WorldWideScience

Sample records for biofuel cell implanted

  1. A glucose biofuel cell implanted in rats.

    Science.gov (United States)

    Cinquin, Philippe; Gondran, Chantal; Giroud, Fabien; Mazabrard, Simon; Pellissier, Aymeric; Boucher, François; Alcaraz, Jean-Pierre; Gorgy, Karine; Lenouvel, François; Mathé, Stéphane; Porcu, Paolo; Cosnier, Serge

    2010-01-01

    Powering future generations of implanted medical devices will require cumbersome transcutaneous energy transfer or harvesting energy from the human body. No functional solution that harvests power from the body is currently available, despite attempts to use the Seebeck thermoelectric effect, vibrations or body movements. Glucose fuel cells appear more promising, since they produce electrical energy from glucose and dioxygen, two substrates present in physiological fluids. The most powerful ones, Glucose BioFuel Cells (GBFCs), are based on enzymes electrically wired by redox mediators. However, GBFCs cannot be implanted in animals, mainly because the enzymes they rely on either require low pH or are inhibited by chloride or urate anions, present in the Extra Cellular Fluid (ECF). Here we present the first functional implantable GBFC, working in the retroperitoneal space of freely moving rats. The breakthrough relies on the design of a new family of GBFCs, characterized by an innovative and simple mechanical confinement of various enzymes and redox mediators: enzymes are no longer covalently bound to the surface of the electron collectors, which enables use of a wide variety of enzymes and redox mediators, augments the quantity of active enzymes, and simplifies GBFC construction. Our most efficient GBFC was based on composite graphite discs containing glucose oxidase and ubiquinone at the anode, polyphenol oxidase (PPO) and quinone at the cathode. PPO reduces dioxygen into water, at pH 7 and in the presence of chloride ions and urates at physiological concentrations. This GBFC, with electrodes of 0.133 mL, produced a peak specific power of 24.4 microW mL(-1), which is better than pacemakers' requirements and paves the way for the development of a new generation of implantable artificial organs, covering a wide range of medical applications. PMID:20454563

  2. A glucose biofuel cell implanted in rats.

    Directory of Open Access Journals (Sweden)

    Philippe Cinquin

    Full Text Available Powering future generations of implanted medical devices will require cumbersome transcutaneous energy transfer or harvesting energy from the human body. No functional solution that harvests power from the body is currently available, despite attempts to use the Seebeck thermoelectric effect, vibrations or body movements. Glucose fuel cells appear more promising, since they produce electrical energy from glucose and dioxygen, two substrates present in physiological fluids. The most powerful ones, Glucose BioFuel Cells (GBFCs, are based on enzymes electrically wired by redox mediators. However, GBFCs cannot be implanted in animals, mainly because the enzymes they rely on either require low pH or are inhibited by chloride or urate anions, present in the Extra Cellular Fluid (ECF. Here we present the first functional implantable GBFC, working in the retroperitoneal space of freely moving rats. The breakthrough relies on the design of a new family of GBFCs, characterized by an innovative and simple mechanical confinement of various enzymes and redox mediators: enzymes are no longer covalently bound to the surface of the electron collectors, which enables use of a wide variety of enzymes and redox mediators, augments the quantity of active enzymes, and simplifies GBFC construction. Our most efficient GBFC was based on composite graphite discs containing glucose oxidase and ubiquinone at the anode, polyphenol oxidase (PPO and quinone at the cathode. PPO reduces dioxygen into water, at pH 7 and in the presence of chloride ions and urates at physiological concentrations. This GBFC, with electrodes of 0.133 mL, produced a peak specific power of 24.4 microW mL(-1, which is better than pacemakers' requirements and paves the way for the development of a new generation of implantable artificial organs, covering a wide range of medical applications.

  3. A glucose biofuel cell implanted in rats.

    OpenAIRE

    Cinquin, Philippe; Gondran, Chantal; Giroud, Fabien; Mazabrard, Simon; Pellissier, Aymeric; Boucher, François; Alcaraz, Jean-Pierre; Gorgy, Karine; Lenouvel, François; Mathé, Stéphane; Porcu, Paolo; Cosnier, Serge

    2010-01-01

    Powering future generations of implanted medical devices will require cumbersome transcutaneous energy transfer or harvesting energy from the human body. No functional solution that harvests power from the body is currently available, despite attempts to use the Seebeck thermoelectric effect, vibrations or body movements. Glucose fuel cells appear more promising, since they produce electrical energy from glucose and dioxygen, two substrates present in physiological fluids. The most powerful o...

  4. Single Glucose Biofuel Cells Implanted in Rats Power Electronic Devices

    OpenAIRE

    Zebda, A.; Cosnier, S.; J.-P. Alcaraz; Holzinger, M.; A. Le Goff; Gondran, C.; Boucher, F.; Giroud, F.; Gorgy, K.; Lamraoui, H.; Cinquin, P.

    2013-01-01

    We describe the first implanted glucose biofuel cell (GBFC) that is capable of generating sufficient power from a mammal's body fluids to act as the sole power source for electronic devices. This GBFC is based on carbon nanotube/enzyme electrodes, which utilize glucose oxidase for glucose oxidation and laccase for dioxygen reduction. The GBFC, implanted in the abdominal cavity of a rat, produces an average open-circuit voltage of 0.57 V. This implanted GBFC delivered a power output of 38.7 μW...

  5. Single Glucose Biofuel Cells Implanted in Rats Power Electronic Devices

    Science.gov (United States)

    Zebda, A.; Cosnier, S.; Alcaraz, J.-P.; Holzinger, M.; Le Goff, A.; Gondran, C.; Boucher, F.; Giroud, F.; Gorgy, K.; Lamraoui, H.; Cinquin, P.

    2013-01-01

    We describe the first implanted glucose biofuel cell (GBFC) that is capable of generating sufficient power from a mammal's body fluids to act as the sole power source for electronic devices. This GBFC is based on carbon nanotube/enzyme electrodes, which utilize glucose oxidase for glucose oxidation and laccase for dioxygen reduction. The GBFC, implanted in the abdominal cavity of a rat, produces an average open-circuit voltage of 0.57 V. This implanted GBFC delivered a power output of 38.7 μW, which corresponded to a power density of 193.5 μW cm−2 and a volumetric power of 161 μW mL−1. We demonstrate that one single implanted enzymatic GBFC can power a light-emitting diode (LED), or a digital thermometer. In addition, no signs of rejection or inflammation were observed after 110 days implantation in the rat. PMID:23519113

  6. Implantable Glucose BioFuel Cells for Medical Devices

    International Nuclear Information System (INIS)

    An Implantable BioFuel Cell (IBFC) is a device that produces power only from the chemicals that are naturally occurring inside the body. We have been working on two approaches to creating an IBFC. The first approach is to use chemicals such as glucose and oxygen to provide the fuel for an enzymatic IBFC. The second approach is to use electrolytes such as sodium to provide the fuel for a biomimetic IBFC

  7. Progress on implantable biofuel cell: Nano-carbon functionalization for enzyme immobilization enhancement.

    Science.gov (United States)

    Babadi, Arman Amani; Bagheri, Samira; Hamid, Sharifah Bee Abdul

    2016-05-15

    Biofuel cells are bio-electrochemical devices, which are suitable for the environmentally friendly generation of energy. Enzymatic biofuel cell (EBFC) operates at ambient temperature and pH. Biofuel cells utilize vegetable and animal fluids (e.g. glucose) as a biofuel to produce energy. Fundamental part of each Glucose biofuel cell (GBFC) is two bioelectrodes which their surface utilizes as an enzyme immobilized site. Glucose oxidase (GOx) or glucose dehydrogenase (GDH) were immobilized on bioanode and oxidize glucose while oxygen reduced in biocathode using immobilized laccase or bilirubin oxidase in order to generate sufficient power. Glucose biofuel cells are capable to generate sufficient power for implanted devices. The key step of manufacturing a bioelectrode is the effective enzyme immobilization on the electrode surface. Due to the thin diameter of carbon nanomaterials, which make them accessible to the enzyme active sites, they are applicable materials to establish electronic communication with redox enzymes. Carbon nanomaterials regenerate the biocatalysts either by direct electron transfer or redox mediators which serve as intermediated for the electron transfer. Nano-carbon functionalization is perfectly compatible with other chemical or biological approaches to enhance the enzyme functions in implantable biofuel cells. Efficient immobilization of enzyme using the functionalized nano-carbon materials is the key point that greatly increases the possibilities of success. Current review highlights the progress on implantable biofuel cell, with focus on the nano-carbon functionalization for enzyme immobilization enhancement in glucose/O2 biofuel cells. PMID:26785309

  8. A wireless transmission system powered by an enzyme biofuel cell implanted in an orange.

    Science.gov (United States)

    MacVittie, Kevin; Conlon, Tyler; Katz, Evgeny

    2015-12-01

    A biofuel cell composed of catalytic electrodes made of "buckypaper" modified with PQQ-dependent glucose dehydrogenase and FAD-dependent fructose dehydrogenase on the anode and with laccase on the cathode was used to activate a wireless information transmission system. The cathode/anode pair was implanted in orange pulp extracting power from its content (glucose and fructose in the juice). The open circuit voltage, Voc, short circuit current density, jsc, and maximum power produced by the biofuel cell, Pmax, were found as ca. 0.6 V, ca. 0.33 mA·cm(-2) and 670 μW, respectively. The voltage produced by the biofuel cell was amplified with an energy harvesting circuit and applied to a wireless transmitter. The present study continues the research line where different implantable biofuel cells are used for the activation of electronic devices. The study emphasizes the biosensor and environmental monitoring applications of implantable biofuel cells harvesting power from natural sources, rather than their biomedical use. PMID:25467135

  9. Biofuel cells and their development

    OpenAIRE

    Bullen, R.A.; Arnot, T.C.; Walsh, F. C.

    2006-01-01

    This review considers the literature published since 1994 on microbial and enzymatic biofuel cells. Types of biofuel cell are classified according to the nature of the electrode reaction and the nature of the biochemical reactions. The performance of fuel cells is critically reviewed and a variety of possible applications is considered. The current direction of development of biofuel cells is carefully analysed. While considerable chemical development of enzyme electrodes has occurred, relati...

  10. Enzymatic biofuel cells: 30 years of critical advancements.

    Science.gov (United States)

    Rasmussen, Michelle; Abdellaoui, Sofiene; Minteer, Shelley D

    2016-02-15

    Enzymatic biofuel cells are bioelectronic devices that utilize oxidoreductase enzymes to catalyze the conversion of chemical energy into electrical energy. This review details the advancements in the field of enzymatic biofuel cells over the last 30 years. These advancements include strategies for improving operational stability and electrochemical performance, as well as device fabrication for a variety of applications, including implantable biofuel cells and self-powered sensors. It also discusses the current scientific and engineering challenges in the field that will need to be addressed in the future for commercial viability of the technology. PMID:26163747

  11. High-power biofuel cell textiles from woven biscrolled carbon nanotube yarns

    Science.gov (United States)

    Kwon, Cheong Hoon; Lee, Sung-Ho; Choi, Young-Bong; Lee, Jae Ah; Kim, Shi Hyeong; Kim, Hyug-Han; Spinks, Geoffrey M.; Wallace, Gordon G.; Lima, Márcio D.; Kozlov, Mikhail E.; Baughman, Ray H.; Kim, Seon Jeong

    2014-06-01

    Biofuel cells that generate electricity from glucose in blood are promising for powering implantable biomedical devices. Immobilizing interconnected enzyme and redox mediator in a highly conducting, porous electrode maximizes their interaction with the electrolyte and minimizes diffusion distances for fuel and oxidant, thereby enhancing power density. Here we report that our separator-free carbon nanotube yarn biofuel cells provide an open-circuit voltage of 0.70 V, and a maximum areal power density of 2.18 mW cm-2 that is three times higher than for previous carbon nanotube yarn biofuel cells. Biofuel cell operation in human serum provides high areal power output, as well as markedly increased lifetime (83% remained after 24 h), compared with previous unprotected biofuel cells. Our biscrolled yarn biofuel cells are woven into textiles having the mechanical robustness needed for implantation for glucose energy harvesting.

  12. Biofuel Cells – Alternative Power Sources

    International Nuclear Information System (INIS)

    Energy generation from renewable sources and effective waste treatment are two key challenges for the sustainable development. Microbiological (or Bio-) Fuel Cells provide an elegant solution by linking both tasks. Biofuel cells, which can directly generate electricity from biodegradable substances, have rapidly gained increasing research attention. Widely available fuel sources and moderate operational conditions make them promising in renewable energy generation, wastewater treatment, power sources for remote devices, etc. This paper reviews the use of microorganisms as biocatalysts in microbiological fuel cells. The principle of biofuel cells and their construction elements are discussed. Keywords: alternative power sources, biofuel cells, biocatalysts

  13. Stability of carbon nanotube yarn biofuel cell in human body fluid

    Science.gov (United States)

    Kwon, Cheong Hoon; Lee, Jae Ah; Choi, Young-Bong; Kim, Hyug-Han; Spinks, Geoffrey M.; Lima, Márcio D.; Baughman, Ray H.; Kim, Seon Jeong

    2015-07-01

    High performance with stability, easy-handling electrodes, and biofluid-flow controllable system with mechanical strength of the biofuel cell can be considered as the critical issues for future human body implant. These three challenges are sufficiently considered by using the effective platform regarding the high surface area from multi-walled carbon nanotube-conducting polymer with poly(3,4-ethylenedioxythiophene), and size/shape dependent flexible yarn electrodes for the implantation of biofuel cell. High power biofuel cell of mW cm-2 range in physiological condition (low glucose-containing phosphate buffered saline solution and human blood serum) controlling the stirring degree is also first demonstrated for future implantation in this study. Biofuel cells for future implantation in human body vitally require long-term stability and high power outputs. We have demonstrated that a high-surface area yarn-based biofuel cell retained over 70% of its initial power output after an extended 20 days period of continuous operation in human blood serum, while delivering a power density of ∼1.0 mW cm-2. Subsequently, our enhanced enzymatic biofuel cell system would be potentially used as an innovative power source for the next generation implantable electronics.

  14. Graphene based enzymatic bioelectrodes and biofuel cells

    Science.gov (United States)

    Karimi, Anahita; Othman, Ali; Uzunoglu, Aytekin; Stanciu, Lia; Andreescu, Silvana

    2015-04-01

    The excellent electrical conductivity and ease of functionalization make graphene a promising material for use in enzymatic bioelectrodes and biofuel cells. Enzyme based biofuel cells have attracted substantial interest due to their potential to harvest energy from organic materials. This review provides an overview of the functional properties and applications of graphene in the construction of biofuel cells as alternative power sources. The review covers the current state-of-the-art research in graphene based nanomaterials (physicochemical properties and surface functionalities), the role of these parameters in enhancing electron transfer, the stability and activity of immobilized enzymes, and how enhanced power density can be achieved. Specific examples of enzyme immobilization methods, enzyme loading, stability and function on graphene, functionalized graphene and graphene based nanocomposite materials are discussed along with their advantages and limitations. Finally, a critical evaluation of the performance of graphene based enzymatic biofuel cells, the current status, challenges and future research needs are provided.

  15. Mitochondrial bioelectrocatalysis for biofuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Arechederra, Robert L.; Boehm, Kevin [Saint Louis University, Department of Chemistry, 3501 Laclede Ave., St. Louis, MO 63103 (United States); Minteer, Shelley D., E-mail: minteers@slu.ed [Saint Louis University, Department of Chemistry, 3501 Laclede Ave., St. Louis, MO 63103 (United States)

    2009-12-01

    Mitochondria modified electrodes have been developed and characterized that utilize whole mitochondria isolated from tubers and immobilized within a quaternary ammonium modified Nafion membrane on a carbon electrode that can oxidize pyruvate and fatty acids. Detailed characterization of the performance of these mitochondria modified electrodes has been accomplished by coupling the mitochondria-based bioanode with a commercial air breathing cathode in a complete pyruvate/air biofuel cell. The studies included the effect of fuel (pyruvate) concentration, mitochondria lysing, temperature and pH on the performance of the mitochondria catalyzed, pyruvate/air biofuel cell. Effect of oxygen and cytochrome c oxidase inhibitors on biofuel cell performance has allowed us to further understand the mechanism of electron transfer with the carbon electrode.

  16. Recent advances on enzymatic glucose/oxygen and hydrogen/oxygen biofuel cells: Achievements and limitations

    Science.gov (United States)

    Cosnier, Serge; J. Gross, Andrew; Le Goff, Alan; Holzinger, Michael

    2016-09-01

    The possibility of producing electrical power from chemical energy with biological catalysts has induced the development of biofuel cells as viable energy sources for powering portable and implanted electronic devices. These power sources employ biocatalysts, called enzymes, which are highly specific and catalytic towards the oxidation of a biofuel and the reduction of oxygen or hydrogen peroxide. Enzymes, on one hand, are promising candidates to replace expensive noble metal-based catalysts in fuel cell research. On the other hand, they offer the exciting prospect of a new generation of fuel cells which harvest energy from body fluids. Biofuel cells which use glucose as a fuel are particularly interesting for generating electricity to power electronic devices inside a living body. Hydrogen consuming biofuel cells represent an emerging alternative to platinum catalysts due to comparable efficiencies and the capability to operate at lower temperatures. Currently, these technologies are not competitive with existing commercialised fuel cell devices due to limitations including insufficient power outputs and lifetimes. The advantages and challenges facing glucose biofuel cells for implantation and hydrogen biofuel cells will be summarised along with recent promising advances and the future prospects of these exotic energy-harvesting devices.

  17. Peroxidase Biocathodes for a Biofuel Cell Development

    DEFF Research Database (Denmark)

    Gomes, Celso; Shipovskov, Stepan; Ferapontova, Elena

    energy sources in the world energy consumption within the period from 2006 to 2030, with a biomass conversion mentioned only briefly. Along with this, the expedient development of new bioenergy technologies may change the future role of biological sources. One example is production of bioethanol as...... alternative fuel5,6; another example is a steadily expanding field of biofuel cells development7-10, with a number of scientific publications and patent applications increased more than 40 times during the last decade11. In terms of sustainable energy production, enzymatic biofuel cells are attractive for a......Among such efficient sustainable energy sources, as wind and solar power, photovoltaics, geothermal and water power and other1-3, biofuels are ranked as less efficient. The latest 2009 report of the International Energy Agency4 plans approximately 100% increase of the contribution of the renewable...

  18. Metal organic frameworks for enzyme immobilization in biofuel cells

    Science.gov (United States)

    Bodell, JaDee

    Interest in biofuel cells has been rapidly expanding as an ever-growing segment of the population gains access to electronic devices. The largest areas of growth for new populations using electronic devices are often in communities without electrical infrastructure. This lack of infrastructure in remote environments is one of the key driving factors behind the development of biofuel cells. Biofuel cells employ biological catalysts such as enzymes to catalyze oxidation and reduction reactions of select fuels to generate power. There are several benefits to using enzymes to catalyze reactions as compared to traditional fuel cells which use metal catalysts. First, enzymes are able to catalyze reactions at or near room temperature, whereas traditional metal catalysts are only efficient at very high temperatures. Second, biofuel cells can operate under mild pH conditions which is important for the eventual design of safe, commercially viable devices. Also, biofuel cells allow for implantable and flexible technologies. Finally, enzymes exhibit high selectivity and can be combined to fully oxidize or reduce the fuel which can generate several electrons from a single molecule of fuel, increasing the overall device efficiency. One of the main challenges which persist in biofuel cells is the instability of enzymes over time which tend to denature after hours or days. For a viable commercial biofuel cell to be produced, the stability of enzymes must be extended to months or years. Enzymes have been shown to have improved stability after being immobilized. The focus of this research was to find a metal organic framework (MOF) structure which could successfully immobilize enzymes while still allowing for electron transport to occur between the catalytic center of the enzyme and the electrode surface within a biofuel cell for power generation. Four MOF structures were successfully synthesized and were subsequently tested to determine the MOF's ability to immobilize the following

  19. Power Harvesting from Human Serum in Buckypaper-Based Enzymatic Biofuel Cell

    Directory of Open Access Journals (Sweden)

    Güray eGüven

    2016-02-01

    Full Text Available The requirement for a miniature, high density, long life, rechargeable power source is common to a vast majority of microsystems, including the implantable devices for medical applications. A model biofuel cell system operating in human serum has been studied for future applications of biomedical and implantable medical devices. Anodic and cathodic electrodes were made of carbon nanotube –buckypaper modified with PQQ-dependent glucose dehydrogenase and laccase, respectively. Modified electrodes were characterized electrochemically and assembled in a biofuel cell set-up. Power density of 16.12 μW/cm2 was achieved in human serum for lower than physiological glucose concentrations. Increasing the glucose concentration and biofuel cell temperature caused an increase on power output leading up to 49.16 μW/cm2.

  20. Power Harvesting from Human Serum in Buckypaper-Based Enzymatic Biofuel Cell

    OpenAIRE

    Güven, Güray; Şahin, Samet; Güven, Arcan; Yu, Eileen H.

    2016-01-01

    The requirement for a miniature, high density, long life, and rechargeable power source is common to a vast majority of microsystems, including the implantable devices for medical applications. A model biofuel cell system operating in human serum has been studied for future applications of biomedical and implantable medical devices. Anodic and cathodic electrodes were made of carbon nanotube-buckypaper modified with PQQ-dependent glucose dehydrogenase and laccase, respectively. Modified elect...

  1. Nanobiocatalysts for biofuel cells and biosensor systems

    Directory of Open Access Journals (Sweden)

    Radivoje M. Prodanović

    2011-10-01

    Full Text Available This overview summarizes the application of enzymes in the manufacture and design of biofuel cells and biosensors. The emphasis will be put on the protein engineering techniques used for improving the properties of enzymes such as nanobiocatalysts, e.g. immobilization orientation, stability, activity and efficiency of electron transfer between immobilized enzymes and electrodes. Some possible applications in the military and some future designs of these electric devices will be discussed as well.

  2. Biofuels

    International Nuclear Information System (INIS)

    Biofuels are fuels made from non-fossil vegetal or animal materials (biomass). They belong to the renewable energy sources as they do not contribute to worsen some global environmental impacts, like the greenhouse effect, providing that their production is performed in efficient energy conditions with low fossil fuel consumption. This article presents: 1 - the usable raw materials: biomass-derived resources, qualitative and quantitative aspects, biomass uses; 2 - biofuels production from biomass: alcohols and ethers, vegetable oils and their esters, synthetic liquid or gaseous biofuels, biogas; 3 - characteristics of liquid biofuels and comparison with gasoline and diesel fuel; 4 - biofuel uses: alcohols and their esters, biofuels with oxygenated compounds; vegetable oils and their derivatives in diesel engines, biogas, example of global environmental impact: the greenhouse effect. (J.S.)

  3. Development of a membraneless ethanol/oxygen biofuel cell

    International Nuclear Information System (INIS)

    Biofuel cells are similar to traditional fuel cells, except the metallic electrocatalyst is replaced with a biological electrocatalyst. This paper details the development of an enzymatic biofuel cell, which employs alcohol dehydrogenase to oxidize ethanol at the anode and bilirubin oxidase to reduce oxygen at the cathode. This ethanol/oxygen biofuel cell has an active lifetime of about 30 days and shows power densities of up to 0.46 mW/cm2. The biocathode described in this paper is unique in that bilirubin oxidase is immobilized within a modified Nafion polymer that acts both to entrap and stabilize the enzyme, while also containing the redox mediator in concentrations large enough for self-exchange based conduction of electrons between the enzyme and the electrode. This biocathode is fuel tolerant, which leads to a unique fuel cell that employs both renewable catalysts and fuel, but does not require a separator membrane to separate anolyte from catholyte

  4. Wired enzymes in mesoporous materials: A benchmark for fabricating biofuel cells.

    Science.gov (United States)

    Catalano, Paolo N; Wolosiuk, Alejandro; Soler-Illia, Galo J A A; Bellino, Martín G

    2015-12-01

    Evolution of fuel cells using metallic inorganic catalysts has led to the development of biofuel cells with potential applications in implantable devices. However, the main disadvantages in real world applications of enzymatic biofuel cells are short lifetime and low power density. Many efforts have been devoted to immobilize redox enzymes on surfaces to allow efficient electrical communication with electrodes and to provide an adequate habitat for biochemical activity. In this context, nanocavities of mesoporous materials offer a tailored environment for protein immobilization. Mesostructured platforms with high surface area and stability have been developed to enhance mass transport, charge transfer from biocatalysts to electrodes and enzyme stability, leading to biofuel cells with improved power density (up to 602 μW cm(-2) at physiological conditions) and overall performance (high stability after 30 h of continuous operation and after 10 days of storage). This review discusses recent developments using mesoporous materials as novel platforms for effective electronic charge transfer in the context of current and emerging technologies in enzymatic fuel cell research, emphasizing their practical implications and potential improvements leading to a major impact on medical science and portable electronics. PMID:26187442

  5. Mathematical Model of Cell Growth for Biofuel Production under Synthetic Feedback

    OpenAIRE

    Ondivillu Mothilal Kirthiga; Lakshmanan Rajendran

    2014-01-01

    In this paper, mathematical model for cell growth and biofuel production under synthetic feedback loop is discussed. The nonlinear differential equations are solved analytically for the maximum production of biofuel under synthetic feedback. The closed-form of analytical expressions pertaining to the concentrations of cell density, repressor proteins, pump expressions, intracellular biofuel and extracellular biofuel are presented. The constant pump model is compared wit...

  6. Paper electrodes for bioelectrochemistry: Biosensors and biofuel cells.

    Science.gov (United States)

    Desmet, Cloé; Marquette, Christophe A; Blum, Loïc J; Doumèche, Bastien

    2016-02-15

    Paper-based analytical devices (PAD) emerge in the scientific community since 2007 as low-cost, wearable and disposable devices for point-of-care diagnostic due to the widespread availability, long-time knowledge and easy manufacturing of cellulose. Rapidly, electrodes were introduced in PAD for electrochemical measurements. Together with biological components, a new generation of electrochemical biosensors was born. This review aims to take an inventory of existing electrochemical paper-based biosensors and biofuel cells and to identify, at the light of newly acquired data, suitable methodologies and crucial parameters in this field. Paper selection, electrode material, hydrophobization of cellulose, dedicated electrochemical devices and electrode configuration in biosensors and biofuel cells will be discussed. PMID:26163746

  7. Stretchable biofuel cell with enzyme-modified conductive textiles.

    Science.gov (United States)

    Ogawa, Yudai; Takai, Yuki; Kato, Yuto; Kai, Hiroyuki; Miyake, Takeo; Nishizawa, Matsuhiko

    2015-12-15

    A sheet-type, stretchable biofuel cell was developed by laminating three components: a bioanode textile for fructose oxidation, a hydrogel sheet containing fructose as fuel, and a gas-diffusion biocathode textile for oxygen reduction. The anode and cathode textiles were prepared by modifying carbon nanotube (CNT)-decorated stretchable textiles with fructose dehydrogenase (FDH) and bilirubin oxidase (BOD), respectively. Enzymatic reaction currents of anode and cathode textiles were stable for 30 cycles of 50% stretching, with initial loss of 20-30% in the first few cycles due to the partial breaking of the CNT network at the junction of textile fibers. The assembled laminate biofuel cell showed power of ~0.2 mW/cm(2) with 1.2 kΩ load, which was stable even at stretched, twisted, and wrapped forms. PMID:26257187

  8. A flexible micro biofuel cell utilizing hydrogel containing ascorbic acid

    International Nuclear Information System (INIS)

    This paper reports on a biofuel cell with a dimension of 13×24 mm2 fabricated on a flexible polyimide substrate. I its porous carbon-coated platinum (Pt) electrodes of 3 mm in width and 10 mm in length were fabricated using photolithography and screen printing techniques. Porous carbon was deposited by screen printing of carbon black ink on the Pt electrode surfaces in order to increase the effective electrode surface area and to absorb more enzymes on the electrode surfaces. It utilizes a solidified ascorbic acid (AA) aqueous solution in an agarose hydrogel to increase the portability. The maximum power and power density for the biofuel cell with the fuel unit containing 100 mM AA were 0.063 μW and 0.21 μW/cm2 at 0.019 V, respectively

  9. Modeling and Simulation of Enzymatic Biofuel Cells with Three-Dimensional Microelectrodes

    Directory of Open Access Journals (Sweden)

    Yin Song

    2014-07-01

    Full Text Available The enzymatic biofuel cells (EBFCs are considered as an attractive candidate for powering future implantable medical devices. In this study, a computational model of EBFCs based on three-dimensional (3-D interdigitated microelectrode arrays was conducted. The main focus of this research is to investigate the effect of different designs and spatial distributions of the microelectrode arrays on mass transport of fuels, enzymatic reaction rate, open circuit output potential and current density. To optimize the performance of the EBFCs, numerical simulations have been performed for cylindrical electrodes with various electrode heights and well widths. Optimized cell performance was obtained when the well width is half of the height of the 3-D electrode. In addition, semi-elliptical shaped electrode is preferred based on the results from current density and resistive heating simulation.

  10. Use of bioelectrode containing DNA-wrapped single-walled carbon nanotubes for enzyme-based biofuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Young; Shin, Hyun Yong; Kang, Seong Woo; Kim, Seung Wook [Department of Chemical and Biological Engineering, Korea University, 1, Anam-dong, Sungbuk-ku, Seoul 136-701 (Korea); Park, Chulhwan [Department of Chemical Engineering, Kwangwoon University, 447-1 Wolgae-dong Nowon-ku, Seoul 139-701 (Korea)

    2010-02-01

    Biofuel cells that utilize enzymes are attractive alternatives to metal catalyst-based cells because they are environmentally friendly, renewable and operate well at room temperature. Glucose oxidase (GOD)/laccase based biofuel cells have been evaluated to determine if they are useful power supplies that can be implanted in vivo. However, the usefulness of GOD/laccase systems is limited because they produce low level of electrical power. The effects of DNA-wrapped single-wall carbon nanotubes (SWNTs) on the electrical properties of a fuel cell are evaluated under ambient conditions in an attempt to increase the electrical power of an enzyme-based biofuel cell (EFC). The anode (GOD) and cathode (laccase) system in the EFC is composed of gold electrodes that are modified with DNA-wrapped SWNTs. Glucose (for anode) and O{sub 2} (for cathode) are used as the substrates. The anodic electrical properties increase significantly with a bioelectrode that contains DNA-wrapped SWNTs as an electron-transfer mediator. Furthermore, the modified bioelectrode results in increased activities and stabilities of GOD and laccase, which enhance power production (442 {mu}W cm{sup -2} at 0.46 V) compared with a basic EFC. (author)

  11. Structural studies of enzyme-based microfluidic biofuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Togo, Makoto; Takamura, Akimasa; Asai, Tatsuya; Kaji, Hirokazu; Nishizawa, Matsuhiko [Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, Aoba 6-6-01, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan)

    2008-03-15

    An enzyme-based glucose/O{sub 2} biofuel cell was constructed within a microfluidic channel to study the influence of electrode configuration and fluidic channel height on cell performance. The cell was composed of a bilirubin oxidase (BOD)-adsorbed O{sub 2} cathode and a glucose anode prepared by co-immobilization of glucose dehydrogenase (GDH), diaphorase (Dp) and VK{sub 3}-pendant poly-L-lysine. The consumption of O{sub 2} at the upstream cathode protected the downstream anode from interfering O{sub 2} molecules, and consequently improved the cell performance (maximum cell current) ca. 10% for the present cell. The cell performance was also affected by the channel height. The output current and power of a 0.1 mm-height cell was significantly less than those of a 1 mm-height cell because of the depletion of O{sub 2}, as determined by the shape of the E-I curve at the cathode. On the other hand, the volume density of current and power was several times higher for the narrower cell. (author)

  12. Structural studies of enzyme-based microfluidic biofuel cells

    Science.gov (United States)

    Togo, Makoto; Takamura, Akimasa; Asai, Tatsuya; Kaji, Hirokazu; Nishizawa, Matsuhiko

    An enzyme-based glucose/O 2 biofuel cell was constructed within a microfluidic channel to study the influence of electrode configuration and fluidic channel height on cell performance. The cell was composed of a bilirubin oxidase (BOD)-adsorbed O 2 cathode and a glucose anode prepared by co-immobilization of glucose dehydrogenase (GDH), diaphorase (Dp) and VK 3-pendant poly- L-lysine. The consumption of O 2 at the upstream cathode protected the downstream anode from interfering O 2 molecules, and consequently improved the cell performance (maximum cell current) ca. 10% for the present cell. The cell performance was also affected by the channel height. The output current and power of a 0.1 mm-height cell was significantly less than those of a 1 mm-height cell because of the depletion of O 2, as determined by the shape of the E- I curve at the cathode. On the other hand, the volume density of current and power was several times higher for the narrower cell.

  13. Cell growing on ion implanted polytetrafluorethylene

    Energy Technology Data Exchange (ETDEWEB)

    Kondyurina, I., E-mail: i.kondyurina@gmail.com [School of Medicine, University of Sydney, Sydney (Australia); Shardakov, I. [Institute of Continuous Media Mechanics, Russian Academy of Science, Perm (Russian Federation); Nechitailo, G. [Institute of Biochemical Physics, Russian Academy of Science, Moscow (Russian Federation); Terpugov, V. [Perm State University, Perm (Russian Federation); Kondyurin, A. [School of Physics, University of Sydney, Sydney (Australia)

    2014-09-30

    Highlights: • PTFE surface becomes rough, carbonized and oxidized after ion implantation. • Ion implanted PTFE contains chemically active free radicals. • Cells adherence on ion implanted PTFE is improved. - Abstract: Polytetrafluorethylene (PTFE and ePTFE) substrates were treated by ion implantation with nitrogen ions of 20 keV energies and 10{sup 13}–10{sup 16} ions/cm{sup 2} ion fluences. The modification of the polymer surface was analyzed by FTIR and XPS spectroscopy, water wetting angle measurements and AFM images. The surface morphology, wettability and chemical activity were changed due to surface modification. The growing of endothelial cells of modified surfaces was improved in comparison with untreated PTFE and ePTFE substrates. The improved cell adherence on the modified surface is based on the improved adhesion of cell proteins.

  14. Enzyme electrode configurations : for application in biofuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaoju

    2012-07-01

    ; their effects on the electrode performance were then investigated. It is proposed that the {eta}-{eta} interaction between the PSS{sup -} and the hydrophobic substrate-binding pocket in the vicinity of the T1 Cu site results in a favorable location of the conducting polymer chain of PEDOT-PSS close to the T1 Cu site and thus facilitates the DET of ThL within this particular architecture. The flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase from Glomerella cingulata (GcGDH) and cellobiose dehydrogense from Corynascus thermophuilus (CtCDH) have been studied to construct different enzyme electrode configurations as bioanodes towards biofuel cell applications. For GcGDH, six Os-containing polymers, whose redox potentials range across a broad potential window between +15 and +489 mV vs. NHE, were used to 'wire' the GcGDH on the graphite electrodes to catalyze the oxidation of glucose. The ratio of GcGDH:Os-polymer in the overall loading onto the electrode surface significantly affected the catalytic performance of the enzyme electrode on the glucose oxidation. Both the Os-polymer and the GcGDH:Os-polymer ratio were optimized for obtaining the maximum current density; a high current density of 493 {mu}A/cm{sup 2} for 30 mM glucose was produced by a GcGDH/Os c modified electrode. DET type biocatalysis of CtCDH on lactose (and glucose) oxidation was accomplished on Au nanoparticle (AuNP) structured electrode. The haem site in the CtCDH enzyme functions as a 'built-in' mediator for communicating the electron transfer between the FAD site and the AuNP surface. The redox potential of the haem site in CtCDH was determined to be E{sub 1/2} = -122 mV vs. Ag/AgCl/KCl(s) (75 mV vs. NHE). The CtCDH/AuNP/Au bioanode can generate a maximum current response for lactose with I{sub max} = 43.3{+-}1.5 ({mu}A/cm{sup 2}) or for glucose with I{sub max} = 31.2{+-}2.3 ({mu}A/cm{sup 2}). The DET type biocatalysis of CtCDH works most efficiently in a more neutral

  15. A repeatedly refuelable mediated biofuel cell based on a hierarchical porous carbon electrode

    OpenAIRE

    Fujita, Shuji; Yamanoi, Shun; Murata, Kenichi; Mita, Hiroki; Samukawa, Tsunetoshi; Nakagawa, Takaaki; Sakai, Hideki; Tokita, Yuichi

    2014-01-01

    Biofuel cells that generate electricity from renewable fuels, such as carbohydrates, must be reusable through repeated refuelling, should these devices be used in consumer electronics. We demonstrate the stable generation of electricity from a glucose-powered mediated biofuel cell through multiple refuelling cycles. This refuelability is achieved by immobilizing nicotinamide adenine dinucleotide (NAD), an electron-transfer mediator, and redox enzymes in high concentrations on porous carbon pa...

  16. Biofuel Cell Based on Microscale Nanostructured Electrodes with Inductive Coupling to Rat Brain Neurons

    Science.gov (United States)

    Andoralov, Viktor; Falk, Magnus; Suyatin, Dmitry B.; Granmo, Marcus; Sotres, Javier; Ludwig, Roland; Popov, Vladimir O.; Schouenborg, Jens; Blum, Zoltan; Shleev, Sergey

    2013-11-01

    Miniature, self-contained biodevices powered by biofuel cells may enable a new generation of implantable, wireless, minimally invasive neural interfaces for neurophysiological in vivo studies and for clinical applications. Here we report on the fabrication of a direct electron transfer based glucose/oxygen enzymatic fuel cell (EFC) from genuinely three-dimensional (3D) nanostructured microscale gold electrodes, modified with suitable biocatalysts. We show that the process underlying the simple fabrication method of 3D nanostructured electrodes is based on an electrochemically driven transformation of physically deposited gold nanoparticles. We experimentally demonstrate that mediator-, cofactor-, and membrane-less EFCs do operate in cerebrospinal fluid and in the brain of a rat, producing amounts of electrical power sufficient to drive a self-contained biodevice, viz. 7 μW cm-2 in vitro and 2 μW cm-2 in vivo at an operating voltage of 0.4 V. Last but not least, we also demonstrate an inductive coupling between 3D nanobioelectrodes and living neurons.

  17. Biofuel cell based on microscale nanostructured electrodes with inductive coupling to rat brain neurons.

    Science.gov (United States)

    Andoralov, Viktor; Falk, Magnus; Suyatin, Dmitry B; Granmo, Marcus; Sotres, Javier; Ludwig, Roland; Popov, Vladimir O; Schouenborg, Jens; Blum, Zoltan; Shleev, Sergey

    2013-01-01

    Miniature, self-contained biodevices powered by biofuel cells may enable a new generation of implantable, wireless, minimally invasive neural interfaces for neurophysiological in vivo studies and for clinical applications. Here we report on the fabrication of a direct electron transfer based glucose/oxygen enzymatic fuel cell (EFC) from genuinely three-dimensional (3D) nanostructured microscale gold electrodes, modified with suitable biocatalysts. We show that the process underlying the simple fabrication method of 3D nanostructured electrodes is based on an electrochemically driven transformation of physically deposited gold nanoparticles. We experimentally demonstrate that mediator-, cofactor-, and membrane-less EFCs do operate in cerebrospinal fluid and in the brain of a rat, producing amounts of electrical power sufficient to drive a self-contained biodevice, viz. 7 μW cm(-2) in vitro and 2 μW cm(-2) in vivo at an operating voltage of 0.4 V. Last but not least, we also demonstrate an inductive coupling between 3D nanobioelectrodes and living neurons. PMID:24253492

  18. Biofuel cell backpacked insect and its application to wireless sensing.

    Science.gov (United States)

    Shoji, Kan; Akiyama, Yoshitake; Suzuki, Masato; Nakamura, Nobuhumi; Ohno, Hiroyuki; Morishima, Keisuke

    2016-04-15

    This study investigated an enzymatic biofuel cell (BFC) which can be backpacked by cockroaches. The BFC generates electric power from trehalose in insect hemolymph by the trehalase and glucose dehydrogenase (GDH) reaction systems which dehydrogenate β-glucose obtained by hydrolyzing trehalose. First, an insect-mountable BFC (imBFC) was designed and fabricated with a 3D printer. The electrochemical reaction of anode-modified poly-L-lysine, vitamin K3, diaphorase, nicotinamide adenine dinucleotide, GDH and poly(sodium 4-styrenesulfonate) in the imBFC was evaluated and an oxidation current of 1.18 mAcm(-2) (at +0.6 V vs. Ag|AgCl) was observed. Then, the performance of the imBFC was evaluated and a maximum power output of 333 μW (285 μW cm(-)(2)) (at 0.5 V) was obtained. Furthermore, driving of both an LED device and a wireless temperature and humidity sensor device were powered by the imBFC. These results indicate that the imBFC has sufficient potential as a battery for novel ubiquitous robots such as insect cyborgs. PMID:26655178

  19. An enzymatic glucose/O2 biofuel cell operating in human blood.

    Science.gov (United States)

    Cadet, Marine; Gounel, Sébastien; Stines-Chaumeil, Claire; Brilland, Xavier; Rouhana, Jad; Louerat, Frédéric; Mano, Nicolas

    2016-09-15

    Enzymatic biofuel cells (BFCs) may power implanted medical devices and will rely on the use of glucose and O2 available in human bodily fluids. Other than well-established experiments in aqueous buffer, little work has been performed in whole human blood because it contains numerous inhibiting molecules. Here, we tested our BFCs in 30 anonymized, random and disease-free whole human blood samples. We show that by designing our anodic and cathodic bioelectrocatalysts with osmium based redox polymers and home-made enzymes we could reach a high selectivity and biofunctionnality. After optimization, BFCs generate power densities directly proportional to the glycaemia of human blood and reached a maximum power density of 129µWcm(-2) at 0.38V vs. Ag/AgCl at 8.22mM glucose. This is to our knowledge the highest power density attained so far in human blood and open the way for the powering of integrated medical feedback loops. PMID:27107143

  20. Cell adhesion and growth on ion-implanted polymer surface

    International Nuclear Information System (INIS)

    The adhesion and growth of endothelial cells on ion-implanted polystyrene and segmented polyurethane surface were investigated. Ions of Na+, N2+, O2+, Ar+ and Kr+ were implanted to the polymer surface with ion fluences between 1 x 1015 and 3 x 1017 ions/cm2 at energy of 150 KeV at room temperature. Ion-implanted polymers were characterized by FT-IR-ATR an Raman spectroscopies. The adhesion and proliferation of bovine aorta endothelial cells on ion-implanted polymer surface were observed by an optical microscope. The rate of growth of BAECs on ion-implanted PSt was faster than that on non-implanted PSt. Complete cell adhesion and growth were observed on ion-implanted SPU, whereas the adhesion and growth of BAECs on the non-implanted SPU was not observed. It was attempted to control the cell culture on the ion-implanted domain fabricated using a mask. (author)

  1. Lymphoscintigraphy and autologous stem cell implantation

    International Nuclear Information System (INIS)

    Lymphoscintigraphy is the criterion standard technique for the diagnosis of lymphedema. Advances of the application of autologous hematopoietic stem cells in ischemic disorders of lower limbs have increased the attention of researchers in this field. Aim: To determine the usefulness of lymphoscintigraphy for the assessment the efficacy of autologous stem cell implantation in patients with chronic lymphedema of the upper and lower limbs. Methods: Sixty-five patients were included. Clinical evaluation and lymphoscintigraphy were performed before and six months after stem cells implantation. The stem cells implantations were carried out by multiple superficial and deep injections in the trajectory of the lymphatic vessels and also in the inguinal region. A volume of 0.75 to 1.00 mL of cell suspension (1.0-2.2 x 109 stem cells) was administered in each injection site. Lymphoscintigraphy: Whole-body scans were acquired at 20 minutes, 1 hour, and 3 hours after administration of 185 to 259 MBq (5–7mCi) of 99mTc-albumin nanocolloids in the interdigital space of both limbs. The anatomy and function of the lymphatic system were evaluated. Results: Functional assessment before implantation of stem cells showed that 69.2% of the patients had severe lymphatic insufficiency. The 61.5% of patients showed clinical improvement, confirmed by the results of the lymphoscintigraphy. The 46.1% of the cases evaluated showed a clear improvement. The study showed that the isotopic lymphography can evaluate the therapeutic response and its intensity. Conclusion: Lymphoscintigraphy is a useful technique for the evaluation and monitoring of autologous stem cell transplantation in patients with chronic lymphedema. (author)

  2. Tris(hydroxymethyl)aminomethane photooxidation on titania based photoanodes and its implication for photoelectrochemical biofuel cells

    Science.gov (United States)

    Filipiak, Marcin S.; Zloczewska, Adrianna; Grzeskowiak, Piotr; Lynch, Robert; Jönsson-Niedziolka, Martin

    2015-09-01

    In many photoelectrochemical biofuel cells tris(hydroxymethyl)aminomethane (TRIS) is used a buffer. We show that TRIS can be readily photooxidised on titania electrodes. Combining a titania nanotube photoanode in a TRIS buffer with an air-breathing enzymatic biocathode we construct a relatively efficient photoelectrochemical biofuel cell using the TRIS buffer as fuel. This shows both the prospect of using air-breathing bio-cathodes in this kind of cells, but more importantly, shows the need for caution when using TRIS as buffer in photoelectrochemical applications.

  3. Stretchable glucose biofuel cell with wirings made of multiwall carbon nanotubes

    Science.gov (United States)

    Fujimagari, Yusuke; Nishioka, Yasushiro

    2015-12-01

    In this study, we fabricated a flexible and stretchable glucose-biofuel cell with wirings made of multi wall carbon nanotube (MWCNTs) on a polydimethylsiloxane substrate. The biofuel cell investigated consists of a porous carbon anode (area of 30 mm2) modified by glucose oxidase and ferrocene, and a cathode (area of 30 mm2) modified by bilirubin oxidase. The anode and the cathode were connected with the MWCNT wirings. The maximum power of 0.31 μW at 76.6 mV, which corresponds to a power density of 1.04 μW/cm2, was realized by immersing the biofuel cell in a phosphate buffer solution with a glucose concentration of 100 mM, at room temperature.

  4. Electrochemical Performance of Glucose/Oxygen Biofuel Cells Based on Carbon Nanostructures.

    Science.gov (United States)

    Koo, Min-Hye; Das, Gautam; Yoon, Hyon Hee

    2016-03-01

    The electrochemical performance of glucose/oxygen biofuel cells based on carbon nanostructures was investigated in the present study. Different types of carbon nanomaterials, including multi-walled carbon nanotubes (MWCNT), functionalized MWCNT (f-MWCNT), carbon nanofibers (CNF), and functionalized CNF (f-CNF) were examined for electrode fabrications. The anode for glucose/oxygen biofuel cells were prepared by sequential coating of carbon nanomaterials, charge transfer complex (CTC), glucose oxidase (GOx) and nafion membrane. The anode was then integrated with a bilirubin oxidase-immobilized cathode for the biofuel cell test. It was found that the electrochemical performance of the enzyme electrodes was remarkably enhanced by the amalgamation of carbon nanomaterials with the CTC. The biofuel cell with anode comprising of f-CNF and the cathode with MWCNT exhibited the best electrochemical performance with a maximum power density of 210 μW/cm2 at a cell voltage of 0.44 V for 20 mM glucose concentration, which is comparable with the best power density value reported earlier. PMID:27455759

  5. Assessment of bio-fuel options for solid oxide fuel cell applications

    Science.gov (United States)

    Lin, Jiefeng

    Rising concerns of inadequate petroleum supply, volatile crude oil price, and adverse environmental impacts from using fossil fuels have spurred the United States to promote bio-fuel domestic production and develop advanced energy systems such as fuel cells. The present dissertation analyzed the bio-fuel applications in a solid oxide fuel cell-based auxiliary power unit from environmental, economic, and technological perspectives. Life cycle assessment integrated with thermodynamics was applied to evaluate the environmental impacts (e.g., greenhouse gas emission, fossil energy consumption) of producing bio-fuels from waste biomass. Landfill gas from municipal solid wastes and biodiesel from waste cooking oil are both suggested as the promising bio-fuel options. A nonlinear optimization model was developed with a multi-objective optimization technique to analyze the economic aspect of biodiesel-ethanol-diesel ternary blends used in transportation sectors and capture the dynamic variables affecting bio-fuel productions and applications (e.g., market disturbances, bio-fuel tax credit, policy changes, fuel specification, and technological innovation). A single-tube catalytic reformer with rhodium/ceria-zirconia catalyst was used for autothermal reformation of various heavy hydrocarbon fuels (e.g., diesel, biodiesel, biodiesel-diesel, and biodiesel-ethanol-diesel) to produce a hydrogen-rich stream reformates suitable for use in solid oxide fuel cell systems. A customized mixing chamber was designed and integrated with the reformer to overcome the technical challenges of heavy hydrocarbon reformation. A thermodynamic analysis, based on total Gibbs free energy minimization, was implemented to optimize the operating environment for the reformations of various fuels. This was complimented by experimental investigations of fuel autothermal reformation. 25% biodiesel blended with 10% ethanol and 65% diesel was determined to be viable fuel for use on a truck travelling with

  6. Wearable Sensor System Powered by a Biofuel Cell for Detection of Lactate Levels in Sweat

    Science.gov (United States)

    Garcia, S. O.; Ulyanova, Y. V.; Figueroa-Teran, R.; Bhatt, K. H.; Singhal, S.; Atanassov, P.

    2016-01-01

    An NAD+-dependent enzymatic sensor with biofuel cell power source system for non-invasive monitoring of lactate in sweat was designed, developed, and tested. The sensor component, based on lactate dehydrogenase, showed linear current response with increasing lactate concentrations with limits of detection from 5 to 100 mM lactate and sensitivity of 0.2 µA.mM−1 in the presence of target analyte. In addition to the sensor patch a power source was also designed, developed and tested. The power source was a biofuel cell designed to oxidize glucose via glucose oxidase. The biofuel cell showed excellent performance, achieving over 80 mA at 0.4 V (16 mW) in a footprint of 3.5 × 3.5 × 0.7 cm. Furthermore, in order to couple the sensor to the power source, system electronic components were designed and fabricated. These consisted of an energy harvester (EH) and a micropotentiostat (MP). The EH was employed for harvesting power provided by the biofuel cell as well as up-converting the voltage to 3.0 V needed for the operation of the MP. The sensor was attached to MP for chronoamperometric detection of lactate. The Sensor Patch System was demonstrated under laboratory conditions.

  7. A quinhydrone biofuel cell based on an enzyme-induced pH gradient

    Energy Technology Data Exchange (ETDEWEB)

    Giroud, Fabien; Gondran, Chantal; Gorgy, Karine; Cosnier, Serge [Departement de Chimie Moleculaire, UMR CNRS 5250 ICMG-FR-2607, Universite Joseph Fourier, BP-53, 38041 Grenoble Cedex 9 (France); Pellissier, Aymeric [Departement de Chimie Moleculaire, UMR CNRS 5250 ICMG-FR-2607, Universite Joseph Fourier, BP-53, 38041 Grenoble Cedex 9 (France); Techniques de l' Ingenierie Medicale et de la Complexite - Informatique, Mathematiques Appliquees Grenoble, UMR CNRS 5525, IFRT-IpV 130, IN3S INstitut de l' INgenierie et de l' INformation de Sante, Faculte de Medecine, Universite Joseph Fourier, 38706 La Tronche cedex (France); Lenouvel, Francois; Cinquin, Philippe [Techniques de l' Ingenierie Medicale et de la Complexite - Informatique, Mathematiques Appliquees Grenoble, UMR CNRS 5525, IFRT-IpV 130, IN3S INstitut de l' INgenierie et de l' INformation de Sante, Faculte de Medecine, Universite Joseph Fourier, 38706 La Tronche cedex (France)

    2011-02-01

    We report on an alternative concept of biofuel cell functioning based on the unconventional use of enzymes to create a pH difference generating a potential difference between electrodes soaked in quinhydrone solutions. The electrode and quinhydrone solution were confined in a dialysis bag placed into a compartment containing either glucose oxidase and catalase for the biocathode or urease for the bioanode. In presence of 0.4 mol L{sup -1} glucose and urea, the enzyme reactions generate a pH difference of 3.55, both compartments being separated by an agar-agar wall. The resulting biofuel cell exhibits an open-circuit voltage and maximum power of 208 mV and 30.6 {mu}W, respectively, without immobilization and electrical connection of the involved enzymes. In addition, this biofuel cell was able to provide continuously10 {mu}A during 23 h, producing 0.133 J and 0.828 C. A similar biofuel cell configuration based only on dialysis bags was also developed. A graphite disk electrode elaborated by mechanical compression of graphite particles and quinhydrone, was placed in a dialysis bag itself confined into another dialysis bag containing enzyme solution. The resulting power and open-circuit voltage at saturating substrate conditions are 7.6 {mu}W and 157 mV, respectively. (author)

  8. Biofuel technologies. Recent developments

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Vijai Kumar [National Univ. of Ireland Galway (Ireland). Dept. of Biochemistry; MITS Univ., Rajasthan (India). Dept. of Science; Tuohy, Maria G. (eds.) [National Univ. of Ireland Galway (Ireland). Dept. of Biochemistry

    2013-02-01

    Written by experts. Richly illustrated. Of interest to both experienced researchers and beginners in the field. Biofuels are considered to be the main potential replacement for fossil fuels in the near future. In this book international experts present recent advances in biofuel research and related technologies. Topics include biomethane and biobutanol production, microbial fuel cells, feedstock production, biomass pre-treatment, enzyme hydrolysis, genetic manipulation of microbial cells and their application in the biofuels industry, bioreactor systems, and economical processing technologies for biofuel residues. The chapters provide concise information to help understand the technology-related implications of biofuels development. Moreover, recent updates on biofuel feedstocks, biofuel types, associated co- and byproducts and their applications are highlighted. The book addresses the needs of postgraduate researchers and scientists across diverse disciplines and industrial sectors in which biofuel technologies and related research and experimentation are pursued.

  9. Efficient Eucalypt Cell Wall Deconstruction and Conversion for Sustainable Lignocellulosic Biofuels.

    Science.gov (United States)

    Healey, Adam L; Lee, David J; Furtado, Agnelo; Simmons, Blake A; Henry, Robert J

    2015-01-01

    In order to meet the world's growing energy demand and reduce the impact of greenhouse gas emissions resulting from fossil fuel combustion, renewable plant-based feedstocks for biofuel production must be considered. The first-generation biofuels, derived from starches of edible feedstocks, such as corn, create competition between food and fuel resources, both for the crop itself and the land on which it is grown. As such, biofuel synthesized from non-edible plant biomass (lignocellulose) generated on marginal agricultural land will help to alleviate this competition. Eucalypts, the broadly defined taxa encompassing over 900 species of Eucalyptus, Corymbia, and Angophora are the most widely planted hardwood tree in the world, harvested mainly for timber, pulp and paper, and biomaterial products. More recently, due to their exceptional growth rate and amenability to grow under a wide range of environmental conditions, eucalypts are a leading option for the development of a sustainable lignocellulosic biofuels. However, efficient conversion of woody biomass into fermentable monomeric sugars is largely dependent on pretreatment of the cell wall, whose formation and complexity lend itself toward natural recalcitrance against its efficient deconstruction. A greater understanding of this complexity within the context of various pretreatments will allow the design of new and effective deconstruction processes for bioenergy production. In this review, we present the various pretreatment options for eucalypts, including research into understanding structure and formation of the eucalypt cell wall. PMID:26636077

  10. Generating electricity from biofluid with a nanowire-based biofuel cell for self-powered nanodevices

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Caofeng; Wu, Hui; Ahmad, Mashkoor; Luo, Zhixiang; Xie, Jianbo; Yan, Xinxu; Wu, Lihua; Zhu, Jing [Beijing National Center for Electron Microscopy, Laboratory of Advanced Materials, State Key Laboratory of New Ceramics and Fine Processing, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); The National Center for Nanoscience and Technology (NCNST) of China, Beijing 100080 (China); Fang, Ying; Li, Qiang [The National Center for Nanoscience and Technology (NCNST) of China, Beijing 100080 (China); Wang, Zhong Lin [School Materials Science and Engineering, Georgia Institute of Technology, Atlanta Georgia 30332-0245 (United States)

    2010-12-14

    We report a nanowire-based biofuel cell based on a single proton conductive polymer nanowire for converting chemical energy from biofluids, such as glucose/blood, into electricity, with glucose oxidase and laccase as catalyst. The glucose is supplied from the biofluid, the nanowire serves as the proton conductor, and the whole cell can be realized at the nano/micrometer scale. The biofuel cell composed of a single nanowire generates an output power as high as 0.5-3 {mu}W, and it has been integrated with a set of nanowire-based sensors for performing self-powered sensing. This study shows the feasibility of building self-powered nanodevices for the biological sciences, environmental monitoring, defense technology, and even personal electronics. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. A repeatedly refuelable mediated biofuel cell based on a hierarchical porous carbon electrode

    Science.gov (United States)

    Fujita, Shuji; Yamanoi, Shun; Murata, Kenichi; Mita, Hiroki; Samukawa, Tsunetoshi; Nakagawa, Takaaki; Sakai, Hideki; Tokita, Yuichi

    2014-01-01

    Biofuel cells that generate electricity from renewable fuels, such as carbohydrates, must be reusable through repeated refuelling, should these devices be used in consumer electronics. We demonstrate the stable generation of electricity from a glucose-powered mediated biofuel cell through multiple refuelling cycles. This refuelability is achieved by immobilizing nicotinamide adenine dinucleotide (NAD), an electron-transfer mediator, and redox enzymes in high concentrations on porous carbon particles constituting an anode while maintaining their electrochemical and enzymatic activities after the immobilization. This bioanode can be refuelled continuously for more than 60 cycles at 1.5 mA cm−2 without significant potential drop. Cells assembled with these bioanodes and bilirubin-oxidase-based biocathodes can be repeatedly used to power a portable music player at 1 mW cm−3 through 10 refuelling cycles. This study suggests that the refuelability within consumer electronics should facilitate the development of long and repeated use of the mediated biofuel cells as well as of NAD-based biosensors, bioreactors, and clinical applications. PMID:24820210

  12. A repeatedly refuelable mediated biofuel cell based on a hierarchical porous carbon electrode

    Science.gov (United States)

    Fujita, Shuji; Yamanoi, Shun; Murata, Kenichi; Mita, Hiroki; Samukawa, Tsunetoshi; Nakagawa, Takaaki; Sakai, Hideki; Tokita, Yuichi

    2014-05-01

    Biofuel cells that generate electricity from renewable fuels, such as carbohydrates, must be reusable through repeated refuelling, should these devices be used in consumer electronics. We demonstrate the stable generation of electricity from a glucose-powered mediated biofuel cell through multiple refuelling cycles. This refuelability is achieved by immobilizing nicotinamide adenine dinucleotide (NAD), an electron-transfer mediator, and redox enzymes in high concentrations on porous carbon particles constituting an anode while maintaining their electrochemical and enzymatic activities after the immobilization. This bioanode can be refuelled continuously for more than 60 cycles at 1.5 mA cm-2 without significant potential drop. Cells assembled with these bioanodes and bilirubin-oxidase-based biocathodes can be repeatedly used to power a portable music player at 1 mW cm-3 through 10 refuelling cycles. This study suggests that the refuelability within consumer electronics should facilitate the development of long and repeated use of the mediated biofuel cells as well as of NAD-based biosensors, bioreactors, and clinical applications.

  13. Ion implantation inhibits cell attachment to glassy polymeric carbon

    International Nuclear Information System (INIS)

    Implantation of MeV gold, oxygen, carbon ions into GPC alters the surface topography of GPC and enhances the already strong tendency for cells to attach to GPC. We have shown that implantation of silver ions near the surface strongly inhibits cell growth on GPC. Both enhanced adhesion of and inhibition of cell growth are desirable improvements on cardiac implants that have long been successfully fabricated from biocompatible glassy polymeric carbon (GPC). In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that ion beam assisted deposition (IBAD) of silver, as well as silver ion bombardment, can favorably influence the surface of GPC for biomedical applications

  14. Expanding xylose metabolism in yeast for plant cell wall conversion to biofuels.

    Science.gov (United States)

    Li, Xin; Yu, Vivian Yaci; Lin, Yuping; Chomvong, Kulika; Estrela, Raíssa; Park, Annsea; Liang, Julie M; Znameroski, Elizabeth A; Feehan, Joanna; Kim, Soo Rin; Jin, Yong-Su; Glass, N Louise; Cate, Jamie H D

    2015-01-01

    Sustainable biofuel production from renewable biomass will require the efficient and complete use of all abundant sugars in the plant cell wall. Using the cellulolytic fungus Neurospora crassa as a model, we identified a xylodextrin transport and consumption pathway required for its growth on hemicellulose. Reconstitution of this xylodextrin utilization pathway in Saccharomyces cerevisiae revealed that fungal xylose reductases act as xylodextrin reductases, producing xylosyl-xylitol oligomers as metabolic intermediates. These xylosyl-xylitol intermediates are generated by diverse fungi and bacteria, indicating that xylodextrin reduction is widespread in nature. Xylodextrins and xylosyl-xylitol oligomers are then hydrolyzed by two hydrolases to generate intracellular xylose and xylitol. Xylodextrin consumption using a xylodextrin transporter, xylodextrin reductases and tandem intracellular hydrolases in cofermentations with sucrose and glucose greatly expands the capacity of yeast to use plant cell wall-derived sugars and has the potential to increase the efficiency of both first-generation and next-generation biofuel production. PMID:25647728

  15. Photoenergy storage and power amplification strategy in membrane-less photoelectrochemical biofuel cells.

    Science.gov (United States)

    Yu, You; Xu, Miao; Dong, Shaojun

    2016-05-10

    The photoelectrochemical biofuel cell (PBFC) has drawn great attention because of its potential in the conversion of both photoenergy and chemical energy from biomass into electricity. Herein, we proposed a novel integrated PBFC by insetting a third electrode with high efficiency energy storage and release between the bioelectrode and the photoelectrode, resulting in a higher power output than that of the original PBFC. PMID:27117777

  16. Enzymatic electrodes nanostructured with functionalized carbon nanotubes for biofuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Nazaruk, E.; Bilewicz, R. [University of Warsaw, Faculty of Chemistry, Warsaw (Poland); Sadowska, K.; Biernat, J.F. [Gdansk University of Technology, Chemical Faculty, Gdansk (Poland); Rogalski, J. [Maria Curie Sklodowska University, Department of Biochemistry, Lublin (Poland); Ginalska, G. [Medical University of Lublin, Department of Biochemistry, Lublin (Poland)

    2010-10-15

    Nanostructured bioelectrodes were designed and assembled into a biofuel cell with no separating membrane. The glassy carbon electrodes were modified with mediator-functionalized carbon nanotubes. Ferrocene (Fc) and 2,2{sup '}-azino-bis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS) bound chemically to the carbon nanotubes were found useful as mediators of the enzyme catalyzed electrode processes. Glucose oxidase from Aspergillus niger AM-11 and laccase from Cerrena unicolor C-139 were incorporated in a liquid-crystalline matrix-monoolein cubic phase. The carbon nanotubes-nanostructured electrode surface was covered with the cubic phase film containing the enzyme and acted as the catalytic surface for the oxidation of glucose and reduction of oxygen. Thanks to the mediating role of derivatized nanotubes the catalysis was almost ten times more efficient than on the GCE electrodes: catalytic current of glucose oxidation was 1 mA cm{sup -2} and oxygen reduction current exceeded 0.6 mA cm{sup -2}. The open circuit voltage of the biofuel cell was 0.43 V. Application of carbon nanotubes increased the maximum power output of the constructed biofuel cell to 100 {mu}W cm{sup -2} without stirring of the solution which was ca. 100 times more efficient than using the same bioelectrodes without nanotubes on the electrode surface. (orig.)

  17. Performance of non-compartmentalized enzymatic biofuel cell based on buckypaper cathode and ferrocene-containing redox polymer anode

    Science.gov (United States)

    Bunte, Christine; Hussein, Laith; Urban, Gerald A.

    2014-02-01

    Novel single compartment Glucose/O2 biofuel cells (BFCs) were developed using immobilized enzymes and the mediated electron transfer (MET) approach. The bioanode was prepared through a ferrocene-containing redox polymer crosslinked in the presence of a biocatalyst on a glassy carbon support. Here, the redox polymer can physically entrap the enzyme and prevent it from leaching. Additionally it provides a biocompatible microenvironment and thus could extend the life time of enzyme. On the other side, the mediated biocathode was prepared based on bilirubin oxidase and 2,2‧-azinobis(3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS2-) system which has been physically entrapped in Nafion matrix and then adsorbed directly on a highly porous, conductive and functionalized buckypaper (fBP). Both electrodes were characterized physically and electrochemically. Employing these electrodes, the resulting BFC generates an open circuit voltage (Voc) of approximately 0.550 V and a peak power density of 26 μW cm-2 at 0.2 V at 37 °C in quiescent O2-saturated physiological buffer containing 5 mM glucose. The cell sustains a load up to 225 μA cm-2. Moreover, a high short circuit current (Isc) of 300 μA cm-2 is approached. This BFC can operate in mild conditions without using any toxic materials which makes it attractive for implantable devices.

  18. Genetic modification of plant cell walls to enhance biomass yield and biofuel production in bioenergy crops.

    Science.gov (United States)

    Wang, Yanting; Fan, Chunfen; Hu, Huizhen; Li, Ying; Sun, Dan; Wang, Youmei; Peng, Liangcai

    2016-01-01

    Plant cell walls represent an enormous biomass resource for the generation of biofuels and chemicals. As lignocellulose property principally determines biomass recalcitrance, the genetic modification of plant cell walls has been posed as a powerful solution. Here, we review recent progress in understanding the effects of distinct cell wall polymers (cellulose, hemicelluloses, lignin, pectin, wall proteins) on the enzymatic digestibility of biomass under various physical and chemical pretreatments in herbaceous grasses, major agronomic crops and fast-growing trees. We also compare the main factors of wall polymer features, including cellulose crystallinity (CrI), hemicellulosic Xyl/Ara ratio, monolignol proportion and uronic acid level. Furthermore, the review presents the main gene candidates, such as CesA, GH9, GH10, GT61, GT43 etc., for potential genetic cell wall modification towards enhancing both biomass yield and enzymatic saccharification in genetic mutants and transgenic plants. Regarding cell wall modification, it proposes a novel groove-like cell wall model that highlights to increase amorphous regions (density and depth) of the native cellulose microfibrils, providing a general strategy for bioenergy crop breeding and biofuel processing technology. PMID:27269671

  19. Biointerface: protein enhanced stem cells binding to implant surface.

    Science.gov (United States)

    Chrzanowski, W; Kondyurin, A; Lee, Jae Ho; Lord, Megan S; Bilek, M M M; Kim, Hae-Won

    2012-09-01

    The number of metallic implantable devices placed every year is estimated at 3.7 million. This number has been steadily increasing over last decades at a rate of around 8 %. In spite of the many successes of the devices the implantation of biomaterial into tissues almost universally leads to the development of an avascular sac, which consists of fibrous tissue around the device and walls off the implant from the body. This reaction can be detrimental to the function of implant, reduces its lifetime, and necessitates repeated surgery. Clearly, to reduce the number of revision surgeries and improve long-term implant function it is necessary to enhance device integration by modulating cell adhesion and function. In this paper we have demonstrated that it is possible to enhance stem cell attachment using engineered biointerfaces. To create this functional interface, samples were coated with polymer (as a precursor) and then ion implanted to create a reactive interface that aids the binding of biomolecules--fibronectin. Both AFM and XPS analyses confirmed the presence of protein layers on the samples. The amount of protein was significant greater for the ion implanted surfaces and was not disrupted upon washing with detergent, hence the formation of strong bonds with the interface was confirmed. While, for non ion implanted surfaces, a decrease of protein was observed after washing with detergent. Finally, the number of stem cells attached to the surface was enhanced for ion implanted surfaces. The studies presented confirm that the developed bionterface with immobilised fibronectin is an effective means to modulate stem cell attachment. PMID:22714559

  20. Ion implantation induced nanotopography on titanium and bone cell adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Braceras, Iñigo, E-mail: inigo.braceras@tecnalia.com [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Vera, Carolina; Ayerdi-Izquierdo, Ana [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Muñoz, Roberto [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); Lorenzo, Jaione; Alvarez, Noelia [Tecnalia, Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastian (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina (Ciber-BBN) (Spain); Maeztu, Miguel Ángel de [Private Practice, P° San Francisco, 43 A-1°, 20400 Tolosa (Spain)

    2014-08-15

    Graphical abstract: Titanium surfaces modified by inert ion implantation affect cell adhesion through modification of the nanotopography in the same dimensional range of that of human bone inorganic phases. - Highlights: • Inert ion implantation on Ti modifies surface nanotopography and bone cell adhesion. • Ion implantation can produce nanostructured surfaces on titanium in the very same range as of those of the mineral phase of the human bone. • Appropriate tool for studying the relevance of nanostructured surfaces on bone mineralization and implant osseointegration. • Ion implantation induced nanotopography have a statistically significant influence on bone cell adhesion. - Abstract: Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40–80 keV), fluence (1–2 e17 ion/cm{sup 2}) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted

  1. Ion implantation induced nanotopography on titanium and bone cell adhesion

    International Nuclear Information System (INIS)

    Graphical abstract: Titanium surfaces modified by inert ion implantation affect cell adhesion through modification of the nanotopography in the same dimensional range of that of human bone inorganic phases. - Highlights: • Inert ion implantation on Ti modifies surface nanotopography and bone cell adhesion. • Ion implantation can produce nanostructured surfaces on titanium in the very same range as of those of the mineral phase of the human bone. • Appropriate tool for studying the relevance of nanostructured surfaces on bone mineralization and implant osseointegration. • Ion implantation induced nanotopography have a statistically significant influence on bone cell adhesion. - Abstract: Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40–80 keV), fluence (1–2 e17 ion/cm2) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted

  2. Ion implantation induced nanotopography on titanium and bone cell adhesion

    Science.gov (United States)

    Braceras, Iñigo; Vera, Carolina; Ayerdi-Izquierdo, Ana; Muñoz, Roberto; Lorenzo, Jaione; Alvarez, Noelia; de Maeztu, Miguel Ángel

    2014-08-01

    Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40-80 keV), fluence (1-2 e17 ion/cm2) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted surfaces, without surface chemistry modification, are in the same range and that such modifications, in certain conditions, do have a statistically significant effect on bone tissue forming cell adhesion.

