‘strategy tripod’ into a ‘strategy quadrapod’. By proposing an organization-resource-institution-competition (ORIC) analysis and a situation-action-performance (SAP) framework, we attempt to make a grand integration of the strategy field....

  15. Determination of catechin in green tea using a catechol oxidase biomimetic sensor

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Suellen C.; Osorio, Renata El-Hage M. de Barros; Anjos, Ademir dos; Neves, Ademir; Micke, Gustavo Amadeu; Vieira, Iolanda C. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Quimica]. E-mail: iolanda@qmc.ufsc.br

    2008-07-01

    A catechol oxidase biomimetic sensor, based on a novel copper(II) complex, was developed for the determination of catechin in green tea and the results were compared with those obtained by capillary electrophoresis. The dinuclear copper(II) complex, [Cu{sub 2}(HL)({mu}-CH{sub 3}COO)](ClO{sub 4}), containing the ligand N,N-[bis-(2-pyridylmethyl)]-N',N'-[(2-hydroxybenzyl)(2-hydroxy-3,5-di-tert - butylbenzyl)]-1,3-propanediamine-2-ol (H{sub 3}L), was synthesized and characterized by IR, {sup 1}H NMR and elemental analysis. The best conditions for the optimization of the biomimetic sensor were established by square wave voltammetry. The best performance for this sensor was obtained in 75:15:10% (m/m/m) of the graphite powder:nujol:copper(II) complex, 0.05 mol L{sup -1} phosphate buffer solution (pH 7.5) and frequency, pulse amplitude, scan increment at 30 Hz, 80 mV, 3.3 mV, respectively. The analytical curve was linear in the concentration range 4.95 x 10{sup -6} to 3.27 x 10{sup -5} mol L{sup -1} (r = 0.9993) with a detection limit of 2.8 x 10{sup -7} mol L{sup -1}. This biomimetic sensor demonstrated long-term stability (9 months; 800 determinations) and reproducibility with a relative standard deviation of 3.5%. The recovery of catechin from green tea samples ranged from 93.8 to 106.9% and the determination, compared with that obtained using capillary electrophoresis, was found to be acceptable at the 95% confidence level. (author)

  16. Biomimetic synthesized chiral mesoporous silica: Structures and controlled release functions as drug carrier

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing; Xu, Lu, E-mail: xl2013109@163.com; Yang, Baixue; Bao, Zhihong; Pan, Weisan; Li, Sanming, E-mail: li_sanming2013@163.com

    2015-10-01

    This work initially illustrated the formation mechanism of chiral mesoporous silica (CMS) in a brand new insight named biomimetic synthesis. Three kinds of biomimetic synthesized CMS (B-CMS, including B-CMS1, B-CMS2 and B-CMS3) were prepared using different pH or stirring rate condition, and their characteristics were tested with transmission electron microscope and small angle X-ray diffraction. The model drug indomethacin was loaded into B-CMS and drug loading content was measured using ultraviolet spectroscopy. The result suggested that pH condition influenced energetics of self-assembly process, mainly packing energetics of the surfactant, while stirring rate was the more dominant factor to determine particle length. In application, indomethacin loading content was measured to be 35.3%, 34.8% and 35.1% for indomethacin loaded B-CMS1, indomethacin loaded B-CMS2 and indomethacin loaded B-CMS3. After loading indomethacin into B-CMS carriers, surface area, pore volume and pore diameter of B-CMS carriers were reduced. B-CMS converted crystalline state of indomethacin to amorphous state, leading to the improved indomethacin dissolution. B-CMS1 controlled drug release without burst-release, while B-CMS2 and B-CMS3 released indomethacin faster than B-CMS1, demonstrating that the particle length, the ordered lever of multiple helixes, the curvature degree of helical channels and pore diameter greatly contributed to the release behavior of indomethacin loaded B-CMS. - Highlights: • Chiral mesoporous silica was synthesized using biomimetic method. • pH influenced energetics of self-assembly process of chiral mesoporous silica. • Stirring rate determined the particle length of chiral mesoporous silica. • Controlled release behaviors of chiral mesoporous silica varied based on structures.

  17. Adsorption of nucleotides on biomimetic apatite: The case of adenosine 5‧ monophosphate (AMP)

    Science.gov (United States)

    Hammami, K.; Feki, H. El; Marsan, O.; Drouet, C.

    2015-10-01

    This work investigates the interaction between the nucleotide adenosine 5‧ monophosphate molecule (AMP) and a biomimetic nanocrystalline carbonated apatite as a model for bone mineral. The analogy of the apatite phase used in this work with biological apatite was first pointed out by complementary techniques. AMP adsorption isotherms were then investigated. Obtained data were fitted to a Sips isotherm with an exponent greater than one suggesting positive cooperativity among adsorbed molecules. The data were compared to a previous study relative to the adsorption of another nucleotide, cytidine monophosphate (CMP) onto a similar substrate, evidencing some effect of the chemical nature of the nucleic base. An enhanced adsorption was observed under acidic (pH 6) conditions as opposed to pH 7.4, which parallels the case of DNA adsorption on biomimetic apatite. An estimated standard Gibbs free energy associated to the adsorption process (ΔG°ads ≅ -22 kJ/mol) intermediate between "physisorption" and "chemisorption" was found. The analysis of the solids after adsorption pointed to the preservation of the main characteristics of the apatite substrate but shifts or enhancements of Raman bands attributed to AMP showed the existence of chemical interactions involving both the phosphate and adenine parts of AMP. This contribution adds to the works conducted in view of better understanding the interaction of DNA/RNA and their constitutive nucleotides and the surface of biomimetic apatites. It could prove helpful in disciplines such as bone diagenesis (DNA/apatite interface in aged bones) or nanomedicine (setup of DNA- or RNA-loaded apatite systems). Also, the adsorption of nucleic acids on minerals like apatites could have played a role in the preservation of such biomolecules in the varying conditions known to exist at the origin of life on Earth, underlining the importance of dedicated adsorption studies.

  18. Biomimetic membranes with aqueous nano channels but without proteins: impedance of impregnated cellulose ester filters.

    Science.gov (United States)

    Kocherginsky, Nikolai M; Lvovich, Vadim F

    2010-12-01

    Earlier we have shown that many important properties of ionic aqueous channels in biological membranes can be imitated using simple biomimetic membranes. These membranes are composed of mixed cellulose ester-based filters, impregnated with isopropyl myristate or other esters of fatty acids, and can be used for high-throughput drug screening. If the membrane separates two aqueous solutions, combination of relatively hydrophilic polymer support with immobilized carboxylic groups results in the formation of thin aqueous layers covering inner surface of the pores, while the pore volume is filled by lipid-like substances. Because of these aqueous layers biomimetic membranes even without proteins have a cation/anion ion selectivity and specific (per unit of thickness) electrical properties, which are similar to typical properties of biological membranes. Here we describe frequency-dependent impedance of the isopropyl myristate-impregnated biomimetic membranes in the 4-electrode arrangement and present the results as Bode and Nyquist diagrams. When the membranes are placed in deionized water, it is possible to observe three different dispersion processes in the frequency range 0.1 Hz to 30 kHz. Only one dispersion is observed in 5 mM KH(2)PO(4) solution. It is suggested that these three dispersion features are determined by (a) conductivity in aqueous structures/channels, formed near the internal walls of the filter pores at high frequencies, (b) dielectric properties of the whole membrane at medium frequencies, determined by polymer support, aqueous layers and impregnating oil, and, finally, (c) by the processes in hydrated liquid crystal structures formed in pores by impregnating oil in contact with water at low frequencies.

  19. Compartmentalisation Strategies for Hydrocarbon-based Biota on Titan

    Science.gov (United States)

    Norman, L.; Fortes, A. D.; Skipper, N.; Crawford, I.

    2013-05-01

    The goal of our study is to determine the nature of compartimentalisation strategies for any organisms inhabiting the hydrocarbon lakes of Titan (the largest moon of Saturn). Since receiving huge amounts of data via the Cassini-Huygens mission to the Saturnian system astrobiologists have speculated that exotic biota might currently inhabit this environment. The biota have been theorized to consume acetylene and hydrogen whilst excreting methane (1,2) leading to an anomalous hydrogen depletion near the surface; and there has been evidence to suggest this depletion exists (3). Nevertheless, many questions still remain concerning the possible physiological traits of biota in these environments, including whether cell-like structures can form in low temperature, low molecular weight hydrocarbons. The backbone of terrestrial cell membranes are vesicular structures composed primarily of a phospholipid bilayer with the hydrophilic head groups arranged around the periphery and are thought to be akin to the first protocells that terrestrial life utilised (4). It my be possible that reverse vesicles composed of a bilayer with the hydrophilic head groups arranged internally and a nonpolar core may be ideal model cell membranes for hydrocarbon-based organisms inhabiting Titan's hydrocarbon lakes (5). A variety of different surfactants have been used to create reverse vesicles in nonpolar liquids to date including; non-ionic ethers (7) and esters (6, 8); catanionic surfactant mixtures (9); zwitterionic gemini surfactants (10); coblock polymer surfactants (11); and zwitterionic phospholipid surfactants (12). In order to discover whether certain phospholipids can exhibit vesicular behaviour within hydrocarbon liquids, and to analyse their structure, we have carried out experimental studies using environmental conditions that are increasing comparable to those found on the surface of Titan. Experimental methods that have been used to determine the presence of vesicles include the

  20. Design and Implementation of a Modular Biomimetic Infochemical Communication System

    NARCIS (Netherlands)

    Rácz, Z.; Cole, M.; Gardner, J.W.; Chowdhury, M.F.; Bula, W.P.; Gardeniers, J.G.E.; Karout, S.; Capurro, A.; Pearce, T.C.

    2013-01-01

    We describe here the design and implementation of a novel biomimetic infochemical communication system that employs airborne molecules alone to communicate over space and time. The system involves the design and fabrication of a microsystem capable of producing and releasing a precise mix of biosynt

  1. Biomimetic flavin-catalysed reactions for organic synthesis.

    Science.gov (United States)

    Iida, H; Imada, Y; Murahashi, S-I

    2015-07-28

    Using simple riboflavin related compounds as biomimetic catalysts, catalytic oxidation of various substrates with hydrogen peroxide or molecular oxygen can be performed selectively under mild conditions. The principle of these reactions is fundamental and will provide a wide scope for environmentally benign future practical methods.

  2. An efficient biomimetic coating methodology for a prosthetic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Adawy, Alaa, E-mail: a.adawy@science.ru.nl [Physics Department, Faculty of Science, Ain Shams University, Abbassia, Cairo (Egypt); Abdel-Fattah, Wafa I. [Biomaterials Department, National Research Centre, Giza (Egypt)

    2013-04-01

    The combination of the load-bearing metallic implants with the bioactive materials in the design of synthetic implants is an important aspect in the biomaterials research. Biomimetic coating of bioinert alloys with calcium phosphate phases provides a good alternative to the prerequisite for the continual replacement of implants because of the failure of bone-implant integration. We attempted to accelerate the biomimetic coating process of stainless steel alloy (316L) with biomimetic apatite. In addition, we investigated the incorporation of functioning minerals such as strontianite and smithsonite into the deposited layer. In order to develop a highly mature apatite coating, our method requires soaking of the pre-treated alloy in highly concentrated synthetic body fluid for only few hours. Surface characterizations were performed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). Also, the deposited apatitic layers were analysed by powder diffraction X-ray analysis (XRD). 316L surface showed the growth of highly crystalline, low carbonated hydroxyapatite, after only 6 h of the whole soaking process. Highlights: ► The manuscript describes a fast and efficient biomimetic coating methodology. ► This methodology can be used for metallic implants. ► 316L was coated with crystalline hydroxyapatite. ► Addition of strontium and zinc lead to the deposition of brushite. ► Coating of all synthetic solutions is highly crystalline.

