Multifunctional thin film surface

DOEpatents

Brozik, Susan M.; Harper, Jason C.; Polsky, Ronen; Wheeler, David R.; Arango, Dulce C.; Dirk, Shawn M.

2015-10-13

A thin film with multiple binding functionality can be prepared on an electrode surface via consecutive electroreduction of two or more aryl-onium salts with different functional groups. This versatile and simple method for forming multifunctional surfaces provides an effective means for immobilization of diverse molecules at close proximities. The multifunctional thin film has applications in bioelectronics, molecular electronics, clinical diagnostics, and chemical and biological sensing.

Recent developments in wireless recording from the nervous system with ultrasonic neural dust (Conference Presentation)

NASA Astrophysics Data System (ADS)

Maharbiz, Michel M.

2017-05-01

The emerging field of bioelectronic medicine seeks methods for deciphering and modulating electrophysiological activity in the body to attain therapeutic effects at target organs. Current approaches to interfacing with peripheral nerves and muscles rely heavily on wires, creating problems for chronic use, while emerging wireless approaches lack the size scalability necessary to interrogate small-diameter nerves. Furthermore, conventional electrode-based technologies lack the capability to record from nerves with high spatial resolution or to record independently from many discrete sites within a nerve bundle. We recently demonstrated (Seo et al., arXiV, 2013; Seo et al., Neuron, 2016) "neural dust," a wireless and scalable ultrasonic backscatter system for powering and communicating with implanted bioelectronics. There, we showed that ultrasound is effective at delivering power to mm-scale devices in tissue; likewise, passive, battery-less communication using backscatter enabled high-fidelity transmission of electromyogram (EMG) and electroneurogram (ENG) signals from anesthetized rats. In this talk, I will review recent developments from my group and collaborators in this area.

Detection and classification of tastants in vivo using a novel bioelectronic tongue in combination with brain-machine interface.

PubMed

Zhen Qin; Bin Zhang; Ning Hu; Ping Wang

2015-01-01

The mammalian gustatory system is acknowledged as one of the most valid chemosensing systems. The sense of taste particularly provides critical information about ingestion of toxic and noxious chemicals. Thus the potential of utilizing rats' gustatory system is investigated in detecting sapid substances. By recording electrical activities of neurons in gustatory cortex, a novel bioelectronic tongue system is developed in combination with brain-machine interface technology. Features are extracted in both spikes and local field potentials. By visualizing these features, classification is performed and the responses to different tastants can be prominently separated from each other. The results suggest that this in vivo bioelectronic tongue is capable of detecting tastants and will provide a promising platform for potential applications in evaluating palatability of food and beverages.

Advances in Materials for Recent Low-Profile Implantable Bioelectronics

PubMed Central

Kim, Yun-Soung; Tillman, Bryan W.; Chun, Youngjae

2018-01-01

The rapid development of micro/nanofabrication technologies to engineer a variety of materials has enabled new types of bioelectronics for health monitoring and disease diagnostics. In this review, we summarize widely used electronic materials in recent low-profile implantable systems, including traditional metals and semiconductors, soft polymers, biodegradable metals, and organic materials. Silicon-based compounds have represented the traditional materials in medical devices, due to the fully established fabrication processes. Examples include miniaturized sensors for monitoring intraocular pressure and blood pressure, which are designed in an ultra-thin diaphragm to react with the applied pressure. These sensors are integrated into rigid circuits and multiple modules; this brings challenges regarding the fundamental material’s property mismatch with the targeted human tissues, which are intrinsically soft. Therefore, many polymeric materials have been investigated for hybrid integration with well-characterized functional materials such as silicon membranes and metal interconnects, which enable soft implantable bioelectronics. The most recent trend in implantable systems uses transient materials that naturally dissolve in body fluid after a programmed lifetime. Such biodegradable metallic materials are advantageous in the design of electronics due to their proven electrical properties. Collectively, this review delivers the development history of materials in implantable devices, while introducing new bioelectronics based on bioresorbable materials with multiple functionalities. PMID:29596359

Advances in Materials for Recent Low-Profile Implantable Bioelectronics.

PubMed

Chen, Yanfei; Kim, Yun-Soung; Tillman, Bryan W; Yeo, Woon-Hong; Chun, Youngjae

2018-03-29

The rapid development of micro/nanofabrication technologies to engineer a variety of materials has enabled new types of bioelectronics for health monitoring and disease diagnostics. In this review, we summarize widely used electronic materials in recent low-profile implantable systems, including traditional metals and semiconductors, soft polymers, biodegradable metals, and organic materials. Silicon-based compounds have represented the traditional materials in medical devices, due to the fully established fabrication processes. Examples include miniaturized sensors for monitoring intraocular pressure and blood pressure, which are designed in an ultra-thin diaphragm to react with the applied pressure. These sensors are integrated into rigid circuits and multiple modules; this brings challenges regarding the fundamental material's property mismatch with the targeted human tissues, which are intrinsically soft. Therefore, many polymeric materials have been investigated for hybrid integration with well-characterized functional materials such as silicon membranes and metal interconnects, which enable soft implantable bioelectronics. The most recent trend in implantable systems uses transient materials that naturally dissolve in body fluid after a programmed lifetime. Such biodegradable metallic materials are advantageous in the design of electronics due to their proven electrical properties. Collectively, this review delivers the development history of materials in implantable devices, while introducing new bioelectronics based on bioresorbable materials with multiple functionalities.

The rise of plastic bioelectronics.

PubMed

Someya, Takao; Bao, Zhenan; Malliaras, George G

2016-12-14

Plastic bioelectronics is a research field that takes advantage of the inherent properties of polymers and soft organic electronics for applications at the interface of biology and electronics. The resulting electronic materials and devices are soft, stretchable and mechanically conformable, which are important qualities for interacting with biological systems in both wearable and implantable devices. Work is currently aimed at improving these devices with a view to making the electronic-biological interface as seamless as possible.

The rise of plastic bioelectronics

NASA Astrophysics Data System (ADS)

Someya, Takao; Bao, Zhenan; Malliaras, George G.

2016-12-01

Plastic bioelectronics is a research field that takes advantage of the inherent properties of polymers and soft organic electronics for applications at the interface of biology and electronics. The resulting electronic materials and devices are soft, stretchable and mechanically conformable, which are important qualities for interacting with biological systems in both wearable and implantable devices. Work is currently aimed at improving these devices with a view to making the electronic-biological interface as seamless as possible.

Hybrid Nanowire Ion-to-Electron Transducers for Integrated Bioelectronic Circuitry.

PubMed

Carrad, D J; Mostert, A B; Ullah, A R; Burke, A M; Joyce, H J; Tan, H H; Jagadish, C; Krogstrup, P; Nygård, J; Meredith, P; Micolich, A P

2017-02-08

A key task in the emerging field of bioelectronics is the transduction between ionic/protonic and electronic signals at high fidelity. This is a considerable challenge since the two carrier types exhibit intrinsically different physics and are best supported by very different materials types-electronic signals in inorganic semiconductors and ionic/protonic signals in organic or bio-organic polymers, gels, or electrolytes. Here we demonstrate a new class of organic-inorganic transducing interface featuring semiconducting nanowires electrostatically gated using a solid proton-transporting hygroscopic polymer. This model platform allows us to study the basic transducing mechanisms as well as deliver high fidelity signal conversion by tapping into and drawing together the best candidates from traditionally disparate realms of electronic materials research. By combining complementary n- and p-type transducers we demonstrate functional logic with significant potential for scaling toward high-density integrated bioelectronic circuitry.

Low-Temperature Cross-Linking of PEDOT:PSS Films Using Divinylsulfone.

PubMed

Mantione, Daniele; Del Agua, Isabel; Schaafsma, Wandert; ElMahmoudy, Mohammed; Uguz, Ilke; Sanchez-Sanchez, Ana; Sardon, Haritz; Castro, Begoña; Malliaras, George G; Mecerreyes, David

2017-05-31

Recent interest in bioelectronics has prompted the exploration of properties of conducting polymer films at the interface with biological milieus. Poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS) from a commercially available source has been used as a model system for these studies. Different cross-linking schemes have been used to stabilize films of this material against delamination and redispersion, but the cost is a decrease in the electrical conductivity and/or additional heat treatment. Here we introduce divinylsulfone (DVS) as a new cross-linker for PEDOT:PSS. Thanks to the higher reactiveness of the vinyl groups of DVS, the cross-linking can be performed at room temperature. In addition, DVS does not reduce electronic conductivity of PEDOT:PSS but rather increases it by acting as a secondary dopant. Cell culture studies show that PEDOT:PSS:DVS films are cytocompatible and support neuroregeneration. As an example, we showed that this material improved the transconductance value and stability of an organic electrochemical transistor (OECT) device. These results open the way for the utilization of DVS as an effective cross-linker for PEDOT:PSS in bioelectronics applications.

Retinal stimulation strategies to restore vision: Fundamentals and systems.

PubMed

Yue, Lan; Weiland, James D; Roska, Botond; Humayun, Mark S

2016-07-01

Retinal degeneration, a leading cause of blindness worldwide, is primarily characterized by the dysfunctional/degenerated photoreceptors that impair the ability of the retina to detect light. Our group and others have shown that bioelectronic retinal implants restore useful visual input to those who have been blind for decades. This unprecedented approach of restoring sight demonstrates that patients can adapt to new visual input, and thereby opens up opportunities to not only improve this technology but also develop alternative retinal stimulation approaches. These future improvements or new technologies could have the potential of selectively stimulating specific cell classes in the inner retina, leading to improved visual resolution and color vision. In this review we will detail the progress of bioelectronic retinal implants and future devices in this genre as well as discuss other technologies such as optogenetics, chemical photoswitches, and ultrasound stimulation. We will discuss the principles, biological aspects, technology development, current status, clinical outcomes/prospects, and challenges for each approach. The review will cover functional imaging documented cortical responses to retinal stimulation in blind patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biological components and bioelectronic interfaces of water splitting photoelectrodes for solar hydrogen production.

PubMed

Braun, Artur; Boudoire, Florent; Bora, Debajeet K; Faccio, Greta; Hu, Yelin; Kroll, Alexandra; Mun, Bongjin S; Wilson, Samuel T

2015-03-09

Artificial photosynthesis (AP) is inspired by photosynthesis in nature. In AP, solar hydrogen can be produced by water splitting in photoelectrochemical cells (PEC). The necessary photoelectrodes are inorganic semiconductors. Light-harvesting proteins and biocatalysts can be coupled with these photoelectrodes and thus form bioelectronic interfaces. We expand this concept toward PEC devices with vital bio-organic components and interfaces, and their integration into the built environment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication of biomolecules self-assembled on Au nanodot array for bioelectronic device.

PubMed

Lee, Taek; Kumar, Ajay Yagati; Yoo, Si-Youl; Jung, Mi; Min, Junhong; Choi, Jeong-Woo

2013-09-01

In the present study, an nano-platform composed of Au nanodot arrays on which biomolecules could be self-assembled was developed and investigated for a stable bioelectronic device platform. Au nanodot pattern was fabricated using a nanoporous alumina template. Two different biomolecules, a cytochrome c and a single strand DNA (ssDNA), were immobilized on the Au nanodot arrays. Cytochorme c and single stranded DNA could be immobilized on the Au nanodot using the chemical linker 11-MUA and thiol-modification by covalent bonding, respectively. The atomic structure of the fabricated nano-platform device was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The electrical conductivity of biomolecules immobilized on the Au nanodot arrays was confirmed by scanning tunneling spectroscopy (STS). To investigate the activity of biomolecule-immobilized Au-nano dot array, the cyclic voltammetry was carried out. This proposed nano-platform device, which is composed of biomolecules, can be used for the construction of a novel bioelectronic device.

Soft, Conformal Bioelectronics for a Wireless Human-Wheelchair Interface

PubMed Central

Mishra, Saswat; Norton, James J. S.; Lee, Yongkuk; Lee, Dong Sup; Agee, Nicolas; Chen, Yanfei; Chun, Youngjae; Yeo, Woon-Hong

2017-01-01

There are more than 3 million people in the world whose mobility relies on wheelchairs. Recent advancement on engineering technology enables more intuitive, easy-to-use rehabilitation systems. A human-machine interface that uses non-invasive, electrophysiological signals can allow a systematic interaction between human and devices; for example, eye movement-based wheelchair control. However, the existing machine-interface platforms are obtrusive, uncomfortable, and often cause skin irritations as they require a metal electrode affixed to the skin with a gel and acrylic pad. Here, we introduce a bioelectronic system that makes dry, conformal contact to the skin. The mechanically comfortable sensor records high-fidelity electrooculograms, comparable to the conventional gel electrode. Quantitative signal analysis and infrared thermographs show the advantages of the soft biosensor for an ergonomic human-machine interface. A classification algorithm with an optimized set of features shows the accuracy of 94% with five eye movements. A Bluetooth-enabled system incorporating the soft bioelectronics demonstrates a precise, hands-free control of a robotic wheelchair via electrooculograms. PMID:28152485

Recent Advances in Flexible and Stretchable Bio-Electronic Devices Integrated with Nanomaterials.

PubMed

Choi, Suji; Lee, Hyunjae; Ghaffari, Roozbeh; Hyeon, Taeghwan; Kim, Dae-Hyeong

2016-06-01

Flexible and stretchable electronics and optoelectronics configured in soft, water resistant formats uniquely address seminal challenges in biomedicine. Over the past decade, there has been enormous progress in the materials, designs, and manufacturing processes for flexible/stretchable system subcomponents, including transistors, amplifiers, bio-sensors, actuators, light emitting diodes, photodetector arrays, photovoltaics, energy storage elements, and bare die integrated circuits. Nanomaterials prepared using top-down processing approaches and synthesis-based bottom-up methods have helped resolve the intrinsic mechanical mismatch between rigid/planar devices and soft/curvilinear biological structures, thereby enabling a broad range of non-invasive, minimally invasive, and implantable systems to address challenges in biomedicine. Integration of therapeutic functional nanomaterials with soft bioelectronics demonstrates therapeutics in combination with unconventional diagnostics capabilities. Recent advances in soft materials, devices, and integrated systems are reviewes, with representative examples that highlight the utility of soft bioelectronics for advanced medical diagnostics and therapies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Charge transport through exciton shelves in cadmium chalcogenide quantum dot-DNA nano-bioelectronic thin films

NASA Astrophysics Data System (ADS)

Goodman, Samuel M.; Noh, Hyunwoo; Singh, Vivek; Cha, Jennifer N.; Nagpal, Prashant

2015-02-01

Quantum dot (QD), or semiconductor nanocrystal, thin films are being explored for making solution-processable devices due to their size- and shape-tunable bandgap and discrete higher energy electronic states. While DNA has been extensively used for the self-assembly of nanocrystals, it has not been investigated for the simultaneous conduction of multiple energy charges or excitons via exciton shelves (ES) formed in QD-DNA nano-bioelectronic thin films. Here, we present studies on charge conduction through exciton shelves, which are formed via chemically coupled QDs and DNA, between electronic states of the QDs and the HOMO-LUMO levels in the complementary DNA nucleobases. While several challenges need to be addressed in optimizing the formation of devices using QD-DNA thin films, a higher charge collection efficiency for hot-carriers and our detailed investigations of charge transport mechanism in these thin films highlight their potential for applications in nano-bioelectronic devices and biological transducers.

Bioelectronic Device Mimicking Human Sensory System based on Nanovesicle-Carbon Nanotube Hybrid Structure

NASA Astrophysics Data System (ADS)

Kim, Daesan; Jin, Hye; Lee, San; Kim, Tae; Park, Juhun; Song, Hyun; Park, Tai; Hong, Seunghun

2013-03-01

We have developed a nanovesicle-based bioelectronic nose (NBN) that could mimic the receptor-mediated signal transmission of human olfactory systems and recognize a specific odorant. The NBN was comprised of a single-walled carbon nanotube (CNT)-based field effect transistor and cell-derived nanovesicles containing human olfactory receptors and calcium ion signal pathways. Importantly, the NBN took advantages of cell signal pathways for sensing signal amplification. It enabled ~100 times higher sensitivity than that of previous bioelectronic noses based on only olfactory receptor protein and CNT transistors. The NBN sensors exhibited a high sensitivity of 1 fM detection limit and a human-like selectivity with single-carbon-atomic resolution. Furthermore, these sensors could mimic a receptor-mediated cellular signal transmission in live cells. This versatile sensor platform should be useful for the study of molecular recognition and biological processes on cell membranes and also for various practical applications such as food conditioning and medical diagnostics.

Nanovesicle-based bioelectronic nose platform mimicking human olfactory signal transduction.

PubMed

Jin, Hye Jun; Lee, Sang Hun; Kim, Tae Hyun; Park, Juhun; Song, Hyun Seok; Park, Tai Hyun; Hong, Seunghun

2012-05-15

We developed a nanovesicle-based bioelectronic nose (NBN) that could recognize a specific odorant and mimic the receptor-mediated signal transmission of human olfactory systems. To build an NBN, we combined a single-walled carbon nanotube-based field effect transistor with cell-derived nanovesicles containing human olfactory receptors and calcium ion signal pathways. Importantly, the NBN took advantages of cell signal pathways for sensing signal amplification, enabling ≈ 100 times better sensitivity than that of previous bioelectronic noses based on only olfactory receptor protein and carbon nanotube transistors. The NBN sensors exhibited a human-like selectivity with single-carbon-atomic resolution and a high sensitivity of 1 fM detection limit. Moreover, this sensor platform could mimic a receptor-meditated cellular signal transmission in live cells. This sensor platform can be utilized for the study of molecular recognition and biological processes occurring at cell membranes and also for various practical applications such as food screening and medical diagnostics. Copyright © 2012 Elsevier B.V. All rights reserved.

Improving biocompatibility by surface modification techniques on implantable bioelectronics.

PubMed

Lin, Peter; Lin, Chii-Wann; Mansour, Raafat; Gu, Frank

2013-09-15

For implantable bioelectronic devices, the interface between the device and the biological environment requires significant attention as it dictates the device performance in vivo. Non-specific protein adsorption onto the device surface is the initial stage of many degradation mechanisms that will ultimately compromise the functionality of the device. In order to preserve the functionality of any implanted bioelectronics overtime, protein adsorption must be controlled. This review paper outlines two major approaches to minimize protein adsorption onto the surface of implantable electronics. The first approach is surface coating, which minimizes close proximity interactions between proteins and device surfaces by immobilizing electrically neutral hydrophilic polymers as surface coating. These coatings reduce protein fouling by steric repulsion and formation of a hydration layer which acts as both a physical and energetic barrier that minimize protein adsorption onto the device. Relevant performances of various conventional hydrophilic coatings are discussed. The second approach is surface patterning using arrays of hydrophobic nanostructures through photolithography techniques. By establishing a large slip length via super hydrophobic surfaces, the amount of proteins adsorbed to the surface of the device can be reduced. The last section discusses emerging surface coating techniques utilizing zwitterionic polymers where ultralow-biofouling surfaces have been demonstrated. These surface modification techniques may significantly improve the long-term functionality of implantable bioelectronics, thus allowing researchers to overcome challenges to diagnose and treat chronic neurological and cardiovascular diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

Towards bioelectronic logic (Conference Presentation)

NASA Astrophysics Data System (ADS)

Meredith, Paul; Mostert, Bernard; Sheliakina, Margarita; Carrad, Damon J.; Micolich, Adam P.

2016-09-01

One of the critical tasks in realising a bioelectronic interface is the transduction of ion and electron signals at high fidelity, and with appropriate speed, bandwidth and signal-to-noise ratio [1]. This is a challenging task considering ions and electrons (or holes) have drastically different physics. For example, even the lightest ions (protons) have mobilities much smaller than electrons in the best semiconductors, effective masses are quite different, and at the most basic level, ions are `classical' entities and electrons `quantum mechanical'. These considerations dictate materials and device strategies for bioelectronic interfaces alongside practical aspects such as integration and biocompatibility [2]. In my talk I will detail these `differences in physics' that are pertinent to the ion-electron transduction challenge. From this analysis, I will summarise the basic categories of device architecture that are possibilities for transducing elements and give recent examples of their realisation. Ultimately, transducing elements need to be combined to create `bioelectronic logic' capable of signal processing at the interface level. In this regard, I will extend the discussion past the single element concept, and discuss our recent progress in delivering all-solids-state logic circuits based upon transducing interfaces. [1] "Ion bipolar junction transistors", K. Tybrandt, K.C. Larsson, A. Richter-Dahlfors and M. Berggren, Proc. Natl Acad. Sci., 107, 9929 (2010). [2] "Electronic and optoelectronic materials and devices inspired by nature", P Meredith, C.J. Bettinger, M. Irimia-Vladu, A.B. Mostert and P.E. Schwenn, Reports on Progress in Physics, 76, 034501 (2013).

A biomimetic bioelectronic tongue: A switch for On- and Off- response of acid sensations.

PubMed

Zhang, Wei; Chen, Peihua; Zhou, Lianqun; Qin, Zhen; Gao, Keqiang; Yao, Jia; Li, Chuanyu; Wang, Ping

2017-06-15

The perception of sour taste in mammals is important for its basic modality properties and avoiding toxic substances. We explore a biomimetic bioelectronic tongue, which integrate MEA (microelectrode array) and taste receptor cell for acid detection as a switch. However, the acid-sensing mechanism and coding of the taste receptor cells in the periphery is not well understood, with long-standing debate. Therefore, we firstly construct a Hodgkin-Huxley type mathematical model of whole-cell acid-sensing taste receptor cells based on the electrophysiologic patch clamp recordings with different acid sensitive receptor expressing and different acidic stimulations. ASICs and PKDL channels are two most promising candidates for acidic sensation. ASICs channels contribute to the On response, and PKDL channels coding the Offset stimulations respectively, which function as a pair for switch. Therefore, with the advantage of effective and noninvasive detection for MEA, a sour taste biosensor based on MEA and taste receptor cells was designed and established to detect sour response from the elementary acid sensitive taste receptor cells during and after stimulus. From simulation and extracelluar potential recordings, we found the biomimetic bioelectronic tongue was acid-sensitive, as acid stimulation pH decrease, the firing frequency significantly increase. Furthermore, this reliable and effective MEA based bioelectronic tongue functioned as a switch for stimulation On and Off. This study provided a powerful platform to recognize sour stimulation and help elucidate the sour taste sensation and coding mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface analytical characterization of Streptavidin/poly(3-hexylthiophene) bilayers for bio-electronic applications

NASA Astrophysics Data System (ADS)

Sportelli, M. C.; Picca, R. A.; Manoli, K.; Re, M.; Pesce, E.; Tapfer, L.; Di Franco, C.; Cioffi, N.; Torsi, L.

2017-10-01

The analytical performance of bioelectronic devices is highly influenced by their fabrication methods. In particular, the final architecture of field-effect transistor biosensors combining spin-cast poly(3-hexylthiophene) (P3HT) film and a biomolecule interlayer deposited on a SiO2/Si substrate can lead to the development of highly performing sensing systems, such as for the case of streptavidin (SA) used for biotin sensing. To gain a better understanding of the quality of the interfacial area, critical is the assessment of the morphological features characteristic of the adopted biolayer deposition protocol, namely: the layer-by-layer (LbL) approach and the spin coating technique. The present study relies on a combined surface spectroscopic and morphological characterization. Specifically, X-ray photoelectron spectroscopy operated in the parallel angle-resolved mode allowed the non-destructive investigation of the in-depth chemical composition of the SA film, alone or in the presence of the P3HT overlayer. Spectroscopic data were supported and corroborated by the results obtained with a Scanning Electron and a Helium Ion microscope investigation performed on the SA layer that provided relevant information on the protein structural arrangement or on its surface morphology. Clear differences emerged between the SA layers prepared by the two approaches, with the layer-by-layer deposition resulting in a smoother and better defined bio-electronic interface. Such findings support the superior analytical performance shown by bioelectronic devices based on LbL-deposited protein layers over spin coated ones.

Bioelectronic tongue of taste buds on microelectrode array for salt sensing.

PubMed

Liu, Qingjun; Zhang, Fenni; Zhang, Diming; Hu, Ning; Wang, Hua; Hsia, K Jimmy; Wang, Ping

2013-02-15

Taste has received great attention for its potential applications. In this work, we combine the biological tissue with micro-chips to establish a novel bioelectronic tongue system for salt taste detection. Before experiment, we established a computational model of action potential in salt taste receptor cell, simulating the responsive results to natural salt stimuli of NaCl solution with various concentrations. Then 36-channel microelectrode arrays (MEA) with the diameter of 30 μm were fabricated on the glass substrate, and taste epithelium was stripped from rat and fixed on MEA. When stimulated by the salt stimuli, electrophysiological activities of taste receptor cells in taste buds were measured through a multi-channel recording system. Both simulation and experiment results showed a dose-dependent increase in NaCl-induced potentials of taste receptor cells, which indicated good applications in salt measurements. The multi-channel analysis demonstrated that different groups of MEA channels were activated during stimulations, indicating non-overlapping populations of receptor cells in taste buds involved in salt taste perception. The study provides an effective and reliable biosensor platform to help recognize and distinguish salt taste components. Copyright © 2012 Elsevier B.V. All rights reserved.

Nickel electrodes as a cheap and versatile platform for studying structure and function of immobilized redox proteins.

PubMed

Han, Xiao Xia; Li, Junbo; Öner, Ibrahim Halil; Zhao, Bing; Leimkühler, Silke; Hildebrandt, Peter; Weidinger, Inez M

2016-10-19

Practical use of many bioelectronic and bioanalytical devices is limited by the need of expensive materials and time consuming fabrication. Here we demonstrate the use of nickel electrodes as a simple and cheap solid support material for bioelectronic applications. The naturally nanostructured electrodes showed a surprisingly high electromagnetic surface enhancement upon light illumination such that immobilization and electron transfer reactions of the model redox proteins cytochrome b 5 (Cyt b 5 ) and cytochrome c (Cyt c) could be followed via surface enhanced resonance Raman spectroscopy. It could be shown that the nickel surface, when used as received, promotes a very efficient binding of the proteins upon preservation of their native structure. The immobilized redox proteins could efficiently exchange electrons with the electrode and could even act as an electron relay between the electrode and solubilized myoglobin. Our results open up new possibility for nickel electrodes as an exceptional good support for bioelectronic devices and biosensors on the one hand and for surface enhanced spectroscopic investigations on the other hand. Copyright © 2016 Elsevier B.V. All rights reserved.

Bioelectronic sniffer for nicotine using enzyme inhibition.

PubMed

Mitsubayashi, Kohji; Nakayama, Kazumi; Taniguchi, Midori; Saito, Hirokazu; Otsuka, Kimio; Kudo, Hiroyuki

2006-07-28

A novel bioelectronic sniffer for nicotine in the gas phase was developed with enzyme inhibition principle to butyrylcholinesterase activity. The bioelectronic devices for nicotine in the gas and liquid phases were constructed using a Clark-type dissolved oxygen electrode and a membrane immobilized butyrylcholinesterase and choline oxidase. After the assessment of the sensor performances to choline and butyrylcholine as pre-examinations, the characteristics of the biosensor and bio-sniffer for nicotine were evaluated in the liquid and gas phases, respectively. The sensor signal of the bio-devices with 300 micromol l(-1) of butyrylcholine decreased quickly following application of nicotine and reached to the steady-state current, thus relating the concentration of nicotine in the liquid and gas phases. The biosensor was used to measure nicotine solution from 10 to 300 micromol l(-1). In the gas-phase experiment, the current signal of the bio-sniffer was also found to be linearly to the nicotine concentration over the range of 10.0-1000 ppb including 75.0 ppb as threshold limit value (TLV) by American Conference of Governmental Industrial Hygienists (ACGIH).

Melanin: spin behaviour and implications for bioelectronic devices (Presentation Recording)

NASA Astrophysics Data System (ADS)

Meredith, Paul; Sheliakina, Margarita; Mostert, Bernard

2015-10-01

The melanins are a broad class of pigmentary macromolecules found through nature that perform a wide range of functions including photo-protection [1]. The most common melanin - the brown, black pigment eumelanin, has been much studied because of its role in melanoma and also for its functional material properties [2]. Synthetic eumelanin has been shown to be photoconductive in the solid state and also possess a water content dependent dark conductivity [3]. It is now well established that these electrical properties arise from hybrid ionic-electronic behaviour, leading to the proposition that melanins could be model biocompatible systems for ion-to-electron transduction in bioelectronics. In my talk, I will discuss the basic science behind these bioelectronics properties - electrical and optical. In this context I will also describe recent electron paramagnetic spin studies which isolate the role of the various chemical moieties responsible for the hybrid ionic-electronic behaviour. I will also highlight preliminary results on prototype melanin-based bioelectronics devices and discuss possible architectures to realise elements such as solid-state switches and transducers. [1] "The physical and chemical properties of eumelanin", P. Meredith and T. Sarna, Pigment Cell Research, 19(6), pp572-594 (2006). [2] "Electronic and optoelectronic materials and devices inspired by nature", P Meredith, C.J. Bettinger, M. Irimia-Vladu, A.B. Mostert and P.E. Schwenn, Reports on Progress in Physics, 76, 034501 (2013). [3] "Is melanin a semiconductor: humidity induced self doping and the electrical conductivity of a biopolymer", A.B. Mostert, B.J. Powell, F.L. Pratt, G.R. Hanson, T. Sarna, I.R. Gentle and P. Meredith, Proceedings of the National Academy of Sciences of the USA, 109(23), 8943-8947 (2012).

Single-Molecule Bioelectronics

PubMed Central

Rosenstein, Jacob K.; Lemay, Serge G.; Shepard, Kenneth L.

2014-01-01

Experimental techniques which interface single biomolecules directly with microelectronic systems are increasingly being used in a wide range of powerful applications, from fundamental studies of biomolecules to ultra-sensitive assays. Here we review several technologies which can perform electronic measurements of single molecules in solution: ion channels, nanopore sensors, carbon nanotube field-effect transistors, electron tunneling gaps, and redox cycling. We discuss the shared features among these techniques that enable them to resolve individual molecules, and discuss their limitations. Recordings from each of these methods all rely on similar electronic instrumentation, and we discuss the relevant circuit implementations and potential for scaling these single-molecule bioelectronic interfaces to high-throughput arrayed sensing platforms. PMID:25529538

Applicability of a bioelectronic cardiac monitoring system for the detection of biological effects of pollution in bioindicator species in the Gulf of Finland

NASA Astrophysics Data System (ADS)

Kholodkevich, Sergey V.; Kuznetsova, Tatiana V.; Sharov, Andrey N.; Kurakin, Anton S.; Lips, Urmas; Kolesova, Natalia; Lehtonen, Kari K.

2017-07-01

Field testing of an innovative technology based on a bioelectronic cardiac monitoring system was carried out in the Gulf of Finland (Baltic Sea). The study shows that the bioelectronic system is suitable for the selected bivalve mollusks Mytilus trossulus, Macoma balthica and Anodonta anatina. Specimens taken from reference sites demonstrated a heart rate recovery time of < 60 min after testing with changed salinity load, while those collected from sites characterized by high anthropogenic pressure demonstrated a prolonged recovery time of up to 110-360 min. These results make possible a discrimination of the study sites based on the assessment of physiological adaptive capacities of inhabiting species. In addition, the approach of measuring heart rate characteristics in M. balthica transplanted in cages to specific target areas was successfully used to evaluate the decline in the adaptive potential of mollusks exposed at polluted sites. Application of the novel system is a useful tool for the biomonitoring of freshwater and brackish water areas. Development of methodological basis for the testing of adaptive capacities (health) of key aquatic organisms provides new knowledge of biological effects of anthropogenic chemical stress in aquatic organisms.

Bioelectronic nose and its application to smell visualization.

PubMed

Ko, Hwi Jin; Park, Tai Hyun

2016-01-01

There have been many trials to visualize smell using various techniques in order to objectively express the smell because information obtained from the sense of smell in human is very subjective. So far, well-trained experts such as a perfumer, complex and large-scale equipment such as GC-MS, and an electronic nose have played major roles in objectively detecting and recognizing odors. Recently, an optoelectronic nose was developed to achieve this purpose, but some limitations regarding the sensitivity and the number of smells that can be visualized still persist. Since the elucidation of the olfactory mechanism, numerous researches have been accomplished for the development of a sensing device by mimicking human olfactory system. Engineered olfactory cells were constructed to mimic the human olfactory system, and the use of engineered olfactory cells for smell visualization has been attempted with the use of various methods such as calcium imaging, CRE reporter assay, BRET, and membrane potential assay; however, it is not easy to consistently control the condition of cells and it is impossible to detect low odorant concentration. Recently, the bioelectronic nose was developed, and much improved along with the improvement of nano-biotechnology. The bioelectronic nose consists of the following two parts: primary transducer and secondary transducer. Biological materials as a primary transducer improved the selectivity of the sensor, and nanomaterials as a secondary transducer increased the sensitivity. Especially, the bioelectronic noses using various nanomaterials combined with human olfactory receptors or nanovesicles derived from engineered olfactory cells have a potential which can detect almost all of the smells recognized by human because an engineered olfactory cell might be able to express any human olfactory receptor as well as can mimic human olfactory system. Therefore, bioelectronic nose will be a potent tool for smell visualization, but only if two technologies are completed. First, a multi-channel array-sensing system has to be applied for the integration of all of the olfactory receptors into a single chip for mimicking the performance of human nose. Second, the processing technique of the multi-channel system signals should be simultaneously established with the conversion of the signals to visual images. With the use of this latest sensing technology, the realization of a proper smell-visualization technology is expected in the near future.

Bioelectronic Nose Using Odorant Binding Protein-Derived Peptide and Carbon Nanotube Field-Effect Transistor for the Assessment of Salmonella Contamination in Food.

PubMed

Son, Manki; Kim, Daesan; Kang, Jinkyung; Lim, Jong Hyun; Lee, Seung Hwan; Ko, Hwi Jin; Hong, Seunghun; Park, Tai Hyun

2016-12-06

Salmonella infection is the one of the major causes of food borne illnesses including fever, abdominal pain, diarrhea, and nausea. Thus, early detection of Salmonella contamination is important for our healthy life. Conventional detection methods for the food contamination have limitations in sensitivity and rapidity; thus, the early detection has been difficult. Herein, we developed a bioelectronic nose using a carbon nanotube (CNT) field-effect transistor (FET) functionalized with Drosophila odorant binding protein (OBP)-derived peptide for easy and rapid detection of Salmonella contamination in ham. 3-Methyl-1-butanol is known as a specific volatile organic compound, generated from the ham contaminated with Salmonella. We designed and synthesized the peptide based on the sequence of the Drosophila OBP, LUSH, which specifically binds to alcohols. The C-terminus of the synthetic peptide was modified with three phenylalanine residues and directly immobilized onto CNT channels using the π-π interaction. The p-type properties of FET were clearly maintained after the functionalization using the peptide. The biosensor detected 1 fM of 3-methyl-1-butanol with high selectivity and successfully assessed Salmonella contamination in ham. These results indicate that the bioelectronic nose can be used for the rapid detection of Salmonella contamination in food.

PREFACE: India-Japan Workshop on Biomolecular Electronics & Organic Nanotechnology for Environment Preservation

NASA Astrophysics Data System (ADS)

Onoda, Mitsuyoshi; Malhotra, Bansi D.

2012-04-01

The 'India-Japan Workshop on Biomolecular Electronics & Organic Nanotechnology for Environment Preservation' (IJWBME 2011) will be held on 7-10 December 2011 at EGRET Himeji, Himeji, Hyogo, Japan. This workshop was held for the first time on 17-19 December 2009 at NPL, New Delhi. Keeping in mind the importance of organic nanotechnology and biomolecular electronics for environmental preservation and their anticipated impact on the economics of both the developing and the developed world, IJWBME 2009 was jointly organized by the Department of Biological Functions, Graduate School of Life Sciences and Systems Engineering, the Kyushu Institute of Technology (KIT), Kitakyushu, Japan, and the Department of Science & Technology Centre on Biomolecular Electronics (DSTCBE), National Physical Laboratory (NPL). Much progress in the field of biomolecular electronics and organic nanotechnology for environmental preservation is expected for the 21st Century. Organic optoelectronic devices, such as organic electroluminescent devices, organic thin-film transistors, organic sensors, biological systems and so on have especially attracted much attention. The main purpose of this workshop is to provide an opportunity for researchers interested in biomolecular electronics and organic nanotechnology for environmental preservation, to come together in an informal and friendly atmosphere and exchange technical knowledge and experience. We are sure that this workshop will be very useful and fruitful for all participants in summarizing the recent progress in biomolecular electronics and organic nanotechnology for environmental preservation and preparing new ground for the next generation. Many papers have been submitted from India and Japan and more than 30 papers have been accepted for presentation. The main topics of interest are as follows: Bioelectronics Biomolecular Electronics Fabrication Techniques Self-assembled Monolayers Nano-sensors Environmental Monitoring Organic Devices Organic Functional Materials We would like to express our sincere thanks to the organizing committee members of this workshop and the many organizations such as the Japan Society for the Promotion of Science (JSPS), Japan, the Department of Science & Technology (DST), India, the Society of Organic Nanometric Interfacial Controlled Electronic (NICE) Devices, the Japan Society of Applied Physics, Himeji City, Himeji Convention & Visitors Bureau, Delhi Technological University, Delhi, India and the University of Hyogo for their financial support. Thanks are also given to The Japan Society of Applied Physics, Division of Molecular Electronics and Bioelectronics, The Japan Society of Applied Physics (M & BE), the Technical Committee on Dielectric and Electrical Insulation Materials of the Institute of Electrical Engineering in Japan (IEEJ), the Technical Group on Organic Molecular Electronics, Electronics Society of the Institute of Electronics, Information and Communication Engineers (IEICE), and the IEEE Dielectrics and Electrical Insulation Society, Japan Chapter, for their cooperation. Finally, we hope that the many young and active researchers who are participating will enjoy stimulating discussions and exchange ideas with each other at IJWBME 2011, Himeji, Japan. 7 April 2011 IJWBME 2011 Chairs Mitsuyoshi Onoda Graduate School of Engineering, University of Hyogo, Himeji, Japan Bansi D Malhotra Department of Biotechnology, Delhi Technological University, Delhi, India Conference photograph Participants of the India-Japan Workshop on Biomolecular Electronics & Organic Nanotechnology for Environment Preservation 2011, December 7-10 2011, EGRET Himeji, Japan The PDF also contains a list of sponsors.

Biologically active compounds to develop bioelectronics and bio photonics

NASA Astrophysics Data System (ADS)

Mishra, Ashok Kumar; Tiwari, Satya Prakash

2018-05-01

Recent reports on biomaterials and biological systems at nano scale provide researchers with a fertile ground with regard to materials, enabling bioelectronics, bio sensing and new nanotechnologies that cover a wide range of applications. The signal transductions have been reported for many biological phenomenons and new field of biophysics namely Biosensors and Bioelectronics have been emerged out. The advances in the study of various aspects of bio molecules like electrical, optical, thermal etc has established the interesting area of research like biophotonics, nanobiotechnology, molecular solid, molecular liquids, bio instrumentation etc. The present study discusses the some aspects and applications of the bioprocess yields nanostructures that are nearly flawless in composition, stereo specific in structure, and flexible. Furthermore, these biomaterials are environment friendly because they are biodegradable in nature. Biological compounds are self assembled into complex nanostructures and behave like a system possessing long range hierarchical nanoscale order. In addition, chemical modification and genetic engineering can be used to modify bio materials to enhance a specific property. Various biomaterials have been reported which allow nanostructure control for nano photonic applications. The dielectric and conduction properties of the bio molecules have been the subject of many investigations. As a result, there exist a wealth of valuable information on the charge transport and rotational properties of many bio molecules. Amino acids and proteins, nucleic acids, lipids, cell and tissues have been characterized over a wide frequency spectrum ranging from a few hertz to Giga hertz. In certain cases, dielectric measurements have been exploited to probe the physical changes taking place in biologically important structures, for example, in lipid phase transition process in membrane. The phase transition in membrane may be analyzed by applying the theory for lyotropic phase transition in liquid crystals. The photosynthesis property in plant systems may be well interpreted by exploiting the theory for excitonic process taking place in organic semiconductors for electroluminescence and photovoltaic. The biosensor for the measurement of compatibility of a graft union based on electrical measurements has been reported. The present paper discusses the some aspects of recent advances in biomaterials research and correlates it as a basis of emergence of a new discipline namely Bioelectronics and Bio photonics.

Computational and theoretical modeling of pH and flow effects on the early-stage non-equilibrium self-assembly of optoelectronic peptides

NASA Astrophysics Data System (ADS)

Mansbach, Rachael; Ferguson, Andrew

Self-assembling π-conjugated peptides are attractive candidates for the fabrication of bioelectronic materials possessing optoelectronic properties due to electron delocalization over the conjugated peptide groups. We present a computational and theoretical study of an experimentally-realized optoelectronic peptide that displays triggerable assembly in low pH to resolve the microscopic effects of flow and pH on the non-equilibrium morphology and kinetics of assembly. Using a combination of molecular dynamics simulations and hydrodynamic modeling, we quantify the time and length scales at which convective flows employed in directed assembly compete with microscopic diffusion to influence assembly. We also show that there is a critical pH below which aggregation proceeds irreversibly, and quantify the relationship between pH, charge density, and aggregate size. Our work provides new fundamental understanding of pH and flow of non-equilibrium π-conjugated peptide assembly, and lays the groundwork for the rational manipulation of environmental conditions and peptide chemistry to control assembly and the attendant emergent optoelectronic properties. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award # DE-SC0011847, and by the Computational Science and Engineering Fellowship from the University of Illinois at Urbana-Champaign.

Conformal phased surfaces for wireless powering of bioelectronic microdevices

PubMed Central

Agrawal, Devansh R.; Tanabe, Yuji; Weng, Desen; Ma, Andrew; Hsu, Stephanie; Liao, Song-Yan; Zhen, Zhe; Zhu, Zi-Yi; Sun, Chuanbowen; Dong, Zhenya; Yang, Fengyuan; Tse, Hung Fat; Poon, Ada S. Y.; Ho, John S.

2017-01-01

Wireless powering could enable the long-term operation of advanced bioelectronic devices within the human body. Although both enhanced powering depth and device miniaturization can be achieved by shaping the field pattern within the body, existing electromagnetic structures do not provide the spatial phase control required to synthesize such patterns. Here, we describe the design and operation of conformal electromagnetic structures, termed phased surfaces, that interface with non-planar body surfaces and optimally modulate the phase response to enhance the performance of wireless powering. We demonstrate that the phased surfaces can wirelessly transfer energy across anatomically heterogeneous tissues in large animal models, powering miniaturized semiconductor devices (<12 mm3) deep within the body (>4 cm). As an illustration of in vivo operation, we wirelessly regulated cardiac rhythm by powering miniaturized stimulators at multiple endocardial sites in a porcine animal model. PMID:29226018

Building Interfaces: Mechanisms, fabrication, and applications at the biotic/abiotic interface for silk fibroin based bioelectronic and biooptical devices

NASA Astrophysics Data System (ADS)

Brenckle, Mark

Recent efforts in bioelectronics and biooptics have led to a shift in the materials and form factors used to make medical devices, including high performance, implantable, and wearable sensors. In this context, biopolymer-based devices must be processed to interface the soft, curvilinear biological world with the rigid, inorganic world of traditional electronics and optics. This poses new material-specific fabrication challenges in designing such devices, which in turn requires further understanding of the fundamental physical behaviors of the materials in question. As a biopolymer, silk fibroin protein has remarkable promise in this space, due to its bioresorbability, mechanical strength, optical clarity, ability to be reshaped on the micro- and nano-scale, and ability to stabilize labile compounds. Application of this material to devices at the biotic/abiotic interface will require the development of fabrication techniques for nano-patterning, lithography, multilayer adhesion, and transfer printing in silk materials. In this work, we address this need through fundamental study of the thermal and diffusional properties of silk protein as it relates to these fabrication strategies. We then leverage these properties to fabricate devices well suited to the biotic/abiotic interface in three areas: shelf-ready sensing, implantable transient electronics, and wearable biosensing. These example devices will illustrate the advantages of silk in this class of bioelectronic and biooptical devices, from fundamentals through application, and contribute to a silk platform for the development of future devices that combine biology with high technology.

Bioelectronic tongue using heterodimeric human taste receptor for the discrimination of sweeteners with human-like performance.

PubMed

Song, Hyun Seok; Jin, Hye Jun; Ahn, Sae Ryun; Kim, Daesan; Lee, Sang Hun; Kim, Un-Kyung; Simons, Christopher T; Hong, Seunghun; Park, Tai Hyun

2014-10-28

The sense of taste helps humans to obtain information and form a picture of the world by recognizing chemicals in their environments. Over the past decade, large advances have been made in understanding the mechanisms of taste detection and mimicking its capability using artificial sensor devices. However, the detection capability of previous artificial taste sensors has been far inferior to that of animal tongues, in terms of its sensitivity and selectivity. Herein, we developed a bioelectronic tongue using heterodimeric human sweet taste receptors for the detection and discrimination of sweeteners with human-like performance, where single-walled carbon nanotube field-effect transistors were functionalized with nanovesicles containing human sweet taste receptors and used to detect the binding of sweeteners to the taste receptors. The receptors are heterodimeric G-protein-coupled receptors (GPCRs) composed of human taste receptor type 1 member 2 (hTAS1R2) and human taste receptor type 1 member 3 (hTAS1R3), which have multiple binding sites and allow a human tongue-like broad selectivity for the detection of sweeteners. This nanovesicle-based bioelectronic tongue can be a powerful tool for the detection of sweeteners as an alternative to labor-intensive and time-consuming cell-based assays and the sensory evaluation panels used in the food and beverage industry. Furthermore, this study also allows the artificial sensor to exam the functional activity of dimeric GPCRs.

Detection of Norepinephrine in Whole Blood via Fast Scan Cyclic Voltammetry.

PubMed

Nicolai, Evan N; Trevathan, James K; Ross, Erika K; Lujan, J Luis; Blaha, Charles D; Bennet, Kevin E; Lee, Kendall H; Ludwig, Kip A

2017-05-01

Bioelectronic Medicines is an emerging field that capitalizes on minimally-invasive technology to stimulate the autonomic nervous system in order to evoke therapeutic biomolecular changes at the end-organ. The goal of Bioelectronic Medicines is to realize both 'precision and personalized' medicine. 'Precise' stimulation of neural circuitry creates biomolecular changes targeted exactly where needed to maximize therapeutic effects while minimizing off-target changes associated with side-effects. The therapy is then 'personalized' by utilizing implanted sensors to measure the biomolecular concentrations at, or near, the end-organ of interest and continually adjusting therapy to account for patient-specific biological changes throughout the day. To realize the promise of Bioelectronic Medicines, there is a need for minimally invasive, real-time measurement of biomarkers associated with the effects of autonomic nerve stimulation to be used for continuous titration of therapy. In this study we examine the feasibility of using fast scan cyclic voltammetry (FSCV) to measure norepinephrine levels, a neurochemical relevant to end-organ function, directly from blood. FSCV is a well-understood method for measuring electroactive neurochemicals in the central nervous system with high temporal and high spatial resolution that has yet to be adapted to the study of the autonomic nervous system. The results demonstrate that while detecting the electroactive neurochemical norepinephrine in blood is more challenging than obtaining the same FSCV measurements in a buffer solution due to biofouling of the electrode, it is feasible to utilize a minimally invasive FSCV electrode to obtain neurochemical measurements in blood.

EDITORIAL: Design and function of molecular and bioelectronics devices

NASA Astrophysics Data System (ADS)

Krstic, Predrag; Forzani, Erica; Tao, Nongjian; Korkin, Anatoli

2007-10-01

Further rapid progress of electronics, in particular the increase of computer power and breakthroughs in sensor technology for industrial, medical diagnostics and environmental applications, strongly depends on the scaling of electronic devices, ultimately to the size of molecules. Design of controllable molecular-scale devices may resolve the problem of energy dissipation at the nanoscale and take advantage of molecular self-assembly in the so-called bottom-up approach. This special issue of Nanotechnology is devoted to a better understanding of the function and design of molecular-scale devices that are relevant to future electronics and sensor technology. Papers contained in this special issue are selected from the symposium Nano and Giga Challenges in Electronics and Photonics: From Atoms to Materials to Devices to System Architecture (12-16 March, 2007, Phoenix, Arizona, USA), as well as from original and novel scientific contributions of invited world-renown researchers. It addresses both theoretical and experimental achievements in the fields of molecular and bioelectronics, chemical and biosensors at the molecular level, including carbon nanotubes, novel nanostructures, as well as related research areas and industrial applications. The conference series Nano and Giga Challenges in Electronics and Photonics was launched as a truly interdisciplinary forum to bridge scientists and engineers to work across boundaries in the design of future information technologies, from atoms to materials to devices to system architecture. Following the first two successful meetings in Moscow, Russia (NGCM2002) and Krakow, Poland (NGCM2004), the third Nano and Giga Forum (NGC2007) was held in 2007 hosted by Arizona State University. Besides this special issue of Nanotechnology, two other collections (in the journal Solid State Electronics and the tutorial book in the series Nanostructure Science and Technology Springer) have published additional selected and invited papers from NGC2007. The NGC2007 meeting, which included two days of tutorials (Spring School) and a three day symposium, attracted approximately 400 participants from academic, industrial and governmental research institutions from 41 countries, and covered recent developments in the fabrication and functionality of nano-scale materials, devices and system architecture from advanced CMOS to molecular electronics, photonics, optoelectronics and magnetic materials and devices. The success of the conference would not have been possible without generous support from many sponsors and research institutions, especially from Arizona State University (conference host and co-organizer), International Science and Technology Center (ISTC), National Science Foundation (NSFT), Defense Advanced Research Agency (DARPA), Office of Naval Research, Army Research Office, Computational Chemistry List (CCL), Springer Publisher, City of Tempe, STMicroelectronics, Quarles & Brady LLP, Oak Ridge National Laboratory, Canadian Consulate in Phoenix, Salt River Project (SRP) and many other local, national and international and individual supporters. We would like to acknowledge the shared responsibility for this special issue of Nanotechnology on molecular and bioelectronics, and the highly professional support from Dr Nina Couzin, Dr Alex Wotherspoon and the Nanotechnology team from the IOP Publishing. We also acknowledge the exception made in allowing the publication of some material that is outside the normal scope of Nanotechnology.

Design and function of molecular and bioelectronics devices.

PubMed

Krstic, Predrag; Forzani, Erica; Tao, Nongjian; Korkin, Anatoli

2007-10-24

Further rapid progress of electronics, in particular the increase of computer power and breakthroughs in sensor technology for industrial, medical diagnostics and environmental applications, strongly depends on the scaling of electronic devices, ultimately to the size of molecules. Design of controllable molecular-scale devices may resolve the problem of energy dissipation at the nanoscale and take advantage of molecular self-assembly in the so-called bottom-up approach. This special issue of Nanotechnology is devoted to a better understanding of the function and design of molecular-scale devices that are relevant to future electronics and sensor technology. Papers contained in this special issue are selected from the symposium Nano and Giga Challenges in Electronics and Photonics: From Atoms to Materials to Devices to System Architecture (12-16 March, 2007, Phoenix, Arizona, USA), as well as from original and novel scientific contributions of invited world-renown researchers. It addresses both theoretical and experimental achievements in the fields of molecular and bioelectronics, chemical and biosensors at the molecular level, including carbon nanotubes, novel nanostructures, as well as related research areas and industrial applications. The conference series Nano and Giga Challenges in Electronics and Photonics was launched as a truly interdisciplinary forum to bridge scientists and engineers to work across boundaries in the design of future information technologies, from atoms to materials to devices to system architecture. Following the first two successful meetings in Moscow, Russia (NGCM2002) and Krakow, Poland (NGCM2004), the third Nano and Giga Forum (NGC2007) was held in 2007 hosted by Arizona State University. Besides this special issue of Nanotechnology, two other collections (in the journal Solid State Electronics and the tutorial book in the series Nanostructure Science and Technology Springer) have published additional selected and invited papers from NGC2007. The NGC2007 meeting, which included two days of tutorials (Spring School) and a three day symposium, attracted approximately 400 participants from academic, industrial and governmental research institutions from 41 countries, and covered recent developments in the fabrication and functionality of nano-scale materials, devices and system architecture from advanced CMOS to molecular electronics, photonics, optoelectronics and magnetic materials and devices. The success of the conference would not have been possible without generous support from many sponsors and research institutions, especially from Arizona State University (conference host and co-organizer), International Science and Technology Center (ISTC), National Science Foundation (NSFT), Defense Advanced Research Agency (DARPA), Office of Naval Research, Army Research Office, Computational Chemistry List (CCL), Springer Publisher, City of Tempe, STMicroelectronics, Quarles & Brady LLP, Oak Ridge National Laboratory, Canadian Consulate in Phoenix, Salt River Project (SRP) and many other local, national and international and individual supporters. We would like to acknowledge the shared responsibility for this special issue of Nanotechnology on molecular and bioelectronics, and the highly professional support from Dr Nina Couzin, Dr Alex Wotherspoon and the Nanotechnology team from the IOP Publishing. We also acknowledge the exception made in allowing the publication of some material that is outside the normal scope of Nanotechnology.

Conjugated Polymers in Bioelectronics.

PubMed

Inal, Sahika; Rivnay, Jonathan; Suiu, Andreea-Otilia; Malliaras, George G; McCulloch, Iain

2018-06-19

The emerging field of organic bioelectronics bridges the electronic world of organic-semiconductor-based devices with the soft, predominantly ionic world of biology. This crosstalk can occur in both directions. For example, a biochemical reaction may change the doping state of an organic material, generating an electronic readout. Conversely, an electronic signal from a device may stimulate a biological event. Cutting-edge research in this field results in the development of a broad variety of meaningful applications, from biosensors and drug delivery systems to health monitoring devices and brain-machine interfaces. Conjugated polymers share similarities in chemical "nature" with biological molecules and can be engineered on various forms, including hydrogels that have Young's moduli similar to those of soft tissues and are ionically conducting. The structure of organic materials can be tuned through synthetic chemistry, and their biological properties can be controlled using a variety of functionalization strategies. Finally, organic electronic materials can be integrated with a variety of mechanical supports, giving rise to devices with form factors that enable integration with biological systems. While these developments are innovative and promising, it is important to note that the field is still in its infancy, with many unknowns and immense scope for exploration and highly collaborative research. The first part of this Account details the unique properties that render conjugated polymers excellent biointerfacing materials. We then offer an overview of the most common conjugated polymers that have been used as active layers in various organic bioelectronics devices, highlighting the importance of developing new materials. These materials are the most popular ethylenedioxythiophene derivatives as well as conjugated polyelectrolytes and ion-free organic semiconductors functionalized for the biological interface. We then discuss several applications and operation principles of state-of-the-art bioelectronics devices. These devices include electrodes applied to sense/trigger electrophysiological activity of cells as well as electrolyte-gated field-effect and electrochemical transistors used for sensing of biochemical markers. Another prime application example of conjugated polymers is cell actuators. External modulation of the redox state of the underlying conjugated polymer films controls the adhesion behavior and viability of cells. These smart surfaces can be also designed in the form of three-dimensional architectures because of the processability of conjugated polymers. As such, cell-loaded scaffolds based on electroactive polymers enable integrated sensing or stimulation within the engineered tissue itself. A last application example is organic neuromorphic devices, an alternative computing architecture that takes inspiration from biology and, in particular, from the way the brain works. Leveraging ion redistribution inside a conjugated polymer upon application of an electrical field and its coupling with electronic charges, conjugated polymers can be engineered to act as artificial neurons or synapses with complex, history-dependent behavior. We conclude this Account by highlighting main factors that need to be considered for the design of a conjugated polymer for applications in bioelectronics-although there can be various figures of merit given the broad range of applications, as emphasized in this Account.

Membrane Protein Incorporation into Nano-Bioelectronics: An insight into Rhodopsin Controlled SiNW-FET Devices

NASA Astrophysics Data System (ADS)

Tunuguntla, Ramya

Biological systems use different energy sources to interact with their environments by creating ion gradients, membrane electric potentials, or a proton motive force to accomplish strikingly complex tasks on the nanometer length scale, such as energy harvesting, and whole organism replication. Most of this activity involves a vast arsenal of active and passive ion channels, membrane receptors and ion pumps that mediate complex and precise transport across biological membranes. Despite the remarkable rate of progress exhibited by modern microelectronic devices, they still cannot compete with the efficiency and precision of biological systems on the component level. At the same time, the sophistication of these molecular machines provides an excellent opportunity to use them in hybrid bioelectronic devices where such a combination could deliver enhanced electronic functionality and enable seamless bi-directional interfaces between man-made and biological assemblies. Artificial membrane systems allow researchers to study the structure and function of membrane proteins in a matrix that approximates their natural environment and to integrate these proteins in ex-vivo devices such as electronic biosensors, thin-film protein arrays, or bio-fuel cells. Since most membrane proteins have vectorial functions, both functional studies and applications require effective control over protein orientation within a lipid bilayer. In our work, we have explored the role of the bilayer surface charge in determining transmembrane protein orientation and functionality during formation of proteoliposomes. We reconstituted a model vectorial ion pump, proteorhodopsin, in liposomes of opposite charges and varying charge densities and determined the resultant protein orientation. Antibody-binding assay and proteolysis of proteoliposomes showed physical evidence of preferential orientation, and functional assays verified vectorial nature of ion transport in this system. Our results indicate that the manipulation of lipid composition can indeed control orientation of an asymmetrically charged membrane protein, proteorhodopsin, in liposomes. One-dimensional inorganic nanostructures, which have critical dimensions comparable to the sizes of biological molecules, form an excellent materials platform for building such integrated structures. Researchers already use silicon nanowire-based field effect transistors functionalized with molecular recognition sites in a diverse array of biosensors. In our group, we have been developing a platform for integration of membrane protein functionality and electronic devices using a 1-D phospholipid bilayer device architecture. In these devices, the membrane proteins reside within the lipid bilayer that covers a nanowire channel of a field-effect transistor. This lipid bilayer performs several functions: it shields the nanowire from the solution species; it serves as a native-like environment for membrane proteins and preserves their functionality, integrity, and even vectorality. In this work, we show that a 1-D bilayer device incorporating a rhodopsin proton pump allows us to couple light-driven proton transport to a bioelectronic circuit. We also report that we were able to adapt another distinctive feature of biological signal processing---their widespread use of modifiers, co-factors, and mediator molecules---to regulate and fine-tune the operational characteristics of the bioelectronic device. In our example, we use co-assembly of protein channels and ionophores in the 1-D bilayer to modify the device output levels and response time.

Iron-sulfur-based single molecular wires for enhancing charge transport in enzyme-based bioelectronic systems.

PubMed

Mahadevan, Aishwarya; Fernando, Teshan; Fernando, Sandun

2016-04-15

When redox enzymes are wired to electrodes outside a living cell (ex vivo), their ability to produce a sufficiently powerful electrical current diminishes significantly due to the thermodynamic and kinetic limitations associated with the wiring systems. Therefore, we are yet to harness the full potential of redox enzymes for the development of self-powering bioelectronics devices (such as sensors and fuel cells). Interestingly, nature uses iron-sulfur complexes ([Fe-S]), to circumvent these issues in vivo. Yet, we have not been able to utilize [Fe-S]-based chains ex vivo, primarily due to their instability in aqueous media. Here, a simple technique to attach iron (II) sulfide (FeS) to a gold surface in ethanol media and then complete the attachment of the enzyme in aqueous media is reported. Cyclic voltammetry and spectroscopy techniques confirmed the concatenation of FeS and glycerol-dehydrogenase/nicotinamide-adenine-dinucleotide (GlDH-NAD(+)) apoenzyme-coenzyme molecular wiring system on the base gold electrode. The resultant FeS-based enzyme electrode reached an open circuit voltage closer to its standard potential under a wide range of glycerol concentrations (0.001-1M). When probed under constant potential conditions, the FeS-based electrode was able to amplify current by over 10 fold as compared to electrodes fabricated with the conventional pyrroloquinoline quinone-based composite molecular wiring system. These improvements in current/voltage responses open up a wide range of possibilities for fabricating self-powering, bio-electronic devices. Copyright © 2015 Elsevier B.V. All rights reserved.

Diamond bio electronics.

PubMed

Linares, Robert; Doering, Patrick; Linares, Bryant

2009-01-01

The use of diamond for advanced applications has been the dream of mankind for centuries. Until recently this dream has been realized only in the use of diamond for gemstones and abrasive applications where tons of diamonds are used on an annual basis. Diamond is the material system of choice for many applications, but its use has historically been limited due to the small size, high cost, and inconsistent (and typically poor) quality of available diamond materials until recently. The recent development of high quality, single crystal diamond crystal growth via the Chemical Vapor Deposition (CVD) process has allowed physcists and increasingly scientists in the life science area to think beyond these limitations and envision how diamond may be used in advanced applications ranging from quantum computing, to power generation and molecular imaging, and eventually even diamond nano-bots. Because of diamond's unique properties as a bio-compatible material, better understanding of diamond's quantum effects and a convergence of mass production, semiconductor-like fabrication process, diamond now promises a unique and powerful key to the realization of the bio-electronic devices being envisioned for the new era of medical science. The combination of robust in-the-body diamond based sensors, coupled with smart bio-functionalized diamond devices may lead to diamond being the platform of choice for bio-electronics. This generation of diamond based bio-electronic devices would contribute substantially to ushering in a paradigm shift for medical science, leading to vastly improved patient diagnosis, decrease of drug development costs and risks, and improved effectiveness of drug delivery and gene therapy programs through better timed and more customized solutions.

Detection of Norepinephrine in Whole Blood via Fast Scan Cyclic Voltammetry

PubMed Central

Nicolai, Evan N.; Trevathan, James K.; Ross, Erika K.; Lujan, J. Luis; Blaha, Charles D.; Bennet, Kevin E.; Lee, Kendall H.; Ludwig, Kip A.

2017-01-01

Bioelectronic Medicines is an emerging field that capitalizes on minimally-invasive technology to stimulate the autonomic nervous system in order to evoke therapeutic biomolecular changes at the end-organ. The goal of Bioelectronic Medicines is to realize both ‘precision and personalized’ medicine. ‘Precise’ stimulation of neural circuitry creates biomolecular changes targeted exactly where needed to maximize therapeutic effects while minimizing off-target changes associated with side-effects. The therapy is then ‘personalized’ by utilizing implanted sensors to measure the biomolecular concentrations at, or near, the end-organ of interest and continually adjusting therapy to account for patient-specific biological changes throughout the day. To realize the promise of Bioelectronic Medicines, there is a need for minimally invasive, real-time measurement of biomarkers associated with the effects of autonomic nerve stimulation to be used for continuous titration of therapy. In this study we examine the feasibility of using fast scan cyclic voltammetry (FSCV) to measure norepinephrine levels, a neurochemical relevant to end-organ function, directly from blood. FSCV is a well-understood method for measuring electroactive neurochemicals in the central nervous system with high temporal and high spatial resolution that has yet to be adapted to the study of the autonomic nervous system. The results demonstrate that while detecting the electroactive neurochemical norepinephrine in blood is more challenging than obtaining the same FSCV measurements in a buffer solution due to biofouling of the electrode, it is feasible to utilize a minimally invasive FSCV electrode to obtain neurochemical measurements in blood. PMID:29177248

Apparatus for Teaching Physics.