  3. Therapeutic Lymphangiogenesis With Implantation of Adipose‐Derived Regenerative Cells

    OpenAIRE

    Shimizu, Yuuki; Shibata, Rei; Shintani, Satoshi; Ishii, Masakazu; Murohara, Toyoaki

    2012-01-01

    Background Lymphedema is one of the serious clinical problems that can occur after surgical resection of malignant tumors such as breast cancer or intra‐pelvic cancers. However, no effective treatment options exist at present. Here, we report that implantation of adipose‐derived regenerative cells (ADRCs) can induce lymphangiogenesis in a mouse model of reparative lymphedema. Methods and Results ADRCs were isolated from C57BL/6J mice. To examine the therapeutic efficacy of ADRC implantation i...

  4. An enzyme-based microfluidic biofuel cell using vitamin K{sub 3}-mediated glucose oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Togo, Makoto; Takamura, Akimasa; Asai, Tatsuya; Kaji, Hirokazu; Nishizawa, Matsuhiko [Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, Aoba 6-6-01, Aramaki, Aoba-ku, Sendai 980-8579 (Japan)

    2007-04-01

    Viamin K{sub 3}-modified poly-L-lysine (PLL-VK{sub 3}) was synthesized and used as the electron transfer mediator during catalytic oxidation of NADH by diaphorase (Dp) at the anode of biofuel cell. PLL-VK{sub 3} and Dp were co-immobilized on an electrode and then coated with NAD{sup +}-dependent glucose dehydrogenase (GDH). The resulting enzymatic bilayer (abbreviated PLL-VK{sub 3}/Dp/GDH) catalyzed glucose oxidation. Addition of carbon black (Ketjenblack, KB) into the bilayer enlarged the effective surface area of the electrode and consequentially increased the catalytic activity. An oxidation current of ca. 2 mA cm{sup -2} was observed when the electrochemical cell contained a stirred 30 mM glucose, 1.0 mM NAD{sup +}, pH 7.0 phosphate-buffered electrolyte solution. The performance of glucose/O{sub 2} biofuel cells, constructed as fluidic chips with controllable fuel flow and containing a KB/PLL-VK{sub 3}/Dp/GDH-coated anode and an Ag/AgCl or a polydimethylsiloxane-coated Pt cathode, were evaluated. The open circuit voltage of the cell with the PDMS-coated Pt cathode was 0.55 V and its maximum power density was 32 {mu}W cm{sup -2} at 0.29 V when a pH 7.0-buffered fuel containing 5.0 mM glucose and 1.0 mM NAD{sup +} was introduced into the cell at a flow rate of 1.0 mL min{sup -1}. The cell's output increased as the flow rate increased. During 18 h of continuous operation of the cell with a load of 100 k{omega}, the output current density declined by ca. 50%, probably due to swelling of the enzyme bilayer. (author)

  5. An enzyme-based microfluidic biofuel cell using vitamin K3-mediated glucose oxidation

    International Nuclear Information System (INIS)

    Viamin K3-modified poly-L-lysine (PLL-VK3) was synthesized and used as the electron transfer mediator during catalytic oxidation of NADH by diaphorase (Dp) at the anode of biofuel cell. PLL-VK3 and Dp were co-immobilized on an electrode and then coated with NAD+-dependent glucose dehydrogenase (GDH). The resulting enzymatic bilayer (abbreviated PLL-VK3/Dp/GDH) catalyzed glucose oxidation. Addition of carbon black (Ketjenblack, KB) into the bilayer enlarged the effective surface area of the electrode and consequentially increased the catalytic activity. An oxidation current of ca. 2 mA cm-2 was observed when the electrochemical cell contained a stirred 30 mM glucose, 1.0 mM NAD+, pH 7.0 phosphate-buffered electrolyte solution. The performance of glucose/O2 biofuel cells, constructed as fluidic chips with controllable fuel flow and containing a KB/PLL-VK3/Dp/GDH-coated anode and an Ag/AgCl or a polydimethylsiloxane-coated Pt cathode, were evaluated. The open circuit voltage of the cell with the PDMS-coated Pt cathode was 0.55 V and its maximum power density was 32 μW cm-2 at 0.29 V when a pH 7.0-buffered fuel containing 5.0 mM glucose and 1.0 mM NAD+ was introduced into the cell at a flow rate of 1.0 mL min-1. The cell's output increased as the flow rate increased. During 18 h of continuous operation of the cell with a load of 100 kΩ, the output current density declined by ca. 50%, probably due to swelling of the enzyme bilayer

  6. Sugar for the fuel cell. Micro fuel cells for implants; Gib der Brennstoffzelle Zucker. Mikro-Brennstoffzellen fuer Implantate

    Energy Technology Data Exchange (ETDEWEB)

    Geitmann, Sven

    2012-04-15

    Scientists are working on micro fuel cells that will be capable of generating electric power from blood glucose. This may be an option for providing energy to cardiac pacemakers, hearing aids and other medical implants on a long-term basis. Surgery for battery exchange would be unnecessary, and patients would enjoy a better quality of life. In Germany, more than 70,000 cardiac pacemakers are implanted every year; batteries must be exchanged after about eight years. (orig.)

  7. A Metabolic Biofuel Cell: Conversion of Human Leukocyte Metabolic Activity to Electrical Currents

    Directory of Open Access Journals (Sweden)

    Cui X Tracy

    2011-05-01

    Full Text Available Abstract An investigation of the electrochemical activity of human white blood cells (WBC for biofuel cell (BFC applications is described. WBCs isolated from whole human blood were suspended in PBS and introduced into the anode compartment of a proton exchange membrane (PEM fuel cell. The cathode compartment contained a 50 mM potassium ferricyanide solution. Average current densities between 0.9 and 1.6 μA cm-2 and open circuit potentials (Voc between 83 and 102 mV were obtained, which were both higher than control values. Cyclic voltammetry was used to investigate the electrochemical activity of the activated WBCs in an attempt to elucidate the mechanism of electron transfer between the cells and electrode. Voltammograms were obtained for the WBCs, including peripheral blood mononuclear cells (PBMCs - a lymphocyte-monocyte mixture isolated on a Ficoll gradient, a B lymphoblastoid cell line (BLCL, and two leukemia cell lines, namely K562 and Jurkat. An oxidation peak at about 363 mV vs. SCE for the PMA (phorbol ester activated primary cells, with a notable absence of a reduction peak was observed. Oxidation peaks were not observed for the BLCL, K562 or Jurkat cell lines. HPLC confirmed the release of serotonin (5-HT from the PMA activated primary cells. It is believed that serotonin, among other biochemical species released by the activated cells, contributes to the observed BFC currents.

  8. Miniature biofuel cell as a potential power source for glucose-sensing contact lenses.

    Science.gov (United States)

    Falk, Magnus; Andoralov, Viktor; Silow, Maria; Toscano, Miguel D; Shleev, Sergey

    2013-07-01

    A microscale membrane-less biofuel cell, capable of generating electrical energy from human lachrymal liquid, was developed by utilizing the ascorbate and oxygen naturally present in tears as fuel and oxidant. The biodevice is based on three-dimensional nanostructured gold electrodes covered with abiotic (conductive organic complex) and biological (redox enzyme) materials functioning as efficient anodic and cathodic catalysts, respectively. Three-dimensional nanostructured electrodes were fabricated by modifying 100 μm gold wires with 17 nm gold nanoparticles, which were further modified with tetrathiafulvalene-tetracyanoquinodimethane conducting complex to create the anode and with Myrothecium verrucaria bilirubin oxidase to create the biocathode. When operated in human tears, the biodevice exhibited the following characteristics: an open circuit voltage of 0.54 V, a maximal power density of 3.1 μW cm(-2) at 0.25 V and 0.72 μW cm(-2) at 0.4 V, with a stable current density output of over 0.55 μA cm(-2) at 0.4 V for 6 h of continuous operation. These findings support our proposition that an ascorbate/oxygen biofuel cell could be a suitable power source for glucose-sensing contact lenses to be used for continuous health monitoring by diabetes patients. PMID:23735164

  9. New trends in enzyme immobilization at nanostructured interfaces for efficient electrocatalysis in biofuel cells

    International Nuclear Information System (INIS)

    Biofuel cells, and among them enzymatic biofuel cells, are expected to take part in a sustainable economy in a next future. The development of such biodevices requires significant improvements in terms of efficiency of enzyme immobilization at the electrodes, so as to enable direct electron transfer, and to increase and stabilize the current densities. Many works during the last years aimed at reaching higher current densities, thus power densities, while increasing the long term stability of the enzymatic bioelectrodes. Search for new enzymes, wild type or mutants, new entrapment procedures, but also new electrode architectures, have been targeted. This review focuses on the materials developed and involved during the last few years to meet these demands via nanostructuration of electrode interfaces. Discussion is essentially focused on cases where direct electron transfer between enzymes and electrochemical interfaces are involved. After having introduced the main reasons for the need of nanostructuration, the materials and methods that are newly developed are described. The consequences on improved performances for enzymatic bioelectrodes are discussed, and finally major challenges for future research are addressed

  10. Dynamic Modeling of Anode Function in Enzyme-Based Biofuel Cells Using High Mediator Concentration

    Directory of Open Access Journals (Sweden)

    Der-Sheng Chan

    2012-07-01

    Full Text Available The working principle of enzyme-based biofuel cells (EBFCs is the same as that of conventional fuel cells. In an EBFC system, the electricity-production process is very intricate. Analysis requires a mathematical model that can adequately describe the EBFC and predict its performance. This paper develops a dynamic model simulating the discharge performance of the anode for which supported glucose oxidase and mediator immobilize in the EBFC. The dynamic transport behavior of substrate, redox state (ROS of enzyme, enzyme-substrate complex, and the mediator creates different potential changes inside the anode. The potential-step method illustrates the dynamic phenomena of substrate diffusion, ROS of enzyme, production of enzyme-substrate complex, and reduction of the mediator with different potential changes.

  11. Life cycle assessment integrated with thermodynamic analysis of bio-fuel options for solid oxide fuel cells.

    Science.gov (United States)

    Lin, Jiefeng; Babbitt, Callie W; Trabold, Thomas A

    2013-01-01

    A methodology that integrates life cycle assessment (LCA) with thermodynamic analysis is developed and applied to evaluate the environmental impacts of producing biofuels from waste biomass, including biodiesel from waste cooking oil, ethanol from corn stover, and compressed natural gas from municipal solid wastes. Solid oxide fuel cell-based auxiliary power units using bio-fuel as the hydrogen precursor enable generation of auxiliary electricity for idling heavy-duty trucks. Thermodynamic analysis is applied to evaluate the fuel conversion efficiency and determine the amount of fuel feedstock needed to generate a unit of electrical power. These inputs feed into an LCA that compares energy consumption and greenhouse gas emissions of different fuel pathways. Results show that compressed natural gas from municipal solid wastes is an optimal bio-fuel option for SOFC-APU applications in New York State. However, this methodology can be regionalized within the U.S. or internationally to account for different fuel feedstock options. PMID:23201905

  12. Ion Implanted Passivated Contacts for Interdigitated Back Contacted Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Young, David L.; Nemeth, William; LaSalvia, Vincenzo; Reedy, Robert; Bateman, Nicholas; Stradins, Pauls

    2015-06-14

    We describe work towards an interdigitated back contacted (IBC) solar cell utilizing ion implanted, passivated contacts. Formation of electron and hole passivated contacts to n-type CZ wafers using tunneling SiO2 and ion implanted amorphous silicon (a-Si) are described. P and B were ion implanted into intrinsic amorphous Si films at several doses and energies. A series of post-implant anneals showed that the passivation quality improved with increasing annealing temperatures up to 900 degrees C. The recombination parameter, Jo, as measured by a Sinton lifetime tester, was Jo ~ 14 fA/cm2 for Si:P, and Jo ~ 56 fA/cm2 for Si:B contacts. The contact resistivity for the passivated contacts, as measured by TLM patterns, was 14 milliohm-cm2 for the n-type contact and 0.6 milliohm-cm2 for the p-type contact. These Jo and pcontact values are encouraging for forming IBC cells using ion implantation to spatially define dopants.

  13. A laccase-glucose oxidase biofuel cell prototype operating in a physiological buffer

    International Nuclear Information System (INIS)

    Here we report on the design and study of a biofuel cell consisting of a glucose oxidase-based anode (Aspergillus niger) and a laccase-based cathode (Trametes versicolor) using osmium-based redox polymers as mediators of the biocatalysts' electron transfer at graphite electrode surfaces. The graphite electrodes of the device are modified with the deposition and immobilization of the appropriate enzyme and the osmium redox polymer mediator. A redox polymer [Os(4,4'-diamino-2,2'bipyridine)2(poly{N-vinylimidazole})-(poly{ N-vinylimidazole})9Cl]Cl (E ' = -0.110 V versus Ag/AgCl) of moderately low redox potential is used for the glucose oxidizing anode and a redox polymer [Os(phenanthroline)2(poly{N-vinylimidazole})2-(poly{N-vinylimidazole})8]Cl2 (E ' = 0.49 V versus Ag/AgCl) of moderately high redox potential is used at the dioxygen reducing cathode. The enzyme and redox polymer are cross-linked with polyoxyethylene bis(glycidyl ether). The working biofuel cell was studied under air at 37 deg. C in a 0.1 M phosphate buffer solution of pH range 4.4-7.4, containing 0.1 M sodium chloride and 10 mM glucose. Under physiological conditions (pH 7.4) maximum power density, evaluated from the geometric area of the electrode, reached 16 μW/cm2 at a cell voltage of 0.25 V. At lower pH values maximum power density was 40 μW/cm2 at 0.4 V (pH 5.5) and 10 μW/cm2 at 0.3 V (pH 4.4)

  14. Biofuel Database

    Science.gov (United States)

    Biofuel Database (Web, free access)   This database brings together structural, biological, and thermodynamic data for enzymes that are either in current use or are being considered for use in the production of biofuels.

  15. Systems Level Engineering of Plant Cell Wall Biosynthesis to Improve Biofuel Feedstock Quality

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Samuel

    2013-09-27

    Our new regulatory model of cell wall biosynthesis proposes original network architecture with several newly incorporated components. The mapped set of protein-DNA interactions will serve as a foundation for 1) understanding the regulation of a complex and integral plant component and 2) the manipulation of crop species for biofuel and biotechnology purposes. This study revealed interesting and novel aspects of grass growth and development and further enforce the importance of a grass model system. By functionally characterizing a suite of genes, we have begun to improve the sparse model for transcription regulation of biomass accumulation in grasses. In the process, we have advanced methodology and brachy molecular genetic tools that will serve as valuable community resource.

  16. A glucose/O{sub 2} biofuel cell base on nanographene platelet-modified electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, W.; Zhao, H.Y.; Zhang, J.X.; Zhou, H.M.; Xu, X.X. [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Zheng, Y.F.; Wang, Y.B.; Cheng, Y. [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Jang, B.Z. [College of Engineering and Computer Science, Wright State University, 3640 Colonel Glenn Hwy., Dayton, OH 45435 (United States)

    2010-07-15

    This study demonstrated a novel nanographene platelets (NGPs)-based glucose/O{sub 2} biofuel cell (BFC) with the glucose oxidase (GOD) as the anodic biocatalysts and the laccase as the cathodic biocatalysts. The GOD/NGPs-modified electrode exhibited good catalytic activity towards glucose oxidation and the laccase/NGPs-modified electrode exhibited good catalytic activity towards O{sub 2} electroreduction. The maximum power density was ca. 57.8 {mu}W cm{sup -} {sup 2} for the assembled glucose/O{sub 2} NGPs-based BFC. These results indicated that the NGPs were very useful for the future development of novel carbon-based nanomaterials BFC device. (author)

  17. Designing a highly active soluble PQQ-glucose dehydrogenase for efficient glucose biosensors and biofuel cells

    International Nuclear Information System (INIS)

    Research highlights: → A new mutant of PQQ-GDH designed for glucose biosensors application. → First mutant of PQQ-GDH with higher activity for D-glucose than the Wild type. → Position N428 is a key point to increase the enzyme activity. → Molecular modeling shows that the N428 C mutant displays a better interaction for PQQ than the WT. -- Abstract: We report for the first time a soluble PQQ-glucose dehydrogenase that is twice more active than the wild type for glucose oxidation and was obtained by combining site directed mutagenesis, modelling and steady-state kinetics. The observed enhancement is attributed to a better interaction between the cofactor and the enzyme leading to a better electron transfer. Electrochemical experiments also demonstrate the superiority of the new mutant for glucose oxidation and make it a promising enzyme for the development of high-performance glucose biosensors and biofuel cells.

  18. Carbon nanofiber mesoporous films: efficient platforms for bio-hydrogen oxidation in biofuel cells.

    Science.gov (United States)

    de Poulpiquet, Anne; Marques-Knopf, Helena; Wernert, Véronique; Giudici-Orticoni, Marie Thérèse; Gadiou, Roger; Lojou, Elisabeth

    2014-01-28

    The discovery of oxygen and carbon monoxide tolerant [NiFe] hydrogenases was the first necessary step toward the definition of a novel generation of hydrogen fed biofuel cells. The next important milestone is now to identify and overcome bottlenecks limiting the current densities, hence the power densities. In the present work we report for the first time a comprehensive study of herringbone carbon nanofiber mesoporous films as platforms for enhanced biooxidation of hydrogen. The 3D network allows mediatorless hydrogen oxidation by the membrane-bound hydrogenase from the hyperthermophilic bacterium Aquifex aeolicus. We investigate the key physico-chemical parameters that enhance the catalytic efficiency, including surface chemistry and hierarchical porosity of the biohybrid film. We also emphasize that the catalytic current is limited by mass transport inside the mesoporous carbon nanofiber film. Provided hydrogen is supplied inside the carbon film, the combination of the hierarchical porosity of the carbon nanofiber film with the hydrophobicity of the treated carbon material results in very high efficiency of the bioelectrode. By optimization of the whole procedure, current densities as high as 4.5 mA cm(-2) are reached with a turnover frequency of 48 s(-1). This current density is almost 100 times higher than when hydrogenase is simply adsorbed at a bare graphite electrode, and more than 5 times higher than the average of the previous reported current densities at carbon nanotube modified electrodes, suggesting that carbon nanofibers can be efficiently used in future sustainable H2/O2 biofuel cells. PMID:24296569

  19. Prolongation of electrode lifetime in biofuel cells by periodic enzyme renewal

    Energy Technology Data Exchange (ETDEWEB)

    Rubenwolf, S.; Sane, S.; Kestel, J.; Stetten, F. von; Kerzenmacher, S. [Freiburg Univ. (Germany). Lab. for MEMS Applications; Hussein, L.; Urban, G.; Krueger, M. [Freiburg Univ. (Germany). Freiburg Materials Research Centre (FMF); Freiburg Univ. (Germany). Lab. for Sensors; Zengerle, R. [Freiburg Univ. (Germany). Lab. for MEMS Applications; Freiburg Univ. (Germany). BIOSS Centre for Biological Signalling Studies

    2012-11-15

    Enzymatically catalyzed biofuel cells show unique specificity and promise high power densities, but suffer from a limited lifetime due to enzyme deactivation. In the present work, we demonstrate a novel concept to extend the lifetime of a laccase-catalyzed oxygen reduction cathode in which we decouple the electrode lifetime from the limited enzyme lifetime by a regular resupply of fresh enzymes. Thereto, the adsorption behavior of laccase from Trametes versicolor to buckypaper electrode material, as well as its time-dependent deactivation characteristics, has been investigated. Laccase shows a Langmuir-type adsorption to the carbon nanotube-based buckypaper electrodes, with a mean residence time of 2 days per molecule. In a citrate buffer of pH 5, laccase does not show any deactivation at room temperature for 2 days and exhibits a half-life of 9 days. In a long-term experiment, the laccase electrodes were operated at a constant galvanostatic load. The laccase-containing catholyte was periodically exchanged against a freshly prepared one every second day to provide sufficient active enzymes in the catholyte for the replacement of desorbed inactive enzymes. Compared to a corresponding control experiment without catholyte exchange, this procedure resulted in a 2.5 times longer cathode lifetime of 19 {+-} 9 days in which the electrode showed a potential above 0.744 V vs. normal hydrogen electrode at 110 {mu}A cm{sup -2}. This clearly indicates the successful exchange of molecules by desorption and re-adsorption and is a first step toward the realization of a self-regenerating enzymatic biofuel cell in which enzyme-producing microorganisms are integrated into the electrode to continuously resupply fresh enzymes. (orig.)

  20. Automatic illumination compensation device based on a photoelectrochemical biofuel cell driven by visible light

    Science.gov (United States)

    Yu, You; Han, Yanchao; Xu, Miao; Zhang, Lingling; Dong, Shaojun

    2016-04-01

    Inverted illumination compensation is important in energy-saving projects, artificial photosynthesis and some forms of agriculture, such as hydroponics. However, only a few illumination adjustments based on self-powered biodetectors that quantitatively detect the intensity of visible light have been reported. We constructed an automatic illumination compensation device based on a photoelectrochemical biofuel cell (PBFC) driven by visible light. The PBFC consisted of a glucose dehydrogenase modified bioanode and a p-type semiconductor cuprous oxide photocathode. The PBFC had a high power output of 161.4 μW cm-2 and an open circuit potential that responded rapidly to visible light. It adjusted the amount of illumination inversely irrespective of how the external illumination was changed. This rational design of utilizing PBFCs provides new insights into automatic light adjustable devices and may be of benefit to intelligent applications.Inverted illumination compensation is important in energy-saving projects, artificial photosynthesis and some forms of agriculture, such as hydroponics. However, only a few illumination adjustments based on self-powered biodetectors that quantitatively detect the intensity of visible light have been reported. We constructed an automatic illumination compensation device based on a photoelectrochemical biofuel cell (PBFC) driven by visible light. The PBFC consisted of a glucose dehydrogenase modified bioanode and a p-type semiconductor cuprous oxide photocathode. The PBFC had a high power output of 161.4 μW cm-2 and an open circuit potential that responded rapidly to visible light. It adjusted the amount of illumination inversely irrespective of how the external illumination was changed. This rational design of utilizing PBFCs provides new insights into automatic light adjustable devices and may be of benefit to intelligent applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00759g

  1. Novel Architectures for Achieving Direct Electron Transfer in Enzymatic Biofuel Cells

    Science.gov (United States)

    Blaik, Rita A.

    Enzymatic biofuel cells are a promising source of alternative energy for small device applications, but still face the challenge of achieving direct electron transfer with high enzyme concentrations in a simple system. In this dissertation, methods of constructing electrodes consisting of enzymes attached to nanoparticle-enhanced substrates that serve as high surface area templates are evaluated. In the first method described, glucose oxidase is covalently attached to gold nanoparticles that are assembled onto genetically engineered M13 bacteriophage. The resulting anodes achieve a high peak current per area and a significant improvement in enzyme surface coverage. In the second system, fructose dehydrogenase, a membrane-bound enzyme that has the natural ability to achieve direct electron transfer, is immobilized into a matrix consisting of binders and carbon nanotubes to extend the lifetime of the anode. For the cathode, bilirubin oxidase is immobilized in a carbon nanotube and sol-gel matrix to achieve direct electron transfer. Finally, a full fuel cell consisting of both an anode and cathode is constructed and evaluated with each system described.

  2. Carbon nanotube-hydroxyapatite nanocomposite: a novel platform for glucose/O2 biofuel cell.

    Science.gov (United States)

    Zhao, H Y; Zhou, H M; Zhang, J X; Zheng, W; Zheng, Y F

    2009-10-15

    This study demonstrates a novel carbon nanotubes-hydroxyapatite (CNTs-HA) nanocomposite-based compartment-less glucose/O(2) biofuel cell (BFC) with the glucose oxidase (GOD) as the anodic biocatalysts and the laccase as the cathodic biocatalysts. CNTs-HA nanocomposite prepared by the self-assembly method via an aqueous solution reaction has been used as the co-immobilization matrix to incorporate biocatalysts, i.e. GOD and laccase successfully. Moreover, the three-dimensional configuration of the CNTs-HA films electrode would be advantageous to the glucose oxidation on the bioanode and O(2) electroreduction on the biocathode of BFC. The maximum power density delivered by the assembled glucose/O(2) BFC could reach 15.8 muWcm(-2) at a cell voltage of 0.28 V with 10 mM glucose. The results indicate that the CNTs-HA nanocomposite is believed to be very useful for the development of novel BFC device. PMID:19713096

  3. Heterologous Expression of Plant Cell Wall Degrading Enzymes for Effective Production of Cellulosic Biofuels

    Directory of Open Access Journals (Sweden)

    Sang-Kyu Jung

    2012-01-01

    Full Text Available A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE, which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such as Escherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinant E. coli or Z. mobilis and allow successful consolidated bioprocessing (CBP in these microorganisms. In-planta expression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies.

  4. Biosynthesis of Bacterial Cellulose/Carboxylic Multi-Walled Carbon Nanotubes for Enzymatic Biofuel Cell Application

    Directory of Open Access Journals (Sweden)

    Pengfei Lv

    2016-03-01

    Full Text Available Novel nanocomposites comprised of bacterial cellulose (BC with carboxylic multi-walled carbon nanotubes (c-MWCNTs incorporated into the BC matrix were prepared through a simple method of biosynthesis. The biocathode and bioanode for the enzyme biological fuel cell (EBFC were prepared using BC/c-MWCNTs composite injected by laccase (Lac and glucose oxidase (GOD with the aid of glutaraldehyde (GA crosslinking. Biosynthesis of BC/c-MWCNTs composite was characterized by digital photos, scanning electron microscope (SEM, and Fourier Transform Infrared (FTIR. The experimental results indicated the successful incorporation of c-MWCNTs into the BC. The electrochemical and biofuel performance were evaluated by cyclic voltammetry (CV and linear sweep voltammetry (LSV. The power density and current density of EBFCs were recorded at 32.98 µW/cm3 and 0.29 mA/cm3, respectively. Additionally, the EBFCs also showed acceptable stability. Preliminary tests on double cells indicated that renewable BC have great potential in the application field of EBFCs.

  5. Synchrotron-based in vivo tracking of implanted mammalian cells

    International Nuclear Information System (INIS)

    We have developed an X-ray imaging protocol that permits 3D visualisation of a small number of implanted cells within bulk tissue. The cells are marked using natural endocytosis of inert gold nano-particles. The resulting local increase in electron density allows high imaging contrast to be obtained from small clusters of these marked cells. Using this technique we have imaged C6 glioma cells within the brain of a model animal. The cells were marked by exposing them to colloidal gold incorporated in the growth media. Gold-loaded glioma cells were implanted into the brains of adult male Wistar rats. After tumours had been allowed to develop for up to 2 weeks, the animals were sacrificed and images of the intact cranium were acquired at the SYRMEP imaging station on the Elettra synchrotron in Italy. Computed tomography was performed using mixed absorption and phase contrast techniques at an X-ray energy of 24 keV. In the resulting volume datasets the tumour bulk is clearly visible and the infiltrating nature of the malignant growth is well demonstrated. Although the protocol was developed using this particular model of malignant brain tumour, it is believed that it will be possible to use it with other cell lines

  6. Ethanol/O2 biofuel cell using a biocathode consisting of laccase/ HOOC-MWCNTs/polydiallyldimethylammonium chloride.

    Science.gov (United States)

    Gouranlou, Farideh; Ghourchian, Hedayatollah

    2016-05-01

    In the present report we focused on the substitution of metallic catalysts by biocatalysts to develop a high efficient biofuel cell. A bioanode and a biocathode were designed using ADH and laccase, respectively. Carboxylated multiwall carbon nanotubes (HOOC-MWCNTs) and polydiallyldimethylammonium chloride (PDDA) were used for immobilizing the enzymes on either polymethylene green (PMG) modified glassy carbon or graphite electrodes. In this way, an ethanol-oxygen biofuel cell was designed in which PDDA/ADH/PDDA/HOOC-MWCNTs/PMG/GC and PDDA/Lac/PDDA/HOOC-MWCNTs/PMG/Gr operated as bioanode and biocathode, respectively. In the optimized condition of O2 saturated PBS (0.1M, pH 7.5) containing 1mM ethanol and 1mM NAD(+) the open-circuit voltage reached to a plateau at 504mV based of which the power density of 3.98mWcm(-2) was obtained. PMID:26992801

  7. Cubic PdNP-based air-breathing cathodes integrated in glucose hybrid biofuel cells

    Science.gov (United States)

    Faggion Junior, D.; Haddad, R.; Giroud, F.; Holzinger, M.; Maduro de Campos, C. E.; Acuña, J. J. S.; Domingos, J. B.; Cosnier, S.

    2016-05-01

    Cubic Pd nanoparticles (PdNPs) were synthesized using ascorbic acid as a reducing agent and were evaluated for the catalytic oxygen reduction reaction. PdNPs were confined with multiwalled carbon nanotube (MWCNT) dispersions to form black suspensions and these inks were dropcast onto glassy carbon electrodes. Different nanoparticle sizes were synthesized and investigated upon oxygen reduction capacities (onset potential and electrocatalytic current densities) under O2 saturated conditions at varying pH values. Strong evidence of O2 diffusion limitation was demonstrated. In order to overcome oxygen concentration and diffusion limitations in solution, we used a gas diffusion layer to create a PdNP-based air-breathing cathode, which delivered -1.5 mA cm-2 at 0.0 V with an onset potential of 0.4 V. This air-breathing cathode was combined with a specially designed phenanthrolinequinone/glucose dehydrogenase-based anode to form a complete glucose/O2 hybrid bio-fuel cell providing an open circuit voltage of 0.554 V and delivering a maximal power output of 184 +/- 21 μW cm-2 at 0.19 V and pH 7.0.Cubic Pd nanoparticles (PdNPs) were synthesized using ascorbic acid as a reducing agent and were evaluated for the catalytic oxygen reduction reaction. PdNPs were confined with multiwalled carbon nanotube (MWCNT) dispersions to form black suspensions and these inks were dropcast onto glassy carbon electrodes. Different nanoparticle sizes were synthesized and investigated upon oxygen reduction capacities (onset potential and electrocatalytic current densities) under O2 saturated conditions at varying pH values. Strong evidence of O2 diffusion limitation was demonstrated. In order to overcome oxygen concentration and diffusion limitations in solution, we used a gas diffusion layer to create a PdNP-based air-breathing cathode, which delivered -1.5 mA cm-2 at 0.0 V with an onset potential of 0.4 V. This air-breathing cathode was combined with a specially designed phenanthrolinequinone

  8. Biofuels worldwide

    International Nuclear Information System (INIS)

    After over 20 years of industrial development, the outlook for biofuels now looks bright. Recent developments indicate that the use of biofuels, previously confined to a handful of countries including Brazil and the United States, is 'going global' and a world market may emerge. However, these prospects could eventually be limited by constraints relative to resources and costs. The future of biofuels probably depends on the development of new technologies to valorize lignocellulosic substances such as wood and straw. (author)

  9. Highly Stretchable Fully-Printed CNT-Based Electrochemical Sensors and Biofuel Cells: Combining Intrinsic and Design-Induced Stretchability.

    Science.gov (United States)

    Bandodkar, Amay J; Jeerapan, Itthipon; You, Jung-Min; Nuñez-Flores, Rogelio; Wang, Joseph

    2016-01-13

    We present the first example of an all-printed, inexpensive, highly stretchable CNT-based electrochemical sensor and biofuel cell array. The synergistic effect of utilizing specially tailored screen printable stretchable inks that combine the attractive electrical and mechanical properties of CNTs with the elastomeric properties of polyurethane as a binder along with a judiciously designed free-standing serpentine pattern enables the printed device to possess two degrees of stretchability. Owing to these synergistic design and nanomaterial-based ink effects, the device withstands extremely large levels of strains (up to 500% strain) with negligible effect on its structural integrity and performance. This represents the highest stretchability offered by a printed device reported to date. Extensive electrochemical characterization of the printed device reveal that repeated stretching, torsional twisting, and indenting stress has negligible impact on its electrochemical properties. The wide-range applicability of this platform to realize highly stretchable CNT-based electrochemical sensors and biofuel cells has been demonstrated by fabricating and characterizing potentiometric ammonium sensor, amperometric enzyme-based glucose sensor, enzymatic glucose biofuel cell, and self-powered biosensor. Highly stretchable printable multianalyte sensor, multifuel biofuel cell, or any combination thereof can thus be realized using the printed CNT array. Such combination of intrinsically stretchable printed nanomaterial-based electrodes and strain-enduring design patterns holds considerable promise for creating an attractive class of inexpensive multifunctional, highly stretchable printed devices that satisfy the requirements of diverse healthcare and energy fields wherein resilience toward extreme mechanical deformations is mandatory. PMID:26694819

  10. Co-immobilization of glucoamylase and glucose oxidase for electrochemical sequential enzyme electrode for starch biosensor and biofuel cell.

    Science.gov (United States)

    Lang, Qiaolin; Yin, Long; Shi, Jianguo; Li, Liang; Xia, Lin; Liu, Aihua

    2014-01-15

    A novel electrochemical sequential biosensor was constructed by co-immobilizing glucoamylase (GA) and glucose oxidase (GOD) on the multi-walled carbon nanotubes (MWNTs)-modified glassy carbon electrode (GCE) by chemical crosslinking method, where glutaraldehyde and bovine serum albumin was used as crosslinking and blocking agent, respectively. The proposed biosensor (GA/GOD/MWNTs/GCE) is capable of determining starch without using extra sensors such as Clark-type oxygen sensor or H2O2 sensor. The current linearly decreased with the increasing concentration of starch ranging from 0.005% to 0.7% (w/w) with the limit of detection of 0.003% (w/w) starch. The as-fabricated sequential biosensor can be applicable to the detection of the content of starch in real samples, which are in good accordance with traditional Fehling's titration. Finally, a stable starch/O2 biofuel cell was assembled using the GA/GOD/MWNTs/GCE as bioanode and laccase/MWNTs/GCE as biocathode, which exhibited open circuit voltage of ca. 0.53 V and the maximum power density of 8.15 μW cm(-2) at 0.31 V, comparable with the other glucose/O2 based biofuel cells reported recently. Therefore, the proposed biosensor exhibited attractive features such as good stability in weak acidic buffer, good operational stability, wide linear range and capable of determination of starch in real samples as well as optimal bioanode for the biofuel cell. PMID:23954673

  11. New Biofuel Alternatives: Integrating Waste Management and Single Cell Oil Production

    OpenAIRE

    Elia Judith Martínez; Vijaya Raghavan; Fernando González-Andrés; Xiomar Gómez

    2015-01-01

    Concerns about greenhouse gas emissions have increased research efforts into alternatives in bio-based processes. With regard to transport fuel, bioethanol and biodiesel are still the main biofuels used. It is expected that future production of these biofuels will be based on processes using either non-food competing biomasses, or characterised by low CO2 emissions. Many microorganisms, such as microalgae, yeast, bacteria and fungi, have the ability to accumulate oils under special culture co...

  12. Synthesis and modification of reduced graphene oxide aerogels for biofuel cell applications

    Directory of Open Access Journals (Sweden)

    Kondratowicz Izabela

    2015-06-01

    Full Text Available We have carried out the preparation of reduced graphene oxide aerogels using eco-friendly method that is based on the Hummers method of graphite oxidation without the use of NaNO3 that produces toxic gases. To obtain a porous 3D structure of reduced graphene oxide, we performed the hydrothermal reduction at elevated temperature. We also prepared the rGO aerogel/CNT composite using multiwalled carbon nanotubes as linkers. The rGO aerogels are promising materials as they possess good electrical conductivity (up to 100 S/m and high surface area and porous structure (~500 m2/g. The main goal was to obtain the material for electrodes in enzymatic biofuel cells. Thus, the proper modification was performed using free radical functionalization. It was shown that in order to synthesize rGO aerogels modified with anthracene, the proper order of reactions needs to be provided. The morphology of anthracene modified electrodes was analyzed using scanning electron microscopy, which confirmed their porous structure with non-uniform pore size distribution that ranged between few nanometers to microns. Data obtained by Raman spectroscopy confirmed the successful oxidation and reduction of analyzed materials. UV-Vis spectra revealed the presence of anthracene moieties in examined materials. We also recorded preliminary cyclic voltammograms that confirm an electric conductivity of the obtained structures.

  13. Cubic PdNP-based air-breathing cathodes integrated in glucose hybrid biofuel cells.

    Science.gov (United States)

    Faggion Junior, D; Haddad, R; Giroud, F; Holzinger, M; Maduro de Campos, C E; Acuña, J J S; Domingos, J B; Cosnier, S

    2016-05-21

    Cubic Pd nanoparticles (PdNPs) were synthesized using ascorbic acid as a reducing agent and were evaluated for the catalytic oxygen reduction reaction. PdNPs were confined with multiwalled carbon nanotube (MWCNT) dispersions to form black suspensions and these inks were dropcast onto glassy carbon electrodes. Different nanoparticle sizes were synthesized and investigated upon oxygen reduction capacities (onset potential and electrocatalytic current densities) under O2 saturated conditions at varying pH values. Strong evidence of O2 diffusion limitation was demonstrated. In order to overcome oxygen concentration and diffusion limitations in solution, we used a gas diffusion layer to create a PdNP-based air-breathing cathode, which delivered -1.5 mA cm(-2) at 0.0 V with an onset potential of 0.4 V. This air-breathing cathode was combined with a specially designed phenanthrolinequinone/glucose dehydrogenase-based anode to form a complete glucose/O2 hybrid bio-fuel cell providing an open circuit voltage of 0.554 V and delivering a maximal power output of 184 ± 21 μW cm(-2) at 0.19 V and pH 7.0. PMID:27142300

  14. Graphene/enzyme-encrusted three-dimensional carbon micropillar arrays for mediatorless micro-biofuel cells

    Science.gov (United States)

    Song, Yin; Chen, Chunhui; Wang, Chunlei

    2015-04-01

    Two-dimensional graphene is a promising candidate material for use in high-performance enzymatic biofuel cells (EBFCs). In this work, graphene/enzyme has been integrated onto three-dimensional (3D) micropillar arrays in order to obtain efficient enzyme immobilisation and enhanced enzyme loading and facilitate direct electron transfer. The fabrication process of this system combines top-down carbon microelectromechanical systems (C-MEMS) to fabricate the 3D micropillar array platform and bottom-up electrophoretic deposition (EPD) to deposit the graphene/enzyme onto the electrode surface. The amperometric response of the graphene-based bioelectrode exhibited excellent electrochemical activity, which indicated the successful co-deposition of graphene with the enzymes. The developed 3D graphene/enzyme network-based EBFC generated a maximum power density of 136.3 μW cm-2 at 0.59 V, which is almost seven times the maximum power density of the bare 3D carbon micropillar array-based EBFC.

  15. A glucose fuel cell for implantable brain-machine interfaces.

    Directory of Open Access Journals (Sweden)

    Benjamin I Rapoport

    Full Text Available We have developed an implantable fuel cell that generates power through glucose oxidation, producing 3.4 μW cm(-2 steady-state power and up to 180 μW cm(-2 peak power. The fuel cell is manufactured using a novel approach, employing semiconductor fabrication techniques, and is therefore well suited for manufacture together with integrated circuits on a single silicon wafer. Thus, it can help enable implantable microelectronic systems with long-lifetime power sources that harvest energy from their surrounds. The fuel reactions are mediated by robust, solid state catalysts. Glucose is oxidized at the nanostructured surface of an activated platinum anode. Oxygen is reduced to water at the surface of a self-assembled network of single-walled carbon nanotubes, embedded in a Nafion film that forms the cathode and is exposed to the biological environment. The catalytic electrodes are separated by a Nafion membrane. The availability of fuel cell reactants, oxygen and glucose, only as a mixture in the physiologic environment, has traditionally posed a design challenge: Net current production requires oxidation and reduction to occur separately and selectively at the anode and cathode, respectively, to prevent electrochemical short circuits. Our fuel cell is configured in a half-open geometry that shields the anode while exposing the cathode, resulting in an oxygen gradient that strongly favors oxygen reduction at the cathode. Glucose reaches the shielded anode by diffusing through the nanotube mesh, which does not catalyze glucose oxidation, and the Nafion layers, which are permeable to small neutral and cationic species. We demonstrate computationally that the natural recirculation of cerebrospinal fluid around the human brain theoretically permits glucose energy harvesting at a rate on the order of at least 1 mW with no adverse physiologic effects. Low-power brain-machine interfaces can thus potentially benefit from having their implanted units

  16. Positive aspects issued from bio-corrosion studies: from hydrogen production to biofuel cells

    International Nuclear Information System (INIS)

    Microbially influenced corrosion or bio-corrosion is a problem that generates heavy global economic losses (several billion euros per year). In spite of the progress made on the understanding of the underlying mechanisms, the complexity of the phenomenon has prevented finding definitive solutions to the problem and continues to inspire many research works. The participation in bio-corrosion of catalytic mechanisms induced by weak acids was studied in this work. Another objective of the thesis has been to take advantage from catalytic phenomena found in bio corrosion research to apply them in other areas: energy production with biofuel cells or electrochemical hydrogen production in mild conditions. This work has shown that the presence of weak acids and amino acids inside bio films could play a major role in steel bio-corrosion accelerating the phenomenon through the catalysis of the water reduction reaction. The reversibility of this mechanism, discerned and proved here, could explain the corrosion increase when hydrogen is removed (bacterial consumption, agitation...). In addition, phosphates allow the production of hydrogen by electrolysis in mild ph conditions (pH 4.0 - 8.0) with an equal or better performance than those found in alkaline electrolysis. Finally, industrial materials like stainless steel and titanium could be used in the fabrication of enzymatic electrodes for biosensors or microsystems. The use of the glucose oxidase / glucose system in an aqueous fuel cell with a stainless steel cathode, allows the improvement of the cell performance thanks to the production of hydrogen peroxide that is easily reduced. Moreover, the use of materials with micro-structured surfaces like sandblasted steels deserve to be studied in detail to exploit the remarkable reactivity they present compared to smooth electrodes. (author)

  17. Positive aspects issued from bio corrosion studies: from hydrogen production to biofuel cells

    International Nuclear Information System (INIS)

    Microbially influenced corrosion or bio corrosion is a problem that generates heavy global economic losses (several billion euros per year). In spite of the progress made on the understanding of the underlying mechanisms, the complexity of the phenomenon has prevented finding definitive solutions to the problem and continues to inspire many research works. The participation in bio corrosion of catalytic mechanisms induced by weak acids was studied in this work. Another objective of the thesis has been to take advantage from catalytic phenomena found in bio corrosion research to apply them in other areas: energy production with biofuel cells or electrochemical hydrogen production in mild conditions. This work has shown that the presence of weak acids and amino acids inside bio-films could play a major role in steel bio corrosion accelerating the phenomenon through the catalysis of the water reduction reaction. The reversibility of this mechanism, discerned and proved here, could explain the corrosion increase when hydrogen is removed (bacterial consumption, agitation...). In addition, phosphates allow the production of hydrogen by electrolysis in mild pH conditions (pH 4.0 - 8.0) with an equal or better performance than those found in alkaline electrolysis. Finally, industrial materials like stainless steel and titanium could be used in the fabrication of enzymatic electrodes for biosensors or microsystems. The use of the glucose oxidase/glucose system in an aqueous fuel cell with a stainless steel cathode, allows the improvement of the cell performance thanks to the production of hydrogen peroxide that is easily reduced. Moreover, the use of materials with micro-structured surfaces like sandblasted steels deserve to be studied in detail to exploit the remarkable reactivity they present compared to smooth electrodes. (author)

  18. Microbial biofuel cell operating effectively through carbon nanotube blended with gold–titania nanocomposites modified electrode

    International Nuclear Information System (INIS)

    In this study, we have explored the possibility to fabricate microbial biofuel cell operating with carbon nanotube–gold–titania nanocomposites (CNT/Au/TiO2) as anode modifier. The results demonstrate that the CNT/Au/TiO2 electrode could be utilized as a new and effective microbial fuel cell (MFC) anode, which integrate the advantages of relevant nanocomposites such as high conductivity, high specific surface area, and easy adsorption of the microorganism. It is evident that the three-dimensional network nanostructures of CNT/Au/TiO2 are propitious to improve the relevant anode surface area and thus the adsorption of the microorganism, which can efficiently promote the electronic transfer rate between the probe and electrode. Meanwhile, it is noted that open circuit voltage of the CNT/Au/TiO2 nanocomposites modified carbon paper anode increased to 0.77 V, which is more than twice that of the open circuit voltage obtained with bare carbon paper anode (0.36 V). And the MFC equipped with CNT/Au/TiO2 nanocomposites modified carbon paper anode delivers a maximum power density of 2.4 mW m−2, which is three times larger than that obtained from the MFC with bare carbon paper. This observation illustrates that the CNT/Au/TiO2 nanocomposites modified electrode could obviously increase the relevant electron transfer rate and promote the electron exchange at electrode surface, which could readily provide enhanced stability and relatively long life-span to facilitate the high electricity production efficiency, suggesting its promising prospect application in MFCs

  19. Stable corneal regeneration four years after implantation of a cell-free recombinant human collagen scaffold

    OpenAIRE

    Fagerholm, Per; Lagali, Neil; Ong, Jeb A.; Merrett, Kimberley; Jackson, W. Bruce; Polarek, James W.; Suuronen, Erik J.; Liu, YuWen; Brunette, Isabelle; Griffith, May

    2014-01-01

    We developed cell-free implants, comprising carbodiimide crosslinked recombinant human collagen (RHC), to enable corneal regeneration by endogenous cell recruitment, to address the worldwide shortage of donor corneas. Patients were grafted with RHC implants. Over four years, the regenerated neo-corneas were stably integrated without rejection, without the long immunosuppression regime needed by donor cornea patients. There was no recruitment of inflammatory dendritic cells into the implant ar...

  20. Seminal fluid and the generation of regulatory T cells for embryo implantation

    NARCIS (Netherlands)

    Robertson, Sarah A; Prins, Jelmer R; Sharkey, David J; Moldenhauer, Lachlan M

    2013-01-01

    T regulatory (Treg) cells are essential mediators of the maternal immune adaptation necessary for embryo implantation. In mice, insufficient Treg cell activity results in implantation failure, or constrains placental function and fetal growth. In women, Treg cell deficiency is linked with unexplaine

  1. Fabrication of biofuel cell containing enzyme catalyst immobilized by layer-by-layer method

    Science.gov (United States)

    Hyun, Kyu Hwan; Han, Sang Won; Koh, Won-Gun; Kwon, Yongchai

    2015-07-01

    Enzymatic biofuel cell (EBC) employing a layer-by-layer (LbL) structure consisting of multiple layers of glucose oxidase (GOx) and poly(ethyleneimine) (PEI) at carbon nanotube (CNT) ([GOx/PEI]n/CNT) is fabricated. The [GOx/PEI]n/CNT serves as anode catalyst for promoting glucose reaction, while Pt is employed as cathode catalyst. To evaluate effect of [GOx/PEI]n/CNT on EBC performance and stability, several characterizations are conducted. The optimal GOx/PEI layer is determined electrochemically, and it turns out that [GOx/PEI]2/CNT is the best. Electron transfer rate constant of the optimal layer is 11.3 s-1, its glucose sensitivity is 83 μAmM-1cm-2, and maximum power density of EBC adopting [GOx/PEI]2/CNT is 1.34 mWcm-2. The values are superior to those of other reference structures, indicating that the [GOx/PEI]2/CNT can produce excellent reactivity, followed by improved EBC performance. In terms of redox reaction mechanism of flavin adenine dinucleotide (FAD) within [GOx/PEI]2/CNT, glucose does not affect the redox reaction of FAD, while oxygen serves as mediator in transferring electrons and protons produced by glucose oxidation into those for reduction reaction of FAD. It is also found that the [GOx/PEI]2/CNT is confined by surface reaction and the reaction is quasi-reversible. Regarding long-term stability, [GOx/PEI]2/CNT maintains ∼83% of initial activity even after two weeks.

  2. Glucose oxidase as a biocatalytic enzyme-based bio-fuel cell using Nafion membrane limiting crossover

    Science.gov (United States)

    Naidoo, S.; Naidoo, Q.; Blottnitz, H.; Vaivars, G.

    2013-12-01

    A novel combination for an Enzyme-based Biofuel cell included a Nafion membrane as an ion transporter that maintained a working cell charge and inhibited membrane degradation. The prototype cell chamber used oxygen (O2) in the cathode cell and glucose in the anode. The Nafion membrane stability studied here was evidently in the region of 0% loss of conductivity as the charge was constant and increased after the addition of glucose. The prototype cell chamber used NaCl in the cathode cell and glucose oxidase (GOx) in the anodic chamber was successfully studied for membrane stability showed in this study no evidence of poisoning from membrane leakage in a controlled pH environment. There was no crossover at the anaerobic operating ambient temperatures and under physiological pH 5 - 7 conditions. In this research we have successfully used a Nafion membrane together with GOx and under controlled conditions produced respectable power densities.

  3. Glucose oxidase as a biocatalytic enzyme-based bio-fuel cell using Nafion membrane limiting crossover

    International Nuclear Information System (INIS)

    A novel combination for an Enzyme-based Biofuel cell included a Nafion membrane as an ion transporter that maintained a working cell charge and inhibited membrane degradation. The prototype cell chamber used oxygen (O2) in the cathode cell and glucose in the anode. The Nafion membrane stability studied here was evidently in the region of 0% loss of conductivity as the charge was constant and increased after the addition of glucose. The prototype cell chamber used NaCl in the cathode cell and glucose oxidase (GOx) in the anodic chamber was successfully studied for membrane stability showed in this study no evidence of poisoning from membrane leakage in a controlled pH environment. There was no crossover at the anaerobic operating ambient temperatures and under physiological pH 5 – 7 conditions. In this research we have successfully used a Nafion membrane together with GOx and under controlled conditions produced respectable power densities

  4. Coupling of an enzymatic biofuel cell to an electrochemical cell for self-powered glucose sensing with optical readout.

    Science.gov (United States)

    Pinyou, Piyanut; Conzuelo, Felipe; Sliozberg, Kirill; Vivekananthan, Jeevanthi; Contin, Andrea; Pöller, Sascha; Plumeré, Nicolas; Schuhmann, Wolfgang

    2015-12-01

    A miniaturized biofuel cell (BFC) is powering an electrolyser invoking a glucose concentration dependent formation of a dye which can be determined spectrophotometrically. This strategy enables instrument free analyte detection using the analyte-dependent BFC current for triggering an optical read-out system. A screen-printed electrode (SPE) was used for the immobilization of the enzymes glucose dehydrogenase (GDH) and bilirubin oxidase (BOD) for the biocatalytic oxidation of glucose and reduction of molecular oxygen, respectively. The miniaturized BFC was switched-on using small sample volumes (ca. 60 μL) leading to an open-circuit voltage of 567 mV and a maximal power density of (6.8±0.6) μW cm(-2). The BFC power was proportional to the glucose concentration in a range from 0.1 to 1.0 mM (R(2)=0.991). In order to verify the potential instrument-free analyte detection the BFC was directly connected to an electrochemical cell comprised of an optically-transparent SPE modified with methylene green (MG). The reduction of the electrochromic reporter compound invoked by the voltage and current flow applied by the BFC let to MG discoloration, thus allowing the detection of glucose. PMID:25892686

  5. Biofuels sources, biofuel policy, biofuel economy and global biofuel projections

    International Nuclear Information System (INIS)

    The term biofuel is referred to liquid, gas and solid fuels predominantly produced from biomass. Biofuels include energy security reasons, environmental concerns, foreign exchange savings, and socioeconomic issues related to the rural sector. Biofuels include bioethanol, biomethanol, vegetable oils, biodiesel, biogas, bio-synthetic gas (bio-syngas), bio-oil, bio-char, Fischer-Tropsch liquids, and biohydrogen. Most traditional biofuels, such as ethanol from corn, wheat, or sugar beets, and biodiesel from oil seeds, are produced from classic agricultural food crops that require high-quality agricultural land for growth. Bioethanol is a petrol additive/substitute. Biomethanol can be produced from biomass using bio-syngas obtained from steam reforming process of biomass. Biomethanol is considerably easier to recover than the bioethanol from biomass. Ethanol forms an azeotrope with water so it is expensive to purify the ethanol during recovery. Methanol recycles easier because it does not form an azeotrope. Biodiesel is an environmentally friendly alternative liquid fuel that can be used in any diesel engine without modification. There has been renewed interest in the use of vegetable oils for making biodiesel due to its less polluting and renewable nature as against the conventional petroleum diesel fuel. Due to its environmental merits, the share of biofuel in the automotive fuel market will grow fast in the next decade. There are several reasons for biofuels to be considered as relevant technologies by both developing and industrialized countries. Biofuels include energy security reasons, environmental concerns, foreign exchange savings, and socioeconomic issues related to the rural sector. The biofuel economy will grow rapidly during the 21st century. Its economy development is based on agricultural production and most people live in the rural areas. In the most biomass-intensive scenario, modernized biomass energy contributes by 2050 about one half of total energy

  6. THE IMPROVEMENT OF INFARCTED MYOCARDIAL CONTRACTILE FORCE AFTER AUTOLOGOUS SKELETAL MUSCLE SATELLITE CELL IMPLANTATION

    Institute of Scientific and Technical Information of China (English)

    钟竑; 朱洪生; 张臻

    2002-01-01

    Objective To study the improvement of infarcted myocardial contractile force after autologous skeletal muscle satellite cell implantation via intracoronary arterial perfusion. Methods Skeletal muscle cells were harvested from gluteus max of adult mongrel dogs and the cells were cultured and expanded before being labeled with DAPI (4, 6-diamidino-2-phenylindone). The labeled cells were then implanted into the acute myocardial infarct site via the ligated left anterior descending (LAD) coronary artery. Specimens were taken at 2nd, 4th, 8th week after myoblast implantation for histologic and contractile force evaluation, respectively. Results The satellite cells with fluorescence had been observed in the infarct site and also in papi-llary muscle with consistent oriented direction of host myocardium. A portion of the implanted cells had differen-tiated into muscle fibers. Two weeks after implantation, the myocardial contractile force showed no significant difference between the cell implant group and control group. At 4 and 8 week, the contractile force in the cell implant group was better than that in control group. Conclusion The skeletal muscle satellite cells, implanted into infarct myocardium by intracoronary arterial perfusion, could disseminate through the entire infarcted zone with myocardial regeneration and improve the contractile function of the infarcted myocardium.

  7. In vitro evaluation of osteoblastic cell adhesion on machined osseointegrated implants

    Directory of Open Access Journals (Sweden)

    Sandra Fabiano Alves

    2009-06-01

    Full Text Available At present the major consideration in planning an implant design is to seek biocompatible surfaces that promote a favorable response from both cells and host tissues. Different treatments of implant surfaces may modulate the adhesion, proliferation and phenotypic expression of osteoblastic cells. For this reason, the aim of the present study was to evaluate the biocompatibility of an implant surface, observing adhesion, cell morphology and proliferation of osteoblast-like cells cultivated on a commercially available titanium dental implant (Titamax Liso®, Neodent, Curitiba, PR, Brazil. The implant samples were immersed into an osteoblast-like cell (Osteo-1 suspension for a period of 24, 48 and 72 hours. After seeding the cells, the samples were prepared for analyses through scanning electron microscopy. Based on the surface analysis, the osteoblastic cells adhered to the machined surface after 24 hours in culture. In 48 hours, the cells spread over the implant surface, and after 72 hours a proliferation of cells with large and flat bodies was observed over the machined implant surface. These results demonstrate that the machined titanium surface studied is biocompatible since it allowed adhesion and proliferation of the osteoblast-like cells, in addition to preserving cell integrity and the morphologic characteristics of cells during the studied period.

  8. Plasma polymerization for cell adhesive/anti-adhesive implant coating

    Science.gov (United States)

    Meichsner, Juergen; Testrich, Holger; Rebl, Henrike; Nebe, Barbara

    2015-09-01

    Plasma polymerization of ethylenediamine (C2H8N2, EDA) and perfluoropropane (C3F8, PFP) with admixture of argon and hydrogen, respectively, was studied using an asymmetric 13.56 MHz CCP. The analysis of the plasma chemical gas phase processes for stable molecules revealed consecutive reactions: C2H8N2 consumption, intermediate product NH3, and main final product HCN. In C3F8- H2 plasma the precursor molecule C3F8 and molecular hydrogen are consumed and HF as well as CF4 and C2F6 are found as main gaseous reaction products. The deposited plasma polymer films on the powered electrode are strongly cross-linked due to ion bombardment. The stable plasma polymerized films from EDA are characterized by high content of nitrogen with N/C ratio of about 0.35. The plasma polymerized fluorocarbon film exhibit a reduced F/C ratio of about 1.2. Adhesion tests with human osteoblast cell line MG-63 on coated Ti6Al4V samples (polished) compared with uncoated reference sample yielded both, the enhanced cell adhesion for plasma polymerized EDA and significantly reduced cell adhesion for fluorocarbon coating, respectively. Aging of the plasma polymerized EDA film, in particular due to the reactions with oxygen from air, showed no significant change in the cell adhesion. The fluorocarbon coating with low cell adhesion is of interest for temporary implants. Funded by the Campus PlasmaMed.

  9. Voltage effects on cells cultured on metallic biomedical implants

    Science.gov (United States)

    Haerihosseini, Seyed Morteza

    Electrochemical voltage shifts in metallic biomedical implants occur in-vivo due to a number of processes including mechanically assisted corrosion. Surface potential of biomedical implants and excursions from resting open circuit potential (OCP), which is the voltage they attain while in contact with an electrolyte, can significantly change the interfacial properties of the metallic surfaces and alter the behavior of the surrounding cells, compromising the biocompatibility of metallic implants. Voltages can also be controlled to modulate cell function and fate. To date, the details of the physico-chemical phenomena and the role of different biomaterial parameters involved in the interaction between cells and metallic surfaces under cathodic bias have not been fully elucidated. In this work, changes in the interfacial properties of a CoCrMo biomedical alloy (ASTM F-1537) in phosphate-buffered saline (PBS) (pH 7.4) at different voltages was studied. Step polarization impedance spectroscopy technique was used to apply 50 mV voltage steps to samples, and the time-based current transients were recorded. A new equation was derived based on capacitive discharge through a Tafel element and generalized to deal with non-ideal impedance behavior. The new function compared to the KWW-Randles function, better matched the time-transient response. The results also showed a voltage dependent oxide resistance and capacitance behavior. Additionally, the in-vitro effect of static voltages on the behavior of MC3T3-E1 pre-osteoblasts cultured on CoCrMo alloy (ASTM-1537) was studied to determine the range of cell viability and mode of cell death beyond the viable range. Cell viability and morphology, changes in actin cytoskeleton, adhesion complexes and nucleus, and mode of cell death (necrosis, or intrinsic or extrinsic apoptosis) were characterized at different voltages ranging from -1000 to +500 mV (Ag/AgCl). Moreover, electrochemical currents and metal ion concentrations at each

  10. PINCH1 regulates cell-matrix and cell-cell adhesions, cell polarity and cell survival during the peri-implantation stage

    DEFF Research Database (Denmark)

    Li, Shaohua; Bordoy, Randi; Stanchi, Fabio;

    2005-01-01

    integrin or Ilk, loss of PINCH1 arrested development at the peri-implantation stage. In contrast to beta1 integrin or Ilk mutants, however, disruption of the PINCH1 gene produced implantation chambers with visible cell clumps even at embryonic day 9.5. In order to define the phenotype leading to the peri...

  11. Electrochemical characterization of methanol/O2 biofuel cell: Use of laccase biocathode immobilized with polypyrrole film and PAMAM dendrimers

    International Nuclear Information System (INIS)

    This paper describes the performance of a mediated electron transfer (MET) biocathode for a methanol/O2 biofuel cell. To this end, we employed PAMAM (polyamidoamine) dendrimers for the immobilization of laccase using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS) in solution or entrapped into polypyrrole films. We used the enzyme immobilized onto the carbon platform obtained either in the presence or in the absence of the electropolymerized film to determine kinetic parameters. The results point to a very similar kinetic rate conversion in both situations; however, substrate affinity seems to increase in the bioelectrode containing the entrapped substrate molecules. The electrochemical characterization tests confirmed that the electropolymerized polypyrrole film was able to retain entrapped ABTS molecules. Additionally, laccase provides enhanced catalytic oxidation current for the mediator compared with the control sample containing PAMAM dendrimer only. Compared to the control sample, which gave power density values around 0.7 μW cm−2, tests employing ABTS as mediator furnished 6 μW cm−2 when the mediator was added in solution and around 25 μW cm−2 when it was entrapped into the biocathode layers. Overall, the developed biocathode is environmentally friendly for immobilization of the enzyme laccase, being satisfactorily stable in the kinetic tests and affording good power data in the biofuel cell tests

  12. Cell attachment of polypropylene surface-modified by COOH+ ion implantation

    International Nuclear Information System (INIS)

    Carboxy ion (COOH+) implantation was performed at the energy of 50 keV with fluences ranging from 1x1014 to 1x1015 ions/cm2 at room temperature for polypropylene (PP). The effects of ion implantation on cells (immune macrophages, 3T3 mouse fibroblasts and human endothelial cells) were studied in vitro. Tests of cell attachment gave interesting results that the 3T3 mouse fibroblasts and human endothelial cells cultured on the surface of the implanted PP showed much better attachment and proliferation than that on pristine PP. At the same time, the COOH+ ion implantation also induced low macrophage attachment with normal cellular morphology. Results of X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FTIR) analysis showed that COOH+ ion implantation caused the rearrangement of chemical bonds and the formation of some new O-containing groups, which was responsible for the enhancement of the biocompatibility of PP

  13. Hybrid adipogenic implants from adipose stem cells for soft tissue reconstruction in vivo.

    Science.gov (United States)

    Moioli, Eduardo K; Chen, Mo; Yang, Rujing; Shah, Bhranti; Wu, June; Mao, Jeremy J

    2010-11-01

    A critical barrier in tissue regeneration is scale-up. Bioengineered adipose tissue implants have been limited to ∼10  mm in diameter. Here, we devised a 40-mm hybrid implant with a cellular layer encapsulating an acellular core. Human adipose-derived stem cells (ASCs) were seeded in alginate. Poly(ethylene)glycol-diacrylate (PEGDA) was photopolymerized into 40-mm-diameter dome-shaped gel. Alginate-ASC suspension was painted onto PEGDA surface. Cultivation of hybrid constructs ex vivo in adipogenic medium for 28 days showed no delamination. Upon 4-week in vivo implantation in athymic rats, hybrid implants well integrated with host subcutaneous tissue and could only be surgically separated. Vascularized adipose tissue regenerated in the thin, painted alginate layer only if ASC-derived adipogenic cells were delivered. Contrastingly, abundant fibrous tissue filled ASC-free alginate layer encapsulating the acellular PEGDA core in control implants. Human-specific peroxisome proliferator-activated receptor-γ (PPAR-γ) was detected in human ASC-seeded implants. Interestingly, rat-specific PPAR-γ was absent in either human ASC-seeded or ASC-free implants. Glycerol content in ASC-delivered implants was significantly greater than that in ASC-free implants. Remarkably, rat-specific platelet/endothelial cell adhesion molecule (PECAM) was detected in both ASC-seeded and ASC-free implants, suggesting anastomosis of vasculature in bioengineered tissue with host blood vessels. Human nuclear staining revealed that a substantial number of adipocytes were of human origin, whereas endothelial cells of vascular wall were of chemaric human and nonhuman (rat host) origins. Together, hybrid implant appears to be a viable scale-up approach with volumetric retention attributable primarily to the acellular biomaterial core, and yet has a biologically viable cellular interface with the host. The present 40-mm soft tissue implant may serve as a biomaterial tissue expander for

  14. Elongation of lifetime of photosynthetic biofuel-cells containing immobilized algae; Koteika aiso wo mochiita kogosei biseibutsu denchi no chojumyoka

    Energy Technology Data Exchange (ETDEWEB)

    Yagishita, T.; Sawayama, S.; Inoue, S.; Ogi, T. [National Institute for Resources and Environment, Tsukuba (Japan)

    1994-12-08

    An experimental study is performed for elongation of lifetime of photosynthetic biofuel-cells using the living blue-green algae and a mediator. In the experiment, correlation between a current generated from cultured Anabaena and the life of the cells is investigated. Anabaena is recovered from the cells after the cells are operated for 10 hours in the dark and is cultured for 10 hours under irradiation with a Xe lamp and ventilation of 3 % CO2. Thereafter, immobilized Anabaena is returned into the cells and the cells are again actuated in repetition. Three load resistances 1 K ohm, 700 ohm, 400 ohm are employed and operation time of the current is lengthened under any conditions compared with the case where the cells are continuously operated. Further, provided a generated current is limited to 0.6 mA or lower, the current is not lowered even if the cells are operated for 90 hours. It is concluded that provided Anabaena is cultured after the electricity of 6.4 mA/h per the amount of chlorophyl in Anabaena is taken out, an output of the cells is kept unchanged for a long time. 7 refs., 4 figs., 1 tab.

  15. Influence of skeletal muscle satellite cells implanted into infarcted myocardium on remnant myocyte volumes

    Institute of Scientific and Technical Information of China (English)

    钟竑; 朱洪生; 卫洪超; 张臻

    2003-01-01

    Objective To study the effects of skeletal muscle satellite cells implanted into infarcted myocardium on the volume of remnant myocytes.Methods Thirty-six adult mongrel canines were divided randomly into implantation group and control group. In the implantation group, skeletal muscle satellite cells taken from the gluteus maximus muscles of the dogs were cultured, proliferated and labeled with 4', 6-diamidino-2-phenylindone (DAPI) in vitro. In both groups, a model of acute myocardial infarction was established in every dog. In the implantation group, each dog was injected with M199 solution containing autologous skeletal muscle satellite cells. The dogs in the control group received M199 solution without skeletal muscle satellite cells. The dogs of both groups were killed 2, 4 and 8 weeks after implantation (six dogs in a separate group each time). Both infarcted myocardium and normal myocytes distal from the infracted regions isolated were observed under optical and fluorescent microscope. Their volumes were determined using a confocal microscopy image analysis system and analyzed using SAS. A P<0.05 was considered significant.Results A portion of the implanted cells differentiated into muscle fiber with striations and were connected with intercalated discs. Cross-sectional area and cell volume were increased in normal myocardium. Hypertrophy of remnant myocytes in the infarcted site after skeletal muscle cell implantation was much more evident than in the control group. Cross-sectional area, cell area and cell volume differed significantly from those of the control group (P< 0.05). Hypertrophy of the cells occurred predominantly in terms of width and thickness, whereas cell length remained unchanged. Conclusion Skeletal muscle satellite cells implanted into infarct myocardium, could induce the hypertrophy of remnant myocyte cells in the infarcted site and could also aid in the recovery of the contractile force of the infarcted myocardium.

  16. Transferring gfp gene with ion implantation and transient expression of gfp in liliaceous pollen cells

    Institute of Scientific and Technical Information of China (English)

    YUAN Shibin; CHEN Qizhong; WANG Yugang; ZHAO Weijiang; XU An; YANG Gen; WANG Wenxian; WU Lijun

    2004-01-01

    Liliaceous pollen cells were implanted by 4.0 MeV C2+ ion beam or by 25.0 keV N+ ion beam. Laser confocal scanning microscopy (LCSM) of the implanted intact samples showed that parts of the implanted pollen cells could be stained by propidium iodide (PI). This indicated that energetic ion beam could directly act on cells beneath the pollen coats and made channels for entry of the molecules from outside of the cells. LCSM analysis of green fluorescent protein (GFP) showed that energetic ion beam could mediate transient expression of gfp in treated pollen cells. Compared with 25.0 keV N+ ion beam, implantation of 4.0 MeV C2+ ion beam greatly improved gene transfer efficiency in pollen cells.

  17. Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

    Science.gov (United States)

    Reichel, Christian; Feldmann, Frank; Müller, Ralph; Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul; Hermle, Martin; Glunz, Stefan W.

    2015-11-01

    Passivated contacts (poly-Si/SiOx/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF2), the ion implantation dose (5 × 1014 cm-2 to 1 × 1016 cm-2), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iVoc) of 725 and 720 mV, respectively. For p-type passivated contacts, BF2 implantations into intrinsic a-Si yield well passivated contacts and allow for iVoc of 690 mV, whereas implanted B gives poor passivation with iVoc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved Voc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with Voc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.

