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Sample records for biomimetic strategies based

  1. BIOMIMETIC STRATEGIES IN ORGANIC SYNTHESIS. TERPENES

    OpenAIRE

    V. Kulcitki

    2012-01-01

    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. Coordination of Multiple Biomimetic Autonomous Underwater Vehicles Using Strategies Based on the Schooling Behaviour of Fish

    Directory of Open Access Journals (Sweden)

    Jonathan McColgan

    2016-01-01

    Full Text Available Biomimetic Autonomous Underwater Vehicles (BAUVs are Autonomous Underwater Vehicles (AUVs that employ similar propulsion and steering principles as real fish. While the real life applicability of these vehicles has yet to be fully investigated, laboratory investigations have demonstrated that at low speeds, the propulsive mechanism of these vehicles is more efficient when compared with propeller based AUVs. Furthermore, these vehicles have also demonstrated superior manoeuvrability characteristics when compared with conventional AUVs and Underwater Glider Systems (UGSs. Further performance benefits can be achieved through coordination of multiple BAUVs swimming in formation. In this study, the coordination strategy is based on the schooling behaviour of fish, which is a decentralized approach that allows multiple AUVs to be self-organizing. Such a strategy can be effectively utilized for large spatiotemporal data collection for oceanic monitoring and surveillance purposes. A validated mathematical model of the BAUV developed at the University of Glasgow, RoboSalmon, is used to represent the agents within a school formation. The performance of the coordination algorithm is assessed through simulation where system identification techniques are employed to improve simulation run time while ensuring accuracy is maintained. The simulation results demonstrate the effectiveness of implementing coordination algorithms based on the behavioural mechanisms of fish to allow a group of BAUVs to be considered self-organizing.

  3. 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.

  4. 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.

  5. 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

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

    Science.gov (United States)

    Wang, Yao; Van Manh, Ngo; Wang, Haorong; Zhong, Xue; Zhang, Xu; Li, Changyi

    2016-01-01

    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 control group. The biomimetic mineralization will assist us in fabricating a novel collagen scaffold for clinical applications. PMID:27274235

  7. 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.

  8. Biomimetic material strategies for cardiac tissue engineering

    International Nuclear Information System (INIS)

    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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Nanoengineering of stimuli-responsive protein-based biomimetic protocells as versatile drug delivery tools.

    Science.gov (United States)

    Zhao, Fenfang; Shen, Guizhi; Chen, Chengjun; Xing, Ruirui; Zou, Qianli; Ma, Guanghui; Yan, Xuehai

    2014-06-01

    We present a general strategy to nanoengineer protein-based colloidal spheres (biomimetic protocells) as versatile delivery carriers with stimuli responsiveness by the electrostatic assembly of binary components (proteins and polypeptides) in association with intermolecular disulfide cross-linking. The size of the colloidal spheres, ranging from nanoscale to microscale, is readily tuned through parameters like protein and polypeptide concentration, the ratio between both, pH, and so on. Moreover, such colloidal spheres show versatile encapsulation of various guest molecules including small organic molecules and biomacromolecules. The pH and redox dual-responsiveness facilitates the rapid release of the payload in an acidic and reductant-enriched ambient such as in lysosomes. Thus, nanoengineering of protein-based biomimetic protocells opens a new alternative avenue for developing delivery vehicles with multifunctional properties towards a range of therapeutic and diagnostic applications. PMID:24828788

  14. 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.

  15. 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.

  16. 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.

  17. Hierarchically organized architecture of potassium hydrogen phthalate and poly(acrylic acid): toward a general strategy for biomimetic crystal design.

    Science.gov (United States)

    Oaki, Yuya; Imai, Hiroaki

    2005-12-28

    A hierarchically organized architecture in multiple scales was generated from potassium hydrogen phthalate crystals and poly(acrylic acid) based on our novel biomimetic approach with an exquisite association of polymers on crystallization. PMID:16333511

  18. Bacteriorhodopsin-based bipolar photosensor for biomimetic sensing

    Science.gov (United States)

    Kasai, Katsuyuki; Haruyama, Yoshihiro; Yamada, Toshiki; Akiba, Makoto; Tominari, Yukihiro; Kaji, Takahiro; Terui, Toshifumi; Peper, Ferdinand; Tanaka, Shukichi; Katagiri, Yoshitada; Kikuchi, Hiroshi; Okada-Shudo, Yoshiko; Otomo, Akira

    2013-10-01

    Bacteriorhodopsin (bR) is a promising biomaterial for several applications. Optical excitation of bR at an electrode-electrolyte interface generates differential photocurrents while an incident light is turned on and off. This unique functional response is similar to that seen in retinal neurons. The bR-based bipolar photosensor consists of the bR dip-coated thin films patterned on two ITO plates and the electrolyte solution. This bipolar photocell will function as a biomimetic photoreceptor cell. The bipolar structure, due to the photocurrent being generated in alignment with the cathodic direction, makes the excitatory and inhibitory regions possible. This scheme shows our bipolar cell can act as a basic unit of edge detection and forms the artificial visual receptive field.

  19. 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.

  20. A biomimetic jellyfish robot based on ionic polymer metal composite actuators

    International Nuclear Information System (INIS)

    A biomimetic jellyfish robot based on ionic polymer metal composite actuators was fabricated and activated to mimic real locomotive behavior with pulse and recovery processes. To imitate the curved shape of the jellyfish, a thermal treatment was applied to obtain a permanent initial deformation of a hemispherical form. The bio-inspired input signal was generated for mimicking real locomotion of the jellyfish. The vertical floating displacement and the thrust force of the biomimetic jellyfish robot under various input signals were measured and compared. The present results show that the bio-inspired electrical input signal with pulse-recovery process generates much higher floating velocity of the biomimetic jellyfish robot in comparison with pure sinusoidal excitations. The curved shape of the IPMC actuator through thermal treatments can be successfully applied to mimic the real biomimetic robots with smooth curves

  1. 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.

  2. 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....

  3. Fingerprint attendance system based on hypersphere covering of biomimetic pattern recognition

    OpenAIRE

    Li, Li; Yin, Ye; Cui, Xiaojing

    2015-01-01

    Hypersphere covering of biomimetic pattern recognition method has the features of fast identification,low rate of false recognition,easy implementation,and so on.It is particularly suitable for a number of strong practical applications.In this paper,we study a biomimetic pattern recognition method based on the hypersphere string covering and apply it in a fingerprint attendance system.On the basis of analyzing actual teaching needs,we design a complete hardware and software system for the fin...

  4. A strategy for biomimetic hybridization of electrospun fiber mat cross-sections

    International Nuclear Information System (INIS)

    Concentrated synthetic body fluid (c-SBF) recipes have been used in biomimetic deposition of calcium phosphate (CaP) phases on electrospun polycaprolactone (PCL) fiber mats. However, cross-sections of mats could not be coated entirely when simple soaking methods had been used. In this study, calcium and phosphate sources that are used in typical c-SBF recipes were placed in two compartments which were separated by PCL fiber mats. By varying the concentrations of calcium and phosphate sources in either compartment according to a thermodynamic model, the difference between pH levels of compartments was adjusted. A gradual and homogeneous increase in supersaturation levels was achieved on both sides of the membrane with the onset of diffusion of species through the membrane. The strategy of separation of c-SBF constituents permitted coatings that extended through the cross-section of mats. In addition, types of CaP phases that can be precipitated on opposite sides of the membrane under different conditions were predicted by the same thermodynamic model. It was possible to coat the cross-sections of mats with the targeted phase mixtures by using the developed modeling approach. Highlights: → A strategy for coating cross-sections of electrospun fiber mats is developed. → Constituents of concentrated CPS were separated with mats to be coated. → Both, sides and the cross-sections of fiber mats were coated simultaneously. → Alternative that resulted in a biphasic and a single phase coating on opposite sides was predicted by thermodynamic model used. → Coatings were changed from single phase to biphasic by decreasing the difference in pH values of the compartments.

  5. A strategy for biomimetic hybridization of electrospun fiber mat cross-sections

    Energy Technology Data Exchange (ETDEWEB)

    Mavis, Bora, E-mail: bmavis@hacettepe.edu.tr

    2011-10-10

    Concentrated synthetic body fluid (c-SBF) recipes have been used in biomimetic deposition of calcium phosphate (CaP) phases on electrospun polycaprolactone (PCL) fiber mats. However, cross-sections of mats could not be coated entirely when simple soaking methods had been used. In this study, calcium and phosphate sources that are used in typical c-SBF recipes were placed in two compartments which were separated by PCL fiber mats. By varying the concentrations of calcium and phosphate sources in either compartment according to a thermodynamic model, the difference between pH levels of compartments was adjusted. A gradual and homogeneous increase in supersaturation levels was achieved on both sides of the membrane with the onset of diffusion of species through the membrane. The strategy of separation of c-SBF constituents permitted coatings that extended through the cross-section of mats. In addition, types of CaP phases that can be precipitated on opposite sides of the membrane under different conditions were predicted by the same thermodynamic model. It was possible to coat the cross-sections of mats with the targeted phase mixtures by using the developed modeling approach. Highlights: {yields} A strategy for coating cross-sections of electrospun fiber mats is developed. {yields} Constituents of concentrated CPS were separated with mats to be coated. {yields} Both, sides and the cross-sections of fiber mats were coated simultaneously. {yields} Alternative that resulted in a biphasic and a single phase coating on opposite sides was predicted by thermodynamic model used. {yields} Coatings were changed from single phase to biphasic by decreasing the difference in pH values of the compartments.

  6. 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.

  7. 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.

  8. Chitosan-based biomimetic scaffolds and methods for preparing the same

    OpenAIRE

    Filée, Patrick; Freichels, Astrid; Jérôme, Christine; Aqil, Abdelhafid; Colige, Alain; Tchemtchoua Tateu, Victor

    2010-01-01

    The invention concerns chitosan-based biomimetic scaffolds and methods for modulating their intrinsic properties such as rigidity, elasticity, resistance to mechanical stress, porosity, biodegradation and absorbance of exudates. Therefore, the present invention relates to a layered chitosan-based scaffold wherein said layered scaffold comprises at least two fused layers, wherein at least one layer consists of a chitosan nanofiber scaffold membrane and at least one of the other layers of a por...

  9. A Biomimetic Strategy to Access the Silybins: Total Synthesis of (−)-Isosilybin A

    OpenAIRE

    McDonald, Benjamin R.; Nibbs, Antoinette E.; Scheidt, Karl A.

    2014-01-01

    We report the first asymmetric, total synthesis of (−)-isosilybin A. A late-stage catalytic biomimetic cyclization of a highly functionalized chalcone is employed to form the characteristic benzopyranone ring. A robust and flexible approach to this chalcone provides an entry to the preparation of the entire isomeric family of silybin natural products.

  10. Plastic deformation in nano-scale multilayer materials — A biomimetic approach based on nacre

    International Nuclear Information System (INIS)

    The paper reports about a biomimetic based comparison of deformation in magnetron sputtered multilayer coatings based on titanium (Ti), titanium nitride (TiN) and diamond-like carbon (DLC) layers and the deformation mechanisms in nacre of mollusc shells. Nacre as highly mineralized tissue combines high stiffness and hardness with high toughness, enabling resistance to fracture and crack propagation during tensile loading. Such behaviour is based on a combination of load transmission by tensile stressed aragonite tablets and shearing in layers between the tablets. Shearing in these polysaccharide and protein interlayers demands hydrated conditions. Otherwise, nacre has similar brittle behaviour to aragonite. To prevent shear failure, shear hardening occurs by progressive tablet locking due to wavy dovetail-like surface geometry of the tablets. Similar effects by shearing and strain hardening mechanisms were found for Ti interlayers between TiN and DLC layers in high-resolution transmission electron microscopy studies, performed in deformed zones beneath spherical indentations. 7 nm thin Ti films are sufficient for strong toughening of the whole multi-layered coating structure, providing a barrier for propagation of cracks, starting from tensile-stressed, hard, brittle TiN or DLC layers. - Highlights: • Biomimetic approach to TiN-diamond-like carbon (DLC) multilayers by sputtering • Investigation of deformation in/around hardness indents by HR-TEM • Plastic deformation with shearing in 7-nm thick Ti interlayers in TiN–DLC multilayers • Biomimetically comparable to nacre deformation

  11. 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.

  12. A biomimetic colorimetric logic gate system based on multi-functional peptide-mediated gold nanoparticle assembly

    Science.gov (United States)

    Li, Yong; Li, Wang; He, Kai-Yu; Li, Pei; Huang, Yan; Nie, Zhou; Yao, Shou-Zhuo

    2016-04-01

    In natural biological systems, proteins exploit various functional peptide motifs to exert target response and activity switch, providing a functional and logic basis for complex cellular activities. Building biomimetic peptide-based bio-logic systems is highly intriguing but remains relatively unexplored due to limited logic recognition elements and complex signal outputs. In this proof-of-principle work, we attempted to address these problems by utilizing multi-functional peptide probes and the peptide-mediated nanoparticle assembly system. Here, the rationally designed peptide probes function as the dual-target responsive element specifically responsive to metal ions and enzymes as well as the mediator regulating the assembly of gold nanoparticles (AuNPs). Taking advantage of Zn2+ ions and chymotrypsin as the model inputs of metal ions and enzymes, respectively, we constructed the peptide logic system computed by the multi-functional peptide probes and outputted by the readable colour change of AuNPs. In this way, the representative binary basic logic gates (AND, OR, INHIBIT, NAND, IMPLICATION) have been achieved by delicately coding the peptide sequence, demonstrating the versatility of our logic system. Additionally, we demonstrated that the three-input combinational logic gate (INHIBIT-OR) could also be successfully integrated and applied as a multi-tasking biosensor for colorimetric detection of dual targets. This nanoparticle-based peptide logic system presents a valid strategy to illustrate peptide information processing and provides a practical platform for executing peptide computing or peptide-related multiplexing sensing, implying that the controllable nanomaterial assembly is a promising and potent methodology for the advancement of biomimetic bio-logic computation.In natural biological systems, proteins exploit various functional peptide motifs to exert target response and activity switch, providing a functional and logic basis for complex cellular

  13. 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

  14. 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 of the bi......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...... of the biological solutions, identification of design principles and design of the desired artefact. We use a search method developed at University of Toronto. It is based on formulation of relevant keywords and search for occurrences in a standard university biology textbook. Most often a simple formulation...... of keywords and a following search is not enough to generate a sufficient amount of useful ideas or the search gives to 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. The paper also reviews a number...

  15. 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.

  16. Embedded SMA wire actuated biomimetic fin: a module for biomimetic underwater propulsion

    Science.gov (United States)

    Wang, Zhenlong; Hang, Guanrong; Wang, Yangwei; Li, Jian; Du, Wei

    2008-04-01

    An embedded shape memory alloy (SMA) wire actuated biomimetic fin is presented, and based on this module for biomimetic underwater propulsion, a micro robot fish (146 mm in length, 30 g in weight) and a robot squid (242 mm in length, 360 g in weight) were developed. Fish swim by undulating their body and/or fins. Squid and cuttlefish can also swim by undulating their fins. To simplify engineering modeling, the undulating swimming movement is assumed to be the integration of the movements of many flexible bending segments connected in parallel or in series. According to this idea, a biomimetic fin which can bend flexibly was developed. The musculature of a cuttlefish fin was investigated to aid the design of the biomimetic fin. SMA wires act as 'muscle fibers' to drive the biomimetic fin just like the transverse muscles of the cuttlefish fin. During the bending phase, elastic energy is stored in the elastic substrate and skin, and during the return phase, elastic energy is released to power the return movement. Theorem analysis of the bending angle was performed to estimate the bending performance of the biomimetic fin. Experiments were carried out on single-face fins with latex rubber skin and silicone skin (SF-L and SF-S) to compare the bending angle, return time, elastic energy storage and reliability. Silicone was found to be the better skin. A dual-face fin with silicone skin (DF-S) was tested in water to evaluate the actuating performance and to validate the reliability. Thermal analysis of the SMA temperature was performed to aid the control strategy. The micro robot fish and robot squid employ one and ten DF-S, respectively. Swimming experiments with different actuation frequencies were carried out. The speed and steering radius of the micro robot fish reached 112 mm s-1 and 136 mm, respectively, and the speed and rotary speed of the robot squid reached 40 mm s-1 and 22° s-1, respectively.

  17. Embedded SMA wire actuated biomimetic fin: a module for biomimetic underwater propulsion

    International Nuclear Information System (INIS)

    An embedded shape memory alloy (SMA) wire actuated biomimetic fin is presented, and based on this module for biomimetic underwater propulsion, a micro robot fish (146 mm in length, 30 g in weight) and a robot squid (242 mm in length, 360 g in weight) were developed. Fish swim by undulating their body and/or fins. Squid and cuttlefish can also swim by undulating their fins. To simplify engineering modeling, the undulating swimming movement is assumed to be the integration of the movements of many flexible bending segments connected in parallel or in series. According to this idea, a biomimetic fin which can bend flexibly was developed. The musculature of a cuttlefish fin was investigated to aid the design of the biomimetic fin. SMA wires act as 'muscle fibers' to drive the biomimetic fin just like the transverse muscles of the cuttlefish fin. During the bending phase, elastic energy is stored in the elastic substrate and skin, and during the return phase, elastic energy is released to power the return movement. Theorem analysis of the bending angle was performed to estimate the bending performance of the biomimetic fin. Experiments were carried out on single-face fins with latex rubber skin and silicone skin (SF-L and SF-S) to compare the bending angle, return time, elastic energy storage and reliability. Silicone was found to be the better skin. A dual-face fin with silicone skin (DF-S) was tested in water to evaluate the actuating performance and to validate the reliability. Thermal analysis of the SMA temperature was performed to aid the control strategy. The micro robot fish and robot squid employ one and ten DF-S, respectively. Swimming experiments with different actuation frequencies were carried out. The speed and steering radius of the micro robot fish reached 112 mm s−1 and 136 mm, respectively, and the speed and rotary speed of the robot squid reached 40 mm s−1 and 22° s−1, respectively

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

    International Nuclear Information System (INIS)

    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.

  19. 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.

  20. 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.

  1. 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. PMID:26512734

  2. 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.

  3. 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.

  4. Biomimetic sensor design

    Science.gov (United States)

    Lee, Ju Hun; Jin, Hyo-Eon; Desai, Malav S.; Ren, Shuo; Kim, Soyoun; Lee, Seung-Wuk

    2015-11-01

    Detection of desired target chemicals in a sensitive and selective manner is critically important to protect human health, environment and national security. Nature has been a great source of inspiration for the design of sensitive and selective sensors. In this mini-review, we overview the recent developments in bio-inspired sensor development. There are four major components of sensor design: design of receptors for specific targets; coating materials to integrate receptors to transducing machinery; sensitive transducing of signals; and decision making based on the sensing results. We discuss the biomimetic methods to discover specific receptors followed by a discussion about bio-inspired nanocoating material design. We then review the recent developments in phage-based bioinspired transducing systems followed by a discussion of biomimetic pattern recognition-based decision making systems. Our review will be helpful to understand recent approaches to reverse-engineer natural systems to design specific and sensitive sensors.

  5. Dioxygen Affinities and Biomimetic Catalytic Performance of Transition-metal Complexes with Crowned Bis-Schiff Bases

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The dioxygen affinities and biomimetic catalytic performance of transition-metal complexes with (15-crown-5) salophen and its substituted derivatives were examined. The oxygenation constants of Co(II) complexes with crowned bis-Schiff bases were measured and their Mn(III) complexes were employed as models to mimic monooxygenase in catalytic epoxidation of styrene. The highest conversion and selectivity were up to 57.2% and 100% respectively at ambient temperature and pressure. The effects of crown ether ring and substituents R on the dioxygen affinities and catalytic activities were also investigated through comparing with the uncrowned analogues.

  6. Biomimetic membranes for sensor and separation applications

    DEFF Research Database (Denmark)

    Helix Nielsen, Claus

    2009-01-01

    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...... current developments of biomimetic sensor/separation devices....

  7. Biomimetic composite scaffolds based on mineralization of hydroxyapatite on electrospun poly(ɛ-caprolactone)/nanocellulose fibers.

    Science.gov (United States)

    Si, Junhui; Cui, Zhixiang; Wang, Qianting; Liu, Qiong; Liu, Chuntai

    2016-06-01

    A biomimetic nanocomposite scaffold with HA formation on the electrospun poly(ɛ-caprolactone) (PCL)/nanocellulose (NC) fibrous matrix was developed in this study. The electrospun PCL/NC fiber mat was built and then biomineralized by treatment in simulated body fluid (SBF). Using such a rapid and effective procedure, a continuous biomimetic crystalline HA layer could be successfully formed without the need of any additional chemical modification of the substrate surface. The results showed that the introduction of NC into composite fibers is an effective approach to induce the deposition of HA nucleus as well as to improve their distribution and growth of a crystalline HA layer on the fibrous scaffolds. The water contact angle (WCA) of the PCL/NC/HA scaffolds decreases with increasing NC content and mineralization time, resulting in the enhancement of their hydrophilicity. These results indicated that HA-mineralized on PCL/NC fiber can be prepared directly by simply using SBF immersion. PMID:27083369

  8. 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.

  9. A new evaporation-based method for the preparation of biomimetic calcium phosphate coatings on metals

    International Nuclear Information System (INIS)

    This study reports a new method to prepare biomimetic calcium phosphate coatings on titanium, stainless steel, CoCrMo, and tantalum. The method does not require surface etching, high supersaturation, or tight control of solution conditions. Metallic samples were dipped into a supersaturated calcium phosphate solution, withdrawn, and left to dry at room temperature. Calcium phosphate crystallites formed on and completely covered the surfaces by repeating the dip-and-dry treatment. The crystallite-covered surfaces readily grew to calcium phosphate coatings when immersed in the supersaturated solution. The mechanism of the treatment was suggested to be an evaporation-induced surface crystallization process.

  10. 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. PMID:24615558

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. A biomimetic nano hybrid coating based on the lotus effect and its anti-biofouling behaviors

    Science.gov (United States)

    Li, Jiang; Wang, Guoqing; Meng, Qinghua; Ding, Chunhua; Jiang, Hong; Fang, Yongzeng

    2014-10-01

    To develop an environmentally friendly anti-biofouling coating in virtue of bionics, a block copolymer containing fluorine (Coplm_F) of low surface energy was prepared by copolymerization. The Ag-loaded mesoporous silica (Ag@SBA) acting as a controlled-release antifoulant was prepared from the mesoporous silica (SBA-15). The nano hybrid coating (Ag@SBA/Coplm_F) composing of the Coplm_F and Ag@SBA was to biomimetically simulate the lotus microstructure. The concentration of fluorine element on surface was analyzed by the energy dispersive spectroscopy (EDS) and found rising to 1.45% after hybridation, which could be explained by the driving effect of SBA-15 via the hydrogen bond. This nanoscale morphology of the hybrid coating was measured and found highly semblable to the microstructure of the lotus surface. The contact angle was determined as 151° which confirmed the superhydrophobicity and lotus effect. The adhesion behaviors of Pseudomonas fluorescens, Diatoms, and Chlorella on the surface of the nano hybrid coating (Ag@SBA/Coplm_F) were studied and good effects of anti-biofouling were observed.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    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...... and design of the desired artefact. The present search method is based on formulation of relevant keywords and search for occurrences in a standard university biology textbook. Most often a simple formulation of keywords and a following search is not enough to generate a sufficient amount of useful ideas...... 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...

