Science.gov

Sample records for harli jrgenson ene

  1. Safety harness

    DOEpatents

    Gunter, Larry W.

    1993-01-01

    A safety harness to be worn by a worker, especially a worker wearing a plastic suit thereunder for protection in a radioactive or chemically hostile environment, which safety harness comprises a torso surrounding portion with at least one horizontal strap for adjustably securing the harness about the torso, two vertical shoulder straps with rings just forward of the of the peak of the shoulders for attaching a life-line and a pair of adjustable leg supporting straps releasibly attachable to the torso surrounding portion. In the event of a fall, the weight of the worker, when his fall is broken and he is suspended from the rings with his body angled slightly back and chest up, will be borne by the portion of the leg straps behind his buttocks rather than between his legs. Furthermore, the supporting straps do not restrict the air supplied through hoses into his suit when so suspended.

  2. NCCS Regression Test Harness

    Energy Science and Technology Software Center (ESTSC)

    2015-09-09

    The NCCS Regression Test Harness is a software package that provides a framework to perform regression and acceptance testing on NCCS High Performance Computers. The package is written in Python and has only the dependency of a Subversion repository to store the regression tests.

  3. Quick-donning backpack harness

    NASA Technical Reports Server (NTRS)

    Thomas, D. F., Jr.

    1972-01-01

    Harness device permits user to quickly put on or take off load carried in backpack arrangement. It can be attached with one hand; has controlled deformation belt that automatically encircles user upon application of pressure; has rigid shoulder harness elements which move automatically into place; and primary attachment components cannot be displaced while harness is in place.

  4. Har Crater on Callisto

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image shows a heavily cratered region near Callisto's equator. It was taken by the Galileo spacecraft Solid State Imaging (CCD) system on its ninth orbit around Jupiter. North is to the top of the image. The 50 kilometer (30 mile) double ring crater in the center of the image is named Har. Har displays an unusual rounded mound on its floor. The origin of the mound is unclear but probably involves uplift of ice-rich materials from below, either as a 'rebound' immediately following the impact that formed the crater or as a later process. Har is older than the prominent 20 kilometer (12 mile) crater superposed on its western rim. The large crater partially visible in the northeast corner of the image is called Tindr. Chains of secondary craters (craters formed from the impact of materials thrown out of the main crater during an impact) originating from Tindr crosscut the eastern rim of Har.

    The image, centered at 3.3 degrees south latitude and 357.9 degrees west longitude, covers an area of 120 kilometers by 115 kilometers (75 miles by 70 miles). The sun illuminates the scene from the west (left). The smallest distinguishable features in the image are about 294 meters (973 feet) across. This image was obtained on June 25, 1997, when Galileo was 14,080 kilometers (8,590 miles) from Callisto.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

  5. Harnessing our very life.

    PubMed

    Wills, Peter R; Williams, David L F; Trussell, Denys; Mann, L R B

    2013-01-01

    The Aristotelian ideas of nature (physis) and technology (techné) are taken as a starting point for understanding what it would mean for technology to be truly living. Heidegger's critique of the conflation of scientific and technological thinking in the current era is accepted as demonstrating that humanity does not have a deep enough appreciation of the nature of life to harness its essence safely. Could the vision of harnessing life be realized, which we strongly doubt, living technology would give selected humans transforming powers that could be expected to exacerbate, rather than solve, current global problems. The source of human purposefulness, and hence of both technology and ethics, is identified in nature's emergent capability to instantiate informational representations in material forms. Ethics that are properly grounded in an appreciation of intrinsic value, especially that of life, demand that proposals to give humanity the capabilities of living technology address the social, political, economic, and environmental problems inherent in its development and potential deployment. Before any development is embarked on, steps must be taken to avoid living technology, whatever the term eventually designates, becoming available for destructive or antisocial purposes such as those that might devastate humanity or irrevocably damage the natural world. PMID:23889745

  6. Catalytic Conia-ene and related reactions.

    PubMed

    Hack, Daniel; Blümel, Marcus; Chauhan, Pankaj; Philipps, Arne R; Enders, Dieter

    2015-10-01

    Since its initial inception, the Conia-ene reaction, known as the intramolecular addition of enols to alkynes or alkenes, has experienced a tremendous development and appealing catalytic protocols have emerged. This review fathoms the underlying mechanistic principles rationalizing how substrate design, substrate activation, and the nature of the catalyst work hand in hand for the efficient synthesis of carbocycles and heterocycles at mild reaction conditions. Nowadays, Conia-ene reactions can be found as part of tandem reactions, and the road for asymmetric versions has already been paved. Based on their broad applicability, Conia-ene reactions have turned into a highly appreciated synthetic tool with impressive examples in natural product synthesis reported in recent years. PMID:26031492

  7. Harnessing DNA intercalation.

    PubMed

    Persil, Ozgül; Hud, Nicholas V

    2007-10-01

    Numerous small molecules are known to bind to DNA through base pair intercalation. Fluorescent dyes commonly used for nucleic acid staining, such as ethidium, are familiar examples. Biological and physical studies of DNA intercalation have historically been motivated by mutation and drug discovery research. However, this same mode of binding is now being harnessed for the creation of novel molecular assemblies. Recent studies have used DNA scaffolds and intercalators to construct supramolecular assemblies that function as fluorescent 'nanotags' for cell labeling. Other studies have demonstrated how intercalators can be used to promote the formation of otherwise unstable nucleic acid assemblies. These applications illustrate how intercalators can be used to facilitate and expand DNA-based nanotechnology. PMID:17825446

  8. Organocatalyzed Intramolecular Carbonyl-Ene Reactions.

    PubMed

    Dahlmann, Heidi A; McKinney, Amanda J; Santos, Maria P; Davis, Lindsey O

    2016-01-01

    An organocatalyzed intramolecular carbonyl-ene reaction was developed to produce carbocyclic and heterocyclic 5- and 6-membered rings from a citronellal-derived trifluoroketone and a variety of aldehydes. A phosphoramide derivative was found to promote the cyclization of the trifluoroketone, whereas a less acidic phosphoric acid proved to be a superior catalyst for the aldehyde substrates. PMID:27258238

  9. ENES the European Network for Earth System modelling and its infrastructure projects IS-ENES

    NASA Astrophysics Data System (ADS)

    Guglielmo, Francesca; Joussaume, Sylvie; Parinet, Marie

    2016-04-01

    The scientific community working on climate modelling is organized within the European Network for Earth System modelling (ENES). In the past decade, several European university departments, research centres, meteorological services, computer centres, and industrial partners engaged in the creation of ENES with the purpose of working together and cooperating towards the further development of the network, by signing a Memorandum of Understanding. As of 2015, the consortium counts 47 partners. The climate modelling community, and thus ENES, faces challenges which are both science-driven, i.e. analysing of the full complexity of the Earth System to improve our understanding and prediction of climate changes, and have multi-faceted societal implications, as a better representation of climate change on regional scales leads to improved understanding and prediction of impacts and to the development and provision of climate services. ENES, promoting and endorsing projects and initiatives, helps in developing and evaluating of state-of-the-art climate and Earth system models, facilitates model inter-comparison studies, encourages exchanges of software and model results, and fosters the use of high performance computing facilities dedicated to high-resolution multi-model experiments. ENES brings together public and private partners, integrates countries underrepresented in climate modelling studies, and reaches out to different user communities, thus enhancing European expertise and competitiveness. In this need of sophisticated models, world-class, high-performance computers, and state-of-the-art software solutions to make efficient use of models, data and hardware, a key role is played by the constitution and maintenance of a solid infrastructure, developing and providing services to the different user communities. ENES has investigated the infrastructural needs and has received funding from the EU FP7 program for the IS-ENES (InfraStructure for ENES) phase I and II

  10. JWST ISIM Harness Thermal Evaluation

    NASA Technical Reports Server (NTRS)

    Kobel, Mark; Glazer, Stuart; Tuttle, Jim; Martins, Mario; Ruppel, Sean

    2008-01-01

    The James Webb Space Telescope (JWST) will be a large infrared telescope with a 6.5-meter primary mirror. Launch is planned for 2013. JWST wl1 be the premier observatory of the next decade serving thousands of astronomers worldwide. The Integrated Science Instrument Module (ISIM) is the unit that will house thc four main JWST instruments. The ISIM enclosure passively cooled to 37 Kelvin and has a tightly managed thermal budget. A significant portion of the ISIM heat load is due to parasitic heat gains from the instrument harnesses. These harnesses provide a thermal path from the Instrument Electronics Control (IEC) to the ISIM. Because of the impact of this load to the ISIM thermal design, understanding the harness parasitic heat gains is critical. To this effect, a thermal test program has been conducted in order to characterize these parasitic loads and verify harness thermal models. Recent parasitic heat loads tests resulted in the addition of a dedicated multiple stage harness radiator. In order for the radiator to efficiently reject heat from the harness, effective thermal contact conductance values for multiple harnesses had to be determined. This presentation will describe the details and the results of this test program.

  11. Environmental Control Unit Harness Project

    NASA Technical Reports Server (NTRS)

    Oliva-Buisson, Yvette J.

    2014-01-01

    Testing four new Environmental Control Unit Harnesses for improved user comfort during SCAPE operations. Phase I, testing in a lab environment, Phase II will continue testing the best candidates in a field environment.

  12. Harness the Power of Technology

    ERIC Educational Resources Information Center

    Duncan, Arne

    2011-01-01

    Today, U.S. educators are teaching in the midst of a technological revolution. Technology promises to provide innovative solutions in the nation's classrooms, just as it has transformed the way people communicate, socialize, and conduct business. In this article, the author argues that now is the time to harness technology to revolutionize the way…

  13. Microfluidic devices using thiol-ene polymers

    NASA Astrophysics Data System (ADS)

    Bou, Simon J. M. C.; Ellis, Amanda V.

    2013-12-01

    Here, a new polymeric microfluidic platform using off-stoichiometric thiol-ene (OSTE) polymers was developed. Thiolene polymers were chosen as they afford rapid UV curing, low volume shrinkage and optical transparency for use in microfluidic devices. Three different off-stoichiometric thiol-ene polymers with 30% excess allyl, 50% excess thiol and a 90% excess thiol (OSTE Allyl-30, OSTE-50 and OSTE-90, respectively) were fabricated. Attenuated reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and solid-state cross polarisation-magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) spectroscopy confirmed which functional groups (thiol or allyl) were present in excess in the OSTE polymers. The polymers were shown to have a more hydrophilic surface (water contact angle of 65°+/- 3) compared to polydimethylsiloxane (water contact angle of 105° +/- 5). Testing of the mechanical properties showed the glass transition temperatures to be 15.09 °C, 43.15 °C and, 57.48 °C for OSTE-90, OSTE Allyl-30 and, OSTE-50, respectively. The storage modulus was shown to be less than 10 MPa for the OSTE-90 polymer and approximately 1750 MPa for the OSTE Allyl-30 and OSTE-50 polymers. The polymers were then utilised to fabricate microfluidic devices via soft lithography practices and devices sealed using a one-step UV lamination "click" reaction technique. Finally, gold nanoparticles were used to form gold films on the OSTE-90 and OSTE-50 polymers as potential electrodes. Atomic force microscopy and sheet resistances were used to characterise the films.

  14. 4. VIEW LOOKING ENE OF UNDERSIDE SHOWING RIBS AND BEAMS. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. VIEW LOOKING ENE OF UNDERSIDE SHOWING RIBS AND BEAMS. NOTE SPALLING ON NORTHERN EDGE AND EXPOSED REBAR. - Morris Run Bridge, Rickert Road (TR 417) spanning Morris Run in Hilltown Township, Dublin, Bucks County, PA

  15. Harnessing spin precession with dissipation

    NASA Astrophysics Data System (ADS)

    Crisan, A. D.; Datta, S.; Viennot, J. J.; Delbecq, M. R.; Cottet, A.; Kontos, T.

    2016-01-01

    Non-collinear spin transport is at the heart of spin or magnetization control in spintronics devices. The use of nanoscale conductors exhibiting quantum effects in transport could provide new paths for that purpose. Here we study non-collinear spin transport in a quantum dot. We use a device made out of a single-wall carbon nanotube connected to orthogonal ferromagnetic electrodes. In the spin transport signals, we observe signatures of out of equilibrium spin precession that are electrically tunable through dissipation. This could provide a new path to harness spin precession in nanoscale conductors.

  16. Harnessing spin precession with dissipation

    PubMed Central

    Crisan, A. D.; Datta, S.; Viennot, J. J.; Delbecq, M. R.; Cottet, A.; Kontos, T.

    2016-01-01

    Non-collinear spin transport is at the heart of spin or magnetization control in spintronics devices. The use of nanoscale conductors exhibiting quantum effects in transport could provide new paths for that purpose. Here we study non-collinear spin transport in a quantum dot. We use a device made out of a single-wall carbon nanotube connected to orthogonal ferromagnetic electrodes. In the spin transport signals, we observe signatures of out of equilibrium spin precession that are electrically tunable through dissipation. This could provide a new path to harness spin precession in nanoscale conductors. PMID:26816050

  17. Investigation of thiol-ene and thiol-ene-methacrylate based resins as dental restorative materials

    PubMed Central

    Cramer, Neil B.; Couch, Charles L.; Schreck, Kathleen M.; Carioscia, Jacquelyn A.; Boulden, Jordan E.; Stansbury, Jeffrey W.; Bowman, Christopher N.

    2009-01-01

    Objectives The objective of this work was to evaluate thiol-norbornene and thiol-ene-methacrylate systems as the resin phase of dental restorative materials and demonstrate their superior performance as compared to dimethacrylate materials. Methods Polymerization kinetics and overall functional group conversions were determined by Fourier transform infrared spectroscopy (FTIR). Flexural strength and modulus were determined with a 3-point flexural test. Polymerization-induced shrinkage stress was measured with a tensometer. Results Thiol-ene polymer systems were demonstrated to exhibit advantageous properties for dental restorative materials in regards to rapid curing kinetics, high conversion, and low shrinkage and stress. However, both the thiol-norbornene and thiol-allyl ether systems studied here exhibit significant reductions in flexural strength and modulus relative to BisGMA/TEGDMA. By utilizing the thiol-ene component as the reactive diluent in dimethacrylate systems, high flexural modulus and strength are achieved while dramatically reducing the polymerization shrinkage stress. The methacrylate-thiol-allyl ether and methacrylate-thiol-norbornene systems both exhibited equivalent flexural modulus (2.1 ± 0.1 GPa) and slightly reduced flexural strength (95 ± 1 and 101 ± 3 MPa, respectively) relative to BisGMA/TEGDMA (flexural modulus; 2.2 + 0.1 GPa and flexural strength; 112 ± 3 MPa). Both the methacrylate-thiol-allyl ether and methacrylate-thiol-norbornene systems exhibited dramatic reductions in shrinkage stress (1.1 ± 0.1 and 1.1 ± 0.2 MPa, respectively) relative to BisGMA/TEGDMA (2.6 ± 0.2 MPa). Significance The improved polymerization kinetics and overall functional group conversion, coupled with reductions in shrinkage stress while maintaining equivalent flexural modulus, result in a superior overall dental restorative material as compared to traditional bulk dimethacrylate resins. PMID:19781757

  18. Redox Initiation of Bulk Thiol-Ene Polymerizations

    PubMed Central

    Cole, Megan A.; Jankousky, Katherine C.; Bowman, Christopher N.

    2013-01-01

    The unique formation-structure-property attributes and reaction behavior of the thiol-ene “click” reaction have been explored extensively for photochemically and thermally initiated reactions but have been much less explored for redox initiation. Therefore, the objective of this work is to characterize fully the impact of the initiation system, monomer structure, degree of functionalization, and inhibitor level on the redox-mediated thiol-ene polymerization rate and behavior. Moreover, this study confirms the ability of redox initiation to achieve full conversion of desired thiol-ene “click” products for small molecules in solution. For the multifunctional thiol-ene systems, polymerization rate was shown to be comparable to photo- and thermally initiated systems, but with the additional advantages of unlimited depth of cure and mild reaction conditions. Additionally, the network properties of the redox-initiated thiol-ene systems were on par with a photocured material formulated with identical monomers and radical initiating potential. Lastly, control over the polymerization rate and preceding induction period was garnered from the concentration of inhibitor included in the reaction mixture. The mechanism of action of quinone inhibition in redox-mediated thiol-ene polymerizations is shown to depend on both the presence of an aniline reducing agent and the concentration of inhibitor, with quinone concentrations in great excess of oxidizing agent concentrations actually leading to heightened polymerization rates when aniline is present. PMID:23565125

  19. Interfacial thiol-ene photoclick reactions for forming multilayer hydrogels.

    PubMed

    Shih, Han; Fraser, Andrew K; Lin, Chien-Chi

    2013-03-13

    Interfacial visible light-mediated thiol-ene photoclick reactions were developed for preparing step-growth hydrogels with multilayer structures. The effect of a noncleavage type photoinitiator eosin-Y on visible-light-mediated thiol-ene photopolymerization was first characterized using in situ photorheometry, gel fraction, and equilibrium swelling ratio. Next, spectrophotometric properties of eosin-Y in the presence of various relevant macromer species were evaluated using ultraviolet-visible light (UV-vis) spectrometry. It was determined that eosin-Y was able to reinitiate the thiol-ene photoclick reaction, even after light exposure. Because of its small molecular weight, most eosin-Y molecules readily leached out from the hydrogels. The diffusion of residual eosin-Y from preformed hydrogels was exploited for fabricating multilayer step-growth hydrogels. Interfacial hydrogel coating was formed via the same visible-light-mediated gelation mechanism without adding fresh initiator. The thickness of the thiol-ene gel coating could be easily controlled by adjusting visible light exposure time, eosin-Y concentration initially loaded in the core gel, or macromer concentration in the coating solution. The major benefits of this interfacial thiol-ene coating system include its simplicity and cytocompatibility. The formation of thiol-ene hydrogels and coatings neither requires nor generates any cytotoxic components. This new gelation chemistry may have great utilities in controlled release of multiple sensitive growth factors and encapsulation of multiple cell types for tissue regeneration. PMID:23384151

  20. Concise Total Synthesis of Lundurines A–C Enabled by Gold Catalysis and a Homodienyl Retro-Ene/Ene Isomerization

    PubMed Central

    2016-01-01

    The total synthesis of lundurines A–C has been accomplished in racemic and enantiopure forms in 11–13 and 12–14 steps, respectively, without protection/deprotection of functional groups, by a novel tandem double condensation/Claisen rearrangement, a gold(I)-catalyzed alkyne hydroarylation, a cyclopropanation via formal [3 + 2] cycloaddition/nitrogen extrusion, and a remarkable olefin migration through a vinylcyclopropane retro-ene/ene reaction that streamlines the endgame. PMID:26963149

  1. Hexaarylbiimidazoles as Visible Light Thiol–Ene Photoinitiators

    PubMed Central

    Clarkson, Brian H.; Scott, Timothy F.

    2015-01-01

    Objectives The aim of this study is to determine if hexaarylbiimidazoles (HABIs) are efficient, visible light-active photoinitiators for thiol–ene systems. We hypothesize that, owing to the reactivity of lophyl radicals with thiols and the necessarily high concentration of thiol in thiol–ene formulations, HABIs will effectively initiate thiol–ene polymerization upon visible light irradiation. Methods UV-vis absorption spectra of photoinitiator solutions were obtained using UV-vis spectroscopy, while EPR spectroscopy was used to confirm radical species generation upon HABI photolysis. Functional group conversions during photopolymerization were monitored using FTIR spectroscopy, and thermomechanical properties were determined using dynamic mechanical analysis. Results The HABI derivatives investigated exhibit less absorptivity than camphorquinone at 469 nm; however, they afford increased sensitivity at this wavelength when compared with bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide. Photolysis of the investigated HABIs affords lophyl radicals. Affixing hydroxyhexyl functional groups to the HABI core significantly improved solubility. Thiol–ene resins formulated with HABI photoinitiators polymerized rapidly upon irradiation with 469 nm. The glass transition temperatures of the thiol–ene resin formulated with a bis(hydroxyhexyl)-functionalized HABI and photopolymerized at room and body temperature were 49.5±0.5°C and 52.2±0.1°C, respectively. Significance Although thiol–enes show promise as continuous phases for composite dental restorative materials, they show poor reactivity with the conventional camphorquinone/tertiary amine photoinitiation system. Conversely, despite their relatively low visible light absorptivity, HABI photoinitiators afford rapid thiol–ene photopolymerization rates. Moreover, minor structural modifications suggest pathways for improved HABI solubility and visible light absorption. PMID:26119702

  2. Harness cavitation to improve processing

    SciTech Connect

    Pandit, A.G.; Moholkar, V.S.

    1996-07-01

    Mention cavitation to most chemical engineers, and they undoubtedly think of it as an operational problem. Indeed, the rapid creation and then collapse of bubbles, which is after all what cavitation involves, can destroy pumps and erode other equipment. Cavitation, however, also can have a positive side--presuming it is designed for and not unplanned. In this article, the authors look at how cavitation can be harnessed to improve processes, and the mechanisms for inducing cavitation--ultrasonics and hydrodynamics--and their likely roles. Sonication, that is, the use of ultrasound, is the conventional approach for creating cavitation, and so they turn to it first. Over the past few years, a number of groups have attempted to solve the problem of scale-up and design of ultrasonic reactors. The authors review the systems that already exist and also explore a simpler and efficient alternative to the ultrasonic reactor, the hydrodynamic cavitation reactor.

  3. The diagenetic fate of taraxer-14-ene and oleanene isomers

    NASA Astrophysics Data System (ADS)

    ten Haven, H. L.; Rullkötter, J.

    1988-10-01

    The extractable organic matter in Holocene to early Miocene deep-sea sediments from Site 645 (ODP Leg 105) in Baffin Bay contains almost exclusively biological markers of terrigenous origin. Pentacyclic triterpenoids of the α-(ursene) and β-amyrin (oleanene) type often occur as the most abundant compounds in the aliphatic hydrocarbon, ketone and alcohol fractions of the sediment extract. A specific diagenetic reaction involves the conversion of taraxer-14-ene into olean-12-ene in the upper 700 metres of the sedimentary sequence. The taraxerene-to-oleanene conversion is complete before the onset of isomerisation of diasterenes at C-20. In the sediment as well as in laboratory simulation experiments, olean-12-ene further isomerises to olean-13(18)-ene and olean-18-ene, the latter of which may be the direct precursor of 18β(H)- and 18α(H)-oleanane found in sediments containing more mature organic matter and in crude oils. The subsurface interconversion of these triterpenoid skeletons indicate that oleanane does not necessarily start life as an oleanoid.

  4. Reactive superhydrophobic surface and its photoinduced disulfide-ene and thiol-ene (bio)functionalization.

    PubMed

    Li, Junsheng; Li, Linxian; Du, Xin; Feng, Wenqian; Welle, Alexander; Trapp, Oliver; Grunze, Michael; Hirtz, Michael; Levkin, Pavel A

    2015-01-14

    Reactive superhydrophobic surfaces are highly promising for biotechnological, analytical, sensor, or diagnostic applications but are difficult to realize due to their chemical inertness. In this communication, we report on a photoactive, inscribable, nonwettable, and transparent surface (PAINTS), prepared by polycondensation of trichlorovinylsilane to form thin transparent reactive porous nanofilament on a solid substrate. The PAINTS shows superhydrophobicity and can be conveniently functionalized with the photoclick thiol-ene reaction. In addition, we show for the first time that the PAINTS bearing vinyl groups can be easily modified with disulfides under UV irradiation. The effect of superhydrophobicity of PAINTS on the formation of high-resolution surface patterns has been investigated. The developed reactive superhydrophobic coating can find applications for surface biofunctionalization using abundant thiol or disulfide bearing biomolecules, such as peptides, proteins, or antibodies. PMID:25486338

  5. Thiol-ene/methacrylate systems for mechanical damping

    NASA Astrophysics Data System (ADS)

    McNair, Olivia; Senyurt, Askim; Wei, Huanyu; Gould, Trent; Piland, Scott; Hoyle, Charles; Savin, Daniel

    2010-03-01

    Ternary thiol-ene-methacrylate (TEMA) networks as materials for mechanical energy damping are unique to the sports world. Using a photoinitiation process, TEMA systems are formed via an initial thiol-ene step-growth mechanism along with traditional radical polymerization of acrylate and ene monomers. Final networks have two-part morphologies: acrylate homopolymer sectors imbedded in a multi-component mesh. Several (TEMA) systems have been synthesized and analyzed via thermal and mechanical probing. Initial studies on these ternary systems have shown excellent properties compared to traditional ethylene vinyl alcohol (EVA) copolymers. For example, PEMA networks exhibit glass transition temperatures 33 K higher than EVA, resulting in improved damping at room temperature. This research will help develop relationships between tan delta, glass transition and their effects on mechanical energy damping for ternary (TEMA) systems.

  6. Ambulatory purchasing: harnessing supply costs.

    PubMed

    Jager, P A

    1997-04-01

    The healthcare system remains in a dynamic state of flux. We have all heard the story: the changing healthcare market brings reduced reimbursement for services, increased competition, and steadily increasing supply, maintenance, and equipment costs. Ambulatory surgery centers (ASCs) must keep in sync with this change or fail to survive the current market forces. However, because they represent a small contract to various vendors, many ASCs pay premium prices for inventory while receiving less from Managed Care Plans (MCPs) and Health Maintenance Organizations (HMOs). This dilemma makes control of supply costs a top priority for ASCs. In reality, purchasing is becoming more strategically connected to the ASC balance sheet than ever before. Apart from personnel costs, supply and pharmaceutical purchasing represents the greatest expense category on our financial statement. Harnessing these costs directly relates to bottom line profitability. In addition, while performing cost savings magic, ASCs must maintain patient and surgeon satisfaction with the superior outcomes and state-of-the-art technology their reputations are based upon. Sound impossible? This article details how Surgery Center Plus, Inc. (SCP) implemented a cost containment project. PMID:10167012

  7. A TCP-Over-UDP Test Harness

    SciTech Connect

    Dunigan, TH

    2002-10-31

    This report describes an implementation of a TCP-like protocol that runs over UDP. This TCP-like implementation, which does not require kernel modifications, provides a test harness for evaluating variations of the TCP transport protocol over the Internet. The test harness provides a tunable and instrumented version of TCP that supports Reno, NewReno, and SACK/FACK. The test harness can also be used to characterize the TCP-performance of a network path. Several case studies illustrate how one can tune the transport protocol to improve performance.

  8. Distributed Real-Time Computing with Harness

    SciTech Connect

    Di Saverio, Emanuele; Cesati, Marco; Di Biagio, Christian; Pennella, Guido; Engelmann, Christian

    2007-01-01

    Modern parallel and distributed computing solutions are often built onto a ''middleware'' software layer providing a higher and common level of service between computational nodes. Harness is an adaptable, plugin-based middleware framework for parallel and distributed computing. This paper reports recent research and development results of using Harness for real-time distributed computing applications in the context of an industrial environment with the needs to perform several safety critical tasks. The presented work exploits the modular architecture of Harness in conjunction with a lightweight threaded implementation to resolve several real-time issues by adding three new Harness plug-ins to provide a prioritized lightweight execution environment, low latency communication facilities, and local timestamped event logging.

  9. 14 CFR 91.521 - Shoulder harness.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... inertia load factors established under the certification basis of the airplane. (b) No person may operate... used; and (2) Safety belt and shoulder harness restraint systems may be designed to the inertia...

  10. 14 CFR 91.521 - Shoulder harness.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... inertia load factors established under the certification basis of the airplane. (b) No person may operate... used; and (2) Safety belt and shoulder harness restraint systems may be designed to the inertia...

  11. 14 CFR 91.521 - Shoulder harness.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... inertia load factors established under the certification basis of the airplane. (b) No person may operate... used; and (2) Safety belt and shoulder harness restraint systems may be designed to the inertia...

  12. 14 CFR 91.521 - Shoulder harness.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... inertia load factors established under the certification basis of the airplane. (b) No person may operate... used; and (2) Safety belt and shoulder harness restraint systems may be designed to the inertia...

  13. 14 CFR 91.521 - Shoulder harness.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... inertia load factors established under the certification basis of the airplane. (b) No person may operate... used; and (2) Safety belt and shoulder harness restraint systems may be designed to the inertia...

  14. Derivatives of cardanol through the ene reaction with diethyl azodicarboxylate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cardanol is an alkyl/alkenyl phenolic material obtained from cashew nut shell liquid (CNSL), which is a byproduct of cashew nut processing. In an effort to develop new uses, cardanol was derivatized for the first time with diethyl azodicarboxylate (DEAD) through the ene reaction. The reaction was fa...

  15. Hybrid Organic/Inorganic Thiol-ene-Based Photopolymerized Networks

    PubMed Central

    Schreck, Kathleen M.; Leung, Diana; Bowman, Christopher N.

    2011-01-01

    The thiol-ene reaction serves as a more oxygen tolerant alternative to traditional (meth)acrylate chemistry for forming photopolymerized networks with numerous desirable attributes including energy absorption, optical clarity, and reduced shrinkage stress. However, when utilizing commercially available monomers, many thiol-ene networks also exhibit decreases in properties such as glass transition temperature (Tg) and crosslink density. In this study, hybrid organic/inorganic thiol-ene resins incorporating silsesquioxane (SSQ) species into the photopolymerized networks were investigated as a route to improve these properties. Thiol- and ene-functionalized SSQs (SH-SSQ and allyl-SSQ, respectively) were synthesized via alkoxysilane hydrolysis/condensation chemistry, using a photopolymerizable monomer [either pentaerythriol tetrakis(3-mercaptopropionate) (PETMP) or 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TATATO)] as the reaction solvent. The resulting SSQ-containing solutions (SSQ-PETMP and SSQ-TATATO) were characterized, and their incorporation into photopolymerized networks was evaluated. PMID:21984847

  16. Hybrid Organic/Inorganic Thiol-ene-Based Photopolymerized Networks.

    PubMed

    Schreck, Kathleen M; Leung, Diana; Bowman, Christopher N

    2011-09-15

    The thiol-ene reaction serves as a more oxygen tolerant alternative to traditional (meth)acrylate chemistry for forming photopolymerized networks with numerous desirable attributes including energy absorption, optical clarity, and reduced shrinkage stress. However, when utilizing commercially available monomers, many thiol-ene networks also exhibit decreases in properties such as glass transition temperature (T(g)) and crosslink density. In this study, hybrid organic/inorganic thiol-ene resins incorporating silsesquioxane (SSQ) species into the photopolymerized networks were investigated as a route to improve these properties. Thiol- and ene-functionalized SSQs (SH-SSQ and allyl-SSQ, respectively) were synthesized via alkoxysilane hydrolysis/condensation chemistry, using a photopolymerizable monomer [either pentaerythriol tetrakis(3-mercaptopropionate) (PETMP) or 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TATATO)] as the reaction solvent. The resulting SSQ-containing solutions (SSQ-PETMP and SSQ-TATATO) were characterized, and their incorporation into photopolymerized networks was evaluated. PMID:21984847

  17. Intelligent electrical harness connector assembly using Bell Helicopter Textron's 'Wire Harness Automated Manufacturing System'

    NASA Astrophysics Data System (ADS)

    Springer, D. W.

    Bell Helicopter Textron, Incorporated (BHTI) installed two Digital Equipment Corporation PDP-11 computers and an American Can Inc. Ink Jet printer in 1980 as the cornerstone of the Wire Harness Automated Manufacturing System (WHAMS). WHAMS is based upon the electrical assembly philosophy of continuous filament harness forming. This installation provided BHTI with a 3 to 1 return-on-investment by reducing wire and cable identification cycle time by 80 percent and harness forming, on dedicated layout tooling, by 40 percent. Yet, this improvement in harness forming created a bottle neck in connector assembly. To remove this bottle neck, BHTI has installed a prototype connector assembly cell that integrates the WHAMS' data base and innovative computer technologies to cut harness connector assembly cycle time. This novel connector assembly cell uses voice recognition, laser identification, and animated computer graphics to help the electrician in the correct assembly of harness connectors.

  18. Fabrication and bonding of thiol-ene-based microfluidic devices

    NASA Astrophysics Data System (ADS)

    Sikanen, Tiina M.; Lafleur, Josiane P.; Moilanen, Maria-Elisa; Zhuang, Guisheng; Jensen, Thomas G.; Kutter, Jörg P.

    2013-03-01

    In this work, the bonding strength of microchips fabricated by thiol-ene free-radical polymerization was characterized in detail by varying the monomeric thiol/allyl composition from the stoichiometric ratio (1:1) up to 100% excess of thiol (2:1) or allyl (1:2) functional groups. Four different thiol-ene to thiol-ene bonding combinations were tested by bonding: (i) two stoichiometric layers, (ii) two layers bearing complementary excess of thiols and allyls, (iii) two layers both bearing excess of thiols, or (iv) two layers both bearing excess of allyls. The results showed that the stiffness of the cross-linked polymer plays the most crucial role regarding the bonding strength. The most rigid polymer layers were obtained by using the stoichiometric composition or an excess of allyls, and thus, the bonding combinations (i) and (iv) withstood the highest pressures (up to the cut-off value of 6 bar). On the other hand, excess of thiol monomers yielded more elastic polymer layers and thus decreased the pressure tolerance for bonding combinations (ii) and (iii). By using monomers with more thiol groups (e.g. tetrathiol versus trithiol), a higher cross-linking ratio, and thus, greater stiffness was obtained. Surface characterization by infrared spectroscopy confirmed that the changes in the monomeric thiol/allyl composition were also reflected in the surface chemistry. The flexibility of being able to bond different types of thiol-enes together allows for tuning of the surface chemistry to yield the desired properties for each application. Here, a capillary electrophoresis separation is performed to demonstrate the attractive properties of stoichiometric thiol-ene microchips.

  19. Evidence for distinct dehydrogenase and isomerase sites within a single 3. beta. -hydroxysteroid dehydrogenase/5-ene-4-ene isomerase protein

    SciTech Connect

    Luu-The, V.; Takahashi, Masakazu; de Launoit, Y.; Dumont, M.; Lachance, Y.; Labrie, F. )

    1991-09-10

    Complementary DNA encoding human 3{beta}-hydroxysteroid dehydrogenase/5-ene-4-ene isomerase (3-{beta}-HSD) has been expressed in transfected GH{sub 4}C{sub 1} with use of the cytomegalovirus promoter. The activity of the expressed protein clearly shows that both dehydrogenase and isomerase enzymatic activities are present within a single protein. However, such findings do not indicate whether the two activities reside within one or two closely related catalytic sites. With use of ({sup 3}H)-5-androstenedione, the intermediate compound in dehydroepiandrosterone (DHEA) transformation into 4-androstenedione by 3{beta}-HSD, the present study shows that 4MA (N,N-diethyl-4-methyl-3-oxo-4-aza-5{alpha}-androstane-17{beta}-carboxamide) and its analogues of 5-androstenedione to 4-androstenedione with an approximately 1,000-fold higher K{sub i} value. The present results thus strongly suggest that dehydrogenase and isomerase activities are present at separate sites on the 3-{beta}-HSD protein. Such data suggest that the irreversible step in the transformation of DHEA to 4-androstenedione is due to a separate site possessing isomerase activity that converts the 5-ene-3-keto to a much more stable 4-ene-3-keto configuration.

  20. N,N′-{[Bis(trifluoro­meth­yl)methyl­ene]di-p-phenyl­ene}diphthalimide

    PubMed Central

    Li, Yitao; Wang, Zhiguo

    2008-01-01

    The molecule of the title compound, C31H16F6N2O4, consists of two phthalimide units linked by a [bis­(trifluoro­meth­yl)methyl­ene]di-p-phenyl­ene bridge, with the two halves of the mol­ecule related to each other by a twofold rotation axis. The dihedral angle between the planes of the two central benzene rings is 70.5 (3)°. The terminal isoindole groups are approximately planar, with a maximum r.m.s. deviation of 0.006 Å from the mean plane, and they form dihedral angles of 46.03 (3)° to the attached benzene rings. Inter­molecular C—H⋯O hydrogen bonds link neighboring mol­ecules into chains along the c axis. PMID:21201418

  1. SRB Altitude Switch Assembly Wire Harness Failure

    NASA Astrophysics Data System (ADS)

    Blanche, Jim

    2002-01-01

    This paper presents an assessment of two wire harness failures that had occurred in Solid Rocket Booster Altitude Switch Assemblies S/N 200001 and S/N 20002. A list of modifications to EDU #4 and modification of qualification units 2000001 and 2000002 are also presented.

  2. Seizing the Moment: Harnessing the Information Technologies.

    ERIC Educational Resources Information Center

    Bankes, Steve; And Others

    1992-01-01

    Discusses the scope of the Information Revolution, considers initiatives for harnessing information technology, and proposes a research agenda. Seven appendices detail specific initiatives relating to a global communication network, a Council for North American Information, the news media, a pan-European security information agency, multinational…

  3. Harnessing Collective Knowledge Inherent in Tag Clouds

    ERIC Educational Resources Information Center

    Cress, U.; Held, C.

    2013-01-01

    Tagging systems represent the conceptual knowledge of a community. We experimentally tested whether people harness this collective knowledge when navigating through the Web. As a within-factor we manipulated people's prior knowledge (no knowledge vs. prior knowledge that was congruent/incongruent to the collective knowledge inherent in the tags).…

  4. Harnessing Collaborative Annotations on Online Formative Assessments

    ERIC Educational Resources Information Center

    Lin, Jian-Wei; Lai, Yuan-Cheng

    2013-01-01

    This paper harnesses collaborative annotations by students as learning feedback on online formative assessments to improve the learning achievements of students. Through the developed Web platform, students can conduct formative assessments, collaboratively annotate, and review historical records in a convenient way, while teachers can generate…

  5. Harnessing the Power of Interactivity for Instruction.

    ERIC Educational Resources Information Center

    Borsook, Terry K.

    Arguing that what sets the computer apart from all other teaching devices is its potential for interactivity, this paper examines the concept of interactivity and explores ways in which its power can be harnessed and put to work. A discussion of interactivity in human-to-human communication sets a context within which to view human/computer…

  6. Harness Traction Technique (HARNESS): Novel Method for Controlling the Transection Plane During Laparoscopic Hepatectomy.

    PubMed

    Itano, Osamu; Oshima, Go; Kitago, Minoru; Suzuki, Keiichi; Hayatsu, Shigeo; Shinoda, Masahiro; Abe, Yuta; Hibi, Taizo; Yagi, Hiroshi; Ikoma, Naruhiko; Aiko, Satoshi; Kitagawa, Yuko

    2015-08-01

    We present our experience using a novel method for controlling the transection plane, which we termed as the Harness Traction Technique (HARNESS) and evaluate its usefulness. From May 2009 to March 2012, laparoscopic hepatectomies using HARNESS were performed on 35 patients. After the superficial hepatic parenchyma on the line was transected at 1 to 2 cm depth, 5 mm tape was placed along the groove of the line and tied to prevent it from slipping off. Tape was tied and pulled using a forceps toward the best direction for minimizing the bleeding, moving the transection point to the appropriate position and creating good tension for parenchymal transection at the transection point. There were no conversions to laparotomy or intraoperative complications. HARNESS is useful for controlling the dissection line during laparoscopic hepatectomy, leading to precise and safe laparoscopic liver parenchymal dissection. PMID:26121541

  7. 46 CFR 197.324 - Diver's safety harness.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.324 Diver's safety harness. Each safety harness used in surface-supplied diving must have— (a) A positive buckling device; and (b) An...

  8. 46 CFR 197.324 - Diver's safety harness.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.324 Diver's safety harness. Each safety harness used in surface-supplied diving must have— (a) A positive buckling device; and (b) An...

  9. 46 CFR 197.324 - Diver's safety harness.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.324 Diver's safety harness. Each safety harness used in surface-supplied diving must have— (a) A positive buckling device; and (b) An...

  10. 46 CFR 197.324 - Diver's safety harness.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.324 Diver's safety harness. Each safety harness used in surface-supplied diving must have— (a) A positive buckling device; and (b) An...

  11. 46 CFR 197.324 - Diver's safety harness.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.324 Diver's safety harness. Each safety harness used in surface-supplied diving must have— (a) A positive buckling device; and (b) An...

  12. Characterization of Thiol-Ene Crosslinked PEG Hydrogels

    PubMed Central

    Toepke, Michael W.; Impellitteri, Nicholas A.; Theisen, Jeffrey M.

    2014-01-01

    The properties of synthetic hydrogels can be tuned to address the needs of many tissue-culture applications. This work characterizes the swelling and mechanical properties of thiol-ene crosslinked PEG hydrogels made with varying prepolymer formulations, demonstrating that hydrogels with a compressive modulus exceeding 600 kPa can be formed. The amount of peptide incorporated into the hydrogel is shown to be proportional to the amount of peptide in the prepolymer solution. Cell attachment and spreading on the surface of the peptide-functionalized hydrogels is demonstrated. Additionally, a method for bonding distinct layers of cured hydrogels is used to create a microfluidic channel. PMID:24883041

  13. Occurrence and significance of prist-1-ene in kerogen pyrolysates.

    PubMed

    Larter, S R; Solli, H; Douglas, A G; DE Lange, F; DE Leeuw, J W

    1979-05-31

    A SERIES of acylic isoprenoid alkanes, of which pristane and phytane are typical, frequently occurs in crude oils, shales, coals, bitumens and so on. It is generally agreed that the primary source of these compounds is the phytyl side chain of chlorophyll(1,2) although the mechanisms of its incorporation into sediments and its subsequent diagenesis, are not completely understood. At present, little is known about the role of kerogen as a source, or sink, of isoprenoid moieties and we report here that the principal isoprenoid, obtained by the high temperature (600 degrees C) pyrolysis of kerogens has been identified as prist-1-ene. PMID:16068167

  14. N,N′-(Oxydi-p-phenyl­ene)diphthalimide

    PubMed Central

    Li, Yi-Tao; Wang, Zhiguo

    2008-01-01

    The title compound, C28H16N2O5, is a bis-imide derivative in which two phthalimide units are linked by an oxydi-p-phenyl­ene bridge. The dihedral angle between the planes of the two central benzene rings is 86.1 (4)°. The isoindole groups make dihedral angles of 46.0 (14) and 77.5 (13)° with the attached benzene rings. Inter­molecular C—H⋯O hydrogen bonds contribute to the stability of the structure. PMID:21200954

  15. 42 CFR 84.178 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Head harnesses; minimum requirements. 84.178... Air-Purifying Particulate Respirators § 84.178 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension...

  16. 42 CFR 84.121 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Head harnesses; minimum requirements. 84.121... § 84.121 Head harnesses; minimum requirements. (a) Facepieces shall be equipped with adjustable and replaceable head harnesses, designed and constructed to provide adequate tension during use and an...

  17. 42 CFR 84.1138 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Head harnesses; minimum requirements. 84.1138... Gas Masks § 84.1138 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension during use and an even...

  18. 42 CFR 84.138 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Head harnesses; minimum requirements. 84.138... Respirators § 84.138 Head harnesses; minimum requirements. Facepieces shall be equipped with adjustable and replaceable head harnesses which are designed and constructed to provide adequate tension during use, and...

  19. 42 CFR 84.1138 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Head harnesses; minimum requirements. 84.1138... Gas Masks § 84.1138 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension during use and an even...

  20. 42 CFR 84.178 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Head harnesses; minimum requirements. 84.178... Air-Purifying Particulate Respirators § 84.178 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension...

  1. 42 CFR 84.121 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Head harnesses; minimum requirements. 84.121... § 84.121 Head harnesses; minimum requirements. (a) Facepieces shall be equipped with adjustable and replaceable head harnesses, designed and constructed to provide adequate tension during use and an...

  2. 42 CFR 84.78 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Head harnesses; minimum requirements. 84.78 Section...-Contained Breathing Apparatus § 84.78 Head harnesses; minimum requirements. (a) Facepieces shall be equipped with adjustable and replaceable head harnesses designed and constructed to provide adequate...

  3. 42 CFR 84.178 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Head harnesses; minimum requirements. 84.178... Air-Purifying Particulate Respirators § 84.178 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension...

  4. 42 CFR 84.138 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Head harnesses; minimum requirements. 84.138... Respirators § 84.138 Head harnesses; minimum requirements. Facepieces shall be equipped with adjustable and replaceable head harnesses which are designed and constructed to provide adequate tension during use, and...

  5. 42 CFR 84.1138 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Head harnesses; minimum requirements. 84.1138... Gas Masks § 84.1138 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension during use and an even...

  6. 42 CFR 84.78 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Head harnesses; minimum requirements. 84.78 Section...-Contained Breathing Apparatus § 84.78 Head harnesses; minimum requirements. (a) Facepieces shall be equipped with adjustable and replaceable head harnesses designed and constructed to provide adequate...

  7. 42 CFR 84.178 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Head harnesses; minimum requirements. 84.178... Air-Purifying Particulate Respirators § 84.178 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension...

  8. 42 CFR 84.121 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Head harnesses; minimum requirements. 84.121... § 84.121 Head harnesses; minimum requirements. (a) Facepieces shall be equipped with adjustable and replaceable head harnesses, designed and constructed to provide adequate tension during use and an...

  9. 42 CFR 84.178 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Head harnesses; minimum requirements. 84.178... Air-Purifying Particulate Respirators § 84.178 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension...

  10. 42 CFR 84.78 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Head harnesses; minimum requirements. 84.78 Section...-Contained Breathing Apparatus § 84.78 Head harnesses; minimum requirements. (a) Facepieces shall be equipped with adjustable and replaceable head harnesses designed and constructed to provide adequate...

  11. 42 CFR 84.138 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Head harnesses; minimum requirements. 84.138... Respirators § 84.138 Head harnesses; minimum requirements. Facepieces shall be equipped with adjustable and replaceable head harnesses which are designed and constructed to provide adequate tension during use, and...

  12. 42 CFR 84.1138 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Head harnesses; minimum requirements. 84.1138... Gas Masks § 84.1138 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension during use and an even...

  13. 42 CFR 84.78 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Head harnesses; minimum requirements. 84.78 Section...-Contained Breathing Apparatus § 84.78 Head harnesses; minimum requirements. (a) Facepieces shall be equipped with adjustable and replaceable head harnesses designed and constructed to provide adequate...

  14. 42 CFR 84.1138 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Head harnesses; minimum requirements. 84.1138... Gas Masks § 84.1138 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension during use and an even...

  15. 42 CFR 84.121 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Head harnesses; minimum requirements. 84.121... § 84.121 Head harnesses; minimum requirements. (a) Facepieces shall be equipped with adjustable and replaceable head harnesses, designed and constructed to provide adequate tension during use and an...

  16. 42 CFR 84.138 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Head harnesses; minimum requirements. 84.138... Respirators § 84.138 Head harnesses; minimum requirements. Facepieces shall be equipped with adjustable and replaceable head harnesses which are designed and constructed to provide adequate tension during use, and...

  17. 42 CFR 84.138 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Head harnesses; minimum requirements. 84.138... Respirators § 84.138 Head harnesses; minimum requirements. Facepieces shall be equipped with adjustable and replaceable head harnesses which are designed and constructed to provide adequate tension during use, and...

  18. 42 CFR 84.78 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Head harnesses; minimum requirements. 84.78 Section...-Contained Breathing Apparatus § 84.78 Head harnesses; minimum requirements. (a) Facepieces shall be equipped with adjustable and replaceable head harnesses designed and constructed to provide adequate...

  19. 42 CFR 84.121 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Head harnesses; minimum requirements. 84.121... § 84.121 Head harnesses; minimum requirements. (a) Facepieces shall be equipped with adjustable and replaceable head harnesses, designed and constructed to provide adequate tension during use and an...

  20. Photopolymerizable thiol-ene nanocomposite materials for holographic applications

    NASA Astrophysics Data System (ADS)

    Tomita, Yasuo; Hata, Eiji; Yasui, Satoru; Mitsube, Ken

    2011-06-01

    We describe an experimental investigation of the photopolymerization kinetics and volume holographic recording characteristics of silica nanoparticle-polymer nanocomposites using thiol-ene monomers capable of step-growth polymerization. We characterize the visible light curing kinetics of a thiol-ene monomer system consisting of secondary dithiol with high self-life stability and low odor and triene with rigid structure and high electron density by using real-time Fourier transform spectroscopy and photocalorimetry. In plane-wave volume holographic recording at a wavelength of 532 nm it is shown that while volume holograms recorded in the nanocomposites exhibit high transparency, their saturated refractive index modulation (Δnsat) and material sensitivity (S) are as large as 1x10-2 and 1615 cm/J, respectively. The polymerization shrinkage is reduced as low as 0.4% as a result of the late gelation in conversion. These values meet the acceptable values for holographic data storage media (i.e., 5x10-3, 500 cm/J and 0.5% for Δnsat, S and shrinkage, respectively). The improved thermal stability of volume holograms recorded in the nanocomposites is also confirmed experimentally.