ERIC Educational Resources Information Center

Gottlieb, Herbert H., Ed.

1979-01-01

Describes the following laboratory equipment: Biophysics modules to perform bioelectronic investigations of the human body; a large sine wave analog for large audience demonstrations; a resonance tube for measurement of speed of sound; and the snooperscope, a gadget to demonstrate infrared waves. (GA)

Disposable biomedical electrode

NASA Technical Reports Server (NTRS)

Frost, J. D., Jr.; Hillman, C. E., Jr.

1977-01-01

Reusable recording cap equipped with compressible snap-on bioelectronic electrodes is worn by patient to allow remote monitoring of electroencephalogram and electro-oculogram waveforms. Electrodes can be attached to inside surface of stretch-textile cap at twelve monitoring positions and at one or two ground positions.

Hybrid thin-film amplifier

NASA Technical Reports Server (NTRS)

Cleveland, G.

1977-01-01

Miniature amplifier for bioelectronic instrumentation consumes only about 100 mW and has frequency response flat to within 0.5 dB from 0.14 to 450 Hz. Device consists of five thin film substrates, which contain eight operational amplifiers and seven field-effect transistor dice.

Hybrid nanowire ion-to-electron transducers for integrated bioelectronic circuitry (Conference Presentation)

NASA Astrophysics Data System (ADS)

Carrad, Damon J.; Mostert, Bernard; Meredith, Paul; Micolich, Adam P.

2016-09-01

A key task in bioelectronics is the transduction between ionic/protonic signals and electronic signals at high fidelity. This is a considerable challenge since the two carrier types exhibit intrinsically different physics. We present our work on a new class of organic-inorganic transducing interface utilising semiconducting InAs and GaAs nanowires directly gated with a proton transporting hygroscopic polymer consisting of undoped polyethylene oxide (PEO) patterned to nanoscale dimensions by a newly developed electron-beam lithography process [1]. Remarkably, we find our undoped PEO polymer electrolyte gate dielectric [2] gives equivalent electrical performance to the more traditionally used LiClO4-doped PEO [3], with an ionic conductivity three orders of magnitude higher than previously reported for undoped PEO [4]. The observed behaviour is consistent with proton conduction in PEO. We attribute our undoped PEO-based devices' performance to the small external surface and high surface-to-volume ratio of both the nanowire conducting channel and patterned PEO dielectric in our devices, as well as the enhanced hydration afforded by device processing and atmospheric conditions. In addition to studying the basic transducing mechanisms, we also demonstrate high-fidelity ionic to electronic conversion of a.c. signals at frequencies up to 50 Hz. Moreover, by combining complementary n- and p-type transducers we demonstrate functional hybrid ionic-electronic circuits can achieve logic (NOT operation), and with some further engineering of the nanowire contacts, potentially also amplification. Our device structures have significant potential to be scaled towards realising integrated bioelectronic circuitry. [1] D.J. Carrad et al., Nano Letters 14, 94 (2014). [2] D.J. Carrad et al., Manuscript in preparation (2016). [3] S.H. Kim et al., Advanced Materials 25, 1822 (2013). [4] S.K. Fullerton-Shirey et al., Macromolecules 42, 2142 (2009).

A novel 384-multiwell microelectrode array for the impedimetric monitoring of Tau protein induced neurodegenerative processes.

PubMed

Jahnke, Heinz-Georg; Krinke, Dana; Seidel, Diana; Lilienthal, Katharina; Schmidt, Sabine; Azendorf, Ronny; Fischer, Michael; Mack, Till; Striggow, Frank; Althaus, Holger; Schober, Andreas; Robitzki, Andrea A

2017-02-15

Over the last decades, countless bioelectronic monitoring systems were developed for the analysis of cells as well as complex tissues. Most studies addressed the sensitivity and specificity of the bioelectronic detection method in comparison to classical molecular biological assays. In contrast, the up scaling as a prerequisite for the practical application of these novel bioelectronic monitoring systems is mostly only discussed theoretically. In this context, we developed a novel 384-multiwell microelectrode array (MMEA) based measurement system for the sensitive label-free real-time monitoring of neurodegenerative processes by impedance spectroscopy. With respect to the needs of productive screening systems for robust and reproducible measurements on high numbers of plates, we focused on reducing the critical contacting of more than 400 electrodes for a 384-MMEA. Therefore, we introduced an on top array of immersive counter electrodes that are individually addressed by a multiplexer and connected all measurement electrodes on the 384-MMEA to a single contact point. More strikingly, our novel approach provided a comparable signal stability and sensitivity similar to an array with integrated counter electrodes. Next, we optimized a SH-SY5Y cell based tauopathy model by introducing a novel 5-fold Tau mutation eliminating the need of artificial tauopathy induction. In combination with our novel 384-MMEA based measurement system, the concentration and time dependent neuroregenerative effect of the kinase inhibitor SRN-003-556 could be quantitatively monitored. Thus, our novel screening system could be a useful tool to identify and develop potential novel therapeutics in the field of Tau-related neurodegenerative diseases. Copyright © 2016. Published by Elsevier B.V.

Bioelectronic Learning: The Effects of Electronic Media on a Developing Brain.

ERIC Educational Resources Information Center

Sylwester, Robert

1997-01-01

Considers the effects of electronic media on the developing brains of children. Topics include the attentional demands of electronic media; commercial sponsorship; brain development, including memory systems and response systems; and what a developing mind can bring to the electronic media. (LRW)

Electrochemically Controlled Reconstitution of Immobilized Ferritins for Bioelectronic Applications

NASA Technical Reports Server (NTRS)

Kim, Jae-Woo; Choi, Sang H.; Lillehei, Peter T.; Chu, Sang-Hong; King, Glen C.; Watt, Gerald D.

2007-01-01

Site-specific reconstituted nanoparticles were fabricated via electrochemically-controlled biomineralization through the immobilization of biomolecules. The work reported herein includes the immobilization of ferritin with various surface modifications, the electrochemical biomineralization of ferritins with different inorganic cores, and the electrocatalytic reduction of oxygen on the reconstituted Pt-cored ferritins. Protein immobilization on the substrate is achieved by anchoring ferritins with dithiobis-N-succinimidyl propionate (DTSP). A reconstitution process of site-specific electrochemical biomineralization with a protein cage loads ferritins with different core materials. The ferritin acts as a nano-scale template, a biocompatible cage, and a separator between the nanoparticles. This first demonstration of electrochemically controlled site-specific reconstitution of biomolecules provides a new tool for biomineralization and opens the way to produce the bio-templated nanoparticles by electrochemical control. The nanosized platinum-cored ferritins on gold displayed good catalytic activity for the electrochemical reduction of oxygen, which is applicable to biofuel cell applications. This results in a smaller catalyst loading on the electrodes for fuel cells or other bioelectronic devices.

Bioelectronic platforms for optimal bio-anode of bio-electrochemical systems: From nano- to macro scopes.

PubMed

Kim, Bongkyu; An, Junyeong; Fapyane, Deby; Chang, In Seop

2015-11-01

The current trend of bio-electrochemical systems is to improve strategies related to their applicability and potential for scaling-up. To date, literature has suggested strategies, but the proposal of correlations between each research field remains insufficient. This review paper provides a correlation based on platform techniques, referred to as bio-electronics platforms (BEPs). These BEPs consist of three platforms divided by scope scale: nano-, micro-, and macro-BEPs. In the nano-BEP, several types of electron transfer mechanisms used by electrochemically active bacteria are discussed. In the micro-BEP, factors affecting the formation of conductive biofilms and transport of electrons in the conductive biofilm are investigated. In the macro-BEP, electrodes and separators in bio-anode are debated in terms of real applications, and a scale-up strategy is discussed. Overall, the challenges of each BEP are highlighted, and potential solutions are suggested. In addition, future research directions are provided and research ideas proposed to develop research interest. Copyright © 2015 Elsevier Ltd. All rights reserved.

A novel 3D bioprinted flexible and biocompatible hydrogel bioelectronic platform.

PubMed

Agarwala, Shweta; Lee, Jia Min; Ng, Wei Long; Layani, Michael; Yeong, Wai Yee; Magdassi, Shlomo

2018-04-15

Bioelectronics platforms are gaining widespread attention as they provide a template to study the interactions between biological species and electronics. Decoding the effect of the electrical signals on the cells and tissues holds the promise for treating the malignant tissue growth, regenerating organs and engineering new-age medical devices. This work is a step forward in this direction, where bio- and electronic materials co-exist on one platform without any need for post processing. We fabricate a freestanding and flexible hydrogel based platform using 3D bioprinting. The fabrication process is simple, easy and provides a flexible route to print materials with preferred shapes, size and spatial orientation. Through the design of interdigitated electrodes and heating coil, the platform can be tailored to print various circuits for different functionalities. The biocompatibility of the printed platform is tested using C2C12 murine myoblasts cell line. Furthermore, normal human dermal fibroblasts (primary cells) are also seeded on the platform to ascertain the compatibility. Copyright © 2017 Elsevier B.V. All rights reserved.

Biologically Derived Nanoparticle Arrays via a Site-Specific Reconstitution of Ferritin and their Electrochemistry

NASA Technical Reports Server (NTRS)

Kim, Jae-Woo; Choi, Sang H.; Lillehei, Peter T.; King, Glen C.; Elliott, James R.; Chu, Sang-Hyon; Park, Yeonjoon; Watt, Gerald D.

2004-01-01

Nanoparticle arrays biologically derived from an electrochemically-controlled site-specific biomineralization were fabricated on a gold substrate through the immobilization process of biomolecules. The work reported herein includes the immobilization of ferritin with various surface modifications, the electrochemical biomineralization of ferritins with different inorganic cores, the fabrication of self-assembled arrays with the immobilized ferritin, and the electrochemical characterization of various core materials. Protein immobilization on the substrate is achieved by anchoring ferritins with dithiobis-N-succinimidyl propionate (DTSP). A reconstitution process of electrochemical site-specific biomineralization with a protein cage loads ferritins with different core materials such as Pt, Co, Mn, and Ni. The ferritin acts as a nano-scale template, a biocompatible cage, and a separator between the nanoparticles. The nano-sized metalcored ferritins on a gold substrate displayed a good electrochemical activity for the electron transport and storage, which is suitable for bioelectronics applications such as biofuel cell, bionanobattery, biosensors, etc. Keywords: Ferritin, immobilization, site-specific reconstitution, biomineralization, and bioelectronics

A portable bioelectronic sensing system (BESSY) for environmental deployment incorporating differential microbial sensing in miniaturized reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Alyssa Y.; Baruch, Moshe; Ajo-Franklin, Caroline M.

Current technologies are lacking in the area of deployable, in situ monitoring of complex chemicals in environmental applications. Microorganisms metabolize various chemical compounds and can be engineered to be analyte-specific making them naturally suited for robust chemical sensing. But, current electrochemical microbial biosensors use large and expensive electrochemistry equipment not suitable for on-site, real-time environmental analysis. We demonstrate a miniaturized, autonomous bioelectronic sensing system (BESSY) suitable for deployment for instantaneous and continuous sensing applications. We developed a 2x2 cm footprint, low power, two-channel, three-electrode electrochemical potentiostat which wirelessly transmits data for on-site microbial sensing. Furthermore, we designed a new waymore » of fabricating self-contained, submersible, miniaturized reactors (m-reactors) to encapsulate the bacteria, working, and counter electrodes. We have validated the BESSY’s ability to specifically detect a chemical amongst environmental perturbations using differential current measurements. This work paves the way for in situ microbial sensing outside of a controlled laboratory environment.« less

nDEP-driven cell patterning and bottom-up construction of cell aggregates using a new bioelectronic chip.

PubMed

Menad, S; Franqueville, L; Haddour, N; Buret, F; Frenea-Robin, M

2015-04-01

Creating cell aggregates of controlled size and shape and patterning cells on substrates using a bottom-up approach constitutes important challenges for tissue-engineering applications and studies of cell-cell interactions. In this paper, we report nDEP (negative dielectrophoresis) driven assembly of cells as compact aggregates or onto defined areas using a new bioelectronic chip. This chip is composed of a quadripolar electrode array obtained using coplanar electrodes partially covered with a thin, micropatterned PDMS membrane. This thin PDMS layer was coated with poly-L-lysine and played the role of adhesive substrate for cell patterning. For the formation of detachable cell aggregates, the PDMS was not pretreated and cells were simply immobilized into assemblies maintained by cell-cell adhesion after the electric field removal. Cell viability after exposition to DEP buffer was also assessed, as well as cell spreading activity following DEP-driven assembly. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A portable bioelectronic sensing system (BESSY) for environmental deployment incorporating differential microbial sensing in miniaturized reactors

DOE PAGES

Zhou, Alyssa Y.; Baruch, Moshe; Ajo-Franklin, Caroline M.; ...

2017-09-15

Current technologies are lacking in the area of deployable, in situ monitoring of complex chemicals in environmental applications. Microorganisms metabolize various chemical compounds and can be engineered to be analyte-specific making them naturally suited for robust chemical sensing. But, current electrochemical microbial biosensors use large and expensive electrochemistry equipment not suitable for on-site, real-time environmental analysis. We demonstrate a miniaturized, autonomous bioelectronic sensing system (BESSY) suitable for deployment for instantaneous and continuous sensing applications. We developed a 2x2 cm footprint, low power, two-channel, three-electrode electrochemical potentiostat which wirelessly transmits data for on-site microbial sensing. Furthermore, we designed a new waymore » of fabricating self-contained, submersible, miniaturized reactors (m-reactors) to encapsulate the bacteria, working, and counter electrodes. We have validated the BESSY’s ability to specifically detect a chemical amongst environmental perturbations using differential current measurements. This work paves the way for in situ microbial sensing outside of a controlled laboratory environment.« less

Micellar Electrolytes in Organic Electrochemical Transistors

NASA Astrophysics Data System (ADS)

Cicoira, Fabio; Giuseppe, Tarabella; Nanda, Gaurav; Iannotta, Salvatore; Santato, Clara

2012-02-01

Organic electrochemical transistors (OECTs) are promising for applications in sensing and bioelectronics. OECTs consist of a conducting polymer film (transistor channel) in contact with an electrolyte. A gate electrode immersed in the electrolyte controls the doping/dedoping level of the conducting polymer. OECTs can be operated in aqueous electrolytes, making possible the implementation of organic electronic materials at the interface with biology. The inherent signal amplification of OECTs has the potential to yield sensors with low detection limits and high sensitivity. In this talk we will present recent studies on OECTs using ionic surfactants (such as hexadecyl-trimethyl-ammonium bromide) as electrolytes. As the conducting polymer we used PEDOT:PSS, i.e. (Poly,3-4 ethylenedioxythiopene) doped with Poly(styrene sulphonate). Interestingly, ionic surfactant electrolytes result in large transistor current modulation, especially beyond the critical micellar concentration (CMC). Since micelles play a primary role in biological processes and drug-delivery systems, the use for micellar electrolytes opens new exciting opportunities for the use of OECTs in bioelectronics.

Molecular Approach to Conjugated Polymers with Biomimetic Properties.

PubMed

Baek, Paul; Voorhaar, Lenny; Barker, David; Travas-Sejdic, Jadranka

2018-06-13

The field of bioelectronics involves the fascinating interplay between biology and human-made electronics. Applications such as tissue engineering, biosensing, drug delivery, and wearable electronics require biomimetic materials that can translate the physiological and chemical processes of biological systems, such as organs, tissues. and cells, into electrical signals and vice versa. However, the difference in the physical nature of soft biological elements and rigid electronic materials calls for new conductive or electroactive materials with added biomimetic properties that can bridge the gap. Soft electronics that utilize organic materials, such as conjugated polymers, can bring many important features to bioelectronics. Among the many advantages of conjugated polymers, the ability to modulate the biocompatibility, solubility, functionality, and mechanical properties through side chain engineering can alleviate the issues of mechanical mismatch and provide better interface between the electronics and biological elements. Additionally, conjugated polymers, being both ionically and electrically conductive through reversible doping processes provide means for direct sensing and stimulation of biological processes in cells, tissues, and organs. In this Account, we focus on our recent progress in molecular engineering of conjugated polymers with tunable biomimetic properties, such as biocompatibility, responsiveness, stretchability, self-healing, and adhesion. Our approach is general and versatile, which is based on functionalization of conjugated polymers with long side chains, commonly polymeric or biomolecules. Applications for such materials are wide-ranging, where we have demonstrated conductive, stimuli-responsive antifouling, and cell adhesive biointerfaces that can respond to external stimuli such as temperature, salt concentration, and redox reactions, the processes that in turn modify and reversibly switch the surface properties. Furthermore, utilizing the advantageous chemical, physical, mechanical and functional properties of the grafts, we progressed into grafting of the long side chains onto conjugated polymers in solution, with the vision of synthesizing solution-processable conjugated graft copolymers with biomimetic functionalities. Examples of the developed materials to date include rubbery and adhesive photoluminescent plastics, biomolecule-functionalized electrospun biosensors, thermally and dually responsive photoluminescent conjugated polymers, and tunable self-healing, adhesive, and stretchable strain sensors, advanced functional biocidal polymers, and filtration membranes. As outlined in these examples, the applications of these biomimetic, conjugated polymers are still in the development stage toward truly printable, organic bioelectronic devices. However, in this Account, we advocate that molecular engineering of conjugated polymers is an attractive approach to a versatile class of organic electronics with both ionic and electrical conductivity as well as mechanical properties required for next-generation bioelectronics.

Bioluminescent bioreporter integrated circuit devices and methods for detecting ammonia

DOEpatents

Simpson, Michael L [Knoxville, TN; Paulus, Michael J [Knoxville, TN; Sayler, Gary S [Blaine, TN; Applegate, Bruce M [West Lafayette, IN; Ripp, Steven A [Knoxville, TN

2007-04-24

Monolithic bioelectronic devices for the detection of ammonia includes a microorganism that metabolizes ammonia and which harbors a lux gene fused with a heterologous promoter gene stably incorporated into the chromosome of the microorganism and an Optical Application Specific Integrated Circuit (OASIC). The microorganism is generally a bacterium.

Bioluminescent bioreporter integrated circuit detection methods

DOEpatents

Simpson, Michael L.; Paulus, Michael J.; Sayler, Gary S.; Applegate, Bruce M.; Ripp, Steven A.

2005-06-14

Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for detection of particular analytes, including ammonia and estrogen compounds.

Silk protein nanowires patterned using electron beam lithography.

PubMed

Pal, Ramendra K; Yadavalli, Vamsi K

2018-08-17

Nanofabrication approaches to pattern proteins at the nanoscale are useful in applications ranging from organic bioelectronics to cellular engineering. Specifically, functional materials based on natural polymers offer sustainable and environment-friendly substitutes to synthetic polymers. Silk proteins (fibroin and sericin) have emerged as an important class of biomaterials for next generation applications owing to excellent optical and mechanical properties, inherent biocompatibility, and biodegradability. However, the ability to precisely control their spatial positioning at the nanoscale via high throughput tools continues to remain a challenge. In this study electron beam lithography (EBL) is used to provide nanoscale patterning using methacrylate conjugated silk proteins that are photoreactive 'photoresists' materials. Very low energy electron beam radiation can be used to pattern silk proteins at the nanoscale and over large areas, whereby such nanostructure fabrication can be performed without specialized EBL tools. Significantly, using conducting polymers in conjunction with these silk proteins, the formation of protein nanowires down to 100 nm is shown. These wires can be easily degraded using enzymatic degradation. Thus, proteins can be precisely and scalably patterned and doped with conducting polymers and enzymes to form degradable, organic bioelectronic devices.

Hierarchical nanostructured conducting polymer hydrogel with high electrochemical activity

PubMed Central

Pan, Lijia; Yu, Guihua; Zhai, Dongyuan; Lee, Hye Ryoung; Zhao, Wenting; Liu, Nian; Wang, Huiliang; Tee, Benjamin C.-K.; Shi, Yi; Cui, Yi; Bao, Zhenan

2012-01-01

Conducting polymer hydrogels represent a unique class of materials that synergizes the advantageous features of hydrogels and organic conductors and have been used in many applications such as bioelectronics and energy storage devices. They are often synthesized by polymerizing conductive polymer monomer within a nonconducting hydrogel matrix, resulting in deterioration of their electrical properties. Here, we report a scalable and versatile synthesis of multifunctional polyaniline (PAni) hydrogel with excellent electronic conductivity and electrochemical properties. With high surface area and three-dimensional porous nanostructures, the PAni hydrogels demonstrated potential as high-performance supercapacitor electrodes with high specific capacitance (∼480 F·g-1), unprecedented rate capability, and cycling stability (∼83% capacitance retention after 10,000 cycles). The PAni hydrogels can also function as the active component of glucose oxidase sensors with fast response time (∼0.3 s) and superior sensitivity (∼16.7 μA·mM-1). The scalable synthesis and excellent electrode performance of the PAni hydrogel make it an attractive candidate for bioelectronics and future-generation energy storage electrodes. PMID:22645374

High-performance transistors for bioelectronics through tuning of channel thickness

PubMed Central

Rivnay, Jonathan; Leleux, Pierre; Ferro, Marc; Sessolo, Michele; Williamson, Adam; Koutsouras, Dimitrios A.; Khodagholy, Dion; Ramuz, Marc; Strakosas, Xenofon; Owens, Roisin M.; Benar, Christian; Badier, Jean-Michel; Bernard, Christophe; Malliaras, George G.

2015-01-01

Despite recent interest in organic electrochemical transistors (OECTs), sparked by their straightforward fabrication and high performance, the fundamental mechanism behind their operation remains largely unexplored. OECTs use an electrolyte in direct contact with a polymer channel as part of their device structure. Hence, they offer facile integration with biological milieux and are currently used as amplifying transducers for bioelectronics. Ion exchange between electrolyte and channel is believed to take place in OECTs, although the extent of this process and its impact on device characteristics are still unknown. We show that the uptake of ions from an electrolyte into a film of poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) leads to a purely volumetric capacitance of 39 F/cm3. This results in a dependence of the transconductance on channel thickness, a new degree of freedom that we exploit to demonstrate high-quality recordings of human brain rhythms. Our results bring to the forefront a transistor class in which performance can be tuned independently of device footprint and provide guidelines for the design of materials that will lead to state-of-the-art transistor performance. PMID:26601178

Bioluminescent bioreporter integrated circuit devices and methods for detecting estrogen

DOEpatents

Simpson, Michael L.; Paulus, Michael J.; Sayler, Gary S.; Applegate, Bruce M.; Ripp, Steven A.

2006-08-15

Bioelectronic devices for the detection of estrogen include a collection of eukaryotic cells which harbor a recombinant lux gene from a high temperature microorganism wherein the gene is operably linked with a heterologous promoter gene. A detectable light-emitting lux gene product is expressed in the presence of the estrogen and detected by the device.

Controlling the growth of palladium aerogels with high-performance toward bioelectrocatalytic oxidation of glucose.

PubMed

Wen, Dan; Herrmann, Anne-Kristin; Borchardt, Lars; Simon, Frank; Liu, Wei; Kaskel, Stefan; Eychmüller, Alexander

2014-02-19

We report the controllable synthesis of Pd aerogels with high surface area and porosity by destabilizing colloidal solutions of Pd nanoparticles with variable concentrations of calcium ions. Enzyme electrodes based on Pd aerogels co-immobilized with glucose oxidase show high activity toward glucose oxidation and are promising materials for applications in bioelectronics.

Bioluminescent bioreporter integrated circuit

DOEpatents

Simpson, Michael L.; Sayler, Gary S.; Paulus, Michael J.

2000-01-01

Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for environmental pollutant detection, oil exploration, drug discovery, industrial process control, and hazardous chemical monitoring.

Ultrathin Graphene-Protein Supercapacitors for Miniaturized Bioelectronics.

PubMed

Mosa, Islam M; Pattammattel, Ajith; Kadimisetty, Karteek; Pande, Paritosh; El-Kady, Maher F; Bishop, Gregory W; Novak, Marc; Kaner, Richard B; Basu, Ashis K; Kumar, Challa V; Rusling, James F

2017-09-06

Nearly all implantable bioelectronics are powered by bulky batteries which limit device miniaturization and lifespan. Moreover, batteries contain toxic materials and electrolytes that can be dangerous if leakage occurs. Herein, an approach to fabricate implantable protein-based bioelectrochemical capacitors (bECs) employing new nanocomposite heterostructures in which 2D reduced graphene oxide sheets are interlayered with chemically modified mammalian proteins, while utilizing biological fluids as electrolytes is described. This protein-modified reduced graphene oxide nanocomposite material shows no toxicity to mouse embryo fibroblasts and COS-7 cell cultures at a high concentration of 1600 μg mL -1 which is 160 times higher than those used in bECs, unlike the unmodified graphene oxide which caused toxic cell damage even at low doses of 10 μg mL -1 . The bEC devices are 1 μm thick, fully flexible, and have high energy density comparable to that of lithium thin film batteries. COS-7 cell culture is not affected by long-term exposure to encapsulated bECs over 4 d of continuous charge/discharge cycles. These bECs are unique, protein-based devices, use serum as electrolyte, and have the potential to power a new generation of long-life, miniaturized implantable devices.

Analysis of the Bipolar Resistive Switching Behavior of a Biocompatible Glucose Film for Resistive Random Access Memory.

PubMed

Park, Sung Pyo; Tak, Young Jun; Kim, Hee Jun; Lee, Jin Hyeok; Yoo, Hyukjoon; Kim, Hyun Jae

2018-06-01

Resistive random access memory (RRAM) devices are fabricated through a simple solution process using glucose, which is a natural biomaterial for the switching layer of RRAM. The fabricated glucose-based RRAM device shows nonvolatile bipolar resistive switching behavior, with a switching window of 10 3 . In addition, the endurance and data retention capability of glucose-based RRAM exhibit stable characteristics up to 100 consecutive cycles and 10 4 s under constant voltage stress at 0.3 V. The interface between the top electrode and the glucose film is carefully investigated to demonstrate the bipolar switching mechanism of the glucose-based RRAM device. The glucose based-RRAM is also evaluated on a polyimide film to verify the possibility of a flexible platform. Additionally, a cross-bar array structure with a magnesium electrode is prepared on various substrates to assess the degradability and biocompatibility for the implantable bioelectronic devices, which are harmless and nontoxic to the human body. It is expected that this research can provide meaningful insights for developing the future bioelectronic devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rectified tunneling current response of bio-functionalized metal-bridge-metal junctions.

PubMed

Liu, Yaqing; Offenhäusser, Andreas; Mayer, Dirk

2010-01-15

Biomolecular bridged nanostructures allow direct electrical addressing of electroactive biomolecules, which is of interest for the development of bioelectronic and biosensing hybrid junctions. In the present paper, the electroactive biomolecule microperoxidase-11 (MP-11) was integrated into metal-bridge-metal (MBM) junctions assembled from a scanning tunneling microscope (STM) setup. Before immobilization of MP-11, the Au working electrode was first modified by a self-assembled monolayer of 1-undecanethiol (UDT). A symmetric and potential independent response of current-bias voltage (I(t)/V(b)) was observed for the Au (substrate)/UDT/Au (tip) junction. However, the I(t)/V(b) characteristics became potential dependent and asymmetrical after binding of MP-11 between the electrodes of the junction. The rectification ratio of the asymmetric current response varies with gate electrode modulation. A resonant tunneling process between metal electrode and MP-11 enhances the tunneling current and is responsible for the observed rectification. Our investigations demonstrated that functional building blocks of proteins can be reassembled into new conceptual devices with operation modes deviating from their native function, which could prove highly useful in the design of future biosensors and bioelectronic devices. Copyright 2009 Elsevier B.V. All rights reserved.

Engineering of Neuron Growth and Enhancing Cell-Chip Communication via Mixed SAMs.

PubMed

Markov, Aleksandr; Maybeck, Vanessa; Wolf, Nikolaus; Mayer, Dirk; Offenhäusser, Andreas; Wördenweber, Roger

2018-06-06

The interface between cells and inorganic surfaces represents one of the key elements for bioelectronics experiments and applications ranging from cell cultures and bioelectronics devices to medical implants. In the present paper, we describe a way to tailor the biocompatibility of substrates in terms of cell growth and to significantly improve cell-chip communication, and we also demonstrate the reusability of the substrates for cell experiments. All these improvements are achieved by coating the substrates or chips with a self-assembled monolayer (SAM) consisting of a mixture of organic molecules, (3-aminopropyl)-triethoxysilane and (3-glycidyloxypropyl)-trimethoxysilane. By varying the ratio of these molecules, we are able to tune the cell density and live/dead ratios of rat cortical neurons cultured directly on the mixed SAM as well as neurons cultured on protein-coated SAMs. Furthermore, the use of the SAM leads to a significant improvement in cell-chip communications. Action potential signals of up to 9.4 ± 0.6 mV (signal-to-noise ratio up to 47) are obtained for HL-1 cells on microelectrode arrays. Finally, we demonstrate that the SAMs facilitate a reusability of the samples for all cell experiments with little re-processing.

Organic bioelectronics probing conformational changes in surface confined proteins

NASA Astrophysics Data System (ADS)

Macchia, Eleonora; Alberga, Domenico; Manoli, Kyriaki; Mangiatordi, Giuseppe F.; Magliulo, Maria; Palazzo, Gerardo; Giordano, Francesco; Lattanzi, Gianluca; Torsi, Luisa

2016-06-01

The study of proteins confined on a surface has attracted a great deal of attention due to its relevance in the development of bio-systems for laboratory and clinical settings. In this respect, organic bio-electronic platforms can be used as tools to achieve a deeper understanding of the processes involving protein interfaces. In this work, biotin-binding proteins have been integrated in two different organic thin-film transistor (TFT) configurations to separately address the changes occurring in the protein-ligand complex morphology and dipole moment. This has been achieved by decoupling the output current change upon binding, taken as the transducing signal, into its component figures of merit. In particular, the threshold voltage is related to the protein dipole moment, while the field-effect mobility is associated with conformational changes occurring in the proteins of the layer when ligand binding occurs. Molecular Dynamics simulations on the whole avidin tetramer in presence and absence of ligands were carried out, to evaluate how the tight interactions with the ligand affect the protein dipole moment and the conformation of the loops surrounding the binding pocket. These simulations allow assembling a rather complete picture of the studied interaction processes and support the interpretation of the experimental results.

Development of dopant-free conductive bioelastomers

PubMed Central

Xu, Cancan; Huang, Yihui; Yepez, Gerardo; Wei, Zi; Liu, Fuqiang; Bugarin, Alejandro; Tang, Liping; Hong, Yi

2016-01-01

Conductive biodegradable materials are of great interest for various biomedical applications, such as tissue repair and bioelectronics. They generally consist of multiple components, including biodegradable polymer/non-degradable conductive polymer/dopant, biodegradable conductive polymer/dopant or biodegradable polymer/non-degradable inorganic additives. The dopants or additives induce material instability that can be complex and possibly toxic. Material softness and elasticity are also highly expected for soft tissue repair and soft electronics. To address these concerns, we designed a unicomponent dopant-free conductive polyurethane elastomer (DCPU) by chemically linking biodegradable segments, conductive segments, and dopant molecules into one polymer chain. The DCPU films which had robust mechanical properties with high elasticity and conductivity can be degraded enzymatically and by hydrolysis. It exhibited great electrical stability in physiological environment with charge. Mouse 3T3 fibroblasts survived and proliferated on these films exhibiting good cytocompatibility. Polymer degradation products were non-toxic. DCPU could also be processed into a porous scaffold and in an in vivo subcutaneous implantation model, exhibited good tissue compatibility with extensive cell infiltration over 2 weeks. Such biodegradable DCPU with good flexibility and elasticity, processability, and electrical stability may find broad applications for tissue repair and soft/stretchable/wearable bioelectronics. PMID:27686216

Organic bioelectronics probing conformational changes in surface confined proteins

PubMed Central

Macchia, Eleonora; Alberga, Domenico; Manoli, Kyriaki; Mangiatordi, Giuseppe F.; Magliulo, Maria; Palazzo, Gerardo; Giordano, Francesco; Lattanzi, Gianluca; Torsi, Luisa

2016-01-01

The study of proteins confined on a surface has attracted a great deal of attention due to its relevance in the development of bio-systems for laboratory and clinical settings. In this respect, organic bio-electronic platforms can be used as tools to achieve a deeper understanding of the processes involving protein interfaces. In this work, biotin-binding proteins have been integrated in two different organic thin-film transistor (TFT) configurations to separately address the changes occurring in the protein-ligand complex morphology and dipole moment. This has been achieved by decoupling the output current change upon binding, taken as the transducing signal, into its component figures of merit. In particular, the threshold voltage is related to the protein dipole moment, while the field-effect mobility is associated with conformational changes occurring in the proteins of the layer when ligand binding occurs. Molecular Dynamics simulations on the whole avidin tetramer in presence and absence of ligands were carried out, to evaluate how the tight interactions with the ligand affect the protein dipole moment and the conformation of the loops surrounding the binding pocket. These simulations allow assembling a rather complete picture of the studied interaction processes and support the interpretation of the experimental results. PMID:27312768

The Integration of Bacteriorhodopsin Proteins with Semiconductor Heterostructure Devices

NASA Astrophysics Data System (ADS)

Xu, Jian

2008-03-01

Bioelectronics has emerged as one of the most rapidly developing fields among the active frontiers of interdisciplinary research. A major thrust in this field is aimed at the coupling of the technologically-unmatched performance of biological systems, such as neural and sensing functions, with the well developed technology of microelectronics and optoelectronics. To this end we have studied the integration of a suitably engineered protein, bacteriorhodopsin (BR), with semiconductor optoelectronic devices and circuits. Successful integration will potentially lead to ultrasensitive sensors with polarization selectivity and built-in preprocessing capabilities that will be useful for high speed tracking, motion and edge detection, biological detection, and artificial vision systems. In this presentation we will summarize our progresses in this area, which include fundamental studies on the transient dynamics of photo-induced charge shift in BR and the coupling mechanism at protein-semiconductor interface for effective immobilizing and selectively integrating light sensitive proteins with microelectronic devices and circuits, and the device engineering of BR-transistor-integrated optical sensors as well as their applications in phototransceiver circuits. Work done in collaboration with Pallab Bhattacharya, Jonghyun Shin, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI; Robert R. Birge, Department of Chemistry, University of Connecticut, Storrs, CT 06269; and György V'ar'o, Institute of Biophysics, Biological Research Center of the Hungarian Academy of Science, H-6701 Szeged, Hungary.

Optical Absorption and Electric Resistivity of an l-Cysteine Film

NASA Astrophysics Data System (ADS)

Kamada, Masao; Hideshima, Takuya; Azuma, Junpei; Yamamoto, Isamu; Imamura, Masaki; Takahashi, Kazutoshi

2016-12-01

The optical and electric properties of an l-cysteine film have been investigated to understand its applicability to bioelectronics. The fundamental absorption is the allowed transition having the threshold at 5.8 eV and the absorption is due to the charge-transfer type transition from sulfur-3sp to oxygen-2p and/or carbon-2p states, while absorptions more than 9 eV can be explained with intra-atomic transitions in the functional groups. The electric resistivity is 2.0 × 104 Ω m at room temperature and increases as the sample temperature decreases. The results indicate that the l-cysteine film is a p-type semiconductor showing the hole conduction caused by the sulfur-3sp occupied states and unknown impurity or defect states as acceptors. The electron affinity of the l-cysteine film is derived as ≦-0.3 eV.

Implementation of a Low-Cost Automated LED Photometer for Enzymatic Reaction Detection to Teach Basic Bioelectronics Technologies in Vocational High Schools

ERIC Educational Resources Information Center

Chen, Huai-Yi; Nieh, Hwa-Ming; Yang, Ming-Feng; Chou, Yu-Kung; Chung, Jui-Hsu; Liou, Je-Wen

2016-01-01

This study proposes a home-assembled, low-cost blue light-emitting diode (LED) photometer that uses simple and low-cost hardware and software, costing about US $150. This 425-nm wavelength photometer is controlled by an 89C51 microcontroller chip. Glucose concentration detection experiments involving enzyme coupling reactions were carried out to…

Research Area 4.1 Nano- and Bio-Electronics: Lester Eastman Conference on High-Performance Devices

DTIC Science & Technology

2017-06-02

temperatures higher than 1600 oC, in-situ generation of carbon vacancies overcomes the effect of carbon implantation, and results in a The authors would like...passivation layers are used in these measurements. B. High Temperature Oxidation The effect of high temperature oxidation treatment on carrier... Temperature Characteristics of In0.7 Ga0.3As PHEMTs ............................................................................................12 S‐W Son, J.H

Enhancing extracellular electron transfer between Pseudomonas aeruginosa PAO1 and light driven semiconducting birnessite.

PubMed

Ren, Guiping; Sun, Yuan; Ding, Yang; Lu, Anhuai; Li, Yan; Wang, Changqiu; Ding, Hongrui

2018-06-02

In recent years, considerable research effort has explored the interaction between semiconducting minerals and microorganisms, such relationship is a promising way to increase the efficiency of bioelectrochemical systems. Herein, the enhancement of electron transfer between birnessite photoanodes and Pseudomonas aeruginosa PAO1 under visible light was investigated. Under light illumination and positive bias, the light-birnessite-PAO1 electrochemical system generated a photocurrent of 279.57 μA/cm 2 , which is 322% and 170% higher than those in the abiotic control and dead culture, suggesting photoenhanced electrochemical interaction between birnessite and Pseudomonas. The I-t curves presented repeatable responses to light on/off cycles, and multi-conditions analyses indicated that the enhanced photocurrent was attributed to the additional redox species associated with P. aeruginosa PAO1 and with the biofilm on birnessite. Electroconductibility analysis was conducted on the biofilm cellularly by conductive atomic force microscope. Pyocyanin was isolated as the biosynthesized extracellular shuttle and characterized by cyclic voltammetry and surface-enhanced Raman spectroscopy. Rapid bioelectron transfer driven by light was observed. The results suggest new opportunities for designing photo-bioelectronic devices and expanding our understanding of extracellular electron transfer with semiconducting minerals under light in nature environments. Copyright © 2018. Published by Elsevier B.V.

Imaging Neuronal Seal Resistance on Silicon Chip using Fluorescent Voltage-Sensitive Dye

PubMed Central

Braun, Dieter; Fromherz, Peter

2004-01-01

The electrical sheet resistance between living cells grown on planar electronic contacts of semiconductors or metals is a crucial parameter for bioelectronic devices. It determines the strength of electrical signal transduction from cells to chips and from chips to cells. We measured the sheet resistance by applying AC voltage to oxidized silicon chips and by imaging the voltage change across the attached cell membrane with a fluorescent voltage-sensitive dye. The phase map of voltage change was fitted with a planar core-coat conductor model using the sheet resistance as a free parameter. For nerve cells from rat brain on polylysine as well as for HEK293 cells and MDCK cells on fibronectin we find a similar sheet resistance of 10 MΩ. Taking into account the independently measured distance of 50 nm between chip and membrane for these cells, we obtain a specific resistance of 50 Ωcm that is indistinguishable from bulk electrolyte. On the other hand, the sheet resistance for erythrocytes on polylysine is far higher, at ∼1.5 GΩ. Considering the distance of 10 nm, the specific resistance in the narrow cleft is enhanced to 1500 Ωcm. We find this novel optical method to be a convenient tool to optimize the interface between cells and chips for bioelectronic devices. PMID:15298937

Imaging neuronal seal resistance on silicon chip using fluorescent voltage-sensitive dye.

PubMed

Braun, Dieter; Fromherz, Peter

2004-08-01

The electrical sheet resistance between living cells grown on planar electronic contacts of semiconductors or metals is a crucial parameter for bioelectronic devices. It determines the strength of electrical signal transduction from cells to chips and from chips to cells. We measured the sheet resistance by applying AC voltage to oxidized silicon chips and by imaging the voltage change across the attached cell membrane with a fluorescent voltage-sensitive dye. The phase map of voltage change was fitted with a planar core-coat conductor model using the sheet resistance as a free parameter. For nerve cells from rat brain on polylysine as well as for HEK293 cells and MDCK cells on fibronectin we find a similar sheet resistance of 10 MOmega. Taking into account the independently measured distance of 50 nm between chip and membrane for these cells, we obtain a specific resistance of 50 Omegacm that is indistinguishable from bulk electrolyte. On the other hand, the sheet resistance for erythrocytes on polylysine is far higher, at approximately 1.5 GOmega. Considering the distance of 10 nm, the specific resistance in the narrow cleft is enhanced to 1500 Omegacm. We find this novel optical method to be a convenient tool to optimize the interface between cells and chips for bioelectronic devices.

Poly(3,4-ethylenedioxythiophene):GlycosAminoGlycan Aqueous Dispersions: Toward Electrically Conductive Bioactive Materials for Neural Interfaces.

PubMed

Mantione, Daniele; Del Agua, Isabel; Schaafsma, Wandert; Diez-Garcia, Javier; Castro, Begona; Sardon, Haritz; Mecerreyes, David

2016-08-01

There is an actual need of advanced materials for the emerging field of bioelectronics. One commonly used material is the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) ( PSS) due to its general use in organic electronics. However, depending on the application in bioelectronics, PSS is not fully biocompatible due to the high acidity of the residual sulfonate protons of PSS. In this paper, the synthesis and biocompatibility properties of new poly(3,4-ethylenedioxythiophene):GlycosAminoGlycan ( GAG) aqueous dispersions and its resulting films are shown. Thus, negatively charged GAGs as an alternative to PSS are presented. Three different commercially available GAGs, hyaluronic acid, heparin, and chondroitin sulfate are used. Indeed, GAGs dispersions are prepared through an oxidative chemical polymerization in water. Biocompatibility assays of the GAGs coatings are performed using SH-SY5Y and CCF-STTG1 cell lines and with ATP and Ca(2+) . Results show full biocompatibility and a pronounced anti-inflammatory effect. This last characteristic becomes crucial if implanted in the body. These materials can be used for in vivo applications, as transistor or electrode for electrical recording and for all the possible situations when there is contact between electronic circuits and living tissues. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prospects of Nanotechnology in Clinical Immunodiagnostics

PubMed Central

Ansari, Anees A.; Alhoshan, Mansour; Alsalhi, Mohamad S.; Aldwayyan, Abdullah S.

2010-01-01

Nanostructured materials are promising compounds that offer new opportunities as sensing platforms for the detection of biomolecules. Having micrometer-scale length and nanometer-scale diameters, nanomaterials can be manipulated with current nanofabrication methods, as well as self-assembly techniques, to fabricate nanoscale bio-sensing devices. Nanostructured materials possess extraordinary physical, mechanical, electrical, thermal and multifunctional properties. Such unique properties advocate their use as biomimetic membranes to immobilize and modify biomolecules on the surface of nanoparticles. Alignment, uniform dispersion, selective growth and diameter control are general parameters which play critical roles in the successful integration of nanostructures for the fabrication of bioelectronic sensing devices. In this review, we focus on different types and aspects of nanomaterials, including their synthesis, properties, conjugation with biomolecules and their application in the construction of immunosensing devices. Some key results from each cited article are summarized by relating the concept and mechanism behind each sensor, experimental conditions and the behavior of the sensor under different conditions, etc. The variety of nanomaterial-based bioelectronic devices exhibiting novel functions proves the unique properties of nanomaterials in such sensing devices, which will surely continue to expand in the future. Such nanomaterial based devices are expected to have a major impact in clinical immunodiagnostics, environmental monitoring, security surveillance and for ensuring food safety. PMID:22163566

Flexible graphene bio-nanosensor for lactate.

PubMed

Labroo, Pratima; Cui, Yue

2013-03-15

The development of a flexible nanosensor for detecting lactate could expand opportunities for using graphene, both in fundamental studies for a variety of device platforms and in practical applications. Graphene is a delicate single-layer, two-dimensional network of carbon atoms with ultrasensitive sensing capabilities. Lactic acid is important for clinical analysis, sports medicine, and the food industry. Recently, wearable and flexible bioelectronics on plastics have attracted great interest for healthcare, sports and defense applications due to their advantages of being light-weight, bendable, or stretchable. Here, we demonstrate for the first time the development of a flexible graphene-based bio-nanosensor to detect lactate. Our results show that flexible lactate biosensors can be fabricated on a variety of plastic substrates. The sensor can detect lactate sensitively from 0.08 μM to 20 μM with a fast steady-state measuring time of 2s. The sensor can also detect lactate under different mechanical bending conditions, the sensor response decreased as the bending angle and number of bending repetitions increased. We anticipate that these results could open exciting opportunities for fundamental studies of flexible graphene bioelectronics by using other bioreceptors, as well as a variety of wearable, implantable, real-time, or on-site applications in fields ranging from clinical analysis to defense. Copyright © 2012 Elsevier B.V. All rights reserved.

Bacteriorhodopsin as an electronic conduction medium for biomolecular electronics.

PubMed

Jin, Yongdong; Honig, Tal; Ron, Izhar; Friedman, Noga; Sheves, Mordechai; Cahen, David

2008-11-01

Interfacing functional proteins with solid supports for device applications is a promising route to possible applications in bio-electronics, -sensors, and -optics. Various possible applications of bacteriorhodopsin (bR) have been explored and reviewed since the discovery of bR. This tutorial review discusses bR as a medium for biomolecular optoelectronics, emphasizing ways in which it can be interfaced, especially as a thin film, solid-state current-carrying electronic element.

Computational prediction of over-annotated protein-coding genes in the genome of Agrobacterium tumefaciens strain C58

NASA Astrophysics Data System (ADS)

Yu, Jia-Feng; Sui, Tian-Xiang; Wang, Hong-Mei; Wang, Chun-Ling; Jing, Li; Wang, Ji-Hua

2015-12-01

Agrobacterium tumefaciens strain C58 is a type of pathogen that can cause tumors in some dicotyledonous plants. Ever since the genome of A. tumefaciens strain C58 was sequenced, the quality of annotation of its protein-coding genes has been queried continually, because the annotation varies greatly among different databases. In this paper, the questionable hypothetical genes were re-predicted by integrating the TN curve and Z curve methods. As a result, 30 genes originally annotated as “hypothetical” were discriminated as being non-coding sequences. By testing the re-prediction program 10 times on data sets composed of the function-known genes, the mean accuracy of 99.99% and mean Matthews correlation coefficient value of 0.9999 were obtained. Further sequence analysis and COG analysis showed that the re-annotation results were very reliable. This work can provide an efficient tool and data resources for future studies of A. tumefaciens strain C58. Project supported by the National Natural Science Foundation of China (Grant Nos. 61302186 and 61271378) and the Funding from the State Key Laboratory of Bioelectronics of Southeast University.

Education of biomedical engineering in Taiwan.

PubMed

Lin, Kang-Ping; Kao, Tsair; Wang, Jia-Jung; Chen, Mei-Jung; Su, Fong-Chin

2014-01-01

Biomedical Engineers (BME) play an important role in medical and healthcare society. Well educational programs are important to support the healthcare systems including hospitals, long term care organizations, manufacture industries of medical devices/instrumentations/systems, and sales/services companies of medical devices/instrumentations/system. In past 30 more years, biomedical engineering society has accumulated thousands people hold a biomedical engineering degree, and work as a biomedical engineer in Taiwan. Most of BME students can be trained in biomedical engineering departments with at least one of specialties in bioelectronics, bio-information, biomaterials or biomechanics. Students are required to have internship trainings in related institutions out of campus for 320 hours before graduating. Almost all the biomedical engineering departments are certified by IEET (Institute of Engineering Education Taiwan), and met the IEET requirement in which required mathematics and fundamental engineering courses. For BMEs after graduation, Taiwanese Society of Biomedical Engineering (TSBME) provides many continue-learning programs and certificates for all members who expect to hold the certification as a professional credit in his working place. In current status, many engineering departments in university are continuously asked to provide joint programs with BME department to train much better quality students. BME is one of growing fields in Taiwan.

Designing small molecule polyaromatic p- and n-type semiconductor materials for organic electronics

NASA Astrophysics Data System (ADS)

Collis, Gavin E.

2015-12-01

By combining computational aided design with synthetic chemistry, we are able to identify core 2D polyaromatic small molecule templates with the necessary optoelectronic properties for p- and n-type materials. By judicious selection of the functional groups, we can tune the physical properties of the material making them amenable to solution and vacuum deposition. In addition to solubility, we observe that the functional group can influence the thin film molecular packing. By developing structure-property relationships (SPRs) for these families of compounds we observe that some compounds are better suited for use in organic solar cells, while others, varying only slightly in structure, are favoured in organic field effect transistor devices. We also find that the processing conditions can have a dramatic impact on molecular packing (i.e. 1D vs 2D polymorphism) and charge mobility; this has implications for material and device long term stability. We have developed small molecule p- and n-type materials for organic solar cells with efficiencies exceeding 2%. Subtle variations in the functional groups of these materials produces p- and ntype materials with mobilities higher than 0.3 cm2/Vs. We are also interested in using our SPR approach to develop materials for sensor and bioelectronic applications.

Bioelectrochemical interface engineering: toward the fabrication of electrochemical biosensors, biofuel cells, and self-powered logic biosensors.

PubMed

Zhou, Ming; Dong, Shaojun

2011-11-15

Over the past decade, researchers have devoted considerable attention to the integration of living organisms with electronic elements to yield bioelectronic devices. Not only is the integration of DNA, enzymes, or whole cells with electronics of scientific interest, but it has many versatile potential applications. Researchers are using these ideas to fabricate biosensors for analytical applications and to assemble biofuel cells (BFCs) and biomolecule-based devices. Other research efforts include the development of biocomputing systems for information processing. In this Account, we focus on our recent progress in engineering at the bioelectrochemical interface (BECI) for the rational design and construction of important bioelectronic devices, ranging from electrochemical (EC-) biosensors to BFCs, and self-powered logic biosensors. Hydrogels and sol-gels provide attractive materials for the immobilization of enzymes because they make EC-enzyme biosensors stable and even functional in extreme environments. We use a layer-by-layer (LBL) self-assembly technique to fabricate multicomponent thin films on the BECI at the nanometer scale. Additionally, we demonstrate how carbon nanomaterials have paved the way for new and improved EC-enzyme biosensors. In addition to the widely reported BECI-based electrochemical impedance spectroscopy (EIS)-type aptasensors, we integrate the LBL technique with our previously developed "solid-state probe" technique for redox probes immobilization on electrode surfaces to design and fabricate BECI-based differential pulse voltammetry (DPV)-type aptasensors. BFCs can directly harvest energy from ambient biofuels as green energy sources, which could lead to their application as simple, flexible, and portable power sources. Porous materials provide favorable microenvironments for enzyme immobilization, which can enhance BFC power output. Furthermore, by introducing aptamer-based logic systems to BFCs, such systems could be applied as self-powered and intelligent aptasensors for the logic detection. We have developed biocomputing keypad lock security systems which can be also used for intelligent medical diagnostics. BECI engineering provides a simple but effective approach toward the design and fabrication of EC-biosensors, BFCs, and self-powered logic biosensors, which will make essential contributions in the development of creative and practical bioelectronic devices. The exploration of novel interface engineering applications and the creation of new fabrication concepts or methods merit further attention.

Graphene Field Effect Transistors for Biomedical Applications: Current Status and Future Prospects.

PubMed

Forsyth, Rhiannan; Devadoss, Anitha; Guy, Owen J

2017-07-26

Since the discovery of the two-dimensional (2D) carbon material, graphene, just over a decade ago, the development of graphene-based field effect transistors (G-FETs) has become a widely researched area, particularly for use in point-of-care biomedical applications. G-FETs are particularly attractive as next generation bioelectronics due to their mass-scalability and low cost of the technology's manufacture. Furthermore, G-FETs offer the potential to complete label-free, rapid, and highly sensitive analysis coupled with a high sample throughput. These properties, coupled with the potential for integration into portable instrumentation, contribute to G-FETs' suitability for point-of-care diagnostics. This review focuses on elucidating the recent developments in the field of G-FET sensors that act on a bioaffinity basis, whereby a binding event between a bioreceptor and the target analyte is transduced into an electrical signal at the G-FET surface. Recognizing and quantifying these target analytes accurately and reliably is essential in diagnosing many diseases, therefore it is vital to design the G-FET with care. Taking into account some limitations of the sensor platform, such as Debye-Hükel screening and device surface area, is fundamental in developing improved bioelectronics for applications in the clinical setting. This review highlights some efforts undertaken in facing these limitations in order to bring G-FET development for biomedical applications forward.

Insect-machine interface based neurocybernetics.

PubMed

Bozkurt, Alper; Gilmour, Robert F; Sinha, Ayesa; Stern, David; Lal, Amit

2009-06-01

We present details of a novel bioelectric interface formed by placing microfabricated probes into insect during metamorphic growth cycles. The inserted microprobes emerge with the insect where the development of tissue around the electronics during the pupal development allows mechanically stable and electrically reliable structures coupled to the insect. Remarkably, the insects do not react adversely or otherwise to the inserted electronics in the pupae stage, as is true when the electrodes are inserted in adult stages. We report on the electrical and mechanical characteristics of this novel bioelectronic interface, which we believe would be adopted by many investigators trying to investigate biological behavior in insects with negligible or minimal traumatic effect encountered when probes are inserted in adult stages. This novel insect-machine interface also allows for hybrid insect-machine platforms for further studies. As an application, we demonstrate our first results toward navigation of flight in moths. When instrumented with equipment to gather information for environmental sensing, such insects potentially can assist man to monitor the ecosystems that we share with them for sustainability. The simplicity of the optimized surgical procedure we invented allows for batch insertions to the insect for automatic and mass production of such hybrid insect-machine platforms. Therefore, our bioelectronic interface and hybrid insect-machine platform enables multidisciplinary scientific and engineering studies not only to investigate the details of insect behavioral physiology but also to control it.

Organic mixed conductors for bioelectronic applications (Conference Presentation)

NASA Astrophysics Data System (ADS)

Rivnay, Jonathan

2016-09-01

Direct measurement and stimulation of electrophysiological activity is a staple of neural and cardiac health monitoring, diagnosis and/or therapy. The ability to sensitively detect these signals can be enhanced by organic electronic materials that show mixed conduction properties (both electronic and ionic transport) in order to bridge the inherent mismatch that is prevalent between biological systems and traditional microelectronic materials/devices. Organic electrochemical transistors (OECTs) are one class of devices that utilize organic mixed conductors as the transistor channel, and have shown considerable promise as amplifying transducers due to their stability in aqueous conditions and high transconductance. These devices are fabricated in flexible, conformable form factors for in vivo recordings of epileptic activity, and for cutaneous EEG and ECG recordings in human subjects. The majority of high performance devices are based on conducting polymers such as poly(3,4-ethylenedioxythiophene) :poly(styrenesulfonate), PEDOT:PSS. By investigating PEDOT-based materials and devices, we are able to construct design rules for new formulations/materials. Introducing glycolated side chains to carefully selected semiconducting polymer backbones has enabled a new class high performance bioelectronic materials that feature high volumetric capacitance, transconductance >10mS (device dimensions ca. 10um), and steep subthreshold switching characteristics. A sub-set of these materials outperform PEDOT:PSS and shows significant promise for low power in vitro and in vivo biosensing applications.

The design and fabrication of supramolecular semiconductor nanowires formed by benzothienobenzothiophene (BTBT)-conjugated peptides.

PubMed

Khalily, Mohammad Aref; Usta, Hakan; Ozdemir, Mehmet; Bakan, Gokhan; Dikecoglu, F Begum; Edwards-Gayle, Charlotte; Hutchinson, Jessica A; Hamley, Ian W; Dana, Aykutlu; Guler, Mustafa O

2018-05-31

π-Conjugated small molecules based on a [1]benzothieno[3,2-b]benzothiophene (BTBT) unit are of great research interest in the development of solution-processable semiconducting materials owing to their excellent charge-transport characteristics. However, the BTBT π-core has yet to be demonstrated in the form of electro-active one-dimensional (1D) nanowires that are self-assembled in aqueous media for potential use in bioelectronics and tissue engineering. Here we report the design, synthesis, and self-assembly of benzothienobenzothiophene (BTBT)-peptide conjugates, the BTBT-peptide (BTBT-C3-COHN-Ahx-VVAGKK-Am) and the C8-BTBT-peptide (C8-BTBT-C3-COHN-Ahx-VVAGKK-Am), as β-sheet forming amphiphilic molecules, which self-assemble into highly uniform nanofibers in water with diameters of 11-13(±1) nm and micron-size lengths. Spectroscopic characterization studies demonstrate the J-type π-π interactions among the BTBT molecules within the hydrophobic core of the self-assembled nanofibers yielding an electrical conductivity as high as 6.0 × 10-6 S cm-1. The BTBT π-core is demonstrated, for the first time, in the formation of self-assembled peptide 1D nanostructures in aqueous media for potential use in tissue engineering, bioelectronics and (opto)electronics. The conductivity achieved here is one of the highest reported to date in a non-doped state.

Duplex Bioelectronic Tongue for Sensing Umami and Sweet Tastes Based on Human Taste Receptor Nanovesicles.

PubMed

Ahn, Sae Ryun; An, Ji Hyun; Song, Hyun Seok; Park, Jin Wook; Lee, Sang Hun; Kim, Jae Hyun; Jang, Jyongsik; Park, Tai Hyun

2016-08-23

For several decades, significant efforts have been made in developing artificial taste sensors to recognize the five basic tastes. So far, the well-established taste sensor is an E-tongue, which is constructed with polymer and lipid membranes. However, the previous artificial taste sensors have limitations in various food, beverage, and cosmetic industries because of their failure to mimic human taste reception. There are many interactions between tastants. Therefore, detecting the interactions in a multiplexing system is required. Herein, we developed a duplex bioelectronic tongue (DBT) based on graphene field-effect transistors that were functionalized with heterodimeric human umami taste and sweet taste receptor nanovesicles. Two types of nanovesicles, which have human T1R1/T1R3 for the umami taste and human T1R2/T1R3 for the sweet taste on their membranes, immobilized on micropatterned graphene surfaces were used for the simultaneous detection of the umami and sweet tastants. The DBT platform led to highly sensitive and selective recognition of target tastants at low concentrations (ca. 100 nM). Moreover, our DBT was able to detect the enhancing effect of taste enhancers as in a human taste sensory system. This technique can be a useful tool for the detection of tastes instead of sensory evaluation and development of new artificial tastants in the food and beverage industry.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gürel, Hikmet Hakan, E-mail: hhakan.gurel@kocaeli.edu.tr; Salmankurt, Bahadır

Graphene as a 2D material has unique chemical and electronic properties. Because of its unique physical, chemical, and electronic properties, its interesting shape and size make it a promising nanomaterial in many biological applications. However, the lower water-solubility and the irreversible aggregation due to the strong π-π stacking hinder the wide application of graphene nanosheets in biomedical field. Thus, graphene oxide (GO), one derivative of graphene, has been used more frequently in the biological system owing to its relatively higher water solubility and biocompatibility. Recently, it has been demonstrated that nanomaterials with different functional groups on the surface can bemore » used to bind the drug molecules with high affinity. GO has different functional groups such as H, OH and O on its surface; it can be a potential candidate as a drug carrier. The interactions of biomolecules and graphene like structures are long-ranged and very weak. Development of new techniques is very desirable for design of bioelectronics sensors and devices. In this work, we present first-principles spin polarized calculations within density functional theory to calculate effects of charging on DNA/RNA nucleobases on graphene oxide. It is shown that how modify structural and electronic properties of nucleobases on graphene oxide by applied charging.« less

Insights into Solid-State Electron Transport through Proteins from Inelastic Tunneling Spectroscopy: The Case of Azurin.

PubMed

Yu, Xi; Lovrincic, Robert; Sepunaru, Lior; Li, Wenjie; Vilan, Ayelet; Pecht, Israel; Sheves, Mordechai; Cahen, David

2015-10-27

Surprisingly efficient solid-state electron transport has recently been demonstrated through "dry" proteins (with only structural, tightly bound H2O left), suggesting proteins as promising candidates for molecular (bio)electronics. Using inelastic electron tunneling spectroscopy (IETS), we explored electron-phonon interaction in metal/protein/metal junctions, to help understand solid-state electronic transport across the redox protein azurin. To that end an oriented azurin monolayer on Au is contacted by soft Au electrodes. Characteristic vibrational modes of amide and amino acid side groups as well as of the azurin-electrode contact were observed, revealing the azurin native conformation in the junction and the critical role of side groups in the charge transport. The lack of abrupt changes in the conductance and the line shape of IETS point to far off-resonance tunneling as the dominant transport mechanism across azurin, in line with previously reported (and herein confirmed) azurin junctions. The inelastic current and hence electron-phonon interaction appear to be rather weak and comparable in magnitude with the inelastic fraction of tunneling current via alkyl chains, which may reflect the known structural rigidity of azurin.

Micrometer sized immobilization of protein molecules onto quartz, silicium and gold.

NASA Astrophysics Data System (ADS)

Petersen, Steffen B.; Neves-Petersen, Maria Teresa; Klitgaard, Søren; Duroux, Meg Crookshanks

2006-02-01

We demonstrate that ultraviolet light can be used to make sterically oriented covalent immobilization of a large variety of protein molecules onto either gold or thiolated quartz or silicium. The reaction mechanism behind the reported new technology involves light induced breakage of disulphide bridges in proteins upon UV illumination of nearby aromatic amino acids, resulting in the formation of free, reactive thiol groups that will form covalent bonds with thiol reactive surfaces. The protein molecules in general retain their function. The size of the immobilization spot is determined by the dimension of the UV beam. In principle, the spot size may be as small as 1 micrometer or less. We have developed the necessary technology for preparing large protein arrays of enzymes and fragments of monoclonal antibodies. Dedicated Image Processing Software has been developed for making quality assessment of the protein arrays. A multitude of important application areas such as drug carriers and drug delivery, bioelectronics, carbon nanotubes, nanoparticles as well as protein glue are discussed.

Biolithography: Slime mould patterning of polyaniline

NASA Astrophysics Data System (ADS)

Berzina, Tatiana; Dimonte, Alice; Adamatzky, Andrew; Erokhin, Victor; Iannotta, Salvatore

2018-03-01

Slime mould Physarum polycephalum develops intricate patterns of protoplasmic networks when foraging on a non-nutrient substrates. The networks are optimised for spanning larger spaces with minimum body mass and for quick transfer of nutrients and metabolites inside the slime mould's body. We hybridise the slime mould's networks with conductive polymer polyaniline and thus produce micro-patterns of conductive networks. This unconventional lithographic method opens new perspectives in development of living technology devices, biocompatible non-silicon hardware for applications in integrated circuits, bioelectronics, and biosensing.