  19. Biomimetic Active Touch with Fingertips and Whiskers.

    Science.gov (United States)

    Lepora, Nathan F

    2016-01-01

    This study provides a synthetic viewpoint that compares, contrasts, and draws commonalities for biomimetic perception over a range of tactile sensors and tactile stimuli. Biomimetic active perception is formulated from three principles: (i) evidence accumulation based on leading models of perceptual decision making; (ii) action selection with an evidence-based policy, here based on overt focal attention; and (iii) sensory encoding of evidence based on neural coding. Two experiments with each of three biomimetic tactile sensors are considered: the iCub (capacitive) fingertip, the TacTip (optical) tactile sensor, and BIOTACT whiskers. For each sensor, one experiment considers a similar task (perception of shape and location) and the other a different tactile perception task. In all experiments, active perception with a biomimetic action selection policy based on focal attention outperforms passive perception with static or random action selection. The active perception also consistently reaches superresolved accuracy (hyperacuity) finer than the spacing between tactile elements. Biomimetic active touch thus offers a common approach for biomimetic tactile sensors to accurately and robustly characterize and explore non-trivial, uncertain environments analogous to how animals perceive the natural world. PMID:27168603

  20. Bio-mimetic Flow Control

    Science.gov (United States)

    Choi, Haecheon

    2009-11-01

    Bio-mimetic engineering or bio-mimetics is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology (from Wikipedia). The concept itself is old, but successful developments have been made recently, especially in the research field of flow control. The objective of flow control based on the bio-mimetic approach is to develop novel concepts for reducing drag, increasing lift and enhancing aerodynamic performance. For skin friction reduction, a few ideas have been suggested such as the riblet from shark, compliant surface from dolphin, microbubble injection and multiple front-body curvature from penguin, and V-shaped protrusion from sailfish. For form drag reduction, several new attempts have been also made recently. Examples include the V-shaped spanwise grooves from saguaro cactus, overall shape of box fish, longitudinal grooves on scallop shell, bill of swordfish, hooked comb on owl wing, trailing-edge protrusion on dragonfly wing, and fillet. For the enhancement of aerodynamic performance, focuses have been made on the birds, fish and insects: e.g., double layered feather of landing bird, leading-edge serration of humpback-whale flipper, pectoral fin of flying fish, long tail on swallowtail-butterfly wing, wing flapping motion of dragonfly, and alula in birds. Living animals adapt their bodies to better performance in multi purposes, but engineering requires single purpose in most cases. Therefore, bio-mimetic approaches often produce excellent results more than expected. However, they are sometimes based on people's wrong understanding of nature and produce unwanted results. Successes and failures from bio-mimetic approaches in flow control will be discussed in the presentation.

  1. Effects of proteoliposome composition and draw solution types on separation performance of aquaporin-based proteoliposomes: implications for seawater desalination using aquaporin-based biomimetic membranes.

    Science.gov (United States)

    Zhao, Yang; Vararattanavech, Ardcharaporn; Li, Xuesong; Hélixnielsen, Claus; Vissing, Thomas; Torres, Jaume; Wang, Rong; Fane, Anthony G; Tang, Chuyang Y

    2013-02-01

    Aquaporins are a large family of water transport proteins in cell membranes. Their high water permeability and solute rejection make them potential building blocks for high-performance biomimetic membranes for desalination. In the current study, proteoliposomes were prepared using AquaporinZ from Escherichia coli cells, and their separation properties were characterized by stopped-flow measurements. The current study systematically investigated the effect of proteoliposome composition (lipid type, protein-to-lipid ratio (PLR), and the addition of cholesterol) on water permeability and NaCl retention. Among the various lipids investigated, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)-based proteoliposomes were found to have excellent osmotic water permeability and NaCl reflection coefficient values. Increasing the PLR of DOPC proteoliposomes up to 1:200 increased their osmotic water permeability. However, further increase in the PLR reduced the osmotic water permeability probably due to the occurrence of defects in the proteoliposomes, whereas the addition of cholesterol improved their osmotic water permeation likely due to defects sealing. The current study also investigated the effect of major dissolved ions in seawater (e.g., Mg(2+) and SO(4)(2-)) on the stability of proteoliposomes, and design criteria for aquaporin-based biomimetic membranes are proposed in the context of desalination. PMID:23311686

  2. 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.

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

    International Nuclear Information System (INIS)

    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 KSV 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 × 10−7–35.0 × 10−7 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

  4. 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 ...

  5. Biomimetic phosphate assay based on nanopores obtained by immobilization of zirconium(IV) on a film of polyethyleneimine

    International Nuclear Information System (INIS)

    A biomimetic ion-responsive single nanopore sensor was constructed by immobilizing zirconium(IV) ion on a film of poly(ethylene terephthalate) whose surface was modified with polyethyleneimine (PEI) to form nanopores. PEI is an excellent metal-chelating ligand that was initially modified on the surface of the membrane through amidation. The Zr-chelated nanopore responds to inorganic phosphate by a change in the ion current–voltage plot. This is due to a reversal of the charge from positive to negative after binding of the phosphate to the tip of the ion channel. Inorganic phosphate can be quantified by measurement of the extent of rectification. The limit of detection of the method is 118 nM, and response is linear in the 0 to 40 μM phosphate concentration range. The formation of the Zr(IV)/phosphate system on the surface was corroborated by X-ray photoelectron spectroscopy and current–voltage characterization. The single synthetic nanopore display excellent selectivity, high sensitivity and a wide response range for phosphate. The accuracy of the method and applicability of the nanopore-based detection scheme was proven by the successful determination of inorganic phosphate in (spiked) lake water and a cola drink. (author)

  6. An Offensive Strategy of Fuzzy Control for 2D-Biomimetic Robot Fish in 1vs1 Game%一种2D仿真机器鱼1vs1比赛的模糊策略

    Institute of Scientific and Technical Information of China (English)

    张月圆; 王玮

    2011-01-01

    Aiming at the deficiency of using the traditional strategy in the 2-dimensional biomimetic robot fish Ivst game, an offensive strategy of fuzzy control is presented. In the analysis of existing the problem in offensive strategy, the various situation of position and distance between the biomimetic robot fish and water polo are analyzed. Compare to the traditional strategy, some advantages are introduced. The result of test shows the program which according to the strategy can work effectively in the game.%针对2D仿真机器鱼1vs1比赛中采用的传统策略的不足,提出一种新的模糊控制策略.在分析目前比赛策略存在的问题的基础上,对机器鱼和水球之间在各种位置和距离情况进行分析,并介绍了该策略相比于其它传统策略的优点.实践结果表明:该策略编写的比赛程序在实际应用中取得了较好的效果.

  7. 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

  8. 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.

  9. Biomimetic Engineering

    OpenAIRE

    Vico Vela, Francisco José

    2008-01-01

    Humankind is a privileged animal species for many reasons. A remarkable one is its ability to conceive and manufacture objects. Human industry is indeed leading the various winning strategies (along with language and culture) that has permitted this primate to extraordinarily increase its life expectancy and proliferation rate. (It is indeed so successful, that it now threatens the whole planet.) The design of this industry kicks off in the brain, a computing machine parti...

  10. 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.

  11. 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.

  12. Development of paper-based devices, using a simple phase separation process for the fabrication of biomimetic superhydrophobic paper substrates

    OpenAIRE

    Sousa, Maria José Peixoto de

    2012-01-01

    Dissertação de mestrado integrado em Engenharia Biomédica For the last two decades, biomimetic superhydrophobic materials have been acquiring huge interest for distinct application fields such as textile and glass industries, biomedical in vivo devices and microfluidic systems. Different methodologies and materials have been employed to fabricate these substrates, prevailing in literature the use of complex processes with non biodegradable and costly materials. In recent yea...

  13. 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...

  14. 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

  15. 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

    2015-09-01

    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.

  16. Biomimetic High-Density Lipoproteins from a Gold Nanoparticle Template

    Science.gov (United States)

    Luthi, Andrea Jane

    For hundreds of years the field of chemistry has looked to nature for inspiration and insight to develop novel solutions for the treatment of human diseases. The ability of chemists to identify, mimic, and modifiy small molecules found in nature has led to the discovery and development of many important therapeutics. Chemistry on the nanoscale has made it possible to mimic natural, macromolecular structures that may also be useful for understanding and treating diseases. One example of such a structure is high-density lipoprotein (HDL). The goal of this work is to use a gold nanoparticle (Au NP) as a template to synthesize functional mimics of HDL and characterize their structure and function. Chapter 1 details the structure and function of natural HDL and how chemistry on the nanoscale provides new strategies for mimicking HDL. This Chapter also describes the first examples of using nanoparticles to mimic HDL. Chapter 2 reports the synthesis and characterization of biomimetic HDL using different sizes of Au NPs and different surface chemistries and how these variables can be used to tailor the properties of biomimetic HDL. From these studies the optimal strategy for synthesizing biomimetic HDL was determined. In Chapter 3, the optimization of the synthesis of biomimetic HDL is discussed as well as a full characterization of its structure. In addition, the work in this chapter shows that biomimetic HDL can be synthesized on a large scale without alterations to its structure or function. Chapter 4 focuses on understanding the pathways by which biomimetic HDL accepts cholesterol from macrophage cells. The results of these studies demonstrate that biomimetic HDL is able to accept cholesterol by both active and passive pathways of cholesterol efflux. In Chapter 5 the preliminary results of in vivo studies to characterize the pharmacokinetics and pharmacodynamics of biomimetic HDL are presented. These studies suggest that biomimetic HDL traffics through tissues prone to

  17. Aloe vera Induced Biomimetic Assemblage of Nucleobase into Nanosized Particles

    OpenAIRE

    Chauhan, Arun; Zubair, Swaleha; Sherwani, Asif; Owais, Mohammad

    2012-01-01

    Aim Biomimetic nano-assembly formation offers a convenient and bio friendly approach to fabricate complex structures from simple components with sub-nanometer precision. Recently, biomimetic (employing microorganism/plants) synthesis of metal and inorganic materials nano-particles has emerged as a simple and viable strategy. In the present study, we have extended biological synthesis of nano-particles to organic molecules, namely the anticancer agent 5-fluorouracil (5-FU), using Aloe vera lea...

  18. 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...

  19. 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.

  20. 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.

  1. A single use electrochemical sensor based on biomimetic nanoceria for the detection of wine antioxidants.

    Science.gov (United States)

    Andrei, Veronica; Sharpe, Erica; Vasilescu, Alina; Andreescu, Silvana

    2016-08-15

    We report the development and characterization of a disposable single use electrochemical sensor based on the oxidase-like activity of nanoceria particles for the detection of phenolic antioxidants. The use of nanoceria in the sensor design enables oxidation of phenolic compounds, particularly those with ortho-dihydroxybenzene functionality, to their corresponding quinones at the surface of a screen printed carbon electrode. Detection is carried out by electrochemical reduction of the resulting quinone at a low applied potential of -0.1V vs the Ag/AgCl electrode. The sensor was optimized and characterized with respect to particle loading, applied potential, response time, detection limit, linear concentration range and sensitivity. The method enabled rapid detection of common phenolic antioxidants including caffeic acid, gallic acid and quercetin in the µM concentration range, and demonstrated good functionality for the analysis of antioxidant content in several wine samples. The intrinsic oxidase-like activity of nanoceria shows promise as a robust tool for sensitive and cost effective analysis of antioxidants using electrochemical detection. PMID:27260442

  2. Biomimetic poly(lactide) based fibrous scaffolds for ligament tissue engineering.

    Science.gov (United States)

    Surrao, Denver C; Waldman, Stephen D; Amsden, Brian G

    2012-11-01

    The aim of this study was to fabricate a fibrous scaffold that closely resembled the micro-structural architecture and mechanical properties of collagen fibres found in the anterior cruciate ligament (ACL). To achieve this aim, fibrous scaffolds were made by electrospinning L-lactide based polymers. L-Lactide was chosen primarily due to its demonstrated biocompatibility, biodegradability and high modulus. The electrospun fibres were collected in tension on a rotating wire mandrel. Upon treating these fibres in a heated aqueous environment, they possessed a crimp-like pattern having a wavelength and amplitude similar to that of native ACL collagen. Of the polymer fibre scaffolds studied, those made from poly(L-lactide-co-D,L-lactide) PLDLA exhibited the highest modulus and were also the most resilient to in vitro hydrolytic degradation, undergoing a slight decrease in modulus compared to the other polymeric fibres over a 6 month period. Bovine fibroblasts seeded on the wavy, crimp-like PLDLA fibres attached, proliferated and deposited extracellular matrix (ECM) molecules on the surface of the fibrous scaffold. In addition, the deposited ECM exhibited bundle formation that resembled the fascicles found in native ACL. These findings demonstrate the importance of replicating the geometric microenvironment in developing effective tissue engineering scaffolds. PMID:22828380

  3. Knowledge Based Strategies for Knowledge Based Organizations

    Directory of Open Access Journals (Sweden)

    Madalina Cristina Tocan

    2012-12-01

    Full Text Available 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 of management- knowledge based management and a new type of enterprise-knowledge based enterprise.Taking in consideration these predictable evolutions, this paper will try to present: • The main ideas of the researches the field of the knowledge based economy • The characteristics and principles of the knowledge based organizations and knowledge based management • The challenges and opportunities for knowledge based organizations.The first part of the paper will present the principles of the new economy- knowledge base economy, the essential and interrelated elements necessary to build and to implement a strategy in a knowledge economy and the opportunities and challenges to the countries as they seek to build regionally and globally competitive knowledge-based economies.The second part of the paper will present the characteristics of the knowledge based organizations, the principles and characteristics of their management. For many organizations, knowledge management is a relatively new concept, because they are discovering the knowledge value in their operations. Many firms have undertaken formal and informal knowledge management initiatives designed to improve process performance, increase customer responsiveness and spur innovation. But while some organizations have reaped significant benefits from their investment in knowledge efforts, others have run into noteworthy challenges.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. Major intrinsic proteins in biomimetic membranes.

    Science.gov (United States)

    Nielsen, Claus Hélix

    2010-01-01

    Biological membranes define the structural and functional boundaries in living cells and their organelles. The integrity of the cell depends on its ability to separate inside from outside and yet at the same time allow 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 transport proteins are incorporated. This raises the question: is it possible to mimic biological membranes and create a membrane based sensor and/or separation device? In the development of a biomimetic sensor/separation technology, a unique class of membrane transport proteins is especially interesting-the major intrinsic proteins (MIPs). Generally, MIPs conduct water molecules and selected solutes in and out of the cell while preventing the passage of other solutes, a property critical for the conservation of the cells internal pH and salt concentration. Also known as water channels or aquaporins they are highly efficient membrane pore proteins some of which are capable of transporting water at very high rates up to 10(9) molecules per second. Some MIPs transport other small, uncharged solutes, such as glycerol and other permeants such as carbon dioxide, nitric oxide, ammonia, hydrogen peroxide and the metalloids antimonite, arsenite, silicic and boric acid depending on the effective restriction mechanism of the protein. The flux properties of MIPs thus lead to the question ifMIPs can be used in separation devices or as sensor devices based on, e.g., the selective permeation of metalloids. In principle a MIP based membrane sensor/separation device requires the supporting biomimetic matrix to be virtually impermeable to anything but water or the solute in question. In practice, however, a biomimetic support matrix will generally have finite permeabilities to both electrolytes and non-electrolytes. The feasibility of a biomimetic MIP device thus depends on the relative transport

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

    OpenAIRE

    Byoung-Ho Kim

    2015-01-01

    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 cons...

  10. Biomimetic hydrogel materials

    Science.gov (United States)

    Bertozzi, Carolyn; Mukkamala, Ravindranath; Chen, Qing; Hu, Hopin; Baude, Dominique

    2000-01-01

    Novel biomimetic hydrogel materials and methods for their preparation. Hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with a hydrophilic or hydrophobic copolymerizing material selected from the group consisting of an acrylamide, methacrylamide, acrylate, methacrylate, vinyl and a derivative thereof present in concentration from about 1 to about 99 wt %. and methods for their preparation. The method of use of the new hydrogels for fabrication of soft contact lenses and biomedical implants.

  11. 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.

  12. 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…

  13. 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.

  14. Biomimetics in Tribology

    Science.gov (United States)

    Gebeshuber, I. C.; Majlis, B. Y.; Stachelberger, H.

    Science currently goes through a major change. Biology is evolving as new Leitwissenschaft, with more and more causation and natural laws being uncovered. The term `technoscience' denotes the field where science and technology are inseparably interconnected, the trend goes from papers to patents, and the scientific `search for truth' is increasingly replaced by search for applications with a potential economic value. Biomimetics, i.e. knowledge transfer from biology to technology, is a field that has the potential to drive major technical advances. The biomimetic approach might change the research landscape and the engineering culture dramatically, by the blending of disciplines. It might substantially support successful mastering of current tribological challenges: friction, adhesion, lubrication and wear in devices and systems from the meter to the nanometer scale. A highly successful method in biomimectics, the biomimicry innovation method, is applied in this chapter to identify nature's best practices regarding two key issues in tribology: maintenance of the physical integrity of a system, and permanent as well as temporary attachment. The best practices identified comprise highly diverse organisms and processes and are presented in a number of tables with detailed references.

  15. 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

  16. 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.

  17. Plants and Animals as Concept Generators for the Development of Biomimetic Cable Entry Systems

    Institute of Scientific and Technical Information of China (English)

    Tom Masseiter; Uwe Scharf; Thomas Speck

    2008-01-01

    Many animals and plants have high potential to serve as concept generators for developing biomimetic materials and structures. We present some ideas based on structural and functional properties of plants and animals that led to the development of two types of biomimetic cable entry systems. Those systems have been realized on the level of functional demonstrators.

  18. 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.

  19. 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.

  20. 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.

  1. 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 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....

  2. 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

  3. Biomaterials-based strategies for salivary gland tissue regeneration.

    Science.gov (United States)

    Ozdemir, Tugba; Fowler, Eric W; Hao, Ying; Ravikrishnan, Anitha; Harrington, Daniel A; Witt, Robert L; Farach-Carson, Mary C; Pradhan-Bhatt, Swati; Jia, Xinqiao

    2016-04-22

    The salivary gland is a complex, secretory tissue that produces saliva and maintains oral homeostasis. Radiation induced salivary gland atrophy, manifested as "dry mouth" or xerostomia, poses a significant clinical challenge. Tissue engineering recently has emerged as an alternative, long-term treatment strategy for xerostomia. In this review, we summarize recent efforts towards the development of functional and implantable salivary glands utilizing designed polymeric substrates or synthetic matrices/scaffolds. Although the in vitro engineering of a complex implantable salivary gland is technically challenging, opportunities exist for multidisciplinary teams to assemble implantable and secretory tissue modules by combining stem/progenitor cells found in the adult glands with biomimetic and cell-instructive materials. PMID:26878077

  4. DISTANCE-BASED UPDATE STRATEGY IN LDCQ

    Institute of Scientific and Technical Information of China (English)

    Dong Yi; Edward Chan; Huang Zailu

    2004-01-01

    A new update strategy, distance-based update strategy, is presented in Location Dependent Continuous Query (LDCQ) under error limitation. There are different possibilities to intersect when the distances between moving objects and the querying boundary are different.Therefore, moving objects have different influences to the query result. We set different deviation limits for different moving objects according to distances. A great number of unnecessary updates are reduced and the payload of the system is relieved.

  5. 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.

  6. 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.

  7. Sustainability assessment of a lightweight biomimetic ceiling structure

    International Nuclear Information System (INIS)

    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. (paper)

  8. 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.

  9. 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.

  10. 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...

  11. 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

  12. Design Strategies for Aptamer-Based Biosensors

    Directory of Open Access Journals (Sweden)

    Kun Han

    2010-05-01

    Full Text Available Aptamers have been widely used as recognition elements for biosensor construction, especially in the detection of proteins or small molecule targets, and regarded as promising alternatives for antibodies in bioassay areas. In this review, we present an overview of reported design strategies for the fabrication of biosensors and classify them into four basic modes: target-induced structure switching mode, sandwich or sandwich-like mode, target-induced dissociation/displacement mode and competitive replacement mode. In view of the unprecedented advantages brought about by aptamers and smart design strategies, aptamer-based biosensors are expected to be one of the most promising devices in bioassay related applications.

  13. 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.

  14. [Biomimetic sensors in biomedical research].

    Science.gov (United States)

    Gayet, Landry; Lenormand, Jean-Luc

    2015-01-01

    The recent research on both the synthesis of membrane proteins by cell-free systems and the reconstruction of planar lipid membranes, has led to the development of a cross-technology to produce biosensors or filters. Numerous biomimetic membranes are currently being standardized and used by the industry, such as filters containing aquaporin for water desalination, or used in routine at the laboratory scale, for example the bacteriorhodopsin as a light sensor. In the medical area, several fields of application of these biomimetic membranes are under consideration today, particularly for the screening of therapeutic molecules and for the developing of new tools in diagnosis, patient monitoring and personalized medicine. PMID:26152170

  15. 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...

  16. Cell-based strategies for vascular regeneration.

    Science.gov (United States)

    Zou, Tongqiang; Fan, Jiabing; Fartash, Armita; Liu, Haifeng; Fan, Yubo

    2016-05-01

    Vascular regeneration is known to play an essential role in the repair of injured tissues mainly through accelerating the repair of vascular injury caused by vascular diseases, as well as the recovery of ischemic tissues. However, the clinical vascular regeneration is still challenging. Cell-based therapy is thought to be a promising strategy for vascular regeneration, since various cells have been identified to exert important influences on the process of vascular regeneration such as the enhanced endothelium formation on the surface of vascular grafts, and the induction of vessel-like network formation in the ischemic tissues. Here are a vast number of diverse cell-based strategies that have been extensively studied in vascular regeneration. These strategies can be further classified into three main categories, including cell transplantation, construction of tissue-engineered grafts, and surface modification of scaffolds. Cells used in these strategies mainly refer to terminally differentiated vascular cells, pluripotent stem cells, multipotent stem cells, and unipotent stem cells. The aim of this review is to summarize the reported research advances on the application of various cells for vascular regeneration, yielding insights into future clinical treatment for injured tissue/organ. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1297-1314, 2016. PMID:26864677

  17. 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. ...