  3. Osteoclastic resorption of biomimetic calcium phosphate coatings in vitro.

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Layrolle, P.; Barrere, F.; Bruijn, J.G.M. de; Schoonman, J.; Blitterswijk, C.A. van; Groot, K. de

    2001-01-01

    A new biomimetic method for coating metal implants enables the fast formation of dense and homogeneous calcium phosphate coatings. Titanium alloy (Ti6Al4V) disks were coated with a thin, carbonated, amorphous calcium phosphate (ACP) by immersion in a saturated solution of calcium, phosphate, magnesi

  4. Hierarcially biomimetic bone materials: from nanometer to millimeter

    Institute of Scientific and Technical Information of China (English)

    ZHANG W.; CUI F. Z.; LIAO S. S.

    2001-01-01

    @@ The bone composite was produced by biomimetic synthesis. It shows some features of natural bone in both composition and microstructure. And the collagen moleculars and the nano-crystal hydroxyapatite assemble into ultrastructure similar to natural bone. It possesses porous structure with porosity from 100μm to 500μm after mixed with PLA (poly lactic acid).

  5. Diffraction from relief gratings on a biomimetic elastomer cast

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, Raphael A., E-mail: rguerrero@admu.edu.ph [Department of Physics, Ateneo de Manila University, Loyola Heights, Quezon City (Philippines); Aranas, Erika B. [Department of Physics, Ateneo de Manila University, Loyola Heights, Quezon City (Philippines)

    2010-10-12

    Biomimetic optical elements combine the optimized designs of nature with the versatility of materials engineering. We employ a beetle carapace as the template for fabricating relief gratings on an elastomer substrate. Biological surface features are successfully replicated by a direct casting procedure. Far-field diffraction effects are discussed in terms of the Fraunhofer approximation in Fourier space.

  6. PROBLEM SOLVING IN SCHOOL MATHEMATICS BASED ON HEURISTIC STRATEGIES

    OpenAIRE

    Novotná, Jarmila; EISENMANN. Petr; PŘIBYL, Jiří; ONDRUŠOVÁ, Jiřina; BŘEHOVSKÝ, Jiří

    2014-01-01

    The paper describes one of the ways of developing pupils’ creative approach to problem solving. The described experiment is a part of a longitudinal research focusing on improvement of culture of problem solving by pupils. It deals with solving of problems using the following heuristic strategies: Analogy, Guess – check – revise, Systematic experimentation, Problem reformulation, Solution drawing, Way back and Use of graphs of functions. Most attention is paid to the question whether short-te...

  7. Students’ Opinions Regarding the Effect of Reading Strategies Instruction Based on Cognitive Academic Language Learning Approach

    Directory of Open Access Journals (Sweden)

    Meral Özkan Gürses

    2013-03-01

    Full Text Available This study aims at investigating students’ opinions regarding the effect of reading strategies instruction—based on Cognitive Academic Language Learning Approach and applied in a French class as a second language in higher education—over their reading skills and strategy use. Data was collected through semi-structured interviews both before and after the intervention. Participants of the study were six students representing high, medium and low proficiency levels in reading. Descriptive analysis was employed for data analysis. Findings generally indicate that students hold positive opinions about the effect of reading strategies instruction over their reading skills and strategy use. Furthermore, after the strategy instruction, a certain variation among the strategies applied by students was detected and students were noted to have higher levels of awareness concerning their reading skills and strategy use

  8. Development of solid supports for electrochemical study of biomimetic membrane systems

    DEFF Research Database (Denmark)

    Mech-Dorosz, Agnieszka

    recording of a steady-state photocurrent while only a transient photocurrent peak was recorded on the polyelectrolyte cushion without a PES membrane. This PhD thesis also comprises the design and fabrication process of a modular microfluidic system with automated fluid delivery (micropumps and valves...... with reconstituted membrane spanning proteins, are attractive tools. However, BLMs suffer from intrinsic fragility, therefore, requiring techniques to increase their robustness and stability. This PhD thesis presents strategies to construct solid supports for electrochemical studies of two biomimetic membrane...... transporter valinomycin. The presented work also includes a comprehensive EIS analysis and cryological scanning electron microscopic (cryo-SEM) imaging of hydrogels formulated in various molar ratios (1:100; 1:200; 1:400) of the cross-linker poly(ethylene glycol)dimethacrylate (PEGDMA) and 2-hydroxyethylene...

  9. Deep UV patterning of acrylic masters for molding biomimetic dry adhesives

    Science.gov (United States)

    Sameoto, D.; Menon, C.

    2010-11-01

    We present a novel fabrication method for the production of biomimetic dry adhesives that allows enormous variation in fiber shapes and sizes. The technology is based on deep-UV patterning of commercial acrylic with semi-collimated light available from germicidal lamps, and combined careful processing conditions, material selection and novel developer choices to produce relatively high-aspect-ratio fibers with overhanging caps on large areas. These acrylic fibers are used as a master mold for subsequent silicone rubber negative mold casting. Because the bulk acrylic demonstrates little inherent adhesion to silicone rubbers, the master molds created in this process do not require any surface treatments to achieve high-yield demolding of interlocked structures. Multiple polymers can be cast from silicone rubber negative molds and this process could be used to structure smart materials on areas over multiple square feet. Using direct photopatterning of acrylic allows many of the desired structures for biomimetic dry adhesives to be produced with relative ease compared to silicon-based molding processes, including angled fibers and hierarchical structures. Optimized fiber shapes for a variety of polymers can be produced using this process, and adhesion measurements on a well-characterized polyurethane, ST-1060, are used to determine the effect of fiber geometry on adhesion performance.

  10. Natural Ventilation with Heat Recovery: A Biomimetic Concept

    Directory of Open Access Journals (Sweden)

    Zulfikar A. Adamu

    2015-05-01

    Full Text Available In temperate countries, heat recovery is often desirable through mechanical ventilation with heat recovery (MVHR. Drawbacks of MVHR include use of electric power and complex ducting, while alternative passive heat recovery systems in the form of roof or chimney-based solutions are limited to low rise buildings. This paper describes a biomimetic concept for natural ventilation with heat recovery (NVHR. The NVHR system mimics the process of water/mineral extraction from urine in the Loop of Henle (part of human kidney. Simulations on a facade-integrated Chamber successfully imitated the geometry and behaviour of the Loop of Henle (LoH. Using a space measuring 12 m2 in area and assuming two heat densities of 18.75 W/m2 (single occupancy or 30 W/m2 (double occupancy, the maximum indoor temperatures achievable are up to 19.3 °C and 22.3 °C respectively. These come with mean relative ventilation rates of 0.92 air changes per hour (ACH or 10.7 L·s−1 and 0.92 ACH (11.55 L·s−1, respectively, for the month of January. With active heating and single occupant, the LoH Chamber consumes between 65.7% and 72.1% of the annual heating energy required by a similar naturally ventilated space without heat recovery. The LoH Chamber could operate as stand-alone indoor cabinet, benefitting refurbishment of buildings and evading constraints of complicated ducting, external aesthetic or building age.

  11. Analytical strategies in mass spectrometry-based phosphoproteomics

    DEFF Research Database (Denmark)

    Rosenqvist, Heidi; Ye, Juanying; Jensen, Ole N

    2011-01-01

    to reveal key regulatory events and phosphorylation-mediated processes in the cell and in whole organisms. We present an overview of sensitive and robust analytical methods for phosphopeptide analysis, including calcium phosphate precipitation and affinity enrichment methods such as IMAC and TiO(2). We......Phosphoproteomics, the systematic study of protein phosphorylation events and cell signaling networks in cells and tissues, is a rapidly evolving branch of functional proteomics. Current phosphoproteomics research provides a large toolbox of strategies and protocols that may assist researchers...

  12. Knowledge revision in systems based on an informed tree search strategy : application to cartographic generalisation

    CERN Document Server

    Taillandier, Patrick; Drogoul, Alexis

    2012-01-01

    Many real world problems can be expressed as optimisation problems. Solving this kind of problems means to find, among all possible solutions, the one that maximises an evaluation function. One approach to solve this kind of problem is to use an informed search strategy. The principle of this kind of strategy is to use problem-specific knowledge beyond the definition of the problem itself to find solutions more efficiently than with an uninformed strategy. This kind of strategy demands to define problem-specific knowledge (heuristics). The efficiency and the effectiveness of systems based on it directly depend on the used knowledge quality. Unfortunately, acquiring and maintaining such knowledge can be fastidious. The objective of the work presented in this paper is to propose an automatic knowledge revision approach for systems based on an informed tree search strategy. Our approach consists in analysing the system execution logs and revising knowledge based on these logs by modelling the revision problem as...

  13. Data Integration Strategy for Database Grids Based on P2P Framework

    Institute of Scientific and Technical Information of China (English)

    WANG Guangqi; SHEN Derong; YU Ge; ZHOU Wensheng; LI Meifang

    2006-01-01

    The differences between the data integration of a dynamic database grid (DBG) and that of a distributed database system are analyzed, and three kinds of data integration strategies are given on the background of DBG based on Peer to Peer (P2P) framework, including the centralized data integration (CDI) strategy, the distributed data integration (DDI) strategy and the filter-based data integration (FDDI) strategy. CDI calls all the database grid services (DGSs) at a single node, DDI disperses the DGSs to multiple nodes, while FDDI schedules the data integration nodes based on filtering the keywords returned from DGSs. The performance of these three integration strategies are compared with and analyzed by simulation experiments. FDDI is more evident for filtering the keywords with data redundancy increasing. Through the reduction of large amount of data transportation, it effectively shortens the executing time for the task and improves its efficiency.

  14. Research on Modulation Strategies Based on Multilevel Inverter Universal Hybrid Topology

    Institute of Scientific and Technical Information of China (English)

    Zhou Jinghua; Su Yanmin; Shen Chuanwen; Zhang Lin

    2005-01-01

    Based on multi-module-cascaded inverter topology, this study presented a universal multilevel inverter hybrid topology and unified the researches on multilevel inverter topology. According to the freedom of this universal topology, several new hybrid topologies were constructed. Also, based on conventional modulation strategies- multi-carrier SPWM (Sinusoidal Pulse Width Modulation), hybrid modulation strategies were introduced corresponding to hybrid topologies, and a multilevel SVPWM (Space Vector Pulse Width Modulation) technique based on phase-shifted theory was naturally produced. Simulation and experiment results prove that hybrid topologies and corresponding modulation strategies are valid, which lay a foundation for practical application of hybrid multilevel inverter topologies.

  15. Enhanced LVRT Control Strategy for DFIG-Based WECS in Weak Grid

    DEFF Research Database (Denmark)

    Abulanwar, Elsayed; Chen, Zhe; Iov, Florin

    2013-01-01

    An enhanced coordinated low voltage ride-through, LVRT, control strategy for a Doubly-fed Induction generator (DFIG)-based wind energy conversion system, WECS, connected to a weak grid is presented in this paper. The compliance with the grid code commitments is also considered. A proposed decoupled...... the effectiveness of the proposed control strategy using MATLAB/SIMULINK platform....

  16. Use of the Metacognitive English Language Learning Strategies Based on Personality Traits

    Science.gov (United States)

    Fazeli, Seyed Hossein

    2012-01-01

    The present study aims to find out the relationship between use of the Metacognitive English Language Learning Strategies (MELLSs) for learners of English as a foreign language based on personality traits, and the role of personality traits in the prediction of use of such Strategies. Four instruments were used, which were Adapted Inventory for…

  17. An estimator-based distributed voltage-predictive control strategy for ac islanded microgrids

    DEFF Research Database (Denmark)

    Wang, Yanbo; Chen, Zhe; Wang, Xiongfei

    2015-01-01

    This paper presents an estimator-based voltage predictive control strategy for AC islanded microgrids, which is able to perform voltage control without any communication facilities. The proposed control strategy is composed of a network voltage estimator and a voltage predictive controller for ea...