  1. Behavior of sandhill cranes harnessed with different satellite transmitters

    USGS Publications Warehouse

    Olsen, G.H.; Ellis, D.H.; Landfried, S.E.; Miller, L.H.; Klugman, S.S.; Fuller, M.R.; Vermillion, C.H.

    1992-01-01

    The effectiveness of various attachment methods and designs of platform transmitting terminals (PTT's) was tested on captive sandhill cranes (Grus canadensis) at the Patuxent Wildlife Research Center, Laurel, Maryland, during 1989-91. Combinations of attachment and transmitter designs included neoprene cord harness with batteries separate from the transmitter (2 harness designs), Teflon ribbon harness with batteries incorporated into the transmitter package (4 transmitter models), and a package attached directly to the bird with epoxy glue only. Physical effects seen on cranes wearing PTT's ranged from skin lacerations (caused by rubbing of harness material) to no observed effects (other than feather wear). The most successful harness material and design utilized a Teflon ribbon harness with the 4 ribbon ends from the transmitter forming a neck loop and a body loop joined at the sternum. Time spent by sandhill cranes performing most activities did not change after transmitter attachment using this harness method.

  2. Harnessing the Microbiome to Enhance Cancer Immunotherapy

    PubMed Central

    Nelson, Michelle H.; Diven, Marshall A.; Huff, Logan W.; Paulos, Chrystal M.

    2015-01-01

    The microbiota plays a key role in regulating the innate and adaptive immune system. Herein, we review the immunological aspects of the microbiota in tumor immunity in mice and man, with a focus on toll-like receptor (TLR) agonists, vaccines, checkpoint modulators, chemotherapy, and adoptive T cell transfer (ACT) therapies. We propose innovative treatments that may safely harness the microbiota to enhance T cell-based therapies in cancer patients. Finally, we highlight recent developments in tumor immunotherapy, particularly novel ways to modulate the microbiome and memory T cell responses to human malignancies. PMID:26101781

  3. Functional graphene by thiol-ene click chemistry.

    PubMed

    Luong, Nguyen Dang; Sinh, Le Hoang; Johansson, Leena-Sisko; Campell, Joseph; Seppälä, Jukka

    2015-02-16

    Thiol-ene click reaction was successfully employed for chemical modification of graphene oxide (GO) by one-step synthesis. Herein, 2,2-azobis(2-methylpropionitrile) (AIBN) was used as thermal catalyst and cysteamine hydrochloride (HS-(CH2 )2 -NH2 HCl) was used as thiol-containing compound, which is incorporated to GO surface upon reaction with the C=C bonds. The hydrochloride acts as protecting group for the amine, which is finally eliminated by adding sodium hydroxide. The modified GO contains both S- and N-containing groups (NS-GO). We found that NS-GO sheets form good dispersion in water, ethanol, and ethylene glycol. These graphene dispersions can be processed into functionalized graphene film. Besides, it was demonstrated that NS-GO was proved to be an excellent host matrix for platinum nanoparticles. The developed method paves a new way for graphene modification and its functional nanocomposites. PMID:25580698

  4. Tetramethyl-1-silacycloprop-2-ene: its characterization and reactions

    SciTech Connect

    Cornett, B.J.

    1980-05-01

    The object of this research is to fully characterize and study some of the reactions of tetramethyl-1-silacycloprop-2-ene. The final characterization of this compound was accomplished by obtaining both Si29 and 13C nuclear magnetic resonance spectra. The reactions studied included those with fluorenone, acetone, styrene, phenylacetylene, acetonitrile, t-butylcyanide, methyl isocyanate, phenyl azide, and azobenzene. Product analyses suggest that aside from addition reactions tetramethylsilacyclopropene can react either via a radical chain polymerization or an anionic chain polymerization mechanism with the latter being the more prevalent. Other reactions studied included the photolysis of tetramethylsilacyclopropene and its reactions in the presence of Pd(PPh/sub 3/)/sub 2/Cl/sub 2/. An appendix includes a study of trimethylsilyl radical disproportionation in the liquid phase to a sila olefin. Trimethylsilyl radicals in solution undergo disproportionation as well as recombination in a 1:5 ratio. The sila olefin formed by disproportionation was trapped by alcohols.

  5. 5-Ene-4-thiazolidinones induce apoptosis in mammalian leukemia cells.

    PubMed

    Senkiv, Julia; Finiuk, Nataliya; Kaminskyy, Danylo; Havrylyuk, Dmytro; Wojtyra, Magdalena; Kril, Iryna; Gzella, Andrzej; Stoika, Rostyslav; Lesyk, Roman

    2016-07-19

    The article presents the synthesis of 5-ene-4-thiazolidinone derivatives with pyrazole core linked by enamine group. The structure and purity of compounds were confirmed by analytical and spectral data including X-ray analysis. Target compounds were screened for their anticancer activity and selective antileukemic action was confirmed. 5-[5-(2-Hydroxyphenyl)-3-phenyl-4,5-dihydropyrazol-1-ylmethylene]-3-(3-acetoxyphenyl)-2-thioxothiazolidin-4-one (compound 1) was selected as most active agent against HL-60 and HL-60/ADR cell lines; IC50 = 118 nM/HL-60 with low toxicity towards pseudonormal cells. The mitochondria-depended apoptosis was identified as the main mode of 1 action. Moreover compound's effect induces G0/G1 arrest of the treated cells and causes inhibition of cell division and is related with activation of ROS production. PMID:27089210

  6. Understanding the polar mechanism of the ene reaction. A DFT study.

    PubMed

    Domingo, Luis R; Aurell, Maria J; Pérez, Patricia

    2014-10-14

    The molecular mechanism of ene reactions has been characterised by DFT methods at the MPWB1K/6-311G(d,p) level of theory. Most reactions take place along a two-stage one-step mechanism in which the C-C bond formation takes place before the hydrogen transfer process. A very good correlation between the polar character of the reaction measured by the global electron density transfer at the transition state and the activation energy has been found. This behaviour allows establishing a useful classification of ene reactions in N-ene having a very high activation energy, P-ene reactions having activation energies between 35 and 20 kcal mol(-1), and H-ene reactions having activation energies below 20 kcal mol(-1). ELF topological analysis allows the characterisation of the two-stage one-step mechanism associated with a two-centre nucleophilic/electrophilic interaction. Formation of the C-C single bond is achieved by the C-to-C coupling of two pseudoradical centres formed at the two interacting carbon atoms in the first stage of the reaction. This topological analysis establishes that bonding changes are non-concerted. Finally, a DFT reactivity analysis makes it possible to characterise the electrophilic/nucleophilic behaviour of the reagents involved in ene reactions, and consequently, to predict the feasibility of ene reactions. PMID:25139695

  7. Harnessing microtubule dynamic instability for nanostructure assembly.

    SciTech Connect

    Bouchard, Ann Marie; Osbourn, Gordon Cecil

    2004-06-01

    Intracellular molecular machines synthesize molecules, tear apart others, transport materials, transform energy into different forms, and carry out a host of other coordinated processes. Many molecular processes have been shown to work outside of cells, and the idea of harnessing these molecular machines to build nanostructures is attractive. Two examples are microtubules and motor proteins, which aid cell movement, help determine cell shape and internal structure, and transport vesicles and organelles within the cell. These molecular machines work in a stochastic, noisy fashion: microtubules switch randomly between growing and shrinking in a process known as dynamic instability; motor protein movement along microtubules is randomly interrupted by the motor proteins falling off. A common strategy in attempting to gain control over these highly dynamic, stochastic processes is to eliminate some processes (e.g., work with stabilized microtubules) in order to focus on others (interaction of microtubules with motor proteins). In this paper, we illustrate a different strategy for building nanostructures, which, rather than attempting to control or eliminate some dynamic processes, uses them to advantage in building nanostructures. Specifically, using stochastic agent-based simulations, we show how the natural dynamic instability of microtubules can be harnessed in building nanostructures, and discuss strategies for ensuring that 'unreliable' stochastic processes yield a robust outcome.

  8. Readout fidelity of coaxial holographic digital data page recording in nanoparticle–(thiol–ene) polymer composites

    NASA Astrophysics Data System (ADS)

    Nagaya, Kohta; Hata, Eiji; Tomita, Yasuo

    2016-09-01

    We report on an experimental investigation of nanoparticle-concentration and thiol-to-ene stoichiometric ratio dependences of symbol error rates (SERs) and signal-to-noise ratios (SNRs) of digital data pages recorded at a wavelength of 532 nm in thiol–ene based nanoparticle–polymer composite (NPC) films by using a coaxial holographic digital data storage method. We show that SERs and SNRs at the optimized material condition can be lower than 1 × 10‑4 and higher than 10, respectively, without error correction coding. These results show the usefulness of thiol–ene based NPCs as coaxial holographic data storage media.

  9. Synthesis and Chemistry of Bicyclo[4.1.0]hept-1,6-ene.

    PubMed

    Billups, W. E.; Luo, Weimei; Lee, Gon-Ann; Chee, Jennifer; Arney, Benny E.; Wiberg, K. B.; Artis, Dean R.

    1996-01-26

    Bicyclo[4.1.0]hept-1,6-ene has been generated by elimination of 1-chloro-2-(trimethysilyl)bicyclo[4.1.0]heptane in the gas phase over solid fluoride at 25 degrees C. The cyclopropene dimerizes by a rapid ene reaction forming two diastereomeric cyclopropenes. In tetrahydrofuran or chloroform the ene dimers couple to form a single crystalline triene tetramer, whereas a mixture of tricyclohexane tetramers is formed when the neat dimers are allowed to warm to room temperature. Oxidation by dimethyldioxirane or dioxygen gives carbonyl products. Quantum mechanical calculations yielded an increase in strain of approximately 17 kcal/mol over that for 1,2-dimethylcyclopropene. The potential enegy barrier to flexing (folding) along the fused double bond of bicyclo[4.1.0]hept-1,6-ene is only approximately 1 kcal/mol at the highest level of theory investigated. PMID:11667002

  10. Manufacturing and quality control of interconnecting wire harnesses, Volume 4

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The document covers interconnecting wire harnesses defined in the design standard, including type 8, flat conductor cable. Volume breadth covers installations of groups of harnesses in a major assembly and the associated post installation inspections and electrical tests. Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into this document.

  11. Interfacial thiol-ene photo-click reactions for forming multilayer hydrogels

    PubMed Central

    Shih, Han; Fraser, Andrew K.; Lin, Chien-Chi

    2014-01-01

    Interfacial visible light-mediated thiol-ene photo-click reactions were developed for preparing step-growth hydrogels with multilayer structures. The effect of a non-cleavage type photoinitiator eosin-Y on visible light-mediated thiol-ene photopolymerization was first characterized using in situ photo-rheometry, gel fraction, and equilibrium swelling ratio. Next, spectrophotometric properties of eosin-Y in the presence of various relevant macromer species were evaluated using UV/Vis spectrometry. It was determined that eosin-Y was able to re-initiate thiol-ene photo-click reaction even after light exposure. Due to its small molecular weight, most eosin-Y molecules readily leached out from the hydrogels. The diffusion of residual eosin-Y from pre-formed hydrogels was exploited for fabricating multilayer step-growth hydrogels. Interfacial hydrogel coating was formed via the same visible light-mediated gelation mechanism without adding fresh initiator. The thickness of the thiol-ene gel coating could be easily controlled by adjusting visible light exposure time, eosin-Y concentration initially loaded in the core gel, or macromer concentration in the coating solution. The major benefits of this interfacial thiol-ene coating system include its simplicity and cytocompatibility. The formation of thiol-ene hydrogels and coatings neither requires nor generates any cytotoxic components. This new gelation chemistry may have great utilities in controlled release of multiple sensitive growth factors and encapsulation of multiple cell types for tissue regeneration. PMID:23384151

  12. Direct thiol-ene photocoating of polyorganosiloxane microparticles.

    PubMed

    Kuttner, Christian; Maier, Petra C; Kunert, Carmen; Schlaad, Helmut; Fery, Andreas

    2013-12-31

    This work presents the modification of polyorganosiloxane microparticles by surface-initiated thiol-ene photochemistry. By this photocoating, we prepared different core/shell particles with a polymeric shell within narrow size distributions (PDI = 0.041-0.12). As core particle, we used highly monodisperse spherical polyorganosiloxane particles prepared from (3-mercaptopropyl)trimethoxysilane (MPTMS) with a radius of 0.49 μm. We utilize the high surface coverage of mercaptopropyl functions to generate surface-localized radicals upon irradiation with UVA-light without additional photoinitiator. The continuous generation of radicals was followed by a dye degradation experiment (UV/vis spectroscopy). Surface-localized radicals were used as copolymer anchoring sites ("grafting-onto" deposition of different PB-b-PS diblock copolymers) and polymerization initiators ("grafting-from" polymerization of PS). Photocoated particles were characterized for their morphology (SEM, TEM), size, and size distribution (DLS). For PS-coated particles, the polymer content (up to 24% in 24 h) was controlled by the polymerization time upon UVA exposure. The coating thickness was evaluated by thermogravimetric analysis (TGA) using a simple analytical core/shell model. Raman spectroscopy was applied to directly follow the time-dependent consumption of thiols by photoinitiation. PMID:24320891

  13. Antifibrotic and anticancer action of 5-ene amino/iminothiazolidinones.

    PubMed

    Kaminskyy, Danylo; den Hartog, Gertjan J M; Wojtyra, Magdalena; Lelyukh, Maryan; Gzella, Andrzej; Bast, Aalt; Lesyk, Roman

    2016-04-13

    Here we describe the synthesis and the antifibrotic and anticancer activity determination of amino(imino)thiazolidinone derivatives. An efficient one-pot three-component reaction which involved [2 + 3]-cyclocondensation and Knoevenagel condensation was used for the synthesis of 5-ene-2-amino(imino)-4-thiazolidinones. Following amino-imino tautomerism, the compound structures were confirmed by X-ray analysis. Comparison of SRB assays on fibroblasts and cancer cells revealed that compounds which significantly reduced the viability of fibroblasts did not possess an anticancer effect. A series of thiazolidinone derivatives as interesting candidates for further testing has been identified. Among the tested compounds 2-{3-furan-2-ylmethyl-2-[(2-methyl-3-phenylallylidene)hydrazono]-thiazolidin-4-one-5-yl}-N-(3-trifluoromethylphenyl)-acetamide (5), N-(2-methoxyphenyl)-2-[5-(4-oxothiazolidin-2-ylideneamino)-[1,3,4]thiadiazol-2-ylsulfanyl]-acetamide (12), 3-[3-allyl-4-oxo-2-(thiazol-2-ylimino)thiazolidin-5-ylidene]-1,3-dihydroindol-2-one (33), and 5(Z)-(thiophen-2-ylmethylene)-4-(4-chlorophenylamino)thiazol-2(5H)-one (34) possessed high antifibrotic activity levels, had a similar effect as Pirfenidone, and did not scavenge superoxide radicals. Their antifibrotic potential was confirmed using the xCelligence system. PMID:26896707

  14. Registration of two double rust resistant germplasms, HA-R12 and HA-R13 for confection sunflower

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The confection sunflower (Helianthus annuus L.) germplasms HA-R12 (Reg. No. ______, PI 673104) and HA-R13 (Reg. No. ______, PI 673105) were developed by the USDA-ARS, Sunflower and Plant Biology Research Unit in collaboration with the North Dakota Agricultural Experiment Station, and released in Jul...

  15. Registration of two confection sunflower germplasm Lines, HA-R10 and HA-R11, Resistant to sunflower rust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two confection sunflower (Helianthus annuus L.) germplasm lines, HA-R10 (Reg. No.xxx, PI670043) and HA-R11 (Reg. No.xxx, PI670044) were developed by the USDA-ARS Sunflower and Plant Biology Research Unit in collaboration with the North Dakota Agricultural Experiment Station and released December, 20...

  16. Small-scale polymer structures enabled by thiol-ene copolymer systems

    NASA Astrophysics Data System (ADS)

    Kasprzak, Scott Edward

    2009-12-01

    The research described herein is aimed at exploring the thermomechanical properties of thiol-ene polymers in bulk form, investigating the ability of thiol-ene polymers to behave desirably as photolithographic media, and providing the first characterization of the mechanical properties of two-photon stereolithography-produced polymer structures. The thiol-ene polymerization reaction itself is well-characterized and described in the literature, but the thermomechanical properties of thiol-ene and thiol-ene/acrylate polymers still require more rigorous study. Understanding the behavior of thiol-ene networks is a crucial step towards their expanded use in bulk form, and particularly in specialized applications such as shape memory devices. Additionally, the thiol-ene polymerization reaction mechanism exhibits unique properties which make these polymers well suited to photolithography, overcoming the typical dichotomy of current materials which either exhibit excellent photolithographic behavior or have controllable properties. Finally, before two-photon stereolithography can create mechanisms and devices which can serve any mechanically functional role, the mechanical properties of the polymers they produce must be quantitatively characterized, which is complicated by the extremely small scale at which these structures are produced. As such, mechanical characterization to date has been strictly qualitative. Fourier transfer infrared spectroscopy revealed functional group conversion information and sol-fraction testing revealed the presence of unconverted monomer and impurities, while dynamic mechanical analysis (DMA) and tensile testing revealed the thermomechanical responses of the systems. Nanoindentation was employed to characterize the mechanical properties of micrometer-scale polymer structures produced by two-photon stereolithography. Optical and electron microscopy were exploited to provide both quantitative and qualitative evaluations of thiol-ene/acrylate and

  17. Harnessing Listeria monocytogenes to target tumors

    PubMed Central

    Gravekamp, Claudia; Paterson, Yvonne

    2010-01-01

    Because of its cytosolic localization, Listeria monocytogenes (LM) has long been considered an attractive tool for delivering tumor-associated antigens (TAA) antigens in vivoto combat cancer. LM directly infects antigen-presenting cells (APC) such as monocytes, macrophages and dendritic cells (DC), thereby delivering the TAA into their cytoplasm, resulting in processing, and presentation of the antigen to the immune system. This activates adaptive and innate immune responses to the TAA, mediating tumor cell cytolysis. Recently we discovered additional pathways by which Listeria can be harnessedto induce tumor cell death, which suggest new directions in the development of vaccines or therapies against cancer. In one approach, we have used Listeria to induce immune responses that destroy tumor vasculature. Another new pathway involves selective infection of cancer cells with Listeria, followed by tumor cell death through the production of high levels of reactive oxygen species (ROS) and through Listeria-specific cytotoxic T lymphocytes (CTL). This review will focus on the most recent studies on the multiple pathways of LM and how they can be harnessed in the battle against cancer. PMID:20139702

  18. Comparative characterization of novel ene-reductases from cyanobacteria.

    PubMed

    Fu, Yilei; Castiglione, Kathrin; Weuster-Botz, Dirk

    2013-05-01

    The growing importance of biocatalysis in the syntheses of enantiopure molecules results from the benefits of enzymes regarding selectivity and specificity of the reaction and ecological issues of the process. Ene-reductases (ERs) from the old yellow enzyme family have received much attention in the last years. These flavo-enzymes catalyze the trans-specific reduction of activated C=C bonds, which is an important reaction in asymmetric synthesis, because up to two stereogenic centers can be created in one reaction. However, limitations of ERs described in the literature such as their moderate catalytic activity and their strong preference for NADPH promote the search for novel ERs with improved properties. In this study, we characterized nine novel ERs from cyanobacterial strains belonging to different taxonomic orders and habitats. ERs were identified with activities towards a broad spectrum of alkenes. The reduction of maleimide was catalyzed with activities of up to 35.5 U mg(-1) using NADPH. Ketoisophorone and (R)-carvone, which were converted to the highly valuable compounds (R)-levodione and (2R,5R)-dihydrocarvone, were reduced with reaction rates of up to 2.2 U mg(-1) with NADPH. In contrast to other homologous ERs from the literature, NADH was accepted at moderate to high rates as well: Enzyme activities of up to 16.7 U mg(-1) were obtained for maleimide and up to 1.3 U mg(-1) for ketoisophorone and (R)-carvone. Additionally, excellent stereoselectivities were achieved in the reduction of (R)-carvone (97-99% de). In particular, AnabaenaER3 from Anabaena variabilis ATCC 29413 and AcaryoER1 from Acaryochloris marina MBIC 11017 were identified as useful biocatalysts. Therefore, novel ERs from cyanobacteria with high catalytic efficiency were added to the toolbox for the asymmetric reduction of alkenes. PMID:23280373

  19. SSME Electrical Harness and Cable Development and Evolution

    NASA Technical Reports Server (NTRS)

    Abrams, Russ; Heflin, Johnny; Burns, Bob; Camper, Scott J.; Hill, Arthur J.

    2010-01-01

    The Space Shuttle Main Engine (SSME) electrical harness and cable system consists of the various interconnecting devices necessary for operation of complex rocket engine functions. Thirty seven harnesses incorporate unique connectors, backshell adapters, conductors, insulation, shielding, and physical barriers for a long maintenance-free life while providing the means to satisfy performance requirements and to mitigate adverse environmental influences. The objective of this paper is to provide a description of the SSME electrical harness and cable designs as well as the development history and lessons learned.

  20. High Performance Computing with Harness over InfiniBand

    SciTech Connect

    Valentini, Alessandro; Di Biagio, Christian; Batino, Fabrizio; Pennella, Guido; Palma, Fabrizio; Engelmann, Christian

    2009-01-01

    Harness is an adaptable and plug-in-based middleware framework able to support distributed parallel computing. By now, it is based on the Ethernet protocol which cannot guarantee high performance throughput and real time (determinism) performance. During last years, both, the research and industry environments have developed new network architectures (InfiniBand, Myrinet, iWARP, etc.) to avoid those limits. This paper concerns the integration between Harness and InfiniBand focusing on two solutions: IP over InfiniBand (IPoIB) and Socket Direct Protocol (SDP) technology. They allow the Harness middleware to take advantage of the enhanced features provided by the InfiniBand Architecture.

  1. Harnessing Earth Observations for Disaster Application Science

    NASA Astrophysics Data System (ADS)

    Green, D. S.

    2015-12-01

    Earth observations have made substantive contributions to the understanding of natural hazards, answering key science questions on the mechanisms, processes and dynamics of changes in the land, air and water. This has been achieved through the ability to advance models and interpret the results through maps and assessments. Disaster application science is focused on the two-way flow of data and information between hazard understanding and the knowledge required for disaster response, relief and recovery. This presentation will examine the integration of results from mature science and technology development in areas including optical imagery, synthetic-aperture radar and geodetic sensors, which together provide new levels of situational awareness. Specific examples will be highlighted from the recent Nepal "Gorkha" earthquake. Optical imagery from a host of satellite missions was used to create a comprehensive mosaic across the region, which when analyzed by a global network of volunteer scientists yielded insight into the extent of induced hazards and impacts. In some cases unique day/night band images provided guidance on areas where energy-dependent infrastructure of livelihoods were disrupted. Earthquake modeling and historical trend analysis revealed areas of potential vulnerability and combined with aftershock analysis to guide areas for urgent analysis and action. The combination of SAR and GPS data, innovative integration and processing approaches and nontraditional data integration approaches resulted in damage proxy maps or where combination with airborne photography, field sightings and crowd sourced reports to assess susceptibility to induced hazards (floods and landslides). Opportunities and challenges to build the science and community relationships, harness the earth observations from multiple agencies and institutions and co-develop timely applications to users will be areas for ongoing collaboration and study.Earth observations have made

  2. Harnessing quantum transport by transient chaos.

    PubMed

    Yang, Rui; Huang, Liang; Lai, Ying-Cheng; Grebogi, Celso; Pecora, Louis M

    2013-03-01

    Chaos has long been recognized to be generally advantageous from the perspective of control. In particular, the infinite number of unstable periodic orbits embedded in a chaotic set and the intrinsically sensitive dependence on initial conditions imply that a chaotic system can be controlled to a desirable state by using small perturbations. Investigation of chaos control, however, was largely limited to nonlinear dynamical systems in the classical realm. In this paper, we show that chaos may be used to modulate or harness quantum mechanical systems. To be concrete, we focus on quantum transport through nanostructures, a problem of considerable interest in nanoscience, where a key feature is conductance fluctuations. We articulate and demonstrate that chaos, more specifically transient chaos, can be effective in modulating the conductance-fluctuation patterns. Experimentally, this can be achieved by applying an external gate voltage in a device of suitable geometry to generate classically inaccessible potential barriers. Adjusting the gate voltage allows the characteristics of the dynamical invariant set responsible for transient chaos to be varied in a desirable manner which, in turn, can induce continuous changes in the statistical characteristics of the quantum conductance-fluctuation pattern. To understand the physical mechanism of our scheme, we develop a theory based on analyzing the spectrum of the generalized non-Hermitian Hamiltonian that includes the effect of leads, or electronic waveguides, as self-energy terms. As the escape rate of the underlying non-attracting chaotic set is increased, the imaginary part of the complex eigenenergy becomes increasingly large so that pointer states are more difficult to form, making smoother the conductance-fluctuation pattern. PMID:23556962

  3. Characterization of photopolymerizable nanoparticle-(thiol-ene) polymer composites for volume holographic recording at 404 nm

    NASA Astrophysics Data System (ADS)

    Kawana, Masaru; Takahashi, Jun-ichiro; Yasui, Satoru; Tomita, Yasuo

    2014-05-01

    We report on volume holographic recording in thiol-ene based nanoparticle-polymer composites (NPCs) at a wavelength of 404 nm by using a highly coherent blue diode laser. We study the photopolymerization dynamics of two types of thiol-ene based NPCs doped with different blue-sensitive initiator/sensitizer systems (Darocur ® TPO and Irgacure ® 784/BzO2) at various doping concentrations. We also characterize a volume holographic grating recorded in these two types of thiol-ene based NPCs. Such material characterization includes the refractive index modulation, the material recording sensitivity and polymerization shrinkage. It is shown that Darocur R _ TPO provides larger refractive index modulation and higher material recording sensitivity than those with Irgacure ® 784/BzO2 but these two blue-sensitive initiator/sensitizer systems amount to meeting the requirements of the refractive index modulation and the material recording sensitivity for holographic data storage. However, it is found that shrinkage reduction of a volume grating recorded in these two types of thiol-ene based NPCs at 404 nm is not as effective as the same thiol-ene based NPC doped with Irgacure ® 784/BzO2 at 532 nm.

  4. Pore surface engineering in a zirconium metal–organic framework via thiol-ene reaction

    SciTech Connect

    Gui, Bo; Hu, Guiping; Zhou, Tailin; Wang, Cheng

    2015-03-15

    A porous olefin-functionalized Zr(IV)-based metal–organic framework, denoted as UiO-68-allyl, has been constructed. Our results clearly demonstrated that the surface of UiO-68-allyl could be decorated with organic molecule (ethanethiol) via thiol-ene reaction. More importantly, the crystallinity of the framework were maintained during the post-synthetic modification process. However, the microporosity of the framework is retained but the surface area decreased, due to the grafting of ethylthio groups into the pores. From our studies, we can conclude that the strategy of post-synthetic modification of UiO-68-allyl via thiol-ene reaction may be general. Furthermore, we may anchor other desired functional group onto the pore walls in Zr-MOFs via thiol-ene reaction, enabling more potential applications. - graphical abstract: In this manuscript, we reported the post-synthetic modification of an olefin-functionalized Zr(IV)-based metal–organic framework via thiol-ene reaction. - Highlights: • A porous olefin-functionalized Zr(IV)-based metal–organic framework has been constructed. • The surface of olefin-functionalized Zr-MOF could be decorated with organic molecules via thiol-ene reaction. • The crystallinity and permanent porosity of the framework were maintained during the post-synthetic modification process.

  5. Investigations of thiol-modified phenol derivatives for the use in thiol–ene photopolymerizations

    PubMed Central

    Reinelt, Sebastian; Tabatabai, Monir; Fischer, Urs Karl; Moszner, Norbert; Utterodt, Andreas

    2014-01-01

    Summary Thiol–ene photopolymerizations gain a growing interest in academic research. Coatings and dental restoratives are interesting applications for thiol–ene photopolymerizations due to their unique features. In most studies the relative flexible and hydrophilic ester derivative, namely pentaerythritoltetra(3-mercaptopropionate) (PETMP), is investigated as the thiol component. Thus, in the present study we are encouraged to investigate the performance of more hydrophobic ester-free thiol-modified bis- and trisphenol derivatives in thiol–ene photopolymerizations. For this, six different thiol-modified bis- and trisphenol derivatives exhibiting four to six thiol groups are synthesized via the radical addition of thioacetic acid to suitable allyl-modified precursors and subsequent hydrolysis. Compared to PETMP better flexural strength and modulus of elasticity are achievable in thiol–ene photopolymerizations employing 1,3,5-triallyl-1,3,5-triazine-2,4,6-trione (TATATO) as the ene derivative. Especially, after storage in water, the flexural strength and modulus of elasticity is twice as high compared to the PETMP reference system. PMID:25161731

  6. Thermal and Mechanical Properties of Sequential and Simultaneous Thiol-Ene-Isocyanate Networks

    NASA Astrophysics Data System (ADS)

    McNair, Olivia; Brent, Davis; Savin, Daniel

    2011-03-01

    Ternary networks containing having stoichiometrically balanced thiol /(ene+isocyanate) ranging from 0 to 20 mol% isocyanate were synthesized via sequential or simultaneous thiol/ene and thiol/isocyanate click reactions. The effects of cross-link density were studied using three thiols, GDMP (difunctional), 3T (trifunctional) and 4T (tetrafunctional) respectively. TEA catalyzes the isocyanate-thiol coupling and chain extension, while the photoinitiator DMPA initiates a radical thiol-ene crosslinking process. Real-time FTIR was used to study kinetics of both light and dark reactions utilizing thiol, ene and isocyanate peaks which appear independently. It was found that difunctional thiols and isocyanates reacted initially, forming chain extended prepolymers end-capped with thiol functionalities. Upon UV irradiation, thiol functionalized prepolymers reacted with TTT, a trifunctional ene, forming networks containing incorporated thiourethane linkages. Initial DSC results indicated higher Tgs for higher cross-linked networks; however, isocyanate content has significant effects on each system. Films were also be thermally characterized via DMA and mechanical properties measured using MTS.

  7. Harnessing Energy from the Sun for Six Billion People

    ScienceCinema

    Daniel Nocera

    2013-07-19

    Daniel Nocera, a Massachusetts Institute of Technology professor whose recent research focuses on solar-powered fuels, presents a Brookhaven Science Associates Distinguished Lecture, titled "Harnessing Energy from the Sun for Six Billion People -- One at a Time."

  8. Harnessing Power from Tides: State of the Art.

    ERIC Educational Resources Information Center

    Ryan, Paul R.

    1979-01-01

    Discussed is the current, world-wide status of tidal energy as a potential power source. Potential sites and global tidal power prospects are identified. New engineering concepts relevant to the harnessing of tidal power are identified and described. (BT)

  9. 42 CFR 84.151 - Harness test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... concrete floor without disarranging the harness or exerting a pull on the facepiece. (5) The arrangement... manner that prevents a pull equivalent to dragging the maximum length of the hose over a concrete...

  10. Harnessing Energy from the Sun for Six Billion People

    SciTech Connect

    Daniel Nocera

    2011-09-12

    Daniel Nocera, a Massachusetts Institute of Technology professor whose recent research focuses on solar-powered fuels, presents a Brookhaven Science Associates Distinguished Lecture, titled "Harnessing Energy from the Sun for Six Billion People -- One at a Time."

  11. 42 CFR 84.151 - Harness test; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... concrete floor without disarranging the harness or exerting a pull on the facepiece. (5) The arrangement... manner that prevents a pull equivalent to dragging the maximum length of the hose over a concrete...

  12. Manufacturing and quality control of interconnecting wire harnesses, Volume 2

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Interconnecting wire harnesses defined in the design standard are considered, including type 4, open bundle (not enclosed). Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into the document.

  13. Pinpointing a Mechanistic Switch Between Ketoreduction and "Ene" Reduction in Short-Chain Dehydrogenases/Reductases.

    PubMed

    Lygidakis, Antonios; Karuppiah, Vijaykumar; Hoeven, Robin; Ní Cheallaigh, Aisling; Leys, David; Gardiner, John M; Toogood, Helen S; Scrutton, Nigel S

    2016-08-01

    Three enzymes of the Mentha essential oil biosynthetic pathway are highly homologous, namely the ketoreductases (-)-menthone:(-)-menthol reductase and (-)-menthone:(+)-neomenthol reductase, and the "ene" reductase isopiperitenone reductase. We identified a rare catalytic residue substitution in the last two, and performed comparative crystal structure analyses and residue-swapping mutagenesis to investigate whether this determines the reaction outcome. The result was a complete loss of native activity and a switch between ene reduction and ketoreduction. This suggests the importance of a catalytic glutamate vs. tyrosine residue in determining the outcome of the reduction of α,β-unsaturated alkenes, due to the substrate occupying different binding conformations, and possibly also to the relative acidities of the two residues. This simple switch in mechanism by a single amino acid substitution could potentially generate a large number of de novo ene reductases. PMID:27411040

  14. Characterization of volume holographic recording in photopolymerizable nanoparticle-(thiol-ene) polymer composites at 404 nm

    NASA Astrophysics Data System (ADS)

    Kawana, Masaru; Takahashi, Jun-ichiro; Yasui, Satoru; Tomita, Yasuo

    2015-02-01

    We report on the photopolymerization dynamics and the volume holographic recording properties of a thiol-ene based nanoparticle-polymer composite (NPC) doped with a blue-sensitive photoinitiator, Darocur® TPO, by using a highly coherent blue diode laser operating at a wavelength of 404 nm. Our study indicates that volume gratings recorded in the NPC amount to meeting the material requirements of refractive index modulation and material recording sensitivity for holographic data storage media. It is also found that polymerization shrinkage of recorded NPC gratings is higher than that of the same thiol-ene based NPC with a green (523 nm)-sensitive photoinitiator, Irgacure® 784/BzO2. We attribute such a difference in shrinkage to the photopolymerization dynamics at these recording wavelengths. We show that this shrinkage increase at 404 nm can be mitigated to some extent by controlling the thiol-ene stoichiometry in the NPC.

  15. Thiol-Ene functionalized siloxanes for use as elastomeric dental impression materials

    PubMed Central

    Cole, Megan A.; Jankousky, Katherine C.; Bowman, Christopher N.

    2014-01-01

    Objectives Thiol- and allyl-functionalized siloxane oligomers are synthesized and evaluated for use as a radical-mediated, rapid set elastomeric dental impression material. Thiol-ene siloxane formulations are crosslinked using a redox-initiated polymerization scheme, and the mechanical properties of the thiol-ene network are manipulated through the incorporation of varying degrees of plasticizer and kaolin filler. Formulations with medium and light body consistencies are further evaluated for their ability to accurately replicate features on both the gross and microscopic levels. We hypothesize that thiol-ene functionalized siloxane systems will exhibit faster setting times and greater detail reproduction than commercially available polyvinylsiloxane (PVS) materials of comparable consistencies. Methods Thiol-ene functionalized siloxane mixtures formulated with varying levels of redox initiators, plasticizer, and kaolin filler are made and evaluated for their polymerization speed (FTIR), consistency (ISO4823.9.2), and surface energy (goniometer). Feature replication is evaluated quantitatively by SEM. The Tg, storage modulus, and creep behavior are determined by DMA. Results Increasing redox initiation rate increases the polymerization rate but at high levels also limits working time. Combining 0.86 wt% oxidizing agent with up to 5 wt% plasticizer gave a working time of 3 min and a setting time of 2 min. The selected medium and light body thiol-ene formulations also achieved greater qualitative detail reproduction than the commercial material and reproduced micrometer patterns with 98% accuracy. Significance Improving detail reproduction and setting speed is a primary focus of dental impression material design and synthesis. Radical-mediated polymerizations, particularly thiol-ene reactions, are recognized for their speed, reduced shrinkage, and ‘click’ nature. PMID:24553250

  16. Episodic nature of the delta 4-ene and delta 5-ene steroidogenic pathways and their relationship to the adreno-gonadal axis in stallions.

    PubMed

    Ganjam, V K

    1979-01-01

    Changes in the daily secretory patterns of testosterone and other 17 beta-hydroxyandrogen, total oestrogens and total corticoids were investigated in 7 stallions. Pulsatile fluctuations in plasma hormone levels were found in the serial blood samples collected hourly for 24 h in all animals. The plasma profiles indicated that corticoids, oestrogens and androgens were secreted episodically at all times in stallions. A significant correlation was observed between the precursor and products of delta 4-ene and delta 5-ene pathways and in inverse correlation (r = -0.68; P less than 0.01) was observed between total androgens and total corticoids. The significance of these episodic fluctuations of the major steroid hormones are discussed. PMID:158088

  17. A Study of Functional Polymer Colloids Prepared Using Thiol-Ene/Yne Click Chemistry

    NASA Astrophysics Data System (ADS)

    Durham, Olivia Z.

    This project demonstrates the first instance of thiol-ene chemistry as the polymerization method for the production of polymer colloids in two-phase heterogeneous suspensions, miniemulsions, and emulsions. This work was also expanded to thiol-yne chemistry for the production of polymer particles containing increased crosslinking density. The utility of thiol-ene and thiol-yne chemistries for polymerization and polymer modification is well established in bulk systems. These reactions are considered 'click' reactions, which can be defined as processes that are both facile and simple, offering high yields with nearly 100% conversion, no side products, easy product separation, compatibility with a diverse variety of commercially available starting materials, and orthogonality with other chemistries. In addition, thiol-ene and thiol-yne chemistry follow a step-growth mechanism for the development of highly uniform polymer networks, where polymer growth is dependent on the coupling of functional groups. These step-growth polymerization systems are in stark contrast to the chain-growth mechanisms of acrylic and styrenic monomers that have dominated the field of conventional heterogeneous polymerizations. Preliminary studies evaluated the mechanism of particle production in suspension and miniemulsion systems. Monomer droplets were compared to the final polymer particles to confirm that particle growth occurred through the polymerization of monomer droplets. Additional parameters examined include homogenization energy (mechanical mixing), diluent species and concentration, and monomer content. These reactions were conducted using photoinitiation to yield particles in a matter of minutes with diameters in the size range of several microns to hundreds of microns in suspensions or submicron particles in miniemulsions. Improved control over the particle size and size distribution was examined through variation of reaction parameters. In addition, a method of seeded suspension

  18. Evaluation of Cable Harness Post-Installation Testing. Part B

    NASA Technical Reports Server (NTRS)

    King, M. S.; Iannello, C. J.

    2011-01-01

    The Cable Harness Post-Installation Testing Report was written in response to an action issued by the Ares Project Control Board (PCB). The action for the Ares I Avionics & Software Chief Engineer and the Avionics Integration and Vehicle Systems Test Work Breakdown Structure (WBS) Manager in the Vehicle Integration Office was to develop a set of guidelines for electrical cable harnesses. Research showed that post-installation tests have been done since the Apollo era. For Ares I-X, the requirement for post-installation testing was removed to make it consistent with the avionics processes used on the Atlas V expendable launch vehicle. Further research for the report involved surveying government and private sector launch vehicle developers, military and commercial aircraft, spacecraft developers, and harness vendors. Responses indicated crewed launch vehicles and military aircraft perform post-installation tests. Key findings in the report were as follows: Test requirements identify damage, human-rated vehicles should be tested despite the identification of statistically few failures, data does not support the claim that post-installation testing damages the harness insulation system, and proper planning can reduce overhead associated with testing. The primary recommendation of the report is for the Ares projects to retain the practice of post-fabrication and post-installation cable harness testing.

  19. Two Ene-Yne Metathesis Approaches to the Total Synthesis of Amphidinolide P.

    PubMed

    Jecs, Edgars; Diver, Steven T

    2015-07-17

    The total synthesis of amphidinolide P was achieved through two different ene-yne metathesis approaches. In each approach, the metathesis step was performed at late stages in the synthesis with all other functionality present. By forging two successful pathways to the synthesis of 1, some of the strengths and weaknesses of metathesis-intensive synthetic strategies were identified. PMID:26114894

  20. Efficient one-pot synthesis of 1-arylcycloprop-2-ene-1-carboxamides.

    PubMed

    Edwards, Andrew; Rubin, Michael

    2016-03-14

    An expeditious and cost-efficient method for synthesis of 1-arylcycloprop-2-ene-1-carboxamides was developed. This one-pot protocol involving coupling of amines with acyl chlorides, generated upon treatment of cyclopenylcarboxylic acids with oxalyl chloride, is applicable for the preparation of sensitive products with a reactive, unsubstituted strained double bond. PMID:26864495

  1. 21 CFR 177.1660 - Poly (tetra-methyl-ene tere-phtha-late).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Poly (tetra-methyl-ene tere-phtha-late). 177.1660 Section 177.1660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and...

  2. 78 FR 717 - ENE (Environment Northeast); Greater Boston Real Estate Board; National Consumer Law Center...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-04

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission ENE (Environment Northeast); Greater Boston Real Estate Board; National Consumer Law Center; NEPOOL Industrial Customer Coalition; v. Bangor Hydro-Electric Company; Central Maine Power Company; New England Power...

  3. Synthesis of the antimalarial drug FR900098 utilizing the nitroso-ene reaction.

    PubMed

    Fokin, Andrey A; Yurchenko, Alexander G; Rodionov, Vladimir N; Gunchenko, Pavel A; Yurchenko, Raisa I; Reichenberg, Armin; Wiesner, Jochen; Hintz, Martin; Jomaa, Hassan; Schreiner, Peter R

    2007-10-11

    The antimalarial drug FR900098 was prepared from diethyl allylphosphonate involving the nitroso-ene reaction with nitrosocarbonyl methane as the key step followed by hydrogenation and dealkylation. The utilization of dibenzyl allylphosphonate as the starting compound allows one-step hydrogenation with dealkylation, which simplifies the preparative scheme further. PMID:17887769

  4. Spectrally formulated modeling of a cable-harnessed structure

    NASA Astrophysics Data System (ADS)

    Choi, Jiduck; Inman, Daniel J.

    2014-07-01

    To obtain predictive modeling of the spacecraft, we investigate the effects of adding cables to a simple structure with the goal of developing an understanding of the effects of cables interacting with a structure. In this paper, we present modeling of a cable-harnessed structure by means of the Spectral Element Method (SEM). A double beam model is used to emulate a cable-harnessed structure. SEM modeling can define the location and the number of connections between the two beams in a convenient fashion. The presented modeling is applied and compared with the conventional FEM. The modeling approach was compared and validated with experimental measurements. The validated modeling was implemented to investigate the effect of the number of connections and of the spring stiffness of interconnections. The results show that the proposed modeling can be used as an accurate and efficient solution methodology for a cable-harnessed structure.

  5. A Study of Functional Polymer Colloids Prepared Using Thiol-Ene/Yne Click Chemistry

    NASA Astrophysics Data System (ADS)

    Durham, Olivia Z.

    This project demonstrates the first instance of thiol-ene chemistry as the polymerization method for the production of polymer colloids in two-phase heterogeneous suspensions, miniemulsions, and emulsions. This work was also expanded to thiol-yne chemistry for the production of polymer particles containing increased crosslinking density. The utility of thiol-ene and thiol-yne chemistries for polymerization and polymer modification is well established in bulk systems. These reactions are considered 'click' reactions, which can be defined as processes that are both facile and simple, offering high yields with nearly 100% conversion, no side products, easy product separation, compatibility with a diverse variety of commercially available starting materials, and orthogonality with other chemistries. In addition, thiol-ene and thiol-yne chemistry follow a step-growth mechanism for the development of highly uniform polymer networks, where polymer growth is dependent on the coupling of functional groups. These step-growth polymerization systems are in stark contrast to the chain-growth mechanisms of acrylic and styrenic monomers that have dominated the field of conventional heterogeneous polymerizations. Preliminary studies evaluated the mechanism of particle production in suspension and miniemulsion systems. Monomer droplets were compared to the final polymer particles to confirm that particle growth occurred through the polymerization of monomer droplets. Additional parameters examined include homogenization energy (mechanical mixing), diluent species and concentration, and monomer content. These reactions were conducted using photoinitiation to yield particles in a matter of minutes with diameters in the size range of several microns to hundreds of microns in suspensions or submicron particles in miniemulsions. Improved control over the particle size and size distribution was examined through variation of reaction parameters. In addition, a method of seeded suspension

  6. 42 CFR 84.201 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... cartridge respirators other than single-use vinyl chloride shall be equipped with adjustable and replaceable... of pressure over the entire area in contact with the face. (2) Facepieces for single-use vinyl chloride respirators shall be equipped with adjustable head harnesses designed and constructed to...

  7. 42 CFR 84.201 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... cartridge respirators other than single-use vinyl chloride shall be equipped with adjustable and replaceable... of pressure over the entire area in contact with the face. (2) Facepieces for single-use vinyl chloride respirators shall be equipped with adjustable head harnesses designed and constructed to...

  8. 42 CFR 84.201 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... cartridge respirators other than single-use vinyl chloride shall be equipped with adjustable and replaceable... of pressure over the entire area in contact with the face. (2) Facepieces for single-use vinyl chloride respirators shall be equipped with adjustable head harnesses designed and constructed to...

  9. 42 CFR 84.201 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... cartridge respirators other than single-use vinyl chloride shall be equipped with adjustable and replaceable... of pressure over the entire area in contact with the face. (2) Facepieces for single-use vinyl chloride respirators shall be equipped with adjustable head harnesses designed and constructed to...

  10. 42 CFR 84.201 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... cartridge respirators other than single-use vinyl chloride shall be equipped with adjustable and replaceable... of pressure over the entire area in contact with the face. (2) Facepieces for single-use vinyl chloride respirators shall be equipped with adjustable head harnesses designed and constructed to...

  11. Harnessing the crowd to accelerate molecular medicine research.

    PubMed

    Smith, Robert J; Merchant, Raina M

    2015-07-01

    Crowdsourcing presents a novel approach to solving complex problems within molecular medicine. By leveraging the expertise of fellow scientists across the globe, broadcasting to and engaging the public for idea generation, harnessing a scalable workforce for quick data management, and fundraising for research endeavors, crowdsourcing creates novel opportunities for accelerating scientific progress. PMID:26141797

  12. Residual dysplasia after successful Pavlik harness treatment: early ultrasound predictors.

    PubMed

    Alexiev, Venelin Alexandrov; Harcke, H Theodore; Kumar, S Jay

    2006-01-01

    The purpose of this study was to evaluate a group of children treated with Pavlik harness for developmental dysplasia of the hip (DDH) to determine early ultrasound characteristics that predict poor acetabular development after walking age. From a group of 487 infants with DDH, 55 met inclusion criteria of (1) ultrasound documentation of major neonatal hip instability, (2) treatment with Pavlik harness, and (3) a minimum of 4 years of follow-up. These 55 infants had 100 abnormal hips. Harness treatment alone was successful in treating 87 of 100 hips. Persistent or late acetabular dysplasia was defined from serial radiographs. At a mean follow-up of 5.3 years, 5 of the 87 (6%) were found to have sequelae (late acetabular dysplasia, avascular necrosis of the femoral head, or both). Three sonographic findings present on the initial ultrasound predicted late sequelae: (1) dynamic coverage index of 22% or less, (2) alpha angle less than 43 degrees, and (3) abnormal echogenicity of the cartilaginous roof on initial ultrasound. Abnormal echogenicity was the most specific single predictor of residual dysplasia (sensitivity 100% and specificity 88%). The structurally normal cartilaginous roof is non-echogenic except for a short triangular fibrous tip (the labrum). Pathologic cartilage becomes echogenic beyond the tip as hyaline cartilage becomes fibrous and deformed. In unstable hips that respond well to Pavlik harness treatment, it would appear that midterm acetabular development can be affected when early transformation of roof cartilage accompanies displacement and instability. PMID:16439895

  13. Harnessing Linguistic Variation to Improve Education. Rethinking Education. Volume 5

    ERIC Educational Resources Information Center

    Yiakoumetti, Androula, Ed.