RETRACTED: Multifunctional magnetic reduced graphene oxide dendrites: synthesis, characterization and their applications.

PubMed

Roy, Ekta; Patra, Santanu; Kumar, Deepak; Madhuri, Rashmi; Sharma, Prashant K

2015-06-15

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief following concerns raised by a reader. The article uses an electron micrograph identical to another publication despite being labelled as different samples. Fig. 3F is the same as Fig. 1D published in Biosensors and Bioelectronics Volume 89 Part1, 15 March 2017, Pages 620-626, 10.1016/j.bios.2015.12.085. In addition, the extraordinary similarities observed between the data presented in Fig. 3C and in Fig. 3C in ACS Biomater. Sci. Eng., 2017, 3 (9), pp 2120–2135, 10.1021/acsbiomaterials.7b00089, Fig. 4A in Colloids and Surfaces B: Biointerfaces, Volume 142, 1 June 2016, Pages 248-258 10.1016/j.colsurfb.2016.02.053 and Fig. 4C in Biosensors and Bioelectronics, Volume 97, 15 November 2017, Pages 208-217, 10.1016/j.bios.2017.06.003 are highly unlikely. This problem with the data casts doubt on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. Copyright © 2015 Elsevier B.V. All rights reserved.

Corrosion Protection of Al/Au/ZnO Anode for Hybrid Cell Application

PubMed Central

Slaughter, Gymama; Stevens, Brian

2015-01-01

Effective protection of power sources from corrosion is critical in the development of abiotic fuel cells, biofuel cells, hybrid cells and biobateries for implantable bioelectronics. Corrosion of these bioelectronic devices result in device inability to generate bioelectricity. In this paper Al/Au/ZnO was considered as a possible anodic substrate for the development of a hybrid cell. The protective abilities of corrosive resistant aluminum hydroxide and zinc phosphite composite films formed on the surface of Al/Au/ZnO anode in various electrolyte environments were examined by electrochemical methods. The presence of phosphate buffer and physiological saline (NaCl) buffer allows for the formation of aluminum hyrdroxide and zinc phosphite composite films on the surface of the Al/Au/ZnO anode that prevent further corrosion of the anode. The highly protective films formed on the Al/Au/ZnO anode during energy harvesting in a physiological saline environment resulted in 98.5% corrosion protective efficiency, thereby demonstrating that the formation of aluminum hydroxide and zinc phosphite composite films are effective in the prevention of anode corrosion during energy harvesting. A cell assembly consisting of the Al/Au/ZnO anode and platinum cathode resulted in an open circuit voltage of 1.03 V. A maximum power density of 955.3 μW/ cm2 in physiological saline buffer at a cell voltage and current density of 345 mV and 2.89 mA/ cm2, respectively. PMID:26580661

Corrosion Protection of Al/Au/ZnO Anode for Hybrid Cell Application.

PubMed

Slaughter, Gymama; Stevens, Brian

2015-11-16

Effective protection of power sources from corrosion is critical in the development of abiotic fuel cells, biofuel cells, hybrid cells and biobateries for implantable bioelectronics. Corrosion of these bioelectronic devices result in device inability to generate bioelectricity. In this paper Al/Au/ZnO was considered as a possible anodic substrate for the development of a hybrid cell. The protective abilities of corrosive resistant aluminum hydroxide and zinc phosphite composite films formed on the surface of Al/Au/ZnO anode in various electrolyte environments were examined by electrochemical methods. The presence of phosphate buffer and physiological saline (NaCl) buffer allows for the formation of aluminum hyrdroxide and zinc phosphite composite films on the surface of the Al/Au/ZnO anode that prevent further corrosion of the anode. The highly protective films formed on the Al/Au/ZnO anode during energy harvesting in a physiological saline environment resulted in 98.5% corrosion protective efficiency, thereby demonstrating that the formation of aluminum hydroxide and zinc phosphite composite films are effective in the prevention of anode corrosion during energy harvesting. A cell assembly consisting of the Al/Au/ZnO anode and platinum cathode resulted in an open circuit voltage of 1.03 V. A maximum power density of 955.3 mW/ cm² in physiological saline buffer at a cell voltage and current density of 345 mV and 2.89 mA/ cm², respectively.

Biosensor development.

PubMed

Ziegler, C; Göpel, W

1998-10-01

Current biosensor developments can be summarised by different trends. For traditional enzymatic biosensors such as glucose sensors, steady improvements of well known basic principles have been made in order to achieve better sensor stability. On the other hand, new affinity sensors such as nucleic acid sensors, transmembrane sensors, and sensors utilising whole cells or even cell networks have become of increasing interest. New ways to miniaturise biosensors and to control their interfaces down to the molecular level have been introduced (the bioelectronics approach). High-throughput screening based on various signal transduction principles has become of increasing importance.

Micellar Drug Delivery and Proteomics Analysis for Effective Treatment of Resistant Prostate Cancer

DTIC Science & Technology

2015-12-01

22.4 g, 0.1 mol) dissolved in pyridine (50 mL) and CH2Cl2 (200 mL), and chilled to −78°C over dry ice. A solution of triphosgene (50 mmol, 14.8 g...chloroform, and precipitate in large amount of isopropanol and diethyl ether, followed by drying under vacuum for 48 h. Purified copolymer (100 mg...immunoassay. Biosens. Bioelectron. 2013, 39 (1), 296−9. (146) Shields, N.; Dodd, K. J.; Abblitt, C. Do children with Down Syndrome perform sufficient

The Monomolecular Organization of a Photodynamic Protein System Through Specific Surface Recognition of Streptavidin to Biotinylated LB Films

DTIC Science & Technology

1991-05-03

REPORT NUJMBER(S) 1148-18_________ 6,1. NAMFEFPERrORMIIG ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION (If applicable ) Unikcrsily of...8b. OFFICE SYMBOL 9 PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGAN17AT ION (If applicable ) I N00014-904J-1 148 tr. AIIRSS (City, 51ni-w.aid ZIP...potential bioelectronic, optical and protein structure research applications . 1 ~ i m rl u l~=iml~lmll emmlllillm Lynne A. Samuelson et al. Introduction Two

Nature's chemical signatures in human olfaction: a foodborne perspective for future biotechnology.

PubMed

Dunkel, Andreas; Steinhaus, Martin; Kotthoff, Matthias; Nowak, Bettina; Krautwurst, Dietmar; Schieberle, Peter; Hofmann, Thomas

2014-07-07

The biocatalytic production of flavor naturals that determine chemosensory percepts of foods and beverages is an ever challenging target for academic and industrial research. Advances in chemical trace analysis and post-genomic progress at the chemistry-biology interface revealed odor qualities of nature's chemosensory entities to be defined by odorant-induced olfactory receptor activity patterns. Beyond traditional views, this review and meta-analysis now shows characteristic ratios of only about 3 to 40 genuine key odorants for each food, from a group of about 230 out of circa 10 000 food volatiles. This suggests the foodborn stimulus space has co-evolved with, and roughly match our circa 400 olfactory receptors as best natural agonists. This perspective gives insight into nature's chemical signatures of smell, provides the chemical odor codes of more than 220 food samples, and beyond addresses industrial implications for producing recombinants that fully reconstruct the natural odor signatures for use in flavors and fragrances, fully immersive interactive virtual environments, or humanoid bioelectronic noses. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ultrasensitive Immunosensor for Cancer Biomarker Proteins using Gold Nanoparticle Film Electrodes and Multienzyme-Particle Amplification

PubMed Central

Mani, Vigneshwaran; Chikkaveeraiah, Bhaskara V.; Patel, Vyomesh; Gutkind, J. Silvio; Rusling, James F.

2009-01-01

A densely packed gold nanoparticle platform combined with a multiple-enzyme labeled detection antibody-magnetic bead bioconjugate was used as the basis for an ultrasensitive electrochemical immunosensor to detect cancer biomarkers in serum. Sensitivity was greatly amplified by synthesizing magnetic bioconjugates particles containing 7500 horseradish peroxidase (HRP) labels along with detection antibodies (Ab2) attached to activated carboxyl groups on 1 µm diameter magnetic beads. These sensors had sensitivity of 31.5 µA mL ng−1 and detection limit (DL) of 0.5 pg mL−1 for prostate specific antigen (PSA) in 10 µL of undiluted serum. This represents an ultralow mass DL of 5 fg PSA, eight fold better than a previously reported carbon nanotube (CNT) forest immunosensor featuring multiple labels on carbon nanotubes, and near or below the normal serum levels of most cancer biomarkers. Measurements of PSA in cell lysates and human serum of cancer patients gave excellent correlations with standard ELISA assays. These easily fabricated AuNP immunosensors show excellent promise for future fabrication of bioelectronic arrays. PMID:19216571

RETRACTED: Bimetallic magnetic nanoparticle as a new platform for fabrication of pyridoxine and pyridoxal-5'-phosphate imprinted polymer modified high throughput electrochemical sensor.

PubMed

Patra, Santanu; Roy, Ekta; Das, Ranajit; Karfa, Paramita; Kumar, Sunil; Madhuri, Rashmi; Sharma, Prashant K

2015-11-15

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief following concerns raised by a reader. The article uses an electron micrograph identical to another publication. Fig. 2B is identical to Fig. 1C published in Biosensors and Bioelectronics Volume 78, 15 April 2016, Pages 454-463, https://doi.org/10.1016/j.bios.2015.11.092. In addition, the extraordinary similarities observed between the data presented in Fig. 1D and in Fig. 3C in ACS Biomater. Sci. Eng., 2017, 3 (9), pp 2120–2135, https://doi.org/10.1021/acsbiomaterials.7b00089, Fig. 4A in Colloids and Surfaces B: Biointerfaces, Volume 142, 1 June 2016, Pages 248–258 https://doi.org/10.1016/j.colsurfb.2016.02.053 and Fig. 4C in Biosensors and Bioelectronics, Volume 97, 15 November 2017, Pages 208–217, https://doi.org/10.1016/j.bios.2017.06.003 are highly unlikely. This problem with the data casts doubt on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. Copyright © 2015 Elsevier B.V. All rights reserved.

Influence of Electrical and Ionic Conductivities of Organic Electronic Ion Pump on Acetylcholine Exchange Performance

PubMed Central

Abdullayeva, Nazrin; Sankir, Mehmet

2017-01-01

By using an easy and effective method of depositing conjugated polymers (PEDOT:PSS) on flexible substrates, a new design for organic bioelectronic devices has been developed. The purpose was to build up a system that mimics the motion of neurotransmitters in the synaptic cleft by obtaining an electrical to chemical signal transport. Fourier transform infrared (FTIR) spectroscopy and Raman measurements have demonstrated that electrochemical overoxidation region which separates the pristine PEDOT:PSS electrodes and allows ionic conduction has been achieved successfully. The influence of both electrical and ionic conductivities on organic electronic ion pump (OEIP) performances has been studied. The ultimate goal was to achieve the highest equilibrium current density at the lowest applied voltage via enhancing the electrical conductivity of PEDOT:PSS and ionic conductivity of electrochemically overoxidized region. The highest equilibrium current density, which corresponds to 4.81 × 1017 number of ions of acetylcholine was about 41 μA cm−2 observed for the OEIP with the electrical conductivities of 54 S cm−1. This was a threshold electrical conductivity beyond which the OEIP performances were not changed much. Once Nafion™ has been applied for enhancing the ionic conductivity, the equilibrium current density increased about ten times and reached up to 408 μA cm−2. Therefore, it has been demonstrated that the OEIP performance mainly scales with the ionic conductivity. A straightforward method of producing organic bioelectronics is proposed here may provide a clue for their effortless mass production in the near future. PMID:28772946

Reflectin as a Material for Neural Stem Cell Growth

PubMed Central

2015-01-01

Cephalopods possess remarkable camouflage capabilities, which are enabled by their complex skin structure and sophisticated nervous system. Such unique characteristics have in turn inspired the design of novel functional materials and devices. Within this context, recent studies have focused on investigating the self-assembly, optical, and electrical properties of reflectin, a protein that plays a key role in cephalopod structural coloration. Herein, we report the discovery that reflectin constitutes an effective material for the growth of human neural stem/progenitor cells. Our findings may hold relevance both for understanding cephalopod embryogenesis and for developing improved protein-based bioelectronic devices. PMID:26703760

Solvent-induced changes in PEDOT:PSS films for organic electrochemical transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Shiming; Kumar, Prajwal; Nouas, Amel Sarah

2015-01-01

Organic electrochemical transistors based on the conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS) are of interest for several bioelectronic applications. In this letter, we investigate the changes induced by immersion of PEDOT:PSS films, processed by spin coating from different mixtures, in water and other solvents of different polarities. We found that the film thickness decreases upon immersion in polar solvents, while the electrical conductivity remains unchanged. The decrease in film thickness is minimized via the addition of a cross-linking agent to the mixture used for the spin coating of the films.

Optical biosensors: a revolution towards quantum nanoscale electronics device fabrication.

PubMed

Dey, D; Goswami, T

2011-01-01

The dimension of biomolecules is of few nanometers, so the biomolecular devices ought to be of that range so a better understanding about the performance of the electronic biomolecular devices can be obtained at nanoscale. Development of optical biomolecular device is a new move towards revolution of nano-bioelectronics. Optical biosensor is one of such nano-biomolecular devices that has a potential to pave a new dimension of research and device fabrication in the field of optical and biomedical fields. This paper is a very small report about optical biosensor and its development and importance in various fields.

Organic bioelectronics for electronic-to-chemical translation in modulation of neuronal signaling and machine-to-brain interfacing.

PubMed

Larsson, Karin C; Kjäll, Peter; Richter-Dahlfors, Agneta

2013-09-01

A major challenge when creating interfaces for the nervous system is to translate between the signal carriers of the nervous system (ions and neurotransmitters) and those of conventional electronics (electrons). Organic conjugated polymers represent a unique class of materials that utilizes both electrons and ions as charge carriers. Based on these materials, we have established a series of novel communication interfaces between electronic components and biological systems. The organic electronic ion pump (OEIP) presented in this review is made of the polymer-polyelectrolyte system poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The OEIP translates electronic signals into electrophoretic migration of ions and neurotransmitters. We demonstrate how spatio-temporally controlled delivery of ions and neurotransmitters can be used to modulate intracellular Ca(2+) signaling in neuronal cells in the absence of convective disturbances. The electronic control of delivery enables strict control of dynamic parameters, such as amplitude and frequency of Ca(2+) responses, and can be used to generate temporal patterns mimicking naturally occurring Ca(2+) oscillations. To enable further control of the ionic signals we developed the electrophoretic chemical transistor, an analog of the traditional transistor used to amplify and/or switch electronic signals. Finally, we demonstrate the use of the OEIP in a new "machine-to-brain" interface by modulating brainstem responses in vivo. This review highlights the potential of communication interfaces based on conjugated polymers in generating complex, high-resolution, signal patterns to control cell physiology. We foresee widespread applications for these devices in biomedical research and in future medical devices within multiple therapeutic areas. This article is part of a Special Issue entitled Organic Bioelectronics-Novel Applications in Biomedicine. Copyright © 2012 Elsevier B.V. All rights reserved.

Nanomedicine photoluminescence crystal-inspired brain sensing approach

NASA Astrophysics Data System (ADS)

Fang, Yan; Wang, Fangzhen; Wu, Rong

2018-02-01

Precision sensing needs to overcome a gap of a single atomic step height standard. In response to the cutting-edge challenge, a heterosingle molecular nanomedicine crystal was developed wherein a nanomedicine crystal height less than 1 nm was designed and selfassembled on a substrate of either a highly ordered and freshly separated graphite or a N-doped silicon with hydrogen bonding by a home-made hybrid system of interacting single bioelectron donor-acceptor and a single biophoton donor-acceptor according to orthogonal mathematical optimization scheme, and an atomic spatial resolution conducting atomic force microscopy (C-AFM) with MHz signal processing by a special transformation of an atomic force microscopy (AFM) and a scanning tunneling microscopy (STM) were employed, wherein a z axis direction UV-VIS laser interferometer and a feedback circuit were used to achieve the minimized uncertainty of a micro-regional structure height and its corresponding local differential conductance quantization (spin state) process was repeatedly measured with a highly time resolution, as well as a pulsed UV-VIS laser micro-photoluminescence (PL) spectrum with a single photon resolution was set up by traceable quantum sensing and metrology relied up a quantum electrical triangle principle. The coupling of a single bioelectron conducting, a single biophoton photoluminescence, a frequency domain temporal spin phase in nanomedicine crystal-inspired sensing methods and sensor technologies were revealed by a combination of C-AFM and PL measurement data-based mathematic analyses1-3, as depicted in Figure 1 and repeated in nanomedicine crystals with a single atomic height. It is concluded that height-current-phase uncertainty correlation pave a way to develop a brain imaging and a single atomic height standard, quantum sensing, national security, worldwide impact1-3 technology and beyond.

Proteins as "dopable" bio-electronic materials

NASA Astrophysics Data System (ADS)

Cahen, David

2013-02-01

Proteins are surprisingly good solid-state electronic conductors. This holds also for proteins without any known biological electron transfer function. How do they do it? To answer this question we measure solid-state electron transport (ETp) across proteins that are "dry" (only tightly bound water, to retain the conformation, still present). We compare results for the electron transfer (ET) protein, Azurin (Az), the proton-pumping membrane protein Bacteriorhodopsin (bR), and for Human and Bovine Serum Albumin (HSA and BSA). Clear differences between these proteins are seen, which preserve their structure in the solid state measurement configuration. Importantly for future bioelectronics, the results are sensitive to protein modification, e.g., removing or disconnecting the retinal in bR and removing or replacing the Cu redox centre in Az. These cofactors can thus be viewed as natural dopants for proteins. Insight in the ETp mechanism comes from temperature-dependent studies. Az shows 40-360K temperature-independent ETp across its 3.5 nm long axis, until its denaturation temperature, indicative of tunneling. Cu removal, replacement (by Zn) or deuteration changes this to thermally activated ETp. This suggests hopping and involvement of the amide backbone in the ETp. The latter, which rhymes with indications from ETp experiments on oligopeptide and simulations of ET in proteins, opens the way for modeling what otherwise is an awfully complex system. Below 200K all proteins and their variants show temperature-independent ETp. We can furthermore make a totally electrically inactive protein, HSA, into an efficient ETp medium by doping it with natural poly-ene. Putting our data in perspective by comparing them to all known protein ETp data in the literature, we conclude that, in general, proteins are well described as dopable molecular wires.

Charging a capacitor from an external fluctuating potential using a single conical nanopore.

PubMed

Gomez, Vicente; Ramirez, Patricio; Cervera, Javier; Nasir, Saima; Ali, Mubarak; Ensinger, Wolfgang; Mafe, Salvador

2015-04-01

We explore the electrical rectification of large amplitude fluctuating signals by an asymmetric nanostructure operating in aqueous solution. We show experimentally and theoretically that a load capacitor can be charged to voltages close to 1 V within a few minutes by converting zero time-average potentials of amplitudes in the range 0.5-3 V into average net currents using a single conical nanopore. This process suggests that significant energy conversion and storage from an electrically fluctuating environment is feasible with a nanoscale pore immersed in a liquid electrolyte solution, a system characteristic of bioelectronics interfaces, electrochemical cells, and nanoporous membranes.

Ion beam processing of surgical materials

NASA Astrophysics Data System (ADS)

Williams, James M.; Buchanan, Raymond A.; Lee, In-Seop

1989-02-01

Ion beam processing has now achieved a secure place in surface treatment of biomaterials. This development is largely a result of the success of the process for wear prevention of orthopedic Ti-alloy in rubbing contact with ultrahigh molecular-weight polyethylene. Basic contributions of the authors in this area, together with other pertinent literature will be reviewed. Research in ion beam processing of biomaterials is turning to other areas. Among these, bioelectronics is considered to be a promising area for further effort. Pertinent experiments on effects of implantation of iridium into titanium and Ti-6Al-4V alloy on corrosion and charge injection properties are presented.

Charging a Capacitor from an External Fluctuating Potential using a Single Conical Nanopore

PubMed Central

Gomez, Vicente; Ramirez, Patricio; Cervera, Javier; Nasir, Saima; Ali, Mubarak; Ensinger, Wolfgang; Mafe, Salvador

2015-01-01

We explore the electrical rectification of large amplitude fluctuating signals by an asymmetric nanostructure operating in aqueous solution. We show experimentally and theoretically that a load capacitor can be charged to voltages close to 1 V within a few minutes by converting zero time-average potentials of amplitudes in the range 0.5–3 V into average net currents using a single conical nanopore. This process suggests that significant energy conversion and storage from an electrically fluctuating environment is feasible with a nanoscale pore immersed in a liquid electrolyte solution, a system characteristic of bioelectronics interfaces, electrochemical cells, and nanoporous membranes. PMID:25830563

On the origin of electrical conductivity in the bio-electronic material melanin

NASA Astrophysics Data System (ADS)

Bernardus Mostert, A.; Powell, Ben J.; Gentle, Ian R.; Meredith, Paul

2012-02-01

The skin pigment melanin is one of a few bio-macromolecules that display electrical and photo-conductivity in the solid-state. A model for melanin charge transport based on amorphous semiconductivity has been widely accepted for 40 years. In this letter, we show that a central pillar in support of this hypothesis, namely experimental agreement with a hydrated dielectric model, is an artefact related to measurement geometry and non-equilibrium behaviour. Our results cast significant doubt on the validity of the amorphous semiconductor model and are a reminder of the difficulties of electrical measurements on low conductivity, disordered organic materials.

A bioinspired flexible organic artificial afferent nerve

NASA Astrophysics Data System (ADS)

Kim, Yeongin; Chortos, Alex; Xu, Wentao; Liu, Yuxin; Oh, Jin Young; Son, Donghee; Kang, Jiheong; Foudeh, Amir M.; Zhu, Chenxin; Lee, Yeongjun; Niu, Simiao; Liu, Jia; Pfattner, Raphael; Bao, Zhenan; Lee, Tae-Woo

2018-06-01

The distributed network of receptors, neurons, and synapses in the somatosensory system efficiently processes complex tactile information. We used flexible organic electronics to mimic the functions of a sensory nerve. Our artificial afferent nerve collects pressure information (1 to 80 kilopascals) from clusters of pressure sensors, converts the pressure information into action potentials (0 to 100 hertz) by using ring oscillators, and integrates the action potentials from multiple ring oscillators with a synaptic transistor. Biomimetic hierarchical structures can detect movement of an object, combine simultaneous pressure inputs, and distinguish braille characters. Furthermore, we connected our artificial afferent nerve to motor nerves to construct a hybrid bioelectronic reflex arc to actuate muscles. Our system has potential applications in neurorobotics and neuroprosthetics.

An analytical model for bio-electronic organic field-effect transistor sensors

NASA Astrophysics Data System (ADS)

Macchia, Eleonora; Giordano, Francesco; Magliulo, Maria; Palazzo, Gerardo; Torsi, Luisa

2013-09-01

A model for the electrical characteristics of Functional-Bio-Interlayer Organic Field-Effect Transistors (FBI-OFETs) electronic sensors is here proposed. Specifically, the output current-voltage characteristics of a streptavidin (SA) embedding FBI-OFET are modeled by means of the analytical equations of an enhancement mode p-channel OFET modified according to an ad hoc designed equivalent circuit that is also independently simulated with pspice. An excellent agreement between the model and the experimental current-voltage output characteristics has been found upon exposure to 5 nM of biotin. A good agreement is also found with the SA OFET parameters graphically extracted from the device transfer I-V curves.

Conducting Polymeric Hydrogel Electrolyte Based on Carboxymethylcellulose and Polyacrylamide/Polyaniline for Supercapacitor Applications

NASA Astrophysics Data System (ADS)

Suganya, N.; Jaisankar, V.; Sivakumar, E. K. T.

Conducting polymer hydrogels represent a unique class of materials that possess enormous application in flexible electronic devices. In the present work, conducting carboxymethylcellulose (CMC)-co-polyacrylamide (PAAm)/polyaniline was synthesized by a two-step interpenetrating network solution polymerization technique. The synthesized CMC-co-PAAm/polyaniline with interpenetrating network structure was prepared by in situ polymerization of aniline to enhance conductivity. The molecular structure and morphology of the copolymer hydrogels were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The novel conducting polymer hydrogels show good electrical and electrochemical behavior, which makes them potentially useful in electronic devices such as supercapacitors, biosensors, bioelectronics, solar cells and memory devices.

Bioelectronic retinal prosthesis

NASA Astrophysics Data System (ADS)

Weiland, James D.

2016-05-01

Retinal prosthesis have been translated to clinical use over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa and one device is in clinical trials for treatment of age-related macular degeneration. These devices provide partial sight restoration and patients use this improved vision in their everyday lives to navigate and to detect large objects. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. In particular, current retinal prostheses do not provide peripheral visions due to technical and surgical limitations, thus limiting the effectiveness of the treatment. This paper reviews recent results from human implant patients and presents technical approaches for peripheral vision.

Photonic activation of disulfide bridges achieves oriented protein immobilization on biosensor surfaces.

PubMed

Neves-Petersen, Maria Teresa; Snabe, Torben; Klitgaard, Søren; Duroux, Meg; Petersen, Steffen B

2006-02-01

Photonic induced immobilization is a novel technology that results in spatially oriented and spatially localized covalent coupling of biomolecules onto thiol-reactive surfaces. Immobilization using this technology has been achieved for a wide selection of proteins, such as hydrolytic enzymes (lipases/esterases, lysozyme), proteases (human plasminogen), alkaline phosphatase, immunoglobulins' Fab fragment (e.g., antibody against PSA [prostate specific antigen]), Major Histocompability Complex class I protein, pepsin, and trypsin. The reaction mechanism behind the reported new technology involves "photonic activation of disulfide bridges," i.e., light-induced breakage of disulfide bridges in proteins upon UV illumination of nearby aromatic amino acids, resulting in the formation of free, reactive thiol groups that will form covalent bonds with thiol-reactive surfaces (see Fig. 1). Interestingly, the spatial proximity of aromatic residues and disulfide bridges in proteins has been preserved throughout molecular evolution. The new photonic-induced method for immobilization of proteins preserves the native structural and functional properties of the immobilized protein, avoiding the use of one or more chemical/thermal steps. This technology allows for the creation of spatially oriented as well as spatially defined multiprotein/DNA high-density sensor arrays with spot size of 1 microm or less, and has clear potential for biomedical, bioelectronic, nanotechnology, and therapeutic applications.

Conducting polymer scaffolds for electrical control of cellular functions (Conference Presentation)

NASA Astrophysics Data System (ADS)

Inal, Sahika; Wan, Alwin M.; Williams, Tiffany V.; Giannelis, Emmanuel P.; Fischbach-Teschl, Claudia; Gourdon, Delphine; Owens, Róisín. M.; Malliaras, George G.

2016-09-01

Considering the limited physiological relevance of 2D cell culture experiments, significant effort was devoted to the development of materials that could more accurately recreate the in vivo cellular microenvironment, and support 3D cell cultures in vitro. (1) One such class of materials is conducting polymers, which are promising due to their compliant mechanical properties, compatibility with biological systems, mixed electrical and ionic conductivity, and ability to form porous structures. (2) In this work, we report the fabrication of a single component, macroporous scaffold made from poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) via an ice-templating method. (3) PEDOT:PSS scaffolds offer tunable pore size, morphology and shape through facile changes in preparation conditions, and are capable of supporting 3D cell cultures due to their biocompatibility and tissue-like elasticity. Moreover, these materials are functional: they exhibit excellent electrochemical switching behavior and significantly lower impedance compared to films. Their electrochemical activity enables their use in the active channel of a state of the art diagnostic tool in the field of bioelectronics, i.e., the organic electrochemical transistor (OECT). The inclusion of cells within the porous architecture affects the impedance of the electrically-conducting polymer network and, thus, may be used as a method to quantify cell growth. The adhesion and pro-angiogenic secretions of mouse fibroblasts cultured within the scaffolds can be controlled by switching the electrochemical state of the polymer prior to cell-seeding. In summary, these smart materials hold promise not only as extracellular matrix-mimicking structures for cell culture, but also as high-performance bioelectronic tools for diagnostic and signaling applications. References [1] M. Holzwarth, P. X. Ma, Journal of Materials Chemistry, 21, 10243-10251 (2011). [2] L. H. Jimison, J. Rivnay, R. M. Owens, in Organic Electronics, Wiley-VCH Verlag GmbH and Co. KGaA, 27-6 (2013). [3] A. M.-D. Wan, S. Inal, T. Williams et al. Journal of Materials Chemistry B, DOI: 10.1039/C5TB00390C (2015).

Nanoscale On-Silico Electron Transport via Ferritins.

PubMed

Bera, Sudipta; Kolay, Jayeeta; Banerjee, Siddhartha; Mukhopadhyay, Rupa

2017-02-28

Silicon is a solid-state semiconducting material that has long been recognized as a technologically useful one, especially in electronics industry. However, its application in the next-generation metalloprotein-based electronics approaches has been limited. In this work, the applicability of silicon as a solid support for anchoring the iron-storage protein ferritin, which has a semiconducting iron nanocore, and probing electron transport via the ferritin molecules trapped between silicon substrate and a conductive scanning probe has been investigated. Ferritin protein is an attractive bioelectronic material because its size (X-ray crystallographic diameter ∼12 nm) should allow it to fit well in the larger tunnel gaps (>5 nm), fabrication of which is relatively more established, than the smaller ones. The electron transport events occurring through the ferritin molecules that are covalently anchored onto the MPTMS-modified silicon surface could be detected at the molecular level by current-sensing atomic force spectroscopy (CSAFS). Importantly, the distinct electronic signatures of the metal types (i.e., Fe, Mn, Ni, and Au) within the ferritin nanocore could be distinguished from each other using the transport band gap analyses. The CSAFS measurements on holoferritin, apoferritin, and the metal core reconstituted ferritins reveal that some of these ferritins behave like n-type semiconductors, while the others behave as p-type semiconductors. The band gaps for the different ferritins are found to be within 0.8 to 2.6 eV, a range that is valid for the standard semiconductor technology (e.g., diodes based on p-n junction). The present work indicates effective on-silico integration of the ferritin protein, as it remains functionally viable after silicon binding and its electron transport activities can be detected. Potential use of the ferritin-silicon nanohybrids may therefore be envisaged in applications other than bioelectronics, too, as ferritin is a versatile nanocore-containing biomaterial (for storage/transport of metals and drugs) and silicon can be a versatile nanoscale solid support (for its biocompatible nature).

Proton mediated control of biochemical reactions with bioelectronic pH modulation

NASA Astrophysics Data System (ADS)

Deng, Yingxin; Miyake, Takeo; Keene, Scott; Josberger, Erik E.; Rolandi, Marco

2016-04-01

In Nature, protons (H+) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H+ channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H+ currents and H+ concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H+ between PdHx contacts and solution. The present transducer records bistable pH modulation from an “enzymatic flip-flop” circuit that comprises glucose dehydrogenase and alcohol dehydrogenase. The transducer also controls bioluminescence from firefly luciferase by affecting solution pH.

A subthreshold aVLSI implementation of the Izhikevich simple neuron model.

PubMed

Rangan, Venkat; Ghosh, Abhishek; Aparin, Vladimir; Cauwenberghs, Gert

2010-01-01

We present a circuit architecture for compact analog VLSI implementation of the Izhikevich neuron model, which efficiently describes a wide variety of neuron spiking and bursting dynamics using two state variables and four adjustable parameters. Log-domain circuit design utilizing MOS transistors in subthreshold results in high energy efficiency, with less than 1pJ of energy consumed per spike. We also discuss the effects of parameter variations on the dynamics of the equations, and present simulation results that replicate several types of neural dynamics. The low power operation and compact analog VLSI realization make the architecture suitable for human-machine interface applications in neural prostheses and implantable bioelectronics, as well as large-scale neural emulation tools for computational neuroscience.

Organic supernanostructures self-assembled via solution process for explosive detection.

PubMed

Wang, Lei; Zhou, Yan; Yan, Jing; Wang, Jian; Pei, Jian; Cao, Yong

2009-02-03

Three different polymorphic crystalline structures, including microbelts and flowerlike supernanostructures, were obtained via a simple solution process by utilizing different solvents from an oligoarene derivative. Explosive chemosensors based on these self-assembled organic crystalline nanostructures were successfully fabricated. The differences in the structures on the microscopic level and in the film morphologies led to dramatic enhancements of the explosive detection speed. With the evolution of structures from the netted 1D microbelts to the flowerlike supernanostructures, the detection speed of the chemosensors for DNT and TNT was improved by more than 700 times. Our discovery demonstrates that the morphology control through self-assembly provides a new platform to utilize organic crystalline microstructures for chemosensors, optoelectronics, biosensors and bioelectronics, and so forth.

High-performance wireless powering for peripheral nerve neuromodulation systems.

PubMed

Tanabe, Yuji; Ho, John S; Liu, Jiayin; Liao, Song-Yan; Zhen, Zhe; Hsu, Stephanie; Shuto, Chika; Zhu, Zi-Yi; Ma, Andrew; Vassos, Christopher; Chen, Peter; Tse, Hung Fat; Poon, Ada S Y

2017-01-01

Neuromodulation of peripheral nerves with bioelectronic devices is a promising approach for treating a wide range of disorders. Wireless powering could enable long-term operation of these devices, but achieving high performance for miniaturized and deeply placed devices remains a technological challenge. We report the miniaturized integration of a wireless powering system in soft neuromodulation device (15 mm length, 2.7 mm diameter) and demonstrate high performance (about 10%) during in vivo wireless stimulation of the vagus nerve in a porcine animal model. The increased performance is enabled by the generation of a focused and circularly polarized field that enhances efficiency and provides immunity to polarization misalignment. These performance characteristics establish the clinical potential of wireless powering for emerging therapies based on neuromodulation.

High-performance wireless powering for peripheral nerve neuromodulation systems

PubMed Central

Liu, Jiayin; Liao, Song-Yan; Zhen, Zhe; Hsu, Stephanie; Shuto, Chika; Zhu, Zi-Yi; Ma, Andrew; Vassos, Christopher; Chen, Peter; Tse, Hung Fat; Poon, Ada S. Y.

2017-01-01

Neuromodulation of peripheral nerves with bioelectronic devices is a promising approach for treating a wide range of disorders. Wireless powering could enable long-term operation of these devices, but achieving high performance for miniaturized and deeply placed devices remains a technological challenge. We report the miniaturized integration of a wireless powering system in soft neuromodulation device (15 mm length, 2.7 mm diameter) and demonstrate high performance (about 10%) during in vivo wireless stimulation of the vagus nerve in a porcine animal model. The increased performance is enabled by the generation of a focused and circularly polarized field that enhances efficiency and provides immunity to polarization misalignment. These performance characteristics establish the clinical potential of wireless powering for emerging therapies based on neuromodulation. PMID:29065141

An enzyme logic bioprotonic transducer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyake, Takeo; Keene, Scott; Deng, Yingxin

2015-01-01

Translating ionic currents into measureable electronic signals is essential for the integration of bioelectronic devices with biological systems. We demonstrate the use of a Pd/PdH{sub x} electrode as a bioprotonic transducer that connects H{sup +} currents in solution into an electronic signal. This transducer exploits the reversible formation of PdH{sub x} in solution according to PdH↔Pd + H{sup +} + e{sup −}, and the dependence of this formation on solution pH and applied potential. We integrate the protonic transducer with glucose dehydrogenase as an enzymatic AND gate for glucose and NAD{sup +}. PdH{sub x} formation and associated electronic current monitorsmore » the output drop in pH, thus transducing a biological function into a measurable electronic output.« less

Graphene based biosensors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gürel, Hikmet Hakan, E-mail: hhakan.gurel@kocaeli.edu.tr; Salmankurt, Bahadır

2016-03-25

Nanometer-sized graphene as a 2D material has unique chemical and electronic properties. Because of its unique physical, chemical, and electronic properties, its interesting shape and size make it a promising nanomaterial in many biological applications. It is expected that biomaterials incorporating graphene will be developed for the graphene-based drug delivery systems and biomedical devices. The interactions of biomolecules and graphene are long-ranged and very weak. Development of new techniques is very desirable for design of bioelectronics sensors and devices. In this work, we present first-principles calculations within density functional theory to calculate effects of charging on nucleobases on graphene. Itmore » is shown that how modify structural and electronic properties of nucleobases on graphene by applied charging.« less

Ion bipolar junction transistors

PubMed Central

Tybrandt, Klas; Larsson, Karin C.; Richter-Dahlfors, Agneta; Berggren, Magnus

2010-01-01

Dynamic control of chemical microenvironments is essential for continued development in numerous fields of life sciences. Such control could be achieved with active chemical circuits for delivery of ions and biomolecules. As the basis for such circuitry, we report a solid-state ion bipolar junction transistor (IBJT) based on conducting polymers and thin films of anion- and cation-selective membranes. The IBJT is the ionic analogue to the conventional semiconductor BJT and is manufactured using standard microfabrication techniques. Transistor characteristics along with a model describing the principle of operation, in which an anionic base current amplifies a cationic collector current, are presented. By employing the IBJT as a bioelectronic circuit element for delivery of the neurotransmitter acetylcholine, its efficacy in modulating neuronal cell signaling is demonstrated. PMID:20479274

Microbial Fuel Cells and Microbial Electrolyzers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borole, Abhijeet P

2015-01-01

Microbial Fuel Cells and microbial electrolyzers represent an upcoming technology for production of electricity and hydrogen using a hybrid electrocatalytic-biocatalytic approach. The combined catalytic efficiency of these processes has potential to make this technology highly efficient among the various renewable energy production alternatives. This field has attracted electrochemists, biologists and many other disciplines due to its potential to contribute to the energy, water and environment sectors. A brief introduction to the technology is provided followed by current research needs from a bioelectrochemical perspective. Insights into the operation and limitations of these systems achieved via cyclic voltammetry and impedance spectroscopy aremore » discussed along with the power management needs to develop the application aspects. Besides energy production, other potential applications in bioenergy, bioelectronics, chemical production and remediation are also highlighted.« less

Cell chips as new tools for cell biology--results, perspectives and opportunities.

PubMed

Primiceri, Elisabetta; Chiriacò, Maria Serena; Rinaldi, Ross; Maruccio, Giuseppe

2013-10-07

Cell culture technologies were initially developed as research tools for studying cell functions, but nowadays they are essential for the biotechnology industry, with rapidly expanding applications requiring more and more advancements with respect to traditional tools. Miniaturization and integration of sensors and microfluidic components with cell culture techniques open the way to the development of cellomics as a new field of research targeting innovative analytic platforms for high-throughput studies. This approach enables advanced cell studies under controllable conditions by providing inexpensive, easy-to-operate devices. Thanks to their numerous advantages cell-chips have become a hotspot in biosensors and bioelectronics fields and have been applied to very different fields. In this review exemplary applications will be discussed, for cell counting and detection, cytotoxicity assays, migration assays and stem cell studies.

Directed evolution of bacteriorhodopsin for applications in bioelectronics

PubMed Central

Wagner, Nicole L.; Greco, Jordan A.; Ranaghan, Matthew J.; Birge, Robert R.

2013-01-01

In nature, biological systems gradually evolve through complex, algorithmic processes involving mutation and differential selection. Evolution has optimized biological macromolecules for a variety of functions to provide a comparative advantage. However, nature does not optimize molecules for use in human-made devices, as it would gain no survival advantage in such cooperation. Recent advancements in genetic engineering, most notably directed evolution, have allowed for the stepwise manipulation of the properties of living organisms, promoting the expansion of protein-based devices in nanotechnology. In this review, we highlight the use of directed evolution to optimize photoactive proteins, with an emphasis on bacteriorhodopsin (BR), for device applications. BR, a highly stable light-activated proton pump, has shown great promise in three-dimensional optical memories, real-time holographic processors and artificial retinas. PMID:23676894

Proton mediated control of biochemical reactions with bioelectronic pH modulation

DOE PAGES

Deng, Yingxin; Miyake, Takeo; Keene, Scott; ...

2016-04-07

In Nature, protons (H +) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H + channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H + currents and H + concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H + between PdH x contacts and solution. The present transducer records bistable pH modulation from an “enzymaticmore » flip-flop” circuit that comprises glucose dehydrogenase and alcohol dehydrogenase. Furthermore, the transducer also controls bioluminescence from firefly luciferase by affecting solution pH.« less

Neural circuitry and immunity

PubMed Central

Pavlov, Valentin A.; Tracey, Kevin J.

2015-01-01

Research during the last decade has significantly advanced our understanding of the molecular mechanisms at the interface between the nervous system and the immune system. Insight into bidirectional neuroimmune communication has characterized the nervous system as an important partner of the immune system in the regulation of inflammation. Neuronal pathways, including the vagus nerve-based inflammatory reflex are physiological regulators of immune function and inflammation. In parallel, neuronal function is altered in conditions characterized by immune dysregulation and inflammation. Here, we review these regulatory mechanisms and describe the neural circuitry modulating immunity. Understanding these mechanisms reveals possibilities to use targeted neuromodulation as a therapeutic approach for inflammatory and autoimmune disorders. These findings and current clinical exploration of neuromodulation in the treatment of inflammatory diseases defines the emerging field of Bioelectronic Medicine. PMID:26512000

Proton mediated control of biochemical reactions with bioelectronic pH modulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Yingxin; Miyake, Takeo; Keene, Scott

In Nature, protons (H +) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H + channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H + currents and H + concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H + between PdH x contacts and solution. The present transducer records bistable pH modulation from an “enzymaticmore » flip-flop” circuit that comprises glucose dehydrogenase and alcohol dehydrogenase. Furthermore, the transducer also controls bioluminescence from firefly luciferase by affecting solution pH.« less

Assessing the potential of surface-immobilized molecular logic machines for integration with solid state technology.

PubMed

Dunn, Katherine E; Trefzer, Martin A; Johnson, Steven; Tyrrell, Andy M

2016-08-01

Molecular computation with DNA has great potential for low power, highly parallel information processing in a biological or biochemical context. However, significant challenges remain for the field of DNA computation. New technology is needed to allow multiplexed label-free readout and to enable regulation of molecular state without addition of new DNA strands. These capabilities could be provided by hybrid bioelectronic systems in which biomolecular computing is integrated with conventional electronics through immobilization of DNA machines on the surface of electronic circuitry. Here we present a quantitative experimental analysis of a surface-immobilized OR gate made from DNA and driven by strand displacement. The purpose of our work is to examine the performance of a simple representative surface-immobilized DNA logic machine, to provide valuable information for future work on hybrid bioelectronic systems involving DNA devices. We used a quartz crystal microbalance to examine a DNA monolayer containing approximately 5×10(11)gatescm(-2), with an inter-gate separation of approximately 14nm, and we found that the ensemble of gates took approximately 6min to switch. The gates could be switched repeatedly, but the switching efficiency was significantly degraded on the second and subsequent cycles when the binding site for the input was near to the surface. Otherwise, the switching efficiency could be 80% or better, and the power dissipated by the ensemble of gates during switching was approximately 0.1nWcm(-2), which is orders of magnitude less than the power dissipated during switching of an equivalent array of transistors. We propose an architecture for hybrid DNA-electronic systems in which information can be stored and processed, either in series or in parallel, by a combination of molecular machines and conventional electronics. In this architecture, information can flow freely and in both directions between the solution-phase and the underlying electronics via surface-immobilized DNA machines that provide the interface between the molecular and electronic domains. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Signal amplification strategy for biomarkers: Structural origins of epitaxial-growth twinned nanocrystals and D-π-A type polymers.

PubMed

Liu, He; Gu, Yue; Dong, Tao; Yan, Liuqing; Yan, Xiaoyi; Zhang, Tingting; Lu, Nannan; Xu, Zhiqian; Xu, Haixin; Zhang, Zhiquan; Bian, Ting

2018-06-30

The combination of nanoparticles and biomarkers yields functional nanostructured biointerface, which is playing a notable role in biotechnology development. Due to the 5-fold twined structure in the Au-Pt star-shaped decahedra not only allowed it to act as efficient scaffold for immobilization of antibody, but it also exhibits superior electrocatalytic activity toward H 2 O 2 reduction, the nanocrystal as the efficient signal transduction label is first employed to construct an electrochemical immunosensor. Donor-π-Acceptor (D-π-A) linking fashion generates a dipolar push-pull system and assures superior intramolecular charge transfer. It is considered as a suitable π-conjugated backbone for conducting polymer on biointerface application. Under a D-π-A architecture which imidazole as the π-bridge and amino phenyl/phenyl groups as peripheral electron-donating/withdrawing functional groups, 4-(2,4,5-triphenyl-1H-imidazol-1-yl) aniline (TPIDA) is designed and synthesized for good biocompatibility and high conductivity. In this proposal, we attempt to integrate the above-mentioned two features from nanobiotechnology and organic bioelectronics. Then, a novel nonenzymatic sandwich-type immunosensor is performed by Au-Pt core-shell with surface-engineered twinning as a label and π-conjugated D-π-A polymers as the signal amplification platform. Human IgG (HIgG) as the model target protein can be detected with a wide linear range from 0.1 pg mL -1 to 100 ng mL -1 . The detection limit is down to 0.06 pg mL -1 (S/N = 3). Moreover, as a practical application, the prepared biosensor is used to monitor HIgG level in human serum with desirable results obtained. Copyright © 2018 Elsevier B.V. All rights reserved.

Brillouin microspectroscopy of nanostructured biomaterials: photonics assisted tailoring mechanical properties

NASA Astrophysics Data System (ADS)

Meng, Zhaokai; Jaiswal, Manish K.; Chitrakar, Chandani; Thakur, Teena; Gaharwar, Akhilesh K.; Yakovlev, Vladislav V.

2016-03-01

Developing new biomaterials is essential for the next-generation of materials for bioenergy, bioelectronics, basic biology, medical diagnostics, cancer research, and regenerative medicine. Specifically, recent progress in nanotechnology has stimulated the development of multifunctional biomaterials for tissue engineering applications. The physical properties of nanocomposite biomaterials, including elasticity and viscosity, play key roles in controlling cell fate, which underlines therapeutic success. Conventional mechanical tests, including uniaxial compression and tension, dynamic mechanical analysis and shear rheology, require mechanical forces to be directly exerted onto the sample and therefore may not be suitable for in situ measurements or continuous monitoring of mechanical stiffness. In this study, we employ spontaneous Brillouin spectroscopy as a viscoelasticity-specific probing technique. We utilized a Brillouin spectrometer to characterize biomaterial's microscopic elasticity and correlated those with conventional mechanical tests (e.g., rheology).

Soft Material-Enabled, Flexible Hybrid Electronics for Medicine, Healthcare, and Human-Machine Interfaces

PubMed Central

Herbert, Robert; Kim, Jong-Hoon; Kim, Yun Soung; Lee, Hye Moon

2018-01-01

Flexible hybrid electronics (FHE), designed in wearable and implantable configurations, have enormous applications in advanced healthcare, rapid disease diagnostics, and persistent human-machine interfaces. Soft, contoured geometries and time-dynamic deformation of the targeted tissues require high flexibility and stretchability of the integrated bioelectronics. Recent progress in developing and engineering soft materials has provided a unique opportunity to design various types of mechanically compliant and deformable systems. Here, we summarize the required properties of soft materials and their characteristics for configuring sensing and substrate components in wearable and implantable devices and systems. Details of functionality and sensitivity of the recently developed FHE are discussed with the application areas in medicine, healthcare, and machine interactions. This review concludes with a discussion on limitations of current materials, key requirements for next generation materials, and new application areas. PMID:29364861

Transparent and flexible resistive switching memory devices with a very high ON/OFF ratio using gold nanoparticles embedded in a silk protein matrix

NASA Astrophysics Data System (ADS)

Gogurla, Narendar; Mondal, Suvra P.; Sinha, Arun K.; Katiyar, Ajit K.; Banerjee, Writam; Kundu, Subhas C.; Ray, Samit K.

2013-08-01

The growing demand for biomaterials for electrical and optical devices is motivated by the need to make building blocks for the next generation of printable bio-electronic devices. In this study, transparent and flexible resistive memory devices with a very high ON/OFF ratio incorporating gold nanoparticles into the Bombyx mori silk protein fibroin biopolymer are demonstrated. The novel electronic memory effect is based on filamentary switching, which leads to the occurrence of bistable states with an ON/OFF ratio larger than six orders of magnitude. The mechanism of this process is attributed to the formation of conductive filaments through silk fibroin and gold nanoparticles in the nanocomposite. The proposed hybrid bio-inorganic devices show promise for use in future flexible and transparent nanoelectronic systems.

Energy transduction and signal averaging of fluctuating electric fields by a single protein ion channel.

PubMed

Verdia-Baguena, C; Gomez, V; Cervera, J; Ramirez, P; Mafe, S

2016-12-21

We demonstrate the electrical rectification and signal averaging of fluctuating signals using a biological nanostructure in aqueous solution: a single protein ion channel inserted in the lipid bilayer characteristic of cell membranes. The conversion of oscillating, zero time-average potentials into directional currents permits charging of a load capacitor to significant steady-state voltages within a few minutes in the case of the outer membrane porin F (OmpF) protein, a bacterial channel of Escherichia coli. The experiments and simulations show signal averaging effects at a more fundamental level than the traditional cell and tissue scales, which are characterized by ensembles of many ion channels operating simultaneously. The results also suggest signal transduction schemes with bio-electronic interfaces and ionic circuits where soft matter nanodiodes can be coupled to conventional electronic elements.

Graphene-based materials for tissue engineering.

PubMed

Shin, Su Ryon; Li, Yi-Chen; Jang, Hae Lin; Khoshakhlagh, Parastoo; Akbari, Mohsen; Nasajpour, Amir; Zhang, Yu Shrike; Tamayol, Ali; Khademhosseini, Ali

2016-10-01

Graphene and its chemical derivatives have been a pivotal new class of nanomaterials and a model system for quantum behavior. The material's excellent electrical conductivity, biocompatibility, surface area and thermal properties are of much interest to the scientific community. Two-dimensional graphene materials have been widely used in various biomedical research areas such as bioelectronics, imaging, drug delivery, and tissue engineering. In this review, we will highlight the recent applications of graphene-based materials in tissue engineering and regenerative medicine. In particular, we will discuss the application of graphene-based materials in cardiac, neural, bone, cartilage, skeletal muscle, and skin/adipose tissue engineering. We will also discuss the potential risk factors of graphene-based materials in tissue engineering. In conclusion, we will outline the opportunities in the usage of graphene-based materials for clinical applications. Published by Elsevier B.V.

Self-Powered Implantable Skin-Like Glucometer for Real-Time Detection of Blood Glucose Level In Vivo

NASA Astrophysics Data System (ADS)

Zhang, Wanglinhan; Zhang, Linlin; Gao, Huiling; Yang, Wenyan; Wang, Shuai; Xing, Lili; Xue, Xinyu

2018-06-01

Implantable bioelectronics for analyzing physiological biomarkers has recently been recognized as a promising technique in medical treatment or diagnostics. In this study, we developed a self-powered implantable skin-like glucometer for real-time detection of blood glucose level in vivo. Based on the piezo-enzymatic-reaction coupling effect of GOx@ZnO nanowire, the device under an applied deformation can actively output piezoelectric signal containing the glucose-detecting information. No external electricity power source or battery is needed for this device, and the outputting piezoelectric voltage acts as both the biosensing signal and electricity power. A practical application of the skin-like glucometer implanted in mouse body for detecting blood glucose level has been simply demonstrated. These results provide a new technique path for diabetes prophylaxis and treatment.

Nanomaterials as analytical tools for genosensors.

PubMed

Abu-Salah, Khalid M; Alrokyan, Salman A; Khan, Muhammad Naziruddin; Ansari, Anees Ahmad

2010-01-01

Nanomaterials are being increasingly used for the development of electrochemical DNA biosensors, due to the unique electrocatalytic properties found in nanoscale materials. They offer excellent prospects for interfacing biological recognition events with electronic signal transduction and for designing a new generation of bioelectronic devices exhibiting novel functions. In particular, nanomaterials such as noble metal nanoparticles (Au, Pt), carbon nanotubes (CNTs), magnetic nanoparticles, quantum dots and metal oxide nanoparticles have been actively investigated for their applications in DNA biosensors, which have become a new interdisciplinary frontier between biological detection and material science. In this article, we address some of the main advances in this field over the past few years, discussing the issues and challenges with the aim of stimulating a broader interest in developing nanomaterial-based biosensors and improving their applications in disease diagnosis and food safety examination.

Soft Material-Enabled, Flexible Hybrid Electronics for Medicine, Healthcare, and Human-Machine Interfaces.

PubMed

Herbert, Robert; Kim, Jong-Hoon; Kim, Yun Soung; Lee, Hye Moon; Yeo, Woon-Hong

2018-01-24

Flexible hybrid electronics (FHE), designed in wearable and implantable configurations, have enormous applications in advanced healthcare, rapid disease diagnostics, and persistent human-machine interfaces. Soft, contoured geometries and time-dynamic deformation of the targeted tissues require high flexibility and stretchability of the integrated bioelectronics. Recent progress in developing and engineering soft materials has provided a unique opportunity to design various types of mechanically compliant and deformable systems. Here, we summarize the required properties of soft materials and their characteristics for configuring sensing and substrate components in wearable and implantable devices and systems. Details of functionality and sensitivity of the recently developed FHE are discussed with the application areas in medicine, healthcare, and machine interactions. This review concludes with a discussion on limitations of current materials, key requirements for next generation materials, and new application areas.

Nanomaterials as Analytical Tools for Genosensors

PubMed Central

Abu-Salah, Khalid M.; Alrokyan, Salman A.; Khan, Muhammad Naziruddin; Ansari, Anees Ahmad

2010-01-01

Nanomaterials are being increasingly used for the development of electrochemical DNA biosensors, due to the unique electrocatalytic properties found in nanoscale materials. They offer excellent prospects for interfacing biological recognition events with electronic signal transduction and for designing a new generation of bioelectronic devices exhibiting novel functions. In particular, nanomaterials such as noble metal nanoparticles (Au, Pt), carbon nanotubes (CNTs), magnetic nanoparticles, quantum dots and metal oxide nanoparticles have been actively investigated for their applications in DNA biosensors, which have become a new interdisciplinary frontier between biological detection and material science. In this article, we address some of the main advances in this field over the past few years, discussing the issues and challenges with the aim of stimulating a broader interest in developing nanomaterial-based biosensors and improving their applications in disease diagnosis and food safety examination. PMID:22315580

N-type organic electrochemical transistors with stability in water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giovannitti, Alexander; Nielsen, Christian B.; Sbircea, Dan -Tiberiu

Organic electrochemical transistors (OECTs) are receiving significant attention due to their ability to efficiently transduce biological signals. A major limitation of this technology is that only p-type materials have been reported, which precludes the development of complementary circuits, and limits sensor technologies. Here, we report the first ever n-type OECT, with relatively balanced ambipolar charge transport characteristics based on a polymer that supports both hole and electron transport along its backbone when doped through an aqueous electrolyte and in the presence of oxygen. This new semiconducting polymer is designed specifically to facilitate ion transport and promote electrochemical doping. Stability measurementsmore » in water show no degradation when tested for 2 h under continuous cycling. Furthermore, this demonstration opens the possibility to develop complementary circuits based on OECTs and to improve the sophistication of bioelectronic devices.« less

N-type organic electrochemical transistors with stability in water

DOE PAGES

Giovannitti, Alexander; Nielsen, Christian B.; Sbircea, Dan -Tiberiu; ...

2016-10-07

Organic electrochemical transistors (OECTs) are receiving significant attention due to their ability to efficiently transduce biological signals. A major limitation of this technology is that only p-type materials have been reported, which precludes the development of complementary circuits, and limits sensor technologies. Here, we report the first ever n-type OECT, with relatively balanced ambipolar charge transport characteristics based on a polymer that supports both hole and electron transport along its backbone when doped through an aqueous electrolyte and in the presence of oxygen. This new semiconducting polymer is designed specifically to facilitate ion transport and promote electrochemical doping. Stability measurementsmore » in water show no degradation when tested for 2 h under continuous cycling. Furthermore, this demonstration opens the possibility to develop complementary circuits based on OECTs and to improve the sophistication of bioelectronic devices.« less

Organic electrochemical transistors

NASA Astrophysics Data System (ADS)

Rivnay, Jonathan; Inal, Sahika; Salleo, Alberto; Owens, Róisín M.; Berggren, Magnus; Malliaras, George G.

2018-02-01

Organic electrochemical transistors (OECTs) make effective use of ion injection from an electrolyte to modulate the bulk conductivity of an organic semiconductor channel. The coupling between ionic and electronic charges within the entire volume of the channel endows OECTs with high transconductance compared with that of field-effect transistors, but also limits their response time. The synthetic tunability, facile deposition and biocompatibility of organic materials make OECTs particularly suitable for applications in biological interfacing, printed logic circuitry and neuromorphic devices. In this Review, we discuss the physics and the mechanism of operation of OECTs, focusing on their identifying characteristics. We highlight organic materials that are currently being used in OECTs and survey the history of OECT technology. In addition, form factors, fabrication technologies and applications such as bioelectronics, circuits and memory devices are examined. Finally, we take a critical look at the future of OECT research and development.

Patterned free-standing conductive nanofilms for ultraconformable circuits and smart interfaces.

PubMed

Greco, Francesco; Zucca, Alessandra; Taccola, Silvia; Mazzolai, Barbara; Mattoli, Virgilio

2013-10-09

A process is presented for the fabrication of patterned ultrathin free-standing conductive nanofilms based on an all-polymer bilayer structure composed of poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) and poly(lactic acid) (PEDOT:PSS/PLA). Based on the strategy recently introduced by our group for producing large area free-standing nanofilms of conductive polymers with ultrahigh conformability, here an inkjet subtractive patterning technique was used, with localized overoxidation of PEDOT:PSS that caused the local irreversible loss of electrical conductivity. Different pattern geometries (e.g., interdigitated electrodes with various spacing, etc.) were tested for validating the proposed process. The fabrication of individually addressable microelectrodes and simple circuits on nanofilm having thickness ∼250 nm has been demonstrated. Using this strategy, mechanically robust, conformable ultrathin polymer films could be produced that can be released in water as free-standing nanofilms and/or collected on surfaces with arbitrary shapes, topography and compliance, including human skin. The patterned bilayer nanofilms were characterized as regards their morphology, thickness, topography, conductivity, and electrochemical behavior. In addition, the electrochemical switching of surface properties has been evaluated by means of contact angle measurements. These novel conductive materials can find use as ultrathin, conformable electronic devices and in many bioelectrical applications. Moreover, by exploiting the electrochemical properties of conducting polymers, they can act as responsive smart biointerfaces and in the field of conformable bioelectronics, for example, as electrodes on tissues or smart conductive substrates for cell culturing and stimulation.

Benchmarking organic mixed conductors for transistors.

PubMed

Inal, Sahika; Malliaras, George G; Rivnay, Jonathan

2017-11-24

Organic mixed conductors have garnered significant attention in applications from bioelectronics to energy storage/generation. Their implementation in organic transistors has led to enhanced biosensing, neuromorphic function, and specialized circuits. While a narrow class of conducting polymers continues to excel in these new applications, materials design efforts have accelerated as researchers target new functionality, processability, and improved performance/stability. Materials for organic electrochemical transistors (OECTs) require both efficient electronic transport and facile ion injection in order to sustain high capacity. In this work, we show that the product of the electronic mobility and volumetric charge storage capacity (µC*) is the materials/system figure of merit; we use this framework to benchmark and compare the steady-state OECT performance of ten previously reported materials. This product can be independently verified and decoupled to guide materials design and processing. OECTs can therefore be used as a tool for understanding and designing new organic mixed conductors.

Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications

PubMed Central

Khan, Asif; Abas, Zafar; Kim, Heung Soo; Kim, Jaehwan

2016-01-01

We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper and its hybrid composites such as blends or coatings with synthetic polymers, biopolymers, carbon nanotubes, chitosan, and metal oxides, are explained. In addition, the integration of cellulose electro-active paper is highlighted to form various functional devices including but not limited to bending actuators, flexible speaker, strain sensors, energy harvesting transducers, biosensors, chemical sensors and transistors for electronic applications. The frontiers in cellulose paper devices are reviewed together with the strategies and perspectives of cellulose electro-active paper and cellulose nanocomposite research and applications. PMID:27472335

Essential Neuroscience in Immunology

PubMed Central

Chavan, Sangeeta S.; Tracey, Kevin J.

2017-01-01

The field of immunology is principally focused on the molecular mechanisms by which hematopoetic cells initiate and maintain innate and adaptive immunity. That cornerstone of attention has been expanded by recent discoveries that neuronal signals occupy a critical regulatory niche in immunity. The discovery is that neuronal circuits operating reflexively regulate innate and adaptive immunity. One particularly well-characterized circuit regulating innate immunity, the inflammatory reflex, is dependent upon action potentials transmitted to the reticuloendothelial system via the vagus and splenic nerves. This field has grown significantly with identification of several other reflexes regulating discrete immune functions. As reviewed here, the delineation of these mechanisms revealed a new understanding of immunity, enabled a first in class clinical trial using bioelectronic devices to inhibit cytokines and inflammation in rheumatoid arthritis patients, and provided a mosaic view of immunity as the integration of hematopoetic and neural responses to infection and injury. PMID:28416717

Essential Neuroscience in Immunology.

PubMed

Chavan, Sangeeta S; Tracey, Kevin J

2017-05-01

The field of immunology is principally focused on the molecular mechanisms by which hematopoietic cells initiate and maintain innate and adaptive immunity. That cornerstone of attention has been expanded by recent discoveries that neuronal signals occupy a critical regulatory niche in immunity. The discovery is that neuronal circuits operating reflexively regulate innate and adaptive immunity. One particularly well-characterized circuit regulating innate immunity, the inflammatory reflex, is dependent upon action potentials transmitted to the reticuloendothelial system via the vagus and splenic nerves. This field has grown significantly with the identification of several other reflexes regulating discrete immune functions. As outlined in this review, the delineation of these mechanisms revealed a new understanding of immunity, enabled a first-in-class clinical trial using bioelectronic devices to inhibit cytokines and inflammation in rheumatoid arthritis patients, and provided a mosaic view of immunity as the integration of hematopoietic and neural responses to infection and injury. Copyright © 2017 by The American Association of Immunologists, Inc.