  18. 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.

  19. 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.

  20. Strategies for reward-based crowdfunding campaigns

    OpenAIRE

    Kraus, Sascha; Richter, Christian; Brem, Alexander; Chang, M.-L.; Cheng, C. -F.

    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 crow...

  1. 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.

  2. 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.

  3. 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.

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

    International Nuclear Information System (INIS)

    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. (paper)

  5. 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.

  6. Reducing Emergency Department Crowding: Evidence Based Strategies.

    Science.gov (United States)

    Khalifa, Mohamed; Zabani, Ibrahim

    2016-01-01

    Emergency department (ED) crowding has become a major barrier to receiving timely care. King Faisal Specialist Hospital & Research Center, Saudi Arabia worked on identifying evidence based strategies for reducing the ED crowding by improving the intake. In addition to a review of literature, qualitative survey methods were used to identify strategies, which were classified into 10 suggested procedures categorized into three types of changes. Physical improvements include using physician cubicles, creating a team triage area and an internal waiting area for less acute patients instead of occupying beds. Technology improvements; include using informatics to update the electronic emergency record with information, using palmar scanning to instantly identify patients and using radio communication devices. Process improvements; include a scribe program to decrease clerical documentation tasks, switching between low flow and high flow processes, placing a physician in triage and using patient segmentation methods. PMID:27350468

  7. A biosensor based on the self-entrapment of glucose oxidase within biomimetic silica nanoparticles induced by a fusion enzyme.

    Science.gov (United States)

    Choi, Okkyoung; Kim, Byung-Chun; An, Ji-Hye; Min, Kyoungseon; Kim, Yong Hwan; Um, Youngsoon; Oh, Min-Kyu; Sang, Byoung-In

    2011-10-10

    We constructed a fusion protein (GOx-R5) consisting of R5 (a polypeptide component of silaffin) and glucose oxidase (GOx) that was expressed in Pichia pastoris. Silaffin proteins are responsible for the formation of a silica-based cell matrix of diatoms, and synthetic variants of the R5 protein can perform silicification in vitro[1]. GOx secreted by P. pastoris was self-immobilized (biosilicification) in a pH 5 citric buffer using 0.1M tetramethoxysilane as a silica source. This self-entrapment property of GOx-R5 was used to immobilize GOx on a graphite rod electrode. An electric cell designed as a biosensor was prepared to monitor the glucose concentrations. The electric cell consisted of an Ag/AgCl reference electrode, a platinum counter electrode, and a working electrode modified with poly(neutral red) (PNR)/GOx/Nafion. Glucose oxidase was immobilized by fused protein on poly(neutral red) and covered by Nafion to protect diffusion to the solution. The morphology of the resulting composite PNR/GOx/Nafion material was analyzed by scanning electron microscopy (SEM). This amperometric transducer was characterized electrochemically using cyclic voltammetry and amperometry in the presence of glucose. An image produced by scanning electron microscopy supported the formation of a PNR/GOx complex and the current was increased to 1.58 μA cm(-1) by adding 1mM glucose at an applied potential of -0.5 V. The current was detected by way of PNR-reduced hydrogen peroxide, a product of the glucose oxidation by GOx. The detection limit was 0.67mM (S/N=3). The biosensor containing the graphite rod/PNR/GOx/Nafion detected glucose at various concentrations in mixed samples, which contained interfering molecules. In this study, we report the first expression of R5 fused to glucose oxidase in eukaryotic cells and demonstrate an application of self-entrapped GOx to a glucose biosensor. PMID:22112615

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

    OpenAIRE

    Wang Y; Van Manh H; Wang H; Zhong X; Zhang X; Li C

    2016-01-01

    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 ...

  9. Biomimetic peptide nanosensors.

    Science.gov (United States)

    Cui, Yue; Kim, Sang N; Naik, Rajesh R; McAlpine, Michael C

    2012-05-15

    The development of a miniaturized sensing platform tailored for sensitive and selective detection of a variety of biochemical analytes could offer transformative fundamental and technological opportunities. Due to their high surface-to-volume ratios, nanoscale materials are extremely sensitive sensors. Likewise, peptides represent robust substrates for selective recognition due to the potential for broad chemical diversity within their relatively compact size. Here we explore the possibilities of linking peptides to nanosensors for the selective detection of biochemical targets. Such systems raise a number of interesting fundamental challenges: What are the peptide sequences, and how can rational design be used to derive selective binders? What nanomaterials should be used, and what are some strategies for assembling hybrid nanosensors? What role does molecular modeling play in elucidating response mechanisms? What is the resulting performance of these sensors, in terms of sensitivity, selectivity, and response time? What are some potential applications? This Account will highlight our early attempts to address these research challenges. Specifically, we use natural peptide sequences or sequences identified from phage display as capture elements. The sensors are based on a variety of nanomaterials including nanowires, graphene, and carbon nanotubes. We couple peptides to the nanomaterial surfaces via traditional surface functionalization methods or self-assembly. Molecular modeling provides detailed insights into the hybrid nanostructure, as well as the sensor detection mechanisms. The peptide nanosensors can distinguish chemically camouflaged mixtures of vapors and detect chemical warfare agents with sensitivities as low as parts-per-billion levels. Finally, we anticipate future uses of this technology in biomedicine: for example, devices based on these sensors could detect disease from the molecular components in human breath. Overall, these results provide a

  10. 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.

  11. A belief-based evolutionarily stable strategy

    OpenAIRE

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

    2014-01-01

    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 st...

  12. 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.

  13. Empirically Based Strategies for Preventing Juvenile Delinquency.

    Science.gov (United States)

    Pardini, Dustin

    2016-04-01

    Juvenile crime is a serious public health problem that results in significant emotional and financial costs for victims and society. Using etiologic models as a guide, multiple interventions have been developed to target risk factors thought to perpetuate the emergence and persistence of delinquent behavior. Evidence suggests that the most effective interventions tend to have well-defined treatment protocols, focus on therapeutic approaches as opposed to external control techniques, and use multimodal cognitive-behavioral treatment strategies. Moving forward, there is a need to develop effective policies and procedures that promote the widespread adoption of evidence-based delinquency prevention practices across multiple settings. PMID:26980128

  14. Design and demonstration of a biomimetic wing section using lightweight piezoceramic composite actuator (LIPCA)

    Science.gov (United States)

    Lim, Sahng M.; Lee, Sangki; Park, Hoon C.; Yoon, Kwang J.; Goo, Nam Seo

    2003-08-01

    Biomimetic wing sections actuated by piezoceramics actuator LIPCA have been designed and their actuation displacements estimated by using the thermal analogy and MSC/NASTRAN based on the linear elasticity. The wing sections are fabricated as the design and tested for evaluation. Measured actuation displacements were larger than the estimated values mainly due to the material non-linearity of the PZT wafer. The biomimetic wing sections can be used for control surfaces of small scale UAVs.

  15. 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.

  16. 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.

  17. Biomimetic strategies for engineering composite tissues.

    Science.gov (United States)

    Lee, Nancy; Robinson, Jennifer; Lu, Helen

    2016-08-01

    The formation of multiple tissue types and their integration into composite tissue units presents a frontier challenge in regenerative engineering. Tissue-tissue synchrony is crucial in providing structural support for internal organs and enabling daily activities. This review highlights the state-of-the-art in composite tissue scaffold design, and explores how biomimicry can be strategically applied to avoid over-engineering the scaffold. Given the complexity of biological tissues, determining the most relevant parameters for recapitulating native structure-function relationships through strategic biomimicry will reduce the burden for clinical translation. It is anticipated that these exciting efforts in composite tissue engineering will enable integrative and functional repair of common soft tissue injuries and lay the foundation for total joint or limb regeneration. PMID:27010653

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

    Science.gov (United States)

    Qian, Yunzhu; Chen, Hanbang; Xu, Yang; Yang, Jianxin; Zhou, Xuefeng; Zhang, Feimin; Gu, Ning

    2016-01-01

    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 growth. Analysis of β1 integrin expression level by immunofluorescence indicated that such biomimetic architecture, especially COL I-grafted surface, plays a key role in cell adhesion and proliferation. The real-time polymerase chain reaction suggested that both surface topography and bioactive properties could facilitate the cell adhesion. The combined effect of biomimetic architecture with enhanced

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

    Science.gov (United States)

    Qian, Yunzhu; Chen, Hanbang; Xu, Yang; Yang, Jianxin; Zhou, Xuefeng; Zhang, Feimin; Gu, Ning

    2016-01-01

    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 growth. Analysis of β1 integrin expression level by immunofluorescence indicated that such biomimetic architecture, especially COL I-grafted surface, plays a key role in cell adhesion and proliferation. The real-time polymerase chain reaction suggested that both surface topography and bioactive properties could facilitate the cell adhesion. The combined effect of biomimetic architecture with enhanced

  20. MARKETING STRATEGIES BASED ON THE BUYING PROCESS

    OpenAIRE

    LIVIU NEAMŢU; ADINA CLAUDIA NEAMŢU

    2016-01-01

    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 st...

  1. 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.

  2. 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.

  3. 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.

  4. Applying Biomimetic Algorithms for Extra-Terrestrial Habitat Generation

    Science.gov (United States)

    Birge, Brian

    2012-01-01

    The objective is to simulate and optimize distributed cooperation among a network of robots tasked with cooperative excavation on an extra-terrestrial surface. Additionally to examine the concept of directed Emergence among a group of limited artificially intelligent agents. Emergence is the concept of achieving complex results from very simple rules or interactions. For example, in a termite mound each individual termite does not carry a blueprint of how to make their home in a global sense, but their interactions based strictly on local desires create a complex superstructure. Leveraging this Emergence concept applied to a simulation of cooperative agents (robots) will allow an examination of the success of non-directed group strategy achieving specific results. Specifically the simulation will be a testbed to evaluate population based robotic exploration and cooperative strategies while leveraging the evolutionary teamwork approach in the face of uncertainty about the environment and partial loss of sensors. Checking against a cost function and 'social' constraints will optimize cooperation when excavating a simulated tunnel. Agents will act locally with non-local results. The rules by which the simulated robots interact will be optimized to the simplest possible for the desired result, leveraging Emergence. Sensor malfunction and line of sight issues will be incorporated into the simulation. This approach falls under Swarm Robotics, a subset of robot control concerned with finding ways to control large groups of robots. Swarm Robotics often contains biologically inspired approaches, research comes from social insect observation but also data from among groups of herding, schooling, and flocking animals. Biomimetic algorithms applied to manned space exploration is the method under consideration for further study.

  5. 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.

  6. 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

  7. 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.

  8. Biomimetic supramolecular metallohosts for binding and activation of dioxygen

    OpenAIRE

    Sprakel, Vera Stefanie Irene

    2004-01-01

    Host-guest chemistry involves the binding of a specific substrate in a receptor via molecular recognition based on supramolecular interactions. Metal-containing derivatives of receptors for the selective supramolecular binding of dihydroxybenzene substrates, which receptors model oxygen binding enzymes both in structure and in function are described in this thesis with the ultimate goal to realize biomimetic catalysis. A PY2-appended receptor 1 and a TPA-appended receptor 2 and the bis-copper...

  9. 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.

  10. 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.

  11. 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.

  12. Biomimetic strengthening polylactide scaffold materials for bone tissue engineering

    Institute of Scientific and Technical Information of China (English)

    XU Guofu; MOU Shenzhou; ZHOU Lingping; LIAO Susan; YIN Zhimin; CUI Fuzhai

    2007-01-01

    In this paper,a new polylactide(PLA)-based scaffold composite by biomimetic synthesis was designed.The novel composite mainly consists ofnano-hydroxyapatite (n-HA),which is the main inorganic content in natural bone tissue for the PLA.The crystal degree of the n-HA in the composite is low and the crystal size is very small,which is similar to that of natural bone.The compressive strength of the composite is higher than that of the PLA scaffold.Using the osteoblast culture technique,we detected cell behaviors on the biomaterial in vitro by SEM,and the cell affinity of the composite was found to be higher than that of the PLA scaffold.The biomimetic three-dimensional porous composite can serve as a kind of excellent scaffold material for bone tissue engineering because of its microstructure and properties.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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. PMID:27040264

  20. 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...

  1. 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.

  2. Enhanced biomimetic CO2 sequestration and CaCO3 crystallization using complex encapsulated metal organic framework

    Science.gov (United States)

    Sahoo, Prakash C.; Jang, Young Nam; Lee, Seung Woo

    2013-06-01

    A new biomimetic complex (Co-BBP) that mimics the active site of carbonic anhydrase (CA) was prepared by the coordination of cobalt (II) with 2, 6-bis(2-benzimidazolyl) and was encapsulated into a metal organic framework (Co-BBP@Tb-MOF). Carbon dioxide (CO2) sequestration was carried out via an in vitro mineralization approach using these biomimetic catalysts. The biomimetic catalysts were expected to enhance CO2 hydration and calcium carbonate (CaCO3) crystallization based on the same mechanism as that of CA.

  3. 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.

  4. 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.

  5. Biomimetic catalysis: Taking on the turnover challenge

    Science.gov (United States)

    Hooley, Richard J.

    2016-03-01

    Emulating the efficiency with which enzymes catalyse reactions has often been used as inspiration to develop self-assembled cages. Now two studies present approaches to achieving catalyst turnover -- one of the biggest challenges in achieving truly biomimetic catalysis.

  6. Biomimetic novelty detection

    Science.gov (United States)

    Ma, Lein W.; Szu, Harold

    2010-04-01

    In the crowded rain forest, how do animals locate camouflaged prey that resemble the environment, such as walking sticks? Birds will observe the suspected stick over a period of time to determine if its behavior matches that of a tree. If the stick's behavior exceeds normal tree behavior, such as moving faster than the other branches, the bird will determine that it is actually a walking stick and not a tree branch. Once this determination is made, they will prey on the insect. Studying this natural process of novelty detection, present in a variety of animals from birds to turkey vultures, can be beneficial for numerous human applications. The spatiotemporal novelty detector will be developed using self-referencing matched filters to go beyond auto-regression. This algorithm is more than the usual change detector for it will detect a novelty behavior that exceeds its predicted value based on past data, e.g. the bird who identifies a walking stick in the forest. A scalar model is presented; however, the application can be expanded to multiple modalities for more detailed applications. Some of these applications include gas pipeline leak detection, persistent surveillance, and the creation of a smart sensor web.

  7. Brain Based Instruction in Correctional Settings: Strategies for Teachers.

    Science.gov (United States)

    Becktold, Toni Hill

    2001-01-01

    Brain-based learning strategies (learner choice, movement, small groups) may be inappropriate in corrections for security reasons. Problems encountered in correctional education (attention deficit disorder, learned helplessness) complicate the use of these strategies. Incorporating brain-based instruction in these settings requires creativity and…

  8. 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.

  9. 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.

  10. Challenges in commercializing biomimetic membranes

    DEFF Research Database (Denmark)

    Perry, Mark; Madsen, Steen Ulrik; Jørgensen, Tine Elkjær;

    2015-01-01

    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...... 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...... 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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...... (up to 6 days) with a bilayer membrane area ~50% of the available aperture area. Highly stable membranes (up to 2 days) with a bilayer membrane area ~24% of the available aperture area were created in the developed microfluidic device. Further, reconstitution of α-hemolysin (α-HL) membrane proteins...

  15. 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.

  16. 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…

  17. 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.

  18. Biomimetic electrochemistry from conducting polymers. A review

    International Nuclear Information System (INIS)

    Highlights: ► Composition and properties of conducting polymers change during reactions. ► These properties are being exploited to develop biomimetic reactive and soft devices. ► The state of the art for artificial muscles sensing working conditions was reviewed. ► Smart membranes, drug delivery devices and nervous interfaces were also reviewed. - Abstract: Films of conducting polymers in the presence of electrolytes can be oxidized or reduced by the flow of anodic or cathodic currents. Ions and solvent are exchanged during a reaction for charge and osmotic pressure balance. A reactive conducting polymer contains ions and solvent. Such variation of composition during a reaction is reminiscent of the biological processes in cells. Along changes to the composition of the material during a reaction, there are also changes to other properties, including: volume (electrochemomechanical), colour (electrochromic), stored charge (electrical storage), porosity or permselectivity (electroporosity), stored chemicals, wettability and so on. Most of those properties mimic similar property changes in organs during their functioning. These properties are being exploited to develop biomimetic reactive and soft devices: artificial muscles and polymeric actuators; supercapacitors and all organic batteries; smart membranes; electron-ion transducers; nervous interfaces and artificial synapses, or drug delivery devices. In this review we focus on the state of the art for artificial muscles, smart membranes and electron-ion transducers. The reactive nature of those devices provide them with a unique advantage related to the present days technologies: any changes in the surrounding physical or chemical variable acting on the electrochemical reaction rate will be sensed by the device while working. Working under constant current (driving signal), the evolution of the device potential or the evolution of the consumed electrical energy (sensing signals) senses and quantifies the

  19. 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.

  20. Lactoferrin Adsorbed onto Biomimetic Hydroxyapatite Nanocrystals Controlling - In Vivo - the Helicobacter pylori Infection

    Science.gov (United States)

    Fulgione, Andrea; Nocerino, Nunzia; Iannaccone, Marco; Roperto, Sante; Capuano, Federico; Roveri, Norberto; Lelli, Marco; Crasto, Antonio; Calogero, Armando; Pilloni, Argenia Paola; Capparelli, Rosanna

    2016-01-01

    Background The resistance of Helicobacter pylori to the antibiotic therapy poses the problem to discover new therapeutic approaches. Recently it has been stated that antibacterial, immunomodulatory, and antioxidant properties of lactoferrin are increased when this protein is surface-linked to biomimetic hydroxyapatite nanocrystals. Objective Based on these knowledge, the aim of the study was to investigate the efficacy of lactoferrin delivered by biomimetic hydroxyapatite nanoparticles with cell free supernatant from probiotic Lactobacillus paracasei as an alternative therapy against Helicobacter pylori infection. Methods Antibacterial and antinflammatory properties, humoral antibody induction, histopathological analysis and absence of side effects were evaluated in both in vitro and in vivo studies. Results The tests carried out have been demonstrated better performance of lactoferrin delivered by biomimetic hydroxyapatite nanoparticles combined with cell free supernatant from probiotic Lactobacillus paracasei compared to both lactoferrin and probiotic alone or pooled. Conclusion These findings indicate the effectiveness and safety of our proposed therapy as alternative treatment for Helicobacter pylori infection. PMID:27384186

  1. 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.

  2. 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.

  3. Biomimetic Pattern Recognition Theory and Its Applications

    Institute of Scientific and Technical Information of China (English)

    WANGShoujue; ZHAOXingtao

    2004-01-01

    Biomimetic pattern recogntion (BPR),which is based on “cognition” instead of “classification”,is much closer to the function of human being. The basis of BPR is the Principle of homology-continuity (PHC),which means the difference between two samples of the same class must be gradually changed. The aim of BPR is to find an optimal covering in the feature space, which emphasizes the “similarity” among homologous group members, rather than “division” in traditional pattern recognition. Some applications of BPR are surveyed, in which the results of BPR are much better than the results of Support Vector Machine. A novel neuron model, Hyper sausage neuron (HSN), is shown as a kind of covering units in BPR. The mathematical description of HSN is given and the 2-dimensional discriminant boundary of HSN is shown. In two special cases, in which samples are distributed in a line segment and a circle, both the HSN networks and RBF networks are used for covering. The results show that HSN networks act better than RBF networks in generalization, especially for small sample set, which are consonant with the results of the applications of BPR. And a brief explanation of the HSN networks' advantages in covering general distributed samples is also given.

  4. On carbon dioxide storage based on biomineralization strategies.

    Science.gov (United States)

    Lee, Seung-Woo; Park, Seung-Bin; Jeong, Soon-Kwan; Lim, Kyoung-Soo; Lee, Si-Hyun; Trachtenberg, Michael C

    2010-06-01

    This study focuses on the separation and storage of the global warming greenhouse gas CO(2), and the use of natural biocatalysts in the development of technologies to improve CO(2) storage rates and provide new methods for CO(2) capture. Carbonic anhydrase (CA) has recently been used as a biocatalyst to sequester CO(2) through the conversion of CO(2) to HCO(-) in the mineralization of CaCO(3). Biomimetic CaCO(3) mineralization for carbon capture and storage offers potential as a stable CO(2) capture technology. In this report, we review recent developments in this field and assess disadvantages and improvements in the use of CA in industrial applications. We discuss the contribution that understanding of mechanisms of CO(2) conversion to CO(3)(-) in the formation and regeneration of bivalve shells will make to developments in biomimetic CO(2) storage. PMID:20144548

  5. 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.

  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. PMID:25221988

  7. Challenges in biomimetic design and innovation

    DEFF Research Database (Denmark)

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

    Biomimetic design copies desired principles found in nature and implement them into artificial applications. Applications could be products we use in our daily life but it can also be used to inspire material innovation. However there are significant challenges in performing biomimetic design. One....... 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...... 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...

  8. 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.

  9. 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

    2015-08-01

    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. PMID:26737943

  10. 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.

  11. Multiwalled carbon nanotube reinforced biomimetic bundled gel fibres.

    Science.gov (United States)

    Kim, Young-Jin; Yamamoto, Seiichiro; Takahashi, Haruko; Sasaki, Naruo; Matsunaga, Yukiko T

    2016-08-19

    This work describes the fabrication and characterization of hydroxypropyl cellulose (HPC)-based biomimetic bundled gel fibres. The bundled gel fibres were reinforced with multiwalled carbon nanotubes (MWCNTs). A phase-separated aqueous solution with MWCNT and HPC was transformed into a bundled fibrous structure after being injected into a co-flow microfluidic device and applying the sheath flow. The resulting MWCNT-bundled gel fibres consist of multiple parallel microfibres. The mechanical and electrical properties of MWCNT-bundled gel fibres were improved and their potential for tissue engineering applications as a cell scaffold was demonstrated. PMID:27200527

  12. Acoustic beam control in biomimetic projector via velocity gradient

    Science.gov (United States)

    Gao, Xiaowei; Zhang, Yu; Cao, Wenwu; Dong, Erqian; Song, Zhongchang; Li, Songhai; Tang, Liguo; Zhang, Sai

    2016-07-01

    A biomimetic projector (BioP) based on computerized tomography of pygmy sperm whale's biosonar system has been designed using gradient-index (GRIN) material. The directivity of this BioP device was investigated as function of frequency and the velocity gradient of the GRIN material. A strong beam control over a broad bandwidth at the subwavelength scale has been achieved. Compared with a bare subwavelength source, the main lobe pressure of the BioP is about five times as high and the angular resolution is one order of magnitude better. Our results indicate that this BioP has excellent application potential in miniaturized underwater sonars.