    2012-01-01

    This volume brings together research carried out in a variety of geographic and linguistic contexts including Africa, Asia, Australia, Canada, the Caribbean, Europe and the United States and explores efforts to incorporate linguistic diversity into education and to "harness" this diversity for learners' benefit. It challenges the largely…

  14. Using Discussion Methods to Inspire Diversity: Harnessing Social & Cultural Capital

    ERIC Educational Resources Information Center

    Raison, Brian; Gordon, Beverly

    2012-01-01

    How can you better harness the powerful social capital that exists within diverse individuals, families, businesses, and schools to make positive impacts in your community? What could you add to your next meeting--a Chamber strategic planning session, an employee wellness program, a non-profit board development--to better connect participants with…

  15. Manufacture and quality control of interconnecting wire harnesses, Volume 3

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The document covers interconnecting wire harnesses defined in the design standard, including type 6, enclosed in TFE heat shrink tubing; and type 7, flexible armored. Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into this document.

  16. Moving ahead on harnessing synthetic lethality to fight cancer

    PubMed Central

    Jerby-Arnon, Livnat; Ruppin, Eytan

    2015-01-01

    We have recently developed a data-mining pipeline that comprehensively identifies cancer unique susceptibilities, following the concept of Synthetic Lethality (SL). The approach enables, for the first time, to identify and harness genome-scale SL-networks to accurately predict gene essentiality, drug response, and clinical prognosis in cancer. PMID:27308440

  17. Immobilization of enzymes via microcontact printing and thiol-ene click chemistry.

    PubMed

    Buhl, Moritz; Vonhören, Benjamin; Ravoo, Bart Jan

    2015-06-17

    This Communication describes a bioconjugation method for the generation of enzyme microarrays on surfaces using photochemical thiol-ene chemistry in combination with microcontact printing. Glucose oxidase and lactase were readily immobilized (i.e., printing time 2 min) on alkene terminated self-assembled monolayers on glass as demonstrated by X-ray photoelectron spectroscopy and fluorescence microscopy. Furthermore, the activity of both immobilized enzymes was confirmed in single enzyme as well as cascade transformations. PMID:26030726

  18. Polyhedral Oligomeric Silsesquioxane-Containing Thiol-ene Fibers with Tunable Thermal and Mechanical Properties.

    PubMed

    Fang, Yichen; Ha, Heonjoo; Shanmuganathan, Kadhiravan; Ellison, Christopher J

    2016-05-01

    Polyhedral oligomeric silsesquioxanes (POSS) are versatile inorganic-organic hybrid building blocks that have potential applications as reinforcement nanofillers, thermal stabilizers, and catalyst supports for metal nanoparticles. However, fabrication of fibrous materials with high POSS content has been a challenge because of the aggregation and solubility limits of POSS units. In this paper, we describe a robust and environmentally friendly fabrication approach of inorganic-organic hybrid POSS fibers by integrating UV initiated thiol-ene polymerization and centrifugal fiber spinning. The use of monomeric liquids in this approach not only reduces the consumption of heat energy and solvent, but it also promotes homogeneous mixing of organic and inorganic components that allows integration of large amount of POSS (up to 80 wt %) into the polymer network. The POSS containing thiol-ene fibers exhibited enhanced thermomechanical properties compared to purely organic analogs as revealed by substantial increases in residual weight and a factor of 4 increase in modulus after thermal treatment at 1000 °C. This simple fabrication approach combined with the tunability in fiber properties afforded by tailoring monomer composition make POSS containing thiol-ene fibers attractive candidates for catalyst supports and filtration media, particularly in high-temperature and harsh environments. PMID:27057758

  19. Thiol-Ene Induced Diphosphonic Acid Functionalization of Superparamagnetic Iron Oxide Nanoparticles

    SciTech Connect

    Rutledge, Ryan D.; Warner, Cynthia L.; Pittman, Jonathan W.; Addleman, Raymond S.; Engelhard, Mark H.; Chouyyok, Wilaiwan; Warner, Marvin G.

    2010-07-20

    Multi-functional organic molecules represent an interesting challenge for nanoparticle functionalization due to the potential for undesirable interactions between the substrate material and the variable functionalities, making it difficult to control the final orientation of the ligand. In the present study, UV-induced thiol-ene click chemistry has been utilized as a means of directed functionalization of bifunctional ligands on an iron oxide nanoparticle surface. Allyl diphosphonic acid ligand was covalently deposited on the surface of thiol-presenting iron oxide nanoparticles via the formation of a UV-induced thioether. This method of thiol-ene click chemistry offers a set of reaction conditions capable of controlling the ligand deposition and circumventing the natural affinity exhibited by the phosphonic acid moiety for the iron oxide surface. These claims are supported via a multimodal characterization platform which includes thermogravimetric analysis, x-ray photoelectron spectroscopy, and metal contact analysis and are consistent with a properly oriented, highly active ligand on the nanoparticle surface. These experiments suggest thiol-ene click chemistry as both a practical and generally applicable strategy for the directed deposition of multi-functional ligands on metal oxide nanoparticle surfaces.

  20. Identification of promiscuous ene-reductase activity by mining structural databases using active site constellations

    PubMed Central

    Steinkellner, Georg; Gruber, Christian C.; Pavkov-Keller, Tea; Binter, Alexandra; Steiner, Kerstin; Winkler, Christoph; Łyskowski, Andrzej; Schwamberger, Orsolya; Oberer, Monika; Schwab, Helmut; Faber, Kurt; Macheroux, Peter; Gruber, Karl

    2014-01-01

    The exploitation of catalytic promiscuity and the application of de novo design have recently opened the access to novel, non-natural enzymatic activities. Here we describe a structural bioinformatic method for predicting catalytic activities of enzymes based on three-dimensional constellations of functional groups in active sites (‘catalophores’). As a proof-of-concept we identify two enzymes with predicted promiscuous ene-reductase activity (reduction of activated C–C double bonds) and compare them with known ene-reductases, that is, members of the Old Yellow Enzyme family. Despite completely different amino acid sequences, overall structures and protein folds, high-resolution crystal structures reveal equivalent binding modes of typical Old Yellow Enzyme substrates and ligands. Biochemical and biocatalytic data show that the two enzymes indeed possess ene-reductase activity and reveal an inverted stereopreference compared with Old Yellow Enzymes for some substrates. This method could thus be a tool for the identification of viable starting points for the development and engineering of novel biocatalysts. PMID:24954722

  1. 14 CFR 137.42 - Fastening of safety belts and shoulder harnesses.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Fastening of safety belts and shoulder... AGRICULTURAL AIRCRAFT OPERATIONS Operating Rules § 137.42 Fastening of safety belts and shoulder harnesses. No... belt and shoulder harness properly secured about that person except that the shoulder harness need...

  2. 14 CFR 91.107 - Use of safety belts, shoulder harnesses, and child restraint systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Safety Standard No. 213 (49 CFR 571.213)), vest- and harness-type child restraint systems, and lap held... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Use of safety belts, shoulder harnesses... OPERATING AND FLIGHT RULES Flight Rules General § 91.107 Use of safety belts, shoulder harnesses, and...

  3. 14 CFR 137.42 - Fastening of safety belts and shoulder harnesses.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Fastening of safety belts and shoulder... AGRICULTURAL AIRCRAFT OPERATIONS Operating Rules § 137.42 Fastening of safety belts and shoulder harnesses. No... belt and shoulder harness properly secured about that person except that the shoulder harness need...

  4. 14 CFR 137.42 - Fastening of safety belts and shoulder harnesses.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Fastening of safety belts and shoulder... AGRICULTURAL AIRCRAFT OPERATIONS Operating Rules § 137.42 Fastening of safety belts and shoulder harnesses. No... belt and shoulder harness properly secured about that person except that the shoulder harness need...

  5. 14 CFR 137.42 - Fastening of safety belts and shoulder harnesses.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fastening of safety belts and shoulder... AGRICULTURAL AIRCRAFT OPERATIONS Operating Rules § 137.42 Fastening of safety belts and shoulder harnesses. No... belt and shoulder harness properly secured about that person except that the shoulder harness need...

  6. 14 CFR 91.107 - Use of safety belts, shoulder harnesses, and child restraint systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Safety Standard No. 213 (49 CFR 571.213)), vest- and harness-type child restraint systems, and lap held... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Use of safety belts, shoulder harnesses... OPERATING AND FLIGHT RULES Flight Rules General § 91.107 Use of safety belts, shoulder harnesses, and...

  7. 14 CFR 137.42 - Fastening of safety belts and shoulder harnesses.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Fastening of safety belts and shoulder... AGRICULTURAL AIRCRAFT OPERATIONS Operating Rules § 137.42 Fastening of safety belts and shoulder harnesses. No... belt and shoulder harness properly secured about that person except that the shoulder harness need...

  8. 14 CFR 91.107 - Use of safety belts, shoulder harnesses, and child restraint systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Safety Standard No. 213 (49 CFR 571.213)), vest- and harness-type child restraint systems, and lap held... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Use of safety belts, shoulder harnesses... OPERATING AND FLIGHT RULES Flight Rules General § 91.107 Use of safety belts, shoulder harnesses, and...

  9. Reactivity of vegetable oil macromonomers in thiol-ene, cationic, and emulsion polymerizations

    NASA Astrophysics Data System (ADS)

    Black, Micah Stephen

    Vegetable oils were, and continue, to be a mainstay in unsaturated polyester ("alkyd") technology. Our endeavor is to use vegetable oil-based polymers in environmentally-friendly coatings. The role of vegetable oil cis-unsaturation has not been fully explored in polymers. To that end, vegetable oil macromonomers (VOMMs) in three different systems were investigated to determine the involvement of cis-unsaturation in chain transfer, auto-oxidation, and copolymerization reactions. VOMMs were incorporated into UV curable thiol-ene coatings, UV cationic coatings, and acrylic solution copolymers and fundamental studies were conducted to determine how and to what extent cis-unsaturation contributes to film performance properties. In thiol-ene UV curable coatings, cis-unsaturation was involved in the initial curing reaction and to lesser degrees, in postcure crosslinking. Its behavior was determined to be dependent on the ene component. Thiol-ene photopolymerization yielded homogeneous networks but formulations containing VOMMs exhibited greater heterogeneity due to non-uniformity in the VOMM chemical structures, and the concurrent reactions occurring during thiol-ene photopolymerization and "dark cure". Partially epoxidized soybean oil was synthesized to contain varying levels of residual cis-unsaturation. Cationic photopolymerization of partially epoxidized soybean oil yielded lightly crosslinked films, but the influence of free radical decomposition byproducts has not been fully investigated. The low involvement of the cis-unsaturation in photopolymerization was attributed to its low reactivity and/or radical combination with antioxidants and molecular oxygen dissolved in the films. When used in emulsion polymerization, VOMMs lower the minimum filming temperature during coalescence and increase the Tg after application via auto-oxidation. Free radical polymerization of VOMMs is accompanied by chain transfer reactions between polymer radicals and VOMMs that reduces

  10. HARNESS: Heterogeneous Adaptable Reconfigurable Networked Systems. Final Progress Report

    SciTech Connect

    Fagg, G. E.

    2004-01-20

    HARNESS was proposed as a system that combined the best of emerging technologies found in current distributed computing research and commercial products into a very flexible, dynamically adaptable framework that could be used by applications to allow them to evolve and better handle their execution environment. The HARNESS system was designed using the considerable experience from previous projects such as PVM, MPI, IceT and Cumulvs. As such, the system was designed to avoid any of the common problems found with using these current systems, such as no single point of failure, ability to survive machine, node and software failures. Additional features included improved intercomponent connectivity, with full support for dynamic down loading of addition components at run-time thus reducing the stress on application developers to build in all the libraries they need in advance.

  11. Uncovering Listeria monocytogenes hypervirulence by harnessing its biodiversity.

    PubMed

    Maury, Mylène M; Tsai, Yu-Huan; Charlier, Caroline; Touchon, Marie; Chenal-Francisque, Viviane; Leclercq, Alexandre; Criscuolo, Alexis; Gaultier, Charlotte; Roussel, Sophie; Brisabois, Anne; Disson, Olivier; Rocha, Eduardo P C; Brisse, Sylvain; Lecuit, Marc

    2016-03-01

    Microbial pathogenesis studies are typically performed with reference strains, thereby overlooking within-species heterogeneity in microbial virulence. Here we integrated human epidemiological and clinical data with bacterial population genomics to harness the biodiversity of the model foodborne pathogen Listeria monocytogenes and decipher the basis of its neural and placental tropisms. Taking advantage of the clonal structure of this bacterial species, we identify clones epidemiologically associated either with food or with human central nervous system (CNS) or maternal-neonatal (MN) listeriosis. The latter clones are also most prevalent in patients without immunosuppressive comorbidities. Strikingly, CNS- and MN-associated clones are hypervirulent in a humanized mouse model of listeriosis. By integrating epidemiological data and comparative genomics, we have uncovered multiple new putative virulence factors and demonstrate experimentally the contribution of the first gene cluster mediating L. monocytogenes neural and placental tropisms. This study illustrates the exceptional power in harnessing microbial biodiversity to identify clinically relevant microbial virulence attributes. PMID:26829754

  12. Uncovering Listeria monocytogenes hypervirulence by harnessing its biodiversity

    PubMed Central

    Charlier, Caroline; Touchon, Marie; Chenal-Francisque, Viviane; Leclercq, Alexandre; Criscuolo, Alexis; Gaultier, Charlotte; Roussel, Sophie; Brisabois, Anne; Disson, Olivier; Rocha, Eduardo P. C.; Brisse, Sylvain; Lecuit, Marc

    2016-01-01

    Microbial pathogenesis studies are typically performed with reference strains, thereby overlooking microbial intra-species virulence heterogeneity. Here we integrated human epidemiological and clinical data with bacterial population genomics to harness the biodiversity of the model foodborne pathogen Listeria monocytogenes and decipher the basis of its neural and placental tropisms. Taking advantage of the clonal structure of this bacterial species, we identify clones epidemiologically associated with either food or human central nervous system (CNS) and maternal-neonatal (MN) listeriosis. The latter are also most prevalent in patients without immunosuppressive comorbidities. Strikingly, CNS and MN clones are hypervirulent in a humanized mouse model of listeriosis. By integrating epidemiological data and comparative genomics, we uncovered multiple novel putative virulence factors and demonstrated experimentally the contribution of the first gene cluster mediating Listeria monocytogenes neural and placental tropisms. This study illustrates the exceptional power of harnessing microbial biodiversity to identify clinically relevant microbial virulence attributes. PMID:26829754

  13. Hello World: Harnessing social media for the Rosetta mission

    NASA Astrophysics Data System (ADS)

    Baldwin, E.; Mignone, C.; O'Flaherty, K. S.; Homfeld, A.-M.; Bauer, M.; McCaughrean, M. J.

    2015-10-01

    The European Space Agency's (ESA) comet-chasing Rosetta mission was launched in 2004, before social media became a popular tool for mainstream communication. By harnessing a range of platforms for communicating the key messages of this unprecedented space adventure as the spacecraft reached its destination ten years later, a wide range of new audiences were reached and could follow this once-in-a-lifetime mission.

  14. High-Density Terminal Box for Testing Wire Harness

    NASA Technical Reports Server (NTRS)

    Pierce, W. B.; Collins, W. G.

    1982-01-01

    Compact terminal box provides access to complex wiring harnesses for testing. Box accommodates more than twice as many wires as previous boxes. Box takes in wires via cable connectors and distributes them to contacts on box face. Instead of separate insulated jacks in metal face panel, box uses pairs of small military-standard metal sockets in precision-drilled plastic panel. Shorting plug provides continuity for wires when not being tested.

  15. Network harness: bundles of routes in public transport networks

    NASA Astrophysics Data System (ADS)

    Berche, B.; von Ferber, C.; Holovatch, T.

    2009-12-01

    Public transport routes sharing the same grid of streets and tracks are often found to proceed in parallel along shorter or longer sequences of stations. Similar phenomena are observed in other networks built with space consuming links such as cables, vessels, pipes, neurons, etc. In the case of public transport networks (PTNs) this behavior may be easily worked out on the basis of sequences of stations serviced by each route. To quantify this behavior we use the recently introduced notion of network harness. It is described by the harness distribution P(r, s): the number of sequences of s consecutive stations that are serviced by r parallel routes. For certain PTNs that we have analyzed we observe that the harness distribution may be described by power laws. These power laws indicate a certain level of organization and planning which may be driven by the need to minimize the costs of infrastructure and secondly by the fact that points of interest tend to be clustered in certain locations of a city. This effect may be seen as a result of the strong interdependence of the evolutions of both the city and its PTN. To further investigate the significance of the empirical results we have studied one- and two-dimensional models of randomly placed routes modeled by different types of walks. While in one dimension an analytic treatment was successful, the two dimensional case was studied by simulations showing that the empirical results for real PTNs deviate significantly from those expected for randomly placed routes.

  16. Flight performance energetics and water turnovers of Tippler Pigeons with a harness and doorsal load

    USGS Publications Warehouse

    Gessaman, James A.; Workman, Gar W.; Fuller, Mark R.

    1991-01-01

    We measured carbon dioxide production and water efflux of 12 tippler pigeons (Columba spp.) during seven experimental flights using the doubly labeled water (DLW) method. Prior to the experiment birds were randomly assigned to one of two groups. One group flew as controls (no load or harness) on all seven flights. The other group wore a harness on two flights, a dorsal load/harness package (weighing about 5% of a birda??s mass) on two flights, and they were without a load in three flights. Plight duration of pigeons with only a harness and with a dorsal load/harness package was 21 and 26% less, respectively, than the controls. Pigeons wearing a harness, or wearing a dorsal load/harness package lost water 50-90%, and 57-100% faster, respectively, than control pigeons. The mean CO, production of pigeons wearing a harness or a load/harness package was not significantly different than pigeons without a harness or load. The small sample sizes and large variability in DLW measurements precluded a good test of the energetic cost of flying with a harness and dorsal load.

  17. Flight performance, energetics and water turnover of tippler pigeons with a harness and dorsal load

    USGS Publications Warehouse

    Gessaman, J.A.; Workman, G.W.; Fuller, M.R.

    1991-01-01

    We measured carbon dioxide production and water efflux of 12 tippler pigeons (Columba spp.) during seven experimental flights using the doubly labeled water (DLW) method. Prior to the experiment birds were randomly assigned to one of two groups. One group flew as controls (no load or harness) on all seven flights. The other group wore a harness on two flights, a dorsal load/harness package (weighing about 5% of a bird's mass) on two flights, and they were without a load in three flights. Flight duration of pigeons with only a harness and with a dorsal load/harness package was 21 and 26% less, respectively, than the controls. Pigeons wearing a harness, or wearing a dorsal load/harness package lost water 50-90%, and 57-100% faster, respectively, than control pigeons. The mean CO2 production of pigeons wearing a harness or a load/harness package was not significantly different than pigeons without a harness or load. The small sample sizes and large variability in DLW measuremets precluded a good test of the energetic cost of flying with a harness and dorsal load.

  18. Advantages and drawbacks of Thiol-ene based resins for 3D-printing

    NASA Astrophysics Data System (ADS)

    Leonards, Holger; Engelhardt, Sascha; Hoffmann, Andreas; Pongratz, Ludwig; Schriever, Sascha; Bläsius, Jana; Wehner, Martin; Gillner, Arnold

    2015-03-01

    The technology of 3D printing is conquering the world and awakens the interest of many users in the most varying of applications. New formulation approaches for photo-sensitive thiol-ene resins in combination with various printing technologies, like stereolithography (SLA), projection based printing/digital light processing (DLP) or two-photon polymerization (TPP) are presented. Thiol-ene polymerizations are known for its fast and quantitative reaction and to form highly homogeneous polymer networks. As the resins are locally and temporally photo-curable the polymerization type is very promising for 3D-printing. By using suitable wavelengths, photoinitiator-free fabrication is feasible for single- and two photon induced polymerization. In this paper divinyl ethers of polyethylene glycols in combination with star-shaped tetrathiols were used to design a simple test-system for photo-curable thiol-ene resins. In order to control and improve curing depth and lateral resolution in 3D-polymerization processes, either additives in chemical formulation or process parameters can be changed. The achieved curing depth and resolution limits depend on the applied fabrication method. While two-/multiphoton induced lithography offers the possibility of micron- to sub-micron resolution it lacks in built-up speed. Hence single-photon polymerization is a fast alternative with optimization potential in sub-10-micron resolution. Absorber- and initiator free compositions were developed in order to avoid aging, yellowing and toxicity of resulting products. They can be cured with UV-laser radiation below 300 nm. The development at Fraunhofer ILT is focusing on new applications in the field of medical products and implants, technical products with respect to mechanical properties or optical properties of 3D-printed objects. Recent process results with model system (polyethylene glycol divinylether/ Pentaerithrytol tetrakis (3-mercaptopropionat), Raman measurements of polymer conversion

  19. Synthesis of anthracene derivatives of 1,3-diazabicyclo[3.1.0]hex-3-ene

    NASA Astrophysics Data System (ADS)

    Mahmoodi, Nosrat O.; Mirkhaef, Safoura; Ghavidast, Atefeh

    2015-02-01

    Novel mono- and bis-photochromic compounds of 1,3-diazabicyclo[3.1.0]hex-3-enes based on anthracene moiety were synthesized efficiently. Photochromic compounds were synthesized through the reaction of 10-(hydroxymethyl)anthracene-9-carbaldehyde and anthracene-9-carbaldehyde or 9,10-anthracenedicarbaldehyde as bis-aldehydes with ketoaziridines in dry DMF at room temperature. Photochromic compounds exhibited photochromic behavior both in solution and in solid state by irradiation under UV light at 254 nm. Compounds bearing 4-NO2 on aziridine moiety showed intensive color change. Compounds were characterized by IR, 1H NMR, 13C NMR, and UV-Vis.

  20. Synthesis of new pyrazolyl-1,3-diazabicyclo[3.1.0]hexe-3-ene derivatives

    NASA Astrophysics Data System (ADS)

    Kiyani, Hamzeh; Albooyeh, Fereshteh; Fallahnezhad, Saied

    2015-07-01

    A series of new of photochromic 1,3-diazabicyclo[3.1.0]hex-3-ene derivatives based on the skeleton of five-membered pyrazole moiety have been synthesized and characterized by spectral techniques, as well as their photochromic properties were examined under UV light irradiation in various solutions. All these newly synthesized compounds showed good photochromic properties in the both solution and solid states. The UV-Visible spectral analysis of the corresponding pyrazolyl bicyclic aziridines established structure-photochromic behavior relationships.

  1. Plasmachemical Double Click Thiol-ene Reactions for Wet Electrical Barrier.

    PubMed

    Fraser, R C; Carletto, A; Wilson, M; Badyal, J P S

    2016-08-24

    Click thiol-ene chemistry is demonstrated for the reaction of thiol containing molecules with surface alkene bonds during electrical discharge activation. This plasmachemical reaction mechanism is shown to be 2-fold for allyl mercaptan (an alkene and thiol group containing precursor), comprising self-cross-linked nanolayer deposition in tandem with interfacial cross-linking to the surface alkene bonds of a polyisoprene base layer. A synergistic multilayer structure is attained which displays high wet electrical barrier performance during immersion in water. PMID:27505445

  2. Synthesis of Non-linear Protein Dimers through a Genetically Encoded Thiol-ene Reaction

    PubMed Central

    Torres-Kolbus, Jessica; Chou, Chungjung; Liu, Jihe; Deiters, Alexander

    2014-01-01

    Site-specific incorporation of bioorthogonal unnatural amino acids into proteins provides a useful tool for the installation of specific functionalities that will allow for the labeling of proteins with virtually any probe. We demonstrate the genetic encoding of a set of alkene lysines using the orthogonal PylRS/PylTCUA pair in Escherichia coli. The installed double bond functionality was then applied in a photoinitiated thiol-ene reaction of the protein with a fluorescent thiol-bearing probe, as well as a cysteine residue of a second protein, showing the applicability of this approach in the formation of heterogeneous non-linear fused proteins. PMID:25181502

  3. How can developing countries harness biotechnology to improve health?

    PubMed Central

    Daar, Abdallah S; Berndtson, Kathryn; Persad, Deepa L; Singer, Peter A

    2007-01-01

    Background The benefits of genomics and biotechnology are concentrated primarily in the industrialized world, while their potential to combat neglected diseases in the developing world has been largely untapped. Without building developing world biotechnology capacity to address local health needs, this disparity will only intensify. To assess the potential of genomics to address health needs in the developing world, the McLaughlin-Rotman Centre for Global Health, along with local partners, organized five courses on Genomics and Public Health Policy in the developing world. The overall objective of the courses was to collectively explore how to best harness genomics to improve health in each region. This article presents and analyzes the recommendations from all five courses. Discussion In this paper we analyze recommendations from 232 developing world experts from 58 countries who sought to answer how best to harness biotechnology to improve health in their regions. We divide their recommendations into four categories: science; finance; ethics, society and culture; and politics. Summary The Courses' recommendations can be summarized across the four categories listed above: Science - Collaborate through national, regional, and international networks - Survey and build capacity based on proven models through education, training, and needs assessments Finance - Develop regulatory and intellectual property frameworks for commercialization of biotechnology - Enhance funding and affordability of biotechnology - Improve the academic-industry interface and the role of small and medium enterprise Ethics, Society, Culture - Develop public engagement strategies to inform and educate the public about developments in genomics and biotechnology - Develop capacity to address ethical, social and cultural issues - Improve accessibility and equity Politics - Strengthen understanding, leadership and support at the political level for biotechnology - Develop policies outlining

  4. On-Orbit Evaluation of a New Treadmill Harness for Improved Crewmember Comfort and Load Distribution

    NASA Technical Reports Server (NTRS)

    Perusek, G. P.; Sheehan, C. C.; Savina, M. C.; Owings, T. M.; Davis, B. L.; Ryder, J. W.

    2011-01-01

    The current design of the International Space Station (ISS) Treadmill Harness has been reported to cause pain and discomfort to crewmembers during exercise. The Harness Station Development Test Objective (SDTO) provided participating crewmembers (n = 6) with a new harness design, the "Glenn Harness," to evaluate for comfort and loading as compared to the current Treadmill Harness. A novel suite of load-sensing instrumentation was developed to noninvasively measure load distribution and provided a first-ever quantification of actual dynamic loads during treadmill exercise. In addition, crew debriefs provided feedback on harness preference and overall impressions. Conclusions: Post-flight analysis in returned Glenn Harnesses (n = 3) showed minimal wear and tear. Four of the six subjects found the Glenn Harness to be more comfortable in this on-orbit, side-by-side comparison as measured by the crew comfort questionnaire and crew debriefs. Specific areas for improvement have been identified, and forward recommendations will be provided to the Human Research Program. The protocol developed for the SDTO provided valuable insight into crew comfort issues, design improvements, and loading preferences for exercise harnessing, which lays the groundwork for better harnessing systems and training protocols.

  5. Harnessing natural product assembly lines: structure, promiscuity, and engineering.

    PubMed

    Ladner, Christopher C; Williams, Gavin J

    2016-03-01

    Many therapeutically relevant natural products are biosynthesized by the action of giant mega-enzyme assembly lines. By leveraging the specificity, promiscuity, and modularity of assembly lines, a variety of strategies has been developed that enables the biosynthesis of modified natural products. This review briefly summarizes recent structural advances related to natural product assembly lines, discusses chemical approaches to probing assembly line structures in the absence of traditional biophysical data, and surveys efforts that harness the inherent or engineered promiscuity of assembly lines for the synthesis of non-natural polyketides and non-ribosomal peptide analogues. PMID:26527577

  6. "Hello, World!" Harnessing Social Media for the Rosetta Mission

    NASA Astrophysics Data System (ADS)

    Baldwin, E.; Mignone, C.; Scuka, D.; Homfeld, A. M.; Ranero, K.; Rolfe, E.; Bennett, M.; Schepers, A.; O'Flaherty, K. S.; Bauer, M.; McCaughrean, M.

    2016-03-01

    The European Space Agency's comet-chasing Rosetta mission was launched in 2004, before social media became a popular tool for mainstream communication. As it reached its destination ten years later, new audiences were reached and inspired by this once-in-a-lifetime event by harnessing a range of outlets for communicating the key messages. These included traditional online platforms, such as news websites, blogs, and Livestream, as well as Twitter, Facebook, Instagram, Flickr, YouTube, Google+ and SoundCloud. In this article, we outline the role social media channels played in making Rosetta one of the European Space Agency's biggest communication and public engagement successes.

  7. Harnessing geometric and magnetic nonlinearities in phononic meta-plates

    NASA Astrophysics Data System (ADS)

    Bilal, Osama; Foehr, Andre; Daraio, Chiara

    Owing to their physical realization, locally resonant metamaterials retain narrow subwavelength band gaps. Moreover, the fixed geometry and dimensions of the unit cell set a hardbound on the central frequency of the operational bandwidth. Real-time tunable metamaterials extend the range of applications and further enable the realization of new sensors, filters, and switches. Our work harnesses the interaction between geometric nonlinearity and nonlinear magnetic potentials to engineer frequency-agile subwavelength band gaps. The concept is general and applicable to various metamaterials systems. Both numerical simulations and experimental realization of the proposed concept will be presented.

  8. Understanding and Harnessing Placebo Effects: Clearing Away the Underbrush

    PubMed Central

    Miller, Franklin G.; Brody, Howard

    2011-01-01

    Despite strong growth in scientific investigation of the placebo effect, understanding of this phenomenon remains deeply confused. We investigate critically seven common conceptual distinctions that impede clear understanding of the placebo effect: (1) verum/placebo, (2) active/inactive, (3) signal/noise, (4) specific/nonspecific, (5) objective/subjective, (6) disease/illness, and (7) intervention/context. We argue that some of these should be eliminated entirely, whereas others must be used with caution to avoid bias. Clearing away the conceptual underbrush is needed to lay down a path to understanding and harnessing placebo effects in clinical medicine. PMID:21220523

  9. The metabolism of gamma-2,3,4,5,6-pentachlorocyclohex-1-ene and gamma-hexachlorocyclohexane in rats.

    PubMed

    Grover, P L; Sims, P

    1965-08-01

    1. After intraperitoneal administration, gamma-hexachlorocyclohexane (Gammexane) and gamma-2,3,4,5,6-pentachlorocyclohex-1-ene were converted by rats into 2,3,5- and 2,4,5-trichlorophenol, which were excreted as free phenols and as sulphuric acid and glucuronic acid conjugates. 2. Derivatives of 2,4,5-trichlorophenol and 2,4,5-trichlorophenyl glucosiduronic acid and 2,4-dichlorophenylmercapturic acid were isolated from the urine as metabolites of gamma-2,3,4,5,6-pentachlorocyclohex-1-ene. 3. The phenolic metabolites of gamma-hexachlorocyclohexane and gamma-2,3,4,5,6-pentachlorocyclohex-1-ene isolated from urine were similar to those of 1,2,4-trichlorobenzene, which indicates that the two latter compounds are intermediates in gamma-hexachlorocyclohexane metabolism in rats. PMID:4158352

  10. Rapid approach to biobased telechelics through two one-pot thiol-ene click reactions.

    PubMed

    Lluch, Cristina; Ronda, Joan C; Galià, Marina; Lligadas, Gerard; Cádiz, Virginia

    2010-06-14

    The application of environmentally friendly thiol-ene chemistry to the preparation of biobased telechelics is presented in this work. This methodology is based on two one-pot photoinitiated thiol-ene click processes: step-growth polymerization using a 3,6-dioxa-1,8-octanedithiol and end-group postpolymerization modification with three functional thiols: 2-mercaptoethanol, 3-mercaptopropionic acid, and 3-mercaptopropyltrimethoxysilane. We applied this approach to a potentially 100% biomass-derived monomer, allyl ester of 10-undecenoic acid (UDA). To show the generality and scope of this methodology, a series of well-defined telechelics with molecular weight ranging from 1000-3000 g/mol and hydroxyl, carboxyl, or trimethoxysilyl groups at the polymer terminus were prepared. An exhaustive (1)H NMR and MALDI-TOF MS analyses demonstrates the highly end-group fidelity of this methodology being an interesting procedure for the accelerated preparation of telechelics derived from divinyl monomers. UDA-based thelechelic diol prepared using this methodology was reacted with 4,4'-methylenebis(phenylisocyanate) and 1,4-butanediol as the chain extender to obtain multiblock poly(ester urethane). PMID:20462176

  11. Preliminary Engineering Report contaminated groundwater seeps 317/319/ENE area

    SciTech Connect

    1996-10-01

    When the Resource Conservation and Recovery Act Facility Investigation (RFI) in the 317/319/ENE Area of Argonne National Laboratory-East (ANL-E) was being completed, groundwater was discovered moving to the surface through a series of seeps. The seeps are located approximately 600 ft south of the ANL fence line in Waterfall Glen Forest Preserve. Samples of this water were collected and analyzed for selected parameters. Two of five seeps sampled were found to contain detectable levels of organic contaminants. Three chemical species were identified: chloroform (14-25 {mu}g/L), carbon tetrachloride (56-340 {mu}g/L), and tetrachloroethylene (3-6 {mu}g/L). The other seeps did not contain detectable levels of volatile organic compounds (VOCs). The water issuing from these two contaminated seeps flows into a narrow ravine, where it is visible as a trickle of water flowing through sand and gravel deposits on the floor of the ravine. Approximately 100-ft downstream of the seep area, the contaminated water is no longer visible, having drained back into the soil in the bed of the ravine. Figure 1 shows the location of the 317/319/ENE Area in relation to the ANL-E site and the Waterfall Glen Forest Preserve.

  12. Which is the better forecasting model? A comparison between HAR-RV and multifractality volatility

    NASA Astrophysics Data System (ADS)

    Ma, Feng; Wei, Yu; Huang, Dengshi; Chen, Yixiang

    2014-07-01

    In this paper, by taking the 5-min high frequency data of the Shanghai Composite Index as example, we compare the forecasting performance of HAR-RV and Multifractal volatility, Realized volatility, Realized Bipower Variation and their corresponding short memory model with rolling windows forecasting method and the Model Confidence Set which is proved superior to SPA test. The empirical results show that, for six loss functions, HAR-RV outperforms other models. Moreover, to make the conclusions more precise and robust, we use the MCS test to compare the performance of their logarithms form models, and find that the HAR-log(RV) has a better performance in predicting future volatility. Furthermore, by comparing the two models of HAR-RV and HAR-log(RV), we conclude that, in terms of performance forecasting, the HAR-log(RV) model is the best model among models we have discussed in this paper.

  13. Transition-Metal-Free Cascade Synthesis of 4-Quinolones: Umpolung of Michael Acceptors via Ene Reaction with Arynes.

    PubMed

    Santhosh Reddy, R; Lagishetti, Chandraiah; Kiran, I N Chaithanya; You, Hengyao; He, Yun

    2016-08-01

    A novel "one-pot" aryne transformation is described that affords various 4-quinolone derivatives without recourse to transition-metal catalysis. Arynes react with aza-Morita-Baylis-Hillman (AMBH) adducts through a cascade sequence involving an insertion/cyclization/ene reaction process to afford 4-quinolones in high yields with a broad substrate scope under mild reaction conditions. Essentially, an umpolung of reactivity at the β carbon of α,β-unsaturated ketone has been achieved by an inverse electron demand aryne-ene reaction to provide a C-arylated product. PMID:27434217

  14. Intramolecular Conjugate Ene Reaction of γ-Difluoromethyl- and γ-Trifluoromethyl-α,β-Unsaturated γ-Butyrolactones.

    PubMed

    Srimontree, Watchara; Masusai, Chonticha; Soorukram, Darunee; Kuhakarn, Chutima; Reutrakul, Vichai; Pohmakotr, Manat

    2015-11-01

    A general synthetic strategy to cis-fused bicyclic γ-butyrolactones via the retro-Diels-Alder reaction/intramolecular conjugate ene cascade (RDA/ICE) reaction under the flash-vacuum pyrolysis of maleic anhydride adducts is developed. The reaction gave high yields of products with high stereoselectivity. The existence of the difluoromethyl or trifluoromethyl group at the γ-position of the in situ-generated homoalkenyl- or homoalkynyl-α,β-unsaturated γ-butyrolactones was found to accelerate the rate of the intramolecular conjugate ene reaction leading to γ-difluoromethylated and γ-trifluoromethylated cis-fused bicyclic γ-butyrolactones. PMID:26417837

  15. Shift-multiplexed holographic digital data page storage in a nanoparticle-(thiol-ene) polymer composite film.

    PubMed

    Momose, Keisuke; Takayama, Shingo; Hata, Eiji; Tomita, Yasuo

    2012-06-15

    We demonstrate shift-multiplexed holographic storage of 180 digital data pages with low symbol-error rates in a thick (250 μm) SiO2 nanoparticle-polymer composite film using step-growth thiol-ene photopolymerization. A two-dimensional 2:4 modulation code was employed for formatting digital data pages in order to reduce the average intensity of code block without decreasing the coding efficiency. This study clearly shows the feasibility of the thiol-ene based nanoparticle-polymer composite system as a holographic data storage medium. PMID:22739871

  16. 42 CFR 84.173 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE... body. (b) Harnesses shall be designed and constructed to permit easy removal and replacement...

  17. 42 CFR 84.1133 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE... hold the components of the respirator in position against the wearer's body. (b) Harnesses shall...

  18. Bispecific antibodies and CARs: generalized immunotherapeutics harnessing T cell redirection.

    PubMed

    Zhukovsky, Eugene A; Morse, Richard J; Maus, Marcela V

    2016-06-01

    To realize the full potential of cancer immunotherapy, the latest generation immunotherapeutics are designed to harness the potent tumor-killing capacity of T cells. Thus, to mobilize T cells, new optimized bispecific antibody (BsAb) designs, enabling efficient polyclonal redirection of cytotoxic activity through binding to CD3 and a Tumor Associated Antigen (TAA) and refined genetically modified T cells have recently expanded the arsenal of available options for cancer treatment. This review presents the current understanding of the parameters crucial to the design of optimal T cell redirecting BsAb and chimeric antigen receptor (CAR)-modified T cells. However, there are additional questions that require thorough elucidation. Both modalities will benefit from design changes that may increase the therapeutic window. One such approach could employ the discrimination afforded by multiple TAA to significantly increase selectivity. PMID:26963133

  19. Harnessing plant-microbe interactions for enhancing farm productivity.

    PubMed

    Macdonald, Catriona; Singh, Brajesh

    2014-01-01

    Declining soil fertility and farm productivity is a major global concern in order to achieve food security for a burgeoning world population. It is reported that improving soil health alone can increase productivity by 10-15% and in combination with efficient plant traits, farm productivity can be increased up to 50-60%. In this article we explore the emerging microbial and bioengineering technologies, which can be employed to achieve the transformational increase in farm productivity and can simultaneously enhance environmental outcomes i.e., low green house gas (GHG) emissions. We argue that metagenomics, meta-transcriptomics and metabolomics have potential to provide fundamental knowledge on plant-microbes interactions necessary for new innovations to increase farm productivity. Further, these approaches provide tools to identify and select novel microbial/gene resources which can be harnessed in transgenic and designer plant technologies for enhanced resource use efficiencies. PMID:23799872

  20. A low-cost float method of harnessing wave energy

    SciTech Connect

    George, M.P.

    1983-12-01

    The author proposes in this paper a low-cost and simple method of harnessing wave energy that should enable coastal regions to be self-sufficient in electric power. The method is eminently applicable to India and such developing countries, being simple and involving a small capital investment. The method was evolved after study of the Indian West Coast fronting the Arabian Sea, and can harness about 50% of the wave energy. A log of wood about 5 metres long and 50 cm. in diameter, having a specific gravity of 0.8 to 0.9, is made to float parallel to the beach and about 50 metres away from it. Its movement is restricted to the vertical plane by means of poles. Two roller chains are attached to the ends of the log which pass over two sprocket free-wheels. When the log is lifted with the crest of the wave, the roller chain moves over the free-wheel. When the trough of the wave reaches the log, its weight is applied to the sprocket wheels through the roller chains. Each sprocket wheel rotates and the rotation is multiplied with a gear wheel. The torque from the high speed spindle of the gear is applied to a small alternating current generator. The AC output from the generator is rectified and used either for charging a battery bank, or connected to the lighting system, or supplied to electrolytic tank for producing hydrogen and other chemicals at the site. A chain of such systems along the coast can supply enough power to light the fishermen's hamlets stretching along the coast.

  1. Light-driven nitrile imine-mediated tetrazole-ene cycloaddition as a versatile platform for fullerene conjugation.

    PubMed

    Sugawara, Yuuki; Jasinski, Nils; Kaupp, Michael; Welle, Alexander; Zydziak, Nicolas; Blasco, Eva; Barner-Kowollik, Christopher

    2015-08-21

    An efficient methodology for modular fullerene functionalization via the photo-induced nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) is introduced. The versatility and platform character of the method is illustrated by the light-driven reaction of fullerenes with small molecule, polymeric and surface-immobilized tetrazoles. The efficient fullerene conjugation is evidenced via mass spectrometric techniques. PMID:26179054

  2. Inorganic-Organic Thiol-ene Coated Mesh for Oil/Water Separation.

    PubMed

    Chen, Qiyi; de Leon, Al; Advincula, Rigoberto C

    2015-08-26

    A highly efficient mesh for oil/water separation was fabricated by using a superhydrophobic and superoleophilic coating of thiol-ene hybrid, consisting of pentaerythritol tetra(3-mercaptopropionate) (PETMP), 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (TMTVSi), and hydrophobic fumed silica nanoparticles, via a simple two-step fabrication process. Spray deposition and UV curing photopolymerization were sequentially performed, during which solvent evaporation provides microscale roughness while nanoparticle aggregation forms nanoscale roughness. The hierarchical morphologies were stabilized after UV curing photopolymerization. High contact angle (>150°) and low roll-off angle (<5°) were achieved due to the multiscale roughness structure of the hierarchical morphologies. These coatings also have excellent chemical resistance, as well as temperature and pH stability, after curing. PMID:26236915

  3. Modular modification of xylan with UV-initiated thiol-ene reaction.

    PubMed

    Nurmi, Leena; Salminen, Reeta; Setälä, Harri

    2015-03-01

    Birch xylan was functionalized with various thiols through UV initiated radical thiol-ene reaction under mild conditions. Xylan was allylated through etherification with allyl glycidyl ether under alkaline conditions. The allylated xylan was then reacted with thiols containing varying functional groups: trimethylbenzyl mercaptan, dodecanethiol, thioglycolic acid, L-cysteine and cysteamine hydrochloride. The reactions were conducted under homogeneous conditions at room temperature, either in water (hydrophilic thiols) or in DMF (hydrophobic thiols). The effect of reaction parameters to the functionalization efficiency was studied, including, for example, thiol excess, thiol character, initiator amount and reaction mixture concentration. The reactions were fast and 100% conversion of allyl groups was reached in most cases, sometimes already within 10 min. Water as solvent resulted generally in faster reactions when compared to DMF, and it was possible to conduct the aqueous reaction even without added UV initiator. It was also possible to incorporate two functionalities simultaneously during one reaction into the xylan structure. PMID:25665780

  4. Blue-sensitized nanoparticle-(thiol-ene) polymer composites for volume holographic recording

    NASA Astrophysics Data System (ADS)

    Takahashi, Jun-ichiro; Kawana, Masaru; Tomita, Yasuo

    2016-04-01

    We describe an experimental investigation of volume holographic recording in photopolymerizable thiol-ene based nanoparticle-polymer composites (NPCs) at a wavelength of 404 nm. We introduce a new photoinitiator, Irgacure819, for efficient volume holographic recording in the blue-violet spectral region and measure the photopolymerization dynamics and the holographic recording properties at its varying concentrations. It is found that doping of 0.1 wt.% Irgacure 819 provides the saturated refractive index modulation amplitude as large as 9.5×10-3 and the material recording sensitiviey as high as 1800 cm/J. These measured values are much larger than the minimum required values for holographic data storage media. It is also shown that the out-of-plane shrinkage can be suppressed more with decreasing the photoinitiator concentration. We compare these results with another blue sensitizer, Darocur TPO, to evaluate the performance of Irgacure 819.

  5. "Ene" Reactions of Singlet Oxygen at the Air-Water Interface.

    PubMed

    Malek, Belaid; Fang, William; Abramova, Inna; Walalawela, Niluksha; Ghogare, Ashwini A; Greer, Alexander

    2016-08-01

    Prenylsurfactants [(CH3)2C═CH(CH2)nSO3(-) Na(+) (n = 4, 6, or 8)] were designed to probe the "ene" reaction mechanism of singlet oxygen at the air-water interface. Increasing the number of carbon atoms in the hydrophobic chain caused an increase in the regioselectivity for a secondary rather than tertiary surfactant hydroperoxide, arguing for an orthogonal alkene on water. The use of water, deuterium oxide, and H2O/D2O mixtures helped to distinguish mechanistic alternatives to homogeneous solution conditions that include dewetting of the π bond and an unsymmetrical perepoxide transition state in the hydroperoxide-forming step. The prenylsurfactants and a photoreactor technique allowed a certain degree of interfacial control of the hydroperoxidation reaction on a liquid support, where the oxidant (airborne (1)O2) is delivered as a gas. PMID:27385423

  6. Microwave Spectrum of 1-Cyano-3-fluoro-but-1-ene.

    PubMed

    Kassi; Grée; Grée; Duflot; Petitprez; Wlodarczak

    2000-07-01

    The rotational spectrum of the 1-cyano-3-fluoro-but-1-ene has been recorded with a pulsed-nozzle microwave Fourier transform spectrometer over the range 6-20 GHz. The frequencies were fitted to the Hamiltonian of Watson (A-reduction, I(r) representation). The resulting rotational constants are A = 7493.404(1) MHz, B = 1211.9831(2) MHz, and C = 1096.0908(1) MHz. By comparing the experimental rotational constants with those obtained by ab initio calculations, we found without ambiguity that the stable conformation for the molecule is the one with the fluorine atom lying in the C&bond;CCN plane (CF-eclipsed conformer). Copyright 2000 Academic Press. PMID:10837163

  7. Tailored Composite Polymer-Metal Nanoparticles by Miniemulsion Polymerization and Thiol-ene Functionalization

    PubMed Central

    van Berkel, Kim Y.

    2010-01-01

    A simple and modular synthetic approach, based on miniemulsion polymerization, has been developed for the fabrication of composite polymer-metal nanoparticle materials. The procedure produces well-defined composite structures consisting of gold, silver or MnFe2O4 nanoparticles (∼10 nm in diameter) encapsulated within larger spherical nanoparticles of poly(divinylbenzene) (∼100 nm in diameter). This methodology readily permits the incorporation of multiple metal domains into a single polymeric particle, while still preserving the useful optical and magnetic properties of the metal nanoparticles. The morphology of the composite particles is retained upon increasing the inorganic content, and also upon redispersion in organic solvents. Finally, the ability to tailor the surface chemistry of the composite nanoparticles and incorporate steric stabilizing groups using simple thiol-ene chemistry is demonstrated. PMID:20657708

  8. Fates of imine intermediates in radical cyclizations of N-sulfonylindoles and ene-sulfonamides

    PubMed Central

    Zhang, Hanmo; Hay, E Ben; Geib, Stephen J

    2015-01-01

    Summary Two new fates of imine intermediates formed on radical cyclizations of ene-sulfonamides have been identified, reduction and hydration/fragmentation. Tin hydride-mediated cyclizations of 2-halo-N-(3-methyl-N-sulfonylindole)anilines provide spiro[indoline-3,3'-indolones] or spiro-3,3'-biindolines (derived from imine reduction), depending on the indole C2 substituent. Cyclizations of 2-haloanilide derivatives of 3-carboxy-N-sulfonyl-2,3-dihydropyrroles also presumably form spiro-imines as primary products. However, the lactam carbonyl group facilitates the ring-opening of these cyclic imines by a new pathway of hydration and retro-Claisen-type reaction, providing rearranged 2-(2'-formamidoethyl)oxindoles. PMID:26664585

  9. Highly stretchable thermoset fibers and nonwovens using thiol-ene photopolymerization.

    PubMed

    Shanmuganathan, Kadhiravan; Elliot, Steven M; Lane, Austin P; Ellison, Christopher J

    2014-08-27

    In this report, we describe the preparation and characterization of a new class of thermoset fibers with high elongation and elastic recovery. Integrating UV-activated thiol-ene photopolymerization and electrospinning, we demonstrate an environmentally friendly single step approach to convert small monomeric precursor molecules into highly elastic fibers and nonwoven mats. The fibers were derived by in situ photopolymerization of a trifunctional vinyl ether monomer and a tetrafunctional thiol. Although thermosets often offer good chemical and thermal stability, these fibers also have a high average elongation at break of 62%. The elastomeric nature of these vinyl-ether based fibers can be partly attributed to their subambient Tg and partly to the cross-link density, monomer structure, and resulting network homogeneity. Nonwoven mats of these fibers were also stretchable and exhibited a much higher elongation at break of about 85%. These thermoset stretchable fibers could have potential applications as textile, biomedical, hot chemical filtration, and composite materials. PMID:25075754

  10. 14 CFR 27.785 - Seats, berths, litters, safety belts, and harnesses.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Seats, berths, litters, safety belts, and... Cargo Accommodations § 27.785 Seats, berths, litters, safety belts, and harnesses. (a) Each seat, safety belt, harness, and adjacent part of the rotorcraft at each station designated for occupancy...