  18. Effects of Guided Writing Strategies on Students' Writing Attitudes Based on Media Richness Theory

    Science.gov (United States)

    Lan, Yu-Feng; Hung, Chun-Ling; Hsu, Hung-Ju

    2011-01-01

    The purpose of this paper is to develop different guided writing strategies based on media richness theory and further evaluate the effects of these writing strategies on younger students' writing attitudes in terms of motivation, enjoyment and anxiety. A total of 66 sixth-grade elementary students with an average age of twelve were invited to…

  19. Study on the Strategies of Distance Learning Support Services Based on Effective Interaction

    Institute of Scientific and Technical Information of China (English)

    王文琳; 靳桂阳

    2014-01-01

    The paper firstly analyzes the problems of distance learning interaction in order to clarify the significance of implement-ing effective interaction. Then it puts forward the learning support services strategies based on effective interaction, which means to design strategies from the perspective of effective interaction to improve the effect of distance learning.

  20. Determining the impacts of time-based logistics strategies in the Dutch food industry

    NARCIS (Netherlands)

    Muilerman, G.; van der Hoorn, A.I.J.M.; van der Heijden, R.

    2005-01-01

    The trend towards logistics acceleration and increasing time-sensitivity can be discerned in numerous industry sectors. The associated logistics concepts are called time-based strategies. In this paper, the logistics impacts of these strategies are analysed on the basis of case studies within the Du

  1. Fundraising Strategies Developed by MBA Students in Project-Based Learning Courses

    Science.gov (United States)

    Arantes do Amaral, Joao Alberto; Petroni, Liége Mariel; Hess, Aurélio

    2016-01-01

    The ability to raise funds is a skill that most modern project managers need. While a good deal of literature exists on the strategies NGOs employ to raise funds for their operations, less attention has been paid to the strategies used by students involved in Project-Based Learning courses that often partner with NGOs. Fundraising is an important…

  2. Effects of Unidirectional vs. Reciprocal Teaching Strategies on Web-Based Computer Programming Learning

    Science.gov (United States)

    Shadiev, Rustam; Hwang, Wu-Yuin; Yeh, Shih-Ching; Yang, Stephen J. H.; Wang, Jing-Liang; Han, Lin; Hsu, Guo-Liang

    2014-01-01

    This study aimed to investigate an effectiveness of unidirectional and reciprocal teaching strategies on programming learning supported by web-based learning system (VPen); particularly, how differently effective these two teaching strategies would work. In this study novice programmers were exposed to three different conditions: 1) applying no…

  3. New Blended Learning Strategy Based on Flipped-Learning for Vocational Work-Linked Training

    Science.gov (United States)

    El Hajji, Mohamed; El Bouzaidi, Rachid Drissi; Douzi, Hassan; Khouya, El Hassane

    2016-01-01

    In a changing Moroccan educational landscape, Addressing teaching development needs is becoming a major issue in vocational work-linked Training. In this context, this paper present a new blended learning strategy based on the flipped classroom, using a social learning platform as support. Through this strategy, we increased the time dedicated to…

  4. Effects of Activity Based Blended Learning Strategy on Prospective of Teachers' Achievement and Motivation

    Science.gov (United States)

    Abdelraheem, Ahmed Yousif; Ahmed, Abdelrahman Mohammed

    2015-01-01

    The study investigates the effect of Activity based Blended Learning strategy and Conventional Blended Learning strategy on students' achievement and motivation. Two groups namely, experimental and control group from Sultan Qaboos University were selected randomly for the study. To assess students' achievement in the different groups, pre- and…

  5. Scaffolding Strategies for Wiki-Based Collaboration: Action Research in a Multicultural Japanese Language Program

    Science.gov (United States)

    Jung, Insung; Suzuki, Yoko

    2015-01-01

    Wikis can be used to encourage and support collaborative constructivist learning. However, their effectiveness depends upon the use of scaffolding strategies to guide the students in their use. This action research investigated three scaffolding strategies for wiki-based multicultural Japanese language learning: worked examples, grouping and peer…

  6. Integration of microfluidic chip with biomimetic hydrogel for 3D controlling and monitoring of cell alignment and migration.

    Science.gov (United States)

    Lee, Kwang Ho; Lee, Ki Hwa; Lee, Jeonghoon; Choi, Hyuk; Lee, Donghee; Park, Yongdoo; Lee, Sang-Hoon

    2014-04-01

    A biomimetic hydrogel was integrated into microfluidic chips to monitor glioma cell alignment and migration. The extracellular matrix-based biomimetic hydrogel was remodeled by matrix metalloprotease (MMP) secreted by glioma cells and the hydrogel could thus be used to assess cellular behavior. Both static and dynamic cell growth conditions (flow rate of 0.1 mL/h) were used. Cell culture medium with and without vascular endothelial growth factor (VEGF), insensitive VEGF and tissue inhibitor of metalloproteinases (TIMP) were employed to monitor cell behavior. A concentration gradient formed in the hydrogel resulted in differences in cell behavior. Glioma cell viability in the microchannel was 75-85%. Cells in the VEGF-loaded microchannels spread extensively, degrading the MMP-sensitive hydrogel, and achieved cell sizes almost fivefold larger than seen in the control medium. Our integrated system can be used as a model for the study of cellular behavior in a controlled microenvironment generated by fluidic conditions in a biomimetic matrix.

  7. A Resource Scheduling Strategy in Cloud Computing Based on Multi-agent Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Wuxue Jiang

    2013-11-01

    Full Text Available Resource scheduling strategies in cloud computing are used either to improve system operating efficiency, or to improve user satisfaction. This paper presents an integrated scheduling strategy considering both resources credibility and user satisfaction. It takes user satisfaction as objective function and resources credibility as a part of the user satisfaction, and realizes optimal scheduling by using genetic algorithm. We integrate this scheduling strategy into Agent subsequently and propose a cloud computing system architecture based on Multi-agent. The numerical results show that this scheduling strategy improves not only the system operating efficiency, but also the user satisfaction.  

  8. Arresting Strategy Based on Dynamic Criminal Networks Changing over Time

    Directory of Open Access Journals (Sweden)

    Junqing Yuan

    2013-01-01

    Full Text Available We investigate a sequence of dynamic criminal networks on a time series based on the dynamic network analysis (DNA. According to the change of networks’ structure, networks’ variation trend is analyzed to forecast its future structure. Finally, an optimal arresting time and priority list are designed based on our analysis. Better results can be expected than that based on social network analysis (SNA.

  9. Transformation strategies in nations based on the socialist model: North Korean companies and their transformation strategies

    OpenAIRE

    Futagami, Shiho

    2000-01-01

    This paper discusses the possibility of the transformation of North Korean socialistic companies. In this paper, three possible future scenarios concerning North Korean companies are presented. The first one is based on the traditional trend which you have seen already. In this scenario, North Korea will keep the principle of national self-reliance and realize the autarky. It will not have a big impact on Northeast Asian economies. The possibility for such a scenario is low, because of the da...

  10. Future Development Strategies for S Group Based on SWOT Analysis

    Institute of Scientific and Technical Information of China (English)

    Guohui; QI; Ligen; CHEN

    2014-01-01

    In recent years,the real estate development enterprises are facing the gradually increased government’s macro-control,and the increasingly fierce market competition,so it is very imperative to timely adjust and change the enterprises’ development strategies to adapt to the new development situation.With S Group as the study object,we use SWOT analysis to analyze the company’s internal and external environment,study the current situation of the company and the existing problems,and clearly point out the opportunities and challenges facing the company.Finally we put forth some targeted strategic recommendations,in order to provide a reference for the development of S Group.

  11. Using 2-Opt based evolution strategy for travelling salesman problem

    Directory of Open Access Journals (Sweden)

    Kenan Karagul

    2016-03-01

    Full Text Available Harmony search algorithm that matches the (µ+1 evolution strategy, is a heuristic method simulated by the process of music improvisation. In this paper, a harmony search algorithm is directly used for the travelling salesman problem. Instead of conventional selection operators such as roulette wheel, the transformation of real number values of harmony search algorithm to order index of vertex representation and improvement of solutions are obtained by using the 2-Opt local search algorithm. Then, the obtained algorithm is tested on two different parameter groups of TSPLIB. The proposed method is compared with classical 2-Opt which randomly started at each step and best known solutions of test instances from TSPLIB. It is seen that the proposed algorithm offers valuable solutions.

  12. Fairness based channel borrowing strategy in multimedia LEO satellite communications

    Institute of Scientific and Technical Information of China (English)

    HUANG Fei; XU Hui; WU Shiqi

    2007-01-01

    A novel bandwidth allocation strategy along with a connection admission control technique was proposed to improve the utilization of network resources.It provides the network with better quality-of-service (QoS) guarantees,such as new call blocking probability (CBP) and handoff call dropping probability (CDP) in multimedia low earth orbit (LEO) satellite networks.Simulation results show that,compared with other bandwidth allocation schemes,the proposed scheme offers very low call dropping probability for real-time connections while,at the same time,keeping resource utilization high.Finally we discussed the fairness for the borrowed nonreal-time connections under three different channel borrowing methods.

  13. Development, fabrication and evaluation of a novel biomimetic human breast tissue derived breast implant surface.

    Science.gov (United States)

    Barr, S; Hill, E W; Bayat, A

    2017-02-01

    Breast implant use has tripled in the last decade with over 320,000 breast implant based reconstructions and augmentations performed in the US per annum. Unfortunately a considerable number of women will experience capsular contracture, the irrepressible and disfiguring, tightening and hardening of the fibrous capsule that envelops the implant. Functionalising implant surfaces with biocompatible tissue-specific textures may improve in vivo performance. A novel biomimetic breast implant is presented here with anti-inflammatory in vitro abilities. Topographical assessment of native breast tissue facilitated the development of a statistical model of adipose tissue. 3D grayscale photolithography and ion etching were combined to successfully replicate a surface modelled upon the statistics of breast tissue. Pro-inflammatory genes ILβ1, TNFα, and IL6 were downregulated (p<0.001) and anti-inflammatory gene IL-10 were upregulated on the novel surface. Pro-inflammatory cytokines Gro-Alpha, TNFα and neutrophil chemoattractant IL8 were produced in lower quantities and anti-inflammatory IL-10 in higher quantities in culture with the novel surface (p<0.01). Immunocytochemistry and SEM demonstrated favourable fibroblast and macrophage responses to these novel surfaces. This study describes the first biomimetic breast tissue derived breast implant surface. Our findings attest to its potential translational ability to reduce the inflammatory phase of the implant driven foreign body reaction.

  14. Biomimetic hemocompatible coatings through immobilization of hyaluronan derivatives on metal surfaces.

    Science.gov (United States)

    Thierry, Benjamin; Winnik, Françoise M; Merhi, Yahye; Griesser, Hans J; Tabrizian, Maryam

    2008-10-21

    Biomimetic coatings offer exciting options to modulate the biocompatibility of biomaterials. The challenge is to create surfaces that undergo specific interactions with cells without promoting nonspecific fouling. This work reports an innovative approach toward biomimetic surfaces based on the covalent immobilization of a carboxylate terminated PEGylated hyaluronan (HA-PEG) onto plasma functionalized NiTi alloy surfaces. The metal substrates were aminated via two different plasma functionalization processes. Hyaluronan, a natural glycosaminoglycan and the major constituent of the extracellular matrix, was grafted to the substrates by reaction of the surface amines with the carboxylic acid terminated PEG spacer using carbodiimide chemistry. The surface modification was monitored at each step by X-ray photoelectron spectroscopy (XPS). HA-immobilized surfaces displayed increased hydrophilicity and reduced fouling, compared to bare surfaces, when exposed to human platelets (PLT) in an in vitro assay with radiolabeled platelets (204.1 +/- 123.8 x 10 (3) PLT/cm (2) vs 538.5 +/- 100.5 x 10 (3) PLT/cm (2) for bare metal, p surfaces were successfully created as demonstrated by XPS chemical imaging. The bioactive surfaces described present unique features, which result from the synergy between the intrinsic biological properties of hyaluronan and the chemical composition and morphology of the polymer layer immobilized on a metal surface.