Bioelectronic Sensors and Devices

NASA Astrophysics Data System (ADS)

Reed, Mark

Nanoscale electronic devices have recently enabled the ability to controllably probe biological systems, from the molecular to the cellular level, opening up new applications and understanding of biological function and response. This talk reviews some of the advances in the field, ranging from diagnostic and therapeutic applications, to cellular manipulation and response, to the emulation of biological response. In diagnostics, integrated nanodevice biosensors compatible with CMOS technology have achieved unprecedented sensitivity, enabling a wide range of label-free biochemical and macromolecule sensing applications down to femtomolar concentrations. These systems have demonstrated integrated assays of biomarkers at clinically important concentrations for both diagnostics and as a quantitative tool for drug design and discovery. Cellular level response can also be observed, including immune response function and dynamics. Finally, the field is beginning to create devices that emulate function, and the demonstration of a solid state artificial ion channel will be discussed.

Solution-processed Al-chelated gelatin for highly transparent non-volatile memory applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Yu-Chi; Wang, Yeong-Her, E-mail: yhw@ee.ncku.edu.tw

2015-03-23

Using the biomaterial of Al-chelated gelatin (ACG) prepared by sol-gel method in the ITO/ACG/ITO structure, a highly transparent resistive random access memory (RRAM) was obtained. The transmittance of the fabricated device is approximately 83% at 550 nm while that of Al/gelatin/ITO is opaque. As to the ITO/gelatin/ITO RRAM, no resistive switching behavior can be seen. The ITO/ACG/ITO RRAM shows high ON/OFF current ratio (>10{sup 5}), low operation voltage, good uniformity, and retention characteristics at room temperature and 85 °C. The mechanism of the ACG-based memory devices is presented. The enhancement of these electrical properties can be attributed to the chelate effect ofmore » Al ions with gelatin. Results show that transparent ACG-based memory devices possess the potential for next-generation resistive memories and bio-electronic applications.« less

Different Ways to Apply a Measurement Instrument of E-Nose Type to Evaluate Ambient Air Quality with Respect to Odour Nuisance in a Vicinity of Municipal Processing Plants

PubMed Central

Szulczyński, Bartosz; Wasilewski, Tomasz; Wojnowski, Wojciech; Majchrzak, Tomasz; Dymerski, Tomasz; Namieśnik, Jacek; Gębicki, Jacek

2017-01-01

This review paper presents different ways to apply a measurement instrument of e-nose type to evaluate ambient air with respect to detection of the odorants characterized by unpleasant odour in a vicinity of municipal processing plants. An emphasis was put on the following applications of the electronic nose instruments: monitoring networks, remote controlled robots and drones as well as portable devices. Moreover, this paper presents commercially available sensors utilized in the electronic noses and characterized by the limit of quantification below 1 ppm v/v, which is close to the odour threshold of some odorants. Additionally, information about bioelectronic noses being a possible alternative to electronic noses and their principle of operation and application potential in the field of air evaluation with respect to detection of the odorants characterized by unpleasant odour was provided. PMID:29156597

Electronic control of H+ current in a bioprotonic device with Gramicidin A and Alamethicin

NASA Astrophysics Data System (ADS)

Hemmatian, Zahra; Keene, Scott; Josberger, Erik; Miyake, Takeo; Arboleda, Carina; Soto-Rodríguez, Jessica; Baneyx, François; Rolandi, Marco

2016-10-01

In biological systems, intercellular communication is mediated by membrane proteins and ion channels that regulate traffic of ions and small molecules across cell membranes. A bioelectronic device with ion channels that control ionic flow across a supported lipid bilayer (SLB) should therefore be ideal for interfacing with biological systems. Here, we demonstrate a biotic-abiotic bioprotonic device with Pd contacts that regulates proton (H+) flow across an SLB incorporating the ion channels Gramicidin A (gA) and Alamethicin (ALM). We model the device characteristics using the Goldman-Hodgkin-Katz (GHK) solution to the Nernst-Planck equation for transport across the membrane. We derive the permeability for an SLB integrating gA and ALM and demonstrate pH control as a function of applied voltage and membrane permeability. This work opens the door to integrating more complex H+ channels at the Pd contact interface to produce responsive biotic-abiotic devices with increased functionality.

Hybrid Circuits with Nanofluidic Diodes and Load Capacitors

NASA Astrophysics Data System (ADS)

Ramirez, P.; Garcia-Morales, V.; Gomez, V.; Ali, M.; Nasir, S.; Ensinger, W.; Mafe, S.

2017-06-01

The chemical and physical input signals characteristic of micro- and nanofluidic devices operating in ionic solutions should eventually be translated into output electric currents and potentials that are monitored with solid-state components. This crucial step requires the design of hybrid circuits showing robust electrical coupling between ionic solutions and electronic elements. We study experimentally and theoretically the connectivity of the nanofluidic diodes in single-pore and multipore membranes with conventional capacitor systems for the cases of constant, periodic, and white-noise input potentials. The experiments demonstrate the reliable operation of these hybrid circuits over a wide range of membrane resistances, electrical capacitances, and solution p H values. The model simulations are based on empirical equations that have a solid physical basis and provide a convenient description of the electrical circuit operation. The results should contribute to advance signal transduction and processing using nanopore-based biosensors and bioelectronic interfaces.

Cyborg cells: functionalisation of living cells with polymers and nanomaterials.

PubMed

Fakhrullin, Rawil F; Zamaleeva, Alsu I; Minullina, Renata T; Konnova, Svetlana A; Paunov, Vesselin N

2012-06-07

Living cells interfaced with a range of polyelectrolyte coatings, magnetic and noble metal nanoparticles, hard mineral shells and other complex nanomaterials can perform functions often completely different from their original specialisation. Such "cyborg cells" are already finding a range of novel applications in areas like whole cell biosensors, bioelectronics, toxicity microscreening, tissue engineering, cell implant protection and bioanalytical chemistry. In this tutorial review, we describe the development of novel methods for functionalisation of cells with polymers and nanoparticles and comment on future advances in this technology in the light of other literature approaches. We review recent studies on the cell viability and function upon direct deposition of nanoparticles, coating with polyelectrolytes, polymer assisted assembly of nanomaterials and hard shells on the cell surface. The cell toxicity issues are considered for many practical applications in terms of possible adverse effects of the deposited polymers, polyelectrolytes and nanoparticles on the cell surface.

Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications.

PubMed

Khan, Asif; Abas, Zafar; Kim, Heung Soo; Kim, Jaehwan

2016-07-26

We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper and its hybrid composites such as blends or coatings with synthetic polymers, biopolymers, carbon nanotubes, chitosan, and metal oxides, are explained. In addition, the integration of cellulose electro-active paper is highlighted to form various functional devices including but not limited to bending actuators, flexible speaker, strain sensors, energy harvesting transducers, biosensors, chemical sensors and transistors for electronic applications. The frontiers in cellulose paper devices are reviewed together with the strategies and perspectives of cellulose electro-active paper and cellulose nanocomposite research and applications.

Role of semiconductivity and ion transport in the electrical conduction of melanin

PubMed Central

Mostert, Albertus B.; Powell, Benjamin J.; Pratt, Francis L.; Hanson, Graeme R.; Sarna, Tadeusz; Gentle, Ian R.; Meredith, Paul

2012-01-01

Melanins are pigmentary macromolecules found throughout the biosphere that, in the 1970s, were discovered to conduct electricity and display bistable switching. Since then, it has been widely believed that melanins are naturally occurring amorphous organic semiconductors. Here, we report electrical conductivity, muon spin relaxation, and electron paramagnetic resonance measurements of melanin as the environmental humidity is varied. We show that hydration of melanin shifts the comproportionation equilibrium so as to dope electrons and protons into the system. This equilibrium defines the relative proportions of hydroxyquinone, semiquinone, and quinone species in the macromolecule. As such, the mechanism explains why melanin at neutral pH only conducts when “wet” and suggests that both carriers play a role in the conductivity. Understanding that melanin is an electronic-ionic hybrid conductor rather than an amorphous organic semiconductor opens exciting possibilities for bioelectronic applications such as ion-to-electron transduction given its biocompatibility. PMID:22615355

Different Ways to Apply a Measurement Instrument of E-Nose Type to Evaluate Ambient Air Quality with Respect to Odour Nuisance in a Vicinity of Municipal Processing Plants.

PubMed

Szulczyński, Bartosz; Wasilewski, Tomasz; Wojnowski, Wojciech; Majchrzak, Tomasz; Dymerski, Tomasz; Namieśnik, Jacek; Gębicki, Jacek

2017-11-19

This review paper presents different ways to apply a measurement instrument of e-nose type to evaluate ambient air with respect to detection of the odorants characterized by unpleasant odour in a vicinity of municipal processing plants. An emphasis was put on the following applications of the electronic nose instruments: monitoring networks, remote controlled robots and drones as well as portable devices. Moreover, this paper presents commercially available sensors utilized in the electronic noses and characterized by the limit of quantification below 1 ppm v / v , which is close to the odour threshold of some odorants. Additionally, information about bioelectronic noses being a possible alternative to electronic noses and their principle of operation and application potential in the field of air evaluation with respect to detection of the odorants characterized by unpleasant odour was provided.

A synthetic redox biofilm made from metalloprotein-prion domain chimera nanowires

NASA Astrophysics Data System (ADS)

Altamura, Lucie; Horvath, Christophe; Rengaraj, Saravanan; Rongier, Anaëlle; Elouarzaki, Kamal; Gondran, Chantal; Maçon, Anthony L. B.; Vendrely, Charlotte; Bouchiat, Vincent; Fontecave, Marc; Mariolle, Denis; Rannou, Patrice; Le Goff, Alan; Duraffourg, Nicolas; Holzinger, Michael; Forge, Vincent

2017-02-01

Engineering bioelectronic components and set-ups that mimic natural systems is extremely challenging. Here we report the design of a protein-only redox film inspired by the architecture of bacterial electroactive biofilms. The nanowire scaffold is formed using a chimeric protein that results from the attachment of a prion domain to a rubredoxin (Rd) that acts as an electron carrier. The prion domain self-assembles into stable fibres and provides a suitable arrangement of redox metal centres in Rd to permit electron transport. This results in highly organized films, able to transport electrons over several micrometres through a network of bionanowires. We demonstrate that our bionanowires can be used as electron-transfer mediators to build a bioelectrode for the electrocatalytic oxygen reduction by laccase. This approach opens opportunities for the engineering of protein-only electron mediators (with tunable redox potentials and optimized interactions with enzymes) and applications in the field of protein-only bioelectrodes.

Development of high-performing semiconducting polymers for organic electrochemical transistors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Nielsen, Christian

2016-11-01

The organic electrochemical transistor (OECT), capable of amplifying small electrical signals in an aqueous environment, is an ideal device to utilize in organic bioelectronic applications involving for example neural interfacing and diagnostics. Currently, most OECTs are fabricated with commercially available conducting poly(3,4-ethylenedioxythiophene)-based suspensions such as PEDOT:PSS and are therefore operated in depletion mode giving rise to devices that are permanently on with non-optimal operational voltage. With the aim to develop and utilize efficient accumulation mode OECT devices, we discuss here our recent results regarding the design, synthesis and performance of novel intrinsic semiconducting polymers. Covering key aspects such as ion and charge transport in the bulk semiconductor and operational voltage and stability of the materials and devices, we have elucidated important structure-property relationships. We illustrate the improvements this approach has afforded in the development of high performance accumulation mode OECT materials.

Maleimide-activated aryl diazonium salts for electrode surface functionalization with biological and redox-active molecules.

PubMed

Harper, Jason C; Polsky, Ronen; Wheeler, David R; Brozik, Susan M

2008-03-04

A versatile and simple method is introduced for formation of maleimide-functionalized surfaces using maleimide-activated aryl diazonium salts. We show for the first time electrodeposition of N-(4-diazophenyl)maleimide tetrafluoroborate on gold and carbon electrodes which was characterized via voltammetry, grazing angle FTIR, and ellipsometry. Electrodeposition conditions were used to control film thickness and yielded submonolayer-to-multilayer grafting. The resulting phenylmaleimide surfaces served as effective coupling agents for electrode functionalization with ferrocene and the redox-active protein cytochrome c. The utility of phenylmaleimide diazonium toward formation of a diazonium-activated conjugate, followed by direct electrodeposition of the diazonium-modified DNA onto the electrode surface, was also demonstrated. Effective electron transfer was obtained between immobilized molecules and the electrodes. This novel application of N-phenylmaleimide diazonium may facilitate the development of bioelectronic devices including biofuel cells, biosensors, and DNA and protein microarrays.

Protein-Based Three-Dimensional Memories and Associative Processors

NASA Astrophysics Data System (ADS)

Birge, Robert

2008-03-01

The field of bioelectronics has benefited from the fact that nature has often solved problems of a similar nature to those which must be solved to create molecular electronic or photonic devices that operate with efficiency and reliability. Retinal proteins show great promise in bioelectronic devices because they operate with high efficiency (˜0.65%), high cyclicity (>10^7), operate over an extended wavelength range (360 -- 630 nm) and can convert light into changes in voltage, pH, absorption or refractive index. This talk will focus on a retinal protein called bacteriorhodopsin, the proton pump of the organism Halobacterium salinarum. Two memories based on this protein will be described. The first is an optical three-dimensional memory. This memory stores information using volume elements (voxels), and provides as much as a thousand-fold improvement in effective capacity over current technology. A unique branching reaction of a variant of bacteriorhodopsin is used to turn each protein into an optically addressed latched AND gate. Although three working prototypes have been developed, a number of cost/performance and architectural issues must be resolved prior to commercialization. The major issue is that the native protein provides a very inefficient branching reaction. Genetic engineering has improved performance by nearly 500-fold, but a further order of magnitude improvement is needed. Protein-based holographic associative memories will also be discussed. The human brain stores and retrieves information via association, and human intelligence is intimately connected to the nature and enormous capacity of this associative search and retrieval process. To a first order approximation, creativity can be viewed as the association of two seemingly disparate concepts to form a totally new construct. Thus, artificial intelligence requires large scale associative memories. Current computer hardware does not provide an optimal environment for creating artificial intelligence due to the serial nature of random access memories. Software cannot provide a satisfactory work-around that does not introduce unacceptable latency. Holographic associative memories provide a useful approach to large scale associative recall. Bacteriorhodopsin has long been recognized for its outstanding holographic properties, and when utilized in the Paek and Psaltis design, provides a high-speed real-time associative memory with variable thresholding and feedback. What remains is to make an associative memory capable of high-speed association and long-term data storage. The use of directed evolution to create a protein with the necessary unique properties will be discussed.

Structure-function study of Poly(sulfobetaine 3,4-ethylenedioxythiophene) (PSBEDOT) and its derivatives.

PubMed

Lee, Chen-Jung; Wang, Huifang; Young, Megan; Li, Shengxi; Cheng, Fang; Cong, Hongbo; Cheng, Gang

2018-06-04

Poly(3,4-ethylenedioxythiophene) (PEDOT) has been widely studied in recent decades due to its high stability, biocompatibility, low redox potential, moderate band gap, and optical transparency in its conducting state. However, for its long-term in vivo applications, the biocompatibility of PEDOT still need to be improved. To address this challenge, zwitterionic Poly(sulfobetaine 3,4-ethylenedioxythiophene) (PSBEDOT) that contains EDOT backbone with sulfobetaine functional side chains were developed in our previous study. Although PSBEDOT showed great resistance to proteins, cells, and bacteria, it is still not clear how the zwitterionic sulfobetaine side chain affects the electrochemical properties of the polymer and reactivity of the monomer. To have better understanding on the structure-function relationship of zwitterionic conducting polymer, we synthesized two derivatives of PSBEDOT, PSBEDOT-4 and PSBEDOT-5, by introducing the alkoxyl spacer between EDOT and sulfobetaine. The interfacial impedance of PSBEDOT-4 and PSBEDOT-5 was examined by electrochemical impedance spectroscopy and showed significant improvement which is about 20 times lower than PSBEDOT on both gold and indium tin oxide substrates at 1 Hz. In the protein adsorption test, PSBEDOT, PSBEDOT-4 and PSBEDOT-5 exhibited comparable resistance to the fibrinogen solution. All three polymers had low protein adsorption around 3%-5% comparing to the control sample, PEDOT, which was normalized to 100%. Additionally, the morphology of PSBEDOT, PSBEDOT-4 and PSBEDOT-5 with different synthesis parameter have been investigated by scanning electron microscope. We believe that these stable and biocompatible materials can be good candidates for developing long-term bioelectronics devices. To address the challenges associated existing conducting materials for bioelectronics, we developed a versatile and high performance zwitterionic conducting material platform with excellent stability, electrochemical, antifouling and controllable antimicrobial/antifouling properties. In this work, we developed two high-performance conducting polymers and systematically investigated how its structure affect their properties. Our study shows we can accurately tune the molecular structure of the monomer to dramatically improve the performance of zwitterionic conducting polymer. This zwitterionic conducting polymer platform may dramatically increase the performance and service life of electrochemical devices for many long-term applications, such as implantable biosensing, tissue engineering, wound healing, robotic prostheses, biofuel cell etc., which all require high performance conducting materials with excellent antifouling/biocompatibility at complex biointerfaces. Copyright © 2018. Published by Elsevier Ltd.

Efficacy of Carotid Artery Stenting by the Universal Protection Method.

PubMed

Goto, Shunsaku; Ohshima, Tomotaka; Kato, Kyozo; Izumi, Takashi; Wakabayashi, Toshihiko

2018-04-18

To avoid distal plaques embolization during carotid artery stenting, we developed Universal Protection Method that combined the use of a proximal common carotid artery balloon, an external carotid artery balloon, and a distal internal carotid artery filter, with continuous flow reversal to the femoral vein. Herein, we assessed the efficacy of the Universal Protection Method by comparing stenting outcomes before and after its introduction. We assessed outcomes for 115 cases before and 41 cases after the Universal Protection Method was adopted (non-Universal Protection Method and Universal Protection Method groups, respectively). We then compared procedure details, magnetic resonance imaging (within 48 hours after the procedure), intraprocedural complications, and postoperative stroke rates. Ischemic stroke was not observed in the Universal Protection Method group, but 1 major stroke and 2 minor strokes were observed in the non-Universal Protection Method group. High-intensity areas were seen in 6 (15.0%) and 49 (42.6%) cases in the Universal Protection Method and non-Universal Protection Method groups, respectively (P = .001). Contrastingly, intraprocedural complications were observed in 9 (22.5%) and 21 (18.3%) cases in the Universal Protection Method and non-Universal Protection Method groups, respectively. Among these intraprocedural complication cases, high-intensity areas were observed in 1 case (11.1%) in the Universal Protection Method group and in 15 cases (71.4%) in the non-Universal Protection Method group. Universal Protection Method is a safe technique that is applicable to all patients undergoing carotid artery stenting, irrespective of individual risk factors. Notably, the incidence rates of both distal embolization and unexpected intraprocedural complications are low. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Positioning University as a Brand: Distinctions between the Brand Promise of Russell Group, 1994 Group, University Alliance, and Million+ Universities

ERIC Educational Resources Information Center

Furey, Sheila; Springer, Paul; Parsons, Christine

2014-01-01

Branding is now widely used by higher education (HE) institutions, yet questions still surround the transference of private sector concepts to a university context. This article reports on findings from studies that investigated the brand promises of four UK universities--one from each of the HE "mission groups." The evidence indicated…

The Roles of a University Professor in a Teacher Study Group

ERIC Educational Resources Information Center

Yeh, Hui-Chin; Hung, Hsiu-Ting; Chen, Yi-Ping

2012-01-01

The opportunities in which university professors collaborate with the practicing school teachers in a teacher study group are few. This study investigated how a university professor facilitated a collaborative teacher study group to enhance teachers' professional growth. Five primary school teachers and a university professor collaborated on…

Control of the hierarchical assembly of π-conjugated optoelectronic peptides by pH and flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mansbach, Rachael A.; Ferguson, Andrew L.

Self-assembled nanoaggregates of p-conjugated peptides possess optoelectronic properties due to electron delocalization over the conjugated peptide groups that make them attractive candidates for the fabrication of bioelectronic materials. We present a computational and theoretical study to resolve the microscopic effects of pH and flow on the non-equilibrium morphology and kinetics of early-stage assembly of an experimentally-realizable optoelectronic peptide that displays pH triggerable assembly. Employing coarse-grained molecular dynamics simulations, we probe the effects of pH on growth kinetics and aggregate morphology to show that control of the peptide protonation state by pH can be used to modulate the assembly rates, degreemore » of molecular alignment, and resulting morphologies within the self-assembling nanoaggregates. We also quantify the time and length scales at which convective flows employed in directed assembly compete with microscopic diffusion to show that flow influences cluster alignment and assembly rate during early-stage assembly only at extremely high shear rates. This suggests that observed improvements in optoelectronic properties at experimentally-accessible shear rates are due to the alignment of large aggregates of hundreds of monomers on time scales in excess of hundreds of nanoseconds. Lastly, our work provides new fundamental understanding of the effects of pH and flow to control the morphology and kinetics of early-stage assembly of p-conjugated peptides and lays the groundwork for the rational manipulation of environmental conditions to direct assembly and the attendant emergent optoelectronic properties.« less

Control of the hierarchical assembly of π-conjugated optoelectronic peptides by pH and flow

DOE PAGES

Mansbach, Rachael A.; Ferguson, Andrew L.

2017-01-01

Self-assembled nanoaggregates of p-conjugated peptides possess optoelectronic properties due to electron delocalization over the conjugated peptide groups that make them attractive candidates for the fabrication of bioelectronic materials. We present a computational and theoretical study to resolve the microscopic effects of pH and flow on the non-equilibrium morphology and kinetics of early-stage assembly of an experimentally-realizable optoelectronic peptide that displays pH triggerable assembly. Employing coarse-grained molecular dynamics simulations, we probe the effects of pH on growth kinetics and aggregate morphology to show that control of the peptide protonation state by pH can be used to modulate the assembly rates, degreemore » of molecular alignment, and resulting morphologies within the self-assembling nanoaggregates. We also quantify the time and length scales at which convective flows employed in directed assembly compete with microscopic diffusion to show that flow influences cluster alignment and assembly rate during early-stage assembly only at extremely high shear rates. This suggests that observed improvements in optoelectronic properties at experimentally-accessible shear rates are due to the alignment of large aggregates of hundreds of monomers on time scales in excess of hundreds of nanoseconds. Lastly, our work provides new fundamental understanding of the effects of pH and flow to control the morphology and kinetics of early-stage assembly of p-conjugated peptides and lays the groundwork for the rational manipulation of environmental conditions to direct assembly and the attendant emergent optoelectronic properties.« less

Composite bonding to stainless steel crowns using a new universal bonding and single-bottle systems.

PubMed

Hattan, Mohammad Ali; Pani, Sharat Chandra; Alomari, Mohammad

2013-01-01

Aim. The aim of this study is to evaluate the shear bond strength of nanocomposite to stainless steel crowns using a new universal bonding system. Material and Methods. Eighty (80) stainless steel crowns (SSCs) were divided into four groups (20 each). Packable nanocomposite was bonded to the lingual surface of the crowns in the following methods: Group A without adhesive (control group), Group B using a new universal adhesive system (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany), and Group C and Group D using two different brands of single-bottle adhesive systems. Shear bond strengths were calculated and the types of failure also were recorded. Results. The shear strength of Group B was significantly greater than that of other groups. No significant differences were found between the shear bond strengths of Groups C and D. The control group had significantly lower shear bond strength (P < 0.05) to composite than the groups that utilized bonding agents. Conclusion. Composites bonding to stainless steel crowns using the new universal bonding agent (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany) show significantly greater shear bond strengths and fewer adhesive failures when compared to traditional single-bottle systems.

Own-Group Face Recognition Bias: The Effects of Location and Reputation

PubMed Central

Yan, Linlin; Wang, Zhe; Huang, Jianling; Sun, Yu-Hao P.; Judges, Rebecca A.; Xiao, Naiqi G.; Lee, Kang

2017-01-01

In the present study, we examined whether social categorization based on university affiliation can induce an advantage in recognizing faces. Moreover, we investigated how the reputation or location of the university affected face recognition performance using an old/new paradigm. We assigned five different university labels to the faces: participants’ own university and four other universities. Among the four other university labels, we manipulated the academic reputation and geographical location of these universities relative to the participants’ own university. The results showed that an own-group face recognition bias emerged for faces with own-university labels comparing to those with other-university labels. Furthermore, we found a robust own-group face recognition bias only when the other university was located in a different city far away from participants’ own university. Interestingly, we failed to find the influence of university reputation on own-group face recognition bias. These results suggest that categorizing a face as a member of one’s own university is sufficient to enhance recognition accuracy and the location will play a more important role in the effect of social categorization on face recognition than reputation. The results provide insight into the role of motivational factors underlying the university membership in face perception. PMID:29066989

Self-assembled three dimensional network designs for soft electronics

PubMed Central

Jang, Kyung-In; Li, Kan; Chung, Ha Uk; Xu, Sheng; Jung, Han Na; Yang, Yiyuan; Kwak, Jean Won; Jung, Han Hee; Song, Juwon; Yang, Ce; Wang, Ao; Liu, Zhuangjian; Lee, Jong Yoon; Kim, Bong Hoon; Kim, Jae-Hwan; Lee, Jungyup; Yu, Yongjoon; Kim, Bum Jun; Jang, Hokyung; Yu, Ki Jun; Kim, Jeonghyun; Lee, Jung Woo; Jeong, Jae-Woong; Song, Young Min; Huang, Yonggang; Zhang, Yihui; Rogers, John A.

2017-01-01

Low modulus, compliant systems of sensors, circuits and radios designed to intimately interface with the soft tissues of the human body are of growing interest, due to their emerging applications in continuous, clinical-quality health monitors and advanced, bioelectronic therapeutics. Although recent research establishes various materials and mechanics concepts for such technologies, all existing approaches involve simple, two-dimensional (2D) layouts in the constituent micro-components and interconnects. Here we introduce concepts in three-dimensional (3D) architectures that bypass important engineering constraints and performance limitations set by traditional, 2D designs. Specifically, open-mesh, 3D interconnect networks of helical microcoils formed by deterministic compressive buckling establish the basis for systems that can offer exceptional low modulus, elastic mechanics, in compact geometries, with active components and sophisticated levels of functionality. Coupled mechanical and electrical design approaches enable layout optimization, assembly processes and encapsulation schemes to yield 3D configurations that satisfy requirements in demanding, complex systems, such as wireless, skin-compatible electronic sensors. PMID:28635956

High Density Shielded MEA / Optrode Arrays

NASA Astrophysics Data System (ADS)

Naughton, Jeff; Varela, Juan M.; Christianson, John P.; Chiles, Thomas C.; Burns, Michael J.; Naughton, Michael J.

We report on the development of a novel, high density, locally-shielded neuroelectronic / optoelectronic array architecture, useful for bioelectronics and neurophysiology. The device has been used in real time to noninvasively couple to leech neurons, allowing for extracellular recording of synaptic activity in the form of spontaneous synapse firing in pre- and post-synaptic somata. In addition, we show by subtly altering the architecture the ability for optical integration with the device - that is, it can function as both a local light delivery conduit and a recording electrode. We utilized this novel device to optically elicit and electrically record membrane currents in HEK293 cells transfected with plasmids encoding ChR2-YFP (i.e. optogenetics). Finally, we show that the local (Faraday) shield is effective in isolating the sensing area, so as to record only from cells in immediate proximity. This effective isolation or cross-talk suppression is important for moving closer to ``ground truth'' measurements of neurons, critical to the development of valid spike sorting algorithms.

Sub-0.5 V Highly Stable Aqueous Salt Gated Metal Oxide Electronics

PubMed Central

Park, Sungjun; Lee, SeYeong; Kim, Chang-Hyun; Lee, Ilseop; Lee, Won-June; Kim, Sohee; Lee, Byung-Geun; Jang, Jae-Hyung; Yoon, Myung-Han

2015-01-01

Recently, growing interest in implantable bionics and biochemical sensors spurred the research for developing non-conventional electronics with excellent device characteristics at low operation voltages and prolonged device stability under physiological conditions. Herein, we report high-performance aqueous electrolyte-gated thin-film transistors using a sol-gel amorphous metal oxide semiconductor and aqueous electrolyte dielectrics based on small ionic salts. The proper selection of channel material (i.e., indium-gallium-zinc-oxide) and precautious passivation of non-channel areas enabled the development of simple but highly stable metal oxide transistors manifested by low operation voltages within 0.5 V, high transconductance of ~1.0 mS, large current on-off ratios over 107, and fast inverter responses up to several hundred hertz without device degradation even in physiologically-relevant ionic solutions. In conjunction with excellent transistor characteristics, investigation of the electrochemical nature of the metal oxide-electrolyte interface may contribute to the development of a viable bio-electronic platform directly interfacing with biological entities in vivo. PMID:26271456

A nanoporous alumina microelectrode array for functional cell-chip coupling.

PubMed

Wesche, Manuel; Hüske, Martin; Yakushenko, Alexey; Brüggemann, Dorothea; Mayer, Dirk; Offenhäusser, Andreas; Wolfrum, Bernhard

2012-12-14

The design of electrode interfaces has a strong impact on cell-based bioelectronic applications. We present a new type of microelectrode array chip featuring a nanoporous alumina interface. The chip is fabricated in a combination of top-down and bottom-up processes using state-of-the-art clean room technology and self-assembled generation of nanopores by aluminum anodization. The electrode characteristics are investigated in phosphate buffered saline as well as under cell culture conditions. We show that the modified microelectrodes exhibit decreased impedance compared to planar microelectrodes, which is caused by a nanostructuring effect of the underlying gold during anodization. The stability and biocompatibility of the device are demonstrated by measuring action potentials from cardiomyocyte-like cells growing on top of the chip. Cross sections of the cell-surface interface reveal that the cell membrane seals the nanoporous alumina layer without bending into the sub-50 nm apertures. The nanoporous microelectrode array device may be used as a platform for combining extracellular recording of cell activity with stimulating topographical cues.

Real-time encoding and compression of neuronal spikes by metal-oxide memristors

NASA Astrophysics Data System (ADS)

Gupta, Isha; Serb, Alexantrou; Khiat, Ali; Zeitler, Ralf; Vassanelli, Stefano; Prodromakis, Themistoklis

2016-09-01

Advanced brain-chip interfaces with numerous recording sites bear great potential for investigation of neuroprosthetic applications. The bottleneck towards achieving an efficient bio-electronic link is the real-time processing of neuronal signals, which imposes excessive requirements on bandwidth, energy and computation capacity. Here we present a unique concept where the intrinsic properties of memristive devices are exploited to compress information on neural spikes in real-time. We demonstrate that the inherent voltage thresholds of metal-oxide memristors can be used for discriminating recorded spiking events from background activity and without resorting to computationally heavy off-line processing. We prove that information on spike amplitude and frequency can be transduced and stored in single devices as non-volatile resistive state transitions. Finally, we show that a memristive device array allows for efficient data compression of signals recorded by a multi-electrode array, demonstrating the technology's potential for building scalable, yet energy-efficient on-node processors for brain-chip interfaces.

Cortical control of intraspinal microstimulation: Toward a new approach for restoration of function after spinal cord injury.

PubMed

Shahdoost, Shahab; Frost, Shawn; Dunham, Caleb; DeJong, Stacey; Barbay, Scott; Nudo, Randolph; Mohseni, Pedram

2015-08-01

Approximately 6 million people in the United States are currently living with paralysis in which 23% of the cases are related to spinal cord injury (SCI). Miniaturized closed-loop neural interfaces have the potential for restoring function and mobility lost to debilitating neural injuries such as SCI by leveraging recent advancements in bioelectronics and a better understanding of the processes that underlie functional and anatomical reorganization in an injured nervous system. This paper describes our current progress toward developing a miniaturized brain-machine-spinal cord interface (BMSI) that converts in real time the neural command signals recorded from the cortical motor regions to electrical stimuli delivered to the spinal cord below the injury level. Using a combination of custom integrated circuit (IC) technology for corticospinal interfacing and field-programmable gate array (FPGA)-based technology for embedded signal processing, we demonstrate proof-of-concept of distinct muscle pattern activation via intraspinal microstimulation (ISMS) controlled in real time by intracortical neural spikes in an anesthetized laboratory rat.

Electronic control of H+ current in a bioprotonic device with Gramicidin A and Alamethicin

PubMed Central

Hemmatian, Zahra; Keene, Scott; Josberger, Erik; Miyake, Takeo; Arboleda, Carina; Soto-Rodríguez, Jessica; Baneyx, François; Rolandi, Marco

2016-01-01

In biological systems, intercellular communication is mediated by membrane proteins and ion channels that regulate traffic of ions and small molecules across cell membranes. A bioelectronic device with ion channels that control ionic flow across a supported lipid bilayer (SLB) should therefore be ideal for interfacing with biological systems. Here, we demonstrate a biotic–abiotic bioprotonic device with Pd contacts that regulates proton (H+) flow across an SLB incorporating the ion channels Gramicidin A (gA) and Alamethicin (ALM). We model the device characteristics using the Goldman–Hodgkin–Katz (GHK) solution to the Nernst–Planck equation for transport across the membrane. We derive the permeability for an SLB integrating gA and ALM and demonstrate pH control as a function of applied voltage and membrane permeability. This work opens the door to integrating more complex H+ channels at the Pd contact interface to produce responsive biotic–abiotic devices with increased functionality. PMID:27713411

Evaluation of in vitro and in vivo biocompatibility of a myo-inositol hexakisphosphate gelated polyaniline hydrogel in a rat model

NASA Astrophysics Data System (ADS)

Sun, Kwang-Hsiao; Liu, Zhao; Liu, Changjian; Yu, Tong; Shang, Tao; Huang, Chen; Zhou, Min; Liu, Cheng; Ran, Feng; Li, Yun; Shi, Yi; Pan, Lijia

2016-04-01

Recent advances in understanding the interaction between electricity and cells/biomolecules have generated great interest in developing biocompatible electrically conductive materials. In this study, we investigated the biocompatibility of a myo-inositol hexakisphosphate gelated polyaniline hydrogel using in vitro and in vivo experiments in a rat model. The polyaniline hydrogel was used to coat a polycaprolactone scaffold and was cultured with rat endothelial progenitor cells differentiated from rat adipose-derived stem cells. Compared with the control sample on a pristine polycaprolactone scaffold, the treated polyaniline hydrogel had the same non-poisonous/cytotoxicity grade, enhanced cell adhesion, and a higher cell proliferation/growth rate. In implant studies, the polyaniline hydrogel sample induced milder inflammatory responses than did the control at the same time points. Combining the advantages of a biocompatible hydrogel and an organic conductor, the inositol phosphate-gelated polyaniline hydrogel could be used in bioelectronics applications such as biosensors, neural probes, cell stimulators, medical electrodes, tissue engineering, and electro-controlled drug delivery.

Designed cell consortia as fragrance-programmable analog-to-digital converters.

PubMed

Müller, Marius; Ausländer, Simon; Spinnler, Andrea; Ausländer, David; Sikorski, Julian; Folcher, Marc; Fussenegger, Martin

2017-03-01

Synthetic biology advances the rational engineering of mammalian cells to achieve cell-based therapy goals. Synthetic gene networks have nearly reached the complexity of digital electronic circuits and enable single cells to perform programmable arithmetic calculations or to provide dynamic remote control of transgenes through electromagnetic waves. We designed a synthetic multilayered gaseous-fragrance-programmable analog-to-digital converter (ADC) allowing for remote control of digital gene expression with 2-bit AND-, OR- and NOR-gate logic in synchronized cell consortia. The ADC consists of multiple sampling-and-quantization modules sensing analog gaseous fragrance inputs; a gas-to-liquid transducer converting fragrance intensity into diffusible cell-to-cell signaling compounds; a digitization unit with a genetic amplifier circuit to improve the signal-to-noise ratio; and recombinase-based digital expression switches enabling 2-bit processing of logic gates. Synthetic ADCs that can remotely control cellular activities with digital precision may enable the development of novel biosensors and may provide bioelectronic interfaces synchronizing analog metabolic pathways with digital electronics.

Nanoscale observation of local bound charges of patterned protein arrays by scanning force microscopy

NASA Astrophysics Data System (ADS)

Oh, Y. J.; Jo, W.; Kim, S.; Park, S.; Kim, Y. S.

2008-09-01

A protein patterned surface using micro-contact printing methods has been investigated by scanning force microscopy. Electrostatic force microscopy (EFM) was utilized for imaging the topography and detecting the electrical properties such as the local bound charge distribution of the patterned proteins. It was found that the patterned IgG proteins are arranged down to 1 µm, and the 90° rotation of patterned anti-IgG proteins was successfully undertaken. Through the estimation of the effective areas, it was possible to determine the local bound charges of patterned proteins which have opposite electrostatic force behaviors. Moreover, we studied the binding probability between IgG and anti-IgG in a 1 µm2 MIMIC system by topographic and electrostatic signals for applicable label-free detections. We showed that the patterned proteins can be used for immunoassay of proteins on the functional substrate, and that they can also be used for bioelectronics device application, indicating distinct advantages with regard to accuracy and a label-free detection.

Self-assembling peptide nanofiber hydrogels in tissue engineering and regenerative medicine: Progress, design guidelines, and applications.

PubMed

Koutsopoulos, Sotirios

2016-04-01

Until the mid-1980s, mainly biologists were conducting peptide research. This changed with discoveries that opened new paths of research involving the use of peptides in bioengineering, biotechnology, biomedicine, nanotechnology, and bioelectronics. Peptide engineering and rational design of novel peptide sequences with unique and tailor-made properties further expanded the field. The discovery of short self-assembling peptides, which upon association form well-defined supramolecular architectures, created new and exciting areas of research. Depending on the amino acid sequence, the pH, and the type of the electrolyte in the medium, peptide self-assembly leads to the formation of nanofibers, which are further organized to form a hydrogel. In this review, the application of ionic complementary peptides which self-assemble to form nanofiber hydrogels for tissue engineering and regenerative medicine will be discussed through a selective presentation of the most important work performed during the last 25 years. © 2016 Wiley Periodicals, Inc.

Bioelectronic neural pixel: Chemical stimulation and electrical sensing at the same site

PubMed Central

Jonsson, Amanda; Inal, Sahika; Uguz, Ilke; Williamson, Adam J.; Kergoat, Loïg; Rivnay, Jonathan; Khodagholy, Dion; Berggren, Magnus; Bernard, Christophe; Malliaras, George G.

2016-01-01

Local control of neuronal activity is central to many therapeutic strategies aiming to treat neurological disorders. Arguably, the best solution would make use of endogenous highly localized and specialized regulatory mechanisms of neuronal activity, and an ideal therapeutic technology should sense activity and deliver endogenous molecules at the same site for the most efficient feedback regulation. Here, we address this challenge with an organic electronic multifunctional device that is capable of chemical stimulation and electrical sensing at the same site, at the single-cell scale. Conducting polymer electrodes recorded epileptiform discharges induced in mouse hippocampal preparation. The inhibitory neurotransmitter, γ-aminobutyric acid (GABA), was then actively delivered through the recording electrodes via organic electronic ion pump technology. GABA delivery stopped epileptiform activity, recorded simultaneously and colocally. This multifunctional “neural pixel” creates a range of opportunities, including implantable therapeutic devices with automated feedback, where locally recorded signals regulate local release of specific therapeutic agents. PMID:27506784

Self-assembled three dimensional network designs for soft electronics

NASA Astrophysics Data System (ADS)

Jang, Kyung-In; Li, Kan; Chung, Ha Uk; Xu, Sheng; Jung, Han Na; Yang, Yiyuan; Kwak, Jean Won; Jung, Han Hee; Song, Juwon; Yang, Ce; Wang, Ao; Liu, Zhuangjian; Lee, Jong Yoon; Kim, Bong Hoon; Kim, Jae-Hwan; Lee, Jungyup; Yu, Yongjoon; Kim, Bum Jun; Jang, Hokyung; Yu, Ki Jun; Kim, Jeonghyun; Lee, Jung Woo; Jeong, Jae-Woong; Song, Young Min; Huang, Yonggang; Zhang, Yihui; Rogers, John A.

2017-06-01

Low modulus, compliant systems of sensors, circuits and radios designed to intimately interface with the soft tissues of the human body are of growing interest, due to their emerging applications in continuous, clinical-quality health monitors and advanced, bioelectronic therapeutics. Although recent research establishes various materials and mechanics concepts for such technologies, all existing approaches involve simple, two-dimensional (2D) layouts in the constituent micro-components and interconnects. Here we introduce concepts in three-dimensional (3D) architectures that bypass important engineering constraints and performance limitations set by traditional, 2D designs. Specifically, open-mesh, 3D interconnect networks of helical microcoils formed by deterministic compressive buckling establish the basis for systems that can offer exceptional low modulus, elastic mechanics, in compact geometries, with active components and sophisticated levels of functionality. Coupled mechanical and electrical design approaches enable layout optimization, assembly processes and encapsulation schemes to yield 3D configurations that satisfy requirements in demanding, complex systems, such as wireless, skin-compatible electronic sensors.

Browsing the Real World using Organic Electronics, Si-Chips, and a Human Touch.

PubMed

Berggren, Magnus; Simon, Daniel T; Nilsson, David; Dyreklev, Peter; Norberg, Petronella; Nordlinder, Staffan; Ersman, Peter Andersson; Gustafsson, Göran; Wikner, J Jacob; Hederén, Jan; Hentzell, Hans

2016-03-09

Organic electronics have been developed according to an orthodox doctrine advocating "all-printed'', "all-organic'' and "ultra-low-cost'' primarily targeting various e-paper applications. In order to harvest from the great opportunities afforded with organic electronics potentially operating as communication and sensor outposts within existing and future complex communication infrastructures, high-quality computing and communication protocols must be integrated with the organic electronics. Here, we debate and scrutinize the twinning of the signal-processing capability of traditional integrated silicon chips with organic electronics and sensors, and to use our body as a natural local network with our bare hand as the browser of the physical world. The resulting platform provides a body network, i.e., a personalized web, composed of e-label sensors, bioelectronics, and mobile devices that together make it possible to monitor and record both our ambience and health-status parameters, supported by the ubiquitous mobile network and the resources of the "cloud". © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Immbolization of uricase enzyme in Langmuir and Langmuir-Blodgett films of fatty acids: possible use as a uric acid sensor.

PubMed

Zanon, Nathaly C M; Oliveira, Osvaldo N; Caseli, Luciano

2012-05-01

Preserving the enzyme structure in solid films is key for producing various bioelectronic devices, including biosensors, which has normally been performed with nanostructured films that allow for control of molecular architectures. In this paper, we investigate the adsorption of uricase onto Langmuir monolayers of stearic acid (SA), and their transfer to solid supports as Langmuir-Blodgett (LB) films. Structuring of the enzyme in β-sheets was preserved in the form of 1-layer LB film, which was corroborated with a higher catalytic activity than for other uricase-containing LB film architectures where the β-sheets structuring was not preserved. The optimized architecture was also used to detect uric acid within a range covering typical concentrations in the human blood. The approach presented here not only allows for an optimized catalytic activity toward uric acid but also permits one to explain why some film architectures exhibit a superior performance. Copyright © 2011 Elsevier Inc. All rights reserved.

Real-time encoding and compression of neuronal spikes by metal-oxide memristors

PubMed Central

Gupta, Isha; Serb, Alexantrou; Khiat, Ali; Zeitler, Ralf; Vassanelli, Stefano; Prodromakis, Themistoklis

2016-01-01

Advanced brain-chip interfaces with numerous recording sites bear great potential for investigation of neuroprosthetic applications. The bottleneck towards achieving an efficient bio-electronic link is the real-time processing of neuronal signals, which imposes excessive requirements on bandwidth, energy and computation capacity. Here we present a unique concept where the intrinsic properties of memristive devices are exploited to compress information on neural spikes in real-time. We demonstrate that the inherent voltage thresholds of metal-oxide memristors can be used for discriminating recorded spiking events from background activity and without resorting to computationally heavy off-line processing. We prove that information on spike amplitude and frequency can be transduced and stored in single devices as non-volatile resistive state transitions. Finally, we show that a memristive device array allows for efficient data compression of signals recorded by a multi-electrode array, demonstrating the technology's potential for building scalable, yet energy-efficient on-node processors for brain-chip interfaces. PMID:27666698

Fabrication of graphene-platinum nanocomposite for the direct electrochemistry and electrocatalysis of myoglobin.

PubMed

Sun, Wei; Li, Linfang; Lei, Bingxin; Li, Tongtong; Ju, Xiaomei; Wang, Xiuzheng; Li, Guangjiu; Sun, Zhenfan

2013-05-01

In this paper a platinum (Pt) nanoparticle decorated graphene (GR) nanosheet was synthesized and used for the investigation on direct electrochemistry of myoglobin (Mb). By integrating GR-Pt nanocomposite with Mb on the surface of carbon ionic liquid electrode (CILE), a new electrochemical biosensor was fabricated. UV-Vis absorption and FT-IR spectra indicated that Mb remained its native structure in the nanocomposite film. Electrochemical behaviors of Nafion/Mb-GR-Pt/CILE were investigated with a pair of well-defined redox peak appeared, which indicated that direct electron transfer of Mb was realized on the underlying electrode with the usage of the GR-Pt nanocomposite. The fabricated electrode showed good electrocatalytic activity to the reduction of trichloroacetic acid in the linear range from 0.9 to 9.0 mmol/L with the detection limit as 0.32 mmol/L (3σ), which showed potential application for fabricating novel electrochemical biosensors and bioelectronic devices. Copyright © 2012 Elsevier B.V. All rights reserved.

Transient Resistive Switching Devices Made from Egg Albumen Dielectrics and Dissolvable Electrodes.

PubMed

He, Xingli; Zhang, Jian; Wang, Wenbo; Xuan, Weipeng; Wang, Xiaozhi; Zhang, Qilong; Smith, Charles G; Luo, Jikui

2016-05-04

Egg albumen as the dielectric, and dissolvable Mg and W as the top and bottom electrodes are used to fabricate water-soluble memristors. 4 × 4 cross-bar configuration memristor devices show a bipolar resistive switching behavior with a high to low resistance ratio in the range of 1 × 10(2) to 1 × 10(4), higher than most other biomaterial-based memristors, and a retention time over 10(4) s without any sign of deterioration, demonstrating its high stability and reliability. Metal filaments accompanied by hopping conduction are believed to be responsible for the switching behavior of the memory devices. The Mg and W electrodes, and albumen film all can be dissolved in water within 72 h, showing their transient characteristics. This work demonstrates a new way to fabricate biocompatible and dissolvable electronic devices by using cheap, abundant, and 100% natural materials for the forthcoming bioelectronics era as well as for environmental sensors when the Internet of things takes off.

Bienzyme system for the biocatalyzed deposition of polyaniline templated by multiwalled carbon nanotubes: a biosensor design.

PubMed

Sheng, Qinglin; Zheng, Jianbin

2009-02-15

A novel method based on covalent attachment of two enzymes, glucose oxidase (GOD) and horseradish peroxide (HRP), onto carboxylic-derived multiwalled carbon nanotubes (MWNTs) for the deposition of electroactive polyaniline (PANI) under ambient conditions is described. Ultraviolet-visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and transmission electron microscopy were used to characterize the assembling of bienzyme and the morphology of PANI|MWNTs. Under the bienzyme biocatalytic condition, a head-to-tail structure of PANI templated by MWNTs was formed. The voltammetric characteristics of the resulting biosensor were investigated by cyclic voltammetry in the presence of glucose. The current response of PANI was linearly related to glucose concentration between 0.05 and 12.0mM with a correlation coefficient of 0.994. The synergistic performance of bienzyme, highly efficient polymerization, and templated deposition provide a general platform for the synthesis of nanowires and nanocircuits, the construction of bioelectronic devices, and the design of novel biosensors.

Magneto-controlled bioelectronics for the antigen-antibody interaction based on magnetic-core/gold-shell nanoparticles functionalized biomimetic interface.

PubMed

Tang, Dianping; Yuan, Ruo; Chai, Yaqin

2008-02-01

A new protein assay system for the antigen-antibody interaction was developed by immobilization of carcinoembryonic antibody (anti-CEA) onto magnetic-core/gold-shell nanoparticles-functionalized biomimetic interface on multiporous polythionine modified magnetic carbon paste electrodes (MCPE). Differential pulse voltammetric (DPV) technique was employed to investigate the antigen-antibody interaction in pH 6.8 acetate acid buffer solution after incubation with various CEA samples for 50 min at room temperature. The peak currents decreased with increased CEA concentration, and were proportional to the CEA concentration in the range of 1.5-60 ng/ml with a detection limit of 0.3 ng/ml at a signal-to-noise ratio of 3. Moreover, the selectivity, reproducibility and stability of the proposed immunoassay system were acceptable. Compared with the conventional immunoassays, the developed immunoassay system was simple and rapid without multiple labeling and separation steps. Importantly, the proposed methodology would be valuable for diagnosis and monitoring of carcinoma and its metastasis.

Electrostatic melting in a single-molecule field-effect transistor with applications in genomic identification

PubMed Central

Vernick, Sefi; Trocchia, Scott M.; Warren, Steven B.; Young, Erik F.; Bouilly, Delphine; Gonzalez, Ruben L.; Nuckolls, Colin; Shepard, Kenneth L.

2017-01-01

The study of biomolecular interactions at the single-molecule level holds great potential for both basic science and biotechnology applications. Single-molecule studies often rely on fluorescence-based reporting, with signal levels limited by photon emission from single optical reporters. The point-functionalized carbon nanotube transistor, known as the single-molecule field-effect transistor, is a bioelectronics alternative based on intrinsic molecular charge that offers significantly higher signal levels for detection. Such devices are effective for characterizing DNA hybridization kinetics and thermodynamics and enabling emerging applications in genomic identification. In this work, we show that hybridization kinetics can be directly controlled by electrostatic bias applied between the device and the surrounding electrolyte. We perform the first single-molecule experiments demonstrating the use of electrostatics to control molecular binding. Using bias as a proxy for temperature, we demonstrate the feasibility of detecting various concentrations of 20-nt target sequences from the Ebolavirus nucleoprotein gene in a constant-temperature environment. PMID:28516911

Taming the Anxious Mind: An 8-Week Mindfulness Meditation Group at a University Counseling Center

ERIC Educational Resources Information Center

Murphy, Michael C.

2006-01-01

This article describes an eight-week mindfulness meditation-based group that took place at a university counseling center. The group is patterned after the Mindfulness-Based Stress Reduction (MBSR) program developed by Dr. Jon Kabat-Zinn at the Stress Reduction Clinic at the University of Massachusetts Medical Center. Group members are taught…

Alpha Group: The Behemoth Apteryx. Final design proposal

NASA Technical Reports Server (NTRS)

1991-01-01

The participation of the University of Notre Dame's Alpha Design Group in the NASA/Universities Space Research Association (USRA) University Advanced Design Program for the 1990 to 1991 academic year is presented. Alpha Design Group presented a design for an aircraft called The Behemoth Apteryx.

Exploring Ethnic Inequalities in Admission to Russell Group Universities

PubMed Central

Boliver, Vikki

2015-01-01

This article analyses national university applications and admissions data to explore why ethnic minority applicants to Russell Group universities are less likely to receive offers of admission than comparably qualified white applicants. Contrary to received opinion, the greater tendency of ethnic minorities to choose highly numerically competitive degree subjects only partially accounts for their lower offer rates from Russell Group universities relative to white applicants with the same grades and ‘facilitating subjects’ at A-level. Moreover, ethnic inequalities in the chances of receiving an admissions offer from a Russell Group university are found to be greater in relation to courses where ethnic minorities make up a larger percentage of applicants. This latter finding raises the possibility that some admissions selectors at some Russell Group universities may be unfairly rejecting a proportion of their ethnic minority applicants in an attempt to achieve a more ethnically representative student body. PMID:27904229

76 FR 4725 - Hewlett Packard Company Application Services Division Including Workers Whose Unemployment...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-26

... Universal Music Group; Fishers, IN; Amended Certification Regarding Eligibility To Apply for Worker... of Universal Music Group and that some workers separated from employment at the Fishers, Indiana... unemployment insurance (UI) tax account under the name Universal Music Group. Accordingly, the Department is...

Demanding Satisfaction

ERIC Educational Resources Information Center

Oguntoyinbo, Lekan

2010-01-01

It was the kind of crisis most universities dread. In November 2006, a group of minority student leaders at Indiana University-Purdue University Indianapolis (IUPUI) threatened to sue the university if administrators did not heed demands that included providing more funding for multicultural student groups. This article discusses how this threat…

Sealing effectiveness of fissure sealant bonded with universal adhesive systems on saliva-contaminated and noncontaminated enamel

PubMed Central

Shafiei, Fereshteh; Zarean, Mehran; Razmjoei, Faranak

2018-01-01

Background The effectiveness of sealants is dependent upon their adhesion to enamel surface. The aim of the study was to evaluate the sealing ability of a pit and fissure sealant used with a universal adhesive (etch-and-rinse vs. self-etch modes) when the site is contaminated with saliva. Adhesive properties were evaluated as microleakage and scanning electron microscopic (SEM) characteristics. Material and Methods A total of 72 mandibular third molars were randomly divided into 6 groups (n=12). Occlusal pits and fissures were sealed with an unfilled resin fissure sealant (FS) material with or without saliva contamination. The groups included: 1) phosphoric acid etching + FS (control), 2) phosphoric acid etching + Scotchbond Universal (etch-and-rinse) + FS, 3) phosphoric acid etching + saliva + Scotchbond Universal (etch-and-rinse) + FS, 4) Scotchbond Universal (self-etching) + FS,5) Scotchbond Universal (self-etching) + saliva + FS, and 6) Scotchbond Universal (self-etching) + saliva + Scotchbond Universal + FS. After thermocycling, the teeth were placed in 0.5% fuchsin, sectioned, and evaluated by digital microscopy. Two samples from each group were also observed by SEM. The data were analyzed with Kruskal-Wallis and Mann-Whitney tests for a significance of p<0.05. Results There were significant differences among groups. Groups 1,2 and 4 showed the least microleakage, with no significant differences among groups. Saliva contamination led to increased microleakage and gap formation in SEM images in groups 3, 5 and 6. Conclusions The fissure sealing ability of the universal adhesive in etch-and-rinse or self-etch modes was similar to that of conventional acid etching. Saliva contamination had a negative effect on sealant adhesion to pretreated enamel. Key words:Pit and fissure sealant, Universal adhesive, Saliva. PMID:29670708

Sealing effectiveness of fissure sealant bonded with universal adhesive systems on saliva-contaminated and noncontaminated enamel.

PubMed

Memarpour, Mahtab; Shafiei, Fereshteh; Zarean, Mehran; Razmjoei, Faranak

2018-01-01

The effectiveness of sealants is dependent upon their adhesion to enamel surface. The aim of the study was to evaluate the sealing ability of a pit and fissure sealant used with a universal adhesive (etch-and-rinse vs. self-etch modes) when the site is contaminated with saliva. Adhesive properties were evaluated as microleakage and scanning electron microscopic (SEM) characteristics. A total of 72 mandibular third molars were randomly divided into 6 groups (n=12). Occlusal pits and fissures were sealed with an unfilled resin fissure sealant (FS) material with or without saliva contamination. The groups included: 1) phosphoric acid etching + FS (control), 2) phosphoric acid etching + Scotchbond Universal (etch-and-rinse) + FS, 3) phosphoric acid etching + saliva + Scotchbond Universal (etch-and-rinse) + FS, 4) Scotchbond Universal (self-etching) + FS,5) Scotchbond Universal (self-etching) + saliva + FS, and 6) Scotchbond Universal (self-etching) + saliva + Scotchbond Universal + FS. After thermocycling, the teeth were placed in 0.5% fuchsin, sectioned, and evaluated by digital microscopy. Two samples from each group were also observed by SEM. The data were analyzed with Kruskal-Wallis and Mann-Whitney tests for a significance of p <0.05. There were significant differences among groups. Groups 1,2 and 4 showed the least microleakage, with no significant differences among groups. Saliva contamination led to increased microleakage and gap formation in SEM images in groups 3, 5 and 6. The fissure sealing ability of the universal adhesive in etch-and-rinse or self-etch modes was similar to that of conventional acid etching. Saliva contamination had a negative effect on sealant adhesion to pretreated enamel. Key words: Pit and fissure sealant, Universal adhesive, Saliva.

How fair is access to more prestigious UK universities?

PubMed

Boliver, Vikki

2013-06-01

Now that most UK universities have increased their tuition fees to £9,000 a year and are implementing new Access Agreements as required by the Office for Fair Access, it has never been more important to examine the extent of fair access to UK higher education and to more prestigious UK universities in particular. This paper uses Universities and Colleges Admissions Service (UCAS) data for the period 1996 to 2006 to explore the extent of fair access to prestigious Russell Group universities, where 'fair' is taken to mean equal rates of making applications to and receiving offers of admission from these universities on the part of those who are equally qualified to enter them. The empirical findings show that access to Russell Group universities is far from fair in this sense and that little changed following the introduction of tuition fees in 1998 and their initial increase to £3,000 a year in 2006. Throughout this period, UCAS applicants from lower class backgrounds and from state schools remained much less likely to apply to Russell Group universities than their comparably qualified counterparts from higher class backgrounds and private schools, while Russell Group applicants from state schools and from Black and Asian ethnic backgrounds remained much less likely to receive offers of admission from Russell Group universities in comparison with their equivalently qualified peers from private schools and the White ethnic group. © London School of Economics and Political Science 2013.

Impaired theory of mind in first-episode schizophrenia: comparison with community, university and depressed controls.

PubMed

Kettle, Jonathan W L; O'Brien-Simpson, Laurie; Allen, Nicholas B

2008-02-01

First order theory of mind, as measured by the 'Reading the Mind in the Eyes Test' Revised, is impaired in schizophrenia. However, no study has investigated whether this occurs in first-episode schizophrenia. Also, it is unclear whether such a deficit is specific to schizophrenia, and whether convenience control samples, particularly undergraduate university students, represent valid comparison groups. This study investigated theory of mind ability, measured by the 'Reading the Mind in the Eyes Test' Revised, in a group of first-episode schizophrenia outpatients (n=13) and three control groups: outpatients with non-psychotic major depression (n=14), individuals from the general community (n=16) and from an undergraduate university course (n=27). The schizophrenia group exhibited significant theory of mind impairments compared to both non-psychiatric control groups but not the depression group. Unexpectedly, the depression group was not significantly impaired compared to the community control group, and the university control group exhibited superior theory of mind ability relative to all three groups. The findings indicate theory of mind deficits in first episode schizophrenia and support the implementation of theory of mind interventions in first-episode schizophrenia treatment programs. Results also indicate that community rather than university control groups represent more valid comparison groups in first-episode schizophrenia research.

The Inherent Dynamics of the Group University.

ERIC Educational Resources Information Center

Kaltefleiter, Werner

1979-01-01

The reorganization of the German universities between the end of the 1960s and the early 1970s into "Group Universities" is discussed. It is suggested that this new organizational system, modeled along the lines of a corporate state, has destroyed the communication system of the university and introduced discontinuity into the academic…

The Effect of Visual of a Courseware towards Pre-University Students' Learning in Literature

NASA Astrophysics Data System (ADS)

Masri, Mazyrah; Wan Ahmad, Wan Fatimah; Nordin, Shahrina Md.; Sulaiman, Suziah

This paper highlights the effect of visual of a multimedia courseware, Black Cat Courseware (BC-C), developed for learning literature at a pre-university level in University Teknologi PETRONAS (UTP). The contents of the courseware are based on a Black Cat story which is covered in an English course at the university. The objective of this paper is to evaluate the usability and effectiveness of BC-C. A total of sixty foundation students were involved in the study. Quasi-experimental design was employed, forming two groups: experimental and control groups. The experimental group had to interact with BC-C as part of the learning activities while the control group used the conventional learning methods. The results indicate that the experimental group achieved a statistically significant compared to the control group in understanding the Black Cat story. The study result also proves that the effect of visual increases the students' performances in literature learning at a pre-university level.

Assessment of Groups Influence on Management Style as Related to University Governance

ERIC Educational Resources Information Center

Irtwange, S. V.; Orsaah, S.

2010-01-01

The study was undertaken with the objective of assessing groups influence on management style as related to University governance with University of Agriculture, Makurdi as a case study from academic staff perspective. The management style of the Vice Chancellor of the University of Agriculture, Makurdi between the period September 3, 1996 to…

The Economic Impact of Mississippi Valley State University on the Local Economy, 1992-93.

ERIC Educational Resources Information Center

Buchanan, Debra; And Others

This study used an American Council on Education model to determine the economic impact of Mississippi Valley State University (MVSU) on the local economy. Data were gathered from university fiscal records and questionnaires disseminated among three university constituent groups: faculty and staff, students, and alumni. Each group was asked to…

Surface chemistry at Swiss Universities of Applied Sciences.

PubMed

Brodard, Pierre; Pfeifer, Marc E; Adlhart, Christian D; Pieles, Uwe; Shahgaldian, Patrick

2014-01-01

In the Swiss Universities of Applied Sciences, a number of research groups are involved in surface science, with different methodological approaches and a broad range of sophisticated characterization techniques. A snapshot of the current research going on in different groups from the University of Applied Sciences and Arts Western Switzerland (HES-SO), the Zurich University of Applied Sciences (ZHAW) and the University of Applied Sciences and Arts Northwestern Switzerland (FHNW) is given.

SDSS-III

Science.gov Websites

Mexico. SDSS-III consists of four surveys, each focused on a different scientific theme. Click on one of Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German

Honors

NASA Astrophysics Data System (ADS)

2011-10-01

More than a dozen AGU members are among 94 researchers announced by U.S. president Barack Obama on 26 September as recipients of the Presidential Early Career Award for Scientists and Engineers. The award, which is coordinated by the Office of Science and Technology Policy within the Executive Office of the President, is considered the highest honor bestowed by the U.S. government on science and engineering professionals in the early stages of their independent research careers. This year's recipients include Jeffrey Book, Naval Research Laboratory; Jonathan Cirtain, NASA Marshall Space Flight Center; Fotini Katopodes Chow, University of California, Berkeley; Elizabeth Cochran, U.S. Geological Survey (USGS); Ian Howat, Ohio State University; Christiane Jablonowski, University of Michigan; Justin Kasper, Smithsonian Astrophysical Observatory; Elena Litchman, Michigan State University; James A. Morris Jr., National Oceanic and Atmospheric Administration (NOAA); Erin M. Oleson, NOAA; Victoria Orphan, California Institute of Technology; Sasha Reed, USGS; David Shelly, USGS; and Feng Wang, University of California, Berkeley. Five AGU members are among 10 U.S. representatives recently selected for International Arctic Science Committee working groups. The AGU members, chosen as representatives through the U.S. National Academies review process, are Atmosphere Working Group member James Overland, Pacific Marine Environmental Laboratory, NOAA; Cryosphere Working Group members Walter Meier, University of Colorado at Boulder, and Elizabeth Hunke, Los Alamos National Laboratory; Marine Working Group member Mary-Louise Timmermans, Yale University; and Terrestrial Working Group member Vanessa Lougheed, University of Texas at El Paso.