  11. 14 CFR 91.107 - Use of safety belts, shoulder harnesses, and child restraint systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...), booster-type child restraint systems (as defined in Federal Motor Vehicle Safety Standard No. 213 (49 CFR... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Use of safety belts, shoulder harnesses... OPERATING AND FLIGHT RULES Flight Rules General § 91.107 Use of safety belts, shoulder harnesses, and...

  12. 14 CFR 29.785 - Seats, berths, litters, safety belts, and harnesses.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Seats, berths, litters, safety belts, and... and Cargo Accommodations § 29.785 Seats, berths, litters, safety belts, and harnesses. (a) Each seat, safety belt, harness, and adjacent part of the rotorcraft at each station designated for occupancy...

  13. 42 CFR 84.116 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... components of the gas mask in position against the wearer's body. (b) Harnesses shall be designed and constructed to permit easy removal and replacement of gas mask parts, and where applicable, provide for... DEVICES Gas Masks § 84.116 Harnesses; installation and construction; minimum requirements. (a) Each...

  14. 42 CFR 84.116 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... components of the gas mask in position against the wearer's body. (b) Harnesses shall be designed and constructed to permit easy removal and replacement of gas mask parts, and where applicable, provide for... DEVICES Gas Masks § 84.116 Harnesses; installation and construction; minimum requirements. (a) Each...

  15. 42 CFR 84.116 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... components of the gas mask in position against the wearer's body. (b) Harnesses shall be designed and constructed to permit easy removal and replacement of gas mask parts, and where applicable, provide for... DEVICES Gas Masks § 84.116 Harnesses; installation and construction; minimum requirements. (a) Each...

  16. 42 CFR 84.116 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... components of the gas mask in position against the wearer's body. (b) Harnesses shall be designed and constructed to permit easy removal and replacement of gas mask parts, and where applicable, provide for... DEVICES Gas Masks § 84.116 Harnesses; installation and construction; minimum requirements. (a) Each...

  17. Harnessing the Power of Information Technology: Open Business Models in Higher Education

    ERIC Educational Resources Information Center

    Sheets, Robert G.; Crawford, Stephen

    2012-01-01

    Higher education is under enormous pressure to improve outcomes and reduce costs. Information technology can help achieve these goals, but only if it is properly harnessed. This article argues that one key to harnessing information technology is business model innovation that results in more "open" and "unbundled" operations in learning and…

  18. 14 CFR 135.171 - Shoulder harness installation at flight crewmember stations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Shoulder harness installation at flight crewmember stations. 135.171 Section 135.171 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... harness installed for each flight crewmember station. (b) Each flight crewmember occupying a...

  19. 14 CFR 135.171 - Shoulder harness installation at flight crewmember stations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Shoulder harness installation at flight crewmember stations. 135.171 Section 135.171 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... harness installed for each flight crewmember station. (b) Each flight crewmember occupying a...

  20. 14 CFR 135.171 - Shoulder harness installation at flight crewmember stations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Shoulder harness installation at flight crewmember stations. 135.171 Section 135.171 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... harness installed for each flight crewmember station. (b) Each flight crewmember occupying a...

  1. 14 CFR 135.171 - Shoulder harness installation at flight crewmember stations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Shoulder harness installation at flight crewmember stations. 135.171 Section 135.171 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... harness installed for each flight crewmember station. (b) Each flight crewmember occupying a...

  2. 14 CFR 135.171 - Shoulder harness installation at flight crewmember stations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Shoulder harness installation at flight crewmember stations. 135.171 Section 135.171 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... harness installed for each flight crewmember station. (b) Each flight crewmember occupying a...

  3. 14 CFR 105.43 - Use of single-harness, dual-parachute systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Use of single-harness, dual-parachute... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES PARACHUTE OPERATIONS Parachute Equipment and Packing § 105.43 Use of single-harness, dual-parachute systems. No person may conduct a...

  4. 14 CFR 105.43 - Use of single-harness, dual-parachute systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Use of single-harness, dual-parachute... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES PARACHUTE OPERATIONS Parachute Equipment and Packing § 105.43 Use of single-harness, dual-parachute systems. No person may conduct a...

  5. 14 CFR 105.43 - Use of single-harness, dual-parachute systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Use of single-harness, dual-parachute... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES PARACHUTE OPERATIONS Parachute Equipment and Packing § 105.43 Use of single-harness, dual-parachute systems. No person may conduct a...

  6. 14 CFR 105.43 - Use of single-harness, dual-parachute systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Use of single-harness, dual-parachute... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES PARACHUTE OPERATIONS Parachute Equipment and Packing § 105.43 Use of single-harness, dual-parachute systems. No person may conduct a...

  7. 14 CFR 105.43 - Use of single-harness, dual-parachute systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Use of single-harness, dual-parachute... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES PARACHUTE OPERATIONS Parachute Equipment and Packing § 105.43 Use of single-harness, dual-parachute systems. No person may conduct a...

  8. Oxidatively Triggered Carbon-Carbon Bond Formation in Ene-amide Complexes.

    PubMed

    Jacobs, Brian P; Wolczanski, Peter T; Lobkovsky, Emil B

    2016-05-01

    Ene-amides have been explored as ligands and substrates for oxidative coupling. Treatment of CrCl2, Cl2Fe(PMe3)2, and Cl2Copy4 with 2 equiv of {(2,6-(i)Pr2C6H3)(1-(c)Hexenyl)N}Li afforded pseudosquare planar {η(3)-C,C,N-(2,6-(i)Pr2C6H3)(1-(c)Hexenyl)N}2Cr (1-Cr, 78%), trigonal {(2,6-(i)Pr2C6H3)(1-(c)Hexenyl)N}2Fe(PMe3) (2-Fe, 80%), and tetrahedral {(2,6-(i)Pr2C6H3)(1-(c)Hexenyl)N}2Co(py)2 (3-Co, 91%) in very good yields. The addition of CrCl3 to 1-Cr, and FeCl3 to 2-Fe, afforded oxidatively triggered C-C bond formation as rac-2,2'-di(2,6-(i)Pr2C6H3N═)2dicyclohexane (EA2) was produced in modest yields. Various lithium ene-amides were similarly coupled, and the mechanism was assessed via stoichiometric reactions. Some ferrous compounds (e.g., 2-Fe, FeCl2) were shown to catalyze C-arylation of {(2,6-(i)Pr2C6H3)(1-(c)Hexenyl)N}Li with PhBr, but the reaction was variable. Structural characterizations of 1-Cr, 2-Fe, and 3-Co are reported. PMID:27064509

  9. Support to Climate Data Dissemination in a Worldwide Data Federation by IS-ENES2

    NASA Astrophysics Data System (ADS)

    Rathmann, Torsten; Toussaint, Frank; Kindermann, Stephan; Lautenschlager, Michael

    2015-04-01

    Thousands of users accessed climate data produced as part of the Coupled Model Intercomparison Project Phase 5 (CMIP5). The data were created by about 30 different institutes and disseminated to a large variety of end users via a worldwide distributed infrastructure (Earth System Grid Federation, ESGF) consisting of data nodes and data portals. Part of the data was also used for the 5th Assessment Report of the Intergovernmental Panel on Climate Change and preserved in a long term archive. A support activity was funded within the IS-ENES2 FP7 project to support the various aspects of data dissemination for large intercomparison projects like CMIP5 and CORDEX. The activity was structured into the following parts: Support for data providers: • Development of basic data quality assurance tools, to be applied by data provider prior to making data accessible in the data federation • Support in installing and using the quality assurance tools • Agreements on best practices of data dissemination (e.g. search facets to be supported across sites etc.) Support for data users: Establishment of basic user support infrastructure components and services: • Askbot based internet forum for user support questions and answers • Support pages on central portals • Continuous maintenance of user support mailing lists Support for data centres and for fostering their collaboration: • Development of automatic consistency checking routines for data federation portals operated at different sites • Organization of data node installation and operation support events • Collection of distributed data usage statistic metrics • Development of Data Management Plans (DMP) • Activities towards common data access policies The experiences gained within the IS-ENES2 support activities will provide the basis of activities for improving the user support process in the future, especially in the context of upcoming large intercomparison projects like CMIP6, which will use the same

  10. (η4-Cyclo­octa­tetra­ene)(η8-cyclo­octa­tetra­ene)iodido­tantalum(V)

    PubMed Central

    Verma, Pratik; Sussman, Victor J.; Brennessel, William W.; Ellis, John E.

    2014-01-01

    The title complex, [Ta(η4-C8H8)(η8-C8H8)I], lies across a crystallographic mirror plane that includes the TaV atom and the iodide ligand. One cyclo­octa­tetra­ene (cot) ring is η4-coordinating and is bis­ected by the mirror plane. The fold angle between the plane of the coordinating butadiene portion and the middle plane of the ring is 27.4 (4)°. An additional minor fold angle of 9.3 (7)° exists between the final plane in the ring and the middle plane. The other cot ring is η8-coordinating and is also cut by the mirror plane. In this case, the ring is disordered over the mirror plane, and one position is modeled with appropriate restraints and constraints with respect to distances, angles and displacement parameters (the second position is generated by symmetry). This ring is nearly planar, with an r.m.s. deviation of only 0.05 Å when all eight C atoms are included in the calculation. Pairs of inter­molecular η8-cot rings are parallel stacked and slightly off center, with a centroid–centroid distance of 3.652 Å. No other significant inter­molecular inter­actions are observed. The compound is of inter­est as the first structurally characterized mixed halogen–cot complex of the group 5 metals and contains the longest terminal Ta—I distance [3.0107 (5) Å] reported to date. PMID:25161515

  11. Harnessing click detectors for the genuine characterization of light states

    PubMed Central

    Heilmann, René; Sperling, Jan; Perez-Leija, Armando; Gräfe, Markus; Heinrich, Matthias; Nolte, Stefan; Vogel, Werner; Szameit, Alexander

    2016-01-01

    The key requirement for harnessing the quantum properties of light is the capability to detect and count individual photons. Of particular interest are photon-number-resolving detectors, which allow one to determine whether a state of light is classical or genuinely quantum. Existing schemes for addressing this challenge rely on a proportional conversion of photons to electrons. As such, they are capable of correctly characterizing small photon fluxes, yet are limited by uncertainties in the conversion rate. In this work, we employ a divide-and-conquer approach to infallibly discerning non-classicality of states of light. This is achieved by transforming the incident fields into uniform spatial distributions that readily lend themselves for characterization by standard on-off detectors. Since the exact statistics of the light stream in multiplexed on-off detectors are click statistics, our technique is freely scalable to accommodate–in principle–arbitrarily large photon fluxes. Our experiments pave the way towards genuine integrated photon-number-resolving detection for advanced on-chip photonic quantum networks. PMID:26771053

  12. Harnessing click detectors for the genuine characterization of light states.

    PubMed

    Heilmann, René; Sperling, Jan; Perez-Leija, Armando; Gräfe, Markus; Heinrich, Matthias; Nolte, Stefan; Vogel, Werner; Szameit, Alexander

    2016-01-01

    The key requirement for harnessing the quantum properties of light is the capability to detect and count individual photons. Of particular interest are photon-number-resolving detectors, which allow one to determine whether a state of light is classical or genuinely quantum. Existing schemes for addressing this challenge rely on a proportional conversion of photons to electrons. As such, they are capable of correctly characterizing small photon fluxes, yet are limited by uncertainties in the conversion rate. In this work, we employ a divide-and-conquer approach to infallibly discerning non-classicality of states of light. This is achieved by transforming the incident fields into uniform spatial distributions that readily lend themselves for characterization by standard on-off detectors. Since the exact statistics of the light stream in multiplexed on-off detectors are click statistics, our technique is freely scalable to accommodate-in principle-arbitrarily large photon fluxes. Our experiments pave the way towards genuine integrated photon-number-resolving detection for advanced on-chip photonic quantum networks. PMID:26771053

  13. Harnessing the protective potential of HIV-1 neutralizing antibodies

    PubMed Central

    Smith, S Abigail; Derdeyn, Cynthia A

    2016-01-01

    Recent biological, structural, and technical advances are converging within the HIV-1 vaccine field to harness the power of antibodies for prevention and therapy. Numerous monoclonal antibodies with broad neutralizing activity against diverse HIV-1 isolates have now been identified, revealing at least five sites of vulnerability on the envelope (Env) glycoproteins. While there are practical and technological barriers blocking a clear path from broadly neutralizing antibodies (bNAb) to a protective vaccine, this is not a dead end. Scientists are revisiting old approaches with new technology, cutting new trails through unexplored territory, and paving new roads in the hopes of preventing HIV-1 infection. Other promising avenues to capitalize on the power of bNAbs are also being pursued, such as passive antibody immunotherapy and gene therapy approaches. Moreover, non-neutralizing antibodies have inhibitory activities that could have protective potential, alone or in combination with bNAbs. With a new generation of bNAbs, and a clinical trial that associated antibodies with reduced acquisition, the field is closer than ever to developing strategies to use antibodies against HIV-1. PMID:26918160

  14. Harnessing click detectors for the genuine characterization of light states

    NASA Astrophysics Data System (ADS)

    Heilmann, René; Sperling, Jan; Perez-Leija, Armando; Gräfe, Markus; Heinrich, Matthias; Nolte, Stefan; Vogel, Werner; Szameit, Alexander

    2016-01-01

    The key requirement for harnessing the quantum properties of light is the capability to detect and count individual photons. Of particular interest are photon-number-resolving detectors, which allow one to determine whether a state of light is classical or genuinely quantum. Existing schemes for addressing this challenge rely on a proportional conversion of photons to electrons. As such, they are capable of correctly characterizing small photon fluxes, yet are limited by uncertainties in the conversion rate. In this work, we employ a divide-and-conquer approach to infallibly discerning non-classicality of states of light. This is achieved by transforming the incident fields into uniform spatial distributions that readily lend themselves for characterization by standard on-off detectors. Since the exact statistics of the light stream in multiplexed on-off detectors are click statistics, our technique is freely scalable to accommodate-in principle-arbitrarily large photon fluxes. Our experiments pave the way towards genuine integrated photon-number-resolving detection for advanced on-chip photonic quantum networks.

  15. Abasic pivot substitution harnesses target specificity of RNA interference

    PubMed Central

    Lee, Hye-Sook; Seok, Heeyoung; Lee, Dong Ha; Ham, Juyoung; Lee, Wooje; Youm, Emilia Moonkyung; Yoo, Jin Seon; Lee, Yong-Seung; Jang, Eun-Sook; Chi, Sung Wook

    2015-01-01

    Gene silencing via RNA interference inadvertently represses hundreds of off-target transcripts. Because small interfering RNAs (siRNAs) can function as microRNAs, avoiding miRNA-like off-target repression is a major challenge. Functional miRNA–target interactions are known to pre-require transitional nucleation, base pairs from position 2 to the pivot (position 6). Here, by substituting nucleotide in pivot with abasic spacers, which prevent base pairing and alleviate steric hindrance, we eliminate miRNA-like off-target repression while preserving on-target activity at ∼80–100%. Specifically, miR-124 containing dSpacer pivot substitution (6pi) loses seed-mediated transcriptome-wide target interactions, repression activity and biological function, whereas other conventional modifications are ineffective. Application of 6pi allows PCSK9 siRNA to efficiently lower plasma cholesterol concentration in vivo, and abolish potentially deleterious off-target phenotypes. The smallest spacer, C3, also shows the same improvement in target specificity. Abasic pivot substitution serves as a general means to harness the specificity of siRNA experiments and therapeutic applications. PMID:26679372

  16. Harnessing non-Markovian quantum memory by environmental coupling

    NASA Astrophysics Data System (ADS)

    Man, Zhong-Xiao; Xia, Yun-Jie; Lo Franco, Rosario

    2015-07-01

    Controlling the non-Markovian dynamics of open quantum systems is essential in quantum information technology since it plays a crucial role in preserving quantum memory. Albeit in many realistic scenarios the quantum system can simultaneously interact with composite environments, this condition remains little understood, particularly regarding the effect of the coupling between environmental parts. We analyze the non-Markovian behavior of a qubit interacting at the same time with two coupled single-mode cavities which in turn dissipate into memoryless or memory-keeping reservoirs. We show that increasing the control parameter, that is the two-mode coupling, allows for triggering and enhancing a non-Markovian dynamics for the qubit starting from a Markovian one in the absence of coupling. Surprisingly, if the qubit dynamics is non-Markovian for the zero control parameter, increasing the latter enables multiple transitions from non-Markovian to Markovian regimes. These results hold independently on the nature of the reservoirs. This work highlights that suitably engineering the coupling between parts of a compound environment can efficiently harness the quantum memory, stored in a qubit, based on non-Markovianity.

  17. Harnessing and understanding feedback technology in applied settings.

    PubMed

    Phillips, Elissa; Farrow, Damian; Ball, Kevin; Helmer, Richard

    2013-10-01

    Research on the influence of augmented feedback effects on both skill learning and performance has been examined from two differing positions, generally reflective of two core movement science disciplines: motor learning and biomechanics. The motor learning approach has been to examine the content and timing of feedback under tightly controlled laboratory settings, with a focus on simple tasks and the influence of movement outcome feedback. At the other end of the spectrum are biomechanical approaches, which have been primarily devoted to demonstrating the capacity of measurement technology to quantify and report on movement pattern effectiveness. This review highlights the gap left by these two approaches and argues that advancement of our understanding of feedback application in practical settings requires a shift towards a multi-disciplinary focus. A particular focus of the review is on how researchers and practitioners need to harness our understanding and subsequent application of the emergent feedback technologies most prevalent in elite sport settings and clinical sports medicine. We highlight important considerations for future applied multidisciplinary research driven by relevant theory and methodological design to more comprehensively capture how feedback systems can be used to facilitate the development of skilled performance. PMID:23828029

  18. Harnessing the electromagnetic absorptions of metamaterials for positive applications

    NASA Astrophysics Data System (ADS)

    Xiang, Yuanjiang; Zou, Yanhong; Luo, Hailu; Dai, Xiaoyu; Wen, Shuangchun; Fan, Dianyuan

    2010-08-01

    Absorption or loss is inevitable for the metal-based metamaterials (MMs) due to the intrinsic loss of the metal, and constitutes a major hurdle to the practical realization of most applications such as a sub-wavelength lens. Thus, to reduce the losses becomes one of the major challenges in the MM field. However, the inevitable loss can also be harnessed to take a positive role in the applications of MMs such as stealth technology or other types of cloaking devices. In this presentation, after a brief review of the advances in MMs-based absorbers, we present several schemes to fulfill the desired electromagnetic absorption properties, both linear and nonlinear. For linear absorption, we have experimentally demonstrated that the absorption performance of an ordinary microwave absorbing material can be evidently improved by using the electric resonance resulting from an array of subwavelength metallic circuit elements. For nonlinear absorption, we show theoretically that the active linear magnetic permeability induces a nonlinear absorption, similar to the two-photon absorption (TPA), of electric field in a lossy MM with a Kerr-type nonlinear polarization.

  19. Harnessing high-dimensional hyperentanglement through a biphoton frequency comb

    NASA Astrophysics Data System (ADS)

    Xie, Zhenda; Zhong, Tian; Shrestha, Sajan; Xu, Xinan; Liang, Junlin; Gong, Yan-Xiao; Bienfang, Joshua C.; Restelli, Alessandro; Shapiro, Jeffrey H.; Wong, Franco N. C.; Wei Wong, Chee

    2015-08-01

    Quantum entanglement is a fundamental resource for secure information processing and communications, and hyperentanglement or high-dimensional entanglement has been separately proposed for its high data capacity and error resilience. The continuous-variable nature of the energy-time entanglement makes it an ideal candidate for efficient high-dimensional coding with minimal limitations. Here, we demonstrate the first simultaneous high-dimensional hyperentanglement using a biphoton frequency comb to harness the full potential in both the energy and time domain. Long-postulated Hong-Ou-Mandel quantum revival is exhibited, with up to 19 time-bins and 96.5% visibilities. We further witness the high-dimensional energy-time entanglement through Franson revivals, observed periodically at integer time-bins, with 97.8% visibility. This qudit state is observed to simultaneously violate the generalized Bell inequality by up to 10.95 standard deviations while observing recurrent Clauser-Horne-Shimony-Holt S-parameters up to 2.76. Our biphoton frequency comb provides a platform for photon-efficient quantum communications towards the ultimate channel capacity through energy-time-polarization high-dimensional encoding.

  20. Mic Flocks in the Cloud: Harnessing Mobile Ubiquitous Sensor Networks

    NASA Astrophysics Data System (ADS)

    Garces, M. A.; Christe, A.

    2015-12-01

    Smartphones provide a commercial, off-the-shelf solution to capture, store, analyze, and distribute infrasound using on-board or external microphones (mics) as well as on-board barometers. Free iOS infrasound apps can be readily downloaded from the Apple App Store, and Android versions are in progress. Infrasound propagates for great distances, has low sample rates, and provides a tractable pilot study scenario for open distributed sensor networks at regional and global scales using one of the most ubiquitous sensors on Earth - microphones. Data collection is no longer limited to selected vendors at exclusive prices: anybody on Earth can record and stream infrasound, and the diversity of recording systems and environments is rapidly expanding. Global deployment may be fast and easy (www.redvox.io), but comes with the cost of increasing data volume, velocity, variety, and complexity. Flocking - the collective motion of mobile agents - is a natural human response to threats or events of interest. Anticipating, modeling and harnessing flocking sensor topologies will be necessary for adaptive array and network processing. The increasing data quantity and complexity will exceed the processing capacity of human analysts and most research servers. We anticipate practical real-time applications will require the on-demand adaptive scalability and resources of the Cloud. Cloud architectures for such heterogeneous sensor networks will consider eventual integration into the Global Earth Observation System of Systems (GEOSS).

  1. Harnessing the Therapeutic Potential of Th17 Cells

    PubMed Central

    Bystrom, Jonas; Taher, Taher E.; Muhyaddin, M. Sherwan; Clanchy, Felix I.; Mangat, Pamela; Jawad, Ali S.; Williams, Richard O.; Mageed, Rizgar A.

    2015-01-01

    Th17 cells provide protective immunity to infections by fungi and extracellular bacteria as well as cancer but are also involved in chronic inflammation. The cells were first identified by their ability to produce interleukin 17A (IL-17A) and, subsequently, associated with chronic inflammation and autoimmunity. Th17 cells have some gene profile similarity with stem cells and can remain dormant in mucosal tissues for long periods. Indeed, recent studies suggest that functionally distinct subsets of pro- and anti-inflammatory Th17 cells can interchange phenotype and functions. For development, Th17 cells require activation of the transcription factors STAT3 and RORγt while RUNX1, c-Maf, and Aiolos are involved in changes of phenotype/functions. Attempts to harness Th17 cells against pathogens and cancer using vaccination strategies are being explored. The cells gain protective abilities when induced to produce interferon γ (IFNγ). In addition, treatment with antibodies to IL-17 is effective in treating patients with psoriasis, psoriatic arthritis, and refectory rheumatoid arthritis. Moreover, since RORγt is a nuclear receptor, it is likely to be a potential future drug target for modulating Th17 functions. This review explores pathways through which Th17 subsets are induced, the molecular basis of their plasticity, and potential therapeutic strategies for their modulation in diseases. PMID:26101460

  2. Application of a modified harness design for attachment of radio transmitters to shorebirds

    USGS Publications Warehouse

    Sanzenbacher, Peter; Haig, Susan M.; Oring, L.W.

    2000-01-01

    Radio transmitter attachment methodology is important to the design of radio telemetry studies. In 1998, we attached 5 transmitters to a captive population of Western Sandpipers(Calidris mauri) and 7 transmitters to wild Killdeer (Charadriusv ociferus) using a modified version of the Rappolea nd Tipton (1991) figure-8 leg-loop harness. Captive birds fitted with harnesses did not exhibit quantifiable differences in behavior relative to control birds. Based on initial success in using the leg-loop harnesses, we used harnesses to attach transmitters in the wild to 30 Killdeer and 49 Dunlin (Calidris alpina) during the winters of 1998-1999 and 1999-2000. This was part of a study on movements of wintering shorebirds in the Willamette Valley of Oregon,USA. Wild birds showed no adverse effects of the harnesses.Thus, the described harness is a practical method for attachment of transmitters to shorebirds. Advantages of this harness method include a reduction in handling time at capture, elimination of the need to clip feathers for attachment, and increased transmitter retention time.

  3. Lumbar spine disc heights and curvature: upright posture vs. supine compression harness

    NASA Technical Reports Server (NTRS)

    Lee, Shi-Uk; Hargens, Alan R.; Fredericson, Michael; Lang, Philipp K.

    2003-01-01

    INTRODUCTION: Spinal lengthening in microgravity is thought to cause back pain in astronauts. A spinal compression harness can compress the spine to eliminate lengthening but the loading condition with harness is different than physiologic conditions. Our purpose was to compare the effect of spine compression with a harness in supine position on disk height and spinal curvature in the lumbar spine to that of upright position as measured using a vertically open magnetic resonance imaging system. METHODS: Fifteen healthy subjects volunteered. On day 1, each subject lay supine for an hour and a baseline scan of the lumbar spine was performed. After applying a load of fifty percent of body weight with the harness for thirty minutes, the lumbar spine was scanned again. On day 2, after a baseline scan, a follow up scan was performed after kneeling for thirty minutes within the gap between two vertically oriented magnetic coils. Anterior and posterior disk heights, posterior disk bulging, and spinal curvature were measured from the baseline and follow up scans. RESULTS: Anterior disk heights increased and posterior disk heights decreased compared with baseline scans both after spinal compression with harness and upright posture. The spinal curvature increased by both loading conditions of the spine. DISCUSSION: The spinal compression with specially designed harness has the same effect as the physiologic loading of the spine in the kneeling upright position. The harness shows some promise as a tool to increase the diagnostic capabilities of a conventional MR system.

  4. Impact of Harness Attachment Point on Kinetics and Kinematics During Sled Towing.

    PubMed

    Bentley, Ian; Atkins, Steve J; Edmundson, Christopher J; Metcalfe, John; Sinclair, Jonathan K

    2016-03-01

    Resisted sprint training is performed in a horizontal direction and involves similar muscles, velocities, and ranges of motion (ROM) to those of normal sprinting. Generally, sleds are attached to the athletes through a lead (3 m) and harness; the most common attachment points are the shoulder or waist. At present, it is not known how the different harness point's impact on the kinematics and kinetics associated with sled towing (ST). The aim of the current investigation was to examine the kinetics and kinematics of shoulder and waist harness attachment points in relation to the acceleration phase of ST. Fourteen trained men completed normal and ST trials, loaded at 10% reduction of sprint velocity. Sagittal plane kinematics from the trunk, hip, knee, and ankle were measured, together with stance phase kinetics (third footstrike). Kinetic and kinematic parameters were compared between harness attachments using one-way repeated-measures analysis of variance. The results indicated that various kinetic differences were present between the normal and ST conditions. Significantly greater net horizontal mean force, net horizontal impulses, propulsive mean force, and propulsive impulses were measured (p < 0.05). Interestingly, the waist harness also led to greater net horizontal impulse when compared with the shoulder attachment (p < 0.001). In kinematic terms, ST conditions significantly increased peak flexion in hip, knee, and ankle joints compared with the normal trials (p < 0.05). Results highlighted that the shoulder harness had a greater impact on trunk and knee joint kinematics when compared with the waist harness (p < 0.05). In summary, waist harnesses seem to be the most suitable attachment point for the acceleration phase of sprinting. Sled towing with these attachments resulted in fewer kinematic alterations and greater net horizontal impulse when compared with the shoulder harness. Future research is necessary in order to explore the long-term adaptations of

  5. Oestrogenic and antioestrogenic actions in a series of triphenylbut-1-enes: modulation of prolactin synthesis in vitro.

    PubMed Central

    Jordan, V. C.; Koch, R.; Mittal, S.; Schneider, M. R.

    1986-01-01

    The oestrogenic and antioestrogenic activities of a series of substituted derivatives of 1,1,2 triphenylbut-1-ene have been determined using primary cultures of rat pituitary gland cells to monitor prolactin synthesis in vitro. The relative binding affinity of the agonists for the oestrogen receptor was consistent with their oestrogenic potency. Bis para substitution at C1 of 1,1,2 triphenylbut-1-ene with either phenolic or acetoxy groups produced partial agonists. The antioestrogenic properties were reversible by the incubation of cells with increasing concentrations of oestradiol. The results lend support to a hypothetical single binding site model of oestrogen action, based upon an adaptation of Belleau's macromolecular perturbation theory. PMID:3955300

  6. Facial Synthesis of o-Carborane-Substituted Alkenes and Allenes by a Regioselective Ene Reaction of 1,3-Dehydro-o-carborane.

    PubMed

    Zhao, Da; Zhang, Jiji; Xie, Zuowei

    2015-07-13

    1,3-Dehydro-o-carborane is a useful synthon for selective cage boron functionalization of o-carboranes. It reacts readily with alkenes or alkynes to give a variety of cage B(3)-alkenyl/allenyl o-carboranes by ene reactions in very high yields and excellent regioselectivity. This can be ascribed to the highly polarized cage C-B multiple bond, which lowers the activation barriers of the ene reaction. PMID:26074122

  7. Copper-catalyzed aerobic oxidation of hydroxamic acids leads to a mild and versatile acylnitroso ene reaction.

    PubMed

    Frazier, Charles P; Engelking, Jarred R; Read de Alaniz, Javier

    2011-07-13

    A mild formation of transient acylnitroso intermediates using a copper chloride catalyst and 1 atm of air as the terminal oxidant is described. The mild reaction conditions enable the inter- and intramolecular acylnitroso ene reaction with a wide range of functionalized alkene partners, as well as the first asymmetric variant. Notably, this transformation provides a practical and operationally simple method for effecting allylic amidation using an environmentally benign oxidant and a readily abundant transition metal. PMID:21678942

  8. Harnessing DNA-induced immune responses for improving cancer vaccines

    PubMed Central

    Herrada, Andrés A.; Rojas-Colonelli, Nicole; González-Figueroa, Paula; Roco, Jonathan; Oyarce, César; Ligtenberg, Maarten A.; Lladser, Alvaro

    2012-01-01

    DNA vaccines have emerged as an attractive strategy to promote protective cellular and humoral immunity against the encoded antigen. DNA vaccines are easy to generate, inexpensive to produce and purify at large-scale, highly stable and safe. In addition, plasmids used for DNA vaccines act as powerful “danger signals” by stimulating several DNA-sensing innate immune receptors that promote the induction of protective adaptive immunity. The induction of tumor-specific immune responses represents a major challenge for DNA vaccines because most of tumor-associated antigens are normal non-mutated self-antigens. As a consequence, induction of potentially self-reactive T cell responses against such poorly immunogenic antigens is controlled by mechanisms of central and peripheral tolerance as well as tumor-induced immunosuppression. Although several DNA vaccines against cancer have reached clinical testing, disappointing results have been observed. Therefore, the development of new adjuvants that strongly stimulate the induction of antitumor T cell immunity and counteract immune-suppressive regulation is an attractive approach to enhance the potency of DNA vaccines and overcome tumor-associated tolerance. Understanding the DNA-sensing signaling pathways of innate immunity that mediate the induction of T cell responses elicited by DNA vaccines represents a unique opportunity to develop novel adjuvants that enhance vaccine potency. The advance of DNA adjuvants needs to be complemented with the development of potent delivery systems, in order to step toward successful clinical application. Here, we briefly discuss recent evidence showing how to harness DNA-induced immune response to improve the potency of cancer vaccines and counteract tumor-associated tolerance. PMID:23111166

  9. Cancer vaccines: harnessing the potential of anti-tumor immunity.

    PubMed

    Suckow, Mark A

    2013-10-01

    Although the presence of cancer suggests failure of the immune system to protect against development of tumors, the possibility that immunity can be redirected and focused to generate an anti-tumor response offers great translational possibility. The key to this is identifying antigens likely to be present in any given tumor and functionally critical to tumor survival and growth. Such tumor-associated antigens (TAAs) are varied and optimally should be absent from normal tissue. Of particular interest are TAAs associated with the tumor stroma, as immunity directed against the stroma may restrict the ability of the tumor to grow and metastasize. Important to directing the immune system toward an effect anti-tumor response is the understanding of how TAAs are processed and how the tumor is able to evade immune elimination. The process of immunoediting happens in response to the selective pressure that the immune system places upon tumor cell populations and allows for emergence of tumor cells capable of escaping immune destruction. Efforts to harness the immune system for clinical application has been aided by vaccines based on purified recombinant protein or nucleic acid TAAs. For example, a vaccine for canine melanoma has been developed and approved based on immunization with DNA components of tyrosinase, a glycoprotein essential to melanin synthesis. The performance of cancer vaccines has been aided in some cases when supplemented with immunostimulatory molecules such as interleukin 2 or a novel extracellular matrix vaccine adjuvant. Vaccines with the broadest menu of antigenic targets may be those most likely to succeed against cancer. For this reason, tissue vaccines produced from harvested tumor material may offer significant benefit. With several cancer vaccines on the veterinary and human markets, efforts to understand basic tumor immunology are soon to yield great dividends. PMID:23850019

  10. Aptamer-based organic-silica hybrid affinity monolith prepared via "thiol-ene" click reaction for extraction of thrombin.

    PubMed

    Wang, Zheng; Zhao, Jin-cheng; Lian, Hong-zhen; Chen, Hong-yuan

    2015-06-01

    A novel strategy for preparing aptamer-based organic-silica hybrid monolithic column was developed via "thiol-ene" click chemistry. Due to the large specific surface area of the hybrid matrix and the simplicity, rapidness and high efficiency of "thiol-ene" click reaction, the average coverage density of aptamer on the organic-silica hybrid monolith reached 420 pmol μL(-1). Human α-thrombin can be captured on the prepared affinity monolithic column with high specificity and eluted by NaClO4 solution. N-p-tosyl-Gly-Pro-Arg p-nitroanilide acetate was used as the sensitive chromogenic substrate of thrombin. The thrombin enriched by this affinity column was detected with a detection of limit of 0.01 μM by spectrophotometry. Furthermore, the extraction recovery of thrombin at 0.15 μM in human serum was 91.8% with a relative standard deviation of 4.0%. These results indicated that "thiol-ene" click chemistry provided a promising technique to immobilize aptamer on organic-inorganic hybrid monolith and the easily-assembled affinity monolithic material could be used to realize highly selective recognition of trace proteins. PMID:25863371

  11. Polymorphism versus thermochromism: interrelation of color and conformation in overcrowded bistricyclic aromatic enes.

    PubMed

    Biedermann, P Ulrich; Stezowski, John J; Agranat, Israel

    2006-04-12

    The nature of the thermochromic form of overcrowded bistricyclic aromatic enes (BAEs) has been controversial for a century. We report the single-crystal X-ray structure analysis of the deep-purple and yellow polymorphs of 9-(2,7-dimethyl-9H-fluoren-9-ylidene)-9H-xanthene (11), which revealed the molecules in a twisted and a folded conformation, respectively. Therefore, the deeply colored thermochromic form B of BAEs is identified as having a twisted conformation and the ambient-temperature form A as having a folded conformation. This relationship between the color and the conformation is further supported by the X-ray structures of the deep-purple crystals of the twisted 9-(9H-fluoren-9-ylidene)-9H-xanthene (10), and of the yellow crystals of the folded 9-(11H-benzo[b]fluoren-11-ylidene)-9H-xanthene (12). Based on this conclusive crystallographic evidence, eleven previously proposed rationales of thermochromism in BAEs are refuted. In the twisted structures, the tricyclic moieties are nearly planar and the central double bond is elongated to 1.40 A and twisted by 42 degrees . In the folded structures, the xanthylidene moieties are folded by 45 degrees and the fluorenylidene moieties by 18-20 degrees . Factors stabilizing the twisted and folded conformations are discussed, including twisting of formal single or double bonds, intramolecular overcrowding, and the significance of a dipolar aromatic "xanthenylium-fluorenide" push-pull structure. PMID:16440387

  12. Simple thiol-ene click chemistry modification of SBA-15 silica pores with carboxylic acids.

    PubMed

    Bordoni, Andrea V; Lombardo, M Verónica; Regazzoni, Alberto E; Soler-Illia, Galo J A A; Wolosiuk, Alejandro

    2015-07-15

    A straightforward approach for anchoring tailored carboxylic groups in mesoporous SiO2 colloidal materials is presented. The thiol-ene photochemical reaction between vinyltrimethoxysilane precursors and various thiocarboxylic acids which has, click chemistry features (i.e. high conversion yields, insensitivity to oxygen, mild reaction conditions), results in carboxylated silane precursors that can be readily used as surface modifiers. The carboxylic groups of acetic, undecanoic and succinic acid were immobilized on the silica mesopore walls of SBA-15 powders employing the synthesized silane precursors. Post-grafting has been confirmed through infrared spectrometry (FTIR), energy dispersive X-ray spectroscopy (EDS), elemental analysis (EA) and zeta potential measurements. Detailed field-emission gun scanning electron microscopy (FESEM) images and small angle X-ray scattering (SAXS) data revealed parallel mesopores and ordered mesostructures. It is shown that the immobilized COOH groups are chemically accessible for acid-base reactions as well as copper adsorption. Immobilization of easily synthesized tailored carboxylic modified alkoxide precursors within mesoporous systems provides a unique chemical nanoenvironment within these ordered frameworks. PMID:25845883

  13. Biostability enhancement of oil core - polysaccharide multilayer shell via photoinitiator free thiol-ene 'click' reaction.

    PubMed

    Calcagno, Vincenzo; Vecchione, Raffaele; Sagliano, Angela; Carella, Antonio; Guarnieri, Daniela; Belli, Valentina; Raiola, Luca; Roviello, Antonio; Netti, Paolo A

    2016-06-01

    Layer-by-layer of polyelectrolytes has emerged as one of the easiest and most controlled techniques to deposit ultrathin polymer layers mainly driven by electrostatic interactions. However, this kind of interaction results to be weak and easily breakable in physiological environment. Here we report on the preparation of nanocapsules completely made of natural biomaterials: a lipophilic core (soybean oil and egg lecithin as surfactant) as nanometric template and a polysaccharide-based multilayer shell (glycol chitosan and heparin) covalently cross-linked. We first modified glycol chitosan with a thiol moiety and heparin with an alkene moiety, respectively, and then we built a polymer multilayer film with a covalent cross-linkage among layers, exploiting the light initiated thiol-ene reaction, known as click chemistry. We showed the possibility to perform the covalent cross-linkage without any photoinitiator or metal catalyst, thus avoiding cytotoxic effects and further purification steps. The so realized nanocapsules resulted to be stable and completely biocompatible and, therefore, of interest for the biotechnology fields, mainly for drug delivery. PMID:26962765

  14. Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso–ene mechanism

    PubMed Central

    Porter, David; Poon, Belinda M-L

    2015-01-01

    Summary Iron(II) complexes of the tetradentate amines tris(2-pyridylmethyl)amine (TPA) and N,N′-bis(2-pyridylmethyl)-N,N′-dimethylethane-1,2-diamine (BPMEN) are established catalysts of C–O bond formation, oxidising hydrocarbon substrates via hydroxylation, epoxidation and dihydroxylation pathways. Herein we report the capacity of these catalysts to promote C–N bond formation, via allylic amination of alkenes. The combination of N-Boc-hydroxylamine with either FeTPA (1 mol %) or FeBPMEN (10 mol %) converts cyclohexene to the allylic hydroxylamine (tert-butyl cyclohex-2-en-1-yl(hydroxy)carbamate) in moderate yields. Spectroscopic studies and trapping experiments suggest the reaction proceeds via a nitroso–ene mechanism, with involvement of a free N-Boc-nitroso intermediate. Asymmetric induction is not observed using the chiral tetramine ligand (+)-(2R,2′R)-1,1′-bis(2-pyridylmethyl)-2,2′-bipyrrolidine ((R,R′)-PDP). PMID:26734101

  15. Photogenerated Lectin Sensors Produced by Thiol-Ene/Yne Photo-Click Chemistry in Aqueous Solution

    PubMed Central

    Norberg, Oscar; Lee, Irene H.; Aastrup, Teodor; Yan, Mingdi; Ramström, Olof

    2012-01-01

    The photoinitiated radical reactions between thiols and alkenes/alkynes (thiol-ene and thiol-yne chemistry) have been applied to a functionalization methodology to produce carbohydrate-presenting surfaces for analyses of biomolecular interactions. Polymer-coated quartz surfaces were functionalized with alkenes or alkynes in a straightforward photochemical procedure utilizing perfluorophenylazide (PFPA) chemistry. The alkene/alkyne surfaces were subsequently allowed to react with carbohydrate thiols in water under UV-irradiation. The reaction can be carried out in a drop of water directly on the surface without photoinitiator and any disulfide side products were easily washed away after the functionalization process. The resulting carbohydrate-presenting surfaces were evaluated in real-time studies of protein-carbohydrate interactions using a quartz crystal microbalance flow-through system with recurring injections of selected lectins with intermediate regeneration steps using low pH buffer. The resulting methodology proved fast, efficient and scalable to high-throughput analysis formats, and the produced surfaces showed significant protein binding with expected selectivities of the lectins used in the study. PMID:22341757

  16. An ene reductase from Clavispora lusitaniae for asymmetric reduction of activated alkenes.

    PubMed

    Ni, Yan; Yu, Hui-Lei; Lin, Guo-Qiang; Xu, Jian-He

    2014-03-01

    A putative ene reductase gene from Clavispora lusitaniae was heterologously overexpressed in Escherichia coli, and the encoded protein (ClER) was purified and characterized for its biocatalytic properties. This NADPH-dependent flavoprotein was identified with reduction activities toward a diverse range of activated alkenes including conjugated enones, enals, maleimide derivative and α,β-unsaturated carboxylic esters. The purified ClER exhibited a relatively high activity of 7.3 U mg(prot)⁻¹ for ketoisophorone while a remarkable catalytic efficiency (k(cat)/K(m)=810 s⁻¹ mM⁻¹) was obtained for 2-methyl-cinnamaldehyde due to the high affinity. A series of prochiral activated alkenes were stereoselectively reduced by ClER furnishing the corresponding saturated products in up to 99% ee. The practical applicability of ClER was further evaluated for the production of (R)-levodione, a valuable chiral compound, from ketoisophorone. Using the crude enzyme of ClER and glucose dehydrogenase (GDH), 500 mM of ketoisophorone was efficiently converted to (R)-levodione with excellent stereoselectivity (98% ee) within 1h. All these positive features demonstrate a high synthetic potential of ClER in the asymmetric reduction of activated alkenes. PMID:24564901

  17. Roll-to-plate fabrication of microfluidic devices with rheology-modified thiol-ene resins

    NASA Astrophysics Data System (ADS)

    Senkbeil, Silja; Aho, Johanna; Yde, Leif; Lindvold, Lars R.; Stensborg, Jan F.; Rantanen, Jukka; Lafleur, Josiane P.; Kutter, Jörg P.

    2016-07-01

    In this paper, the replication possibilities of microfluidic channels by UV-roll-to-plate fabrication were investigated and a study of rheology-modified thiol-ene for the application in such a UV-roll-to-plate setup was conducted. The system allows the manufacture of channels with aspect ratios of 2:1 and a maximal channel depth of 90 μm as well as the sealing of the finished devices with patterning and sealing speeds of up to 19 m min‑1. By adding fumed silica nanoparticles to the uncured resins, it was possible to alter the rheological behavior of the resin system to fabricate shallow microfluidic channels with 40  ×  95 μm cross-sectional dimensions. Moreover, deeper (90 μm) channels can be fabricated with highly viscous resins based on thiol-terminated oligomers. As a demonstration, capillary electrophoresis chips were prepared and tested for a simple separation of two fluorescent dyes.

  18. Responsive hybrid microcapsules by the one-step interfacial thiol-ene photopolymerization.

    PubMed

    Liu, Dandan; Yu, Bing; Jiang, Xuesong; Yin, Jie

    2013-04-30

    We here demonstrated a general, convenient, and robust method to fabricate the hybrid microcapsules through the one-step thiol-ene photopolymerization at the interface between toluene and water. In the presence of amphiphilic polyhedral oligomeric silsesquioxane (POSS) containing thiol groups (PTPS) as reactive surfactants and trimethylolpropane triacrylate (TMPTA) as a cross-linker, the wall of hybrid microcapsules can be photo-cross-linked. The obtained hybrid microcapsules (HMCs) were well-characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), and confocal laser scanning microscopy (CLSM). The results revealed that the obtained HMCs are uniform with the tunable size in diameter (2-4 μm) and wall thickness (55-120 nm). The size of HMCs increased with the increasing content of toluene. The wall thickness of HMCs decreased with the increasing content of toluene, while the wall thickness of HMCs increased with the increasing content of cross-linker TMPTA. Furthermore, HMCs are thermoresponsive in aqueous solution, can encapsulate both hydrophobic and dydrophilic dyes, and can be used in the controlled dispersion of dyes in different mediums. It is believed that this simple, robust, and general method to fabricate the hybrid microcapsules will extend the potential application fields of microcapsules, such as in the controlled dispersion and drug delivery. PMID:23547914

  19. Use of thiol-ene click chemistry to modify mechanical and thermal properties of polyhydroxyalkanoates (PHAs).

    PubMed

    Levine, Alex C; Heberlig, Graham W; Nomura, Christopher T

    2016-02-01

    In order to diversify the number of applications for poly[(R)-3-hydroxyalkanoates] (PHAs), methods must be developed to alter their physical properties so they are not limited to aliphatic polyesters. Recently we developed Escherichia coli LSBJ as a living biocatalyst with the ability to control the repeating unit composition of PHA polymers, including the ability to incorporate unsaturated repeating units into the PHA polymer at specific ratios. The incorporation of repeating units with terminal alkenes in the side chain of the polymer allowed for the production of random PHA copolymers with defined repeating unit ratios that can be chemically modified for the purpose of tailoring the physical properties of these materials beyond what are available in current PHAs. In this study, unsaturated PHA copolymers were chemically modified via thiol-ene click chemistry to contain an assortment of new functional groups, and the mechanical and thermal properties of these materials were measured. Results showed that cross-linking the copolymer resulted in a unique combination of improved strength and pliability and that the addition of polar functional groups increased the tensile strength, Young's modulus, and hydrophilic profile of the materials. This work demonstrates that unsaturated PHAs can be chemically modified to extend their physical properties to distinguish them from currently available PHA polymers. PMID:26616449

  20. Inspection and monitoring plan, contaminated groundwater seeps 317/319/ENE Area, Argonne National Laboratory

    SciTech Connect

    1996-10-11

    During the course of completing the Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) in the 317/319/East-Northeast (ENE) Area of Argonne National Laboratory-East (ANL-E), groundwater was discovered moving to the surface through a series of groundwater seeps. The seeps are located in a ravine approximately 600 ft south of the ANL-E fence line in Waterfall Glen Forest Preserve. Samples of the seep water were collected and analyzed for selected parameters. Two of the five seeps sampled were found to contain detectable levels of organic contaminants. Three chemical species were identified: chloroform (14--25 {micro}g/L), carbon tetrachloride (56--340 {micro}g/L), and tetrachloroethylene (3--6 {micro}g/L). The other seeps did not contain detectable levels of volatile organics. The nature of the contaminants in the seeps will also be monitored on a regular basis. Samples of surface water flowing through the bottom of the ravine and groundwater emanating from the seeps will be collected and analyzed for chemical and radioactive constituents. The results of the routine sampling will be compared with the concentrations used in the risk assessment. If the concentrations exceed those used in the risk assessment, the risk calculations will be revised by using the higher numbers. This revised analysis will determine if additional actions are warranted.