  18. Ferrocene Entrapped In Polypyrrole Film and PAMAM Dendrimers as Matrix for Mediated Glucose/O2 Biofuel Cell

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • The bioanode efficiently transfers electrons between GOx and the electrode surface. • The bioelectrode furnished a high output power. • PAMAM dendrimers retains the enzyme activity and does not change the substrate affinity. • Fc entrapped in polypyrrole network has a considerable shift in catalytic peak potential. - Abstract: We fabricated bioanodes based on PAMAM (polyamidoamine) dendrimers to immobilize glucose oxidase (GOx), using ferrocenium hexafluorophosphate (Fc) entrapped in electropolymerized polypyrrole films (Fc-polypyrrole) as mediator. We conducted a comparative study of the GOx kinetic parameters as a function of the enzyme environment; i.e., in solution and immobilized onto carbon platforms. Kinetic studies revealed that the Michaelis-Menten constants (KM) of the anchored and soluble GOx were quite similar, KM = 21.2 (± 0.6) mmol L−1 in solution, and 21.5 (± 0.8) mmol L−1 when immobilized, demonstrating that enzyme immobilization did not affect the enzyme-substrate affinity. However, the maximum reaction rate (Vmax) obtained for the immobilized GOx (Vmax = 0.72 (± 0.03) μmol min−1 mg−1) was lower than the reaction rate achieved for the free enzyme in solution (Vmax = 64 (± 2) μmol min−1 mg−1), due to diffusional effects. Cyclic voltammetry assays confirmed the incorporation of entrapped Fc species into the polypyrrole net films. The performance of the prepared bioelectrodes in a glucose/O2 semi-cell revealed a maximum power density around 130 (± 15) μW cm−2 at pH 5.0, in 100 mmol L−1 glucose. Considering all the electrochemical data and biofuel cell tests, we can infer that the bioanode based on Fc and polypyrrole presented here, is easy to prepare, and the electrocatalyst film efficiently transfers electrons between GOx and the electrode surface. Therefore, it has potential application in glucose/O2 biofuel cells

  19. New Biofuel Alternatives: Integrating Waste Management and Single Cell Oil Production

    Science.gov (United States)

    Martínez, Elia Judith; Raghavan, Vijaya; González-Andrés, Fernando; Gómez, Xiomar

    2015-01-01

    Concerns about greenhouse gas emissions have increased research efforts into alternatives in bio-based processes. With regard to transport fuel, bioethanol and biodiesel are still the main biofuels used. It is expected that future production of these biofuels will be based on processes using either non-food competing biomasses, or characterised by low CO2 emissions. Many microorganisms, such as microalgae, yeast, bacteria and fungi, have the ability to accumulate oils under special culture conditions. Microbial oils might become one of the potential feed-stocks for biodiesel production in the near future. The use of these oils is currently under extensive research in order to reduce production costs associated with the fermentation process, which is a crucial factor to increase economic feasibility. An important way to reduce processing costs is the use of wastes as carbon sources. The aim of the present review is to describe the main aspects related to the use of different oleaginous microorganisms for lipid production and their performance when using bio-wastes. The possibilities for combining hydrogen (H2) and lipid production are also explored in an attempt for improving the economic feasibility of the process. PMID:25918941

  20. New Biofuel Alternatives: Integrating Waste Management and Single Cell Oil Production

    Directory of Open Access Journals (Sweden)

    Elia Judith Martínez

    2015-04-01

    Full Text Available Concerns about greenhouse gas emissions have increased research efforts into alternatives in bio-based processes. With regard to transport fuel, bioethanol and biodiesel are still the main biofuels used. It is expected that future production of these biofuels will be based on processes using either non-food competing biomasses, or characterised by low CO2 emissions. Many microorganisms, such as microalgae, yeast, bacteria and fungi, have the ability to accumulate oils under special culture conditions. Microbial oils might become one of the potential feed-stocks for biodiesel production in the near future. The use of these oils is currently under extensive research in order to reduce production costs associated with the fermentation process, which is a crucial factor to increase economic feasibility. An important way to reduce processing costs is the use of wastes as carbon sources. The aim of the present review is to describe the main aspects related to the use of different oleaginous microorganisms for lipid production and their performance when using bio-wastes. The possibilities for combining hydrogen (H2 and lipid production are also explored in an attempt for improving the economic feasibility of the process.

  1. Use of low-energy hydrogen ion implants in high-efficiency crystalline-silicon solar cells

    Science.gov (United States)

    Fonash, S. J.; Sigh, R.; Mu, H. C.

    1986-01-01

    The use of low-energy hydrogen implants in the fabrication of high-efficiency crystalline silicon solar cells was investigated. Low-energy hydrogen implants result in hydrogen-caused effects in all three regions of a solar cell: emitter, space charge region, and base. In web, Czochralski (Cz), and floating zone (Fz) material, low-energy hydrogen implants reduced surface recombination velocity. In all three, the implants passivated the space charge region recombination centers. It was established that hydrogen implants can alter the diffusion properties of ion-implanted boron in silicon, but not ion-implated arsenic.

  2. Immobilization of CotA, an extremophilic laccase from Bacillus subtilis, on glassy carbon electrodes for biofuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Beneyton, T.; El Harrak, A.; Griffiths, A.D.; Taly, V. [Institut de Science et d' Ingenierie Supramoleculaire, CNRS UMR, Strasbourg (France); Hellwig, P. [Institut de Chimie, Universite de Strasbourg, CNRS UMR, Strasbourg (France)

    2011-01-15

    Thanks to their high stability over a wide range of experimental conditions, extremophilic enzymes represent an interesting alternative to mesophilic enzymes as catalysts for biofuel cell applications. In the present work, we report for the first time the immobilization of a thermophilic laccase (CotA from Bacillus subtilis endospore coat) on glassy carbon electrodes functionalized via electrochemical reduction of in situ generated aminophenyl monodiazonium salts. We compare the performance of CotA-modified electrodes for the reduction of O{sub 2} to mutant variants and demonstrate that the measured electrical current is directly correlated to the catalytic efficiencies (k{sub cat}/K{sub m}) of the immobilized enzyme. CotA-modified electrodes showed an optimal operation temperature of 45-50 C and stable catalytic activity for at least 7 weeks. (author)

  3. Development of a glucose oxidase-based biocatalyst adopting both physical entrapment and crosslinking, and its use in biofuel cells.

    Science.gov (United States)

    Chung, Yongjin; Ahn, Yeonjoo; Christwardana, Marcelinus; Kim, Hansung; Kwon, Yongchai

    2016-04-28

    New enzymatic catalysts prepared using physical entrapment and chemical bonding were used as anodic catalysts to enhance the performance of enzymatic biofuel cells (EBCs). For estimating the physical entrapment effect, the best glucose oxidase (GOx) concentration immobilized on polyethyleneimine (PEI) and carbon nanotube (CNT) (GOx/PEI/CNT) was determined, while for inspecting the chemical bonding effect, terephthalaldehyde (TPA) and glutaraldehyde (GA) crosslinkers were employed. According to the enzyme activity and XPS measurements, when the GOx concentration is 4 mg mL(-1), they are most effectively immobilized (via the physical entrapment effect) and TPA-crosslinked GOx/PEI/CNT(TPA/[GOx/PEI/CNT]) forms π conjugated bonds via chemical bonding, inducing the promotion of electron transfer by delocalization of electrons. Due to the optimized GOx concentration and π conjugated bonds, TPA/[GOx/PEI/CNT], including 4 mg mL(-1) GOx displays a high electron transfer rate, followed by excellent catalytic activity and EBC performance. PMID:27074999

  4. Effects of nitrogen ion implantation on Ca2+ concentration and membrane potential of pollen cell

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effects of low energy nitrogen ion implantation on Ca2+ concentration and membrane potential of lily (lilium davidii Duch) pollen cell have been studied. The results showed that the Ca2+ concentration was increased when pollen grain was implanted by nitrogen ion with energy 100keV and dose 1013 ions/cra2. However, the increase of Ca2+ concentration was partly inhibited by the addition of Ca2+channel inhibitor depending on dose. And nitrogen ion implantation caused depolarization of pollen cell membrane potential. In other words, membrane potential was increased,but the effect decreased by adding Ca2+ channel inhibitor.However, it was still significantly higher than the membrane potential of control cells. It was indicated that the depolarization of cell membrane potential opened the calcium channel on the membrane that caused the increasing of intraceilular calcium concentration. This might be an earlier step of the effect of low energy nitrogen ion implantation on pollen germination.

  5. The rationality of biofuels

    International Nuclear Information System (INIS)

    In an editorial of a recent issue of a known academic journal, Prof. Hartmut Michel affirmed that “…the production of biofuels constitutes an extremely inefficient land use… We should not grow plants for biofuel production.”, after comparing the area occupied with plants for bioenergy production with the one required for photovoltaic cells to supply the same amount of energy for transportation. This assertion is not correct for all situations and this comparison deserves a more careful analysis, evaluating the actual and prospective technological scenarios and other relevant aspects, such as capacity requirements, energy consumed during the life cycle of energy systems and the associated impacts. In this communication this comparison is revaluated, presenting a different perspective, more favorable for the bioenergy routes. - Highlights: • Energy systems and life cycle impacts are compared under equal conditions. • The comparison is done between biofuels and photovoltaic/battery in mobility uses. • Biofuels are a valuable option when produced sustainably by efficient routes

  6. Optimization of Cell Adhesion on Mg Based Implant Materials by Pre-Incubation under Cell Culture Conditions

    Directory of Open Access Journals (Sweden)

    Regine Willumeit

    2014-05-01

    Full Text Available Magnesium based implants could revolutionize applications where orthopedic implants such as nails, screws or bone plates are used because they are load bearing and degrade over time. This prevents a second surgery to remove conventional implants. To improve the biocompatibility we studied here if and for how long a pre-incubation of the material under cell culture conditions is favorable for cell attachment and proliferation. For two materials, Mg and Mg10Gd1Nd, we could show that 6 h pre-incubation are already enough to form a natural protective layer suitable for cell culture.

  7. Immobilization of Enzymes by Electrochemical and Chemical Oxidative Polymerization of L-DOPA to Fabricate Amperometric Biosensors and Biofuel Cells.

    Science.gov (United States)

    Dai, Mengzhen; Sun, Lingen; Chao, Long; Tan, Yueming; Fu, Yingchun; Chen, Chao; Xie, Qingji

    2015-05-27

    Electrochemical/chemical oxidative synthesis and biosensing/biofuel cell applications of poly(L-DOPA) (PD) are studied versus polydopamine (PDA) as a recent hotspot biomaterial. The enzyme electrode developed by coelectrodeposition of PD and glucose oxidase (GOx), uricase, or tyrosinase shows biosensing performance superior to that of the corresponding PDA-based enzyme electrode. The chemical oxidative polymerization of L-DOPA (PDC) by NaAuCl4 in GOx-containing neutral aqueous solution is used to immobilize GOx and gold nanoparticles (AuNPs). The thus-prepared chitosan (CS)/GOx-PDC-AuNPs/Au(plate)/Au electrode working in the first-generation biosensing mode responds linearly to glucose concentration with a sensitivity of 152 μA mM(-1) cm(-2), which is larger than those of the CS/GOx-PDAC-AuNPs/Au(plate)/Au electrode, the CS/GOx-poly(3-anilineboronic acid) (PABA)-AuNPs/Au(plate)/Au electrode, and the most reported GOx-based enzyme electrodes. This PDC-based enzyme electrode also works well in the second-generation biosensing mode and as an excellent bioanode in biofuel cell construction, probably because PD as an amino acid polymer has the higher biocompatibility and the more favorable affinity to the enzyme than PDA. The PD material of great convenience in synthesis, outstanding biocompatibility for preparing high-performance bionanocomposites, and strong capability of multifunctional coatings on many surfaces may find wide applications in diversified fields including biotechnology and surface-coating. PMID:25938891

  8. Morphology and Differentiation of MG63 Osteoblast Cells on Saliva Contaminated Implant Surfaces

    Directory of Open Access Journals (Sweden)

    Neda Shams

    2015-11-01

    Full Text Available Objectives: Osteoblasts are the most important cells in the osseointegration process. Despite years of study on dental Implants, limited studies have discussed the effect of saliva on the adhesion process of osteoblasts to implant surfaces. The aim of this in vitro study was to evaluate the effect of saliva on morphology and differentiation of osteoblasts attached to implant surfaces.Materials and Methods: Twelve Axiom dental implants were divided into two groups. Implants of the case group were placed in containers, containing saliva, for 40 minutes. Then, all the implants were separately stored in a medium containing MG63 human osteoblasts for a week. Cell morphology and differentiation were assessed using a scanning electron microscope and their alkaline phosphatase (ALP activity was determined. The t-test was used to compare the two groups.Results: Scanning electron microscopic observation of osteoblasts revealed round or square cells with fewer and shorter cellular processes in saliva contaminated samples, whereas elongated, fusiform and well-defined cell processes were seen in the control group. ALP level was significantly lower in case compared to control group (P<0.05.Conclusion: Saliva contamination alters osteoblast morphology and differentiation and may subsequently interfere with successful osseointegration. Thus, saliva contamination of bone and implant must be prevented or minimized.

  9. Cell adhesion and in vivo osseointegration of sandblasted/acid etched/anodized dental implants.

    Science.gov (United States)

    Kim, Mu-Hyon; Park, Kyeongsoon; Choi, Kyung-Hee; Kim, Soo-Hong; Kim, Se Eun; Jeong, Chang-Mo; Huh, Jung-Bo

    2015-01-01

    The authors describe a new type of titanium (Ti) implant as a Modi-anodized (ANO) Ti implant, the surface of which was treated by sandblasting, acid etching (SLA), and anodized techniques. The aim of the present study was to evaluate the adhesion of MG-63 cells to Modi-ANO surface treated Ti in vitro and to investigate its osseointegration characteristics in vivo. Four different types of Ti implants were examined, that is, machined Ti (control), SLA, anodized, and Modi-ANO Ti. In the cell adhesion study, Modi-ANO Ti showed higher initial MG-63 cell adhesion and induced greater filopodia growth than other groups. In vivo study in a beagle model revealed the bone-to-implant contact (BIC) of Modi-ANO Ti (74.20%±10.89%) was much greater than those of machined (33.58%±8.63%), SLA (58.47%±12.89), or ANO Ti (59.62%±18.30%). In conclusion, this study demonstrates that Modi-ANO Ti implants produced by sandblasting, acid etching, and anodizing improve cell adhesion and bone ongrowth as compared with machined, SLA, or ANO Ti implants. These findings suggest that the application of Modi-ANO surface treatment could improve the osseointegration of dental implant. PMID:25955650

  10. Cell Adhesion and in Vivo Osseointegration of Sandblasted/Acid Etched/Anodized Dental Implants

    Directory of Open Access Journals (Sweden)

    Mu-Hyon Kim

    2015-05-01

    Full Text Available The authors describe a new type of titanium (Ti implant as a Modi-anodized (ANO Ti implant, the surface of which was treated by sandblasting, acid etching (SLA, and anodized techniques. The aim of the present study was to evaluate the adhesion of MG-63 cells to Modi-ANO surface treated Ti in vitro and to investigate its osseointegration characteristics in vivo. Four different types of Ti implants were examined, that is, machined Ti (control, SLA, anodized, and Modi-ANO Ti. In the cell adhesion study, Modi-ANO Ti showed higher initial MG-63 cell adhesion and induced greater filopodia growth than other groups. In vivo study in a beagle model revealed the bone-to-implant contact (BIC of Modi-ANO Ti (74.20% ± 10.89% was much greater than those of machined (33.58% ± 8.63%, SLA (58.47% ± 12.89, or ANO Ti (59.62% ± 18.30%. In conclusion, this study demonstrates that Modi-ANO Ti implants produced by sandblasting, acid etching, and anodizing improve cell adhesion and bone ongrowth as compared with machined, SLA, or ANO Ti implants. These findings suggest that the application of Modi-ANO surface treatment could improve the osseointegration of dental implant.

  11. Influences of Low Energy Ion Implantation on Properties of Polyaniline/Si Heterojunction Solar Cells

    Institute of Scientific and Technical Information of China (English)

    WU Chang-jiang; ZHENG Jian-bang; LI En-pu

    2005-01-01

    Ion implantation may favorably modify the properties ofpolyaniline/Si heterojunction solar cells fabricated by the electrochemical method. Influences of the implantation on the absorption spectrum and the thermal stability were discussed and output properties were measured. The results show that the absorption spectrum of the polyaniline films modified by ion implantation is much wider; its pyrolytic temperature increases by 40℃, and the polyaniline/Si cell efficiency increases 18 and 3 times under the illumination of 10.92 and 37.2 W/m2, respectively.

  12. Cell Adhesion and in Vivo Osseointegration of Sandblasted/Acid Etched/Anodized Dental Implants

    OpenAIRE

    Mu-Hyon Kim; Kyeongsoon Park; Kyung-Hee Choi; Soo-Hong Kim; Se Eun Kim; Chang-Mo Jeong; Jung-Bo Huh

    2015-01-01

    The authors describe a new type of titanium (Ti) implant as a Modi-anodized (ANO) Ti implant, the surface of which was treated by sandblasting, acid etching (SLA), and anodized techniques. The aim of the present study was to evaluate the adhesion of MG-63 cells to Modi-ANO surface treated Ti in vitro and to investigate its osseointegration characteristics in vivo. Four different types of Ti implants were examined, that is, machined Ti (control), SLA, anodized, and Modi-ANO Ti. In the cell adh...

  13. Interaction of osteogenic cells with hydroxylapatite implant materials in vitro and in vivo.

    Science.gov (United States)

    Bagambisa, F B; Joos, U; Schilli, W

    1990-01-01

    In a series of scanning electron microscopic studies, the reaction of osteogenic cells to hydroxylapatite (HA) implant materials was investigated in culture and following implantation. Tissue components as found in normal rat and dog bone were identified at the interface in both test systems. In vivo, implant bed cells showed an intimate contact with the HA surfaces. Osteoblasts deposited organic matrix and bone mineral in direct apposition to HA, with no evidence of encapsulation or granulation tissue. The development of such a direct spatial relationship appears to involve mechanisms more encompassing than epitaxis. PMID:2098325

  14. Implantation of bFGF-treated islet progenitor cells ameliorates streptozotocin-induced diabetes in rats

    OpenAIRE

    Li, Ge; Huang, Li-song; Jiang, Ming-hong; Wu, Hui-Ling; Chen, Jing; Huang, Yin; Shen, Yan; He-Xi-Ge, SaiYin; Fan, Wei-wei; Lu, Zhi-qiang; Da-ru LU

    2010-01-01

    Aim: To examine whether implantation of islet preparation-derived proliferating islet cells (PIC) could ameliorate diabetes in rats. Methods: PIC were expanded from rat islet preparation by supplementation of basic fibroblast growth factor (bFGF) and implanted into rats with streptozotocin (STZ)-induced diabetes through the portal vein. Body weight and blood glucose levels were measured. Serum insulin levels were measured by radioimmunoassay. The presence of insulin-positive cells was determi...

  15. Development of Bioactive Patch for Maintenance of Implanted Cells at the Myocardial Infarcted Site

    OpenAIRE

    Castells-Sala, C.; Vallés-Lluch, A.; Soler-Botija, C.; Arnal-Pastor, M.; C. Martínez-Ramos; T. Fernandez-Muiños; Marí-Buyé, N.; Llucià-Valldeperas, A.; Sanchez, B.; Chachques, J. C.; Bayes-Genis, A.; Monleón Pradas, M.; C. E. Semino

    2015-01-01

    Ischemia produced as a result of myocardial infarction might cause moderate or severe tissue death. Studies under development propose grafting stem cells into the affected area and we hypothesize that this mechanism could be enhanced by the application of a “bioactive implant.” The implant herein proposed consists of a thin porous elastomeric membrane, filled with self-assembling nanofibers and human subcutaneous adipose tissue derived progenitor cells. We describe the development and charact...

  16. Plasma protein adsorption onto cell attachment controlled ion implanted collagen

    International Nuclear Information System (INIS)

    Ion implantation into collagen (Type I) coated inner surfaces of test tubes with a length of 50 mm and inner diameter of 2 and 3 mm were performed to develop hybrid type small-diameter artificial vascular grafts. He+ ion implanted collagen coated grafts with a fluence of 1x1014 ions/cm2 replacing femoral arteries exhibited excellent graft patency. To obtain information about the relationship between plasma protein adsorption and antithrombogenicity of ion implanted collagen surfaces, protein adsorption measurements, platelet adhesion test, and animal study were performed. The amount of fibrinogen, fibronectin and albumin showed minimum value at a fluence of 1x1014 ions/cm2. The adsorption of fibrinogen and fibronectin to surfaces is known to promote the adhesion of platelets. The results indicated that antithrombogenicity of He+ ion-implanted collagen with a fluence of 1x1014 ions/cm2 was caused by the reduction of the amount of adsorbed proteins

  17. Extrathyroidal Implantation of Thyroid Hyperplastic/neoplastic Cells after Endoscopic Thyroid Surgery

    Institute of Scientific and Technical Information of China (English)

    Cao Xi; Xie-qun Xu; Tao Hong; Bing-lu Li; Wei Liu

    2014-01-01

    Objective To report a case of the implantation of thyroid hyperplastic or neoplastic tissue after endoscopic thyroidectomy and discuss this complication in aspects of prevalence, pathogenesis, protection, and therapies. Methods A systematic search of literature from the PubMed database was conducted for identifying eligible studies on implantation of thyroid hyperplastic or neoplastic cells after endoscopic thyroid surgery. Results Overall, 5 reported cases on patients suffering from endoscopic thyroid surgery with implantation of thyroid hyperplastic or neoplastic cells were included in the systematic review. Conclusions Unskilled surgeons, rough intraoperative surgical treatment, scarification or rupture of tumor, contamination of instruments, chimney effect, aerosolization of tumor cells may be associated with the implantation after endoscopic thyroidectomy. To minimize the risk of such complication, we should be more meticulous and strict the endoscopic surgery indications.

  18. Breeding grasses for capacity to biofuel production or silage feeding value: an updated list of genes involved in maize secondary cell wall biosynthesis and assembly

    OpenAIRE

    Courtial, Audrey; Soler, Marçal; Chateigner-Boutin, Anne Laure; Reymond, Matthieu; Mechin, Valerie; WANG Hua; Grima-Pettenati, Jacqueline

    2013-01-01

    In the near future, maize, sorghum, or switchgrass stovers and cereal straws will be a significant source of carbohydratesfor sustainable biofuel production, in addition to the current use of grass silage in cattle feeding. However, cell wall properties, including the enzymatic degradability of structural polysaccharides in industrial fermenters or animal rumen, is greatly influenced by the embedding of cell wall carbohydrates in lignin matrix, and the linkages between lignins, p-hydroxycinna...

  19. Modeling Stem/Progenitor Cell-Induced Neovascularization and Oxygenation Around Solid Implants

    KAUST Repository

    Jain, Harsh Vardhan

    2012-07-01

    Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O(2)) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O(2)-sensitive crystals, consisting of a polymeric capsule limited by a nanoporous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bone marrow progenitor cells in order to stimulate peri-implant neovascularization. The sensor provided local partial O(2) pressure (pO(2)) using noninvasive electron paramagnetic resonance signal measurements. A consistently higher level of peri-implant oxygenation was observed in the cell-treatment case than in the control over a 10-week period. To provide a mechanistic explanation of these experimental observations, we present in this article a mathematical model, formulated as a system of coupled partial differential equations, that simulates peri-implant vascularization. In the control case, vascularization is considered to be the result of a foreign body reaction, while in the cell-treatment case, adipogenesis in response to paracrine stimuli produced by the stem cells is assumed to induce neovascularization. The model is validated by fitting numerical predictions of local pO(2) to measurements from the implanted sensor. The model is then used to investigate further the potential for using stem cell treatment to enhance the vascular integration of biomedical implants. We thus demonstrate how mathematical modeling combined with experimentation can be used to infer how vasculature develops around biomedical implants in control and stem cell-treated cases.

  20. Biocompatibility of magnesium implants in primary human reaming debris-derived cells stem cells in vitro

    OpenAIRE

    Charyeva, Olga; Dakischew, Olga; Sommer, Ursula; Heiss, Christian; Schnettler, Reinhard; Lips, Katrin Susanne

    2015-01-01

    Background Use of magnesium for resorbable metal implants is a new concept in orthopaedic and dental medicine. The majority of studies on magnesium’s biocompatibility in vitro have assessed the short-term effect of magnesium extract on cells. The aim of this study was to evaluate the influence of direct exposure to magnesium alloys on the bioactivity of primary human reaming debris-derived (HRD) cells. Materials and methods Pure Mg, Mg2Ag, WE43 and Mg10Gd were tested for biocompatibility. The...

  1. Removal of an oral squamous cell carcinoma including parts of osseointegrated implants in the marginal mandibulectomy. A case report.

    NARCIS (Netherlands)

    Meijer, G.J.; Dieleman, F.J.; Berge, S.J.; Merkx, M.A.W.

    2010-01-01

    PURPOSE: The incidence of oral squamous cell carcinomas (OSCC) arising around dental implants will increase because of the rising popularity of dental implants. In this case, a novel surgical treatment of an OSCC in the vicinity of endosseous implants is reported. MATERIALS AND METHODS: In a 69-year

  2. Macrophages, Foreign Body Giant Cells and Their Response to Implantable Biomaterials

    Directory of Open Access Journals (Sweden)

    Zeeshan Sheikh

    2015-08-01

    Full Text Available All biomaterials, when implanted in vivo, elicit cellular and tissue responses. These responses include the inflammatory and wound healing responses, foreign body reactions, and fibrous encapsulation of the implanted materials. Macrophages are myeloid immune cells that are tactically situated throughout the tissues, where they ingest and degrade dead cells and foreign materials in addition to orchestrating inflammatory processes. Macrophages and their fused morphologic variants, the multinucleated giant cells, which include the foreign body giant cells (FBGCs are the dominant early responders to biomaterial implantation and remain at biomaterial-tissue interfaces for the lifetime of the device. An essential aspect of macrophage function in the body is to mediate degradation of bio-resorbable materials including bone through extracellular degradation and phagocytosis. Biomaterial surface properties play a crucial role in modulating the foreign body reaction in the first couple of weeks following implantation. The foreign body reaction may impact biocompatibility of implantation devices and may considerably impact short- and long-term success in tissue engineering and regenerative medicine, necessitating a clear understanding of the foreign body reaction to different implantation materials. The focus of this review article is on the interactions of macrophages and foreign body giant cells with biomaterial surfaces, and the physical, chemical and morphological characteristics of biomaterial surfaces that play a role in regulating the foreign body response. Events in the foreign body response include protein adsorption, adhesion of monocytes/macrophages, fusion to form FBGCs, and the consequent modification of the biomaterial surface. The effect of physico-chemical cues on macrophages is not well known and there is a complex interplay between biomaterial properties and those that result from interactions with the local environment. By having a

  3. Strategies for the production of cell wall-deconstructing enzymes in lignocellulosic biomass and their utilization for biofuel production.

    Science.gov (United States)

    Park, Sang-Hyuck; Ong, Rebecca Garlock; Sticklen, Mariam

    2016-06-01

    Microbial cell wall-deconstructing enzymes are widely used in the food, wine, pulp and paper, textile, and detergent industries and will be heavily utilized by cellulosic biorefineries in the production of fuels and chemicals. Due to their ability to use freely available solar energy, genetically engineered bioenergy crops provide an attractive alternative to microbial bioreactors for the production of cell wall-deconstructing enzymes. This review article summarizes the efforts made within the last decade on the production of cell wall-deconstructing enzymes in planta for use in the deconstruction of lignocellulosic biomass. A number of strategies have been employed to increase enzyme yields and limit negative impacts on plant growth and development including targeting heterologous enzymes into specific subcellular compartments using signal peptides, using tissue-specific or inducible promoters to limit the expression of enzymes to certain portions of the plant or certain times, and fusion of amplification sequences upstream of the coding region to enhance expression. We also summarize methods that have been used to access and maintain activity of plant-generated enzymes when used in conjunction with thermochemical pretreatments for the production of lignocellulosic biofuels. PMID:26627868

  4. Analgesia Induced by Isolated Bovine Chromaffin Cells Implanted in Rat Spinal Cord

    Science.gov (United States)

    Sagen, Jacqueline; Pappas, George D.; Pollard, Harvey B.

    1986-10-01

    Chromaffin cells synthesize and secrete several neuroactive substances, including catecholamines and opioid peptides, that, when injected into the spinal cord, induce analgesia. Moreover, the release of these substances from the cells can be stimulated by nicotine. Since chromaffin cells from one species have been shown to survive when transplanted to the central nervous system of another species, these cells are ideal candidates for transplantation to alter pain sensitivity. Bovine chromaffin cells were implanted into the subarachnoid space of the lumbar spinal region in adult rats. Pain sensitivity and response to nicotine stimulation was determined at various intervals following cell implantation. Low doses of nicotine were able to induce potent analgesia in implanted animals as early as one day following their introduction into the host spinal cord. This response could be elicited at least through the 4 months the animals were tested. The induction of analgesia by nicotine in implanted animals was dose related. This analgesia was blocked by the opiate antagonist naloxone and partially attenuated by the adrenergic antagonist phentolamine. These results suggest that the analgesia is due to the stimulated release of opioid peptides and catecholamines from the implanted bovine chromaffin cells and may provide a new therapeutic approach for the relief of pain.

  5. Effect of low-energy hydrogen ion implantation on dendritic web silicon solar cells

    Science.gov (United States)

    Rohatgi, A.; Meier, D. L.; Rai-Choudhury, P.; Fonash, S. J.; Singh, R.

    1986-01-01

    The effect of a low-energy (0.4 keV), short-time (2-min), heavy-dose (10 to the 18th/sq cm) hydrogen ion implant on dendritic web silicon solar cells and material was investigated. Such an implant was observed to improve the cell open-circuit voltage and short-circuit current appreciably for a number of cells. In spite of the low implant energy, measurements of internal quantum efficiency indicate that it is the base of the cell, rather than the emitter, which benefits from the hydrogen implant. This is supported by the observation that the measured minority-carrier diffusion length in the base did not change when the emitter was removed. In some cases, a threefold increase of the base diffusion length was observed after implantation. The effects of the hydrogen implantation were not changed by a thermal stress test at 250 C for 111 h in nitrogen. It is speculated that hydrogen enters the bulk by traveling along dislocations, as proposed recently for edge-defined film-fed growth silicon ribbon.

  6. Mg ion implantation on SLA-treated titanium surface and its effects on the behavior of mesenchymal stem cell

    International Nuclear Information System (INIS)

    Magnesium (Mg) is one of the most important ions associated with bone osseointegration. The aim of this study was to evaluate the cellular effects of Mg implantation in titanium (Ti) surfaces treated with sand blast using large grit and acid etching (SLA). Mg ions were implanted into the surface via vacuum arc source ion implantation. The surface morphology, chemical properties, and the amount of Mg ion release were evaluated by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), Rutherford backscattering spectroscopy (RBS), and inductively coupled plasma-optical emission spectrometer (ICP-OES). Human mesenchymal stem cells (hMSCs) were used to evaluate cellular parameters such as proliferation, cytotoxicity, and adhesion morphology by MTS assay, live/dead assay, and SEM. Furthermore, osteoblast differentiation was determined on the basis of alkaline phosphatase (ALP) activity and the degree of calcium accumulation. In the Mg ion-implanted disk, 2.3 × 1016 ions/cm2 was retained. However, after Mg ion implantation, the surface morphology did not change. Implanted Mg ions were rapidly released during the first 7 days in vitro. The MTS assay, live/dead assay, and SEM demonstrated increased cell attachment and growth on the Mg ion-implanted surface. In particular, Mg ion implantation increased the initial cell adhesion, and in an osteoblast differentiation assay, ALP activity and calcium accumulation. These findings suggest that Mg ion implantation using the plasma source ion implantation (PSII) technique may be useful for SLA-treated Ti dental implants to improve their osseointegration capacity. - Highlights: ► Mg ion was coated onto surface of SLA treated titanium via vacuum arc source ion implantation method. ► The morphological characteristics did not change after Mg ion implantation. ► Mg ion implanted SLA Ti is highly cytocompatible. ► Initial cell adhesion of MSCs is improved by Mg ion implantation. ► Mg ion implantation improved

  7. Mg ion implantation on SLA-treated titanium surface and its effects on the behavior of mesenchymal stem cell

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Beom-Su; Kim, Jin Seong [Wonkwang Bone Regeneration Research Institute, Wonkwang University, Iksan 570-749 (Korea, Republic of); Bonecell Biotech Inc., 77, Dunsan-ro, Seo-gu, Daejeon 302-830 (Korea, Republic of); Park, Young Min [DIO Corporation, 66, Centum seo-ro, Haeundae-gu, Busan (Korea, Republic of); Choi, Bo-Young [Department of Oral and maxillofacial Surgery, Wonkwang University Daejeon Dental Hospital, Daejeon 302-830 (Korea, Republic of); Lee, Jun, E-mail: omslee@wku.ac.kr [Wonkwang Bone Regeneration Research Institute, Wonkwang University, Iksan 570-749 (Korea, Republic of); Bonecell Biotech Inc., 77, Dunsan-ro, Seo-gu, Daejeon 302-830 (Korea, Republic of)

    2013-04-01

    Magnesium (Mg) is one of the most important ions associated with bone osseointegration. The aim of this study was to evaluate the cellular effects of Mg implantation in titanium (Ti) surfaces treated with sand blast using large grit and acid etching (SLA). Mg ions were implanted into the surface via vacuum arc source ion implantation. The surface morphology, chemical properties, and the amount of Mg ion release were evaluated by scanning electron microscopy (SEM), Auger electron spectroscopy (AES), Rutherford backscattering spectroscopy (RBS), and inductively coupled plasma-optical emission spectrometer (ICP-OES). Human mesenchymal stem cells (hMSCs) were used to evaluate cellular parameters such as proliferation, cytotoxicity, and adhesion morphology by MTS assay, live/dead assay, and SEM. Furthermore, osteoblast differentiation was determined on the basis of alkaline phosphatase (ALP) activity and the degree of calcium accumulation. In the Mg ion-implanted disk, 2.3 × 10{sup 16} ions/cm{sup 2} was retained. However, after Mg ion implantation, the surface morphology did not change. Implanted Mg ions were rapidly released during the first 7 days in vitro. The MTS assay, live/dead assay, and SEM demonstrated increased cell attachment and growth on the Mg ion-implanted surface. In particular, Mg ion implantation increased the initial cell adhesion, and in an osteoblast differentiation assay, ALP activity and calcium accumulation. These findings suggest that Mg ion implantation using the plasma source ion implantation (PSII) technique may be useful for SLA-treated Ti dental implants to improve their osseointegration capacity. - Highlights: ► Mg ion was coated onto surface of SLA treated titanium via vacuum arc source ion implantation method. ► The morphological characteristics did not change after Mg ion implantation. ► Mg ion implanted SLA Ti is highly cytocompatible. ► Initial cell adhesion of MSCs is improved by Mg ion implantation. ► Mg ion implantation

  8. Stem Cell Implants for Cancer Therapy: TRAIL-Expressing Mesenchymal Stem Cells Target Cancer Cells In Situ

    OpenAIRE

    Reagan, Michaela Ruth; Seib, F. Philipp; McMillin, Douglas William; Elizabeth K. Sage; Mitsiades, Constantine S; Janes, Sam M.; Ghobrial, Irene; Kaplan, David L.

    2012-01-01

    Purpose Tumor-specific delivery of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), an apoptosis-inducing peptide, at effective doses remains challenging. Herein we demonstrate the utility of a scaffold-based delivery system for sustained therapeutic cell release that capitalizes on the tumor-homing properties of mesenchymal stem cells (MSCs) and their ability to express genetically-introduced therapeutic genes. Methods: Implants were formed from porous, biocompatible silk sca...

  9. Laccase electrodes based on the combination of single-walled carbon nanotubes and redox layered double hydroxides: Towards the development of biocathode for biofuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Shou-Nian; Holzinger, Michael; Cosnier, Serge [Departement de Chimie Moleculaire UMR-5250, ICMG FR-2607, CNRS Universite Joseph Fourier, BP-53, 38041 Grenoble Cedex 9 (France); Mousty, Christine [Laboratoire des Materiaux Inorganiques, Universite Blaise Pascal, CNRS UMR-6002, 63177 Aubiere Cedex (France)

    2010-08-01

    Single-walled carbon nanotubes (SWCNT) were combined with layered double hydroxides (LDH) intercalated with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) diammonium salt [ZnCr-ABTS] to entrap and electrically connect laccase enzyme. The resulting laccase electrodes exhibited an electro-enzymatic activity for O{sub 2} reduction. To improve this electrocatalytic activity, varying SWCNT quantities and loading methods were tested to optimize the configuration of the laccase electrodes. Furthermore, the resulting bioelectrode was successfully used as a biocathode for the elaboration of a membrane-less glucose/air biofuel cell. In 0.1 M phosphate buffer (PBS) of pH 6.0, containing glucose (5 mM) under ambient conditions, the assembled biofuel cell yielded a maximum power density of 18 {mu}W cm{sup -2} at a cell voltage of 0.3 V whereas this power decreased to 8.3 {mu}W cm{sup -2} for a biofuel cell based on the identical biocathode setup without SWCNT. (author)

  10. Synthetic Feedback Loop Model for Increasing Microbial Biofuel Production Using a Biosensor

    OpenAIRE

    Harrison, Mary E.; Dunlop, Mary J.

    2012-01-01

    Current biofuel production methods use engineered bacteria to break down cellulose and convert it to biofuel. A major challenge in microbial fuel production is that increasing biofuel yields can be limited by the toxicity of the biofuel to the organism that is producing it. Previous research has demonstrated that efflux pumps are effective at increasing tolerance to various biofuels. However, when overexpressed, efflux pumps burden cells, which hinders growth and slows biofuel production. The...

  11. Synthetic feedback loop model for increasing microbial biofuel production using a biosensor

    OpenAIRE

    MaryDunlop

    2012-01-01

    Current biofuel production methods use engineered bacteria to break down cellulose and convert it to biofuel. A major challenge in microbial fuel production is that increasing biofuel yields can be limited by the toxicity of the biofuel to the organism that is producing it. Previous research has demonstrated that efflux pumps are effective at increasing tolerance to various biofuels. However, when overexpressed, efflux pumps burden cells, which hinders growth and slows biofuel production. ...

  12. Lifecycle Analyses of Biofuels

    OpenAIRE

    Delucchi, Mark

    2006-01-01

    This manuscript on lifecycle analysis (LCA) of biofuels for transportation has three major parts: * I. An analysis of greenhouse-gas emissions from biofuels, estimated using the Lifecycle Emissions Model (LEM). * II. A review of recent LCAs of biofuels. * III. A comprehensive conceptual framework for doing LCAs of biofuels.

  13. Selective natural induction of laccases in Pleurotus sajor-caju, suitable for application at a biofuel cell cathode at neutral pH.

    Science.gov (United States)

    Fokina, Oleksandra; Eipper, Jens; Kerzenmacher, Sven; Fischer, Reinhard

    2016-10-01

    Laccases are multicopper oxidoreductases with broad substrate specificity and are applied in biofuel cells at the cathode to improve its oxygen reduction performance. However, the production of laccases by e.g. fungi is often accompanied by the need of synthetic growth supplements for increased enzyme production. In this study we present a strategy for the white-rot fungus Pleurotus sajor-caju for natural laccase activity induction using lignocellulose substrates and culture supernatant of Aspergillus nidulans. P. sajor-caju laccases were secreted into the supernatant, which was directly used at a carbon-nanotube buckypaper cathode in a biofuel cell. Maximal current densities of -148±3μAcm(-2) and -102±9μAcm(-2) at 400mV were achieved at pH 5 and 7, respectively. Variations in cathode performance were observed with culture supernatants produced under different conditions due to the induction of specific laccases. PMID:27393835

  14. An easy compartment-less biofuel cell construction based on the physical co-inclusion of enzyme and mediator redox within pressed graphite discs

    Energy Technology Data Exchange (ETDEWEB)

    Cosnier, Serge [Department de Chimie Moleculaire UMR-5250, ICMG FR-2607, CNRS Universite Joseph Fourier, BP-53, 38041 Grenoble (France); Shan, Dan [Department de Chimie Moleculaire UMR-5250, ICMG FR-2607, CNRS Universite Joseph Fourier, BP-53, 38041 Grenoble (France); School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Ding, Shou-Nian [Department de Chimie Moleculaire UMR-5250, ICMG FR-2607, CNRS Universite Joseph Fourier, BP-53, 38041 Grenoble (France); School of Chemistry and Chemical Engineering, Shouthest University, Nanjing 211189 (China)

    2010-02-15

    We report on the easy and fast immobilization of glucose oxidase (GOD) and laccase by mechanical compression with graphite particles to form disc electrodes. The electrical wiring of GOD and laccase was efficiently carried out by their co-inclusion with ferrocene (Fc) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS) respectively. A glucose/air compartment-less biofuel cell was constructed based on the association of GOD-ferrocene-graphite disc and laccase-ABTS - graphite disc electrodes as bioanode and biocathode respectively. Such biofuel cell yielded a power density of 23 {mu}W cm{sup -2} at 0.33 V as well as an open-circuit voltage and a short-circuit current of 0.63 V and 166 {mu}A, respectively. (author)

  15. Development of a glucose oxidase-based biocatalyst adopting both physical entrapment and crosslinking, and its use in biofuel cells

    Science.gov (United States)

    Chung, Yongjin; Ahn, Yeonjoo; Christwardana, Marcelinus; Kim, Hansung; Kwon, Yongchai

    2016-04-01

    New enzymatic catalysts prepared using physical entrapment and chemical bonding were used as anodic catalysts to enhance the performance of enzymatic biofuel cells (EBCs). For estimating the physical entrapment effect, the best glucose oxidase (GOx) concentration immobilized on polyethyleneimine (PEI) and carbon nanotube (CNT) (GOx/PEI/CNT) was determined, while for inspecting the chemical bonding effect, terephthalaldehyde (TPA) and glutaraldehyde (GA) crosslinkers were employed. According to the enzyme activity and XPS measurements, when the GOx concentration is 4 mg mL-1, they are most effectively immobilized (via the physical entrapment effect) and TPA-crosslinked GOx/PEI/CNT(TPA/[GOx/PEI/CNT]) forms π conjugated bonds via chemical bonding, inducing the promotion of electron transfer by delocalization of electrons. Due to the optimized GOx concentration and π conjugated bonds, TPA/[GOx/PEI/CNT], including 4 mg mL-1 GOx displays a high electron transfer rate, followed by excellent catalytic activity and EBC performance.New enzymatic catalysts prepared using physical entrapment and chemical bonding were used as anodic catalysts to enhance the performance of enzymatic biofuel cells (EBCs). For estimating the physical entrapment effect, the best glucose oxidase (GOx) concentration immobilized on polyethyleneimine (PEI) and carbon nanotube (CNT) (GOx/PEI/CNT) was determined, while for inspecting the chemical bonding effect, terephthalaldehyde (TPA) and glutaraldehyde (GA) crosslinkers were employed. According to the enzyme activity and XPS measurements, when the GOx concentration is 4 mg mL-1, they are most effectively immobilized (via the physical entrapment effect) and TPA-crosslinked GOx/PEI/CNT(TPA/[GOx/PEI/CNT]) forms π conjugated bonds via chemical bonding, inducing the promotion of electron transfer by delocalization of electrons. Due to the optimized GOx concentration and π conjugated bonds, TPA/[GOx/PEI/CNT], including 4 mg mL-1 GOx displays a high

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

    Science.gov (United States)

    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

  17. Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Reichel, Christian, E-mail: christian.reichel@ise.fraunhofer.de [Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstrasse 2, 79110 Freiburg (Germany); National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway, Golden, Colorado 80401 (United States); Feldmann, Frank; Müller, Ralph; Hermle, Martin; Glunz, Stefan W. [Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstrasse 2, 79110 Freiburg (Germany); Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul [National Renewable Energy Laboratory (NREL), 15013 Denver West Parkway, Golden, Colorado 80401 (United States)

    2015-11-28

    Passivated contacts (poly-Si/SiO{sub x}/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF{sub 2}), the ion implantation dose (5 × 10{sup 14 }cm{sup −2} to 1 × 10{sup 16 }cm{sup −2}), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iV{sub oc}) of 725 and 720 mV, respectively. For p-type passivated contacts, BF{sub 2} implantations into intrinsic a-Si yield well passivated contacts and allow for iV{sub oc} of 690 mV, whereas implanted B gives poor passivation with iV{sub oc} of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved V{sub oc} of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF{sub 2} implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with V{sub oc} of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.

  18. Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

    International Nuclear Information System (INIS)

    Passivated contacts (poly-Si/SiOx/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF2), the ion implantation dose (5 × 1014 cm−2 to 1 × 1016 cm−2), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iVoc) of 725 and 720 mV, respectively. For p-type passivated contacts, BF2 implantations into intrinsic a-Si yield well passivated contacts and allow for iVoc of 690 mV, whereas implanted B gives poor passivation with iVoc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved Voc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with Voc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts

  19. Co-delivery of siRNA and doxorubicin to cancer cells from additively manufactured implants

    DEFF Research Database (Denmark)

    Chen, Muwan; Andersen, Morten Østergaard; Dillschneider, Philipp; Chang, Chi-Chih (Clare); Gao, Shan; Le, Dang Quang Svend; Yang, Chuanxu; Hein, San; Bünger, Cody; Kjems, Jørgen

    2015-01-01

    , capable of physically supporting the void while killing residual cancer cells, would be an attractive solution. Here we describe a novel additively manufactured implant that can be functionalized with chitosan/siRNA nanoparticles. These induce long term gene silencing in adjacent cancer cells without...

  20. Terrestrial silicon P-N junction solar cells obtained by ionic-implantation

    International Nuclear Information System (INIS)

    The possibilities of ionic implantation for the realization of silicon p-n junction solar-cells and essentially the properties of the thin layer doped with boron ions, the structure defects and the annealing are studied. The electrical characteristics of the cells are also reported

  1. Evaluation of Biofuel Cells with Hemoglobin as Cathodic Electrocatalysts for Hydrogen Peroxide Reduction on Bare Indium-Tin-Oxide Electrodes

    Directory of Open Access Journals (Sweden)

    Yusuke Ayato

    2013-12-01

    Full Text Available A biofuel cell (BFC cathode has been developed based on direct electron transfer (DET of hemoglobin (Hb molecules with an indium-tin-oxide (ITO electrode and their electrocatalysis for reduction of hydrogen peroxide (H2O2. In this study, the ITO-coated glass plates or porous glasses were prepared by using a chemical vapor deposition (CVD method and examined the electrochemical characteristics of the formed ITO in pH 7.4 of phosphate buffered saline (PBS solutions containing and not containing Hb. In half-cell measurements, the reduction current of H2O2 due to the electrocatalytic activity of Hb increased with decreasing electrode potential from around 0.1 V versus Ag|AgCl|KCl(satd. in the PBS solution. The practical open-circuit voltage (OCV on BFCs utilizing H2O2 reduction at the Hb-ITO cathode with a hydrogen (H2 oxidation anode at a platinum (Pt electrode was expected to be at least 0.74 V from the theoretical H2 oxidation potential of −0.64 V versus Ag|AgCl|KCl(satd. in pH 7.4. The assembled single cell using the ITO-coated glass plate showed the OCV of 0.72 V and the maximum power density of 3.1 µW cm−2. The maximum power per single cell was recorded at 21.5 µW by using the ITO-coated porous glass.

  2. Liquid biofuels

    International Nuclear Information System (INIS)

    This is a brief conference paper on the use of biofuels in vehicles, especially in Sweden. Vegetable oils replace only diesel. In Sweden, the vegetable oil most often used is rape-seed oil. These oils are not very efficient in ''raw'' form and are used as basis in esters, such as rape-seed methyl ester (RME). Although RME is renewable, biobased and reduces the atmospheric CO2 emission, it increases the emission of nitrogen oxides, it may cause startup problems in cold weather and is not stable when stored for long. Most RME available in Sweden is imported and the potential for increased Swedish production is very limited. By using methanol and ethanol both petrol and diesel can be replaced. While mixtures of petrol and alcohols are being used increasingly, mixtures of diesel and alcohols are unstable and their use requires technological development

  3. Low potential biofuel cell anodes based on redox polymers with covalently bound phenothiazine derivatives for wiring flavin adenine dinucleotide-dependent enzymes

    International Nuclear Information System (INIS)

    The design of biofuel cell anodes with substantially decreased potential is a prerequisite for the development of biofuel cells with large open-circuit voltage and power density. Redox polymers with covalently attached phenothiazine derivatives such of thionine acetate, toluidine blue, azure B simultaneously providing epoxide functions for covalent binding to suitably modified electrode surfaces and crosslinking were synthesized and evaluated for their ability to transfer electrons from the FAD cofactor of the flavodehydrogenase domain of cellobiose dehydrogenase from Myriococcum thermophilum (FAD-MtCDH), the flavodehydrogenase domain of cellobiose dehydrogenase from Corynascus thermophilus (FAD-CtCDH), or glucose oxidase from Aspergillus niger (GOx). Polymer/enzyme films were covalently bound via polymer bound epoxy groups to terminal amino functions introduced to graphite electrode surfaces by electrochemically induced grafting of diaminoheptane or Boc-protected ethylene diamine (EDA). The electrodes were optimized for biocatalytic glucose oxidation with respect to the hydrophilicity of the polymer backbone, the nature of the phenothiazine derivative, the pH value, as well as the relative amount of enzyme, polymer and crosslinker. Biofuel cells based on toluidine blue-modified redox polymers with integrated FAD-MtCDH, FAD-CtCDH, or GOx in combination with a bilirubin oxidase based biocathode exhibited open-circuit voltages of more than 0.7 V and maximum power densities in the range of 4 to 6 μW cm−2 at a pH value of 7.8

  4. Breast Implant Informed Consent Should Include the Risk of Anaplastic Large Cell Lymphoma.

    Science.gov (United States)

    Clemens, Mark W; Miranda, Roberto N; Butler, Charles E

    2016-04-01

    Breast implant-associated anaplastic large cell lymphoma (ALCL) is a rare T-cell lymphoma arising around breast implants. Public awareness has increased following a safety communication warning of the association of breast implant-associated ALCL by the U.S. Food and Drug Administration in 2011. Difficulty with determining an accurate assessment of risk, including diagnosis, or standardized treatment regimen has led surgeons to commonly omit preoperative discussion of this rare and frequently misunderstood cancer. Risk disclosure is a form of respect for patient autonomy, and informed consent has positive practical and moral consequences for the practice of plastic surgery. A model of breast implant-associated ALCL informed consent implementation and health care provider education are reviewed with 1-year process follow-up at a tertiary cancer center. Breast implant-associated ALCL should be included during preoperative counseling on the risks of breast implantation when obtaining informed consent. Pertinent aspects of decision-making include disease awareness, presenting symptoms, and resources for concerned patients. Education of health care professionals and provision of patient-focused materials ensures effectiveness of the informed consent process. PMID:27018666

  5. Fuelling biofuel

    International Nuclear Information System (INIS)

    The Canadian government has recently committed to legislation ensuring that all transportation fuels will be supplemented with biofuels by 2010. This article provided details of a position paper written by the Canadian Renewable Fuels Association in response to the legislation. Details of new research to optimize the future biodiesel industry were also presented. Guiding principles of the paper included the creation of open markets across provincial boundaries; the manipulation of tax structures to make products competitive in the United States; and establishing quality standards via the Canadian General Standards Board. It is expected that the principles will reassure petroleum producers and retailers, as ethanol behaves differently than gasoline in storage tanks. As ethanol is water-absorbing, retailers must flush and vacuum their tanks to remove water, then install 10 micron filters to protect fuel lines and dispenser filters from accumulated gasoline residue loosened by the ethanol. Refineries are concerned that the average content of ethanol remains consistent across the country, as refiners will be reluctant to make different blends for different provinces. Critics of biodiesel claim that it is not energy-intensive enough to meet demand, and biodiesel crops are not an efficient use of soils that could otherwise be used to grow food crops. However, researchers in Saskatchewan are committed to using a variety of methods such as reduced tillage systems to make biodiesel production more efficient. Laboratory research has resulted in improved refining processes and genetic manipulation of potential biodiesel crops. Membrane technology is now being used to select water from ethanol. A process developed by the Ottawa company Iogen Corporation uses enzymatic hydrolysis to break down the tough fibres found in corn stalks, leaves, wood and other biomass into sugars. Scientists are also continuing to improve oil content yields in canola and soybean crops. It was

  6. Fabrication of Mediatorless/Membraneless Glucose/Oxygen Based Biofuel Cell using Biocatalysts Including Glucose Oxidase and Laccase Enzymes.

    Science.gov (United States)

    Christwardana, Marcelinus; Kim, Ki Jae; Kwon, Yongchai

    2016-01-01

    Mediatorless and membraneless enzymatic biofuel cells (EBCs) employing new catalytic structure are fabricated. Regarding anodic catalyst, structure consisting of glucose oxidase (GOx), poly(ethylenimine) (PEI) and carbon nanotube (CNT) is considered, while three cathodic catalysts consist of glutaraldehyde (GA), laccase (Lac), PEI and CNT that are stacked together in different ways. Catalytic activities of the catalysts for glucose oxidation and oxygen reduction reactions (GOR and ORR) are evaluated. As a result, it is confirmed that the catalysts work well for promotion of GOR and ORR. In EBC tests, performances of EBCs including 150 μm-thick membrane are measured as references, while those of membraneless EBCs are measured depending on parameters like glucose flow rate, glucose concentration, distance between two electrodes and electrolyte pH. With the measurements, how the parameters affect EBC performance and their optimal conditions are determined. Based on that, best maximum power density (MPD) of membraneless EBC is 102 ± 5.1 μW · cm(-2) with values of 0.5 cc · min(-1) (glucose flow rate), 40 mM (glucose concentration), 1 mm (distance between electrodes) and pH 3. When membrane and membraneless EBCs are compared, MPD of the membraneless EBC that is run at the similar operating condition to EBC including membrane is speculated as about 134 μW · cm(-2). PMID:27426264

  7. Fabrication of Mediatorless/Membraneless Glucose/Oxygen Based Biofuel Cell using Biocatalysts Including Glucose Oxidase and Laccase Enzymes

    Science.gov (United States)

    Christwardana, Marcelinus; Kim, Ki Jae; Kwon, Yongchai

    2016-07-01

    Mediatorless and membraneless enzymatic biofuel cells (EBCs) employing new catalytic structure are fabricated. Regarding anodic catalyst, structure consisting of glucose oxidase (GOx), poly(ethylenimine) (PEI) and carbon nanotube (CNT) is considered, while three cathodic catalysts consist of glutaraldehyde (GA), laccase (Lac), PEI and CNT that are stacked together in different ways. Catalytic activities of the catalysts for glucose oxidation and oxygen reduction reactions (GOR and ORR) are evaluated. As a result, it is confirmed that the catalysts work well for promotion of GOR and ORR. In EBC tests, performances of EBCs including 150 μm-thick membrane are measured as references, while those of membraneless EBCs are measured depending on parameters like glucose flow rate, glucose concentration, distance between two electrodes and electrolyte pH. With the measurements, how the parameters affect EBC performance and their optimal conditions are determined. Based on that, best maximum power density (MPD) of membraneless EBC is 102 ± 5.1 μW · cm‑2 with values of 0.5 cc · min‑1 (glucose flow rate), 40 mM (glucose concentration), 1 mm (distance between electrodes) and pH 3. When membrane and membraneless EBCs are compared, MPD of the membraneless EBC that is run at the similar operating condition to EBC including membrane is speculated as about 134 μW · cm‑2.

  8. Fabrication of Mediatorless/Membraneless Glucose/Oxygen Based Biofuel Cell using Biocatalysts Including Glucose Oxidase and Laccase Enzymes

    Science.gov (United States)

    Christwardana, Marcelinus; Kim, Ki Jae; Kwon, Yongchai

    2016-01-01

    Mediatorless and membraneless enzymatic biofuel cells (EBCs) employing new catalytic structure are fabricated. Regarding anodic catalyst, structure consisting of glucose oxidase (GOx), poly(ethylenimine) (PEI) and carbon nanotube (CNT) is considered, while three cathodic catalysts consist of glutaraldehyde (GA), laccase (Lac), PEI and CNT that are stacked together in different ways. Catalytic activities of the catalysts for glucose oxidation and oxygen reduction reactions (GOR and ORR) are evaluated. As a result, it is confirmed that the catalysts work well for promotion of GOR and ORR. In EBC tests, performances of EBCs including 150 μm-thick membrane are measured as references, while those of membraneless EBCs are measured depending on parameters like glucose flow rate, glucose concentration, distance between two electrodes and electrolyte pH. With the measurements, how the parameters affect EBC performance and their optimal conditions are determined. Based on that, best maximum power density (MPD) of membraneless EBC is 102 ± 5.1 μW · cm−2 with values of 0.5 cc · min−1 (glucose flow rate), 40 mM (glucose concentration), 1 mm (distance between electrodes) and pH 3. When membrane and membraneless EBCs are compared, MPD of the membraneless EBC that is run at the similar operating condition to EBC including membrane is speculated as about 134 μW · cm−2. PMID:27426264

  9. Visible-light driven biofuel cell based on hierarchically branched titanium dioxide nanorods photoanode for tumor marker detection.

    Science.gov (United States)

    Gao, Chaomin; Zhang, Lina; Wang, Yanhu; Yu, Jinghua; Song, Xianrang

    2016-09-15

    In this work, a novel sensing platform based on visible light driven biofuel cell (BFC) has been facilely designed for sensitive detection of prostate-specific antigen (PSA) with the photo-response bioanode, realizing the dual route energy conversion of light energy and chemical energy to electricity. The hierarchical branched TiO2 nanorods (B-TiO2 NRs) decorated with CdS quantum dots (QDs) act as the substrate to confine glucose dehydrogenase (GDH) for the visible light driven glucose oxidation at the bioanode. Three dimensional flowers like hierarchical carbon/gold nanoparticles/bilirubin oxidase (3D FCM/AuNPs/BOD) bioconjugate served as biocatalyst for O2 reduction at the biocathode. With an increase in the concentration of PSA, the amount of BOD labels on biocathode increases, thus leading to the higher current output of the as-proposed visible light driven BFC. Based on this, this sensing platform provide great performance in sensitivity and specificity, increasing linear detection range from 0.3pgmL(-1) to 7μgmL(-1) with a detection limit of 0.1pgmL(-1). Most importantly, our new sensing strategy provided a simple and inexpensive sensing platform for tumor markers detection, suggesting its wide potential applications for clinical diagnostics. PMID:27135937

  10. Effects of multiple polyaniline layers immobilized on carbon nanotube and glutaraldehyde on performance and stability of biofuel cell

    Science.gov (United States)

    Christwardana, Marcelinus; Kwon, Yongchai

    2015-12-01

    Enzymatic biofuel cell (EBC) employing new catalyst for anode electrode is fabricated. The new catalyst consists of glucose oxidase (GOx), polyaniline (PANI) and carbon nanotube (CNT) that are multiply stacked together and finally the stack layer is surrounded by glutaraldehyde (GA) (GA/[GOx/PANI/CNT]n). To evaluate how the GA/[GOx/PANI/CNT]n layer affects EBC performance and stability, electrochemical characterizations are implemented. Regarding optimization, GA/[GOx/PANI/CNT]3 is determined. For elucidating reaction mechanism between glucose and flavin adenine dinucleotide (FAD) of GA/[GOx/PANI/CNT]3, associated investigations are performed. In the evaluations, drop in reduction current peak of FAD is observed with provisions of glucose and O2, while glucose does not influence FAD reaction without O2, confirming O2 makes mediator role. When the GA/[GOx/PANI/CNT]3 layer is adopted, superior catalytic activity and EBC performance are gained (electron transfer rate constant of 5.1 s-1, glucose sensitivity of 150 ìA mM-1 cm-2, and EBC maximum power density (MPD) of 0.29 mW cm-2). Regarding EBC stability, MPD of EBC adopting GA/[GOx/PANI/CNT]3 maintains up to 93% of their initial value even after four weeks. Although GA is little effective for improving EBC performance, EBC stability is helped by GA due to its adhesion promotion capability with [GOx/PANI/CNT]n layer.

  11. Removal of an oral squamous cell carcinoma including parts of osseointegrated implants in the marginal mandibulectomy. A case report

    OpenAIRE

    Meijer, Gert J; Dieleman, Francois J.; Stefaan J Bergé; Merkx, Matthias A.W.

    2010-01-01

    Purpose The incidence of oral squamous cell carcinomas (OSCC) arising around dental implants will increase because of the rising popularity of dental implants. In this case, a novel surgical treatment of an OSCC in the vicinity of endosseous implants is reported. Materials and methods In a 69-year-old woman, a recurrent OSCC (cT2N0M0) developed in the floor of the mouth extending to the attached keratinized peri-implant mucosa of both interforaminal-placed dental implants. Radiographically, n...

  12. RTV silicone rubber surface modification for cell biocompatibility by negative-ion implantation

    Science.gov (United States)

    Zheng, Chenlong; Wang, Guangfu; Chu, Yingjie; Xu, Ya; Qiu, Menglin; Xu, Mi

    2016-03-01

    A negative cluster ion implantation system was built on the injector of a GIC4117 tandem accelerator. Next, the system was used to study the surface modification of room temperature vulcanization silicone rubber (RTV SR) for cell biocompatibility. The water contact angle was observed to decrease from 117.6° to 99.3° as the C1- implantation dose was increased to 1 × 1016 ions/cm2, and the effects of C1-, C2- and O1- implantation result in only small differences in the water contact angle at 3 × 1015 ions/cm2. These findings indicate that the hydrophilicity of RTV SR improves as the dose is increased and that the radiation effect has a greater influence than the doping effect on the hydrophilicity. There are two factors influence hydrophilicity of RTV: (1) based on the XPS and ATR-FTIR results, it can be inferred that ion implantation breaks the hydrophobic functional groups (Sisbnd CH3, Sisbnd Osbnd Si, Csbnd H) of RTV SR and generates hydrophilic functional groups (sbnd COOH, sbnd OH, Sisbnd (O)x (x = 3,4)). (2) SEM reveals that the implanted surface of RTV SR appears the micro roughness such as cracks and wrinkles. The hydrophilicity should be reduced due to the lotus effect (Zhou Rui et al., 2009). These two factors cancel each other out and make the C-implantation sample becomes more hydrophilic in general terms. Finally, cell culture demonstrates that negative ion-implantation is an effective method to improve the cell biocompatibility of RTV SR.

  13. Peripheral white blood cells profile of biodegradable metal implant in mice animal model

    International Nuclear Information System (INIS)

    Biocompatibility or safety of the medical device is considered important. It can be determined by blood profile examination. The aim of this study was to assess the biocompatibility of biodegradable metal implant through peripheral white blood cells (WBCs) profile approach. Forty eight male ddy mice were divided into four groups according to the materials implanted: iron wire (Fe), magnesium rod (Mg), stainless steel surgical wire (SS316L) and control with sham (K). Implants were inserted and attached onto the right femoral bone on latero-medial region. In this study, peripheral white blood cells and leukocyte differentiation were the parameters examined. The result showed that the WBCs value of all groups were decreased at the first day after implantation, increased at the 10th day and continued increasing at the 30th day of observation, except Mg group which has decreased. Neutrophil, as an inflammatory cells, was increased at the early weeks and decreased at the day-30 after surgery in all groups. Despite, these values during the observation were still within the normal range. As a conclus ion, biodegradable metal implants lead to an inflammatory reaction, with no adverse effect on WBC value found

  14. Peripheral white blood cells profile of biodegradable metal implant in mice animal model

    Energy Technology Data Exchange (ETDEWEB)

    Paramitha, Devi; Noviana, Deni, E-mail: deni@ipb.ac.id; Estuningsih, Sri [Faculty of Veterinary Medicine, Bogor Agricultural University (IPB), Bogor (Indonesia); Ulum, Mokhamad Fakhrul [Faculty of Veterinary Medicine, Bogor Agricultural University (IPB), Bogor (Indonesia); Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru (Malaysia); Nasution, Ahmad Kafrawi [Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru (Malaysia); Faculty of Engineering, Muhammadiyah University of Riau (UMRI), Pekanbaru (Indonesia); Hermawan, Hendra [Department of Mining, Metallurgical and Materials Engineering & CHU de Québec Research Center, Laval University (ULaval) (Canada)

    2015-09-30

    Biocompatibility or safety of the medical device is considered important. It can be determined by blood profile examination. The aim of this study was to assess the biocompatibility of biodegradable metal implant through peripheral white blood cells (WBCs) profile approach. Forty eight male ddy mice were divided into four groups according to the materials implanted: iron wire (Fe), magnesium rod (Mg), stainless steel surgical wire (SS316L) and control with sham (K). Implants were inserted and attached onto the right femoral bone on latero-medial region. In this study, peripheral white blood cells and leukocyte differentiation were the parameters examined. The result showed that the WBCs value of all groups were decreased at the first day after implantation, increased at the 10th day and continued increasing at the 30th day of observation, except Mg group which has decreased. Neutrophil, as an inflammatory cells, was increased at the early weeks and decreased at the day-30 after surgery in all groups. Despite, these values during the observation were still within the normal range. As a conclus ion, biodegradable metal implants lead to an inflammatory reaction, with no adverse effect on WBC value found.

  15. Al and Cu Implantation into Silicon Substrate for Ohmic Contact in Solar Cell Fabrication

    International Nuclear Information System (INIS)

    Research on the implantation of Al and Cu ions into silicon substrate for ohmic contact in solar cell fabrication has been carried using ion accelerator machine. Al and Cu ions are from 98% Al and 99.9% Cu powder ionized in ion source system. provided in ion implantor machine. Before implantation process, (0.5 x 1) cm2 N type and P type silicon were washed in water and then etched in Cp-4A solution. After that, P type silicon were implanted with Al ions and N type silicon were implanted with Cu ions with the ions dose from 1013 ion/cm2 - 1016 ion/cm2 and energy 20 keV - 80 keV. Implanted samples were then annealed at temperature 400 oC - 850 oC. Implanted and annealed samples were characterized their resistivities using four point probe FPP-5000. It was found that at full electrically active conditions the ρs for N type was 1.30 x 108 Ω/sq, this was achieved at ion dose 1013 ion/cm2 and annealing temperature 500 oC. While for P type, the ρs was 1.13 x 102 Ω/sq, this was achieved at ion dose 1013 ion/cm2 and energy 40 keV, and annealing temperature 500 oC. (author)

  16. Effects of Vascular Endothelial Cell Growth Factor on Fibrovascular Ingrowth into Rabbit's Hydroxyapatite Orbital Implant

    Institute of Scientific and Technical Information of China (English)

    张虹; 李贵刚; 纪彩霓; 何花; 王军明; 胡维琨; 吴华; 陈憬

    2004-01-01

    Summary: The effects of different concentrations of vascular endothelial cell growth factor (VEGF)on the fibrovascular ingrowth into rabbits hydroxyapatite orbital implant were investigated. Twelve New Zealand white rabbits were divided into 3 groups and received hydroxyapatite orbital implant surgery in their right eyes. Before and after the operation, the implants were treated with 10 ng/ml VEGF, 100 ng/ml VEGF, or normal saline as control group. The animals received technetium bones scan at 2, 4, and 6 weeks postoperatively. The mean radioactivity counts within region of interest (ROI) of the surgery eye (R) and the non-surgery eye (L) in the same animal were tested,and the R/L ratios were calculated. The implants were harvested at 6th weeks and examined histopathologically. The results showed that at second week, there was no significant difference in mean R/L ratios between VEGF group and control group (F=2.83, P=0. 111);At 4th week (F=7. 728, P=0.011) and 6th week (F=7.831, P=0.011) postoperatively, the mean ratios in VEGF groups were significantly higher than that in control group. At 6th week postoperatively,the fibrovascularization rates in VEGF groups were higher than in control group significantly (F=8. 711, P = 0. 008), It was suggested that VEGF could promote the fibrovascular ingrowth into hydroxyapatite orbital implant, thus might shorten the time required for complete vascularization of the HA orbital implant.

  17. The convergence of cochlear implantation with induced pluripotent stem cell therapy.

    Science.gov (United States)

    Gunewardene, Niliksha; Dottori, Mirella; Nayagam, Bryony A

    2012-09-01

    According to 2010 estimates from The National Institute on Deafness and other Communication Disorders, approximately 17% (36 million) American adults have reported some degree of hearing loss. Currently, the only clinical treatment available for those with severe-to-profound hearing loss is a cochlear implant, which is designed to electrically stimulate the auditory nerve in the absence of hair cells. Whilst the cochlear implant has been revolutionary in terms of providing hearing to the severe-to-profoundly deaf, there are variations in cochlear implant performance which may be related to the degree of degeneration of auditory neurons following hearing loss. Hence, numerous experimental studies have focused on enhancing the efficacy of cochlear implants by using neurotrophins to preserve the auditory neurons, and more recently, attempting to replace these dying cells with new neurons derived from stem cells. As a result, several groups are now investigating the potential for both embryonic and adult stem cells to replace the degenerating sensory elements in the deaf cochlea. Recent advances in our knowledge of stem cells and the development of induced pluripotency by Takahashi and Yamanaka in 2006, have opened a new realm of science focused on the use of induced pluripotent stem (iPS) cells for therapeutic purposes. This review will provide a broad overview of the potential benefits and challenges of using iPS cells in combination with a cochlear implant for the treatment of hearing loss, including differentiation of iPS cells into an auditory neural lineage and clinically relevant transplantation approaches. PMID:21956409

  18. Nanotechnology and Dental Implants

    OpenAIRE

    Sandrine Lavenus; Guy Louarn; Pierre Layrolle

    2010-01-01

    The long-term clinical success of dental implants is related to their early osseointegration. This paper reviews the different steps of the interactions between biological fluids, cells, tissues, and surfaces of implants. Immediately following implantation, implants are in contact with proteins and platelets from blood. The differentiation of mesenchymal stem cells will then condition the peri-implant tissue healing. Direct bone-to-implant contact is desired for a biomechanical anchoring of i...

  19. Current-potential response and concentration profiles of redox polymer-mediated enzyme catalysis in biofuel cells - Estimation of Michaelis-Menten constants

    Science.gov (United States)

    Saravanakumar, K.; Rajendran, L.; Sangaranarayanan, M. V.