General university requirements and holistic development in university students in Hong Kong.

PubMed

Shek, Daniel T L; Yu, Lu

2017-02-01

The General University Requirements (GUR) at The Hong Kong Polytechnic University (PolyU) is an integral part of the new 4-year undergraduate curriculum which attempts to promote holistic student development. To evaluate the effectiveness of the GUR, a study adopting a static group comparison design was conducted, with a sample of Year 3 PolyU students studied in the 4-year undergraduate degree program (n=566) compared with a control Year 3 sample recruited from a comparable university in Hong Kong (n=285). The students in both samples responded to measures on empathy, positive youth development, and engagement in university study. Results showed that although both groups basically did not differ in the major background demographic variables, PolyU students performed better than did the students of the control group on measures of holistic development. Bearing in mind the intrinsic problems of the static comparison group design, the present findings provide support for the effectiveness of the GUR at PolyU.

Effects of yogic exercise on nonspecific neck pain in university students.

PubMed

Kim, Sang Dol

2018-05-01

To assess the effects of yogic exercise on nonspecific neck pain in university students. This study is a pretest-posttest design with a non-equivalent control group. Thirty-eight university students were selected by convenience sampling, with 18 assigned to an exercise group and 20 assigned to a control group. The yoga group participated in one-hour sessions of yogic exercise two days a week for eight weeks. The exercise comprised eight stages: relaxation, flexion of neck, extension of neck, right lateral flexion of neck, left lateral flexion of neck, right rotation of neck, left rotation of neck, and relaxation. Neck pain intensity was measured using a 100 mm visual analogue scale. The yoga group showed significantly decreased neck pain scores compared with those of the control group. These findings indicate that yogic exercises could reduce neck pain in university students. Copyright © 2017 Elsevier Ltd. All rights reserved.

Marathon Group Therapy: Potential for University Counseling Centers and Beyond

ERIC Educational Resources Information Center

Stanger, Thomas; Harris, Rafael S., Jr.

2005-01-01

A descriptive analysis of marathon group therapy was conducted, specifying issues of set-up, screening, preparation, start-up, introduction to group process, facilitating therapeutic moments throughout the weekend, termination, and follow-up. Factors and dynamics unique to this modality are outlined for marathon groups in university counseling…

Mechanisms of transport and electron transfer at conductive polymer/liquid interfaces

NASA Astrophysics Data System (ADS)

Ratcliff, Erin

Organic semiconductors (OSCs) have incredible prospects for next-generation, flexible electronic devices including bioelectronics, thermoelectrics, opto-electronics, and energy storage and conversion devices. Yet many fundamental challenges still exist. First, solution processing prohibits definitive control over microstructure, which is fundamental for controlling electrical, ionic, and thermal transport properties. Second, OSCs generally suffer from poor electrical conductivities due to a combination of low carriers and low mobility. Third, polymeric semiconductors have potential-dependent, dynamically evolving electronic and chemical states, leading to complex interfacial charge transfer properties in contact with liquids. This talk will focus on the use of alternative synthetic strategies of oxidative chemical vapor deposition and electrochemical deposition to control physical, electronic, and chemical structure. We couple our synthetic efforts with energy-, time-, and spatially resolved spectroelectrochemical and microscopy techniques to understand the critical interfacial chemistry-microstructure-property relationships: first at the macroscale, and then moving towards the nanoscale. In particular, approaches to better understand electron transfer events at polymer/liquid interfaces as a function of: 1.) chemical composition; 2.) electronic density of states (DOS); and 3.) crystallinity and microstructure will be discussed.

Human eye-inspired soft optoelectronic device using high-density MoS2-graphene curved image sensor array.

PubMed

Choi, Changsoon; Choi, Moon Kee; Liu, Siyi; Kim, Min Sung; Park, Ok Kyu; Im, Changkyun; Kim, Jaemin; Qin, Xiaoliang; Lee, Gil Ju; Cho, Kyoung Won; Kim, Myungbin; Joh, Eehyung; Lee, Jongha; Son, Donghee; Kwon, Seung-Hae; Jeon, Noo Li; Song, Young Min; Lu, Nanshu; Kim, Dae-Hyeong

2017-11-21

Soft bioelectronic devices provide new opportunities for next-generation implantable devices owing to their soft mechanical nature that leads to minimal tissue damages and immune responses. However, a soft form of the implantable optoelectronic device for optical sensing and retinal stimulation has not been developed yet because of the bulkiness and rigidity of conventional imaging modules and their composing materials. Here, we describe a high-density and hemispherically curved image sensor array that leverages the atomically thin MoS 2 -graphene heterostructure and strain-releasing device designs. The hemispherically curved image sensor array exhibits infrared blindness and successfully acquires pixelated optical signals. We corroborate the validity of the proposed soft materials and ultrathin device designs through theoretical modeling and finite element analysis. Then, we propose the ultrathin hemispherically curved image sensor array as a promising imaging element in the soft retinal implant. The CurvIS array is applied as a human eye-inspired soft implantable optoelectronic device that can detect optical signals and apply programmed electrical stimulation to optic nerves with minimum mechanical side effects to the retina.

Investigation of surface topography and stiffness on adhesion and neurites extension of PC12 cells on crosslinked silica aerogel substrates

PubMed Central

Lynch, Kyle J.; Skalli, Omar

2017-01-01

Fundamental understanding and characterization of neural response to substrate topography is essential in the development of next generation biomaterials for nerve repair. Aerogels are a new class of materials with great potential as a biomaterial. In this work, we examine the extension of neurites by PC12 cells plated on matrigel-coated and collagen-coated mesoporous aerogel surfaces. We have successfully established the methodology for adhesion and growth of PC12 cells on polyurea crosslinked silica aerogels. Additionally, we have quantified neurite behaviors and compared their response on aerogel substrates with their behavior on tissue culture (TC) plastic, and polydimethylsiloxane (PDMS). We found that, on average, PC12 cells extend longer neurites on crosslinked silica aerogels than on tissue culture plastic, and, that the average number of neurites per cluster is lower on aerogels than on tissue culture plastic. Aerogels are an attractive candidate for future development of smart neural implants and the work presented here creates a platform for future work with this class of materials as a substrate for bioelectronic interfacing. PMID:29049304

Photo-switchable microbial fuel-cells.

PubMed

Schlesinger, Orr; Dandela, Rambabu; Bhagat, Ashok; Adepu, Raju; Meijler, Michael M; Xia, Lin; Alfonta, Lital

2018-05-01

Regulation of Bio-systems in a clean, simple, and efficient way is important for the design of smart bio-interfaces and bioelectronic devices. Light as a non-invasive mean to control the activity of a protein enables spatial and temporal control far superior to other chemical and physical methods. The ability to regulate the activity of a catalytic enzyme in a biofuel-cell reduces the waste of resources and energy and turns the fuel-cell into a smart and more efficient device for power generation. Here we present a microbial-fuel-cell based on a surface displayed, photo-switchable alcohol dehydrogenase. The enzyme was modified near the active site using non-canonical amino acids and a small photo-reactive molecule, which enables reversible control of enzymatic activity. Depending on the modification site, the enzyme exhibits reversible behavior upon irradiation with UV and visible light, in both biochemical, and electrochemical assays. The change observed in power output of a microbial fuel cell utilizing the modified enzyme was almost five-fold, between inactive and active states. © 2018 Wiley Periodicals, Inc.

Hybrid hydrogels containing vertically aligned carbon nanotubes with anisotropic electrical conductivity for muscle myofiber fabrication.

PubMed

Ahadian, Samad; Ramón-Azcón, Javier; Estili, Mehdi; Liang, Xiaobin; Ostrovidov, Serge; Shiku, Hitoshi; Ramalingam, Murugan; Nakajima, Ken; Sakka, Yoshio; Bae, Hojae; Matsue, Tomokazu; Khademhosseini, Ali

2014-03-19

Biological scaffolds with tunable electrical and mechanical properties are of great interest in many different fields, such as regenerative medicine, biorobotics, and biosensing. In this study, dielectrophoresis (DEP) was used to vertically align carbon nanotubes (CNTs) within methacrylated gelatin (GelMA) hydrogels in a robust, simple, and rapid manner. GelMA-aligned CNT hydrogels showed anisotropic electrical conductivity and superior mechanical properties compared with pristine GelMA hydrogels and GelMA hydrogels containing randomly distributed CNTs. Skeletal muscle cells grown on vertically aligned CNTs in GelMA hydrogels yielded a higher number of functional myofibers than cells that were cultured on hydrogels with randomly distributed CNTs and horizontally aligned CNTs, as confirmed by the expression of myogenic genes and proteins. In addition, the myogenic gene and protein expression increased more profoundly after applying electrical stimulation along the direction of the aligned CNTs due to the anisotropic conductivity of the hybrid GelMA-vertically aligned CNT hydrogels. We believe that platform could attract great attention in other biomedical applications, such as biosensing, bioelectronics, and creating functional biomedical devices.

Hybrid hydrogels containing vertically aligned carbon nanotubes with anisotropic electrical conductivity for muscle myofiber fabrication

PubMed Central

Ahadian, Samad; Ramón-Azcón, Javier; Estili, Mehdi; Liang, Xiaobin; Ostrovidov, Serge; Shiku, Hitoshi; Ramalingam, Murugan; Nakajima, Ken; Sakka, Yoshio; Bae, Hojae; Matsue, Tomokazu; Khademhosseini, Ali

2014-01-01

Biological scaffolds with tunable electrical and mechanical properties are of great interest in many different fields, such as regenerative medicine, biorobotics, and biosensing. In this study, dielectrophoresis (DEP) was used to vertically align carbon nanotubes (CNTs) within methacrylated gelatin (GelMA) hydrogels in a robust, simple, and rapid manner. GelMA-aligned CNT hydrogels showed anisotropic electrical conductivity and superior mechanical properties compared with pristine GelMA hydrogels and GelMA hydrogels containing randomly distributed CNTs. Skeletal muscle cells grown on vertically aligned CNTs in GelMA hydrogels yielded a higher number of functional myofibers than cells that were cultured on hydrogels with randomly distributed CNTs and horizontally aligned CNTs, as confirmed by the expression of myogenic genes and proteins. In addition, the myogenic gene and protein expression increased more profoundly after applying electrical stimulation along the direction of the aligned CNTs due to the anisotropic conductivity of the hybrid GelMA-vertically aligned CNT hydrogels. We believe that platform could attract great attention in other biomedical applications, such as biosensing, bioelectronics, and creating functional biomedical devices. PMID:24642903

Melanins and melanogenesis: from pigment cells to human health and technological applications.

PubMed

d'Ischia, Marco; Wakamatsu, Kazumasa; Cicoira, Fabio; Di Mauro, Eduardo; Garcia-Borron, Josè Carlos; Commo, Stephane; Galván, Ismael; Ghanem, Ghanem; Kenzo, Koike; Meredith, Paul; Pezzella, Alessandro; Santato, Clara; Sarna, Tadeusz; Simon, John D; Zecca, Luigi; Zucca, Fabio A; Napolitano, Alessandra; Ito, Shosuke

2015-09-01

During the past decade, melanins and melanogenesis have attracted growing interest for a broad range of biomedical and technological applications. The burst of polydopamine-based multifunctional coatings in materials science is just one example, and the list may be expanded to include melanin thin films for organic electronics and bioelectronics, drug delivery systems, functional nanoparticles and biointerfaces, sunscreens, environmental remediation devices. Despite considerable advances, applied research on melanins and melanogenesis is still far from being mature. A closer intersectoral interaction between research centers is essential to raise the interests and increase the awareness of the biomedical, biomaterials science and hi-tech sectors of the manifold opportunities offered by pigment cells and related metabolic pathways. Starting from a survey of biological roles and functions, the present review aims at providing an interdisciplinary perspective of melanin pigments and related pathway with a view to showing how it is possible to translate current knowledge about physical and chemical properties and control mechanisms into new bioinspired solutions for biomedical, dermocosmetic, and technological applications. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

PEMFs: new post-surgical management in dentristry

NASA Astrophysics Data System (ADS)

Tonetti, Luca

2014-01-01

Aim of study: the possible effects on dental postsurgical management using small and not invasive devices: RecoveryRx or ActiPatch producted by Bioelectronics company (USA) Materials and methods: review of literature using searching engines Keywords: PEMFs, postsurgical treatment, pain, wound healing, RecoveryRx, ActiPatch Results: Pulsed Electro Magnetic Fields have been used extensively for decades for many conditions and medical disciplines. Imperceptible cell dysfunction that is not corrected early can lead to disease. Fine-tuning can be done daily in only minutes, using pulsed electromagnetic fields (PEMFs). In addition, when there is a known imbalance (when symptoms are present) or there is a known disease or condition, PEMF treatments, used either alone or along with other therapies, can often help cells rebalance dysfunction faster. It is seen in literature that RecoveryRX and ActiPatch improve the cell metabolism, rebalance the membrane potential difference, improve the circulation and the oxigenation of the tissues, acceleration of osteogenesis, acceleration repair of soft tissues, reduce pain. Conclusion: the RecoveryRX and ActiPatch devices could improve the postsurgical healing reducing the patient discomfort.

Electrochemical corrosion, wear and cell behavior of ZrO2/TiO2 alloyed layer on Ti-6Al-4V.

PubMed

Li, Jianfang; He, Xiaojing; Zhang, Guannan; Hang, Ruiqiang; Huang, Xiaobo; Tang, Bin; Zhang, Xiangyu

2018-06-01

Ti-6Al-4V (TC4) has received increasing attention as biomaterial but also raised concerns about the long-term safety of releasing of metal ions and poor wear resistance. In this work, an ZrO 2 /TiO 2 alloyed layer was prepared on TC4 by plasma surface alloying with Zr and subsequently annealed in the air for improved corrosion and wear resistant. To assess the corrosion performance of the alloyed layer, the specimens were measured by open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization in simulated body fluid solution. The result shows that the ZrO 2 /TiO 2 alloyed layer exhibits strikingly high polarization resistance, wide passive region and very low current density, indicating the excellent corrosion resistance. The layer also displays significant improvement of wear resistance. Furthermore, the alloyed layer restricts cell adhesion and spreading. We infer that the ZrO 2 /TiO 2 alloyed layer might be potentially useful implanted devices such as biosensors, bioelectronics or drug delivery devices. Copyright © 2018 Elsevier B.V. All rights reserved.

Stimuli-enabled zipper-like graphene interface for auto-switchable bioelectronics.

PubMed

Mishra, Sachin; Ashaduzzaman, Md; Mishra, Prashant; Swart, Hendrik C; Turner, Anthony P F; Tiwari, Ashutosh

2017-03-15

Graphene interfaces with multi-stimuli responsiveness are of particular interest due to their diverse super-thin interfacial behaviour, which could be well suited to operating complex physiological systems in a single miniaturised domain. In general, smart graphene interfaces switch bioelectrodes from the hydrophobic to hydrophilic state, or vice versa, upon triggering. In the present work, a stimuli encoded zipper-like graphene oxide (GrO)/polymer interface was fabricated with in situ poly(N-isopropylacrylamide-co-diethylaminoethylmethylacrylate), i.e., poly(NIPAAm-co-DEAEMA) directed hierarchical self-assembly of GrO and glucose oxidase (GOx). The designed interface exhibited reversible on/off-switching of bio-electrocatalysis on changing the pH between 5 and 8, via phase transition from super hydrophilic to hydrophobic. The study further indicated that the zipper-like interfacial bioelectrochemical properties could be tuned over a modest change of temperature (i.e., 20-40°C). The resulting auto-switchable interface has implications for the design of novel on/off-switchable biodevices with 'in-built' self-control. Copyright © 2016 Elsevier B.V. All rights reserved.

Programmable Hydrogel Ionic Circuits for Biologically Matched Electronic Interfaces.

PubMed

Zhao, Siwei; Tseng, Peter; Grasman, Jonathan; Wang, Yu; Li, Wenyi; Napier, Bradley; Yavuz, Burcin; Chen, Ying; Howell, Laurel; Rincon, Javier; Omenetto, Fiorenzo G; Kaplan, David L

2018-06-01

The increased need for wearable and implantable medical devices has driven the demand for electronics that interface with living systems. Current bioelectronic systems have not fully resolved mismatches between engineered circuits and biological systems, including the resulting pain and damage to biological tissues. Here, salt/poly(ethylene glycol) (PEG) aqueous two-phase systems are utilized to generate programmable hydrogel ionic circuits. High-conductivity salt-solution patterns are stably encapsulated within PEG hydrogel matrices using salt/PEG phase separation, which route ionic current with high resolution and enable localized delivery of electrical stimulation. This strategy allows designer electronics that match biological systems, including transparency, stretchability, complete aqueous-based connective interface, distribution of ionic electrical signals between engineered and biological systems, and avoidance of tissue damage from electrical stimulation. The potential of such systems is demonstrated by generating light-emitting diode (LED)-based displays, skin-mounted electronics, and stimulators that deliver localized current to in vitro neuron cultures and muscles in vivo with reduced adverse effects. Such electronic platforms may form the basis of future biointegrated electronic systems. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomolecule-embedded metal-organic frameworks as an innovative sensing platform.

PubMed

Kempahanumakkagari, Sureshkumar; Kumar, Vanish; Samaddar, Pallabi; Kumar, Pawan; Ramakrishnappa, Thippeswamy; Kim, Ki-Hyun

Technological advancements combined with materials research have led to the generation of enormous types of novel substrates and materials for use in various biological/medical, energy, and environmental applications. Lately, the embedding of biomolecules in novel and/or advanced materials (e.g., metal-organic frameworks (MOFs), nanoparticles, hydrogels, graphene, and their hybrid composites) has become a vital research area in the construction of an innovative platform for various applications including sensors (or biosensors), biofuel cells, and bioelectronic devices. Due to the intriguing properties of MOFs (e.g., framework architecture, topology, and optical properties), they have contributed considerably to recent progresses in enzymatic catalysis, antibody-antigen interactions, or many other related approaches. Here, we aim to describe the different strategies for the design and synthesis of diverse biomolecule-embedded MOFs for various sensing (e.g., optical, electrochemical, biological, and miscellaneous) techniques. Additionally, the benefits and future prospective of MOFs-based biomolecular immobilization as an innovative sensing platform are discussed along with the evaluation on their performance to seek for further development in this emerging research area. Copyright © 2018. Published by Elsevier Inc.

Wood mimetic hydrogel beads for enzyme immobilization.

PubMed

Park, Saerom; Kim, Sung Hee; Won, Keehoon; Choi, Joon Weon; Kim, Yong Hwan; Kim, Hyung Joo; Yang, Yung-Hun; Lee, Sang Hyun

2015-01-22

Wood component-based composite hydrogels have potential applications in biomedical fields owing to their low cost, biodegradability, and biocompatibility. The controllable properties of wood mimetic composites containing three major wood components are useful for enzyme immobilization. Here, lipase from Candida rugosa was entrapped in wood mimetic beads containing cellulose, xylan, and lignin by dissolving wood components with lipase in [Emim][Ac], followed by reconstitution. Lipase entrapped in cellulose/xylan/lignin beads in a 5:3:2 ratio showed the highest activity; this ratio is very similar to that in natural wood. The lipase entrapped in various wood mimetic beads showed increased thermal and pH stability. The half-life times of lipase entrapped in cellulose/alkali lignin hydrogel were 31- and 82-times higher than those of free lipase during incubation under denaturing conditions of high temperature and low pH, respectively. Owing to their biocompatibility, biodegradability, and controllable properties, wood mimetic hydrogel beads can be used to immobilize various enzymes for applications in the biomedical, bioelectronic, and biocatalytic fields. Copyright © 2014 Elsevier Ltd. All rights reserved.

Charge transport and intrinsic fluorescence in amyloid-like fibrils

PubMed Central

del Mercato, Loretta Laureana; Pompa, Pier Paolo; Maruccio, Giuseppe; Torre, Antonio Della; Sabella, Stefania; Tamburro, Antonio Mario; Cingolani, Roberto; Rinaldi, Ross

2007-01-01

The self-assembly of polypeptides into stable, conductive, and intrinsically fluorescent biomolecular nanowires is reported. We have studied the morphology and electrical conduction of fibrils made of an elastin-related polypeptide, poly(ValGlyGlyLeuGly). These amyloid-like nanofibrils, with a diameter ranging from 20 to 250 nm, result from self-assembly in aqueous solution at neutral pH. Their morphological properties and conductivity have been investigated by atomic force microscopy, scanning tunneling microscopy, and two-terminal transport experiments at the micro- and nanoscales. We demonstrate that the nanofibrils can sustain significant electrical conduction in the solid state at ambient conditions and have remarkable stability. We also show intrinsic blue-green fluorescence of the nanofibrils by confocal microscopy analyses. These results indicate that direct (label-free) excitation can be used to investigate the aggregation state or the polymorphism of amyloid-like fibrils (and possibly of other proteinaceous material) and open up interesting perspectives for the use of peptide-based nanowire structures, with tunable physical and chemical properties, for a wide range of nanobiotechnological and bioelectronic applications. PMID:17984067

Structural control of mixed ionic and electronic transport in conducting polymers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivnay, Jonathan; Inal, Sahika; Collins, Brian A.

Poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate), PEDOT:PSS, has been utilized for over two decades as a stable, solution-processable hole conductor. While its hole transport properties have been the subject of intense investigation, recent work has turned to PEDOT:PSS as a mixed ionic/electronic conductor in applications including bioelectronics, energy storage and management, and soft robotics. Conducting polymers can efficiently transport both holes and ions when sufficiently hydrated, however, little is known about the role of morphology on mixed conduction. Here, we show that bulk ionic and electronic mobilities are simultaneously affected by processing-induced changes in nano- and meso-scale structure in PEDOT:PSS films. Wemore » quantify domain composition, and find that domain purification on addition of dispersion co-solvents limits ion mobility, even while electronic conductivity improves. We show that an optimal morphology allows for the balanced ionic and electronic transport that is critical for prototypical mixed conductor devices. As a result, these findings may pave the way for the rational design of polymeric materials and processing routes to enhance devices reliant on mixed conduction.« less

Neuro-immune interactions in inflammation and host defense: Implications for transplantation.

PubMed

Chavan, Sangeeta S; Ma, Pingchuan; Chiu, Isaac M

2018-03-01

Sensory and autonomic neurons of the peripheral nervous system (PNS) play a critical role in regulating the immune system during tissue inflammation and host defense. Recent studies have identified the molecular mechanisms underlying the bidirectional communication between the nervous system and the immune system. Here, we highlight the studies that demonstrate the importance of the neuro-immune interactions in health and disease. Nociceptor sensory neurons detect immune mediators to produce pain, and release neuropeptides that act on the immune system to regulate inflammation. In parallel, neural reflex circuits including the vagus nerve-based inflammatory reflex are physiological regulators of inflammatory responses and cytokine production. In transplantation, neuro-immune communication could significantly impact the processes of host-pathogen defense, organ rejection, and wound healing. Emerging approaches to target the PNS such as bioelectronics could be useful in improving the outcome of transplantation. Therefore, understanding how the nervous system shapes the immune response could have important therapeutic ramifications for transplantation medicine. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

Hybrid hydrogels containing vertically aligned carbon nanotubes with anisotropic electrical conductivity for muscle myofiber fabrication

NASA Astrophysics Data System (ADS)

Ahadian, Samad; Ramón-Azcón, Javier; Estili, Mehdi; Liang, Xiaobin; Ostrovidov, Serge; Shiku, Hitoshi; Ramalingam, Murugan; Nakajima, Ken; Sakka, Yoshio; Bae, Hojae; Matsue, Tomokazu; Khademhosseini, Ali

2014-03-01

Biological scaffolds with tunable electrical and mechanical properties are of great interest in many different fields, such as regenerative medicine, biorobotics, and biosensing. In this study, dielectrophoresis (DEP) was used to vertically align carbon nanotubes (CNTs) within methacrylated gelatin (GelMA) hydrogels in a robust, simple, and rapid manner. GelMA-aligned CNT hydrogels showed anisotropic electrical conductivity and superior mechanical properties compared with pristine GelMA hydrogels and GelMA hydrogels containing randomly distributed CNTs. Skeletal muscle cells grown on vertically aligned CNTs in GelMA hydrogels yielded a higher number of functional myofibers than cells that were cultured on hydrogels with randomly distributed CNTs and horizontally aligned CNTs, as confirmed by the expression of myogenic genes and proteins. In addition, the myogenic gene and protein expression increased more profoundly after applying electrical stimulation along the direction of the aligned CNTs due to the anisotropic conductivity of the hybrid GelMA-vertically aligned CNT hydrogels. We believe that platform could attract great attention in other biomedical applications, such as biosensing, bioelectronics, and creating functional biomedical devices.

Influence of non-adherent yeast cells on electrical characteristics of diamond-based field-effect transistors

NASA Astrophysics Data System (ADS)

Procházka, Václav; Cifra, Michal; Kulha, Pavel; Ižák, Tibor; Rezek, Bohuslav; Kromka, Alexander

2017-02-01

Diamond thin films provide unique features as substrates for cell cultures and as bio-electronic sensors. Here we employ solution-gated field effect transistors (SGFET) based on nanocrystalline diamond thin films with H-terminated surface which exhibits the sub-surface p-type conductive channel. We study an influence of yeast cells (Saccharomyces cerevisiae) on electrical characteristics of the diamond SGFETs. Two different cell culture solutions (sucrose and yeast peptone dextrose-YPD) are used, with and without the cells. We have found that transfer characteristics of the SGFETs exhibit a negative shift of the gate voltage by -26 mV and -42 mV for sucrose and YPD with cells in comparison to blank solutions without the cells. This effect is attributed to a local pH change in close vicinity of the H-terminated diamond surface due to metabolic processes of the yeast cells. The pH sensitivity of the diamond-based SGFETs, the role of cell and protein adhesion on the gate surface and the role of negative surface charge of yeast cells on the SGFETs electrical characteristics are discussed as well.

RETRACTED: A fluorescent molecularly-imprinted polymer gate with temperature and pH as inputs for detection of alpha-fetoprotein.

PubMed

Karfa, Paramita; Roy, Ekta; Patra, Santanu; Kumar, Deepak; Madhuri, Rashmi; Sharma, Prashant K

2016-04-15

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor following concerns raised by a reader. The article reuses an electron micrograph from a previous publication while claiming that these are different particles. Fig. 1C/D were reused from Fig. 2B published in Biosensors and Bioelectronics, Volume 73, 15 November 2015, Pages 234–244, https://doi.org/10.1016/j.bios.2015.06.005. This problem with the data presented casts doubt on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. Copyright © 2015 Elsevier B.V. All rights reserved.

Photochemical and Thermal Stability of Green and Blue Proteorhodopsins: Implications for Protein-Based Bioelectronic Devices

PubMed Central

Ranaghan, Matthew J.; Shima, Sumie; Ramos, Lavosier; Poulin, Daniel S.; Whited, Gregg; Rajasekaran, Sanguthevar; Stuart, Jeffery A.; Albert, Arlene D.; Birge, Robert R.

2010-01-01

The photochemical and thermal stability of the detergent solubilized blue- and green-absorbing proteorhodpsins, BPR and GPR respectively, are investigated to determine viability of these proteins for photonic device applications. Photochemical stability is studied by using pulsed laser excitation and differential uv-vis spectroscopy to assign the photocyclicity. GPR, with a cyclicity of 7×104 photocycles protein−1, is 4–5 times more stable than BPR (9×103 photocycles protein−1), but is less stable than native bacteriorhodopsin (9×105 photocycles protein−1) or the 4-keto-bacteriorhodopsin analog (1×105 photocycles protein−1). The thermal stabilities are assigned by using differential scanning calorimetry and thermal bleaching experiments. Both proteorhodopsins display excellent thermal stability, with melting temperatures above 85°C, and remain photochemically stable up to 75°C. The biological relevance of our results is also discussed. The lower cyclicity of BPR is found to be adequate for the long-term biological function of the host organism at ocean depths of 50 m or more. PMID:20964279

High-performance, polymer-based direct cellular interfaces for electrical stimulation and recording

NASA Astrophysics Data System (ADS)

Kim, Seong-Min; Kim, Nara; Kim, Youngseok; Baik, Min-Seo; Yoo, Minsu; Kim, Dongyoon; Lee, Won-June; Kang, Dong-Hee; Kim, Sohee; Lee, Kwanghee; Yoon, Myung-Han

2018-04-01

Due to the trade-off between their electrical/electrochemical performance and underwater stability, realizing polymer-based, high-performance direct cellular interfaces for electrical stimulation and recording has been very challenging. Herein, we developed transparent and conductive direct cellular interfaces based on a water-stable, high-performance poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) film via solvent-assisted crystallization. The crystallized PEDOT:PSS on a polyethylene terephthalate (PET) substrate exhibited excellent electrical/electrochemical/optical characteristics, long-term underwater stability without film dissolution/delamination, and good viability for primarily cultured cardiomyocytes and neurons over several weeks. Furthermore, the highly crystallized, nanofibrillar PEDOT:PSS networks enabled dramatically enlarged surface areas and electrochemical activities, which were successfully employed to modulate cardiomyocyte beating via direct electrical stimulation. Finally, the high-performance PEDOT:PSS layer was seamlessly incorporated into transparent microelectrode arrays for efficient, real-time recording of cardiomyocyte action potentials with a high signal fidelity. All these results demonstrate the strong potential of crystallized PEDOT:PSS as a crucial component for a variety of versatile bioelectronic interfaces.

Flexible and stretchable electronics for wearable healthcare devices and minimally invasive surgical tools

NASA Astrophysics Data System (ADS)

Kim, Dae-Hyeong; Lee, Mincheol; Lee, Hyunjae

2016-05-01

Recent advances in soft electronics have attracted great attention, largely due to their potential applications in personalized, bio-integrated healthcare devices. The mechanical mismatch between conventional electronic/optoelectronic devices and soft human tissues/organs have presented many challenges, such as the low signalto- noise ratio of biosensors because of the incomplete integration of rigid devices with the body, inflammation and excessive immune responses of implanted stiff devices originated from friction and their foreign nature to biotic systems, and the considerable discomfort and consequent stress experienced by users when wearing/implanting these devices. Ultra-flexible and stretchable electronic devices are being highlighted due to their low system modulus and the intrinsic system-level softness that are important to solve these issues. Here, we describe our unique strategies for the nanomaterial synthesis and fabrication, their seamless assembly and integration, and the design and development of corresponding wearable healthcare devices and minimally invasive surgical tools. These bioelectronic systems fully utilize recent breakthroughs in unconventional soft electronics based on nanomaterials to address unsolved issues in clinical medicine and to provide new opportunities in the personalized healthcare.

Tunneling explains efficient electron transport via protein junctions.

PubMed

Fereiro, Jerry A; Yu, Xi; Pecht, Israel; Sheves, Mordechai; Cuevas, Juan Carlos; Cahen, David

2018-05-15

Metalloproteins, proteins containing a transition metal ion cofactor, are electron transfer agents that perform key functions in cells. Inspired by this fact, electron transport across these proteins has been widely studied in solid-state settings, triggering the interest in examining potential use of proteins as building blocks in bioelectronic devices. Here, we report results of low-temperature (10 K) electron transport measurements via monolayer junctions based on the blue copper protein azurin (Az), which strongly suggest quantum tunneling of electrons as the dominant charge transport mechanism. Specifically, we show that, weakening the protein-electrode coupling by introducing a spacer, one can switch the electron transport from off-resonant to resonant tunneling. This is a consequence of reducing the electrode's perturbation of the Cu(II)-localized electronic state, a pattern that has not been observed before in protein-based junctions. Moreover, we identify vibronic features of the Cu(II) coordination sphere in transport characteristics that show directly the active role of the metal ion in resonance tunneling. Our results illustrate how quantum mechanical effects may dominate electron transport via protein-based junctions.

Structural control of mixed ionic and electronic transport in conducting polymers

DOE PAGES

Rivnay, Jonathan; Inal, Sahika; Collins, Brian A.; ...

2016-04-19

Poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate), PEDOT:PSS, has been utilized for over two decades as a stable, solution-processable hole conductor. While its hole transport properties have been the subject of intense investigation, recent work has turned to PEDOT:PSS as a mixed ionic/electronic conductor in applications including bioelectronics, energy storage and management, and soft robotics. Conducting polymers can efficiently transport both holes and ions when sufficiently hydrated, however, little is known about the role of morphology on mixed conduction. Here, we show that bulk ionic and electronic mobilities are simultaneously affected by processing-induced changes in nano- and meso-scale structure in PEDOT:PSS films. Wemore » quantify domain composition, and find that domain purification on addition of dispersion co-solvents limits ion mobility, even while electronic conductivity improves. We show that an optimal morphology allows for the balanced ionic and electronic transport that is critical for prototypical mixed conductor devices. As a result, these findings may pave the way for the rational design of polymeric materials and processing routes to enhance devices reliant on mixed conduction.« less

Investigation of surface topography and stiffness on adhesion and neurites extension of PC12 cells on crosslinked silica aerogel substrates.

PubMed

Lynch, Kyle J; Skalli, Omar; Sabri, Firouzeh

2017-01-01

Fundamental understanding and characterization of neural response to substrate topography is essential in the development of next generation biomaterials for nerve repair. Aerogels are a new class of materials with great potential as a biomaterial. In this work, we examine the extension of neurites by PC12 cells plated on matrigel-coated and collagen-coated mesoporous aerogel surfaces. We have successfully established the methodology for adhesion and growth of PC12 cells on polyurea crosslinked silica aerogels. Additionally, we have quantified neurite behaviors and compared their response on aerogel substrates with their behavior on tissue culture (TC) plastic, and polydimethylsiloxane (PDMS). We found that, on average, PC12 cells extend longer neurites on crosslinked silica aerogels than on tissue culture plastic, and, that the average number of neurites per cluster is lower on aerogels than on tissue culture plastic. Aerogels are an attractive candidate for future development of smart neural implants and the work presented here creates a platform for future work with this class of materials as a substrate for bioelectronic interfacing.

Flexible graphene transistors for recording cell action potentials

NASA Astrophysics Data System (ADS)

Blaschke, Benno M.; Lottner, Martin; Drieschner, Simon; Bonaccini Calia, Andrea; Stoiber, Karolina; Rousseau, Lionel; Lissourges, Gaëlle; Garrido, Jose A.

2016-06-01

Graphene solution-gated field-effect transistors (SGFETs) are a promising platform for the recording of cell action potentials due to the intrinsic high signal amplification of graphene transistors. In addition, graphene technology fulfills important key requirements for in-vivo applications, such as biocompability, mechanical flexibility, as well as ease of high density integration. In this paper we demonstrate the fabrication of flexible arrays of graphene SGFETs on polyimide, a biocompatible polymeric substrate. We investigate the transistor’s transconductance and intrinsic electronic noise which are key parameters for the device sensitivity, confirming that the obtained values are comparable to those of rigid graphene SGFETs. Furthermore, we show that the devices do not degrade during repeated bending and the transconductance, governed by the electronic properties of graphene, is unaffected by bending. After cell culture, we demonstrate the recording of cell action potentials from cardiomyocyte-like cells with a high signal-to-noise ratio that is higher or comparable to competing state of the art technologies. Our results highlight the great capabilities of flexible graphene SGFETs in bioelectronics, providing a solid foundation for in-vivo experiments and, eventually, for graphene-based neuroprosthetics.

On the other side of the fence: effects of social categorization and spatial grouping on memory and attention for own-race and other-race faces.

PubMed

Kloth, Nadine; Shields, Susannah E; Rhodes, Gillian

2014-01-01

The term "own-race bias" refers to the phenomenon that humans are typically better at recognizing faces from their own than a different race. The perceptual expertise account assumes that our face perception system has adapted to the faces we are typically exposed to, equipping it poorly for the processing of other-race faces. Sociocognitive theories assume that other-race faces are initially categorized as out-group, decreasing motivation to individuate them. Supporting sociocognitive accounts, a recent study has reported improved recognition for other-race faces when these were categorized as belonging to the participants' in-group on a second social dimension, i.e., their university affiliation. Faces were studied in groups, containing both own-race and other-race faces, half of each labeled as in-group and out-group, respectively. When study faces were spatially grouped by race, participants showed a clear own-race bias. When faces were grouped by university affiliation, recognition of other-race faces from the social in-group was indistinguishable from own-race face recognition. The present study aimed at extending this singular finding to other races of faces and participants. Forty Asian and 40 European Australian participants studied Asian and European faces for a recognition test. Faces were presented in groups, containing an equal number of own-university and other-university Asian and European faces. Between participants, faces were grouped either according to race or university affiliation. Eye tracking was used to study the distribution of spatial attention to individual faces in the display. The race of the study faces significantly affected participants' memory, with better recognition of own-race than other-race faces. However, memory was unaffected by the university affiliation of the faces and by the criterion for their spatial grouping on the display. Eye tracking revealed strong looking biases towards both own-race and own-university faces. Results are discussed in light of the theoretical accounts of the own-race bias.

On the Other Side of the Fence: Effects of Social Categorization and Spatial Grouping on Memory and Attention for Own-Race and Other-Race Faces

PubMed Central

Kloth, Nadine; Shields, Susannah E.; Rhodes, Gillian

2014-01-01

The term “own-race bias” refers to the phenomenon that humans are typically better at recognizing faces from their own than a different race. The perceptual expertise account assumes that our face perception system has adapted to the faces we are typically exposed to, equipping it poorly for the processing of other-race faces. Sociocognitive theories assume that other-race faces are initially categorized as out-group, decreasing motivation to individuate them. Supporting sociocognitive accounts, a recent study has reported improved recognition for other-race faces when these were categorized as belonging to the participants' in-group on a second social dimension, i.e., their university affiliation. Faces were studied in groups, containing both own-race and other-race faces, half of each labeled as in-group and out-group, respectively. When study faces were spatially grouped by race, participants showed a clear own-race bias. When faces were grouped by university affiliation, recognition of other-race faces from the social in-group was indistinguishable from own-race face recognition. The present study aimed at extending this singular finding to other races of faces and participants. Forty Asian and 40 European Australian participants studied Asian and European faces for a recognition test. Faces were presented in groups, containing an equal number of own-university and other-university Asian and European faces. Between participants, faces were grouped either according to race or university affiliation. Eye tracking was used to study the distribution of spatial attention to individual faces in the display. The race of the study faces significantly affected participants' memory, with better recognition of own-race than other-race faces. However, memory was unaffected by the university affiliation of the faces and by the criterion for their spatial grouping on the display. Eye tracking revealed strong looking biases towards both own-race and own-university faces. Results are discussed in light of the theoretical accounts of the own-race bias. PMID:25180902

Communicative Anxiety in English as a Third Language

ERIC Educational Resources Information Center

Santos, Alaitz; Cenoz, Jasone; Gorter, Durk

2017-01-01

The present study focuses on the link between three factors, proficiency, language certificates and bilingualism, and levels of communicative anxiety in the third language (English) in two groups of adult users, university students and young professionals. The first group consisted of 217 university students who were enrolled at the University of…

Smoot Cosmology Group

Science.gov Websites

Links We bring the universe to you! University of California Berkeley Cosmology Group Lawrence Computational Cosmology Center Institute for Nuclear & Particle Astrophysics Supernova Acceleration Probe

Methods of Costing in Universities. Brief Comparison Between the NCHEMS Approach and the Approach Used by the French-Speaking Research Group Associated with the IMHE Programme.

ERIC Educational Resources Information Center

Cossu, Claude

1975-01-01

A group of French universities modified the NCHEMS accounting method for use in a study of its budget control procedures and cost-evaluation methods. The conceptual differences in French university education (as compared to American higher education) are keyed to the adjustments in the accounting method. French universities, rather than being…

Effect of Reduced Phosphoric Acid Pre-etching Times 
on Enamel Surface Characteristics and Shear Fatigue Strength Using Universal Adhesives.

PubMed

Tsujimoto, Akimasa; Fischer, Nicholas; Barkmeier, Wayne; Baruth, Andrew; Takamizawa, Toshiki; Latta, Mark; Miyazaki, Masashi

2017-01-01

To examine the effect of reduced phosphoric acid pre-etching times on enamel fatigue bond strength of universal adhesives and surface characteristics by using atomic force microscopy (AFM). Three universal adhesives were used in this study (Clearfil Universal Bond [C], G-Premio Bond [GP], Scotchbond Universal Adhesive [SU]). Four pre-etching groups were employed: enamel pre-etched with phosphoric acid and immediately rinsed with an air-water spray, and enamel pre-etched with phosphoric acid for 5, 10, or 15 s. Ground enamel was used as the control group. For the initial bond strength test, 15 specimens per etching group for each adhesive were used. For the shear fatigue test, 20 specimens per etching group for each adhesive were loaded using a sine wave at a frequency of 20 Hz for 50,000 cycles or until failure occurred. Initial shear bond strengths and fatigue shear strengths of composite adhesively bonded to ground and pre-etched enamel were determined. AFM observations of ground and pre-etched enamel were also conducted, and surface roughness as well as surface area were evaluated. The initial shear bond strengths and fatigue shear strengths of the universal adhesives in the pre-etched groups were significantly higher than those of the control group, and were not influenced by the pre-etching time. Significantly higher surface roughness and surface area of enamel surfaces in pre-etched groups were observed compared with those in the control group. While the surface area was not significantly influenced by etching time, surface roughness of the enamel surfaces in the pre-etched groups significantly increased with pre-etching time. The results of this in vitro study suggest that reduced phosphoric acid pre-etching times do not impair the fatigue bond strength of universal adhesives. Although fatigue bond strength and surface area were not influenced by phosphoric-acid etching times, surface roughness increased with increasing etching time.

The stability and predictors of peer group deviance in university students.

PubMed

Kendler, Kenneth S; Myers, John; Dick, Danielle

2015-09-01

Peer group deviance (PGD) is strongly associated with current and future externalizing behaviors. Debate remains about the degree to which this association arises from social selection. The first year of university constitutes a social experiment in which most individuals leave their home environment and recreate for themselves a new peer group. PGD was measured in newly arrived university students and then 6 and 18 months later. Other personality and family traits were also assessed. PGD reported for high school friends at the start of university and university friends 6 months later were substantially correlated (+0.60). This correlation was only slightly diminished if restricted to students whose home was greater than 50 miles from the university. PGD was strongly predicted across three cohorts by male sex (+), extraversion (+), conscientiousness (-), a family history of alcohol use disorders (+) and depression (+), and religiosity (-).These predictors of PGD had a relatively stable impact over 18 months and, aside from sex, differed only modestly in males and females. As individuals change social groups from high school to university, the level of PGD remains relatively stable, suggesting that individuals play a strong role in selecting peer groups with consistent characteristics. PGD is also predicted cross-sectionally and longitudinally by personality, family background and religiosity. Our results suggest that the association between personal and peer deviance is due at least in part to the effects of social selection.

Lifelong Learning from Natural Disasters: Transformative Group-Based Learning at Philippine Universities

ERIC Educational Resources Information Center

Dahl, Kari Kragh Blume; Millora, Christopher Malagad

2016-01-01

This study explores reflective experience during transformative, group-based learning among university leaders following a natural disaster such as a typhoon in two Philippine universities. Natural disasters are recurrent phenomena in many parts of the world, but the literature largely ignores their impact on lifelong human learning, for instance…

Role of Peers in Student Academic Achievement in Exogenously Formed University Groups

ERIC Educational Resources Information Center

Androushchak, Gregory; Poldin, Oleg; Yudkevich, Maria

2013-01-01

We estimate the influence of classmates' ability characteristics on student achievement in exogenously formed university student groups. The study uses administrative data on undergraduate students at a large selective university in Russia. The presence of high-ability classmates has a significant positive effect on individual grades in key…

Universal parent support groups for parents of adolescents: Which parents participate and why?

PubMed

Alfredsson, Elin K; Broberg, Anders G

2016-04-01

Leader-led parent support groups, offered universally to parents of adolescents, are increasingly common, yet little is known of the parents who use this support. The study presented here explored the characteristics of parents of 10- to 17-year-olds (N = 192) who had enlisted in universal support groups and their reasons for enrollment. Sociodemographic factors (parents' country of origin, educational level, long-term sick-leave or unemployment, and marital status) were compared to the general population (Statistics Sweden, 2012) and parents' psychological health and children's psychiatric symptoms were compared to a control group (the BITA study). Results showed that support group parents reported more psychosocial difficulties, such as higher frequency of long-term sick-leave or unemployment, more symptoms of anxiety and depression and more psychiatric symptoms in their children than parents in general. While about a fifth of the parents had problem-oriented (targeted) reasons for enrollment, most parents had general (universal) reasons. Thus, the universal approach does seem to reach its intended recipients. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Effects of Mindfulness-Based versus Interpersonal Process Group Intervention on Psychological Well-Being with a Clinical University Population

ERIC Educational Resources Information Center

Byrne, Ciara; Bond, Lynne A.; London, Miv

2013-01-01

This quasi-experimental study compared a group mindfulness-based intervention (MI) with an interpersonal process (IP) group intervention and a no-treatment (NT) control condition in reducing psychological distress among 112 students at 2 universities. At postintervention, IP and MI group participants exhibited significant reductions in anxiety,…

An Analysis of Small Group Interactions of Vietnamese Students under the Bourdieusian Theoretical Lens

ERIC Educational Resources Information Center

Pham, Thanh; Pham, Lam

2018-01-01

Group work has been increasingly encouraged and applied in Vietnamese universities. However, very little has been known about how Vietnamese university students work in a group and what the conditions are that help establish an effective group. This study attempted to redress this gap. The research applied Bourdieu's social field theory to examine…

Extended Sessions in Ongoing Process Groups at University Counseling Centers.

ERIC Educational Resources Information Center

Reinhardt, Brian

Common in the 1960s, marathon groups are now rarely used. With the emerging effects of managed care, short-term brief focused therapies have become the therapeutic norm, and group counseling has become popular because of its low cost and therapeutic effectiveness. Most groups at university counseling centers run for one semester. A strategically…

Screening and brief interventions for hazardous and harmful alcohol use among university students in South Africa: results from a randomized controlled trial.

PubMed

Pengpid, Supa; Peltzer, Karl; van der Heever, Hendry; Skaal, Linda

2013-05-21

The aim of this study was to assess the effectiveness of Screening and Brief Intervention (SBI) for alcohol problems among university students in South Africa. The study design for this efficacy study is a randomized controlled trial with 6- and 12-month follow-ups to examine the effects of a brief alcohol intervention to reduce alcohol use by hazardous and harmful drinkers in a university setting. The unit of randomization is the individual university student identified as a hazardous or harmful drinker attending public recruitment venues in a university campus. University students were screened for alcohol problems, and those identified as hazardous or harmful drinkers were randomized into an experimental or control group. The experimental group received one brief counseling session on alcohol risk reduction, while the control group received a health education leaflet. Results indicate that of the 722 screened for alcohol and who agreed to participate in the trial 152 (21.1%) tested positive for the Alcohol Use Disorder Identification Test (AUDIT) (score 8 or more). Among the 147 (96.7%) university students who also attended the 12-month follow-up session, the intervention effect on the AUDIT score was -1.5, which was statistically significant (P = 0.009). Further, the depression scores marginally significantly decreased over time across treatment groups, while other substance use (tobacco and cannabis use), self-rated health status and Posttraumatic Stress Disorder (PTSD) scores did not change over time across treatment groups. The study provides evidence of effective brief intervention by assistant nurses with hazardous and harmful drinkers in a university setting in South Africa. The short duration of the brief intervention makes it a realistic candidate for use in a university setting.

A glossary of policy frameworks: the many forms of 'universalism' and policy 'targeting'.

PubMed

Carey, Gemma; Crammond, Brad

2017-03-01

The recognition that certain characteristics (such as poverty, disadvantage or membership of marginalised social or cultural groups) can make individuals more susceptible to illness has reignited interest in how to combine universal programmes and policies with ones targeted at specific groups. However, 'universalism' and 'targeting' are used in different ways for different purposes. In this glossary, we define different types and approaches to universalism and targeting. We anticipate that greater clarity in relation to what is meant by 'universalism' and 'targeting' will lead to a more nuanced debate and practice in this area. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Focus Groups Help To Focus the Marketing Strategy.

ERIC Educational Resources Information Center

Ashar, Hanna; Lane, Maureen

1996-01-01

A university-based degree completion program for adults conducted focus group research to refine market positioning and promotion. Focus groups averaged five current students and recent graduates who reflected, demographically, the current student population. Results gave insight into reasons for selecting the university, aspects of the program…

Influence of Sport Education on Group Cohesion in University Physical Education

ERIC Educational Resources Information Center

Jenkins, Jayne M.; Alderman, Brandon L.

2011-01-01

The Sport Education ("SE") curricular model incorporated within university physical education Basic Instruction Program (BIP) may increase group cohesion. This study's purpose was to identify student perceptions of a BIP course taught within "SE," and investigate group cohesion in differing activity content. Participants…

Tracing Assessment Policy Discourses in Neoliberalised Higher Education Settings

ERIC Educational Resources Information Center

Raaper, Rille

2017-01-01

This article explores assessment policy in two European universities with different political, historical and social backgrounds: the University of Glasgow and Tallinn University. The University of Glasgow is a well-established Russell Group university in the UK; Tallinn University is a relatively new university in post-Soviet Estonia, shaped by…

Effect of various bleaching treatments on shear bond strength of different universal adhesives and application modes

PubMed Central

2018-01-01

Objectives The aim of this in vitro study was to evaluate the bond strength of 2 universal adhesives used in different application modes to bleached enamel. Materials and Methods Extracted 160 sound human incisors were used for the study. Teeth were divided into 4 treatment groups: No treatment, 35% hydrogen peroxide, 16% carbamid peroxide, 7.5% carbamid peroxide. After bleaching treatments, groups were divided into subgroups according to the adhesive systems used and application modes (n = 10): 1) Single Bond Universal, etch and rinse mode; 2) Single Bond Universal, self-etch mode; 3) Gluma Universal, etch and rinse mode; 4) Gluma Universal, self-etch mode. After adhesive procedures nanohybrid composite resin cylinders were bonded to the enamel surfaces. All specimens were subjected to shear bond strength (SBS) test after thermocycling. Data were analyzed using a 3-way analysis of variance (ANOVA) and Tukey post hoc test. Results No significant difference were found among bleaching groups (35% hydrogen peroxide, 16% carbamid peroxide, 7.5% carbamid peroxide, and no treatment groups) in the mean SBS values. There was also no difference in SBS values between Single Bond Universal and Gluma Universal at same application modes, whereas self-etch mode showed significantly lower SBS values than etch and rinse mode (p < 0.05). Conclusions The bonding performance of the universal adhesives was enhanced with the etch and rinse mode application to bleached enamel and non-bleached enamel. PMID:29765900

Using community-based participatory research and organizational diagnosis to characterize relationships between community leaders and academic researchers.

PubMed

Wang, Karen H; Ray, Natasha J; Berg, David N; Greene, Ann T; Lucas, Georgina; Harris, Kenn; Carroll-Scott, Amy; Tinney, Barbara; Rosenthal, Marjorie S

2017-09-01

Sustaining collaborations between community-based organization leaders and academic researchers in community-engaged research (CEnR) in the service of decreasing health inequities necessitates understanding the collaborations from an inter-organizational perspective. We assessed the perspectives of community leaders and university-based researchers conducting community-engaged research in a medium-sized city with a history of community-university tension. Our research team, included experts in CEnR and organizational theory, used qualitative methods and purposeful, snowball sampling to recruit local participants and performed key informant interviews from July 2011-May 2012. A community-based researcher interviewed 11 community leaders, a university-based researcher interviewed 12 university-based researchers. We interviewed participants until we reached thematic saturation and performed analyses using the constant comparative method. Unifying themes characterizing community leaders and university-based researchers' relationships on the inter-organizational level include: 1) Both groups described that community-engaged university-based researchers are exceptions to typical university culture; 2) Both groups described that the interpersonal skills university-based researchers need for CEnR require a change in organizational culture and training; 3) Both groups described skepticism about the sustainability of a meaningful institutional commitment to community-engaged research 4) Both groups described the historical impact on research relationships of race, power, and privilege, but only community leaders described its persistent role and relevance in research relationships. Challenges to community-academic research partnerships include researcher interpersonal skills and different perceptions of the importance of organizational history. Solutions to improve research partnerships may include transforming university culture and community-university discussions on race, power, and privilege.

A Demonstration of the Universal Problem-Solving Approach to Address Children's Inappropriate Behavior in Head Start Classrooms

ERIC Educational Resources Information Center

Snell, Martha E.; Voorhees, Mary D.; Walker, Virginia L.; Berlin, Rebecca A.; Jamison, Kristen Roorbach; Stanton-Chapman, Tina L.

2014-01-01

The purpose of this demonstration was to evaluate a universal intervention during teacher-identified routines that were characterized by significant classwide problem behavior. Six Head Start classrooms (seven groups of children, with one classroom divided into two groups) received two workshops and two coaching sessions on universal Positive…

The Effect of Peer Support on University Level Students' English Language Achievements

ERIC Educational Resources Information Center

Sari, Irfan; Çeliköz, Nadir; Ünal, Süleyman

2017-01-01

The purpose of the study is to investigate the effect of peer support on university level students' English language achievements. An experimental model with pretest-posttest experimental and control group was used with 800 students who were studying at a university in Istanbul vicinity. As experiment group, 400 students (200 of whom…

Do matrix metalloproteinase inhibitors improve the bond durability of universal dental adhesives?

PubMed

Tekçe, Neslihan; Tuncer, Safa; Demirci, Mustafa; Balci, Sibel

2016-11-01

The aim of this study was to evaluate the effects of matrix metalloproteinases (MMPs) inhibitors on the microtensile bond strength (μTBS) and the adhesive-dentin interface of two universal dentin bonding agents, Single Bond Universal and All Bond Universal, after 12 months of water storage. Seventy extracted, caries-free, human third molars were used in this study. Of these, 50 were used for μTBS testing and 20 were used for scanning electron microscopy. The two bonding agents were applied to flat dentin surfaces in five different ways: self-etch mode, etch-and-rinse mode with 37% phosphoric acid, etch-and-rinse mode with phosphoric acid containing 1% benzalkonium chloride, etch-and-rinse mode with phosphoric acid and 2% chlorhexidine, and etch-and-rinse mode with 0.5 M ethylenediaminetetraacetic acid (EDTA) (n = 5 for each bonding agent in each group; N = 50). Half the specimens were subjected to μTBS tests at 24 h, while half were subjected to the tests after 12 months of water storage. For each bonding agent, inhibition, storage, and their interaction effects were tested by two-way analysis of variance and Bonferroni tests. For Single Bond Universal, the benzalkonium chloride (p = 0.024) and chlorhexidine groups (p = 0.033) exhibited significantly higher μTBS values at 24 h compared with the self-etch group. For All Bond Universal, all groups displayed similar bond strengths at 24 h (p > 0.05). After 12 months of water storage, the μTBS values decreased significantly in the benzalkonium chloride group for Single Bond Universal (p = 0.001) and the self-etch (p = 0.029), chlorhexidine (p = 0.046), and EDTA (p = 0.032) groups for All Bond Universal. These results suggest that the immediate dentin bond strength increases when universal bonding systems are applied in the etch-and-rinse mode, although the durability decreases. The use of chlorhexidine and EDTA can increase the bond durability of mild adhesives such as Single Bond Universal. SCANNING 38:535-544, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

The stability and predictors of peer group deviance in university students

PubMed Central

Myers, John; Dick, Danielle

2015-01-01

Background Peer group deviance (PGD) is strongly associated with current and future externalizing behaviors. Debate remains about the degree to which this association arises from social selection. The first year of university constitutes a social experiment in which most individuals leave their home environment and recreate for themselves a new peer group. Methods PGD was measured in newly arrived university students and then 6 and 18 months later. Other personality and family traits were also assessed. Results PGD reported for high school friends at the start of university and university friends 6 months later were substantially correlated (+0.60). This correlation was only slightly diminished if restricted to students whose home was greater than 50 miles from the university. PGD was strongly predicted across three cohorts by male sex (+), extraversion (+), conscientiousness (−), a family history of alcohol use disorders (+) and depression (+), and religiosity (−). These predictors of PGD had a relatively stable impact over 18 months and, aside from sex, differed only modestly in males and females. Conclusions As individuals change social groups from high school to university, the level of PGD remains relatively stable, suggesting that individuals play a strong role in selecting peer groups with consistent characteristics. PGD is also predicted cross-sectionally and longitudinally by personality, family background and religiosity. Our results suggest that the association between personal and peer deviance is due at least in part to the effects of social selection. PMID:25702166

A comparative evaluation of efficacy of protaper universal rotary retreatment system for gutta-percha removal with or without a solvent.

PubMed

Kumar, M Sita Ram; Sajjan, Girija S; Satish, Kalyan; Varma, K Madhu

2012-09-01

The aim was to evaluate and compare the efficacy of ProTaper Universal rotary retreatment system with or without solvent and stainless steel hand files for endodontic filling removal from root canals and also to compare retreatment time for each system. Thirty extracted mandibular premolars with single straight canals were endodontically treated. Teeth were divided into three major groups, having 10 specimens each. Removal of obturating material in group 1 by stainless steel hand files with RC Solve, group 2 by ProTaper Universal retreatment instruments and group 3 by ProTaper Universal retreatment instruments along with RC solve was done. Retreatment was considered complete for all groups when no filling material was observed on the instruments. The retreatment time was recorded for each tooth. All specimens were grooved longitudinally in a buccolingual direction. The split halves were examined under a stereomicroscope and images were captured and analyzed. The remaining filling debris area ratios were considered for statistical analysis. With ANOVA test, statistical analysis showed that there was statistically no significant difference regarding the amount of filling remnants between the groups (P < 0.05). Differences between the means of groups are statistically significant regarding the retreatment time. Irrespective of the technique used, all the specimens had some remnants on the root canal wall. ProTaper Universal retreatment system files alone proved to be faster than the other experimental groups.

Final report for Texas A&M University Group Contribution to DE-FG02-09ER25949/DE-SC0002505: Topology for Statistical Modeling of Petascale Data (and ASCR-funded collaboration between Sandia National Labs, Texas A&M University and University of Utah)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rojas, Joseph Maurice

We summarize the contributions of the Texas A\\&M University Group to the project (DE-FG02-09ER25949/DE-SC0002505: Topology for Statistical Modeling of Petascale Data - an ASCR-funded collaboration between Sandia National Labs, Texas A\\&M U, and U Utah) during 6/9/2011 -- 2/27/2013.

Factors Among Select Donors and Non-Donors Related to Major Gifts to a Private University.

ERIC Educational Resources Information Center

McKinney, Ricardo J.; And Others

A study was conducted at the University of Miami to identify factors that might distinguish between donors and nondonors to the financial support of private universities. The theoretical framework for the study was based largely upon Lecky's self-consistency theory of personality. Three groups of donors and a group of nondonors to the University…

Engagement with a Teaching Career--How a Group of Finnish University Teachers Experience Teacher Identity and Professional Growth

ERIC Educational Resources Information Center

Korhonen, Vesa; Törmä, Sirpa

2016-01-01

The aim of this qualitative study was to identify teachers' ways of experiencing their identity and development challenges as teachers in the social and professional context of university. Identity and development as a teacher were examined based on interviews and drawings of career paths collected from a group of university teachers representing…

Australian and International Student Success Rates in Group of Eight Universities. Go8 Backgrounder 5

ERIC Educational Resources Information Center

Group of Eight (NJ1), 2008

2008-01-01

This Go8 Backgrounder compares the academic performance of three cohorts of students in Group of Eight (Go8) universities: Australian students, international students on campus in Australia (onshore) and international students overseas (offshore). Analysis of data supplied by Go8 universities shows that in 2007 students passed 91.8% of the courses…

The Effect Of Sex Education And Life Skills For Preventive Sexual Risk Behaviours Among University Of Students In Thailand.

PubMed

Seangpraw, Katekaew; Somrongthong, Rattana; Choowanthanapakorn, Monchanok; Kumar, Ramesh

2017-01-01

Currently, the problem of sexual risk behaviour of adolescents has increased worldwide, including Thailand. This study compared the effectiveness of promoting life skills to prevent sexual risk behaviours among university students in the Phayao Province of Thailand. A quasi-experimental design was employed with a pre- and post-test study for a sample of freshmen university students. The students were then split into an intervention group comprised of 300 students, with a second group of 250 students from the same faculty as the control group. The intervention group participated in the integrated life skills model for preventing sexual risk behaviours and participatory learning. The educational activities included; lectures, brainstorming, group discussion, roleplaying, game simulations and naming experiences through six weekly life skills training sessions of 90 minutes each. Data were collected by self-questionnaires and analysed using descriptive statistics and independent sample t-testing. Three different time periods were examined using ANOVA repeated measures analysis of variance. Compared between the intervention and control groups determined that implementation of increased knowledge and improved life skills was statistically significant (p<0.001) in the intervention group. The intervention group also showed significantly improved communication skills and behavioural preventive measures towards sexual risk than the control group (p<0.001). The life skills model also effectively reduced the sexual risk behaviours of students at the university. Therefore, this program was beneficial for the development of strategies to increase self-efficacy and it should be integrated into the universities' curriculum. In the long-term sexual risk behaviour changes must be monitored for programme sustainability.

Beyond Disciplines: Providing Outreach to Underserved Groups by Demographic

ERIC Educational Resources Information Center

Rutledge, Lorelei; LeMire, Sarah

2016-01-01

As more students, faculty, and staff from traditionally underrepresented groups enter universities and colleges, academic libraries must find ways to reach out to these groups in order to better meet their unique educational needs. In this article, librarians from two large public universities describe how they used data about their communities to…

Impact of severity of congenital heart diseases on university graduation rate among male patients.

PubMed

Özcan, Emin Evren; Küçük, Alaattin

2012-04-01

This study examines university graduation rates among individuals with congenital heart disease (CHD) in comparison to their healthy peers. The effect of disease severity, type of surgery, and timing of surgery on graduation rate was also evaluated. One hundred forty-five male patients with CHD at military age were enrolled in the study between the dates of January 2005 and May 2007. Severity of disease was operationalised in term of initial diagnosis (According to classification of 32th ACC Bethesta Conference Task Force 1). University graduation rates of among two groups of CHD patients (mild disease (group 1) or moderate to severe disease (group 2)) are compared to each other and to healthy peers. Patients with CHD have reduced rates of participation in higher education compared with healthy individuals (13.1% vs 20.7%, p=0.01). Furthermore, this negative effect on education participation rate is independent of the severity of disease (group 1, 16.4%, p=0.01; group 2, 9.7%, p<0.001). Although the university graduation rate was relatively higher in patients with mild disease severity, no significant difference was found between the two patient groups (p=0.23). Having an operation does not effect graduation rate (p=0.58), however greater age at the time of operation increases the likelihood of graduation (p=0.02). Being born with CHD significantly reduces the chance of completing higher education. This negative impact on university graduation rate is independent of the severity of the disease. No negative effects of disease related surgery or subsequent corrective surgery on education were observed. Patients who were operated on later in life were more likely to complete university education. Mean operation age of this group corresponds to the typical age during the last year of elementary school in Turkey.