  1. 42 CFR 84.73 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self... hold the components of the apparatus in position against the wearer's body. (b) Harnesses shall...

  2. STS-39 MS Hieb is suspended over JSC's WETF Bldg 29 pool via harness

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-39 Mission Specialist (MS) Richard J. Hieb, wearing launch and entry suit (LES) and launch and entry helmet (LEH), is hoisted above JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool via his parachute harness. Hieb will be dropped from the harness into the WETF's 25 ft deep pool to simulate an emergency egress bailout from the Space Shuttle into the ocean. Divers in the pool will ensure Hieb's safety during the exercise.

  3. From Resting State to the Steady State: Mechanistic Studies of Ene-Yne Metathesis Promoted by the Hoveyda Complex.

    PubMed

    Griffiths, Justin R; Keister, Jerome B; Diver, Steven T

    2016-04-27

    The kinetics of intermolecular ene-yne metathesis (EYM) with the Hoveyda precatalyst (Ru1) has been studied. For 1-hexene metathesis with 2-benzoyloxy-3-butyne, the experimental rate law was determined to be first-order in 1-hexene (0.3-4 M), first-order in initial catalyst concentration, and zero-order for the terminal alkyne. At low catalyst concentrations (0.1 mM), the rate of precatalyst initiation was observed by UV-vis and the alkyne disappearance was observed by in situ FT-IR. Comparison of the rate of precatalyst initiation and the rate of EYM shows that a low, steady-state concentration of active catalyst is rapidly produced. Application of steady-state conditions to the carbene intermediates provided a rate treatment that fit the experimental rate law. Starting from a ruthenium alkylidene complex, competition between 2-isopropoxystyrene and 1-hexene gave a mixture of 2-isopropoxyarylidene and pentylidene species, which were trappable by the Buchner reaction. By varying the relative concentration of these alkenes, 2-isopropoxystyrene was found to be 80 times more effective than 1-hexene in production of their respective Ru complexes. Buchner-trapping of the initiation of Ru1 with excess 1-hexene after 50% loss of Ru1 gave 99% of the Buchner-trapping product derived from precatalyst Ru1. For the initiation process, this shows that there is an alkene-dependent loss of precatalyst Ru1, but this does not directly produce the active catalyst. A faster initiating precatalyst for alkene metathesis gave similar rates of EYM. Buchner-trapping of ene-yne metathesis failed to deliver any products derived from Buchner insertion, consistent with rapid decomposition of carbene intermediates under ene-yne conditions. An internal alkyne, 1,4-diacetoxy-2-butyne, was found to obey a different rate law. Finally, the second-order rate constant for ene-yne metathesis was compared to that previously determined by the Grubbs second-generation carbene complex: Ru1 was found to

  4. Management of dislocated hips with Pavlik harness treatment and ultrasound monitoring.

    PubMed

    Harding, M G; Harcke, H T; Bowen, J R; Guille, J T; Glutting, J

    1997-01-01

    We studied the outcome of ultrasound-monitored Pavlik harness treatment of 47 infants (nine boys and 38 girls) with 55 frankly dislocated hips documented by dynamic ultrasonography. The success and failure groups were of similar ultrasound status (hip-status score) at the time of initial examination, but a significant difference emerged at the 7- and 14-day examinations. Detection of frank dislocation and institution of treatment with the Pavlik harness within 3 weeks of birth increased the probability of a successful result. Of 33 infants (27 girls and six boys) with 41 dislocated hips who were seen before the age of 21 days, 26 (63%) hips were reducible in the Pavlik harness alone, and 15 (37%) hips were irreducible and required a subsequent procedure to achieve reduction. Fourteen infants (three boys and 11 girls) with 14 dislocated hips were first seen after the age of 21 days. Three (20%) were successfully treated in the Pavlik harness alone, and 11 (80%) required further treatment. In our opinion, persistent dislocation without improvement after 3 weeks of treatment in the Pavlik harness mandates discontinuation of use of this device. No anatomic factors were seen at the time of the initial ultrasound examination that permitted prediction of those hips likely to succeed or fail treatment with the Pavlik harness. PMID:9075094

  5. Epithelial-to-Mesenchymal Plasticity Harnesses Endocytic Circuitries

    PubMed Central

    Corallino, Salvatore; Malabarba, Maria Grazia; Zobel, Martina; Di Fiore, Pier Paolo; Scita, Giorgio

    2015-01-01

    execution of different biological processes, with a primary role in the control of polarized functions. Thus, they may be relevant for controlling EMT or certain aspects of it. Here, by discussing a few paradigmatic cases, we will outline how endocytosis may be harnessed by the EMT process to promote dynamic changes in cellular identity, and to increase cellular flexibility and adaptation to micro-environmental cues, ultimately impacting on physiological and pathological processes, first and foremost cancer progression. PMID:25767773

  6. Hello, world: Harnessing social media for the Rosetta mission

    NASA Astrophysics Data System (ADS)

    Baldwin, Emily; Mignone, Claudia; O'Flaherty, Karen; Homfeld, Anne-Mareike; Bauer, Markus; McCaughrean, Mark

    2015-04-01

    The European Space Agency's (ESA) comet-chasing Rosetta mission was launched in 2004, before social media became a popular tool for mainstream communication. By harnessing a range of platforms for communicating the key messages of this unprecedented mission as it reached its destination ten years later, new audiences were reached and a global impact was achieved. Rosetta-specific social media accounts - @ESA_Rosetta on Twitter, the Rosetta Mission Facebook page and the rosettamission Instagram account - were developed during 2013/14 and used alongside the traditional reporting line of the main ESA website and the Rosetta blog to build awareness about the mission. Coordinated with ESA's existing social media channels (Flickr, YouTube, G+, Twitter, Facebook and Livestream) and with the support of ESA's country desks and Rosetta partner agency accounts (including @philae2014), information could be shared in a number of European languages, ensuring a wide reach across Europe - and the world. We discuss the roles of the various social media accounts in supporting and promoting the competitions and social media campaigns that were built around the key mission milestones of 2014: waking up from deep space hibernation (January), arriving at Comet 67P/Churyumov-Gerasimenko (August) and naming the landing site for Philae ahead of the landing event in November. We discuss the different approach to each channel, such as the first person twitter accounts, the dialogue with and between blog users, and the discussions held live via G+ Hangouts with leading scientists and spacecraft operators. We compare and contrast the audiences, the interaction we had with them and how challenges were overcome. We also use the science-fiction-meets-science-fact Ambition short movie, and its "undercover" dissemination on social media, as an example of how the profile of the Rosetta mission was raised in a unique way. By using a variety of social media platforms to target different audiences with

  7. An evaluation of backpack harness systems in non-neutral torso postures.

    PubMed

    Southard, Stephanie A; Mirka, Gary A

    2007-09-01

    Much of the research on backpack design has been focused on spinal loading/biomechanics while the wearer is in a neutral/upright trunk posture, such as those employed by outdoor enthusiasts and schoolchildren. This research has led to some important harness design improvements that reduce trunk muscle exertions, fatigue and improve overall comfort. There are number of occupations, however, wherein workers wear back-mounted packs/devices (e.g. air tanks) while working in non-neutral trunk postures. The objective of the current study was to evaluate the effects of these non-neutral postures on biomechanical loading and then reconsider the backpack system design recommendations. Fifteen participants were asked to support a 18.2 kg load on their back while assuming static forward flexed postures of the torso (15 degrees , 30 degrees , 45 degrees , and 60 degrees of sagittal bend). The mass on the back was attached to the participant through two different harness mechanisms: a basic harness design (as seen on college student backpacks) and a more advanced design containing lateral stiffness rods and a weight-bearing hip belt (as seen on backpacks for hikers). While performing these static, posture maintenance tasks, the activation levels of the bilateral trapezius, erector spinae, and rectus abdominis were collected. Participants also provided subjective ratings of comfort. The results showed that there was a significant interaction between harness type and forward flexion angle for the trapezius and the erector spinae muscles. The normalized EMG for the trapezius muscles showed a 14% and 11% reduction in muscle activity at 15 degrees and 30 degrees , respectively, with the advanced design but these positive effects of the advanced design were not found at the greater flexion angles. Likewise the erector spinae muscles showed a 24% and 14% reduction in muscle activity at 15 degrees and 30 degrees , respectively, with the advanced design harness but these effects of the

  8. Thiol–ene-based biological/synthetic hybrid biomatrix for 3-D living cell culture

    PubMed Central

    Xu, Kedi; Fu, Yao; Chung, WeiJu; Zheng, Xiaoxiang; Cui, Yujia; Hsu, Ian C.; Kao, Weiyuan John

    2013-01-01

    Although various cell encapsulation materials are available commercially for a wide range of potential therapeutic cells, their combined clinical impact remains inconsistent. Synthetic materials such as poly(ethylene glycol) (PEG) hydrogels are mechanically robust and have been extensively explored but lack natural biofunctionality. Naturally derived materials including collagen, fibrin and alginate-chitosan are often labile and mechanically weak. In this paper we report the development of a hybrid biomatrix based on the thiol-ene reaction of PEG diacrylate (PEGdA) and cysteine/PEG-modified gelatin (gel-PEG-Cys). We hypothesized that covalent crosslinking decreases gelatin dissolution thus increasing gelatin resident time within the matrix and the duration of its biofunctionality; at the same time the relative ratio of PEGdA to gel-PEG-Cys in the matrix formulation directly affects hydrogel bulk and local microenvironment properties. Bulk viscoelastic properties were highly dependent on PEGdA concentration and total water content, while gel-PEG-Cys concentration was more critical to swelling profiles. Microviscoelastic properties were related to polymer concentration. The covalently crosslinked gel-PEG-Cys with PEGdA decreased gelatin dissolution out of the matrix and collagenase-mediated degradation. Fibroblasts and keratinocyte increased adhesion density and formed intercellular connections on stiffer hydrogel surfaces, while cells exhibited more cytoplasmic spreading and proliferation when entrapped within softer hydrogels. Hence, this material system contains multiparametric factors that can easily be controlled to modulate the chemical, physical and biological properties of the biomatrix for soft tissue scaffolding and cell presentation to reconstruct lost tissue architecture and physical functionality. PMID:22484717

  9. Chalcogenidobis(ene-1,2-dithiolate)molybdenum(IV) complexes (chalcogenide E = O, S, Se): probing Mo≡E and ene-1,2-dithiolate substituent effects on geometric and electronic structure.

    PubMed

    Sugimoto, Hideki; Tano, Hiroyuki; Suyama, Koichiro; Kobayashi, Tomoya; Miyake, Hiroyuki; Itoh, Shinobu; Mtei, Regina P; Kirk, Martin L

    2011-02-01

    New square-pyramidal bis(ene-1,2-dithiolate)MoSe complexes, [Mo(IV)Se(L)(2)](2-), have been synthesised along with their terminal sulfido analogues, [Mo(IV)S(L)(2)](2-), using alkyl (L(C(4)H(8))), phenyl (L(Ph)) and methyl carboxylate (L(COOMe)) substituted dithiolene ligands (L). These complexes now complete three sets of Mo(IV)O, Mo(IV)S and Mo(IV)Se species that are coordinated with identical ene-1,2-dithiolate ligands. The [alkyl substituted Mo(S/Se)(L(C(4)H(8)))(2)](2-) complexes were reported in prior investigations (H. Sugimoto, T. Sakurai, H. Miyake, K. Tanaka and H. Tsukube, Inorg. Chem. 2005, 44, 6927, H. Tano, R. Tajima, H. Miyake, S. Itoh and H. Sugimoto, Inorg. Chem. 2008, 47, 7465). The new series of complexes enable a systematic investigation of terminal chalcogenido and supporting ene-1,2-dithiolate ligand effects on geometric structure, electronic structure, and spectroscopic properties. X-ray crystallographic analysis of these (Et(4)N)(2)[MoEL(2)] (E = terminal chalocogenide) complexes reveals an isostructural Mo centre that adopts a distorted square pyramidal geometry. The M≡E bond distances observed in the crystal structures and the ν(M≡E) vibrational frequencies indicate that these bonds are weakened with an increase in L→Mo electron donation (L(COOMe) < L(Ph) < L(C(4)H(8))), and this order is confirmed by an electrochemical study of the complexes. The (77)Se NMR resonances in MoSeL complexes appear at lower magnetic fields as the selenido ion became less basic from MoSeL(C(4)H(8)), MoSeL(Ph) and MoSeL(COOMe). Electronic absorption and resonance Raman spectroscopies have been used to assign key ligand-field, MLCT, LMCT and intraligand CT bands in complexes that possess the L(COOMe) ligand. The presence of low-energy intraligand CT transition in these MoEL(COOMe) compounds directly probes the electron withdrawing nature of the -COOMe substituents, and this underscores the complex electronic structure of square pyramidal bis(ene-1

  10. C27-C30 neohop-13(18)-enes and their saturated and aromatic derivatives in sediments: Indicators for diagenesis and water column stratification

    NASA Astrophysics Data System (ADS)

    Sinninghe Damsté, Jaap S.; Schouten, Stefan; Volkman, John K.

    2014-05-01

    A limited suite of C27, C29 and C30 rearranged hopenes identified as neohop-13(18)-enes have been reported in immature Recent and ancient marine/lacustrine sediments and their presence has been explained by dehydration and isomerisation of ubiquitous hopanols or hopenes. Here we investigated the source and fate of neohop-13(18)-enes in a range of Recent and ancient sediments. The analysis of δ13C values of hop-17(21)-ene and neohop-13(18)-ene in Arabian Sea surface sediments, in the Monterey Formation and in immature Cenomanian black shales show that they differ by 2-3‰, suggesting that the C30 neohop-13(18)-ene has a source different from those of the non-rearranged C30 hopenes. A new member of the family of neohop-13(18)-enes, the C28 hopene 28,30-dinorhop-13(18)-ene, was identified based on comparison of its mass spectral data with that of other members of the family of neohopenes. Its occurrence explains the formation of a series of orphan aromatic hopanoids bearing an ethyl group at C-21, known to occur in high concentrations in some organic-rich ancient sediments. Circumstantial evidence for this formation pathway is provided by identical δ13C values for the C28 28,30-dinorhop-13(18)-ene and two aromatic hopanoids in two Cretaceous black shales. Relatively abundant C28 28,30-dinorhopene and related aromatic derivatives were present in ancient sediments where the distribution of other biomarkers (i.e. isorenieratene derivatives) indicated a stratified palaeo water column. Therefore, it is suggested that these compounds are derived from bacteria dwelling at or below the chemocline and may be used as indicators of stratified water bodies in the past. 28,30-Dinorhop-13(18)-ene may also be a precursor of the unusual C28 desmethylhopane 28,30-dinorhopane found in high concentrations in anoxic sediments and a limited suite of crude oils, which is consistent with the proposal that it too ultimately derives from bacteria living at the oxic-anoxic interface.

  11. Amino-zinc-ene-enolate cyclization: a short access to cis-3-substituted prolino-homotryptophane derivatives.

    PubMed

    Mothes, Céline; Lavielle, Solange; Karoyan, Philippe

    2008-09-01

    Proline chimeras are useful tools for medicinal chemistry and/or biological applications. The asymmetric synthesis of cis-3-substituted prolines can be easily achieved via amino-zinc-ene-enolate cyclization followed by transmetalation of the cyclic zinc intermediate for further functionalization. Syntheses of prolino-homotryptophane derivatives were achieved through Negishi cross-coupling of the zinc intermediate with indole rings. The use of Pd catalyst derived from Fu's [(t-Bu3)PH]-BF4 was required to avoid the undesired beta-hydride elimination. Optically pure and orthogonally protected compounds were obtained readily usable for peptide synthesis. PMID:18656982

  12. Thermodynamic properties and ideal-gas enthalpies of formation for butyl vinyl ether, 1,2-dimethoxyethane, methyl glycolate, bicyclo[2.2.1]hept-2-ene, 5-vinylbicyclo[2.2.1]hept-2-ene, trans-azobenzene, butyl acrylate, di-tert-butyl ether, and hexane-1,6-diol

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Smith, N.K.

    1996-11-01

    Ideal-gas enthalpies of formation of butyl vinyl ether, 1,2-dimethoxyethane, methyl glycolate, bicyclo-[2.2.1]hept-2-ene, 5-vinylbicyclo[2.2.1]hept-2-ene, trans-azobenzene, butyl acrylate, di-tert-butyl ether, and hexane-1,6-diol are reported. Enthalpies of fusion were determined for bicyclo[2.2.1]hept-2-ene and trans-azobenzene. Two-phase (solid + vapor) or (liquid + vapor) heat capacities were determined from 300 K to the critical region or earlier decomposition temperature for each compound studied. Liquid-phase densities along the saturation line were measured for bicyclo[2.2.1]hept-2-ene. For butyl vinyl ether and 1,2-dimethoxyethane, critical temperatures and critical densities were determined from the dsc results and corresponding critical pressures derived from the fitting procedures. Fitting procedures were used to derive critical temperatures, critical pressures, and critical densities for bicyclo[2.2.1]hept-2-ene, 5-vinylbicyclo[2.2.1]hept-2-ene, trans-azobenzene, butyl acrylate, and di-tert-butyl ether. Group-additivity parameters or ring-correction terms useful in the application of the Benson group-contribution correlations were derived.

  13. Thiol-ene and photo-cleavage chemistry for controlled presentation of biomolecules in hydrogels.

    PubMed

    Grim, Joseph C; Marozas, Ian A; Anseth, Kristi S

    2015-12-10

    photochemical methods have led to important advances in the tissue regeneration community, namely the thiol-ene photo-click reaction for bioconjugation and photocleavage reactions that allow for the removal of protecting groups. Specific examples will be highlighted where these methodologies have been used to engineer hydrogels that control and direct cell function with the aim of inspiring their use in regenerative medicine. PMID:26315818

  14. Subject Load-Harness Interaction During Zero-Gravity Treadmill Exercise

    NASA Technical Reports Server (NTRS)

    McCrory, Jean L.; Baron, Heidi A.; Derr, Janice A.; Davis, Brian L.; Cavanagh, Peter R.

    1996-01-01

    When astronauts exercise on orbit, a subject load device (SLD) must be used to return the subject back to the supporting surface. The load in the SLD needs to be transferred the body by a harness which typically distributes this load between the pelvis and We shoulders. Through the use of a zero-gravity simulator, this research compared subject comfort and ground reaction forces during treadmill running at three levels of subject load (60%,80%, and 100% of body weight) in two harness designs ("shoulder only" and "waist "and shoulder ").

  15. Beyond PDMS: off-stoichiometry thiol-ene (OSTE) based soft lithography for rapid prototyping of microfluidic devices.

    PubMed

    Carlborg, Carl Fredrik; Haraldsson, Tommy; Öberg, Kim; Malkoch, Michael; van der Wijngaart, Wouter

    2011-09-21

    In this article we introduce a novel polymer platform based on off-stoichiometry thiol-enes (OSTEs), aiming to bridge the gap between research prototyping and commercial production of microfluidic devices. The polymers are based on the versatile UV-curable thiol-ene chemistry but takes advantage of off-stoichiometry ratios to enable important features for a prototyping system, such as one-step surface modifications, tuneable mechanical properties and leakage free sealing through direct UV-bonding. The platform exhibits many similarities with PDMS, such as rapid prototyping and uncomplicated processing but can at the same time mirror the mechanical and chemical properties of both PDMS as well as commercial grade thermoplastics. The OSTE-prepolymer can be cast using standard SU-8 on silicon masters and a table-top UV-lamp, the surface modifications are precisely grafted using a stencil mask and the bonding requires only a single UV-exposure. To illustrate the potential of the material we demonstrate key concepts important in microfluidic chip fabrication such as patterned surface modifications for hydrophobic stops, pneumatic valves using UV-lamination of stiff and rubbery materials as well as micromachining of chip-to-world connectors in the OSTE-materials. PMID:21804987

  16. A robust platform for functional microgels via thiol-ene achemistry with reactive polyether-based nanoparticles

    PubMed Central

    Fleischmann, Carolin; Gopez, Jeffrey; Lundberg, Pontus; Ritter, Helmut; Killops, Kato L.

    2015-01-01

    We herein report the development of crosslinked polyether particles as a reactive platform for the preparation of functional microgels. Thiol-ene crosslinking of poly(allyl glycidyl ether) in miniemulsion droplets - stabilized by a surface active, bio-compatible polyethylene glycol block copolymer - resulted in colloidal gels with a PEG corona and an inner polymeric network containing reactive allyl units. The stability of the allyl groups allows the microgels to be purified and stored before a second, subsequent thiol-ene functionalization step allows a wide variety of pH- and chemically-responsive groups to be introduced into the nanoparticles. The facile nature of this synthetic platform enables the preparation of microgel libraries that are responsive to different triggers but are characterized by the same size distribution, surface functionality, and crosslinking density. In addition, the utilization of a crosslinker containing cleavable ester groups renders the resulting hydrogel particles degradable at elevated pH or in the presence of esterase under physiological conditions. PMID:26005499

  17. A colorimetric detection of acrylamide in potato chips based on nucleophile-initiated thiol-ene Michael addition.

    PubMed

    Hu, Qinqin; Fu, Yingchun; Xu, Xiahong; Qiao, Zhaohui; Wang, Ronghui; Zhang, Ying; Li, Yanbin

    2016-02-01

    Acrylamide (AA), a neurotoxin and a potential carcinogen, has been found in various thermally processed foods such as potato chips, biscuits, and coffee. Simple, cost-effective, and sensitive methods for the rapid detection of AA are needed to ensure food safety. Herein, a novel colorimetric method was proposed for the visual detection of AA based on a nucleophile-initiated thiol-ene Michael addition reaction. Gold nanoparticles (AuNPs) were aggregated by glutathione (GSH) because of a ligand-replacement, accompanied by a color change from red to purple. In the presence of AA, after the thiol-ene Michael addition reaction between GSH and AA with the catalysis of a nucleophile, the sulfhydryl group of GSH was consumed by AA, which hindered the subsequent ligand-replacement and the aggregation of AuNPs. Therefore, the concentration of AA could be determined by the visible color change caused by dispersion/aggregation of AuNPs. This new method showed high sensitivity with a linear range from 0.1 μmol L(-1) to 80 μmol L(-1) and a detection limit of 28.6 nmol L(-1), and especially revealed better selectivity than the fluorescence sensing method reported previously. Moreover, this new method was used to detect AA in potato chips with a satisfactory result in comparison with the standard methods based on chromatography, which indicated that the colorimetric method can be expanded for the rapid detection of AA in thermally processed foods. PMID:26699696

  18. Asymmetric Glyoxylate-Ene Reactions Catalyzed by Chiral Pd(II) Complexes in the Ionic Liquid [bmim][PF6

    PubMed Central

    He, Xi Jun; Shen, Zhen Lu; Mo, Wei Min; Hu, Bao Xiang; Sun, Nan

    2007-01-01

    The room temperature ionic liquid [bmim][PF6] was employed as the reaction medium in the asymmetric glyoxylate-ene reaction of α-methyl styrene (4a) with ethyl glyoxylate using chiral palladium(II) complexes as the catalysts. [Pd(S-BINAP)(3,5-CF3-PhCN)2](SbF6)2 (1b) showed the highest catalytic activity. Under the reaction conditions of 40 °C, 0.5 h, and 1b/4a molar ratio of 0.05, ethyl α-hydroxy-4-phenyl-4-pentenoate was obtained in excellent chemical yield (94 %) with high enantioselectivity (70 %). Other α-hydroxy esters can also be obtained in high chemical yields and enantioselectities through the glyoxylate-ene reactions of alkenes with glyoxylates catalyzed by 1b in [bmim][PF6]. Moreover, the ionic liquid [bmim][PF6] which contained the palladium(II) complex could be recycled and reused several times without significant loss of the catalytic activity.

  19. Facile preparation of organic-silica hybrid monolith for capillary hydrophilic liquid chromatography based on "thiol-ene" click chemistry.

    PubMed

    Chen, Ming-Luan; Zhang, Jun; Zhang, Zheng; Yuan, Bi-Feng; Yu, Qiong-Wei; Feng, Yu-Qi

    2013-04-01

    In this work, a one-step approach to facile preparation of organic-inorganic hybrid monoliths was successfully developed. After vinyl-end organic monomers and azobisisobutyronitrile (AIBN) were mixed with hydrolyzed tetramethoxysilane (TMOS) and 3-mercaptopropyltrimethoxysilane (MPTMS), the homogeneous mixture was introduced into a fused-silica capillary for simultaneous polycondensation and "thiol-ene" click reaction to form the organic-silica hybrid monoliths. By employing this strategy, two types of organic-silica hybrid monoliths with positively charged quaternary ammonium and amide groups were prepared, respectively. The functional groups were successfully introduced onto the monoliths during the sol-gel process with "thiol-ene" click reaction, which was demonstrated by ζ-potential assessment, energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FT-IR) spectroscopy. The porous structure of the prepared monolithic columns was examined by scanning electron microscopy (SEM), nitrogen adsorption-desorption measurement, and mercury intrusion porosimetry. These results indicate the prepared organic-silica hybrid monoliths possess homogeneous column bed, large specific surface area, good mechanical stability, and excellent permeability. The prepared monolithic columns were then applied for anion-exchange/hydrophilic interaction liquid chromatography. Different types of analytes, including benzoic acids, inorganic ions, nucleosides, and nucleotides, were well separated with high column efficiency around 80,000-130,000 plates/m. Taken together, we present a facile and universal strategy to prepare organic-silica hybrid monoliths with a variety of organic monomers using one-step approach. PMID:23434082

  20. Thiol-ene click chemistry derived cationic cyclodextrin chiral stationary phase and its enhanced separation performance in liquid chromatography.

    PubMed

    Yao, Xiaobin; Tan, Timothy Thatt Yang; Wang, Yong

    2014-01-24

    This work is the first demonstration of a simple thiol-ene click chemistry to anchor vinyl imidazolium β-CD onto thiol silica to form a novel cationic native cyclodextrin (CD) chiral stationary phase (CSP). The CSP afforded high enantioseparation ability towards dansyl (Dns) amino acids, carboxylic aryl compounds and flavonoids in chiral HPLC. The current CSP demonstrates the highest resolving ability (selectivity >1.1, resolution >1.5) towards Dns amino acids in a mobile phase buffered at pH=6.5, with the resolution of Dns-dl-leucine as high as 6.97. 2,4-dichloride propionic acid (2,4-ClPOPA) was well resolved with the selectivity and resolution of 1.37 and 4.88, respectively. Compared to a previously reported native CD-CSP based on a triazole linkage, the current cationic CD-CSP shows a stronger retention and higher resolution towards acidic chiral compounds, ascribed to the propitious strong electrostatic attraction. Stability evaluation results indicated that thiol-ene reaction can provide a facile and robust approach for the preparation of positively charged CD CSPs. PMID:24411138

  1. Polysiloxane-Based Autonomic Self-Healing Elastomers Obtained through Dynamic Boronic Ester Bonds Prepared by Thiol-Ene "Click" Chemistry.

    PubMed

    Zuo, Yujing; Gou, Zhiming; Zhang, Changqiao; Feng, Shengyu

    2016-07-01

    Cross-linked silicone elastomers constructed with dynamic-covalent boronic esters are first synthesized by photoinitiated radical thiol-ene "click" chemistry. The resultant samples can be cut with a sharp knife into two pieces and then healed via the reversibility of the boronic ester cross-linkages to restore the original silicone sample within 30 min. Regulation of luminescent properties is achieved by incorporating organic dye into the elastomers through a "one-pot" thiol-ene reaction. The proposed synthesis procedure demonstrates a new strategy to produce boronic acid silicone materials capable of self-healing without external forces. PMID:27159536

  2. Reliability and Validity of the Zephyr[TM] BioHarness[TM] to Measure Respiratory Responses to Exercise

    ERIC Educational Resources Information Center

    Hailstone, Jono; Kilding, Andrew E.

    2011-01-01

    The Zephyr[TM] BioHarness[TM] (Zephyr Technology, Auckland, New Zealand) is a wireless physiological monitoring system that has the ability to measure respiratory rate unobtrusively. However, the ability of the BioHarness[TM] to accurately and reproducibly determine respiratory rate across a range of intensities is currently unknown. The aim of…

  3. 14 CFR 121.311 - Seats, safety belts, and shoulder harnesses.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... defined in Federal Motor Vehicle Safety Standard No. 213 (49 CFR 571.213)), vest- and harness-type child.... Editorial Note: For Federal Register citations affecting § 121.311, see the List of CFR Sections Affected... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Seats, safety belts, and shoulder...

  4. 14 CFR 121.311 - Seats, safety belts, and shoulder harnesses.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... defined in Federal Motor Vehicle Safety Standard No. 213 (49 CFR 571.213)), vest- and harness-type child.... Editorial Note: For Federal Register citations affecting § 121.311, see the List of CFR Sections Affected... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Seats, safety belts, and shoulder...

  5. 14 CFR 121.311 - Seats, safety belts, and shoulder harnesses.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... defined in Federal Motor Vehicle Safety Standard No. 213 (49 CFR 571.213)), vest- and harness-type child.... Editorial Note: For Federal Register citations affecting § 121.311, see the List of CFR Sections Affected... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Seats, safety belts, and shoulder...

  6. 42 CFR 84.116 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Harnesses; installation and construction; minimum requirements. 84.116 Section 84.116 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.116...

  7. 42 CFR 84.1133 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Harnesses; installation and construction; minimum requirements. 84.1133 Section 84.1133 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and...

  8. The Facebook-in-Action: Challenging, Harnessing and Enhancing Students Class Assignments and Projects

    ERIC Educational Resources Information Center

    Saifudin, Adam Mohd; Yacob, Aizan; Saad, Rohaizah

    2016-01-01

    Issues of universities students harnessing and capitalizing the usage of Facebook for their own learning capabilities and effective thinking is always the focus of education scholars, in assessing the quality class assignments and projects produced by them. Therefore, Facebook is now becoming unbearable influence since the internet activation in…

  9. Harnessing the power of big data: infusing the scientific method with machine learning to transform ecology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most efforts to harness the power of big data for ecology and environmental sciences focus on data and metadata sharing, standardization, and accuracy. However, many scientists have not accepted the data deluge as an integral part of their research because the current scientific method is not scalab...

  10. Improving Students' Educational Experience by Harnessing Digital Technology: elgg in the ODL Environment

    ERIC Educational Resources Information Center

    Tung, Lai Cheng

    2013-01-01

    Given the rising popularity of both open and distance learning (ODL) and social networking tools, it seems logical to merge and harness these two popular technologies with the goal of improving student educational experience. The integration seems to hold tremendous promise for the open and distance learning mode. To reduce the gap in the…

  11. 14 CFR 91.107 - Use of safety belts, shoulder harnesses, and child restraint systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Vehicle Safety Standard No. 213 (49 CFR 571.213)), vest- and harness-type child restraint systems, and lap....-registered civil aircraft (except a free balloon that incorporates a basket or gondola, or an airship type... aircraft (except a free balloon that incorporates a basket or gondola, or an airship type...

  12. Harnessing Sparse and Low-Dimensional Structures for Robust Clustering of Imagery Data

    ERIC Educational Resources Information Center

    Rao, Shankar Ramamohan

    2009-01-01

    We propose a robust framework for clustering data. In practice, data obtained from real measurement devices can be incomplete, corrupted by gross errors, or not correspond to any assumed model. We show that, by properly harnessing the intrinsic low-dimensional structure of the data, these kinds of practical problems can be dealt with in a uniform…

  13. 42 CFR 84.173 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Harnesses; installation and construction; minimum requirements. 84.173 Section 84.173 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Non-Powered...

  14. 42 CFR 84.196 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Harnesses; installation and construction; minimum requirements. 84.196 Section 84.196 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Chemical Cartridge Respirators...

  15. 42 CFR 84.133 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Harnesses; installation and construction; minimum requirements. 84.133 Section 84.133 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators...

  16. 42 CFR 84.73 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Harnesses; installation and construction; minimum requirements. 84.73 Section 84.73 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing...

  17. [Functional principles of the lumbotrain harness. A clinical and experimental study].

    PubMed

    Yücel, M; Breitenfelder, J; Liebscher, F; Nicol, K

    1984-01-01

    This paper presents the results of pressure measurements on the truss pad of the lumbotrain harness. As compared to the pressure measurements carried out previously on truss pads of rigid orthotic devices by the same authors, a much more uniform pressure distribution was found. PMID:6475218

  18. Color-Transformable Silicone Elastomers Prepared by Thiol-Ene Reaction with Potential Application in UV-LEDs.

    PubMed

    Zuo, Yujing; Gou, Zhiming; Zhang, Jie; Feng, Shengyu

    2016-04-01

    A series of high-efficiency, full-color fluorescent elastomers based on polysiloxane matrix prepared by an easy thiol-ene "click" reaction is reported here. It is found for the first time that the same elastomer can emit transformable colors by conveniently altering the excitation wavelength because of the effect of energy transfer and the "fluorescence switch" of lanthanide ions. A fluent change in emission colors can also be feasible and conveniently reproducible by varying the stoichiometric ratio of lanthanide ions and rhodamine-B in solution and in polymer elastomers. The obtained elastomers are further coated onto commercially available UV-LED cells from the solution medium followed by an in situ cross-linking step. PMID:26847367

  19. Design of Redox/Radical Sensing Molecules via Nitrile Imine-Mediated Tetrazole-ene Cycloaddition (NITEC).

    PubMed

    Lederhose, Paul; Haworth, Naomi L; Thomas, Komba; Bottle, Steven E; Coote, Michelle L; Barner-Kowollik, Christopher; Blinco, James P

    2015-08-21

    The current study introduces a novel synthetic avenue for the preparation of profluorescent nitroxides via nitrile imine-mediated tetrazole-ene cycloaddition (NITEC). The photoinduced cycloaddition was performed under metal-free, mild conditions allowing the preparation of a library of the nitroxide functionalized pyrazolines and corresponding methoxyamines. High reaction rates and full conversion were observed, with the presence of the nitroxide having no significant impact on the cycloaddition performance. The formed products were investigated with respect to their photophysical properties in order to quantify their "switch on/off" behavior. The fluorescence quenching performance is strongly dependent on the distance between the chromophore and the free radical spin as demonstrated theoretically and experimentally. Highest levels of fluorescence quenching were achieved for pyrazolines with the nitroxide directly fused to the chromophore. Importantly, the pyrazoline profluorescent nitroxides were shown to efficiently act as sensors for redox/radical processes. PMID:26168007

  20. Divinyl-end-functionalized polyethylenes: ready access to a range of telechelic polyethylenes through thiol-ene reactions.

    PubMed

    Norsic, Sebastien; Thomas, Coralie; D'Agosto, Franck; Boisson, Christophe

    2015-04-01

    Telechelic α,ω-iodo-vinyl-polyethylenes (Vin-PE-I) were obtained by catalytic ethylene polymerization in the presence of [(C5 Me5 )2 NdCl2 Li(OEt2 )2 ] in combination with a functionalized chain-transfer agent, namely, di(10-undecenyl)magnesium, followed by treatment of the resulting di(vinylpolyethylenyl)magnesium compounds ((vinyl-PE)2 Mg) with I2 . The iodo-functionalized vinylpolyethylenes (Vin-PE-I) were transformed into unique divinyl-functionalized polyethylenes (Vin-PE-Vin) by simple treatment with tBuOK in toluene at 95 °C. Thiol-ene reactions were then successfully performed on Vin-PE-Vin with functionalized thiols in the presence of AIBN. A range of homobifunctional telechelic polyethylenes were obtained on which a hydroxy, diol, carboxylic acid, amine, ammonium chloride, trimethoxysilyl, chloro, or fluoroalkyl group was installed quantitatively at each chain end. PMID:25688747

  1. Stereochemistry of 16a-hydroxyfriedelin and 3-Oxo-16-methylfriedel-16-ene established by 2D NMR spectroscopy.

    PubMed

    Duarte, Lucienir Pains; Silva de Miranda, Roqueline Rodrigues; Rodrigues, Salomão Bento Vasconcelos; de Fátima Silva, Grácia Divina; Vieira Filho, Sidney Augusto; Knupp, Vagner Fernandes

    2009-01-01

    Friedelin (1), 3beta-friedelinol (2), 28-hydroxyfriedelin (3), 16alpha-hydroxyfriedelin (4), 30-hydroxyfriedelin (5) and 16alpha,28-dihydroxyfriedelin (6) were isolated through fractionation of the hexane extract obtained from branches of Salacia elliptica. After a week in CDCl(3) solution, 16alpha-hydroxyfriedelin (4) reacted turning into 3-oxo-16-methylfriedel-16-ene (7). This is the first report of a dehydration followed by a Nametkin rearrangement of a pentacyclic triterpene in CDCl(3) solution occurring in the NMR tube. These seven pentacyclic triterpenes was identified through NMR spectroscopy and the stereochemistry of compound 4 and 7 was established by 2D NMR (NOESY) spectroscopy and mass spectrometry (GC-MS). It is also the first time that all the (13)C-NMR and 2D NMR spectral data are reported for compounds 4 and 7. PMID:19214150

  2. Facile Synthesis of Prussian Blue Derivate-Modified Mesoporous Material via Photoinitiated Thiol-Ene Click Reaction for Cesium Adsorption.

    PubMed

    Qian, Jun; Ma, Jiaqi; He, Weiwei; Hua, Daoben

    2015-08-01

    A novel strategy to synthesize a functional mesoporous material for efficient removal of cesium is reported. Specifically, Prussian blue derivate-modified SBA-15 (SBA-15@FC) was prepared by photoinitiated thiol-ene reaction between thiol-modified SBA-15 and pentacyano(4-vinyl pyridine)ferrate complex. The effects of weight percentage of the Prussian blue derivate, pH, adsorbent dose, co-existing ions, and initial concentration were evaluated on the adsorption of cesium ions. The adsorption kinetically follows a pseudo-second-order model and reaches equilibrium within 2 h with a high adsorption capacity of about 13.90 mg Cs g(-1) , which indicates that SBA-15@FC is a promising adsorbent to effectively remove cesium from aqueous solutions. PMID:25965318

  3. Formation and validation of questionnaire to assess Jāṭharāgni

    PubMed Central

    Eswaran, H. T.; Kavita, M. B.; Tripaty, T. B.; Shivakumar

    2015-01-01

    Background: Jāṭharāgni (metabolic fire) is of the prime importance in the maintenance of health as well as causation of diseases. Food which is consumed by the person shares the major responsibility for being healthy or manifestation of diseases. The relation between food and health is mediated by Jāṭharāgni (the metabolic agent in Ayurveda). There are four different states of Jāṭharāgni viz, Mandāgni (mild or weak state of metabolic fire), Viṣamāgni (irregular state of metabolic fire), Tīkṣnāgni (sharp or intense state of metabolic fire), and Samāgni (Normal state of metabolic fire). Samāgni (Normal state of metabolic fire) is said to be the normal State and maintains the health of an individual. All the other states are considered as abnormal. Objectives: To frame and validate a Questionnaire to assess the state of Jāṭharāgni. Materials and Methods: A qualitative research that involved interview method and cluster sampling method. A total of 500 volunteers of either gender in two groups viz., apparently healthy and unhealthy were assessed for their Jāṭharāgni. Questionnaire was framed with 64 items. A total of 14 questions under Viṣamāgni (irregular state of metabolic fire), 13 under Tīkshṇāgni, 13 under Mandāgni and 24 questions under Samāgni were framed. The questionnaire was in optional format with 5 item likert's scale pattern and the validation was done by Cronbach's Alpha for internal consistency. Result: The internal consistency of the questionnaire using Cronbach's Alpha was 0.916. The internal consistency of Viṣamāgni domain was 0.909; Teekshnagni domain was 0.873; Mandāgni domain was 0.894; and Samāgni domain was 0.876. Conclusion: The internal consistency of the questionnaire was 0.909 which is indicative of the excellent internal consistency of questionnaire. The lacuna of tool to assess state of Jāṭharāgni in Ayurveda is filled by this questionnaire. PMID:26283805

  4. Design of thermal-noise-harnessing single-electron circuit for efficient signal propagation

    NASA Astrophysics Data System (ADS)

    Hirashima, Ryo; Oya, Takahide

    2016-06-01

    We propose a new single-electron (SE) circuit that can improve the signal propagation speed by harnessing thermal noise efficiently. Generally, an SE circuit has some weaknesses. It is very sensitive to thermal noise and it takes a long time for signal propagation. To solve these problems, we focus on a unique function at an output terminal (an axon) of a neuron that can improve the signal propagation speed because of its distinctive structure. It is expected that a new high-speed SE circuit can be realized by mimicking the structure of the neuron. Here, we indicate the possibility of improving the signal propagation speed by harnessing the thermal noise in one-dimensional neuromorphic single-electron oscillators. Moreover, we designed a two-dimensional neuromorphic single-electron oscillator as an advanced circuit and confirmed its tolerance to thermal noise. Our study will be useful for constructing novel devices that actively use noise energy in the future.

  5. 'Soft' harness for external attachment of large radio transmitters to northern pike (Esox lucius)

    USGS Publications Warehouse

    Herke, S.W.; Moring, J.R.

    1999-01-01

    We developed a 'soft' harness for dorsally attaching large, external radio transmitters to northern pike (Esox lucius). The key harness component was a soft, flexible, thick-walled tubing that prevented tissue abrasion by the attachment lines which passed through the tubing. Six field-tagged fish (1.5-7.5 kg) were monitored for 45-115 days before tracking was terminated. Tracking patterns of fish indicated no apparent effect of these large, external transmitters on movement behavior; further, the transmitters did not appear to entangle the fish in vegetation. One fish with its transmitter still secure was recaptured after 54 days, and there was minimal tissue erosion under the transmitter. With minor improvements for the attachment lines and the transmitter saddle, the method is suitable for externally attaching large telemetry transmitters to fish.

  6. Theoretical Study of Decomposition Pathways for HArF and HKrF

    NASA Technical Reports Server (NTRS)

    Chaban, Galina M.; Lundell, Jan; Gerber, R. Benny; Kwak, Donchan (Technical Monitor)

    2002-01-01

    To provide theoretical insights into the stability and dynamics of the new rare gas compounds HArF and HKrF, reaction paths for decomposition processes HRgF to Rg + HF and HRgF to H + Rg + F (Rg = Ar, Kr) are calculated using ab initio electronic structure methods. The bending channels, HRgF to Rg + HF, are described by single-configurational MP2 and CCSD(T) electronic structure methods, while the linear decomposition paths, HRgF to H + Rg + F, require the use of multi-configurational wave functions that include dynamic correlation and are size extensive. HArF and HKrF molecules are found to be energetically stable with respect to atomic dissociation products (H + Rg + F) and separated by substantial energy barriers from Rg + HF products, which ensure their kinetic stability. The results are compatible with experimental data on these systems.

  7. Toxic but Drank: Gustatory Aversive Compounds Induce Post-ingestional Malaise in Harnessed Honeybees

    PubMed Central

    Ayestaran, Ainara

    2010-01-01

    Background Deterrent substances produced by plants are relevant due to their potential toxicity. The fact that most of these substances have an unpalatable taste for humans and other mammals contrasts with the fact that honeybees do not reject them in the range of concentrations in which these compounds are present in flower nectars. Here we asked whether honeybees detect and ingest deterrent substances and whether these substances are really toxic to them. Results We show that pairing aversive substances with an odor retards learning of this odor when it is subsequently paired with sucrose. Harnessed honeybees in the laboratory ingest without reluctance a considerable volume (20 µl) of various aversive substances, even if some of them induce significant post-ingestional mortality. These substances do not seem, therefore, to be unpalatable to harnessed bees but induce a malaise-like state that in some cases results in death. Consistently with this finding, bees learning that one odor is associated with sugar, and experiencing in a subsequent phase that the sugar was paired with 20 µl of an aversive substance (devaluation phase), respond less than control bees to the odor and the sugar. Such stimulus devaluation can be accounted for by the malaise-like state induced by the aversive substances. Conclusion Our results indicate that substances that taste bitter to humans as well as concentrated saline solutions base their aversive effect on the physiological consequences that their ingestion generates in harnessed bees rather than on an unpalatable taste. This conclusion is only valid for harnessed bees in the laboratory as freely-moving bees might react differently to aversive compounds could actively reject aversive substances. Our results open a new possibility to study conditioned taste aversion based on post-ingestional malaise and thus broaden the spectrum of aversive learning protocols available in honeybees. PMID:21060877

  8. Harnessing localized ridges for high-aspect-ratio hierarchical patterns with dynamic tunability and multifunctionality.

    PubMed

    Cao, Changyong; Chan, Hon Fai; Zang, Jianfeng; Leong, Kam W; Zhao, Xuanhe

    2014-03-19

    A simple method for fabricating high-aspect-ratio, hierarchical, and dynamically tunable surface patterns is invented by harnessing localized-ridge instabilities in gold nanofilms coated on elastomer substrates (a); a theoretical model to calculate the critical parameters (e.g., wavelength and amplitude) for designing the new patterns is developed (b); and novel applications of the patterns as super-hydrophobic coatings (c) and biomimetic cell-culture substrates (d) capable of on-demand tunability are demonstrated. PMID:24339233

  9. The relevance of netnography to the harness of Romanian health care electronic word-of-mouth.

    PubMed

    Bratucu, R; Gheorghe, I R; Radu, A; Purcarea, V L

    2014-09-15

    Nowadays, consumers use the computer mediated communication to make purchase decisions on a large variety of products and services. Since health care services are archetypal by nature, consumers in this field are one of the most encountered users of electronic word-of-mouth. The objective of this paper is to explain and support the necessity of adopting a different qualitative method when electronic word of mouth is harnessed on health care dedicated forums, that is, netnography. PMID:25408755

  10. World Bank: harnessing civil society expertise in undertaking and disseminating research findings.

    PubMed

    Simms, Ben

    2013-01-01

    The UK Consortium on AIDS and International Development was an essential partner to the evaluation leaders in harnessing the contribution and expertise of civil society. This article describes what the partnership entailed, the additional value it brought and how civil society might use the evaluation findings both as a tool for advocacy and a means for improving its own engagement with the individuals directly affected by HIV and with those who care for them. PMID:23745623

  11. The relevance of netnography to the harness of Romanian health care electronic word-of-mouth

    PubMed Central

    Bratucu, R; Gheorghe, IR; Radu, A; Purcarea, VL

    2014-01-01

    Abstract Nowadays, consumers use the computer mediated communication to make purchase decisions on a large variety of products and services. Since health care services are archetypal by nature, consumers in this field are one of the most encountered users of electronic word-of-mouth. The objective of this paper is to explain and support the necessity of adopting a different qualitative method when electronic word of mouth is harnessed on health care dedicated forums, that is, netnography. PMID:25408755

  12. Mapping the Sea Floor of the Historic Area Remediation Site (HARS) Offshore of New York City

    USGS Publications Warehouse

    Butman, Bradford

    2002-01-01

    The area offshore of New York City has been used for the disposal of dredged material for over a century. The area has also been used for the disposal of other materials such as acid waste, industrial waste, municipal sewage sludge, cellar dirt, and wood. Between 1976 and 1995, the New York Bight Dredged Material Disposal Site, also known as the Mud Dump Site (MDS), received on average about 6 million cubic yards of dredged material annually. In September 1997 the MDS was closed as a disposal site, and it and the surrounding area were designated as the Historic Area Remediation Site (HARS). The sea floor of the HARS, approximately 9 square nautical miles in area, currently is being remediated by placing a minimum 1-m-thick cap of clean dredged material on top of the surficial sediments that are contaminated from previous disposal of dredged and other materials. The U.S. Geological Survey (USGS) is working cooperatively with the U.S. Army Corps of Engineers (USACE) to map the sea floor geology of the HARS and changes in the characteristics of the surficial sediments over time.