    2015-02-01

    The current-potential response of the enzyme-catalyzed, redox polymer mediated kinetic scheme pertaining to biofuel cells is analyzed. The ping-pong reaction scheme is solved analytically using the homotopy method for estimating the current density. The validity of the approach is demonstrated using the known experimental data for a series of osmium based redox polymers, involving oxygen as the substrate with laccase being the enzyme for biocathode fuel cell reactions. The significance of the results has been demonstrated by suggesting two new graphical procedures for estimating the Michaelis-Menten constants and catalytic rate constants from the experimental current densities.

  20. Production of fatty acid-derived oleochemicals and biofuels by synthetic yeast cell factories.

    Science.gov (United States)

    Zhou, Yongjin J; Buijs, Nicolaas A; Zhu, Zhiwei; Qin, Jiufu; Siewers, Verena; Nielsen, Jens

    2016-01-01

    Sustainable production of oleochemicals requires establishment of cell factory platform strains. The yeast Saccharomyces cerevisiae is an attractive cell factory as new strains can be rapidly implemented into existing infrastructures such as bioethanol production plants. Here we show high-level production of free fatty acids (FFAs) in a yeast cell factory, and the production of alkanes and fatty alcohols from its descendants. The engineered strain produces up to 10.4 g l(-1) of FFAs, which is the highest reported titre to date. Furthermore, through screening of specific pathway enzymes, endogenous alcohol dehydrogenases and aldehyde reductases, we reconstruct efficient pathways for conversion of fatty acids to alkanes (0.8 mg l(-1)) and fatty alcohols (1.5 g l(-1)), to our knowledge the highest titres reported in S. cerevisiae. This should facilitate the construction of yeast cell factories for production of fatty acids derived products and even aldehyde-derived chemicals of high value. PMID:27222209

  1. Production of fatty acid-derived oleochemicals and biofuels by synthetic yeast cell factories

    DEFF Research Database (Denmark)

    Zhou, Yongjin J.; Buijs, Nicolaas A; Zhu, Zhiwei;

    2016-01-01

    alcohol dehydrogenases and aldehyde reductases, we reconstruct efficient pathways for conversion of fatty acids to alkanes (0.8 mg l−1) and fatty alcohols (1.5 g l−1), to our knowledge the highest titres reported in S. cerevisiae. This should facilitate the construction of yeast cell factories for...

  2. Indirect measurements of Brachiaria brizantha cv. Marandu fermentable cell wall sugars for second generation biofuels production.

    Science.gov (United States)

    Results of a study conducted to evaluate the possibility of using IVDMD values of B. brizantha cv. Marandu to predict cell wall sugars that would be available in a biorefinery for ethanol production are reported. The study was conducted based on the similarity between rumen enzymes and those used i...

  3. Arthroplasty implant biomaterial particle associated macrophages differentiate into lacunar bone resorbing cells.

    OpenAIRE

    Pandey, R.; Quinn, J.; Joyner, C.; Murray, D W; Triffitt, J T; N. A. Athanasou

    1996-01-01

    OBJECTIVE: To study the pathogenesis of aseptic loosening: in particular, to determine whether macrophages responding to particles of biomaterials commonly used in arthroplasty surgery for arthritis are capable of differentiating into osteoclastic bone resorbing cells, and the cellular and hormonal conditions required for this to occur. METHODS: Biomaterial particles (polymethylmethacrylate, high density polyethylene, titanium, chromium-cobalt, stainless steel) were implanted subcutaneously i...

  4. Treatment of radiation syndrome with emphasis on stem cell implantation

    International Nuclear Information System (INIS)

    Within few years, the possibility that the human body contains cells that can repair and regenerate damaged and diseased tissue has gone from an unlikely proposition to a virtual certainty. Patients who have received doses of radiation in the potentially low to mid-lethal range (2-6 Gy) will have depression in bone-marrow function with cessation of blood-cell production leading to pancytopenia. Selection of cases for stem cell transplantation is based upon clinical signs and symptoms. Hematopoietic stem cell which produces blood cell progeny provides support for hematopoietic and other cells within the marrow, and has also been a focus for possible tissue repair. Another cell type termed mesenchymal or stromal also exists in the marrow. This cell provides support for hematopoietic and other cells within the marrow, and has also been a focus for possible tissue repair. Stem cells are obtained from bone marrow, peripheral blood, placental and umbilical cord blood, embryonic stem cells and embryonic germ cells. These cells have great potential for clinical research due to their potential to regenerate tissue. As well known, the cryo preservation process can store any cell type, particularly blood cells, for an indeterminate time. (author)

  5. Nitrogen fertilization affects silicon concentration, cell wall composition and biofuel potential of wheat straw

    DEFF Research Database (Denmark)

    Murozuka, Emiko; Laursen, Kristian Holst; Lindedam, Jane;

    2014-01-01

    at six different levels of nitrogen supply ranging from 48 to 288kg nitrogen ha-1 was analyzed for major cell wall components and mineral elements. Enzymatic digestion of the straw was carried out to evaluate the saccharification efficiency. The nitrogen concentration in the straw dry matter...... supplies. The enzymatic saccharification efficiency was negatively correlated with the rate of nitrogen supply. We conclude that the level of nitrogen supply to wheat plants alters the composition of cell wall components in the straw and that this may result in reduced saccharification efficiency. © 2014......Nitrogen is an essential input factor required for plant growth and biomass production. However, very limited information is available on how nitrogen fertilization affects the quality of crop residues to be used as lignocellulosic feedstock. In the present study, straw of winter wheat plants grown...

  6. Biosynthesis of Bacterial Cellulose/Carboxylic Multi-Walled Carbon Nanotubes for Enzymatic Biofuel Cell Application

    OpenAIRE

    Pengfei Lv; Quan Feng; Qingqing Wang; Guohui Li; Dawei Li; Qufu Wei

    2016-01-01

    Novel nanocomposites comprised of bacterial cellulose (BC) with carboxylic multi-walled carbon nanotubes (c-MWCNTs) incorporated into the BC matrix were prepared through a simple method of biosynthesis. The biocathode and bioanode for the enzyme biological fuel cell (EBFC) were prepared using BC/c-MWCNTs composite injected by laccase (Lac) and glucose oxidase (GOD) with the aid of glutaraldehyde (GA) crosslinking. Biosynthesis of BC/c-MWCNTs composite was characterized by digital photos, scan...

  7. Perspective of harnessing energy from landfill leachate via microbial fuel cells: novel biofuels and electrogenic physiologies.

    Science.gov (United States)

    Wu, Dong; Wang, Ting; Huang, Xinghua; Dolfing, Jan; Xie, Bing

    2015-10-01

    Organic carbon, nitrogen, and sulfur are highly concentrated in municipal solid waste (MSW) landfill leachate, which usually frustrates conventional leachate treatment technologies from the perspective of energy costs. Therefore, the possibility of converting leachate to a new energy source via microbial fuel cell (MFC) technology has been examined recently. This paper summarizes the power output and energy recovery efficiency of the leachate-fed MFCs according to different feeding patterns, cell structures, and loading rates. Also, we assess potential energy-generating chemicals in leachate like nitrogen and sulfur compounds and propose alternative pathways, which may lift strict ratios between organic carbon and nitrogen content in conventional denitrification of leachate and are expected to achieve a higher voltage than traditional organic-oxygen based cells. Although currently power output of leachate-fed MFCs is limited, it seems well possible that dynamic characteristics of MSW leachates and microbial physiologies underlying some bio-electrochemically efficient activities (e.g., direct interspecies electron transfer) could be stimulated in MFC systems to improve the present status. PMID:26239072

  8. Hybrid Adipogenic Implants from Adipose Stem Cells for Soft Tissue Reconstruction In Vivo

    OpenAIRE

    MOIOLI, EDUARDO K.; Chen, Mo; Yang, Rujing; Shah, Bhranti; Wu, June; Mao, Jeremy J

    2010-01-01

    A critical barrier in tissue regeneration is scale-up. Bioengineered adipose tissue implants have been limited to ∼10 mm in diameter. Here, we devised a 40-mm hybrid implant with a cellular layer encapsulating an acellular core. Human adipose-derived stem cells (ASCs) were seeded in alginate. Poly(ethylene)glycol-diacrylate (PEGDA) was photopolymerized into 40-mm-diameter dome-shaped gel. Alginate-ASC suspension was painted onto PEGDA surface. Cultivation of hybrid constructs ex vivo in adipo...

  9. p-Type Quasi-Mono Silicon Solar Cell Fabricated by Ion Implantation

    OpenAIRE

    Chien-Ming Lee; Sheng-Po Chang; Shoou-Jinn Chang; Ching-In Wu

    2013-01-01

    The p-type quasi-mono wafer is a novel type of silicon material that is processed using a seed directional solidification technique. This material is a promising alternative to traditional high-cost Czochralski (CZ) and float-zone (FZ) material. Here, we evaluate the application of an advanced solar cell process featuring a novel method of ion implantation on p-type quasi-mono silicon wafer. The ion implantation process has simplified the normal industrial process flow by eliminating two proc...

  10. Biofuels of the Future

    OpenAIRE

    Oxburgh, Ron

    2007-01-01

    There are good biofuels and bad biofuels. The good ones offer the prospect of transport fuels that have much lower environmental impact than fossil fuels and could before long be less expensive as well. Bad or irresponsibly produced biofuels may at best bring little environmental advantage; at worst they may also cause serious environmental damage, habitat destruction and food shortages. The biofuel industry of the future will make a significant contribution to the greening of the world’s veh...

  11. Scope of algae as third generation biofuels

    Directory of Open Access Journals (Sweden)

    Shuvashish eBehera

    2015-02-01

    Full Text Available An initiative has been taken to develop different solid, liquid and gaseous biofuels as the alternative energy resources. The current research and technology based on the third generation biofuels derived from algal biomass have been considered as the best alternative bioresource that avoids the disadvantages of first and second generation biofuels. Algal biomass have been investigated for the implementation of economic conversion processes producing different biofuels such as biodiesel, bioethanol, biogas, biohydrogen and other valuable co-products. In the present review, the recent findings and advance developments in algal biomass for improved biofuel production. This review discusses about the importance of the algal cell contents, various strategies for product formation through various conversion technologies, and its future scope as an energy security.

  12. Genome Wide assessment of Early Osseointegration in Implant-Adherent Cells

    Science.gov (United States)

    Thalji, Ghadeer N.

    Objectives: To determine the molecular processes involved in osseointegration. Materials and methods: A structured literature review concerning in vitro and in vivo molecular assessment of osseointegration was performed. A rat and a human model were then used to identify the early molecular processes involved in osseointegration associated with a micro roughened and nanosurface superimposed featured implants. In the rat model, 32 titanium implants with surface topographies exhibiting a micro roughened (AT-II) and nanosurface superimposed featured implants (AT-I) were placed in the tibiae of 8 rats and subsequently harvested at 2 and 4 days after placement. Whereas in the human model, four titanium mini-implants with either a moderately roughened surface (TiOblast) or super-imposed nanoscale topography (Osseospeed) were placed in edentulous sites of eleven systemically healthy subjects and subsequently removed after 3 and 7 days. Total RNA was isolated from cells adherent to retrieved implants. A whole genome microarray using the Affymetrix 1.1 ST Array platform was used to describe the gene expression profiles that were differentially regulated by the implant surfaces. Results: The literature review provided evidence that particular topographic cues can be specifically integrated among the many extracellular signals received by the cell in its signal transduction network. In the rat model, functionally relevant categories related to ossification, skeletal system development, osteoblast differentiation, bone development and biomineral tissue development were upregulated and more prominent at AT-I compared to AT-II. In the human model, there were no significant differences when comparing the two-implant surfaces at each time point. However, the microarray identified several genes that were differentially regulated at day 7 vs. day 3 for both implant surfaces. Functionally relevant categories related to the extracellular matrix, collagen fibril organization and

  13. Panorama 2007: Biofuels Worldwide

    International Nuclear Information System (INIS)

    The biofuels market is booming: after more than 20 years of industrial development, global bio-fuel production is growing fast. Willingness to reduce their oil dependence and necessity to promote low-carbon energies are the two main drivers for states to support biofuels development. (author)

  14. Biofuel production in Vietnam

    NARCIS (Netherlands)

    Thanh, le L.

    2016-01-01

    Biofuel production has continued to develop and is driven by government support around the world. A comprehensive analysis of biofuel production and the policy implementation is crucial for the biofuel sustainability development. The objective of this thesis is to study the energy efficiency, GHG em

  15. Use of low energy hydrogen ion implants in high efficiency crystalline silicon solar cells

    Science.gov (United States)

    Fonash, S. J.; Singh, R.

    1985-01-01

    This program is a study of the use of low energy hydrogen ion implantation for high efficiency crystalline silicon solar cells. The first quarterly report focuses on two tasks of this program: (1) an examination of the effects of low energy hydrogen implants on surface recombination speed; and (2) an examination of the effects of hydrogen on silicon regrowth and diffusion in silicon. The first part of the project focussed on the measurement of surface properties of hydrogen implanted silicon. Low energy hydrogen ions when bombarded on the silicon surface will create structural damage at the surface, deactivate dopants and introduce recombination centers. At the same time the electrically active centers such as dangling bonds will be passivated by these hydrogen ions. Thus hydrogen is expected to alter properties such as the surface recombination velocity, dopant profiles on the emitter, etc. In this report the surface recombination velocity of a hydrogen emplanted emitter was measured.

  16. REFUEL: an EU road map for biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Londo, M.; Deurwarder, E.; Lensink, S. (and others)

    2007-05-15

    A successful mid-term development of biofuels calls for a robust road map. REFUEL assesses inter alia least-cost biofuel chain options, their benefits, outlines the technological, legislative and other developments that should take place, and evaluate different policy strategies for realisation. Some preliminary conclusions of the project are discussed here. There is a significant domestic land potential for energy crops in the EU, which could supply between one quarter and one third of gasoline and diesel demand by 2030 if converted into advanced biofuels. A biomass supply of 8 to 10 EJ of primary energy could be available at costs around or below 3 EURO/GJ. However, the introduction of advanced biofuel options may meet a considerable introductory cost barrier, which will not be overcome when EU policy is oriented to the introduction of biofuels at least cost. Therefore, conventional biodiesel and ethanol may dominate the market for decades to come, unless biofuels incentives are differentiated, e.g. on the basis of the differences in greenhouse gas performance among biofuels.The introduction of advanced biofuels may also be enhanced by creating stepping stones or searching introduction synergies. A stepping stone can be the short-term development of lignocellulosic biomass supply chains for power generation by co-firing; synergies can be found between advanced FT-diesel production and hydrogen production for the fuel cell. (au)

  17. Squamous cell carcinoma in association with dental implants: an assessment of previously hypothesized carcinogenic mechanisms and a case report.

    Science.gov (United States)

    Bhatavadekar, Neel B

    2012-12-01

    Although dental implants have seen tremendous clinical success over the past few decades, there are some worrying reports in literature describing squamous cell carcinoma (SCC) in close association with dental implants. This article also provides a critical assessment of the published literature relating to the presence of carcinoma in association with dental implants, analyzing the previously published and hypothesized carcinogenic responses to an implant, to try and come to a conclusion regarding the plausibility and clinical risk for cancer formation in association with dental implants. An unusual case of an SCC noted in close proximity to a dental implant is also presented. A systematic search was conducted using Medline (PubMed), Cochrane Database, and Google Scholar with the search terms "cancer," "squamous cell carcinoma," "dental implant," "SCC," "peri-implantitis," "oral cancer," and "implantology" and using multiple combinations using Boolean operators "or" and "and." The search was not limited to dental literature; orthopedic and biomedical literature was also included. The results were then hand screened to pick out the relevant articles. In total, 14 previous published reports were found, where 24 dental implants were reported to be associated with SCC. Not all the reported patients had a history of cancer, but contributory factors such as smoking were found. An analysis of the biological plausibility of previously proposed carcinogenic mechanisms, such as corrosion, metallic ion release, and particulate debris, did not support the etiologic role for dental implants in cancer development, and the standardized incidence ratio was found to be extremely low (0.00017). Peri-implantitis should be assessed cautiously in patients receiving implants who have a previous history of cancer. Dental implants are a safe treatment modality based on the published data, and any change in surgical protocol is not mandated. PMID:21574824

  18. Biofuels, poverty, and growth

    DEFF Research Database (Denmark)

    Arndt, Channing; Benfica, Rui; Tarp, Finn;

    2010-01-01

    This paper assesses the implications of large-scale investments in biofuels for growth and income distribution. We find that biofuels investment enhances growth and poverty reduction despite some displacement of food crops by biofuels. Overall, the biofuel investment trajectory analyzed increases...... Mozambique's annual economic growth by 0.6 percentage points and reduces the incidence of poverty by about 6 percentage points over a 12-year phase-in period. Benefits depend on production technology. An outgrower approach to producing biofuels is more pro-poor, due to the greater use of unskilled labor and...

  19. Porous Co3O4 hollow nanododecahedra for nonenzymatic glucose biosensor and biofuel cell.

    Science.gov (United States)

    Zhang, Erhuan; Xie, Yu; Ci, Suqin; Jia, Jingchun; Wen, Zhenhai

    2016-07-15

    Cobalt oxide hollow nanododecahedra (Co3O4-HND) is synthesized by a facile thermal transformation of cobalt-based metal-organic framework (Co-MOF, ZIF-67) template. The morphology and properties of the Co3O4-HND are characterized by a set of techniques, including transmission electron microscope (TEM), powder X-ray diffraction (XRD), scanning electron microscope (SEM) and Brunner-Emmet-Teller (BET). When tested as a non-enzymatic electrocatalyst for glucose oxidation reaction, the Co3O4-HND exhibits a high activity and shows an outstanding performance for determining glucose with a wide window of 2.0μM to 6.06mM, a high sensitivity of 708.4μAmM(-1)cm(-2), a low detection limit of 0.58μM (S/N=3), and fast response time(glucose, Co3O4-HND could be served as an attractive non-enzyme and noble-metal-free electrocatalyst in glucose fuel cell (GFC) due to its excellent electrochemical properties, low cost and facile preparation. PMID:26918617

  20. Co-delivery of siRNA and doxorubicin to cancer cells from additively manufactured implants

    DEFF Research Database (Denmark)

    Chen, Muwan; Andersen, Morten Østergaard; Dillschneider, Philipp;

    2015-01-01

    , capable of physically supporting the void while killing residual cancer cells, would be an attractive solution. Here we describe a novel additively manufactured implant that can be functionalized with chitosan/siRNA nanoparticles. These induce long term gene silencing in adjacent cancer cells without...... showing toxicity to normal cells. When scaffolds are functionalized with siRNA/chitosan nanoparticles and doxorubicin in combination, their effects synergized leading to cancer cell death. This technology may be used to target resistance genes by RNA interference and thereby re-sensitizing the cancer...

  1. BioMEMS for medicine: On-chip cell characterization and implantable microelectrodes

    Science.gov (United States)

    Cheung, Karen C.; Renaud, Philippe

    2006-04-01

    This paper surveys a few of the emerging bioMEMS technologies at EPFL for improved, inexpensive health care. The lab-on-a-chip systems use dielectrophoretic forces to direct cell movement within microfluidic networks and impedance spectroscopy for label-free in-flow characterization of living cells. The implantable microelectrodes for neural applications are based on thin-film polymer foils with embedded microelectrodes for both recording and stimulation. Applications for these biomedical microdevices will include stem cell research, cancer cell characterization, drug discovery, treatments for neurological disorders, and neuroprosthetic devices.

  2. Mga is essential for the survival of pluripotent cells during peri-implantation development

    OpenAIRE

    Washkowitz, Andrew J.; Schall, Caroline; Zhang, Kun; Wurst, Wolfgang; FLOSS, Thomas; Mager, Jesse; Papaioannou, Virginia E

    2015-01-01

    The maintenance and control of pluripotency is of great interest in stem cell biology. The dual specificity T-box/basic-helix-loop-helix-zipper transcription factor Mga is expressed in the pluripotent cells of the inner cell mass (ICM) and epiblast of the peri-implantation mouse embryo, but its function has not been investigated previously. Here, we use a loss-of-function allele and RNA knockdown to demonstrate that Mga depletion leads to the death of proliferating pluripotent ICM cells in vi...

  3. Optimisation of p+ doping level of n+-p-p+ bifacial b.s.f. solar cells by ion implantation

    International Nuclear Information System (INIS)

    High-low junctions of n+-p-p+ bifacial back surface field solar cells have been fabricated by B11+ implantation. After an isothermal annealing step at 9000C for 10 min, an optimum surface concentration of 5x1019cm-3 is observed. Its origin is found to lie in the partial electrical activation of the implanted impurities. (author)

  4. Decoding the chemokine network that links leukocytes with decidual cells and the trophoblast during early implantation.

    Science.gov (United States)

    Ramhorst, Rosanna; Grasso, Esteban; Paparini, Daniel; Hauk, Vanesa; Gallino, Lucila; Calo, Guillermina; Vota, Daiana; Pérez Leirós, Claudia

    2016-03-01

    Chemokine network is central to the innate and adaptive immunity and entails a variety of proteins and membrane receptors that control physiological processes such as wound healing, angiogenesis, embryo growth and development. During early pregnancy, the chemokine network coordinates not only the recruitment of different leukocyte populations to generate the maternal-placental interface, but also constitutes an additional checkpoint for tissue homeostasis maintenance. The normal switch from a pro-inflammatory to an anti-inflammatory predominant microenvironment characteristic of the post-implantation stage requires redundant immune tolerance circuits triggered by key master regulators. In this review we will focus on the recruitment and conditioning of maternal immune cells to the uterus at the early implantation period with special interest on high plasticity macrophages and dendritic cells and their ability to induce regulatory T cells. We will also point to putative immunomodulatory polypeptides involved in immune homeostasis maintenance at the maternal-placental interface. PMID:26891097

  5. Hierarchical micro/nanostructured titanium with balanced actions to bacterial and mammalian cells for dental implants

    Directory of Open Access Journals (Sweden)

    Zhu Y

    2015-10-01

    Full Text Available Yu Zhu,1,* Huiliang Cao,2,* Shichong Qiao,1,* Manle Wang,2,3 Yingxin Gu,1 Huiwen Luo,1 Fanhao Meng,2 Xuanyong Liu,2 Hongchang Lai1 1Department of Oral and Maxillofacial Implantology, Shanghai Key Laboratory of Stomatology, Shanghai Ninth People’s Hospital, School of Medicine, Shanghai Jiao Tong University, 2State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 3School of Materials Engineering, Shanghai University of Engineering Science, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: A versatile strategy to endow dental implants with long-term antibacterial ability without compromising the cytocompatibility is highly desirable to combat implant-related infection. Silver nanoparticles (Ag NPs have been utilized as a highly effective and broad-spectrum antibacterial agent for surface modification of biomedical devices. However, the high mobility and subsequent hazardous effects of the particles on mammalian cells may limit its practical applications. Thus, Ag NPs were immobilized on the surface of sand-blasted, large grit, and acid-etched (SLA titanium by manipulating the atomic-scale heating effect of silver plasma immersion ion implantation. The silver plasma immersion ion implantation-treated SLA surface gave rise to both good antibacterial activity and excellent compatibility with mammalian cells. The antibacterial activity rendered by the immobilized Ag NPs was assessed using Fusobacterium nucleatum and Staphylococcus aureus, commonly suspected pathogens for peri-implant disease. The immobilized Ag NPs offered a good defense against multiple cycles of bacteria attack in both F. nucleatum and S. aureus, and the mechanism was independent of silver release. F. nucleatum showed a higher susceptibility to Ag NPs than S. aureus, which might be explained by the presence of different wall structures. Moreover, the

  6. Comparison of biological characteristics of mesenchymal stem cells grown on two different titanium implant surfaces

    International Nuclear Information System (INIS)

    This study examined the biological characteristics of mesenchymal stem cells (MSCs) grown on sand-blasted, large-grit, acid-etched (SLA) surface and hydroxyapatite (HA) coating on the SLA (HA/SLA) surface of titanium dental implants. The HA/SLA surfaces of titanium dental implants were formed by the ion beam assisted deposition (IBAD) method. Rabbit bone marrow derived mesenchymal stem cells cultured in vitro were seeded onto the surface of SLA and HA/SLA; the growth states of MSCs on the two samples were observed by a scanning electron microscope; the proliferation index, alkaline phosphatase (ALP) activity, osteocalcin (OCN) content of MSCs and mRNA relative expression level of osteopontin (opn) were compared between two groups. MSCs were found to be easier to adhere to the HA/SLA surface compared to the SLA surface. At the same time, the ALP activity and the OCN content of MSCs grown on the HA/SLA surface were obviously higher, and the relative expression level of opn mRNA was 4.78 times higher than that on the SLA surface. The HA coating formed by the IBAD method on the SLA surface of titanium dental implants significantly improves proliferation and well-differentiated osteoblastic phenotype of MSCs, which indicates a promising method for the surface modification of titanium dental implants

  7. Real-time in vivo monitoring of viable stem cells implanted on biocompatible scaffolds

    International Nuclear Information System (INIS)

    Three-dimensional fibrous scaffolds provide an environment that enhances transplanted stem cell survival in vivo and facilitates imaging their localization, viability, and growth in vivo. To assess transplanted stem cell viability on biocompatible polymer scaffolds in vivo, we developed in vivo imaging systems for evaluation of implanted viable neural stem cells (NSC) and mesenchymal stem cells (MSC) on scaffolds using luciferase or sodium/iodide symporter (NIS) genes. Firefly luciferase stably expressing-C6 cell was established (C6-Fluc). The human neural stem cell, F3, was infected with adenoviral vector carrying luciferase gene (F3-Fluc) and MSC expressing NIS controlled by ubiquitin C promoter using lentiviral vector was established by treating blasticidine for 2 weeks (MSC-NIS). Chitosan and poly l-lactic acid (PLLA) scaffolds were used for in vivo image. In vivo expression of luciferase and human NIS was examined by bioluminescence image or 99mTc-pertechnetate gamma camera image, respectively. The cell/scaffold complex was implanted into subcutaneous or abdominal area of BALB/C nude mouse. For quantitative evaluation of cell viability, regions of interest were drawn on 99mTc-pertechnetate scintigraphy by manual. The gradual increase of luciferase activity was observed in C6-Fluc seeded with chitosan according to the increase in the number of cells. C6-Fluc/chitosan complex subcutaneously implanted into nude mice showed longitudinal bioluminescence image until 34 days. Luciferase image of abdominal-injected C6-Fluc/PLLA complex was saturated in only 14 days, showing great cell growth due to abundant nutrients. F3 cells showed well-incorporated pattern with fibrous chitosan scaffold using scanning electron microscopy. F3 infected with Ad-Fluc showed >100-fold higher luciferase activity than luciferase activity in F3. Cell-number-dependent increase of luciferase activity was shown in F3-Fluc seeded on chitosan. F3-Fluc incorporation into chitosan after abdominal

  8. Engineering microbes for tolerance to next-generation biofuels

    Directory of Open Access Journals (Sweden)

    Dunlop Mary J

    2011-09-01

    Full Text Available Abstract A major challenge when using microorganisms to produce bulk chemicals such as biofuels is that the production targets are often toxic to cells. Many biofuels are known to reduce cell viability through damage to the cell membrane and interference with essential physiological processes. Therefore, cells must trade off biofuel production and survival, reducing potential yields. Recently, there have been several efforts towards engineering strains for biofuel tolerance. Promising methods include engineering biofuel export systems, heat shock proteins, membrane modifications, more general stress responses, and approaches that integrate multiple tolerance strategies. In addition, in situ recovery methods and media supplements can help to ease the burden of end-product toxicity and may be used in combination with genetic approaches. Recent advances in systems and synthetic biology provide a framework for tolerance engineering. This review highlights recent targeted approaches towards improving microbial tolerance to next-generation biofuels with a particular emphasis on strategies that will improve production.

  9. Irradiation effect of carbon negative-ion implantation on polytetrafluoroethylene for controlling cell-adhesion property

    Science.gov (United States)

    Sommani, Piyanuch; Tsuji, Hiroshi; Kojima, Hiroyuki; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo; Takaoka, Gikan H.

    2010-10-01

    We have investigated the irradiation effect of negative-ion implantation on the changes of physical surface property of polytetrafluoroethylene (PTFE) for controlling the adhesion property of stem cells. Carbon negative ions were implanted into PTFE sheets at fluences of 1 × 10 14-1 × 10 16 ions/cm 2 and energies of 5-20 keV. Wettability and atomic bonding state including the ion-induced functional groups on the modified surfaces were investigated by water contact angle measurement and XPS analysis, respectively. An initial value of water contact angles on PTFE decreased from 104° to 88° with an increase in ion influence to 1 × 10 16 ions/cm 2, corresponding to the peak shifting of XPS C1s spectra from 292.5 eV to 285 eV with long tail on the left peak-side. The change of peak position was due to decrease of C-F 2 bonds and increase of C-C bonds with the formation of hydrophilic oxygen functional groups of OH and C dbnd O bonds after the ion implantation. After culturing rat mesenchymal stem cells (MSC) for 4 days, the cell-adhesion properties on the C --patterned PTFE were observed by fluorescent microscopy with staining the cell nuclei and their actin filament (F-actin). The clear adhesion patterning of MSCs on the PTFE was obtained at energies of 5-10 keV and a fluence of 1 × 10 15 ions/cm 2. While the sparse patterns and the uncontrollable patterns were found at a low fluence of 3 × 10 14 ions/cm 2 and a high fluence of 3 × 10 15 ions/cm 2, respectively. As a result, we could improve the surface wettability of PTFE to control the cell-adhesion property by carbon negative-ion implantation.

  10. Biofuels Baseline 2008

    Energy Technology Data Exchange (ETDEWEB)

    Hamelinck, C.; Koper, M.; Berndes, G.; Englund, O.; Diaz-Chavez, R.; Kunen, E.; Walden, D.

    2011-10-15

    The European Union is promoting the use of biofuels and other renewable energy in transport. In April 2009, the Renewable Energy Directive (2009/28/EC) was adopted that set a 10% target for renewable energy in transport in 2020. The directive sets several requirements to the sustainability of biofuels marketed in the frame of the Directive. The Commission is required to report to the European Parliament on a regular basis on a range of sustainability impacts resulting from the use of biofuels in the EU. This report serves as a baseline of information for regular monitoring on the impacts of the Directive. Chapter 2 discusses the EU biofuels market, the production and consumption of biofuels and international trade. It is derived where the feedstock for EU consumed biofuels originally come from. Chapter 3 discusses the biofuel policy framework in the EU and major third countries of supply. It looks at various policy aspects that are relevant to comply with the EU sustainability requirements. Chapter 4 discusses the environmental and social sustainability aspects associated with EU biofuels and their feedstock. Chapter 5 discusses the macro-economic effects that indirectly result from increased EU biofuels consumption, on commodity prices and land use. Chapter 6 presents country factsheets for main third countries that supplied biofuels to the EU market in 2008.

  11. Limits to biofuels

    Science.gov (United States)

    Johansson, S.

    2013-06-01

    Biofuel production is dependent upon agriculture and forestry systems, and the expectations of future biofuel potential are high. A study of the global food production and biofuel production from edible crops implies that biofuel produced from edible parts of crops lead to a global deficit of food. This is rather well known, which is why there is a strong urge to develop biofuel systems that make use of residues or products from forest to eliminate competition with food production. However, biofuel from agro-residues still depend upon the crop production system, and there are many parameters to deal with in order to investigate the sustainability of biofuel production. There is a theoretical limit to how much biofuel can be achieved globally from agro-residues and this amounts to approximately one third of todays' use of fossil fuels in the transport sector. In reality this theoretical potential may be eliminated by the energy use in the biomass-conversion technologies and production systems, depending on what type of assessment method is used. By surveying existing studies on biofuel conversion the theoretical limit of biofuels from 2010 years' agricultural production was found to be either non-existent due to energy consumption in the conversion process, or up to 2-6000TWh (biogas from residues and waste and ethanol from woody biomass) in the more optimistic cases.

  12. Limits to biofuels

    Directory of Open Access Journals (Sweden)

    Johansson S.

    2013-06-01

    Full Text Available Biofuel production is dependent upon agriculture and forestry systems, and the expectations of future biofuel potential are high. A study of the global food production and biofuel production from edible crops implies that biofuel produced from edible parts of crops lead to a global deficit of food. This is rather well known, which is why there is a strong urge to develop biofuel systems that make use of residues or products from forest to eliminate competition with food production. However, biofuel from agro-residues still depend upon the crop production system, and there are many parameters to deal with in order to investigate the sustainability of biofuel production. There is a theoretical limit to how much biofuel can be achieved globally from agro-residues and this amounts to approximately one third of todays’ use of fossil fuels in the transport sector. In reality this theoretical potential may be eliminated by the energy use in the biomass-conversion technologies and production systems, depending on what type of assessment method is used. By surveying existing studies on biofuel conversion the theoretical limit of biofuels from 2010 years’ agricultural production was found to be either non-existent due to energy consumption in the conversion process, or up to 2–6000TWh (biogas from residues and waste and ethanol from woody biomass in the more optimistic cases.

  13. A two-dimensional DNA lattice implanted polymer solar cell

    International Nuclear Information System (INIS)

    A double crossover tile based artificial two-dimensional (2D) DNA lattice was fabricated and the dry-wet method was introduced to recover an original DNA lattice structure in order to deposit DNA lattices safely on the organic layer without damaging the layer. The DNA lattice was then employed as an electron blocking layer in a polymer solar cell causing an increase of about 10% up to 160% in the power conversion efficiency. Consequently, the resulting solar cell which had an artificial 2D DNA blocking layer showed a significant enhancement in power conversion efficiency compared to conventional polymer solar cells. It should be clear that the artificial DNA nanostructure holds unique physical properties that are extremely attractive for various energy-related and photonic applications.

  14. Antigen presenting cells costimulatory signaling during pre-implantation pregnancy 

    Directory of Open Access Journals (Sweden)

    Anna Sławek

    2012-09-01

    Full Text Available  Success of pregnancy depends on many factors. Three phenomena inducing immune tolerance against semi-allogeneic conceptus may play a crucial role in the pre-implantation period of pregnancy: influence of sex hormones in sex cycle, presence of oocyte or embryo and the presence of semen in the female reproductive tract. On the other hand dendritic cells are the most effective antigen-presenting cells in regulation of immune phenomena and also are considered as potent participants in inducing immune tolerance in the pregnancy. They communicate with T cells in cell contact-dependent manner or via cytokines. During cell-cell contacts, costimulatory molecules play a key role and their expression is often dependent on cytokines milieu. Both costimulatory molecules and cytokines influence generation of T regulatory cells. Interactions of these molecules are closely related. In this paper we would like to pay attention to the importance of antigen presenting cells costimulatory potency in immune regulation during a pre-implantation period of pregnancy.

  15. Inhibition of subcutaneously implanted human pituitary tumor cells in nude mice by LRIG1.

    Science.gov (United States)

    Wang, X; He, X J; Xu, H Q; Chen, Z W; Fan, H H

    2016-01-01

    The aim of this study was to explore the inhibition of subcutaneously implanted human pituitary tumor cells in nude mice by LRIG1 and its mechanism. For this study, athymic nude mice were injected with either normal pituitary tumor RC-4B/C cells or LRIG1-transfected RC-4B/C cells. We then calculated the volume inhibition rate of the tumors, as well as the apoptosis index of tumor cells and the expression of Ras, Raf, AKt, and ERK mRNA in tumor cells. Tumor cell morphological and structural changes were also observed under electron microscope. Our data showed that subcutaneous tumor growth was slowed or even halted in LRIG1-transfected tumors. The tumor volumes were significantly different between the two groups of mice (χ2 = 2.14, P tumor apoptosis index was found to be 8.72% in the control group and 39.7% in LRIG1-transfected mice (χ2 = 7.59, P tumor cells appeared to be in early or late apoptosis under an electron microscope, while only a few subcutaneous tumor cells appeared to be undergoing apoptosis in the control group. In conclusion, the LRIG1 gene is able to inhibit proliferation and promote apoptosis in subcutaneously implanted human pituitary tumors in nude mice. The mechanism of LRIG1 may involve the inhibition of the PI3K/ Akt and Ras/Raf/ERK signal transduction pathways. PMID:27173312

  16. Layer-by-layer self-assembled osmium polymer-mediated laccase oxygen cathodes for biofuel cells: the role of hydrogen peroxide.

    Science.gov (United States)

    Scodeller, Pablo; Carballo, Romina; Szamocki, Rafael; Levin, Laura; Forchiassin, Flavia; Calvo, Ernesto J

    2010-08-18

    High potential purified Trametes trogii laccase has been studied as a biocatalyst for oxygen cathodes composed of layer-by-layer self-assembled thin films by sequential immersion of mercaptopropane sulfonate-modified Au electrode surfaces in solutions containing laccase and osmium-complex bound to poly(allylamine), (PAH-Os). The polycation backbone carries the Os redox relay, and the polyanion is the enzyme adsorbed from a solution of a suitable pH so that the protein carries a net negative charge. Enzyme thin films were characterized by quartz crystal microbalance, ellipsometry, cyclic voltammetry, and oxygen reduction electrocatalysis under variable oxygen partial pressures with a rotating disk electrode. New kinetic evidence relevant to biofuel cells is presented on the detection of traces of H(2)O(2), intermediate in the O(2) reduction, with scanning electrochemical microscopy (SECM). Furthermore the inhibitory effect of peroxide on the biocatalytic current resulted in abnormal current dependence on the O(2) partial pressure and peak shape with hysteresis in the polarization curves under stagnant conditions, which is offset upon stirring with the RDE. The new kinetic evidence reported in the present work is very relevant for the operation of biofuel cells under stagnant conditions of O(2) mass transport. PMID:20698679

  17. Bone Marrow Derived Adult Stem Cell Implantation: A Possible Permanent Treatment Modality for Type 2 Diabetics

    OpenAIRE

    R.S. KAHLON; M.K. Manchanda; P. KANWAL

    2011-01-01

    Introduction: Diabetes is one of the most prevalent chronic disease that exists in the world. Type 2Diabetes is the predominant type of diabetes. Management is basically limited to exercise, diet and oralhypoglycemic drugs before insulin therapy has to be instituted. But bone marrow derived stem cellimplantation into the islets has shown very encouraging results for diabetics.Methods: Bone marrow derived stem cells when implanted in the pancreas leads to regeneration ofinsulin producing Beta ...

  18. Pyogenic Granuloma/Peripheral Giant-Cell Granuloma Associated with Implants

    Science.gov (United States)

    Jané-Salas, Enric; Albuquerque, Rui; Font-Muñoz, Aura; González-Navarro, Beatríz; Estrugo Devesa, Albert; López-López, Jose

    2015-01-01

    Introduction. Pyogenic granuloma (PG) and peripheral giant-cell granuloma (PGCG) are two of the most common inflammatory lesions associated with implants; however, there is no established pathway for treatment of these conditions. This paper aims to illustrate the successful treatment of PG and PGCG and also report a systematic review of the literature regarding the various treatments proposed. Methods. To collect relevant information about previous treatments for PG and PGCG involving implants we carried out electronic searches of publications with the key words “granuloma”, “oral”, and “implants” from the last 15 years on the databases Pubmed, National Library of Medicine's Medline, Scielo, Scopus, and Cochrane Library. Results. From the electronic search 16 case reports were found showing excision and curettage as the main successful treatment. As no clinical trials or observational studies were identified the authors agreed to present results from a review perspective. Conclusion. This is the largest analysis of PG and PGCG associated with implants published to date. Our review would suggest that PGCG associated with implants appears to have a more aggressive nature; however the level of evidence is very limited. Further cohort studies with representative sample sizes and standard outcome measures are necessary for better understanding of these conditions. PMID:26697068

  19. Analysis of nitrogen implanted tin oxide films used in dye-sensitised solar cells

    International Nuclear Information System (INIS)

    Full text: Tin oxide film was implanted with N+ at energy between 10 to 40 keV and ion dose 1014 -1016 cm-2. The microstructure of the tin oxide film was modified by the ion implantation giving a film of amorphous property as analysed using Transmission Electron Microscopy. The thickness of the implanted films was found to increase with increasing ion energy and these agree well with theoretical calculations. The distribution and amount of nitrogen in the film were investigated using Secondary Ion Mass Spectroscopy (SIMS) and Photoelectron Spectroscopy (XPS) depth profiling. From the depth profile the distribution of nitrogen in the tin oxide film varied depending on the applied energy as was obtained from theoretical calculations. The concentration of nitrogen was found to increase with increasing ion dose and energy but the relative amount of nitrogen compared to tin decreased with increasing depth of the film. The amount of nitrogen for the highest ion dose and ion energy was quantified to be about 5 at%. From pervious analysis the electrical and optical properties of the nitrogen implanted tin oxide film was found to decrease with increasing ion dose and energy. The objective is to determine whether this modified film can reduce heterojunction effects at the interface between the titania layer and the tin oxide layer in order to improve the performance of dye-sensitised solar cells

  20. Changes of the intestinal endocrine cells in the C57BL/6 mouse after implantation of murine lung carcinoma (3LL): An immunohistochemical quantitative study

    Institute of Scientific and Technical Information of China (English)

    Sae-Kwang Ku; Seung-Kyoo Seong; Dae-Young Kim; Hyeung-Sik Lee; Jong-Dae Kim; Hae-Yun Choi; Bu-Il Seo; Jae-Hyun Lee

    2005-01-01

    AIM: To study the distributions and frequencies of intestinal endocrine cells in the C57BL/6 mouse with immunohistochemical method using seven types of specific antisera against chromogranin A (CGA), serotonin,somatostatin, glucagons, gastrin, cholecystokinin (CCK)-8 and human pancreatic polypeptide (hPP) after abdominal subcutaneous implantation of murine lung carcinoma (3LL).METHODS: The experimental animals were divided into two groups, one is non-implanted Sham and the other is 3LL-implanted group. Samples were collected from six regions of intestinal tract at 28th d after implantation of 3LL cells (1×105 cell/mouse).RESULTS: In this study, five types of immunoreactive (IR) cells were identified except for gastrin and hPP. The regional distributions of the intestinal endocrine cells in the 3LL-implanted group were similar to those of the non-implanted Sham. However, significant decreases of IR cells were detected in 3LL-implanted group compared to those of non-implanted Sham. CGA- and serotonin-IR cells significantly decreased in 3LL-implanted groups compared to that of non-implanted Sham. Somatostatin-IR cells in the jejunum and ileum and CCK-8-IR cells in the jejunum of 3LL-implanted groups significantly decreased compared to that of non-implanted Sham. In addition,glucagon-IR cells were restricted to the ileum and colon of non-implanted Sham.CONCLUSION: Implantation of tumor cell mass (3LL)induced severe quantifiable changes of intestinal endocrine cell density and the abnormality in density of intestinal endocrine cells may contribute to the development of gastrointestinal symptoms such as anorexia and indigestion, frequently encountered in patients with cancer.

  1. Identification, Characterization, and Expression Analysis of Cell Wall Related Genes in Sorghum bicolor (L.) Moench, a Food, Fodder, and Biofuel Crop

    Science.gov (United States)

    Rai, Krishan M.; Thu, Sandi W.; Balasubramanian, Vimal K.; Cobos, Christopher J.; Disasa, Tesfaye; Mendu, Venugopal

    2016-01-01

    Biomass based alternative fuels offer a solution to the world's ever-increasing energy demand. With the ability to produce high biomass in marginal lands with low inputs, sorghum has a great potential to meet second-generation biofuel needs. Despite the sorghum crop importance in biofuel and fodder industry, there is no comprehensive information available on the cell wall related genes and gene families (biosynthetic and modification). It is important to identify the cell wall related genes to understand the cell wall biosynthetic process as well as to facilitate biomass manipulation. Genome-wide analysis using gene family specific Hidden Markov Model of conserved domains identified 520 genes distributed among 20 gene families related to biosynthesis/modification of various cell wall polymers such as cellulose, hemicellulose, pectin, and lignin. Chromosomal localization analysis of these genes revealed that about 65% of cell wall related genes were confined to four chromosomes (Chr. 1–4). Further, 56 tandem duplication events involving 169 genes were identified in these gene families which could be associated with expansion of genes within families in sorghum. Additionally, we also identified 137 Simple Sequence Repeats related to 112 genes and target sites for 10 miRNAs in some important families such as cellulose synthase, cellulose synthase-like, and laccases, etc. To gain further insight into potential functional roles, expression analysis of these gene families was performed using publically available data sets in various tissues and under abiotic stress conditions. Expression analysis showed tissue specificity as well as differential expression under abiotic stress conditions. Overall, our study provides a comprehensive information on cell wall related genes families in sorghum which offers a valuable resource to develop strategies for altering biomass composition by plant breeding and genetic engineering approaches.

  2. Hydrogel limits stem cell dispersal in the deaf cochlea: implications for cochlear implants

    Science.gov (United States)

    Nayagam, Bryony A.; Backhouse, Steven S.; Cimenkaya, Cengiz; Shepherd, Robert K.

    2012-12-01

    Auditory neurons provide the critical link between a cochlear implant and the brain in deaf individuals, therefore their preservation and/or regeneration is important for optimal performance of this neural prosthesis. In cases where auditory neurons are significantly depleted, stem cells (SCs) may be used to replace the lost population of neurons, thereby re-establishing the critical link between the periphery (implant) and the brain. For such a therapy to be therapeutically viable, SCs must be differentiated into neurons, retained at their delivery site and damage caused to the residual auditory neurons minimized. Here we describe the transplantation of SC-derived neurons into the deaf cochlea, using a peptide hydrogel to limit their dispersal. The described approach illustrates that SCs can be delivered to and are retained within the basal turn of the cochlea, without a significant loss of endogenous auditory neurons. In addition, the tissue response elicited from this surgical approach was restricted to the surgical site and did not extend beyond the cochlear basal turn. Overall, this approach illustrates the feasibility of targeted cell delivery into the mammalian cochlea using hydrogel, which may be useful for future cell-based transplantation strategies, for combined treatment with a cochlear implant to restore function.

  3. Search for Chemically Defined Culture Medium to Assist Initial Regeneration of Diseased Renal Parenchyma After Stem/Progenitor Cell Implantation

    OpenAIRE

    Minuth WW; Denk L; Gruber M

    2013-01-01

    Before an intended implantation stem/progenitor cells are usually kept in the beneficial atmosphere of a selected culture medium. However, after implantation the situation is drastically changing for them. Yet stem/progenitor cells must stand the harmful fluid environment within a diseased organ. In this coherence it is unknown, to which degree alterations in molecular composition of interstitial fluid can influence the initial regeneration of parenchyma. To obtain first ins...

  4. Combining 3-dimensional degradable electrostatic spinning scaffold and dental follicle cells to build peri-implant periodontium

    Directory of Open Access Journals (Sweden)

    Ximu Zhang

    2013-01-01

    Full Text Available Introduction: Some inevitable problems, such as concentrated bite force and lacked ability of self-renewal, are proved to be the major challenge in the management of implants failures. Thus, it is meaningful to find an ideal dental implant harboring its own peri-implant periodontium, just as the natural teeth. Various studies attempted to reconstruct the periodontium around implants, but unfortunately, it was previously revealed that the artificial periodotium around implants was just a wilderness of fibers, while without the physiological function of natural periodontium, like sensory and homeostatic. The Hypothesis: In this paper, we propose a hypothesis that a modified three-dimensional scaffold with reconstructed peri-implant tissues can be a network for stem cells differentiation. After seeded on the scaffold, stem cells produce various growth factors and differentiate to different orientations in places necessary. This hypothesis, if proven to be valid, will offer a novel and effective therapy for the restoration of missing teeth by implant. Evaluation of the Hypothesis: The scaffold involves three different tissues. Though degradation rate of electrospinning scaffold is under control, its degradation rate should be in consistent with the generation of three tissues. Therefore, the relative experiments are necessary to define the best rate of degradation. Further verification is necessary to check whether the rebuilt cementum, bone and periodontium are strong enough to keep the implant stable and maintain its function.

  5. Electrochemical behavior and biological response of Mesenchymal Stem Cells on cp-Ti after N-ions implantation

    International Nuclear Information System (INIS)

    Highlights: • Nitrogen ions of known dosage were implanted on cp-Ti. • Increase in surface roughness with increase in ions dose was confirmed by AFM. • TiN0.3 and Ti3N2−x nitride phases were formed and validated by XRD. • The ions implantation reduced the corrosion rate and stabilized the passive film. • Surface roughness greatly affected the morphology and growth of Mesenchymal Stem Cells. - Abstract: Titanium and its alloys are most widely used as implant materials due to their excellent biocompatibility, mechanical properties and chemical stability. In this study Nitrogen ions of known dosage were implanted over cp-Ti by Pelletron accelerator with beam energy of 0.25 MeV.The atomic force microscopy of bare and nitrogen implanted specimens confirmed increase in surface roughness with increase in nitrogen ions concentration. X-ray diffraction patterns of ions implanted surfaces validated the formation of TiN0.3 and Ti3N2-xnitride phases. The tendency to form passive film and electrochemical behavior of these surfaces in ringer lactate (RL) solution was evaluated by Potentiodynamic polarization and electrochemical impedance spectroscopy respectively. It is proved that nitrogen ions implantation was beneficial to reduce corrosion rate and stabilizing passive film by increasing charge transfer resistance in RL. It was concluded that morphology and proliferation of Mesenchymal Stem Cells on nitrogen ions implanted surfaces strongly depends on surface roughness and nitride phases

  6. Bone marrow mesenchymal stem cells differentiation and proliferation on the surface of coral implant

    International Nuclear Information System (INIS)

    This study was designed to evaluate the ability of natural coral implant to provide an environment for marrow cells to differentiate into osteoblasts and function suitable for mineralized tissue formation. DNA content, alkaline phosptatase (ALP) activity, calcium (Ca) content and mineralized nodules, were measured at day 3, day 7 and day 14, in rat bone marrow stromal cells cultured with coral discs glass discs, while cells alone and coral disc alone cultured as control. DNA content, ALP activity, Ca content measurements showed no difference between coral, glass and cells groups at 3 day which were higher than control (coral disc alone), but there were higher asurement at day 7 and 14 in the cell cultured on coral than on glass discs, control cells and control coral discs. Mineralized nodules formation (both in area and number) was more predominant on the coral surface than in control groups. These results showed that natural coral implant provided excellent and favorable situation for marrow cell to differentiate to osteoblasts, lead to large amount of mineralized tissue formation on coral surface. This in vitro result could explain the rapid bone bonding of coral in vivo. (Author)

  7. Surface-induced modulation of human mesenchymal progenitor cells. An in vitro model for early implant integration.

    Science.gov (United States)

    Baschong, Werner; Jaquiery, Claude; Martin, Ivan; Lambrecht, Thomas J

    2007-01-01

    Clinical experience indicates that the surface architecture of dental implants has an important impact on their integration. This has been related to the finding that differentially treated substrates can modulate the expression of osteogenic markers in various bone-related cell lines and primary cells. Here, we investigated the influence of surface architecture on the differentiation of human mesenchymal progenitor cells (HMPC) from adult bone marrow, i. e. the cells likely involved in initial bone synthesis at the bone-implant interface. Cells were seeded on machine surfaced (MS) or sandblasted/acid etched (SE) titanium discs in agarose-coated dishes, and on polystyrene (PS) controls. On all substrates cell densities did not change between days 7 and 14. Cell numbers were higher on SE, likely due to increased attachment to the rougher material. Alkaline phosphatase activity (ALP) was similar on all substrates, whereas mRNA expression of bone sialoprotein (BSP) at day 14 was about tenfold higher on SE (p < 0.05%). The SE-related increase of BSP in progenitor cells indicates an earlier differentiation of immigrated cells and could thus explain earlier implant integration and shorter time to functional loading observed in the clinic. The in vitro model and BSP quantification could be used to screen for changes in osteogenic cell differentiation induced by specific implant surfaces, with potential relevance on the prediction of bone-implant integration. PMID:17966928

  8. Biomass, biogas and biofuels

    International Nuclear Information System (INIS)

    This article reviews the different ways to produce biofuels. It appears that there are 3 generations of biofuels. The first generation was based on the use of the energetic reserves of the plants for instance sugar from beetroot or starch from cereals or oil from oleaginous plants. The second generation is based on a more complete use of the plant, the main constituents of the plant: cellulose and lignin are turned into energy. The third generation of biofuels relies on the use of energy plants and algae. The second generation of biofuels reduces drastically the competition between an alimentary use and a non-alimentary use of plants. In 2008 the production of biofuels reached 43 Mtep which represents only 2% of all the energy used in the transport sector. The international agency for energy expects that the production of biofuels would be multiplied by a factor 6 (even 10 if inciting measures are taken) by 2030. (A.C.)

  9. Biofuel goes underground

    Energy Technology Data Exchange (ETDEWEB)

    Tollinsky, Norm

    2011-09-15

    Kirkland Lake Gold, a gold producer, is switching to a blend of biofuel to power the mine's underground equipment. Kirkland Lake Gold is using a soy-based product which has several advantages: less expensive: for example, the soybean-based biofuel used by Kirkland Lake Gold is 10 cents a liter less expensive than diesel; cleaner: biofuel can reduce emissions by up to 80 per cent compared to conventional diesel; and safer: biofuel is safer than miner's diesel because it has a much higher flash point. Testing with soybean-based biofuel began in the early 90s but its price was too high at that time. The federal government's regulation of renewable fuel quotas has led to the better availability of biofuel now. The supply should be doubled to meet government quotas.

  10. Antitumor effects of interleukin-18 gene-modified hepatocyte cell line on implanted liver carcinoma

    Institute of Scientific and Technical Information of China (English)

    冷建杭; 张立煌; 姚航平; 曹雪涛

    2003-01-01

    Objective To investigate the antitumor effects of intrasplenically transplanted interleukin-18 (IL-18) gene-modified hepatocytes on murine implanted liver carcinoma.Methods Embryonic murine hepatocyte cell line (BNL-CL2) was transfected with a recombinant adenovirus encoding IL-18 and used as delivery cells for IL-18 gene transfer. Two cell lines, BNL-LacZ and BNL-CL2, were used as controls. One week after intrasplenic injection of C26 cells (colon carcinoma line), tumor-bearing syngeneic mice underwent the intrasplenic transplantation of IL-18 gene-modified hepatocyte cell line and were divided into treatment group (BNL IL-18) and control groups (BNL-LacZ and BNL-CL2 ). Two weeks later, the serum levels of IL-18, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) in the implanted liver carcinoma-bearing mice were assayed, the cytotoxicity of murine splenic cytotoxic T-lymphocytes (CTLs) was measured, and the morphology of the hepatic tumors was studied to evaluate the antitumor effects of the approach. Results In the treatment group, the serum levels of IL-18, IFN-γ, TNF-α and NO increased significantly. The splenic CTL activity increased markedly (P<0.01) , accompanied by a substantial decrease in tumor volume and the percentage of tumor area and prolonged survival of liver carcinomo-being mice.Conclusions In vivo IL-18 expression by ex vivo manipulated cells with IL-18 recombinant adenovirus is able to exert potent antitumor effects by inducing a predominantly T-cell-helper type 1 (Th1) immune response. Intrasplenic transplantation of adenovirus-mediated IL-18 gene-modified hepatocytes could be used as a targeting treatment for implanted liver carcinoma.

  11. Biofuels and Food Security

    OpenAIRE

    Fischer, G; Hizsnyik, E.; Prieler, S.; Shah, M; van Velthuizen, H.T.

    2009-01-01

    Biofuels development has received increased attention in recent times as a means to mitigate climate change, alleviate global energy concerns and foster rural development. Its perceived importance in these three areas has seen biofuels feature prominently on the international agenda. Nevertheless, the rapid growth of biofuels production has raised many concerns among experts worldwide, in particular with regard to sustainability issues and the threat posed to food security. The UN Secretary G...

  12. Biofuels in China

    Science.gov (United States)

    Tan, Tianwei; Yu, Jianliang; Lu, Jike; Zhang, Tao

    The Chinese government is stimulating the biofuels development to replace partially fossil fuels in the transport sector, which can enhance energy security, reduce greenhouse gas emissions, and stimulate rural development. Bioethanol, biodiesel, biobutanol, biogas, and biohydrogen are the main biofuels developed in China. In this chapter, we mainly present the current status of biofuel development in China, and illustrate the issues of feedstocks, food security and conversion processes.

  13. LCA of Transportation Biofuels

    OpenAIRE

    Adlam, Elisabeth

    2007-01-01

    An increasing need to find alternatives to fossil fuels, and a growing awareness of the global warming effect has resulted in substantial research and development on biofuels. Biofuels are being considered a potential substitution of petroleum based fuels in the transport sector.With this increasing interest in biofuels comes the need to establish the environmental effect of the fuels. Results from several life cycle assessments reviewed in this report show that there are some benefits of bio...

  14. An in vitro multi-parametric approach to measuring the effect of implant surface characteristics on cell behaviour

    International Nuclear Information System (INIS)

    Orthopaedic implants are designed to promote biocompatibility and hence their integration with surrounding tissue. This involves influencing cell-implant interactions through changes in both surface topography and surface roughness. However, the large range of machining techniques used in implant manufacture and inconsistencies in the measurement techniques used for surface characterization make it difficult to measure the impact of surface characteristics on cell-implant interactions. Here, we describe a new in vitro multi-parametric approach that uses commercially available arrays of engineered surfaces that linearly increase in roughness, as measured by Ra, and that can be used to obtain quantitative measurements of cell attachment, differentiation and bone formation. Using this model, we demonstrate that cell attachment above 50% confluency occurs over a narrow range of roughness (Ra from 0.0125 μm to 6.3 μm) and that promotion of cell differentiation and bone development, while significantly influenced by surface topography, does not correlate directly with initial levels of cell attachment. These results compare well with published in vivo implant biocompatibility data indicating that this approach has the potential to offer a rapid, reliable and reproducible in vitro prediction of in vivo implant biocompatibility.

  15. NREL biofuels program overview

    Energy Technology Data Exchange (ETDEWEB)

    Mielenz, J.R. [National Renewable Energy Laboratory, Golden, CO (United States)

    1996-09-01

    The NREL Biofuels Program has been developing technology for conversion of biomass to transportation fuels with support from DOE Office of Transportation Technologies Biofuels System Program. This support has gone to both the National Renewable Energy Laboratory, and over 100 subcontractors in universities and industry. This overview will outline the value of the Biofuels development program to the Nation, the current status of the technology development, and what research areas still need further support and progress for the development of a biofuels industry in the US.

  16. Plasma immersion ion implantation of boron for ribbon silicon solar cells

    Directory of Open Access Journals (Sweden)

    Derbouz K.

    2013-09-01

    Full Text Available In this work, we report for the first time on the solar cell fabrication on n-type silicon RST (for Ribbon on Sacrificial Template using plasma immersion ion implantation. The experiments were also carried out on FZ silicon as a reference. Boron was implanted at energies from 10 to 15 kV and doses from 1015 to 1016 cm-2, then activated by a thermal annealing in a conventional furnace at 900 and 950 °C for 30 min. The n+ region acting as a back surface field was achieved by phosphorus spin-coating. The frontside boron emitter was passivated either by applying a 10 nm deposited SiOX plasma-enhanced chemical vapor deposition (PECVD or with a 10 nm grown thermal oxide. The anti-reflection coating layer formed a 60 nm thick SiNX layer. We show that energies less than 15 kV and doses around 5 × 1015 cm-2 are appropriate to achieve open circuit voltage higher than 590 mV and efficiency around 16.7% on FZ-Si. The photovoltaic performances on ribbon silicon are so far limited by the bulk quality of the material and by the quality of the junction through the presence of silicon carbide precipitates at the surface. Nevertheless, we demonstrate that plasma immersion ion implantation is very promising for solar cell fabrication on ultrathin silicon wafers such as ribbons.

  17. A superhydrophilic titanium implant functionalized by ozone gas modulates bone marrow cell and macrophage responses.

    Science.gov (United States)

    Sunarso; Toita, Riki; Tsuru, Kanji; Ishikawa, Kunio

    2016-08-01

    Bone-forming cells and Mϕ play key roles in bone tissue repair. In this study, we prepared a superhydrophilic titanium implant functionalized by ozone gas to modulate osteoconductivity and inhibit inflammatory response towards titanium implants. After 24 h of ozone gas treatment, the water contact angle of the titanium surface became zero. XPS analysis revealed that hydroxyl groups were greatly increased, but carbon contaminants were largely decreased 24 h after ozone gas functionalization. Also, ozone gas functionalization did not alter titanium surface topography. Superhydrophilic titanium (O3-Ti) largely increased the aspect ratio, size and perimeter of cells when compared with untreated titanium (unTi). In addition, O3-Ti facilitated rat bone marrow derived MSCs differentiation and mineralization evidenced by greater ALP activity and bone-like nodule formation. Interestingly, O3-Ti did not affect RAW264.7 Mϕ proliferation. However, naive RAW264.7 Mϕ cultured on unTi produced a two-fold larger amount of TNFα than that on O3-Ti. Furthermore, O3-Ti greatly mitigated proinflammatory cytokine production, including TNFα and IL-6 from LSP-stimulated RAW264.7 Mϕ. These results demonstrated that a superhydrophilic titanium prepared by simple ozone gas functionalization successfully increased MSCs proliferation and differentiation, and mitigated proinflammatory cytokine production from both naive and LPS-stimulated Mϕ. This superhydrophilic surface would be useful as an endosseous implantable biomaterials and as a biomaterial for implantation into other tissues. PMID:27344451

  18. Enhanced cell adhesion to silicone implant material through plasma surface modification.

    Science.gov (United States)

    Hauser, J; Zietlow, J; Köller, M; Esenwein, S A; Halfmann, H; Awakowicz, P; Steinau, H U

    2009-12-01

    Silicone implant material is widely used in the field of plastic surgery. Despite its benefits the lack of biocompatibility this material still represents a major problem. Due to the surface characteristics of silicone, protein adsorption and cell adhesion on this polymeric material is rather low. The aim of this study was to create a stable collagen I surface coating on silicone implants via glow-discharge plasma treatment in order to enhance cell affinity and biocompatibility of the material. Non-plasma treated, collagen coated and conventional silicone samples (non-plasma treated, non-coated) served as controls. After plasma treatment the change of surface free energy was evaluated by drop-shape analysis. The quality of the collagen coating was analysed by electron microscopy and Time-Of-Flight Secondary Ion Mass Spectrometry. For biocompatibility tests mouse fibroblasts 3T3 were cultivated on the different silicone surfaces and stained with calcein-AM and propidium iodine to evaluate cell viability and adherence. Analysis of the different surfaces revealed a significant increase in surface free energy after plasma pre-treatment. As a consequence, collagen coating could only be achieved on the plasma activated silicone samples. The in vitro tests showed that the collagen coating led to a significant increase in cell adhesion and cell viability. PMID:19641852

  19. Mesenchymal stem cell interaction with ultra-smooth nanostructured diamond for wear-resistant orthopaedic implants.

    Science.gov (United States)

    Clem, William C; Chowdhury, Shafiul; Catledge, Shane A; Weimer, Jeffrey J; Shaikh, Faheem M; Hennessy, Kristin M; Konovalov, Valery V; Hill, Michael R; Waterfeld, Alfred; Bellis, Susan L; Vohra, Yogesh K

    2008-01-01

    Ultra-smooth nanostructured diamond (USND) can be applied to greatly increase the wear resistance of orthopaedic implants over conventional designs. Herein we describe surface modification techniques and cytocompatibility studies performed on this new material. We report that hydrogen (H)-terminated USND surfaces supported robust mesenchymal stem cell (MSC) adhesion and survival, while oxygen- (O) and fluorine (F)-terminated surfaces resisted cell adhesion, indicating that USND can be modified to either promote or prevent cell/biomaterial interactions. Given the favorable cell response to H-terminated USND, this material was further compared with two commonly used biocompatible metals, titanium alloy (Ti-6Al-4V) and cobalt chrome (CoCrMo). MSC adhesion and proliferation were significantly improved on USND compared with CoCrMo, although cell adhesion was greatest on Ti-6Al-4V. Comparable amounts of the pro-adhesive protein, fibronectin, were deposited from serum on the three substrates. Finally, MSCs were induced to undergo osteoblastic differentiation on the three materials, and deposition of a mineralized matrix was quantified. Similar amounts of mineral were deposited onto USND and CoCrMo, whereas mineral deposition was slightly higher on Ti-6Al-4V. When coupled with recently published wear studies, these in vitro results suggest that USND has the potential to reduce debris particle release from orthopaedic implants without compromising osseointegration. PMID:18490051

  20. Silver nanoparticle-enriched diamond-like carbon implant modification as a mammalian cell compatible surface with antimicrobial properties

    Science.gov (United States)

    Gorzelanny, Christian; Kmeth, Ralf; Obermeier, Andreas; Bauer, Alexander T.; Halter, Natalia; Kümpel, Katharina; Schneider, Matthias F.; Wixforth, Achim; Gollwitzer, Hans; Burgkart, Rainer; Stritzker, Bernd; Schneider, Stefan W.

    2016-03-01

    The implant-bone interface is the scene of competition between microorganisms and distinct types of tissue cells. In the past, various strategies have been followed to support bony integration and to prevent bacterial implant-associated infections. In the present study we investigated the biological properties of diamond-like carbon (DLC) surfaces containing silver nanoparticles. DLC is a promising material for the modification of medical implants providing high mechanical and chemical stability and a high degree of biocompatibility. DLC surface modifications with varying silver concentrations were generated on medical-grade titanium discs, using plasma immersion ion implantation-induced densification of silver nanoparticle-containing polyvinylpyrrolidone polymer solutions. Immersion of implants in aqueous liquids resulted in a rapid silver release reducing the growth of surface-bound and planktonic Staphylococcus aureus and Staphylococcus epidermidis. Due to the fast and transient release of silver ions from the modified implants, the surfaces became biocompatible, ensuring growth of mammalian cells. Human endothelial cells retained their cellular differentiation as indicated by the intracellular formation of Weibel-Palade bodies and a high responsiveness towards histamine. Our findings indicate that the integration of silver nanoparticles into DLC prevents bacterial colonization due to a fast initial release of silver ions, facilitating the growth of silver susceptible mammalian cells subsequently.

  1. Silver nanoparticle-enriched diamond-like carbon implant modification as a mammalian cell compatible surface with antimicrobial properties

    Science.gov (United States)

    Gorzelanny, Christian; Kmeth, Ralf; Obermeier, Andreas; Bauer, Alexander T.; Halter, Natalia; Kümpel, Katharina; Schneider, Matthias F.; Wixforth, Achim; Gollwitzer, Hans; Burgkart, Rainer; Stritzker, Bernd; Schneider, Stefan W.

    2016-01-01

    The implant-bone interface is the scene of competition between microorganisms and distinct types of tissue cells. In the past, various strategies have been followed to support bony integration and to prevent bacterial implant-associated infections. In the present study we investigated the biological properties of diamond-like carbon (DLC) surfaces containing silver nanoparticles. DLC is a promising material for the modification of medical implants providing high mechanical and chemical stability and a high degree of biocompatibility. DLC surface modifications with varying silver concentrations were generated on medical-grade titanium discs, using plasma immersion ion implantation-induced densification of silver nanoparticle-containing polyvinylpyrrolidone polymer solutions. Immersion of implants in aqueous liquids resulted in a rapid silver release reducing the growth of surface-bound and planktonic Staphylococcus aureus and Staphylococcus epidermidis. Due to the fast and transient release of silver ions from the modified implants, the surfaces became biocompatible, ensuring growth of mammalian cells. Human endothelial cells retained their cellular differentiation as indicated by the intracellular formation of Weibel-Palade bodies and a high responsiveness towards histamine. Our findings indicate that the integration of silver nanoparticles into DLC prevents bacterial colonization due to a fast initial release of silver ions, facilitating the growth of silver susceptible mammalian cells subsequently. PMID:26955791

  2. Nickel-phendione complex covalently attached onto carbon nanotube/cross linked glucose dehydrogenase as bioanode for glucose/oxygen compartment-less biofuel cell

    Science.gov (United States)

    Korani, Aazam; Salimi, Abdollah; Hadadzadeh, Hasan

    2015-05-01

    Here, [Ni(phendion) (phen)]Cl2 complex, (phendion and phen are 1,10-phenanthroline-5,6-dione and 5-amino-1, 10-phenanthrolin) covalently attached onto carboxyl functionalized multi walls carbon nanotube modified glassy carbon electrode (GCE/MWCNTs-COOH) using solid phase interactions and combinatorial approaches.The attached [Ni(phendion) (phen)]Cl2 complex displays a surface controlled electrode process and it acts as an effective redox mediator for electrocatalytic oxidation of dihydronicotinamide adenine dinucleotide (NADH) at reduced overpotentials. With co-immobilization of glucose dehydrogenase enzyme (GDH) by crosslinking an effective biocatalyst for glucose oxidation designed. The onset potential and current density are -0.1 V versus Ag/AgCl electrode and 0.550 mA cm-2, which indicate the applicability of the proposed system as an efficient bioanode for biofuel cell (BFC) design. A GCE/MWCNTs modified with electrodeposited gold nanoparticles (AuNPs) as a platform for immobilization of bilirubin oxidase (BOD) and the prepared GCE/MWCNTs/AuNPs/BOD biocathode exhibits an onset potential of 0.56 V versus Ag/AgCl. The performance of the fabricated bioanode and biocathode in a membraneless enzyme based glucose/O2 biofuel cell is evaluated. The open circuit voltage of the cell and maximum current density are 520 mV and 0.233 mA cm-2, respectively, while maximum power density of 40 μWcm-2 achieves at voltage of 280 mV with stable output power after 24 h continues operation.