Comparison of microleakage of Scotchbond™ Universal Adhesive with methacrylate resin in Class V restorations by two methods: Swept source optical coherence tomography and dye penetration

PubMed Central

Kermanshah, Hamid; Khorsandian, Hossein

2017-01-01

Background: One of the most important factors in restoration failure is microleakage at the restoration interface. Furthermore, a new generation of bonding, Scotchbond Universal (multi-mode adhesive), has been introduced to facilitate the bonding steps. The aim of this study was to compare the microleakage of Class V cavities restored using Scotchbond™ Universal with Scotchbond Multi-Purpose in two procedures. Materials and Methods: Eighteen freshly extracted human molars were used in this study. Thirty-six standardized Class V cavities were prepared on the buccal and lingual surfaces. The teeth were divided into three groups: (1) Group A: Scotchbond Universal with “self-etching” procedure and nanohybrid composite Filtek Z350. (2) Group B: Scotchbond Universal with “total etching” procedure and Filtek Z350. (3) Group C: Scotchbond Multi-Purpose and Filtek Z350. Microleakage at enamel and dentinal margins was evaluated after thermocycling under 5000 cycles by two methods of microleakage assay: swept source optical coherence tomography (OCT) and dye penetration. Wilcoxon's signed-rank test and Kruskal–Wallis test were used to analyze microleakage. Results: In silver nitrate dye penetration method, group A exhibited the minimum microleakage at dentin margins and group C exhibited the minimum microleakage at enamel margins (P < 0.05). Furthermore, in OCT method, group C demonstrated the minimum microleakage at enamel margins (P = 0.047), with no difference in the microleakage rate at dentin margins. Conclusion: Scotchbond Universal with “self-etching” procedure at dentin margin exhibited more acceptable performance compared to the Scotchbond Multi-Purpose with the two methods. PMID:28928782

Random Walks on Cartesian Products of Certain Nonamenable Groups and Integer Lattices

NASA Astrophysics Data System (ADS)

Vishnepolsky, Rachel

A random walk on a discrete group satisfies a local limit theorem with power law exponent \\alpha if the return probabilities follow the asymptotic law. P{ return to starting point after n steps } ˜ Crhonn-alpha.. A group has a universal local limit theorem if all random walks on the group with finitely supported step distributions obey a local limit theorem with the same power law exponent. Given two groups that obey universal local limit theorems, it is not known whether their cartesian product also has a universal local limit theorem. We settle the question affirmatively in one case, by considering a random walk on the cartesian product of a nonamenable group whose Cayley graph is a tree, and the integer lattice. As corollaries, we derive large deviations estimates and a central limit theorem.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giorda, Paolo; Zanardi, Paolo; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

We analyze the dynamical-algebraic approach to universal quantum control introduced in P. Zanardi and S. Lloyd, e-print quant-ph/0305013. The quantum state space H encoding information decomposes into irreducible sectors and subsystems associated with the group of available evolutions. If this group coincides with the unitary part of the group algebra CK of some group K then universal control is achievable over the K-irreducible components of H. This general strategy is applied to different kinds of bosonic systems. We first consider massive bosons in a double well and show how to achieve universal control over all finite-dimensional Fock sectors. We thenmore » discuss a multimode massless case giving the conditions for generating the whole infinite-dimensional multimode Heisenberg-Weyl enveloping algebra. Finally we show how to use an auxiliary bosonic mode coupled to finite-dimensional systems to generate high-order nonlinearities needed for universal control.« less

Motivating University Researchers

ERIC Educational Resources Information Center

Hendriks, Paul; Sousa, Celio

2008-01-01

This paper presents an empirical investigation into how universities approach the need and means for motivating university researchers through their management practices. The role of work motivation for this group deserves attention because pressures from outside and within the universities are said to have made university research less of a…

Academic Norms and the University Committee.

ERIC Educational Resources Information Center

Fenton, Joann C.

The metropolitan university is viewed from the context of individual, group, and university level of social interaction. Metropolitan universities are defined as state-supported public universities located in urban areas and legislatively mandated as teaching institutions. Resources are usually dependent upon the number of full-time equivalent…

The Group-Based Assessment Approach in Nursing Education: The Perspective of Nursing Students on Group-Based Assessment Process at a Namibian University

ERIC Educational Resources Information Center

Nuuyoma, Vistolina

2017-01-01

Group-based assessments used in the Bachelor of Nursing Science (clinical) Honours programme at a public university in Namibia are usually in the form of assignments and projects. Completing tasks in groups helps students to develop important skills like critical thinking and debating. In addition, it prepares them to work in the health-care…

Promoting University Students' Engagement in Learning through Instructor-Initiated EFL Writing Groups

ERIC Educational Resources Information Center

Mutwarasibo, Faustin

2014-01-01

This article examines how to promote university students' engagement in learning by means of instructor-initiated English as a foreign language (EFL) writing groups. The research took place in Rwanda and was undertaken as a case study involving 34 second-year undergraduate students, divided into 12 small working groups, and one instructor. The…

Promoting University Students' Collaborative Learning through Instructor-Guided Writing Groups

ERIC Educational Resources Information Center

Mutwarasibo, Faustin

2013-01-01

This paper aims to examine how to promote university students' engagement in learning by means of instructor-initiated EFL writing groups. The research took place in Rwanda and was undertaken as a case study involving 34 second year undergraduate students, divided into 12 small working groups and one instructor. The data were collected by means of…

Effects of Training in Universal Design for Learning on Lesson Plan Development

ERIC Educational Resources Information Center

Spooner, Fred; Baker, Joshua N.; Harris, Amber A.; Ahlgrim-Delzell, Lynn; Browder, Diane M.

2007-01-01

The effects of training in Universal Design for Learning (UDL) on lesson plan development of special and general educators in a college classroom environment were investigated. A true experimental group design with a control group was used for this study. A one-hour teacher training session introduced UDL to the experimental group; the control…

The Relations Between Student Organizations and the Wider University. Final Report.

ERIC Educational Resources Information Center

Gamson, Zelda F.

This report presents the findings from a study of student organizations at the University of Michigan. Four religious groups, 5 political groups, 10 sororities and 10 fraternities were chosen to represent a range of groups within each of the types. The study was undertaken to determine (1) the impact of formal student organizations on their…

Religion and Spirituality in Group Counseling: Beliefs and Practices of University Counseling Center Counselors

ERIC Educational Resources Information Center

Post, Brian C.; Cornish, Marilyn A.; Wade, Nathaniel G.; Tucker, Jeritt R.

2013-01-01

Fifty-four counselors at 9 university counseling centers participated in a study regarding religion and spirituality (R/S) in group counseling. The majority indicated that R/S is an appropriate topic for group counseling and that some religious and spiritual interventions are appropriate to use. However, counselors rarely use these interventions.…

The influence of pelvic adjustment on vertical jump height in female university students with functional leg length inequality.

PubMed

Gong, Wontae

2015-01-01

[Purpose] This study aimed to investigate the effect of pelvic adjustment on vertical jump height (VJH) in female university students with functional leg length inequality (FLLI). [Subjects] Thirty female university students with FLLI were divided into a pelvic adjustment group (n = 15) and a stretching (control) group (n = 15). [Methods] VJH was measured using an OptoGait. [Results] After the intervention, jump height improved significantly compared with the pre-intervention height only in the pelvic adjustment group, while FLLI showed statistically significant improvement in both groups. [Conclusion] Pelvic adjustment as per the Gonstead method can be applied as a method of reducing FLLI and increasing VJH.

Should medical students learn to develop a personal formulary?

PubMed Central

Daniels, J. M. A.; Mulder, C. W.; Groot, O. A.; Wewerinke, L.; Barnes, K. I.; Bakathir, H. A.; Hassan, N. A. G. M.; Van Bortel, L.; Kriska, M.; Santoso, B.; Sanz, E. J.; Thomas, M.; Ziganshina, L. E.; Bezemer, P. D.; Van Kan, C.; Richir, M. C.; Hogerzeil, H. V.

2008-01-01

Objective This study was performed to determine whether students who are trained in developing a personal formulary become more competent in rational prescribing than students who have only learned to use existing formularies. Methods This was a multicentre, randomised, controlled study conducted in eight universities in India, Indonesia, the Netherlands, the Russian Federation, Slovakia, South Africa, Spain and Yemen. Five hundred and eighty-three medical students were randomised into three groups: the personal formulary group (PF; 94), the existing formulary group (EF; 98) and the control group (C; 191). The PF group was taught how to develop and use a personal formulary, whereas e the EF group was taught how to review and use an existing formulary. The C group received no additional training and participated only in the tests. Student’s prescribing skills were measured by scoring their treatment plans for written patient cases. Results The mean PF group score increased by 23% compared with 19% for the EF group (p < 0.05) and 6% for controls (p < 0.05). The positive effect of PF training was only significant in universities that had a mainly classic curriculum. Conclusion Training in development and use of a personal formulary was particularly effective in universities with a classic curriculum and with traditional pharmacology teaching. In universities with a general problem-based curriculum, pharmacotherapy teaching can be based on either existing or personal formularies. PMID:18338161

Nigerian University Libraries: What Future?

ERIC Educational Resources Information Center

Aguolu, I. E.

1996-01-01

Nigerian university libraries are threatened by underfunding and inadequate collections and facilities. This article examines factors influencing the future prospects of Nigerian university libraries. Discusses Nigeria's mineral oil resources; political instability and stratification of ethnic groups; and the National Universities Commission, the…

Bacterial Cellulose (BC) as a Functional Nanocomposite Biomaterial

NASA Astrophysics Data System (ADS)

Nandgaonkar, Avinav Ghanashyam

Cellulosic is the most abundant biopolymer in the landscape and can be found in many different organisms. It has been already seen use in the medical field, for example cotton for wound dressings and sutures. Although cellulose is naturally occurring and has found a number of applications inside and outside of the medical field, it is not typically produced in its pure state. A lengthy process is required to separate the lignin, hemicelluloses and other molecules from the cellulose in most renewables (wood, agricultural fibers such as cotton, monocots, grasses, etc.). Although bacterial cellulose has a similar chemical structure to plant cellulose, it is easier to process because of the absence of lignin and hemicelluloses which require a lot of energy and chemicals for removal. Bacterial cellulose (BC) is produced from various species of bacteria such as Gluconacetobacter xylinus. Due to its high water uptake, it has the tendency to form gels. It displays high tensile strength, biocompatibility, and purity compared to wood cellulose. It has found applications in fields such as paper, paper products, audio components (e.g., speaker diaphragms), flexible electronics, supercapacitors, electronics, and soft tissue engineering. In my dissertation, we have functionalized and studied BC-based materials for three specific applications: cartilage tissue engineering, bioelectronics, and dye degradation. In our first study, we prepared a highly organized porous material based on BC by unidirectional freezing followed by a freeze-drying process. Chitosan was added to impart additional properties to the resulting BC-based scaffolds that were evaluated in terms of their morphological, chemical, and physical properties for cartilage tissue engineering. The properties of the resulting scaffold were tailored by adjusting the concentration of chitosan over 1, 1.5, and 2 % (by wt-%). The scaffolds containing chitosan showed excellent shape recovery and structural stability after compressive tests. In our second study, we developed a one-pot in-situ biosynthetic method to fabricate structurally controllable bacterial cellulose (BC)/reduced graphene oxide (RGO) composites. The graphene oxide (GO) was highly reduced during a standard autoclave process using a traditional mannitol culture medium as the reducing agent. The electrical conductivity of the RGO was found to be 23.75 S m-1. The final BC/RGO composites were developed in three distinct forms: 1) sealed structures in the water, 2) aerogels characterized by a porous cross section and aligned longitudinal structure, and 3) films embedded within the RGO sheets. Because of the simplicity and non-toxic nature of this work, it can be used in biomedical and bioelectronics applications. The last study was on dye degradation using BC as the substrate. The surface of the BC was chemically oxidized to produce aldehyde groups to successfully covalently crosslink laccase. TiO2 and laccase (Lac) were co-immobilized on the surface of OBC and the dye degradation process was carried out under specific conditions. Compared with free laccase, the optimum pH of the immobilized laccase system shifted to lower pH, while the optimum temperature decreased from 55 °C to 50 °C. The dye degradation experiments showed that the optimum pH for dye degradation was pH 5.0-6.0, while the optimum temperature was ca. 40 ºC. Under UV illumination, the dye degradation efficiency significantly improved characteristic of a synergy in the system. This dissertation contributes to the basic research of bacterial cellulose which will result in novel ideas that can possibly result in future industrial applications. The research provides a fundamental underpinning of specialized structure-property relationships between BC and the materials used to fabricate the BC nanocomposites that have value-added applications that are environmentally safe and eco-friendly.

Engaging Élitism: The Mediating Effect of Work Engagement on Affective Commitment and Quit Intentions in Two Australian University Groups

ERIC Educational Resources Information Center

Ferrer, Justine L.; Morris, Leanne

2013-01-01

Some universities rely on their élitism as one mechanism to attract and retain talented faculty. This paper examines two groups of élite and non-élite universities and the mediating effect that work engagement has on affective commitment and intention to quit. Findings indicate partial support for the mediating effect of work engagement in the…

A Study of Media Use and Reliance Patterns, Interest Levels, Attitudes and Preferences of Black Students at a Predominantly White and a Predominantly Black University.

ERIC Educational Resources Information Center

Morah, Tanya M.

A study was conducted to examine the relationship between American mass media and the black community. Subjects were two groups of black midwestern college students--one group studying at a predominantly black university and the other at a mostly white university--with similar social and economic backgrounds. It was hypothesized that black…

Relationship among food-safety knowledge, beliefs, and risk-reduction behavior in university students in Japan.

PubMed

Takeda, Sayaka; Akamatsu, Rie; Horiguchi, Itsuko; Marui, Eiji

2011-01-01

To identify whether university students who have both food-safety knowledge and beliefs perform risk-reduction behaviors. Cross-sectional research using a questionnaire that included food-safety knowledge, perceptions, risk-reduction behavior, stages for the selection of safer food based on the Transtheoretical Model, and demographic characteristics. Four universities in eastern Japan and 2 universities in western Japan. University students (n = 799). Food-safety knowledge, beliefs, and risk-reduction behaviors. Answers on measures assessing risk perception and food-safety knowledge were combined to form 4 groups of participants. Relationships among demographic characteristics, the 4 groups, risk-reduction behaviors, stage of change, and severity and susceptibility were assessed. The proportion of students who had more knowledge of food safety and a belief that "there are no 100% safe food items" was high in the group that frequently performed risk-reduction behaviors, as it was in the group who had taken a basic class about food or health care and who had, or were working toward, a food or nutrition qualification. University students who thought that there were no 100% safe food items and who had more knowledge about food safety were more likely to confirm food-safety information when selecting food. Copyright © 2011 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Distributing Expertise: A Dutch Experiment in Public Interest Science.

ERIC Educational Resources Information Center

Nelkin, Dorothy; Rip, Arie

1979-01-01

In order to provide public access to scientific expertise, the Dutch have instituted a science shops program. Science advisory groups, located at five universities, promote socially relevant research in the universities and provide technical information to client groups. (BB)

The Effectiveness of Group Training of CBT-Based Stress Management on Anxiety, Psychological Hardiness and General Self-Efficacy Among University Students.

PubMed

Molla Jafar, Hamdam; Salabifard, Seddigheh; Mousavi, Seyedeh Maryam; Sobhani, Zahra

2015-09-28

Admission to university is a very sensitive period of life for efficient, active, and young workforces in any country, and it is mostly associated with many changes in social and human relationships. These changes lead to anxiety in students. Moreover, humans need certain functions in order to adaptively deal with different life situations and challenges. By training stress management, these functions can help human acquire the required abilities. The present study was aimed at investigating the effectiveness of stress management training in anxiety, psychological hardiness, and general self-efficacy among university students. The study was a quasi-experimental intervention (pretest-posttest-follow-up) including a control group, it was a fundamental applied study. The statistical population consisted of all students of Islamic Azad University, Karaj, Iran. Convenient sampling was employed to select 30 students who were divided into an experimental group (n=15) and a control group (n=15). Before stress management training, both groups filled out Beck Anxiety Inventory, Long and Goulet scale of psychological hardiness, and General Self-efficacy Scale (GSE-10). Afterwards, the experimental group was provided with stress management training. And after the experiment, the abovementioned questionnaires and scales were responded by the two groups. Finally the collected data were analyzed and compared using one-way MANOVA. The results of MANOVA indicated that there was a significant difference between the two groups in terms of anxiety, hardiness, and general self-efficacy (p<0.001). According to the results of the present study and those of previous investigations that are in agreement with those of the present study, it can be concluded that stress management among university students cause anxiety to drop; moreover, it enhances their psychological hardiness and self-efficacy. In regard with the role and importance of stress management, training this skill should be included in educational plans of university.

The Effectiveness of Group Training of CBT-Based Stress Management on Anxiety, Psychological Hardiness and General Self-Efficacy among University Students

PubMed Central

Jafar, Hamdam Molla; Salabifard, Seddigheh; Mousavi, Seyedeh Maryam; Sobhani, Zahra

2016-01-01

Background: Admission to university is a very sensitive period of life for efficient, active, and young workforces in any country, and it is mostly associated with many changes in social and human relationships. These changes lead to anxiety in students. Moreover, humans need certain functions in order to adaptively deal with different life situations and challenges. By training stress management, these functions can help human acquire the required abilities. Objective: The present study was aimed at investigating the effectiveness of stress management training in anxiety, psychological hardiness, and general self-efficacy among university students. Method: The study was a quasi-experimental intervention (pretest-posttest-follow-up) including a control group, it was a fundamental applied study. The statistical population consisted of all students of Islamic Azad University, Karaj, Iran. Convenient sampling was employed to select 30 students who were divided into an experimental group (n=15) and a control group (n=15). Before stress management training, both groups filled out Beck Anxiety Inventory, Long and Goulet scale of psychological hardiness, and General Self-efficacy Scale (GSE-10). Afterwards, the experimental group was provided with stress management training. And after the experiment, the abovementioned questionnaires and scales were responded by the two groups. Finally the collected data were analyzed and compared using one-way MANOVA. Results: The results of MANOVA indicated that there was a significant difference between the two groups in terms of anxiety, hardiness, and general self-efficacy (p<0.001). Conclusion: According to the results of the present study and those of previous investigations that are in agreement with those of the present study, it can be concluded that stress management among university students cause anxiety to drop; moreover, it enhances their psychological hardiness and self-efficacy. In regard with the role and importance of stress management, training this skill should be included in educational plans of university. PMID:26755483

Organophosphonate biofunctionalization of diamond electrodes.

PubMed

Caterino, R; Csiki, R; Wiesinger, M; Sachsenhauser, M; Stutzmann, M; Garrido, J A; Cattani-Scholz, A; Speranza, Giorgio; Janssens, S D; Haenen, K

2014-08-27

The modification of the diamond surface with organic molecules is a crucial aspect to be considered for any bioapplication of this material. There is great interest in broadening the range of linker molecules that can be covalently bound to the diamond surface. In the case of protein immobilization, the hydropathicity of the surface has a major influence on the protein conformation and, thus, on the functionality of proteins immobilized at surfaces. For electrochemical applications, particular attention has to be devoted to avoid that the charge transfer between the electrode and the redox center embedded in the protein is hindered by a thick insulating linker layer. This paper reports on the grafting of 6-phosphonohexanoic acid on OH-terminated diamond surfaces, serving as linkers to tether electroactive proteins onto diamond surfaces. X-ray photoelectron spectroscopy (XPS) confirms the formation of a stable layer on the surface. The charge transfer between electroactive molecules and the substrate is studied by electrochemical characterization of the redox activity of aminomethylferrocene and cytochrome c covalently bound to the substrate through this linker. Our work demonstrates that OH-terminated diamond functionalized with 6-phosphonohexanoic acid is a suitable platform to interface redox-proteins, which are fundamental building blocks for many bioelectronics applications.

A Stimuli-Responsive Biosensor of Glucose on Layer-by-Layer Films Assembled through Specific Lectin-Glycoenzyme Recognition.

PubMed

Yao, Huiqin; Gan, Qianqian; Peng, Juan; Huang, Shan; Zhu, Meilin; Shi, Keren

2016-04-20

The research on intelligent bioelectrocatalysis based on stimuli-responsive materials or interfaces is of great significance for biosensors and other bioelectronic devices. In the present work, lectin protein concanavalin A (Con A) and glycoenzyme glucose oxidase (GOD) were assembled into {Con A/GOD}n layer-by-layer (LbL) films by taking advantage of the biospecific lectin-glycoenzyme affinity between them. These film electrodes possess stimuli-responsive properties toward electroactive probes such as ferrocenedicarboxylic acid (Fc(COOH)₂) by modulating the surrounding pH. The CV peak currents of Fc(COOH)₂ were quite large at pH 4.0 but significantly suppressed at pH 8.0, demonstrating reversible stimuli-responsive on-off behavior. The mechanism of stimuli-responsive property of the films was explored by comparative experiments and attributed to the different electrostatic interaction between the films and the probes at different pH. This stimuli-responsive films could be used to realize active/inactive electrocatalytic oxidation of glucose by GOD in the films and mediated by Fc(COOH)₂ in solution, which may establish a foundation for fabricating novel stimuli-responsive electrochemical biosensors based on bioelectrocatalysis with immobilized enzymes.

Generation of electrical power under human skin by subdermal solar cell arrays for implantable bioelectronic devices.

PubMed

Song, Kwangsun; Han, Jung Hyun; Yang, Hyung Chae; Nam, Kwang Il; Lee, Jongho

2017-06-15

Medical electronic implants can significantly improve people's health and quality of life. These implants are typically powered by batteries, which usually have a finite lifetime and therefore must be replaced periodically using surgical procedures. Recently, subdermal solar cells that can generate electricity by absorbing light transmitted through skin have been proposed as a sustainable electricity source to power medical electronic implants in bodies. However, the results to date have been obtained with animal models. To apply the technology to human beings, electrical performance should be characterized using human skin covering the subdermal solar cells. In this paper, we present electrical performance results (up to 9.05mW/cm 2 ) of the implantable solar cell array under 59 human skin samples isolated from 10 cadavers. The results indicate that the power densities depend on the thickness and tone of the human skin, e.g., higher power was generated under thinner and brighter skin. The generated power density is high enough to operate currently available medical electronic implants such as pacemakers that require tens of microwatt. Copyright © 2016 Elsevier B.V. All rights reserved.

An optically transparent, flexible, patterned and conductive silk biopolymer film (Conference Presentation)

NASA Astrophysics Data System (ADS)

Umar, Muhammad; Min, Kyungtaek; Kim, Sunghwan

2017-02-01

Transparent, flexible, and conducting films are of great interest for wearable electronics. For better biotic/abiotic interface, the films to integrate the electronics components requires the patterned surface conductors with optical transparency, smoothness, good electrical conductivity, along with the biofriendly traits of films. We focus on silk fibroin, a natural biopolymer extracted from the Bombyx mori cocoons, for this bioelectronics applications. Here we report an optically transparent, flexible, and patterned surface conductor on a silk film by burying a silver nanowires (AgNW) network below the surface of the silk film. The conducting silk film reveals high optical transparency of 80% and the excellent electronic conductivity of 15 Ω/sq, along with smooth surface. The integration of light emitting diode (LED) chip on the patterned electrodes confirms that the current can flow through the transparent and patterned electrodes on the silk film, and this result shows an application for integration of functional electronic/opto-electronic devices. Additionally, we fabricate a transparent and flexible radio frequency (RF) antenna and resistor on a silk film and apply these as a food sensor by monitoring the increasing resistance by the flow of gases from the spoiled food.

Recent advances in large-scale assembly of semiconducting inorganic nanowires and nanofibers for electronics, sensors and photovoltaics.

PubMed

Long, Yun-Ze; Yu, Miao; Sun, Bin; Gu, Chang-Zhi; Fan, Zhiyong

2012-06-21

Semiconducting inorganic nanowires (NWs), nanotubes and nanofibers have been extensively explored in recent years as potential building blocks for nanoscale electronics, optoelectronics, chemical/biological/optical sensing, and energy harvesting, storage and conversion, etc. Besides the top-down approaches such as conventional lithography technologies, nanowires are commonly grown by the bottom-up approaches such as solution growth, template-guided synthesis, and vapor-liquid-solid process at a relatively low cost. Superior performance has been demonstrated using nanowires devices. However, most of the nanowire devices are limited to the demonstration of single devices, an initial step toward nanoelectronic circuits, not adequate for production on a large scale at low cost. Controlled and uniform assembly of nanowires with high scalability is still one of the major bottleneck challenges towards the materials and device integration for electronics. In this review, we aim to present recent progress toward nanowire device assembly technologies, including flow-assisted alignment, Langmuir-Blodgett assembly, bubble-blown technique, electric/magnetic- field-directed assembly, contact/roll printing, planar growth, bridging method, and electrospinning, etc. And their applications in high-performance, flexible electronics, sensors, photovoltaics, bioelectronic interfaces and nano-resonators are also presented.

Electronic Conductivity in Biomimetic α-Helical Peptide Nanofibers and Gels.

PubMed

Ing, Nicole L; Spencer, Ryan K; Luong, Son H; Nguyen, Hung D; Hochbaum, Allon I

2018-03-27

Examples of long-range electronic conductivity are rare in biological systems. The observation of micrometer-scale electronic transport through protein wires produced by bacteria is therefore notable, providing an opportunity to study fundamental aspects of conduction through protein-based materials and natural inspiration for bioelectronics materials. Borrowing sequence and structural motifs from these conductive protein fibers, we designed self-assembling peptides that form electronically conductive nanofibers under aqueous conditions. Conductivity in these nanofibers is distinct for two reasons: first, they support electron transport over distances orders of magnitude greater than expected for proteins, and second, the conductivity is mediated entirely by amino acids lacking extended conjugation, π-stacking, or redox centers typical of existing organic and biohybrid semiconductors. Electrochemical transport measurements show that the fibers support ohmic electronic transport and a metallic-like temperature dependence of conductance in aqueous buffer. At higher solution concentrations, the peptide monomers form hydrogels, and comparisons of the structure and electronic properties of the nanofibers and gels highlight the critical roles of α-helical secondary structure and supramolecular ordering in supporting electronic conductivity in these materials. These findings suggest a structural basis for long-range electronic conduction mechanisms in peptide and protein biomaterials.

Recent Advances in the Field of Bionanotechnology: An Insight into Optoelectric Bacteriorhodopsin, Quantum Dots, and Noble Metal Nanoclusters

PubMed Central

Knoblauch, Christopher; Griep, Mark; Friedrich, Craig

2014-01-01

Molecular sensors and molecular electronics are a major component of a recent research area known as bionanotechnology, which merges biology with nanotechnology. This new class of biosensors and bioelectronics has been a subject of intense research over the past decade and has found application in a wide variety of fields. The unique characteristics of these biomolecular transduction systems has been utilized in applications ranging from solar cells and single-electron transistors (SETs) to fluorescent sensors capable of sensitive and selective detection of a wide variety of targets, both organic and inorganic. This review will discuss three major systems in the area of molecular sensors and electronics and their application in unique technological innovations. Firstly, the synthesis of optoelectric bacteriorhodopsin (bR) and its application in the field of molecular sensors and electronics will be discussed. Next, this article will discuss recent advances in the synthesis and application of semiconductor quantum dots (QDs). Finally, this article will conclude with a review of the new and exciting field of noble metal nanoclusters and their application in the creation of a new class of fluorescent sensors. PMID:25340449

A Method for Growing Bio-memristors from Slime Mold.

PubMed

Miranda, Eduardo Reck; Braund, Edward

2017-11-02

Our research is aimed at gaining a better understanding of the electronic properties of organisms in order to engineer novel bioelectronic systems and computing architectures based on biology. This specific paper focuses on harnessing the unicellular slime mold Physarum polycephalum to develop bio-memristors (or biological memristors) and bio-computing devices. The memristor is a resistor that possesses memory. It is the 4th fundamental passive circuit element (the other three are the resistor, the capacitor, and the inductor), which is paving the way for the design of new kinds of computing systems; e.g., computers that might relinquish the distinction between storage and a central processing unit. When applied with an AC voltage, the current vs. voltage characteristic of a memristor is a pinched hysteresis loop. It has been shown that P. polycephalum produces pinched hysteresis loops under AC voltages and displays adaptive behavior that is comparable with the functioning of a memristor. This paper presents the method that we developed for implementing bio-memristors with P. polycephalum and introduces the development of a receptacle to culture the organism, which facilitates its deployment as an electronic circuit component. Our method has proven to decrease growth time, increase component lifespan, and standardize electrical observations.

Body Implanted Medical Device Communications

NASA Astrophysics Data System (ADS)

Yazdandoost, Kamya Yekeh; Kohno, Ryuji

The medical care day by day and more and more is associated with and reliant upon concepts and advances of electronics and electromagnetics. Numerous medical devices are implanted in the body for medical use. Tissue implanted devices are of great interest for wireless medical applications due to the promising of different clinical usage to promote a patient independence. It can be used in hospitals, health care facilities and home to transmit patient measurement data, such as pulse and respiration rates to a nearby receiver, permitting greater patient mobility and increased comfort. As this service permits remote monitoring of several patients simultaneously it could also potentially decrease health care costs. Advancement in radio frequency communications and miniaturization of bioelectronics are supporting medical implant applications. A central component of wireless implanted device is an antenna and there are several issues to consider when designing an in-body antenna, including power consumption, size, frequency, biocompatibility and the unique RF transmission challenges posed by the human body. The radiation characteristics of such devices are important in terms of both safety and performance. The implanted antenna and human body as a medium for wireless communication are discussed over Medical Implant Communications Service (MICS) band in the frequency range of 402-405MHz.

Peptides and peptidomimetics in medicine, surgery and biotechnology.

PubMed

Gentilucci, Luca; Tolomelli, Alessandra; Squassabia, Federico

2006-01-01

Despite the fact that they have been used for a century to treat several kinds of diseases, peptides and short proteins are now considered the new generation of biologically active tools. Indeed, recent findings suggest a wide range of novel applications in medicine, biotechnology, and surgery. The efficacy of native peptides has been greatly enhanced by introducing structural modifications in the original sequences, giving rise to the class of peptidomimetics. This review gives an overview of both classical applications and promising new categories of biologically active peptides and analogs. Besides the new entries in well known peptide families, such as antibiotic macrocyclic peptides, integrin inhibitors, as well as immunoactive, anticancer, neuromodulator, opioid, and hormone peptides, a number of novel applications have been recently reported. Outstanding examples include peptide-derived semi-synthetic vaccines, drug delivery systems, radiolabeled peptides, self-assembling peptides, which can serve as biomaterials in tissue engineering for creating cartilage, blood vessels, and other tissues, or as substrates for neurite outgrowth and synapse formation, immobilized peptides, and proteins. Finally, peptide-based biomaterials can find applications in bio-nanotechnology for bio-microchips, peptide nanorods and nanotubes, bio-sensors, bio-electronic devices, and peptide-metal wires.

Conducting polymers with immobilised fibrillar collagen for enhanced neural interfacing.

PubMed

Liu, Xiao; Yue, Zhilian; Higgins, Michael J; Wallace, Gordon G

2011-10-01

Conducting polymers with pendant functionality are advantageous in various bionic and organic bioelectronic applications, as they allow facile incorporation of bio-regulative cues to provide bio-mimicry and conductive environments for cell growth, differentiation and function. In this work, polypyrrole substrates doped with chondroitin sulfate (CS), an extracellular matrix molecule bearing carboxylic acid moieties, were electrochemically synthesized and conjugated with type I collagen. During the coupling process, the conjugated collagen formed a 3-dimensional fibrillar matrix in situ at the conducting polymer interface, as evidenced by atomic force microscopy (AFM) and fluorescence microscopy under aqueous physiological conditions. Cyclic voltammetry (CV) and impedance measurement confirmed no significant reduction in the electroactivity of the fibrillar collagen-modified conducting polymer substrates. Rat pheochromocytoma (nerve) cells showed increased differentiation and neurite outgrowth on the fibrillar collagen, which was further enhanced through electrical stimulation of the underlying conducting polymer substrate. Our study demonstrates that the direct coupling of ECM components such as collagen, followed by their further self-assembly into 3-dimensional matrices, has the potential to improve the neural-electrode interface of implant electrodes by encouraging nerve cell attachment and differentiation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Programmable single-cell mammalian biocomputers.

PubMed

Ausländer, Simon; Ausländer, David; Müller, Marius; Wieland, Markus; Fussenegger, Martin

2012-07-05

Synthetic biology has advanced the design of standardized control devices that program cellular functions and metabolic activities in living organisms. Rational interconnection of these synthetic switches resulted in increasingly complex designer networks that execute input-triggered genetic instructions with precision, robustness and computational logic reminiscent of electronic circuits. Using trigger-controlled transcription factors, which independently control gene expression, and RNA-binding proteins that inhibit the translation of transcripts harbouring specific RNA target motifs, we have designed a set of synthetic transcription–translation control devices that could be rewired in a plug-and-play manner. Here we show that these combinatorial circuits integrated a two-molecule input and performed digital computations with NOT, AND, NAND and N-IMPLY expression logic in single mammalian cells. Functional interconnection of two N-IMPLY variants resulted in bitwise intracellular XOR operations, and a combinatorial arrangement of three logic gates enabled independent cells to perform programmable half-subtractor and half-adder calculations. Individual mammalian cells capable of executing basic molecular arithmetic functions isolated or coordinated to metabolic activities in a predictable, precise and robust manner may provide new treatment strategies and bio-electronic interfaces in future gene-based and cell-based therapies.

A Stimuli-Responsive Biosensor of Glucose on Layer-by-Layer Films Assembled through Specific Lectin-Glycoenzyme Recognition

PubMed Central

Yao, Huiqin; Gan, Qianqian; Peng, Juan; Huang, Shan; Zhu, Meilin; Shi, Keren

2016-01-01

The research on intelligent bioelectrocatalysis based on stimuli-responsive materials or interfaces is of great significance for biosensors and other bioelectronic devices. In the present work, lectin protein concanavalin A (Con A) and glycoenzyme glucose oxidase (GOD) were assembled into {Con A/GOD}n layer-by-layer (LbL) films by taking advantage of the biospecific lectin-glycoenzyme affinity between them. These film electrodes possess stimuli-responsive properties toward electroactive probes such as ferrocenedicarboxylic acid (Fc(COOH)2) by modulating the surrounding pH. The CV peak currents of Fc(COOH)2 were quite large at pH 4.0 but significantly suppressed at pH 8.0, demonstrating reversible stimuli-responsive on-off behavior. The mechanism of stimuli-responsive property of the films was explored by comparative experiments and attributed to the different electrostatic interaction between the films and the probes at different pH. This stimuli-responsive films could be used to realize active/inactive electrocatalytic oxidation of glucose by GOD in the films and mediated by Fc(COOH)2 in solution, which may establish a foundation for fabricating novel stimuli-responsive electrochemical biosensors based on bioelectrocatalysis with immobilized enzymes. PMID:27104542

Stretchable Biofuel Cells as Wearable Textile-based Self-Powered Sensors.

PubMed

Jeerapan, Itthipon; Sempionatto, Juliane R; Pavinatto, Adriana; You, Jung-Min; Wang, Joseph

2016-12-21

Highly stretchable textile-based biofuel cells (BFCs), acting as effective self-powered sensors, have been fabricated using screen-printing of customized stress-enduring inks. Due to synergistic effects of nanomaterial-based engineered inks and the serpentine designs, these printable bioelectronic devices endure severe mechanical deformations, e.g., stretching, indentation, or torsional twisting. Glucose and lactate BFCs with the single enzyme and membrane-free configurations generated the maximum power density of 160 and 250 µW cm -2 with the open circuit voltages of 0.44 and 0.46 V, respectively. The textile-BFCs were able to withstand repeated severe mechanical deformations with minimal impact on its structural integrity, as was indicated from their stable power output after 100 cycles of 100% stretching. By providing power signals proportional to the sweat fuel concentration, these stretchable devices act as highly selective and stable self-powered textile sensors. Applicability to sock-based BFC and self-powered biosensor and mechanically compliant operations was demonstrated on human subjects. These stretchable skin-worn "scavenge-sense-display" devices are expected to contribute to the development of skin-worn energy harvesting systems, advanced non-invasive self-powered sensors and wearable electronics on a stretchable garment.

Computational studies of sequence-specific driving forces in peptide self-assembly

NASA Astrophysics Data System (ADS)

Jeon, Joohyun

Peptides are biopolymers made from various sequences of twenty different types of amino acids, connected by peptide bonds. There are practically an infinite number of possible sequences and tremendous possible combinations of peptide-peptide interactions. Recently, an increasing number of studies have shown a stark variety of peptide self-assembled nanomaterials whose detailed structures depend on their sequences and environmental factors; these have end uses in medical and bio-electronic applications, for example. To understand the underlying physics of complex peptide self-assembly processes and to delineate sequence specific effects, in this study, I use various simulation tools spanning all-atom molecular dynamics to simple lattice models and quantify the balance of interactions in the peptide self-assembly processes. In contrast to the existing view that peptides' aggregation propensities are proportional to the net sequence hydrophobicity and inversely proportional to the net charge, I show the more nuanced effects of electrostatic interactions, including the cooperative effects between hydrophobic and electrostatic interactions. Notably, I suggest rather unexpected, yet important roles of entropies in the small scale oligomerization processes. Overall, this study broadens our understanding of the role of thermodynamic driving forces in peptide self-assembly.

Graphene paper supported MoS2 nanocrystals monolayer with Cu submicron-buds: High-performance flexible platform for sensing in sweat.

PubMed

Wang, Zhengyun; Dong, Shuang; Gui, Mengxi; Asif, Muhammad; Wang, Wei; Wang, Feng; Liu, Hongfang

2018-02-15

Flexible sweat biosensors are of considerable current interest for the development of wearable smart miniature devices. In this work, we report a novel type of flexible and electrochemical sweat platform fabricated by depositing Cu submicron buds on freestanding graphene paper (GP) carrying MoS 2 nanocrystals monolayer for bio-functional detection of glucose and lactate. Quantitative analysis of glucose and lactate was carried out by using amperometric i-t method. Linear ranges were obtained between 5 and 1775 μM for glucose and 0.01-18.4 mM for lactate, and their corresponding limits of detection were 500 nM and 0.1 μM, respectively. The platform demonstrates fast response, good selectivity, superb reproducibility and outstanding flexibility, which enable its use for monitoring glucose and lactate in human perspiration. The strategy of structurally integrating 3D transition metal, 0D transition metal sulfide and 2D graphene will provide new insight into the design of flexible electrodes for sweat glucose and lactate monitoring and a wider range of applications in biosensing, bioelectronics, and lab-on-a-chip devices. Copyright © 2017. Published by Elsevier Inc.

PEGylated Polyaniline Nanofibers: Antifouling and Conducting Biomaterial for Electrochemical DNA Sensing.

PubMed

Hui, Ni; Sun, Xiaotian; Niu, Shuyan; Luo, Xiliang

2017-01-25

Biofouling arising from nonspecific adsorption is a substantial outstanding challenge in diagnostics and disease monitoring, and antifouling sensing interfaces capable of reducing the nonspecific adsorption of proteins from biological complex samples are highly desirable. We present herein the preparation of novel composite nanofibers through the grafting of polyethylene glycol (PEG) polymer onto polyaniline (PANI) nanofibers and their application in the development of antifouling electrochemical biosensors. The PEGylated PANI (PANI/PEG) nanofibers possessed large surface area and remained conductive and at the same time demonstrated excellent antifouling performances in single protein solutions as well as complex human serum samples. Sensitive and low fouling electrochemical biosensors for the breast cancer susceptibility gene (BRCA1) can be easily fabricated through the attachment of DNA probes to the PANI/PEG nanofibers. The biosensor showed a very high sensitivity to target BRCA1 with a linear range from 0.01 pM to 1 nM and was also efficient enough to detect DNA mismatches with satisfactory selectivity. Moreover, the DNA biosensor based on the PEGylated PANI nanofibers supported the quantification of BRCA1 in complex human serum, indicating great potential of this novel biomaterial for application in biosensors and bioelectronics.

Fabrication of an electrochemical platform based on the self-assembly of graphene oxide-multiwall carbon nanotube nanocomposite and horseradish peroxidase: direct electrochemistry and electrocatalysis

NASA Astrophysics Data System (ADS)

Zhang, Qian; Yang, Shaojun; Zhang, Jing; Zhang, Ling; Kang, Pingli; Li, Jinghong; Xu, Jingwei; Zhou, Hua; Song, Xi-Ming

2011-12-01

A novel hybrid nanomaterial (GO-MWNTs) was explored based on the self-assembly of multiwall carbon nanotubes (MWNTs) and graphene oxide (GO). Compared with pristine MWNTs, such a nanocomposite could be well dispersed in aqueous solution and exhibit a negative charge. Driven by the electrostatic interaction, positively charged horseradish peroxidase (HRP) could then be immobilized onto GO-MWNTs at the surface of a glassy carbon (GC) electrode to form a HRP/GO-MWNT/GC electrode under mild conditions. TEM was used to characterize the morphology of the GO-MWNT nanocomposite. UV-vis and FTIR spectra suggested that HRP was immobilized onto the hybrid matrix without denaturation. Furthermore, the immobilized HRP showed enhanced direct electron transfer for the HRP-Fe(III)/Fe(II) redox center. Based on the direct electron transfer of the immobilized HRP, the HRP/GO-MWNT/GC electrode exhibited excellent electrocatalytic behavior to the reduction of H2O2 and NaNO2, respectively. Therefore, GO-MWNTs could provide a novel and efficient platform for the immobilization and biosensing of redox enzymes, and thus may find wide potential applications in the fabrication of biosensors, biomedical devices, and bioelectronics.

Free-Standing Bilayered Nanoparticle Superlattice Nanosheets with Asymmetric Ionic Transport Behaviors.

PubMed

Rao, Siyuan; Si, Kae Jye; Yap, Lim Wei; Xiang, Yan; Cheng, Wenlong

2015-11-24

Natural cell membranes can directionally and selectively regulate the ion transport, which is critical for the functioning of living cells. Here, we report on the fabrication of an artificial membrane based on an asymmetric nanoparticle superlattice bilayered nanosheet, which exhibits similar ion transport characteristics. The superlattice nanosheets were fabricated via a drying-mediated self-assembly of polystyrene-capped gold nanoparticles at the liquid-air interface. By adopting a layer-by-layer assembly process, an asymmetric nanomembrane could be obtained consisting of two nanosheets with different nanoparticle size. The resulting nanomembranes exhibit an asymmetric ion transport behavior, and diode-like current-voltage curves were observed. The asymmetric ion transport is attributed to the cone-like nanochannels formed within the membranes, upon which a simulation map was established to illustrate the relationship between the channel structure and the ionic selectivity, in consistency with our experimental results. Our superlattice nanosheet-based design presents a promising strategy for the fabrication of next-generation smart nanomembranes for rationally and selectively regulating the ion transport even at a large ion flux, with potential applications in a wide range of fields, including biosensor devices, energy conversion, biophotonics, and bioelectronics.

Microbial fuel cell as a biocapacitor by using pseudo-capacitive anode materials

NASA Astrophysics Data System (ADS)

Lv, Zhisheng; Xie, Daohai; Li, Fusheng; Hu, Yun; Wei, Chaohai; Feng, Chunhua

2014-01-01

Here, we report that the microbial fuel cell (MFC) containing pseudo-capacitive anode materials such as polypyrrole (PPy)/9,10-anthraquinone-2-sulfonic acid sodium salt (AQS) composite films and RuO2 nanoparticles can function as a biocapacitor, able to store bioelectrons generated from microbial oxidation of substrate and release the accumulated charge upon requirement. Influences of the specific capacitance of the PPy/AQS- and RuO2-modified carbon felt anodes on the extent of accumulated charge are examined. Results show that increasing anode capacitance is responsible for the increases in the amount of electrons stored and released, and thereby leading to more energy stored and average power dissipated. The long-term charging-discharging tests indicate that the RuO2-modified biocapacitor with a specific capacitance of 3.74 F cm-2 exhibits 6% loss in the amount of released charge over 10 cycles for one-month operation, and 40% loss over 60 cycles for six-month operation. Our findings suggest that the MFC anode incorporating pseudo-capacitive materials shows potential for storing energy from waste organic matter and releasing in a short time of high power to the electronic device.

Liquid-Solid Dual-Gate Organic Transistors with Tunable Threshold Voltage for Cell Sensing.

PubMed

Zhang, Yu; Li, Jun; Li, Rui; Sbircea, Dan-Tiberiu; Giovannitti, Alexander; Xu, Junling; Xu, Huihua; Zhou, Guodong; Bian, Liming; McCulloch, Iain; Zhao, Ni

2017-11-08

Liquid electrolyte-gated organic field effect transistors and organic electrochemical transistors have recently emerged as powerful technology platforms for sensing and simulation of living cells and organisms. For such applications, the transistors are operated at a gate voltage around or below 0.3 V because prolonged application of a higher voltage bias can lead to membrane rupturing and cell death. This constraint often prevents the operation of the transistors at their maximum transconductance or most sensitive regime. Here, we exploit a solid-liquid dual-gate organic transistor structure, where the threshold voltage of the liquid-gated conduction channel is controlled by an additional gate that is separated from the channel by a metal-oxide gate dielectric. With this design, the threshold voltage of the "sensing channel" can be linearly tuned in a voltage window exceeding 0.4 V. We have demonstrated that the dual-gate structure enables a much better sensor response to the detachment of human mesenchymal stem cells. In general, the capability of tuning the optimal sensing bias will not only improve the device performance but also broaden the material selection for cell-based organic bioelectronics.

Single Molecule Bioelectronics and Their Application to Amplification-Free Measurement of DNA Lengths

PubMed Central

Gül, O. Tolga; Pugliese, Kaitlin M.; Choi, Yongki; Sims, Patrick C.; Pan, Deng; Rajapakse, Arith J.; Weiss, Gregory A.; Collins, Philip G.

2016-01-01

As biosensing devices shrink smaller and smaller, they approach a scale in which single molecule electronic sensing becomes possible. Here, we review the operation of single-enzyme transistors made using single-walled carbon nanotubes. These novel hybrid devices transduce the motions and catalytic activity of a single protein into an electronic signal for real-time monitoring of the protein’s activity. Analysis of these electronic signals reveals new insights into enzyme function and proves the electronic technique to be complementary to other single-molecule methods based on fluorescence. As one example of the nanocircuit technique, we have studied the Klenow Fragment (KF) of DNA polymerase I as it catalytically processes single-stranded DNA templates. The fidelity of DNA polymerases makes them a key component in many DNA sequencing techniques, and here we demonstrate that KF nanocircuits readily resolve DNA polymerization with single-base sensitivity. Consequently, template lengths can be directly counted from electronic recordings of KF’s base-by-base activity. After measuring as few as 20 copies, the template length can be determined with <1 base pair resolution, and different template lengths can be identified and enumerated in solutions containing template mixtures. PMID:27348011

Single Molecule Bioelectronics and Their Application to Amplification-Free Measurement of DNA Lengths.

PubMed

Gül, O Tolga; Pugliese, Kaitlin M; Choi, Yongki; Sims, Patrick C; Pan, Deng; Rajapakse, Arith J; Weiss, Gregory A; Collins, Philip G

2016-06-24

As biosensing devices shrink smaller and smaller, they approach a scale in which single molecule electronic sensing becomes possible. Here, we review the operation of single-enzyme transistors made using single-walled carbon nanotubes. These novel hybrid devices transduce the motions and catalytic activity of a single protein into an electronic signal for real-time monitoring of the protein's activity. Analysis of these electronic signals reveals new insights into enzyme function and proves the electronic technique to be complementary to other single-molecule methods based on fluorescence. As one example of the nanocircuit technique, we have studied the Klenow Fragment (KF) of DNA polymerase I as it catalytically processes single-stranded DNA templates. The fidelity of DNA polymerases makes them a key component in many DNA sequencing techniques, and here we demonstrate that KF nanocircuits readily resolve DNA polymerization with single-base sensitivity. Consequently, template lengths can be directly counted from electronic recordings of KF's base-by-base activity. After measuring as few as 20 copies, the template length can be determined with <1 base pair resolution, and different template lengths can be identified and enumerated in solutions containing template mixtures.

Influence of dentin pretreatment on bond strength of universal adhesives.

PubMed

Poggio, Claudio; Beltrami, Riccardo; Colombo, Marco; Chiesa, Marco; Scribante, Andrea

2017-01-01

Objective: The purpose of the present study was to compare bond strength of different universal adhesives under three different testing conditions: when no pretreatment was applied, after 37% phosphoric acid etching and after glycine application. Materials and methods: One hundred and fifty bovine permanent mandibular incisors were used as a substitute for human teeth. Five different universal adhesives were tested: Futurabond M+, Scotchbond Universal, Clearfil Universal Bond, G-Premio BOND, Peak Universal Bond. The adhesive systems were applied following each manufacturer's instructions. The teeth were randomly assigned to three different dentin surface pretreatments: no pretreatment agent (control), 37% phosphoric acid etching, glycine pretreatment. The specimens were placed in a universal testing machine in order to measure and compare bond strength values. Results: The Kruskal-Wallis analysis of variance and the Mann-Whitney test were applied to assess significant differences among the groups. Dentin pretreatments provided different bond strength values for the adhesives tested, while similar values were registered in groups without dentin pretreatment. Conclusions: In the present report, dentin surface pretreatment did not provide significant differences in shear bond strength values of almost all groups. Acid pretreatment lowered bond strength values of Futurabond and Peak Universal Adhesives, whereas glycine pretreatment increased bond strength values of G Praemio Bond adhesive system.

Influence of dentin pretreatment on bond strength of universal adhesives

PubMed Central

Poggio, Claudio; Beltrami, Riccardo; Colombo, Marco; Chiesa, Marco; Scribante, Andrea

2017-01-01

Abstract Objective: The purpose of the present study was to compare bond strength of different universal adhesives under three different testing conditions: when no pretreatment was applied, after 37% phosphoric acid etching and after glycine application. Materials and methods: One hundred and fifty bovine permanent mandibular incisors were used as a substitute for human teeth. Five different universal adhesives were tested: Futurabond M+, Scotchbond Universal, Clearfil Universal Bond, G-Premio BOND, Peak Universal Bond. The adhesive systems were applied following each manufacturer’s instructions. The teeth were randomly assigned to three different dentin surface pretreatments: no pretreatment agent (control), 37% phosphoric acid etching, glycine pretreatment. The specimens were placed in a universal testing machine in order to measure and compare bond strength values. Results: The Kruskal–Wallis analysis of variance and the Mann–Whitney test were applied to assess significant differences among the groups. Dentin pretreatments provided different bond strength values for the adhesives tested, while similar values were registered in groups without dentin pretreatment. Conclusions: In the present report, dentin surface pretreatment did not provide significant differences in shear bond strength values of almost all groups. Acid pretreatment lowered bond strength values of Futurabond and Peak Universal Adhesives, whereas glycine pretreatment increased bond strength values of G Praemio Bond adhesive system. PMID:28642929

Understanding help-seeking amongst university students: the role of group identity, stigma, and exposure to suicide and help-seeking

PubMed Central

Kearns, Michelle; Muldoon, Orla T.; Msetfi, Rachel M.; Surgenor, Paul W. G.

2015-01-01

Background: Despite a high prevalence of suicide ideation and mental health issues amongst university students, the stigma of help-seeking remains a barrier to those who are in real need of professional support. Social identity theory states that help received from an ingroup source is more welcome and less threatening to one's identity than that from a source perceived as outgroup. Therefore, we hypothesized that students' stigma toward seeking help from their university mental health service would differ based on the strength of their identification with the university. Method: An online survey including measures of stigma of suicide, group identification, experience with help-seeking and exposure to suicide was administered to Irish university students (N = 493). Results: Group identification was a significant predictor of help-seeking attitudes after controlling for already known predictors. Contrary to our expectations, those who identified more strongly with their university demonstrated a higher stigma of seeking help from their university mental health service. Conclusions: Results are discussed in relation to self-categorization theory and the concept of normative fit. Practical implications for mental health service provision in universities are also addressed, specifically the need for a range of different mental health services both on and off-campus. PMID:26483722

The Immigrant's University: A Study of Academic Performance and the Experiences of Recent Immigrant Groups at the University of California

ERIC Educational Resources Information Center

Douglass, John Aubrey; Thomson, Gregg

2010-01-01

One of the major characteristics of globalization is the large influx of immigrant groups moving largely from underdeveloped regions to developed economies. California offers one of the most robust examples of a large-scale, postmodern demographic transition that includes a great racial, ethnic, and cultural diversity of immigrant groups, many of…

Group Work at University: Significance of Personal Goals in the Regulation Strategies of Students with Positive and Negative Appraisals

ERIC Educational Resources Information Center

Volet, Simone; Mansfield, Caroline

2006-01-01

This paper examines the mediating role of students' goals in group work at university. Research on cooperative and collaborative learning has provided empirical support for the cognitive, motivational and social benefits of group work but the antecedents of motivation and ongoing management of emerging motivational and socio-emotional issues have…

The effect of note-taking skills training on the achievement motivation in learning on B.A students in Shahid Bahonar University of Kerman and Kerman University of Medical Sciences (Iran).

PubMed

Sharifi, Parvane; Rahmati, Abbas; Saber, Maryam

2013-10-01

To evaluate the effect of note-taking skills training on the achievement motivation in learning. The experimental study comprised graduate students of the 2010-11 batch at Kerman's Bahonar University and Kerman's Medical Sciences University, Iran. The study sample included 110 people; 55 in the test group, and 55 in the control group. They were randomly selected and replaced through the single-stage cluster sampling. To collect the data, a questionnaire was used. Pre-test was performed before the training session in two groups. After training course, a post-test was taken. For data analysis, the independent t-test, was used. The average pre-test score of the test group was 182 +/- 34.15, while for the control group it was 191 +/- 30.37 (p < 0.089). After the training, the post-test showed statistically significant change. The test group scored 220 +/- 20.94 against the controls who scored 195 +/- 27.26 (p < 0.001). The findings showed that achievement motivation in learning increased significantly after imparting training in note-taking skills. Authorities in the educational system should invest more for promotion of such skills.

Nickel-cysteine nanoparticles: Synthesis, characterization and application for direct electron transfer studies.

PubMed

Sharifi, Ensiyeh; Shams, Esmaeil; Salimi, Abdollah; Noorbakhsh, Abdollah; Amini, Mohammad K

2018-05-01

Nickel-cysteine nanostructures (Ni-CysNSs) are prepared by a simple wet chemistry procedure under mild conditions, in which l-cysteine acts both as precursor and structure directing agent. This method involves the reaction of nickel chloride with l-cysteine, followed by simultaneous adjusting the pH in the range of 6-8.5 by addition of an aqueous NaOH solution. The structure and morphology of the prepared products are characterized using various techniques, including X-ray powder diffraction (XRD), Fourier transform-infrared (FT-IR) spectroscopy, CHNS elemental analysis, Field emission scanning electron microscopy (FESEM) and Transmission electron microscopy (TEM). The effects of a variety of synthetic conditions on the structure and morphology of the Ni-CysNSs are studied, including the molar ratio of precursors, dispersing solvent, pH value of the reaction solution, reaction time and reaction temperature. FT-IR measurements reveal that synthesized Ni-CysNSs contain many free carboxylic groups on the surface, which could be used as binding sites to anchor biological molecules in order to develop various bioelectronic devices. In this work, the applicability of synthesized nanostructure in biosensing is studied by using Ni-CysNSs as a platform for covalently immobilization of GOx, as a model enzyme, on the surface. Cyclic voltammetric measurements reveal that the direct electron transfer from the active center of GOx to the glassy carbon electrode facilitated upon its immobilization on the Ni-CysNSs film. More importantly, GOx preserves its native structure and catalytic activity for the oxidation of glucose after immobilization on the Ni-CysNSs surface. The electrocatalytic characteristics of the GC/NiCysNS/GOx electrode toward the oxidation of glucose are investigated by cyclic voltammetry, which displayed acceptable electrical and sensing performance. Simple preparation of Ni-CysNPs and their biocompatibility make them attractive platforms for integration of various biomolecules such as proteine/enzymes with surface. Copyright © 2018. Published by Elsevier B.V.

Electrochemical sensor with flavin-containing monooxygenase for triethylamine solution.

PubMed

Saito, Hirokazu; Shirai, Takeshi; Kudo, Hiroyuki; Mitsubayashi, Kohji

2008-06-01

A bioelectronic sensor for triethylamine (TEA) was developed with a flavin-containing monooxygenase type 3 (FMO-3). The TEA biosensor consisted of a Clark-type dissolved-oxygen electrode and an FMO-3 immobilized membrane. The FMO-3 solution was mixed with a poly(vinyl alcohol) containing stilbazolium groups (PVA-SbQ), coated on to the dialysis membrane, and the membrane was irradiated with a fluorescent light to immobilize the enzyme. In order to amplify the biosensor output, a substrate regeneration cycle, obtained by coupling the monooxygenase with L-ascorbic acid (AsA) as reducing reagent system, was applied. The effect of pH on the determination of TEA was studied. The maximum response was achieved at pH >9.0. A drop of the phosphate buffer solution with the AsA was put on the sensing area of the oxygen electrode, and the FMO-3 immobilized membrane was placed on the oxygen electrode and covered with a supporting Nylon mesh net which was secured with a silicone O-ring. A measurement system for TEA solution was constructed using the FMO-3 biosensor, a personal computer, a computer-controlled potentiostat, and an A/D converter. The FMO-3 biosensor was used to measure TEA solution from 0.5 to 4.0 mmol L(-1) with 10.0 mmol L(-1) AsA. The biosensor also had good reproducibility, for example a 6.31% coefficient of variation for five measurements, and the output current was maintained over a few hours. In order to improve the selectivity of the TEA biosensor, three type of biosensor with FMO isomer types 1, 3, and 5 were constructed and used to measure nitrogen and sulfur compounds. The outputs of the isomer biosensors indicated individual patterns for each sample solution. The selectivity of TEA biosensor would be improved, and determination of sulfur and nitrogen compounds would be possible, by using the different output of biosensors prepared from different FMO isomers.

Development and Management of University Research Groups.

ERIC Educational Resources Information Center

Smith, Robert V.

Guidelines for managers of university research groups cover securing resources, personnel, and services and choosing collaborators, as well as organizing, supervising, and controlling research activities. Attention is directed to: orientation of personnel; reporting mechanisms; boosting morale; the needs of different personnel; handling travel,…

The Process in Completing a Nontraditional Group Dissertation in Practice for the Carnegie Project on the Education Doctorate, the Ed.D. Educational Leadership Program at Lynn University

ERIC Educational Resources Information Center

Vickers, Jerome

2016-01-01

This study focused on how a cohort of scholarly practitioners extended the traditional Doctorate in Education (Ed.D.) model at Lynn University by undertaking a nontraditional group Dissertation in Practice (DiP). The participants were a cohort of 11 scholarly practitioners known as Cohort 5 who became the first Lynn University doctoral students to…

Process Consultancy. The Demand for Consultancy on Group Processes in the Open University--Implications of Change (Report No. 59). Process Consultancy within the Open University 1981-1991 (Report No. 61).

ERIC Educational Resources Information Center

Nicodemus, Robert

The two reports combined here provide introductory information on consultancy work at Great Britain's Open University Institution of Educational Technology. The approach at the institution was influenced by the theories and methods developed at the Tavistock Institute of Human Relations and applied to group relations training. It is noted that the…

Prostate Cancer Clinical Trials Group: The University of Michigan Site

DTIC Science & Technology

2012-04-01

and fusion-negative strata. UM will be the lead site for this trial with the Univ. of Chicago N01 Phase II consortium as the coordinating center. Ten...sensitive prostate cancer: a University of Chicago Phase II Consortium/Department of Defense Prostate Cancer Clinical Trials Consortium study. JE Ward, T...N01 contract with CTEP (University of Chicago – Early Therapeutics Development with Phase II emphasis group). The Program is committed to creating

Evaluation of Root Canal Cleaning and Shaping Efficacy of Three Engine-driven Instruments: SafeSider, ProTaper Universal and Lightspeed LSX.

PubMed

Wigler, Ronald; Koren, Tal; Tsesis, Igor

2015-11-01

To compare the cleaning effectiveness and shaping ability of SafeSider, ProTaper Universal and Lightspeed rotary instruments during the preparation of curved root canals in extracted human teeth. A total of 63 roots with curved root canals were divided into three groups. Canals were prepared using SafeSider, ProTaper Universal or Lightspeed LSX. Using pre- and post-instrumentation radiographs, straightening of the canal curvatures and loss of working length were determined with a computer image analysis program. The amounts of debris at the apical 5 mm were quantified on the basis of a numerical evaluation scale. The data were analyzed statistically using the two-way analysis of variance (ANOVA). There was significantly more transportation among the Lightspeed LSX group compared to the SafeSider and ProTaper Universal groups only at the 4 mm level (p < 0.05). The ProTaper Universal instruments performed significantly faster than other groups. No significant differences were observed between the three engine-driven instruments with regards to debris removal. SafeSider, ProTaper Universal and Lightspeed LSX rotary instruments maintained the original canal curvature well at the apical 3 mm and were safe to use. No difference was found in cleaning efficacy and none rendered the apical part of the canal free of debris. SafeSider, ProTaper Universal and Lightspeed LSX rotary instruments are safe to use in curved root canals.

The influence of unstable modified wall squat exercises on the posture of female university students

PubMed Central

Lee, Yoonmi

2015-01-01

[Purpose] The purpose of this study was to examine the effect of unstable modified wall squat exercises on the posture of female university students. [Subjects] The subjects of this study were 30 female university students who were equally and randomly allocated to an unstable modified wall squat exercises group the experimental group and a stable modified wall squat exercises group the control group. [Methods] Both groups performed their respective exercises for 30 minutes three times per week over a six-week period. Using BackMapper, trunk inclination, trunk imbalance, pelvic position, pelvic torsion, pelvic rotation, and position of the scapulae were evaluated. [Results] The unstable modified wall squat exercises group obtained significant results for trunk inclination, trunk imbalance, pelvic position, pelvic torsion, position of the scapulae, while the stable modified wall squat exercises group obtained significant results for trunk imbalance and pelvic position. [Conclusion] Unstable modified wall squat exercises may be applied as a method to correct the posture of average adults. PMID:26356770

World University Rankings: Ambiguous Signals. Go8 Backgrounder 30

ERIC Educational Resources Information Center

Group of Eight (NJ1), 2012

2012-01-01

The current main world university rankings broadly group the leading research universities of nations. Australia's Go8 universities are generally within the top 250 ranked universities, with several institutions in the top 50-100 on some measures. This recognition is commendable, however imperfect the individual rankings may be. Use is made of…

The Promise & The Peril.