  13. Molecular mapping of a sunflower rust resistance gene from HAR6

    PubMed Central

    Bulos, Mariano; Ramos, María L.; Altieri, Emiliano; Sala, Carlos A.

    2013-01-01

    Sunflower rust, caused by Puccinia helianthi Schw., can result in significant yield losses in cultivated sunflower (Helianthus annuus L. var. macrocarpus Ckll.). HAR6 is a germplasm population resistant to most predominant rust races. The objectives of this study were to map the resistance factor present in HAR6 (RHAR6), and to provide and validate molecular tools for the identification of this gene for marker assisted selection purposes. Virulence reaction of seedlings for the F2 population and F2:3 families suggested that a single dominant gene confers rust resistance in HAR6-1, a selected rust resistance line from the original population. Genetic mapping with eight markers covered 97.4 cM of genetic distance on linkage group 13 of the sunflower consensus map. A co-dominant marker ZVG61 is the closest marker distal to RHAR6 at a genetic distance of 0.7 cM, while ORS581, a dominant marker linked in the coupling phase, is proximal to RHAR6 at a genetic distance of 1.5 cM. Validation of these markers was assessed by converting a susceptible line into a rust resistant isoline by means of marker assisted backcrossing. The application of these results to assist the breeding process and to design new strategies for rust control in sunflower is discussed. PMID:23641190

  14. Accelerations and Passenger Harness Loads Measured in Full-Scale Light-Airplane Crashes

    NASA Technical Reports Server (NTRS)

    Eiband, A. Martin; Simpkinson, Scott H.; Black, Dugald O.

    1953-01-01

    Full-scale light-airplane crashes simulating stall-spin accidents were conducted to determine the decelerations to which occupants are exposed and the resulting harness forces encountered in this type of accident. Crashes at impact speeds from 42 to 60 miles per hour were studied. The airplanes used were of the familiar steel-tube, fabric-covered, tandem, two-seat type. In crashes up to an impact speed of 60 miles per hour, crumpling of the forward fuselage structure prevented the maximum deceleration at the rear-seat location from exceeding 26 to 33g. This maximum g value appeared independent of the impact speed. Restraining forces in the seatbelt - shoulder-harness combination reached 5800 pounds. The rear-seat occupant can survive crashes of the type studied at impact speeds up to 60 miles per hour, if body movement is restrained by an adequate seatbelt-shoulder-harness combination so as to prevent injurious contact with obstacles normally present in the cabin. Inwardly collapsing cabin structure, however, is a potential hazard in the higher-speed crashes.

  15. The Belem Framework for Action: Harnessing the Power and Potential of Adult Learning and Education for a Viable Future

    ERIC Educational Resources Information Center

    Adult Learning, 2012

    2012-01-01

    This article presents the Belem Framework for Action. This framework focuses on harnessing the power and potential of adult learning and education for a viable future. This framework begins with a preamble on adult education and towards lifelong learning.

  16. Harnessing steam

    SciTech Connect

    Petroski, H.

    1996-01-01

    This article describes the history of steam power, starting with the elements of the steam engine known to the Greeks. The story continues in the 17th century, goes through the late 18th century when steam engine use changed from use as pumps by Watt`s invention of a double acting cylinder which drove a piston, and followed both the way it shaped industry and society and the major questions posed by the hazards of steam energy. The article concludes with an explaination of the development and a summary of the Boiler and Pressure Vessel Code now in effect. 7 refs., 3 figs.

  17. The IS-ENES climate4impact portal: bridging the CMIP5 and CORDEX data to impact users

    NASA Astrophysics Data System (ADS)

    Som de Cerff, Wim; Plieger, Maarten; Page, Christian; Tatarinova, Natalia; Hutjes, Ronald; de Jong, Fokke; Bärring, Lars; Sjökvist, Elin; Vega Saldarriaga, Manuel; Santiago Cofiño Gonzalez, Antonio

    2015-04-01

    The aim of climate4impact (climate4impact.eu) is to enhance the use of Climate Research Data and to enhance the interaction with climate effect/impact communities. The portal is based on 17 impact use cases from 5 different European countries, and is evaluated by a user panel consisting of use case owners. It has been developed within the IS-ENES European project and is currently operated and further developed in the IS ENES2 project. As the climate impact community is very broad, the focus is mainly on the scientific impact community. Climate4impact is connected to the Earth System Grid Federation (ESGF) nodes containing global climate model data (GCM data) from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) and regional climate model data (RCM) data from the Coordinated Regional Climate Downscaling Experiment (CORDEX). This global network of climate model data centers offers services for data description, discovery and download. The climate4impact portal connects to these services using OpenID, and offers a user interface for searching, visualizing and downloading global climate model data and more. A challenging task is to describe the available model data and how it can be used. The portal informs users about possible caveats when using climate model data. All impact use cases are described in the documentation section, using highlighted keywords pointing to detailed information in the glossary. Climate4impact currently has two main objectives. The first one is to work on a web interface which automatically generates a graphical user interface on WPS endpoints. The WPS calculates climate indices and subset data using OpenClimateGIS/icclim on data stored in ESGF data nodes. Data is then transmitted from ESGF nodes over secured OpenDAP and becomes available in a new, per user, secured OpenDAP server. The results can then be visualized again using ADAGUC WMS. Dedicated wizards for processing of climate indices will be developed in close

  18. Formation of three new bonds and two stereocenters in acyclic systems by zinc-mediated enantioselective alkynylation of acylsilanes, Brook rearrangement, and ene-allene carbocyclization reactions.

    PubMed

    Smirnov, Polina; Katan, Einat; Mathew, Jomon; Kostenko, Arseni; Karni, Miriam; Nijs, Anne; Bolm, Carsten; Apeloig, Yitzhak; Marek, Ilan

    2014-12-19

    Diastereoisomerically pure (dr > 99:1) and enantiomerically enriched (er up to 98:2) substituted propargyl diols possessing a tertiary hydroxyl group were synthesized in a single-pot operation from simple acylsilanes through a combined catalytic enantioselective alkynylation of acylsilanes, followed by an allenyl-Zn-Brook rearrangement and Zn-ene-allene (or Zn-yne-allene) cyclization reaction. Two remarkable features of these reactions are the near complete transfer of chirality in the allenyl-Zn-Brook rearrangement and the highly organized six-membered transition state of the Zn-ene-allene carbocyclization found by DFT calculations. In this process, three new bonds and two new stereogenic centers are created in a single-pot operation in excellent diastereo- and enantiomeric ratios. DFT calculations show that the allenyl-Zn-Brook rearrangement occurs in preference to the classic [1,2]-Zn-Brook rearrangement owing to its significantly lower activation barrier. PMID:25271364

  19. Design, synthesis, and evaluation of novel 3-amino-4-hydrazine-cyclobut-3-ene-1,2-diones as potent and selective CXCR2 chemokine receptor antagonists.

    PubMed

    Liu, Shilan; Liu, Yinhui; Wang, Hongmei; Ding, Yili; Wu, Hao; Dong, Jingchao; Wong, Angela; Chen, Shu-Hui; Li, Ge; Chan, Manuel; Sawyer, Nicole; Gervais, Francois G; Henault, Martin; Kargman, Stacia; Bedard, Leanne L; Han, Yongxin; Friesen, Rick; Lobell, Robert B; Stout, David M

    2009-10-01

    We describe herein a novel series of 3-amino-4-hydrazine-cyclobut-3-ene-1,2-diones as potent and selective inhibitors against the CXCR2 chemokine receptor and IL-8-mediated chemotaxis of a CXCR2-expressing cell line. Furthermore, these alkyl-hydrazine series inhibitors such as 5b demonstrated acceptable metabolic stability when incubated in human and rat microsomes. PMID:19713110

  20. Preparation and Characterization of Polyhedral Oligomeric Silsesquioxane-Containing, Titania-Thiol-Ene Composite Photocatalytic Coatings, Emphasizing the Hydrophobic-Hydrophilic Transition.

    PubMed

    Jefferson, LaCrissia U; Netchaev, Anton D; Jefcoat, Jennifer A; Windham, Amber D; McFarland, Frederick M; Guo, Song; Buchanan, Randy K; Buchanan, J Paige

    2015-06-17

    Coatings prepared from titania-thiol-ene compositions were found to be both self-cleaning, as measured by changes in water contact angle, and photocatalytic toward the degradation of an organic dye. Stable titania-thiol-ene dispersions at approximately 2 wt % solids were prepared using a combination of high-shear mixing and sonication in acetone solvent from photocatalytic titania, trisilanol isobutyl polyhedral oligomeric silsesquioxane (POSS) dispersant, and select thiol-ene monomers, i.e., trimethylolpropane tris(3-mercaptopropionate) (TMPMP), pentaerythritol allyl ether (APE), and 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TTT). The dispersed particle compositions were characterized by DLS and TEM. The synthetic methods employed yield a strongly bound particle/POSS complex, supported by IR, 29Si NMR, and TGA. The factors of spray techniques, carrier solvent volatility, and particle size and size distributions, in combination, likely all contribute to the highly textured but uniform surfaces observed via SEM and AFM. Polymer composites possessed thermal transitions (e.g., Tg) consistent with composition. In general, the presence of polymer matrix provided mechanical integrity, without significantly compromising or prohibiting other critical performance characteristics, such as film processing, photocatalytic degradation of adsorbed contaminants, and the hydrophobic-hydrophilic transition. In all cases, coatings containing photocatalytic titania were converted from superhydrophobic to superhydrophilic, as defined by changes in the water contact angle. The superhydrophilic state of samples was considered persistent, since long time durations in complete darkness were required to observe any significant hydrophobic return. In a preliminary demonstration, the photocatalytic activity of prepared coatings was confirmed through the degradation of crystal violet dye. This work demonstrates that a scalable process can be found to prepare titania-thiol-ene

  1. 1-Meth­oxy-3-o-tolyl­bicyclo­[2.2.2]oct-5-ene-2,2-dicarbonitrile

    PubMed Central

    Büyükgüngör, Orhan; Yavuz, Serkan; Odabaşoğlu, Mustafa; Pamir, Özgür; Yıldırır, Yılmaz

    2009-01-01

    In the title compound, C18H18N2O, the cyclo­hexene and cyclo­hexane rings of the bicyclo­[2.2.2]oct-5-ene unit adopt distorted boat conformations. In the crystal, mol­ecules exist as C—H⋯N hydrogen-bonded centrosymmetric R 2 2(14) dimers, which are further linked by C—H⋯π inter­actions. PMID:21577609

  2. Total synthesis of (+)-asteriscanolide: further exploration of the rhodium(I)-catalyzed [(5+2)+1] reaction of ene-vinylcyclopropanes and CO.

    PubMed

    Liang, Yong; Jiang, Xing; Fu, Xu-Fei; Ye, Siyu; Wang, Tao; Yuan, Jie; Wang, Yuanyuan; Yu, Zhi-Xiang

    2012-03-01

    The total synthesis of (+)-asteriscanolide is reported. The synthetic route features two key reactions: 1) the rhodium(I)-catalyzed [(5+2)+1] cycloaddition of a chiral ene-vinylcyclopropane (ene-VCP) substrate to construct the [6.3.0] carbocyclic core with excellent asymmetric induction, and 2) an alkoxycarbonyl-radical cyclization that builds the bridging butyrolactone ring with high efficiency. Other features of this synthetic route include the catalytic asymmetric alkynylation of an aldehyde to synthesize the chiral ene-VCP substrate, a highly regioselective conversion of the [(5+2)+1] cycloadduct into its enol triflate, and the inversion of the inside-outside tricycle to the outside-outside structure by an ester-reduction/elimination to enol-ether/hydrogenation procedure. In addition, density functional theory (DFT) rationalization of the chiral induction of the [(5+2)+1] reaction and the diastereoselectivity of the radical annulation has been presented. Equally important is that we have also developed other routes to synthesize asteriscanolide using the rhodium(I)-catalyzed [(5+2)+1] cycloaddition as the key step. Even though these routes failed to achieve the total synthesis, these experiments gave further useful information about the scope of the [(5+2)+1] reaction and paved the way for its future application in synthesis. PMID:22223465

  3. Synthesis and Applications of Silyl 2-Methylprop-2-ene-1-sulfinates in Preparative Silylation and GC-Derivatization Reactions of Polyols and Carbohydrates.

    PubMed

    Marković, Dean; Tchawou, Wandji Augustin; Novosjolova, Irina; Laclef, Sylvain; Stepanovs, Dmitrijs; Turks, Māris; Vogel, Pierre

    2016-03-14

    Trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, and triisopropylsilyl 2-methylprop-2-ene-1-sulfinates were prepared through (CuOTf)2⋅C6H6-catalyzed sila-ene reactions of the corresponding methallylsilanes with SO2 at 50 °C. Sterically hindered, epimerizable, and base-sensitive alcohols gave the corresponding silyl ethers in high yields and purities at room temperature and under neutral conditions. As the byproducts of the silylation reaction (SO2 +isobutylene) are volatile, the workup was simplified to solvent evaporation. The developed method can be employed for the chemo- and regioselective semiprotection of polyols and glycosides and for the silylation of unstable aldols. The high reactivity of the developed reagents is shown by the synthesis of sterically hindered per-O-tert-butyldimethylsilyl-α-D-glucopyranose, the X-ray crystallographic analysis of which is the first for a per-O-silylated hexopyranose. The per-O-silylation of polyols, hydroxy carboxylic acids, and carbohydrates with trimethylsilyl 2-methylprop-2-ene-1-sulfinate was coupled with the GC analysis of nonvolatile polyhydroxy compounds both qualitatively and quantitatively. PMID:26864218

  4. Facile preparation of biocompatible sulfhydryl cotton fiber-based sorbents by "thiol-ene" click chemistry for biological analysis.

    PubMed

    He, Xiao-Mei; Zhu, Gang-Tian; Zhu, Yuan-Yuan; Chen, Xi; Zhang, Zheng; Wang, Shao-Ting; Yuan, Bi-Feng; Feng, Yu-Qi

    2014-10-22

    Sulfhydryl cotton fiber (SCF) has been widely used as adsorbent for a variety of metal ions since 1971. Thanks to the abundant thiols on SCF, in this study, we reported a universal method for the facile preparation of SCF-based materials using "thiol-ene" click chemistry for the first time. With the proposed method, two types of SCF-based materials, phenylboronic acid grafted sulfhydryl cotton fiber (SCF-PBA) and zirconium phosphonate-modified sulfhydryl cotton fiber (SCF-pVPA-Zr(4+)), were successfully prepared. The grafted functional groups onto the thiol group of SCF were demonstrated by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX). The prepared fibrous materials exhibited excellent fiber strength, good stability in aqueous or nonaqueous solutions, and great biocompatibility. Moreover, we developed filter-free in-pipet-tip SPE using these SCF-based materials as adsorbent for the enrichment of ribonucleosides, glycopeptides and phosphopeptides. Our results showed that SCF-PBA adsorbent can selectively capture ribonucleosides and glycopeptides from complex biological samples. And SCF-pVPA-Zr(4+) adsorbent exhibited high selectivity and capacity in the enrichment of phosphopeptides from the digestion mixture of β-casein and bovine serum albumin (BSA), as well as human serum and nonfat milk digest. Generally, the preparation strategy can be a universal method for the synthesis of other functionalized cotton-based adsorbents with special requirement in microscale biological analysis. PMID:25268138

  5. Fabrication of rigid microstructures with thiol-ene-based soft lithography for continuous-flow cell lysis

    PubMed Central

    Burke, Jeffrey M.; Pandit, Kunal R.; Goertz, John P.

    2014-01-01

    In this work, we introduce a method for the soft-lithography-based fabrication of rigid microstructures and a new, simple bonding technique for use as a continuous-flow cell lysis device. While on-chip cell lysis techniques have been reported previously, these techniques generally require a long on-chip residence time, and thus cannot be performed in a rapid, continuous-flow manner. Microstructured microfluidic devices can perform mechanical lysis of cells, enabling continuous-flow lysis; however, rigid silicon-based devices require complex and expensive fabrication of each device, while polydimethylsiloxane (PMDS), the most common material used for soft lithography fabrication, is not rigid and expands under the pressures required, resulting in poor lysis performance. Here, we demonstrate the fabrication of microfluidic microstructures from off-stoichiometry thiol-ene (OSTE) polymer using soft-lithography replica molding combined with a post-assembly cure for easy bonding. With finite element simulations, we show that the rigid microstructures generate an energy dissipation rate of nearly 107, which is sufficient for continuous-flow cell lysis. Correspondingly, with the OSTE device we achieve lysis of highly deformable MDA-MB-231 breast cancer cells at a rate of 85%, while a comparable PDMS device leads to a lysis rate of only 40%. PMID:25538814

  6. Thiol-ene hydrogels as desmoplasia-mimetic matrices for modeling pancreatic cancer cell growth, invasion, and drug resistance

    PubMed Central

    Ki, Chang Seok; Lin, Tsai-Yu; Korc, Murray; Lin, Chien-Chi

    2014-01-01

    The development of pancreatic ductal adenocarcinoma (PDAC) is heavily influenced by local stromal tissues, or desmoplasia. Biomimetic hydrogels capable of mimicking tumor niches are particularly useful for discovering the role of independent matrix cues on cancer cell development. Here, we report a photo-curable and bio-orthogonal thiol-ene (i.e., cross-linked by mutually reactive norbornene and thiol groups via photoinitiation) hydrogel platform for studying the growth, morphogenesis, drug resistance, and cancer stem cell marker expression in PDAC cells cultured in 3D. The hydrogels were prepared from multi-arm poly(ethylene glycol)-norbornene cross-linked with protease sensitive peptide to permit cell-mediated matrix remodeling. Collagen 1 fibrils were incorporated into the covalent network while cytokines (e.g., EGF and TGF-β1) were supplemented in the culture media for controlling cell fate. We found that the presence of collagen 1 enhanced cell proliferation and Yes-associated protein (YAP) translocation to cell nuclei. Cytokines and collagen 1 synergistically up-regulated MT1-MMP expression and induced cell spreading, suggestive of epithelial-mesenchymal transition (EMT) in the encapsulated cells. Furthermore, PDAC cells cultured in 3D developed chemo-resistance even in the absence of collagen 1 and cytokines. This phenotype is likely a consequence of the enrichment of pancreatic cancer stem cells that expressed high levels of CD24, sonic hedgehog (SHH), and vascular endothelial growth factor (VEGF). PMID:25176061

  7. Functional characterization and stability improvement of a ‘thermophilic-like’ ene-reductase from Rhodococcus opacus 1CP

    PubMed Central

    Riedel, Anika; Mehnert, Marika; Paul, Caroline E.; Westphal, Adrie H.; van Berkel, Willem J. H.; Tischler, Dirk

    2015-01-01

    Ene-reductases (ERs) are widely applied for the asymmetric synthesis of relevant industrial chemicals. A novel ER OYERo2 was found within a set of 14 putative old yellow enzymes (OYEs) obtained by genome mining of the actinobacterium Rhodococcus opacus 1CP. Multiple sequence alignment suggested that the enzyme belongs to the group of ‘thermophilic-like’ OYEs. OYERo2 was produced in Escherichia coli and biochemically characterized. The enzyme is strongly NADPH dependent and uses non-covalently bound FMNH2 for the reduction of activated α,β-unsaturated alkenes. In the active form OYERo2 is a dimer. Optimal catalysis occurs at pH 7.3 and 37°C. OYERo2 showed highest specific activities (45-50 U mg-1) on maleimides, which are efficiently converted to the corresponding succinimides. The OYERo2-mediated reduction of prochiral alkenes afforded the (R)-products with excellent optical purity (ee > 99%). OYERo2 is not as thermo-resistant as related OYEs. Introduction of a characteristic intermolecular salt bridge by site-specific mutagenesis raised the half-life of enzyme inactivation at 32°C from 28 to 87 min and improved the tolerance toward organic co-solvents. The suitability of OYERo2 for application in industrial biocatalysis is discussed. PMID:26483784

  8. Photophysical properties of sol-gel derived luminescent silicone hybrids synthesized via facile amino-ene reaction.

    PubMed

    Yue, Yuanzhi; Liang, Yan; Wang, Hua; Feng, Linglong; Feng, Shengyu; Lu, Haifeng

    2013-01-01

    Novel luminescent silicone hybrids (LSHs) containing lanthanide ions were prepared via different sol-gel processes. The precursor, dimethyl ester-functionalized silane, was synthesized via a facile amino-ene reaction. The coordinated assembly of the ester ligands and lanthanide ions (Eu(3+), Tb(3+) and Dy(3+)) occurred. The ester ligands were immobilized onto the Si-O network backbone during the preparation of the silicone hybrid materials. The particle size can be controlled to ca 50 nm by adjusting the solvent ratio. The obtained materials were characterized by Fourier transform infrared, (1)H nuclear magnetic resonance spectroscopy (NMR), (13)C NMR, (28)Si NMR, X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, high-resolution scanning electronic microscopy and luminescent (excitation and emission) spectroscopy. The coordination state and photophysical performance of the compounds were studied in detail. The terbium- and europium-containing materials show sharp green and red emissions, respectively, which indicate that efficient intramolecular energy transfer took place in these LSHs. PMID:22774939

  9. Synthesis and Characterization of High Performance Polyimides Containing the Bicyclo(2.2.2)oct-7-ene Ring System

    NASA Technical Reports Server (NTRS)

    Alvarado, M.; Harruna, I. I.; Bota, K. B.

    1997-01-01

    Due to the difficulty in processing polyimides with high temperature stability and good solvent resistance, we have synthesized high performance polyimides with bicyclo(2.2.2)-oct-7-ene ring system which can easily be fabricated into films and fibers and subsequently converted to the more stable aromatic polyimides. In order to improve processability, we prepared two polyimides by reacting 1,4-phenylenediamine and 1,3phenylediamine with bicyclo(2.2.2)-7-octene-2,3,5,6-tetracarboxylic dianhydride. The polyimides were characterized by FTIR, FTNMR, solubility and thermal analysis. Thermogravimetric analysis (TGA) showed that the 1,4-phenylenediamine and 1,3-phenylenediamine containing polyimides were stable up to 460 and 379 C, respectively under nitrogen atmosphere. No melting transitions were observed for both polyimides. The 1,4-phenylenediamine containing polyimide is partially soluble in dimethyl sulfoxide, methane sulfonic acid and soluble in sulfuric acid at room temperature. The 1,3-phenylenediamine containing polyimide is partially soluble in dimethyl sulfoxide, tetramethyl urea, N,N-dimethyl acetamide and soluble in methane sulfonic acid and sulfuric acid.

  10. Structure, thermal and spectral study of 16α,17-epoxypregn-4-ene-3,11,20-trione monohydate

    NASA Astrophysics Data System (ADS)

    Nie, Qiang; Wang, JingKang

    2005-10-01

    16α,17-epoxypregn-4-ene-3,11,20-trione is an important steroid intermediate in synthesis of many hormone pharmaceuticals, such as cortisone acetate and betamethason. It does not dissolve in water, but the single crystals grown from acetone with some water shows evident hydration behavior. The thermal analyses by DSC and TG-DTA and the IR spectra characterization of the anhydrous and hydrous crystals were performed and compared. The hydrate was also proved by IR spectral and thermal analyses. Single crystal structure of the hydrate indicates one water molecule per host molecule is included into the host lattice. The incorporation of water molecules does not change the crystal cell dimensions significantly, except for some increment of the cell along the axis b. In the crystal cell, two steroid molecules are linked through the water molecules as a bridge by forming two different hydrogen bonds. The incorporation of one water molecule makes some conformation changes of the molecules in the crystal unit cell.

  11. Classical conditioning of proboscis extension in harnessed Africanized honey bee queens (Apis mellifera L.).

    PubMed

    Aquino, Italo S; Abramson, Charles I; Soares, Ademilson E E; Fernandes, Andrea Cardoso; Benbassat, Danny

    2004-06-01

    Experiments are reported on learning in virgin Africanized honey bee queens (Apis mellifera L.). Queens restrained in a "Pavlovian harness" received a pairing of hexanal odor with a 1.8-M feeding of sucrose solution. Compared to explicitly unpaired controls, acquisition was rapid in reaching about 90%. Acquisition was also rapid in queens receiving an unconditioned stimulus of "bee candy" or an unconditioned stimulus administered by worker bees. During extinction the conditioned response declines. The steepest decline was observed in queens receiving an unconditioned stimulus of bee candy. These findings extend previous work on learning of Afrianized honey bee workers to a population of queen bees. PMID:15362396

  12. Effects of harness transmitters on behavior and reproduction of wild mallards

    USGS Publications Warehouse

    Pietz, Pamela J.; Krapu, Gary L.; Greenwood, Raymond J.; Lokemoen, John T.

    1993-01-01

    Radio telemetry has been an important research tool in waterfowl studies for >20 years, yet little effort has been made to evaluate potential effects of transmitters on the birds that carry them. As part of a 4-year mallard (Anas platyrhynchos) study in the prairie pothole region of North Dakota and Minnesota, we compared radio-marked and unmarked female mallards in terms of percent time observed feeding, resting, and preening; nest initiation date; and clutch size and egg volume. Radio-marked females carried a 23-g back-mounted transmitter attached with a 2-loop harness (Dwyer 1972). On average, radio-marked females tended to feed less, rest and preen more, initiate nests later, and lay smaller clutches and eggs than unmarked females. Thus, behavioral and reproductive data from ducks marked with back-mounted harness-attached transmitters may be biased. We recommend that new designs of radio packages be field tested and caution that effects may be masked under extreme environmental conditions.

  13. Water gate array for current flow or tidal movement pneumatic harnessing system

    DOEpatents

    Gorlov, Alexander M.

    1991-01-01

    The invention, which provides a system for harnessing power from current flow or tidal movement in a body of water, comprises first and second hydro-pneumatic chambers each having ingress and egress below the water surface near the river or ocean floor and water gates operative to open or seal the ports to the passage of water. In an exemplary embodiment, the gates are sychronized by shafts so that the ingress ports of each chamber are connected to the egress ports of each other chamber. Thus, one set of gates is closed, while the other is open, thereby allowing water to flow into one chamber and build air pressure therein and allowing water to flow out of the other chamber and create a partial vacuum therein. A pipe connects the chambers, and an air turbine harnesses the air movement within the pipe. When water levels are equilibrated, the open set of gates is closed by a counterweight, and the other set is allowed to open by natural force of the water differential. The water gates may be comprised of a plurality of louvers which are ganged for simultaneous opening and closing. The system is designed to operate with air turbines or other pneumatic devices. Its design minimizes construction cost and environmental impact, yet provides a clean renewable energy source.

  14. Harnessing large deformation and instabilities of soft dielectrics: Theory, experiment, and application

    NASA Astrophysics Data System (ADS)

    Zhao, Xuanhe; Wang, Qiming

    2014-06-01

    Widely used as insulators, capacitors, and transducers in daily life, soft dielectrics based on polymers and polymeric gels play important roles in modern electrified society. Owning to their mechanical compliance, soft dielectrics subject to voltages frequently undergo large deformation and mechanical instabilities. The deformation and instabilities can lead to detrimental failures in some applications of soft dielectrics such as polymer capacitors and insulating gels but can also be rationally harnessed to enable novel functions such as artificial muscle, dynamic surface patterning, and energy harvesting. According to mechanical constraints on soft dielectrics, we classify their deformation and instabilities into three generic modes: (i) thinning and pull-in, (ii) electro-creasing to cratering, and (iii) electro-cavitation. We then provide a systematic understanding of different modes of deformation and instabilities of soft dielectrics by integrating state-of-the-art experimental methods and observations, theoretical models, and applications. Based on the understanding, a systematic set of strategies to prevent or harness the deformation and instabilities of soft dielectrics for diverse applications are discussed. The review is concluded with perspectives on future directions of research in this rapidly evolving field.

  15. New Padded Harness for Self-Acquisition of Resting 12-Lead ECGs

    NASA Technical Reports Server (NTRS)

    Schlegel, T. T.; Rood, A. T.

    2011-01-01

    We have developed a dry-electrode harness that permits easy, rapid, and unsupervised self-acquisition of resting 12-lead ECGs without the use of any disposables. Various other advantageous features of the harness include: 1) padded or inflatable cushions at the lateral sides of the torso that function to press the left arm (LA) and right arm (RA) dry electrodes mounted on cushions against sideward (as shown in the Figure below) or downward-rested arms of the subject; 2) sufficient distal placement of the arm electrodes with good abutment and without the need for adhesives, straps, bands, bracelets, or gloves on the arms; 3) padding over the sternum to avoid "tenting" in the V1 through V3 (and V3R, when present) electrode positions; 4) easy-to-don, one-piece design with an adjustable single point of connection and an adjustable shoulder strap; and 5) Lund or "modified Lund" placement of the dry electrodes, the results of which more effectively reproduce results from "standard" 12-lead ECG placements than do results from Mason-Likar lead placements.

  16. Plug-and-play design approach to smart harness for modular small satellites

    NASA Astrophysics Data System (ADS)

    Mughal, M. Rizwan; Ali, Anwar; Reyneri, Leonardo M.

    2014-02-01

    A typical satellite involves many different components that vary in bandwidth demand. Sensors that require a very low data rate may reside on a simple two- or three-wire interface such as I2C, SPI, etc. Complex sensors that require high data rate and bandwidth may reside on an optical interface. The AraMiS architecture is an enhanced capability architecture with different satellite configurations. Although keeping the low-cost and COTS approach of CubeSats, it extends the modularity concept as it also targets different satellite shapes and sizes. But modularity moves beyond the mechanical structure: the tiles also have thermo-mechanical, harness and signal-processing functionalities. Further modularizing the system, every tile can also host a variable number of small sensors, actuators or payloads, connected using a plug-and-play approach. Every subsystem is housed in a small daughter board and is supplied, by the main tile, with power and data distribution functions, power and data harness, mechanical support and is attached and interconnected with space-grade spring-loaded connectors. The tile software is also modular and allows a quick adaptation to specific subsystems. The basic software for the CPU is properly hardened to guarantee high level of radiation tolerance at very low cost.

  17. Potential of mixed microalgae to harness biodiesel from ecological water-bodies with simultaneous treatment.

    PubMed

    Mohan, S Venkata; Devi, M Prathima; Mohanakrishna, G; Amarnath, N; Babu, M Lenin; Sarma, P N

    2011-01-01

    Biodiesel as an eco-friendly fuel is gaining much acceptance in recent years. This communication provides an overview on the possibility of using mixed microalgae existing in ecological water-bodies for harnessing biodiesel. Microalgal cultures from five water-bodies are cultivated in domestic wastewater in open-ponds and the harvested algal-biomass was processed through acid-catalyzed transesterification. Experiments evidenced the potential of using mixed microalgae for harnessing biodiesel. Presence of palmitic acid (C16:0) in higher fraction and physical properties of algal oil correlated well with the biodiesel properties. Functional characteristics of water-bodies showed to influence both species diversity and lipid accumulation. Microalgae from stagnant water-bodies receiving domestic discharges documented higher lipid accumulation. Algal-oil showed to consist 33 types of saturated and unsaturated fatty acids having wide food and fuel characteristics. Simultaneous wastewater treatment was also noticed due to the syntrophic association in the water-body microenvironment. Diversity studies visualized the composition of algae species known to accumulate higher lipids. PMID:20864335

  18. The effects of a harness safety system during maximal treadmill run testing in collegiate middle- and long-distance runners.

    PubMed

    Mermier, Christine M; Zuhl, Micah N; Wilmerding, M Virginia; Beam, Jason R; White, Ailish C; Salgado, Roy M; Beverly, J Marc

    2013-11-01

    This study compared the results of graded maximal treadmill testing with and without a safety harness (SH) spotting system among collegiate middle- and long-distance runners. Thirteen (n = 8 men, n = 5 women) collegiate runners completed 2 randomly selected maximal treadmill tests. One trial used an SH, and one trial used no harness. All tests were separated by at least 48 hours. The subjects began the test at a velocity of 14.5 or 12 km · h with 1% grade for men and women, respectively, and increased 0.80 kilometers/hr per stage. During each trial, metabolic data and running speed values were recorded along with the completion of a safety questionnaire. No significant difference was found for maximal oxygen consumption (60.84 ± 8.89 vs. 60.733 ± 9.38 ml · kg · min) and velocity at maximal oxygen consumption (5.33 ± 0.62 vs. 5.24 ± 0.57 m · s) between the no harness and harness trials, respectively. Test time was found to be significantly longer in the no harness trial (611.06 ± 119.34 vs. 537.38 ± 91.83 seconds, p < 0.05). The results of the safety questionnaire demonstrated that the runners felt significantly more comfortable during the SH trial (p < 0.05). PMID:23442275

  19. Regulation of a putative corticosteroid, 17, 21-dihydroxypregn-4-ene, 3, 20-one, in sea lamprey, Petromyzon marinus.

    USGS Publications Warehouse

    Roberts, Brent W.; Didier, Wes; Satbir, Rai; Johnson, Nicholas S.; Libants, Scot V.; Sang-Seon, Yun; Close, David

    2013-01-01

    In higher vertebrates, in response to stress, the hypothalamus produces corticotropin-releasing hormone (CRH), which stimulates cells in the anterior pituitary to produce adrenocorticotropic hormone (ACTH), which in turn stimulates production of either cortisol (F) or corticosterone (B) by the adrenal tissues. In lampreys, however, neither of these steroids is present. Instead, it has been proposed that the stress steroid is actually 17,21-dihydroxypregn-4-ene-3,20-dione (11-deoxycortisol; S). However, there have been no studies yet to determine its mechanism of regulation or site of production. Here we demonstrate that (1) intraperitoneal injections of lamprey-CRH increase plasma S in a dose dependent manner, (2) intraperitoneal injections of four lamprey-specific ACTH peptides at 100 lg/kg, did not induce changes in plasma S concentrations in either males or females; (3) two lamprey-specific gonadotropin-releasing hormones (GnRH I and III) and arginine-vasotocin (AVT), all at single doses, stimulated S production as well as, or to an even greater extent than CRH; (4) sea lamprey mesonephric kidneys, in vitro, converted tritiated 17a-hydroxyprogesterone (17a-P) into a steroid that had the same chromatographic properties (on HPLC and TLC) as S; (5) kidney tissues released significantly more immunoassayable S into the incubation medium than gill, liver or gonad tissues. One interpretation of these results is that the corticosteroid production of the sea lamprey, one of the oldest extant vertebrates, is regulated through multiple pathways rather than the classical HPI-axis. However, the responsiveness of this steroid to the GnRH peptides means that a reproductive rather than a stress role for this steroid cannot yet be ruled out.

  20. Introduction of thiol moieties, including their thiol-ene reactions and air oxidation, onto polyelectrolyte multilayer substrates.

    PubMed

    Madaan, Nitesh; Romriell, Naomi; Tuscano, Joshua; Schlaad, Helmut; Linford, Matthew R

    2015-12-01

    We describe the derivatization of uncross-linked and cross-linked layer-by-layer (LbL) assemblies of polyelectrolytes (polyallylamine hydrochloride and polyacrylic acid) with sulfydryl groups via Traut's reagent (2-iminothiolane). This thiolation was optimized with regards to temperature, concentration, and pH. The stability of the resulting -SH groups in the air was determined by X-ray photoelectron spectroscopy (XPS). This air oxidation has obvious implications for the use of thiol-ene reactions in materials chemistry, and there appears to be little on this topic in the literature. Three main S 2s signals were observed by XPS: at 231.5 eV (oxidized sulfur), 227.6 eV (thiol groups), and 225.4 eV (thiolate groups). Due to their rapid oxidation, we recommend that thiolated surfaces be used immediately after they are prepared. As driven by 254 nm UV light, thiol groups on polyelectrolyte multilayers react with 1,2-polybutadiene (PBd), and residual carbon-carbon double bonds on adsorbed PBd similarly react with another thiol. In the case of a fluorinated thiol, surfaces with high water contact angles (ca. 120°) are obtained. Modest exposures to light result in derivatization, while longer exposures damage the assemblies. Polyelectrolyte-thiol-PBd-thiol assemblies delaminate from their substrates when immersed for long periods of time in water. Surface silanization with an amino silane prevents this delamination and leads to stable assemblies. These assemblies withstand various stability tests. Techniques used to analyze the materials in this study include X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), atomic force microscopy (AFM), and contact angle goniometry. PMID:26295196

  1. Quantitative and qualitative toxicological evaluation of thiol-ene "click" chemistry-based polyanhydrides and their degradation products.

    PubMed

    Mohammed, Halimatu S; Snyder, Brittany L; Samways, Damien S K; Shipp, Devon A

    2016-08-01

    Quantitative and qualitative toxicological analyses of crosslinked, surface-eroding polyanhydrides (PAHs) made from thiol-ene "click" polymerizations are reported. The cytotoxicity of these PAHs was investigated against three skin-based cell types; melanoma (A-375), human dermal fibroblast adult (HDFa), and 3T3-J2 (mouse fibroblast) cells, thus providing insight into the potential for these PAHs to be used in dermal drug delivery applications. Apoptosis was evaluated quantitatively and qualitatively using MTT assay and fluorescence microscopic imaging as indication of cytotoxicity. Upon exposure of A-375 and HDFa cells to high concentrations (4000 mg/L) of crosslinked PAH, the respective morphologies remained relatively unchanged compared with nonexposed cells. The 3T3-J2 cell type was more sensitive towards the PAH, exhibiting minimal deformation of cell morphology at 4000 mg/L. The MTT assay and fluorescence imaging revealed that this PAH and its degradation products are highly cytocompatible at high concentrations and cytotoxicity observed is dosage/time dependent. Further, the PAH did not induce inhibition of tested cells' proliferation at high polymer concentration up to 2000 mg/L. The IC50 (concentration of the crosslinked PAH required to inhibit 50% cell viability) for HDFa and A-375 cells was determined to be 4300 ± 70 and 8500 ± 50 mg/L, respectively. The high cytocompatibility of this type of crosslinked PAH, in addition to their degradation products, towards these skin cells (standard and cancer cell types) suggests that the polymer may be viable for dermal-based drug delivery to normal and cancerous diseased tissues. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1936-1945, 2016. PMID:27012532

  2. Fabrication of Thiol-Ene "Clickable" Copolymer-Brush Nanostructures on Polymeric Substrates via Extreme Ultraviolet Interference Lithography.

    PubMed

    Dübner, Matthias; Gevrek, Tugce N; Sanyal, Amitav; Spencer, Nicholas D; Padeste, Celestino

    2015-06-01

    We demonstrate a new approach to grafting thiol-reactive nanopatterned copolymer-brush structures on polymeric substrates by means of extreme ultraviolet (EUV) interference lithography. The copolymer brushes were designed to contain maleimide functional groups as thiol-reactive centers. Fluoropolymer films were exposed to EUV radiation at the X-ray interference lithography beamline (XIL-II) at the Swiss Light Source, in order to create radical patterns on their surfaces. The radicals served as initiators for the copolymerization of thiol-ene "clickable" brushes, composed of a furan-protected maleimide monomer (FuMaMA) and different methacrylates, namely, methyl methacrylate (MMA), ethylene glycol methyl ether methacrylate (EGMA), or poly(ethylene glycol) methyl ether methacrylate (PEGMA). Copolymerization with ethylene-glycol-containing monomers provides antibiofouling properties to these surfaces. The number of reactive centers on the grafted brush structures can be tailored by varying the monomer ratios in the feed. Grafted copolymers were characterized by using attenuated total reflection infrared (ATR-IR) spectroscopy. The reactive maleimide methacrylate (MaMA) units were utilized to conjugate thiol-containing moieties using the nucleophilic Michael-addition reaction, which proceeds at room temperature without the need for any metal-based catalyst. Using this approach, a variety of functionalities was introduced to yield polyelectrolytes, as well as fluorescent and light-responsive polymer-brush structures. Functionalization of the brush structures was demonstrated via ATR-IR and UV-vis spectroscopy and fluorescence microscopy, and was also indicated by a color switch. Furthermore, grafted surfaces were generated via plasma activation, showing a strongly increased wettability for polyelectrolytes and a reversible switch in static water contact angle (CA) of up to 18° for P(EGMA-co-MaMA-SP) brushes, upon exposure to alternating visible and UV-light irradiation

  3. Mechanistic Study of the Asymmetric Carbonyl-Ene Reaction between Alkyl Enol Ethers and Isatin Catalyzed by the N,N'-Dioxide-Mg(OTf)2 Complex.

    PubMed

    Wang, Junming; Su, Zhishan; Yang, Na; Hu, Changwei

    2016-08-01

    The mechanism and origin of the stereoselectivity of the asymmetric carbonyl-ene reaction between N-methyl-protected isatin and 2-methyloxypropene catalyzed by the N,N'-dioxide-Mg(OTf)2 complex were investigated by DFT and ONIOM methods. The background reaction occurred via a two-stage, one-step mechanism with a high activation barrier of 30.4 kcal mol(-1) at the B3LYP-D3(BJ)/6-311G**(SMD, CH2Cl2)//B3LYP/6-31G*(SMD, CH2Cl2) level at 303 K. Good linear correlations between the global nucleophilicity index (N) and the activation energy barrier (ΔG(⧧)) were found. The chiral N,N'-Mg(II) complex catalyst could enhance the electrophilicity of the isatin substrate by forming hexacoordinate Mg(II) reactive species. The substituent at the ortho positions of aniline combined with the aliphatic ring of the backbone in the chiral N,N'-dioxide ligand played an important role in the construction of a favorable "pocket-like" chiral environment (chiral pocket) around the Mg(II) center, directing the preferential orientation of the incoming substrate. An unfavorable steric arrangement in the re-face attack pathway translated into a more destabilizing activation strain of the ene substrate, enhancing enantiodifferentiation of two competing pathways for the desired R product. This work also suggested a new phosphine ligand (N-L1) for the formation of the Mg(II) complex catalyst for the asymmetric carbonyl-ene reaction. The chiral environment and Lewis acidity of the Mg(II) complex could be fine-tuned by introduction of P-donor units into the ligand for highly efficient asymmetric catalysis. PMID:27400326

  4. Harnessing immune cells to enhance β-cell mass in type 1 diabetes.

    PubMed

    Dirice, Ercument; Kulkarni, Rohit N

    2016-01-01

    Type 1 diabetes is characterized by early β-cell loss leading to insulin dependence in virtually all patients with the disease in order to maintain glucose homeostasis. Most studies over the past few decades have focused on limiting the autoimmune attack on the β cells. However, emerging data from patients with long-standing diabetes who continue to harbor functional insulin-producing cells in their diseased pancreas have prompted scientists to examine whether proliferation of existing β cells can be enhanced to promote better glycemic control. In support of this concept, several studies indicate that mononuclear cells that infiltrate the islets have the capacity to trigger proliferation of islet cells including β cells. These observations indicate the exciting possibility of identifying those mononuclear cell types and their soluble factors and harnessing their ability to promote β-cell growth concomitant with autoimmune therapy to prevent the onset and/or halt the progression of the disease. PMID:26755809

  5. Harnessing the Affordable Care Act to Catalyze Delivery System Reform and Strengthen Emergency Care in America

    PubMed Central

    Maa, John

    2015-01-01

    As health care reform in the US evolves beyond insurance reform to encompass delivery system reform, the opportunity arises to harness the Affordable Care Act to strengthen patient care in America. One area for dedicated individuals to lead this effort is by improving transitions in patient care across the continuum of team members, specialties, settings, and systems. This article will describe innovations of the surgicalist and acute care surgeon that have emerged in response to the challenges facing surgery in specialization, geography, and the need to comply with health care reform mandates. Three ways will be described to integrate these innovations with pilot programs in the Affordable Care Act: to promote teamwork, to reduce readmissions, and to strengthen emergency care because the key location where the joint efforts intersect most acutely with patient need is in our nation’s Emergency Departments. PMID:25663212

  6. Harnessing Yarrowia lipolytica lipogenesis to create a platform for lipid and biofuel production.

    PubMed

    Blazeck, John; Hill, Andrew; Liu, Leqian; Knight, Rebecca; Miller, Jarrett; Pan, Anny; Otoupal, Peter; Alper, Hal S

    2014-01-01

    Economic feasibility of biosynthetic fuel and chemical production hinges upon harnessing metabolism to achieve high titre and yield. Here we report a thorough genotypic and phenotypic optimization of an oleaginous organism to create a strain with significant lipogenesis capability. Specifically, we rewire Yarrowia lipolytica's native metabolism for superior de novo lipogenesis by coupling combinatorial multiplexing of lipogenesis targets with phenotypic induction. We further complete direct conversion of lipid content into biodiesel. Tri-level metabolic control results in saturated cells containing upwards of 90% lipid content and titres exceeding 25 g l(-1) lipids, which represents a 60-fold improvement over parental strain and conditions. Through this rewiring effort, we advance fundamental understanding of lipogenesis, demonstrate non-canonical environmental and intracellular stimuli and uncouple lipogenesis from nitrogen starvation. The high titres and carbon-source independent nature of this lipogenesis in Y. lipolytica highlight the potential of this organism as a platform for efficient oleochemical production. PMID:24445655

  7. Cold water cleaning of brain proteins, biofilm and bone - harnessing an ultrasonically activated stream.

    PubMed

    Birkin, P R; Offin, D G; Vian, C J B; Howlin, R P; Dawson, J I; Secker, T J; Hervé, R C; Stoodley, P; Oreffo, R O C; Keevil, C W; Leighton, T G

    2015-08-28

    In the absence of sufficient cleaning of medical instruments, contamination and infection can result in serious consequences for the health sector and remains a significant unmet challenge. In this paper we describe a novel cleaning system reliant on cavitation action created in a free flowing fluid stream where ultrasonic transmission to a surface, through the stream, is achieved using careful design and control of the device architecture, sound field and the materials employed. Cleaning was achieved with purified water at room temperature, moderate fluid flow rates and without the need for chemical additives or the high power consumption associated with conventional strategies. This study illustrates the potential in harnessing an ultrasonically activated stream to remove biological contamination including brain tissue from surgical stainless steel substrates, S. epidermidis biofilms from glass, and fat/soft tissue matter from bone structures with considerable basic and clinical applications. PMID:26200694

  8. Substantial influence on solar energy harnessing ability by geometries of ordered Si nanowire array

    PubMed Central

    2014-01-01

    The reflectance of the controlled periodic Si nanowire (NW) arrays is systematically explored, which characterizes the influence on the solar energy harnessing ability by the geometries of the NW. A unique dependence of the reflectance of the Si NW array on the diameter, the height, and the bending of the NW are disclosed. The solar energy loss caused by the reflection of the Si NW array exhibits the minimum for the NW with intermediate diameter and length. A plane-wave-based transfer-matrix method (TMM) simulation is performed, which is well consistent with the experimental results. Our results demonstrate the design principle to optimize the Si NW arrays for high-efficiency solar cells. PACS 81.07.-b; 78.67.-n; 81.16.-c PMID:25258613

  9. Amplifying the response of soft actuators by harnessing snap-through instabilities

    PubMed Central

    Overvelde, Johannes T. B.; Kloek, Tamara; D’haen, Jonas J. A.; Bertoldi, Katia

    2015-01-01

    Soft, inflatable segments are the active elements responsible for the actuation of soft machines and robots. Although current designs of fluidic actuators achieve motion with large amplitudes, they require large amounts of supplied volume, limiting their speed and compactness. To circumvent these limitations, here we embrace instabilities and show that they can be exploited to amplify the response of the system. By combining experimental and numerical tools we design and construct fluidic actuators in which snap-through instabilities are harnessed to generate large motion, high forces, and fast actuation at constant volume. Our study opens avenues for the design of the next generation of soft actuators and robots in which small amounts of volume are sufficient to achieve significant ranges of motion. PMID:26283372

  10. Harnessing Vehicle Automation for Public Mobility -- An Overview of Ongoing Efforts

    SciTech Connect

    Young, Stanley E.