  3. MR imaging features of gadofluorine-labeled matrix-associated stem cell implants in cartilage defects.

    Directory of Open Access Journals (Sweden)

    Hossein Nejadnik

    Full Text Available OBJECTIVES: The purpose of our study was to assess the chondrogenic potential and the MR signal effects of GadofluorineM-Cy labeled matrix associated stem cell implants (MASI in pig knee specimen. MATERIALS AND METHODS: Human mesenchymal stem cells (hMSCs were labeled with the micelle-based contrast agent GadofluorineM-Cy. Ferucarbotran-labeled hMSCs, non-labeled hMSCs and scaffold only served as controls. Chondrogenic differentiation was induced and gene expression and histologic evaluation were performed. The proportions of spindle-shaped vs. round cells of chondrogenic pellets were compared between experimental groups using the Fisher's exact test. Labeled and unlabeled hMSCs and chondrocytes in scaffolds were implanted into cartilage defects of porcine femoral condyles and underwent MR imaging with T1- and T2-weighted SE and GE sequences. Contrast-to-noise ratios (CNR between implants and adjacent cartilage were determined and analyzed for significant differences between different experimental groups using the Kruskal-Wallis test. Significance was assigned for p0.017. However, hMSC differentiation into chondrocytes was superior for unlabeled and GadofluorineM-Cy-labeled cells compared with Ferucarbotran-labeled cells, as evidenced by a significantly higher proportion of spindle cells in chondrogenic pellets (p<0.05. GadofluorineM-Cy-labeled hMSCs and chondrocytes showed a positive signal effect on T1-weighted images and a negative signal effect on T2-weighted images while Ferucarbotran-labeled cells provided a negative signal effect on all sequences. CNR data for both GadofluorineM-Cy-labeled and Ferucarbotran-labeled hMSCs were significantly different compared to unlabeled control cells on T1-weighted SE and T2*-weighted MR images (p<0.017. CONCLUSION: hMSCs can be labeled by simple incubation with GadofluorineM-Cy. The labeled cells provide significant MR signal effects and less impaired chondrogenesis compared to Ferucarbotran-labeled h

  4. Spatially Controlled Delivery of siRNAs to Stem Cells in Implants Generated by Multi-Component Additive Manufacturing

    DEFF Research Database (Denmark)

    Andersen, Morten Østergaard; Le, Dang Quang Svend; Chen, Muwan;

    2013-01-01

    Additive manufacturing is a promising technique in tissue engineering, as it enables truly individualized implants to be made to fit a particular defect. As previously shown, a feasible strategy to produce complex multicellular tissues is to deposit different small interfering RNA (siRNA) in porous...... implants that are subsequently sutured together. In this study, an additive manufacturing strategy to deposit carbohydrate hydrogels containing different siRNAs is applied into an implant, in a spatially controlled manner. When the obtained structures are seeded with mesenchymal stem (stromal) cells, the...... selected siRNAs are delivered to the cells and induces specific and localized gene silencing. Here, it is demonstrated how to replicate part of a patient's spinal cord from a computed tomography scan, using an additive manufacturing technique to produce an implant with compartmentalized siRNAs in the...

  5. Significance of Nano- and Microtopography for Cell-Surface Interactions in Orthopaedic Implants

    Directory of Open Access Journals (Sweden)

    M. Jäger

    2007-09-01

    Full Text Available Cell-surface interactions play a crucial role for biomaterial application in orthopaedics. It is evident that not only the chemical composition of solid substances influence cellular adherence, migration, proliferation and differentiation but also the surface topography of a biomaterial. The progressive application of nanostructured surfaces in medicine has gained increasing interest to improve the cytocompatibility and osteointegration of orthopaedic implants. Therefore, the understanding of cell-surface interactions is of major interest for these substances. In this review, we elucidate the principle mechanisms of nano- and microscale cell-surface interactions in vitro for different cell types onto typical orthopaedic biomaterials such as titanium (Ti, cobalt-chrome-molybdenum (CoCrMo alloys, stainless steel (SS, as well as synthetic polymers (UHMWPE, XLPE, PEEK, PLLA. In addition, effects of nano- and microscaled particles and their significance in orthopaedics were reviewed. The significance for the cytocompatibility of nanobiomaterials is discussed critically.

  6. Mind-controlled transgene expression by a wireless-powered optogenetic designer cell implant.

    Science.gov (United States)

    Folcher, Marc; Oesterle, Sabine; Zwicky, Katharina; Thekkottil, Thushara; Heymoz, Julie; Hohmann, Muriel; Christen, Matthias; Daoud El-Baba, Marie; Buchmann, Peter; Fussenegger, Martin

    2014-01-01

    Synthetic devices for traceless remote control of gene expression may provide new treatment opportunities in future gene- and cell-based therapies. Here we report the design of a synthetic mind-controlled gene switch that enables human brain activities and mental states to wirelessly programme the transgene expression in human cells. An electroencephalography (EEG)-based brain-computer interface (BCI) processing mental state-specific brain waves programs an inductively linked wireless-powered optogenetic implant containing designer cells engineered for near-infrared (NIR) light-adjustable expression of the human glycoprotein SEAP (secreted alkaline phosphatase). The synthetic optogenetic signalling pathway interfacing the BCI with target gene expression consists of an engineered NIR light-activated bacterial diguanylate cyclase (DGCL) producing the orthogonal second messenger cyclic diguanosine monophosphate (c-di-GMP), which triggers the stimulator of interferon genes (STING)-dependent induction of synthetic interferon-β promoters. Humans generating different mental states (biofeedback control, concentration, meditation) can differentially control SEAP production of the designer cells in culture and of subcutaneous wireless-powered optogenetic implants in mice. PMID:25386727

  7. Implantation of stem cells in the treatment of acute myocardial infarction

    International Nuclear Information System (INIS)

    A lot of investigations demonstrate the possibility of regeneration of the cardiomiocity from stem cells. A longitudinal, prospective, observational study was conducted in patients with acute myocardial infarction in CIMEQ'S hospital since January 2004 up to January 2007 with the purpose to evaluate the security and efficacy of the intracoronary transfer of autologous bone-marrow-cells during acute myocardial infarction. Patients within seven days of the onset of symptoms of a first ST-segment elevation myocardial infarction, and between 18 and 70 years old. The patients are evaluated previous to apply the procedure and 6 months for clinic, electrocardiography, echocardiography, ergometry and coronariography. The drug eluting stent is placed on the culprit lesion and the bone marrow is stimulated with granulocyte colony-stimulating factor (G-CSF). The mononuclear's cells which are obtained have been implanted using the intracoronary way. The implantation by means of the intracoronary way of stem cells, after of stimulation of bone marrow during acute myocardial infarction demonstrated to be an effective and safety procedure

  8. A critical review of cell culture strategies for modelling intracortical brain implant material reactions.

    Science.gov (United States)

    Gilmour, A D; Woolley, A J; Poole-Warren, L A; Thomson, C E; Green, R A

    2016-06-01

    The capacity to predict in vivo responses to medical devices in humans currently relies greatly on implantation in animal models. Researchers have been striving to develop in vitro techniques that can overcome the limitations associated with in vivo approaches. This review focuses on a critical analysis of the major in vitro strategies being utilized in laboratories around the world to improve understanding of the biological performance of intracortical, brain-implanted microdevices. Of particular interest to the current review are in vitro models for studying cell responses to penetrating intracortical devices and their materials, such as electrode arrays used for brain computer interface (BCI) and deep brain stimulation electrode probes implanted through the cortex. A background on the neural interface challenge is presented, followed by discussion of relevant in vitro culture strategies and their advantages and disadvantages. Future development of 2D culture models that exhibit developmental changes capable of mimicking normal, postnatal development will form the basis for more complex accurate predictive models in the future. Although not within the scope of this review, innovations in 3D scaffold technologies and microfluidic constructs will further improve the utility of in vitro approaches. PMID:26994876

  9. Anodized titania: Processing and characterization to improve cell-materials interactions for load bearing implants

    Science.gov (United States)

    Das, Kakoli

    The objective of this study is to investigate in vitro cell-materials interactions using human osteoblast cells on anodized titanium. Titanium is a bioinert material and, therefore, gets encapsulated after implantation into the living body by a fibrous tissue that isolates them from the surrounding tissues. In this work, bioactive nonporous and nanoporous TiO2 layers were grown on commercially pure titanium substrate by anodization process using different electrolyte solutions namely (1) H3PO 4, (2) HF and (3) H2SO4, (4) aqueous solution of citric acid, sodium fluoride and sulfuric acid. The first three electrolytes produced bioactive TiO2 films with a nonporous structure showing three distinctive surface morphologies. Nanoporous morphology was obtained on Ti-surfaces from the fourth electrolyte at 20V for 4h. Cross-sectional view of the nanoporous surface reveals titania nanotubes of length 600 nm. It was found that increasing anodization time initially increased the height of the nanotubes while maintaining the tubular array structure, but beyond 4h, growth of nanotubes decreased with a collapsed array structure. Human osteoblast (HOB) cell attachment and growth behavior were studied using an osteoprecursor cell line (OPC 1) for 3, 7 and 11 days. Colonization of the cells was noticed with distinctive cell-to-cell attachment on HF anodized surfaces. TiO2 layer grown in H2SO4 electrolyte did not show significant cell growth on the surface, and some cell death was also noticed. Good cellular adherence with extracellular matrix extensions in between the cells was noticed for samples anodized with H3PO 4 electrolyte and nanotube surface. Cell proliferation was excellent on anodized nanotube surfaces. An abundant amount of extracellular matrix (ECM) between the neighboring cells was also noticed on nanotube surfaces with filopodia extensions coming out from cells to grasp the nanoporous surface for anchorage. To better understand and compare cell-materials interactions

  10. Mga is essential for the survival of pluripotent cells during peri-implantation development.

    Science.gov (United States)

    Washkowitz, Andrew J; Schall, Caroline; Zhang, Kun; Wurst, Wolfgang; Floss, Thomas; Mager, Jesse; Papaioannou, Virginia E

    2015-01-01

    The maintenance and control of pluripotency is of great interest in stem cell biology. The dual specificity T-box/basic-helix-loop-helix-zipper transcription factor Mga is expressed in the pluripotent cells of the inner cell mass (ICM) and epiblast of the peri-implantation mouse embryo, but its function has not been investigated previously. Here, we use a loss-of-function allele and RNA knockdown to demonstrate that Mga depletion leads to the death of proliferating pluripotent ICM cells in vivo and in vitro, and the death of embryonic stem cells (ESCs) in vitro. Additionally, quiescent pluripotent cells lacking Mga are lost during embryonic diapause. Expression of Odc1, the rate-limiting enzyme in the conversion of ornithine into putrescine in the synthesis of polyamines, is reduced in Mga mutant cells, and the survival of mutant ICM cells as well as ESCs is rescued in culture by the addition of exogenous putrescine. These results suggest a mechanism whereby Mga influences pluripotent cell survival through regulation of the polyamine pool in pluripotent cells of the embryo, whether they are in a proliferative or quiescent state. PMID:25516968

  11. Design of a bioelectrocatalytic electrode interface for oxygen reduction in biofuel cells based on a specifically adapted Os-complex containing redox polymer with entrapped Trametes hirsuta laccase

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, Yvonne; Guschin, Dmitrii A.; Eckhard, Kathrin; Schuhmann, Wolfgang [Analytische Chemie - Elektroanalytik and Sensorik, Ruhr-Universitaet Bochum, Universitaetsstr. 150, D-44780 Bochum (Germany); Shleev, Sergey [Biomedical Laboratory Science, Faculty of Health and Society, Malmoe University, Soedra Foerstadsgatan 101, SE-20506 Malmoe (Sweden)

    2010-05-15

    The design of the coordination shell of an Os-complex and its integration within an electrodeposition polymer enables fast electron transfer between an electrode and a polymer entrapped high-potential laccase from the basidiomycete Trametes hirsuta. The redox potential of the Os{sup 3+/2+}-centre tethered to the polymer backbone (+ 720 mV vs. NHE) is perfectly matching the potential of the enzyme (+ 780 mV vs. NHE at pH 6.5). The laccase and the Os-complex modified anodic electrodeposition polymer were simultaneously precipitated on the surface of a glassy carbon electrode by means of a pH-shift to 2.5. The modified electrode was investigated with respect to biocatalytic O{sub 2} reduction to H{sub 2}O. The proposed modified electrode has potential applications as biofuel cell cathode. (author)

  12. Aging effects of plasma polymerized ethylenediamine (PPEDA) thin films on cell-adhesive implant coatings

    Energy Technology Data Exchange (ETDEWEB)

    Testrich, H., E-mail: holger.testrich@uni-greifswald.de [University of Greifswald, Institute of Physics, Felix-Hausdorff Str. 6, 17489 Greifswald (Germany); Rebl, H. [University of Rostock, Biomedical Research Center, Department of Cell Biology, Schillingallee 69, 18057 Rostock (Germany); Finke, B.; Hempel, F. [Leibniz Institute for Plasma Science and Technology, Felix-Hausdorff Str. 2, 17489 Greifswald (Germany); Nebe, B. [University of Rostock, Biomedical Research Center, Department of Cell Biology, Schillingallee 69, 18057 Rostock (Germany); Meichsner, J. [University of Greifswald, Institute of Physics, Felix-Hausdorff Str. 6, 17489 Greifswald (Germany)

    2013-10-15

    Thin plasma polymer films from ethylenediamine were deposited on planar substrates placed on the powered electrode of a low pressure capacitively coupled 13.56 MHz discharge. The chemical composition of the plasma polymer films was analyzed by Fourier Transform Infrared Reflection Absorption Spectroscopy (FT-IRRAS) as well as by X-ray photoelectron spectroscopy (XPS) after derivatization of the primary amino groups. The PPEDA films undergo an alteration during the storage in ambient air, particularly, due to reactions with oxygen. The molecular changes in PPEDA films were studied over a long-time period of 360 days. Simultaneously, the adhesion of human osteoblast-like cells MG-63 (ATCC) was investigated on PPEDA coated corundum blasted titanium alloy (Ti-6Al-4V), which is applied as implant material in orthopedic surgery. The cell adhesion was determined by flow cytometry and the cell shape was analyzed by scanning electron microscopy. Compared to uncoated reference samples a significantly enhanced cell adhesion and proliferation were measured for PPEDA coated samples, which have been maintained after long-time storage in ambient air and additional sterilization by γ−irradiation. - Highlights: • Development of cell-adhesive nitrogen-rich coatings for biomedical applications. • Plasma polymer films from low pressure 13.56 MHz discharge in argon-ethylenediamine. • Enhanced osteoblast adhesion/proliferation on coated implant material (Ti-6Al-4V). • Despite film aging over 360 days the enhanced cell adhesion of the coating remains. • No influence of additional y-sterilization on the enhanced cell adhesion.

  13. Implantable tissue-engineered blood vessels from human induced pluripotent stem cells.

    Science.gov (United States)

    Gui, Liqiong; Dash, Biraja C; Luo, Jiesi; Qin, Lingfeng; Zhao, Liping; Yamamoto, Kota; Hashimoto, Takuya; Wu, Hongwei; Dardik, Alan; Tellides, George; Niklason, Laura E; Qyang, Yibing

    2016-09-01

    Derivation of functional vascular smooth muscle cells (VSMCs) from human induced pluripotent stem cells (hiPSCs) to generate tissue-engineered blood vessels (TEBVs) holds great potential in treating patients with vascular diseases. Herein, hiPSCs were differentiated into alpha-smooth muscle actin (α-SMA) and calponin-positive VSMCs, which were seeded onto polymer scaffolds in bioreactors for vascular tissue growth. A functional TEBV with abundant collagenous matrix and sound mechanics resulted, which contained cells largely positive for α-SMA and smooth muscle myosin heavy chain (SM-MHC). Moreover, when hiPSC-derived TEBV segments were implanted into nude rats as abdominal aorta interposition grafts, they remained unruptured and patent with active vascular remodeling, and showed no evidence of teratoma formation during a 2-week proof-of-principle study. Our studies represent the development of the first implantable TEBVs based on hiPSCs, and pave the way for developing autologous or allogeneic grafts for clinical use in patients with vascular disease. PMID:27336184

  14. UV-activated 7-dehydrocholesterol-coated titanium implants promote differentiation of human umbilical cord mesenchymal stem cells into osteoblasts.

    Science.gov (United States)

    Satué, María; Ramis, Joana M; Monjo, Marta

    2016-01-01

    Vitamin D metabolites are essential for bone regeneration and mineral homeostasis. The vitamin D precursor 7-dehydrocholesterol can be used after UV irradiation to locally produce active vitamin D by osteoblastic cells. Furthermore, UV-irradiated 7-dehydrocholesterol is a biocompatible coating for titanium implants with positive effects on osteoblast differentiation. In this study, we examined the impact of titanium implants surfaces coated with UV-irradiated 7-dehydrocholesterol on the osteogenic differentiation of human umbilical cord mesenchymal stem cells. First, the synthesis of cholecalciferol (D3) was achieved through the incubation of the UV-activated 7-dehydrocholesterol coating for 48 h at 23℃. Further, we investigated in vitro the biocompatibility of this coating in human umbilical cord mesenchymal stem cells and its potential to enhance their differentiation towards the osteogenic lineage. Human umbilical cord mesenchymal stem cells cultured onto UV-irradiated 7-dehydrocholesterol-coated titanium implants surfaces, combined with osteogenic supplements, upregulated the gene expression of several osteogenic markers and showed higher alkaline phosphatase activity and calcein blue staining, suggesting increased mineralization. Thus, our results show that the use of UV irradiation on 7-dehydrocholesterol -treated titanium implants surfaces generates a bioactive coating that promotes the osteogenic differentiation of human umbilical cord mesenchymal stem cells, with regenerative potential for improving osseointegration in titanium-based bone anchored implants. PMID:25899927

  15. Extremophiles in biofuel synthesis.

    Science.gov (United States)

    Barnard, Desire; Casanueva, Ana; Tuffin, Marla; Cowan, Donald

    2010-01-01

    The current global energy situation has demonstrated an urgent need for the development of alternative fuel sources to the continually diminishing fossil fuel reserves. Much research to address this issue focuses on the development of financially viable technologies for the production of biofuels. The current market for biofuels, defined as fuel products obtained from organic substrates, is dominated by bioethanol, biodiesel, biobutanol and biogas, relying on the use of substrates such as sugars, starch and oil crops, agricultural and animal wastes, and lignocellulosic biomass. This conversion from biomass to biofuel through microbial catalysis has gained much momentum as biotechnology has evolved to its current status. Extremophiles are a robust group of organisms producing stable enzymes, which are often capable of tolerating changes in environmental conditions such as pH and temperature. The potential application of such organisms and their enzymes in biotechnology is enormous, and a particular application is in biofuel production. In this review an overview of the different biofuels is given, covering those already produced commercially as well as those under development. The past and present trends in biofuel production are discussed, and future prospects for the industry are highlighted. The focus is on the current and future application of extremophilic organisms and enzymes in technologies to develop and improve the biotechnological production of biofuels. PMID:20662378

  16. Bone regeneration by implantation of adipose-derived stromal cells expressing BMP-2

    International Nuclear Information System (INIS)

    In this study, we reported that the adipose-derived stromal cells (ADSCs) genetically modified by bone morphogenetic protein 2 (BMP-2) healed critical-sized canine ulnar bone defects. First, the osteogenic and adipogenic differentiation potential of the ADSCs derived from canine adipose tissue were demonstrated. And then the cells were modified by the BMP-2 gene and the expression and bone-induction ability of BMP-2 were identified. Finally, the cells modified by BMP-2 gene were applied to a β-tricalcium phosphate (TCP) carrier and implanted into ulnar bone defects in the canine model. After 16 weeks, radiographic, histological, and histomorphometry analysis showed that ADSCs modified by BMP-2 gene produced a significant increase of newly formed bone area and healed or partly healed all of the bone defects. We conclude that ADSCs modified by the BMP-2 gene can enhance the repair of critical-sized bone defects in large animals

  17. Implantable synthetic cytokine converter cells with AND-gate logic treat experimental psoriasis.

    Science.gov (United States)

    Schukur, Lina; Geering, Barbara; Charpin-El Hamri, Ghislaine; Fussenegger, Martin

    2015-12-16

    Psoriasis is a chronic inflammatory skin disease characterized by a relapsing-remitting disease course and correlated with increased expression of proinflammatory cytokines, such as tumor necrosis factor (TNF) and interleukin 22 (IL22). Psoriasis is hard to treat because of the unpredictable and asymptomatic flare-up, which limits handling of skin lesions to symptomatic treatment. Synthetic biology-based gene circuits are uniquely suited for the treatment of diseases with complex dynamics, such as psoriasis, because they can autonomously couple the detection of disease biomarkers with the production of therapeutic proteins. We designed a mammalian cell synthetic cytokine converter that quantifies psoriasis-associated TNF and IL22 levels using serially linked receptor-based synthetic signaling cascades, processes the levels of these proinflammatory cytokines with AND-gate logic, and triggers the corresponding expression of therapeutic levels of the anti-inflammatory/psoriatic cytokines IL4 and IL10, which have been shown to be immunomodulatory in patients. Implants of microencapsulated cytokine converter transgenic designer cells were insensitive to simulated bacterial and viral infections as well as psoriatic-unrelated inflammation. The designer cells specifically prevented the onset of psoriatic flares, stopped acute psoriasis, improved psoriatic skin lesions and restored normal skin-tissue morphology in mice. The antipsoriatic designer cells were equally responsive to blood samples from psoriasis patients, suggesting that the synthetic cytokine converter captures the clinically relevant cytokine range. Implanted designer cells that dynamically interface with the patient's metabolism by detecting specific disease metabolites or biomarkers, processing their blood levels with synthetic circuits in real time, and coordinating immediate production and systemic delivery of protein therapeutics may advance personalized gene- and cell-based therapies. PMID:26676608

  18. The biofuels in France

    International Nuclear Information System (INIS)

    The biofuels are liquid renewable energies sources resulting from vegetal matters. Today are two channels of biofuels: the ethanol channel for gasoline and the vegetal oils channel for the diesel. In the first part, the document presents the different channels and the energy efficiency of the products. It shows in the second part the advantages for the environment (CO2 accounting) and for the energy independence. It discusses then the future developments and the projects. The fourth part is devoted to the legislation, regulations, taxes and financial incentives. The last part presents the french petroleum industry actions and attitudes in the framework of the biofuels development. (A.L.B.)

  19. DMF - A New Biofuel Candidate

    OpenAIRE

    Tian, Guohong; Daniel, Ritchie; Xu, Hongming

    2011-01-01

    This book aspires to be a comprehensive summary of current biofuels issues and thereby contribute to the understanding of this important topic. Readers will find themes including biofuels development efforts, their implications for the food industry, current and future biofuels crops, the successful Brazilian ethanol program, insights of the first, second, third and fourth biofuel generations, advanced biofuel production techniques, related waste treatment, emissions and environmental impacts...

  20. Biofuels: which interest, which perspectives?

    International Nuclear Information System (INIS)

    This paper is a synthesis of several studies concerning the production and utilization of bio-fuels: energy balance and greenhouse effect of the various bio-fuel systems; economical analysis and profitability of bio-fuel production; is the valorization of bio-fuel residues and by-products in animal feeding a realistic hypothesis?; assessment of the cost for the community due to tax exemption for bio-fuels

  1. Peen treatment on a titanium implant: effect of roughness, osteoblast cell functions, and bonding with bone cement

    Directory of Open Access Journals (Sweden)

    Khandaker M

    2016-02-01

    Full Text Available Morshed Khandaker,1,4 Shahram Riahinezhad,1 Fariha Sultana,1 Melville B Vaughan,2,4 Joshua Knight,2 Tracy L Morris3,4 1Department of Engineering & Physics, 2Department of Biology, 3Department of Mathematics and Statistics, 4Center for Interdisciplinary Biomedical Education and Research, University of Central Oklahoma, Edmond, OK, USA Abstract: Implant failure due to poor integration of the implant with the surrounding biomaterial is a common problem in various orthopedic and orthodontic surgeries. Implant fixation mostly depends upon the implant surface topography. Micron to nanosize circular-shaped groove architecture with adequate surface roughness can enhance the mechanical interlock and osseointegration of an implant with the host tissue and solve its poor fixation problem. Such groove architecture can be created on a titanium (Ti alloy implant by laser peening treatment. Laser peening produces deep, residual compressive stresses in the surfaces of metal parts, delivering increased fatigue life and damage tolerance. The scientific novelty of this study is the controlled deposition of circular-shaped rough spot groove using laser peening technique and understanding the effect of the treatment techniques for improving the implant surface properties. The hypothesis of this study was that implant surface grooves created by controlled laser peen treatment can improve the mechanical and biological responses of the implant with the adjoining biomaterial. The objective of this study was to measure how the controlled laser-peened groove architecture on Ti influences its osteoblast cell functions and bonding strength with bone cement. This study determined the surface roughness and morphology of the peen-treated Ti. In addition, this study compared the osteoblast cell functions (adhesion, proliferation, and differentiation between control and peen-treated Ti samples. Finally, this study measured the fracture strength between each kind of Ti samples

  2. Locally advanced breast implant associated anaplastic large cell lymphoma: A case report of successful treatment with radiation and chemotherapy

    Directory of Open Access Journals (Sweden)

    Christopher Fleighton Estes

    2015-02-01

    Full Text Available The development of breast implant associated anaplastic large cell lymphoma (ALCL is a rare phenomenon. A typical presentation is an effusion associated with a breast implant. Less commonly, disease can become more advanced locoregionally or distantly. The optimal treatment schema is a topic of debate: localized ALCL can potentially be cured with implant removal alone, while other cases in the literature, including those that are more advanced, have been treated with varying combinations of surgery, chemotherapy, and external beam radiotherapy. This is a case report of breast implant ALCL with pathologically proven lymph node involvement, the fifth such patient reported. Our patient experienced a favorable outcome with radiation therapy and chemotherapy.

  3. Biofunctionalization of conductive hydrogel coatings to support olfactory ensheathing cells at implantable electrode interfaces.

    Science.gov (United States)

    Hassarati, Rachelle T; Marcal, Helder; John, L; Foster, R; Green, Rylie A

    2016-05-01

    Mechanical discrepancies between conventional platinum (Pt) electrodes and neural tissue often result in scar tissue encapsulation of implanted neural recording and stimulating devices. Olfactory ensheathing cells (OECs) are a supportive glial cell in the olfactory nervous system which can transition through glial scar tissue while supporting the outgrowth of neural processes. It has been proposed that this function can be used to reconnect implanted electrodes with the target neural pathways. Conductive hydrogel (CH) electrode coatings have been proposed as a substrate for supporting OEC survival and proliferation at the device interface. To determine an ideal CH to support OECs, this study explored eight CH variants, with differing biochemical composition, in comparison to a conventional Pt electrodes. All CH variants were based on a biosynthetic hydrogel, consisting of poly(vinyl alcohol) and heparin, through which the conductive polymer (CP) poly(3,4-ethylenedioxythiophene) was electropolymerized. The biochemical composition was varied through incorporation of gelatin and sericin, which were expected to provide cell adherence functionality, supporting attachment, and cell spreading. Combinations of these biomolecules varied from 1 to 3 wt %. The physical, electrical, and biological impact of these molecules on electrode performance was assessed. Cyclic voltammetry and electrochemical impedance spectroscopy demonstrated that the addition of these biological molecules had little significant effect on the coating's ability to safely transfer charge. Cell attachment studies, however, determined that the incorporation of 1 wt % gelatin in the hydrogel was sufficient to significantly increase the attachment of OECs compared to the nonfunctionalized CH. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 104B: 712-722, 2016. PMID:26248597

  4. Electrochemical behavior and biological response of Mesenchymal Stem Cells on cp-Ti after N-ions implantation

    Energy Technology Data Exchange (ETDEWEB)

    Rizwan, M.; Ahmad, A. [Department of Metallurgical and Materials Engineering, University of Engineering and Technology, 54890 Lahore (Pakistan); Deen, K.M. [Corrosion Control Research Cell, Department of Metallurgy and Materials Engineering, CEET, University of the Punjab, 54590 Lahore (Pakistan); Haider, W., E-mail: haiderw@utpa.edu [Mechanical Engineering Department, University of Texas Pan American, Edinburg, TX 78539 (United States)

    2014-11-30

    Highlights: • Nitrogen ions of known dosage were implanted on cp-Ti. • Increase in surface roughness with increase in ions dose was confirmed by AFM. • TiN{sub 0.3} and Ti{sub 3}N{sub 2−x} nitride phases were formed and validated by XRD. • The ions implantation reduced the corrosion rate and stabilized the passive film. • Surface roughness greatly affected the morphology and growth of Mesenchymal Stem Cells. - Abstract: Titanium and its alloys are most widely used as implant materials due to their excellent biocompatibility, mechanical properties and chemical stability. In this study Nitrogen ions of known dosage were implanted over cp-Ti by Pelletron accelerator with beam energy of 0.25 MeV.The atomic force microscopy of bare and nitrogen implanted specimens confirmed increase in surface roughness with increase in nitrogen ions concentration. X-ray diffraction patterns of ions implanted surfaces validated the formation of TiN{sub 0.3} and Ti{sub 3}N{sub 2-x}nitride phases. The tendency to form passive film and electrochemical behavior of these surfaces in ringer lactate (RL) solution was evaluated by Potentiodynamic polarization and electrochemical impedance spectroscopy respectively. It is proved that nitrogen ions implantation was beneficial to reduce corrosion rate and stabilizing passive film by increasing charge transfer resistance in RL. It was concluded that morphology and proliferation of Mesenchymal Stem Cells on nitrogen ions implanted surfaces strongly depends on surface roughness and nitride phases.

  5. Silicon Heterojunction Solar Cells Using AlOx and Plasma-Immersion Ion Implantation

    Directory of Open Access Journals (Sweden)

    Yu-Hsien Lin

    2014-06-01

    Full Text Available Aluminum oxide (AlOx and plasma immersion ion implantation (PIII were studied in relation to passivated silicon heterojunction solar cells. When aluminum oxide (AlOx was deposited on the surface of a wafer; the electric field near the surface of wafer was enhanced; and the mobility of the carrier was improved; thus reducing carrier traps associated with dangling bonds. Using PIII enabled implanting nitrogen into the device to reduce dangling bonds and achieve the desired passivation effect. Depositing AlOx on the surface of a solar cell increased the short-circuit current density (Jsc; open-circuit voltage (Voc; and conversion efficiency from 27.84 mA/cm2; 0.52 V; and 8.97% to 29.34 mA/cm2; 0.54 V; and 9.68%; respectively. After controlling the depth and concentration of nitrogen by modulating the PIII energy; the ideal PIII condition was determined to be 2 keV and 10 min. As a result; a 15.42% conversion efficiency was thus achieved; and the Jsc; Voc; and fill factor were 37.78 mA/cm2; 0.55 V; and 0.742; respectively.

  6. Single-cell RNA sequencing: revealing human pre-implantation development, pluripotency and germline development.

    Science.gov (United States)

    Petropoulos, S; Panula, S P; Schell, J P; Lanner, F

    2016-09-01

    Early human development is a dynamic, heterogeneous, complex and multidimensional process. During the first week, the single-cell zygote undergoes eight to nine rounds of cell division generating the multicellular blastocyst, which consists of hundreds of cells forming spatially organized embryonic and extra-embryonic tissues. At the level of transcription, degradation of maternal RNA commences at around the two-cell stage, coinciding with embryonic genome activation. Although numerous efforts have recently focused on delineating this process in humans, many questions still remain as thorough investigation has been limited by ethical issues, scarce availability of human embryos and the presence of minute amounts of DNA and RNA. In vitro cultures of embryonic stem cells provide some insight into early human development, but such studies have been confounded by analysis on a population level failing to appreciate cellular heterogeneity. Recent technical developments in single-cell RNA sequencing have provided a novel and powerful tool to explore the early human embryo in a systematic manner. In this review, we will discuss the advantages and disadvantages of the techniques utilized to specifically investigate human development and consider how the technology has yielded new insights into pre-implantation development, embryonic stem cells and the establishment of the germ line. PMID:27046137

  7. Biofuels - 5 disturbing questions

    International Nuclear Information System (INIS)

    Initially considered as the supreme weapon against greenhouse gas emissions, biofuels are today hold responsible to all harms of the Earth: leap of agriculture products price, deforestation, food crisis. Considered some time ago as the perfect clean substitute to petroleum, biofuels are now suspected to have harmful effects on the environment. Should it be just an enormous technical, environmental and human swindle? Should we abandon immediately biofuels to protect the earth and fight the threatening again starvation? Should we wait for the second generation of efficient biofuels, made from non food-derived products and cultivation wastes? This book analyses this delicate debate through 5 main questions: do they starve the world? Are they a clean energy source? Do they contribute to deforestation? Are they economically practicable? Is the second generation ready? (J.S.)

  8. Market possibilities for biofuels

    International Nuclear Information System (INIS)

    The market for biofuels in Sweden after introduction of a proposed CO2-tax on fossil fuels is forecast. The competition between biofuels, fossil fuels and electricity is described for important market segments such as: Paper industry, Sawmills, Other energy-intensive industry, Power and heat producers, small Heat producers, and for Space heating of one-family houses. A market increase of the use of biofuels is probable for the segment small (district) heating centrals, 10 TWh in the next ten year period and even more during a longer period. Other market segments will not be much affected. An increased use of biofuels in paper and pulp industry will not influence the fuel market, since the increase will happen in the industry's normal lumber purchase. (2 figs., 18 tabs.)

  9. The biofuels, situation, perspectives

    International Nuclear Information System (INIS)

    The climatic change with the fight against the greenhouse effect gases, sees the development of ''clean'' energy sources. Meanwhile the biofuels remain penalized by their high production cost, the interest is increasing. Facing their development ecologists highlight the environmental and social negative impacts of the development of the biofuels. The author aims to take stock on the techniques and the utilizations. (A.L.B.)

  10. Microalgae: biofuel production

    OpenAIRE

    Babita Kumari; Vinay Sharma

    2013-01-01

    In the present day, microalgae feedstocks are gaining interest in energy scenario due to their fast growth potential coupled with relatively high lipid, carbohydrate and nutrients contents. All of these properties render them an excellent source for biofuels such as biodiesel, bioethanol and biomethane; as well as a number of other valuable pharmaceutical and nutraceutical products. The present review is a critical appraisal of the commercialization potential of microalgae biofuels....

  11. Turbomachinery in Biofuel Production

    OpenAIRE

    Görling, Martin

    2011-01-01

    The aim for this study has been to evaluate the integration potential of turbo-machinery into the production processes of biofuels. The focus has been on bio-fuel produced via biomass gasification; mainly methanol and synthetic natural gas. The research has been divided into two parts; gas and steam turbine applications. Steam power generation has a given role within the fuel production process due to the large amounts of excess chemical reaction heat. However, large amounts of the steam prod...

  12. Outlook for advanced biofuels

    OpenAIRE

    Hamelinck, Carlo Noël

    2004-01-01

    Modern use of biomass can play an important role in a sustainable energy supply. Biomass abounds in most parts of the world and substantial amounts could be produced at low costs. Motor biofuels seem a sensible application of biomass: they are among the few sustainable alternatives to the transportation sector and can address many of the problems associated with mineral oil. Many biofuels are conceivable. Biodiesel (from oil crops) and ethanol from sugar beets or grains are already used in pr...

  13. Public acceptance of biofuels

    International Nuclear Information System (INIS)

    The public acceptance of biofuels in Greece is examined in this work. The analysis of 571 face to face interviews shows that 90.7% of the respondents believe that climatic changes are related to fossil fuel consumption, while only 23.8% know the difference between biodiesel and bioethanol. 76.1% believe that energy saving should precede the use of an alternative source of energy. Only 27.3% believe that priority must be given to biofuels over other renewable energy sources. Only 49.9% think that the use of biofuels can be an effective solution against climatic changes and 53.9% believe that the use of biofuels can be an effective solution for the energy problem. Finally, 80.9% of the car owners are willing to use biofuels, 44.8% are willing to pay the supplementary amount of 0.06 Euro /L of the fuel market price, while the average amount reported as willing to pay was 0.079 Euro /L on top of the fuel market price. Furthermore, eight models correlating the eight main responses with several socioeconomic variables are developed and analyzed. Those findings heave important policy implications related to the use and promotion of biofuels.

  14. Public acceptance of biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Savvanidou, Electra; Zervas, Efthimios; Tsagarakis, Konstantinos P. [Department of Environmental Engineering, Democritus University of Thrace, Vas. Sofias 12, 67100 Xanthi (Greece)

    2010-07-15

    The public acceptance of biofuels in Greece is examined in this work. The analysis of 571 face to face interviews shows that 90.7% of the respondents believe that climatic changes are related to fossil fuel consumption, while only 23.8% know the difference between biodiesel and bioethanol. 76.1% believe that energy saving should precede the use of an alternative source of energy. Only 27.3% believe that priority must be given to biofuels over other renewable energy sources. Only 49.9% think that the use of biofuels can be an effective solution against climatic changes and 53.9% believe that the use of biofuels can be an effective solution for the energy problem. Finally, 80.9% of the car owners are willing to use biofuels, 44.8% are willing to pay the supplementary amount of 0.06 EUR/L of the fuel market price, while the average amount reported as willing to pay was 0.079 EUR/L on top of the fuel market price. Furthermore, eight models correlating the eight main responses with several socioeconomic variables are developed and analyzed. Those findings heave important policy implications related to the use and promotion of biofuels. (author)

  15. Intrauterine insemination of cultured peripheral blood mononuclear cells prior to embryo transfer improves clinical outcome for patients with repeated implantation failures.

    Science.gov (United States)

    Madkour, Aicha; Bouamoud, Nouzha; Louanjli, Noureddine; Kaarouch, Ismail; Copin, Henri; Benkhalifa, Moncef; Sefrioui, Omar

    2016-02-01

    Implantation failure is a major limiting factor in assisted reproduction improvement. Dysfunction of embryo-maternal immuno-tolerance pathways may be responsible for repeated implantation failures. This fact is supported by immunotropic theory stipulating that maternal immune cells, essentially uterine CD56+ natural killer cells, are determinants of implantation success. In order to test this hypothesis, we applied endometrium immuno-modulation prior to fresh embryo transfer for patients with repeated implantation failures. Peripheral blood mononuclear cells were isolated from repeated implantation failure patients undergoing assisted reproductive technology cycles. On the day of ovulation induction, cells were isolated and then cultured for 3 days and transferred into the endometrium cavity prior to fresh embryo transfer. This immunotherapy was performed on 27 patients with repeated implantation failures and compared with another 27 patients who served as controls. Implantation and clinical pregnancy were increased significantly in the peripheral blood mononuclear cell test versus control (21.54, 44.44 vs. 8.62, 14.81%). This finding suggests a clear role for endometrium immuno-modulation and the inflammation process in implantation success. Our study showed the feasibility of intrauterine administration of autologous peripheral blood mononuclear cells as an effective therapy to improve clinical outcomes for patients with repeated implantation failures and who are undergoing in vitro fertilization cycles. PMID:25613318

  16. IGF-1,bFGF EXPRESSION AND VASCULAR REGENERATION IN ACUTE INFARCTED CANINE MYOCARDIUM AFTER AUTOLOGUS SKELETAL MUSCLE SATELLITE CELL IMPLANTATION

    Institute of Scientific and Technical Information of China (English)

    朱洪生; 钟竑; 张臻

    2003-01-01

    Objective To study the cell growth factor secretion and vascular regeneration in acute infarcted myocardium after autologous skeletal muscle satellite cell implantation.MethodsAutologous skeletal muscle satellite cells from adult mongrel canine were implanted into the acute myocardial infarct site via the ligated left anterior descending (LAD) artery. Specimens were harvested at 2, 4, 8 weeks after implantation for the expression of insulin like growth factor-1 (IGF-1), basic fibroblast growth factor (Bfgf) and the vascular density.ResultsThe expression of IGF-1, Bfgf and the vascular density in skeletal muscle satellite cell implant group were higher than that in the control group.ConclusionThe skeletal muscle satellite cells, after being implanted into the acute myocardial infarction, not only showed myocardial regeneration, but also showed the ability to secrete the cell factors, hence representing a positive effect on the regeneration of the infarcted myocardium.

  17. Making biofuels sustainable

    International Nuclear Information System (INIS)

    Full text: As the twentieth century drew to a close, there was considerable support for the use of biofuels as a source of renewable energy. To many people, they offered significant savings in greenhouse gas emissions compared to fossil fuels, an opportunity for reduced dependency on oil for transport, and potential as a counter weight to increasing oil prices. They also promised an opportunity for rural economies to benefit from a new market for their products and a chance of narrowing the gap between rich and poor nations. Biofuel development was encouraged by government subsidies, and rapid growth occurred in many parts of the world. Forty per cent of Brazilian sugar cane is used for biofuel production, for example, as is almost a quarter of maize grown in the United States. Although only around 1 per cent of arable land is cultivated to grow feedstock for biofuels, there has been increasing concern over the way a largely unchecked market has developed, and about its social and environmental consequences. Recent research has confirmed that food prices have been driven significantly higher by competition for prime agricultural land and that savings in greenhouse gas emissions are much smaller - and in some cases entirely eliminated - when environmentally important land, such as rainforest, is destroyed to grow biofuels. As a result, many now believe that the economic benefits of biofuels have been obtained at too high a social and environmental price, and they question whether they can be a truly sustainable source of energy. The United Kingdom has always had sustainability at the heart of its biofuel policies and set up the Renewable Fuels Agency to ensure that this goal was met. The direct effects of biofuel production are already being assessed through five measures of environmental performance and two measures of social performance, as well as measures of the energy efficiency of the production processes used and of the greenhouse gas savings achieved

  18. Characterization of the aspects of osteoprogenitor cell interactions with physical tetracalcium phosphate anchorage on titanium implant surfaces

    International Nuclear Information System (INIS)

    Well-designed implants are used not only to modify the geometry of the implant but also to change the chemical properties of its surfaces. The present study aims to assess the biofunctional effects of tetracalcium phosphate (TTCP) particles as a physical anchor on the implant surface derived through sandblasting. The characteristics of the surface, cell viability, and alkaline phosphatase (ALP) activity toward osteoprogenitor cells (D1) were obtained. D1 cells were cultured on a plain surface that underwent sandblasting and acid etching (SLA) (control SLA group) and on different SLA surfaces with different anchoring TTCP rates (new test groups, M and H). The mean anchoring rates were 57% (M) and 74% (H), and the anchored thickness was estimated to range from 12.6 μm to 18.3 μm. Compared with the control SLA surface on Ti substrate, the new test groups with different TTCP anchoring rates (M and H) failed to improve cell proliferation significantly but had a well-differentiated D1 cell phenotype that enhanced ALP expression in the early stage of cell cultures, specifically, at day 7. Results suggest that the SLA surface with anchored TTCP can accelerate progenitor bone cell mineralization. This study shows the potential clinical application of the constructed geometry in TTCP anchorage on Ti for dental implant surface modification. - Highlights: • TTCP (tetracalcium phosphate) as a physical anchorage on implant is characterized. • Theoretical values of anchored thickness and capping areas were estimated. • TTCP anchored by sandblasting can accelerate progenitor bone cell mineralization. • TTCP anchored on SLA (sandblasting and acid etching) surface is a promising method

  19. Characterization of the aspects of osteoprogenitor cell interactions with physical tetracalcium phosphate anchorage on titanium implant surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Chia-Ling [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University, Taichung 40724, Taiwan (China); Dental Medical Devices and Materials Research Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chang, Ya-Yuan; Liou, Cian-Hua [Alliance Global Technology Co., Ltd., Kaohsiung Medical Device Special Zone in Southern Taiwan Science Park, Kaohsiung 82151, Taiwan (China); Chen, Wen-Cheng, E-mail: wencchen@fcu.edu.tw [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, Feng Chia University, Taichung 40724, Taiwan (China)

    2015-04-01

    Well-designed implants are used not only to modify the geometry of the implant but also to change the chemical properties of its surfaces. The present study aims to assess the biofunctional effects of tetracalcium phosphate (TTCP) particles as a physical anchor on the implant surface derived through sandblasting. The characteristics of the surface, cell viability, and alkaline phosphatase (ALP) activity toward osteoprogenitor cells (D1) were obtained. D1 cells were cultured on a plain surface that underwent sandblasting and acid etching (SLA) (control SLA group) and on different SLA surfaces with different anchoring TTCP rates (new test groups, M and H). The mean anchoring rates were 57% (M) and 74% (H), and the anchored thickness was estimated to range from 12.6 μm to 18.3 μm. Compared with the control SLA surface on Ti substrate, the new test groups with different TTCP anchoring rates (M and H) failed to improve cell proliferation significantly but had a well-differentiated D1 cell phenotype that enhanced ALP expression in the early stage of cell cultures, specifically, at day 7. Results suggest that the SLA surface with anchored TTCP can accelerate progenitor bone cell mineralization. This study shows the potential clinical application of the constructed geometry in TTCP anchorage on Ti for dental implant surface modification. - Highlights: • TTCP (tetracalcium phosphate) as a physical anchorage on implant is characterized. • Theoretical values of anchored thickness and capping areas were estimated. • TTCP anchored by sandblasting can accelerate progenitor bone cell mineralization. • TTCP anchored on SLA (sandblasting and acid etching) surface is a promising method.

  20. A Comparison of Epithelial Cells, Fibroblasts, and Osteoblasts in Dental Implant Titanium Topographies

    OpenAIRE

    Fu-Yuan Teng; Chia-Ling Ko; Hsien-Nan Kuo; Jin-Jia Hu; Jia-Horng Lin; Ching-Wen Lou; Chun-Cheng Hung; Yin-Lai Wang; Cheng-Yi Cheng; Wen-Cheng Chen

    2012-01-01

    The major challenge for dental implants is achieving optimal esthetic appearance and a concept to fulfill this criterion is evaluated. The key to an esthetically pleasing appearance lies in the properly manage the soft tissue profile around dental implants. A novel implant restoration technique on the surface was proposed as a way to augment both soft- and hard-tissue profiles at potential implant sites. Different levels of roughness can be attained by sandblasting and acid etching, and a tet...

  1. Circadian continuous chemotherapy of renal cell carcinoma with an implantable, programmable infusion pump.

    Science.gov (United States)

    Damascelli, B; Marchianò, A; Spreafico, C; Lutman, R; Salvetti, M; Bonalumi, M G; Mauri, M; Garbagnati, F; Del Nero, A; Comeri, G

    1990-07-15

    The authors treated 42 metastatic renal cell carcinoma (RCC) patients who had received no previous chemotherapy or radiation therapy with circadian venous continuous infusion of 5-fluoro-2-deoxyuridine (FUDR). The drug was delivered by Medtronic Synchromed implantable pump (Medtronic, Inc., Minneapolis, MN) in 14-day cycles alternating with 14-day intervals of heparinized physiologic saline infusion. In the course of 24 months 444 cycles of therapy have been given for a total of 12449 days of pump function. Of the patients observed for at least 3 months (range, 3 to 23 months; median, 7 months) three showed complete response (7%; 95% confidence interval, 0% to 15%), three partial response (7%; confidence interval, 0% to 15%), 18 stable disease, and 18 showed progression. Eighteen patients, all with advanced disease at the time of implantation, were living 6 months after treatment started. Circadian continuous central venous infusion of FUDR is minimally toxic. The FUDR can be delivered safely and conveniently in this way for long spans. This therapy is as active as any currently available treatment, is administered in an entirely outpatient setting, and is associated with a normal quality of life. PMID:2142443

  2. Biocorrosion behavior and cell viability of adhesive polymer coated magnesium based alloys for medical implants

    Science.gov (United States)

    Abdal-hay, Abdalla; Dewidar, Montasser; Lim, Jae Kyoo

    2012-11-01

    The present study was ultimately aimed to design novel adhesive biodegradable polymer, poly(vinyl acetate) (PVAc), coatings onto Mg based alloys by the dip-coating technique in order to control the degradation rate and enhance the biocompatibility of magnesium alloys. The influence of various solvents on PVAc surface topography and their protection of Mg alloys were dramatically studied in vitro. Electrochemical polarization, degradation, and PVAc film cytocompatibility were also tested. Our results showed that the solvent had a significant effect on coating quality. PVAc/dichloromethane solution showed a porous structure and solution concentration could control the porous size. The coatings prepared using tetrahydrofuran and dimethylformamide solvents are exceptional in their ability to generate porous morphology even at low polymer concentration. In general, the corrosion performance appears to be different on different PVAc-solvent system. Immersion tests illustrated that the porous morphology on PVAc stabilized corrosion rates. A uniform corrosion attack in artificial simulation body fluid was also exhibited. The cytocompatibility of osteoblast cells (MC3T3) revealed high adherence, proliferation, and survival on the porous structure of PVAc coated Mg alloy, which was not observed for the uncoated samples. This novel PVAc coating is a promising candidate for biodegradable implant materials, which might widen the use of Mg based implants.

  3. Nanoporous metals for biodegradable implants: Initial bone mesenchymal stem cell adhesion and degradation behavior.

    Science.gov (United States)

    Heiden, Michael; Huang, Sabrina; Nauman, Eric; Johnson, David; Stanciu, Lia

    2016-07-01

    Nanostructured Fe-Mn and Fe-Mn-Zn metal scaffolds were generated through a well-controlled selective leaching process in order to fulfill the growing demand for adjustable degradation rates and improved cellular response of resorbable materials. Mouse bone marrow mesenchymal stem cells (D1 ORL UVA) were seeded onto eleven, carefully chosen nanoporous surfaces for 24 h in vitro. Using a combination of fluorescence microscopy, scanning electron microscopy (SEM), and an MTS assay, it was discovered that scaffolds with nanoscale roughened surfaces had increased cell attachment by up to 123% compared to polished smooth Fe-Mn surfaces. Significant cell spreading and construction of cell multilayers were also apparent after 24 h, suggesting better adhesion. Additionally, static electrochemical polarization experiments revealed an improvement of up to 26% in the actual rate of biodegradation for Fe-Mn surface-modified materials. However, any residual concentration of zinc after leaching was shown to slightly increase corrosion resistance. The results demonstrate that selectively leached, nanostructured Fe-Mn surfaces have the potential of being tailored to a diverse set of transient implant scenarios, while also effectively boosting overall biocompatibility, initial cell attachment, and degradation rate. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1747-1758, 2016. PMID:26990484

  4. Thyroid Autoimmunity is Associated with Decreased Cytotoxicity T Cells in Women with Repeated Implantation Failure

    Directory of Open Access Journals (Sweden)

    Chunyu Huang

    2015-08-01

    Full Text Available Thyroid autoimmunity (TAI, which is defined as the presence of autoantibodies against thyroid peroxidase (TPO and/or thyroglobulin (TG, is related to repeated implantation failure (RIF. It is reported that TAI was involved in reproductive failure not only through leading thyroid function abnormality, but it can also be accompanied with immune imbalance. Therefore, this study was designed to investigate the association of thyroid function, immune status and TAI in women with RIF. Blood samples were drawn from 72 women with RIF to evaluate the prevalence of TAI, the thyroid function, the absolute numbers and percentages of lymphocytes. The prevalence of thyroid function abnormality in RIF women with TAI was not significantly different from that in RIF women without TAI (c2 = 0.484, p > 0.05. The absolute number and percentage of T cells, T helper (Th cells, B cells and natural killer (NK cells were not significantly different in RIF women with TAI compared to those without TAI (all p > 0.05. The percentage of T cytotoxicity (Tc cells was significantly decreased in RIF women with TAI compared to those without TAI (p < 0.05. Meanwhile, Th/Tc ratio was significantly increased (p < 0.05. These results indicated that the decreased Tc percentage and increased Th/Tc ratio may be another influential factor of adverse pregnancy outcomes in RIF women with TAI.

  5. Producing biofuels using polyketide synthases

    Science.gov (United States)

    Katz, Leonard; Fortman, Jeffrey L; Keasling, Jay D

    2013-04-16

    The present invention provides for a non-naturally occurring polyketide synthase (PKS) capable of synthesizing a carboxylic acid or a lactone, and a composition such that a carboxylic acid or lactone is included. The carboxylic acid or lactone, or derivative thereof, is useful as a biofuel. The present invention also provides for a recombinant nucleic acid or vector that encodes such a PKS, and host cells which also have such a recombinant nucleic acid or vector. The present invention also provides for a method of producing such carboxylic acids or lactones using such a PKS.

  6. Anti-tumor effects of 125I radioactive particles implantation on transplantated tumor model of human breast cancer cells in nude mice

    International Nuclear Information System (INIS)

    Objective: To study the anti-tumor effects of 125I radioactive particles implantation on transplantated tumor model of human breast cancer cells in nude mice and clarify their anti-tumor mechanisms. Methods 120 nude mice transplantated with human breast cancer cells MCF-7 were randomly divided into 3 groups (n=40): 125I radioactive particles implanted group, non-radioactive particles implanted group and non-particles implanted group. The articles were implanted into mice according to Pairs system principle. The expressions of Fas mRNA and protein and the activaties of caspase-3 and caspase-8 enzyme were detected by RT-PCR and Western blotting. The changes of cell cycle were detected by flow cytometry. Results: Compared with non-radioactive particles implanted group and non-particles implanted group, the size of cancer tissues in 125I radioactive particles implanted group was reduced significantly (P0/G1 phase was significantly increased (P125I radioactive particles into transplantated tumor model of human breast cancer cells can kill tumor cells, inhibit the growth cycle of tumor cells and induce the apoptosis of tumor cells in nude mice. (authors)

  7. Titanium Implant Impairment and Surrounding Muscle Cell Death Following High-Salt Diet: An In Vivo Study.

    Directory of Open Access Journals (Sweden)

    Mathieu Lecocq

    Full Text Available High-salt consumption has been widely described as a risk factor for cardiovascular, renal and bone functions. In the present study, the extent to which high-salt diet could influence Ti6Al4V implant surface characteristic, its adhesion to rat tibial crest, and could modify muscle cell viability of two surrounding muscles, was investigated in vivo. These parameters have also been assessed following a NMES (neuro-myoelectrostimulation program similar to that currently used in human care following arthroplasty.After a three-week diet, a harmful effect on titanium implant surface and muscle cell viability was noted. This is probably due to salt corrosive effect on metal and then release of toxic substance around biologic tissue. Moreover, if the use of NMES with high-salt diet induced muscles damages, the latter were higher when implant was added. Unexpectedly, higher implant-to-bone adhesion was found for implanted animals receiving salt supplementation.Our in vivo study highlights the potential dangerous effect of high-salt diet in arthroplasty based on titanium prosthesis. This effect appears to be more important when high-salt diet is combined with NMES.

  8. Implanted hair follicle stem cells form Schwann cells that support repair of severed peripheral nerves

    OpenAIRE

    Amoh, Yasuyuki; Li, Lingna; Campillo, Raul; Kawahara, Katsumasa; Katsuoka, Kensei; Penman, Sheldon; Robert M Hoffman

    2005-01-01

    The hair follicle bulge area is an abundant, easily accessible source of actively growing, pluripotent adult stem cells. Nestin, a protein marker for neural stem cells, also is expressed in follicle stem cells and their immediate, differentiated progeny. The fluorescent protein GFP, whose expression is driven by the nestin regulatory element in transgenic mice, served to mark the follicle cell fate. The pluripotent nestin-driven GFP stem cells are positive for the stem cell marker CD34 but ne...

  9. COCHLEAR IMPLANTATION: MY EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Shankar

    2015-12-01

    Full Text Available Cochlear implant is a small, surgically implanted complex electronic device that can help to provide a sense of sound to a person with severe to profound sensorineural hearing loss. This type of hearing loss, typically involves damage to hair cells in the cochlea, as a result sound cannot reach the auditory nerve which usually receives information from hair cells. A cochlear implant skips the damaged hair cells and to stimulate the auditory nerve directly. An implant does not restore normal hearing, instead it can give a deaf person a useful representation of sounds in the environment and help him or her to understand speech. I am here presenting this article in relation to the indications, intraoperative and postoperative complications of cochlear implantation in our institute since January 2013. Children who receive implants at earlier age, outperform their peers who are implanted at a later age. This is reflected in all the areas of speech and language development.

  10. World Biofuels Study

    Energy Technology Data Exchange (ETDEWEB)

    Alfstad,T.

    2008-10-01

    This report forms part of a project entitled 'World Biofuels Study'. The objective is to study world biofuel markets and to examine the possible contribution that biofuel imports could make to help meet the Renewable Fuel Standard (RFS) of the Energy Independence and Security Act of 2007 (EISA). The study was sponsored by the Biomass Program of the Assistant Secretary for Energy Efficiency and Renewable Energy (EERE), U.S. Department of Energy. It is a collaborative effort among the Office of Policy and International Affairs (PI), Department of Energy and Oak Ridge National Laboratory (ORNL), National Renewable Energy Laboratory (NREL) and Brookhaven National Laboratory (BNL). The project consisted of three main components: (1) Assessment of the resource potential for biofuel feedstocks such as sugarcane, grains, soybean, palm oil and lignocellulosic crops and development of supply curves (ORNL). (2) Assessment of the cost and performance of biofuel production technologies (NREL). (3) Scenario-based analysis of world biofuel markets using the ETP global energy model with data developed in the first parts of the study (BNL). This report covers the modeling and analysis part of the project conducted by BNL in cooperation with PI. The Energy Technology Perspectives (ETP) energy system model was used as the analytical tool for this study. ETP is a 15 region global model designed using the MARKAL framework. MARKAL-based models are partial equilibrium models that incorporate a description of the physical energy system and provide a bottom-up approach to study the entire energy system. ETP was updated for this study with biomass resource data and biofuel production technology cost and performance data developed by ORNL and NREL under Tasks 1 and 2 of this project. Many countries around the world are embarking on ambitious biofuel policies through renewable fuel standards and economic incentives. As a result, the global biofuel demand is expected to grow very

  11. Temporal network based analysis of cell specific vein graft transcriptome defines key pathways and hub genes in implantation injury.

    Directory of Open Access Journals (Sweden)

    Manoj Bhasin

    Full Text Available Vein graft failure occurs between 1 and 6 months after implantation due to obstructive intimal hyperplasia, related in part to implantation injury. The cell-specific and temporal response of the transcriptome to vein graft implantation injury was determined by transcriptional profiling of laser capture microdissected endothelial cells (EC and medial smooth muscle cells (SMC from canine vein grafts, 2 hours (H to 30 days (D following surgery. Our results demonstrate a robust genomic response beginning at 2 H, peaking at 12-24 H, declining by 7 D, and resolving by 30 D. Gene ontology and pathway analyses of differentially expressed genes indicated that implantation injury affects inflammatory and immune responses, apoptosis, mitosis, and extracellular matrix reorganization in both cell types. Through backpropagation an integrated network was built, starting with genes differentially expressed at 30 D, followed by adding upstream interactive genes from each prior time-point. This identified significant enrichment of IL-6, IL-8, NF-κB, dendritic cell maturation, glucocorticoid receptor, and Triggering Receptor Expressed on Myeloid Cells (TREM-1 signaling, as well as PPARα activation pathways in graft EC and SMC. Interactive network-based analyses identified IL-6, IL-8, IL-1α, and Insulin Receptor (INSR as focus hub genes within these pathways. Real-time PCR was used for the validation of two of these genes: IL-6 and IL-8, in addition to Collagen 11A1 (COL11A1, a cornerstone of the backpropagation. In conclusion, these results establish causality relationships clarifying the pathogenesis of vein graft implantation injury, and identifying novel targets for its prevention.

  12. Bio-fuels

    International Nuclear Information System (INIS)

    This report presents an overview of the technologies which are currently used or presently developed for the production of bio-fuels in Europe and more particularly in France. After a brief history of this production since the beginning of the 20. century, the authors describe the support to agriculture and the influence of the Common Agricultural Policy, outline the influence of the present context of struggle against the greenhouse effect, and present the European legislative context. Data on the bio-fuels consumption in the European Union in 2006 are discussed. An overview of the evolution of the activity related to bio-fuels in France, indicating the locations of ethanol and bio-diesel production facilities, and the evolution of bio-fuel consumption, is given. The German situation is briefly presented. Production of ethanol by fermentation, the manufacturing of ETBE, the bio-diesel production from vegetable oils are discussed. Second generation bio-fuels are then presented (cellulose enzymatic processing), together with studies on thermochemical processes and available biomass resources

  13. In vivo PET imaging of implanted cells in a Parkinson's disease rat model

    International Nuclear Information System (INIS)

    Objective: It is a major hurdle for the researchers to mornitor the implanted cells differentiation in vivo. This study was designed as a proof of concept of the feasibility to track the efficacy of transplanted human retinal pigment epithelial (RPE) cells in a Parkinson's disease (PD) rat model using PET. Methods: RPE cells or normal saline were injected into striatum of the injured side of the models in treated group(12 rats) and control group(11 rats), respectively. PET imaging on both groups was under- taken before and at certain intervals after the transplantation using 11C-raclopride and 11C-CFT as the markers. Behavioral observation and immunofluorescence confocal microscopy also conducted to prove PET results. Results: PET studies showed increased 11C-raclopride accumulation and decreased 11C-CFT in the injured side of striatum in both groups before transplantation. The 11C-raclopride striatum/cerebellum ratio at ipsilateral side decreased from 1.870 ± 0.465 to 1.601 ± 0.257 after transplantation, along with a concomitant increase of 11C-CFT accumulation in the same area (1.827 ± 0.347 to 2.336 ± 0.326) in treated group. The changes of PET studies paralleled the behavior states and confocal microscopic observations in the treated animals. Conclusion: Even a clinical PET scanner could provide to certain extent some information on the existence and in vivo differentiation of RPE cells in a PD rat model. (authors)

  14. Lithium-manganese dioxide cells for implantable defibrillator devices-Discharge voltage models

    Science.gov (United States)

    Root, Michael J.

    The discharge potential behavior of lithium-manganese dioxide cells designed for implantable cardiac defibrillators was characterized as a function of extent of cell depletion for tests designed to discharge the cells for times between 1 and 7 years. The discharge potential curves may be separated into two segments from 0 ≤ x ≤ ∼0.51 and ∼0.51 ≤ x ≤ 1.00, where x is the dimensionless extent of discharge referenced to the rated cell capacity. The discharge potentials conform to Tafel kinetics in each segment. This behavior allows the discharge potential curves to be predicted for an arbitrary discharge load and long term discharge performance may be predicted from short term test results. The discharge potentials may subsequently be modeled by fitting the discharge curves to empirical functions like polynomials and Padé approximants. A function based on the Nernst equation that includes a term accounting for nonideal interactions between lithium ions and the cathode host material, such as the Redlich-Kister relationship, also may be used to predict discharge behavior.

  15. Lithium-manganese dioxide cells for implantable defibrillator devices - Discharge voltage models

    Energy Technology Data Exchange (ETDEWEB)

    Root, Michael J. [Cardiac Rhythm Management Research and Development, Boston Scientific Corp., 4100 Hamline Ave. N., St. Paul, MN 55112 (United States)

    2010-08-01

    The discharge potential behavior of lithium-manganese dioxide cells designed for implantable cardiac defibrillators was characterized as a function of extent of cell depletion for tests designed to discharge the cells for times between 1 and 7 years. The discharge potential curves may be separated into two segments from 0 {<=} x {<=} {proportional_to}0.51 and {proportional_to}0.51 {<=} x {<=} 1.00, where x is the dimensionless extent of discharge referenced to the rated cell capacity. The discharge potentials conform to Tafel kinetics in each segment. This behavior allows the discharge potential curves to be predicted for an arbitrary discharge load and long term discharge performance may be predicted from short term test results. The discharge potentials may subsequently be modeled by fitting the discharge curves to empirical functions like polynomials and Pade approximants. A function based on the Nernst equation that includes a term accounting for nonideal interactions between lithium ions and the cathode host material, such as the Redlich-Kister relationship, also may be used to predict discharge behavior. (author)

  16. Plasma-deposited fluorocarbon polymer films on titanium for preventing cell adhesion: a surface finishing for temporarily used orthopaedic implants

    Science.gov (United States)

    Finke, B.; Testrich, H.; Rebl, H.; Walschus, U.; Schlosser, M.; Zietz, C.; Staehlke, S.; Nebe, J. B.; Weltmann, K. D.; Meichsner, J.; Polak, M.

    2016-06-01

    The design of a titanium implant surface should ideally support its later application in clinical use. Temporarily used implants have to fulfil requirements different from permanent implants: they should ensure the mechanical stabilization of the bone stock but in trauma surgery they should not be integrated into the bone because they will be removed after fracture healing. Finishing of the implant surface by a plasma-fluorocarbon-polymer (PFP) coating is a possible approach for preventing cell adhesion of osteoblasts. Two different low pressure gas-discharge plasma processes, microwave (MW 2.45 GHz) and capacitively coupled radio frequency (RF 13.56 MHz) plasma, were applied for the deposition of the PFP film using a mixture of the precursor octafluoropropane (C3F8) and hydrogen (H2). The thin films were characterized by x-ray photoelectron spectroscopy, Fourier transform infrared reflection absorption spectroscopy, and water contact angle measurements. Cell culture experiments show that cell adhesion and spreading of MG-63 osteoblasts were clearly reduced or nonexistent on these surfaces, also after 24 h of storage in the cell culture medium. In vivo data demonstrated that the local inflammatory tissue response for the PFP films deposited in MW and RF plasma were comparable to uncoated controls.

  17. Biocorrosion behavior and cell viability of adhesive polymer coated magnesium based alloys for medical implants

    International Nuclear Information System (INIS)

    Highlights: ► The corrosion behavior of magnesium for orthopedic applications is extremely poor. ► The solvent (DCM, THF and DMF) had a strong effect on the coatings performance. ► Mg bar alloy coated with PVAc/DCM layers provided an excellent bonding strength. ► Treated samples indicated significant damping for the degradation rate. ► Cytocompatibility on MC3T3 cells of the PVAc/DCM samples revealed a good behavior. - Abstract: The present study was ultimately aimed to design novel adhesive biodegradable polymer, poly(vinyl acetate) (PVAc), coatings onto Mg based alloys by the dip-coating technique in order to control the degradation rate and enhance the biocompatibility of magnesium alloys. The influence of various solvents on PVAc surface topography and their protection of Mg alloys were dramatically studied in vitro. Electrochemical polarization, degradation, and PVAc film cytocompatibility were also tested. Our results showed that the solvent had a significant effect on coating quality. PVAc/dichloromethane solution showed a porous structure and solution concentration could control the porous size. The coatings prepared using tetrahydrofuran and dimethylformamide solvents are exceptional in their ability to generate porous morphology even at low polymer concentration. In general, the corrosion performance appears to be different on different PVAc–solvent system. Immersion tests illustrated that the porous morphology on PVAc stabilized corrosion rates. A uniform corrosion attack in artificial simulation body fluid was also exhibited. The cytocompatibility of osteoblast cells (MC3T3) revealed high adherence, proliferation, and survival on the porous structure of PVAc coated Mg alloy, which was not observed for the uncoated samples. This novel PVAc coating is a promising candidate for biodegradable implant materials, which might widen the use of Mg based implants.

  18. Biocorrosion behavior and cell viability of adhesive polymer coated magnesium based alloys for medical implants

    Energy Technology Data Exchange (ETDEWEB)

    Abdal-hay, Abdalla [Departmentt of Bionano System Engineering, College of Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Mechanical Design Engineering, Advanced wind power system research institute, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Dewidar, Montasser [Department of Materials and Mechanical Design, Faculty of Energy Engineering, South Valley University, Aswan (Egypt); Lim, Jae Kyoo, E-mail: jklim@jbnu.ac.kr [Department of Mechanical Design Engineering, Advanced wind power system research institute, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer The corrosion behavior of magnesium for orthopedic applications is extremely poor. Black-Right-Pointing-Pointer The solvent (DCM, THF and DMF) had a strong effect on the coatings performance. Black-Right-Pointing-Pointer Mg bar alloy coated with PVAc/DCM layers provided an excellent bonding strength. Black-Right-Pointing-Pointer Treated samples indicated significant damping for the degradation rate. Black-Right-Pointing-Pointer Cytocompatibility on MC3T3 cells of the PVAc/DCM samples revealed a good behavior. - Abstract: The present study was ultimately aimed to design novel adhesive biodegradable polymer, poly(vinyl acetate) (PVAc), coatings onto Mg based alloys by the dip-coating technique in order to control the degradation rate and enhance the biocompatibility of magnesium alloys. The influence of various solvents on PVAc surface topography and their protection of Mg alloys were dramatically studied in vitro. Electrochemical polarization, degradation, and PVAc film cytocompatibility were also tested. Our results showed that the solvent had a significant effect on coating quality. PVAc/dichloromethane solution showed a porous structure and solution concentration could control the porous size. The coatings prepared using tetrahydrofuran and dimethylformamide solvents are exceptional in their ability to generate porous morphology even at low polymer concentration. In general, the corrosion performance appears to be different on different PVAc-solvent system. Immersion tests illustrated that the porous morphology on PVAc stabilized corrosion rates. A uniform corrosion attack in artificial simulation body fluid was also exhibited. The cytocompatibility of osteoblast cells (MC3T3) revealed high adherence, proliferation, and survival on the porous structure of PVAc coated Mg alloy, which was not observed for the uncoated samples. This novel PVAc coating is a promising candidate for biodegradable implant materials, which might

  19. BioFuels Atlas (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Moriarty, K.

    2011-02-01

    Presentation for biennial merit review of Biofuels Atlas, a first-pass visualization tool that allows users to explore the potential of biomass-to-biofuels conversions at various locations and scales.