  13. 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.

  14. UAV Robust Strategy Control Based on MAS

    OpenAIRE

    Jian Han; Changhong Wang; Guoxing Yi

    2014-01-01

    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 coo...

  15. 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

  16. 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.

  17. Tissue bionics: examples in biomimetic tissue engineering

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. The study of biomimetic pattern iris recognition algorithm based on the wavelet transform and SVD%一种基于小波奇异值分解的仿生模式虹膜识别算法

    Institute of Scientific and Technical Information of China (English)

    翟懿奎; 曾军英

    2012-01-01

    本文给出了一种基于仿生模式识别理论的虹膜识别算法,该识别算法首先进行虹膜的边界定位、归一化及有效区域的选择,并采用Daubechies-4小波变换及奇异值分解的方法进行虹膜特征的提取,最后利用基于超香肠神经元的双权值神经网络对同类虹膜样本构建出了其对应的高维闭合空间覆盖面.在中科院自动化所的虹膜数据库( CASIA ver.1.0)中的仿真实验表明,本文所提算法取得了良好的正确识别率,并且对于未参与训练的待识别虹膜样本能具有较高的拒识率.%an iris recognition algorithm based on the biomimetic pattern recognition (BPR) theory is presented in this paper. First, edge location, normalization and the selection of the effective location is applied to the iris image, and Daubechies-4 wavelet transform (WT) and singular value decomposition (SVD) are used to extract the feature of it, then hyper sausage neuron is adopted in double-weights neural network to construct the high-dimensional closed covering space of the same class iris samples. Tested samples is recognized or rejected by judging whether tested samples are covered with any hyper sausage chain. Simulation results in CASIA iris database 1.0 show that the proposed method can achieve high correct recognition rate, and maintain high rejection rate with the iris samples untrained.

  4. 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

  5. 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

  6. 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

  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. Efficient Power Allocation Strategy Based Co-Operative Networks

    Directory of Open Access Journals (Sweden)

    Srinivas MRSP

    2013-09-01

    Full Text Available Here the networks based on the cooperative phenomena used for improving the potential of the system followed by the followed by the capacity of the network oriented with reliability of the effective transmission of the data in a well efficient fashion. There is a huge research going on this particular technology where from the ancient times and increasing the efficiency of the system but till now there is no particular method each and every method is effective with its particular strategy based phenomena but none of them are satisfied each and every properties of the system respectively. Here the cooperative based strategy is well efficient in terms of the network related to the three node oriented phenomena in a well efficient manner and also the and also applied in the network oriented strategies related to the AD HOC and also the scheme oriented with the relay fashion respectively which are mainly dependent on the antennas of the single parameters in a well respective fashion. Here there is some of the limiting condition which is mentioned in above statement that is due to the lack of knowledge on the present communication oriented system followed by its particular analysis in a very respective fashion. Here in this paper a method is designed with a well effective strategy and also with an oriented framework where strategy of the power allocation based phenomena with respect to the structural aspect in a well respective fashion in terms of the accurate power constraints of the node followed by the respective MIMO based strategy in a well efficient manner respectively. Experiments are conducted on the present method and its analysis based on the performance oriented strategy in a well efficient manner isdisplayed in the present phenomena respectively.

  9. Future View: Web Navigation based on Learning User's Browsing Strategy

    Science.gov (United States)

    Nagino, Norikatsu; Yamada, Seiji

    In this paper, we propose a Future View system that assists user's usual Web browsing. The Future View will prefetch Web pages based on user's browsing strategies and present them to a user in order to assist Web browsing. To learn user's browsing strategy, the Future View uses two types of learning classifier systems: a content-based classifier system for contents change patterns and an action-based classifier system for user's action patterns. The results of learning is applied to crawling by Web robots, and the gathered Web pages are presented to a user through a Web browser interface. We experimentally show effectiveness of navigation using the Future View.

  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. 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. PMID:24749460

  12. Activity-Based Information Integrating the operations strategy

    OpenAIRE

    José Augusto da Rocha de Araujo; Reinaldo Pacheco da Costa

    2005-01-01

    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 suffici...

  13. Long-Term Disaster-Prevention Strategies Based on Education

    OpenAIRE

    Musacchio, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia; Bernhardsdottir, A. E.; Earthquake Engineering Research Centre, Selfoss, Iceland; Ferreira, M. A.; Instituto Superior Tecnico, Portugal; Falsaperla, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; UPStrat-MAFA Outreach Working Group, .

    2014-01-01

    Although human behavior is the crucial factor in the degree of vulnerability and the likelihood of disasters taking place, preparedness and prevention programs are not mandatory in all countries around the world. Within the framework of UPStrat-MAFA (Urban disaster Prevention Strategies using MAcroseismic FAults), we have defined the disaster prevention strategies based on education management information and actions taken in Iceland, Portugal, Spain, and Italy. A detailed comparative study sh...

  14. An investigation of students' computer-based learning strategies

    OpenAIRE

    Di Paolo, Terry

    2002-01-01

    In recent decades, there has been a significant increase in the development and use of computer based learning technology in tertiary education. At the same time, researchers in the field of education have begun to develop an understanding of student learning in terms of learning strategies. Such constructs represent motives, behaviours and thought processes adopted by the student that are believed to mediate learning. This thesis investigates the learning strategies adopted by students using...

  15. Rights-based strategies in the prevention of domestic violence

    OpenAIRE

    Pradeep Kumar Panda

    2003-01-01

    This study is an attempt to broaden the discussion about the prevention of domestic violence against women informed by a rights-based strategy. Specifically, the study discusses the critical elements of a human rights framework to reduce domestic violence, present research findings on the prevalence and correlates of domestic violence in intimate relationships in Kerala, and explore strategies for the prevention of domestic violence on the basis of research and analysis.

  16. 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

  17. 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.

  18. Integrating Biologically Inspired Nanomaterials and Table-top Stereolithography for 3D Printed Biomimetic Osteochondral Scaffolds

    OpenAIRE

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

    2015-01-01

    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. I...

  19. 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...

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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....

  5. 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.

  6. 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.

  7. 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.

  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

    2016-01-01

    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. PMID:27556472

  10. 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。

  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. 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. 

  13. Service Strategies for Higher Educational Institutions Based on Student Segmentation

    Science.gov (United States)

    Ghosh, Amit K.; Javalgi, Rajshekhar; Whipple, Thomas W.

    2008-01-01

    Over the last decade, higher education institutions in the U.S. have faced increased competition and expenditures coupled with declines in financial support. Furthermore, they often have been forced to cater to the needs of an increasingly diverse group of students and must design service strategies based on the unique needs of each group. This…

  14. Design Strategies of Fluorescent Biosensors Based on Biological Macromolecular Receptors

    Directory of Open Access Journals (Sweden)

    Takashi Morii

    2010-02-01

    Full Text Available Fluorescent biosensors to detect the bona fide events of biologically important molecules in living cells are increasingly demanded in the field of molecular cell biology. Recent advances in the development of fluorescent biosensors have made an outstanding contribution to elucidating not only the roles of individual biomolecules, but also the dynamic intracellular relationships between these molecules. However, rational design strategies of fluorescent biosensors are not as mature as they look. An insatiable request for the establishment of a more universal and versatile strategy continues to provide an attractive alternative, so-called modular strategy, which permits facile preparation of biosensors with tailored characteristics by a simple combination of a receptor and a signal transducer. This review describes an overview of the progress in design strategies of fluorescent biosensors, such as auto-fluorescent protein-based biosensors, protein-based biosensors covalently modified with synthetic fluorophores, and signaling aptamers, and highlights the insight into how a given receptor is converted to a fluorescent biosensor. Furthermore, we will demonstrate a significance of the modular strategy for the sensor design.

  15. Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging

    Science.gov (United States)

    Ghassemi, Pejhman; Wang, Jianting; Melchiorri, Anthony J.; Ramella-Roman, Jessica C.; Mathews, Scott A.; Coburn, James C.; Sorg, Brian S.; Chen, Yu; Joshua Pfefer, T.

    2015-12-01

    The emerging technique of rapid prototyping with three-dimensional (3-D) printers provides a simple yet revolutionary method for fabricating objects with arbitrary geometry. The use of 3-D printing for generating morphologically biomimetic tissue phantoms based on medical images represents a potentially major advance over existing phantom approaches. Toward the goal of image-defined phantoms, we converted a segmented fundus image of the human retina into a matrix format and edited it to achieve a geometry suitable for printing. Phantoms with vessel-simulating channels were then printed using a photoreactive resin providing biologically relevant turbidity, as determined by spectrophotometry. The morphology of printed vessels was validated by x-ray microcomputed tomography. Channels were filled with hemoglobin (Hb) solutions undergoing desaturation, and phantoms were imaged with a near-infrared hyperspectral reflectance imaging system. Additionally, a phantom was printed incorporating two disjoint vascular networks at different depths, each filled with Hb solutions at different saturation levels. Light propagation effects noted during these measurements-including the influence of vessel density and depth on Hb concentration and saturation estimates, and the effect of wavelength on vessel visualization depth-were evaluated. Overall, our findings indicated that 3-D-printed biomimetic phantoms hold significant potential as realistic and practical tools for elucidating light-tissue interactions and characterizing biophotonic system performance.

  16. 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

  17. 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.

  18. Helicoidal microstructure of Scarabaei cuticle and biomimetic research

    Energy Technology Data Exchange (ETDEWEB)

    Chen, B. [Department of Engineering Mechanics, Chongqing University, Chongqing 400044 (China)]. E-mail: bchen@cqu.edu.cn; Peng, X. [Department of Engineering Mechanics, Chongqing University, Chongqing 400044 (China); Cai, C. [Department of Applied Physics, Chongqing University, Chongqing 400044 (China); Niu, H. [Department of Engineering Mechanics, Chongqing University, Chongqing 400044 (China); Wu, X. [Department of Engineering Mechanics, Chongqing University, Chongqing 400044 (China)

    2006-05-15

    Insect cuticles as a natural biocomposite include many favorable microstructures which have been refined over centuries and endow the cuticles excellent mechanical and physical properties, such as light weight, high strength and toughness, etc. The various microstructures of a Scarabaei cuticle are investigated with a scanning electronic microscope and reported in this paper. It is found that the cuticle is a kind of fiber-reinforced biocomposite composed of chitin-fiber layers and sclerous protein matrixes. Different chitin-fiber layers have different orientations, composed of crossed and helicoidal structures at different location. In the helicoidal structure, each fiber layer rotates with an almost fixed angle against its neighboring layer. The maximum pullout energy of the helicoidal structure is analyzed based on the representative model of the structure. The result shows that the pullout energy of the helicoidal structure is markedly larger than that of the conventional 0{sup o}-structure. A biomimetic composite with the observed helicoidal structure is designed and fabricated. A comparative test shows that the fracture toughness of the biomimetic composite is markedly larger than that of the 0{sup o}-layer composite.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. Carbon nitride nanosheet-supported porphyrin: a new biomimetic catalyst for highly efficient bioanalysis.

    Science.gov (United States)

    Deng, Shengyuan; Yuan, Peixin; Ji, Xubo; Shan, Dan; Zhang, Xueji

    2015-01-14

    A highly efficient biomimetic catalyst was fabricated based on ultrathin carbon nitride nanosheets (C3N4)-supported cobalt(II) proto-porphyrin IX (CoPPIX). The periodical pyridinic nitrogen units in C3N4 backbone could serve as electron donors for great affinity with Co(2+) in PPIX, which resembled the local electronic structure as vitamin B12 and heme cofactor of hemoglobin. UV-vis kinetics and electrochemistry revealed its competitive (electro)catalysis with conventional peroxidase, while X-ray photoelectron spectroscopy and theoretical calculations suggest that the rehybridization of Co 3d with N orbitals from the backside can result in significant changes in enthalpy and charge density, which greatly promoted the activity of CoPPIX. The prepared nanocatalyst was further conjugated with streptavidin via multiple amines on the edge plane of C3N4 for facile tagging. Using biotinylated molecular beacon as the capture probe, a sensitive electrochemiluminescence-based DNA assay was developed via the electroreduction of H2O2 as the coreactant after the hairpin unfolded by the target, exhibiting linearity from 1.0 fM to 0.1 nM and a detection limit of 0.37 fM. Our results demonstrate a new paradigm to rationally design inexpensive and durable biomimics for electrochemiluminescence quenching strategy, showing great promise in bioanalytical applications.

  4. 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

  5. Self-assembled Biodegradable Nanoparticles and Polysaccharides as Biomimetic ECM Nanostructures for the Synergistic effect of RGD and BMP-2 on Bone Formation.

    Science.gov (United States)

    Wang, Zhenming; Dong, Li; Han, Lu; Wang, Kefeng; Lu, Xiong; Fang, Liming; Qu, Shuxin; Chan, Chun Wai

    2016-01-01

    Producing biomimetic extracellular matrix (ECM) is an effective approach to improve biocompatibility of medical devices. In this study, biomimetic ECM nanostructures are constructed through layer-by-layer self-assembling positively charged chitosan (Chi), negatively charged oxidized sodium alginate (OAlg), and positively charged bovine serum albumin (BSA)-based nanoparticles. The BSA-based nanoparticles in the self-assembled films not only result in porous nanostructures similar to natural ECM, but also preserve the activity and realize the sustained release of Bone morphogenetic protein-2 (BMP-2). The results of bone marrow stem cells (BMSCs) culture demonstrate that the penta-peptide glycine-arginine-glycine-aspartate-serine (GRGDS) grafted Chi/OAlg films favor cell adhesion and proliferation. GRGDS and BMP-2 in biomimetic ECM nanostructures synergistically promote BMSC functions and new bone formation. The RGD and BMP incorporated biomimetic ECM coatings could be applied on a variety of biomedical devices to improve the bioactivity and biocompatibility. PMID:27121121

  6. Therapeutic strategies based on glucagon-like peptide 1

    DEFF Research Database (Denmark)

    Deacon, Carolyn F

    2004-01-01

    -lasting effects. GLP-1 is highly susceptible to enzymatic degradation in vivo, and cleavage by dipeptidyl peptidase IV (DPP-IV) is probably the most relevant, since this occurs rapidly and generates a noninsulinotropic metabolite. Strategies for harnessing GLP-1's therapeutic potential, based on an understanding...... of factors influencing its metabolic stability and pharmacokinetic/pharmacodynamic profile, have therefore been the focus of intense research in both academia and the pharmaceutical industry. Such strategies include DPP-IV-resistant GLP-1 analogs and selective enzyme inhibitors to prevent in vivo degradation...

  7. REPLICATION STRATEGY BASED ON DATA RELATIONSHIP IN GRID COMPUTING

    Directory of Open Access Journals (Sweden)

    Yuhanis Yusof

    2013-11-01

    Full Text Available This study discusses the utilization of three types of relationships in performing data replication. As grid computing offers the ability of sharing huge amount of resources, resource availability is an important issue to be addressed. The undertaken approach combines the viewpoint of user, system and the grid itself in ensuring resource availability. The realization of the proposed strategy is demonstrated via OptorSim and evaluation is made based on execution time, storage usage, network bandwidth and computing element usage. Results suggested that the proposed strategy produces a better outcome than an existing method even though various job workload is introduced.

  8. Biomimetic cardiovascular stents for in vivo re-endothelialization.

    Science.gov (United States)

    Liang, Chunyong; Hu, Yuecheng; Wang, Hongshui; Xia, Dan; Li, Qiang; Zhang, Jiao; Yang, Jianjun; Li, Baoe; Li, Haipeng; Han, Dong; Dong, Mingdong

    2016-10-01

    The use of cardiovascular stents for rapid in vivo re-endothelialization is a promising strategy for reducing cardiovascular implantation or preventing local thrombus formation and restenosis. Surface-patterned intravascular endoprosthetic stents have been developed to prevent life-threatening complications. In this study, vascular smooth muscle cell (VSMC)-biomimetic surface patterns were fabricated on 316L cardiovascular stents using a femtosecond laser and then implanted into the iliac artery of rabbit. The in vitro data revealed that the bionic surface patterns matched the morphology of the VSMCs well, which promotes the adhesion, proliferation, and migration of human umbilical vein endothelial cells. In addition, the patterned surfaces can significantly enhance re-endothelialization. Consequently, the surface biomimetic stent with the VSMC surface pattern is likely an effective approach to ensure rapid re-endothelialization and possibly reduce the incidence of in-stent restenosis. PMID:27380443

  9. From natural to bioassisted and biomimetic artificial water channel systems.

    Science.gov (United States)

    Barboiu, Mihail; Gilles, Arnaud

    2013-12-17

    Within biological systems, natural channels and pores transport metabolites across the cell membranes. Researchers have explored artificial ion-channel architectures as potential mimics of natural ionic conduction. All these synthetic systems have produced an impressive collection of alternative artificial ion-channels. Amazingly, researchers have made far less progress in the area of synthetic water channels. The development of synthetic biomimetic water channels and pores could contribute to a better understanding of the natural function of protein channels and could offer new strategies to generate highly selective, advanced water purification systems. Despite the imaginative work by synthetic chemists to produce sophisticated architectures that confine water clusters, most synthetic water channels have used natural proteins channels as the selectivity components, embedded in the diverse arrays of bioassisted artificial systems. These systems combine natural proteins that present high water conductance states under natural conditions with artificial lipidic or polymeric matrixes. Experimental results have demonstrated that natural biomolecules can be used as bioassisted building blocks for the construction of highly selective water transport through artificial membranes. A next step to further the potential of these systems was the design and construction of simpler compounds that maintain the high conduction activity obtained with natural compounds leading to fully synthetic artificial biomimetic systems. Such studies aim to use constitutional selective artificial superstructures for water/proton transport to select functions similar to the natural structures. Moving to simpler water channel systems offers a chance to better understand mechanistic and structural behaviors and to uncover novel interactive water-channels that might parallel those in biomolecular systems. This Account discusses the incipient development of the first artificial water channels

  10. 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.

  11. 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).

  12. 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.

  13. 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.

  14. 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.

  15. Fabrication of a biomimetic adsorbent imprinted with a common specificity determinant for the removal of α- and β-amanitin from plasma.

    Science.gov (United States)

    Tan, Lei; He, Rong; Li, Yongxian; Liang, Yong; Li, He; Tang, Youwen

    2016-08-12

    α-Amanitin and β-amanitin are the main toxins of mushroom poisoning. The application of traditional non-selective adsorbents is not satisfactory in clinical treatment of amanita mushroom poisoning due to lack of specificity adsorption capability of these adsorbents toward amanitin toxins. In the current work, we introduce a novel molecularly imprinted biomimetic adsorbent based on a ligand specificity determinant through surface imprinted strategy. Owing to the expensive price of the amanitin sources, we selected a typical common moiety of α, β-amanitin as specificity determinant to synthesize a template necessary for the preparation of molecularly imprinted polymers (MIPs). Computer simulation was used to initially select acidic methacrylic acid (MAA) and basic 4-vinyl pyridine (4-VP) together as functional monomers. The experiments further demonstrated that the synergistic interaction of MAA and 4-VP played a primary role in the recognition of α, β-amanitin by MIPs. By means of batch and packed-bed column experiment and the hemocompatibility evaluation, the resultant biomimetic adsorbent has been proved to be capable of selectively removing α, β-amanitin and possess good hemocompatibility. This novel adsorbent has great potential to find application in human plasma purification. PMID:27394089

  16. Action of Chicory Fructooligosaccharides on Biomimetic Membranes

    OpenAIRE

    Barbosa, A. F.; Henrique, R. S.; A. S. Lucho; V. Paffaro; J.M. Schneedorf

    2014-01-01

    Fructooligosaccharides from chicory (FOSC) are functional prebiotic foods recognized to exert several well-being effects in human health and animal production, as decreasing blood lipids, modulating the gut immune system, enhancing mineral bioavailability, and inhibiting microbial growth, among others. Mechanisms of actions directly on cell metabolism and structure are however little known. In this sense this work was targeted to investigate the interaction of FOSC with biomimetic membranes (...

  17. Design of graded biomimetic osteochondral composite scaffolds

    OpenAIRE

    Tampieri, Anna; Sandri, Monica; Landi, Elena; Pressato, Daniele; Francioli, Silvia; Quarto, Rodolfo; Martin, Ivan

    2008-01-01

    With the ultimate goal to generate suitable materials for the repair of osteochondral defects, in this work we aimed at developing composite osteochondral scaffolds organized in different integrated layers, with features which are biomimetic for articular cartilage and subchondral bone and can differentially support formation of such tissues. A biologically inspired mineralization process was first developed to nucleate Mg-doped hydroxyapatite crystals on type I collagen fibers during their s...

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

    Science.gov (United States)

    Seinfeld, Sofia; Sanchez-Vives, Maria V

    2015-10-01

    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.

  19. 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.

  20. Biomimetic anchors applied to the host-guest antifouling functionalization of titanium substrates.

    Science.gov (United States)

    Cai, Xiao Yan; Li, Ning Ning; Chen, Jiu Cun; Kang, En-Tang; Xu, Li Qun

    2016-08-01

    A biomimetic strategy was developed for the construction of antifouling titanium oxide (Ti(oxide)) surfaces based on host-guest interactions. Two catecholic derivatives, dopamine 4-(phenylazo)benzamide (AZODopa) and dopamine 1-adamantanecarboxamide (AdaDopa) were synthesized and immobilized onto the Ti(oxide) surfaces. The guest molecules-anchored Ti(oxide) surfaces were further functionalized with zwitterionic heptakis[6-deoxy-6-(N-3-sulfopropyl-N,N-dimethylammonium ethyl sulfanyl)]-β-cyclodextrin (SBCD) and hydrophilic β-CD polymer (CDP). The surface elemental compositions and hydrophobic/hydrophilic properties of the Ti(oxide) surfaces before and after modification were characterized by X-ray photoelectron spectroscopy (XPS) and static water contact angle measurements, respectively. The antifouling properties of the modified Ti(oxide) surfaces were evaluated by the protein adsorption and bacterial adhesion assays. The zwitterionic SBCD- and hydrophilic CDP-functionalized Ti(oxide) surfaces can reduce the adsorption of bovine plasma fibrinogen and adhesion of Escherichia coli, as compared to the pristine and guest molecules-anchored Ti(oxide) surfaces. PMID:27135943

  1. Synthetic nanoparticles camouflaged with biomimetic erythrocyte membranes for reduced reticuloendothelial system uptake

    Science.gov (United States)

    Rao, Lang; Xu, Jun-Hua; Cai, Bo; Liu, Huiqin; Li, Ming; Jia, Yan; Xiao, Liang; Guo, Shi-Shang; Liu, Wei; Zhao, Xing-Zhong

    2016-02-01

    Suppression of the reticuloendothelial system (RES) uptake is one of the most challenging tasks in nanomedicine. Coating stratagems using polymers, such as poly(ethylene glycol) (PEG), have led to great success in this respect. Nevertheless, recent observations of immunological response toward these synthetic polymers have triggered a search for better alternatives. In this work, natural red blood cell (RBC) membranes are camouflaged on the surface of Fe3O4 nanoparticles for reducing the RES uptake. In vitro macrophage uptake, in vivo biodistribution and pharmacokinetic studies demonstrate that the RBC membrane is a superior alternative to the current gold standard PEG for nanoparticle ‘stealth’. Furthermore, we systematically investigate the in vivo potential toxicity of RBC membrane-coated nanoparticles by blood biochemistry, whole blood panel examination and histology analysis based on animal models. The combination of synthetic nanoparticles and natural cell membranes embodies a novel and biomimetic nanomaterial design strategy and presents a compelling property of functional materials for a broad range of biomedical applications.