ERIC Educational Resources Information Center

Roach, Ronald

1997-01-01

Experiences of three historically black universities illustrate advantages and problems of college ownership of hotels and conference centers. Tuskegee University (Alabama) hopes its city, university, and conference facility will draw African American groups. Clark Atlanta University (Georgia) has purchased and renovated a hotel and restaurant.…

Parochial cooperation in nested intergroup dilemmas is reduced when it harms out-groups.

PubMed

Aaldering, Hillie; Ten Velden, Femke S; van Kleef, Gerben A; De Dreu, Carsten K W

2018-06-01

In intergroup settings, humans often contribute to their in-group at a personal cost. Such parochial cooperation benefits the in-group and creates and fuels intergroup conflict when it simultaneously hurts out-groups. Here, we introduce a new game paradigm in which individuals can display universal cooperation (which benefits both in- and out-group) as well as parochial cooperation that does, versus does not hurt the out-group. Using this set-up, we test hypotheses derived from group selection theory, social identity, and bounded generalized reciprocity theory. Across three experiments we find, first, that individuals choose parochial over universal cooperation. Second, there was no evidence for a motive to maximize differences between in- and out-group, which is central to both group selection and social identity theory. However, fitting bounded generalized reciprocity theory, we find that individuals with a prosocial value orientation display parochial cooperation, provided that this does not harm the out-group; individualists, in contrast, display parochialism whether or not nut it hurts the out-group. Our findings were insensitive to cognitive taxation (Experiments 2-3), and emerged even when universal cooperation served social welfare more than parochialism (Experiment 3). (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Impact of the Systemic Approach on Literacy Achievement of Jordanian 1st Graders at Mu'tah University Model School

ERIC Educational Resources Information Center

Al-Hajaya, Nail

2012-01-01

This study investigates the effect of the systemic approach in literacy achievement of the first grade students at Mu'tah University's Model School. The sample (N = 45) consisted of all first grade students, who were assigned into two groups; a control group taught traditionally while the other group was exposed to the system approach during the…

THE ABILITIES OF YOUNG CHILDREN. CEC RESEARCH MONOGRAPH SERIES B, NO. B-4.

ERIC Educational Resources Information Center

MARTINSON, RUTH A.; SEAGOE, MAY V.

IN ORDER TO ASSESS THE QUALITY OF CREATIVE PRODUCTS IN ART, MUSIC, WRITING, SOCIAL STUDIES, AND SCIENCE, CHILDREN ATTENDING GRADES 3 TO 6 OF THE UNIVERSITY ELEMENTARY SCHOOL OF THE UNIVERSITY OF CALIFORNIA, LOS ANGELES, WERE DIVIDED INTO TWO GROUPS ON THE BASIS OF INTELLIGENCE. THE HIGHER GROUP (49 PUPILS, IQ OF 130 OR MORE) AND THE LOW GROUP (57…

Reflections and Conclusions on the Work Developed by the Group of Teaching Innovation in Electronics at the University of Valladolid

ERIC Educational Resources Information Center

Herrero, Luis Carlos; Pardo, Fernando; Fernando, María Luisa; González, María Luisa

2011-01-01

We hereby present the main conclusions and perspectives obtained by the Group of Teaching Innovation in Electronics (Grupo de Innovación Docente en Electrónica, GIDEN) of the University of Valladolid (UVa) with regard to its main areas of work. This group comprises teachers of the "Specialty in Industrial Electronics" degree, and the…

The effectiveness of a learning strategies program for university students.

PubMed

Roces Montero, Cristina; Sierra Y Arizmendiarrieta, Beatriz

2017-11-01

University lecturers often complain about their students’ lack of learning strategies, but not many universities in Spain offer specific courses in this area. Studies on their effectiveness are also rare. This study presents the results of a Learning Strategies Course implemented at the School of Teacher Training and Education, University of Oviedo, Spain. A quasi-experimental design was used with an experi-mental (n = 60) and a control group (n = 57) of students on the Educational Psychology course. A Spanish adaptation of the Motivated Strategies for Learning Questionnaire (MSLQ): the CEAMR2 was used as a pre and post-test measure. Group A (EG) received training in learning strategies, while group B (CG) received no training. Post-test measures showed significant differences in five out of the ten learning strategies assessed: elaboration, organization, repetition, self-questioning and study space, and also an improvement in one out of the six motivational scales: control of learning beliefs. The results suggest that learning strategies courses with proven effectiveness should be offered to university students.

Mobile phone brief intervention applications for risky alcohol use among university students: a randomized controlled study.

PubMed

Gajecki, Mikael; Berman, Anne H; Sinadinovic, Kristina; Rosendahl, Ingvar; Andersson, Claes

2014-07-02

Brief interventions via the internet have been shown to reduce university students' alcohol intake. This study tested two smartphone applications (apps) targeting drinking choices on party occasions, with the goal of reducing problematic alcohol intake among Swedish university students. Students were recruited via e-mails sent to student union members at two universities. Those who gave informed consent, had a smartphone, and showed risky alcohol consumption according to the Alcohol Use Disorders Identification Test (AUDIT) were randomized into three groups. Group 1 had access to the Swedish government alcohol monopoly's app, Promillekoll, offering real-time estimated blood alcohol concentration (eBAC) calculation; Group 2 had access to a web-based app, PartyPlanner, developed by the research group, offering real-time eBAC calculation with planning and follow-up functions; and Group 3 participants were controls. Follow-up was conducted at 7 weeks. Among 28574 students offered participation, 4823 agreed to join; 415 were excluded due to incomplete data, and 1932 fulfilled eligibility criteria for randomization. Attrition was 22.7-39.3 percent, higher among heavier drinkers and highest in Group 2. Self-reported app use was higher in Group 1 (74%) compared to Group 2 (41%). Per-protocol analyses revealed only one significant time-by-group interaction, where Group 1 participants increased the frequency of their drinking occasions compared to controls (p = 0.001). Secondary analyses by gender showed a significant difference among men in Group 1 for frequency of drinking occasions per week (p = 0.001), but not among women. Among all participants, 29 percent showed high-risk drinking, over the recommended weekly drinking levels of 9 (women) and 14 (men) standard glasses. Smartphone apps can make brief interventions available to large numbers of university students. The apps studied using eBAC calculation did not, however, seem to affect alcohol consumption among university students and one app may have led to a negative effect among men. Future research should: 1) explore ways to increase user retention, 2) include apps facilitating technical manipulation for evaluation of added components, 3) explore the effects of adapting app content to possible gender differences, and 4) offer additional interventions to high-risk users. clinicaltrials.gov: NCT01958398.

Investigation of Aggression Levels of University Students (Kocaeli University Case)

ERIC Educational Resources Information Center

Keskin, Özlem; Akdeniz, Hakan

2018-01-01

The aim of this study was to investigate the aggression levels of university students in different departments in terms of sport and other variables. The population of the study consists of university students studying at Kocaeli University; the sample group consists of a total of 700 students, 378 male and 322 female, studying in the Faculty of…

Agreement between University of Cincinnati and AAUP, University of Cincinnati Chapter, September 1, 1986 to August 31, 1989.

ERIC Educational Resources Information Center

American Association of Univ. Professors, Washington, DC.

The collective bargaining agreement between the University of Cincinnati and the university chapter of the American Association of University Professors (AAUP) covering the period September 1, 1986 through August 31, 1989 is presented. The 42 articles, grouped into seven categories, cover the following: (1) basic principles (recognition and…

University Opinion Poll 9: Child Care, MPIRG, Lettuce. Preliminary Report.

ERIC Educational Resources Information Center

Matross, Ronald; And Others

The University Opinion Poll conducted a survey of student opinion on issues related to University-sponsored day care, the role of the Minnesota Public Interest Research Group (MPIRG) and the University's policy on buying lettuce for its food services. Four hundred fifty-two respondents, 76% of a random sample of University of Minnesota students,…

Volcanic influences: International working group on volcanogenic sediments

NASA Astrophysics Data System (ADS)

A conclusion of the Geological Society of America Penrose Conference on Volcanic Influences on Terrestrial Sedimentation (August 28 to September 2, 1988) was that establishment of an informal working group would enhance our understanding of volcanogenic sedimentation. To establish the group, an ad hoc steering committee was formed at the conference and consists of W. J. Fritz (Georgia State University), R. S. Hildebrand (Geological Survey of Canada), R. Iverson (U.S. Geological Survey), P. Kokelaar (Chairman, University of Liverpool), T. C. Pierson (USGS), and G. A. Smith (University of New Mexico). The working group is open to researchers of any nation interested in the study of secondary transport and deposition of volcaniclastic materials in subaerial or subaqueous environments (e.g., transport, deposition, nomenclature, volcanic history, experiment, theory, hazard).

Ethical Decision-Making for Homeland Security

DTIC Science & Technology

2013-09-01

how the universal laws of an ideal state could reconcile the interests of both individuals and groups . Cohen’s emphasis on the universal character...unethical decision as an ethical one . Excellence was another personal trait, listed 12 times in the surveyed group . This is another good quality for...and improve the ethical climate of leadership and groups . A booklet or field guide for employees on ethics would be a good opportunity for the

The Effect of Training Program for Staff Members to Develop Their Skills of Using Virtual Classrooms at King Saud University

ERIC Educational Resources Information Center

Alotaibi, Khaled Nahes; Almutairy, Sultan

2012-01-01

The present study aims at showing the effectiveness of a suggested training program for staff members at Teachers' College of King Saud University to develop their skills of using virtual classrooms. The research is empirical as it used two experimental groups. The first group is taught how to use the common teaching method and the second group is…

Group Treatment of Eating Disorders in a University Counseling Center.

ERIC Educational Resources Information Center

Snodgrass, Gregory; And Others

Sociocultural pressures to pursue an unrealistic ideal of thinness have contributed to an increasing number of students seeking help at a university counseling center for the eating disorders of anorexia nervosa and bulimia. To help these students, a group treatment technique was developed using a cognitive-behavioral approach. Treatment…

Support Group for International Students: A Counseling Center's Experience

ERIC Educational Resources Information Center

Dipeolu, Abiola; Kang, Jinhee; Cooper, Caren

2007-01-01

Statistics suggest a steady increase in the number of international students attending universities in the U.S. However, limited information is available to guide professionals in the delivery of effective mental health services to this diverse group. University counseling centers have repeatedly reported little to no success with international…

Streaming in First-Year University Classes.

ERIC Educational Resources Information Center

Jones, John; And Others

1990-01-01

The practice of dividing up a group of students on the basis of previous educational experience or achievement, and subjecting the different groups to different educational experiences is defended. Two case-studies of streaming in the departments of accountancy and physics at a university in New Zealand are presented. (Author/MLW)

Organizational respect dampens the impact of group-based relative deprivation on willingness to protest pay cuts.

PubMed

Osborne, Danny; Huo, Yuen J; Smith, Heather J

2015-03-01

Although group-based relative deprivation predicts people's willingness to protest unfair outcomes, perceiving that one's subgroup is respected increases employees' support for organizations. An integration of these perspectives suggests that subgroup respect will dampen the impact of group-based relative deprivation on workers' responses to unfair organizational outcomes. We examined this hypothesis among university faculty (N = 804) who underwent a system-wide pay cut. As expected, group-based relative deprivation predicted protest intentions. This relationship was, however, muted among those who believed university administrators treated their area of expertise (i.e., their subgroup) with a high (vs. low) level of respect. Moderated mediation analyses confirmed that group-based relative deprivation had a conditional indirect effect on protest intentions via participants' (dis)identification with their university at low to moderate, but not high, levels of subgroup respect. Our finding that satisfying relational needs can attenuate responses to group-based relative deprivation demonstrates the benefits of integrating insights from distinct research traditions. © 2014 The British Psychological Society.

Accounting for Tibetan University Students' and Teachers' Intellectual Styles

ERIC Educational Resources Information Center

Zhang, Li-Fang; Fu, Hong; Jiao, Ben

2008-01-01

The primary objective of this study was to further understand Tibetan university students' learning styles through investigating Tibetan university teachers' teaching styles and their preferred student learning styles. This objective was achieved by analysing the interview data from a group of Tibetan university teachers and the comparative survey…

Evaluation of the NSF Industry/University Cooperative Research Centers: Descriptive and Correlative Findings.

ERIC Educational Resources Information Center

National Science Foundation, Washington, DC. Directorate for Engineering.

This report presents results of a survey of participants in the National Science Foundation (NSF) Industry-University Cooperative Research Centers program. The program promotes more rapid technological innovation by creating linkages between industry and university scientists. The Centers function as university research groups, with partial…

Secular trends in the timing of skeletal maturation as assessed by the cervical vertebrae maturation method.

PubMed

Montasser, Mona A; Viana, Grace; Evans, Carla A

2017-04-01

To investigate the presence of secular trends in skeletal maturation of girls and boys as assessed by the use of cervical vertebrae bones. The study compared two main groups: the first included data collected from the Denver growth study (1930s to 1960s) and the second included data collected from recent pretreatment records (1980s to 2010s) of patients from the orthodontic clinic of a North American University. The records from the two groups were all for Caucasian subjects. The sample for each group included 78 lateral cephalographs for girls and the same number for boys. The age of the subjects ranged from 7 to 18 years. Cervical vertebrae maturation (CVM) stages were directly assessed from the radiographs according to the method described by Hassel and Farman in which six CVM stages were designated from cervical vertebrae 2, 3, and 4. The mean age of girls from the Denver growth study and girls from the university clinic in each of the six CVM stages was not different at P ≤0.05. However, the mean age of boys from the two groups was not different only in stage 3 (P = 0.139) and stage 4 (P = 0.211). The results showed no evidence to indicate a tendency for earlier skeletal maturation of girls or boys. Boys in the university group started their skeletal maturation later than boys in the Denver group and completed their maturation earlier. Gender was a significant factor affecting skeletal maturation stages in both Denver and university groups. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com

Prevalence of the colonization of Helicobacter pylori among students of the school of dentistry, University of Granada, Spain

PubMed Central

García-Casas, Violeta; Liébana-Cabanillas, Francisco; Arias-Moliz, María-Teresa

2016-01-01

Background The oral cavity is a reservoir for Helicobacter pylori, and occupations that involve close contact with it, like Dentistry, could entail a higher risk of colonization. The aim of this study was to evaluate if the length of stay at the School of Dentistry of the University of Granada could influence colonization by H. pylori, and to furthermore correlate colonization by H. pylori, with the state of oral health and oral hygiene habits. Material and Methods The study groups were: Group 1, 35 students of Odontology in their first year of studies; Group 2, the same 35 students when they were in their fifth academic year; Group 3, 35 students from University study programs unrelated with Health and of the same age as the group 2 students. All underwent H. pylori, colonization determinations by means of the urea breath test (UBT), stool antigen test and a serological test. Also studied were the variables plaque index, gingival index and the number of times teeth were brushed per day. The Student t test was used for comparisons among the three studied groups. The Chi-squared test and Pearson correlation coefficient were used to determine any connection between colonization by H. pylori, and the variables studied. Results Comparisons between groups 1 and 2 and between groups 2 and 3 showed significant differences regarding colonization by H. pylori, plaque index, gingival bleeding index and tooth brushing. A positive correlation was found between being colonized by H. pylori, and having a gingival index higher than 10% and tooth brushing once a day or less, in all the studied groups. Conclusions Colonization by H. pylori, among Dentistry students at the University of Granada decreased over a four-year time period at the University. Factors related with better oral health, such as a lower gingival index and more frequent tooth brushings, would explain these results. Key words:Dental students, Helicobacter pylori, serological test, stool antigen test, urea breath test. PMID:27475692

Prevalence of the colonization of Helicobacter pylori among students of the school of dentistry, University of Granada, Spain.

PubMed

Liébana, J; García-Casas, V; Liébana-Cabanillas, F; Arias-Moliz, M-T

2016-09-01

The oral cavity is a reservoir for Helicobacter pylori, and occupations that involve close contact with it, like Dentistry, could entail a higher risk of colonization. The aim of this study was to evaluate if the length of stay at the School of Dentistry of the University of Granada could influence colonization by H. pylori, , and to furthermore correlate colonization by H. pylori, with the state of oral health and oral hygiene habits. The study groups were: Group 1, 35 students of Odontology in their first year of studies; Group 2, the same 35 students when they were in their fifth academic year; Group 3, 35 students from University study programs unrelated with Health and of the same age as the group 2 students. All underwent H. pylori, colonization determinations by means of the urea breath test (UBT), stool antigen test and a serological test. Also studied were the variables plaque index, gingival index and the number of times teeth were brushed per day. The Student t test was used for comparisons among the three studied groups. The Chi-squared test and Pearson correlation coefficient were used to determine any connection between colonization by H. pylori, and the variables studied. Comparisons between groups 1 and 2 and between groups 2 and 3 showed significant differences regarding colonization by H. pylori, plaque index, gingival bleeding index and tooth brushing. A positive correlation was found between being colonized by H. pylori, and having a gingival index higher than 10% and tooth brushing once a day or less, in all the studied groups. Colonization by H. pylori, among Dentistry students at the University of Granada decreased over a four-year time period at the University. Factors related with better oral health, such as a lower gingival index and more frequent tooth brushings, would explain these results.

Pittsburgh-Tuskegee Prostate Training Program

DTIC Science & Technology

2013-05-01

February 2012, Tuskegee University sophomore trainees will be selected as “Prostate Cancer Scholars” for summer internship at the University of...selected as “Prostate Cancer Scholars” for summer internship at the University of Pittsburgh. This is being reported on as the second group of... internship at the University of Pittsburgh. February – April 2012, Trainees will be selectively paired with University of Pittsburgh Faculty

The Howard University Hospital Transplant and Dialysis Support Group: twenty years and going strong.

PubMed

Stewart, A M; Kelly, B; Robinson, J D; Callender, C O

1995-10-01

This article discusses group therapy as part of a multidisciplinary approach to the management of the various psychological and physical rehabilitation concerns posed by kidney and liver transplant candidates and recipients at Howard University Hospital in Washington, DC. The group's history, format, intervention foci, and roles of clinicians and patients attending the group are described and evaluated. Given the relative paucity of research literature in this area, the authors offer recommendations for empirical evaluation of the benefits of multidisciplinary group psychotherapy in ameliorating physical and emotional suffering and prolonging life among transplant patients.

Implementation of internet training on posture reform of computer users in iran.

PubMed

Keykhaie, Zohreh; Zareban, Iraj; Shahrakipoor, Mahnaz; Hormozi, Maryam; Sharifi-Rad, Javad; Masoudi, Gholamreza; Rahimi, Fatemeh

2014-12-01

Musculoskeletal disorders are of common problems among computer (PC) users. Training of posture reform plays a significant role in the prevention of the emergence, progression and complications of these diseases. The present research was performed to study the effect of the Internet training on the posture reform of the Internet users working in two Iranian universities including Sistan and Baluchestan University and Islamic Azad University of Zahedan in 2014. This study was a quasi-experimental intervention with control group and conducted in two Iranian universities including Sistan and Baluchestan University and Islamic Azad University of Zahedan. The study was done on 160 PC users in the two groups of intervention (80 people) and control (80 people). Training PowerPoint was sent to the intervention group through the Internet and a post test was given to them after 45 days. Statistical software of SPSS 19 and statistical tests of Kolmogrov, t-test, Fisher Exact test, and correlation coefficient were used for data analysis. After the training, the mean scores of knowledge, attitude, performance and self-efficacy in the intervention group were 24.21 ± 1.34, 38.36 ± 2.89, 7.59 ± 1.16, and 45.06 ± 4.11, respectively (P <0.001). The mean scores of knowledge in the intervention group 5.45±2.81 and in the control group 1.20 ± 1.07 showed a significant change. Mean scores of attitude in the intervention group 3.60 ± 3.59 and in the control group 0.48± 1.03 showed a significant change as well. Mean scores of self-efficacy in the intervention group 14.83 ± 4.67 and in the control group 0.88 ± 1.93 indicated a significant change and mean scores of performance in the intervention group 5.28 ± 1.24 and in the control group 0.62 ± 0.73 indicated a significant change (P <0.001). The results of the study showed that training through the Internet had a significant impact on the posture reform of the PC users. According to the findings observed, there was a significant relationship between the scores of self-efficacy-performance after training. Therefore, based on the findings of the study, it is suggested that Internet training to increase self-efficacy approach in the successive periods can be effective to reform the postures of PC users.

Postoperative Pain Relief in Major Gynaecological Surgery by Perioperative Parecoxib Administration: Thammasat University Hospital Study.

PubMed

Arponrat, Pawat; Pongrojpaw, Densak; Tanprasertkul, Chamnan; Suwannarurk, Komsun; Bhamarapravatana, Kornkarn

2015-07-01

To study postoperative pain relief in major gynaecological surgery by perioperative parecoxib administration in Thammasat University Hospital. This double-blind randomized controlled clinical trial was conducted in Thammasat University Hospital, Pathumthani, Thailand from October 2013 to May 2014. One hundred and twenty patients who underwent elective gynaecological surgery were randomized assigned to study and control groups. Study group (n = 60) received 40 mg parecoxib and control group (n = 60) received placebo at 1 hour before surgery. The postoperative visual analog scale (VAS) at 3, 6, 12 and 24 hours, frequency of meperidine consumption in 24 hours and side effects of parecoxib were recorded. VAS of study group after operation at 3, 6, 12 and 24 hours was significantly lower than control group. Meperidine consumption in placebo group was significantly higher than study group (27.50 ± 19.36 and 48.75 ± 28.15 mg, respectively; p < 0.001). There was no side effect from parecoxib in this study. Intravenous postoperativeparecoxib injection could relief pain and reduced meperidine consumption. Parecoxib could be safely used in gynaecological surgery for postoperative pain relief

Effects of Plymetrics Training and Weight Training on selected Motor Ability Components among University Male Students

NASA Astrophysics Data System (ADS)

Shaikh, Alauddin; Mallick, Nazrul Islam

2012-11-01

Introduction: The aim of this study was to find out the effects of plyometrics training and weight training among university male students.Procedure: 60 male students from the different colleges of the Burdwan University were randomly selected as subjects and their age were 19-25 years served as Weight training Group (WTG), second group served as Plyometric Training Group (PTG) and the third group served as Control Group (CT). Eight weeks weight training and six weeks plyometric training were given for experiment accordingly. The control group was not given any training except of their routine. The selected subjects were measured of their motor ability components, speed, endurance, explosive power and agility. ANCOVA was calculation for statistical treatment.Finding: Plyometric training and weight training groups significantly increase speed, endurance, explosive power and agility.Conclusion: The plyometric training has significantly improved speed, explosive power, muscular endurance and agility. The weight training programme has significantly improved agility, muscular endurance, and explosive power. The plometric training is superior to weight training in improving explosive power, agility and muscular endurance.

A "Brief History" of Developmental Biology in Israel.

PubMed

Sela-Donenfeld, Dalit; Frank, Dale

2017-01-01

While the history of developmental biology in Israel is relatively short, its impact is far-reaching, so we wanted to present a concise perspective on the Israeli developmental biology community, past-present-future. This community has undergone a wonderful, nearly exponential growth over the last three decades. How exactly did this happen? There are approximately fifty research groups that focus on developmental biology questions in Israel today that are members of the Israel Society of Developmental Biology (IsSDB; http://issdb.org/). The community has representative groups in a plethora of model systems, such as Nematostella, C. elegans, Drosophila, sea urchin, ascidians, zebrafish, Xenopus, chick and mouse, as well as plants, representing all the major universities and their branches, which include Bar-Ilan University, Ben-Gurion University of the Negev, The Hebrew University of Jerusalem, The University of Haifa, Technion - Israel Institute of Technology, Tel Aviv University and the Weizmann Institute of Science.

Alcohol use among university students: Considering a positive deviance approach.

PubMed

Tucker, Maryanne; Harris, Gregory E

2016-09-01

Harmful alcohol consumption among university students continues to be a significant issue. This study examined whether variables identified in the positive deviance literature would predict responsible alcohol consumption among university students. Surveyed students were categorized into three groups: abstainers, responsible drinkers and binge drinkers. Multinomial logistic regression modelling was significant (χ(2) = 274.49, degrees of freedom = 24, p < .001), with several variables predicting group membership. While the model classification accuracy rate (i.e. 71.2%) exceeded the proportional by chance accuracy rate (i.e. 38.4%), providing further support for the model, the model itself best predicted binge drinker membership over the other two groups. © The Author(s) 2015.

Effects of Universal and Conventional MDP Primers on the Shear Bond Strength of Zirconia Ceramic and Nanofilled Composite Resin

PubMed Central

Sharafeddin, Farahnaz; Shoale, Soodabe

2018-01-01

Statement of the Problem: The clinical success of ceramic depends on the quality of the bond between the zirconia and resin cement. Purpose: In the present study, the effects of universal and conventional MDP-containing primers were evaluated on the shear bond strength of zirconia ceramic and nanofilled composite resin. Materials and Method: Thirty blocks of zirconia ceramic (6mm×2mm) were prepared. Then the inner surfaces were air-abraded and divided into three groups (n= 10) as follows: untreated with primer (control group, I); All- Bond Universal (group II) and Z-Prime Plus (group III). The specimens in each group were bonded with Variolink N cement to cylinders of composite resin Z350XT. After 24 hour water storage, the shear bond strength test was performed with a universal testing machine at a crosshead speed of 1mm/ min and bond strength values (MPa) were calculated and analyzed with one-way ANOVA and post hoc Tukey tests (p< 0.05). The failure mode of each specimen was evaluated under a stereomicroscope and representative specimens were analyzed by scanning electron microscopy (SEM). Results: The mean shear bond strength values (MPa) were 7.58±1.62, 17.51±1.34 and 22.45±3.60 in groups I, II and III, respectively. These results indicated that the shear bond strength were significantly higher in groups II and III compared to the control group (p< 0.001). Chemical pre-treatment of zirconia with Z- Prime Plus revealed significantly higher bond strength than the All-Bond Universal adhesive (p< 0.002). All the failure modes were adhesive in the control group (I) and when using primer treatment, mixed failures occurred in 40% and 50% of specimens in groups II and III, respectively. Conclusion: Treatment with both primers resulted in higher bond strength values compared to the control group. The use of Z-Prime Plus treatment in combination with air-abrasion procedure resulted in the highest bond strength. PMID:29492416

A bibliometric analysis of digestive health research in Canada.

PubMed

Tuitt, Desiree; Knight, Frank; Lipman, Tara

2011-11-01

Measurement of the impact and influence of medical⁄scientific journals, and of individual researchers has become more widely practiced in recent decades. This is driven, in part, by the increased availability of data regarding citations of research articles, and by increased competition for research funding. Digestive disease research has been identified as a particularly strong discipline in Canada. The authors collected quantitative data on the impact and influence of Canadian digestive health research. The present study involved an analysis of the research impact (Hirsch factor) and research influence (Influence factor) of 106 digestive health researchers in Canada. Rankings of the top 25 researchers on the basis of the two metrics were dominated by the larger research groups at the University of Toronto (Toronto, Ontario), McMaster University (Hamilton, Ontario), and the Universities of Calgary (Calgary, Alberta) and Alberta (Edmonton, Alberta), but with representation by other research groups at the Universities of Manitoba (Winnipeg, Manitoba), Western Ontario (London, Ontario) and McGill University (Montreal, Quebec). Female and male researchers had similar scores for the two metrics, as did basic scientists versus clinical investigators. Strategic recruitment, particularly of established investigators, can have a major impact on the ranking of research groups. Comparing these metrics over different time frames can provide insights into the vulnerabilities and strengths of research groups.

Computer Output Microform (COM) Catalog Requirements for the Virginia Commonwealth University Libraries.

ERIC Educational Resources Information Center

White, Robert L.

Generated as the result of the deliberations of the COM Catalog Advisory Work Group, which depended heavily on a review of the available literature, individual analysis, and group discussion, this report is intended as a general planning document for Virginia Commonwealth university libraries concerning their possible implementation of a COM…

Leisure Activities of University College Staff

ERIC Educational Resources Information Center

Biernat, Elzbieta; Roguski, Karol

2009-01-01

Study aim: To determine the participation of academic teachers in leisure activities for that group contribute to shaping habits of a large percentage of young people. Material and methods: A group of 52 staff members (about 30%) of a private university college, aged 25-70 years, were interviewed with respect to their participation in sports,…

Incivility among Group Mates in English Classes at a Japanese Women's University

ERIC Educational Resources Information Center

Jacobs, George M.; Kimura, Harumi; Greliche, Nicolas

2016-01-01

Incivilities are words and actions that may be perceived as impolite. This article reports a study of perceptions of and experiences with incivilities during group activities in English class. Participants were 119 students at a women's university in Japan. They completed the Pair/Groupwork Incivility Scale, a Japanese-language instrument, which…

Relationships between Psychological Well-Being, Happiness, and Educational Satisfaction in a Group of University Music Students

ERIC Educational Resources Information Center

Demirbatir, Rasim Erol

2015-01-01

Few studies have been conducted on music students' psychological well-being and happiness. The purpose was to assess the psychological well-being, happiness and educational satisfaction among a group of university music students. Students participated voluntarily and filled out a sociodemographic questionnaire, Depression Anxiety Stress Scale…

Effectiveness of a Universal, Interdependent Group Contingency Program on Children's Academic Achievement: A Countywide Evaluation

ERIC Educational Resources Information Center

Weis, Robert; Osborne, Karen J.; Dean, Emily L.

2015-01-01

The Good Behavior Game (GBG) is a universal prevention program designed to increase academic engagement and to decrease disruptive behavior in elementary school-age children. Teachers and other school personnel use interdependent group contingencies to improve students' behavior in the classroom. Previous research indicates the GBG is efficacious…

Constructing the Cultural "Other": Prejudice and Intergroup Conflict in University Students' Discourses about "The Other"

ERIC Educational Resources Information Center

Ladegaard, Hans J.; Cheng, Ho Fai

2014-01-01

This article analyses how university students in Hong Kong talk about "self" and "other". Three groups of students, Hong Kong Chinese, Mainland Chinese, and Overseas Exchange students, were asked to characterise these three groups in a pre-discussion questionnaire, and subsequently discuss freely what they had written. Selected…

Accountability Groups to Enhance Language Learning in a University Intensive English Program

ERIC Educational Resources Information Center

Lippincott, Dianna

2017-01-01

This mixed methods classroom research examined if accountability groups in the lower proficiency levels of a university intensive English program would improve students' language acquisition. Students were assigned partners for the study period with whom they completed assignments inside and outside of class, as well as set goals for use of…

Recruiting Minority Trustees to Independent College and University Governing Boards. AGB Special Report.

ERIC Educational Resources Information Center

Grigsby, J. Eugene, III; Galloway, Sylvia W.

1996-01-01

The report combines survey findings and data from interviews and focus-group sessions on recruiting minority group members for the private college or university governing board. It discusses real and perceived obstacles and recommends resources to assist institutions. Recommendations are based on two premises: (1) more minorities are needed on…

Research & Consultation on: Access and Transition into Ontario Teacher Education for Under-Represented Groups.

ERIC Educational Resources Information Center

Meyer, John R.; And Others

This research project analyzed results of data collection from surveys of and interviews with a population of underrepresented groups at three Canadian university sites: Windsor, London, and Thunder Bay (Ontario). The project designed a program for transition from secondary and/or undergraduate university level education or concurrent or…

The Role of Campus Ministry at State-Supported Universities: A Judgment Analysis.

ERIC Educational Resources Information Center

Whittington, Barbara; And Others

The judgmental policies of campus ministry held by campus ministers at state-supported universities were studied. The campus ministers were grouped according to the campus minister's ministry group, years of personal campus ministry experience, size of student body, campus minister's position at the school, and the campus minister's age by decade…

On Their LEVEL: How Participation in a University Student Group Shapes Members' Perceptions of Disability

ERIC Educational Resources Information Center

Bialka, Christa S.; Brown, Kara S.; Morro, Danielle; Hannah, Gregory

2017-01-01

This qualitative case study examines the experiences of 27 university students participating in LEVEL, a campus-based group that pairs undergraduates (enactors) and their classmates, who self-identify as having physical disabilities (recipients). The purpose of this research was to understand how enactors' perceptions of physical disability were…

Wait Time for Counseling Affecting Perceived Stigma and Attitude toward the University

ERIC Educational Resources Information Center

Blau, Gary; DiMino, John; Sheridan, Natalie; Stein, Alexander; Casper, Steven; Chessler, Marcy; Beverly, Clyde

2015-01-01

A sample of 99 undergraduates in counseling was divided into two groups based on wait time from triage to intake, "less wait time" (up to two weeks) versus "more wait time" (at least two weeks). The less wait time group showed "higher willingness to recommend the university," "higher institutional…

An Email Exchange Project between Non-Native Speakers of English.

ERIC Educational Resources Information Center

Fedderholdt, Karen

2001-01-01

Describes a recent email writing project between nonnative speakers of English. The project was carried out by a group of Japanese university students, and a group of Danish students preparing for university entrance examinations. Explains the reasons for choosing to use email in writing classes and why nonnative speakers were chosen. (Author/VWL)

Collaboration or Cooperation? Analyzing Group Dynamics and Revision Processes in Wikis

ERIC Educational Resources Information Center

Arnold, Nike; Ducate, Lara; Kost, Claudia

2012-01-01

This study examines the online writing and revision behaviors of university language learners. In small groups, 53 intermediate German students from three classes at three different universities created wiki pages with background information about a novel read in class. All meaning- and language-related revisions were analyzed to determine whether…

Topic Appropriateness in Cross-Cultural Social Conversations.

ERIC Educational Resources Information Center

Hinkel, Eli

A group of university students consisting of native speakers of Chinese (n=63), Japanese (n=33), Korean (n=21), Indonesian (n=20), and Arabic (n=13) with relatively extensive exposure to the American university environment and a control group of 20 native English-speakers were asked to rank the social appropriateness of 104 conversation topics.…

Student Performance in an Introductory Business Statistics Course: Does Delivery Mode Matter?

ERIC Educational Resources Information Center

Haughton, Jonathan; Kelly, Alison

2015-01-01

Approximately 600 undergraduates completed an introductory business statistics course in 2013 in one of two learning environments at Suffolk University, a mid-sized private university in Boston, Massachusetts. The comparison group completed the course in a traditional classroom-based environment, whereas the treatment group completed the course in…

Validation of the Arabic Version of the Group Personality Projective Test among university students in Bahrain.

PubMed

Al-Musawi, Nu'man M

2003-04-01

Using confirmatory factor analytic techniques on data generated from 200 students enrolled at the University of Bahrain, we obtained some construct validity and reliability data for the Arabic Version of the 1961 Group Personality Projective Test by Cassel and Khan. In contrast to the 5-factor model proposed for the Group Personality Projective Test, a 6-factor solution appeared justified for the Arabic Version of this test, suggesting some variance between the cultural groups in the United States and in Bahrain.

Effect of silane pretreatment on the immediate bonding of universal adhesives to computer-aided design/computer-aided manufacturing lithium disilicate glass ceramics.

PubMed

Yao, Chenmin; Zhou, Liqun; Yang, Hongye; Wang, Yake; Sun, Hualing; Guo, Jingmei; Huang, Cui

2017-04-01

The aim of this study was to investigate the effect of silane pretreatment on the universal adhesive bonding between lithium disilicate glass ceramic and composite resin. IPS e.max ceramic blocks etched with hydrofluoric acid were randomly assigned to one of eight groups treated with one of four universal adhesives (two silane-free adhesives and two silane-containing adhesives), each with or without silane pretreatment. Bonded specimens were stored in water for 24 h. The shear bond strength (SBS) of the ceramic-resin interface was measured to evaluate bond strength, and the debonded interface after the SBS test was analysed using field-emission scanning electron microscopy to determine failure mode. Light microscopy was performed to analyse microleakage and marginal sealing ability. Silane pretreatment significantly and positively influenced SBS and marginal sealing ability. For all the universal adhesive groups, SBS increased and the percentage of microleakage decreased after the pretreatment. Without the pretreatment, SBS and the percentage of microleakage were not significantly different between the silane-containing universal adhesive groups and the silane-free groups. Cohesive failure was the main fracture pattern. The results suggest that additional silane pretreatment can effectively improve the bonding strength and marginal sealing of adhesives to lithium disilicate glass ceramics. The bonding performance of silane-containing universal adhesives without pretreatment is similar to that of silane-free adhesives. © 2017 Eur J Oral Sci.

The Role of the University: A Global Perspective.

ERIC Educational Resources Information Center

Husen, Torsten, Ed.

This collection of 12 essays is drawn from a May 1990 panel meeting in Paris, France in conjunction with a joint United Nations University/United Nations Educational, Scientific, and Cultural Organization project on "The Changing Role of the Universities." Papers are grouped into those on: the general role of the university, regional…

Exploring the Heterogeneity of Class in Higher Education: Social and Cultural Differentiation in Danish University Programmes

ERIC Educational Resources Information Center

Thomsen, Jens Peter

2012-01-01

This paper examines the relationship between social background, choice of university programme and academic culture among Danish university students. Statistically and sociologically, university students are often treated as a homogeneous group, but the ever-increasing number of students in higher education demands a closer examination of the…

Re-Becoming ESL: Multilingual University Students and a Deficit Identity

ERIC Educational Resources Information Center

Marshall, Steve

2010-01-01

In this article, I analyze how a group of multilingual students at a university in British Columbia, Canada, go through the process of "re-becoming ESL" during their first year of university. I highlight a central contradiction. Despite bringing a diverse and rich range of languages and cultures to the university, multilingual students…

The UK-Japan Young Scientist Workshop Programme...

ERIC Educational Resources Information Center

Albone, Eric; Okano, Toru

2012-01-01

The authors have been running UK-Japan Young Scientist Workshops at universities in Britain and Japan since 2001: for the past three years in England with Cambridge University and, last year, also with Kyoto University and Kyoto University of Education. For many years they have worked jointly with colleagues in a group of Super Science High…

God and Gays at Georgetown: Observations on Gay Rights Coalition of Georgetown University Law Center v. Georgetown University.

ERIC Educational Resources Information Center

Dutile, Ferdinand N.

1988-01-01

A case in which a Georgetown University gay student group sued the institution for its refusal to allow use of university facilities is discussed, focusing on the conflicts between freedom of religious exercise and statutory civil rights and between libertarian and egalitarian values. (MSE)

History of the Universe Poster

Science.gov Websites

History of the Universe Poster You are free to use these images if you give credit to: Particle Data Group at Lawrence Berkeley National Lab. New Version (2014) History of the Universe Poster Download: JPEG version PDF version Old Version (2013) History of the Universe Poster Download: JPEG version

Cataloguing Costed and Restructured at Curtin University of Technology.

ERIC Educational Resources Information Center

Wade, Rona; Williamson, Vicki

1998-01-01

Outlines the results of a review of the cataloging operations at the library at Curtin University of Technology and the three other publicly funded universities in WAGUL (the Western Australian Group of University Librarians). Identifies cost savings to be achieved by re-engineering cataloging and related operations, and separates them from the…

Recruiting Talent: Indiana University-Purdue University Indianapolis Graduates the First Participants in its Research Scholars Program.

ERIC Educational Resources Information Center

Lords, Erik

2001-01-01

Describes the Minority Research Scholars Program (MRSP) at Indiana University-Purdue University Indianapolis, which funds the education of a group of minority students in seven disciplines: science, engineering and technology, social work, nursing, dental hygiene, physical education, and allied health. The program includes research projects,…

University of Utrecht 1636-1676: "Res Ecclesia, Res Publica and … Res Pecunia"

ERIC Educational Resources Information Center

van Rinsum, Henk; Koops, Willem

2016-01-01

The early history of Utrecht University (founded 1636) reflects an emerging public sphere (Habermas's "bürgerliche öffentlichkeit") of a major town in the Netherlands. This public sphere was a contested field among the different groups establishing and administering the university: university professors, town magistrates and…

Universals of Nonverbal Behavior: A Review of Literature and Statement of Implications.

ERIC Educational Resources Information Center

Garner, Patrick H.

Universals in nonverbal behavior represent an important issue in the study of the cross-cultural communication. Perhaps the most well-known research in nonverbal universals was conducted by Paul Ekman, who examined literate and preliterate cultures from various language groups and identified six universal facial expressions: happiness, sadness,…

Key Performance Indicators of Public Universities Based on Quality Assessment Criteria in Thailand

ERIC Educational Resources Information Center

Sukboonyasatit, Kritsana; Thanapaisarn, Chaiwit; Manmar, Lampang

2011-01-01

The research objective was to develop public universities' key performance indicators. Qualitative research and interviews were employed with each public university's senior executive and quality assessors. The sample group was selected by the office of the public sector development commission and Thailand's public universities can be separated…

Universal Breadwinner Versus Universal Caregiver Model: Fathers' Involvement in Caregiving and Well-Being of Mothers of Offspring with Intellectual Disabilities.

PubMed

Chou, Yueh-Ching; Kröger, Teppo; Pu, Cheng-yun

2016-01-01

The universal breadwinner model means both parents are employed; while the universal caregiver model implies that the father's hours of caregiving are equal or higher to those of the mother. This study aims to examine the hypothesis that the universal caregiver model is more related to the overall well-being of mothers of children with intellectual disabilities than the universal breadwinner model. Face-to-face interview surveys were conducted in 2011 in Taiwan with 876 working-age mothers who had an offspring with intellectual disabilities. The survey included 574 mothers living with their husbands who became our participants. Both anova and regression analyses indicated that, compared with mothers in the universal breadwinner group, mothers in the universal caregiver group had higher levels of maternal marital and family life satisfaction, but not of work satisfaction and quality of life. An incentive policy is critical for supporting the fathers involved in lifelong caregiving and to promote the mothers' quality of life. © 2015 John Wiley & Sons Ltd.

Renormalization group evolution of the universal theories EFT

DOE PAGES

Wells, James D.; Zhang, Zhengkang

2016-06-21

The conventional oblique parameters analyses of precision electroweak data can be consistently cast in the modern framework of the Standard Model effective field theory (SMEFT) when restrictions are imposed on the SMEFT parameter space so that it describes universal theories. However, the usefulness of such analyses is challenged by the fact that universal theories at the scale of new physics, where they are matched onto the SMEFT, can flow to nonuniversal theories with renormalization group (RG) evolution down to the electroweak scale, where precision observables are measured. The departure from universal theories at the electroweak scale is not arbitrary, butmore » dictated by the universal parameters at the matching scale. But to define oblique parameters, and more generally universal parameters at the electroweak scale that directly map onto observables, additional prescriptions are needed for the treatment of RG-induced nonuniversal effects. Finally, we perform a RG analysis of the SMEFT description of universal theories, and discuss the impact of RG on simplified, universal-theories-motivated approaches to fitting precision electroweak and Higgs data.« less

Renormalization group evolution of the universal theories EFT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wells, James D.; Zhang, Zhengkang

The conventional oblique parameters analyses of precision electroweak data can be consistently cast in the modern framework of the Standard Model effective field theory (SMEFT) when restrictions are imposed on the SMEFT parameter space so that it describes universal theories. However, the usefulness of such analyses is challenged by the fact that universal theories at the scale of new physics, where they are matched onto the SMEFT, can flow to nonuniversal theories with renormalization group (RG) evolution down to the electroweak scale, where precision observables are measured. The departure from universal theories at the electroweak scale is not arbitrary, butmore » dictated by the universal parameters at the matching scale. But to define oblique parameters, and more generally universal parameters at the electroweak scale that directly map onto observables, additional prescriptions are needed for the treatment of RG-induced nonuniversal effects. Finally, we perform a RG analysis of the SMEFT description of universal theories, and discuss the impact of RG on simplified, universal-theories-motivated approaches to fitting precision electroweak and Higgs data.« less

A Comparative Study between Universal Eclectic Septoplasty Technique and Cottle

PubMed Central

Amaral Neto, Odim Ferreira do; Mizoguchi, Flavio Massao; Freitas, Renato da Silva; Maniglia, João Jairney; Maniglia, Fábio Fabrício; Maniglia, Ricardo Fabrício

2017-01-01

Introduction  Since the last century surgical correction of nasal septum deviation has been improved. The Universal Eclectic Technique was recently reported and there are still few studies dedicated to address this surgical approach. Objective  The objective of this study is to compare the results of septal deviation correction achieved using the Universal Eclectic Technique (UET) with those obtained through Cottle's Technique. Methods  This is a prospective study with two consecutive case series totaling 90 patients (40 women and 50 men), aged between 18 and 55 years. We divided patients into two groups according to the surgical approach. Fifty-three patients underwent septoplasty through Universal Eclectic Technique (UET) and thirty-seven patients were submitted to classical Cottle's septoplasty technique. All patients have answered the Nasal Obstruction Symptom Evaluation Scale (NOSE) questionnaire to assess pre and postoperative nasal obstruction. Results  Statistical analysis showed a significantly shorter operating time for the UET group. Nasal edema assessment performed seven days after the surgery showed a prevalence of mild edema in UET group and moderate edema in Cottle's technique group. In regard to complication rates, UET presented a single case of septal hematoma while in Cottle's technique group we observed: 02 cases of severe edemas, 01 case of incapacitating headache, and 01 complaint of nasal pain. Conclusion  The Universal Eclectic Technique (UET) has proven to be a safe and effective surgical technique with faster symptomatic improvement, low complication rates, and reduced surgical time when compared with classical Cottle's technique. PMID:28680499

[Comparison between the quality of life and nutritional status of nutrition students and those of other university careers at the Santo Thomas University in Chile].

PubMed

Durán Agüero, S; Bazaez Díaz, G; Figueroa Velásquez, K; Berlanga Zúñiga, Ma del R; Encina Vega, C; Rodríguez Noel, M P

2012-01-01

To determine and compare the quality of life, nutritional status, and self-perceived body image between nutrition students and students from other careers from the University Santo Tomás-Viña del Mar. We evaluated 200 student volunteers (100 nutrition students and 100 students from other careers) with a quality of life survey, a nutritional evaluation, and a survey of body image perception. The group of nutritional students perceived a lower quality of life, consumed less tobacco, and was less sedentary. Women of the nutritional group had a lower BMI and showed a lower hip circumference. Men of the nutritional group also showed a lower hip circumference. The nutritional group consumed more milk, chicken, and fish in their diet. Both groups presented an elevated consumption of alcohol. The concordance between BMI and body image was low, 34% in the nutritional group and 38% in the other careers group (Kappa 0.04 and 0.02). With respect to perception of quality of life, students from other careers perceived a better quality of life, however students from the nutritional group presented better nutritional status and selection of food.

Role of students' context in predicting academic performance at a medical school: a retrospective cohort study.

PubMed

Thiele, Tamara; Pope, Daniel; Singleton, A; Stanistreet, D

2016-03-11

This study examines associations between medical students' background characteristics (postcode-based measures of disadvantage, high school attended, sociodemographic characteristics), and academic achievement at a Russell Group University. Retrospective cohort analysis. Applicants accepted at the University of Liverpool medical school between 2004 and 2006, finalising their studies between 2010 and 2011. 571 students (with an English home postcode) registered on the full-time Medicine and Surgery programme, who successfully completed their medical degree. Final average at year 4 of the medical programme (represented as a percentage). Entry grades were positively associated with final attainment (p<0.001). Students from high-performing schools entered university with higher qualifications than students from low-performing schools (p<0.001), though these differences did not persist at university. Comprehensive school students entered university with higher grades than independent school students (p<0.01), and attained higher averages at university, though differences were not significant after controlling for multiple effects. Associations between school type and achievement differed between sexes. Females attained higher averages than males at university. Significant academic differences were observed between ethnic groups at entry level and university. Neither of the postcode-based measures of disadvantage predicted significant differences in attainment at school or university. The findings of this study suggest that educational attainment at school is a good, albeit imperfect, predictor of academic attainment at medical school. Most attainment differences observed between students either decreased or disappeared during university. Unlike previous studies, independent school students did not enter university with the highest grades, but achieved the lowest attainment at university. Such variations depict how patterns may differ between subjects and higher-education institutions. Findings advocate for further evidence to help guide the implementation of changes in admissions processes and widen participation at medical schools fairly. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Effect of Surface Treatment, Silane, and Universal Adhesive on Microshear Bond Strength of Nanofilled Composite Repairs.

PubMed

Fornazari, I A; Wille, I; Meda, E M; Brum, R T; Souza, E M

 The aim of this study was to evaluate the effect of surface treatment and universal adhesive on the microshear bond strength of nanoparticle composite repairs.  One hundred and forty-four specimens were built with a nanofilled composite (Filtek Supreme Ultra, 3M ESPE). The surfaces of all the specimens were polished with SiC paper and stored in distilled water at 37°C for 14 days. Half of the specimens were then air abraded with Al 2 O 3 particles and cleaned with phosphoric acid. Polished specimens (P) and polished and air-abraded specimens (A), respectively, were randomly divided into two sets of six groups (n=12) according to the following treatments: hydrophobic adhesive only (PH and AH, respectively), silane and hydrophobic adhesive (PCH, ACH), methacryloyloxydecyl dihydrogen phosphate (MDP)-containing silane and hydrophobic adhesive (PMH, AMH), universal adhesive only (PU, AU), silane and universal adhesive (PCU, ACU), and MDP-containing silane and universal adhesive (PMU, AMU). A cylinder with the same composite resin (1.1-mm diameter) was bonded to the treated surfaces to simulate the repair. After 48 hours, the specimens were subjected to microshear testing in a universal testing machine. The failure area was analyzed under an optical microscope at 50× magnification to identify the failure type, and the data were analyzed by three-way analysis of variance and the Games-Howell test (α=0.05).  The variables "surface treatment" and "adhesive" showed statistically significant differences for p<0.05. The highest mean shear bond strength was found in the ACU group but was not statistically different from the means for the other air-abraded groups except AH. All the polished groups except PU showed statistically significant differences compared with the air-abraded groups. The PU group had the highest mean among the polished groups. Cohesive failure was the most frequent failure mode in the air-abraded specimens, while mixed failure was the most common mode in the polished specimens.  While air abrasion with Al 2 O 3 particles increased the repair bond strength of the nanoparticle composite, the use of MDP-containing silane did not lead to a statistically significant increase in bond strength. Silane-containing universal adhesive on its own was as effective as any combination of silane and adhesive, particularly when applied on air-abraded surfaces.

Co-researching with people who have intellectual disabilities: insights from a national survey.

PubMed

O'Brien, Patricia; McConkey, Roy; García-Iriarte, Edurne

2014-01-01

Inclusive research with people with intellectual disabilities is growing internationally but with few studies examining its feasibility. In undertaking a national study exploring what life was like in Ireland for people with intellectual disabilities, a community of practice was developed involving a core group of co-researchers: five people with intellectual disabilities, four university researchers and three service support staff. An additional cadre of 15 co-researchers with intellectual disabilities was recruited to undertake data gathering and analysis with 23 focus groups involving 168 participants. The research experience was documented through oral feedback, progress reports, minutes and a project review. The key learning is documented arising from the setting up of an inclusive advisory group and implementation of each of six research steps. The study demonstrates feasibility and the added value of university co-researchers recruiting and developing skills together with co-researchers with intellectual disabilities. Topics for further research and development are identified. This paper tells you about how people with intellectual disabilities worked with a group of university researchers. Both groups were called co-researchers and together they ran 23 focus groups across Ireland. People with intellectual disabilities talked about their lives and what could make them better. They said they needed to have a good place to live; a job; enough money; relationships; and acceptance as respected citizens. The university co-researchers wrote about what it was like doing research together and how people with intellectual disabilities joined the advisory group; decided on the questions; ran focus groups; and presented findings. Together they grew into a community of researchers where the university co-researchers shared their research skills and people with intellectual disabilities shared what it was like living with a disability. They both saw great value in working together and plan to work more to make this type of research happen. © 2013 John Wiley & Sons Ltd.

Effectiveness of ProTaper Universal retreatment instruments used with rotary or reciprocating adaptive motion in the removal of root canal filling material.

PubMed

Capar, I D; Arslan, H; Ertas, H; Gök, T; Saygılı, G

2015-01-01

To compare the effectiveness of ProTaper Universal retreatment instruments with continuous rotation and adaptive motion (AM; a modified reciprocating motion that combines rotational and reciprocating motion) in the removal of filling material. Mesiobuccal root canals in 36 mandibular first molars were instrumented up to size F2 with the ProTaper Universal instrument (Dentsply Maillefer, Ballaigues, Switzerland) and filled using sealer and ProTaper Universal F2 gutta-percha cones. Gutta-percha was then down-packed and the root canal backfilled using the extruder hand-piece of the Elements Obturation System (SybronEndo, Orange, CA, USA). The teeth were assigned to two groups (n = 18), and removal of the root fillings was performed using one of the following techniques: group 1) ProTaper Universal retreatment files used with rotational motion (RM) and group 2) ProTaper Universal retreatment files used with adaptive motion (AM) (600° clockwise/0° counter-clockwise to 370° clockwise/50° counter-clockwise). The teeth were sectioned, and both halves were analysed at 8 × magnification. The percentage of remaining filling material was recorded. The data were analysed statistically using the Student's t-test at a 95% confidence level (P < 0.05). There was no significant difference between the groups with respect to the total time required for retreatment (P = 0.481). The AM technique left significantly less filling material than the RM method (P = 0.013). The use of ProTaper Universal retreatment files with adaptive motion removed more filling materials from root canals than the rotational movement. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Relationship of smartphone use severity with sleep quality, depression, and anxiety in university students.

PubMed

Demirci, Kadir; Akgönül, Mehmet; Akpinar, Abdullah

2015-06-01

The usage of smartphones has increased rapidly in recent years, and this has brought about addiction. The aim of the current study was to investigate the relationship between smartphone use severity and sleep quality, depression, and anxiety in university students. In total, 319 university students (203 females and 116 males; mean age = 20.5 ± 2.45) were included in the study. Participants were divided into the following three groups: a smartphone non-user group (n = 71, 22.3%), a low smartphone use group (n = 121, 37.9%), and a high smartphone use group (n = 127, 39.8%). All participants were evaluated using the Pittsburgh Sleep Quality Index, Beck Depression Inventory, Beck Anxiety Inventory; moreover, participants other than those in the smartphone non-user group were also assessed with the Smartphone Addiction Scale. The findings revealed that the Smartphone Addiction Scale scores of females were significantly higher than those of males. Depression, anxiety, and daytime dysfunction scores were higher in the high smartphone use group than in the low smartphone use group. Positive correlations were found between the Smartphone Addiction Scale scores and depression levels, anxiety levels, and some sleep quality scores. The results indicate that depression, anxiety, and sleep quality may be associated with smartphone overuse. Such overuse may lead to depression and/or anxiety, which can in turn result in sleep problems. University students with high depression and anxiety scores should be carefully monitored for smartphone addiction.

Relationship of Smartphone Use Severity with Sleep Quality, Depression, and Anxiety in University Students

PubMed Central

Demi̇rci̇, Kadi̇r; Akgönül, Mehmet; Akpinar, Abdullah

2015-01-01

Background and Aims The usage of smartphones has increased rapidly in recent years, and this has brought about addiction. The aim of the current study was to investigate the relationship between smartphone use severity and sleep quality, depression, and anxiety in university students. Methods In total, 319 university students (203 females and 116 males; mean age = 20.5 ± 2.45) were included in the study. Participants were divided into the following three groups: a smartphone non-user group (n = 71, 22.3%), a low smartphone use group (n = 121, 37.9%), and a high smartphone use group (n = 127, 39.8%). All participants were evaluated using the Pittsburgh Sleep Quality Index, Beck Depression Inventory, Beck Anxiety Inventory; moreover, participants other than those in the smartphone non-user group were also assessed with the Smartphone Addiction Scale. Results The findings revealed that the Smartphone Addiction Scale scores of females were significantly higher than those of males. Depression, anxiety, and daytime dysfunction scores were higher in the high smartphone use group than in the low smartphone use group. Positive correlations were found between the Smartphone Addiction Scale scores and depression levels, anxiety levels, and some sleep quality scores. Conclusion The results indicate that depression, anxiety, and sleep quality may be associated with smartphone overuse. Such overuse may lead to depression and/or anxiety, which can in turn result in sleep problems. University students with high depression and anxiety scores should be carefully monitored for smartphone addiction. PMID:26132913

Bringing optics to Fab Labs in Europe

NASA Astrophysics Data System (ADS)

Adam, Aurèle; Zuidwijk, Thim; Urbach, Paul

2017-08-01

The Optics Group of Delft University of Technology plays a major role in teaching optics to bachelor and master students. In addition, the group has a long record of introducing, demonstrating and teaching optics to quite diverse groups of people from outside of the university. We will describe some of these activities and focus on a recently started project funded by the European Commission called Phablabs 4.0, which aims to bring photonics to European Fab labs.

Comparison of shear bond strength of universal adhesives on etched and nonetched enamel.

PubMed

Beltrami, Riccardo; Chiesa, Marco; Scribante, Andrea; Allegretti, Jessica; Poggio, Claudio

2016-04-06

The purpose of this study was to evaluate the effect of surface pretreatment with 37% phosphoric acid on the enamel bond strength of different universal adhesives. One hundred and sixty bovine permanent mandibular incisors freshly extracted were used as a substitute for human teeth. The materials tested in this study included 6 universal adhesives, and 2 self-etch adhesives as control. The teeth were assigned into 2 groups: In the first group, etching was performed using 37% phosphoric acid for 30 seconds. In the second group, no pretreatment agent was applied. After adhesive application, a nanohybrid composite resin was inserted into the enamel surface by packing the material into cylindrical-shaped plastic matrices. After storing, the specimens were placed in a universal testing machine. The normality of the data was calculated using the Kolmogorov-Smirnov test. Analysis of variance (ANOVA) was applied to determine whether significant differences in debond strength values existed among the various groups. Groups with phosphoric acid pretreatment showed significantly higher shear bond strength values than groups with no enamel pretreatment (p<0.001). No significant variation in shear strength values was detected when comparing the different adhesive systems applied onto enamel after orthophosphoric acid application (p>0.05). All adhesives provide similar bond strength values when enamel pretreatment is applied even if compositions are different. Bond strength values are lower than promised by manufacturers.

Evaluation of the virtual mentor cataract training program.

PubMed

Henderson, Bonnie An; Kim, Jae Yong; Golnik, Karl C; Oetting, Thomas A; Lee, Andrew G; Volpe, Nicholas J; Aaron, Maria; Uhler, Tara A; Arnold, Anthony; Dunn, James P; Prajna, N Venkatesh; Lane, Anne Marie; Loewenstein, John I

2010-02-01

Evaluate the effectiveness of an interactive cognitive computer simulation for teaching the hydrodissection portion of cataract surgery compared with standard teaching and to assess the attitudes of residents about the teaching tools and their perceived confidence in the knowledge gained after using the tools. Case-control study. Residents at academic institutions. Prospective, multicenter, single-masked, controlled trial was performed in 7 academic departments of ophthalmology (Harvard Medical School/Massachusetts Eye and Ear Infirmary, University of Iowa, Emory University, University of Cincinnati, University of Pennsylvania/Scheie Eye Institute, Jefferson Medical College of Thomas Jefferson University/Wills Eye Institute, and the Aravind Eye Institute). All residents from these centers were asked to participate and were randomized into 2 groups. Group A (n = 30) served as the control and received traditional teaching materials; group B (n = 38) received a digital video disc of the Virtual Mentor program. This program is an interactive cognitive simulation, specifically designed to separate cognitive aspects (such as decision making and error recognition) from the motor aspects. Both groups took online anonymous pretests (n = 68) and posttests (n = 58), and answered satisfaction questionnaires (n = 53). Wilcoxon tests were completed to compare pretest and posttest scores between groups. Analysis of variance was performed to assess differences in mean scores between groups. Scores on pretests, posttests, and satisfaction questionnaires. There was no difference in the pretest scores between the 2 groups (P = 0.62). However, group B (Virtual Mentor [VM]) scored significantly higher on the posttest (P = 0.01). Mean difference between pretest and posttest scores were significantly better in the VM group than in the traditional learning group (P = 0.04). Questionnaire revealed that the VM program was "more fun" to use (24.1% vs 4.2%) and residents were more likely to use this type of program again compared with the likelihood of using the traditional tools (58.6% vs 4.2%). The VM, a cognitive computer simulation, augmented teaching of the hydrodissection step of phacoemulsification surgery compared with traditional teaching alone. The program was more enjoyable and more likely to be used repetitively by ophthalmology residents. Copyright (c) 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Mexico's Oxbridge.

ERIC Educational Resources Information Center

Haussman, Fay

1979-01-01

For 400 years the National Autonomous University of Mexico has remained at the hub of the country's intellectual and political life. The history of the University from the Mayas and the Aztecs, University expansion, upward mobility of students, and student pressure groups and politics are described. (MLW)

Report of the DoD-University Forum for Calendar Year 1984.

DTIC Science & Technology

1984-12-01

COUNCIL ON EDUCATION - DEPARTMENT OF DEFENSE ; Fnr * t CALENDAR YEAR 1984 REPORT OF THE DOD-UNIVERSITY FORUM CHARTERED: DECEMBER 15, 1983 CONTENTS- PAGE...PART IV: Report of the DoD-University Forum Working Group on Engineering and Science Education 31 PART V: Report of the DoD-University Forum Working...Land Grant Colleges and the American Council on Education . Forum members are drawn equally from DoD and the university community, with university

Center for Research on Minority Health -- Prostate Cancer and Health Disparities Research

DTIC Science & Technology

2008-05-01

making in various ethnic  groups . The “POP” model may facilitate further research with  underserved  communities and result in enhanced knowledge and...and about 65 students from Rice, Texas Southern University, UT Health Science Center, University of Houston-Main Campus and the University of...journal articles. 5. Hand in assigned work in a timely fashion. Group Research Projects for Powerpoint Presentations and Papers Students in

Attitudes and Attained English Language Proficiency of University Students in Thailand: A Sociolinguistic Study.

ERIC Educational Resources Information Center

Boykin, Arsene; Trungamphai, Arunthadee

English proficiency of Thai university students studying English as a Foreign Language (EFL) was studied in relation to attitudinal scores on social, economic, travel, or prestige scales. Secondarily, the subjects' attitudes toward their native group and toward the target language group, and their motives for learning English were studied in…

Educating an Aging Society: The University of the Third Age in Finland.