  20. Toward angiogenesis of implanted bio-artificial liver using scaffolds with type I collagen and adipose tissue-derived stem cells

    OpenAIRE

    Lee, Jae Geun; Bak, Seon Young; Nahm, Ji Hae; Lee, Sang Woo; Min, Seon Ok; Kim, Kyung Sik

    2015-01-01

    Backgrounds/Aims Stem cell therapies for liver disease are being studied by many researchers worldwide, but scientific evidence to demonstrate the endocrinologic effects of implanted cells is insufficient, and it is unknown whether implanted cells can function as liver cells. Achieving angiogenesis, arguably the most important characteristic of the liver, is known to be quite difficult, and no practical attempts have been made to achieve this outcome. We carried out this study to observe the ...

  1. The legitimacy of biofuel certification

    OpenAIRE

    Partzsch, Lena

    2009-01-01

    Abstract The biofuel boom is placing enormous demands on existing cropping systems, with the most crucial consequences in the agri-food sector. The biofuel industry is responding by initiating private governance and certification. The Roundtable on Sustainable Palm Oil (RSPO) and the Cramer Commission, among others, have formulated criteria on ?sustainable? biofuel production and processing. This article explores the legitimacy of private governance and certification by the biofuel...

  2. Microalgae biofuel potentials (review).

    Science.gov (United States)

    Ghasemi, Y; Rasoul-Amini, S; Naseri, A T; Montazeri-Najafabady, N; Mobasher, M A; Dabbagh, F

    2012-01-01

    With the decrease of fossil based fuels and the environmental impact of them over the planet, it seems necessary to seek the sustainable sources of clean energy. Biofuels, is becoming a worldwide leader in the development of renewable energy resources. It is worthwhile to say that algal biofuel production is thought to help stabilize the concentration of carbon dioxide in the atmosphere and decrease global warming impacts. Also, among algal fuels' attractive characteristics, algal biodiesel is non toxic, with no sulfur, highly biodegradable and relatively harmless to the environment if spilled. Algae are capable of producing in excess of 30 times more oil per acre than corn and soybean crops. Currently, algal biofuel production has not been commercialized due to high costs associated with production, harvesting and oil extraction but the technology is progressing. Extensive research was conducted to determine the utilization of microalgae as an energy source and make algae oil production commercially viable. PMID:22586908

  3. Biofuels: making tough choices

    Energy Technology Data Exchange (ETDEWEB)

    Vermeulen, Sonja; Dufey, Annie; Vorley, Bill

    2008-02-15

    The jury is still out on biofuels. But one thing at least is certain: serious trade-offs are involved in the production and use of these biomass-derived alternatives to fossil fuels. This has not been lost on the European Union. The year kicked off with an announcement from the EU environment commissioner that it may be better for the EU to miss its target of reaching 10 per cent biofuel content in road fuels by 2020 than to compromise the environment and human wellbeing. The 'decision tree' outlined here can guide the interdependent processes of deliberation and analysis needed for making tough choices in national biofuels development.

  4. The Danish Biofuel Debate

    DEFF Research Database (Denmark)

    Hansen, Janus

    2014-01-01

    from the molecular level and envisions positive synergies in the use of biomass. The other is a holistic bioscarcity perspective originating in life-cycle analysis and ecology. This perspective works downwards from global resource scope conditions, and envisions negative consequences from an increased...... of biofuels enrol scientific authority to support their positions? The sociological theory of functional differentiation combined with the concept of advocacy coalition can help in exploring this relationship between scientific claims-making and the policy stance of different actors in public debates...... about biofuels. In Denmark two distinct scientific perspectives about biofuels map onto the policy debates through articulation by two competing advocacy coalitions. One is a reductionist biorefinery perspective originating in biochemistry and neighbouring disciplines. This perspective works upwards...

  5. Biogas and biofuels barometer

    International Nuclear Information System (INIS)

    European union countries are becoming more and more interested by the characteristics of biogas in terms of environment and energy production and are developing their proper channels of valorization according to their potential. In this way, biogas production reached nearly 5,3 million tons oil equivalent in 2006, representing a 13,6% increase with respect to 2005. Statistical data are provided on the primary energy production of biogas, the electricity production from biogas, gross heat production from biogas, and the representative firms of the biogas sector. In a second part the biofuels barometer is presented. The agricultural environment and landscape of the European Union countries is redefined a little more each year by energy crops for biofuel production. According to the first estimates for 2006, biofuel consumption reached 5,38 Mtoe last year in the EU, corresponding to a 1,8% share of the total consumption of fuels devoted to transport. (A.L.B.)

  6. Locally Advanced Breast Implant-Associated Anaplastic Large-Cell Lymphoma: A Case Report of Successful Treatment with Radiation and Chemotherapy

    OpenAIRE

    Estes, Christopher F.; Zhang, Da; Reyes, Ruben; Korentager, Richard; McGinness, Marilee; Lominska, Christopher

    2015-01-01

    The development of breast implant-associated anaplastic large-cell lymphoma (ALCL) is a rare phenomenon. A typical presentation is an effusion associated with a breast implant. Less commonly, disease can be more advanced locoregionally or distantly. The optimal treatment schema is a topic of debate: localized ALCL can potentially be cured with implant removal alone, while other cases in the literature, including those that are more advanced, have been treated with varying combinations of surg...

  7. Hydrogen bioelectrooxidation on gold nanoparticle-based electrodes modified by Aquifex aeolicus hydrogenase: Application to hydrogen/oxygen enzymatic biofuel cells.

    Science.gov (United States)

    Monsalve, Karen; Roger, Magali; Gutierrez-Sanchez, Cristina; Ilbert, Marianne; Nitsche, Serge; Byrne-Kodjabachian, Deborah; Marchi, Valérie; Lojou, Elisabeth

    2015-12-01

    For the first time, gold nanoparticle-based electrodes have been used as platforms for efficient immobilization of the [NiFe] hydrogenase from the hyperthermophilic bacterium Aquifex aeolicus. AuNPs were characterized by electronic microscopy, dynamic light scattering and UV-Vis spectroscopy. Two sizes around 20.0±5.3 nm and 37.2±4.3 nm nm were synthesized. After thiol-based functionalization, the AuNPs were proved to allow direct H2 oxidation over a large range of temperatures. A high current density up to 1.85±0.15 mA·cm(-2) was reached at the smallest AuNPs, which is 170 times higher than the one recorded at the bare gold electrode. The catalytic current was especially studied as a function of the AuNP size and amount, and procedure for deposition. A synergetic effect between the AuNP porous deposit and the increase surface area was shown. Compared to previously used nanomaterials such as carbon nanofibers, the covalent grafting of the enzyme on the thiol-modified gold nanoparticles was shown to enhance the stability of the hydrogenase. This bioanode was finally coupled to a biocathode where BOD from Myrothecium verrucaria was immobilized on AuNP-based film. The performance of the so-mounted H2/O2 biofuel cell was evaluated, and a power density of 0.25 mW·cm(-2) was recorded. PMID:25960259

  8. Electrochemistry of bilirubin oxidase and its use in preparation of a low cost enzymatic biofuel cell based on a renewable composite binder chitosan

    International Nuclear Information System (INIS)

    Graphical abstract: - Abstract: Spherical carbon nanoparticles KetjenBlack (KB) with a high sorption capacity together with conductivity increasing single walled carbon nanotubes (CNTs) were “glued” together by chitosan for the preparation of a composite. A biocathode with bilirubin oxidase (BOD) adsorbed within the composite was characterised and its composition optimised. A renewable biopolymer chitosan present in the composite offered (1) pre-concentration of BOD within the matrix via electrostatic interactions, (2) favourable orientation of BOD for a direct electron transfer (DET) between BOD and the composite, (3) electrochemical visibility of 3 redox sites present in BOD, (4) low charge transfer resistance, (5) high proton conductivity and (6) low overpotential for oxygen reduction. Electrochemical investigation of BOD revealed interesting internal redox communication within the enzyme with some novel insights provided. At least one of tyrosines present in BOD seems to be involved in electron transfer route, as well. The composite used for the biocathode was directly applied for the preparation of a bioanode with fructose dehydrogenase immobilised, working in a DET mode of operation. Finally, integration of the biocathode and the bioanode into a biofuel cell operated in a reagentless and membraneless mode offered a power density of 50 μW cm−2 at 300 mV.

  9. The Brazilian biofuels industry

    Directory of Open Access Journals (Sweden)

    Goldemberg José

    2008-05-01

    Full Text Available Abstract Ethanol is a biofuel that is used as a replacement for approximately 3% of the fossil-based gasoline consumed in the world today. Most of this biofuel is produced from sugarcane in Brazil and corn in the United States. We present here the rationale for the ethanol program in Brazil, its present 'status' and its perspectives. The environmental benefits of the program, particularly the contribution of ethanol to reducing the emission of greenhouse gases, are discussed, as well as the limitations to its expansion.

  10. Improved endothelialization of titanium vascular implants by extracellular matrix secreted from endothelial cells.

    Science.gov (United States)

    Tu, Qiufen; Zhao, Yuancong; Xue, Xiaoqing; Wang, Jin; Huang, Nan

    2010-12-01

    A variety of metals have been widely used in construction of cardiovascular implants (CVIs), such as artificial heart valves, ventricular pumps, and vascular stents. Although great effects have been put into rigorous anticoagulation, late thrombosis still occurred due to inferior blood and cell compatibility. Natural endothelium is popularly regarded as the only substance that has long-term anticoagulant ability. So, establishment of a compact endothelial cell (EC) monolayer on CVIs surface is a guarantee for their long-term potency. In the work described here, titanium (Ti) disks were coated with extracellular matrix (ECM) directly secreted by human umbilical vein endothelial cells (HUVECs), so as to help ECs proliferate and migrate and to improve their endothelialization in vivo. Deposition of ECM on Ti disks was detected by immunofluorescence microscopy, diffuse reflectance Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy. The surface topography and wettability of the Ti disks significantly changed after ECM deposition. Most importantly, it was found that ECM deposition inhibited platelet adhesion, stimulated EC proliferation, increased EC migration speed in vitro, and eventually accelerated the re-cellularization speed of Ti disks in vivo. These important results render it reasonable and feasible to modify CVIs with ECM secreted from ECs for improving their long-term potency. PMID:20666613

  11. BMP signalling regulates the pre-implantation development of extra-embryonic cell lineages in the mouse embryo

    OpenAIRE

    Graham, Sarah J. L.; Wicher, Krzysztof B.; Jedrusik, Agnieszka; Guo, Guoji; Herath, Wishva; Robson, Paul; Zernicka-Goetz, Magdalena

    2014-01-01

    Pre-implantation development requires the specification and organization of embryonic and extra-embryonic lineages. The separation of these lineages takes place when asymmetric divisions generate inside and outside cells that differ in polarity, position and fate. Here we assess the global transcriptional identities of these precursor cells to gain insight into the molecular mechanisms regulating lineage segregation,. Unexpectedly, this reveals that complementary components of the BMP signall...

  12. Dental Implants

    Medline Plus

    Full Text Available Dental Implants A fuller, more complete smile is within reach. The following information is designed to provide helpful ... whether dental implants are right for your situation. Dental Implants and Roots The key benefit of dental implants ...

  13. Rational Tuning of the Electrocatalytic Nanobiointerface for a "Turn-Off" Biofuel-Cell-Based Self-Powered Biosensor for p53 Protein.

    Science.gov (United States)

    Han, Yajing; Chabu, Johnny Muya; Hu, Shengqiang; Deng, Liu; Liu, You-Nian; Guo, Shaojun

    2015-09-01

    Herein, a novel tunable electrocatalytic nanobiointerface for the construction of a high-sensitivity and high-selectivity biofuel-cell (BFC)-based self-powered biosensor for the detection of transcription factor protein p53 is reported, in which bilirubin oxidase (BOD)/DNA supramolecular modified graphene/platinum nanoparticles hybrid nanosheet (GPNHN) works as a new enhanced material of biocathode to control the attachment of target, and thus tune the electron-transfer process of oxygen reduction for transducing signaling magnification. It is found that in the presence of p53, the strong interaction between the wild-type p53 and its consensus DNA sequence on the electrode surface can block the electron transfer from the BOD to the electrode, thus providing a good opportunity for reducing the electrocatalytic activity of oxygen reduction in the biocathode. This in combination with the glucose oxidation at the carbon nanotube/Meldola's blue/glucose dehydrogenase bioanode can result in a current/or power decrease of BFC in the presence of wild-type p53. The specially designed BFC-based self-powered p53 sensor shows a wide linear range from 1 pM to 1 μM with a detection limit of 1 pM for analyzing wild-type p53. Most importantly, our BFC-based self-powered sensors can detect the concentrations of wild-type p53 in normal and cancer cell lysates without any extensive sample pretreatment/separation or specialized instruments. The present BFC-based self-powered sensor can provide a simple, economical, sensitive, and rapid way for analyzing p53 protein in normal and cancer cells at clinical level, which shows great potential for creating the treatment modalities that capitalize on the concentration variation of the wild-type p53. PMID:26211519

  14. Performance of a glucose/O{sub 2} enzymatic biofuel cell containing a mediated melanocarpus albomyces laccase cathode in a physiological buffer

    Energy Technology Data Exchange (ETDEWEB)

    Kavanagh, P.; Boland, S.; Jenkins, P.; Leech, D. [Department of Chemistry, National University of Ireland, Galway (Ireland)

    2009-02-15

    We report on the performance of a prototype glucose/O{sub 2} biofuel cell in a physiological buffer. The cell consists of cathode based on Melanocarpus albomyces laccase (with a reported T1 copper redox potential of +0.26 V vs. Ag/AgCl) co-immobilised with an osmium redox polymer mediating film on glassy carbon (GC) separated by a Nafion 117 membrane from a GC anode in anolyte of glucose oxidase, N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) as a mediator, all immersed in pH 7.4 phosphate buffer solution containing 0.15 M NaCl and dissolved oxygen, thermostated at 37 C, mimicking physiological conditions. Two osmium redox polymers are employed for cathodic mediation: [Os(2,2'-bipyridine){sub 2}(polyvinylimidazole){sub 10}Cl]{sup +/2+} (E ' 0.22 V vs. Ag/AgCl) and [Os(4,4'-dichloro-2,2'-bipyridine){sub 2}(polyvinylimidazole){sub 10}Cl]{sup +/2+} (E ' 0.35 V vs. Ag/AgCl). Power outputs of 52 {mu}W cm{sup -2} at 0.21 V and 17 {mu}W cm{sup -2} at 0.34 V were obtained for assembled fuel cells containing the respective redox polymer-mediated laccase cathodes, illustrating the increased power obtained as a result of higher biocatalytic efficiency using a redox polymer with redox potential tailored for the enzyme. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  15. A novel poly(propylene-co-imidazole) based biofuel cell: System optimization and operation for energy generation

    International Nuclear Information System (INIS)

    This study describes the construction of an enzymatic fuel cell comprised of novel gold nanoparticles embedded poly(propylene-co-imidazole) coated anode and cathode. Working electrode fabrication steps and operational conditions for the fuel cell have been optimized to get enhanced power output. Electrical generation capacity of the optimized cell was tested by using the municipal wastewater sample. The enzymatic fuel cell system reached to maximum power density with 1 μg and 8 μg of polymer quantity and bilirubin oxidase on electrode surface, respectively. The maximum power output was calculated to be 5 μW cm−2 at + 0.56 V (vs. Ag/AgCl) in phosphate buffer (pH 7.4, 100 mM, 20 °C) by the addition of 15 mM of glucose as a fuel source. The optimized enzymatic fuel cell generated a power density of 0.46 μW cm−2 for the municipal wastewater sample. Poly(propylene-co-imidazole) was easily used for a fuel cell system owing to its metallic nanoparticle content. The developed fuel cell will play a significant role for energy conversion by using glucose readily found in wastewater and in vivo mediums. - Highlights: • Gold nanoparticles provided faster electron transfer in the circuit. • The maximum power density of 5 μW cm−2 was generated at + 0.56 V cell potential. • The cell can be easily operated for in vivo mediums

  16. Technology Roadmaps: Biofuels for Transport

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Biofuels could provide up to 27% of total transport fuel worldwide by 2050. The use of transport fuels from biomass, when produced sustainably, can help cut petroleum use and reduce CO2 emissions in the transport sector, especially in heavy transport. Sustainable biofuel technologies, in particular advanced biofuels, will play an important role in achieving this roadmap vision. The roadmap describes the steps necessary to realise this ambitious biofuels target; identifies key actions by different stakeholders, and the role for government policy to adopt measures needed to ensure the sustainable expansion of both conventional and advanced biofuel production.

  17. Histopathological Features of Secondary Squamous Cell Carcinoma Around a Dental Implant in the Mandible After Chemoradiotherapy: A Case Report With a Clinicopathological Review.

    Science.gov (United States)

    Nariai, Yoshiki; Kanno, Takahiro; Sekine, Joji

    2016-05-01

    Oral squamous cell carcinoma (OSCC) around a dental implant is a rare pathologic condition. This report describes a case of recurrent OSCC surrounding a dental implant, histopathologic findings, and a literature review of this condition. A 58-year-old Japanese woman underwent chemoradiotherapy for OSCC in the right lower gingiva, resulting in a complete response. Nine years after primary chemoradiotherapy, a dental implant was placed in her atrophic mandible. Three years later, an OSCC developed around the dental implant in the right lower premolar region. Marginal mandibulectomy was performed. Microscopic examination showed medullary invasion around the implant surface, suggesting that tumor infiltration of the bone was through the interface between the implant and bone. However, no downward invasion through the interface was evident. OSCC can develop around dental implants that are placed for oral rehabilitation after ablative surgery. Staging of OSCC and planning of surgical management should be carried out carefully, because implants placed adjacent to the OSCC can influence tumor invasion. A high degree of vigilance for OSCC is required during follow-up of patients with dental implants who have OSCC risk factors such as premalignant lesions. Detailed evaluation, including biopsy examination, is essential for distinguishing peri-implantitis from OSCC. PMID:26679554

  18. Modulation of human dermal microvascular endothelial cell and human gingival fibroblast behavior by micropatterned silica coating surfaces for zirconia dental implant applications

    Science.gov (United States)

    Laranjeira, Marta S.; Carvalho, Ângela; Pelaez-Vargas, Alejandro; Hansford, Derek; Ferraz, Maria Pia; Coimbra, Susana; Costa, Elísio; Santos-Silva, Alice; Fernandes, Maria Helena; Monteiro, Fernando Jorge

    2014-04-01

    Dental ceramic implants have shown superior esthetic behavior and the absence of induced allergic disorders when compared to titanium implants. Zirconia may become a potential candidate to be used as an alternative to titanium dental implants if surface modifications are introduced. In this work, bioactive micropatterned silica coatings were produced on zirconia substrates, using a combined methodology of sol-gel processing and soft lithography. The aim of the work was to compare the in vitro behavior of human gingival fibroblasts (HGFs) and human dermal microvascular endothelial cells (HDMECs) on three types of silica-coated zirconia surfaces: flat and micropatterned (with pillars and with parallel grooves). Our results showed that cells had a higher metabolic activity (HGF, HDMEC) and increased gene expression levels of fibroblast-specific protein-1 (FSP-1) and collagen type I (COL I) on surfaces with pillars. Nevertheless, parallel grooved surfaces were able to guide cell growth. Even capillary tube-like networks of HDMEC were oriented according to the surface geometry. Zirconia and silica with different topographies have shown to be blood compatible and silica coating reduced bacteria adhesion. All together, the results indicated that microstructured bioactive coating seems to be an efficient strategy to improve soft tissue integration on zirconia implants, protecting implants from peri-implant inflammation and improving long-term implant stabilization. This new approach of micropatterned silica coating on zirconia substrates can generate promising novel dental implants, with surfaces that provide physical cues to guide cells and enhance their behavior.

  19. Modulation of human dermal microvascular endothelial cell and human gingival fibroblast behavior by micropatterned silica coating surfaces for zirconia dental implant applications

    Directory of Open Access Journals (Sweden)

    Marta S Laranjeira

    2014-03-01

    Full Text Available Dental ceramic implants have shown superior esthetic behavior and the absence of induced allergic disorders when compared to titanium implants. Zirconia may become a potential candidate to be used as an alternative to titanium dental implants if surface modifications are introduced. In this work, bioactive micropatterned silica coatings were produced on zirconia substrates, using a combined methodology of sol–gel processing and soft lithography. The aim of the work was to compare the in vitro behavior of human gingival fibroblasts (HGFs and human dermal microvascular endothelial cells (HDMECs on three types of silica-coated zirconia surfaces: flat and micropatterned (with pillars and with parallel grooves. Our results showed that cells had a higher metabolic activity (HGF, HDMEC and increased gene expression levels of fibroblast-specific protein-1 (FSP-1 and collagen type I (COL I on surfaces with pillars. Nevertheless, parallel grooved surfaces were able to guide cell growth. Even capillary tube-like networks of HDMEC were oriented according to the surface geometry. Zirconia and silica with different topographies have shown to be blood compatible and silica coating reduced bacteria adhesion. All together, the results indicated that microstructured bioactive coating seems to be an efficient strategy to improve soft tissue integration on zirconia implants, protecting implants from peri-implant inflammation and improving long-term implant stabilization. This new approach of micropatterned silica coating on zirconia substrates can generate promising novel dental implants, with surfaces that provide physical cues to guide cells and enhance their behavior.

  20. Modulation of human dermal microvascular endothelial cell and human gingival fibroblast behavior by micropatterned silica coating surfaces for zirconia dental implant applications

    International Nuclear Information System (INIS)

    Dental ceramic implants have shown superior esthetic behavior and the absence of induced allergic disorders when compared to titanium implants. Zirconia may become a potential candidate to be used as an alternative to titanium dental implants if surface modifications are introduced. In this work, bioactive micropatterned silica coatings were produced on zirconia substrates, using a combined methodology of sol–gel processing and soft lithography. The aim of the work was to compare the in vitro behavior of human gingival fibroblasts (HGFs) and human dermal microvascular endothelial cells (HDMECs) on three types of silica-coated zirconia surfaces: flat and micropatterned (with pillars and with parallel grooves). Our results showed that cells had a higher metabolic activity (HGF, HDMEC) and increased gene expression levels of fibroblast-specific protein-1 (FSP-1) and collagen type I (COL I) on surfaces with pillars. Nevertheless, parallel grooved surfaces were able to guide cell growth. Even capillary tube-like networks of HDMEC were oriented according to the surface geometry. Zirconia and silica with different topographies have shown to be blood compatible and silica coating reduced bacteria adhesion. All together, the results indicated that microstructured bioactive coating seems to be an efficient strategy to improve soft tissue integration on zirconia implants, protecting implants from peri-implant inflammation and improving long-term implant stabilization. This new approach of micropatterned silica coating on zirconia substrates can generate promising novel dental implants, with surfaces that provide physical cues to guide cells and enhance their behavior. (paper)

  1. Improving EU biofuels policy?

    DEFF Research Database (Denmark)

    Swinbank, Alan; Daugbjerg, Carsten

    2013-01-01

    in the WTO, as there would be a clearer link between policy measures and the objective of reductions in GHG emissions; and the combination of the revised RED and the FQD would lessen the commercial incentive to import biofuels with modest GHG emission savings, and thus reduce the risk of trade tension....

  2. Outlook for advanced biofuels

    NARCIS (Netherlands)

    Hamelinck, Carlo Noël

    2004-01-01

    Modern use of biomass can play an important role in a sustainable energy supply. Biomass abounds in most parts of the world and substantial amounts could be produced at low costs. Motor biofuels seem a sensible application of biomass: they are among the few sustainable alternatives to the tran

  3. Biofuel impacts on water.

    Energy Technology Data Exchange (ETDEWEB)

    Tidwell, Vincent Carroll; Malczynski, Leonard A.; Sun, Amy Cha-Tien

    2011-01-01

    Sandia National Laboratories and General Motors Global Energy Systems team conducted a joint biofuels systems analysis project from March to November 2008. The purpose of this study was to assess the feasibility, implications, limitations, and enablers of large-scale production of biofuels. 90 billion gallons of ethanol (the energy equivalent of approximately 60 billion gallons of gasoline) per year by 2030 was chosen as the book-end target to understand an aggressive deployment. Since previous studies have addressed the potential of biomass but not the supply chain rollout needed to achieve large production targets, the focus of this study was on a comprehensive systems understanding the evolution of the full supply chain and key interdependencies over time. The supply chain components examined in this study included agricultural land use changes, production of biomass feedstocks, storage and transportation of these feedstocks, construction of conversion plants, conversion of feedstocks to ethanol at these plants, transportation of ethanol and blending with gasoline, and distribution to retail outlets. To support this analysis, we developed a 'Seed to Station' system dynamics model (Biofuels Deployment Model - BDM) to explore the feasibility of meeting specified ethanol production targets. The focus of this report is water and its linkage to broad scale biofuel deployment.

  4. Biofuel seeks endorsement

    NARCIS (Netherlands)

    Jongeneel, C.; Rentmeester, S.

    2015-01-01

    Biofuels such as ethanol from sugar cane and cellulose ‘waste’ are theoretically sustainable, as their combustion releases no more CO2 than is absorbed during production. Even so, they are also controversial, because they are believed to be grown at the expense of food crops, or because areas of rai

  5. Biofuels from urban landscapes

    Science.gov (United States)

    Biomass from urban landscapes is an untapped resource. Lawn thatch and clippings, fallen leaves and tree limbs are all potential sources of biofuels. Most cities already collect and transport these materials to disposal sites; but, alternatively could collect and transport these materials to a loc...

  6. A model for improving microbial biofuel production using a synthetic feedback loop

    Energy Technology Data Exchange (ETDEWEB)

    Dunlop, Mary; Keasling, Jay; Mukhopadhyay, Aindrila

    2011-07-14

    Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation, and alternative control architectures can be compared. We propose a model for microbial biofuel production where a synthetic control system is used to increase cell viability and biofuel yields. Although microbes can be engineered to produce biofuels, the fuels are often toxic to cell growth, creating a negative feedback loop that limits biofuel production. These toxic effects may be mitigated by expressing efflux pumps that export biofuel from the cell. We developed a model for cell growth and biofuel production and used it to compare several genetic control strategies for their ability to improve biofuel yields. We show that controlling efflux pump expression directly with a biofuel-responsive promoter is a straight forward way of improving biofuel production. In addition, a feed forward loop controller is shown to be versatile at dealing with uncertainty in biofuel production rates.

  7. A novel poly(propylene-co-imidazole) based biofuel cell: System optimization and operation for energy generation

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Muhammet Samet [Department of Chemistry, Bulent Ecevit University, 67100 Zonguldak (Turkey); Korkut, Seyda, E-mail: s.korkut@beun.edu.tr [Department of Environmental Engineering, Bulent Ecevit University, 67100 Zonguldak (Turkey); Hazer, Baki [Department of Chemistry, Bulent Ecevit University, 67100 Zonguldak (Turkey)

    2015-02-01

    This study describes the construction of an enzymatic fuel cell comprised of novel gold nanoparticles embedded poly(propylene-co-imidazole) coated anode and cathode. Working electrode fabrication steps and operational conditions for the fuel cell have been optimized to get enhanced power output. Electrical generation capacity of the optimized cell was tested by using the municipal wastewater sample. The enzymatic fuel cell system reached to maximum power density with 1 μg and 8 μg of polymer quantity and bilirubin oxidase on electrode surface, respectively. The maximum power output was calculated to be 5 μW cm{sup −2} at + 0.56 V (vs. Ag/AgCl) in phosphate buffer (pH 7.4, 100 mM, 20 °C) by the addition of 15 mM of glucose as a fuel source. The optimized enzymatic fuel cell generated a power density of 0.46 μW cm{sup −2} for the municipal wastewater sample. Poly(propylene-co-imidazole) was easily used for a fuel cell system owing to its metallic nanoparticle content. The developed fuel cell will play a significant role for energy conversion by using glucose readily found in wastewater and in vivo mediums. - Highlights: • Gold nanoparticles provided faster electron transfer in the circuit. • The maximum power density of 5 μW cm{sup −2} was generated at + 0.56 V cell potential. • The cell can be easily operated for in vivo mediums.

  8. Biofuel on contaminated land

    Science.gov (United States)

    Suer, Pascal; Andersson-Sköld, Yvonne; Blom, Sonja; Bardos, Paul; Polland, Marcel; Track, Thomas

    2010-05-01

    Desktop studies of two Swedish contaminated sites has indicated that growing biofuel crops on these sites may be more environmentally beneficial than alternative risk management approaches such as excavation / removal or containment The demand for biofuel increases pressure on the cultivatable soil of the world. While contaminated land is not very suitable for food production, cultivation of low and medium contaminated soil may remove some pressure from agricultural soils. For larger sites, biofuel cultivation may be economically viable without a remediation bonus. Suitable sites have topographic conditions that allow agricultural machinery, are not in urgent need of remediation, and contamination levels are not plant toxic. Life cycle assessment (LCA) was done for two cases. The (desk top) case studies were - Case K, a 5000 m2 site where salix (willow) was cultivated with hand-held machinery and the biofuel harvest was left on site, and - Case F, a 12 ha site were on site ensuring was being considered, and were salix might have rented an economic profit if the remediation had not been urgent due to exploitation pressure. Some selected results for biofuel K; biofuel F; excavation K; and on site ensuring F respectively: Energy: 0,05; 1,4; 3,5; 19 TJ Waste: 1; 9; 1200; 340 ton Land use off-site: 190; 3 500; 200 000; 1 400 000 m² a Global warming: 3; 86; 230; 1 200 ton CO2 eq Acidification: 25; 1 000; 2 600; 14 000 kg SO2 eq Photochemical smog: 10; 180; 410; 2 300 kg ethene eq Human health: 2; 51; 150; 620 index The environmental impact of the traditional remediation methods of excavation and on-site ensuring was mainly due to the transport of contaminated soil and replacement soil, and landfilling of the contaminated soil. Biofuel cultivation avoids these impacts, while fertiliser production and agricultural machinery would have a lower environmental impact than moving large volumes of soil around. Journeys of a controller to check on the groundwater quality also

  9. Iodine-125 seed implantation as an adjunct to surgery in advanced recurrent squamous cell cancer of the head and neck

    Energy Technology Data Exchange (ETDEWEB)

    Park, R.I.; Liberman, F.Z.; Lee, D.J.; Goldsmith, M.M.; Price, J.C. (Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Hospital, Baltimore, MD (United States))

    1991-04-01

    Survival for extensive recurrent squamous cell carcinomas of the head and neck remains poor, with the major cause of death being local recurrence. Surgical implantation of iodine-125 interstitial seeds allows tumoricidal doses of radiation to be delivered to residual tumor while minimizing radiation doses to the surrounding tissues. From 1978 to 1988, 39 implantations were performed on 35 patients for extensive recurrent squamous cell carcinoma of the head and neck. The decision for implantation was based on positive margins or close to resection margins from frozen sections after salvage resection. The determinate 5-year disease-free survival was 41%, with both the overall and no evidence of disease 5-year survivals being 29%. Significant complications occurred in 36% of all cases. This figure increased to 56% when flap reconstruction was required. Possible reasons for this seemingly high complication rate are discussed. Considering the advanced nature of these recurrent carcinomas, surgical resection with iodine-125 seed implantation appears to be an effective method of managing disease that might otherwise be judged unresectable and treated for palliation only.

  10. Iodine-125 seed implantation as an adjunct to surgery in advanced recurrent squamous cell cancer of the head and neck

    International Nuclear Information System (INIS)

    Survival for extensive recurrent squamous cell carcinomas of the head and neck remains poor, with the major cause of death being local recurrence. Surgical implantation of iodine-125 interstitial seeds allows tumoricidal doses of radiation to be delivered to residual tumor while minimizing radiation doses to the surrounding tissues. From 1978 to 1988, 39 implantations were performed on 35 patients for extensive recurrent squamous cell carcinoma of the head and neck. The decision for implantation was based on positive margins or close to resection margins from frozen sections after salvage resection. The determinate 5-year disease-free survival was 41%, with both the overall and no evidence of disease 5-year survivals being 29%. Significant complications occurred in 36% of all cases. This figure increased to 56% when flap reconstruction was required. Possible reasons for this seemingly high complication rate are discussed. Considering the advanced nature of these recurrent carcinomas, surgical resection with iodine-125 seed implantation appears to be an effective method of managing disease that might otherwise be judged unresectable and treated for palliation only

  11. Autologous Cell Delivery to the Skin-Implant Interface via the Lumen of Percutaneous Devices in vitro

    Directory of Open Access Journals (Sweden)

    Antonio Peramo

    2010-11-01

    Full Text Available Induced tissue regeneration around percutaneous medical implants could be a useful method to prevent the failure of the medical device, especially when the epidermal seal around the implant is disrupted and the implant must be maintained over a long period of time. In this manuscript, a novel concept and technique is introduced in which autologous keratinocytes were delivered to the interfacial area of a skin-implant using the hollow interior of a fixator pin as a conduit. Full thickness human skin explants discarded from surgeries were cultured at the air-liquid interface and were punctured to fit at the bottom of hollow cylindrical stainless steel fixator pins. Autologous keratinocytes, previously extracted from the same piece of skin and cultured separately, were delivered to the specimens thorough the interior of the hollow pins. The delivered cells survived the process and resembled undifferentiated epithelium, with variations in size and shape. Viability was demonstrated by the lack of morphologic evidence of necrosis or apoptosis. Although the cells did not form organized epithelial structures, differentiation toward a keratinocyte phenotype was evident immunohistochemically. These results suggest that an adaptation of this technique could be useful for the treatment of complications arising from the contact between skin and percutaneous devices in vivo.

  12. Biofuels in Europe

    International Nuclear Information System (INIS)

    This article contains a short overview of biomass consumption in Eu countries. The market share of biomass comparing with the other renewable energy sources, analysis, figures of development options and potential barriers are presented. Some special paragraphs were devoted to liquid biofuels like ethanol, methanol and bio-diesel oils. Lacking of the distribution system of liquid biofuels is one of the barriers in implementation. The granulated wood pellets is going to be one of the most widespread bio fuel for households in Austria and Southern Germany and for small scale district heating in Denmark and Sweden. From the analyse follows, that in countries with the state support and subsidies, the biomass consumption is much more developed and is competing with the fossil fuels in heat and power market. But in countries without this support the share of biofuels is decreasing. The last paragraph is describing the situation of biomass consumption in Estonia. Up to now here are positive as well as negative examples of biomass boilers implementation. Comparison of the heat prices in Estonia and in E U countries is presented in Fig. 2. Considering that our heat prices are about 2 times less than the E U average, implementation of the quite expensive western burning technology in Estonia would be more complicated than in E U countries. This points out even bigger necessity of the state support or subsidizing in Estonia. But there is another, economically more feasible way for subsidizing - to start the production of the small bio-fuelled boilers and the fuel handling technology in Estonia. This should reduce the total investment cost of the bio-fuelled heating systems. (author)

  13. Corneal Endothelial Cell Changes Due to Combined Phacoemulsification-Posterior Chamber Intraocular Lens Implantation and Transpupillary Silicone Oil Removal

    Directory of Open Access Journals (Sweden)

    Mehmet Hanifi Alp

    2014-12-01

    Full Text Available Objectives: The aim of this study was to evaluate the effects of combined phacoemulsification-posterior chamber intraocular lens (PCIOL implantation and removal of transpupillary silicone oil on the corneal endothelial cell layer. Materials and Methods: In this study, we included seven eyes of 7 patients who had intravitreal hemorrhage resulting from retinal detachment or tractional retinal detachment due to proliferative diabetic retinopathy and who underwent pars plana vitrectomy and silicone oil injection. Complicated cataract developed, and phacoemulsification-PC-IOL implantation combined with transpupillary silicon oil removal were performed. Preoperative and postoperative corneal endothelial cell count values were taken by Topcon SP-2000P automatic non-contact specular microscopy and were assessed by IMAGEnet 2000 Endothelial Cell Analysis. The results were compared with the findings in the literature. Results: The mean endothelial cell density (ECD was 2461 cell/mm2 preoperatively. The silicone oil removal was performed after an average of 10±3.5 months (range 5-14 months, and then endothelial cells were counted after a mean of 17±21.2 months (range 1-49 months of the combined surgery. The mean ECD was determined as 1906 cell/mm2 postoperatively. While mean endothelial cell loss was found to be 32% in two patients with diabetes mellitus, five non-diabetic patients had 19% cell loss. Corneal decompensation was not observed in any patient during the follow-up period. Conclusion: After combined phacoemulsification-PC-IOL implantation and transpupillary silicone oil removal, significant reduction in endothelial cells was observed. We detected that this reduction was greater in diabetics. (Turk J Ophthalmol 2014; 44: 424-7

  14. Characterization of gastric cancer models from different cell lines orthotopically constructed using improved implantation techniques

    Institute of Scientific and Technical Information of China (English)

    Yan Li; Bo Li; Chun-Ping Xiang; Yu Zhang; Yuan-Yuan Li; Xiao-Ling Wu

    2012-01-01

    AIM: To develop orthotopic gastric cancer mouse models from different cell lines and characterize the tumor features to assist further in preclinical trials and clinical treatment strategies. METHODS: Human gastric cancer SGC-7901 and BGC- 823 cell suspensions were injected subcutaneously into nude mice to develop solid tumors, and tumor tissue pieces were then implanted under the serous coat of the stomach. An autopsy was performed on all animals of the SGC-7901 and BGC-823 models to observe the primary tumor growth and metastases using pathological and immunohistochemical methods. RESULTS: Both models showed large tumors in situ resulting in pressure and infiltration of the adjacent organs. The gastric cavity became smaller, along with stenosis of the cardia or pylorus. There were biological and statistical differences between the two models. The metastasis rate in involved organs (lymph nodes, kidney, spleen, testis) was significantly higher in the BGC-823 model compared to the SGC-7901 model (P < 0.05 or P < 0.01). The median survival of the BGC-823 model was shorter than that of SGC-7901 (23 d vs 84 d, P < 0.05). Histopathologically, the primary tumor and metastatic lesions of the two models showed obvious atypia and mucus in the cytoplasm. Compared with the SGC-7901 model, BGC-823 appeared more poorly differentiated (absence of adenoid structure), had a smaller volume, and richer capillary structure. Immunohistochemical staining revealed cytokeratin 20 and epithelial membrane antigen expression was positive in the SGC-7901 tumors, while negative in BGC-823 ones. CONCLUSION: Models using the SGC-7901 and BGC-823 cell lines were established which could function in gastric cancer research on carcinogenesis mechanism and drug discovery. The two models showed different tumor behavior and the latter was more malignant than the former.

  15. Fabrication of a biofuel cell improved by the π-conjugated electron pathway effect induced from a new enzyme catalyst employing terephthalaldehyde

    Science.gov (United States)

    Chung, Yongjin; Hyun, Kyu Hwan; Kwon, Yongchai

    2015-12-01

    A model explaining the π-conjugated electron pathway effect induced by a novel cross-linker adopted enzyme catalyst is suggested and the performance and stability of an enzymatic biofuel cell (EBC) adopting the new catalyst are evaluated. For this purpose, new terephthalaldehyde (TPA) and conventional glutaraldehyde (GA) cross-linkers are adopted on a glucose oxidase (GOx), polyethyleneimine (PEI) and carbon nanotube (CNT)(GOx/PEI/CNT) structure. GOx/PEI/CNT cross-linked by TPA (TPA/[GOx/PEI/CNT]) results in a superior EBC performance and stability to other catalysts. It is attributed to the π bonds conjugated between the aldehyde of TPA and amine of the GOx/PEI molecules. By π conjugation, electrons bonded with carbon and nitrogen are delocalized, promoting the electron transfer and catalytic activity with an excellent EBC performance. The maximum power density (MPD) of an EBC adopting TPA/[GOx/PEI/CNT] (0.66 mW cm-2) is far better than that of the other EBCs (the MPD of EBC adopting GOx/PEI/CNT is 0.40 mW cm-2). Regarding stability, the covalent bonding formed between TPA and GOx/PEI plays a critical role in preventing the denaturation of GOx molecules, leading to an excellent stability. By repeated measurements of the catalytic activity, TPA/[GOx/PEI/CNT] maintains its activity to 92% of its initial value even after five weeks.A model explaining the π-conjugated electron pathway effect induced by a novel cross-linker adopted enzyme catalyst is suggested and the performance and stability of an enzymatic biofuel cell (EBC) adopting the new catalyst are evaluated. For this purpose, new terephthalaldehyde (TPA) and conventional glutaraldehyde (GA) cross-linkers are adopted on a glucose oxidase (GOx), polyethyleneimine (PEI) and carbon nanotube (CNT)(GOx/PEI/CNT) structure. GOx/PEI/CNT cross-linked by TPA (TPA/[GOx/PEI/CNT]) results in a superior EBC performance and stability to other catalysts. It is attributed to the π bonds conjugated between the aldehyde of

  16. Arid Lands Biofuel

    Science.gov (United States)

    Neupane, B. P.

    2013-05-01

    Dependence on imported petroleum, as well as consequences from burning fossil fuels, has increased the demand for biofuel sources in the United States. Competition between food crops and biofuel crops has been an increasing concern, however, since it has the potential to raise prices for US beef and grain products due to land and resource competition. Biofuel crops that can be grown on land not suitable for food crops are thus attractive, but also need to produce biofuels in a financially sustainable manner. In the intermountain west of Nevada, biofuel crops need to survive on low-organic soils with limited precipitation when grown in areas that are not competing with food and feed. The plants must also yield an oil content sufficiently high to allow economically viable fuel production, including growing and harvesting the crop as well as converting the hydrocarbons into a liquid fuel. Gumweed (Grindelia squarrosa) currently appears to satisfy all of these requirements and is commonly observed throughout the west. The plant favors dry, sandy soils and is most commonly found on roadsides and other freshly disturbed land. A warm season biennial, the gumweed plant is part of the sunflower family and normally grows 2-4 feet high with numerous yellow flowers and curly leaves. The gumweed plant contains a large store of diterpene resins—most abundantly grindelic acid— similar to the saps found on pine trees that are used to make inks and adhesives. The dry weight harvest on the experimental field is 5130 lbs/acre. Whole plant biomass yields between 11-15% (average 13%) biocrude when subjected to acetone extraction whereas the buds alone contains up to a maximum of 35% biocrude when harvested in 'white milky' stage. The extract is then converted to basic form (sodium grindelate) followed by extraction of nonpolar constituents (mostly terpenes) with hexane and extracted back to ethyl acetate in acidified condition. Ethyl acetate is removed under vacuum to leave a dark

  17. Energy crops for biofuel feedstocks: facts and recent patents on genetic manipulation to improve biofuel crops.

    Science.gov (United States)

    Kumar, Suresh

    2013-12-01

    Burning fossil-fuels to meet the global energy requirements by human being has intensified the concerns of increasing concentrations of greenhouse gases. Therefore, serious efforts are required to develop nonfossil-based renewable energy sources. Plants are more efficient in utilizing solar energy to convert it into biomass which can be used as feedstocks for biofuel production. Hence with the increasing demands of energy and the needs of cost-effective, sustainable production of fuels, it has become necessary to switch over to plant biomass as a renewable source of energy. Biofuels derived from more sustainable biological materials such as lignocellulosic plant residues, considered as second generation biofuels, are more dependable. However, there are technical challenges such as pretreatment and hydrolysis of lignocellulosic biomass to convert it into fermentable sugars. Plant genetic engineering has already proven its potential in modifying cell wall composition of plants for enhancing the efficiency of biofuel production. Interest and potential in the area are very much evident from the growing number of patents in the recent years on the subject. In this review, recent trends in genetic engineering of energy crops for biofuel production have been introduced, and strategies for the future developments have been discussed. PMID:24456235

  18. Biofuels and Food Security: Implications of an Accelerated Biofuels Production

    OpenAIRE

    Fischer, G; Hizsnyik, E.; Prieler, S.; Shah, M; van Velthuizen, H.T.

    2009-01-01

    Biofuels development has received increased attention in recent times as a means to mitigate climate change, alleviate global energy concerns and foster rural development. Its perceived importance in these three areas has seen biofuels feature prominently on the international agenda. Nevertheless, the rapid growth of biofuels production has raised many concerns among experts worldwide, in particular with regard to sustainability issues and the threat posed to food security. The UN Secretary G...

  19. Experimental study of electrochemotherapy on implanted liver tumor cells apoptosis of rats

    International Nuclear Information System (INIS)

    Objective: To compare the effects of electrochemotherapy (EChT) on implanted liver tumor cells apoptosis of rats. Methods: Immediate cancerous ascites injection method was used for the formation of rats liver tumor model and then followed by rats liver tumor treatment with EChT. Tumor size, necrosis and apoptosis indexes were observed after one week by imaging or pathologic method. The results were compared with those of control group. Results: Before EChT, rats liver tumor volume appeared as (100 ± 6) mm3 and turned to be (125 ± 10) mm3 one week after EChT, which were significantly smaller than those of the control group [(190 ± 11) mm3], P<0.05. Apoptosis indexes were 9.625 ± 1.172 and 3.523 ± 0.894 in EChT group and control group respectively (P<0.01). Tumor necrosis in EChT group increased significantly than those of the control group. Conclusions: The growth of rats liver tumor is obviously inhibited through inducing apoptosis and promoting necrosis by EChT

  20. Altered cell cycle gene expression and apoptosis in post-implantation dog parthenotes.

    Science.gov (United States)

    Park, Jung Eun; Kim, Min Jung; Ha, Seung Kwon; Hong, So Gun; Oh, Hyun Ju; Kim, Geon A; Park, Eun Jung; Kang, Jung Taek; Saadeldin, Islam M; Jang, Goo; Lee, Byeong Chun

    2012-01-01

    Mature oocytes can be parthenogenetically activated by a variety of methods and the resulting embryos are valuable for studies of the respective roles of paternal and maternal genomes in early mammalian development. In the present study, we report the first successful development of parthenogenetic canine embryos to the post-implantation stage. Nine out of ten embryo transfer recipients became pregnant and successful in utero development of canine parthenotes was confirmed. For further evaluation of these parthenotes, their fetal development was compared with artificially inseminated controls and differentially expressed genes (DEGs) were compared using ACP RT-PCR, histological analysis and immunohistochemistry. We found formation of the limb-bud and no obvious differences in histological appearance of the canine parthenote recovered before degeneration occurred; however canine parthenotes were developmentally delayed with different cell cycle regulating-, mitochondria-related and apoptosis-related gene expression patterns compared with controls. In conclusion, our protocols were suitable for activating canine oocytes artificially and supported early fetal development. We demonstrated that the developmental abnormalities in canine parthenotes may result from defective regulation of apoptosis and aberrant gene expression patterns, and provided evidence that canine parthenotes can be a useful tool for screening and for comparative studies of imprinted genes. PMID:22905100

  1. Altered cell cycle gene expression and apoptosis in post-implantation dog parthenotes.

    Directory of Open Access Journals (Sweden)

    Jung Eun Park

    Full Text Available Mature oocytes can be parthenogenetically activated by a variety of methods and the resulting embryos are valuable for studies of the respective roles of paternal and maternal genomes in early mammalian development. In the present study, we report the first successful development of parthenogenetic canine embryos to the post-implantation stage. Nine out of ten embryo transfer recipients became pregnant and successful in utero development of canine parthenotes was confirmed. For further evaluation of these parthenotes, their fetal development was compared with artificially inseminated controls and differentially expressed genes (DEGs were compared using ACP RT-PCR, histological analysis and immunohistochemistry. We found formation of the limb-bud and no obvious differences in histological appearance of the canine parthenote recovered before degeneration occurred; however canine parthenotes were developmentally delayed with different cell cycle regulating-, mitochondria-related and apoptosis-related gene expression patterns compared with controls. In conclusion, our protocols were suitable for activating canine oocytes artificially and supported early fetal development. We demonstrated that the developmental abnormalities in canine parthenotes may result from defective regulation of apoptosis and aberrant gene expression patterns, and provided evidence that canine parthenotes can be a useful tool for screening and for comparative studies of imprinted genes.

  2. Beam dynamics of a double-gap acceleration cell for ion implantation with multiple atomic species

    International Nuclear Information System (INIS)

    As a result of our work on ion implantation, we derived equations for the beam dynamics of a two-gap-resonator cavity for accelerating and bunching various ion species of varying energies with the cavity designed for one particular ion species of a given energy (the design-reference particle). A two gap structure is useful at low resonant frequencies where lumped circuit elements (inductors) can be used and the structure kept small. A single gap structure has the advantage that each gap can be independently phased to produce the desired beam dynamics behavior for various ion species and ion energies. However at low frequencies, single gap resonant structures can be large. We find that the two-gap structure, where the phase difference between gaps, for the design reference particle, is fixed at π radians can give acceptable performance provided that the individual two gap cells in the entire accelerator are optimized for the ion species having the largest mass to charge ratio and having the maximum required output energy. Our equations show how to adjust the cavity phases and electric fields to obtain equivalent first-order accelerator performance for various ion species and energies. These equations allow for the effective evaluation of various accelerator concepts and can facilitate the tuning of a linac when changing energies and ion species. Extensive simulations have confirmed the efficacy of our equations. copyright 1997 American Institute of Physics

  3. Ciliary neurotrophic factor (CNTF) for human retinal degeneration: Phase I trial of CNTF delivered by encapsulated cell intraocular implants

    OpenAIRE

    Sieving, Paul A.; Caruso, Rafael C.; Tao, Weng; Coleman, Hanna R.; Thompson, Darby J. S.; Fullmer, Keri R.; Bush, Ronald A.

    2006-01-01

    Neurotrophic factors are agents with a promising ability to retard progression of neurodegenerative diseases and are effective in slowing photoreceptor degeneration in animal models of retinitis pigmentosa. Here we report a human clinical trial of a neurotrophic factor for retinal neurodegeneration. In this Phase I safety trial, human ciliary neurotrophic factor (CNTF) was delivered by cells transfected with the human CNTF gene and sequestered within capsules that were surgically implanted in...

  4. Corneal Endothelial Cell Changes Due to Combined Phacoemulsification-Posterior Chamber Intraocular Lens Implantation and Transpupillary Silicone Oil Removal

    OpenAIRE

    Mehmet Hanifi Alp; Haluk Esgin

    2014-01-01

    Objectives: The aim of this study was to evaluate the effects of combined phacoemulsification-posterior chamber intraocular lens (PCIOL) implantation and removal of transpupillary silicone oil on the corneal endothelial cell layer. Materials and Methods: In this study, we included seven eyes of 7 patients who had intravitreal hemorrhage resulting from retinal detachment or tractional retinal detachment due to proliferative diabetic retinopathy and who underwent pars plana vitrectomy ...

  5. Radiation protective nursing intervene of 125I seed implantation in non-small cell lung carcinoma guided by CT

    International Nuclear Information System (INIS)

    Objective: To research radiation protective nursing intervene and important notice of 125I seeds minimally invasive implantation in non-small cell lung carcinoma (NSCLC) by CT. Methods: Under the system of therapy planning system (TPS) and posologic validation, 125I seeds were implanted in 89 cases of NSCLC patients. The consistent radiation protective nursing intervene was used in perioperative period management. The operative successful rate, therapeutic effect and complication rate, therapeutic effect and complication rate was observed. Results: The scientific radiation protective nursing intervene can ensure that the radioactive dose distribution of 125I seed implantation brachytherapy is consistent with the principles of effective and minimally invasive. The operative successful rate was 100%. The local control rate and 1 year survival rate respectively was 97.4% and 92.2%. But the early and later incidence rate of radioactive damaging effect was 14.6% and 1.1% respectively. Leakage of radioactive contamination has not occurred. Conclusion: The consistent TPS and posologic validation 125I seeds implantation integrated scientific radiation protective nursing intervene. It is very important to improve the therapeutic effect of NSCLC and reduce the incidence of complications. (authors)

  6. Fermentative biofuels production

    International Nuclear Information System (INIS)

    The limited reserves and increasing prices of fossil carbohydrates, as well as the global warming due to their utilization, impose the finding of renewable energy sources. Because of this, since decades an increasing interest in production of alcohols, which can be used as a fuel additives or fuels for direct replacement in gasoline engines, is observed. Alcohols can be obtained chemically or as products of microbial metabolism of different species in fermentation of sugars or starchy materials. In the present review are summarized different fermentative pathways for production of all alcohols, which are or could be used as biofuels. The focus of the paper is on production limitations, strains development and economical perspectives. Key words: fermentation, biofuel, alcohols

  7. Microalgae: biofuel production

    Directory of Open Access Journals (Sweden)

    Babita Kumari

    2013-04-01

    Full Text Available In the present day, microalgae feedstocks are gaining interest in energy scenario due to their fast growth potential coupled with relatively high lipid, carbohydrate and nutrients contents. All of these properties render them an excellent source for biofuels such as biodiesel, bioethanol and biomethane; as well as a number of other valuable pharmaceutical and nutraceutical products. The present review is a critical appraisal of the commercialization potential of microalgae biofuels. The available literature on various aspects of microalgae for e.g. its cultivation, life cycle assessment, and conceptualization of an algal biorefinery, has been done. The evaluation of available information suggests the operational and maintenance cost along with maximization of oil-rich microalgae production is the key factor for successful commercialization of microalgae-based fuels.

  8. Carbon-negative biofuels

    International Nuclear Information System (INIS)

    Current Kyoto-based approaches to reducing the earth's greenhouse gas problem involve looking for ways to reduce emissions. But these are palliative at best, and at worst will allow the problem to get out of hand. It is only through sequestration of atmospheric carbon that the problem can be solved. Carbon-negative biofuels represent the first potentially huge assault on the problem, in ways that are already technically feasible and practicable. The key to carbon negativity is to see it not as technically determined but as an issue of strategic choice, whereby farmers and fuel producers can decide how much carbon to return to the soil. Biochar amendment to the soil not only sequesters carbon but also enhances the fertility and vitality of the soil. The time is approaching when biofuels will be carbon negative by definition, and, as such, they will sweep away existing debates over their contribution to the solution of global warming. (author)

  9. Biofuels made easy

    International Nuclear Information System (INIS)

    Much has been said and written in Australia since the Federal Government introduced its Clean Fuels Policy in September 2001. Various biofuel projects are now being considered in different states of Australia for the manufacture of bioethanol and biodiesel from renewable resources. However, the economic viability required to establish an Australian liquid biofuels industry is predicated on supportive government legislation and an encouraging fuel excise regime. On the other hand, the benefits of such an industry are also in debate. In an attempt to clarify some of the concerns being raised, this paper endeavours to provide an overview of the current use of bioethanol and biodiesel around the world, to summarise the process technologies involved, to review the benefits and non-benefits of renewable fuels to the transport industry and to address the issues for such an industry here in Australia

  10. Biofuel market and carbon modeling to evaluate French biofuel policy

    International Nuclear Information System (INIS)

    In order to comply with European objectives, France has set up an ambitious biofuel plan. This plan is evaluated considering two criteria: tax exemption need and GHG emission savings. An economic marginal analysis and a life cycle assessment (LCA) are provided using a coupling procedure between a partial agro-industrial equilibrium model and a refining optimization model. Thus, we are able to determine the minimum tax exemption needed to place on the market a targeted quantity of biofuel by deducing the agro-industrial marginal cost of biofuel production to the biofuel refining long-run marginal revenue. In parallel, a biofuels LCA is carried out using model outputs. Such a method avoid common allocation problems between joint products. The French biofuel plan is evaluated for 2008, 2010 and 2012 using prospective scenarios. Results suggest that biofuel competitiveness depends on crude oil prices and petroleum products demands. Consequently, biofuel tax exemption does not always appear to be necessary. LCA results show that biofuels production and use, from 'seed to wheel', would facilitate the French Government's to compliance with its 'Plan Climat' objectives by reducing up to 5% GHG emissions in the French road transport sector by 2010. (authors)

  11. Biofuel market and carbon modeling to analyse French biofuel policy

    International Nuclear Information System (INIS)

    In order to comply with European Union objectives, France has set up an ambitious biofuel plan. This plan is evaluated on the basis of two criteria: tax exemption on fossil fuels and greenhouse gases (GHG) emission savings. An economic marginal analysis and a life cycle assessment (LCA) are provided using a coupling procedure between a partial agro-industrial equilibrium model and an oil refining optimization model. Thus, we determine the minimum tax exemption needed to place on the market a targeted quantity of biofuel by deducting the biofuel long-run marginal revenue of refiners from the agro-industrial marginal cost of biofuel production. With a clear view of the refiner's economic choices, total pollutant emissions along the biofuel production chains are quantified and used to feed an LCA. The French biofuel plan is evaluated for 2008, 2010 and 2012 using prospective scenarios. Results suggest that biofuel competitiveness depends on crude oil prices and demand for petroleum products and consequently these parameters should be taken into account by authorities to modulate biofuel tax exemption. LCA results show that biofuel production and use, from ''seed to wheel'', would facilitate the French Government's compliance with its ''Plan Climat'' objectives by reducing up to 5% GHG emissions in the French road transport sector by 2010. (author)

  12. Bio-fuels - biohazard

    International Nuclear Information System (INIS)

    Politicians have a clear explanation for growing commodity prices. It is all the fault of speculators. It is easy to point the finger at an imaginary enemy. It is more difficult and from the point of view of a political career suicidal to admit one's mistakes. And there are reasons for remorse. According to studies prepared by the OECD and the World Bank bio-fuels are to be blame for high food prices. The bio-fuel boom that increases the demand for agro-commodities has been created by politicians offering generous subsidies. And so farming products do not end up on the table, but in the fuel tanks of cars in the form of additives. And their only efficiency is that they make food more expensive. The first relevant indication that environmentalist tendencies in global politics have resulted in shortages and food price increases can be found in a confidential report prepared by the World Bank. Parts of the report were leaked to the media last month. According to this information growing bio-fuel production has resulted in a food price increase by 75%. The theory that this development was caused by speculators and Chinese and Indian demand received a serious blow. And the OECD report definitely contradicted the excuse used by the politicians. According to the report one of the main reasons for growing food prices are generously subsidized bio-fuels. Their share of the increase of demand for agro-commodities in 2005 -2007 was 60% according to the study. (author)

  13. Biofuels barometer: Crops pending

    International Nuclear Information System (INIS)

    The actors and production capacities have changed only little in the biofuel sector from year to another. Nevertheless, it is interesting to take stock of the development of this sector at the end of 2002, so as to update the more complete barometer published in issue 144 of Systemes Solaires. Indeed, European ethanol production grew by 13% and that of bio-diesel by more than 20% in 2001. (authors)

  14. Biofuels - the UFIP position

    International Nuclear Information System (INIS)

    Since 2003 a directive promote the biofuels use. The industry is then using them in ETBE (Ethyl Tertio Butyl Ether) fuels and in diesel oil of vegetal oils esters EMHV. Meanwhile some of them present technical difficulties and must free themselves from fiscal incentives which make them competitive. For these reasons, the UFIP (french union of petroleum industries) do not agree their obligatory incorporation. (A.L.B.)

  15. Protein network signatures associated with exogenous biofuels treatments in cyanobacterium Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Guangsheng ePei

    2014-11-01

    Full Text Available Although recognized as a promising microbial cell factory for producing biofuels, current productivity in cyanobacterial systems is low. To make the processes economically feasible, one of the hurdles which needs to be overcome is the low tolerance of hosts to toxic biofuels. Meanwhile, little information is available regarding the cellular responses to biofuels stress in cyanobacteria, which makes it challenging for tolerance engineering. Using large proteomic datasets of Synechocystis under various biofuels stress and environmental perturbation, a protein co-expression network was first constructed and then combined with the experimentally determined protein-protein interaction (PPI network. Proteins with statistically higher topological overlap in the integrated network were identified as common responsive proteins to both biofuels stress and environmental perturbations. In addition, a WGCNA network analysis was performed to distinguish unique responses to biofuels from those to environmental perturbations and to uncover metabolic modules and proteins uniquely associated with biofuels stress. The results showed that biofuel-specific proteins and modules were enriched in several functional categories, including photosynthesis, carbon fixation and amino acid metabolism, which may represent potential key signatures for biofuels stress responses in Synechocystis. Network-based analysis allowed determination of the responses specifically related to biofuels stress, and the results constituted an important knowledge foundation for tolerance engineering against biofuels in Synechocystis.

  16. Evaluation of the inflammatory potential of implant materials in a mouse model by bioluminescent imaging of intravenously injected bone marrow cells.

    Science.gov (United States)

    Rais, Bushra; Köster, Mario; Rahim, Muhammad Imran; Pils, Marina; Seitz, Jan-Marten; Hauser, Hansjörg; Wirth, Dagmar; Mueller, Peter P

    2016-09-01

    To evaluate the inflammatory potential of implants a bioluminescent imaging assay was developed using luciferase-expressing bone marrow cells that were injected into the blood circulation of wild-type mice. After subcutaneous implantation of titanium discs as an example for a clinically established biocompatible material, the luminosity was modest. Similarly, low luminosity signals were generated by pure magnesium implants that were used to represent metallic alloys that are presently under investigation as novel degradable implant materials. Increased luminosity was observed in response to degradable polymeric PLGA implants. Surgical wounds induced a basic luminescent response even in the absence of an implant. However, the material-independent response to injury could be minimized using injectable microparticle suspensions. In parallel with the resorption of biodegradable microparticles, the signal induced by PLGA declined faster when compared to non-degradable polystyrene suspensions. By using an interferon type I inducible Mx2 promoter construct to drive luciferase gene expression, the highest luminosity was observed in response to bacteria, indicating that the system could also be employed to monitor implant infections. Overall, labeled bone marrow cells yielded specific, well-defined localized signals that correlated with the inflammatory responses to implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2149-2158, 2016. PMID:27102724

  17. An in vitro model for investigating impedance changes with cell growth and electrical stimulation: implications for cochlear implants

    Science.gov (United States)

    Newbold, Carrie; Richardson, Rachael; Huang, Christie Q.; Milojevic, Dusan; Cowan, Robert; Shepherd, Robert

    2004-12-01

    The impedance of stimulating electrodes used in cochlear implants and other neural prostheses often increases post-implantation, and is thought to be due to fibrous tissue encapsulation of the electrode array. Increased impedance results in higher power requirements to stimulate target neurons at set charge densities. We developed an in vitro model to investigate the electrode-tissue interface in a highly controlled environment. This model was tested using three cell types, with and without charge-balanced biphasic electrical stimulation. Under standard tissue culture conditions, a monolayer of cells was grown over the electrode surface. Electrode impedance increased in proportion to the extent of cell coverage of the electrode. Cell type was a significant factor in the amount of impedance increase, with kidney epithelial cells (MDCK) creating the greatest impedance, followed by dissociated rat skin fibroblasts and then macrophages (J774). The application of electrical stimulation to cell-covered electrodes caused impedance fluctuations similar to that seen in vivo, with a lowering of impedance immediately following stimulation, and a recovery to pre-stimulation levels during inactive periods. Examination of these electrodes suggests that the stimulation-induced impedance changes were due to the amount of cell cover over the electrodes. This in vitro technique accurately models the changes in impedance observed with neural prostheses in vivo, and shows the close relationship between impedance and tissue coverage adjacent to the electrode surface. We believe that this in vitro approach holds great promise to further our knowledge of the mechanisms contributing to electrode impedance.

  18. Yarrowia lipolytica as an oleaginous cell factory platform for the production of fatty acid-based biofuel and bioproducts

    Directory of Open Access Journals (Sweden)

    Ali eAbghari

    2014-06-01

    Full Text Available Today’s biotechnologists seek new biocatalysts to meet the growing demand for the bioproducts. This review critically evaluates the potential use of Y. lipolytica as an oleaginous cell factory platform. This yeast has undergone extensive modifications for converting a wide range of hydrophobic and hydrophilic biomass, including alkane, oil, glycerol and sugars to fatty acid-based products. This article highlights challenges in the development of this platform and provides an overview of strategies to enhance its potential in the sustainable production of biodiesel, functional dietary lipid compounds and other value-added oleochemical compounds. Future applications of the recombinant Y. lipolytica platform are also discussed.

  19. Plants producing biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Papavinasam, S. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Lab

    2009-08-15

    Biofuels are currently produced primarily from five plants, namely corn, canola, sugar cane, palm oil, jatropha. However, research and development efforts are underway around the world produce biofuels from other sources, particularly from algae. This paper described the characteristics of the top 5 plants and their role in the production of biofuels. Countries where these plants are cultivated were also summarized. The article indicated that producing ethanol from corn, is not very efficient since growing corn requires more fertilizer and pesticides than most other crops, plus the corn kernels have to undergo energy-intensive distillation and chemical extraction processes. China is the world's largest producer of rapeseed oil, with an annual production of 12 million tons. The countries of the European Union collectively produce another 16 million tons, of which nearly 4 million tons were used in 2006 to produce biodiesel. Brazil is the world's largest producer of sugar cane, and accounts for about 45 per cent of global ethanol production. Malaysia and Indonesia are the key players in the palm oil market, accounting for 85 per cent of global production. India has identified more than 11 million hectares that would be suitable for growing jatropha, whose seeds contain up to 40 per cent oil that can be burned in a conventional diesel engine after extraction. 1 tab.

  20. Benchmarking biofuels; Biobrandstoffen benchmarken

    Energy Technology Data Exchange (ETDEWEB)

    Croezen, H.; Kampman, B.; Bergsma, G.

    2012-03-15

    A sustainability benchmark for transport biofuels has been developed and used to evaluate the various biofuels currently on the market. For comparison, electric vehicles, hydrogen vehicles and petrol/diesel vehicles were also included. A range of studies as well as growing insight are making it ever clearer that biomass-based transport fuels may have just as big a carbon footprint as fossil fuels like petrol or diesel, or even bigger. At the request of Greenpeace Netherlands, CE Delft has brought together current understanding on the sustainability of fossil fuels, biofuels and electric vehicles, with particular focus on the performance of the respective energy carriers on three sustainability criteria, with the first weighing the heaviest: (1) Greenhouse gas emissions; (2) Land use; and (3) Nutrient consumption [Dutch] Greenpeace Nederland heeft CE Delft gevraagd een duurzaamheidsmeetlat voor biobrandstoffen voor transport te ontwerpen en hierop de verschillende biobrandstoffen te scoren. Voor een vergelijk zijn ook elektrisch rijden, rijden op waterstof en rijden op benzine of diesel opgenomen. Door onderzoek en voortschrijdend inzicht blijkt steeds vaker dat transportbrandstoffen op basis van biomassa soms net zoveel of zelfs meer broeikasgassen veroorzaken dan fossiele brandstoffen als benzine en diesel. CE Delft heeft voor Greenpeace Nederland op een rijtje gezet wat de huidige inzichten zijn over de duurzaamheid van fossiele brandstoffen, biobrandstoffen en elektrisch rijden. Daarbij is gekeken naar de effecten van de brandstoffen op drie duurzaamheidscriteria, waarbij broeikasgasemissies het zwaarst wegen: (1) Broeikasgasemissies; (2) Landgebruik; en (3) Nutriëntengebruik.

  1. Biofuels: The African experience

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo, L.A.; Nkolo, M. [German Agency for Technical Cooperation GTZ, Delegation Regionale des Eaux et Forets, Bertoua (Cameroon)

    2009-07-01

    In July 2006, the African Non-Petroleum Producers Association was formed in Senegal, Africa to develop alternative energy sources. It involved 13 of Africa's poorest nations, who joined forces to become global suppliers of biofuels, and some have set mandatory mixing of ethanol into gasoline. Although several biofuel production projects have been launched in western Africa, many of the new projects and plantations have not yet reached maturity due to the time lag between plantation and full-scale production, which is about 6 years. Major projects that could be producing significant quantities of biofuels in the next few years are not yet reflected in production statistics. Although ethanol is not yet being produced in large quantities in Africa, short-term opportunities exist. Countries in the South African Development Community are using molasses from the sugar can industry to produce ethanol. Biodiesel is also not currently produced on a significant scale in western Africa, but several other countries are gaining experience with cotton and palm oil resources, and Jatropha. Biomass residue also represents a large potential for all African countries involved in timber production. Unlike biodiesel production, land use conflicts are not an issue with biomass residue production.

  2. Potentials of biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Munack, A.; Schroder, O. [Johann Heinrich von Thunen Inst., Braunschweig (Germany); Krahl, J. [Coburg Univ. of Applied Sciences, Coburg (Germany); Bunger, J. [Inst. for Prevention and Occupational Medicine of the German Social Accident Insurance, Ruhr-Univ. Inst., Bochum (Germany)

    2010-07-01

    This paper discussed the potential of biofuels with particular reference to the situation in Germany and Europe. Emphasis was on technical potential, such as biofuel production, utilization and environmental aspects. The Institute of Agricultural Technology and Biosystems Engineering ran vTI emission tests on diesel engines to evaluate the environmental impacts of biofuels. This testing facility is able to drive heavy-duty diesel engines in both stationary and dynamic test cycles, such as the European ESC and ETC. Additional analyses were conducted to determine the fine and ultra-fine particles, polycyclic aromatic hydrocarbons (PAH), aldehydes, ketones, and the usual regulated exhaust gas compounds. Ames tests were conducted to assess the mutagenic potential of tailpipe emissions. Previous study results showed that neat vegetable oils can render the exhaust high in mutagenic potency. Some of the non-regulated exhaust gas compounds were found to vary nonlinearly with the blend composition. B20 was found to have high mutagenic potential and was subject to sedimentation.

  3. Mesenchymal stem cell implantation in atrophic nonunion of the long bones

    Science.gov (United States)

    Phedy, P.; Kholinne, E.; Djaja, Y. P.; Kusnadi, Y.; Merlina, M.; Yulisa, N. D.