  2. 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.

  3. Local Economic Development Strategy Based on Localindustrial Core Competence

    OpenAIRE

    Rahab Bintara; Najmudin Najmudin; Istiqomah Istiqomah

    2013-01-01

    Local economy can be promoted through the development of small and medium industries by building up localindustrial core competence. Local core competence is one of the strategies to increase local competitiveadvantage through the optimization of local competitive potency. This study was aimed at drafting the strategyof local economic development through local industrial core competence based on competitive commodities ofBanyumas district.This study employed qualitative as well as quantitativ...

  4. 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.

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

    OpenAIRE

    Deng-yin Zhang; Min Yang; Lei Cui

    2014-01-01

    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 t...

  6. Launch strategy for a GPS-based package tracker product

    OpenAIRE

    Biermann, Jürgen

    2006-01-01

    The objective of this paper is to present a recommendation for a launch strategy for a new Package Tracker Product based on enhanced GPS location technology for a GPS software company, Guardian Mobile Monitoring Systems. We will first give an overview of Global Positioning System (GPS) technology and its more recent advancements and explain the potential for a package tracker product. Secondly, we will examine possible target market segments. Thirdly, we will perform an internal analysis of G...

  7. Cell-Based Strategies for Meniscus Tissue Engineering

    OpenAIRE

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

    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 ...

  8. Oligonucleotide-based strategies to combat polyglutamine diseases

    OpenAIRE

    Fiszer, Agnieszka; Krzyzosiak, Wlodzimierz J.

    2014-01-01

    Considerable advances have been recently made in understanding the molecular aspects of pathogenesis and in developing therapeutic approaches for polyglutamine (polyQ) diseases. Studies on pathogenic mechanisms have extended our knowledge of mutant protein toxicity, confirmed the toxicity of mutant transcript and identified other toxic RNA and protein entities. One very promising therapeutic strategy is targeting the causative gene expression with oligonucleotide (ON) based tools. This straig...

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

    OpenAIRE

    Hongtao Liu; Lianglun Cheng

    2012-01-01

    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 retrans...

  10. Simulation of Biomimetic Recognition between Polymers and Surfaces

    Science.gov (United States)

    Golumbfskie, Aaron J.; Pande, Vijay S.; Chakraborty, Arup K.

    1999-10-01

    Many biological processes, such as transmembrane signaling and pathogen-host interactions, are initiated by a protein recognizing a specific pattern of binding sites on part of a membrane or cell surface. By recognition, we imply that the polymer quickly finds and then adsorbs strongly on the pattern-matched region and not on others. The development of synthetic systems that can mimic such recognition between polymers and surfaces could have significant impact on advanced applications such as the development of sensors, molecular-scale separation processes, and synthetic viral inhibition agents. Attempting to affect recognition in synthetic systems by copying the detailed chemistries to which nature has been led over millenia of evolution does not seem practical for most applications. This leads us to the following question: Are there any universal strategies that can affect recognition between polymers and surfaces? Such generic strategies may be easier to implement in abiotic applications. We describe results that suggest that biomimetic recognition between synthetic polymers and surfaces is possible by exploiting certain generic strategies, and we elucidate the kinetic mechanisms by which this occurs. Our results suggest convenient model systems for experimental studies of dynamics in free energy landscapes characteristic of frustrated systems.

  11. Time and volume based optimal pricing strategies for telecommunication networks

    OpenAIRE

    Kasap, Nihat

    2008-01-01

    In the recent past, there have been several initiatives by major network providers such as Turk Telekom lead the industry towards network capacity distribution in Turkey. In this study, we use a monopoly pricing model to examine the optimal pricing strategies for “pay-per-volume” and “pay-per-time” based leasing of data networks. Traditionally, network capacity distribution includes short/long term bandwidth and/or usage time leasing. Each consumer has a choice to select volume based pricing ...

  12. 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.

  13. 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. PMID:27577464

  14. 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 

  15. 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.

  16. [Staging Based Strategies and Practice for Prostate Cancer].

    Science.gov (United States)

    Chen, Zhi-qiang; Wang, Shu-sheng; Bai, Zun-guang; Wang, Zhao-hui; Lv, Li-guo; Gu, Chi-ming; Xiang, Song-tao; Dai, Rui-xin; Zhu, Shou-lun

    2016-06-01

    Authors raised that staging based strategies and practice of integrative medicine (IM) by combining syndrome typing and disease identification, and choosing suitable measures in accordance with different persons and seasonal conditions after more than ten years' clinical practice and researches. Radical operation as prior (as evil eliminating) and strengthening vital qi in perioerative period are best strategy for promoting rapid rehabilitation of early stage prostate cancer patients. Strengthening body resistance to eliminate evil was used in treating advanced prostate cancer patients. For example, a comprehensive treatment program for hormone-dependent patients was combined with endocrinotherapy and Chinese herbs for synergisic efficacy-enhancing actions. In this way, these patients' quality of life (QOL) were improved and time to castration resistant prostate cancer (CRPC) was delayed, even some patients were clinically cured. There are lack of effective medicines and methods for CRPC patients. Greatly tonifying original qi is mainly used for improving their clinical symptoms and prolonging survivals. Practice has proved staging based strategies and practice of IM has favorable advantages in treating prostate cancer, especially showing prospect in prolonging survival and postponing progression of advanced prostate cancer patients. Besides, it also could provide beneficial considerations and inspiration for combination of syndrome typing and disease identification. PMID:27491237

  17. View-based strategy for reorientation by geometry.

    Science.gov (United States)

    Pecchia, Tommaso; Vallortigara, Giorgio

    2010-09-01

    Human and non-human animals can use geometric information (metric information and left-right discrimination sense) to reorient themselves in an environment. The hypothesis that in so doing they rely on allocentric (map-like) representations has received wide consensus. However, theoretical models suggest that egocentric representations may represent efficient strategies for visuo-spatial navigation. Here, we provide, for the first time, evidence that a view-based strategy is effectively used by animals to reorient themselves in an array of landmarks. Domestic chicks were trained to locate a food-reward in a rectangular array of either four indistinguishable or distinctive pipes. In the key experimental series, the pipes had four openings, only one of which allowed the chicks to access the reward. The direction of the open access relative to the array was either maintained stable or it was changed throughout training. The relative position of the pipes in the array was maintained stable in both training conditions. Chicks reoriented according to configural geometry as long as the open access pointed in the same direction during training but failed when the positions of the openings was changed throughout training. When the correct pipe was characterized by a distinctive featural cue, chicks learnt to locate the reward irrespective of the stability of the direction to openings, indicating that place-navigation was dissociated from non-spatial learning. These findings provide evidence that view-based strategies to reorient by geometry could be used by animals. PMID:20709927

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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. PMID:27142155

  3. 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.

  4. 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.

  5. Locomotion Performance of Biomimetic Fish-like Swimming Devices

    Science.gov (United States)

    Epps, Brenden P.; Valdivia Y Alvarado, Pablo; Techet, Alexandra H.

    2007-11-01

    The swimming performance of a biomimetic, fish-like swimming device, designed to exploit the natural dynamics of its compliant body to achieve locomotion, is studied experimentally. A theoretical model combines beam-bending stress analysis and unsteady hydrodynamic forcing with known material properties of the robot to reveal desired geometry distributions and actuation modes. Swimming kinematics and corresponding performance of the device are also predicted and tested for a carangiform prototype device in a quiescent tank of water. Experimental swimming tests show good agreement with the simplified theoretical models. The hydrodynamic characteristics of the wake behind the device are investigated using time-resolved particle imaging velocimetry (PIV) over a range of tail beat frequencies, from 1 to 4 Hz, to asses vortical wake patterns and hydrodynamic forces. PIV data are compared to theoretical model predictions. Reynolds numbers for the swimming device are between 2500 and 8500 based on body length.

  6. CPG Network Optimization for a Biomimetic Robotic Fish via PSO.

    Science.gov (United States)

    Yu, Junzhi; Wu, Zhengxing; Wang, Ming; Tan, Min

    2016-09-01

    In this brief, we investigate the parameter optimization issue of a central pattern generator (CPG) network governed forward and backward swimming for a fully untethered, multijoint biomimetic robotic fish. Considering that the CPG parameters are tightly linked to the propulsive performance of the robotic fish, we propose a method for determination of relatively optimized control parameters. Within the framework of evolutionary computation, we use a combination of dynamic model and particle swarm optimization (PSO) algorithm to seek the CPG characteristic parameters for an enhanced performance. The PSO-based optimization scheme is validated with extensive experiments conducted on the actual robotic fish. Noticeably, the optimized results are shown to be superior to previously reported forward and backward swimming speeds. PMID:26259223

  7. 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

    2016-01-01

    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. PMID:27529208

  8. 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.

  9. The Design and Implementation of a Biomimetic Robot Fish

    Directory of Open Access Journals (Sweden)

    Chao Zhou

    2008-11-01

    Full Text Available In this paper, a novel design of a biomimetic robot fish is presented. Based on the propulsion and maneuvering mechanisms of real fishes, a tail mechanical structure with cams and connecting rods for fitting carangiform fish body wave is designed, which provides the main propulsion. Two pectoral fins are mounted, and each pectoral fin can flap separately and rotate freely. Coordinating the movements of the tail and pectoral fins, the robot fish can simulate the movements of fishes in water. In order to obtain the necessary environmental information, several kinds of sensors (video, infrared, temperature, pressure and PH value sensors were mounted. Finally, the realization of the robot fish is presented.

  10. 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.

  11. 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.

  12. Robust High Performance Aquaporin based Biomimetic Membranes

    DEFF Research Database (Denmark)

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

    2013-01-01

    -free ABMs that can be easily scaled up. We have constructed robust thin film composite (TFC) ABMs with surface areas up to 600 cm2 prepared by interfacial polymerization where Aquaporin Z-containing proteoliposomes were added to a m-phenylene-diamine aqueous solution thereby creating a polymer-rich film...

  13. A small biomimetic quadruped robot driven by multistacked dielectric elastomer actuators

    Science.gov (United States)

    Nguyen, Canh Toan; Phung, Hoa; Dat Nguyen, Tien; Lee, Choonghan; Kim, Uikyum; Lee, Donghyouk; Moon, Hyungpil; Koo, Jachoon; Nam, Jae-do; Ryeol Choi, Hyouk

    2014-06-01

    A kind of dielectric elastomer (DE) material, called ‘synthetic elastomer’, has been developed based on acrylonitrile butadiene rubber (NBR) to be used as a dielectric elastomer actuator (DEA). By stacking single layers of synthetic elastomer, a linear actuator, called a multistacked actuator, is produced, and used by mechatronic and robotic systems to generate linear motion. In this paper, we demonstrate the application of the multistacked dielectric elastomer actuator in a biomimetic legged robot. A miniature robot driven by a biomimetic actuation system with four 2-DOF (two-degree-of-freedom) legged mechanisms is realized. Based on the experimental results, we evaluate the performance of the proposed robot and validate the feasibility of the multistacked actuator in a locomotion system as a replacement for conventional actuators.

  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

    2014-10-01

    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 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. A small biomimetic quadruped robot driven by multistacked dielectric elastomer actuators

    International Nuclear Information System (INIS)

    A kind of dielectric elastomer (DE) material, called ‘synthetic elastomer’, has been developed based on acrylonitrile butadiene rubber (NBR) to be used as a dielectric elastomer actuator (DEA). By stacking single layers of synthetic elastomer, a linear actuator, called a multistacked actuator, is produced, and used by mechatronic and robotic systems to generate linear motion. In this paper, we demonstrate the application of the multistacked dielectric elastomer actuator in a biomimetic legged robot. A miniature robot driven by a biomimetic actuation system with four 2-DOF (two-degree-of-freedom) legged mechanisms is realized. Based on the experimental results, we evaluate the performance of the proposed robot and validate the feasibility of the multistacked actuator in a locomotion system as a replacement for conventional actuators. (paper)

  16. Resource-based learning strategies: implications for students and institutions

    Directory of Open Access Journals (Sweden)

    Malcolm Ryan

    1996-12-01

    Full Text Available In its strategic plan, the University of Greenwich envisages a significant shift to resource-based learning (RBL. Enterprise in Higher Education (EHE has funded five pilot RBL projects during the past year, including one in introductory economics. The project was managed by three lecturers in the School of Social Sciences, supported by an Academic Development Officer. Learning outcomes were completely revised, and a range of assessment strategies, including computer-based tests, was identified. A resources guide was produced which identified the materials and activities that would enable students to achieve the learning outcomes. A number of innovations were adopted, including: • computer-based curriculum delivery, assessment, and student evaluation of the course; • an open approach to assessment; • abolishing lectures in favour of a diverse range of teaching and learning activities.

  17. 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.

  18. 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.

  19. 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.

  20. Conservation Strategies for Kavandi Lake Based on Water Quality

    OpenAIRE

    D. D. Bhutekar; S. B. Aher; M. G. Babare

    2014-01-01

    Kavandi Lake (located at 18° 07’ N, 75° 37’ E, 530 m above MSL, in Ambad town, Maharashtra, India) was constructed by Devi Ahilyabai Holkar to fulfill the demand of drinking water for Ambad town. The physico-chemical and ecological study of the water body was conducted to assess the present status of water quality and to suggest the conservation strategies based on the findings. In order to determine the water quality, samples were collected monthly during 2012-13 from five different sampling...

  1. 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).

  2. Triangular prism-shaped β-peptoid helices as unique biomimetic scaffolds

    DEFF Research Database (Denmark)

    Laursen, Jonas Striegler; Harris, Pernille; Fristrup, Peter;

    2015-01-01

    β-Peptoids are peptidomimetics based on N-alkylated β-aminopropionic acid residues (or N-alkyl-β-alanines). This type of peptide mimic has previously been incorporated in biologically active ligands and has been hypothesized to be able to exhibit foldamer properties. Here we show, for the first t...... novel biomimetics that display functional groups with high accuracy in three dimensions, which has potential for development of new functional materials....

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

    OpenAIRE

    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 use...

  4. Biomimetic synthesis for precursor of muscone

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Muscone is a precious fragrant compound scarce in nature. Many attempts have been made to synthesize this unique natural product. In this work, the one- carbon unit transfer reaction of tetrahydrofolate coenzyme was initiated. Benzimidazolium salt was used as the tetrahydrofolate coenzyme model at formic acid oxidation level and di-Grignard reagent as the nucleophile to which one-carbon unit was transferred; the biomimetic synthesis of 2,15- hexade-canedione, a precursor of muscone, was successfully accomplished by using the addition-hydrolysis reaction of benzimidazolium salt with Grignard reagent. And an impor-tant useful method for the synthesis of muscone is provided.

  5. 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.

  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. Effect of urea on biomimetic aggregates

    Directory of Open Access Journals (Sweden)

    F.H. Florenzano

    1997-02-01

    Full Text Available The effect of urea on biomimetic aggregates (aqueous and reversed micelles, vesicles and monolayers was investigated to obtain insights into the effect of the denaturant on structured macromolecules. Direct evidence obtained from light scattering (static and dynamic, monolayer maximum isothermal compression and ionic conductivity measurements, together with indirect evidence from fluorescence photodissociation, fluorescence suppression, and thermal reactions, strongly indicates the direct interaction mechanism of urea with the aggregates. Preferential solvation of the surfactant headgroups by urea results in an increase in the monomer dissociation degree (when applied, which leads to an increase in the area per headgroup and also in the loss of counterion affinities

  8. Effect of urea on biomimetic aggregates.

    Science.gov (United States)

    Florenzano, F H; Politi, M J

    1997-02-01

    The effect of urea on biomimetic aggregates (aqueous and reversed micelles, vesicles and monolayers) was investigated to obtain insights into the effect of the denaturant on structured macromolecules. Direct evidence obtained from light scattering (static and dynamic), monolayer maximum isothermal compression and ionic conductivity measurements, together with indirect evidence from fluorescence photodissociation, fluorescence suppression, and thermal reactions, strongly indicates the direct interaction mechanism of urea with the aggregates. Preferential solvation of the surfactant headgroups by urea results in an increase in the monomer dissociation degree (when applied), which leads to an increase in the area per headgroup and also in the loss of counterion affinities. PMID:9239302

  9. Bioactive Gyroid Scaffolds Formed by Sacrificial Templating of Nanocellulose and Nanochitin Hydrogels as Instructive Platforms for Biomimetic Tissue Engineering

    OpenAIRE

    Torres-Rendon, Jose Guillermo; Femmer, Tim; De Laporte, Laura; Tigges, Thomas; Rahimi, Khoshrow; Gremse, Felix; Zafarnia, Sara; Lederle, Wiltrud; Ifuku, Shinsuke; Wessling, Matthias; Hardy, John G.; Walther, Andreas

    2015-01-01

    A sacrificial templating process using lithographically printed minimal surface structures allows complex de novo geometries of delicate hydrogel materials. The hydrogel scaffolds based on cellulose and chitin nanofibrils show differences in terms of attachment of human mesenchymal stem cells, and allow their differentiation into osteogenic outcomes. The approach here serves as a first example toward designer hydrogel scaffolds viable for biomimetic tissue engineering.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Warped document image correction method based on heterogeneous registration strategies

    Science.gov (United States)

    Tong, Lijing; Zhan, Guoliang; Peng, Quanyao; Li, Yang; Li, Yifan

    2013-03-01

    With the popularity of digital camera and the application requirement of digitalized document images, using digital cameras to digitalize document images has become an irresistible trend. However, the warping of the document surface impacts on the quality of the Optical Character Recognition (OCR) system seriously. To improve the warped document image's vision quality and the OCR rate, this paper proposed a warped document image correction method based on heterogeneous registration strategies. This method mosaics two warped images of the same document from different viewpoints. Firstly, two feature points are selected from one image. Then the two feature points are registered in the other image base on heterogeneous registration strategies. At last, image mosaics are done for the two images, and the best mosaiced image is selected by OCR recognition results. As a result, for the best mosaiced image, the distortions are mostly removed and the OCR results are improved markedly. Experimental results show that the proposed method can resolve the issue of warped document image correction more effectively.

  15. 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…

  16. 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 ...

  17. 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.

  18. Developing a Comprehensive Search Strategy for Evidence Based Systematic Reviews

    Directory of Open Access Journals (Sweden)

    Sekhar Thadiparthi

    2008-03-01

    % MEDLINE, 18% PsycINFO, 8% EMBASE, 2% Sociological Abstracts.Conclusions ‐ Development of a comprehensive review of the literature requires searching multiple databases and methods of manual searching in order to locate all relevant citations. Understanding the project needs, recognizing the limitations and strengths of specific electronic databases, and being aware of other methods for developing and refining a search are vital in planning an effective and comprehensive search strategy. Reporting standards for literature searches as part of the broader push for procedurally transparent and reproducible systematic reviews is not only advisable, but good evidence based practice.

  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. 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.

  1. 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.

  2. Arg-Gly-Asp (RGD) Modified Biomimetic Polymeric Materials

    Institute of Scientific and Technical Information of China (English)

    Xufeng NIU; Yuanliang WANG; Yanfeng LUO; Juan XIN; Yonggang LI

    2005-01-01

    The new generation of biomaterials focuses on the design of biomimetic polymeric materials that are capable of eliciting specific cellular responses and directing new tissue formation. Since Arg-Gly-Asp (RGD) sequences have been found to promote cell adhesion in 1984, numerous polymers have been functionalized with RGD peptides for tissue engineering applications. This review gave the advance in RGD modified biomimetic polymeric materials,focusing on the mechanism of RGD, the surface and bulk modification of polymer with RGD peptides and the evaluation in vitro and in vivo of the modified biomimetic materials.

  3. 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...

  4. 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...

  5. Biomimetic multifunctional surfaces inspired from animals.

    Science.gov (United States)

    Han, Zhiwu; Mu, Zhengzhi; Yin, Wei; Li, Wen; Niu, Shichao; Zhang, Junqiu; Ren, Luquan

    2016-08-01

    Over millions of years, animals have evolved to a higher intelligent level for their environment. A large number of diverse surface structures on their bodies have been formed to adapt to the extremely harsh environment. Just like the structural diversity existed in plants, the same also applies true in animals. Firstly, this article provides an overview and discussion of the most common functional surface structures inspired from animals, such as drag reduction, noise reduction, anti-adhesion, anti-wear, anti-erosion, anti-fog, water capture, and optical surfaces. Then, some typical characteristics of morphologies, structures, and materials of the animal multifunctional surfaces were discussed. The adaptation of these surfaces to environmental conditions was also analyzed. It mainly focuses on the relationship between their surface functions and their surface structural characteristics. Afterwards, the multifunctional mechanisms or principles of these surfaces were discussed. Models of these structures were provided for the development of structure materials and machinery surfaces. At last, fabrication techniques and existing or potential technical applications inspired from biomimetic multifunctional surfaces in animals were also discussed. The application prospects of the biomimetic functional surfaces are very broad, such as civil field of self-cleaning textile fabrics and non-stick pots, ocean field of oil-water separation, sports field of swimming suits, space development field of lens arrays. PMID:27085632

  6. Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications.