  15. Electrospray-assisted characterization and deposition of chlorosomes to fabricate a biomimetic light-harvesting device

    Energy Technology Data Exchange (ETDEWEB)

    Modesto-Lopez, Luis B.; Thimsen, Elijah J.; Collins, Aaron M.; Blankenship, R. E.; Biswas, Pratim

    2010-01-01

    Photosynthesis is an efficient process by which solar energy is converted into chemical energy. Green photosynthetic bacteria such as Chloroflexus aurantiacus have supramolecular antenna complexes called chlorosomes attached to their cytoplasmic membrane that increase the cross section for light absorption even in low-light conditions. Self-assembled bacteriochlorophyll pigments in the chlorosome interior play a key role in the efficient transfer and funneling of the harvested energy. In this work it was demonstrated that chlorosomes can be rapidly and precisely size-characterized online in real time using an electrospray-assisted mobility-based technique. Chlorosomes were electrospray-deposited onto TiO{sub 2} nanostructured films with columnar morphology to fabricate a novel biomimetic device to overcome the solvent compatibility issues associated with biological particles and synthetic dyes. The assembled unit retained the viability of the chlorosomes, and the harvesting of sunlight over a broader range of wavelengths was demonstrated. It was shown that the presence of chlorosomes in the biomimetic device had a 30-fold increase in photocurrent.

  16. Biomimetic walking trajectory generation of humanoid robot on an inclined surface using Fourier series.

    Science.gov (United States)

    Park, Ill-Woo; Kim, Jung-Yup

    2014-10-01

    This article describes a novel method to generate a biomimetic walking trajectory for a biped humanoid robot on an inclined surface. We assume that the configuration of the inclined surface is known, and we solve the human-like walking trajectory generation problem by obtaining the solution from the desired zero moment point (ZMP) trajectory to the center of gravity (CoG) trajectory. We present an analytic solution for the walking trajectory generation by using Fourier series. From the given ZMP trajectory biomimetically represented by the Fourier series, we focus on how to find the CoG trajectory in an analytical way. A time-segmentation based approach is adopted for generating the trajectories. The trajectory functions need to be continuous between the segments; thus, the solution is found by calculating the coefficients under these connectivity conditions. We derive a general form of the ZMP equation using a simple inverted pendulum model (SIPM), which includes the ZMP and the CoG trajectories in the horizontal and vertical directions to quantify the walking parameters on the inclined surface. The performance of the proposed approach is verified by conducting walking simulations using a full-body dynamic simulator on three different inclined surfaces and comparing them to the authors' previous approach.

  17. μ-Biomimetic flow-sensors--introducing light-guiding PDMS structures into MEMS.

    Science.gov (United States)

    Herzog, Hendrik; Klein, Adrian; Bleckmann, Horst; Holik, Peter; Schmitz, Sam; Siebke, Georg; Tätzner, Simon; Lacher, Manfred; Steltenkamp, Siegfried

    2015-04-16

    In the area of biomimetics, engineers use inspiration from natural systems to develop technical devices, such as sensors. One example is the lateral line system of fish. It is a mechanoreceptive system consisting of up to several thousand individual sensors called neuromasts, which enable fish to sense prey, predators, or conspecifics. So far, the small size and high sensitivity of the lateral line is unmatched by man-made sensor devices. Here, we describe an artificial lateral line system based on an optical detection principle. We developed artificial canal neuromasts using MEMS technology including thick film techniques. In this work, we describe the MEMS fabrication and characterize a sensor prototype. Our sensor consists of a silicon chip, a housing, and an electronic circuit. We demonstrate the functionality of our μ-biomimetic flow sensor by analyzing its response to constant water flow and flow fluctuations. Furthermore, we discuss the sensor robustness and sensitivity of our sensor and its suitability for industrial and medical applications. In sum, our sensor can be used for many tasks, e.g. for monitoring fluid flow in medical applications, for detecting leakages in tap water systems or for air and gas flow measurements. Finally, our flow sensor can even be used to improve current knowledge about the functional significance of the fish lateral line.

  18. Extreme biomimetic approach for developing novel chitin-GeO2 nanocomposites with photoluminescent properties

    Institute of Scientific and Technical Information of China (English)

    Marcin Wysokowski[1; Mykhailo Motylenko[2; Jan Beyer[3; Anna Makarova[4; Hartmut Stocker[5; Juliane Walter[5; Roberta Galli[6; Sabine Kaiser[5; Denis Vyalikh[4,7; Vasilii V. Bazhenov[5; laroslav Petrenko[5; Allison L Stelling[8; Serguei L. Molodtsovs[5,9,10; Dawid Stawski[11; Krzysztof J.Kurzydfowski[12; Enrico Langer[13; Mikhail V Tsurkan[14; Teofil Jesionowski[1; Johannes Heitmann[3; Dirk C. Meyer[5; Hermann Ehrlich[5

    2015-01-01

    This work presents an extreme biomimetics route for the creation of nano- structured biocomposites utilizing a chitinous template of poriferan origin. The specific thermal stability of the nanostructured chitinous template allowed for the formation under hydrothermal conditions of a novel germanium oxide- chitin composite with a defined nanoscale structure. Using a variety of analytical techniques (FTIR, Raman, energy dispersive X-ray (EDX), near-edge X-ray absorption fine structure (NEXAFS), and photoluminescence (PL) spectroscopy, EDS-mapping, selected area for the electron diffraction pattern (SAEDP), and transmission electron microscopy (TEM)), we showed that this bioorganic scaffold induces the growth of GeO2 nanocrystals with a narrow (150-300 nm) size distri- bution and predominantly hexagonal phase, demonstrating the chitin template's control over the crystal morphology. The formed GeO2-chitin composite showed several specific physical properties, such as a striking enhancement in photo- luminescence exceeding values previously reported in GeOR-based biomaterials. These data demonstrate the potential of extreme biomimetics for developing new-generation nanostructured materials.

  19. Application and numerical simulation research on biomimetic drag-reducing technology for gas pipelining

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Deyuan; Luo Yuehao; Chen Huawei [Beihang Univ., Beijing (China). School of Mechanical Engineering and Automation

    2011-06-15

    For the purpose of increasing the transmission capacity of gas pipelines, the internal coating technology has been vastly put into application, and a remarkable benefit has been achieved so far. However, with the reduction of wall roughness, the small convex parts are all completely submerged in the viscous sublayer, the gas pipeline becomes a 'hydraulic smooth pipe', even by smoothing the coating surface further, it is difficult to reduce wall friction. Therefore, in order to increase the transportation capacity on the basis of internal coating, the new methods and technologies should be researched and investigated, and perhaps, the biomimetic drag-reducing technology is a good approach. In this paper, according to the planning parameters of the second pipeline of the West-to-East gas transmission project, the best drag reducing effect grooves are calculated and designed, and based on the characteristics and properties of internal coating (AW-01 epoxy resin), the Pre-Cured Micro- Rolling Technology (PCMRT) is discussed and presented, the rolling equipment is also designed and analyzed, the rolling process can be easily added on the available production line. Aiming at the field operating parameters of the gas pipeline in China, and the drag-reducing effect of the grooved surface is analyzed and discussed comprehensively. In addition, the economic benefit of adopting the biomimetic drag reduction technology is investigated. (orig.)

  20. Block-based image hashing with restricted blocking strategy for rotational robustness

    Science.gov (United States)

    Xiang, Shijun; Yang, Jianquan

    2012-12-01

    Image hashing is a potential solution for image content authentication (a desired image hashing algorithm should be robust to common image processing operations and various geometric distortions). In the literature, researchers pay more attention to block-based image hashing algorithms due to their robustness to common image processing operations (such as lossy compression, low-pass filtering, and additive noise). However, the block-based hashing strategies are sensitive to rotation processing operations. This indicates that the robustness of the block-based hashing methods against rotation operations is an important issue. Towards this direction, in this article we propose a restricted blocking strategy by investigating effect of two rotation operations on an image and its blocks in both theoretical and experimental ways. Furthermore, we apply the proposed blocking strategy for the recently reported non-negative matrix factorization (NMF) hashing. Experimental results have demonstrated the validity of the block-based hashing algorithms with restricted blocking strategy for rotation operations.

  1. One4All Cooperative Media Access Strategy in Infrastructure Based Distributed Wireless Networks

    DEFF Research Database (Denmark)

    Zhang, Qi; Fitzek, Frank H.P.; Iversen, Villy Bæk

    2008-01-01

    In this paper we propose the one4all cooperative access strategy to introduce a more efficient media access strategy for wireless networks. The one4all scheme is designed for the infrastructure based distributed wireless network architecture. The basic idea is that mobile devices can form...... a cooperative cluster using their short-range air interface and one device contends the channel for all the devices within the cluster. This strategy reduces the number of mobile devices involved in the collision process for the wireless medium resulting in larger throughput, smaller access delay, and less...... energy consumption. Based on an analytical model, the proposed strategy is compared with the two existing strategies RTS/CTS (request to send/ clear to send) and packet aggregation. The results show that the proposed cooperative scheme has similar throughput performance as packet aggregation and it has...

  2. An Ontology-Based Service Matching Strategy in Grid Environments

    Institute of Scientific and Technical Information of China (English)

    YIN Nan; SHEN De-rong; YU Ge; KOU Yue; NIE Tie-zheng; CAO Yu

    2004-01-01

    An efficient ontology-based service searching scheme is put forward in this paper by introducing semantic information into grid systems.The ideas of ontology and OWL (Web ontology language) are applied to establish a uniform abstract concept model and standardization for grid services.We propose a general framework of ontology-based service discovery sub-system, which includes ontology storage module, context-based domain selection module and specific service matching module.Implementation policies are also presented in this paper.

  3. Decentralized Event-Based Communication Strategy on Leader-Follower Consensus Control

    OpenAIRE

    Duosi Xie; Xiaochun Yin; Jianquan Xie

    2016-01-01

    This paper addresses the leader-follower consensus problem of networked systems by using a decentralized event-based control strategy. The event-based control strategy makes the controllers of agents update at aperiodic event instants. Two decentralized event functions are designed to generate these event instants. In particular, the second event function only uses its own information and the neighbors’ states at their latest event instants. By using this event function, no continuous communi...

  4. Biomimetic tissue-engineered systems for advancing cancer research: NCI Strategic Workshop report.

    Science.gov (United States)

    Schuessler, Teresa K; Chan, Xin Yi; Chen, Huanhuan Joyce; Ji, Kyungmin; Park, Kyung Min; Roshan-Ghias, Alireza; Sethi, Pallavi; Thakur, Archana; Tian, Xi; Villasante, Aranzazu; Zervantonakis, Ioannis K; Moore, Nicole M; Nagahara, Larry A; Kuhn, Nastaran Z

    2014-10-01

    Advanced technologies and biomaterials developed for tissue engineering and regenerative medicine present tractable biomimetic systems with potential applications for cancer research. Recently, the National Cancer Institute convened a Strategic Workshop to explore the use of tissue biomanufacturing for development of dynamic, physiologically relevant in vitro and ex vivo biomimetic systems to study cancer biology and drug efficacy. The workshop provided a forum to identify current progress, research gaps, and necessary steps to advance the field. Opportunities discussed included development of tumor biomimetic systems with an emphasis on reproducibility and validation of new biomimetic tumor models, as described in this report.

  5. STRATEGI PENGEMBANGAN KAWASAN AGROPOLITAN BERBASIS TANAMAN PANGAN DI KOTA PADANG (Agropolitan Development Strategy Based on Food Crops in Padang City

    Directory of Open Access Journals (Sweden)

    Ilham Martadona

    2014-11-01

    Full Text Available The role of Agricultural sector isn't only to ensure food supplies but also as an income generating through export activities. Padang is potentially developed to modern agriculture due to vast number of agriculture land.  Base on regulation No.18 of 2004 on RPJP and Regulation No.9 of 2009 on RPJM, Padang is declared as Agropolitan area. The Agropolitan concept is expected to increase agriculture-based development, because the GDP share of agriculture is relatively small. This study aims are to  analyze a basic food crops, 2 to choose the region which will develop as agropolitan area base on availability of facilities and infrastructure in that region and 3 to formulate development strategies of agropolitan area. The analysis of LQ indicate rice crop as the basic commodity with the LQ greater than one. Skalogram analysis and diamond porter show that Sub District Kuranji is potentially developed as a growth center in the Agropolitan Area because it has the most complete facilities and infrastructure. In this research the development strategies are to develop agricultural infrastructure (sub terminal of agribusiness and institutional strengthening of capital institution.