    2016-01-01

    Objectives To explore the therapeutic potential of combining bone marrow-derived mesenchymal stem cells (BM-MSCs) and hydroxyapatite (HA) granules to treat nonunion of the long bone. Methods Ten patients with an atrophic nonunion of a long bone fracture were selectively divided into two groups. Five subjects in the treatment group were treated with the combination of 15 million autologous BM-MSCs, 5g/cm3 (HA) granules and internal fixation. Control subjects were treated with iliac crest autograft, 5g/cm3 HA granules and internal fixation. The outcomes measured were post-operative pain (visual analogue scale), level of functionality (LEFS and DASH), and radiograph assessment. Results Post-operative pain evaluation showed no significant differences between the two groups. The treatment group demonstrated faster initial radiographic and functional improvements. Statistically significant differences in functional scores were present during the first (p = 0.002), second (p = 0.005) and third (p = 0.01) month. Both groups achieved similar outcomes by the end of one-year follow-up. No immunologic or neoplastic side effects were reported. Conclusions All cases of nonunion of a long bone presented in this study were successfully treated using autologous BM-MSCs. The combination of autologous BM-MSCs and HA granules is a safe method for treating nonunion. Patients treated with BM-MSCs had faster initial radiographic and functional improvements. By the end of 12 months, both groups had similar outcomes. Cite this article: H.D. Ismail, P. Phedy, E. Kholinne, Y. P. Djaja, Y. Kusnadi, M. Merlina, N. D. Yulisa. Mesenchymal stem cell implantation in atrophic nonunion of the long bones: A translational study. Bone Joint Res 2016;5:287–293. DOI: 10.1302/2046-3758.57.2000587. PMID:27412657

  4. BIOFUELS: FROM HOPES TO REALITY

    OpenAIRE

    José Osvaldo Beserra CARIOCA; Friedrich, Horst E.; Ehrenberger, Simone

    2011-01-01

    This paper combines the research for biofuels processing development with the vehicle conception to focus on realistic scenarios for biofuels to attend vehicle specifications and future green mobility. Actually, these are two important segments of fuels and biofuels context which should converge to a sustainable and realistic model. Recently, due to the climate changes versus fossil fuels use, and its consequences, the United Nations System addressed to the world a report on green economy ind...

  5. Power sources and electrical recharging strategies for implantable medical devices

    Institute of Scientific and Technical Information of China (English)

    Xiaojuan WEI; Jing LIU

    2008-01-01

    Implantable medical devices (IMDs) are crit-ically requested for the survival of patients subject to certain serious diseases such as bradycardia, fibrillation, diabetes, and disability, etc. Appropriate working of an active implantable medical device (IMD) heavily relies on the continuous supply of electricity. In this sense, long-term powering and recharging of an IMD via a highly safe, efficient and convenient way is, therefore, extremely important in clinics. Several conventional batteries, such as lithium cell, nuclear cell and bio-fuel cell, etc., have been developed to power IMDs. Meanwhile, the recharge of IMD from outside of the human body is also under investigation. In this paper, some of the most typical IMD batteries are reviewed. Their advantages and disadvantages are compared. In addition, several emer-ging innovations to recharge or directly drive the implanted batteries, including electromagnetic energy transmission, piezoelectric power generation, thermoelec-tric devices, ultrasonic power motors, radio frequency recharging and optical recharging methods, etc., are also discussed. Some fundamental and practical issues thus involved are summarized, and future prospects in this area are made.

  6. Biofuel technology handbook. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Rutz, Dominik; Janssen, Rainer

    2008-01-15

    This comprehensive handbook was created in order to promote the production and use of biofuels and to inform politicians, decision makers, biofuel traders and all other relevant stakeholders about the state-of-the-art of biofuels and relevant technologies. The large variety of feedstock types and different conversion technologies are described. Explanations about the most promising bio fuels provide a basis to discuss about the manifold issues of biofuels. The impartial information in this handbook further contributes to diminish existing barriers for the broad use of biofuels. Emphasis of this handbook is on first generation biofuels: bio ethanol, Biodiesel, pure plant oil, and bio methane. It also includes second generation biofuels such as BTL-fuels and bio ethanol from lingo-cellulose as well as bio hydrogen. The whole life cycle of bio fuels is assessed under technical, economical, ecological, and social aspect. Characteristics and applications of bio fuels for transport purposes are demonstrated and evaluated. This is completed by an assessment about the most recent studies on biofuel energy balances. This handbook describes the current discussion about green house gas (GHG) balances and sustainability aspects. GHG calculation methods are presented and potential impacts of biofuel production characterized: deforestation of rainforests and wetlands, loss of biodiversity, water pollution, human health, child labour, and labour conditions.

  7. Biofuel Subsidies and International Trade

    OpenAIRE

    Bandyopadhyay, Subhayu; Bhaumik, Sumon; Wall, Howard J.

    2010-01-01

    This paper explores optimal biofuel subsidization in the context of a general equilibrium trade model. The focus is on biofuels such as corn-based ethanol, which diverts corn from use as food to use as an intermediate input in energy production. In the small-country case, when a Pigouvian tax on conventional fuels such as crude is in place, the optimal biofuel subsidy is zero. When the tax on crude is not available as a policy option, however, a second-best biofuel subsidy (or tax) is opti...

  8. Chemotherapy-resistant breast implant-associated anaplastic large cell lymphoma

    OpenAIRE

    Parthasarathy, Muralidharan; Orrell, Julian; Mortimer, Caroline; Ball, Liz

    2013-01-01

    A 43-year-old woman presented with a few weeks’ history of discomfort and swelling in her left breast. She had undergone bilateral breast augmentation 8 years previously. There were no risk factors for breast cancer. Clinical examination, mammography and breast ultrasound revealed a large left breast mass adjacent to the breast implant with enlarged axillary lymph nodes. Owing to diagnostic uncertainty, core biopsies were sent to a specialist unit which confirmed breast implant-associated ana...

  9. Modeling Stem/Progenitor Cell-Induced Neovascularization and Oxygenation around Solid Implants

    OpenAIRE

    Jain, H. V.; Moldovan, N. I.; Byrne, H. M.

    2012-01-01

    Tissue engineering constructs and other solid implants with biomedical applications, such as drug delivery devices or bioartificial organs, need oxygen (O2) to function properly. To understand better the vascular integration of such devices, we recently developed a novel model sensor containing O2-sensitive crystals, consisting of a polymeric capsule limited by a nano-porous filter. The sensor was implanted in mice with hydrogel alone (control) or hydrogel embedded with mouse CD117/c-kit+ bon...

  10. Dental Implants

    Medline Plus

    Full Text Available Dental Implants A fuller, more complete smile is within reach. The following information is designed to provide ... whether dental implants are right for your situation. Dental Implants and Roots The key benefit of dental ...

  11. Dental Implants

    Science.gov (United States)

    Dental Implants A fuller, more complete smile is within reach. The following information is designed to provide ... whether dental implants are right for your situation. Dental Implants and Roots The key benefit of dental ...

  12. Attachment and proliferation of human osteoblast-like cells (MG-63) on laser-ablated titanium implant material

    International Nuclear Information System (INIS)

    Demand is increasing for shortening the long (3–6 months) osseointegration period to rehabilitate patients' damaged chewing apparatus in as short a time as possible. For dental implants, as for biomaterials in general, the bio- and osseointegration processes can be controlled at molecular and cellular levels by modification of the implant surface. One of the most promising of such surface modifications is laser ablation, as demonstrated by our previous results [46]. Commercially pure (CP4) sand-blasted, acid-etched titanium disks (Denti® System Ltd., Hungary) were irradiated with a KrF excimer laser (248 nm, fluence 0.4 J/cm2, FWHM 18 ns, 2000 pulses), or with a Nd:YAG laser (532 nm, 1.3 J/cm2, 10 ns, 200 pulses) then examined by SEM, AFM, and XPS. In vitro attachment (24 h) and proliferation (72 h) of MG-63 osteoblast cells were investigated via dimethylthiazol-diphenyl tetrazolium bromide (MTT), alamarBlue (AB) assays alkaline phosphatase quantification (ALP) and SEM. SEM and AFM revealed significant changes in morphology and roughness. XPS confirmed the presence of TiO2 on each sample; after Nd:YAG treatment a reduced state of Ti (Ti3+) was also observed. MTT, AB and ALP measurements detected an increase in the number of cells between the 24- and 72 hour observations; however, laser treatment did not affect cell attachment and proliferation significantly. - Highlights: • CP4 titanium implant surfaces were modified with Nd:YAG and KrF excimer laser. • SEM and AFM revealed significant changes in morphology and roughness. • XPS confirmed the presence of TiO2 on each sample; after Nd:YAG treatment a reduced state of Ti (Ti3+) was found. • Cell proliferation experiments detected an increased number of MG-63 cells between the 24 h and 72 h observations. • Laser treatments neither disturbed, nor enhanced MG-63 cell attachment and proliferation significantly

  13. Biosensors and Biofuel Cells based on Vertically Aligned Carbon Nanotubes for Integrated Energy Sensing, Generation, and Storage (SGS) Systems

    Science.gov (United States)

    Pandey, Archana; Prasad, Abhishek; Khin Yap, Yoke

    2010-03-01

    Diabetes is a growing health issue in the nation. Thus in-situ glucose sensors that can monitor the glucose level in our body are in high demand. Furthermore, it will be exciting if the excessive blood sugar can be converted into usable energy, and be stored in miniature batteries for applications. This will be the basis for an integrated energy sensing, generation, and storage (SGS) system in the future. Here we report the use of functionalized carbon nanotubes arrays as the glucose sensors as well as fuel cells that can convert glucose into energy. In principle, these devices can be integrated to detect excessive blood glucose and then convert the glucose into energy. They are also inline with our efforts on miniature 3D microbatteries using CNTs [1]. All these devices will be the basis for future SGS systems. Details of these results will be discussed in the meeting. [1] Wang et al., in 206^th Meeting of the Electrochemical Society, October 3-8, Honolulu, Hawaii (2004), Symposium Q1, abstract 1492. Y. K. Yap acknowledges supports from DARPA (DAAD17-03-C-0115), USDA (2007-35603-17740), and the Multi-Scale Technologies Institute (MuSTI) at MTU.

  14. Effects of the contraceptive skin patch and subdermal contraceptive implant on markers of endothelial cell activation and inflammation.

    Science.gov (United States)

    Hernandez-Juarez, Jesus; Sanchez-Serrano, Juan Carlos; Moreno-Hernandez, Manuel; Alvarado-Moreno, Jose Antonio; Hernandez-Lopez, Jose Rubicel; Isordia-Salas, Irma; Majluf-Cruz, Abraham

    2015-07-01

    Changes in blood coagulation factors may partially explain the association between hormonal contraceptives and thrombosis. Therefore, the likely effects of the contraceptive skin patch and subdermal contraceptive implant on levels of inflammatory markers and endothelial activation were analyzed. This was an observational, prospective, longitudinal, nonrandomized study composed of 80 women between 18 and 35 years of age who made the decision to use the contraceptive skin patch or subdermal contraceptive implant. vascular cell adhesion molecule-1 (VCAM-1), endothelial cell leukocyte adhesion molecule-1 (ELAM-1), von Willebrand factor (VWF), and plasminogen activator inhibitor type 1(PAI-1) as well as high-sensitivity C-reactive protein (hsCRP) were assayed before and after 4 months of use of the contraceptive method. VCAM-1, VWF, and PAI-1 remained unchanged in the contraceptive skin patch group; however, a significant increase in hsCRP (0.29-0.50 mg/dL; P =.012) and a significant decrease in ELAM-1 (44-25 ng/mL; P =.022) were observed. A significant diminution in VCAM-1 (463-362 ng/mL; P =.022) was also found in the subdermal contraceptive implant group. Our results strongly suggest that these contraceptive methods do not induce endothelial activation after 4 months of use. Increase in hsCRP levels was unrelated to changes in markers of endothelial activation. PMID:25655356

  15. Biofuels versus food production: Does biofuels production increase food prices?

    International Nuclear Information System (INIS)

    Rapidly growing fossil energy consumption in the transport sector in the last two centuries caused problems such as increasing greenhouse gas emissions, growing energy dependency and supply insecurity. One approach to solve these problems could be to increase the use of biofuels. Preferred feedstocks for current 1st generation biofuels production are corn, wheat, sugarcane, soybean, rapeseed and sunflowers. The major problem is that these feedstocks are also used for food and feed production. The core objective of this paper is to investigate whether the recent increase of biofuels production had a significant impact on the development of agricultural commodity (feedstock) prices. The most important impact factors like biofuels production, land use, yields, feedstock and crude oil prices are analysed. The major conclusions of this analysis are: In recent years the share of bioenergy-based fuels has increased moderately, but continuously, and so did feedstock production, as well as yields. So far, no significant impact of biofuels production on feedstock prices can be observed. Hence, a co-existence of biofuel and food production seems possible especially for 2nd generation biofuels. However, sustainability criteria should be seriously considered. But even if all crops, forests and grasslands currently not used were used for biofuels production it would be impossible to substitute all fossil fuels used today in transport.

  16. Neonatal human retinal pigment epithelial cells secrete limited trophic factors in vitro and in vivo following striatal implantation in parkinsonian rats

    DEFF Research Database (Denmark)

    Russ, Kaspar; Flores, Joseph; Brudek, Tomasz; Doudet, Doris

    2015-01-01

    Human retinal pigment epithelial (hRPE) cell implants into the striatum have been investigated as a potential cell-based treatment for Parkinson's disease in a Phase II clinical trial that recently failed. We hypothesize that the trophic factor potential of the hRPE cells could potentially...... influence the function and/or survival of the implants and may be involved in an alternative mechanism of action. However, it is unclear if hRPE cells secreted trophic factors when handled in the manner used in the clinical Phase II trial. To address these questions, we investigated two neonatal hRPE cell...... lots, cultured in a similar manner to hRPE cells used in a Phase II clinical study, and longitudinally determined brain-derived neurotrophic factor (BDNF), fibroblast growth factor 2 (FGF2), and pigment epithelium-derived factor concentrations in vitro and following striatal implantation into 6...

  17. The price for biofuels sustainability

    International Nuclear Information System (INIS)

    The production and usage of biofuels has increased worldwide, seeking goals of energy security, low-carbon energy and rural development. As biofuels trade increased, the European Union introduced sustainability regulations in an attempt to reduce the risks associated with biofuels. Producers were then confronted with costs of sustainability certification, in order to access the EU market. Hopes were that sustainably-produced biofuels would be rewarded with higher prices in the EU. Based on a review of recent literature, interviews with traders and price data from Platts, this paper explores whether sustainability premiums emerged and if so, did they represent an attracting feature in the market for sustainable biofuels. This article finds that premiums for ethanol and biodiesel evolved differently between 2011 and 2012, but have been in general very small or inexistent, with certified fuels becoming the new norm in the market. For different reasons, there has been an apparent convergence between biofuel policies in the EU and the US. As market operators perceive a long-term trend for full certification in the biofuels market, producers in developing countries are likely to face additional challenges in terms of finance and capacity to cope with the sustainability requirements. - Highlights: • EU biofuel sustainability rules were once thought to reward compliant producers with price-premiums. • Premiums for certified biofuels, however, have been small for biodiesel and almost non-existent for ethanol. • As sustainable biofuels became the new norm, premiums disappeared almost completely in 2012. • Early stages of supply chains concentrate the highest compliance costs, affecting specially developing country producers. • Producers are now in a market where sustainable biofuels have become the new norm

  18. Advanced biofuel production by the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Buijs, Nicolaas A; Siewers, Verena; Nielsen, Jens

    2013-06-01

    Replacement of conventional transportation fuels with biofuels will require production of compounds that can cover the complete fuel spectrum, ranging from gasoline to kerosene. Advanced biofuels are expected to play an important role in replacing fossil fuels because they have improved properties compared with ethanol and some of these may have the energy density required for use in heavy duty vehicles, ships, and aviation. Moreover, advanced biofuels can be used as drop-in fuels in existing internal combustion engines. The yeast cell factory Saccharomyces cerevisiae can be turned into a producer of higher alcohols (1-butanol and isobutanol), sesquiterpenes (farnesene and bisabolene), and fatty acid ethyl esters (biodiesel), and here we discusses progress in metabolic engineering of S. cerevisiae for production of these advanced biofuels. PMID:23628723

  19. Biomarkers Provide Clues to Early Events in the Pathogenesis of Breast Implant-Associated Anaplastic Large Cell Lymphoma.

    Science.gov (United States)

    Kadin, Marshall E; Deva, Anand; Xu, Haiying; Morgan, John; Khare, Pranay; MacLeod, Roderick A F; Van Natta, Bruce W; Adams, William P; Brody, Garry S; Epstein, Alan L

    2016-07-01

    Almost 200 women worldwide have been diagnosed with breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). The unique location and specific lymphoma type strongly suggest an etio-pathologic link between breast implants and BIA-ALCL. It is postulated that chronic inflammation via bacterial infection may be an etiological factor. BIA-ALCL resembles primary cutaneous ALCL (pcALCL) in morphology, activated T-cell phenotype, and indolent clinical course. Gene expression array analysis, flow cytometry, and immunohistochemistry were used to study pcALCL and BIA-ALCL cell lines. Clinical samples were also studied to characterize transcription factor and cytokine profiles of tumor cells and surrounding lymphocytes. BIA-ALCL and pcALCL were found to have common expression of transcription factors SOCS3, JunB, SATB1, and a cytokine profile suggestive of a Th1 phenotype. Similar patterns were observed in a CD30+ cutaneous lymphoproliferative disorder (LPD). The patterns of cytokine and transcription factor expression suggest that BIA-ALCL is likely to arise from chronic bacterial antigen stimulation of T-cells. Further analysis of cytokine and transcription factor profiles may allow early detection and treatment of BIA-ALCL leading to better prognosis and survival. LEVEL OF EVIDENCE 5: Risk. PMID:26979456

  20. Protein network signatures associated with exogenous biofuels treatments in cyanobacterium Synechocystis sp. PCC 6803

    OpenAIRE

    Guangsheng ePei; Lei eChen; Jiangxin eWang; jianjun eQiao; Weiwen eZhang

    2014-01-01

    Although recognized as a promising microbial cell factory for producing biofuels, current productivity in cyanobacterial systems is low. To make the processes economically feasible, one of the hurdles which needs to be overcome is the low tolerance of hosts to toxic biofuels. Meanwhile, little information is available regarding the cellular responses to biofuels stress in cyanobacteria, which makes it challenging for tolerance engineering. Using large proteomic datasets of Synechocystis under...

  1. CONNECTICUT BIOFUELS TECHNOLOGY PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    BARTONE, ERIK

    2010-09-28

    DBS Energy Inc. (“DBS”) intends on using the Connecticut Biofuels Technology Project for the purpose of developing a small-scale electric generating systems that are located on a distributed basis and utilize biodiesel as its principle fuel source. This project will include research and analysis on the quality and applied use of biodiesel for use in electricity production, 2) develop dispatch center for testing and analysis of the reliability of dispatching remote generators operating on a blend of biodiesel and traditional fossil fuels, and 3) analysis and engineering research on fuel storage options for biodiesel of fuels for electric generation.

  2. Biofuels: Project summaries

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The US DOE, through the Biofuels Systems Division (BSD) is addressing the issues surrounding US vulnerability to petroleum supply. The BSD goal is to develop technologies that are competitive with fossil fuels, in both cost and environmental performance, by the end of the decade. This document contains summaries of ongoing research sponsored by the DOE BSD. A summary sheet is presented for each project funded or in existence during FY 1993. Each summary sheet contains and account of project funding, objectives, accomplishments and current status, and significant publications.

  3. National Algal Biofuels Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, John [Dept. of Energy (DOE), Washington DC (United States); Sarisky-Reed, Valerie [Dept. of Energy (DOE), Washington DC (United States)

    2010-05-01

    The framework for National Algal Biofuels Technology Roadmap was constructed at the Algal Biofuels Technology Roadmap Workshop, held December 9-10, 2008, at the University of Maryland-College Park. The Workshop was organized by the Biomass Program to discuss and identify the critical challenges currently hindering the development of a domestic, commercial-scale algal biofuels industry. This Roadmap presents information from a scientific, economic, and policy perspectives that can support and guide RD&D investment in algal biofuels. While addressing the potential economic and environmental benefits of using algal biomass for the production of liquid transportation fuels, the Roadmap describes the current status of algae RD&D. In doing so, it lays the groundwork for identifying challenges that likely need to be overcome for algal biomass to be used in the production of economically viable biofuels.

  4. Biofuels. An overview. Final Report

    International Nuclear Information System (INIS)

    The overall objective of this desk study is to get an overview of the most relevant liquid biofuels especially in the African context, and more specifically in the Netherlands' relevant partner countries. The study will focus on biofuels for transport, but will also consider biofuels for cooking and power generation. Biogas as the result of anaerobic fermentation which can be used for cooking, lighting and electricity generation will not be considered in this study. Liquid biofuels are usually divided into alcohols that are used to substitute for gasoline and oils that are used to substitute for diesel and are often called Biodiesel, and this division will be followed in this study. In chapter 2 we will analyse several aspects of the use of alcohols particularly ethanol, in chapter 3 the same analysis will be done for oils, using as example the very promising Jatropha oil. In chapter we will analyse socio-economic issues of the use of these biofuels

  5. Hybrid approach of ventricular assist device and autologous bone marrow stem cells implantation in end-stage ischemic heart failure enhances myocardial reperfusion

    Directory of Open Access Journals (Sweden)

    Khayat Andre

    2011-01-01

    Full Text Available Abstract We challenge the hypothesis of enhanced myocardial reperfusion after implanting a left ventricular assist device together with bone marrow mononuclear stem cells in patients with end-stage ischemic cardiomyopathy. Irreversible myocardial loss observed in ischemic cardiomyopathy leads to progressive cardiac remodelling and dysfunction through a complex neurohormonal cascade. New generation assist devices promote myocardial recovery only in patients with dilated or peripartum cardiomyopathy. In the setting of diffuse myocardial ischemia not amenable to revascularization, native myocardial recovery has not been observed after implantation of an assist device as destination therapy. The hybrid approach of implanting autologous bone marrow stem cells during assist device implantation may eventually improve native cardiac function, which may be associated with a better prognosis eventually ameliorating the need for subsequent heart transplantation. The aforementioned hypothesis has to be tested with well-designed prospective multicentre studies.

  6. Evaluation of innate, humoral and cell-mediated immunity in mice following in vivo implantation of electrospun polycaprolactone

    International Nuclear Information System (INIS)

    Electrospun polycaprolactone (EPCL) is currently being investigated for use in tissue engineering applications such as vascular grafts. However, the effects of electrospun polymers on systemic immune responses following in vivo exposure have not previously been examined. The work presented evaluates whether EPCL in either a microfibrous or nanofibrous form affects innate, humoral and/or cell-mediated immunity using a standard immunotoxicological testing battery. Holistic in vivo endpoints examined include the antibody-forming cell assay (AFC or plaque assay) and the delayed-type hypersensitivity response to Candida albicans. In addition, natural killer cell cytotoxic activity was assessed using an ex vivo assay and splenic cell population phenotypes were analyzed by flow cytometry for material exposure-related changes. Results indicated that 28 day subcutaneous implantation of EPCL, either in microfibrous or nanofibrous form, did not affect the systemic functions of the immune system in 12–16 week old female B6C3F1 mice. (paper)

  7. Does homeobox-related "positional" genomic information contribute to implantation of metastatic cancer cells at non-random sites?

    Science.gov (United States)

    Anderson, K M; Darweesh, M; Jajah, A; Tsui, P; Guinan, P; Rubenstein, M

    2007-01-01

    Reasons for the lodgment of metastases from several types of solid cancer at apparently non-random sites have not been established. Recently, a group of genes expressed in human fibroblasts obtained from different anatomic locations was implicated in "positional" genomic information. Essentially, a Cartesian coordinate system identifying fibroblasts originally resident at anterior or more posterior, proximal or distal and dermal or non-dermal (heart, lung, etc.) locations was proposed. The determinants used for these identifications included HOX genes, central to embryonic segmental development, some of which are expressed in differentiated, post-embryonic cells. To the extent that HOX or other homeobox genes are expressed in ectodermal, mesodermal or endodermally-derived, malignantly transformed cells, they might contribute "positional" information to nidation of specific malignant clones at non-random sites. As understood in the past, interdiction of HOX or homeobox-related gene expression might reduce the probability of cancer cell implantation or alter their destinations in complex ways. Ideally, by interfering with HOX or other homeobox gene-related expression of antigenic determinants potentially contributing to their "homing" and nidation, reduced implantation of circulating cancer cells could render them more susceptible to systemic chemotherapy or immunotherapy, as demonstrated in mice. Furthermore, HOX or other homeobox genes or their products could provide novel intra- or extracellular targets for therapy. PMID:17695497

  8. Dental Implants

    Medline Plus

    Full Text Available ... helpful facts so you can make an informed decision as to whether dental implants are right for your situation. Dental Implants and Roots The key benefit of dental implants over other tooth replacement systems is that an implant connects directly to the ...

  9. Uterine autonomic nerve innervation plays a crucial role in regulating rat uterine mast cell functions during embryo implantation.

    Science.gov (United States)

    Yuan, Xue-Jun; Huang, Li-Bo; Qiao, Hui-Li; Deng, Ze-Pei; Fa, Jing-Jing

    2009-12-01

    To explore the potential mechanism of how uterine innervations would affect the uterine mast cell (MC) population and functions during the periimplantation. We herein first examined the consequence of uterine neurectomy on embryo implantation events. We observed that amputation of autonomic nerves innervating the uterus led to on-time implantation failure in rats. Exploiting MC culture and ELISA approaches, we then further analyzed the effect of neurectomy on cellular histamine levels and its release from uterine MCs, to elucidate the relation of the autonomic nerves and local cellular immunity in the uterine during early pregnancy. We observed that disconnection of autonomic nerve innervation significantly increased the population of uterine MCs. Most interestingly, these increased number of uterine MCs in neuroectomized rats contained a much reduced cellular level of histamine. Our subsequent challenge experiments revealed that uterine MCs in nerve amputated rats exhibited enhanced histamine releasing rate in response to substance P and antiIgE, suggesting loss of nerve innervation in the uterus not only increases the population of uterine MCs, but also facilitates the release of histamine from MCs, thus subsequently interfere with the normal implantation process. Collectively, our findings provide a new line of evidence supporting the concept that immune-neuro-endocrine network plays important role during pregnancy establishment and maintenance. PMID:19765668

  10. Limited external irradiation and interstitial 192iridium implant in the treatment of squamous cell carcinoma of the tonsillar region

    International Nuclear Information System (INIS)

    Between January 1976 and March 1982, 80 patients with histologically proven diagnosis of squamous cell carcinoma of the tonsillar region were treated with definitive radiotherapy. Sixty-five (81%) of these patients had locally advanced tumors (Stage III and IV); 49% of patients had clinically palpable cervical lymphadenopathy. All patients received a combined external megavoltage and interstitial irradiation. The dose of external irradiation was limited to 4500-5000 cGy over 41/2 to 51/2 weeks. This was followed by interstitial 192iridium implants to doses of 2000-2500 cGy in 50-60 hours for T1, T2 lesions and 3000-4000 cGy in 60-100 hours for T3, T4 lesions. The neck masses were also separately implanted to deliver additional doses of 2000-4000 cGy in 50-80 hours. Overall local tumor control was observed in 84% of patients with a minimum follow-up period of 2 years. An absolute 3-year disease free survival of the entire group was 72%. Treatment related complications such as soft tissue necrosis or osteoradionecrosis occurred in 6% (5/80) of patients. The salvage of neck failures and local failures was possible in 78 and 38% of patients, respectively, either by surgery or by re-irradiation employing interstitial 192iridium implants. Functional and esthetic integrity was well preserved in most cases

  11. [Tobacco--a source of biofuels].

    Science.gov (United States)

    Budzianowska, Anna; Budzianowski, Jaromir

    2012-01-01

    One of the concepts of global protection of environment is to reduce greenhouse gas emissions, mainly carbon dioxide, into the atmosphere by replacing fossil fuels by the so-called biofuels, which can be obtained from cultivated plants or any plant waste biomass. Currently applied industrial technologies allow the production of biofuels to receive ethanol, mostly from the reserve carbohydrates of sugar cane and corn as well as biodiesel from oil, mainly from rapeseed or oil palm. Tobacco, which provides a high biomass, can be used to produce biogas, bioethanol and biodiesel. The latter derived from oil from seeds and leaves of tobacco has proved useful for driving cars. Modest oil content in tobacco leaves can be increased by the expression of foreign genes encoding its biosynthesis. Promising future source of biofuels is a waste plant biomass consisting mainly of cell walls, which can be subjected to the degradation to produce sugars suitable for fermentation and the production of bioethanol. A number of enzymes needed for efficient degradation of plant cell walls can be produced using recombinant DNA technology in a variety of plants, particularly in chloroplasts of tobacco. PMID:23421113

  12. A holistic high-throughput screening framework for biofuel feedstock assessment that characterises variations in soluble sugars and cell wall composition in Sorghum bicolor

    OpenAIRE

    Martin, Antony P.; PALMER, WILLIAM M.; Byrt, Caitlin S; Furbank, Robert T.; Grof, Christopher PL

    2013-01-01

    Background A major hindrance to the development of high yielding biofuel feedstocks is the ability to rapidly assess large populations for fermentable sugar yields. Whilst recent advances have outlined methods for the rapid assessment of biomass saccharification efficiency, none take into account the total biomass, or the soluble sugar fraction of the plant. Here we present a holistic high-throughput methodology for assessing sweet Sorghum bicolor feedstocks at 10 days post-anthesis for total...

  13. Analysis of advanced biofuels.

    Energy Technology Data Exchange (ETDEWEB)

    Dec, John E.; Taatjes, Craig A.; Welz, Oliver; Yang, Yi

    2010-09-01

    Long chain alcohols possess major advantages over ethanol as bio-components for gasoline, including higher energy content, better engine compatibility, and less water solubility. Rapid developments in biofuel technology have made it possible to produce C{sub 4}-C{sub 5} alcohols efficiently. These higher alcohols could significantly expand the biofuel content and potentially replace ethanol in future gasoline mixtures. This study characterizes some fundamental properties of a C{sub 5} alcohol, isopentanol, as a fuel for homogeneous-charge compression-ignition (HCCI) engines. Wide ranges of engine speed, intake temperature, intake pressure, and equivalence ratio are investigated. The elementary autoignition reactions of isopentanol is investigated by analyzing product formation from laser-photolytic Cl-initiated isopentanol oxidation. Carbon-carbon bond-scission reactions in the low-temperature oxidation chemistry may provide an explanation for the intermediate-temperature heat release observed in the engine experiments. Overall, the results indicate that isopentanol has a good potential as a HCCI fuel, either in neat form or in blend with gasoline.

  14. Biofuels: 1995 project summaries

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    Domestic transportation fuels are derived primarily from petroleum and account for about two-thirds of the petroleum consumption in the United States. In 1994, more than 40% of our petroleum was imported. That percentage is likely to increase, as the Middle East has about 75% of the world`s oil reserves, but the United States has only about 5%. Because we rely so heavily on oil (and because we currently have no suitable substitutes for petroleum-based transportation fuels), we are strategically and economically vulnerable to disruptions in the fuel supply. Additionally, we must consider the effects of petroleum use on the environment. The Biofuels Systems Division (BSD) is part of the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EE). The day-to-day research activities, which address these issues, are managed by the National Renewable Energy Laboratory in Golden, Colorado, and Oak Ridge National Laboratory in Oak Ridge, Tennessee. BSD focuses its research on biofuels-liquid and gaseous fuels made from renewable domestic crops-and aggressively pursues new methods for domestically producing, recovering, and converting the feedstocks to produce the fuels economically. The biomass resources include forage grasses, oil seeds, short-rotation woody crops, agricultural and forestry residues, algae, and certain industrial and municipal waste streams. The resulting fuels include ethanol, methanol, biodiesel, and ethers.

  15. Biofuel from "humified" biomass

    Science.gov (United States)

    Kpogbemabou, D.; Lemée, L.; Amblès, A.

    2009-04-01

    In France, 26% of the emissions of greenhouse effect gas originate from transportation which depends for 87% on fossil fuels. Nevertheless biofuels can contribute to the fight against climate change while reducing energetic dependence. Indeed biomass potentially represents in France 30 Mtoe a year that is to say 15% national consumption. But 80% of these resources are made of lignocellulosic materials which are hardly exploitable. First-generation biofuels are made from sugar, starch, vegetable oil, or animal fats. Due to their competition with human food chain, first-generation biofuels could lead to food shortages and price rises. At the contrary second-generation biofuel production can use a variety of non food crops while using the lignocellulosic part of biomass [1]. Gasification, fermentation and direct pyrolysis are the most used processes. However weak yields and high hydrogen need are limiting factors. In France, the National Program for Research on Biofuels (PNRB) aims to increase mobilizable biomass resource and to develop lignocellulosic biomass conversion. In this context, the LIGNOCARB project studies the liquefaction of biodegraded biomass in order to lower hydrogen consumption. Our aim was to develop and optimize the biodegradation of the biomass. Once the reactor was achieved, the influence of different parameters (starting material, aeration, moisture content) on the biotransformation process was studied. The monitored parameters were temperature, pH and carbon /nitrogen ratio. Chemical (IHSS protocol) and biochemical (van Soest) fractionations were used to follow the maturity ("humic acid"/"fulvic acid" ratio) and the biological stability (soluble, hemicelluloses, celluloses, lignin) of the organic matter (OM). In example, the increase in lignin can be related to the stabilization since the OM becomes refractory to biodegradation whereas the increase in the AH/AF ratio traduces "humification". However, contrarily to the composting process, we do

  16. Changes in corneal endothelium cell characteristics after cataract surgery with and without use of viscoelastic substances during intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Schulze SD

    2015-11-01

    Full Text Available Stephan D Schulze,1 Thomas Bertelmann,1 Irena Manojlovic,2 Stefan Bodanowitz,2 Sebastian Irle,3 Walter Sekundo11Department of Ophthalmology, Philipps University of Marburg, Marburg, 2Private Practice and Ambulatory Surgical Center, Bremen, 3Freelance Statistician, Friedberg, GermanyPurpose: To evaluate whether the use of balanced salt solution (BSS or an ophthalmic viscoelastic device (OVD during hydrophilic acrylic intraocular lens (IOL implantation variously impacts corneal endothelial cell characteristics in eyes undergoing uneventful phacoemulsifications.Methods: Prospective nonrandomized observational clinical trial. Patients were assigned either to the BSS plus® or to the OVD Z-Celcoat™ group depending on the substance used during IOL implantation. Corneal endothelium cell characteristics were obtained before, 1 week, and 6 weeks after surgery. Intraoperative parameters (eg, surgery time, phacoemulsification energy were recorded.Results: Ninety-seven eyes were assigned to the BSS plus and 86 eyes to the Z-Celcoat group. Preoperative corneal endothelium cell density (ECD and endothelium cell size were 2,506±310 cells/mm2/2,433±261 cells/mm2 and 406±47 µm2/416±50 µm2 (P=0.107/P=0.09. After 1 and 6 weeks, ECD decreased and endothelium cell size increased significantly in both groups (each P<0.001 without significant differences between both groups (each P>0.05. Irrigation–aspiration suction time (30.3±16.6 versus 36.3±14.5 seconds and overall surgical time (7.2±1.2 versus 8.0±1.4 minutes were significantly longer in the OVD Z-Celcoat group (each P<0.001. No complications or serious side effects occurred.Conclusion: Implantation of a hydrophilic acrylic IOL under BSS infusion seems to be a useful and faster alternative in experienced hands without generating higher ECD loss rates.Keywords: phacoemulsification, ophthalmic viscoelastic device, endothelial cell density, IOL

  17. Considering Trade Policies for Liquid Biofuels

    OpenAIRE

    Kojima, Masami; Mitchell, Donald; Ward, William

    2007-01-01

    This report addresses the issues associated with trade in liquid biofuels is a second Energy Sector Management Assistance Program report on biofuels, and part of a broader assessment of bioenergy undertaken by the World Bank. The report asks how liberalizing trade in liquid biofuels might affect biofuel production and consumption. Bioenergy is playing an increasingly important role as an a...

  18. Impact of implanted phosphorus on the diffusivity of boron and its applicability to silicon solar cells

    International Nuclear Information System (INIS)

    Boron diffusivity reduction in extrinsically doped silicon was investigated in the context of a process combination consisting of BBr3 furnace diffusion and preceding Phosphorus ion implantation. The implantation of Phosphorus leads to a substantial blocking of Boron during the subsequent Boron diffusion. First, the influences of ion implantation induced point defects as well as the initial P doping on B diffusivity were studied independently. Here, it was found that not the defects created during ion implantation but the P doping itself results in the observed B diffusion retardation. The influence of the initial P concentration was investigated in more detail by varying the P implantation dose. A secondary ion mass spectrometry (SIMS) analysis of the BSG layer after the B diffusion revealed that the B diffusion retardation is not due to potential P content in the BSG layer but rather caused by the n-type doping of the crystalline silicon itself. Based on the observations the B diffusion retardation was classified into three groups: (i) no reduction of B diffusivity, (ii) reduced B diffusivity, and (iii) blocking of the B diffusion. The retardation of B diffusion can well be explained by the phosphorus doping level resulting in a Fermi level shift and pairing of B and P ions, both reducing the B diffusivity. Besides these main influences, there are probably additional transient phenomena responsible for the blocking of boron. Those might be an interstitial transport mechanism caused by P diffusion that reduces interstitial concentration at the surface or the silicon/BSG interface shift due to oxidation during the BBr3 diffusion process. Lifetime measurements revealed that the residual (non-blocked) B leads to an increased dark saturation current density in the P doped region. Nevertheless, electrical quality is on a high level and was further increased by reducing the B dose as well as by removing the first few nanometers of the silicon surface after the BBr3

  19. Biofuels and the biorefinery concept

    International Nuclear Information System (INIS)

    Liquid fuels can be made by refining a range of biomass materials, including oil-rich and sugar-rich crops such as oil-seed rape and sugar beet, biomass that consists mainly of plant cell walls (second generation lignocellulosics), macro- and micro-alga, or material that would now be discarded as waste. This can include animal bi-products as well as waste wood and other resources. In the medium-term, plant cell (lignocellulosic) material is likely to be favoured as the feedstock for biorefineries because of its availability. The UK may make use of a number of these options because of its complex agricultural landscape. There are now a range of targets for biofuel use in the UK, although their environmental effects are disputed. The technology of refining these materials is well known. Possible outputs include biodiesel and bioethanol, both of which can be used as transport fuel. Other potential products include hydrogen, polymers and a wide range of value-added chemicals, making this technology important in a post-petrochemical world. Biorefineries could use cogeneration to produce electricity. The paper identifies a range of research and development priorities which must be met if this opportunity is to be exploited fully. (author)

  20. Progenitor Hematopoietic Cells Implantation Improves Functional Capacity of End Stage Coronary Artery Disease Patients with Advanced Heart Failure

    Directory of Open Access Journals (Sweden)

    Yoga Yuniadi

    2016-01-01

    Full Text Available Background. Proangiogenic Hematopoietic Cells (PHC which comprise diverse mixture of cell types are able to secrete proangiogenic factors and interesting candidate for cell therapy. The aim of this study was to seek for benefit in implantation of PHC on functional improvement in end stage coronary artery disease patients with advanced heart failure. Methods. Patients with symptomatic heart failure despite guideline directed medical therapy and LVEF less than 35% were included. Peripheral blood mononuclear cells were isolated, cultivated for 5 days, and then harvested. Flow cytometry and cell surface markers were used to characterize PHC. The PHC were delivered retrogradely via sinus coronarius. Echocardiography, myocardial perfusion, and clinical and functional data were analyzed up to 1-year observation. Results. Of 30 patients (56.4±7.40 yo preimplant NT proBNP level is 5124.5±4682.50 pmol/L. Harvested cells characterized with CD133, CD34, CD45, and KDR showed 0.87±0.41, 0.63±0.66, 99.00±2.60, and 3.22±3.79%, respectively. LVEF was improved (22±5.68 versus 26.8±7.93, p<0.001 during short and long term observation. Myocardial perfusion significantly improved 6 months after treatment. NYHA Class and six-minute walk test are improved during short term and long term follow-up. Conclusion. Expanded peripheral blood PHC implantation using retrograde delivery approach improved LV systolic function, myocardial perfusion, and functional capacity.

  1. International Trade of Biofuels (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2013-05-01

    In recent years, the production and trade of biofuels has increased to meet global demand for renewable fuels. Ethanol and biodiesel contribute much of this trade because they are the most established biofuels. Their growth has been aided through a variety of policies, especially in the European Union, Brazil, and the United States, but ethanol trade and production have faced more targeted policies and tariffs than biodiesel. This fact sheet contains a summary of the trade of biofuels among nations, including historical data on production, consumption, and trade.

  2. Algal Biofuels; Algal Biofuels R&D at NREL (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2010-09-01

    An overview of NREL's algal biofuels projects, including U.S. Department of Energy-funded work, projects with U.S. and international partners, and Laboratory Directed Research and Development projects.

  3. Repair of the myocardium infarct, with intracoronary implant of mother cells (stem cells) precocious improvement of the ventricular function and the ischemy (first reports of the TECELCOR report)

    International Nuclear Information System (INIS)

    Twenty patients who suffered extensive anterior myocardial infarction with an evolution of 5 to 72 hours were submitted to a primary PTCA with Stent. The ventricular ejection fraction oscillated between 21 to 30% in correlation to the bidimensional echocardiography. Between the 7th and 12th day, mononuclear CD 34(+) and CD 38(-) cells extracted from the patient's bone marrow were implanted through the anterior descendent coronary artery, with occlusion of the anterior coronary vein, in an average amount of 22 x 10 P6. echocardiographic controls were performed each 7 days until 60 days, noticing a progressive increment in the ejection fraction (EF) from 25 to 45% in the first 60 days, and an improvement of the EF up to 80% after 90 days. Between 90 and 120 days after, a coronary ventriculography was performed, and the permeability of all the implanted stents and an improvement of the EF up to 80% with respect to the basal EF, were observed. The Spect studies were negative with negative ergonometry at 700 kgm. This group of patients was comparing red with 16 patients who were submitted only to primary PTCA with Stent. They had an increase of only 45% of the EF respect to the basal one in the next 90 days and 12 % presented restenosis. Stems cells implant improves the left ventricular performance after a myocardial infarction and it seems to avoid the coronary post-restenosis

  4. Locally advanced breast implant-associated anaplastic large-cell lymphoma: a case report of successful treatment with radiation and chemotherapy.

    Science.gov (United States)

    Estes, Christopher F; Zhang, Da; Reyes, Ruben; Korentager, Richard; McGinness, Marilee; Lominska, Christopher

    2015-01-01

    The development of breast implant-associated anaplastic large-cell lymphoma (ALCL) is a rare phenomenon. A typical presentation is an effusion associated with a breast implant. Less commonly, disease can be more advanced locoregionally or distantly. The optimal treatment schema is a topic of debate: localized ALCL can potentially be cured with implant removal alone, while other cases in the literature, including those that are more advanced, have been treated with varying combinations of surgery, chemotherapy, and external beam radiotherapy. This is a case report of breast implant ALCL with pathologically proven lymph node involvement, the fifth such patient reported. Our patient experienced a favorable outcome with radiation therapy and chemotherapy. PMID:25741471

  5. Attachment and proliferation of human osteoblast-like cells (MG-63) on laser-ablated titanium implant material

    Energy Technology Data Exchange (ETDEWEB)

    Györgyey, Ágnes; Ungvári, Krisztina [Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, H-6720 Szeged (Hungary); Kecskeméti, Gabriella; Kopniczky, Judit [Department of Optics and Quantum Electronics, Faculty of Science and Informatics, University of Szeged, H-6720 Szeged (Hungary); Hopp, Béla [Research Group on Laser Physics, Hungarian Academy of Sciences and University of Szeged, H-6720 Szeged (Hungary); Oszkó, Albert [Department of Physical Chemistry and Materials Science, Faculty of Science and Informatics, University of Szeged, H-6720 Szeged (Hungary); Pelsöczi, István; Rakonczay, Zoltán [Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, H-6720 Szeged (Hungary); Nagy, Katalin [Department of Oral Surgery, Faculty of Dentistry, University of Szeged, H-6720 Szeged (Hungary); Turzó, Kinga, E-mail: kturzo@yahoo.com [Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, H-6720 Szeged (Hungary)

    2013-10-15

    Demand is increasing for shortening the long (3–6 months) osseointegration period to rehabilitate patients' damaged chewing apparatus in as short a time as possible. For dental implants, as for biomaterials in general, the bio- and osseointegration processes can be controlled at molecular and cellular levels by modification of the implant surface. One of the most promising of such surface modifications is laser ablation, as demonstrated by our previous results [46]. Commercially pure (CP4) sand-blasted, acid-etched titanium disks (Denti® System Ltd., Hungary) were irradiated with a KrF excimer laser (248 nm, fluence 0.4 J/cm{sup 2}, FWHM 18 ns, 2000 pulses), or with a Nd:YAG laser (532 nm, 1.3 J/cm{sup 2}, 10 ns, 200 pulses) then examined by SEM, AFM, and XPS. In vitro attachment (24 h) and proliferation (72 h) of MG-63 osteoblast cells were investigated via dimethylthiazol-diphenyl tetrazolium bromide (MTT), alamarBlue (AB) assays alkaline phosphatase quantification (ALP) and SEM. SEM and AFM revealed significant changes in morphology and roughness. XPS confirmed the presence of TiO{sub 2} on each sample; after Nd:YAG treatment a reduced state of Ti (Ti{sup 3+}) was also observed. MTT, AB and ALP measurements detected an increase in the number of cells between the 24- and 72 hour observations; however, laser treatment did not affect cell attachment and proliferation significantly. - Highlights: • CP4 titanium implant surfaces were modified with Nd:YAG and KrF excimer laser. • SEM and AFM revealed significant changes in morphology and roughness. • XPS confirmed the presence of TiO{sub 2} on each sample; after Nd:YAG treatment a reduced state of Ti (Ti{sup 3+}) was found. • Cell proliferation experiments detected an increased number of MG-63 cells between the 24 h and 72 h observations. • Laser treatments neither disturbed, nor enhanced MG-63 cell attachment and proliferation significantly.

  6. Radiation protective nursing intervene of 125I seed implantation in non-small cell lung cancer

    International Nuclear Information System (INIS)

    Lung cancer is the most common primary malignant tumor. Because most sufferers have already been in later stage in their first diagnosis, the lump body infringing upon the important organs often influences the excision of tumor. 125I seeds permanent implantation is a new method for tumor brachytherapy, which contributes to kill the tumor completely, ensures the normal physiological functions of organs,reduces tissue injuries and treatment of complications, and raises the survival rate of sufferers. The rapid promotion of this technique is also followed by radiation risks in the treatment. Currently, the researches of 125I seeds implantation is limited to the aspects of treatment means and effects, with no detailed study in intraoperative usage, disinfection and protection. Although a satisfactory curative effect is the key in the treatment,the studies in protection principles, means and technological upgradation are also too important to be ignored. (authors)

  7. Osteoblast adhesion to orthopaedic implant alloys: effects of cell adhesion molecules and diamond-like carbon coating.

    Science.gov (United States)

    Kornu, R; Maloney, W J; Kelly, M A; Smith, R L

    1996-11-01

    In total joint arthroplasty, long-term outcomes depend in part on the biocompatibility of implant alloys. This study analyzed effects of surface finish and diamond-like carbon coating on osteoblast cell adhesion to polished titanium-aluminum-vanadium and polished or grit-blasted cobalt-chromium-molybdenum alloys. Osteoblast binding was tested in the presence and absence of the cell adhesion proteins fibronectin, laminin, fibrinogen, and vitronectin and was quantified by measurement of DNA content. Although adherence occurred in serum-free medium, maximal osteoblast binding required serum and was similar for titanium and cobalt alloys at 2 and 12 hours. With the grit-blasted cobalt alloy, cell binding was reduced 48% (p Coating the alloys with diamond-like carbon did not alter osteoblast adhesion, whereas fibronectin pretreatment increased cell binding 2.6-fold (p enhance cell adhesion. These results support the hypothesis that cell adhesion proteins can modify cell binding to orthopaedic alloys. Although osteoblast binding was not affected by the presence of diamond-like carbon, this coating substance may influence other longer term processes, such as bone formation, and deserves further study. PMID:8982128

  8. Altered Cell Cycle Gene Expression and Apoptosis in Post-Implantation Dog Parthenotes

    OpenAIRE

    Park, Jung Eun; Kim, Min Jung; Ha, Seung Kwon; Hong, So Gun; Oh, Hyun Ju; Kim, Geon A; Park, Eun Jung; Kang, Jung Taek; SAADELDIN, Islam M.; Jang, Goo; Lee, Byeong Chun

    2012-01-01

    Mature oocytes can be parthenogenetically activated by a variety of methods and the resulting embryos are valuable for studies of the respective roles of paternal and maternal genomes in early mammalian development. In the present study, we report the first successful development of parthenogenetic canine embryos to the post-implantation stage. Nine out of ten embryo transfer recipients became pregnant and successful in utero development of canine parthenotes was confirmed. For further evalua...

  9. Biofuels: policies, standards and technologies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-09-15

    Skyrocketing prices of crude oil in the middle of the first decade of the 21st century accompanied by rising prices for food focused political and public attention on the role of biofuels. On the one hand, biofuels were considered as a potential automotive fuel with a bright future, on the other hand, biofuels were accused of competing with food production for land. The truth must lie somewhere in-between and is strongly dependent on the individual circumstance in different countries and regions. As food and energy are closely interconnected and often compete with each other for other resources, such as water, the World Energy Council - following numerous requests of its Member Committees - decided to undertake an independent assessment of biofuels policies, technologies and standards.

  10. Transgenic woody plants for biofuel

    Institute of Scientific and Technical Information of China (English)

    Wei Tang; Anna Y.Tang

    2014-01-01

    Transgenic trees as a new source for biofuel have brought a great interest in tree biotechnology. Genetically modifying forest trees for ethanol production have advantages in technical challenges, costs, environmental concerns, and financial problems over some of crops. Genetic engineering of forest trees can be used to reduce the level of lignin, to produce the fast-growing trees, to develop trees with higher cellulose, and to allow the trees to be grown more widely. Trees can establish themselves in the field with less care of farmers, compared to most of crops. Transgenic crops as a new source for biofuel have been recently reviewed in several reviews. Here, we overview transgenic woody plants as a new source for biofuel including genetically modified woody plants and environment; main focus of woody plants genetic modifications;solar to chemical energy transfer; cellulose biosynthesis;lignin biosynthesis;and cellulosic ethanol as biofuel.

  11. Third generation biofuels from microalgae

    OpenAIRE

    Dragone, Giuliano; Fernandes, Bruno Daniel; A.A. Vicente; Teixeira, J. A.

    2010-01-01

    Biofuel production from renewable sources is widely considered to be one of the most sustainable alternatives to petroleum sourced fuels and a viable means for environmental and economic sustainability. Microalgae are currently being promoted as an ideal third generation biofuel feedstock because of their rapid growth rate, CO2 fixation ability and high production capacity of lipids; they also do not compete with food or feed crops, and can be produced on non-arable land. Microalg...

  12. Carmustine Implant

    Science.gov (United States)

    Carmustine implant is used along with surgery and sometimes radiation therapy to treat malignant glioma (a certain type of ... Carmustine implant comes as a small wafer that is placed in the brain by a doctor during surgery to ...

  13. Goserelin Implant

    Science.gov (United States)

    Goserelin implant is used in combination with radiation therapy and other medications to treat localized prostate cancer and is ... treatment of abnormal bleeding of the uterus. Goserelin implant is in a class of medications called gonadotropin- ...

  14. Dental Implants

    Medline Plus

    Full Text Available ... is lost for the most predictable esthetic outcome. Timeline Replacing a tooth with an implant and a ... months to complete the process . Due to the timeline, dental implants are actually a series of steps; ...

  15. Effect of biofuel on environment

    International Nuclear Information System (INIS)

    Biofuels are alcohols, esters, and other chemical made from cellulosic biomass such as herbaceous and woody plants, agricultural and forestry residues, and a large portion of municipal solid and industrial waste. Biofuels are renewable and mostly suitable for diesel engines due to their similar physiochemical properties as traditional diesel oil. Demand of biofuel is increasing and some European countries have started using biofuel in diesel engine. This interest has been grown in many countries mainly due to fluctuating oil prices because of diminishing availability of conventional sources and polluted environment. However, the use of biofuel for diesel engine would be more beneficial to oil importing countries by saving foreign exchange, because biofuel is domestic renewable fuels. This paper presents the evaluation results of a multi-cylinder diesel engine operated on blends of ten, twenty, thirty, forty and fifty percent of ordinary coconut oil (COCO) with ordinary diesel (OD). The test results from all the COCO blends were compared with OD. The fuels were compared based on the emissions results including, exhaust temperature, NOx, smoke, CO, HC, benzene and polycyclic aromatic hydrocarbon (PAH). Carbon deposit on injector nozzles was also monitored. Exhaust emissions results showed that increasing coconut oil in blend decreases all the exhaust emissions. Carbon deposited on injector nozzles was observed where no hard carbon was found on injector tip when the engine was running on COCO blends. (Author)

  16. Stem cell homing using local delivery of plerixafor and stromal derived growth factor-1alpha for improved bone regeneration around Ti-implants.

    Science.gov (United States)

    Karlsson, Johan; Harmankaya, Necati; Palmquist, Anders; Atefyekta, Saba; Omar, Omar; Tengvall, Pentti; Andersson, Martin

    2016-10-01

    Triggering of the early healing events, including the recruitment of progenitor cells, has been suggested to promote bone regeneration. In implantology, local drug release technologies could provide an attractive approach to promote tissue regeneration. In this study, we targeted the chemotactic SDF-1α/CXCR4 axis that is responsible e.g. for the homing of stem cells to trauma sites. This was achieved by local delivery of plerixafor, an antagonist to CXCR4, and/or SDF-1α, from titanium implants coated with mesoporous titania thin films with a pore size of 7.5 nm. In vitro drug delivery experiments demonstrated that the mesoporous coating provided a high drug loading capacity and controlled release. The subsequent in vivo study in rat tibia showed beneficial effects with respect to bone-implant anchorage and bone-formation along the surface of the implants when plerixafor and SDF-1α were delivered locally. The effect was most prominent by the finding that the combination of the drugs significantly improved the mechanical bone anchorage. These observations suggest that titanium implants with local delivery of drugs for enhanced local recruitment of progenitor cells have the ability to promote osseointegration. This approach may provide a potential strategy for the development of novel implant treatments. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2466-2475, 2016. PMID:27213764

  17. Effects of neonatal neural progenitor cell implantation on adult neuroanatomy and cognition in the Ts65Dn model of Down syndrome.

    Directory of Open Access Journals (Sweden)

    Angela L Rachubinski

    Full Text Available As much of the aberrant neural development in Down syndrome (DS occurs postnatally, an early opportunity exists to intervene and influence life-long cognitive development. Recent success using neural progenitor cells (NPC in models of adult neurodegeneration indicate such therapy may be a viable option in diseases such as DS. Murine NPC (mNPC, C17.2 cell line or saline were implanted bilaterally into the dorsal hippocampus of postnatal day 2 (PND 2 Ts65Dn pups to explore the feasibility of early postnatal treatment in this mouse model of DS. Disomic littermates provided karyotype controls for trisomic pups. Pups were monitored for developmental milestone achievement, and then underwent adult behavior testing at 14 weeks of age. We found that implanted mNPC survived into adulthood and migrated beyond the implant site in both karyotypes. The implantation of mNPC resulted in a significant increase in the density of dentate granule cells. However, mNPC implantation did not elicit cognitive changes in trisomic mice either neonatally or in adulthood. To the best of our knowledge, these results constitute the first assessment of mNPC as an early intervention on cognitive ability in a DS model.

  18. Preliminary study on effects of nitrogen ion implantation on corn (Zea mays) somatic cell culture

    International Nuclear Information System (INIS)

    Immature embryos from three self-bred series of M1 corn (Zea mays) were cultured in MN and AG medium after dry seeds were implanted to 2 x 1016 cm-2 N+ ions of 60 keV and grown into M1 plants. The experiments indicated that all genotypes formed pale-yellow or yellow callus in the two media. The average callus induction frequency of M1 immature embryos was 11.7% higher than that of the control. Percentages of callus were different not only for various genotypes of the culture material in the two media, but also for different concentration of 2,4-D and 6-BA

  19. Murine Wee1 Plays a Critical Role in Cell Cycle Regulation and Pre-Implantation Stages of Embryonic Development

    Directory of Open Access Journals (Sweden)

    Yohei Tominaga, Cuiling Li, Rui-Hong Wang, Chu-Xia Deng

    2006-01-01

    Full Text Available Wee1 kinase regulates the G2/M cell cycle checkpoint by phosphorylating and inactivating the mitotic cyclin-dependent kinase 1 (Cdk1. Loss of Wee1 in many systems, including yeast and drosophila, leads to premature mitotic entry. However, the developmental role of Wee1 in mammals remains unclear. In this study, we established Wee1 knockout mice by gene targeting. We found that Wee-/- embryos were defective in the G2/M cell cycle checkpoint induced by γ-irradiation and died of apoptosis before embryonic (E day 3.5. To study the function of Wee1 further, we have developed MEF cells in which Wee1 is disrupted by a tamoxifen inducible Cre-LoxP approach. We found that acute deletion of Wee1 resulted in profound growth defects and cell death. Wee1 deficient cells displayed chromosome aneuploidy and DNA damage as revealed by γ-H2AX foci formation and Chk2 activation. Further studies revealed a conserved mechanism of Wee1 in regulating mitotic entry and the G2/M checkpoint compared with other lower organisms. These data provide in vivo evidence that mammalian Wee1 plays a critical role in maintaining genome integrity and is essential for embryonic survival at the pre-implantation stage of mouse development.

  20. From Biomass to Biofuels: NREL Leads the Way

    Energy Technology Data Exchange (ETDEWEB)

    2006-08-01

    This brochure covers how biofuels can help meet future needs for transportation fuels, how biofuels are produced, U.S. potential for biofuels, and NREL's approach to efficient affordable biofuels.

  1. Nanomaterial N-CP/DLPLG as potent1onal tissue graft in osteoreparation in combination with bone marrow cells on subcutaneous implantation model

    Directory of Open Access Journals (Sweden)

    Janićijević Jelena M.

    2008-01-01

    Full Text Available The need for bone graft materials in osteoreparation is tremendous. Many researches have shown that calcium-phosphate bioceramics have good biocompatibility and osteoconductivity. We used nanocomposite biomaterial calcium phosphate coated with poly (dl-lactide-co-glycolide or N-CP/DLPLG. The goal of this investigation was to examine weather N-CP/DLPLG has ability to sustain growth of bone marrow cells after subcutaneous implantation in Balb/c mice. For that purpose N-CP/DLPLG implants with and without bone marrow cells (control were made. Implants were extracted after eight days and eight weeks. In implants loaded with bone marrow cells after eight days and eight weeks we observed fields rich in cells, angiogenesis and collagen genesis. These results showed that N-CP/DLPLG has property of tissue scaffold which sustain bone marrow cells growth and collagen production. This represents a good way for further examination of N-CP/DLPLG as potentional tissue scaffold in osteoreparation.

  2. Back-junction back-contact n-type silicon solar cell with diffused boron emitter locally blocked by implanted phosphorus

    International Nuclear Information System (INIS)

    The highest energy conversion efficiencies in the field of silicon-based photovoltaics have been achieved with back-junction back-contact (BJBC) silicon solar cells by several companies and research groups. One of the most complex parts of this cell structure is the fabrication of the locally doped p- and n-type regions, both on the back side of the solar cell. In this work, we introduce a process sequence based on a synergistic use of ion implantation and furnace diffusion. This sequence enables the formation of all doped regions for a BJBC silicon solar cell in only three processing steps. We observed that implanted phosphorus can block the diffusion of boron atoms into the silicon substrate by nearly three orders of magnitude. Thus, locally implanted phosphorus can be used as an in-situ mask for a subsequent boron diffusion which simultaneously anneals the implanted phosphorus and forms the boron emitter. BJBC silicon solar cells produced with such an easy-to-fabricate process achieved conversion efficiencies of up to 21.7%. An open-circuit voltage of 674 mV and a fill factor of 80.6% prove that there is no significant recombination at the sharp transition between the highly doped emitter and the highly doped back surface field at the device level.

  3. Foresight Brief: Seaweed & Algae as Biofuels Feedstocks

    OpenAIRE

    Institute, Marine

    2008-01-01

    Seaweed is a known potential carbon-dioxide (CO2) neutral source of second generation biofuels. When seaweed grows it absorbs CO2 from the atmosphere and this CO2 is released back to the atmosphere during combustion. What makes seaweed, and in particular micro algae, so promising as a fuel source is their growth rates and high lipid (oil) content. Algae are among the fastest-growing plants in the world. Energy is stored inside the cell as lipids and carbohydrates, and can be converted into fu...

  4. Sustainable Biofuels Development Center

    Energy Technology Data Exchange (ETDEWEB)

    Reardon, Kenneth F. [Colorado State Univ., Fort Collins, CO (United States)

    2015-03-01

    The mission of the Sustainable Bioenergy Development Center (SBDC) is to enhance the capability of America’s bioenergy industry to produce transportation fuels and chemical feedstocks on a large scale, with significant energy yields, at competitive cost, through sustainable production techniques. Research within the SBDC is organized in five areas: (1) Development of Sustainable Crops and Agricultural Strategies, (2) Improvement of Biomass Processing Technologies, (3) Biofuel Characterization and Engine Adaptation, (4) Production of Byproducts for Sustainable Biorefining, and (5) Sustainability Assessment, including evaluation of the ecosystem/climate change implication of center research and evaluation of the policy implications of widespread production and utilization of bioenergy. The overall goal of this project is to develop new sustainable bioenergy-related technologies. To achieve that goal, three specific activities were supported with DOE funds: bioenergy-related research initiation projects, bioenergy research and education via support of undergraduate and graduate students, and Research Support Activities (equipment purchases, travel to attend bioenergy conferences, and seminars). Numerous research findings in diverse fields related to bioenergy were produced from these activities and are summarized in this report.

  5. Biofuels feedstock development program

    International Nuclear Information System (INIS)

    The Department of Energy's (DOE's) Biofuels Feedstock Development Program (BFDP) leads the nation in the research, development, and demonstration of environmentally acceptable and commercially viable dedicated feedstock supply systems (DFSS). The purpose of this report is to highlight the status and accomplishments of the research that is currently being funded by the BFDP. Highlights summarized here and additional accomplishments are described in more detail in the sections associated with each major program task. A few key accomplishments include (1) development of a methodology for doing a cost-supply analysis for energy crops and the application of that methodology to looking at possible land use changes around a specific energy facility in East Tennessee; (2) preliminary documentation of the relationship between woody crop plantation locations and bird diversity at sites in the Midwest, Canada, and the pacific Northwest supplied indications that woody crop plantations could be beneficial to biodiversity; (3) the initiation of integrated switchgrass variety trials, breeding research, and biotechnology research for the south/southeast region; (4) development of a data base management system for documenting the results of herbaceous energy crop field trials; (5) publication of three issues of Energy Crops Forum and development of a readership of over 2,300 individuals or organizations as determined by positive responses on questionnaires

  6. Biofuels and sustainability in Africa

    International Nuclear Information System (INIS)

    The combined effects of climate change, the continued volatility of fuel prices, the recent food crisis and global economic turbulence have triggered a sense of urgency among policymakers, industries and development practitioners to find sustainable and viable solutions in the area of biofuels. This sense of urgency is reflected in the rapid expansion of global biofuels production and markets over the past few years. Biofuels development offers developing countries some prospect of self-reliant energy supplies at national and local levels, with potential economic, ecological, social, and security benefits. Forty-two African countries are net oil importers. This makes them particularly vulnerable to volatility in global fuel prices and dependent on foreign exchange to cover their domestic energy needs. The goal therefore is to reduce the high dependence on imported petroleum by developing domestic, renewable energy. But can this objective be achieved while leaving a minimal social and environmental footprint? A fundamental question is if biofuels can be produced with consideration of social, economic and environmental factors without setting unrealistic expectation for an evolving renewable energy industry that holds such great promise. The overall performance of different biofuels in reducing non-renewable energy use and greenhouse gas emissions varies when considering the entire lifecycle from production through to use. The net performance depends on the type of feedstock, the production process and the amount of non-renewable energy needed. This paper presents an overview of the development of biofuels in Africa, and highlights country-specific economic, environmental and social issues. It proposes a combination framework of policy incentives as a function of technology maturity, discusses practices, processes and technologies that can improve efficiency, lower energy and water demand, and further reduce the social and environmental footprint of biofuels

  7. Edema-induced increase in tumour cell survival for 125I and 103Pd prostate permanent seed implants - a bio-mathematical model

    Science.gov (United States)

    Yue, Ning; Chen, Zhe; Nath, Ravinder

    2002-04-01

    Edema caused by the surgical procedure of prostate seed implantation expands the source-to-point distances within the prostate and hence decreases the dose coverage. The decrease of dose coverage results in an increase in tumour cell survival. To investigate the effects of edema on tumour cell survival, a bio-mathematical model of edema and the corresponding cell killing by continuous low dose rate irradiation (CLDRI) was developed so that tumour cell surviving fractions can be estimated in an edematous prostate for both 125I and 103Pd seed implants. The dynamic nature of edema and its resolution were modelled with an exponential function V(T) = Vp (1 + M exp(-0.693T/Te)) where Vp is the prostate volume before implantation, M is the edema magnitude and Te is edema half-life (EHL). The dose rate of a radioactive seed was calculated according to AAPM TG43, i.e. Λg(r) αBED), where α is the linear coefficient of the survival curve. The tumour cell survival was calculated for both 125I and 103Pd seed implants and for different tumour potential doubling time (TPDT) (from 5 days to 30 days) and for edemas of different magnitudes (from 0% to 95%) and edema half-lives (from 4 days to 30 days). Tumour cell survival increased with the increase of edema magnitude and EHL. For a typical edema of a half-life of 10 days and a magnitude of 50%, the edema increased tumour cell survival by about 1 and 2 orders of magnitude for 125I and 103Pd seed implants respectively. At the extreme (95% edema magnitude and an edema half-life of 30 days), the increase was more than 3 and 5 orders of magnitude for 125I and 103Pd seed implants respectively. The absolute increases were almost independent of TPDT and the prostate edema did not significantly change the effective treatment time. Tumour cell survival for prostate undergoing CLDRI using 125I or 103Pd seeds may be increased substantially due to the presence of edema caused by surgical trauma. This effect appears to be more pronounced for

  8. Global production of biofuels in the context of food security

    OpenAIRE

    Rosiak, Ewa; Łopaciuk, Wiesław; Szajner, Piotr; Grochowska, Renata

    2014-01-01

    The main objective of the study is the issue of global production of biofuels in the context of food security. Production of biofuels and food security – competition and correlations. Raw materials for production of biofuels as compared to conditions on global markets. Global market of biofuels. Impact of production of biofuels on cereal market. Impact of production of biofuels on oilseed market.

  9. The promising application of graphene oxide as coating materials in orthopedic implants: preparation, characterization and cell behavior

    International Nuclear Information System (INIS)

    To investigate the potential application of graphene oxide (GO) in bone repair, this study is focused on the preparation, characterization and cell behavior of graphene oxide coatings on quartz substrata. GO coatings were prepared on the substrata using a modified dip-coating procedure. Atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman spectroscopy results demonstrated that the as-prepared coatings in this study were homogeneous and had an average thickness of ∼67 nm. The rapid formation of a hydroxyapatite (HA) layer in the simulated body fluid (SBF) on GO coated substrata at day 14, as proved by SEM and x-ray diffraction (XRD), strongly indicated the bioactivity of coated substrata. In addition, MC3T3-E1 cells were cultured on the coated substrata to evaluate cellular activities. Compared with the non-coated substrata and tissue culture plates, no significant difference was observed on the coated substrata in terms of cytotoxicity, viability, proliferation and apoptosis. However, interestingly, higher levels of alkaline phosphatase (ALP) activity and osteocalcin (OC) secretion were observed on the coated substrata, indicating that GO coatings enhanced cell differentiation compared with non-coated substrata and tissue culture plates. This study suggests that GO coatings had excellent biocompatibility and more importantly promoted MC3T3-E1 cell differentiation and might be a good candidate as a coating material for orthopedic implants. (paper)

  10. In vitro cell culture, platelet adhesion tests and in vivo implant tests of plasma-polymerized para-xylene films

    International Nuclear Information System (INIS)

    Plasma-polymerized para-xylene (PPX) was developed in a previous study by adjusting the process parameters: pulse frequency of the power supply (ωp) and para-xylene monomer flow rate (fp). All the obtained PPX films exhibit an amorphous structure and present hydrophobicity (water contact angle ranging from 98.5° to 121.1°), higher film growth rate and good fibroblast cell proliferation. In this study, in vitro tests (fibroblast cell compatibility and platelet adhesion) and an in vivo animal study were performed by using PPX deposited industrial-grade silicone sheets (IGS) and compared with medical-grade silicone ones (MS), which were commonly manufactured into catheters or drainage tubes in clinical use. The results reveal that PPX deposited at high ωp or high fp, in comparison with MS, exhibit better cell proliferation and clearly shows less cell adhesion regardless of ωp and fp. PPX also exhibit a comparatively lower level of platelet adhesion than MS. In the animal study, PPX-coated IGS result in similar local tissue responses at 3, 7 and 28 days (short-term) and 84 days (long-term) after subcutaneous implantation the abdominal wall of rodents compared with respective responses to MS. These results suggest that PPX-coated industrial-grade silicone is one alternative to high cost medical-grade silicone.