    Science.gov (United States)

    Barthlott, W; Mail, M; Neinhuis, C

    2016-08-01

    A comprehensive survey of the construction principles and occurrences of superhydrophobic surfaces in plants, animals and other organisms is provided and is based on our own scanning electron microscopic examinations of almost 20 000 different species and the existing literature. Properties such as self-cleaning (lotus effect), fluid drag reduction (Salvinia effect) and the introduction of new functions (air layers as sensory systems) are described and biomimetic applications are discussed: self-cleaning is established, drag reduction becomes increasingly important, and novel air-retaining grid technology is introduced. Surprisingly, no evidence for lasting superhydrophobicity in non-biological surfaces exists (except technical materials). Phylogenetic trees indicate that superhydrophobicity evolved as a consequence of the conquest of land about 450 million years ago and may be a key innovation in the evolution of terrestrial life. The approximate 10 million extant species exhibit a stunning diversity of materials and structures, many of which are formed by self-assembly, and are solely based on a limited number of molecules. A short historical survey shows that bionics (today often called biomimetics) dates back more than 100 years. Statistical data illustrate that the interest in biomimetic surfaces is much younger still. Superhydrophobicity caught the attention of scientists only after the extreme superhydrophobicity of lotus leaves was published in 1997. Regrettably, parabionic products play an increasing role in marketing.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. PMID:27354736

  7. 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

  8. Conservation Strategies for Kavandi Lake Based on Water Quality

    Directory of Open Access Journals (Sweden)

    D. D. Bhutekar

    2014-08-01

    Full Text Available Kavandi Lake (located at 18° 07’ N, 75° 37’ E, 530 m above MSL, in Ambad town, Maharashtra, India was constructed by Devi Ahilyabai Holkar to fulfill the demand of drinking water for Ambad town. The physico-chemical and ecological study of the water body was conducted to assess the present status of water quality and to suggest the conservation strategies based on the findings. In order to determine the water quality, samples were collected monthly during 2012-13 from five different sampling points and analyzed for pH, EC, BOD, DO, COD, phosphates, nitrates etc. Present investigation revealed that, the urban development in the town led adverse changes in the physico-chemical and ecological characteristics of lake water. The discharge of sewage, the agricultural and urban runoff and dumping of solid waste deteriorated the water quality of lake and it is getting enriched with plant nutrients and other pollutants, becoming more and more infested with macrophytes, getting slowly shallower and shallower and shrinking gradually in size. In conclusion, the water is moderately polluted and unfit for drinking purpose without any treatment. The eutrophic condition affected the aesthetic value of lake. The best suggested strategies among conservation of lake on the basis of conducted study includes prevention of pollution, lake cleaning by de-silting, de-weeding, bioremediation, public awareness and public participation.

  9. On the partitioning strategy based on symmetry transformations

    Science.gov (United States)

    Noor, Ahmed K.; Peters, J. M.; Chien, L. S.

    1990-01-01

    A computational procedure is presented for the analysis of unsymmetric structures. The procedure is based on a modified version of the symmetry-transformation partitioning strategy, in which the response of the structure is approximated by a linear combination of symmetric/antisymmetric response vectors, each obtained by using only a fraction of the degrees of freedom of the original FEM model. The three key elements of the procedure are: (1) mixed (or primitive-variable) formulation with independent shape functions for the different fields; (2) restructuring of the governing discrete equations of the structure into uncoupled sets in the symmetric and antisymmetric response vectors; and (3) a stable and efficient iterative process for generating the response of the structure. The effectiveness of the proposed procedure and its advantages over classical substructuring are demonstrated by means of numerical examples.

  10. 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.

  11. Development and Application of Aphosphoproteomic Strategy Based Ontitanium Dioxideaffinity Chromatography

    Institute of Scientific and Technical Information of China (English)

    Mingquan Guo

    2012-01-01

    A sensitive and highly selective phosphoproteomic strategy,which allows simultaneous genome and transcriptome profiling from a single sample,has been developed by a combination of a highly selective titanium dioxide (TiO2)-based phosphopeptide enrichment method and a TRIzol-based protein extraction method.To establish more efficient phosphopeptide enrichment methods for complex cellular proteins,TiO2 method was comparedwith the most widely used IMAC method using model peptide mixturesbased on two criteria:one is the efficacy of the phosphopeptide enrichment (how many phosphopeptides each method can capture),and the other is the extent of exclusion of nonphosphopeptides from the pool of enriched phosphopeptides.The results indicate that the TiO2 enrichment method appears to be more effective than the IMAC method.This methodology was then further applied to the phosphoproteomic analysis of a small number of HeLa cells with and without calyculin A (CL-A) treatment.Significant increases in the number of identified phosphopeptides and phosphosites were observed in the CL-A-treated samples compared with nontreated samples as expected in the biological studies.Meanwhile,some novel phosphorylation sites,such as T19 and S20 of the myosin regulatory light chain and S116 and S379 in the heterogeneous nuclear ribonucleoprotein K transcript variant in the CL-A-treated samples,were revealed as well.Thus,the robustness,generality,and simplicity of this strategy should enable this methodology to find broad applications for phosphoproteomic analyses in systems biology,especially in cases of limited starting material requiring a systems-level analysis such as small clinical specimens.

  12. Advantages of the Biomimetic Nanostructured Films as an Immobilization Method vs. the Carbon Paste Classical Method

    Directory of Open Access Journals (Sweden)

    Maria Luz Rodríguez-Méndez

    2012-11-01

    Full Text Available Tyrosinase-based biosensors containing a phthalocyanine as electron mediator have been prepared by two different methods. In the first approach, the enzyme and the electron mediator have been immobilized in carbon paste electrodes. In the second method, they have been introduced in an arachidic acid Langmuir-Blodgett nanostructured film that provides a biomimetic environment. The sensing properties of non-nanostructured and nanostructured biosensors towards catechol, catechin and phenol have been analyzed and compared. The enzyme retains the biocatalytic properties in both matrixes. However, the nanostructured biomimetic films show higher values of maximum reaction rates and lowest apparent Michaelis-Menten constants. In both types of sensors, the sensitivity follows the decreasing order catechol > catechin > phenol. The detection limits observed are in the range of 1.8–5.4 μM for Langmuir-Blodgett biosensors and 8.19–8.57 μM for carbon paste biosensors. In summary, it has been demonstrated that the Langmuir-Blodgett films provide a biomimetic environment and nanostructured biosensors show better performances in terms of kinetic, detection limit and stability.

  13. 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.

  14. 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. PMID:10409946

  15. A review paper on biomimetic calcium phosphate coatings

    OpenAIRE

    Lin, X.; De Groot,, P.A.J.; Wang, D.; Hu, Q; Wismeijer, D.; Liu, Y

    2015-01-01

    Biomimetic calcium phosphate coatings have been developed for bone regeneration and repair because of their biocompatibility, osteoconductivity, and easy preparation. They can be rendered osteoinductive by incorporating an osteogenic agent, such as bone morphogenetic protein 2 (BMP-2), into the crystalline lattice work in physiological situations. The biomimetic calcium phosphate coating enables a controlled, slow and local release of BMP-2 when it undergoes cell mediated coating degradation ...

  16. 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…

  17. 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…

  18. 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.

  19. 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

  20. Biomimetic electrospun nanofibers for tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Susan; Li Bojun; Ma Zuwei; Wei He; Chan Casey; Ramakrishna, Seeram [Nanoscience and Nanotechnology Initiative (NUSNNI), Faculty of Engineering, National University of Singapore, 117576 Singapore (Singapore)

    2006-09-15

    Nanofibers exist widely in human tissue with different patterns. Electrospinning nanotechnology has recently gained a new impetus due to the introduction of the concept of biomimetic nanofibers for tissue regeneration. The advanced electrospinning technique is a promising method to fabricate a controllable continuous nanofiber scaffold similar to the natural extracellular matrix. Thus, the biomedical field has become a significant possible application field of electrospun fibers. Although electrospinning has developed rapidly over the past few years, electrospun nanofibers are still at a premature research stage. Further comprehensive and deep studies on electrospun nanofibers are essential for promoting their biomedical applications. Current electrospun fiber materials include natural polymers, synthetic polymers and inorganic substances. This review briefly describes several typically electrospun nanofiber materials or composites that have great potential for tissue regeneration, and describes their fabrication, advantages, drawbacks and future prospects. (topical review)

  1. 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.

  2. Biomimetic Hybrid Nanocontainers with Selective Permeability.

    Science.gov (United States)

    Messager, Lea; Burns, Jonathan R; Kim, Jungyeon; Cecchin, Denis; Hindley, James; Pyne, Alice L B; Gaitzsch, Jens; Battaglia, Giuseppe; Howorka, Stefan

    2016-09-01

    Chemistry plays a crucial role in creating synthetic analogues of biomacromolecular structures. Of particular scientific and technological interest are biomimetic vesicles that are inspired by natural membrane compartments and organelles but avoid their drawbacks, such as membrane instability and limited control over cargo transport across the boundaries. In this study, completely synthetic vesicles were developed from stable polymeric walls and easy-to-engineer membrane DNA nanopores. The hybrid nanocontainers feature selective permeability and permit the transport of organic molecules of 1.5 nm size. Larger enzymes (ca. 5 nm) can be encapsulated and retained within the vesicles yet remain catalytically active. The hybrid structures constitute a new type of enzymatic nanoreactor. The high tunability of the polymeric vesicles and DNA pores will be key in tailoring the nanocontainers for applications in drug delivery, bioimaging, biocatalysis, and cell mimicry. PMID:27560310

  3. 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...

  4. Biomimetic Membrane Arrays on Cast Hydrogel Supports

    DEFF Research Database (Denmark)

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

    2011-01-01

    , 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......-supporting ETFE/hydrogel sandwiches. We demonstrate how the ETFE/hydrogel sandwich support promotes rapid self-thinning of lipid bilayers suitable for hosting membrane-spanning proteins....

  5. 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...

  6. 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.

  7. 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.

  8. 胶原多糖基纳米羟基磷灰石仿生骨支架材料的研制%Preparation of mineralized collagen-polyose based biomimetic scaffold material for bone tissue Engineering

    Institute of Scientific and Technical Information of China (English)

    陈学忠; 李志宏; 李瑞欣; 郭勇; 刘璐; 王亮; 张西正

    2011-01-01

    目的 依据仿生原理制备新型的胶原多糖基纳米羟基磷灰石(HA)复合骨支架材料,并与成骨细胞复合培养,检测其细胞相容性.方法 以胶原分子与透明质酸钠的交联产物为模板,调制钙磷盐在液相中沉积其上,得到矿化胶原多糖基复合材料;采用液相分离法与少量聚乳酸复合进一步制备成为三维多孔支架,使用成骨细胞(MC3T3-E1)接种于该支架上培养.用X-ray衍射、扫描电镜、万能材料测试机等对材料进行观察和测试分析;并用倒置相差显微镜、荧光显微镜、扫描电镜、CCK-8细胞计数试剂盒、碱性磷酸酶(ALP)活性测定等观察和分析细胞在支架材料中的生长、分化情况.结果 胶原多糖基纳米HA仿生复合材料的晶粒度较低,晶体极为细小,与天然骨中羟基磷灰石的组装结构类似;该复合支架为多孔状,孔隙率约82%,孔径大小为200~650 μm;抗压性能好,成骨细胞可在其上贴附、生长和繁殖,并表现出较高的成骨活性.结论 所制备的胶原多糖基纳米HA仿生骨支架材料,无论从组分和结构上均与天然松质骨类似,与成骨细胞相容性好,可望成为较理想的骨组织工程支架材料.%Objective To prepare a novel bioactive and degradable scaffold with mineralized collagenpolyose based composite by biomimetic synthesis for bone tissue engineering and explore the compatibility of osteoblast culturing on the scaffold.Methods Using the cross-linking product of collagenⅠ and sodium hyaluronate as the template,the calcium phosphate was deposited on it to produce a mineralized composite.The 3-D porous scaffolds were prepared by liquid phase separation after the mineralized composite combining with polylactic acid (PLA) and NaCl.The materials and scaffolds were investigated by x-ray diffraction (XRD),scanning electronic microscopy (SEM) and universal testing machine.In addition,inverted microscope,fluorescence microscope

  9. 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.

  10. 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.

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

    International Nuclear Information System (INIS)

    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

  12. Biomimetic/Optical Sensors for Detecting Bacterial Species

    Science.gov (United States)

    Homer, Margie; Ksendzov, Alexander; Yen, Shiao-Pin; Ryan, Margaret; Lazazzera, Beth

    2006-01-01

    Biomimetic/optical sensors have been proposed as means of real-time detection of bacteria in liquid samples through real-time detection of compounds secreted by the bacteria. Bacterial species of interest would be identified through detection of signaling compounds unique to those species. The best-characterized examples of quorum-signaling compounds are acyl-homoserine lactones and peptides. Each compound, secreted by each bacterium of an affected species, serves as a signal to other bacteria of the same species to engage in a collective behavior when the population density of that species reaches a threshold level analogous to a quorum. A sensor according to the proposal would include a specially formulated biomimetic film, made of a molecularly imprinted polymer (MIP), that would respond optically to the signaling compound of interest. The MIP film would be integrated directly onto an opticalwaveguide- based ring resonator for optical readout. Optically, the sensor would resemble the one described in Chemical Sensors Based on Optical Ring Resonators (NPO-40601), NASA Tech Briefs, Vol. 29, No. 10 (October 2005), page 32. MIPs have been used before as molecular- recognition compounds, though not in the manner of the present proposal. Molecular imprinting is an approach to making molecularly selective cavities in a polymer matrix. These cavities function much as enzyme receptor sites: the chemical functionality and shape of a cavity in the polymer matrix cause the cavity to bind to specific molecules. An MIP matrix is made by polymerizing monomers in the presence of the compound of interest (template molecule). The polymer forms around the template. After the polymer solidifies, the template molecules are removed from the polymer matrix by decomplexing them from their binding sites and then dissolving them, leaving cavities that are matched to the template molecules in size, shape, and chemical functionality. The cavities thus become molecular-recognition sites

  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. 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.

  15. 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.

  16. Didactic Strategy Discussion Based on Artificial Neural Networks Results.

    Science.gov (United States)

    Andina, D.; Bermúdez-Valbuena, R.

    2009-04-01

    Artificial Neural Networks (ANNs) are a mathematical model of the main known characteristics of biological brian dynamics. ANNs inspired in biological reality have been useful to design machines that show some human-like behaviours. Based on them, many experimentes have been succesfully developed emulating several biologial neurons characteristics, as learning how to solve a given problem. Sometimes, experimentes on ANNs feedback to biology and allow advances in understanding the biological brian behaviour, allowing the proposal of new therapies for medical problems involving neurons performing. Following this line, the author present results on artificial learning on ANN, and interpret them aiming to reinforce one of this two didactic estrategies to learn how to solve a given difficult task: a) To train with clear, simple, representative examples and feel confidence in brian generalization capabilities to achieve succes in more complicated cases. b) To teach with a set of difficult cases of the problem feeling confidence that the brian will efficiently solve the rest of cases if it is able to solve the difficult ones. Results may contribute in the discussion of how to orientate the design innovative succesful teaching strategies in the education field.

  17. Design and Dynamic Analysis of a Novel Biomimetic Robotics Hip Joint

    OpenAIRE

    Bingyan Cui; Liwen Chen; Zhijun Wang; Yuanhao Zhao; Zhanxian Li; Zhenlin Jin

    2015-01-01

    In order to increase the workspace and the carrying capacity of biomimetic robotics hip joint, a novel biomimetic robotics hip joint was developed. The biomimetic robotics hip joint is mainly composed of a moving platform, frame, and 3-RRR orthogonal spherical parallel mechanism branched chains, and has the characteristics of compact structure, large bearing capacity, high positioning accuracy, and good controllability. The functions of the biomimetic robotics hip joint are introduced, such a...

  18. 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.

  19. 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.

  20. Retinopathy of Prematurity: Therapeutic Strategies Based on Pathophysiology.

    Science.gov (United States)

    Cayabyab, Rowena; Ramanathan, Rangasamy

    2016-01-01

    retinal detachment. Long-term complications such as refractory errors, recurrence of ROP and risk of retinal detachment require continued follow-up with an ophthalmologist through adolescence and beyond. Optimal nutrition including adequate intake of omega-3 polyunsaturated fatty acids and decreasing infection/inflammation to promote normal vascularization are important strategies. Screening guidelines for ROP based on local incidence of ROP in different regions of the world are very important. Oxygen therapy is clearly a modifiable risk factor to decrease ROP that needs further study. Understanding the two phases of ROP will help to identify appropriate therapeutic strategies and improve visual outcomes in many preterm infants globally. PMID:27251645

  1. 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.

  2. 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. PMID:26234364

  3. 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.

  4. 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.

  5. 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.

  6. Developing a marketing strategy for launching Intel-based mobile broadband dongles for the Russian market

    OpenAIRE

    Kasatkin, Dmitry

    2012-01-01

    The purpose of the study is to suggest a potential marketing strategy for launching Intel-based mobile broadband dongles for the Russian market. One objective is to identify what should be overall marketing strategy and another objective is to estimate potential demand for the Intel-based mobile broadband dongles. The conceptual framework is based on literature and articles about marketing strategies and consumer behavior. Concepts such as Marketing Mix (4Ps), Brand Image, Perceived Produc...

  7. LMOP Based Hybrid Routing Strategy for Delay/Disruption Tolerant Networks

    OpenAIRE

    Qian Liu; Chao Chen; Fuhong Lin; Haitao Xu; Kraser Michael

    2014-01-01

    In this paper, routing problem of Delay Tolerant Networks (DTN) was investigated and a new routing scheme was proposed based on the Epidemic routing. By combining the advantage of a variety of related routing algorithm, a Limited Multi-copy Optimal Path-Hybrid Routing (LMOP-HR) was put forward belonging to the flooding message copies strategy. An optimal tree mixed strategy based on priority was proposed for the message distribution. Further, this strategy adopted priority-based c...

  8. 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.

  9. Diary-Based Strategy Assessment and Its Relationship to Performance in a Group of Trainee Teachers

    Science.gov (United States)

    Gilar, Raquel; de los Angeles Martinez Ruiz, Maria; Costa, Juan Luiz Castejon

    2007-01-01

    Our work is based on the study of learning strategies used by a group of trainee teachers in a real learning situation, and how this use of strategies influences the results of the learning process. We use a diary as a tool to assess the learning strategies and compare the results obtained with those using an inventory. Our findings indicate that…

  10. 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…

  11. 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

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

    International Nuclear Information System (INIS)

    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

  13. 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.

  14. Biomimetic remineralization of demineralized dentine using scaffold of CMC/ACP nanocomplexes in an in vitro tooth model of deep caries.

    Directory of Open Access Journals (Sweden)

    Zhen Chen

    Full Text Available Currently, it is still a tough task for dentists to remineralize dentine in deep caries. The aim of this study was to remineralize demineralized dentine in a tooth model of deep caries using nanocomplexes of carboxymethyl chitosan/amorphous calcium phosphate (CMC/ACP based on mimicking the stabilizing effect of dentine matrix protein 1 (DMP1 on ACP in the biomineralization of dentine. The experimental results indicate that CMC can stabilize ACP to form nanocomplexes of CMC/ACP, which is able to be processed into scaffolds by lyophilization. In the single-layer collagen model, ACP nanoparticles are released from scaffolds of CMC/ACP nanocomplexes dissolved and then infiltrate into collagen fibrils via the gap zones (40 nm to accomplish intrafibrillar mineralization of collagen. With this method, the completely demineralized dentine was partially remineralized in the tooth mode. This is a bottom-up remineralizing strategy based on non-classical crystallization theory. Since nanocomplexes of CMC/ACP show a promising effect of remineralization on demineralized dentine via biomimetic strategy, thereby preserving dentinal tissue to the maximum extent possible, it would be a potential indirect pulp capping (IPC material for the management of deep caries during vital pulp therapy based on the concept of minimally invasive dentistry (MID.

  15. Optimal attack strategy of complex networks based on tabu search

    Science.gov (United States)

    Deng, Ye; Wu, Jun; Tan, Yue-jin

    2016-01-01

    The problem of network disintegration has broad applications and recently has received growing attention, such as network confrontation and disintegration of harmful networks. This paper presents an optimized attack strategy model for complex networks and introduces the tabu search into the network disintegration problem to identify the optimal attack strategy, which is a heuristic optimization algorithm and rarely applied to the study of network robustness. The efficiency of the proposed solution was verified by comparing it with other attack strategies used in various model networks and real-world network. Numerical experiments suggest that our solution can improve the effect of network disintegration and that the "best" choice for node failure attacks can be identified through global searches. Our understanding of the optimal attack strategy may also shed light on a new property of the nodes within network disintegration and deserves additional study.

  16. Stable isotope labeling strategy based on coding theory

    International Nuclear Information System (INIS)

    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

  17. 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...... develop a contingency view on complex problem solving which structures the argument into three steps:1) Characterising the problem architectures addressed by different types of DBFs;2) Testing and confirming that DBFs form requisite research strategies, by which we refer to problem solving approaches...... developed as congruent responses to problem architectures; 3) Testing and confirming that financial valuation of firms is driven by achievements conforming to requisite research strategies. These strategies, in turn, require careful combination of multiple dimensions of research.Findings demonstrate...

  18. Analytical strategies in mass spectrometry-based phosphoproteomics

    DEFF Research Database (Denmark)

    Rosenqvist, Heidi; Ye, Juanying; Jensen, Ole N

    2011-01-01

    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 to...

  19. 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.

  20. 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 participants,…

  1. Multiobjective Optimization Based Vessel Collision Avoidance Strategy Optimization

    OpenAIRE

    Qingyang Xu; Chuang Zhang; Ning Wang

    2014-01-01

    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 ...

  2. 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

  3. Perception-based pricing strategies for mobile services in customer marketing context

    OpenAIRE

    Munnukka, Juha

    2004-01-01

    Traditional pricing research has focused on analysing price setting procedures and cost or competition based pricing strategies. Customer- or perception-oriented pricing strategies have been left on little attention among business practitioners and academics. The need for development and investigation of these new pricing strategies has occurred after the emergence of new electronic and mobile services; traditional pricing strategies have resulted unsatisfactory results. With this study we ha...

  4. 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

  5. Effects of Biomimetic Surface Designs on Furrow Opener Performance

    Institute of Scientific and Technical Information of China (English)

    Jin Tong; Ballel. Z. Moayad; Yun-hai Ma; Ji-yu Sun; Dong-hui Chen; Hong-lei Jia; Lu-quan Ren

    2009-01-01

    The effects of biomimetic designs of tine furrow opener surface on equivalent pressure and pressure in the direction of motion on opener surface against soil were studied by finite element method (FEM) simulation and the effects of these designs on tool force and power requirements were examined experimentally. Geometrical structures of the cuticle surfaces of dung beetle (Copris ochus Motschulsky) were examined by stereoscopy. The structures of the cuticle surfaces and Ultra High Mo-lecular Weight Polyethylene (UHMWPE) material were modeled on surface of tine furrow opener as biomimetic designs. Seven furrow openers were analyzed in ANSYS program (a FEM simulation software). The biomimetic furrow opener surfaces with UHMWPE structures were found to have lower equivalent pressure and pressure in the direction of motion as compared to the conventional surface and to the biomimetic surfaces with textured steel-35 structures. It was found that the tool force and power were increased with the cutting depth and operating speed and the biomimetic furrow opener with UHMWPE tubular section ridges showed the lowest resistance and power requirement against soil.