  6. A Regional PD Strategy for EPR Systems: Evidence-Based IT Development

    DEFF Research Database (Denmark)

    Simonsen, Jesper; Hertzum, Morten

    2006-01-01

    systems. We present this PD strategy and our related research on evidence-based IT development. We report from a newly completed PD experiment with EPR in the region conducted through a close collaboration compris-ing a neurological stroke unit, the region’s EPR unit, the vendor, as well as the authors.......One of the five regions in Denmark has initiated a remark-able and alternative strategy for the development of Elec-tronic Patient Record (EPR) systems. This strategy is driven by Participatory Design (PD) experiments and based on evidence of positive effects on the clinical practice when using EPR...

  7. PROXY-BASED PATCHING STREAM TRANSMISSION STRATEGY IN MOBILE STREAMING MEDIA SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Liao Jianxin; Lei Zhengxiong; Ma Xutao; Zhu Xiaomin

    2006-01-01

    A mobile transmission strategy, PMPatching (Proxy-based Mobile Patching) transmission strategy is proposed, it applies to the proxy-based mobile streaming media system in Wideband Code Division Multiple Access (WCDMA) network. Performance of the whole system can be improved by using patching stream to transmit anterior part of the suffix that had been played back, and by batching all the demands for the suffix arrived in prefix period and patching stream transmission threshold period. Experimental results show that this strategy can efficiently reduce average network transmission cost and number of channels consumed in central streaming media server.

  8. Language Learning Strategies for Medical and Nursing School Students : Based on a Survey of Their Preferences for Language Learning Strategies

    OpenAIRE

    shigeru, SASAJIMA

    1998-01-01

    Today self-learning has been getting more important for English learners in Japan. Language Learning Strategies (LLSs) are now considered to encourage overall self-learning for them. This paper reports on LLSs based on the survey of what LLSs Japanese Medical School Students (MSSs) and Nursing School Students (NSSs) think are effective in their English learning. The purpose of this research is to find the better LLSs for MSSs and NSSs. I found out three things : 1) They have some LLS preferen...

  9. Validity of Basing Authors' Publication Strategy on Journal Impact Factors

    CERN Document Server

    Milojević, Staša; Bar-Ilan, Judit

    2016-01-01

    Choosing the best scientific venue for the submission of a manuscript, with the aim of maximizing the impact of the future publication, is a frequent task faced by scholars. In this paper, we show that the Impact Factor (IF) of a journal allows to rationally achieve this goal. We take advantage of a comprehensive bibliographic and citation dataset of about 2.5 million articles from 16,000 journals, and demonstrate that the probability of receiving more citations in one journal compared to another is a universal function of the IF values of the two journals. The relation is well described by a modified logistic function, and provides an easy-to-use rule to guide a publication strategy. The benefit of publishing in a journal with a higher IF value, instead of another with a lower one grows slowly as a function of the ratio of their IF values. For example, receiving more citations is granted in 90\\% of the cases only if the IF ratio is greater than $\\sim$6, while targeting a journal with an IF 2$\\times$ higher t...

  10. Control strategy of maglev vehicles based on particle swarm algorithm

    Institute of Scientific and Technical Information of China (English)

    Hui Wang; Gang Shen; Jinsong Zhou

    2014-01-01

    Taking a single magnet levitation system as the object, a nonlinear numerical model of the vehicle-guide-way coupling system was established to study the levitation control strategies. According to the similarity in dynamics, the single magnet-guideway coupling system was simpli-fied into a magnet-suspended track system, and the corre-sponding hardware-in-loop test rig was set up using dSPACE. A full-state-feedback controller was developed using the levitation gap signal and the current signal, and controller parameters were optimized by particle swarm algorithm. The results from the simulation and the test rig show that, the proposed control method can keep the sys-tem stable by calculating the controller output with the full-state information of the coupling system, Step responses from the test rig show that the controller can stabilize the system within 0.15 s with a 2% overshot, and performs well even in the condition of violent external disturbances. Unlike the linear quadratic optimal method, the particle swarm algorithm carries out the optimization with the nonlinear controlled object included, and its optimized results make the system responses much better.

  11. Analyzing “Etka Chain Stores” Strategies and Proposing Optimal Strategies; Using SWOT Model based on Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Mohammad Aghaei

    2013-10-01

    Full Text Available To maintain and achieve optimal growth, development and to be more competitive, organizations need a comprehensive and coherent plan compatible with their objectives and goals which is called strategic planning. This research aims to analyse strategically “Etka Chain Stores” and to propose optimal strategies by using SWOT model and based on fuzzy logic. The scope of this research is limited to “Etka Chain stores in Tehran”. As instrumentation, a questioner, consisting of 138 questions, was used. The data have been extracted from interviews to managers and the expert in Etka Chain stores and from studying the available reports in the organization. Validity and reliability of research have been measured. The research consists of two main and four subsidiary questions and lacks hypothesis and regarding type of the objective, this research is an applied one and regarding the data gathering, it is experimental-descriptive and a case study. Analysing the data consists of five steps. In the first step, all the documents, interviews to organization experts and “Etka Chain stores” reports were analysed by tests and a list of environmental opportunities and threats together with strengths and weaknesses was prepared. In the second step, all the above-mentioned factors were screened and opportunities, threats, strengths and weaknesses were identified. In the third stage, by using key factors and SWOT model, the most suitable strategies for the company have been proposed. In the fifth step, an operational program is proposed. The findings of the research indicate that to be more competitive in key axis which includes customers, supply chain, expanses control, competitive smartness, human resources and operational productivity, the company should adopt suitable strategies. In this regard, the suitable strategies were identified, codified and proposed. In this research, planning a strategic management model, analysing value chain for spotting

  12. [Problem-based learning, a strategy to employ it].

    Science.gov (United States)

    Guillamet Lloveras, Ana; Celma Vicente, Matilde; González Carrión, Pilar; Cano-Caballero Gálvez, Ma Dolores; Pérez Ramírez, Francisca

    2009-02-01

    The Virgen de las Nieves University School of Nursing has adopted the methodology of Problem-Based Learning (ABP in Spanish acronym) as a supplementary method to gain specific transversal competencies. In so doing, all basic required/obligatory subjects necessary for a degree have been partially affected. With the objective of identifying and administering all the structural and cultural barriers which could impede the success or effectiveness of its adoption, a strategic analysis at the School was carried out. This technique was based on a) knowing the strong and weak points the School has for adopting the Problem-Based Learning methodology; b) describing the structural problems and necessities to carry out this teaching innovation; c) to discover the needs professors have regarding knowledge and skills related to Problem-Based Learning; d) to prepare students by informing them about the characteristics of Problem-Based Learning; e) to evaluate the results obtained by means of professor and student opinions, f) to adopt the improvements identified. The stages followed were: strategic analysis, preparation, pilot program, adoption and evaluation.

  13. Hybrid artificial photosynthetic systems comprising semiconductors as light harvesters and biomimetic complexes as molecular cocatalysts.

    Science.gov (United States)

    Wen, Fuyu; Li, Can

    2013-11-19

    Solar fuel production through artificial photosynthesis may be a key to generating abundant and clean energy, thus addressing the high energy needs of the world's expanding population. As the crucial components of photosynthesis, the artificial photosynthetic system should be composed of a light harvester (e.g., semiconductor or molecular dye), a reduction cocatalyst (e.g., hydrogenase mimic, noble metal), and an oxidation cocatalyst (e.g., photosystem II mimic for oxygen evolution from water oxidation). Solar fuel production catalyzed by an artificial photosynthetic system starts from the absorption of sunlight by the light harvester, where charge separation takes place, followed by a charge transfer to the reduction and oxidation cocatalysts, where redox reaction processes occur. One of the most challenging problems is to develop an artificial photosynthetic solar fuel production system that is both highly efficient and stable. The assembly of cocatalysts on the semiconductor (light harvester) not only can facilitate the charge separation, but also can lower the activation energy or overpotential for the reactions. An efficient light harvester loaded with suitable reduction and oxidation cocatalysts is the key for high efficiency of artificial photosynthetic systems. In this Account, we describe our strategy of hybrid photocatalysts using semiconductors as light harvesters with biomimetic complexes as molecular cocatalysts to construct efficient and stable artificial photosynthetic systems. We chose semiconductor nanoparticles as light harvesters because of their broad spectral absorption and relatively robust properties compared with a natural photosynthesis system. Using biomimetic complexes as cocatalysts can significantly facilitate charge separation via fast charge transfer from the semiconductor to the molecular cocatalysts and also catalyze the chemical reactions of solar fuel production. The hybrid photocatalysts supply us with a platform to study the

  14. Color-producing mechanism of morpho butterfly wings and biomimetics; Cho no hasshoku kiko to biomimetics

    Energy Technology Data Exchange (ETDEWEB)

    Tabata, H. [Nissan Motor Co. Ltd., Tokyo (Japan)

    1999-07-01

    Although the synthetic dyes and pigments originating in the 19th century are now at the height of their prosperity, there is an earnest hope for technology for realizing `supercolor.` If it is presumed that the features of such supercolor are to be found in outstanding clearness and high resistance to fading in the presence of ultraviolet rays, etc., the supercolor will be quite tough to deal with. When attention is steered toward the living world, however, there are cases of easily producing such by morphogenesis at the level of several tens of nanometers. In this paper, the development of a novel material is presented from the viewpoint of biomimetic engineering that the author et al. are engaged in. The coloring on the wings of a butterfly Morpho Sulkowskyi of South American origin is the product of interaction between light and the physical, microscopic structure of scales, and the coloring is extremely clear and remains free of fading except in case the microstructure is destroyed. This mechanism is applied for the development of a supercolor fiber. As the result, a structurally coloring fiber is created by stretching a molten composite string. In this effort, reformed polyester and polyamide different in refraction factor are used in place of substance layers and air layers on the butterfly wings. (NEDO)

  15. Indoor biology pollution control based on system-based humidity priority control strategy

    Institute of Scientific and Technical Information of China (English)

    刘亚昱; 谢慧; 石博强

    2009-01-01

    Indoor biological contamination and HVAC system secondary contamination problems caused wide public concerns. Biological contamination control will be the next step to achieve better IAQ. The most efficient and safe way to control biological contamination was to limit relative humidity in HVAC system and conditioned environment in the range that is more unsuitable for microorganism to survive. In this paper,by referring to bio-clean project experiences,a system-based humidity priority control manner came into being by lowering outdoor air humidity ratio to eliminate all indoor latent load and using self recirculation units to bear indoor sensible load. Based on the whole-course residue humidity contaminant control concept,dynamic step models for coil and conditioned zone were developed to describe mass and energy conservation and transformation processes. Then,HVAC system and conditioned zone dynamic models were established on LabVIEW+Matlab platform to investigate optimized regulation types,input signatures and control logics. Decoupling between cooling and dehumidification processes can be achieved and a more simplified and stable control system can be acquired by the system-based humidity priority control strategy. Therefore,it was a promising way for controlling biological pollution in buildings in order to achieve better IAQ.

  16. Models and prototypes of biomimetic devices to architectural purposes

    Directory of Open Access Journals (Sweden)

    Silvia Titotto

    2014-12-01

    Full Text Available This paper presents some results of an ongoing interdisciplinary research about models and prototypes of biomimetic devices via installations and the focus of this paper is to outline this research role in architectural purposes as it perpasses the cultural and heritage contexts by being a way of understanding and living in the world as well as taking place in the world as devices or environments that pass on to future generations to use, learn from and be inspired by. Both the theoretical and the experimental work done so far point out that installations built with association of laser cutting and rapid prototyping techniques might be on the best feasible ways for developing and testing new technologies involved in biomimetic devices to architectural purposes that put both tectonics and nature as their central theme. 