ERIC Educational Resources Information Center

Yenerall, Joseph D.

2003-01-01

The University of the Third Age in Finland has evolved from English and French models to include lectures, discussion groups, and research groups. A survey of 165 adult learners found their primary reason for participating was to acquire general education and self-knowledge. Socializing and meeting people were among the lowest ranked motivations.…

Aboriginal Self-Determination in Australia: The Effects of Minority-Majority Frames and Target Universalism on Majority Collective Guilt and Compensation Attitudes

ERIC Educational Resources Information Center

Reid, Scott A.; Gunter, Helen N.; Smith, Joanne R.

2005-01-01

In the context of Aboriginal-Anglo Australian relations, we tested the effect of framing (multiculturalism versus separatism) and majority group members' social values (universalism) on the persuasiveness of Aboriginal group rhetoric, majority collective guilt, attitudes toward compensation, and reparations for Aboriginals. As predicted, Anglo…

Exploring the Cross-Cultural Experiences of College Students with Diverse Backgrounds Performing International Service-Learning in Myanmar

ERIC Educational Resources Information Center

Liu, Ruo-lan; Lee, Hsin-hua

2011-01-01

Background: In view of the growing globalization, volunteer service organizations, local universities, colleges, and student groups have begun extending their service programs from Taiwan to other countries. This study employs a self-organized, self-funded group of university students participating in international service-learning as its subject,…

The Effect of Note-Taking on University Students' Listening Comprehension of Lectures

ERIC Educational Resources Information Center

Kiliçkaya, Ferit; Çokal Karadas, Derya

2009-01-01

The study investigated the effect of note-taking on comprehension of lectures by 44 undergraduate EFL students who are in the first year of their undergraduate level in the Department of Foreign Language Education in Middle East Technical University. The participants were divided into two groups, namely experimental and control groups. The…

Group Face in Korea and the United States: Taking Responsibility for the Individual and the Group

ERIC Educational Resources Information Center

Hahn, Jee-Won; Hatfield, Hunter

2011-01-01

Brown and Levinson's ([1978] Politeness: Some universals in language use, Cambridge University Press, 1987) politeness theory has been criticized as being ethnocentric by displaying a Western preoccupation with autonomy and individualism. Many non-western societies, it is argued, are better understood by appealing to cultural discernment or group…

Attitudes of Jordanian Students towards Using Group Work in EFL Classrooms

ERIC Educational Resources Information Center

Ababneh, Sana'

2017-01-01

This paper addresses itself to the outcomes of a field study which was carried out to identify Jordanian EFL students' attitudes towards using group work in EFL classrooms. The study sample consisted of 179 students enrolled in English 101, an elementary language skills course taught at Al- Huson University College, Al -Balqa' Applied University,…

The Use of Photo Elicitation to Explore the Benefits of Queer Student Advocacy Groups in University

ERIC Educational Resources Information Center

Joy, Phillip; Numer, Matthew

2017-01-01

University can be a critical time for queer identifying youth as they attempt to navigate new relationships and heteronormative and, sometimes, hostile environments. Involvement in queer student groups is one strategy to develop protective mechanisms for these students. This research examines the effect of participation in a queer advocacy group…

The Strategic Study Group on the Status of Women: Report to the President and the Commission for Women--Recommendation Package #2.

ERIC Educational Resources Information Center

Pennsylvania State Univ., University Park.

The document presents partial recommendations of a Pennsylvania State University Study Group on the Status of Women at the University. Recommendations concern family-responsive and flexible employee benefits, clerical advancement and development, retention and advancement of women faculty, and sexual harassment of students. Among specific…

A Comparison of Large Lecture, Fully Online, and Hybrid Sections of Introduction to Special Education

ERIC Educational Resources Information Center

O'brien, Chris; Hartshorne, Richard; Beattie, John; Jordan, Luann

2011-01-01

This study evaluated the effectiveness of flexible learning options at a university serving multiple geographic areas (including remote and rural areas) and age groups by teaching an introduction to special education course to three large groups of pre-teacher education majors using three modes of instruction. The university offered sections as…

Building Interdisciplinary Qualitative Research Networks: Reflections on Qualitative Research Group (QRG) at the University of Manitoba

ERIC Educational Resources Information Center

Roger, Kerstin Stieber; Halas, Gayle

2012-01-01

As qualitative research methodologies continue to evolve and develop, both students and experienced researchers are showing greater interest in learning about and developing new approaches. To meet this need, faculty at the University of Manitoba created the Qualitative Research Group (QRG), a community of practice that utilizes experiential…

Language Choice and Identity Construction in Peer Interactions: Insights from a Multilingual University in Hong Kong

ERIC Educational Resources Information Center

Gu, Mingyue

2011-01-01

Informed by linguistic ecological theory and the notion of identity, this study investigates language uses and identity construction in interactions among students with different linguistic and cultural backgrounds in a multilingual university. Individual and focus-group interviews were conducted with two groups of students: Hong Kong (HK) and…

The Strategic Study Group on the Status of Women: Report to the President and the Commission for Women--Recommendation Package #4.

ERIC Educational Resources Information Center

Pennsylvania State Univ., University Park.

The document presents partial recommendations of a Pennsylvania State University Study Group on the Status of Women at the University. Recommendations concern: special populations, sexual harassment in the workplace, sexual violence against women, women's athletics, and health services for women students. Among specific recommendations are the…

An Exploration into Inquiry-Based Learning by a Multidisciplinary Group of Higher Education Faculty

ERIC Educational Resources Information Center

Friedman, Daniela B.; Crews, Tena B.; Caicedo, Juan M.; Besley, John C.; Weinberg, Justin; Freeman, Miriam L.

2010-01-01

This manuscript describes faculty and student experiences and future activities of a multidisciplinary group of university faculty who are implementing inquiry-based learning (IBL) in their classrooms for the first time. This opportunity to implement the IBL instructional method was provided to the faculty through a grant from the university's…

Alcohol-Related Consequences among First-Year University Students: Effectiveness of a Web-Based Personalized Feedback Program

ERIC Educational Resources Information Center

Doumas, Diana M.; Nelson, Kinsey; DeYoung, Amanda; Renteria, Camryn Conrad

2014-01-01

This study evaluated the effectiveness of a web-based personalized feedback program using an objective measure of alcohol-related consequences. Participants were assigned to either the intervention group or an assessment-only control group during university orientation. Sanctions received for campus alcohol policy violations were tracked over the…

Using Technology for Teaching Arabic Language Grammar

ERIC Educational Resources Information Center

Arrabtah, Adel; Nusour, Tayseer

2012-01-01

This study investigates the effect of using technology such as CD-ROM, computers, and internet to teach Arabic language grammar to students at Princess Alia University College at Al-Balqa University. The sample of the study consisted of 122 third year female students; (64) for the experimental group and (58) for the control group. The subjects of…

The Effect of Group Diversity on Learning on a University-Based Foundation Course

ERIC Educational Resources Information Center

Chipperfield, Sarah R.

2012-01-01

To date, there appears to be a paucity of literature regarding the student experience on university-based foundation courses. There is some thought that such non-traditional, diverse groups of students might present problems during the learning and teaching experience and some students appear to have little insight into what foundation courses…

Doing It Differently: The Ups and Downs of Peer Group Learning

ERIC Educational Resources Information Center

Belward, Shaun; Balatti, Jo

2012-01-01

Peer group learning is the name we have given to a particular type of collaborative learning that has been implemented as part of an action research project designed to improve teaching and learning of first year university mathematics at James Cook University. Using an innovation-decision process model we analysed the response of academics to the…

Undertaking an Institutional "Stock-Take" of SoTL: New Zealand University Case Studies

ERIC Educational Resources Information Center

Haigh, Neil; Gossman, Peter; Jiao, Xiaomin

2011-01-01

A working group was established at AUT University in 2005 with a brief to identify initiatives that might be taken to promote and support staff engagement in the Scholarship of Teaching and Learning (SoTL). The working group recognized that a "stock-taking" exercise would need to be undertaken before appropriate initiatives could be…

Effect of Cognitive-Behavioral-Theory-Based Skill Training on Academic Procrastination Behaviors of University Students

ERIC Educational Resources Information Center

Toker, Betül; Avci, Rasit

2015-01-01

This study examined the effectiveness of a cognitive-behavioral theory (CBT) psycho-educational group program on the academic procrastination behaviors of university students and the persistence of any training effect. This was a quasi-experimental research based on an experimental and control group pretest, posttest, and followup test model.…

Moral Problems Perceived by Industry in Collaboration with a Student Group: Balancing between Beneficial Objectives and Upholding Relations

ERIC Educational Resources Information Center

Vartiainen, Tero

2009-01-01

Industry-university partnerships are common in the IT field. This paper reports on moral problems perceived by client representatives collaborating with student groups taking part in a project course in information systems education in a Finnish university. Twenty-two client representatives from IT organizations were interviewed during the course…

Diverse Educational Leadership Training Academy at Northeastern State University-Broken Arrow Campus in Oklahoma: Why Is It Working?

ERIC Educational Resources Information Center

Mahan, Melissa Kaye

2009-01-01

Scope and method of study. This study used a descriptive design in which quantitative subject profile data were expanded upon by qualitative data from focus group interviews. Specifically, institutional data from Northeastern State University and focus group interviews with DELTA graduates were used. The institutional data collected consisted of…

The Woodcock Johnson III Tests of Achievement in Foreign Language Course Substitution Decisions for University Students with Learning Disabilities: An Exploratory Analysis

ERIC Educational Resources Information Center

Madaus, Joseph W.

2005-01-01

Selected subtests from the Woodcock Johnson III Tests of Achievement (Woodcock, McGrew, & Mather, 2001) were administered to three groups of university students. The groups included students with learning disabilities who received course substitutions for the institution's foreign language requirement, students with learning disabilities who…

Characterising Learning Interactions: A Study of University Students Solving Physics Problems in Groups

ERIC Educational Resources Information Center

Berge, Maria; Danielsson, Anna T.

2013-01-01

The purpose of this article is to explore how a group of four university physics students addressed mechanics problems, in terms of student direction of attention, problem solving strategies and their establishment of and ways of interacting. Adapted from positioning theory, the concepts "positioning" and "storyline" are used to describe and to…

Distance Education and Virtual Reference: Implementing a Marketing Plan at Texas A&M University

ERIC Educational Resources Information Center

MacDonald, Karen I.; vanDuinkerken, Wyoma

2005-01-01

Texas A&M University Libraries has been testing virtual reference services since February 2004, but during the fall semester 2005, the Libraries began implementing and actively promoting the services to various target groups. Distance education students were identified as a primary target group for virtual reference services, and as of the…

Sleep Quality in University Students with Premenstrual Dysphoric Disorder

PubMed Central

KHAZAIE, Habibolah; GHADAMI, Mohammad Rasoul; KHALEDI-PAVEH, Behnam; CHEHRI, Azita; NASOURI, Marzieh

2016-01-01

Background Up to 8% of women in their reproductive years are affected by Premenstral Dysphoric Disorder (PMDD). Sleep disturbances such as insomnia or hypersomnia are one of the DSM-IV-TR’s defining criteria for the diagnosis of PMDD and are found in about 70% of women with the disorder. However, studies are lacking that specifically address the effects of PMDD on quality of sleep. Aim This study was designed to evaluate the prevalence of Premenstrual DysphoricDisorder (PMDD) and its impact on sleep quality in female university students. Methods We developed an 18-item PMDD scale based on The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) to diagnose PMDD in female university studentswho ranged in age from 18 to 30 years and had regular menstrual cycles.Participants were categorized into a PMDD group or a No/PMDD group and sleep quality was compared between the two groups. The evaluation tool used to measure sleep quality was the Pittsburgh Sleep Quality Index (PSQI). Results The prevalence of PMDD in female universitystudents was 25.5%. Analysis of the PSQI demonstrated that 80.5% of those in PMDD group had a PSQI that scored >5; however, only 56.4% in the No/PMDD grouphad a PSQI that scored >5 (χ2=12.459, p<0.001). The mean PSQI score was 8.2(3.4) in the PMDD group and was 6.5(3.1) in the No/PMDD group (t=3.648, p<0.001). Conclusions Female university students who experience PMDD are deeply affected by sleep problems. Lower sleep quality, daytime dysfunction, and sleep disturbance are common sleep problems among female university students with PMDD. PMID:28638182

Can Universities Develop Advanced Technology and Solve Social Problems?

NASA Astrophysics Data System (ADS)

Pérez Ones, Isarelis; Núñez Jover, Jorge

This paper presents case studies on how Cuban universities have increasingly become directly involved with the economic and social development of the country. The paper shows how Cuban universities, from the early 1980s and early 1990s, started reorientation and organization of their scientific research, becoming more directly and intensely involved in the economic and social development of the country. In this way, special reference is made to the case of a research group at the University of Havana: the Laboratory of Synthetic Antigens. This group developed the first synthetic vaccine for human use approved in the world. In the article, public policies involved in this success as well as different obstacles are discussed. These obstacles demonstrate the difficulties and challenges that universities face when carrying out research and innovation activities related to economic and social development.

A Virtual Mental Health Clinic for University Students: A Qualitative Study of End-User Service Needs and Priorities

PubMed Central

Gulliver, Amelia; Chan, Jade KY; Bennett, Kylie; Griffiths, Kathleen M

2015-01-01

Background Help seeking for mental health problems among university students is low, and Internet-based interventions such as virtual clinics have the potential to provide private, streamlined, and high quality care to this vulnerable group. Objective The objective of this study was to conduct focus groups with university students to obtain input on potential functions and features of a university-specific virtual clinic for mental health. Methods Participants were 19 undergraduate students from an Australian university between 19 and 24 years of age. Focus group discussion was structured by questions that addressed the following topics: (1) the utility and acceptability of a virtual mental health clinic for students, and (2) potential features of a virtual mental health clinic. Results Participants viewed the concept of a virtual clinic for university students favorably, despite expressing concerns about privacy of personal information. Participants expressed a desire to connect with professionals through the virtual clinic, for the clinic to provide information tailored to issues faced by students, and for the clinic to enable peer-to-peer interaction. Conclusions Overall, results of the study suggest the potential for virtual clinics to play a positive role in providing students with access to mental health support. PMID:26543908

The antiporter-like subunit constituent of the universal adaptor of complex I, group 4 membrane-bound [NiFe]-hydrogenases and related complexes.

PubMed

Batista, Ana P; Marreiros, Bruno C; Pereira, Manuela M

2013-05-01

We have recently investigated the long-recognized relationship between complex I and group 4 [NiFe] hydrogenases and we have established the so-called Energy-converting hydrogenase related (Ehr) complex as a new member of the family. We have also observed that four subunits, homologues to NuoB, D, H and L, are common to the members of the family. We have designated this common group of subunits the universal adaptor. Taking into account the similarity of the Na(+)/H(+) antiporter-like subunits of complex I (NuoL, NuoM and NuoN) and the unique structural characteristic of the long amphipathic α helix part of NuoL, the nature of the antiporter-like subunit of the universal adaptor was questioned. Thus, in this work we further explore the properties of the universal adaptor, investigating which antiporter-like subunit is part of the universal adaptor. We observe that the universal adaptor contains an antiporter-like subunit with a long amphipathic α helix, similar to NuoL. Consequently, the long helix is a common denominator that has been conserved in all members of the family. Such conservation surely reflects the key role of such helix in the energy transduction mechanism of this family of enzymes.

Compendium of University Statistics, 1986 Edition = Compendium de statistique concernant les universities, edition 1986.

ERIC Educational Resources Information Center

Association of Universities and Colleges of Canada, Ottawa (Ontario).

Statistics on Canadian universities are presented in 30 tables in both English and French. The data cover: total population and age group 18-24 by province for 1971, 1976, 1981, and 1985; full-time enrollment rates by educational level; graduation rates for secondary schools, community colleges and universities; unemployment rate by educational…

Determining the Factors of Social Phobia Levels of University Students: A Logistic Regression Analysis

ERIC Educational Resources Information Center

Ozen, Hamit

2016-01-01

Experiencing social phobia is an important factor which can hinder academic success during university years. In this study, research of social phobia with several variables is conducted among university students. The research group of the study consists of total 736 students studying at various departments at universities in Turkey. Students are…

Apres le Deluge at State U: A Comprehensive Public University Responds to the Great Recession

ERIC Educational Resources Information Center

Skinner, Richard A.; Miller, Emily R.

2013-01-01

In this article, the authors describe one institution--East Carolina University--that they think is representative of an important type and a large proportion of American universities, the comprehensive public university, and its responses to the lingering Great Recession. As a group, comprehensives handle almost 40 per cent of the total student…

Curriculum Transformation in a Post-Apartheid South African University: The Arts Faculty, Tshwane University of Technology

ERIC Educational Resources Information Center

Ebewo, Patrick J.; Sirayi, Mzo

2018-01-01

During the apartheid rule in South Africa, established universities and other tertiary institutions were forcibly segregated to serve particular racial groups. Some critics have stated that the apartheid regime in South Africa supported an exclusively Western model of education, and that university education was based on a mono-cultural approach…

Effect of Learning Organization Perception to the Organizational Commitment: A Comparison between Private and Public University

ERIC Educational Resources Information Center

Balay, Refik

2012-01-01

This research aims to examine the impact of faculty members' learning organization perceptions to the organizational commitment through quantitative method. The study group consists of 172 faculty members working in two universities, which are private (Zirve University) and public (Harran University) ones. The research results show that faculty…

Are There Distinctive Clusters of Higher and Lower Status Universities in the UK?

ERIC Educational Resources Information Center

Boliver, Vikki

2015-01-01

In 1992 the binary divide between universities and polytechnics was dismantled to create a nominally unitary system of higher education for the UK. Just a year later, the first UK university league table was published, and the year after that saw the formation of the Russell Group of self-proclaimed "leading" universities. This paper…

Modifying the Sleep Treatment Education Program for Students to include technology use (STEPS-TECH): Intervention effects on objective and subjective sleep outcomes.

PubMed

Barber, Larissa K; Cucalon, Maria S

2017-12-01

University students often have sleep issues that arise from poor sleep hygiene practices and technology use patterns. Yet, technology-related behaviors are often neglected in sleep hygiene education. This study examined whether the Sleep Treatment Education Program for Students-modified to include information regarding managing technology use (STEPS-TECH)-helps improve both subjective and objective sleep outcomes among university students. Results of an experimental study among 78 university students showed improvements in objective indicators of sleep quantity (total sleep time) and sleep quality (less awakenings) during the subsequent week for students in the STEPS-TECH intervention group compared to a control group. Exploratory analyses indicated that effects were driven by improvements in weekend days immediately following the intervention. There were also no intervention effects on subjective sleep quality or quantity outcomes. In terms of self-reported behavioral responses to educational content in the intervention, there were no group differences in sleep hygiene practices or technology use before bedtime. However, the intervention group reported less technology use during sleep periods than the control group. These preliminary findings suggest that STEPS-TECH may be a useful educational tool to help improve objective sleep and reduce technology use during sleep periods among university students. Copyright © 2017 John Wiley & Sons, Ltd.

Characteristics of Selected Anthropometric Foot Indicators in Physically Active Students.

PubMed

Bac, Aneta; Bogacz, Gabriela; Ogrodzka-Ciechanowicz, Katarzyna; Kulis, Aleksandra; Szaporów, Tomasz; Woźniacka, Renata; Radlińska, Natalia

2018-05-01

The aim of this study was to determine the type of medial longitudinal arch (MLA) in students of Krakow universities, investigate the relationship between physical activity and the shaping of the feet, and examine the relationship between hallux valgus angle and the type of footwear chosen most often. The study group consisted of 120 students, of which 56 respondents were students of the University School of Physical Education in Krakow, whereas the remaining 64 respondents were students of the Pedagogical University of Krakow. To evaluate the MLA, a podoscope was used, which allowed us to determine the length and width of the foot, and calculation of the Clarke angle, heel angle γ, and the angle of hallux valgus. All students were also subjected to a measurement of body weight and height. There was a statistically significant relationship between physical activity and the Clarke angle in the group of women studying at the University School of Physical Education. There was no correlation between the hallux valgus angle and the type of footwear chosen most often in the research groups. The most frequently diagnosed type of longitudinal and transverse arch foot in the research group was normal MLA. There was no relationship between physical activity and transverse arch foot in any of the research groups.

Building an Entrepreneurial University in Brazil: The Role and Potential of University-Industry Linkages in Promoting Regional Economic Development

ERIC Educational Resources Information Center

Amaral, Marcelo; Ferreira, Andre; Teodoro, Pitias

2011-01-01

This study is part of a broader research project, conducted by the Triple Helix Research Group--Brazil, focusing on university-industry-government linkages in the state of Rio de Janeiro. The case study reported here is that of the Regional University of Volta Redonda: the aim was to develop an understanding of how a regional university can be…

Statistical universals reveal the structures and functions of human music.

PubMed

Savage, Patrick E; Brown, Steven; Sakai, Emi; Currie, Thomas E

2015-07-21

Music has been called "the universal language of mankind." Although contemporary theories of music evolution often invoke various musical universals, the existence of such universals has been disputed for decades and has never been empirically demonstrated. Here we combine a music-classification scheme with statistical analyses, including phylogenetic comparative methods, to examine a well-sampled global set of 304 music recordings. Our analyses reveal no absolute universals but strong support for many statistical universals that are consistent across all nine geographic regions sampled. These universals include 18 musical features that are common individually as well as a network of 10 features that are commonly associated with one another. They span not only features related to pitch and rhythm that are often cited as putative universals but also rarely cited domains including performance style and social context. These cross-cultural structural regularities of human music may relate to roles in facilitating group coordination and cohesion, as exemplified by the universal tendency to sing, play percussion instruments, and dance to simple, repetitive music in groups. Our findings highlight the need for scientists studying music evolution to expand the range of musical cultures and musical features under consideration. The statistical universals we identified represent important candidates for future investigation.

Statistical universals reveal the structures and functions of human music

PubMed Central

Savage, Patrick E.; Brown, Steven; Sakai, Emi; Currie, Thomas E.

2015-01-01

Music has been called “the universal language of mankind.” Although contemporary theories of music evolution often invoke various musical universals, the existence of such universals has been disputed for decades and has never been empirically demonstrated. Here we combine a music-classification scheme with statistical analyses, including phylogenetic comparative methods, to examine a well-sampled global set of 304 music recordings. Our analyses reveal no absolute universals but strong support for many statistical universals that are consistent across all nine geographic regions sampled. These universals include 18 musical features that are common individually as well as a network of 10 features that are commonly associated with one another. They span not only features related to pitch and rhythm that are often cited as putative universals but also rarely cited domains including performance style and social context. These cross-cultural structural regularities of human music may relate to roles in facilitating group coordination and cohesion, as exemplified by the universal tendency to sing, play percussion instruments, and dance to simple, repetitive music in groups. Our findings highlight the need for scientists studying music evolution to expand the range of musical cultures and musical features under consideration. The statistical universals we identified represent important candidates for future investigation. PMID:26124105

How good is the obesity associated with blood groups in a cohort of female university going students?

PubMed

Jawed, Shireen; Atta, Komal; Tariq, Saba; Amir, Farah

2018-01-01

To find out frequency of obesity in female University students in Faisalabad and to investigate its association with blood groups of ABO system. A cross sectional study was conducted with a sample size of 200 female University students, recruited from the Faisalabad based institutes from May 2017 to July 2017. Relevant information was taken by administering questionnaire. Height in meters and weight in kg were taken by stadiometer. BMI was calculated using formula BMI=weight in kg/height m 2 . Blood groups were determined by classic (antigen-antibody agglutination test). The data was analyzed through SPSS 20. Descriptive were presented as mean± SD and association of BMI with blood groups was assessed by regression analysis. P value ≤0.05 deemed statistically significant. Out of students, 192 attempted the questionnaire and participated in study (96% response rate), 30% of the 192 females were obese, distribution of ABO blood group showed 43%, followed by O, A and AB. 90% were Rh positive and 10% were Rh negative. Blood group O showed a trend towards obesity and blood group AB showed a trend towards lean body. The blood group O showed the significant positive association with obesity. Population with blood group O showed greatest susceptibility to be overweight and obese.

Effect of bulk-fill base material on fracture strength of root-filled teeth restored with laminate resin composite restorations.

PubMed

Taha, N A; Maghaireh, G A; Ghannam, A S; Palamara, J E

2017-08-01

To evaluate the effect of using a bulk-fill flowable base material on fracture strength and fracture patterns of root-filled maxillary premolars with MOD preparations restored with laminate restorations. Fifty extracted maxillary premolars were selected for the study. Standardized MOD cavities with endodontic treatment were prepared for all teeth, except for intact control. The teeth were divided randomly into five groups (n=10); (Group 1) sound teeth, (Group 2) unrestored teeth; (Group 3) MOD cavities with Vitrebond base and resin-based composite (Ceram. X One Universal); (Group 4) MOD cavities with 2mm GIC base (Fuji IX GP) and resin-based composite (Ceram. X One Universal) open laminate, (Group 5) MOD cavities were restored with 4mm of bulk-fill flowable base material (SDR) and resin-based composite (Ceram. X One Universal). All teeth were thermocycled and subjected to a 45° ramped oblique load in a universal testing machine. Fracture load and fracture patterns were recorded. Data were analyzed using one-way ANOVA and Dunnett's T3 test. Restoration in general increased the fracture strength compared to unrestored teeth. The fracture strength of group 5 (bulk-fill) was significantly higher than the fracture strength of the GIC laminate groups and not significantly different from the intact teeth (355±112N, P=0.118). The type of failure was unfavorable for most of the groups, with the majority being mixed failures. The use of a bulk-fill flowable base material significantly increased the fracture strength of extracted root-filled teeth with MOD cavities; however it did not improve fracture patterns to more favorable ones. Investigating restorative techniques that may improve the longevity of root-filled premolar teeth restored with direct resin restorations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solution Based Functionalization of Nanostructured Oxides with Organic Molecules

NASA Astrophysics Data System (ADS)

Pearce, Brady Lawrence

The surface modification of wide bandgap semiconductors with organic molecules provides novel functionalities to the composite material. These functionalities can include tuning of the optical properties, providing solution stability of the inorganic material, as well as many others. The use of an in-situ functionalization method for surface attachment of phosphonic group containing molecules to the surface of gallium nitride (GaN) has shown promise. This technique is particularly advantageous due to the etching and functionalization steps occurring at the same time, in the same beaker, as well as not being reliant on organic solvents or high temperatures. In this functionalization process, surface hydroxide groups are preferentially grown on the surface of GaN, which serve as attachment sites for phosphonic groups on organic moieties. Molecules with these hydroxyl groups available natively on their surface, such as AlOOH and GaOOH, provide a unique advantage. The requirement for an etching step is removed, and the functionalization process could be performed in a simple one-step modification. The work in this dissertation seeks to address the possibility of using these materials as the inorganic component in organic/inorganic composite material in devices. Of particular importance in solar cell and bioelectronic devices is the ability to withstand varying pH environments, and to avoid the leaching of toxic ionic species. Lysine has shown to reduce the leaching of ionic species, when particles of inorganic molecules are cross-linking agents for the amino acid. In this work, the aqueous stability of both AlOOH and GaOOH in a lysine environment will be explored. The optical and size characteristics observed in nanostructured forms of the mixed composition AlxGa1-xOOH material system is of interest, due optical tunability providing a distinct advantage in optoelectronic devices containing these organic/inorganic hybrids. Immobilizing phosphonic group containing organic dyes on the surface of GaN, GaOOH, AlOOH and mixed compositions of AlGaOOH using surface bonding sites, and possible covalent attachments mechanisms, seeks to provide an improvement in the long term stability of the inorganic/organic interface for devices. Future work in this area will test device efficiency using these hybrids, explore additional mixed oxyhydroxide composition systems and continue the advancement of the understanding of the important role of phosphonic groups in organic/inorganic devices. The nature of chemical and surface species in these materials will be characterized with Fourier Transformed-Infrared Spectroscopy (FT-IR) and X-Ray Photoelectric Spectroscopy (XPS). The optical properties of the materials were tested with photoluminescence (PL) spectroscopy, and the stability was examined with fluorescence spectroscopy. The crystallographic nature of the nanostructured inorganic materials before and after functionalization was determined with X-Ray Diffraction (XRD). Images of the nanostructures were obtained with mainly Scanning Electron Microscopy (SEM) as well as Transmission Electron Microscopy (TEM). The work in this dissertation seeks to address the improvement of the development of nanostructured inorganic/organic hybrid materials, the investigation of novel composites for these applications and the improvement of the long term stability in aqueous medium as well as of the organic/inorganic interface itself.

2014 Fall Enrollment Report

ERIC Educational Resources Information Center

Weber, Jennifer; Williams, Carmen

2014-01-01

To improve student access and success in North Dakota University System (NDUS) institutions, the State Board of Higher Education has implemented enrollment policies that better reflect the differentiated missions of research universities, regional universities, and community colleges. This report addresses the transition in policy by grouping data…

University Access, Inclusion and Social Justice

ERIC Educational Resources Information Center

Hlalele, D.; Alexander, G.

2012-01-01

University access programmes inherently and inevitably provide students with a "label". Firstly, students are generally segregated and stigmatised as they are treated as a separate group that accessed university somewhat "illegitimately". Access programmes generally place more emphasis on academic development and in so doing…

Howard University: A Comparative Fiscal Analysis.

ERIC Educational Resources Information Center

Inman, Deborah; And Others

This report presents a fiscal analysis of Howard University (District of Columbia) including: (1) general education revenues; (2) education and general expenditures; and (3) faculty salaries. The study compared Howard University to four different groups of higher education institutions: similar private institutions with hospitals; public…

Can we look past people's race? The effect of combining race and a non-racial group affiliation on holistic processing.

PubMed

Sadozai, Ayesha K; Kempen, Kate; Tredoux, Colin; Robbins, Rachel A

2018-03-01

Face memory is worse for races other than one's own, in part because other-race faces are less holistically processed. Both experiential factors and social factors have been suggested as reasons for this other-race effect. Direct measures of holistic processing for race and a non-racial category in faces have never been employed, making it difficult to establish how experience and group membership interact. This study is the first to directly explore holistic processing of own-race and other-race faces, also classed by a non-racial category (university affiliation). Using a crossover design, White undergraduates (in Australia) completed the part-whole task for White (American) and Black South African faces attributed to the University of Western Sydney (own) and University of Sydney (other). Black South African undergraduates completed the same task for White and Black South African faces attributed to the University of Cape Town (own) and Stellenbosch University (other). It was hypothesised that own-race faces would be processed more holistically than other-race faces and that own-university faces would be processed more holistically than other-university faces. Results showed a significant effect of race for White participants (White faces were matched more accurately than Black faces), and wholes were matched more accurately than parts, suggesting holistic processing, but only for White faces. No effect of university was found. Black South African participants, who have more experience with other-race faces, processed wholes better than parts irrespective of race and university category. Overall, results suggest that experiential factors of race outweigh any effects of a non-racial shared group membership. The quality of experience for the named populations, stimuli presentation, and degree of individuation are discussed.

PREFACE: 4th Workshop on Theory, Modelling and Computational Methods for Semiconductors (TMCSIV)

NASA Astrophysics Data System (ADS)

Tomić, Stanko; Probert, Matt; Migliorato, Max; Pal, Joydeep

2014-06-01

These conference proceedings contain the written papers of the contributions presented at the 4th International Conference on Theory, Modelling and Computational Methods for Semiconductor materials and nanostructures. The conference was held at the MediaCityUK, University of Salford, Manchester, UK on 22-24 January 2014. The previous conferences in this series took place in 2012 at the University of Leeds, in 2010 at St William's College, York and in 2008 at the University of Manchester, UK. The development of high-performance computer architectures is finally allowing the routine use of accurate methods for calculating the structural, thermodynamic, vibrational, optical and electronic properties of semiconductors and their hetero- and nano-structures. The scope of this conference embraces modelling, theory and the use of sophisticated computational tools in semiconductor science and technology, where there is substantial potential for time-saving in R&D. Theoretical approaches represented in this meeting included: Density Functional Theory, Semi-empirical Electronic Structure Methods, Multi-scale Approaches, Modelling of PV devices, Electron Transport, and Graphene. Topics included, but were not limited to: Optical Properties of Quantum Nanostructures including Colloids and Nanotubes, Plasmonics, Magnetic Semiconductors, Photonic Structures, and Electronic Devices. This workshop ran for three days, with the objective of bringing together UK and international leading experts in the theoretical modelling of Group IV, III-V and II-VI semiconductors, as well as students, postdocs and early-career researchers. The first day focused on providing an introduction and overview of this vast field, aimed particularly at students, with several lectures given by recognized experts in various theoretical approaches. The following two days showcased some of the best theoretical research carried out in the UK in this field, with several contributions also from representatives of renowned theoretical groups from many European countries (Spain, France, Ireland, Germany, Switzerland, Luxemburg, Norway, Italy, Poland, Denmark, Sweden, Serbia, etc.), as well as Asia (Iran, Japan) and USA. We would like to thank all participants for making this a very successful meeting and for their contribution to the conference programme and these proceedings. We would also like to acknowledge the financial support from the Institute of Physics (Semiconductor Physics Group and Computational Physics Group), EPSRC-UK, the CECAM UK-Hartree Node, CCP9, and Quantum Wise (distributors of Atomistix). The Editors Acknowledgments Conference Organising Committee: Stanko Tomić (Chair, University of Salford) Matt Probert (University of York) Max Migliorato (University of Manchester) Joydeep Pal (University of Manchester) Programme Committee: David Whittaker (University of Sheffield, UK) John Robertson (University of Cambridge, UK) Risto Nieminen (Helsinki University of Technology Finland) Eoin O'Reilly (Tyndall Institute Cork Republic of Ireland) Marco Califano (University of Leeds, UK) Stewart Clark (University of Durham, UK) Stanko Tomić (University of Salford, UK) Mauro Pereira (Sheffield Hallam University, UK) Aldo Di Carlo (University of Rome ''Tor Vergata,'' Italy) Lev Kantorovich (King's College London, UK) Mervin Roy (University of Leicester, UK) Ben Hourahine (University of Strathclyde, UK) Rita Magri (University of Modena and Reggio Emilia, Italy) Zoran Ikonic (University of Leeds) John Barker (University of Glasgow) The proceedings were edited and compiled by Joydeep Pal, Max Migliorato and Stanko Tomić.

Poly(aniline) nanowires in sol-gel coated ITO: A pH-responsive substrate for planar supported lipid bilayers

PubMed Central

Ge, Chenhao; Orosz, Kristina S.; Armstrong, Neal R.; Saavedra, S. Scott

2011-01-01

Facilitated ion transport across an artificial lipid bilayer coupled to a solid substrate is a function common to several types of bioelectronic devices based on supported membranes, including biomimetic fuel cells and ion channel biosensors. Described here is fabrication of a pH-sensitive transducer composed of a porous sol-gel layer derivatized with poly(aniline) (PANI) nanowires grown from an underlying planar indium-tin oxide (ITO) electrode. The upper sol-gel surface is hydrophilic, smooth, and compatible with deposition of a planar supported lipid bilayer (PSLB) formed via vesicle fusion. Conducting tip AFM was used to show that the PANI wires are connected to the ITO, which convert this electrode into a potentiometric pH sensor. The response to changes in the pH of the buffer contacting the PANI nanowire/sol-gel/ITO electrode is blocked by the very low ion permeability of the overlying, fluid PSLB. The feasibility of using this assembly to monitor facilitated proton transport across the PSLB was demonstrated by doping the membrane with lipophilic ionophores that respond to a transmembrane pH gradient, which produced an apparent proton permeability several orders of magnitude greater than values measured for undoped lipid bilayers. PMID:21707069

Biomolecular engineering for nanobio/bionanotechnology

NASA Astrophysics Data System (ADS)

Nagamune, Teruyuki

2017-04-01

Biomolecular engineering can be used to purposefully manipulate biomolecules, such as peptides, proteins, nucleic acids and lipids, within the framework of the relations among their structures, functions and properties, as well as their applicability to such areas as developing novel biomaterials, biosensing, bioimaging, and clinical diagnostics and therapeutics. Nanotechnology can also be used to design and tune the sizes, shapes, properties and functionality of nanomaterials. As such, there are considerable overlaps between nanotechnology and biomolecular engineering, in that both are concerned with the structure and behavior of materials on the nanometer scale or smaller. Therefore, in combination with nanotechnology, biomolecular engineering is expected to open up new fields of nanobio/bionanotechnology and to contribute to the development of novel nanobiomaterials, nanobiodevices and nanobiosystems. This review highlights recent studies using engineered biological molecules (e.g., oligonucleotides, peptides, proteins, enzymes, polysaccharides, lipids, biological cofactors and ligands) combined with functional nanomaterials in nanobio/bionanotechnology applications, including therapeutics, diagnostics, biosensing, bioanalysis and biocatalysts. Furthermore, this review focuses on five areas of recent advances in biomolecular engineering: (a) nucleic acid engineering, (b) gene engineering, (c) protein engineering, (d) chemical and enzymatic conjugation technologies, and (e) linker engineering. Precisely engineered nanobiomaterials, nanobiodevices and nanobiosystems are anticipated to emerge as next-generation platforms for bioelectronics, biosensors, biocatalysts, molecular imaging modalities, biological actuators, and biomedical applications.

Racing to learn: statistical inference and learning in a single spiking neuron with adaptive kernels

PubMed Central

Afshar, Saeed; George, Libin; Tapson, Jonathan; van Schaik, André; Hamilton, Tara J.

2014-01-01

This paper describes the Synapto-dendritic Kernel Adapting Neuron (SKAN), a simple spiking neuron model that performs statistical inference and unsupervised learning of spatiotemporal spike patterns. SKAN is the first proposed neuron model to investigate the effects of dynamic synapto-dendritic kernels and demonstrate their computational power even at the single neuron scale. The rule-set defining the neuron is simple: there are no complex mathematical operations such as normalization, exponentiation or even multiplication. The functionalities of SKAN emerge from the real-time interaction of simple additive and binary processes. Like a biological neuron, SKAN is robust to signal and parameter noise, and can utilize both in its operations. At the network scale neurons are locked in a race with each other with the fastest neuron to spike effectively “hiding” its learnt pattern from its neighbors. The robustness to noise, high speed, and simple building blocks not only make SKAN an interesting neuron model in computational neuroscience, but also make it ideal for implementation in digital and analog neuromorphic systems which is demonstrated through an implementation in a Field Programmable Gate Array (FPGA). Matlab, Python, and Verilog implementations of SKAN are available at: http://www.uws.edu.au/bioelectronics_neuroscience/bens/reproducible_research. PMID:25505378

In vivo polymerization and manufacturing of wires and supercapacitors in plants

PubMed Central

Stavrinidou, Eleni; Nilsson, K. Peter R.; Singh, Sandeep Kumar; Franco-Gonzalez, Juan Felipe; Volkov, Anton V.; Jonsson, Magnus P.; Grimoldi, Andrea; Elgland, Mathias; Zozoulenko, Igor V.; Berggren, Magnus

2017-01-01

Electronic plants, e-Plants, are an organic bioelectronic platform that allows electronic interfacing with plants. Recently we have demonstrated plants with augmented electronic functionality. Using the vascular system and organs of a plant, we manufactured organic electronic devices and circuits in vivo, leveraging the internal structure and physiology of the plant as the template, and an integral part of the devices. However, this electronic functionality was only achieved in localized regions, whereas new electronic materials that could be distributed to every part of the plant would provide versatility in device and circuit fabrication and create possibilities for new device concepts. Here we report the synthesis of such a conjugated oligomer that can be distributed and form longer oligomers and polymer in every part of the xylem vascular tissue of a Rosa floribunda cutting, forming long-range conducting wires. The plant’s structure acts as a physical template, whereas the plant’s biochemical response mechanism acts as the catalyst for polymerization. In addition, the oligomer can cross through the veins and enter the apoplastic space in the leaves. Finally, using the plant’s natural architecture we manufacture supercapacitors along the stem. Our results are preludes to autonomous energy systems integrated within plants and distribute interconnected sensor–actuator systems for plant control and optimization. PMID:28242683

Advancing the frontiers of silk fibroin protein-based materials for futuristic electronics and clinical wound-healing (Invited review).

PubMed

Koh, Leng-Duei; Yeo, Jingjie; Lee, Yeong Yuh; Ong, Qunya; Han, Mingyong; Tee, Benjamin C-K

2018-05-01

The present review will introduce the basic concepts of silk-based electronics/optoelectronics including the latest technological advances on the use of silk fibroin in combination with other functional components, with an emphasis on improving the performance of next-generation silk-based materials. It also highlights the patterning of silk fibroin to produce micro/nano-scale features, as well as the functionalization of silk fibroin to impart antimicrobial (i.e. antibacterial) properties. Silk-based bioelectronics have great potential for advanced or futuristic bio-applications including e-skins, e-bandages, biosensors, wearable displays, implantable devices, artificial muscles, etc. Notably, silk-based organic field-effect transistors have highly promising applications in e-skins and biosensors; silk-based electrodes/antennas are used for in vivo bioanalysis or sensing purpose (e.g., measurement of neurotransmitter such as dopamine) in addition to their use as food sensors; silk-based diodes can be applied as light sources for wound healing or tissue engineering, e.g., in cutaneous wound closure or induction of photothrombosis of corneal neovascularization; silk-based actuators have promising applications as artificial muscles; whereas silk-based memristors have exciting applications as logic or synaptic network for realizing e-skins or bionic brains. Copyright © 2018 Elsevier B.V. All rights reserved.

New archetypes in self-assembled Phe-Phe motif induced nanostructures from nucleoside conjugated-diphenylalanines.

PubMed

Datta, Dhrubajyoti; Tiwari, Omshanker; Ganesh, Krishna N

2018-02-15

During the last two decades, the molecular self-assembly of the short peptide diphenylalanine (Phe-Phe) motif has attracted increasing focus due to its unique morphological structure and utility for potential applications in biomaterial chemistry, sensors and bioelectronics. Due to the ease of their synthetic modifications and a plethora of available experimental tools, the self-assembly of free and protected diphenylalanine scaffolds (H-Phe-Phe-OH, Boc-Phe-Phe-OH and Boc-Phe-Phe-OMe) has unfurled interesting tubular, vesicular or fibrillar morphologies. Developing on this theme, here we attempt to examine the effect of structure and properties (hydrophobic and H-bonding) modifying the functional C-terminus conjugated substituents on Boc-Phe-Phe on its self-assembly process. The consequent self-sorting due to H-bonding, van der Waals force and π-π interactions, generates monodisperse nano-vesicles from these peptides characterized via their SEM, HRTEM, AFM pictures and DLS experiments. The stability of these vesicles to different external stimuli such as pH and temperature, encapsulation of fluorescent probes inside the vesicles and their release by external trigger are reported. The results point to a new direction in the study and applications of the Phe-Phe motif to rationally engineer new functional nano-architectures.

Characterization of conductive nanobiomaterials derived from viral assemblies by low-voltage STEM imaging and Raman scattering

NASA Astrophysics Data System (ADS)

Plascencia-Villa, Germán; Carreño-Fuentes, Liliana; Bahena, Daniel; José-Yacamán, Miguel; Palomares, Laura A.; Ramírez, Octavio T.

2014-09-01

New technologies require the development of novel nanomaterials that need to be fully characterized to achieve their potential. High-resolution low-voltage scanning transmission electron microscopy (STEM) has proven to be a very powerful technique in nanotechnology, but its use for the characterization of nanobiomaterials has been limited. Rotavirus VP6 self-assembles into nanotubular assemblies that possess an intrinsic affinity for Au ions. This property was exploited to produce hybrid nanobiomaterials by the in situ functionalization of recombinant VP6 nanotubes with gold nanoparticles. In this work, Raman spectroscopy and advanced analytical electron microscopy imaging with spherical aberration-corrected (Cs) STEM and nanodiffraction at low-voltage doses were employed to characterize nanobiomaterials. STEM imaging revealed the precise structure and arrangement of the protein templates, as well as the nanostructure and atomic arrangement of gold nanoparticles with high spatial sub-Angstrom resolution and avoided radiation damage. The imaging was coupled with backscattered electron imaging, ultra-high resolution scanning electron microscopy and x-ray spectroscopy. The hybrid nanobiomaterials that were obtained showed unique properties as bioelectronic conductive devices and showed enhanced Raman scattering by their precise arrangement into superlattices, displaying the utility of viral assemblies as functional integrative self-assembled nanomaterials for novel applications.

Frontiers of More than Moore in Bioelectronics and the Required Metrology Needs

NASA Astrophysics Data System (ADS)

Guiseppi-Elie, Anthony; Kotanen, Christian; Wilson, A. Nolan

2011-11-01

Silicon's intersection with biology is a premise inherent in Moore's prediction. Distinct from biologically inspired molecular logic and storage devices (more Moore) are the integration of solid state electronic devices with the soft condensed state of the body (more than Moore). Developments in biomolecular recognition events per sq. cm parallel those of Moore's Law. However, challenges continue in the area of "More than Moore". Two grand challenge problems must be addressed—the biocompatibility of synthetic materials with the myriad of tissue types within the human body and the interfacing of solid state micro- and nano-electronic devices with the electronics of biological systems. Electroconductive hydrogels have been developed as soft, condensed, biomimetic but otherwise inherently electronically conductive materials to address the challenge of interfacing solid state devices with the electronics of the body, which is predominantly ionic. Nano-templated interfaces via the oriented immobilization of single walled carbon nanotubes (SWCNTs) onto metallic electrodes have engendered reagentless, direct electron transfer between biological redox enzymes and solid state electrodes. In addressing these challenges, metrology needs and opportunities are found in such widely diverse areas as single molecule counting and addressing, sustainable power requirements such as the development of implantable biofuel cells for the deployment of implantable biochips, and new manufacturing paradigms to address plura-biology needs on solid state devices.

Enzyme-Based Logic Gates and Networks with Output Signals Analyzed by Various Methods.

PubMed

Katz, Evgeny

2017-07-05

The paper overviews various methods that are used for the analysis of output signals generated by enzyme-based logic systems. The considered methods include optical techniques (optical absorbance, fluorescence spectroscopy, surface plasmon resonance), electrochemical techniques (cyclic voltammetry, potentiometry, impedance spectroscopy, conductivity measurements, use of field effect transistor devices, pH measurements), and various mechanoelectronic methods (using atomic force microscope, quartz crystal microbalance). Although each of the methods is well known for various bioanalytical applications, their use in combination with the biomolecular logic systems is rather new and sometimes not trivial. Many of the discussed methods have been combined with the use of signal-responsive materials to transduce and amplify biomolecular signals generated by the logic operations. Interfacing of biocomputing logic systems with electronics and "smart" signal-responsive materials allows logic operations be extended to actuation functions; for example, stimulating molecular release and switchable features of bioelectronic devices, such as biofuel cells. The purpose of this review article is to emphasize the broad variability of the bioanalytical systems applied for signal transduction in biocomputing processes. All bioanalytical systems discussed in the article are exemplified with specific logic gates and multi-gate networks realized with enzyme-based biocatalytic cascades. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Technology modules from micro- and nano-electronics for the life sciences.

PubMed

Birkholz, M; Mai, A; Wenger, C; Meliani, C; Scholz, R

2016-05-01

The capabilities of modern semiconductor manufacturing offer remarkable possibilities to be applied in life science research as well as for its commercialization. In this review, the technology modules available in micro- and nano-electronics are exemplarily presented for the case of 250 and 130 nm technology nodes. Preparation procedures and the different transistor types as available in complementary metal-oxide-silicon devices (CMOS) and BipolarCMOS (BiCMOS) technologies are introduced as key elements of comprehensive chip architectures. Techniques for circuit design and the elements of completely integrated bioelectronics systems are outlined. The possibility for life scientists to make use of these technology modules for their research and development projects via so-called multi-project wafer services is emphasized. Various examples from diverse fields such as (1) immobilization of biomolecules and cells on semiconductor surfaces, (2) biosensors operating by different principles such as affinity viscosimetry, impedance spectroscopy, and dielectrophoresis, (3) complete systems for human body implants and monitors for bioreactors, and (4) the combination of microelectronics with microfluidics either by chip-in-polymer integration as well as Si-based microfluidics are demonstrated from joint developments with partners from biotechnology and medicine. WIREs Nanomed Nanobiotechnol 2016, 8:355-377. doi: 10.1002/wnan.1367 For further resources related to this article, please visit the WIREs website. © 2015 Wiley Periodicals, Inc.

Stretchable conducting materials with multi-scale hierarchical structures for biomedical applications

NASA Astrophysics Data System (ADS)

Kim, Hyun; Shim, Bong Sup

2014-08-01

Electrogenetic tissues in human body such as central and peripheral nerve systems, muscular and cardiomuscular systems are soft and stretchable materials. However, most of the artificial materials, interfacing with those conductive tissues, such as neural electrodes and cardiac pacemakers, have stiff mechanical properties. The rather contradictory properties between natural and artificial materials usually cause critical incompatibility problems in implanting bodymachine interfaces for wide ranges of biomedical devices. Thus, we developed a stretchable and electrically conductive material with complex hierarchical structures; multi-scale microstructures and nanostructural electrical pathways. For biomedical purposes, an implantable polycaprolactone (PCL) membrane was coated by molecularly controlled layer-bylayer (LBL) assembly of single-walled carbon nanotubes (SWNTs) or poly(3,4-ethylenedioxythiophene) (PEDOT). The soft PCL membrane with asymmetric micro- and nano-pores provides elastic properties, while conductive SWNT or PEDOT coating preserves stable electrical conductivity even in a fully stretched state. This electrical conductivity enhanced ionic cell transmission and cell-to-cell interactions as well as electrical cellular stimulation on the membrane. Our novel stretchable conducting materials will overcome long-lasting challenges for bioelectronic applications by significantly reducing mechanical property gaps between tissues and artificial materials and by providing 3D interconnected electro-active pathways which can be available even at a fully stretched state.

A Method for Growing Bio-memristors from Slime Mold

PubMed Central

Miranda, Eduardo Reck; Braund, Edward

2017-01-01

Our research is aimed at gaining a better understanding of the electronic properties of organisms in order to engineer novel bioelectronic systems and computing architectures based on biology. This specific paper focuses on harnessing the unicellular slime mold Physarum polycephalum to develop bio-memristors (or biological memristors) and bio-computing devices. The memristor is a resistor that possesses memory. It is the 4th fundamental passive circuit element (the other three are the resistor, the capacitor, and the inductor), which is paving the way for the design of new kinds of computing systems; e.g., computers that might relinquish the distinction between storage and a central processing unit. When applied with an AC voltage, the current vs. voltage characteristic of a memristor is a pinched hysteresis loop. It has been shown that P. polycephalum produces pinched hysteresis loops under AC voltages and displays adaptive behavior that is comparable with the functioning of a memristor. This paper presents the method that we developed for implementing bio-memristors with P. polycephalum and introduces the development of a receptacle to culture the organism, which facilitates its deployment as an electronic circuit component. Our method has proven to decrease growth time, increase component lifespan, and standardize electrical observations. PMID:29155754

Development and Characterization of Organic Electronic Scaffolds for Bone Tissue Engineering.

PubMed

Iandolo, Donata; Ravichandran, Akhilandeshwari; Liu, Xianjie; Wen, Feng; Chan, Jerry K Y; Berggren, Magnus; Teoh, Swee-Hin; Simon, Daniel T

2016-06-01

Bones have been shown to exhibit piezoelectric properties, generating electrical potential upon mechanical deformation and responding to electrical stimulation with the generation of mechanical stress. Thus, the effects of electrical stimulation on bone tissue engineering have been extensively studied. However, in bone regeneration applications, only few studies have focused on the use of electroactive 3D biodegradable scaffolds at the interphase with stem cells. Here a method is described to combine the bone regeneration capabilities of 3D-printed macroporous medical grade polycaprolactone (PCL) scaffolds with the electrical and electrochemical capabilities of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT). PCL scaffolds have been highly effective in vivo as bone regeneration grafts, and PEDOT is a leading material in the field of organic bioelectronics, due to its stability, conformability, and biocompatibility. A protocol is reported for scaffolds functionalization with PEDOT, using vapor-phase polymerization, resulting in a conformal conducting layer. Scaffolds' porosity and mechanical stability, important for in vivo bone regeneration applications, are retained. Human fetal mesenchymal stem cells proliferation is assessed on the functionalized scaffolds, showing the cytocompatibility of the polymeric coating. Altogether, these results show the feasibility of the proposed approach to obtain electroactive scaffolds for electrical stimulation of stem cells for regenerative medicine. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microwave assisted synthesis and characterisation of a zinc oxide/tobacco mosaic virus hybrid material. An active hybrid semiconductor in a field-effect transistor device.

PubMed

Sanctis, Shawn; Hoffmann, Rudolf C; Eiben, Sabine; Schneider, Jörg J

2015-01-01

Tobacco mosaic virus (TMV) has been employed as a robust functional template for the fabrication of a TMV/zinc oxide field effect transistor (FET). A microwave based approach, under mild conditions was employed to synthesize stable zinc oxide (ZnO) nanoparticles, employing a molecular precursor. Insightful studies of the decomposition of the precursor were done using NMR spectroscopy and material characterization of the hybrid material derived from the decomposition was achieved using dynamic light scattering (DLS), transmission electron microscopy (TEM), grazing incidence X-ray diffractometry (GI-XRD) and atomic force microscopy (AFM). TEM and DLS data confirm the formation of crystalline ZnO nanoparticles tethered on top of the virus template. GI-XRD investigations exhibit an orientated nature of the deposited ZnO film along the c-axis. FET devices fabricated using the zinc oxide mineralized virus template material demonstrates an operational transistor performance which was achieved without any high-temperature post-processing steps. Moreover, a further improvement in FET performance was observed by adjusting an optimal layer thickness of the deposited ZnO on top of the TMV. Such a bio-inorganic nanocomposite semiconductor material accessible using a mild and straightforward microwave processing technique could open up new future avenues within the field of bio-electronics.

Chemical Modification of Semiconductor Surfaces for Molecular Electronics.

PubMed

Vilan, Ayelet; Cahen, David

2017-03-08

Inserting molecular monolayers within metal/semiconductor interfaces provides one of the most powerful expressions of how minute chemical modifications can affect electronic devices. This topic also has direct importance for technology as it can help improve the efficiency of a variety of electronic devices such as solar cells, LEDs, sensors, and possible future bioelectronic ones. The review covers the main aspects of using chemistry to control the various aspects of interface electrostatics, such as passivation of interface states and alignment of energy levels by intrinsic molecular polarization, as well as charge rearrangement with the adjacent metal and semiconducting contacts. One of the greatest merits of molecular monolayers is their capability to form excellent thin dielectrics, yielding rich and unique current-voltage characteristics for transport across metal/molecular monolayer/semiconductor interfaces. We explain the interplay between the monolayer as tunneling barrier on the one hand, and the electrostatic barrier within the semiconductor, due to its space-charge region, on the other hand, as well as how different monolayer chemistries control each of these barriers. Practical tools to experimentally identify these two barriers and distinguish between them are given, followed by a short look to the future. This review is accompanied by another one, concerning the formation of large-area molecular junctions and charge transport that is dominated solely by molecules.

Biologically templated assembly of hybrid semiconducting nanomesh for high performance field effect transistors and sensors

NASA Astrophysics Data System (ADS)

Byeon, Hye-Hyeon; Lee, Seung-Woo; Lee, Eun-Hee; Kim, Woong; Yi, Hyunjung

2016-10-01

Delicately assembled composites of semiconducting nanomaterials and biological materials provide an attractive interface for emerging applications, such as chemical/biological sensors, wearable health monitoring devices, and therapeutic agent releasing devices. The nanostructure of composites as a channel and a sensing material plays a critical role in the performance of field effect transistors (FETs). Therefore, it is highly desirable to prepare elaborate composite that can allow the fabrication of high performance FETs and also provide high sensitivity and selectivity in detecting specific chemical/biological targets. In this work, we demonstrate that high performance FETs can be fabricated with a hydrodynamically assembled composite, a semiconducting nanomesh, of semiconducting single-walled carbon nanotubes (S-SWNTs) and a genetically engineered M13 phage to show strong binding affinity toward SWNTs. The semiconducting nanomesh enables a high on/off ratio (~104) of FETs. We also show that the threshold voltage and the channel current of the nanomesh FETs are sensitive to the change of the M13 phage surface charge. This biological gate effect of the phage enables the detection of biologically important molecules such as dopamine and bisphenol A using nanomesh-based FETs. Our results provide a new insight for the preparation of composite material platform for highly controllable bio/electronics interfaces.

Optical properties and electronic transitions of DNA oligonucleotides as a function of composition and stacking sequence.

PubMed

Schimelman, Jacob B; Dryden, Daniel M; Poudel, Lokendra; Krawiec, Katherine E; Ma, Yingfang; Podgornik, Rudolf; Parsegian, V Adrian; Denoyer, Linda K; Ching, Wai-Yim; Steinmetz, Nicole F; French, Roger H

2015-02-14

The role of base pair composition and stacking sequence in the optical properties and electronic transitions of DNA is of fundamental interest. We present and compare the optical properties of DNA oligonucleotides (AT)10, (AT)5(GC)5, and (AT-GC)5 using both ab initio methods and UV-vis molar absorbance measurements. Our data indicate a strong dependence of both the position and intensity of UV absorbance features on oligonucleotide composition and stacking sequence. The partial densities of states for each oligonucleotide indicate that the valence band edge arises from a feature associated with the PO4(3-) complex anion, and the conduction band edge arises from anti-bonding states in DNA base pairs. The results show a strong correspondence between the ab initio and experimentally determined optical properties. These results highlight the benefit of full spectral analysis of DNA, as opposed to reductive methods that consider only the 260 nm absorbance (A260) or simple purity ratios, such as A260/A230 or A260/A280, and suggest that the slope of the absorption edge onset may provide a useful metric for the degree of base pair stacking in DNA. These insights may prove useful for applications in biology, bioelectronics, and mesoscale self-assembly.

Acetylene-sourced CVD-synthesised catalytically active graphene for electrochemical biosensing.

PubMed

Osikoya, Adeniyi Olugbenga; Parlak, Onur; Murugan, N Arul; Dikio, Ezekiel Dixon; Moloto, Harry; Uzun, Lokman; Turner, Anthony Pf; Tiwari, Ashutosh

2017-03-15

In this study, we have demonstrated the use of chemical vapour deposition (CVD) grown-graphene to develop a highly-ordered graphene-enzyme electrode for electrochemical biosensing. The graphene sheets were deposited on 1.00mm thick copper sheet at 850°C using acetylene (C 2 H 2 ) as carbon source in an argon (Ar) and nitrogen (N 2 ) atmosphere. An anionic surfactant was used to increase wettability and hydrophilicity of graphene; thereby facilitating the assembly of biomolecules on the electrode surface. Meanwhile, the theoretical calculations confirmed the successful modification of hydrophobic nature of graphene through the anionic surface assembly, which allowed high-ordered immobilisation of glucose oxidase (GOx) on the graphene. The electrochemical sensing activities of the graphene-electrode was explored as a model for bioelectrocatalysis. The bioelectrode exhibited a linear response to glucose concentration ranging from 0.2 to 9.8mM, with sensitivity of 0.087µA/µM/cm 2 and a detection limit of 0.12µM (S/N=3). This work sets the stage for the use of acetylene-sourced CVD-grown graphene as a fundamental building block in the fabrication of electrochemical biosensors and other bioelectronic devices. Copyright © 2016 Elsevier B.V. All rights reserved.

In vivo polymerization and manufacturing of wires and supercapacitors in plants.

PubMed

Stavrinidou, Eleni; Gabrielsson, Roger; Nilsson, K Peter R; Singh, Sandeep Kumar; Franco-Gonzalez, Juan Felipe; Volkov, Anton V; Jonsson, Magnus P; Grimoldi, Andrea; Elgland, Mathias; Zozoulenko, Igor V; Simon, Daniel T; Berggren, Magnus

2017-03-14

Electronic plants, e -Plants, are an organic bioelectronic platform that allows electronic interfacing with plants. Recently we have demonstrated plants with augmented electronic functionality. Using the vascular system and organs of a plant, we manufactured organic electronic devices and circuits in vivo, leveraging the internal structure and physiology of the plant as the template, and an integral part of the devices. However, this electronic functionality was only achieved in localized regions, whereas new electronic materials that could be distributed to every part of the plant would provide versatility in device and circuit fabrication and create possibilities for new device concepts. Here we report the synthesis of such a conjugated oligomer that can be distributed and form longer oligomers and polymer in every part of the xylem vascular tissue of a Rosa floribunda cutting, forming long-range conducting wires. The plant's structure acts as a physical template, whereas the plant's biochemical response mechanism acts as the catalyst for polymerization. In addition, the oligomer can cross through the veins and enter the apoplastic space in the leaves. Finally, using the plant's natural architecture we manufacture supercapacitors along the stem. Our results are preludes to autonomous energy systems integrated within plants and distribute interconnected sensor-actuator systems for plant control and optimization.

Deformable Organic Nanowire Field-Effect Transistors.

PubMed

Lee, Yeongjun; Oh, Jin Young; Kim, Taeho Roy; Gu, Xiaodan; Kim, Yeongin; Wang, Ging-Ji Nathan; Wu, Hung-Chin; Pfattner, Raphael; To, John W F; Katsumata, Toru; Son, Donghee; Kang, Jiheong; Matthews, James R; Niu, Weijun; He, Mingqian; Sinclair, Robert; Cui, Yi; Tok, Jeffery B-H; Lee, Tae-Woo; Bao, Zhenan

2018-02-01

Deformable electronic devices that are impervious to mechanical influence when mounted on surfaces of dynamically changing soft matters have great potential for next-generation implantable bioelectronic devices. Here, deformable field-effect transistors (FETs) composed of single organic nanowires (NWs) as the semiconductor are presented. The NWs are composed of fused thiophene diketopyrrolopyrrole based polymer semiconductor and high-molecular-weight polyethylene oxide as both the molecular binder and deformability enhancer. The obtained transistors show high field-effect mobility >8 cm 2 V -1 s -1 with poly(vinylidenefluoride-co-trifluoroethylene) polymer dielectric and can easily be deformed by applied strains (both 100% tensile and compressive strains). The electrical reliability and mechanical durability of the NWs can be significantly enhanced by forming serpentine-like structures of the NWs. Remarkably, the fully deformable NW FETs withstand 3D volume changes (>1700% and reverting back to original state) of a rubber balloon with constant current output, on the surface of which it is attached. The deformable transistors can robustly operate without noticeable degradation on a mechanically dynamic soft matter surface, e.g., a pulsating balloon (pulse rate: 40 min -1 (0.67 Hz) and 40% volume expansion) that mimics a beating heart, which underscores its potential for future biomedical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.