  6. Strategies towards advanced ion track-based biosensors

    Science.gov (United States)

    Alfonta, L.; Bukelman, O.; Chandra, A.; Fahrner, W. R.; Fink, D.; Fuks, D.; Golovanov, V.; Hnatowicz, V.; Hoppe, K.; Kiv, A.; Klinkovich, I.; Landau, M.; Morante, J. R.; Tkachenko, N. V.; Vacík, J.; Valden, M.

    Three approaches towards ion track-based biosensors appear to be feasible. The development of the first one began a decade ago [Siwy, Z.; Trofin, L.; Kohl, P.; Baker, L.A.; Martin, C.R.; Trautmann, C. J. Am. Chem. Soc. 2005, 127, 5000-5001; Siwy, Z.S.; Harrell, C.C.; Heins, E.; Martin, C.R.; Schiedt, B.; Trautmann, C.; Trofin, L.; Polman, A. Presented at the 6th International Conference on Swift Heavy Ions in Matter, Aschaffenburg, Germany, May 28-31, 2005] and makes use of the concept that the presence of certain biomolecules within liquids can block the passage through narrow pores if being captured there, thus switching off the pore's electrical conductivity. The second, having been successfully tested half a year ago [Fink, D.; Klinkovich, I.; Bukelman, O.; Marks, R.S.; Fahrner, W.; Kiv, A.; Fuks, D.; Alfonta, L. Biosens. Bioelectron. 2009, 24, 2702-2706], is based on the accumulation of enzymatic reaction products within the confined volume of narrow etched ion tracks which modifies the pore's electrical conductivity. The third and most elegant, at present under development, will exploit the charge transfer from enzymes to semiconductors embedded within etched tracks, enabling the enzymes undergoing specific reactions with the biomolecules to be detected. These strategies can be realized either within carrier-free nanoporous polymeric membranes embedded in the corresponding bioliquids, or within contacted nanoporous insulating layers on semiconducting substrates, the so-called TEMPOS structures [Fink, D.; Petrov, A.; Hoppe, H.; Fahrner, W.R.; Papaleo, R.M.; Berdinsky, A.; Chandra, A.; Biswas, A.; Chadderton, L.T. Nucl. Instrum. Methods B 2004, 218, 355-361]. The latter have the advantage of exhibiting a number of peculiar electronic properties, such as the ability for logic and/or combination of input signals, tunable polarity, negative differential resistances, tunability by external parameters such as light, magnetic fields, etc. and self-pulsations, which

  7. 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.

  8. 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.

  9. 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.

  10. 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

    2016-08-01

    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. PMID:27385421

  11. Optimization of a tensegrity wing for biomimetic applications

    Science.gov (United States)

    Moored, Keith W., III; Taylor, Stuart A.; Bart-Smith, Hilary

    2006-03-01

    Current attempts to build fast, efficient, and maneuverable underwater vehicles have looked to nature for inspiration. However, they have all been based on traditional propulsive techniques, i.e. rotary motors. In the current study a promising and potentially revolutionary approach is taken that overcomes the limitations of these traditional methods-morphing structure concepts with integrated actuation and sensing. Inspiration for this work comes from the manta ray (Manta birostris) and other batoid fish. These creatures are highly maneuverable but are also able to cruise at high speeds over long distances. In this paper, the structural foundation for the biomimetic morphing wing is a tensegrity structure. A preliminary procedure is presented for developing morphing tensegrity structures that include actuating elements. A shape optimization method is used that determines actuator placement and actuation amount necessary to achieve the measured biological displacement field of a ray. Lastly, an experimental manta ray wing is presented that measures the static and dynamic pressure field acting on the ray's wings during a normal flapping cycle.

  12. 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.

  13. 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.

  14. 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. PMID:27628170

  15. 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. PMID:27157717

  16. 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.

  17. Bactericidal activity of biomimetic diamond nanocone surfaces.

    Science.gov (United States)

    Fisher, Leanne E; Yang, Yang; Yuen, Muk-Fung; Zhang, Wenjun; Nobbs, Angela H; Su, Bo

    2016-03-01

    The formation of biofilms on implant surfaces and the subsequent development of medical device-associated infections are difficult to resolve and can cause considerable morbidity to the patient. Over the past decade, there has been growing recognition that physical cues, such as surface topography, can regulate biological responses and possess bactericidal activity. In this study, diamond nanocone-patterned surfaces, representing biomimetic analogs of the naturally bactericidal cicada fly wing, were fabricated using microwave plasma chemical vapor deposition, followed by bias-assisted reactive ion etching. Two structurally distinct nanocone surfaces were produced, characterized, and the bactericidal ability examined. The sharp diamond nanocone features were found to have bactericidal capabilities with the surface possessing the more varying cone dimension, nonuniform array, and decreased density, showing enhanced bactericidal ability over the more uniform, highly dense nanocone surface. Future research will focus on using the fabrication process to tailor surface nanotopographies on clinically relevant materials that promote both effective killing of a broader range of microorganisms and the desired mammalian cell response. This study serves to introduce a technology that may launch a new and innovative direction in the design of biomaterials with capacity to reduce the risk of medical device-associated infections. PMID:26992656

  18. Development of Underwater Microrobot with Biomimetic Locomotion

    Directory of Open Access Journals (Sweden)

    W. Zhang

    2006-01-01

    Full Text Available Microrobots have powerful applications in biomedical and naval fields. They should have a compact structure, be easy to manufacture, have efficient locomotion, be driven by low voltage and have a simple control system. To meet these purposes, inspired by the leg of stick insects, we designed a novel type of microrobot with biomimetic locomotion with 1-DOF (degree of freedom legs. The locomotion includes two ionic conducting polymer film (ICPF actuators to realize the 2-DOF motion. We developed several microrobots with this locomotion. Firstly, we review a microrobot, named Walker-1, with 1-DOF motion. And then a new microrobot, named Walker-2, utilizing six ICPF actuators, with 3-DOF motion is introduced. It is 47 mm in diameter and 8 mm in height (in static state. It has 0.61 g of dried weight. We compared the two microrobot prototypes, and the result shows that Walker-2 has some advantages, such as more flexible moving motion, good balance, less water resistance, more load-carrying ability and so on. We also compared it with some insect-inspired microrobots and some microrobots with 1-DOF legs, and the result shows that a microrobot with this novel type of locomotion has some advantages. Its structure has fewer actuators and joints, a simpler control system and is compact. The ICPF actuator decides that it can be driven by low voltage (less than 5 V and move in water. A microrobot with this locomotion has powerful applications in biomedical and naval fields.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. A Novel Exploration Algorithm Based on a Improvement Strategy

    OpenAIRE

    John Illingworth; Phil Palmer; Rachel Gartshore

    2008-01-01

    In this paper we present a strategy for the problem of exploring an unknown 2D environment. Existing techniques can be methodical, goal oriented or non-reactive to additional knowledge received at each new viewpoint. We present an approach which is not goal driven, but rather seeks new unseen areas to view and explore. The novelty of the strategy presented is the use of a view-improvement technique along with an optimal viewpoint planning method for the calculation and selection of the next-b...

  5. 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.

  6. Towards biomimetic scaffolds: anhydrous scaffold fabrication from biodegradable amine-reactive diblock copolymers.

    Science.gov (United States)

    Hacker, Michael; Tessmar, Jörg; Neubauer, Markus; Blaimer, Andrea; Blunk, Torsten; Göpferich, Achim; Schulz, Michaela B

    2003-11-01

    The development of biomimetic materials and their processing into three-dimensional cell carrying scaffolds is one promising tissue engineering strategy to improve cell adhesion, growth and differentiation on polymeric constructs developing mature and viable tissue. This study was concerned with the fabrication of scaffolds made from amine-reactive diblock copolymers, N-succinimidyl tartrate monoamine poly(ethylene glycol)-block-poly(D,L-lactic acid), which are able to suppress unspecific protein adsorption and to covalently bind proteins or peptides. An appropriate technique for their processing had to be both anhydrous, to avoid hydrolysis of the active ester, and suitable for the generation of interconnected porous structures. Attempts to fabricate scaffolds utilizing hard paraffin microparticles as hexane-extractable porogens failed. Consequently, a technique was developed involving lipid microparticles, which served as biocompatible porogens on which the scaffold forming polymer was precipitated in the porogen extraction media (n-hexane). Porogen melting during the extraction and polymer precipitation step led to an interconnected network of pores. Suitable lipid mixtures and their melting points, extraction conditions (temperature and time) and a low-toxic polymer solvent system were determined for their use in processing diblock copolymers of different molecular weights (22 and 42 kDa) into highly porous off-the-shelf cell carriers ready for easy surface modification towards biomimetic scaffolds. Insulin was employed to demonstrate the principal of instant protein coupling to a prefabricated scaffold. PMID:12922156

  7. 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.

  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

    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......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...

  9. Biomimetic Precapillary Flow Patterns for Enhancing Blood Plasma Separation: A Preliminary Study

    Science.gov (United States)

    Namgung, Bumseok; Tan, Justin Kok Soon; Wong, Peter Agustinus; Park, Sung-Yong; Leo, Hwa Liang; Kim, Sangho

    2016-01-01

    In this study, a biomimetic microfluidic plasma separation device is discussed. The design of the device drew inspiration from in vivo observations of enhanced cell-free layer (CFL) formation downstream of vascular bifurcations. The working principle for the plasma separation was based on the plasma skimming effect in an arteriolar bifurcation, which is modulated by CFL formation. The enhancement of the CFL width was achieved by a local hematocrit reduction near the collection channel by creating an uneven hematocrit distribution at the bifurcation of the channel. The device demonstrated a high purity of separation (~99.9%) at physiological levels of hematocrit (~40%). PMID:27657090

  10. Optimization of the efficiency of a biomimetic marine propulsor using CFD

    Directory of Open Access Journals (Sweden)

    Carlos Gervasio Rodríguez Vidal

    2014-03-01

    Full Text Available The purpose of this paper is to employ a CFD (Computational Fluid Dynamics procedure to optimize a biomimetic marine propulsor. This propulsor is based on an undulating panel which emulates the movement of a fin fish. The numerical model has been employed to analyze the hydrodynamics and improve the efficiency. Particularly, the fin shape has been studied as measure to improve the efficiency. Three fin shapes have been analyzed, rectangular, elliptic and lunate. The results have indicated that, for the same area, the lunate shape is the most efficient.

  11. 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

  12. 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

  13. 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.

  14. 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...... method and control strategy....

  15. 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…

  16. An AFLP-based genome-wide mapping strategy.

    NARCIS (Netherlands)

    Peters, J.L.; Cnops, G.; Neyt, P.; Zethof, J.; Cornelis, K.; Lijsebettens, M. van; Gerats, A.G.M.

    2004-01-01

    To efficiently determine the chromosomal location of phenotypic mutants, we designed a genome-wide mapping strategy that can be used in any crop for which a dense AFLP (Amplified Fragment Length Polymorphism) map is available or can be made. The AFLP technique is particularly suitable to initiate ma

  17. 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.

  18. MALEO: Modular Assembly in Low Earth Orbit. A strategy for an IOC lunar base

    Science.gov (United States)

    Thangavelu, M.; Schierle, G. G.

    1990-01-01

    Modular Assembly in Low Earth Orbit (MALEO) is a new strategy for building an initial operational capability lunar habitation base. In this strategy, the modular lunar base components are brought up to Low Earth Orbit by the Space Transportation System/Heavy Lift Launch Vehicle fleet, and assembled there to form a complete lunar base. Modular propulsion systems are then used to transport the MALEO lunar base, complete and intact, all the way to the moon. Upon touchdown on the lunar surface, the MALEO lunar habitation base is operational. An exo-skeletal truss superstructure is employed in order to uniformly absorb and distribute the rocket engine thrusting forces incurred by the MALEO lunar base during translunar injection, lunar orbit insertion, and lunar surface touchdown. The components, configuration, and structural aspects of the MALEO lunar base are discussed. Advantages of the MALEO strategy over conventional strategies are pointed out. It is concluded that MALEO holds promise for lunar base deployment.

  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. PROBLEM SOLVING IN SCHOOL MATHEMATICS BASED ON HEURISTIC STRATEGIES

    Directory of Open Access Journals (Sweden)

    NOVOTNÁ, Jarmila

    2014-03-01

    Full Text Available 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-term work, in this case only over the period of three months, can result in improvement of pupils’ abilities to solve problems whose solving algorithms are easily accessible. It also answers the question which strategies pupils will prefer and with what results. The experiment shows that even short-term work can bear positive results as far as pupils’ approach to problem solving is concerned.

  1. Modulation of Dendritic Cells by Nanotechnology-Based Immunotherapeutic Strategies.

    Science.gov (United States)

    Mogrão, Joana; da Costa, Catarina A; Gaspar, Rogério; Florindo, Helena F

    2016-03-01

    In preceding decades, different mechanisms have been proposed to "instruct" dendritic cells (DCs) to induce immune responses against tumor antigens (TAs), thus breaking immune tolerance. Immunotherapy has been, for the last two decades, an attractive and promising therapeutic approach to fight cancer. This review will approach the nature of the immune response during cancer development and its correlation with DC function, as well as cancer vaccine principles and limitations. An overview of several delivery strategies used for in vivo modulation of DCs and direct activation of T cells will be provided, highlighting their advantages, limitations, and optimization strategies. This manuscript also presents a critical and systematic review of recent clinical trials that are investigating the therapeutic effect of these approaches, discussing prognostic outcomes of combined-treatment modalities. PMID:27280242

  2. European Strategy for Accelerator-Based Neutrino Physics

    CERN Document Server

    Bertolucci, Sergio; Cervera, Anselmo; Donini, Andrea; Dracos, Marcos; Duchesneau, Dominique; Dufour, Fanny; Edgecock, Rob; Efthymiopoulos, Ilias; Gschwendtner, Edda; Kudenko, Yury; Long, Ken; Maalampi, Jukka; Mezzetto, Mauro; Pascoli, Silvia; Palladino, Vittorio; Rondio, Ewa; Rubbia, Andre; Rubbia, Carlo; Stahl, Achim; Stanco, Luca; Thomas, Jenny; Wark, David; Wildner, Elena; Zito, Marco

    2012-01-01

    Massive neutrinos reveal physics beyond the Standard Model, which could have deep consequences for our understanding of the Universe. Their study should therefore receive the highest level of priority in the European Strategy. The discovery and study of leptonic CP violation and precision studies of the transitions between neutrino flavours require high intensity, high precision, long baseline accelerator neutrino experiments. The community of European neutrino physicists involved in oscillation experiments is strong enough to support a major neutrino long baseline project in Europe, and has an ambitious, competitive and coherent vision to propose. Following the 2006 European Strategy for Particle Physics (ESPP) recommendations, two complementary design studies have been carried out: LAGUNA/LBNO, focused on deep underground detector sites, and EUROnu, focused on high intensity neutrino facilities. LAGUNA LBNO recommends, as first step, a conventional neutrino beam CN2PY from a CERN SPS North Area Neutrino Fac...

  3. Hybrid Electric Vehicle Control Strategy Based on Power Loss Calculations

    OpenAIRE

    Boyd, Steven J

    2006-01-01

    Defining an operation strategy for a Split Parallel Architecture (SPA) Hybrid Electric Vehicle (HEV) is accomplished through calculating powertrain component losses. The results of these calculations define how the vehicle can decrease fuel consumption while maintaining low vehicle emissions. For a HEV, simply operating the vehicle's engine in its regions of high efficiency does not guarantee the most efficient vehicle operation. The results presented are meant only to define a literal str...

  4. Investment Strategies based on Social Responsibility and Bubbles

    OpenAIRE

    Günster, Nadja

    2009-01-01

    textabstractIn contrast to the classical efficient market theory, the behavioral Finance literature acknowledges that people are neither rational utility maximizers nor able to process all available information. Instead, people tend to focus on the most salient aspects of their environment and neglect other information. This dissertation studies this phenomenon through six studies on investment strategies related to investors' attention failures. In the first four chapters, I analyze whether ...

  5. 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.

  6. Improved routing strategy based on gravitational field theory

    Science.gov (United States)

    Song, Hai-Quan; Guo, Jin

    2015-10-01

    Routing and path selection are crucial for many communication and logistic applications. We study the interaction between nodes and packets and establish a simple model for describing the attraction of the node to the packet in transmission process by using the gravitational field theory, considering the real and potential congestion of the nodes. On the basis of this model, we propose a gravitational field routing strategy that considers the attractions of all of the nodes on the travel path to the packet. In order to illustrate the efficiency of proposed routing algorithm, we introduce the order parameter to measure the throughput of the network by the critical value of phase transition from a free flow phase to a congested phase, and study the distribution of betweenness centrality and traffic jam. Simulations show that, compared with the shortest path routing strategy, the gravitational field routing strategy considerably enhances the throughput of the network and balances the traffic load, and nearly all of the nodes are used efficiently. Project supported by the Technology and Development Research Project of China Railway Corporation (Grant No. 2012X007-D) and the Key Program of Technology and Development Research Foundation of China Railway Corporation (Grant No. 2012X003-A).

  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. 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.

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

    International Nuclear Information System (INIS)

    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, [Cu2(HL)(μ-CH3COO)](ClO4), containing the ligand N,N-[bis-(2-pyridylmethyl)]-N',N'-[(2-hydroxybenzyl)(2-hydroxy-3,5-di-tert - butylbenzyl)]-1,3-propanediamine-2-ol (H3L), was synthesized and characterized by IR, 1H 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-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 10-6 to 3.27 x 10-5 mol L-1 (r = 0.9993) with a detection limit of 2.8 x 10-7 mol L-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)

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

    International Nuclear Information System (INIS)

    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

  11. 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)

  12. 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.

  13. 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.

  14. Interactions between structural and chemical biomimetism in synthetic stem cell niches

    International Nuclear Information System (INIS)

    Advancements in understanding stem cell functions and differentiation are of key importance for the clinical success of stem-cell-based therapies. 3D structural niches fabricated by two-photon polymerization are a powerful platform for controlling stem cell growth and differentiation. In this paper, we investigate the possibility of further controlling stem cell fate by tuning the mechanical properties of such niches through coating with thin layers of biomimetic hyaluronan-based and gelatin-based hydrogels. We first assess the biocompatibility of chemical coatings and then study the interactions between structural and chemical biomimetism on the response of MSCs in terms of proliferation and differentiation. We observed a clear effect of the hydrogel coating on otherwise identical 3D scaffolds. In particular, in gelatin-coated niches we observed a stronger metabolic activity and commitment toward the osteo-chondral lineage with respect to hyaluronan-coated niches. Conversely, a reduction in the homing effect was observed in all the coated niches, especially in gelatin-coated niches. This study demonstrates the feasibility of controlling independently different mechanical cues, in bioengineered stem cell niches, i.e. the 3D scaffold geometry and the surface stiffness. This will allow, on the one hand, understanding their specific role in stem cell proliferation and differentiation and, on the other hand, finely tuning their synergistic effect. (paper)

  15. Brand Equity Management for Luxury Food Products based on the Customer Service Strategy

    OpenAIRE

    Qishen Zhou; Yalan Xu; Zuowei Yin

    2014-01-01

    This study aims to analyze the brand equity management for luxury food products based on the customer service strategy. The literature review is delivered to launch the foundation of the service strategic analysis. The importance of the customer service strategy is enlightened to analyze the brand equity of luxury food products. The Kotler mode was adopted to establish the brand equity management system to investigate the customer service strategy. Then, the famous luxury food products brand,...

  16. Use of research-based instructional strategies: how to avoid faculty quitting

    OpenAIRE

    Wieman, Carl; Deslauriers, Louis; Gilley, Brett

    2013-01-01

    We have examined the teaching practices of faculty members who adopted research-based instructional strategies as part of the Carl Wieman Science Education Initiative (CWSEI) at the University of British Columbia. Of the 70 that adopted such strategies with the support of the CWSEI program, only one subsequently stopped using these strategies. This is a tiny fraction of the 33% stopping rate for physics faculty in general [Henderson, Dancy, and Niewiadomska-Bugaj, PRST-PER, 8, 020104 (2012)]....

  17. 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).

  18. 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.

  19. 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.

  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. Case Study in Biomimetic Design: Handling and Assembly of Microparts

    DEFF Research Database (Denmark)

    Shu, Li; Hansen, Hans Nørgaard; Gegeckaite, Asta;

    2006-01-01

    This paper describes the application of the biomimetic design process to the development of automated gripping devices for microparts. Handling and assembly of micromechanical parts is complicated by size effects that occur when part dimensions are scaled down. A common complication involves...

  2. Diffraction from relief gratings on a biomimetic elastomer cast

    International Nuclear Information System (INIS)

    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.

  3. A Laboratory Exercise to Introduce Inorganic Biomimetic Compounds.

    Science.gov (United States)

    Baird, Donald M.

    1985-01-01

    Biomimetic chemistry is concerned with the synthesis of small, molecular weight molecules which mimic the properties of metal-containing sites within certain biologically significant species. A series of experiments for an advanced undergraduate laboratory is described as a way to introduce this area into the chemistry curriculum. (JN)

  4. MIND MAPPING: A BRAIN-BASED WRITING STRATEGY

    OpenAIRE

    Ary Setya Budhi Ningrum

    2012-01-01

    In EFL context, it is believed that developing writing skills is more complicated than developing other language skills. In order to be able to write well, the foreign language learners need to be equipped with early and continued writing experiences. Thus, the teacher’s task to develop the students’ writing skill is more complicated than the other skills. One of the most current issues to deal with such phenomena is to ferret out the writing strategy that is able to enhance the students’ wri...

  5. Reduced stress shielding with limited micromotions using a carbon fibre composite biomimetic hip stem: a finite element model.

    Science.gov (United States)

    Caouette, C; Yahia, L H; Bureau, M N

    2011-09-01

    Total hip arthroplasty (THA) enjoys excellent rates of success in older patients, but younger patients are still at risk of aseptic loosening and bone resorption from stress shielding. One solution to the stress shielding problem is to use a hip stem with mechanical properties matching those of cortical bone. The objective of the present study was to investigate numerically the biomechanical performance of such a biomimetic hip stem based on a hydroxyapatite (HA)-coated carbon fibre composite. A finite element model (FEM) of the biomimetic stem was constructed. Contact elements were studied to model the bone-implant interface in a non-osseointegrated and osseointegrated state in the best way. Three static load cases representing slow walking, stair climbing, and gait in a healthy individual were considered. Stress shielding and bone-implant interface micromotions were evaluated and compared with the results of a similar FEM based on titanium alloy (Ti-6Al-4V). The composite stems allowed for reduced stress shielding when compared with a traditional Ti-6Al-4V stem. Micromotions were slightly higher with the composite stem, but remained below 40 microm on most of the HA-coated surface. It is concluded that a biomimetic composite stem might offer a better compromise between stress shielding and micromotions than the Ti-6Al-4V stem with the same external geometry.