    2015-11-05

    This presentation takes a look at the efforts to harness automated vehicle technology for public transport. The European CityMobil2 is the leading demonstration project in which automated shuttles were, or are planned to be, demonstrated in several cities and regions. The presentation provides a brief overview of the demonstrations at Oristano, Italy (July 2014), LaRochelle, France (Dec 2014), Lausanne, Switzerland (Apr 2015), Vantaa, Finland (July 2015), and Trikala, Greece (Sept 2015). In addition to technology exposition, the objectives included generating a legal framework for operation in each location and gaging the reaction of the public to unmanned shuttles, both of which were successfully achieved. Several such demonstrations are planned throughout the world, including efforts in North America in conjunction with the GoMentum Station in California. These early demonstration with low-speed automated shuttles provide a glimpse of the possible with a fully automated fleet of driverless vehicle providing a public transit service.

  11. Thiol-ene click synthesis of L-Cysteine-bonded zwitterionic hydrophilic magnetic nanoparticles for selective and efficient enrichment of glycopeptides.

    PubMed

    Wu, Runqing; Xie, Yang; Deng, Chunhui

    2016-11-01

    Efficient and specific enrichment of low-abundant glycopeptides from complex biological samples is essential to glycoproteomics analysis. Herein, novel magnetic zwitterionic hydrophilic nanoparticles based on thiol-ene click chemistry were synthesized. The functionalized magnetic nanoparticles exhibited superior performance in glycopeptide enrichment of HRP tryptic digest, demonstrating low detection limit (0.04ng/μL), high selectivity (a mixture of HRP and BSA at the mass ratio of 1:50) and reproducibility (5 repeating cycles). In addition, the material was successfully applied to glycopeptide enrichment from human serum. The outstanding results indicate the potential of the method in the development of glycoproteomics analysis in real biological samples. PMID:27591639

  12. A novel triterpene from the roots of Paullinia pinnata: 6α-(3'-methoxy-4'-hydroxybenzoyl)-lup-20(29)-ene-3-one.

    PubMed

    Jackson, Nora; Annan, Kofi; Mensah, Abraham Y; Ekuadzi, Edmund; Mensah, Merlin L K; Habtemariam, Solomon

    2015-04-01

    Paullinia pinnata L. (Sapindaceae) is an endemic West African plant that is extensively used in traditional medicine to treat various diseases. Previous phytochemical analysis by various groups led to the isolation of several novel lupene-based triterpenene derivatives along with other classes of compounds. As part of our continued phytochemical studies on the roots of this plant, we have now identified yet another novel triterpene, 6a-(3'-methoxy-4'-hydroxybenzoyl)-lup-20(29)-ene-3-one. The identification of the compound through comprehensive spectroscopic studies is discussed. PMID:25973476

  13. EB curing and cure grafting of novel CT monomer complexes: comparison with UV process and extension of the technique to thiol-ene systems

    NASA Astrophysics Data System (ADS)

    Dennis, Gary R.; Garnett, John L.; Zilic, Elvis

    2004-09-01

    EB curing and cure grafting of charge transfer (CT) monomer complexes is discussed. The complexes studied involve representative donors (D) such as vinyl ethers and typical acceptors (A) including maleates, maleimides and acrylates also oligomers. The EB results are compared with UV curing and cure grafting of the same complexes. The work has been extended to include EB/UV curing and cure grafting of thiol-ene systems. The significance of these results in the potential commercial application of these complexes is discussed.

  14. Cytotoxic activity of moronic acid and identification of the new triterpene 3,4-seco-olean-18-ene-3,28-dioic acid from Phoradendron reichenbachianum.

    PubMed

    Rios, M Y; Salina, D; Villarreal, M L

    2001-07-01

    The cytotoxic compound moronic acid (1) and the new tetracyclic triterpene 3,4-seco-olean-18-ene-3,28-dioic acid (2), were isolated from the aerial parts of the medicinal plant Phoradendron reichenbachianum (mistletoe, Loranthaceae) through a bioassay-guided fractionation. In addition, squalene, glycerol trilinoleate, morolic acid, betulonaldehyde, betulinaldehyde, alpha-germanicol, lupeol, beta-sitosterol and beta-sitosteril glucopyranoside, were identified in this plant species. The structures were elucidated on the basis of chemical and spectroscopic evidence. PMID:11488459

  15. Crystal structure of 1,2,3,4-di-O-methyl­ene-α-d-galacto­pyran­ose

    PubMed Central

    Tiritiris, Ioannis; Tussetschläger, Stefan; Kantlehner, Willi

    2015-01-01

    The title compound, C8H12O6, was synthesized by de­acetyl­ation of 6-acetyl-1,2,3,4-di-O-methyl­ene-α-d-galactose with sodium methoxide. The central part of the mol­ecule consists of a six-membered C5O pyran­ose ring with a twist-boat conformation. Both fused dioxolane rings adopt an envelope conformation with C and O atoms as the flap. In the crystal, O—H⋯O and C—H⋯O hydrogen bonds are present between adjacent mol­ecules, generating a three-dimensional network. PMID:26870551

  16. Modelling the effect of electrical harness on microvibration response of structures

    NASA Astrophysics Data System (ADS)

    Remedia, Marcello; Aglietti, Guglielmo S.; Richardson, Guy

    2015-04-01

    The term "microvibrations" generally refers to accelerations in the region of micro-g, occurring over a wide frequency range, up to say 500-1000 Hz. The main issues related to microvibrations are their control and minimisation, which requires their modelling and analysis. A particular challenge is posed in the mid-frequency range, where many of the micro-vibration sources on board a spacecraft tend to act. In this case, in addition to the typical issues related to predicting responses in the mid-frequency, the low amplitude of the inputs can produce further non-linear behaviour which can manifest as uncertainties. A typical example is the behaviour of cables secured onto panels; when very low forces are applied, the presence of harness can influence the characteristics of the panel in terms of stiffness and damping values. In these circumstances, the cables themselves couple with the panel, hence become paths for vibration transmission. The common practise is to model such cables as Non-Structural Mass; however, this paper illustrates that this method does not yield accurate results. In order to demonstrate this, an experimental campaign was conducted investigating a honeycomb panel, which was tested bare and with different configurations of harness secured to it. The results of this experimental campaign showed significantly different behaviour of the structure depending on the amplitude of the loads and the frequency. In particular, it was found that the effects the addition of the cables had on the panel were different depending on the frequency range considered. Based on this observation, a general methodology to deal with the whole frequency range is presented here and the basis to extend it to the case of more complex structures is also proposed.

  17. Trunk Muscle Activation and Estimating Spinal Compressive Force in Rope and Harness Vertical Dance.

    PubMed

    Wilson, Margaret; Dai, Boyi; Zhu, Qin; Humphrey, Neil

    2015-12-01

    Rope and harness vertical dance takes place off the floor with the dancer suspended from his or her center of mass in a harness attached to a rope from a point overhead. Vertical dance represents a novel environment for training and performing in which expected stresses on the dancer's body are different from those that take place during dance on the floor. Two male and eleven female dancers with training in vertical dance performed six typical vertical dance movements with electromyography (EMG) electrodes placed bilaterally on rectus abdominus, external oblique, erector spinae, and latissimus dorsi. EMG data were expressed as a percentage of maximum voluntary isometric contraction (MVIC). A simplified musculoskeletal model based on muscle activation for these four muscle groups was used to estimate the compressive force on the spine. The greatest muscle activation for erector spinae and latissimus dorsi and the greatest trunk compressive forces were seen in vertical axis positions where the dancer was moving the trunk into a hyper-extended position. The greatest muscle activation for rectus abdominus and external oblique and the second highest compressive force were seen in a supine position with the arms and legs extended away from the center of mass (COM). The least muscle activation occurred in positions where the limbs were hanging below the torso. These movements also showed relatively low muscle activation compression forces. Post-test survey results revealed that dancers felt comfortable in these positions; however, observation of some positions indicated insufficient muscular control. Computing the relative contribution of muscles, expressed as muscle activation and estimated spinal compression, provided a measure of how much the muscle groups were working to support the spine and the rest of the dancer's body in the different movements tested. Additionally, identifying typical muscle recruitment patterns in each movement will help identify key exercises

  18. PROPOSED BIOACCUMULATION TESTING EVALUATION FRAMEWORK FOR ASSESSING THE SUITABILITY OF DREDGED MATERIAL TO BE PLACED AT THE HISTORIC AREA REMEDIATION SITE (HARS) - PHASE 1 HUMAN HEALTH.

    EPA Science Inventory

    The August 29, 1997 Final Rule, Simultaneous De-designation and Termination of the Mud Dump Site and Designation of the HARS, specifies that the HARS will be remediated by covering it with uncontaminated dredged material (i.e., dredged material that meets current Category I stand...

  19. Genetic mapping of HA-R4 identified the downy mildew resistance gene to races 300, 770, and 734

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The major genes for sunflower downy mildew resistance have been designated as Pl genes. Many Pl genes have been reported, with 10 of them having been mapped. In this study, we report the molecular mapping of the Pl gene in a downy mildew differential line HA-R4, which has been temporarily named PlHA...

  20. Registration of a male fertility restorer oilseed sunflower germplasm HA-R9 resistant to sunflower rust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sunflower (Helianthus annuus L.) germplasm HA-R9 (Reg. No.xxx, PI 667595) was developed by the USDA-ARS, Sunflower and Plant Biology Research Unit in collaboration with the Agricultural Experiment Station of North Dakota State University and released in January, 2013. Sunflower rust (caused by P...

  1. Opportunities for high aspect ratio micro-electro-magnetic-mechanical systems (HAR-MEMMS) at Lawrence Berkeley Laboratory

    SciTech Connect

    Hunter, S.

    1993-10-01

    This report contains viewgraphs on the following topics: Opportunities for HAR-MEMMS at LBL; Industrial Needs and Opportunities; Deep Etch X-ray Lithography; MEMS Activities at BSAC; DNA Amplification with Microfabricated Reaction Chamber; Electrochemistry Research at LBL; MEMS Activities at LLNL; Space Microsensors and Microinstruments; The Advanced Light Source; Institute for Micromaching; IBM MEMS Interests; and Technology Transfer Opportunities at LBL.

  2. GENERATION OF TWO NOVEL CELL LINES THAT STABLY EXPRESS HAR AND FIREFLY LUCIFERASE GENES FOR ENDOCRINE SCREENING

    EPA Science Inventory

    Generation of Two Novel Cell Lines that Stably Express hAR and Firefly Luciferase Genes for Endocrine Screening
    K.L. Bobseine*1, W.R. Kelce2, P.C. Hartig*1, and L.E. Gray, Jr.1
    1USEPA, NHEERL, Reproductive Toxicology Division, RTP, NC, 2Searle, Reproductive Toxicology Divi...

  3. Long-term health effects of harness-mounted radio transmitters in red kites (Milvus milvus) in England.

    PubMed

    Peniche, G; Vaughan-Higgins, R; Carter, I; Pocknell, A; Simpson, D; Sainsbury, A

    2011-09-17

    In 1989, the Nature Conservancy Council and the Royal Society for the Protection of Birds commenced reintroduction of the red kite (Milvus milvus) according to International Union for Conservation of Nature criteria. Following 22 years of intensive effort, the red kite reintroduction programme has been a success with an estimated 1000 pairs now breeding in England. Post-release health surveillance is ongoing and has been achieved through radio-tracking, monitoring breeding at nest sites and pathological examinations of any red kites found dead. Tail-mounted radio transmitters were fitted from 1989 with harness-mounted radio transmitters being preferentially used since 2000. Since 2000, 180 individuals have been recovered for postmortem examination. Eighteen of these birds had previously had a harness-mounted radio transmitter fitted and four of these (22 per cent) had moderate to severe lesions associated with the presence of the harness and radio transmitter including chronic necrogranulomatous inflammation, deep muscular exposure and distorted muscular conformation. Failure to breed was also reported in two of these individuals over the preceding year(s), although it is not known whether the presence of the harness contributed to this failure. Duration of deployment may have been a significant factor in the formation of these lesions as those with lesions (n=4) had a statistically significant (P=0.009) longer duration of deployment compared to those without lesions (n=14). No lesions were reported in those red kites fitted with tail-transmitters. PMID:21846683

  4. Harnessing the instabilities of soft matter: Dynamically tuning of wetting, assembly and pattern transformation in polymer microstructures

    NASA Astrophysics Data System (ADS)

    Zhang, Ying

    2008-10-01

    In this dissertation, we have investigated the fabrication, mechanical instability and applications of two kinds of polymer micro/nano-structures: high-aspect-ratio (HAR) polymer pillar arrays, and periodic porous elastomer membranes. For HAR polymer pillar arrays, we demonstrated the fabrication of high-aspect-ratio (up to 18) polymer micropillars with different shapes and dimensions by replica molding. Capillary force lithography (CFL) is also demonstrated as a simple and flexible method to fabricate microstructures with controlled aspect ratios. Meanwhile, by introducing conventional photoresist SU-8, CFL is successfully coupled with photolithography and used to create hierarchical 2D or 3D structures, which greatly expand the capability of current capillary force lithography. The mechanical stability of HAR structures with varied materials and different aspect ratio, density and shape were also studied and the results show that the adhesive forces from environment are the major cause of structure collapsing. When HAR polymer pillars are subjected to different solvents treatment, both capillary force and solvent swelling need to be considered to completely understand the structure instability. On HAR micropillar array, thermoresponsive polymer brushes, poly ( N-isopropylacrylamide) (PNIPAAm), were selectively grafted at different locations for dynamically tuning surface wetting or pattern assembly. When the temperature changed from 40°C to 20°, depending on the location of polymer brushes, different wetting transitions, either from a composite solid/air state (Cassie state) to a composite solid/liquid state (Hemi-wicking state) or a transition between two Cassie states were observed. Meanwhile, the dynamically tuning of water contact angle enables us to control capillary drying force and thus harness pattern collapse to create superlattice micropatterns. For periodic porous elastomer membrane, a novel pattern transformation effect is discovered due to the

  5. Effect of Concomitant Administration of L-Glutamine and Cycloart-23-ene-3β, 25-diol (B2) with Sitagliptin in GLP-1 (7–36) Amide Secretion, Biochemical and Oxidative Stress in Streptozotocin - Nicotinamide Induced Diabetic Sprague Dawley Rats

    PubMed Central

    Raut, Chandrashekhar G.; Zanwar, Anand A.

    2013-01-01

    Previously we have reported that, cycloart-23-ene-3β, 25-diol (called as B2) and L-glutamine stimulated glucagon like peptide-1 (GLP-1) (7–36) amide secretion diabetic rats. The objective of present investigation was to investigate the concomitant administration of cycloart-23-ene-3β, 25-diol+sitagliptin and L-glutamine+sitagliptin in streptozotocin - nicotinamide induced diabetic Sprague Dawley. Type 2 diabetes was induced in overnight fasted male Sprague Dawley rats pre-treated with nicotinamide (100 mg/kg, i.p.) followed by administration of streptozotocin (55 mg/kg, i.p.) 20 min after. The rats were divided into; I- non-diabetic, II- diabetic control, III- Sitagliptin (5 mg/kg, p.o.)+cycloart-23-ene-3β, 25-diol (1 mg/kg, p.o.), IV- Sitagliptin (5 mg/kg, p.o.)+L-glutamine (1000 mg/kg, p.o.). The concomitant treatment of cycloart-23-ene-3β, 25-diol and L-glutamine with sitagliptin was 8 weeks. Plasma glucose, body weight, food and water intake were determined every week. Glycosylated haemoglobin, lipid profile, plasma and colonic active (GLP-1) (7–36) amide, plasma and pancreatic insulin, histology of pancreata and biomarkers of oxidative stress were measured after 8th week treatment. Concomitant administration of cycloart-23-ene-3β, 25-diol and L-glutamine with sitagliptin significantly (p<0.001) reduced plasma glucose, glyoxylated haemoglobin, lipid profile and oxidative stress parameters compared to diabetic control groups. Both concomitant treatment increased plasma and pancreatic insulin as well as plasma and colonic active (GLP-1) (7–36) amide secretion. Histological analysis by Gomori staining observed less destruction of pancreatic β cells. The result obtained from this study; it is concluded that concomitant administration of cycloart-23-ene-3β, 25-diol+sitagliptin and L-glutamine+sitagliptin showed additive antihyperglycaemic effect in diabetic rats. PMID:24023648

  6. Thiol-ene "click" reaction triggered by neutral ionic liquid: the "ambiphilic" character of [hmim]Br in the regioselective nucleophilic hydrothiolation.

    PubMed

    Kumar, Rajesh; Saima; Shard, Amit; Andhare, Nitin H; Richa; Sinha, Arun K

    2015-01-12

    Thiol-ene "click" chemistry has emerged as a powerful strategy to construct carbon-heteroatom (C-S) bonds, which generally results in the formation of two regioisomers. To this end, the neutral ionic liquid [hmim]Br has been explored as a solvent cum catalyst for the synthesis of linear thioethers from activated and inactivated styrene derivatives or secondary benzyl alcohols and thiols without the requirement of using a metal complex, base, or free radical initiator. Furthermore, detailed mechanistic investigations using (1)H NMR spectroscopy and quadrupole time-of-flight electrospray ionization mass spectrometry (Q-TOF ESI-MS) revealed that the "ambiphilic" character of the ionic liquid promotes the nucleophilic addition of thiol to styrene through an anti-Markovnikov pathway. The catalyst recyclability and the extension of the methodology for thiol-yne click chemistry are additional benefits. A competitive study among thiophenol, styrene, and phenyl acetylene revealed that the rate of reaction is in the order of thiol-yne>thiol-ene>dimerization of thiol in [hmim]Br. PMID:25430704

  7. Kinetics of thermal rearrangements in the Delta2-Thujene system: a full quadrisection of a perturbed bicyclo[3.1.0]hex-2-ene.

    PubMed

    Doering, William von E; Zhang, Ting-Hu; Schmidt, Eckhart K G

    2006-07-21

    Further insight into the behavior of suppositional diradicals in a caldera is sought in the thermal rearrangements among the four "Delta2-thujenes", two 1-isopropyl-4-methylbicyclo[3.1.0]hex-2-enes [(-)-cis-1 and (+)-trans-2] and two isomers, exo- and endo-3-isopropyl-6-methylbicyclo[3.1.0]hex-2-ene [(+)-exo-3 and (-)-endo-4]. Optically pure trans-3-isopropyl-5-vinylcyclopentene (5) is the final, strongly thermochemically favored product, the result of an intramolecular homodienyl shift of a methyl hydrogen atom in (-)-endo-4. The set of twelve specific rate constants, four sets of three each, that define the interrelations among the four isomers has been extracted from data acquired starting from each isomer. An attractive mechanistic hypothesis involving an intermediate diradical of iso conformation, common, for example, to both (-)-cis-1 and (+)-exo-3 (as educts), that proceeds to an anticonformer common to both (+)-trans-2 and (-)-endo-4 does not lead to a satisfactory rationalization of the product distribution. Addition of a second mechanistic conceptual scheme, that of a diradical-in-transit behaving as if there were a measure of continuous bonding (for example, (+)-trans-2 proceeding directly to (-)-cis-1), improves agreement with experiment. Over a 30 degrees C range of temperature, there is no credible change in product distribution. PMID:16839150

  8. (2.2.2-Cryptand)potassium tetra­kis­(η2-ethyl­ene)cobaltate(−I)

    PubMed Central

    Brennessel, William W.; Ellis, John E.

    2012-01-01

    The title salt, [K(C18H36N2O6)][Co(C2H4)4], is one of only two known homoleptic ethyl­enemetalates. The cation and anion are well separated, which gives an unperturbed tetra­hedral anion as is expected for a formally Co−I d 10 metal center. The considerable elongation of the C=C bonds of the ethyl­ene ligands [average 1.401 (6) Å], relative to that of free ethyl­ene (1.333 Å), is consistent with metal→π* back-bonding models. One arm of the 2.2.2-cryptand (4,7,13,16,21,24-hexa­oxa-1,10-diaza­bicyclo­[8.8.8]hexa­cosa­ne) complexant is disordered and was modeled over two positions with a refined occupancy ratio of 0.559 (2):0.441 (2). In the crystal, the cationic K(2.2.2-cryptand) units are linked via C—H⋯O hydrogen bonds, forming inversion dimers. There are no other significant inter­molecular inter­actions in the crystal structure. PMID:23125588

  9. Activation of Ene-Diamido Samarium Methoxide with Hydrosilane for Selectively Catalytic Hydrosilylation of Alkenes and Polymerization of Styrene: an Experimental and Theoretical Mechanistic Study.

    PubMed

    Li, Jianfeng; Zhao, Chaoyue; Liu, Jinxi; Huang, Hanmin; Wang, Fengxin; Xu, Xiufang; Cui, Chunming

    2016-09-01

    Samarium methoxide incorporating the ene-diamido ligand L(DME)Sm(μ-OMe)2Sm(DME)L (1; L = [DipNC(Me)C(Me)NDip](2-), Dip = 2,6-iPr2C6H3, and DME = 1,2-dimethoxyethane) has been prepared and structurally characterized. Complex 1 catalyzed the syndiospecific polymerization of styrene upon activation with phenylsilane and regioselective hydrosilylation of styrenes and nonactivated terminal alkenes. Unprecedented regioselectivity (>99.0%) for both types of alkenes has been achieved with the formation of Markovnikov and anti-Markovnikov products in high yields, respectively, whereas the polymerization of styrene resulted in the formation of syndiotactic silyl-capped oligostyrenes. The kinetic experiments and density functional theory calculations strongly support a samarium hydride intermediate generated by σ-bond metathesis of the Sm-OMe bond in 1 with PhSiH3. In addition, the observed regioselectvity for hydrosilylation and polymerization is consistent with the calculated energy profiles, which suggests that the bulky ene-diamido ligand and samarium hydride intermediate have important roles for regio- and stereoselectivity. PMID:27547859

  10. Assessment of the role of in situ generated (E)-2,4-diene-valproic acid in the toxicity of valproic acid and (E)-2-ene-valproic acid in sandwich-cultured rat hepatocytes

    SciTech Connect

    Surendradoss, Jayakumar; Chang, Thomas K.H.; Abbott, Frank S.

    2012-11-01

    Valproic acid (VPA) undergoes cytochrome P450-mediated desaturation to form 4-ene-VPA, which subsequently yields (E)-2,4-diene-VPA by β-oxidation. Another biotransformation pathway involves β-oxidation of VPA to form (E)-2-ene-VPA, which also generates (E)-2,4-diene-VPA by cytochrome P450-mediated desaturation. Although the synthetic form of (E)-2,4-diene-VPA is more hepatotoxic than VPA as shown in various experimental models, there is no conclusive evidence to implicate the in situ generated (E)-2,4-diene-VPA in VPA hepatotoxicity. The present study investigated the effects of modulating the in situ formation of (E)-2,4-diene-VPA on markers of oxidative stress (formation of 2′,7′-dichlorofluorescein; DCF), steatosis (accumulation of BODIPY 558/568 C{sub 12}), necrosis (release of lactate dehydrogenase; LDH), and on cellular total glutathione (GSH) levels in sandwich-cultured rat hepatocytes treated with VPA or (E)-2-ene-VPA. Treatment with either of these chemicals alone increased each of the toxicity endpoints. In VPA-treated hepatocytes, (E)-2,4-diene-VPA was detected only at trace levels, even after phenobarbital (PB) pretreatment and there was no effect on the toxicity of VPA. Furthermore, pretreatment with a cytochrome P450 enzyme inhibitor, 1-aminobenzotriazole (1-ABT), did not influence the extent of VPA toxicity in both PB-pretreated and vehicle-pretreated hepatocytes. However, in (E)-2-ene-VPA-treated hepatocytes, PB pretreatment greatly enhanced the levels of (E)-2,4-diene-VPA and this was accompanied by a further enhancement of the effects of (E)-2-ene-VPA on DCF formation, BODIPY accumulation, LDH release, and GSH depletion. Pretreatment with 1-ABT reduced the concentrations of (E)-2,4-diene-VPA and the extent of (E)-2-ene-VPA toxicity; however, this occurred in PB-pretreated hepatocytes, but not in control hepatocytes. In conclusion, in situ generated (E)-2,4-diene-VPA is not responsible for the hepatocyte toxicity of VPA, whereas it

  11. Harnessing genomics to improve health in the Eastern Mediterranean Region - an executive course in genomics policy.

    PubMed

    Acharya, Tara; Rab, Mohammed Abdur; Singer, Peter A; Daar, Abdallah S

    2005-01-21

    BACKGROUND: While innovations in medicine, science and technology have resulted in improved health and quality of life for many people, the benefits of modern medicine continue to elude millions of people in many parts of the world. To assess the potential of genomics to address health needs in EMR, the World Health Organization's Eastern Mediterranean Regional Office and the University of Toronto Joint Centre for Bioethics jointly organized a Genomics and Public Health Policy Executive Course, held September 20th-23rd, 2003, in Muscat, Oman. The 4-day course was sponsored by WHO-EMRO with additional support from the Canadian Program in Genomics and Global Health. The overall objective of the course was to collectively explore how to best harness genomics to improve health in the region. This article presents the course findings and recommendations for genomics policy in EMR. METHODS: The course brought together senior representatives from academia, biotechnology companies, regulatory bodies, media, voluntary, and legal organizations to engage in discussion. Topics covered included scientific advances in genomics, followed by innovations in business models, public sector perspectives, ethics, legal issues and national innovation systems. RESULTS: A set of recommendations, summarized below, was formulated for the Regional Office, the Member States and for individuals.* Advocacy for genomics and biotechnology for political leadership;* Networking between member states to share information, expertise, training, and regional cooperation in biotechnology; coordination of national surveys for assessment of health biotechnology innovation systems, science capacity, government policies, legislation and regulations, intellectual property policies, private sector activity;* Creation in each member country of an effective National Body on genomics, biotechnology and health to:- formulate national biotechnology strategies- raise biotechnology awareness- encourage teaching and

  12. Harnessing the immunomodulatory effect of thermal and non-thermal ablative therapies for cancer treatment.

    PubMed

    Bastianpillai, Christopher; Petrides, Neophytos; Shah, Taimur; Guillaumier, Stephanie; Ahmed, Hashim U; Arya, Manit

    2015-12-01

    Minimally invasive interventional therapies are evolving rapidly and their use for the treatment of solid tumours is becoming more extensive. The in situ destruction of solid tumours by such therapies is thought to release antigens that can prime an antitumour immune response. In this review, we offer an overview of the current evidence for immune response activation associated with the utilisation of the main thermal and non-thermal ablation therapies currently in use today. This is followed by an assessment of the hypothesised mechanisms behind this immune response priming and by a discussion of potential methods of harnessing this specific response, which may subsequently be applicable in the treatment of cancer patients. References were identified through searches of PubMed/MEDLINE and Cochrane databases to identify peer-reviewed original articles, meta-analyses and reviews. Papers were searched from 1850 until October 2014. Articles were also identified through searches of the authors' files. Only papers published in English were reviewed. Thermal and non-thermal therapies have the potential to stimulate antitumour immunity although the current body of evidence is based mostly on murine trials or small-scale phase 1 human trials. The evidence for this immune-modulatory response is currently the strongest in relation to cryotherapy and radiotherapy, although data is accumulating for related ablative treatments such as high-intensity focused ultrasound, radiofrequency ablation and irreversible electroporation. This effect may be greatly enhanced by combining these therapies with other immunostimulatory interventions. Evidence is emerging into the immunomodulatory effect associated with thermal and non-thermal ablative therapies used in cancer treatment in addition to the mechanism behind this effect and how it may be harnessed for therapeutic use. A potential exists for treatment approaches that combine ablation of the primary tumour with control and possible

  13. Harnessing heterologous and endogenous CRISPR-Cas machineries for efficient markerless genome editing in Clostridium

    PubMed Central

    Pyne, Michael E.; Bruder, Mark R.; Moo-Young, Murray; Chung, Duane A.; Chou, C. Perry

    2016-01-01

    Application of CRISPR-Cas9 systems has revolutionized genome editing across all domains of life. Here we report implementation of the heterologous Type II CRISPR-Cas9 system in Clostridium pasteurianum for markerless genome editing. Since 74% of species harbor CRISPR-Cas loci in Clostridium, we also explored the prospect of co-opting host-encoded CRISPR-Cas machinery for genome editing. Motivation for this work was bolstered from the observation that plasmids expressing heterologous cas9 result in poor transformation of Clostridium. To address this barrier and establish proof-of-concept, we focus on characterization and exploitation of the C. pasteurianum Type I-B CRISPR-Cas system. In silico spacer analysis and in vivo interference assays revealed three protospacer adjacent motif (PAM) sequences required for site-specific nucleolytic attack. Introduction of a synthetic CRISPR array and cpaAIR gene deletion template yielded an editing efficiency of 100%. In contrast, the heterologous Type II CRISPR-Cas9 system generated only 25% of the total yield of edited cells, suggesting that native machinery provides a superior foundation for genome editing by precluding expression of cas9 in trans. To broaden our approach, we also identified putative PAM sequences in three key species of Clostridium. This is the first report of genome editing through harnessing native CRISPR-Cas machinery in Clostridium. PMID:27157668

  14. LncRNAWiki: harnessing community knowledge in collaborative curation of human long non-coding RNAs.

    PubMed

    Ma, Lina; Li, Ang; Zou, Dong; Xu, Xingjian; Xia, Lin; Yu, Jun; Bajic, Vladimir B; Zhang, Zhang

    2015-01-01

    Long non-coding RNAs (lncRNAs) perform a diversity of functions in numerous important biological processes and are implicated in many human diseases. In this report we present lncRNAWiki (http://lncrna.big.ac.cn), a wiki-based platform that is open-content and publicly editable and aimed at community-based curation and collection of information on human lncRNAs. Current related databases are dependent primarily on curation by experts, making it laborious to annotate the exponentially accumulated information on lncRNAs, which inevitably requires collective efforts in community-based curation of lncRNAs. Unlike existing databases, lncRNAWiki features comprehensive integration of information on human lncRNAs obtained from multiple different resources and allows not only existing lncRNAs to be edited, updated and curated by different users but also the addition of newly identified lncRNAs by any user. It harnesses community collective knowledge in collecting, editing and annotating human lncRNAs and rewards community-curated efforts by providing explicit authorship based on quantified contributions. LncRNAWiki relies on the underling knowledge of scientific community for collective and collaborative curation of human lncRNAs and thus has the potential to serve as an up-to-date and comprehensive knowledgebase for human lncRNAs. PMID:25399417

  15. An overhead harness and trolly system for balance and ambulation assessment and training.

    PubMed

    Harburn, K L; Hill, K M; Kramer, J F; Noh, S; Vandervoort, A A; Matheson, J E

    1993-02-01

    Safe assessment of standing balance and gait is often jeopardized by the potential for falls, which may have major physical and legal consequences. This article describes the design and use of a system that enhances the safety of the patient and clinician during balance and gait assessment and training. The system consists of an overhead track and moveable trolly that allows the patient, while secured in a simple body harness, the freedom to ambulate, perform functional types of activities, and fall with minimal risk of injury. As a result, a single therapist can more readily assess balance and ambulation, as well as provide training for these skills. In addition, the therapist is free to observe the patient's movements from any position, without direct physical contact. Practically, the system described may allow ambulation training sooner after injury or surgery, permit training in weight-bearing or partial weight-bearing activities with or without assistive devices, and allow the clinician to focus on assessment and training, rather than on patient safety. PMID:8431110

  16. Harnessing heterologous and endogenous CRISPR-Cas machineries for efficient markerless genome editing in Clostridium.

    PubMed

    Pyne, Michael E; Bruder, Mark R; Moo-Young, Murray; Chung, Duane A; Chou, C Perry

    2016-01-01

    Application of CRISPR-Cas9 systems has revolutionized genome editing across all domains of life. Here we report implementation of the heterologous Type II CRISPR-Cas9 system in Clostridium pasteurianum for markerless genome editing. Since 74% of species harbor CRISPR-Cas loci in Clostridium, we also explored the prospect of co-opting host-encoded CRISPR-Cas machinery for genome editing. Motivation for this work was bolstered from the observation that plasmids expressing heterologous cas9 result in poor transformation of Clostridium. To address this barrier and establish proof-of-concept, we focus on characterization and exploitation of the C. pasteurianum Type I-B CRISPR-Cas system. In silico spacer analysis and in vivo interference assays revealed three protospacer adjacent motif (PAM) sequences required for site-specific nucleolytic attack. Introduction of a synthetic CRISPR array and cpaAIR gene deletion template yielded an editing efficiency of 100%. In contrast, the heterologous Type II CRISPR-Cas9 system generated only 25% of the total yield of edited cells, suggesting that native machinery provides a superior foundation for genome editing by precluding expression of cas9 in trans. To broaden our approach, we also identified putative PAM sequences in three key species of Clostridium. This is the first report of genome editing through harnessing native CRISPR-Cas machinery in Clostridium. PMID:27157668

  17. Harnessing the power of reputation: strengths and limits for promoting cooperative behaviors.

    PubMed

    Barclay, Pat

    2012-01-01

    Evolutionary approaches have done much to identify the pressures that select for cooperative sentiment. This helps us understand when and why cooperation will arise, and applied research shows how these pressures can be harnessed to promote various types of cooperation. In particular, recent evidence shows how opportunities to acquire a good reputation can promote cooperation in laboratory and applied settings. Cooperation can be promoted by tapping into forces like indirect reciprocity, costly signaling, and competitive altruism. When individuals help others, they receive reputational benefits (or avoid reputational costs), and this gives people an incentive to help. Such findings can be applied to promote many kinds of helping and cooperation, including charitable donations, tax compliance, sustainable and pro-environmental behaviors, risky heroism, and more. Despite the potential advantages of using reputation to promote positive behaviors, there are several risks and limits. Under some circumstances, opportunities for reputation will be ineffective or promote harmful behaviors. By better understanding the dynamics of reputation and the circumstances under which cooperation can evolve, we can better design social systems to increase the rate of cooperation and reduce conflict. PMID:23253792

  18. Harnessing Elastic Instability for the self-assembly of complex patterns

    NASA Astrophysics Data System (ADS)

    Matsumoto, Elisabetta; Zhang, Ying; Peter, Anna; Lin, Pei-Chun; Kamien, Randall; Yang, Shu

    2008-03-01

    Directed pattern formation through the self-assembly of complex polymer systems promises to be a powerful approach in the pursuit of novel, transformative technologies. Current approaches to create desired motifs at the nanoscale utilize flow, shear, fields, and other externally imposed, top-down forces. Nature, on the other hand, provides us with a plethora of examples of intrinsic, bottom-up effects: from the phyllotactic growth of plants to animal stripes to fingerprints, instabilities, packing constraints, and simple geometries can drive the formation of delicate, detailed, and beautiful patterns. By harnessing the elastic instability in flexible poly(dimethylsiloxane) (PDMS) membranes with a square lattice of circular pores exposed to a solvent, we distort the pores into a pattern featuring long-range orientational order. Within linear elasticity theory, we find the groundstate configuration of a lattice of interacting deformation elements, or ``dislocation dipoles'' to be in complete agreement with the observed pattern. Our theory allows us a means to design the patterns formed by such elastic frustration.

  19. Harnessing the secretome of cardiac stem cells as therapy for ischemic heart disease.

    PubMed

    Khanabdali, Ramin; Rosdah, Ayeshah A; Dusting, Gregory J; Lim, Shiang Y

    2016-08-01

    Adult stem cells continue to promise opportunities to repair damaged cardiac tissue. However, precisely how adult stem cells accomplish cardiac repair, especially after ischemic damage, remains controversial. It has been postulated that the clinical benefit of adult stem cells for cardiovascular disease results from the release of cytokines and growth factors by the transplanted cells. Studies in animal models of myocardial infarction have reported that such paracrine factors released from transplanted adult stem cells contribute to improved cardiac function by several processes. These include promoting neovascularization of damaged tissue, reducing inflammation, reducing fibrosis and scar formation, as well as protecting cardiomyocytes from apoptosis. In addition, these factors might also stimulate endogenous repair by activating cardiac stem cells. Interestingly, stem cells discovered to be resident in the heart appear to be functionally superior to extra-cardiac adult stem cells when transplanted for cardiac repair and regeneration. In this review, we discuss the therapeutic potential of cardiac stem cells and how the proteins secreted from these cells might be harnessed to promote repair and regeneration of damaged cardiac tissue. We also highlight how recent controversies about the efficacy of adult stem cells in clinical trials of ischemic heart disease have not dampened enthusiasm for the application of cardiac stem cells and their paracrine factors for cardiac repair: the latter have proved superior to the mesenchymal stem cells used in most clinical trials in the past, some of which appear to have been conducted with sub-optimal rigor. PMID:26903387

  20. Harnessing intrinsic localized modes to identify impurities in nonlinear periodic systems

    NASA Astrophysics Data System (ADS)

    Thota, M.; Harne, R. L.; Wang, K. W.

    2015-02-01

    Intrinsic localized modes (ILMs) are concentrations of vibrational energy in periodic systems/lattices due to the combined influences of nonlinearity and discreteness. Moreover, ILMs can move within the system and may strongly interact with an impurity, such as a stiffness change, mass variation, etc. Numerous scientific fields have uncovered examples and evidence of ILMs, motivating a multidisciplinary pursuit to rigorously understand the underlying principles. In spite of the diverse technical studies, a characterization of ILM interaction behaviors with multiple impurities in dissipative lattices remains outstanding. The insights on such behaviors may be broadly useful when dynamic measurements are the only accessible features of the periodic system. For instance, one may guide an ILM within the lattice using a deliberately applied and steered impurity and harness the observed interaction behaviors with a second, static (immovable) impurity/defect to identify how the underlying lattice is different at the second, defected site, whether or not one knew the position of the defect a priori. In this spirit, this research studies, analyzes, and characterizes the interaction types amongst an ILM and multiple impurities, and devises a method to identify a static defect impurity using quantitatively and qualitatively distinct interaction phenomena. The method is found to be robust to moderate levels of lattice stiffness heterogeneity and is applicable to monitor various property changes that represent impurities. Finally, experimental studies verify that ILMs interact with multiple impurities in unique ways such that defect features may be effectively identified.

  1. Harnessing snap-through instability for shape-recoverable energy-absorbing structure

    NASA Astrophysics Data System (ADS)

    Kang, Sung; Shan, Sicong; Raney, Jordan; Wang, Pai; Candido, Francisco; Lewis, Jennifer; Bertoldi, Katia

    2015-03-01

    Energy absorbing materials and structures are used in numerous areas for maintaining structural integrity, protection and comfort. To absorb/dissipate energy from shock/vibration, one generally relies on processes such as plastic deformation and damping as the case of metal foams and suspensions. Because plastic deformation and damping induce irreversible change in the energy-absorbing systems such as shape changes and degradation of damping elements by heat dissipation, it would be desirable to develop a new energy-absorption mechanism with reversibility. Furthermore, it would be desirable to implement energy-absorption mechanisms whose behavior is not affected by the rate of loading. Here, we report a shape-recoverable system that absorbs energy without degradation by harnessing multistability in elastic structures. Using numerical simulations, we investigate geometrical parameters that determine the onset of the snap-through and multi-stability. We subsequently manufacture structures with different geometrical parameters and sizes using a scalable direct-write 3D printing approach. We experimentally demonstrate reversible energy-absorption in these structures at strain rates over three orders of magnitudes, with reduced peak acceleration under impact by up to one order of magnitude compared with control samples. Our findings can open new opportunities for scalable design and manufacturing of energy-absorbing materials and structures.

  2. Harnessing happiness? Uncontrollable positive emotion in bipolar disorder, major depression, and healthy adults.

    PubMed

    Kang, Yoona; Gruber, June

    2013-04-01

    The ability to adaptively exert control over negative emotions is associated with beneficial mental health outcomes. Less is known about the associated emotional sequelae surrounding controllable versus uncontrollable positive emotional experiences. The ability to harness positive emotions is of particular importance in populations involving disrupted positive emotion functioning. In the present study, participants engaged in a relived memory task in which they recalled either a controllable or uncontrollable past positive emotional experience in counterbalanced order, while concurrent experiential and autonomic responses were measured. Participants included adults with bipolar I disorder (BD; n = 32), major depression (MDD; n = 32), and or nonpsychiatric controls (CTLs; n = 31). Across all participants, reliving a controllable positive emotion experience was associated with exhibited increased respiratory sinus arrhythmia, an autonomic marker of regulatory control. Interestingly, only the MDD group reported increased positive emotion and decreased cardiovascular arousal when reliving an event involving uncontrollable positive emotion, compared to the BD and CTL groups. No other group differences emerged. These findings suggest that although controllable positive emotion experiences may be adaptive for most, individuals with a history of restricted affect and depressed mood may actually derive more pleasure from times of unharnessed happiness. PMID:23205524

  3. Harnessing surface-bound enzymatic reactions to organize microcapsules in solution.

    PubMed

    Shklyaev, Oleg E; Shum, Henry; Sen, Ayusman; Balazs, Anna C

    2016-03-01

    By developing new computational models, we examine how enzymatic reactions on an underlying surface can be harnessed to direct the motion and organization of reagent-laden microcapsules in a fluid-filled microchannel. In the presence of appropriate reagents, surface-bound enzymes can act as pumps, which drive large-scale fluid flows. When the reagents diffuse through the capsules' porous shells, they can react with enzymatic sites on the bottom surface. The ensuing reaction generates fluid density variations, which result in fluid flows. These flows carry the suspended microcapsules and drive them to aggregate into "colonies" on and near the enzyme-covered sites. This aggregation continues until the reagent has been depleted and the convection stops. We show that the shape of the assembled colonies can be tailored by patterning the distribution of enzymes on the surface. This fundamental physicochemical mechanism could have played a role in the self-organization of early biological cells (protocells) and can be used to regulate the autonomous motion and targeted delivery of microcarriers in microfluidic devices. PMID:27034990

  4. Strategies and Advancements in Harnessing the Immune System for Gastric Cancer Immunotherapy

    PubMed Central

    Subhash, Vinod Vijay; Yeo, Mei Shi; Tan, Woei Loon; Yong, Wei Peng

    2015-01-01

    In cancer biology, cells and molecules that form the fundamental components of the tumor microenvironment play a major role in tumor initiation, and progression as well as responses to therapy. Therapeutic approaches that would enable and harness the immune system to target tumor cells mark the future of anticancer therapy as it could induce an immunological memory specific to the tumor type and further enhance tumor regression and relapse-free survival in cancer patients. Gastric cancer is one of the leading causes of cancer-related mortalities that has a modest survival benefit from existing treatment options. The advent of immunotherapy presents us with new approaches in gastric cancer treatment where adaptive cell therapies, cancer vaccines, and antibody therapies have all been used with promising outcomes. In this paper, we review the current advances and prospects in the gastric cancer immunotherapy. Special focus is laid on new strategies and clinical trials that attempt to enhance the efficacy of various immunotherapeutic modalities in gastric cancer. PMID:26579545

  5. Harnessing Potential Evaporation as a Renewable Energy Resource With Water-Saving Benefits

    NASA Astrophysics Data System (ADS)

    Cavusoglu, A. H.; Chen, X.; Gentine, P.; Sahin, O.

    2015-12-01

    Water's large latent heat of vaporization makes evaporation a critical component of the energy balance at the Earth's surface. An immense amount of energy drives the hydrological cycle and is an important component of various weather and climate patterns. However, the potential of harnessing evaporation has received little attention as a renewable energy resource compared to wind and solar energy. Here, we investigate the potential of harvesting energy from naturally evaporating water. Using weather data across the contiguous United States and a modified model of potential evaporation, we estimate the power availability, intermittency, and the changes in evaporation rates imposed by energy conversion. Our results indicate that natural evaporation can deliver power densities similar to existing renewable energy platforms and require little to no energy storage to match the varying power demands of urban areas. This model also predicts additional, and substantial, water savings by reducing evaporative losses. These findings suggest that evaporative energy harvesting can address significant challenges with water/energy interactions that could be of interest to the hydrology community.

  6. Harnessing surface-bound enzymatic reactions to organize microcapsules in solution

    PubMed Central

    Shklyaev, Oleg E.; Shum, Henry; Sen, Ayusman; Balazs, Anna C.

    2016-01-01

    By developing new computational models, we examine how enzymatic reactions on an underlying surface can be harnessed to direct the motion and organization of reagent-laden microcapsules in a fluid-filled microchannel. In the presence of appropriate reagents, surface-bound enzymes can act as pumps, which drive large-scale fluid flows. When the reagents diffuse through the capsules’ porous shells, they can react with enzymatic sites on the bottom surface. The ensuing reaction generates fluid density variations, which result in fluid flows. These flows carry the suspended microcapsules and drive them to aggregate into “colonies” on and near the enzyme-covered sites. This aggregation continues until the reagent has been depleted and the convection stops. We show that the shape of the assembled colonies can be tailored by patterning the distribution of enzymes on the surface. This fundamental physicochemical mechanism could have played a role in the self-organization of early biological cells (protocells) and can be used to regulate the autonomous motion and targeted delivery of microcarriers in microfluidic devices. PMID:27034990

  7. Harnessing structural darkness in the visible and infrared wavelengths for a new source of light

    NASA Astrophysics Data System (ADS)

    Huang, Jianfeng; Liu, Changxu; Zhu, Yihan; Masala, Silvia; Alarousu, Erkki; Han, Yu; Fratalocchi, Andrea

    2016-01-01

    Engineering broadband light absorbers is crucial to many applications, including energy-harvesting devices and optical interconnects. The performances of an ideal absorber are that of a black body, a dark material that absorbs radiation at all angles and polarizations. Despite advances in micrometre-thick films, the absorbers available to date are still far from an ideal black body. Here, we describe a disordered nanostructured material that shows an almost ideal black-body absorption of 98-99% between 400 and 1,400 nm that is insensitive to the angle and polarization of the incident light. The material comprises nanoparticles composed of a nanorod with a nanosphere of 30 nm diameter attached. When diluted into liquids, a small concentration of nanoparticles absorbs on average 26% more than carbon nanotubes, the darkest material available to date. By pumping a dye optical amplifier with nanosecond pulses of ˜100 mW power, we harness the structural darkness of the material and create a new type of light source, which generates monochromatic emission (˜5 nm wide) without the need for any resonance. This is achieved through the dynamics of light condensation in which all absorbed electromagnetic energy spontaneously generates single-colour energy pulses.

  8. Periodic trends governing the interactions between impurity atoms [H-Ar] and (alpha)-U

    SciTech Connect

    Taylor, Christopher David

    2008-01-01

    The binding energies, geometries, charges and electronic structures of a series of impurity atoms [H-Ar] interacting with the {alpha}-U lattice in various configurations were assessed by means of density functional theory calculations. Periodic trends governing the binding energy were highlighted and related to the electronic properties of the impurity atoms, with some consideration given to the band-structure of {alpha}-U. The strongest bound impurity atoms include [C, N, O] and [Si, P, S]. The general trends in the binding energy can be reproduced by a simple parameterisation in terms of the electronegativity (charge-transfer) and covalent radius (elasticity theory) of the impurity atom. The strongest bound atoms deviate from this model, due to their ability to bind with an optimum mixture of covalency and ionicity. This last point is evidenced by the partial overlap of the impurity atom p-band with the hybrid d-/f-band of {alpha}-U. It is expected that the trends and general behaviour reported in this work can be extended to the interactions of impurity atoms with other metallic systems.

  9. A new technology for harnessing the dye polluted water and dye collection in a chemical factory.

    PubMed

    Pu, J P; Pu, P M; Hu, C H; Qian, J L; Pu, J X; Hua, J K

    2001-04-01

    A new technology for harnessing the dye polluted water and dye collection was developed. It is based on the enhanced evaporation by using solar, wind and air temperature energy and additional heat-electric energy. It consists of four parts: (1) evaporation carrier system (evaporation carrier and frame for evaporation carrier) for polluted water; (2) polluted water circulating system (pumping-spraying-collecting); (3) heating system; (4) workshop with polluted water reservoir-tanks and rainfall prevention roof. The polluted water was (heated in case necessary) sprayed to the evaporation carrier system and the water was evaporated when it moved in the space and downward along the carrier mainly by using natural (solar, wind and air temperature energy). In case, when there is no roof for the carrier system, the polluted water can be stored in the reservoirs (storage volume for about 20 days). The first 10-25 mm rainfall also need to be stored in the reservoirs to meet the state standard for discharging wastewater. The dye may be collected at the surface in the reservoir-tanks and the crystallized salt may be collected at the bottom plate. The black-color wastewater released by the factory is no more discharged to the surface water system of Taihu Lake Basin. About 2 kg dye and 200 kg industrial salt may be collected from each tone of the polluted water. The non-pollution production of dye may be realized by using this technology with environmental, economical and social benefits. PMID:11590742

  10. Harnessing Geothermal Energy from CO2 Enhanced Oil Recovery (EOR) Operations

    NASA Astrophysics Data System (ADS)

    Saar, M. O.; Randolph, J. B.