  11. In vitro cell culture, platelet adhesion tests and in vivo implant tests of plasma-polymerized para-xylene films

    Science.gov (United States)

    Chou, Chia-Man; Yeh, Chou-Ming; Chung, Chi-Jen; He, Ju-Liang

    2013-09-01

    Plasma-polymerized para-xylene (PPX) was developed in a previous study by adjusting the process parameters: pulse frequency of the power supply (ωp) and para-xylene monomer flow rate (fp). All the obtained PPX films exhibit an amorphous structure and present hydrophobicity (water contact angle ranging from 98.5° to 121.1°), higher film growth rate and good fibroblast cell proliferation. In this study, in vitro tests (fibroblast cell compatibility and platelet adhesion) and an in vivo animal study were performed by using PPX deposited industrial-grade silicone sheets (IGS) and compared with medical-grade silicone ones (MS), which were commonly manufactured into catheters or drainage tubes in clinical use. The results reveal that PPX deposited at high ωp or high fp, in comparison with MS, exhibit better cell proliferation and clearly shows less cell adhesion regardless of ωp and fp. PPX also exhibit a comparatively lower level of platelet adhesion than MS. In the animal study, PPX-coated IGS result in similar local tissue responses at 3, 7 and 28 days (short-term) and 84 days (long-term) after subcutaneous implantation the abdominal wall of rodents compared with respective responses to MS. These results suggest that PPX-coated industrial-grade silicone is one alternative to high cost medical-grade silicone.

  12. [Standardized testing of bone implant surfaces with an osteoblast cell culture system. II. Titanium surfaces of different degrees of roughness].

    Science.gov (United States)

    Nöth, U; Hendrich, C; Merklein, F; Altvater, T; Rader, C P; Schütze, N; Eulert, J; Thull, R

    1999-01-01

    The effect of titanium surfaces with different degrees of roughness on osteoblast proliferation and differentiation was investigated using a standardised cell culture system. Human foetal osteoblasts (hFOB 1.19) were cultured on polished (Ti pol), sandblasted (Ti sb) and sandblasted/heat treated (Ti sb-ht) titanium surfaces for 17 days. Cell culture quality polystyrene (Ps) was used as a control. Cell number and viability were determined for assessment of proliferation. Alkaline phosphatase activity, collagen I and osteocalcin production were measured as parameters for osteoblast differentiation. In the early phase, higher proliferation values were measured on Ti pol. However, on Ti sb and Ti sb-ht higher proliferation was found in the late phase. The activity of the early differentiation marker alkaline phosphatase was higher on Ti pol. No differences were seen for the late differentiation parameters collagen I and osteocalcin. The test system permits the influence of the surface structure on the dynamics of the osteoblast development cycle to be determined. The larger surface area of rough materials leads to an initially delayed, but then prolonged cell proliferation. This model correlates with recent in vivo findings, and confirms the use of rough surfaces for implants in direct contact with bone, even at the cellular level. PMID:10194879

  13. In vitro cell culture, platelet adhesion tests and in vivo implant tests of plasma-polymerized para-xylene films

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Chia-Man [Department of Surgery, Taichung Veterans General Hospital, Taiwan, ROC (China); National Yang-Ming University, Taipei, Taiwan, ROC (China); Yeh, Chou-Ming, E-mail: cmchou4301@gmail.com [Taichung Hospital, Department of Health, Executive Yuan, Taiwan, ROC (China); Chung, Chi-Jen [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC (China); He, Ju-Liang [Department of Materials Science and Engineering, Feng Chia University, Taiwan, ROC (China)

    2013-09-01

    Plasma-polymerized para-xylene (PPX) was developed in a previous study by adjusting the process parameters: pulse frequency of the power supply (ω{sub p}) and para-xylene monomer flow rate (f{sub p}). All the obtained PPX films exhibit an amorphous structure and present hydrophobicity (water contact angle ranging from 98.5° to 121.1°), higher film growth rate and good fibroblast cell proliferation. In this study, in vitro tests (fibroblast cell compatibility and platelet adhesion) and an in vivo animal study were performed by using PPX deposited industrial-grade silicone sheets (IGS) and compared with medical-grade silicone ones (MS), which were commonly manufactured into catheters or drainage tubes in clinical use. The results reveal that PPX deposited at high ω{sub p} or high f{sub p}, in comparison with MS, exhibit better cell proliferation and clearly shows less cell adhesion regardless of ω{sub p} and f{sub p}. PPX also exhibit a comparatively lower level of platelet adhesion than MS. In the animal study, PPX-coated IGS result in similar local tissue responses at 3, 7 and 28 days (short-term) and 84 days (long-term) after subcutaneous implantation the abdominal wall of rodents compared with respective responses to MS. These results suggest that PPX-coated industrial-grade silicone is one alternative to high cost medical-grade silicone.

  14. Lab-on-a-brain: Implantable micro-optical fluidic devices for neural cell analysis in vivo

    Science.gov (United States)

    Takehara, Hiroaki; Nagaoka, Akira; Noguchi, Jun; Akagi, Takanori; Kasai, Haruo; Ichiki, Takanori

    2014-10-01

    The high-resolution imaging of neural cells in vivo has brought about great progress in neuroscience research. Here, we report a novel experimental platform, where the intact brain of a living mouse can be studied with the aid of a surgically implanted micro-optical fluidic device; acting as an interface between neurons and the outer world. The newly developed device provides the functions required for the long-term and high-resolution observation of the fine structures of neurons by two-photon laser scanning microscopy and the microfluidic delivery of chemicals or drugs directly into the brain. A proof-of-concept experiment of single-synapse stimulation by two-photon uncaging of caged glutamate and observation of dendritic spine shrinkage over subsequent days demonstrated a promising use for the present technology.

  15. Biofuels system economics

    International Nuclear Information System (INIS)

    Biofuels, or fuels produced from biomass resources, represent an environmentally responsible source of liquid fuels. The combustion of petroleum and coal releases large volumes of carbon dioxide which have been stored millions of years ago that contribute to the enhanced greenhouse effect. Biomass resources sequester carbon during their growing period, and when processed, this recently stored carbon is released as carbon dioxide. If biomass is replanted after harvesting, the carbon is again sequestered, resulting in a short cycle carbon loop. Another growing problem is waste disposal. Biomass wastes such as wood residues and municipal solid waste (MSW) often are landfilled and produce methane, another greenhouse gas. Diverting these wastes to a processing facility can eliminate methane production from landfilling. The Tennessee Valley Authority (TVA) is developing technology to convert biomass resources to fuels, chemicals, and solid residue that can be used for power generation. There is an estimated 1,118 to 2,945 million tons of biomass resources available annually that can be converted to renewable fuels using newly developed conversion processes. Economic evaluation of these processes have shown promise. This paper compares the economics of six biomass conversion systems. Prices and costs vary for site-specific areas, and the cost numbers used in the TVA comparison represent general systems. The rate of return on investments vary from 15.5% to 19.8% depending on the feedstock, process, and products. TVA is continuing research and development activities to improve economics of biomass systems and make them more attractive to commercial users. These technologies are environmentally friendly and can help to reduce the rate of atmospheric carbon dioxide and methane accumulation

  16. The second generation biofuels from the biomass

    International Nuclear Information System (INIS)

    The author takes stock on the second generation biofuels in the world, the recent technologies, their advantages, the research programs and the economical and environmental impacts of the biofuels development. (A.L.B.)

  17. Design of high-performance memristor cell using W-implanted SiO2 films

    Science.gov (United States)

    Li, Wenqing; Liu, Xinqiang; Wang, Yongqiang; Dai, Zhigao; Wu, Wei; Cheng, Li; Zhang, Yupeng; Liu, Qi; Xiao, Xiangheng; Jiang, Changzhong

    2016-04-01

    Highly reproducible bipolar resistance switching was demonstrated in a composite material of W-implanted silicon dioxide. Because of its excellent dielectric properties, SiO2 was selected as the sole active material for fabricating the resistance switching devices. The device employed a metal-insulator-semiconductor structure, showing an excellent resistance switching performance (the ON/OFF ratio is close to ˜106). In addition, this sandwich structure device shows a forming-free resistance switching behavior. The overall device performance of the SiO2-based memristor has the potential to open up a new avenue to a large-scale high-performance resistive random access memory, which could significantly impact their existing applications.

  18. Primary anaplastic large cell lymphoma of the breast arising in reconstruction mammoplasty capsule of saline filled breast implant after radical mastectomy for breast cancer: an unusual case presentation

    Directory of Open Access Journals (Sweden)

    Sur Monalisa

    2009-04-01

    Full Text Available Abstract Background Primary non-Hodgkin lymphoma (NHL of the breast represents 0.04–0.5% of malignant lesions of the breast and accounts for 1.7–2.2% of extra-nodal NHL. Most primary cases are of B-cell phenotype and only rare cases are of T-cell phenotype. Anaplastic large cell lymphoma (ALCL is a rare T-cell lymphoma typically seen in children and young adults with the breast being one of the least common locations. There are a total of eleven cases of primary ALCL of the breast described in the literature. Eight of these cases occurred in proximity to breast implants, four in relation to silicone breast implant and three in relation to saline filled breast implant with three out of the eight implant related cases having previous history of breast cancer treated surgically. Adjuvant postoperative chemotherapy is given in only one case. Secondary hematological malignancies after breast cancer chemotherapy have been reported in literature. However in contrast to acute myeloid leukemia (AML, the association between lymphoma and administration of chemotherapy has never been clearly demonstrated. Case Presentation In this report we present a case of primary ALCL of the breast arising in reconstruction mamoplasty capsule of saline filled breast implant after radical mastectomy for infiltrating ductal carcinoma followed by postoperative chemotherapy twelve years ago. Conclusion Primary ALK negative ALCL arising at the site of saline filled breast implant is rare. It is still unclear whether chemotherapy and breast implantation increases risk of secondary hematological malignancies significantly. However, it is important to be aware of these complications and need for careful pathologic examination of tissue removed for implant related complications to make the correct diagnosis for further patient management and treatment. It is important to be aware of this entity at this site as it can be easily misdiagnosed on histologic grounds and to exclude

  19. Biofuels and Sustainable Transport: A Conceptual Discussion

    OpenAIRE

    Geoffrey Gilpin; Erling Holden

    2013-01-01

    Strategies for sustainably using biofuels must be thoroughly assessed at several levels. First, the use of biofuels must comply with sustainable development’s main dimensions. Second, the use of biofuels must comply with sustainable transport’s main dimensions. Third, gains from using biofuels strategies must compare favorably to gains from other sustainable transport strategies, such as altering transport patterns and reducing transport volume. Fourth, the gains must compare favorably to...

  20. In vitro osteogenic induction of bone marrow stromal cells with encapsulated gene-modified bone marrow stromal cells and in vivo implantation for orbital bone repair.

    Science.gov (United States)

    Deng, Yuan; Zhou, Huifang; Yan, Chenxi; Wang, Yefei; Xiao, Caiwen; Gu, Ping; Fan, Xianqun

    2014-07-01

    Osteogenic induction with either growth factors or genetic modification has limitations due to the short half-life and cost of the former, or safety concerns regarding the latter. The objective of this study was to employ a microcapsulation technique to separate genetically modified and nonmodified bone marrow stromal cells (BMSCs) to establish a cost-effective and biosafe osteogenic induction methodology with functional evaluation in vitro and in vivo in a canine model. Autologous BMSCs were isolated and transduced with adenoviral vectors containing either BMP-2 or vascular endothelial growth factor (VEGF) or were dual transduced followed by encapsulation in alginate microcapsules using an electrostatic bead generator. After cocultured with encapsulated cells, normal autologous BMSCs were analyzed for osteogenic differentiation and seeded onto tricalcium phosphate (TCP) scaffolds for in vivo implantation to repair orbital wall bone defects (12 mm in diameter) in a canine model. In vitro assays showed that the expression of the transduced genes was significantly upregulated, with significantly more transduced proteins released from the transduced cells compared with control cells. Importantly, examination of the BMSCs induced by soluble factors released from the encapsulated cells revealed a significant upregulation of expression of osteogenic markers Runx2, BSP, OPN, and OCN in dual-transduction or induction groups. In addition, dual transduction and induction resulted in the highest increase of alkaline phosphatase activity and mineralization compared with other experimental groups. In vivo assays using CT, micro-CT, and histology further supported the qPCR and western blot findings. In conclusion, encapsulation of genetically modified BMSCs was able to release a sufficient amount of BMP-2 and VEGF, which effectively induced osteogenic differentiation of normal-cultured BMSCs and demonstrated bone repair of the orbital wall defect after implantation with

  1. Biofuels from food processing wastes.

    Science.gov (United States)

    Zhang, Zhanying; O'Hara, Ian M; Mundree, Sagadevan; Gao, Baoyu; Ball, Andrew S; Zhu, Nanwen; Bai, Zhihui; Jin, Bo

    2016-04-01

    Food processing industry generates substantial high organic wastes along with high energy uses. The recovery of food processing wastes as renewable energy sources represents a sustainable option for the substitution of fossil energy, contributing to the transition of food sector towards a low-carbon economy. This article reviews the latest research progress on biofuel production using food processing wastes. While extensive work on laboratory and pilot-scale biosystems for energy production has been reported, this work presents a review of advances in metabolic pathways, key technical issues and bioengineering outcomes in biofuel production from food processing wastes. Research challenges and further prospects associated with the knowledge advances and technology development of biofuel production are discussed. PMID:26874262

  2. Interaction of progenitor bone cells with different surface modifications of titanium implant

    International Nuclear Information System (INIS)

    Changes in the physical and chemical properties of Ti surfaces can be attributed to cell performance, which improves surface biocompatibility. The cell proliferation, mineralization ability, and gene expression of progenitor bone cells (D1 cell) were compared on five different Ti surfaces, namely, mechanical grinding (M), electrochemical modification through potentiostatic anodization (ECH), sandblasting and acid etching (SLA), sandblasting, hydrogen peroxide treatment, and heating (SAOH), and sandblasting, alkali heating, and etching (SMART). SAOH treatment produced the most hydrophilic surface, whereas SLA produced the most hydrophobic surface. Cell activity indicated that SLA and SMART produced significantly rougher surfaces and promoted D1 cell attachment within 1 day of culturing, whereas SAOH treatment produced moderate roughness (Ra = 1.26 μm) and accelerated the D1 cell proliferation up to 7 days after culturing. The ECH surface significantly promoted alkaline phosphatase (ALP) expression and osteocalcin (OCN) secretion in the D1 cells compared with the other surface groups. The ECH and SMART-treated Ti surfaces resulted in maximum ALP and OCN expressions during the D1 cell culture. SLA, SAOH, and SMART substrate surfaces were rougher and exhibited better cell metabolic responses during the early stage of cell attachment, proliferation, and morphologic expressions within 1 day of D1 cell culture. The D1 cells cultured on the ECH and SMART substrates exhibited higher differentiation, and higher ALP and OCN expressions after 10 days of culture. Thus, the ECH and SMART treatments promote better ability of cell mineralization in vitro, which demonstrate their great potential for clinical use. - Highlights: • Progenitor bone cells onto Ti with different modifications are characterized. • Surface roughness and hydrophilicity encourage early stage cell attachment. • Composition and surface treatments are more vital in bone cell mineralization.

  3. Interaction of progenitor bone cells with different surface modifications of titanium implant

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wen-Cheng, E-mail: wencchen@fcu.edu.tw [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Chen, Ya-Shun [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Ko, Chia-Ling [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Dental Medical Devices and Materials Research Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Lin, Yi; Kuo, Tzu-Huang; Kuo, Hsien-Nan [Medical Device Development Division, Metal Industries Research and Development Centre, Kaohsiung 82151, Taiwan (China)

    2014-04-01

    Changes in the physical and chemical properties of Ti surfaces can be attributed to cell performance, which improves surface biocompatibility. The cell proliferation, mineralization ability, and gene expression of progenitor bone cells (D1 cell) were compared on five different Ti surfaces, namely, mechanical grinding (M), electrochemical modification through potentiostatic anodization (ECH), sandblasting and acid etching (SLA), sandblasting, hydrogen peroxide treatment, and heating (SAOH), and sandblasting, alkali heating, and etching (SMART). SAOH treatment produced the most hydrophilic surface, whereas SLA produced the most hydrophobic surface. Cell activity indicated that SLA and SMART produced significantly rougher surfaces and promoted D1 cell attachment within 1 day of culturing, whereas SAOH treatment produced moderate roughness (Ra = 1.26 μm) and accelerated the D1 cell proliferation up to 7 days after culturing. The ECH surface significantly promoted alkaline phosphatase (ALP) expression and osteocalcin (OCN) secretion in the D1 cells compared with the other surface groups. The ECH and SMART-treated Ti surfaces resulted in maximum ALP and OCN expressions during the D1 cell culture. SLA, SAOH, and SMART substrate surfaces were rougher and exhibited better cell metabolic responses during the early stage of cell attachment, proliferation, and morphologic expressions within 1 day of D1 cell culture. The D1 cells cultured on the ECH and SMART substrates exhibited higher differentiation, and higher ALP and OCN expressions after 10 days of culture. Thus, the ECH and SMART treatments promote better ability of cell mineralization in vitro, which demonstrate their great potential for clinical use. - Highlights: • Progenitor bone cells onto Ti with different modifications are characterized. • Surface roughness and hydrophilicity encourage early stage cell attachment. • Composition and surface treatments are more vital in bone cell mineralization.

  4. Biofuels, a bad thing?; Boeser Biokraftstoff?

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, D.; Bensmann, M.

    2008-05-15

    The discussions over biofuels are still going on. Critics claim that biofuels ruin engine components, destroy rainforests and cause high food prices and global hunger. According to this contribution, the Federal government's biofuels policy was wrong and was doomed to fail. (orig.)

  5. Overview on Biofuels from a European Perspective

    Science.gov (United States)

    Ponti, Luigi; Gutierrez, Andrew Paul

    2009-01-01

    In light of the recently developed European Union (EU) Biofuels Strategy, the literature is reviewed to examine (a) the coherency of biofuel production with the EU nonindustrial vision of agriculture, and (b) given its insufficient land base, the implications of a proposed bioenergy pact to grow biofuel crops in the developing world to meet EU…

  6. Biofuels in Africa : Opportunities, Prospects, and Challenges

    OpenAIRE

    Mitchell, Donald

    2011-01-01

    Biofuels offer new opportunities for African countries. They can contribute to economic growth, employment, and rural incomes. They can become an important export for some countries and provide low-cost fuel for others. There is also a potentially large demand for biofuels to meet the rapidly growing need for local fuel. Abundant natural resources and low-cost labor make producing biofuel ...

  7. Assessing the environmental sustainability of biofuels.

    Science.gov (United States)

    Kazamia, Elena; Smith, Alison G

    2014-10-01

    Biofuels vary in their potential to reduce greenhouse gas emissions when displacing fossil fuels. Savings depend primarily on the crop used for biofuel production, and on the effect that expanding its cultivation has on land use. Evidence-based policies should be used to ensure that maximal sustainability benefits result from the development of biofuels. PMID:25281367

  8. Nutrient management studies in biofuel cropping systems

    Science.gov (United States)

    Research was conducted to determine the effect of nutrient management practices on biofuel crop production, and to evaluate long term effects of biofuel crop production on selected chemical, physical and microbiological properties. Experimental plots for research on biofuel crop production were esta...

  9. Analgesia induced by isolated bovine chromaffin cells implanted in rat spinal cord.

    OpenAIRE

    Sagen, J.; Pappas, G. D.; Pollard, H B

    1986-01-01

    Chromaffin cells synthesize and secrete several neuroactive substances, including catecholamines and opioid peptides, that, when injected into the spinal cord, induce analgesia. Moreover, the release of these substances from the cells can be stimulated by nicotine. Since chromaffin cells from one species have been shown to survive when transplanted to the central nervous system of another species, these cells are ideal candidates for transplantation to alter pain sensitivity. Bovine chromaffi...

  10. Panorama 2007: Biofuels in Europe

    International Nuclear Information System (INIS)

    The current leader on the world bio-diesel market, Europe is, after the United States and Brazil, one of the regions driving the production and utilization of biofuels. Its ambitious bio-fuel content targets for motor fuels (5.75% by 2010 and 8% by 2015) encourage Member States to significantly develop those pathways. This raises certain questions, especially about available biomass resources. It is likely that, beyond 2010, technologies other than those in existence today, using ligno-cellulosic biomass, will have to be implemented. (author)

  11. Policies promoting Biofuels in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Holmgren, Kristina [IVL Swedish Environmental Research Inst., Goeteborg (Sweden); Chalmers Univ. of Technology, Div. of Heat and Power Technology., Goeteborg (Sweden)

    2012-07-01

    This report was written as part of a course in Environmental Economics and Policy Instruments at the University of Gothenburg. It aims at summarizing the policy instruments introduced to directly affect the production and use of biofuels in Sweden. Since Sweden is part of the EU also EU policies were included. There are additional policy instruments which affect the production and utilization of biofuels in a more indirect way that are not presented here. The economic analysis in this paper is limited and could be developed from the information presented in order to draw further conclusions on necessary changes in order to reach set targets.

  12. Methods and materials for deconstruction of biomass for biofuels production

    Energy Technology Data Exchange (ETDEWEB)

    Schoeniger, Joseph S; Hadi, Masood Zia

    2015-05-05

    The present invention relates to nucleic acids, peptides, vectors, cells, and plants useful in the production of biofuels. In certain embodiments, the invention relates to nucleic acid sequences and peptides from extremophile organisms, such as SSO1949 and Ce1A, that are useful for hydrolyzing plant cell wall materials. In further embodiments, the invention relates to modified versions of such sequences that have been optimized for production in one or both of monocot and dicot plants. In other embodiments, the invention provides for targeting peptide production or activity to a certain location within the cell or organism, such as the apoplast. In further embodiments, the invention relates to transformed cells or plants. In additional embodiments, the invention relates to methods of producing biofuel utilizing such nucleic acids, peptides, targeting sequences, vectors, cells, and/or plants.

  13. Implanted stem cells - a promising tool for therapy of brain and spinal cord injuries

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva

    Krakow, 2004. s. 24. [Annual Meeting of the European Stem Cell Therapeutics Excellence Centre (STEC) /2./. 07.06.2004-08.06.2004, Krakow] R&D Projects: GA MŠk LN00A065 Keywords : bone marrow stem cells * bone marow hematopoetic cells Subject RIV: FH - Neurology

  14. Biofuel supply chain, market, and policy analysis

    Science.gov (United States)

    Zhang, Leilei

    Renewable fuel is receiving an increasing attention as a substitute for fossil based energy. The US Department of Energy (DOE) has employed increasing effort on promoting the advanced biofuel productions. Although the advanced biofuel remains at its early stage, it is expected to play an important role in climate policy in the future in the transportation sector. This dissertation studies the emerging biofuel supply chain and markets by analyzing the production cost, and the outcomes of the biofuel market, including blended fuel market price and quantity, biofuel contract price and quantity, profitability of each stakeholder (farmers, biofuel producers, biofuel blenders) in the market. I also address government policy impacts on the emerging biofuel market. The dissertation is composed with three parts, each in a paper format. The first part studies the supply chain of emerging biofuel industry. Two optimization-based models are built to determine the number of facilities to deploy, facility locations, facility capacities, and operational planning within facilities. Cost analyses have been conducted under a variety of biofuel demand scenarios. It is my intention that this model will shed light on biofuel supply chain design considering operational planning under uncertain demand situations. The second part of the dissertation work focuses on analyzing the interaction between the key stakeholders along the supply chain. A bottom-up equilibrium model is built for the emerging biofuel market to study the competition in the advanced biofuel market, explicitly formulating the interactions between farmers, biofuel producers, blenders, and consumers. The model simulates the profit maximization of multiple market entities by incorporating their competitive decisions in farmers' land allocation, biomass transportation, biofuel production, and biofuel blending. As such, the equilibrium model is capable of and appropriate for policy analysis, especially for those policies

  15. A model for improving microbial biofuel production using a synthetic feedback loop

    OpenAIRE

    Dunlop, Mary J.; Keasling, Jay D; Mukhopadhyay, Aindrila

    2010-01-01

    Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation, and alternative control architectures can be compared. We propose a model for microbial biofuel production where a synthetic control system is used to increase cell viability and biofuel yields. Although microbes can be engineered to produce biofu...

  16. A model for improving microbial biofuel production using a synthetic feedback loop

    OpenAIRE

    Dunlop, Mary

    2012-01-01

    Cells use feedback to implement a diverse range of regulatory functions. Building synthetic feedback control systems may yield insight into the roles that feedback can play in regulation since it can be introduced independently of native regulation, and alternative control architectures can be compared. We propose a model for microbial biofuel production where a synthetic control system is used to increase cell viability and biofuel yields. Although microbes can be eng...

  17. Imaging long-term fate of intramyocardially implanted mesenchymal stem cells in a porcine myocardial infarction model.

    Directory of Open Access Journals (Sweden)

    Emerson C Perin

    Full Text Available The long-term fate of stem cells after intramyocardial delivery is unknown. We used noninvasive, repetitive PET/CT imaging with [(18F]FEAU to monitor the long-term (up to 5 months spatial-temporal dynamics of MSCs retrovirally transduced with the sr39HSV1-tk gene (sr39HSV1-tk-MSC and implanted intramyocardially in pigs with induced acute myocardial infarction. Repetitive [(18F]FEAU PET/CT revealed a biphasic pattern of sr39HSV1-tk-MSC dynamics; cell proliferation peaked at 33-35 days after injection, in periinfarct regions and the major cardiac lymphatic vessels and lymph nodes. The sr39HSV1-tk-MSC-associated [(18F]FEAU signals gradually decreased thereafter. Cardiac lymphography studies using PG-Gd-NIRF813 contrast for MRI and near-infrared fluorescence imaging showed rapid clearance of the contrast from the site of intramyocardial injection through the subepicardial lymphatic network into the lymphatic vessels and periaortic lymph nodes. Immunohistochemical analysis of cardiac tissue obtained at 35 and 150 days demonstrated several types of sr39HSV1-tk expressing cells, including fibro-myoblasts, lymphovascular cells, and microvascular and arterial endothelium. In summary, this study demonstrated the feasibility and sensitivity of [(18F]FEAU PET/CT imaging for long-term, in-vivo monitoring (up to 5 months of the fate of intramyocardially injected sr39HSV1-tk-MSC cells. Intramyocardially transplanted MSCs appear to integrate into the lymphatic endothelium and may help improve myocardial lymphatic system function after MI.

  18. Biofuelled heating plants

    International Nuclear Information System (INIS)

    The purpose of this report is to serve as a basis to enable establishment and operation of small and medium-sized bio-fuel plants, district heating plants and local district heating plants. Furthermore, the purpose of this report is to serve as a guideline and basis when realizing projects, from the first concept to established plant. Taking into account all the phases, from selection of heating system, fuel type, selection of technical solutions, authorization request or application to operate a plant, planning, construction and buying, inspection, performance test, take-over and control system of the plant. Another purpose of the report is to make sure that best available technology is used and to contribute to continuous development of the technology. The report deals mainly with bio-fuelled plants in the effect range 0.3 to10 MW. The term 'plant' refers to combined power and heating plants as well as 'simpler' district heating plants. The last-mentioned is also often referred to as 'local heating plant'. In this context, the term bio fuel refers to a wide range of fuel types. The term bio fuel includes processed fractions like powders, pellets, and briquettes along with unprocessed fractions, such as by-products from the forest industry; chips and bark. Bio fuels also include straw, energy crops and cereal waste products, but these have not been expressly studied in this report. The report is structured with appendixes regarding the various phases of the projects, with the purpose of serving as a helping handbook, or manual for new establishment, helping out with technical and administrative advice and environmental requirements. Plants of this size are already expanding considerably, and the need for guiding principles for design/technology and environmental requirements is great. These guiding principles should comply with the environmental legislation requirements, and must contain advice and recommendations for bio fuel plants in this effect range, also in

  19. Estimates of US biofuels consumption, 1990

    International Nuclear Information System (INIS)

    This report is the sixth in the series of publications developed by the Energy Information Administration to quantify the amount of biofuel-derived primary energy used by the US economy. It provides preliminary estimates of 1990 US biofuels energy consumption by sector and by biofuels energy resource type. The objective of this report is to provide updated annual estimates of biofuels energy consumption for use by congress, federal and state agencies, and other groups involved in activities related to the use of biofuels. 5 figs., 10 tabs

  20. Functional effect of mouse embryonic stem cell implantation after spinal cord injury

    OpenAIRE

    Lee, Tae-Hoon

    2013-01-01

    We transplanted mouse embryonic stem cells (mESCs) to improve functional loss in a rat model of clip-compression spinal cord injury (SCI). The mouse embryonic stem cells were transplanted to injured cord 7 days after injury. We include minimizing the progression of secondary injury, manipulating the neuroinhibitory environment of the spinal cord, replacing lost tissue with transplanted cells and substantial improvement of motor. A number of potential approaches optimize functional recovery af...

  1. Cell lineage specific distribution of H3K27 trimethylation accumulation in an in vitro model for human implantation.

    Directory of Open Access Journals (Sweden)

    Gijs Teklenburg

    Full Text Available Female mammals inactivate one of their two X-chromosomes to compensate for the difference in gene-dosage with males that have just one X-chromosome. X-chromosome inactivation is initiated by the expression of the non-coding RNA Xist, which coats the X-chromosome in cis and triggers gene silencing. In early mouse development the paternal X-chromosome is initially inactivated in all cells of cleavage stage embryos (imprinted X-inactivation followed by reactivation of the inactivated paternal X-chromosome exclusively in the epiblast precursors of blastocysts, resulting temporarily in the presence of two active X-chromosomes in this specific lineage. Shortly thereafter, epiblast cells randomly inactivate either the maternal or the paternal X-chromosome. XCI is accompanied by the accumulation of histone 3 lysine 27 trimethylation (H3K27me3 marks on the condensed X-chromosome. It is still poorly understood how XCI is regulated during early human development. Here we have investigated lineage development and the distribution of H3K27me3 foci in human embryos derived from an in-vitro model for human implantation. In this system, embryos are co-cultured on decidualized endometrial stromal cells up to day 8, which allows the culture period to be extended for an additional two days. We demonstrate that after the co-culture period, the inner cell masses have relatively high cell numbers and that the GATA4-positive hypoblast lineage and OCT4-positive epiblast cell lineage in these embryos have segregated. H3K27me3 foci were observed in ∼25% of the trophectoderm cells and in ∼7.5% of the hypoblast cells, but not in epiblast cells. In contrast with day 8 embryos derived from the co-cultures, foci of H3K27me3 were not observed in embryos at day 5 of development derived from regular IVF-cultures. These findings indicate that the dynamics of H3K27me3 accumulation on the X-chromosome in human development is regulated in a lineage specific fashion.

  2. Efficacy of a small cell-binding peptide coated hydroxyapatite substitute on bone formation and implant fixation in sheep

    DEFF Research Database (Denmark)

    Ding, Ming; Andreasen, Christina Møller; Dencker, Mads L.;

    2015-01-01

    hydroxyapatite (ABM/P-15); hydroxyapatite + βtricalciumphosphate+ Poly-Lactic-Acid (HA/βTCP-PDLLA); or ABM/P-15+HA/βTCP-PDLLA. After nine weeks, bone-implant blocks were harvested and sectioned for micro-CT scanning, push-out test, and histomorphometry. Significant bone formation and implant fixation could...... implant were not significantly different among the four groups. The ABM/P-15 group had similar shear mechanical properties on implant fixation as the allograft group. Adding HA/βTCP-PDLLA to ABM/P-15 did not significantly change these parameters. This study revealed that ABM/P-15 had significantly bone...

  3. Advancing Biofuels: Balancing for Sustainability

    Science.gov (United States)

    As with most technologies, use of biofuels has both benefits and risks, which vary by feedstock. Expected benefits include increased energy independence, reduced consumption of fossil fuels, reduced emission of greenhouse gases and invigorated rural economies. Anticipated risks include potential com...

  4. An Outlook on Microalgal Biofuels

    NARCIS (Netherlands)

    Wijffels, R.H.; Barbosa, M.J.

    2010-01-01

    Microalgae are considered one of the most promising feedstocks for biofuels. The productivity of these photosynthetic microorganisms in converting carbon dioxide into carbon-rich lipids, only a step or two away from biodiesel, greatly exceeds that of agricultural oleaginous crops, without competing

  5. Ion implantation

    International Nuclear Information System (INIS)

    It is the purpose of the present paper to give a review of surface alloy processing by ion implantation. However, rather than covering this vast subject as a whole, the survey is confined to a presentation of the microstructures that can be found in metal surfaces after ion implantation. The presentation is limited to alloys processed by ion implantation proper, that is to processes in which the alloy compositions are altered significantly by direct injection of the implanted ions. The review is introduced by a presentation of the processes taking place during development of the fundamental event in ion implantation - the collision cascade, followed by a summary of the various microstructures which can be formed after ion implantation into metals. This is compared with the variability of microstructures that can be achieved by rapid solidification processing. The microstructures are subsequently discussed in the light of the processes which, as the implantations proceed, take place during and immediately after formation of the individual collision cascades. These collision cascades define the volumes inside which individual ions are slowed down in the implanted targets. They are not only centres for vigorous agitation but also the sources for formation of excess concentrations of point defects, which will influence development of particular microstructures. A final section presents a selection of specific structures which have been observed in different alloy systems. (orig./GSCH)

  6. Four myths surrounding U.S. biofuels

    International Nuclear Information System (INIS)

    The rapid growth of biofuels has elicited claims and predictions concerning the current and future role of these fuels in the U.S. vehicle-fuel portfolio. These assertions are at times based on a false set of assumptions concerning the biofuel's market related to the petroleum and agricultural commodities markets, and the nonmarket consequences of our automobile driving. As an aid in clarifying these market relations, the following four biofuel myths are presented: (1) biofuels will be adopted because we will soon run out of oil, (2) biofuels will solve the major external costs associated with our automobile driving, (3) biofuels cause food price inflation (the food before fuel issue), and (4) biofuels will become a major vehicle fuel. - Highlights: → Biofuels will be adopted because we will soon run out of oil. → Biofuels will solve the major external costs associated with our automobile driving. → Biofuels cause food price inflation (the food before fuel issue). → Biofuels will become a major vehicle fuel.

  7. Improvement of myocardial perfusion reserve detected by cardiovascular magnetic resonance after direct endomyocardial implantation of autologous bone marrow cells in patients with severe coronary artery disease

    Directory of Open Access Journals (Sweden)

    Lau Chu-Pak

    2010-01-01

    Full Text Available Abstract Background Recent studies suggested that bone marrow (BM cell implantation in patients with severe chronic coronary artery disease (CAD resulted in modest improvement in symptoms and cardiac function. This study sought to investigate the functional changes that occur within the chronic human ischaemic myocardium after direct endomyocardial BM cells implantation by cardiovascular magnetic resonance (CMR. Methods and Results We compared the interval changes of left ventricular ejection fraction (LVEF, myocardial perfusion reserve and the extent of myocardial scar by using late gadolinium enhancement CMR in 12 patients with severe CAD. CMR was performed at baseline and at 6 months after catheter-based direct endomyocardial autologous BM cell (n = 12 injection to viable ischaemic myocardium as guided by electromechanical mapping. In patients randomized to receive BM cell injection, there was significant decrease in percentage area of peri-infarct regions (-23.6%, P = 0.04 and increase in global LVEF (+9.0%, P = 0.02, the percentage of regional wall thickening (+13.1%, P= 0.04 and MPR (+0.25%, P = 0.03 over the target area at 6-months compared with baseline. Conclusions Direct endomyocardial implantation of autologous BM cells significantly improved global LVEF, regional wall thickening and myocardial perfusion reserve, and reduced percentage area of peri-infarct regions in patients with severe CAD.

  8. Resetting global expectations from agricultural biofuels

    International Nuclear Information System (INIS)

    Aggressive renewable energy policies have helped the biofuels industry grow at a rate few could have predicted. However, while discourse on the energy balance and environmental impacts of agricultural biofuel feedstocks are common, the potential they hold for additional production has received considerably less attention. Here we present a new biofuel yield analysis based on the best available global agricultural census data. These new data give us the first opportunity to consider geographically-specific patterns of biofuel feedstock production in different regions, across global, continental, national and sub-national scales. Compared to earlier biofuel yield tables, our global results show overestimates of biofuel yields by ∼100% or more for many crops. To encourage the use of regionally-specific data for future biofuel studies, we calculated complete results for 20 feedstock crops for 238 countries, states, territories and protectorates.

  9. Regulatory Action of Calcium Ion on Cyclic AMP-Enhanced Expression of Implantation-Related Factors in Human Endometrial Cells.

    Directory of Open Access Journals (Sweden)

    Kazuya Kusama

    Full Text Available Decidualization of human endometrial stroma and gland development is mediated through cyclic AMP (cAMP, but the role of intracellular calcium ion (Ca2+ on cAMP mediated-signaling in human endometrial stroma and glandular epithelia has not been well-characterized. The present study was designed to investigate the role of intracellular Ca2+ on cAMP mediated-decidualization and gland maturation events, which can be identified by the up-regulation of prolactin and IGF-binding protein (IGFBP1 in human endometrial stromal cells (ESCs, and cyclooxygenase 2 (COX2 and prostaglandin E2 (PGE2 and glandular epithelial EM-1 cells. Increases in decidual prolactin and IGFBP-1 transcript levels, induced by cAMP-elevating agents forskolin or dibutyryl cyclic AMP, were inhibited by Ca2+ influx into ESCs with Ca2+ ionophores (alamethicin, ionomycin in a dose-dependent manner. Conversely, inhibitors of Ca2+ influx through L-type voltage-dependent Ca2+ channel (VDCC, nifedipine and verapamil, enhanced the decidual gene expression. Furthermore, dantrolene, an inhibitor of Ca2+ release from the intracellular Ca2+ store, up-regulated prolactin and IGFBP-1 expression. Ca2+ ionophores decreased intracellular cAMP concentrations, whereas nifedipine, verapamil or dantrolene increased cAMP concentrations in ESCs. In glandular epithelial cells, similar responses in COX2 expression and PGE2 production were found when intracellular cAMP levels were up-regulated by decreases in Ca2+ concentrations. Thus, a marked decrease in cytosolic Ca2+ levels caused the elevation of cAMP concentrations, resulting in enhanced expression of implantation-related factors including decidual markers. These findings suggest that fluctuation in cytosolic Ca2+ concentrations alters intracellular cAMP levels, which then regulate differentiation of endometrial stromal and glandular epithelial cells.

  10. Cochlear implants in genetic deafness

    Institute of Scientific and Technical Information of China (English)

    Xuezhong Liu

    2014-01-01

    Genetic defects are one of the most important etiologies of severe to profound sensorineural hearing loss and play an important role in determining cochlear implantation outcomes. While the pathogenic mutation types of a number of deafness genes have been cloned, the pathogenesis mechanisms and their relationship to the outcomes of cochlear implantation remain a hot research area. The auditory performance is considered to be affected by the etiology of hearing loss and the number of surviving spiral ganglion cells, as well as others. Current research advances in cochlear implantation for hereditary deafness, especially the relationship among clinic-types, genotypes and outcomes of cochlear implantation, will be discussed in this review.

  11. Peptide-mediated microalgae harvesting method for efficient biofuel production

    OpenAIRE

    Maeda, Yoshiaki; Tateishi, Takuma; Niwa, Yuta; Muto, Masaki; Yoshino, Tomoko; Kisailus, David; Tanaka, Tsuyoshi

    2016-01-01

    Background Production of biofuels from microalgae has been recognized to be a promising route for a sustainable energy supply. However, the microalgae harvesting process is a bottleneck for industrialization because it is energy intensive. Thus, by displaying interactive protein factors on the cell wall, oleaginous microalgae can acquire the auto- and controllable-flocculation function, yielding smarter and energy-efficient harvesting. Results Towards this goal, we established a cell-surface ...

  12. Mind-controlled transgene expression by a wireless-powered optogenetic designer cell implant

    OpenAIRE

    Marc Folcher; Sabine Oesterle; Katharina Zwicky; Thushara Thekkottil; Julie Heymoz; Muriel Hohmann; Matthias Christen; Marie Daoud El-Baba; Peter Buchmann; Martin Fussenegger

    2014-01-01

    Synthetic devices for traceless remote control of gene expression may provide new treatment opportunities in future gene- and cell-based therapies. Here we report the design of a synthetic mind-controlled gene switch that enables human brain activities and mental states to wirelessly programme the transgene expression in human cells. An electroencephalography (EEG)-based brain–computer interface (BCI) processing mental state-specific brain waves programs an inductively linked wireless-powered...

  13. Therapeutic effects of NogoA vaccine and olfactory ensheathing glial cell implantation on acute spinal cord injury

    Directory of Open Access Journals (Sweden)

    Zhang Z

    2013-10-01

    Full Text Available Zhicheng Zhang, Fang Li, Tiansheng Sun, Dajiang Ren, Xiumei Liu PLA Institute of Orthopedics, Beijing Army General Hospital, Beijing, People's Republic of China Background: Many previous studies have focused on the effects of IN-1, a monoclonal antibody that neutralizes Nogo (a neurite growth inhibitory protein, on neurologic regeneration in spinal cord injury (SCI. However, safety problems and the short half-life of the exogenous antibody are still problematic. In the present study, the NogoA polypeptide was used as an antigen to make a therapeutic NogoA vaccine. Rats were immunized with this vaccine and were able to secrete the polyclonal antibody before SCI. The antibody can block NogoA within the injured spinal cord when the antibody gains access to the spinal cord due to a compromised blood–spinal cord barrier. Olfactory ensheathing glial cell transplantation has been used in a spinal cord contusion model to promote the recovery of SCI. The present study was designed to verify the efficacy and safety of NogoA polypeptide vaccine, the effects of immunotherapy with this vaccine, and the synergistic effects of the vaccine and olfactory ensheathing glial cells in repair of SCI. Methods: A 13-polypeptide fragment of NogoA was synthesized. This fragment was then coupled with keyhole limpet hemocyanin to improve the immunogenicity of the polypeptide vaccine. Immunization via injection into the abdominal cavity was performed in rats before SCI. The serum antibody level and ability of the vaccine to bind with Nogo were detected by enzyme-linked immunosorbent assay. The safety of the vaccine was evaluated according to the incidence and severity of experimental autoimmune encephalomyelitis. Olfactory ensheathing glia cells were obtained, purified, and subsequently implanted into a Wistar rat model of thoracic spinal cord contusion injury. The rats were divided into four groups, ie, an SCI model group, an olfactory ensheathing glia group, a vaccine

  14. Edema-induced increase in tumour cell survival for 125I and 103Pd prostate permanent seed implants - a bio-mathematical model

    International Nuclear Information System (INIS)

    Edema caused by the surgical procedure of prostate seed implantation expands the source-to-point distances within the prostate and hence decreases the dose coverage. The decrease of dose coverage results in an increase in tumour cell survival. To investigate the effects of edema on tumour cell survival, a bio-mathematical model of edema and the corresponding cell killing by continuous low dose rate irradiation (CLDRI) was developed so that tumour cell surviving fractions can be estimated in an edematous prostate for both 125I and 103Pd seed implants. The dynamic nature of edema and its resolution were modelled with an exponential function V(T)=Vp (1+M exp(-0.693T/Te)) where Vp is the prostate volume before implantation, M is the edema magnitude and Te is edema half-life (EHL). The dose rate of a radioactive seed was calculated according to AAPM TG43, i.e. D radical SkΔg(r) φ-baran/r2, where r is the distance between a seed and a given point. The distance r is now a function of time because of edema. The g(r) was approximated as 1/r0.4 and 1/r0.8 for 125I and 103Pd, respectively. By expanding the mathematical expression of the resultant dose rate in a Taylor series of exponential functions of time, the dose rate was made equivalent to that produced from multiple fictitious radionuclides of different decay constants and strengths. The biologically effective dose (BED) for an edematous prostate implant was then calculated using a generalized Dale equation. The cell surviving fraction was computed as exp(-αBED), where α is the linear coefficient of the survival curve. The tumour cell survival was calculated for both 125I and 103Pd seed implants and for different tumour potential doubling time (TPDT) (from 5 days to 30 days) and for edemas of different magnitudes (from 0% to 95%) and edema half-lives (from 4 days to 30 days). Tumour cell survival increased with the increase of edema magnitude and EHL. For a typical edema of a half-life of 10 days and a magnitude of

  15. Edema-induced increase in tumour cell survival for {sup 125}I and {sup 103}Pd prostate permanent seed implants - a bio-mathematical model

    Energy Technology Data Exchange (ETDEWEB)

    Yue Ning; Chen Zhe; Nath, Ravinder [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT (United States)

    2002-04-01

    Edema caused by the surgical procedure of prostate seed implantation expands the source-to-point distances within the prostate and hence decreases the dose coverage. The decrease of dose coverage results in an increase in tumour cell survival. To investigate the effects of edema on tumour cell survival, a bio-mathematical model of edema and the corresponding cell killing by continuous low dose rate irradiation (CLDRI) was developed so that tumour cell surviving fractions can be estimated in an edematous prostate for both {sup 125}I and {sup 103}Pd seed implants. The dynamic nature of edema and its resolution were modelled with an exponential function V(T)=V{sub p} (1+M exp(-0.693T/T{sub e})) where V{sub p} is the prostate volume before implantation, M is the edema magnitude and T{sub e} is edema half-life (EHL). The dose rate of a radioactive seed was calculated according to AAPM TG43, i.e. D radical S{sub k}{delta}g(r) {phi}-bar{sub an}/r{sup 2}, where r is the distance between a seed and a given point. The distance r is now a function of time because of edema. The g(r) was approximated as 1/r{sup 0.4} and 1/r{sup 0.8} for {sup 125}I and {sup 103}Pd, respectively. By expanding the mathematical expression of the resultant dose rate in a Taylor series of exponential functions of time, the dose rate was made equivalent to that produced from multiple fictitious radionuclides of different decay constants and strengths. The biologically effective dose (BED) for an edematous prostate implant was then calculated using a generalized Dale equation. The cell surviving fraction was computed as exp(-{alpha}BED), where {alpha} is the linear coefficient of the survival curve. The tumour cell survival was calculated for both {sup 125}I and {sup 103}Pd seed implants and for different tumour potential doubling time (TPDT) (from 5 days to 30 days) and for edemas of different magnitudes (from 0% to 95%) and edema half-lives (from 4 days to 30 days). Tumour cell survival increased

  16. Iatrogenic Tumor Implantation

    Institute of Scientific and Technical Information of China (English)

    Ying Ma; Ping Bai

    2008-01-01

    Iatrogenic tumor implantation is a condition that results from various medical procedures used during diagnosis or treatment of a malignancy. It involves desquamation and dissemination of tumor cells that develop into a local recurrence or distant metastasis from the tumor under treatment. The main clinical feature of the condition is nodules at the operation's porous channel or incision, which is easily diagnosed in accordance with the case history. Final diagnosis can be made based on pathological examination. Tumor implantation may occur in various puncturing porous channels, including a laparoscopic port, abdominal wall incision, and perineal incision, etc. Besides a malignant tumor,implantation potential exists with diseases, such as a borderline tumor and endometriosis etc. Once a tumor implantation is diagnosed, or suspected, surgical resection is usually conducted.During the diagnosis and treatment of diseases, avoiding and reducing iatrogenic implantation and dissemination has been regarded as an important principle for surgical treatment of tumors. In a clinical practice setting, if possible, excisional biopsy should be employed, if a biopsy is needed. Repeated puncturing should be avoided during a paracentesis. In a laparoscopic procedure, the tissue is first put into a sample bag and then is taken out from the point of incision. After a laparoscopic procedure, the peritoneum, abdominal muscular fasciae, and skin should be carefully closed, and/or the punctured porous channel be excised. In addition, the sample/tissue should be rinsed with distilled water before surgical closure of the abdominal cavity,allowing the exfoliated tumor cells to swell and rupture in the hypo-osmolar solution. Then surgical closure can be conducted following a change of gloves and equipment. The extent of hysteromyomectomy should as far as possible be away from the uterine cavity. The purpose of this study is to make clinicians aware of the possibility of tumor implantation

  17. From first generation biofuels to advanced solar biofuels.

    Science.gov (United States)

    Aro, Eva-Mari

    2016-01-01

    Roadmaps towards sustainable bioeconomy, including the production of biofuels, in many EU countries mostly rely on biomass use. However, although biomass is renewable, the efficiency of biomass production is too low to be able to fully replace the fossil fuels. The use of land for fuel production also introduces ethical problems in increasing the food price. Harvesting solar energy by the photosynthetic machinery of plants and autotrophic microorganisms is the basis for all biomass production. This paper describes current challenges and possibilities to sustainably increase the biomass production and highlights future technologies to further enhance biofuel production directly from sunlight. The biggest scientific breakthroughs are expected to rely on a new technology called "synthetic biology", which makes engineering of biological systems possible. It will enable direct conversion of solar energy to a fuel from inexhaustible raw materials: sun light, water and CO2. In the future, such solar biofuels are expected to be produced in engineered photosynthetic microorganisms or in completely synthetic living factories. PMID:26667057

  18. A novel co-culture model of murine K12 osteosarcoma cells and S. aureus on common orthopedic implant materials: 'the race to the surface' studied in vitro.

    Science.gov (United States)

    McConda, David B; Karnes, Jonathan M; Hamza, Therwa; Lindsey, Brock A

    2016-07-01

    Infection is a major cause of orthopedic implant failure. There are few studies assessing both tissue cell and bacterial adherence on common orthopedic implant materials in a co-culture environment. An in vitro co-culture model was created using K12 osteosarcoma cells and Staphylococcus aureus in a medium incubated over metal disks for 48 h. The results showed that, in the presence of S. aureus, there were fewer osteosarcoma cells attached to the disks for all substrata tested. There were significantly more osteosarcoma cells adhering to the cobalt chrome than the stainless steel and titanium disks. Overall, in the presence of osteosarcoma cells, there were more bacteria adhering to the disks for all the substrata tested, with significantly more bacteria adhering to the stainless steel disks compared to cobalt chrome and titanium disks. Scanning electron microscopy verified that osteosarcoma cells and bacteria were adherent to the metal disks after incubation for 48 h. Furthermore, the observation that more bacteria were in the co-culture than in the control sample suggests that the osteosarcoma cells serve as a nutrient source for the bacteria. Future models assessing the interaction of osteogenic cells with bacteria on a substratum would be improved if the model accounted for the role of the immune system in secondary bone healing. PMID:27142312

  19. Integrated biofuel facility, with carbon dioxide consumption and power generation

    Energy Technology Data Exchange (ETDEWEB)

    Powell, E.E.; Hill, G.A. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Chemical Engineering

    2009-07-01

    This presentation provided details of an economical design for a large-scale integrated biofuel facility for coupled production of bioethanol and biodiesel, with carbon dioxide capture and power generation. Several designs were suggested for both batch and continuous culture operations, taking into account all costs and revenues associated with the complete plant integration. The microalgae species Chlorella vulgaris was cultivated in a novel photobioreactor (PBR) in order to consume industrial carbon dioxide (CO{sub 2}). This photosynthetic culture can also act as a biocathode in a microbial fuel cell (MFC), which when coupled to a typical yeast anodic half cell, results in a complete biological MFC. The photosynthetic MFC produces electricity as well as valuable biomass and by-products. The use of this novel photosynthetic microalgae cathodic half cell in an integrated biofuel facility was discussed. A series of novel PBRs for continuous operation can be integrated into a large-scale bioethanol facility, where the PBRs serve as cathodic half cells and are coupled to the existing yeast fermentation tanks which act as anodic half cells. These coupled MFCs generate electricity for use within the biofuel facility. The microalgae growth provides oil for biodiesel production, in addition to the bioethanol from the yeast fermentation. The photosynthetic cultivation in the cathodic PBR also requires carbon dioxide, resulting in consumption of carbon dioxide from bioethanol production. The paper also discussed the effect of plant design on net present worth and internal rate of return. tabs., figs.

  20. Magnetic resonance tracking of implanted adult and embryonic stem cells in injured brain and spinal cord

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva; Jendelová, Pavla

    2005-01-01

    Roč. 1049, - (2005), s. 146-160. ISSN 0077-8923 R&D Projects: GA ČR GA304/03/1189; GA MŠk(CZ) 1M0538 Institutional research plan: CEZ:AV0Z5039906 Keywords : cell transplantation * magnetic resonance Subject RIV: FJ - Surgery incl. Transplants Impact factor: 1.971, year: 2005

  1. Imaging the fate of implanted stem cells in brain and spinal cord injury

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva

    Innsbruck : organizátor, 2003, s. 1. [FENS Winter School 2003. Kitzbuehel (AT), 07.12.2003-14.12.2003] R&D Projects: GA MŠk LN00A065 Institutional research plan: CEZ:AV0Z5039906 Keywords : Stem cells * spinal cord injury Subject RIV: FH - Neurology

  2. Invasion of primary glioma- and cell line-derived spheroids implanted into corticostriatal slice cultures

    DEFF Research Database (Denmark)

    Aaberg-Jessen, Charlotte; Nørregaard, Annette; Christensen, Karina Garnier; Pedersen, CB; Andersen, Claus; Kristensen, Bjarne Winther

    2013-01-01

    Gliomas are highly invasive tumors and the pronounced invasive features of gliomas prevent radical surgical resection. In the search for new therapeutics targeting invasive glioma cells, in vivo-like in vitro models are of great interest. We developed and evaluated an in vivo-like in vitro model...

  3. Invasion of primary glioma- and cell line-derived spheroids implanted into corticostriatal slice cultures

    DEFF Research Database (Denmark)

    Aaberg-Jessen, Charlotte; Nørregaard, Annette; Christensen, Karina;

    2013-01-01

    Gliomas are highly invasive tumors and the pronounced invasive features of gliomas prevent radical surgical resection. In the search for new therapeutics targeting invasive glioma cells, in vivo-like in vitro models are of great interest. We developed and evaluated an in vivo-like in vitro model ...

  4. Study of percutaneous 125I seeds implantation guided by CT in elderly patients of stage I peripheral non-small cell lung cancer

    International Nuclear Information System (INIS)

    Objective: To evaluate the efficacy, feasibility and safety of CT guided percutaneous 125I seeds implantation in elderly patients of stage I peripheral non-small cell lung cancer (NSCLC). Methods: Clinical data of 16 elderly peripheral stage I NSCLC patients (10 squamous carcinoma and 6 adenocarcinoma; 13 stage IA and 3 stage IB) who received radioactive 125I seeds implantation because of refusal or being unsuited to operation or external radiotherapy were retrospectively analyzed. Prescribed dose was 140 - 160 Gy. Under CT guidance, 125I seeds were implanted percutaneously into tumors for interstitial radiotherapy according to treatment plan system. Results: Mean number of 125I seeds each patient received was 21.1. 12 complete response (CR) and 4 partial response (PR) were achieved. Total response rate (CR + PR) was 100%. 100% patients completed 10 to 56 months of follow-up, 15, 13, 8 and 6 patients completed 1-, 2-, 3-and 4-years' follow-up, respectively. The median local progression free time was 14 months. The 1-, 2-, 3-and 4-year overall survival rate were 60%, 54%, 50% and 33%, respectively (median : 14 months). 7 cases died of non-tumor disease and 5 died of metastasis. No severe complications were observed. Conclusions: CT guided 125I seeds implantation is a safe, reliable and effective radical treatment method for elderly stage I peripheral NSCLC patients, who refuse to or are unsuitable to operation or external radiotherapy. (authors)

  5. Zirconia coated titanium for implants and their interactions with osteoblast cells

    Energy Technology Data Exchange (ETDEWEB)

    Kaluđerović, Milena R., E-mail: milena.kaluderovic@medizin.uni-leipzig.de [Department of Oral, Maxillary, Facial and Reconstructive Plastic Surgery, University Hospital of Leipzig, Leipzig (Germany); Schreckenbach, Joachim P. [ZL Microdent Co, Breckerfeld (Germany); Department of Chemistry, Technical University of Chemnitz (Germany); Graf, Hans-Ludwig [Department of Oral, Maxillary, Facial and Reconstructive Plastic Surgery, University Hospital of Leipzig, Leipzig (Germany)

    2014-11-01

    The anodic plasma-electrochemical oxidation in aqueous electrolytes of Zr(SO{sub 4}){sub 2} was used to prepare new zirconia/titania-based surfaces M1 (Ti, Zr and O: 7–10, 22–27 and 65–69 at.%) and M2 (Ti, Zr and O: 11–13, 20–23 and 64–69 at.%). The chemical composition and the microstructure of these coatings were characterized by surface and solid state techniques such as scanning electron microscopy, electron probe microanalysis, Raman spectroscopy and X-ray diffraction. These mixed oxides of ZrO{sub 2}/TiO{sub 2} surfaces consist up to 84% (m/m) of ZrO{sub 2} and 16% (m/m) of TiO{sub 2}. Monoclinic zirconia was detected as the dominant microcrystalline phase. In vitro studies were conducted on primary human osteoblast cells. MTT and DAPI assays were used for assessment on cell proliferation. Immunohistochemical analyses of morphology, cell cluster formation and expression of bone sialoprotein (BSP) and osteocalcin (OC) were performed. Novel surfaces M1 and M2 induced proliferation and expression of OC and BSP similarly to Ticer, used in clinical practice. Furthermore, the presence of zirconia on titanium surface has a higher beneficial effect on the osteoblast morphological changes and cell cluster formation. - Highlights: • Surfaces M1 and M2 (up to 84% (m/m) ZrO{sub 2} and 16% (m/m) TiO{sub 2}) were prepared. • Novel materials promote proliferation of human osteoblasts similarly to Ticer. • Morphological changes and cell cluster formation are induced faster on M1 and M2. • Higher expression of OC and BSP is caused by M1 and M2. • M1 and M2 may influence the rate of bone formation.

  6. Zirconia coated titanium for implants and their interactions with osteoblast cells

    International Nuclear Information System (INIS)

    The anodic plasma-electrochemical oxidation in aqueous electrolytes of Zr(SO4)2 was used to prepare new zirconia/titania-based surfaces M1 (Ti, Zr and O: 7–10, 22–27 and 65–69 at.%) and M2 (Ti, Zr and O: 11–13, 20–23 and 64–69 at.%). The chemical composition and the microstructure of these coatings were characterized by surface and solid state techniques such as scanning electron microscopy, electron probe microanalysis, Raman spectroscopy and X-ray diffraction. These mixed oxides of ZrO2/TiO2 surfaces consist up to 84% (m/m) of ZrO2 and 16% (m/m) of TiO2. Monoclinic zirconia was detected as the dominant microcrystalline phase. In vitro studies were conducted on primary human osteoblast cells. MTT and DAPI assays were used for assessment on cell proliferation. Immunohistochemical analyses of morphology, cell cluster formation and expression of bone sialoprotein (BSP) and osteocalcin (OC) were performed. Novel surfaces M1 and M2 induced proliferation and expression of OC and BSP similarly to Ticer, used in clinical practice. Furthermore, the presence of zirconia on titanium surface has a higher beneficial effect on the osteoblast morphological changes and cell cluster formation. - Highlights: • Surfaces M1 and M2 (up to 84% (m/m) ZrO2 and 16% (m/m) TiO2) were prepared. • Novel materials promote proliferation of human osteoblasts similarly to Ticer. • Morphological changes and cell cluster formation are induced faster on M1 and M2. • Higher expression of OC and BSP is caused by M1 and M2. • M1 and M2 may influence the rate of bone formation

  7. Dental Implants

    Medline Plus

    Full Text Available ... are lost, it’s not uncommon to suffer from social consequences and poor nutrition. Rebuilding Bone When the ... not a one-day procedure. The implant needs time to properly adhere to the bone and create ...

  8. Cochlear Implants

    Science.gov (United States)

    ... on this topic can be found in our Audiology Information Series [PDF]. How does a cochlear implant ... speech-language pathologists; speech, language, and hearing scientists; audiology and speech-language pathology support personnel; and students. ...

  9. Toward nitrogen neutral biofuel production.

    Science.gov (United States)

    Huo, Yi-Xin; Wernick, David G; Liao, James C

    2012-06-01

    Environmental concerns and an increasing global energy demand have spurred scientific research and political action to deliver large-scale production of liquid biofuels. Current biofuel processes and developing approaches have focused on closing the carbon cycle by biological fixation of atmospheric carbon dioxide and conversion of biomass to fuels. To date, these processes have relied on fertilizer produced by the energy-intensive Haber-Bosch process, and have not addressed the global nitrogen cycle and its environmental implications. Recent developments to convert protein to fuel and ammonia may begin to address these problems. In this scheme, recycling ammonia to either plant or algal feedstocks reduces the demand for synthetic fertilizer supplementation. Further development of this technology will realize its advantages of high carbon fixation rates, inexpensive and simple feedstock processing, in addition to reduced fertilizer requirements. PMID:22054644

  10. Effects of zirconium and nitrogen plasma immersion ion implantation on the electrochemical corrosion behavior of Mg–Y–RE alloy in simulated body fluid and cell culture medium

    International Nuclear Information System (INIS)

    Highlights: • Dual Zr and N plasma ion implantation are conducted on WE43Mg alloy. • Zr and N implanted WE43 (ZrN-WE43) enhanced corrosion resistance in cell culture medium. • ZrN-WE43 enhanced corrosion resistance in simulated body fluid (SBF). • ZrN-WE43 shows near capacitive impedance spectra in cell culture medium. • Calcium phosphate is formed on the corrosion product. - Abstract: The effects of dual Zr and N plasma immersion ion implantation (PIII) on the corrosion behavior of WE43Mg alloy are evaluated in simulated body fluid (SBF) and cell culture medium (cDMEM). Zr and N PIII improves the corrosion resistance of WE43 which exhibits smaller icorr, larger R1 and R2, smaller CPE2, and larger phase angle maxima in SBF and cDMEM. The Zr and N PIII WE43 samples exhibit 12-folds decrease in icorr in SBF and 71-folds decrease in icorr with near capacitive EIS in cDMEM. Analysis of the corrosion products reveals calcium phosphate

  11. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies

    Directory of Open Access Journals (Sweden)

    Heng-feng Yuan

    2016-02-01

    Full Text Available The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 - 0.32; p<0.001, a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p<0.01 and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 - 8.28; p<0.01. The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings.

  12. Clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation: a meta-analysis of seven case-control studies.

    Science.gov (United States)

    Yuan, Heng-Feng; Zhang, Jing; Guo, Chang-An; Yan, Zuo-Qin

    2016-02-01

    The purpose of this study was to evaluate the clinical outcomes of osteonecrosis of the femoral head after autologous bone marrow stem cell implantation. We searched the PubMed, Embase and Web of Science databases and included all case-control trials that reported on the clinical outcomes of osteonecrosis progression, incidence of total hip arthroplasty and improvement in Harris hip scores. Overall, seven case-control trials were included. Compared with the controls, patients treated with the bone marrow stem cells implantation treatment showed improved clinical outcomes with delayed osteonecrosis progression (odds ratio = 0.17, 95% CI: 0.09 - 0.32; p <0.001), a lower total hip arthroplasty incidence (odds ratio = 0.30, 95% CI: 0.12 - 0.72; p <0.01) and increased Harris hip scores (mean difference = 4.76, 95% CI: 1.24 - 8.28; p<0.01). The heterogeneity, publication bias, and sensitivity analyses showed no statistical difference significant differences between studies. Thus, our study suggests that autologous bone marrow stem cells implantation has a good therapeutic effect on osteonecrosis of the femoral, resulting in beneficial clinical outcomes. However, trials with larger sample sizes are needed to confirm these findings. PMID:26934241

  13. Synthetic Biology Guides Biofuel Production

    OpenAIRE

    2010-01-01

    The advancement of microbial processes for the production of renewable liquid fuels has increased with concerns about the current fuel economy. The development of advanced biofuels in particular has risen to address some of the shortcomings of ethanol. These advanced fuels have chemical properties similar to petroleum-based liquid fuels, thus removing the need for engine modification or infrastructure redesign. While the productivity and titers of each of these processes remains to be improve...

  14. MECHANICAL PROCESSING OF SOLID BIOFUELS

    OpenAIRE

    GÜRDİL, Gürkan A.K; Malaťák, Jan; Vaculík, Petr

    2012-01-01

    Solid biofuels are preferred as alternative source of energy in recent years. Although it’s not yet popular in Turkey but, there’s a big potential concerning agricultural residues. With the depletion of fossil fuels world wide researches for alternative energy sources, especially efforts for obtaining the energy from agricultural non-food products became important. Generally, two methods are used in mechanical processing of biofules obtained from plants and agricultural residues. These are pe...

  15. Application of FTIR Absorption Spectroscopy to Characterize Waste and Biofuels for Pyrolysis and Gasification

    OpenAIRE

    KALISZ Sylwester; Svoboda, Karel; ROBAK Zbigniew; Baxter, David; Andersen, Lars

    2008-01-01

    The paper discusses the various applications of FTIR absorption spectroscopy as a tool for characterizing waste biofuels for pyrolysis and gasification. The FTIR spectrometer used in the study allows for analysis of solid and liquid waste and biofuel samples. Further, an attached dedicated gas cell is used in the characterization of gases evolving during pyrolysis in a versatile pyrolyser/gasifier attached to the FTIR. The pyrolyser operates in a batch mode and generates large quantities o...

  16. How policies affect international biofuel price linkages

    International Nuclear Information System (INIS)

    We estimate the role of biofuel policies in determining which country is the price leader in world biofuel markets using a cointegration analysis and a Vector Error Correction (VEC) model. Weekly prices are analyzed for the EU, US, and Brazilian ethanol and biodiesel markets in the 2002–2010 and 2005–2010 time periods, respectively. The US blender's tax credit and Brazil's consumer tax exemption are found to play a role in determining the ethanol prices in other countries. For biodiesel, our results demonstrate that EU policies – the consumer tax exemption and blending target – tend to determine the world biodiesel price. - Highlights: • We estimate the role of biofuel policies in determining biofuel prices. • We use a cointegration analysis and the Vector Error Correction (VEC) model. • The biofuel policies in US and Brazil determine the world ethanol prices. • EU biofuel policies tend to form the world biodiesel price

  17. Carbon dioxide neutral, integrated biofuel facility

    Energy Technology Data Exchange (ETDEWEB)

    Powell, E.E.; Hill, G.A. [Department of Chemical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Saskatchewan, S7N 5A9 (Canada)

    2010-12-15

    Algae are efficient biocatalysts for both capture and conversion of carbon dioxide in the environment. In earlier work, we have optimized the ability of Chlorella vulgaris to rapidly capture CO{sub 2} from man-made emission sources by varying environmental growth conditions and bioreactor design. Here we demonstrate that a coupled biodiesel-bioethanol facility, using yeast to produce ethanol and photosynthetic algae to produce biodiesel, can result in an integrated, economical, large-scale process for biofuel production. Each bioreactor acts as an electrode for a coupled complete microbial fuel cell system; the integrated cultures produce electricity that is consumed as an energy source within the process. Finally, both the produced yeast and spent algae biomass can be used as added value byproducts in the feed or food industries. Using cost and revenue estimations, an IRR of up to 25% is calculated using a 5 year project lifespan. (author)

  18. Positive aspects issued from bio corrosion studies: from hydrogen production to biofuel cells; Des aspects positifs issus des recherches en biocorrosion: de la production d'hydrogene aux biopiles a combustible

    Energy Technology Data Exchange (ETDEWEB)

    Silva Munoz, L. de

    2007-12-15

    Microbially influenced corrosion or bio corrosion is a problem that generates heavy global economic losses (several billion euros per year). In spite of the progress made on the understanding of the underlying mechanisms, the complexity of the phenomenon has prevented finding definitive solutions to the problem and continues to inspire many research works. The participation in bio corrosion of catalytic mechanisms induced by weak acids was studied in this work. Another objective of the thesis has been to take advantage from catalytic phenomena found in bio corrosion research to apply them in other areas: energy production with biofuel cells or electrochemical hydrogen production in mild conditions. This work has shown that the presence of weak acids and amino acids inside bio-films could play a major role in steel bio corrosion accelerating the phenomenon through the catalysis of the water reduction reaction. The reversibility of this mechanism, discerned and proved here, could explain the corrosion increase when hydrogen is removed (bacterial consumption, agitation...). In addition, phosphates allow the production of hydrogen by electrolysis in mild pH conditions (pH 4.0 - 8.0) with an equal or better performance than those found in alkaline electrolysis. Finally, industrial materials like stainless steel and titanium could be used in the fabrication of enzymatic electrodes for biosensors or microsystems. The use of the glucose oxidase/glucose system in an aqueous fuel cell with a stainless steel cathode, allows the improvement of the cell performance thanks to the production of hydrogen peroxide that is easily reduced. Moreover, the use of materials with micro-structured surfaces like sandblasted steels deserve to be studied in detail to exploit the remarkable reactivity they present compared to smooth electrodes. (author)

  19. Food Aid and Biofuels: The Effects of Biofuel Policies on Procurement and Delivery

    OpenAIRE

    Cardwell, Ryan T.; Kerr, William A.

    2009-01-01

    The food-aid community almost unanimously condemns policies that encourage crop production for fuel. Both food-aid donors and recipients are concerned that biofuels will increase foodgrain prices and leave donors unable to meet commitments. The effects of biofuel-induced higher cereal prices on food-aid recipients are complicated functions of several factors, each of which must be considered in an analysis of the effects of biofuel policies. These factors include the level of biofuel-induced ...

  20. Contrasts and synergies in different biofuel reports

    OpenAIRE

    Michalopoulos, A; Landeweerd, L.; Van der Werf-Kulichova, Z.; Puylaert, P. G. B.; Osseweijer, P.

    2011-01-01

    The societal debate on biofuels is characterised by increased complexity. This can hinder the effective governance of the field. This paper attempts a quantitative bird's eye meta-analysis of this complexity by mapping different stakeholder perspectives and expected outcomes as seen in the secondary literature on biofuels, along the lines of the People-Planet-Profit framework. Our analysis illustrates the tension between stated and actual drivers of large scale biofuel development, especially...