  17. Biomimetic Adhesive Materials Containing Cyanoacryl Group for Medical Application

    Directory of Open Access Journals (Sweden)

    Sueng Hwan Jo

    2014-10-01

    Full Text Available For underwater adhesives with biocompatible and more flexible bonds using biomimetic adhesive groups, DOPA-like adhesive molecules were modified with cyanoacrylates to obtain different repeating units and chain length copolymers. The goal of this work is to copy the mechanisms of underwater bonding to create synthetic water-borne underwater medical adhesives through blending of the modified DOPA and a triblock copolymer (PEO-PPO-PEO for practical application to repair wet living tissues and bones, and in turn, to use the synthetic adhesives to test mechanistic hypotheses about the natural adhesive. The highest values in stress and modulus of the biomimetic adhesives prepared in wet state were 165 kPa and 33 MPa, respectively.

  18. Biomimetic adhesive materials containing cyanoacryl group for medical application.

    Science.gov (United States)

    Jo, Sueng Hwan; Sohn, Jeong Sun

    2014-10-17

    For underwater adhesives with biocompatible and more flexible bonds using biomimetic adhesive groups, DOPA-like adhesive molecules were modified with cyanoacrylates to obtain different repeating units and chain length copolymers. The goal of this work is to copy the mechanisms of underwater bonding to create synthetic water-borne underwater medical adhesives through blending of the modified DOPA and a triblock copolymer (PEO-PPO-PEO) for practical application to repair wet living tissues and bones, and in turn, to use the synthetic adhesives to test mechanistic hypotheses about the natural adhesive. The highest values in stress and modulus of the biomimetic adhesives prepared in wet state were 165 kPa and 33 MPa, respectively.

  19. Evaluation of Inventory Reduction Strategies: Balad Air Base Case Study

    Science.gov (United States)

    2012-03-01

    the USAF supply system amounts to basic ABC inventory management methods in that backorders are managed in a fashion where certain parts are given...M., & North, M. J. (2008). Agent-Based Modeling and Simulation: ABMS Examples. Proceedings of the 2008 Winter Simulation Conference (pp. 101-112

  20. Strategy Training in a Task-Based Language Classroom

    Science.gov (United States)

    Lai, Chun; Lin, Xiaolin

    2015-01-01

    Recent literature that examines the implementation of task-based language teaching (TBLT) in classroom settings has reported various challenges related to educational cultures, classroom management, teacher cognition and learner perceptions. To facilitate the smooth transition of TBLT from laboratory settings to classroom contexts, measures need…

  1. Luminescence imaging strategies for drone-based PV array inspection

    DEFF Research Database (Denmark)

    Benatto, Gisele Alves dos Reis; Riedel, Nicholas; Thorsteinsson, Sune

    2017-01-01

    he goal of this work is to perform outdoor defect detection imaging that will be used in a fast, accurate and automatic drone-based survey system for PV power plants. The imaging development focuses on techniques that do not require electrical contact, permitting automatic drone inspections...

  2. Targeting base excision repair as a sensitization strategy in radiotherapy.

    NARCIS (Netherlands)

    Vens, C.; Begg, A.C.

    2010-01-01

    Cellular DNA repair determines survival after ionizing radiation. Human tumors commonly exhibit aberrant DNA repair since they drive mutagenesis and chromosomal instability. Recent reports have shown alterations in the base excision repair (BER) and single strand break repair (SSBR) pathways in huma

  3. THE STRATEGY OF RESOURCE MANAGEMENT BASED ON GRID COMPUTING

    Institute of Scientific and Technical Information of China (English)

    Wang Ruchuan; Han Guangfa; Wang Haiyan

    2006-01-01

    This paper analyzes the defaults of traditional method according to the resource management method of grid computing based on virtual organization. It supports the concept to ameliorate the resource management with mobile agent and gives the ameliorated resource management model. Also pointed out is the methodology of ameliorating resource management and the way to realize in reality.

  4. Syllable-Based Reading Strategy for Mastery of Scientific Information

    Science.gov (United States)

    Bhattacharya, Alpana

    2006-01-01

    This article describes a strategic approach for reading and comprehending scientific information from a middle school science textbook. First, the word-reading skills of children with and without reading difficulties are compared. Second, studies investigating the effectiveness of a syllable-based reading approach on the word-reading skills of…

  5. Co-precipitation of tobramycin into biomimetically coated orthopedic fixation pins employing submicron-thin seed layers of hydroxyapatite.

    Science.gov (United States)

    Sörensen, Jan H; Lilja, Mirjam; Åstrand, Maria; Sörensen, Torben C; Procter, Philip; Strømme, Maria; Steckel, Hartwig

    2014-01-01

    The migration, loosening and cut-out of implants and nosocomial infections are current problems associated with implant surgery. New innovative strategies to overcome these issues are emphasized in today's research. The current work presents a novel strategy involving co-precipitation of tobramycin with biomimetic hydroxyapatite (HA) formation to produce implant coatings that control local drug delivery to prevent early bacterial colonization of the implant. A submicron- thin HA layer served as seed layer for the co-precipitation process and allowed for incorporation of tobramycin in the coating from a stock solution of antibiotic concentrations as high as 20 mg/ml. Concentrations from 0.5 to 20 mg/ml tobramycin and process temperatures of 37 °C and 60 °C were tested to assess the optimal parameters for a thin tobramycin- delivering HA coating on discs and orthopedic fixation pins. The morphology and thickness of the coating and the drug-release profile were evaluated via scanning electron microscopy and high performance liquid chromatography. The coatings delivered pharmaceutically relevant amounts of tobramycin over a period of 12 days. To the best of our knowledge, this is the longest release period ever observed for a fast-loaded biomimetic implant coating. The presented approach could form the foundation for development of combination device/antibiotic delivery vehicles tailored to meet well-defined clinical needs while combating infections and ensuring fast implant in-growth.

  6. Biomimetic Architecture in Building Envelope Maintenance (A Literature)

    OpenAIRE

    2014-01-01

    The study of biomimetic architecture on building envelope is the main structure of this research. The concept is believed more sustainable and efficient for energy saving, operating cost consumption, waste recycle and design renewal in the future. The inspiration from the nature developed the intention on this study to explore on what and how this concept to overcome the problems through design. Biomimicry does catch the attention of human to study more on the system and function of its natur...

  7. Flisht mechanism and design of biomimetic micro air vehicles

    Institute of Scientific and Technical Information of China (English)

    ANG HaiSong; XIAO TianHang; DUAN WenBo

    2009-01-01

    This paper summaries the investigations on natural flyers and development of bio-mimetic micro air vehicles(MAVs)at NUAA,China,where the authors have led a group to conduct research for a decade.The investigations include the studies of low Reynolds number aerodynamics,unsteady computational fluid dynamics and flight control for the fixed-wing MAVs,the bird-like MAVs,the dragonfly-like MAVs and the bee-like MAVs.

  8. Flight mechanism and design of biomimetic micro air vehicles

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper summaries the investigations on natural flyers and development of bio-mimetic micro air vehicles(MAVs)at NUAA,China,where the authors have led a group to conduct research for a decade. The investigations include the studies of low Reynolds number aerodynamics,unsteady computational fluid dynamics and flight control for the fixed-wing MAVs,the bird-like MAVs,the dragonfly-like MAVs and the bee-like MAVs.

  9. Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

    OpenAIRE

    Bharat Bhushan

    2011-01-01

    The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices, and processes which provide desirable properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature and possess properties of interest. There are a large number of objects including bacteria, plants, land and aquatic animals, and seashells with properties of commercial interest. Certain plant leaves, such a...

  10. Linear and Nonlinear Relative Navigation Strategies for Small Satellite Formation Flying Based on Relative Position Measurement

    Science.gov (United States)

    Zhang, Xiaomin; Zheng, You

    Based on linear and nonlinear mathematical model of spacecraft formation flying and technology of relative position measurement of small satellites, the linear and nonlinear relative navigation strategies are developed in this paper. The dynamical characteristics of multi spacecraft formation flying have been researched in many references, including the authors' several International Astronautical Congress papers with numbers of IAF-98-A.2.06, IAA-99-IAA.11.1.09, IAA-01-IAA.11.4.08. Under conditions of short distance and short time, the linear model can describe relative orbit motion; otherwise, nonlinear model must be adopted. Furthermore the means of measurement and their error will influence relative navigation. Thus three kinds of relative navigation strategy are progressed. With consideration of difficulty in relative velocity measurement of small satellites, the three relative navigation strategies are proposed and only depend on sequential data of relative position through measuring the relative distance and relative orientation. The first kind of relative navigation strategy is based on linear model. The second relative navigation strategy is based on nonlinear model, with inclusion of the second order item. In fact the measurement error can not be avoided especially for small satellites, it is mainly considered in the third relative navigation strategy. This research is theoretical yet and a series of formulas of relative navigation are presented in this paper. Also the authors analyzed the three strategies qualitatively and quantitatively. According to results of simulation, the ranges of application are indicated and suggested in allusion to the three strategies of relative navigation. On the view of authors, the relative navigation strategies for small satellite formation flying based on relative position measurement are significant for engineering of small satellite formation flying.

  11. Agent based models for testing city evacuation strategies under a flood event as strategy to reduce flood risk

    Science.gov (United States)

    Medina, Neiler; Sanchez, Arlex; Nokolic, Igor; Vojinovic, Zoran

    2016-04-01

    This research explores the uses of Agent Based Models (ABM) and its potential to test large scale evacuation strategies in coastal cities at risk from flood events due to extreme hydro-meteorological events with the final purpose of disaster risk reduction by decreasing human's exposure to the hazard. The first part of the paper corresponds to the theory used to build the models such as: Complex adaptive systems (CAS) and the principles and uses of ABM in this field. The first section outlines the pros and cons of using AMB to test city evacuation strategies at medium and large scale. The second part of the paper focuses on the central theory used to build the ABM, specifically the psychological and behavioral model as well as the framework used in this research, specifically the PECS reference model is cover in this section. The last part of this section covers the main attributes or characteristics of human beings used to described the agents. The third part of the paper shows the methodology used to build and implement the ABM model using Repast-Symphony as an open source agent-based modelling and simulation platform. The preliminary results for the first implementation in a region of the island of Sint-Maarten a Dutch Caribbean island are presented and discussed in the fourth section of paper. The results obtained so far, are promising for a further development of the model and its implementation and testing in a full scale city

  12. Research on Application of Metacognitive Strategy in English Listening in the Web-based Self-access Learning Environment

    Institute of Scientific and Technical Information of China (English)

    罗雅清

    2012-01-01

      Metacognitive strategies are regarded as advanced strategies in all the learning strategies. This study focuses on the ap⁃plication of metacognitive strategies in English listening in the web-based self-access learning environment (WSLE) and tries to provide some references for those students and teachers in the vocational colleges.

  13. A Monte Carlo based spent fuel analysis safeguards strategy assessment

    Energy Technology Data Exchange (ETDEWEB)

    Fensin, Michael L [Los Alamos National Laboratory; Tobin, Stephen J [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Menlove, Howard O [Los Alamos National Laboratory; Sandoval, Nathan P [Los Alamos National Laboratory

    2009-01-01

    assessment process, the techniques employed to automate the coupled facets of the assessment process, and the standard burnup/enrichment/cooling time dependent spent fuel assembly library. We also clearly define the diversion scenarios that will be analyzed during the standardized assessments. Though this study is currently limited to generic PWR assemblies, it is expected that the results of the assessment will yield an adequate spent fuel analysis strategy knowledge that will help the down-select process for other reactor types.

  14. Web-based Information Tools and Communication and Participation Strategies

    OpenAIRE

    2007-01-01

    The report summarizes the activities and the action-oriented research work of Pilot Project 4 (PP4) “Web-based Information Tools and Communication and Participation Strategies“. Research objectives were divided in two areas: a) communication issues, namely the development of a Project-Homepage with interactive elements (http://www.sustainable-hyderabad.in/ ) and two documentary films and b) participation issues, namely citizens participation in India as a whole and in Hyderabad in particular....