  6. 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.

  7. 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.

  8. 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.

  9. 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 each...

  10. 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…

  11. 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…

  12. Nine State Strategies To Support School-Based Health Centers: A Making the Grade Monograph.

    Science.gov (United States)

    Asay, Marilyn; Behrens, Donna; Guernsey, Bruce P.; Koppelman, Jane; Lear, Julia Graham; Malone, Claire; Noyes, Lynn; Nystrom, Robert J.; Reilly-Chammat, Rosemary; Rosenberg, Steve; Schaedel, Garry; Simpson, Sara; Sterne, Sylvia

    In 1993, nine states were awarded Making the Grade grants to develop financial and other strategies to foster replication of school-based health centers (SBHCs). This report details the financial strategies used by Vermont, Rhode Island, Oregon, North Carolina, New York, Maryland, Louisiana, Connecticut, and Colorado, as reported in a meeting of…

  13. On-Line Project-Based Peer Assessed Competitions as an Instructional Strategy in Higher Education

    Science.gov (United States)

    Hammer, Ronen; Ronen, Miky; Kohen-Vacs, Dan

    2012-01-01

    Project-based team competition is a well established instructional strategy with a sound constructivist rationale. However the implementation of this strategy in Higher-Education rarely includes socio-constructivist activities such as peer assessments, which have considerable advantages both for assessees and assessors. It seems that the logistics…

  14. 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…

  15. Adult Professional Development: Can Brain-Based Teaching Strategies Increase Learning Effectiveness?

    Science.gov (United States)

    Tilton, Wendy

    2011-01-01

    Brain-based teaching strategies, compared to facilitative student-centered teaching strategies, were employed with 62 real estate professionals in a quasi-mixed-methods study. Participants attended a 2-day proprietary real estate continuing education course. Both the experimental and control groups received the same facilitative instruction, as…

  16. Guidance for Schools Selecting Antibullying Approaches: Translating Evidence-Based Strategies to Contemporary Implementation Realities

    Science.gov (United States)

    Ansary, Nadia S.; Elias, Maurice J.; Greene, Michael B.; Green, Stuart

    2015-01-01

    This article synthesizes the current research on bullying prevention and intervention in order to provide guidance to schools seeking to select and implement antibullying strategies. Evidence-based best practices that are shared across generally effective antibullying approaches are elucidated, and these strategies are grounded in examples…

  17. Man-tailored biomimetic sensor of molecularly imprinted materials for the potentiometric measurement of oxytetracycline.

    Science.gov (United States)

    Moreira, Felismina T C; Kamel, Ayman H; Guerreiro, Joana R L; Sales, M Goreti F

    2010-10-15

    A novel biomimetic sensor for the potentiometric transduction of oxytetracycline is presented. The artificial host was imprinted in methacrylic acid and/or acrylamide based polymers. Different amounts of molecularly imprinted and non-imprinted polymers were dispersed in different plasticizing solvents and entrapped in a poly(vinyl chloride) matrix. Only molecularly imprinted based sensors allowed a potentiometric transduction, suggesting the existence of host-guest interactions. These sensors exhibited a near-Nernstian response in steady state evaluations; slopes and detection limits ranged 42-63 mV/decade and 2.5-31.3 μg/mL, respectively. Sensors were independent from the pH of test solutions within 2-5. Good selectivity was observed towards glycine, ciprofloxacin, creatinine, acid nalidixic, sulfadiazine, cysteine, hydroxylamine and lactose. In flowing media, the biomimetic sensors presented good reproducibility (RSD of ±0.7%), fast response, good sensitivity (65 mV/decade), wide linear range (5.0×10(-5) to 1.0×10(-2) mol/L), low detection limit (19.8 μg/mL), and a stable baseline for a 5×10(-3) M citrate buffer (pH 2.5) carrier. The sensors were successfully applied to the analysis of drugs and urine. This work confirms the possibility of using molecularly imprinted polymers as ionophores for organic ion recognition in potentiometric transduction. PMID:20688507

  18. 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.

  19. 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.

  20. First Principles Molecular Modeling of Sensing Material Selection for Hybrid Biomimetic Nanosensors

    Science.gov (United States)

    Blanco, Mario; McAlpine, Michael C.; Heath, James R.

    Hybrid biomimetic nanosensors use selective polymeric and biological materials that integrate flexible recognition moieties with nanometer size transducers. These sensors have the potential to offer the building blocks for a universal sensing platform. Their vast range of chemistries and high conformational flexibility present both a problem and an opportunity. Nonetheless, it has been shown that oligopeptide aptamers from sequenced genes can be robust substrates for the selective recognition of specific chemical species. Here we present first principles molecular modeling approaches tailored to peptide sequences suitable for the selective discrimination of small molecules on nanowire arrays. The modeling strategy is fully atomistic. The excellent performance of these sensors, their potential biocompatibility combined with advanced mechanistic modeling studies, could potentially lead to applications such as: unobtrusive implantable medical sensors for disease diagnostics, light weight multi-purpose sensing devices for aerospace applications, ubiquitous environmental monitoring devices in urban and rural areas, and inexpensive smart packaging materials for active in-situ food safety labeling.

  1. 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.  

  2. Full cost transportation and cost-based pricing strategies

    International Nuclear Information System (INIS)

    A study was performed to determine the true costs of transportation. Estimates of the costs and revenues associated with various modes of transportation, the magnitude of transportation subsidies, and externalities generated by transportation in the Canadian context, were described. These estimates were compared to international estimates of transportation costs. The wide variety of cost elements included: (1) costs to governments, carriers and users. (2) revenues to governments, such as fuel taxes and licensing fees; (3) subsidies, and (5) externalities such as accident and health costs, pollution and emission costs, and policing costs. It was suggested that pricing/incentive strategies could be developed to move all modes of transportation closer to sustainability and curb the growth of CO2 emissions. Transportation system users could reduce external costs by changing usage and operating practices, by increasing operating efficiencies and by adopting new technologies. refs., tabs., figs

  3. 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.

  4. 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.

  5. 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.

  6. Biomimetic design of affinity peptide ligand for capsomere of virus-like particle.

    Science.gov (United States)

    Li, Yanying; Liu, Xiaodan; Dong, Xiaoyan; Zhang, Lin; Sun, Yan

    2014-07-22

    Virus-like particle (VLP) of murine polyomavirus (MPV) is a T = 7d icosahedral capsid that self-assembles from 72 capsomeres (Caps), each of which is a pentamer of major coat protein VP1. VLP has great potential in vaccinology, gene therapy, drug delivery, and materials science. However, its application is hindered by high cost downstream processes, leading to an urgent demand of a highly efficient affinity ligand for the separation and purification of Cap by affinity chromatography. Herein a biomimetic design strategy of an affinity peptide ligand of Cap has been developed on the basis of the binding structure of the C-terminus of minor coat protein (VP2-C) on the inner surface of Cap. The molecular interactions between VP2-C and Cap were first examined using all-atom molecular dynamics (MD) simulations coupled with the molecular mechanics/Poisson-Boltzmann surface area (MM/PBSA) method, where V283, P285, D286, W287, L289, and Y296 of VP2-C were identified as the hot spots. An affinity peptide library (DWXLXLXY, X denotes arbitrary amino acids except cysteine) was then constructed for virtual screening sequently by docking with AUTODOCK VINA, binding structure comparison, and final docking with ROSETTA FlexPepDock. Ten peptide candidates were selected and further confirmed by MD simulations and MM/PBSA, where DWDLRLLY was found to have the highest affinity to Cap. In DWDLRLLY, six residues are favorable for the binding, including W2, L4, L6 and Y8 inheriting from VP2-C, and R5 and L7 selected in the virtual screening. This confirms the high efficiency and accuracy of the biomimetic design strategy. DWDLRLLY was then experimentally validated by a one-step purification of Cap from crude cell lysate using affinity chromatography with the octapeptide immobilized on Sepharose gel. The purified Caps were observed to self-assemble into VLP with consistent structure of authentic MPV. PMID:24976378

  7. Rapid biomimetic mineralization of collagen fibrils and combining with human umbilical cord mesenchymal stem cells for bone defects healing.

    Science.gov (United States)

    Ye, Bihua; Luo, Xueshi; Li, Zhiwen; Zhuang, Caiping; Li, Lihua; Lu, Lu; Ding, Shan; Tian, Jinhuan; Zhou, Changren

    2016-11-01

    Collagen biomineralization is regulated by complicated interactions between the collagen matrix and non-collagenous extracellular proteins. Here, the use of sodium tripolyphosphate to simulate the templating functional motif of the C-terminal fragment of non-collagenous proteins is reported, and a low molecular weight polyacrylic acid served as a sequestration agent to stabilize amorphous calcium phosphate into nanoprecursors. Self-assembled collagen fibrils served as a fixed template for achieving rapid biomimetic mineralization in vitro. Results demonstrated that, during the mineralization process, intrafibrillar and extrafibrillar hydroxyapatite mineral with collagen fibrils formed and did so via bottom-up nanoparticle assembly based on the non-classical crystallization approach in the presence of these dual biomimetic functional analogues. In vitro human umbilical cord mesenchymal stem cell (hUCMSC) culture found that the mineralized scaffolds have a better cytocompatibility in terms of cell viability, adhesion, proliferation, and differentiation into osteoblasts. A rabbit femoral condyle defect model was established to confirm the ability of the n-HA/collagen scaffolds to facilitate bone regeneration and repair. The images of gross anatomy, MRI, CT and histomorphology taken 6 and 12weeks after surgery showed that the biomimetic mineralized collagen scaffolds with hUCMSCs can promote the healing speed of bone defects in vivo, and both of the scaffolds groups performing better than the bone defect control group. As new bone tissue formed, the scaffolds degraded and were gradually absorbed. All these results demonstrated that both of the scaffolds and cells have better histocompatibility. PMID:27523994

  8. 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.

  9. 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.

  10. A monolithic strategy based on an hybrid domain decomposition method for multiphysic problems

    OpenAIRE

    Gosselet, Pierre; Chiaruttini, Vincent; Rey, Christian; Feyel, Frédéric

    2004-01-01

    International audience A monolithic strategy based on an hybrid domain decomposition method for the numerical simulation of multiphysic problems is presented. It relies on a "physical" choice of primal interface unknowns. First numerical assessments are described for poroelasticity problems.

  11. 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.

  12. 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...

  13. An attitude-based reasoning strategy to enhance interaction with augmented objects

    OpenAIRE

    Iglesias Alvarez, Josué; Gómez Cordero, David; Bernardos Barbolla, Ana M.; Casar Corredera, Jose Ramon

    2012-01-01

    This paper describes a mobile-based system to interact with objects in smart spaces, where the offer of resources may be extensive. The underlying idea is to use the augmentation capabilities of the mobile device to enable it as user-object mediator. In particular, the paper details how to build an attitude-based reasoning strategy that facilitates user-object interaction and resource filtering. The strategy prioritizes the available resources depending on the spatial history of the user, his...

  14. The effect of computer-based learning on distance learners self regulated learning strategies

    OpenAIRE

    Mehran Farajollahi, Mahdi Moenikia

    2011-01-01

    The present research was done to compare self regulated learning strategies (SRLS) between computer-based and print-based learning students. To do so, 53 participants as experimental group and 50 participants as control group from Payame Noor University were selected randomly. The experimental group was taught via computer and control group was taught via printed materials for 8 weeks. The instrument of this research was the self regulated learning strategies (SRLS) questionnaire modified by ...

  15. Concept, strategy and realization of lectin-based glycan profiling.

    Science.gov (United States)

    Hirabayashi, Jun

    2008-08-01

    Lectins are a diverse group of carbohydrate-binding proteins. Each lectin has its own specificity profile. It is believed that lectins exist in all living organisms that produce glycans. From a practical viewpoint, lectins have been used extensively in biochemical fields including proteomics due to their usefulness as detection and enrichment tools for specific glycans. Nevertheless, they have often been underestimated as probes, especially compared with antibodies, because of their low affinity and broad specificity. However, together with the concept of glycomics, such properties of lectins are now considered to be suitable for the task of 'profiling' in order to cover a wider range of ligands. Recently there has been rapid movement in the field of proteomics aimed at the investigation of glycan-related biomarkers. This is partly because of limitations of the present approach of simply following changes in protein-level expression, without paying sufficient attention to the fact and effects of glycosylation. The trend is reflected in the frequent use of lectins in the contexts of glycoprotein enrichment and glycan profiling. However, there are many aspects to be considered in using lectins, which differ considerably from antibodies. In this article, the author, as a developer of two unique methodologies, frontal affinity chromatography (FAC) and the lectin microarray, describes critical points concerning the use of lectins, together with the concept, strategy and means to achieve advances in these emerging glycan profiling technologies. PMID:18390573

  16. 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...

  17. 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.

  18. A Regional PD Strategy for EPR Systems: Evidence-Based IT Development

    DEFF Research Database (Denmark)

    Simonsen, Jesper; Hertzum, Morten

    2006-01-01

    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...... 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....

  19. 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.

  20. Mechanical design, fabrication, and test of biomimetic fish robot using LIPCA as artificial muscle

    Science.gov (United States)

    Wiguna, T.; Syaifuddin, M.; Park, Hoon C.; Heo, S.

    2006-03-01

    This paper presents a mechanical design, fabrication and test of biomimetic fish robot using the Lightweight Piezocomposite Curved Actuator (LIPCA). We have designed a mechanism for converting actuation of the LIPCA into caudal fin movement. This linkage mechanism consists of rack-pinion system and four-bar linkage. We also have tested four types of caudal fin in order to examine effect of different shape of caudal fin on thrust generation by tail beat. Subsequently, based on the caudal fin test, four caudal fins which resemble fish caudal fin shapes of ostraciiform, subcarangiform, carangiform and thunniform, respectively, are attached to the posterior part of the robotic fish. The swimming test using 300 V pp input with 1 Hz to 1.5 Hz frequency was conducted to investigate effect of changing tail beat frequency and shape of caudal fin on the swimming speed of the robotic fish. The maximum swimming speed was reached when the device was operated at its natural swimming frequency. At the natural swimming frequency 1 Hz, maximum swimming speeds of 1.632 cm/s, 1.776 cm/s, 1.612 cm/s and 1.51 cm/s were reached for ostraciiform-, subcarangiform-, carangiform- and thunniform-like caudal fins, respectively. Strouhal numbers, which are a measure of thrust efficiency, were calculated in order to examine thrust performance of the present biomimetic fish robot. We also approximated the net forward force of the robotic fish using momentum conservation principle.

  1. 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.

  2. 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. PMID:25942821

  3. Alternate dipping preparation of biomimetic apatite layers in the presence of carbonate ions

    International Nuclear Information System (INIS)

    The classical simulated body fluids method cannot be employed to prepare biomimetic apatites encompassing metallic ions that lead to very stable phosphates. This is the case for heavy metals such as uranium, whose presence in bone mineral after contamination deserves toxicological study. We have demonstrated that existing methods, based on alternate dipping into calcium and phosphate ions solutions, can be adapted to achieve this aim. We have also especially studied the impact of the presence of carbonate ions in the medium as these are necessary to avoid hydrolysis of the contaminating metallic cations. Both the apatite–collagen complex method and a standard chemical (STD) method employing only mineral solutions lead to biomimetic apatites when calcium and carbonate ions are introduced simultaneously. The obtained materials were fully characterized and we established that the STD method tolerates the presence of carbonate ions much better, and this leads to homogeneous samples. Emphasis was set on the repeatability of the method to ensure the relevancy of further work performed on series of samples. Finally, osteoblasts cultured on these samples also proved a similar yield and standard-deviation in their adenosine triphosphate content when compared to commercially available substrates designed to study of such cell cultures. (paper)

  4. 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.

  5. 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.)

  6. 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.

  7. Biomimetic synthesized bimodal nanoporous silica: Bimodal mesostructure formation and application for ibuprofen delivery.

    Science.gov (United States)

    Li, Jing; Xu, Lu; Zheng, Nan; Wang, Hongyu; Lu, Fangzheng; Li, Sanming

    2016-01-01

    The present paper innovatively reports bimodal nanoporous silica synthesized using biomimetic method (B-BNS) with synthesized polymer (C16-L-serine) as template. Formation mechanism of B-BNS was deeply studied and exploration of its application as carrier of poorly water-soluble drug ibuprofen (IBU) was conducted. The bimodal nanopores and curved mesoscopic channels of B-BNS were achieved due to the dynamic self-assembly of C16-L-serine induced by silane coupling agent (3-aminopropyltriethoxysilane, APTES) and silica source (tetraethoxysilane, TEOS). Characterization results confirmed the successful synthesis of B-BNS, and particularly, nitrogen adsorption/desorption measurement demonstrated that B-BNS was meso-meso porous silica material. In application, B-BNS loaded IBU with high drug loading content due to its enlarged nanopores. After being loaded, IBU presented amorphous phase because nanoporous space and curved mesoscopic channels of B-BNS prevented the crystallization of IBU. In vitro release result revealed that B-BNS controlled IBU release with two release phases based on bimodal nanopores and improved dissolution in simulated gastric fluid due to crystalline conversion of IBU. It is convincible that biomimetic method provides novel theory and insight for synthesizing bimodal nanoporous silica, and unique functionalities of B-BNS as drug carrier can undoubtedly promote the application of bimodal nanoporous silica and development of pharmaceutical science.

  8. Random sampling or geostatistical modelling? Choosing between design-based and model-based sampling strategies for soil (with discussion)

    NARCIS (Netherlands)

    Brus, D.J.; Gruijter, de J.J.

    1997-01-01

    Classical sampling theory has been repeatedly identified with classical statistics which assumes that data are identically and independently distributed. This explains the switch of many soil scientists from design-based sampling strategies, based on classical sampling theory, to the model-based app

  9. 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.

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

    OpenAIRE

    Xia Pu; Guangji Li; Hanlu Huang

    2016-01-01

    ABSTRACT 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 s...

  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. Affinity chromatography based on a combinatorial strategy for rerythropoietin purification.

    Science.gov (United States)

    Martínez-Ceron, María C; Marani, Mariela M; Taulés, Marta; Etcheverrigaray, Marina; Albericio, Fernando; Cascone, Osvaldo; Camperi, Silvia A

    2011-05-01

    Small peptides containing fewer than 10 amino acids are promising ligand candidates with which to build affinity chromatographic systems for industrial protein purification. The application of combinatorial peptide synthesis strategies greatly facilitates the discovery of suitable ligands for any given protein of interest. Here we sought to identify peptide ligands with affinity for recombinant human erythropoietin (rhEPO), which is used for the treatment of anemia. A combinatorial library containing the octapeptides X-X-X-Phe-X-X-Ala-Gly, where X = Ala, Asp, Glu, Phe, His, Leu, Asn, Pro, Ser, or Thr, was synthesized on HMBA-ChemMatrix resin by the divide-couple-recombine method. For the library screening, rhEPO was coupled to either Texas Red or biotin. Fluorescent beads or beads showing a positive reaction with streptavidin-peroxidase were isolated. After cleavage, peptides were sequenced by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Fifty-seven beads showed a positive reaction. Peptides showing more consensuses were synthesized, and their affinity to rhEPO was assessed using a plasma resonance biosensor. Dissociation constant values in the range of 1-18 μM were obtained. The best two peptides were immobilized on Sepharose, and the resultant chromatographic matrixes showed affinity for rhEPO with dissociation constant values between 1.8 and 2.7 μM. Chinese hamster ovary (CHO) cell culture supernatant was spiked with rhEPO, and the artificial mixture was loaded on Peptide-Sepharose columns. The rhEPO was recovered in the elution fraction with a yield of 90% and a purity of 95% and 97% for P1-Sepharose and P2-Sepharose, respectively. PMID:21495625

  13. 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…

  14. 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.

  15. 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

  16. D4 S4: A Four Dimensions Instructional Strategy for Web-based and Blended Learning

    Directory of Open Access Journals (Sweden)

    Hamdy A. ABDELAZIZ,

    2012-08-01

    Full Text Available Web-based education is facing a paradigm shift under the rapid development of information and communication technology. The new paradigm of learning requires special techniques of course design, special instructional models, and special methods of evaluation. This paper investigates the effectiveness of an adaptive instructional strategy for teaching and learning through the Web and blended learning environments. The central theme of this strategy is that instructional strategies give instructors and students a conceptual as well as a practical mode of delivery from which to teach and learn. Considering and applying new instructional strategy can help instructors to understand the uses of pedagogical content knowledge, as well as to reflect the role of technological content knowledge that can be adapted and/or adopted in teaching in all educational levels and environments. The main objective of this paper was to develop a holonomic instructional strategy for Web-based and blended learning. This strategy is guided by the non-linear and interactive features of learning environments. The strategy is consisted of four dimensions: designing, developing, delving and distributing. In this new instructional strategy, learning is holonomic and adaptive. Learning occurs in an open learning environment, in which instructors are designing a shared vision, developing a sharable e-learning task, delving students’ learning through scaffolding and salvaging students’ knowledge. The expected outcome of this instructional strategy is that each learner will develop a cognitive schema to be used to organize and construct knowledge and meaning in similar context of learning which may increase the generalizability, trustworthiness and transferability of learning. The results of applying this new strategy showed that this strategy is effective on developing both achievement and deep learning levels among a sample of graduate students.

  17. Strategies Based on Momentum and Term Structure in Financialized Commodity Markets

    Directory of Open Access Journals (Sweden)

    Adam Zaremba

    2016-01-01

    Full Text Available The aim of this paper is to investigate the impact of the financialization of commodity markets on the profitability of strategies based on momentum and term structure. The performance of an array of portfolios from double-sorts on non-commercial traders’ participation, historical returns and term spreads are tested against a risk model. The analysis covers the listing of 26 commodities in the period 1986 – 2013. First and foremost, the paper provides a fresh evidence for the validity of strategies based on momentum and term structure investing in commodity markets. Secondly, it proves that term structure strategies generate significantly higher performance results in non-financialized markets. Moreover, it supports the thesis that market financialization adversely affects momentum profits. The results are important in terms of tactical and strategic asset allocation in commodity markets. They imply that investors who implement momentum or term structure based strategies should also consider the composition of market participants.

  18. 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.

  19. 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.

  20. Price promotions based strategy : is brand equity created?

    OpenAIRE

    Pinheiro, Duarte de Lemos

    2013-01-01

    The food distribution market has been characterized by strong and fierce price competition. Players in this market constantly make use of price appeal to attract customers and increase sales. Two main techniques have emerged over the recent years: EDLP and Hi-lo promotions. The first consists of keeping prices lower than competitors based on an efficient cost structure. The latter consists of having particular products on promotion for a certain period of time. As consumers are being bombarde...