  15. Biomimetic coating of calcium phosphate on biometallic materials

    Institute of Scientific and Technical Information of China (English)

    ZHANG Er-lin; YANG Ke

    2005-01-01

    The biomimetic coating process in comparison with other processes is reviewed. This processing shows advantages in the surface bio-modification, such as low cost and flexible processing, wide range of apatite composition and thickness, non-line-of-sight characteristic and possibility to coat polymers and porous implants. The bio-mimetic apatite coating is made up of larger number of globules with size of 1-5μm. Each globule is a group of numerous flakes with a size range of 100-200nm to 30μm in length and 0.1-1μm in thickness. In-vitro and in-vivo studies show that the biomimetic apatite coating can promote an early and strong bonding to bone or promote the bone in-growth into the porous structure, which will be beneficial to the cementless stable fixation of orthopaedic implants. Recently developed co-precipitation of a kind of protein molecules into the HA coating shows much promising.

  16. Fabrication of Biomimetic Water Strider Legs Covered with Setae

    Institute of Scientific and Technical Information of China (English)

    Zhi-guo Zhou; Zhi-wen Liu

    2009-01-01

    Water striders have remarkable water-repellent legs that enable them to stand effortlessly and move quickly on water. Fluid physics indicates this feature is due to a surface-tension effect caused by the special hierarchical structure of the legs, which are covered with a large number of inclined setae with fine nanogrooves inducing water resistance. This inspires us to fabricate special water-repellent structure on functional surfaces through the cooperation between the surface treatment and the surface micro- and nanostructures, which may bring great advantages in a wide variety of applications. In this paper we present a procedure for fabricating biomimetic water strider legs covered with setae using Polycarbonate Track-Etched (PCTE) membranes as templates. By choosing appropriate membrane lengths, diameters, pitches and densities of the setae, the biomimetic legs can be fabricated conveniently and at a low cost. Furthermore we investigated the relationship between stiffness of the molding materials, high aspect ratio and density, which affect the fidelity of fabrication and self adhesion, to optimize the stability of setae. The knowledge we gained from this study will offer important insights into the biomimetic design and fabrication of water strider setae.

  17. Direct laser writing: biomimetic photonics and superresolution nanolithography

    Science.gov (United States)

    Gu, Min

    2014-03-01

    Biomimetic photonics is inspired by nature's ability to self-assemble complex nanostructured materials with superior properties to that of conventional materials. Biomimetic engineering of novel nanophotonic devices has led to optical nano-fountains, artificial compound eyes and optical gas sensors. Direct laser writing (DLW) is a powerful tool toward the development of ultimate three-dimensional (3D) biomimetic photonic devices. Here we demonstrate the fabrication (DWL) of a novel class of 3D photonic microstructures inspired by a recent finding in butterfly wing-scales and show that these nano-engineered 3D gyroid structures have the ability to redirect circularly polarized light as a chiral beamsplitter. Because of the increasing demand for realising nanogeometries, the diffraction-limited resolution associated with DLW, should be overcomed to access to the nanoscale. We will report on our recent progress on optical beam nanolithography by using the superresolution photoinduction-inhibited nanolithography (SPIN) technique. The smallest feature size of 9 nm for free-standing lines has been demonstrated.

  18. Biomimetically triggered inorganic crystal transformation by biomolecules: a new understanding of biomineralization.

    Science.gov (United States)

    Jiang, Wenge; Chu, Xiaobin; Wang, Ben; Pan, Haihua; Xu, Xurong; Tang, Ruikang

    2009-08-06

    Phase transformation is an important strategy in biomineralization. However, the role of biomolecules in the mineral transition is poorly understood despite the fact that the biomineralization society greatly highlights the organic controls in the formation of the inorganic phase. Here, we report an induced biomimetic phase transformation from brushite (a widely used calcium phosphate precursor in biological cement) to hydroxyapatite (main inorganic composition of skeletal mineral) by citrate (a rich organic component in bone tissue). The transformation in the absence of the organic additive cannot be spontaneously initiated in an aqueous solution with a pH of 8.45 (no phase transition is detected in 4 days), which is explained by a high interfacial energy barrier between brushite-solution and hydroxyapatite-solution interfaces. Citrate can oppositely regulate these two interfaces, which decreases and increases the stabilities of brushite and hydroxyapatite surfaces in the solution, respectively. Thus, the interfacial energy barrier can be greatly reduced in the presence of citrate and the reaction is triggered; e.g., at 1 mM citrate, the total transformation from brushite to hydroxyapatite can be completed within 3 days. The relationship between the transition kinetics and citrate concentration is also studied. The work reveals how the organic components direct solid-solid phase transformation, which can be understood by an energetic control of the interfacial barrier. It is emphasized that the terms of interfacial energy must be taken into account in the studies of phase transformation. We suggest that this biomimetic approach may provide an in-depth understanding of biomineralization.

  19. Trading strategy based on dynamic mode decomposition: Tested in Chinese stock market

    Science.gov (United States)

    Cui, Ling-xiao; Long, Wen

    2016-11-01

    Dynamic mode decomposition (DMD) is an effective method to capture the intrinsic dynamical modes of complex system. In this work, we adopt DMD method to discover the evolutionary patterns in stock market and apply it to Chinese A-share stock market. We design two strategies based on DMD algorithm. The strategy which considers only timing problem can make reliable profits in a choppy market with no prominent trend while fails to beat the benchmark moving-average strategy in bull market. After considering the spatial information from spatial-temporal coherent structure of DMD modes, we improved the trading strategy remarkably. Then the DMD strategies profitability is quantitatively evaluated by performing SPA test to correct the data-snooping effect. The results further prove that DMD algorithm can model the market patterns well in sideways market.

  20. Evidence-based evaluation of treatment strategy for multiple sclerosis

    Directory of Open Access Journals (Sweden)

    LI Meng-qiu

    2012-04-01

    Full Text Available Objective To formulate the best treatment plan for multiple sclerosis (MS patients by evaluating the therapeutic efficacy and side effect of various evidence-based programs. Methods Key words were defined as multiple sclerosis, immunomodulatory therapy and therapy, etc. We searched MEDLINE, Cochrane Library, Wanfang data bases for Scientific Journals in China and National Knowledge Infrastructure for Chinese Scientific Journals Database. Additionally, we applied manual searching and screened out conference paper and academic dissertation, etc, from various references. After that we obtained and evaluated by Jadad scales on systematic reviews, randomized controlled trials, controlled clinical trials and observational study cases about glucocorticoids, plasmapheresis, intravenous immunoglobulin, IFN-β, glatiramer acetate, mitoxantrone, natalizumab, fingolimod. Results After screening, all seventeen selected resources included systematic reviews 6 articles, randomized controlled trials 7 articles, controlled clinical trials 2 articles, observational study cases 2 articles, among which fifteen articles were proved to be high quality (according to Jadad scoring system, five score 4, six score 5, four score 7, two chapters were judged to be low quality scoring 3. Finally, we summerize that: 1 The first choice of treatment for acute relapses is glucocorticoids and we suggest that plasmapheresis or intravenous immunoglobulin may be tried as an alternative therapy in acute MS relapse, especially in case of contraindications to intravenous methylprednisolone. 2 Immunomodulatory or immunosuppressive treatment (IFN-β, glatiramer acetate, mitoxantrone, natalizumab can be an option to prevent new relapses and progression of disability. 3 Fingolimod is an oral treatment for multiple sclerosis to improve treatment adherence. Conclusion Using evidence-based medicine methods can provide us best clinical evidence on MS treatment.

  1. Material-based engineering strategies for cardiac regeneration.

    Science.gov (United States)

    Marion, Mieke H van; Bax, Noortje A M; Spreeuwel, Ariane C C van; van der Schaft, Daisy W J; Bouten, Carlijn V C

    2014-01-01

    Cardiac tissue is composed of muscle and non-muscle cells, surrounded by extracellular matrix (ECM) and spatially organized into a complex three-dimensional (3D) architecture to allow for coordinated contraction and electrical pulse propagation. Despite emerging evidence for cardiomyocyte turnover in mammalian hearts, the regenerative capacity of human cardiac tissue is insufficient to recover from damage, e.g. resulting from myocardial infarction (MI). Instead, the heart 'repairs' lost or injured tissue by ongoing synthesis and remodeling of scar tissue. Conventional therapies and timely (stem) cell delivery to the injured tissue markedly improve short-term function and remodeling, but do not attenuate later stage adverse remodeling, leading to functional deterioration and eventually failure of the heart. Material-based therapies have been successfully used to mechanically support and constrain the post-MI failing heart, preventing it from further remodeling and dilation. When designed to deliver the right microenvironment for endogenous or exogenous cells, as well as the mechanical and topological cues to guide neo-tissue formation, material-based therapies may even reverse remodeling and boost cardiac regeneration. This paper reviews the up-to-date status of material-based cardiac regeneration with special emphasis on 1) the use of bare biomaterials to deliver passive constraints that unload the heart, 2) the use of materials and cells to create engineered cardiac constructs for replacement, support, or regeneration of damaged myocardium, and 3) the development of bio-inspired and bioactive materials that aim to enhance the endogenous regenerative capacity of the heart. As the therapies should function in the infarcted heart, the damaged host environment and engineered in vitro test systems that mimic this environment, are reviewed as well.

  2. Investment Strategies Optimization based on a SAX-GA Methodology

    CERN Document Server

    Canelas, António M L; Horta, Nuno C G

    2013-01-01

    This book presents a new computational finance approach combining a Symbolic Aggregate approXimation (SAX) technique with an optimization kernel based on genetic algorithms (GA). While the SAX representation is used to describe the financial time series, the evolutionary optimization kernel is used in order to identify the most relevant patterns and generate investment rules. The proposed approach considers several different chromosomes structures in order to achieve better results on the trading platform The methodology presented in this book has great potential on investment markets.

  3. Intelligent Financial Portfolio Composition based on Evolutionary Computation Strategies

    CERN Document Server

    Gorgulho, Antonio; Horta, Nuno C G

    2013-01-01

    The management of financial portfolios or funds constitutes a widely known problematic in financial markets which normally requires a rigorous analysis in order to select the most profitable assets. This subject is becoming popular among computer scientists which try to adapt known Intelligent Computation techniques to the market’s domain. This book proposes a potential system based on Genetic Algorithms, which aims to manage a financial portfolio by using technical analysis indicators. The results are promising since the approach clearly outperforms the remaining approaches during the recent market crash.

  4. Strategies for soil-based precision agriculture in cotton

    Science.gov (United States)

    Neely, Haly L.; Morgan, Cristine L. S.; Stanislav, Scott; Rouze, Gregory; Shi, Yeyin; Thomasson, J. Alex; Valasek, John; Olsenholler, Jeff

    2016-05-01

    The goal of precision agriculture is to increase crop yield while maximizing the use efficiency of farm resources. In this application, UAV-based systems are presenting agricultural researchers with an opportunity to study crop response to environmental and management factors in real-time without disturbing the crop. The spatial variability soil properties, which drive crop yield and quality, cannot be changed and thus keen agronomic choices with soil variability in mind have the potential to increase profits. Additionally, measuring crop stress over time and in response to management and environmental conditions may enable agronomists and plant breeders to make more informed decisions about variety selection than the traditional end-of-season yield and quality measurements. In a previous study, seed-cotton yield was measured over 4 years and compared with soil variability as mapped by a proximal soil sensor. It was found that soil properties had a significant effect on seed-cotton yield and the effect was not consistent across years due to different precipitation conditions. However, when seed-cotton yield was compared to the normalized difference vegetation index (NDVI), as measured using a multispectral camera from a UAV, predictions improved. Further improvement was seen when soil-only pixels were removed from the analysis. On-going studies are using UAV-based data to uncover the thresholds for stress and yield potential. Long-term goals of this research include detecting stress before yield is reduced and selecting better adapted varieties.

  5. Kinship-based management strategies for captive breeding programs when pedigrees are unknown or uncertain.

    Science.gov (United States)

    Putnam, Andrea S; Ivy, Jamie A

    2014-01-01

    Zoo-based captive breeding programs typically rely on accurate pedigrees to maintain long-term population genetic diversity and prevent close inbreeding. For many mixed-sex captive populations, it is difficult to assign parentage of offspring with certainty without conducting DNA-based parentage analyses. Using the demographic parameters of a North American captive population of Arabian oryx (Oryx leucoryx), 2 kinship-based breeding-pair selection strategies were modeled for their performance in handling pedigrees with varying degrees of parentage uncertainty. We also compared these strategies with 2 nonkinship-based methods. Pedigrees simulated under different management strategies were compared for their long-term ability to maintain gene diversity (GD) and avoid inbreeding. For the Arabian oryx, results indicate that recording multiple possible parents instead of removing the unknown genomic portion of the pedigree can more efficiently utilize all animals available for breeding without compromising GD and inbreeding avoidance. Both kinship-based breeding-pair selection strategies significantly outperformed the nonkinship-based strategies.

  6. Optimum Performance Enhancing Strategies of the Gas Turbine Based on the Effective Temperatures

    Directory of Open Access Journals (Sweden)

    Ibrahim Thamir K.

    2016-01-01

    Full Text Available Gas turbines (GT have come to play a significant role in distributed energy systems due to its multi-fuel capability, compact size and low environmental impact and reduced cost. Nevertheless, the low electrical efficiency, typically about 30% (LHV, is an important obstruction to the development of the GT plants. New strategies are designed for the GT plant, to increase the overall performance based on the operational modeling and optimization of GT power plants. The enhancing strategies effect on the GT power plant’s performance (with intercooler, two-shaft, reheat and regenerative based on the real power plant of GT. An analysis based on thermodynamics has been carried out on the modifications of the cycle configurations’ enhancements. Then, the results showed the effect of the ambient and turbine inlet temperatures on the performance of the GT plants to select an optimum strategy for the GT. The performance model code to compare the strategies of the GT plants were developed utilizing the MATLAB software. The results show that, the best thermal efficiency occurs in the intercooler-regenerative-reheated GT strategy (IRHGT; it decreased from 51.5 to 48%, when the ambient temperature increased (from 273 to 327K. Furthermore, the thermal efficiency of the GT for the strategies without the regenerative increased (about 3.3%, while thermal efficiency for the strategies with regenerative increased (about 22% with increased of the turbine inlet temperature. The lower thermal efficiency occurs in the IHGT strategy, while the higher thermal efficiency occurs in the IRHGT strategy. However, the power output variation is more significant at a higher value of the turbine inlet temperature. The simulation model gives a consistent result compared with Baiji GT plant. The extensive modeling performed in this study reveals that; the ambient temperature and turbine inlet temperature are strongly influenced on the performance of GT plant.

  7. AN EMPIRICAL STUDY OF THE EFFECT OF STRATEGIES-BASED INSTRUCTION ON LISTENING COMPREHENSION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper reports a typical interventionist learningstrategies study,aiming at investigating the effect of strategies-based study on listening comprehension.The study took the formof an experiment in which two parallel classes of eighty-five first-year non-English majors were assigned into an experimental anda control group.Both groups participated in the same 18-weeklistening program,the only difference being that theexperimental group students were trained systematically inthirteen listening strategies.Results of this study reveal thatadding explicit strategy training into the regular listeningclassroom instruction has produced significant effects in areasinvestigated.First,the experimental group outperformed thecontrol group on listening comprehension achievements.Second,the strategies-based instruction had more impact on studentswith average listening ability than students above or belowaverage.The primary objective of this study is to provideimplications for the effective teaching of listening in China andfor the development of language learners’learning and languageskills.

  8. QoE-based transmission strategies for multi-user wireless information and power transfer

    Directory of Open Access Journals (Sweden)

    Taehun Jung

    2015-12-01

    Full Text Available One solution to the problem of supplying energy to wireless networks is wireless power transfer. One such technology–electromagnetic radiation enabled wireless power transfer–will change traditional wireless networks. In this paper, we investigate a transmission strategy for multi-user wireless information and power transfer. We consider a multi-user multiple-input multiple-output (MIMO channel that includes one base station (BS and two user terminals (UT consisting of one energy harvesting (EH receiver and one information decoding (ID receiver. Our system provides transmission strategies that can be executed and implemented in practical scenarios. The paper then analyzes the rate–energy (R–E pair of our strategies and compares them to those of the theoretical optimal strategy. We furthermore propose a QoE-based mode selection algorithm by mapping the R–E pair to the utility functions.

  9. Biomimetic properties of an injectable chitosan/nano-hydroxyapatite/collagen composite

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zhi [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Feng Qingling, E-mail: biomater@mail.tsinghua.edu.cn [Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Yu Bo; Li Songjian [Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou 510282 (China)

    2011-04-08

    To meet the challenges of designing an injectable scaffold and regenerating bone with complex three-dimensional (3D) structures, a biomimetic and injectable hydrogel scaffold based on nano-hydroxyapatite (HA), collagen (Col) and chitosan (Chi) is synthesized. The chitosan/nano-hydroxyapatite/collagen (Chi/HA/Col) solution rapidly forms a stable gel at body temperature. It shows some features of natural bone both in main composition and microstructure. The Chi/HA/Col system can be expected as a candidate for workable systemic minimally invasive scaffolds with surface properties similar to physiological bone based on scanning electron microscopic (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) results.

  10. Hydroxyapatite coating by biomimetic method on titanium alloy using concentrated SBF

    Indian Academy of Sciences (India)

    S Bharati; M K Sinha; D Basu

    2005-10-01

    This article reports a biomimetic approach for coating hydroxyapatite on titanium alloy at ambient temperature. In the present study, coating was obtained by soaking the substrate in a 5 times concentrated simulated body fluid (5XSBF) solution for different periods of time with and without the use of CaO–SiO2 based glass as a possible source of nucleating agent of apatite formation. Optical microscopic and SEM observations revealed the deposition of Ca–P layer on the titanium alloy by both the methods. Thickness of coating was found to increase with the increase in immersion time. The use of glass did not help the formation of apatite nuclei on the substrate and the coating obtained by this method was also not uniform. EDX analysis indicated that the coating consisted of Ca–P based apatite globules, mostly in agglomerated form, and its crystallinity was poor as revealed by XRD.

  11. Carrying Network Accessing Architecture and Strategy Based on Business Differentiation

    Directory of Open Access Journals (Sweden)

    Yanyan Han

    2013-07-01

    Full Text Available Due to the abilities of real-time sensing and information sharing, Wireless Sensor Network (WSN has been applied in more and more fields. Basing on the emergence of Internet of Things (IoT, the issue about heterogeneous network integration is becoming more important. We first analyze the new businesses that arise recently for cell phone users as well as the potential effect on carrying network. After that we mainly discuss the influence on traditional carrying network for WSN accessing and taking concurrent businesses as the study case, common access architecture from WSN to carrying network is constructed, which makes use of business differentiation. Furthermore, we propose the idea of tortuous access from WSN to the gateway in the carrying network to avoid congested paths with simulation and verification. Finally, we conclude the possible impacts for the integration of these two networks and present possible solutions.

  12. Study on National Sustainable Development Strategy Management Based on Stakeholders Management Theory

    Institute of Scientific and Technical Information of China (English)

    Chen Huarong; Wang Xiaoming

    2012-01-01

    Based on the stakeholders management theory, this pa- per provides a new strategic management method for the National Sustainable Development Strategy. By taking China's National Sustainable Development Strategy Management as an example, this paper identifies all the stakeholders involved and then as- sesses stakeholders from two dimensions, namely "Importance" and "Attitude", by which all of the stakeholders are divided into six categories. On this basis, further analysis is made to work out strategic management programme by scheduling the strate- gic emphases, steps and management countermeasures for dif- ferent types of stakeholders so as to provide theortical evidence for the practice of National Sustainable Developnent Strategy management.

  13. Real-Time Pricing-Based Scheduling Strategy in Smart Grids: A Hierarchical Game Approach

    Directory of Open Access Journals (Sweden)

    Jie Yang

    2014-01-01

    Full Text Available This paper proposes a scheduling strategy based on real-time pricing in smart grids. A hierarchical game is employed to analyze the decision-making process of generators and consumers. We prove the existence and uniqueness of Nash equilibrium and utilize a backward induction method to obtain the generation and consumption strategies. Then, we propose two dynamic algorithms for the generators and consumers to search for the equilibrium in a distributed fashion. Simulation results demonstrate that the proposed scheduling strategy can match supply with demand and shift load away from peak time.

  14. Swarm Robots Search for Multiple Targets Based on an Improved Grouping Strategy.

    Science.gov (United States)

    Tang, Qirong; Ding, Lu; Yu, Fangchao; Zhang, Yuan; Li, Yinghao; Tu, Haibo

    2017-03-14

    Swarm robots search for multiple targets in collaboration in unknown environments has been addressed in this paper. An improved grouping strategy based on constriction factors Particle Swarm Optimization is proposed. Robots are grouped under this strategy after several iterations of stochastic movements, which considers the influence range of targets and environmental information they have sensed. The group structure may change dynamically and each group focuses on searching one target. All targets are supposed to be found finally. Obstacle avoidance is considered during the search process. Simulation compared with previous method demonstrates the adaptability, accuracy and efficiency of the proposed strategy in multiple targets searching.

  15. Model-based comparison of strategies for reduction of stormwater micropollutant emissions

    DEFF Research Database (Denmark)

    Vezzaro, Luca; Sharma, Anitha Kumari; Mikkelsen, Peter Steen

    to improve the recipient quality by reducing the fluxes of heavy metals (copper, zinc) and organic compounds (fluoranthene) to natural waters. MP sources were identified by using GIS land usage data. When comparing the different control strategies, the integrated model showed the greater benefits...... of the source-control strategy in terms of MP loads discharged in the environment and sediment accumulated in the pond. None of the simulated pollution control strategies managed to fulfil water quality criteria based on Emission Limit Values. This study highlights the great contribution that integrated models...... can provide to the management of stormwater pollution....

  16. Nonlinear Dynamical Behavior in Neuron Model Based on Small World Network with Attack and Repair Strategy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xue; YANG Qiu-Ying; ZHENG Tai-Yu; ZHANG Ying-Yue; ZHENG Li; ZHANG Gui-Qing; CHEN Tian-Lun

    2008-01-01

    In this paper, we investigate the effect due to the change of topology structure of network on the nonlinear dynamical behavior, by virtue of the OFC neuron evolution model with attack and repair strategy based on the small world. In particular, roles of various parameters relating to the dynamical behavior are carefully studied and analyzed. In addition, the avalanche and EEG-like wave activities with attack and repair strategy are also explored in detail in this work.

  17. Improving water management efficiency by using optimization-based control strategies: the Barcelona case study

    OpenAIRE

    2009-01-01

    This paper describes the application of model-based predictive control (MPC) techniques to the flow management in large-scale drinking water networks including a telemetry/telecontrol system. MPC technique is used to generate flow control strategies from the sources to the consumer areas to meet future demands, optimizing performance indexes associated to operational goals such as economic cost, network safety volumes and flow control stability. The designed management strategies are...

  18. Evaluation of different frontier-based multi-robot exploration strategies

    Directory of Open Access Journals (Sweden)

    Benkrid Abdenour

    2016-01-01

    Full Text Available In this paper, we focus on the problem of exploring an unknown environment by a team of mobile robots. The main objective is to compare four different coordination strategies based on frontier concept (boundaries between unexplored and explored open areas and analyze their performance in term of assignment quality, overall exploration time and computational complexity. In order to provide a suitable qualitative study we used three optimization criteria. Each strategy has been implemented and tested extensively in computerized simulation.

  19. How Teaching Science Using Project-Based Learning Strategies Affects the Classroom Learning Environment

    Science.gov (United States)

    Hugerat, Muhamad

    2016-01-01

    This study involved 458 ninth-grade students from two different Arab middle schools in Israel. Half of the students learned science using project-based learning strategies and the other half learned using traditional methods (non-project-based). The classes were heterogeneous regarding their achievements in the sciences. The adapted questionnaire…

  20. Study on transient stability of wind turbine with induction generator based on variable pitch control strategy

    DEFF Research Database (Denmark)

    Zhao, B.; Li, H.; Han, L.

    2011-01-01

    In order to enhance and improve the transient stability of a grid-connected wind turbine generator system under the power grid fault, based on typical pitch control strategy of wind turbine, considering the wind turbine system oscillation caused by the drive-train shaft flexibility, Based on Matlab/Simulink...