    2012-12-01

    Recent geotechnical research shows that geothermal heat can be efficiently mined by circulating CO2 through naturally permeable, porous rock formations. This method, called CO2 Plume Geothermal (CPG), targets the same geologic reservoirs that are suitable for deep saline aquifer CO2 sequestration or enhanced oil recovery (EOR). While previous investigations have focused on CO2-based heat mining from saline aquifers, here we present new research that is primarily concerned with EOR reservoirs, specifically those using a CO2 flood. EOR operations provide excellent opportunities for economically-favorable geothermal energy recovery, assuming subsurface temperatures are sufficient, because the majority of costly infrastructure (i.e., wells) is in place. Moreover, the subsurface characteristics that make a site suitable for hydrocarbon recovery -- at least moderate reservoir permeability and porosity, and a low-permeability capping feature -- help ensure that fluid can be circulated for heat extraction and that CO2 will be contained. However, heat extraction from the CO2 + water/brine + hydrocarbon EOR production stream is challenging, requiring fluid separation and multiple binary and/or direct power systems (depending on site-specific fluid composition and conditions). We discuss several scenarios, encompassing multiple power system configurations, for harnessing geothermal energy from CO2 EOR operations. In addition, we present preliminary numerical modeling results for net power production from such EOR operations -- accounting for wide variation in produced fluid temperature, pressure, and composition -- and consider the economic implications of power sales for EOR sites.

  11. Harnessing disorder: onychophorans use highly unstructured proteins, not silks, for prey capture.

    PubMed

    Haritos, Victoria S; Niranjane, Ajay; Weisman, Sarah; Trueman, Holly E; Sriskantha, Alagacone; Sutherland, Tara D

    2010-11-01

    Onychophora are ancient, carnivorous soft-bodied invertebrates which capture their prey in slime that originates from dedicated glands located on either side of the head. While the biochemical composition of the slime is known, its unusual nature and the mechanism of ensnaring thread formation have remained elusive. We have examined gene expression in the slime gland from an Australian onychophoran, Euperipatoides rowelli, and matched expressed sequence tags to separated proteins from the slime. The analysis revealed three categories of protein present: unique high-molecular-weight proline-rich proteins, and smaller concentrations of lectins and small peptides, the latter two likely to act as protease inhibitors and antimicrobial agents. The predominant proline-rich proteins (200 kDa+) are composed of tandem repeated motifs and distinguished by an unusually high proline and charged residue content. Unlike the highly structured proteins such as silks used for prey capture by spiders and insects, these proteins lack ordered secondary structure over their entire length. We propose that on expulsion of slime from the gland onto prey, evaporative water loss triggers a glass transition change in the protein solution, resulting in adhesive and enmeshing thread formation, assisted by cross-linking of complementary charged and hydrophobic regions of the protein. Euperipatoides rowelli has developed an entirely new method of capturing prey by harnessing disordered proteins rather than structured, silk-like proteins. PMID:20519222

  12. Multiscale Simulation of Damage Progression in 5-Harness Satin Weave Composites

    NASA Astrophysics Data System (ADS)

    Xu, Qiang; Qu, Shaoxing

    2015-07-01

    A multiscale finite element (FE) model is developed to predict damage and failure of 5-harness satin weave composites both at the micro-scale (fiber, matrix and interface) and meso-scale (ply). In the meso-scale damage model, specific characteristics of the 5HS, such as the yarn undulation, shape and orientation, are taken into account to characterize the failure mechanisms of the interlaced yarns. In the micro-scale damage model of the study, a micro-model including matrix, interface and fibers is considered and simplified to a two-dimensional problem in the plane of a cross-section of the yarn. In the micro-FE model, cohesive elements based on a traction-separation law have been used which allows for some detailed interpretation of the micro-mechanical interaction of fiber and matrix under unidirectional tension. The predictions based on the numerical simulations are compared to the experimental data from the literature. The results indicate that the meso-FE model accurately captures weft yarn transverse damage. Moreover, the micro-FE model shows the contributions of failure from micro-mechanisms, including the in-plane matrix cracking and interfacial debonding.

  13. A Bottom-Up Engineered Broadband Optical Nanoabsorber for Radiometry and Energy Harnessing Applications

    NASA Technical Reports Server (NTRS)

    Kaul, Anupama B.; Coles, James B.; Megerian, Krikor G.; Eastwood, Michael; Green, Robert O.; Bandaru, Prabhakar R.

    2013-01-01

    Optical absorbers based on vertically aligned multi-walled carbon nanotubes (MWCNTs), synthesized using electric-field assisted growth, are described here that show an ultra-low reflectance, 100X lower compared to Au-black from wavelength lamba approximately 350 nm - 2.5 micron. A bi-metallic Co/Ti layer was shown to catalyze a high site density of MWCNTs on metallic substrates and the optical properties of the absorbers were engineered by controlling the bottom-up synthesis conditions using dc plasma-enhanced chemical vapor deposition (PECVD). Reflectance measurements on the MWCNT absorbers after heating them in air to 400deg showed negligible changes in reflectance which was still low, approximately 0.022 % at lamba approximately 2 micron. In contrast, the percolated structure of the reference Au-black samples collapsed completely after heating, causing the optical response to degrade at temperatures as low as 200deg. The high optical absorption efficiency of the MWCNT absorbers, synthesized on metallic substrates, over a broad spectral range, coupled with their thermal ruggedness, suggests they have promise in solar energy harnessing applications, as well as thermal detectors for radiometry.

  14. Harnessing Innovative Technologies to Advance Children’s Mental Health: Behavioral Parent Training As an Example

    PubMed Central

    Jones, Deborah J.; Forehand, Rex; Cuellar, Jessica; Kincaid, Carlye; Parent, Justin; Fenton, Nicole; Goodrum, Nada

    2012-01-01

    Disruptive behaviors of childhood are among the most common reasons for referral of children to mental health professionals. Behavioral parent training (BPT) is the most efficacious intervention for these problem behaviors, yet BPT is substantially underutilized beyond university research and clinic settings. With the aim of addressing this research-to-practice gap, this article highlights the considerable, but largely unrealized, potential for technology to overcome the two most pressing challenges hindering the diffusion of BPT: (1). The dearth of BPT training and supervision opportunities for therapists who work with families of children with disruptive behaviors and; (2). The failure to engage and retain families in BPT services when services are available. To this end, this review presents a theoretical framework to guide technological innovations in BPT and highlights examples of how technology is currently being harnessed to overcome these challenges. This review also discusses recommendations for using technology as a delivery vehicle to further advance the field of BPT and the potential implications of technological innovations in BPT for other areas of children’s mental health are discussed. PMID:23313761

  15. Highly sensitive electrochemical lead ion sensor harnessing peptide probe molecules on porous gold electrodes.

    PubMed

    Su, Wenqiong; Cho, Misuk; Nam, Jae-Do; Choe, Woo-Seok; Lee, Youngkwan

    2013-10-15

    Lead ion is one of the most hazardous and ubiquitous heavy metal pollutants and poses an increasing threat to the environment and human health. This necessitates rapid and selective detection and/or removal of lead ions from various soil and water resources. Recently, we identified several Pb²⁺ binding peptides via phage display technique coupled with chromatographic biopanning (Nian et al., 2010) where a heptapeptide (TNTLSNN) capable of recognizing Pb²⁺ with high affinity and specificity evolved. In the present study, an electrochemical sensor harnessing this Pb²⁺ affinity peptide as a probe on a porous gold electrode was developed. The three dimensional porous gold electrode was obtained from electrochemical deposition using the dynamic hydrogen bubble template method. A thin layer of poly(thiophene acetic acid) (PTAA) was coated on the porous gold surface. The Pb²⁺ recognizing peptide was immobilized via amide linkage on the PTAA. The developed biosensor was demonstrated to be fast, selective and reproducible in Pb²⁺ etection, exhibiting Pb²⁺-specific peak current values around -0.15 V in a broad concentration range (1-1×10⁷ nM) in 10 min despite the repeated use after regeneration. PMID:23707872

  16. Helmet Use Amongst Equestrians: Harnessing Social and Attitudinal Factors Revealed in Online Forums.

    PubMed

    Haigh, Laura; Thompson, Kirrilly

    2015-01-01

    Equestrian activities pose significant head injury risks to participants. Yet, helmet use is not mandatory in Australia outside of selected competitions. Awareness of technical countermeasures and the dangers of equestrian activities has not resulted in widespread adoption of simple precautionary behaviors like helmet use. Until the use of helmets whilst riding horses is legislated in Australia, there is an urgent need to improve voluntary use. To design effective injury prevention interventions, the factors affecting helmet use must first be understood. To add to current understandings of these factors, we examined the ways horse riders discussed helmet use by analyzing 103 posts on two helmet use related threads from two different Australian equestrian forums. We found evidence of social influence on helmet use behaviors as well as three attitudes that contributed towards stated helmet use that we termed: "I Can Control Risk", "It Does Not Feel Right" and "Accidents Happen". Whilst we confirm barriers identified in previous literature, we also identify their ability to support helmet use. This suggests challenging but potentially useful complexity in the relationship between risk perception, protective knowledge, attitudes, decision-making and behavior. Whilst this complexity is largely due to the involvement of interspecies relationships through which safety, risk and trust are distributed; our findings about harnessing the potential of barriers could be extended to other high risk activities. PMID:26479375

  17. Towards safer, better healthcare: harnessing the natural properties of complex sociotechnical systems

    PubMed Central

    Braithwaite, J; Runciman, W B; Merry, A F

    2009-01-01

    Objectives: To sustain an argument that harnessing the natural properties of sociotechnical systems is necessary to promote safer, better healthcare. Methods: Triangulated analyses of discrete literature sources, particularly drawing on those from mathematics, sociology, marketing science and psychology. Results: Progress involves the use of natural networks and exploiting features such as their scale-free and small world nature, as well as characteristics of group dynamics like natural appeal (stickiness) and propagation (tipping points). The agenda for change should be set by prioritising problems in natural categories, addressed by groups who self select on the basis of their natural interest in the areas in question, and who set clinical standards and develop tools, the use of which should be monitored by peers. This approach will facilitate the evidence-based practice that most agree is now overdue, but which has not yet been realised by the application of conventional methods. Conclusion: A key to health system transformation may lie under-recognised under our noses, and involves exploiting the naturally-occurring characteristics of complex systems. Current strategies to address healthcare problems are insufficient. Clinicians work best when their expertise is mobilised, and they flourish in groupings of their own interests and preference. Being invited, empowered and nurtured rather than directed, micro-managed and controlled through a hierarchy is preferable. PMID:19204130

  18. MRI Evaluation of Spinal Length and Vertebral Body Angle During Loading with a Spinal Compression Harness

    NASA Technical Reports Server (NTRS)

    Campbell, James A.; Hargens, Alan R.; Murthy, G.; Ballard, R. E.; Watenpaugh, D. E.; Hargens, Alan, R.; Sanchez, E.; Yang, C.; Mitsui, I.; Schwandt, D.; Fechner, K. P.; Holton, Emily M. (Technical Monitor)

    1998-01-01

    Weight bearing by the spinal column during upright posture often plays a role in the common problem of low back pain. Therefore, we developed a non-ferromagnetic spinal compression harness to enable MRI investigations of the spinal column during axial loading. Human subjects were fitted with a Nest and a footplate which were connected by adjustable straps to an analog load cell. MRI scans of human subjects (5 males and 1 female with age range of 27-53 yrs) during loaded and unloaded conditions were accomplished with a 1.5 Tesla GE Signa scanner. Studies of two subjects undergoing sequentially increasing spinal loads revealed significant decreases (r(sup 2) = 0.852) in spinal length between T4 and L5 culminating in a 1.5 to 2% length decrease during loading with 75% body weight. Sagittal vertebral body angles of four subjects placed under a constant 50% body weight load for one hour demonstrated increased lordotic and kyphotic curvatures. In the lumbar spine, the L2 vertebral body experienced the greatest angular change (-3 deg. to -5 deg.) in most subjects while in the thoracic spine, T4 angles increased from the unloaded state by +2 deg. to +9 deg. Overall, our studies demonstrate: 1) a progressive, although surprisingly small, decrease in spinal length with increasing load and 2) relatively large changes in spinal column angulation with 50% body weight.

  19. Humeral remodeling and soft tissue injury of the wings caused by backpack harnesses for radio transmitters in New Zealand Takahē (Porphyrio hochstetteri).

    PubMed

    Michael, Sarah; Gartrell, Brett; Hunter, Stuart

    2013-07-01

    Backpack harnesses are commonly used to attach radio and satellite transmitters to a wide range of bird species for research and conservation management. They are an integral part of the conservation management of the New Zealand Takahē (Porphyrio hochstetteri), an endangered flightless rail. Radio transmitters mounted on backpack harnesses enable the birds to be tracked in their remaining native range of remote, mountainous Fiordland, New Zealand. We evaluated 26 Takahē retrospectively at necropsy by gross examination, radiography, and computed tomography to assess damage from the backpack harness. Ten birds that had never worn a harness had no evidence of wing injury. Of the 16 birds that had worn a harness, 10 (63%) had superficial soft tissue injury to skin or patagium or more severe injury, such as remodeling of the distal humerus at the harness cord-wing interface, or pathologic fractures. Such injuries are hypothesized to be associated with discomfort, increased risk of infection or fracture, and therefore reduced fitness. These findings have implications for all avian species deployed with backpack harnesses. PMID:23778604

  20. A Loss-of-Function Variant in the Human Histidyl-tRNA Synthetase (HARS) Gene is Neurotoxic In Vivo

    PubMed Central

    Vester, Aimee; Velez-Ruiz, Gisselle; McLaughlin, Heather M.; Lupski, James R.; Talbot, Kevin; Vance, Jeffery M.; Züchner, Stephan; Roda, Ricardo H.; Fischbeck, Kenneth H.; Biesecker, Leslie G.; Nicholson, Garth; Beg, Asim; Antonellis, Anthony

    2012-01-01

    Aminoacyl-tRNA synthetases (ARSs) are ubiquitously expressed enzymes responsible for ligating amino acids to cognate tRNA molecules. Mutations in four genes encoding an ARS have been implicated in inherited peripheral neuropathy with an axonal pathology, suggesting that all ARS genes are relevant candidates for disease in patients with related phenotypes. Here, we present results from a mutation screen of the histidyl-tRNA synthetase (HARS) gene in a large cohort of patients with peripheral neuropathy. These efforts revealed a rare missense variant (p.Arg137Gln) that resides at a highly conserved amino acid, represents a loss-of-function allele when evaluated in yeast complementation assays, and is toxic to neurons when expressed in a worm model. In addition to the patient with peripheral neuropathy, p.Arg137Gln HARS was detected in three individuals by genome-wide exome sequencing. These findings suggest that HARS is the fifth ARS locus associated with axonal peripheral neuropathy. Implications for identifying ARS alleles in human populations and assessing them for a role in neurodegenerative phenotypes are discussed. PMID:22930593

  1. Avascular necrosis rate in early reduction after failed Pavlik harness treatment of developmental dysplasia of the hip.

    PubMed

    Senaran, Hakan; Bowen, J Richard; Harcke, H Theodore

    2007-03-01

    Our hypothesis is that hips with developmental dysplasia (DDH), which fail Pavlik harness treatment and are reduced within 3 months of age, have a low rate of avascular necrosis (AVN). Inclusion criteria are as follows: diagnosis of DDH within 2 months of birth, failure of reduction or stabilization by Pavlik harness treatment, surgical reduction of the hip advised to be performed within 3 months of age, and follow-up for Salter criteria of AVN. Twenty-one consecutive cases (35 hips) met the inclusion criteria. Nineteen cases (31 hips) were initially reduced within 3 months of age, and none of these cases developed AVN. After Pavlik harness failure, initial closed reduction was achieved in 33 (94%) of 35 hips, and open reduction required in 2 (6%) of 35 hips. At latest follow-up, one (3%) of 35 hips had AVN. At the time of reporting, 1 (3%) of the 35 hips has required an additional procedure (Pemberton osteotomy) for residual dysplasia. There were 2 outlier cases (4 hips) in which the parents delayed the reduction and 1 case developed unilateral AVN, which was reduced after the proximal femoral ossification center developed at 7 months of age. The data presented in the current study support our hypothesis. PMID:17314645

  2. Monodisperse colloidal metal particle from nonaqueous solutions: catalytic behavior in hydrogenation of but-1-ene of platinum, palladium, and rhodium particles supported on pumice

    SciTech Connect

    Boutonnet, M.; Kizling, J.; Mintsa-Eya, V.; Choplin, A.; Touroude, R.; Maire, G.; Stenius, P.

    1987-01-01

    Metal catalysts have been prepared by depositing monodisperse particles of platinum (2-3 nm), rhodium (2-3 nm), or palladium (5 nm) prepared in reversed micellar solutions on pumice. The particles are well dispersed on the support whereas particles deposited from aqueous or alcoholic solution give large aggregates. The catalytic properties of these different catalysts in the deuteration, isomerization, and hydrogen-deuterium exchange of but-1-ene have been compared. The activities calculated per metal surface atom are similar. However, platinum prepared from microemulsions show unusually high selectivity in the isomerization reaction, and for such particles dehydrogenated species are active in the exchange reaction. The specificity of rhodium and palladium catalysts is independent of the mode of preparation. The reaction mechanisms are discussed.

  3. Effects of symbol modulation coding on readout fidelity of shift-multiplexed holographic digital data page storage in a photopolymerizable nanoparticle-(thiol-ene)polymer composite film.

    PubMed

    Takayama, Shingo; Nagaya, Kohta; Momose, Keisuke; Tomita, Yasuo

    2014-04-01

    We report on shift-multiplexed holographic storage of 250 digital data pages in a photopolymerizable SiO₂ nanoparticle-polymer composite film being capable of step-growth thiol-ene polymerization in the green. Various two-dimensional symbol modulation codes for the digital data page format were employed to examine the dependence of the readout fidelity on modulation coding schemes. It is found that, as compared to 1:2 and 2:4 modulation codes, higher-order 5:9, 9:16, and 13:25 modulation codes possessing reduced white rates and higher coding efficiencies give lower symbol-error rates of ~1×10⁻³ and higher signal-to-noise ratios (>4). PMID:24787217

  4. Synthesis and photochromic properties of a novel thiol-terminated 1,3-diazabicyclo[3.1.0]hex-3-ene on silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Ghavidast, Atefeh; Mahmoodi, Nosrat O.; Zanjanchi, Mohammad Ali

    2013-09-01

    Inorganic nanoparticles functionalized with organic photochromes have been used for a much wider variety of applications. In this work, we have designed and synthesized a novel photochromic 1,3-diazabicyclo[3.1.0]hex-3-ene with a thiol-terminal group to form a self-assembled monolayer on the silver nanoparticles (AgNPs). The prepared photochromic material was characterized using X-ray diffraction, scanning electron microscopy, UV-Vis, NMR and IR methods. Analysis of the results showed that there is a chemical interaction between the AgNPs and terminal-thiol group of the photochromic. The photochromic structure behavior relationship (PSBR) of photochromic ligand and photochromic/AgNPs assemblies has been analyzed.

  5. Preparation of polyhedral oligomeric silsesquioxane-based hybrid monolith by ring-opening polymerization and post-functionalization via thiol-ene click reaction.

    PubMed

    Liu, Zhongshan; Ou, Junjie; Lin, Hui; Wang, Hongwei; Dong, Jing; Zou, Hanfa

    2014-05-16

    A polyhedral oligomeric silsesquioxane (POSS) hybrid monolith was simply prepared by using octaglycidyldimethylsilyl POSS (POSS-epoxy) and cystamine dihydrochloride as monomers via ring-opening polymerization. The effects of composition of prepolymerization solution and polycondensation temperature on the morphology and permeability of monolithic column were investigated in detail. The obtained POSS hybrid monolithic column showed 3D skeleton morphology and exhibited high column efficiency of ∼71,000 plates per meter in reversed-phase mechanism. Owing to this POSS hybrid monolith essentially possessing a great number of disulfide bonds, the monolith surface would expose thiol groups after reduction with dithiothreitol (DTT), which supplied active sites to functionalize with various alkene monomers via thiol-ene click reaction. The results indicated that the reduction with DTT could not destroy the 3D skeleton of hybrid monolith. Both stearyl methylacrylate (SMA) and benzyl methacrylate (BMA) were selected to functionalize the hybrid monolithic columns for reversed-phase liquid chromatography (RPLC), while [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl)-ammonium hydroxide (MSA) was used to modify the hybrid monolithic column in hydrophilic interaction chromatography (HILIC). These modified hybrid monolithic columns could be successfully applied for separation of small molecules with high efficiency. It is demonstrated that thiol-ene click reaction supplies a facile way to introduce various functional groups to the hybrid monolith possessing thiol groups. Furthermore, due to good permeability of the resulting hybrid monoliths, we also prepared long hybrid monolithic columns in narrow-bore capillaries. The highest column efficiency reached to ∼70,000 plates using a 1-m-long column of 75μm i.d. with a peak capacity of 147 for isocratic chromatography, indicating potential application in separation and analysis of complex biosamples. PMID:24725471

  6. The HARNESS Workbench: Unified and Adaptive Access to Diverse HPC Platforms

    SciTech Connect

    Sunderam, Vaidy S.

    2012-03-20

    The primary goal of the Harness WorkBench (HWB) project is to investigate innovative software environments that will help enhance the overall productivity of applications science on diverse HPC platforms. Two complementary frameworks were designed: one, a virtualized command toolkit for application building, deployment, and execution, that provides a common view across diverse HPC systems, in particular the DOE leadership computing platforms (Cray, IBM, SGI, and clusters); and two, a unified runtime environment that consolidates access to runtime services via an adaptive framework for execution-time and post processing activities. A prototype of the first was developed based on the concept of a 'system-call virtual machine' (SCVM), to enhance portability of the HPC application deployment process across heterogeneous high-end machines. The SCVM approach to portable builds is based on the insertion of toolkit-interpretable directives into original application build scripts. Modifications resulting from these directives preserve the semantics of the original build instruction flow. The execution of the build script is controlled by our toolkit that intercepts build script commands in a manner transparent to the end-user. We have applied this approach to a scientific production code (Gamess-US) on the Cray-XT5 machine. The second facet, termed Unibus, aims to facilitate provisioning and aggregation of multifaceted resources from resource providers and end-users perspectives. To achieve that, Unibus proposes a Capability Model and mediators (resource drivers) to virtualize access to diverse resources, and soft and successive conditioning to enable automatic and user-transparent resource provisioning. A proof of concept implementation has demonstrated the viability of this approach on high end machines, grid systems and computing clouds.

  7. Harnessing Diversity towards the Reconstructing of Large Scale Gene Regulatory Networks

    PubMed Central

    Yamanaka, Ryota; Kitano, Hiroaki

    2013-01-01

    Elucidating gene regulatory network (GRN) from large scale experimental data remains a central challenge in systems biology. Recently, numerous techniques, particularly consensus driven approaches combining different algorithms, have become a potentially promising strategy to infer accurate GRNs. Here, we develop a novel consensus inference algorithm, TopkNet that can integrate multiple algorithms to infer GRNs. Comprehensive performance benchmarking on a cloud computing framework demonstrated that (i) a simple strategy to combine many algorithms does not always lead to performance improvement compared to the cost of consensus and (ii) TopkNet integrating only high-performance algorithms provide significant performance improvement compared to the best individual algorithms and community prediction. These results suggest that a priori determination of high-performance algorithms is a key to reconstruct an unknown regulatory network. Similarity among gene-expression datasets can be useful to determine potential optimal algorithms for reconstruction of unknown regulatory networks, i.e., if expression-data associated with known regulatory network is similar to that with unknown regulatory network, optimal algorithms determined for the known regulatory network can be repurposed to infer the unknown regulatory network. Based on this observation, we developed a quantitative measure of similarity among gene-expression datasets and demonstrated that, if similarity between the two expression datasets is high, TopkNet integrating algorithms that are optimal for known dataset perform well on the unknown dataset. The consensus framework, TopkNet, together with the similarity measure proposed in this study provides a powerful strategy towards harnessing the wisdom of the crowds in reconstruction of unknown regulatory networks. PMID:24278007

  8. Harnessing Petaflop-Scale Multi-Core Supercomputing for Problems in Space Science

    NASA Astrophysics Data System (ADS)

    Albright, B. J.; Yin, L.; Bowers, K. J.; Daughton, W.; Bergen, B.; Kwan, T. J.

    2008-12-01

    The particle-in-cell kinetic plasma code VPIC has been migrated successfully to the world's fastest supercomputer, Roadrunner, a hybrid multi-core platform built by IBM for the Los Alamos National Laboratory. How this was achieved will be described and examples of state-of-the-art calculations in space science, in particular, the study of magnetic reconnection, will be presented. With VPIC on Roadrunner, we have performed, for the first time, plasma PIC calculations with over one trillion particles, >100× larger than calculations considered "heroic" by community standards. This allows examination of physics at unprecedented scale and fidelity. Roadrunner is an example of an emerging paradigm in supercomputing: the trend toward multi-core systems with deep hierarchies and where memory bandwidth optimization is vital to achieving high performance. Getting VPIC to perform well on such systems is a formidable challenge: the core algorithm is memory bandwidth limited with low compute-to-data ratio and requires random access to memory in its inner loop. That we were able to get VPIC to perform and scale well, achieving >0.374 Pflop/s and linear weak scaling on real physics problems on up to the full 12240-core Roadrunner machine, bodes well for harnessing these machines for our community's needs in the future. Many of the design considerations encountered commute to other multi-core and accelerated (e.g., via GPU) platforms and we modified VPIC with flexibility in mind. These will be summarized and strategies for how one might adapt a code for such platforms will be shared. Work performed under the auspices of the U.S. DOE by the LANS LLC Los Alamos National Laboratory. Dr. Bowers is a LANL Guest Scientist; he is presently at D. E. Shaw Research LLC, 120 W 45th Street, 39th Floor, New York, NY 10036.

  9. Humans robustly adhere to dynamic walking principles by harnessing motor abundance to control forces

    PubMed Central

    Toney, Megan E.

    2013-01-01

    Human walking dynamics are typically framed in the context of mechanics and energetics rather than in the context of neuromuscular control. Dynamic walking principles describe one helpful theoretical approach to characterize efficient human walking mechanics over many steps. These principles do not, however, address how such walking is controlled step-by-step despite small perturbations from natural variability. Our purpose was to identify neuromechanical control strategies used to achieve consistent and robust locomotion despite natural step-to-step force variability. We used the uncontrolled manifold concept to test whether human walkers select combinations of leading and trailing leg-forces that generate equivalent net-force trajectories during step-to-step transitions. Subjects selected leading and trailing leg-force combinations that generated consistent vertical net-force during step-to-step transitions. We conclude that vertical net-force is an implicit neuromechanical goal of human walking whose trajectory is stabilized for consistent step-to-step transitions, which agrees with the principles of dynamic walking. In contrast, inter-leg-force combinations modulated anterior–posterior net-force trajectories with each step to maintain constant walking speed, indicating that a consistent anterior–posterior net-force trajectory is not an implicit goal of walking. For a more complete picture of hierarchical locomotor control, we also tested whether each individual leg-force trajectory was stabilized through the selection of leg-force equivalent joint-torque combinations. The observed consistent vertical net-force trajectory was achieved primarily through the selection of joint-torque combinations that modulated trailing leg-force during step-to-step transitions. We conclude that humans achieve robust walking by harnessing inherent motor abundance of the joints and legs to maintain consistent step-by-step walking performance. PMID:24081680

  10. Harnessing peer networks as an instrument for AIDS prevention: results from a peer-driven intervention.

    PubMed Central

    Broadhead, R S; Heckathorn, D D; Weakliem, D L; Anthony, D L; Madray, H; Mills, R J; Hughes, J

    1998-01-01

    OBJECTIVE: Since 1985, community outreach efforts to combat acquired immunodeficiency syndrome (AIDS) among injecting drug users (IDUs) in the United States have overwhelmingly depended on a provider-client model that relies on staffs of professional outreach workers. We report on a comparison of this traditional outreach model with an innovative social network model, termed "a peer-driven intervention" (PDI). The latter provides IDUs with guidance and structured incentives that permit them to play a much more active role in the outreach process, thereby harnessing peer pressure on behalf of human immunodeficiency virus (HIV) prevention efforts. METHODS: We compare the performance of a traditional outreach intervention (TOI) and a PDI that were implemented in medium-sized towns in eastern and central Connecticut. Comparisons are based on the number and representativeness of IDUs recruited at each site, the effectiveness of HIV prevention education, compliance rates with AIDS risk reduction recommendations, and relative cost. The analyses are based on 522 initial interviews and 190 six-month follow-up interviews conducted during the first two years of each intervention's operation. RESULTS: Both interventions produced significant reductions in HIV risk behaviors, as measured using self-reports. The PDI outperformed the traditional intervention with respect to the number of IDUs recruited, the ethnic and geographic representativeness of the recruits, and the effectiveness of HIV prevention education. In addition, the costs of recruiting IDUs into the intervention and educating them about HIV in the community was only one-thirtieth as much in the PDI as in the traditional intervention. CONCLUSIONS: The findings suggest that given guidance and nominal incentives, IDUs can play a more extensive role in community outreach efforts than the traditional model allows. The findings also suggest that both interventions reduce HIV-associated risk behaviors, but the PDI reaches

  11. Helmet Use Amongst Equestrians: Harnessing Social and Attitudinal Factors Revealed in Online Forums

    PubMed Central

    Haigh, Laura; Thompson, Kirrilly

    2015-01-01

    relationship between risk perception, protective knowledge, attitudes, decision-making and behavior. Whilst this complexity is largely due to the involvement of interspecies relationships through which safety, risk and trust are distributed; our findings about harnessing the potential of barriers could be extended to other high risk activities. PMID:26479375

  12. Role of ultrasound assessment and harness treatment in the management of developmental dysplasia of the hip.

    PubMed Central

    Sochart, D. H.; Paton, R. W.

    1996-01-01

    The effect of the introduction of a programme combining clinical hip screening supplemented by limited targeted ultrasound assessment on splintage for developmental dysplasia of the hip (DDH) was evaluated over a 3-year period. The use of ultrasound is of both diagnostic and therapeutic value as it allows monitoring of the effects of splintage and decreases the total treatment time required. In all, 82 dysplastic hips were identified in 65 infants and the period of splintage averaged 6.3 weeks (range 3-12 weeks). The overall splintage rate can also be reduced as hips with only minor dysplasia can be assessed by serial scans until resolution or progression occurs rather than automatic treatment of all abnormal hips and in this series the rate was 6 per 1000 (0.6%). The Wheaton-Pavlik harness is a dynamic light-weight splint which is user friendly, easy to apply and adjust, and with no major complications being encountered in this series. Unnecessary exposure to radiation was reduced as plain radiographs were not performed before ossification of the capital epiphysis; prolonged splintage was prevented and a weaning period from the brace was not used. All children remained under follow-up for 1 year after the hips were confirmed to be clinically and radiologically normal and there were no cases of late re-dislocation or subluxation. There were no cases of avascular necrosis and a markedly reduced need for diagnostic arthrograms, with only two being performed during the 3 years. This regimen has resulted in a low rate of late presenting DDH requiring surgery of 0.28/1000, as well as a low splintage rate of 6/1000 (0.6%). Most of the improvement in the results can be attributed to the more accurate evaluation of DDH by ultrasound, but the absence of avascular necrosis and other complications is likely to be due to the shorter period of time spent in a dynamic splint without the use of excessive abduction. PMID:8943633

  13. Epidemiology of musculoskeletal injuries in a population of harness Standardbred racehorses in training

    PubMed Central

    2014-01-01

    Background There is a substantial paucity of studies concerning musculoskeletal injuries in harness Standardbred racehorses. Specifically, little is known about the epidemiology of exercise-related musculoskeletal injuries. Most studies on this subject involve Thoroughbred racehorses, whose biomechanics and racing speed differ from Standardbred, making comparisons difficult. Here, a population of Standardbred racehorses trained at the same racecourse was studied over four years and a classification system for exercise-related musculoskeletal injuries was designed. The incidence rates of musculoskeletal injuries causing horses’ withdrawal from training for 15 days or longer were investigated. A mixed-effects Poisson regression model was used to estimate musculoskeletal injury rates and to describe significance of selected risk factors for exercise-related injuries in this population. Results A total of 356 trotter racehorses from 10 different stables contributed 8961 months at risk of musculoskeletal injuries. Four-hundred-and-twenty-nine injuries were reported and classified into 16 categories, based on their aetiology and anatomical localisation. The overall exercise-related injury rate was 4.79 per 100 horse months. When considering risk factors one by one in separate univariable analyses, we obtained the following results: rates did not differ significantly between genders and classes of age, whereas one driver seemed to cause fewer injuries than the others. Racing speed and racing intensity, as well as recent medical history, seemed to be significant risk factors (p < 0.001), while being shod or unshod during racing was not. On the other hand, when pooling several risk factors in a multivariable approach, only racing intensity turned out to be significant (p < 0.001), since racing speed and the racing intensity were partially confounded, being strongly correlated to one another. Conclusion Characterizing epidemiology of exercise-related musculoskeletal

  14. Harnessing the power of mobile technologies for collaborating, crowdsourcing, and creating

    NASA Astrophysics Data System (ADS)

    Crompton, H.

    2015-12-01

    Today's digital technologies can have a powerful influence on teaching and learning. M-learning and u-learning in particular are changing pedagogical practice. Sub categories are rapidly emerging, such as context-aware ubiquitous learning, that involve students learning subject content while immersed in authentic and relevant surroundings. Learning cultures are a nebulous blend of traditions, values, beliefs, and rituals built up over time. For a long time, education has long been conceived as classroom-based and predominantly sedentary (Merchant, 2012). Recent mobile technologies are disrupting this culture in favor of learning that is contextualized, personalized, on demand, and ubiquitous (Crompton, 2013). 21st century students are a different breed than past generations (Prensky, 2001). These students have grown up in a time that has not only altered their perceptions and practices but modified the wiring of the brain through neuroplasticity (Crompton, 2012). Students now cognitively receive information quickly through non-linear methods (Gross, 2003, Oblinger & Oblinger, 2005). They think differently. They also seem to be attached to mobile devices 24/7, although the content of the lesson does not match what they seem to be doing on the mobile devices. This presentation will showcase how to get your students to harness the power of mobile devices for educational purposes. For example, students in your classes will be using devices to collaborate on activities with Google Forms, crowdsourcing the best class questions in Slido, and screencasting thoughts and ideas to share with others with Educreations. These are examples of free apps or Web 2.0 tools that can be used on all the major mobile platforms. Crompton, H. (2013). Mobile learning: New approach, new theory. In Z. L. Berge & L. Y. Muilenburg (Eds.), Handbook of mobile learning (pp. 47-57). Prensky, M. (2001). Digital natives, digital immigrants. Mcb University Press, 9(5). Oblinger, D., & Oblinger, J

  15. A method to harness global crowd-sourced data to understand travel behavior in avalanche terrain.

    NASA Astrophysics Data System (ADS)

    Hendrikx, J.; Johnson, J.

    2015-12-01

    To date, most studies of the human dimensions of decision making in avalanche terrain has focused on two areas - post-accident analysis using accident reports/interviews and, the development of tools as decision forcing aids. We present an alternate method using crowd-sourced citizen science, for understanding decision-making in avalanche terrain. Our project combines real-time GPS tracking via a smartphone application, with internet based surveys of winter backcountry users as a method to describe and quantify travel practices in concert with group decision-making dynamics, and demographic data of participants during excursions. Effectively, we use the recorded GPS track taken within the landscape as an expression of the decision making processes and terrain usage by the group. Preliminary data analysis shows that individual experience levels, gender, avalanche hazard, and group composition all influence the ways in which people travel in avalanche terrain. Our results provide the first analysis of coupled real-time GPS tracking of the crowd while moving in avalanche terrain combined with psychographic and demographic correlates. This research will lead to an improved understanding of real-time decision making in avalanche terrain. In this paper we will specifically focus on the presentation of the methods used to solicit, and then harness the crowd to obtain data in a unique and innovative application of citizen science where the movements within the terrain are the desired output data (Figure 1). Figure 1: Example GPS tracks sourced from backcountry winter users in the Teton Pass area (Wyoming), from the 2014-15 winter season, where tracks in red represent those recorded as self-assessed experts (as per our survey), and where tracks in blue represent those recorded as self-assessed intermediates. All tracks shown were obtained under similar avalanche conditions. Statistical analysis of terrain metrics showed that the experts used steeper terrain than the

  16. Determining Damping Trends from a Range of Cable Harness Assemblies on a Launch Vehicle Panel from Test Measurements

    NASA Technical Reports Server (NTRS)

    Smith, Andrew; Davis, R. Ben; LaVerde, Bruce; Jones, Douglas

    2012-01-01

    The team of authors at Marshall Space Flight Center (MSFC) has been investigating estimating techniques for the vibration response of launch vehicle panels excited by acoustics and/or aero-fluctuating pressures. Validation of the approaches used to estimate these environments based on ground tests of flight like hardware is of major importance to new vehicle programs. The team at MSFC has recently expanded upon the first series of ground test cases completed in December 2010. The follow on tests recently completed are intended to illustrate differences in damping that might be expected when cable harnesses are added to the configurations under test. This validation study examines the effect on vibroacoustic response resulting from the installation of cable bundles on a curved orthogrid panel. Of interest is the level of damping provided by the installation of the cable bundles and whether this damping could be potentially leveraged in launch vehicle design. The results of this test are compared with baseline acoustic response tests without cables. Damping estimates from the measured response data are made using a new software tool that employs a finite element model (FEM) of the panel in conjunction with advanced optimization techniques. This paper will report on the \\damping trend differences. observed from response measurements for several different configurations of cable harnesses. The data should assist vibroacoustics engineers to make more informed damping assumptions when calculating vibration response estimates when using model based analysis approach. Achieving conservative estimates that have more flight like accuracy is desired. The paper may also assist analysts in determining how ground test data may relate to expected flight response levels. Empirical response estimates may also need to be adjusted if the measured response used as an input to the study came from a test article without flight like cable harnesses.

  17. Harnessing the Risk-Related Data Supply Chain: An Information Architecture Approach to Enriching Human System Research and Operations Knowledge

    NASA Technical Reports Server (NTRS)

    Buquo, Lynn E.; Johnson-Throop, Kathy A.

    2011-01-01

    An Information Architecture facilitates the understanding and, hence, harnessing of the human system risk-related data supply chain which enhances the ability to securely collect, integrate, and share data assets that improve human system research and operations. By mapping the risk-related data flow from raw data to useable information and knowledge (think of it as a data supply chain), the Human Research Program (HRP) and Space Life Science Directorate (SLSD) are building an information architecture plan to leverage their existing, and often shared, IT infrastructure.

  18. High-affinity binding of the staphylococcal HarA protein to haptoglobin and hemoglobin involves a domain with an antiparallel eight-stranded beta-barrel fold.

    PubMed

    Dryla, Agnieszka; Hoffmann, Bernd; Gelbmann, Dieter; Giefing, Carmen; Hanner, Markus; Meinke, Andreas; Anderson, Annaliesa S; Koppensteiner, Walter; Konrat, Robert; von Gabain, Alexander; Nagy, Eszter

    2007-01-01

    Iron scavenging from the host is essential for the growth of pathogenic bacteria. In this study, we further characterized two staphylococcal cell wall proteins previously shown to bind hemoproteins. HarA and IsdB harbor homologous ligand binding domains, the so called NEAT domain (for "near transporter") present in several surface proteins of gram-positive pathogens. Surface plasmon resonance measurements using glutathione S-transferase (GST)-tagged HarAD1, one of the ligand binding domains of HarA, and GST-tagged full-length IsdB proteins confirmed high-affinity binding to hemoglobin and haptoglobin-hemoglobin complexes with equilibrium dissociation constants (K(D)) of 5 to 50 nM. Haptoglobin binding could be detected only with HarA and was in the low micromolar range. In order to determine the fold of this evolutionarily conserved ligand binding domain, the untagged HarAD1 protein was subjected to nuclear magnetic resonance spectroscopy, which revealed an eight-stranded, purely antiparallel beta-barrel with the strand order (-beta1 -beta2 -beta3 -beta6 -beta5 -beta4 -beta7 -beta8), forming two Greek key motifs. Based on structural-homology searches, the topology of the HarAD1 domain resembles that of the immunoglobulin (Ig) fold family, whose members are involved in protein-protein interactions, but with distinct structural features. Therefore, we consider that the HarAD1/NEAT domain fold is a novel variant of the Ig fold that has not yet been observed in other proteins. PMID:17041047

  19. Three decades of harnessing the GPS data explosion for geophysics (Vening Meinesz Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Blewitt, Geoffrey

    2015-04-01

    In this presentation, I attempt to convey the immensity of the task that faced the geodesy community three decades ago, and continues to challenge us, to harness all potentially valuable GPS data available in the world for geophysical science. It would be fair to see that three decades ago, we were struggling with controlled tests just to get GPS geodesy working, and had little time to imagine the flood of data today. Yet the geodesy community has succeeded in meeting this challenge. Today, for example, the Nevada Geodetic Laboratory produces and makes publicly available coordinate time series for over 12,000 geodetic GPS station around the globe with various data intervals, latencies, and reference frames. About 8,000 stations have their daily time series updated every week, with 4,000 being updated the next day with coordinates at daily and 5 minute intervals. About 2,000 stations have their time series updated every hour with coordinates at 5 minute intervals. I will show examples of how these time series are being used by NGL and many other scientists to study a wide variety of geophysical topics, including plate tectonics, earthquake modeling, seismic and tsunami hazard, volcanic deformation, water resources, mountain growth, terrestrial reference frame realization, glacial isostatic adjustment, ice sheet melting, sea level rise and coastal subsidence, and even fundamental physics, using GPS atomic clocks to probe the nature of dark matter in the universe. The explosion in GPS data has challenged us to invent new data processing algorithms and develop robust automation in order to keep up with the flood. This explosion has been exponential, and therefore it can be said that it is not a recent phenomena, but rather that it began in the earliest years of GPS geodesy, and has always posed a challenge to us. Over the course of my post-doctoral career starting in late 1985, I have had the good fortune to witness the key developments that have taken place since the

  20. "Harnessing genomics to improve health in Africa" – an executive course to support genomics policy

    PubMed Central

    Smith, Alyna C; Mugabe, John; Singer, Peter A; Daar, Abdallah S

    2005-01-01

    Background Africa in the twenty-first century is faced with a heavy burden of disease, combined with ill-equipped medical systems and underdeveloped technological capacity. A major challenge for the international community is to bring scientific and technological advances like genomics to bear on the health priorities of poorer countries. The New Partnership for Africa's Development has identified science and technology as a key platform for Africa's renewal. Recognizing the timeliness of this issue, the African Centre for Technology Studies and the University of Toronto Joint Centre for Bioethics co-organized a course on Genomics and Public Health Policy in Nairobi, Kenya, the first of a series of similar courses to take place in the developing world. This article presents the findings and recommendations that emerged from this process, recommendations which suggest that a regional approach to developing sound science and technology policies is the key to harnessing genome-related biotechnology to improve health and contribute to human development in Africa. Methods The objectives of the course were to familiarize participants with the current status and implications of genomics for health in Africa; to provide frameworks for analyzing and debating the policy and ethical questions; and to begin developing a network across different sectors by sharing perspectives and building relationships. To achieve these goals the course brought together a diverse group of stakeholders from academic research centres, the media, non-governmental, voluntary and legal organizations to stimulate multi-sectoral debate around issues of policy. Topics included scientific advances in genomics innovation systems and business models, international regulatory frameworks, as well as ethical and legal issues. Results Seven main recommendations emerged: establish a network for sustained dialogue among participants; identify champions among politicians; use the New Plan for African

  1. "Harnessing genomics to improve health in Africa" - an executive course to support genomics policy.

    PubMed

    Smith, Alyna C; Mugabe, John; Singer, Peter A; Daar, Abdallah S

    2005-01-24

    BACKGROUND: Africa in the twenty-first century is faced with a heavy burden of disease, combined with ill-equipped medical systems and underdeveloped technological capacity. A major challenge for the international community is to bring scientific and technological advances like genomics to bear on the health priorities of poorer countries. The New Partnership for Africa's Development has identified science and technology as a key platform for Africa's renewal. Recognizing the timeliness of this issue, the African Centre for Technology Studies and the University of Toronto Joint Centre for Bioethics co-organized a course on Genomics and Public Health Policy in Nairobi, Kenya, the first of a series of similar courses to take place in the developing world. This article presents the findings and recommendations that emerged from this process, recommendations which suggest that a regional approach to developing sound science and technology policies is the key to harnessing genome-related biotechnology to improve health and contribute to human development in Africa. METHODS: The objectives of the course were to familiarize participants with the current status and implications of genomics for health in Africa; to provide frameworks for analyzing and debating the policy and ethical questions; and to begin developing a network across different sectors by sharing perspectives and building relationships. To achieve these goals the course brought together a diverse group of stakeholders from academic research centres, the media, non-governmental, voluntary and legal organizations to stimulate multi-sectoral debate around issues of policy. Topics included scientific advances in genomics innovation systems and business models, international regulatory frameworks, as well as ethical and legal issues. RESULTS: Seven main recommendations emerged: establish a network for sustained dialogue among participants; identify champions among politicians; use the New Plan for African

  2. Harness That S.O.B.: Distributing Remote Sensing Analysis in a Small Office/Business

    NASA Astrophysics Data System (ADS)

    Kramer, J.; Combe, J.; McCord, T. B.

    2009-12-01

    Researchers in a small office/business (SOB) operate with limited funding, equipment, and software availability. To mitigate these issues, we developed a distributed computing framework that: 1) leverages open source software to implement functionality otherwise reliant on proprietary software and 2) harnesses the unused power of (semi-)idle office computers with mixed operating systems (OSes). This abstract outlines some reasons for the effort, its conceptual basis and implementation, and provides brief speedup results. The Multiple-Endmember Linear Spectral Unmixing Model (MELSUM)1 processes remote-sensing (hyper-)spectral images. The algorithm is computationally expensive, sometimes taking a full week or more for a 1 million pixel/100 wavelength image. Analysis of pixels is independent, so a large benefit can be gained from parallel processing techniques. Job concurrency is limited by the number of active processing units. MELSUM was originally written in the Interactive Data Language (IDL). Despite its multi-threading capabilities, an IDL instance executes on a single machine, and so concurrency is limited by the machine's number of central processing units (CPUs). Network distribution can access more CPUs to provide a greater speedup, while also taking advantage of (often) underutilized extant equipment. appropriately integrating open source software magnifies the impact by avoiding the purchase of additional licenses. Our method of distribution breaks into four conceptual parts: 1) the top- or task-level user interface; 2) a mid-level program that manages hosts and jobs, called the distribution server; 3) a low-level executable for individual pixel calculations; and 4) a control program to synchronize sequential sub-tasks. Each part is a separate OS process, passing information via shell commands and/or temporary files. While the control and low-level executables are short-lived, the top-level program and distribution server run (at least) for the entirety of

  3. Enhancement of the helical content and stability induced in a linear oligopeptide by an i, i+4 intramolecularly double stapled, overlapping, bicyclic [31, 22, 5]-(E)ene motif.

    PubMed

    Mazzier, Daniela; Peggion, Cristina; Toniolo, Claudio; Moretto, Alessandro

    2014-01-01

    Two consecutive i, i+4 intramolecular, side chain-to-side chain, macrocyclizations of different type carried out on a preformed, partially helical peptide result in a largely predominant, double stapled, overlapping, bicyclic [31,22,5]-(E)ene motif. A detailed ECD and NMR conformational study revealed a significant enhancement of the original helical content and stability, accompanied by an increase of the α-helix amount over that of the 3(10)-helix. PMID:24436043

  4. Identification of 5alpha-androst-1-ene-3beta,17beta-diol in the fat of Sus scrofa L.: a "nutritional supplement" not found previously in the food supply.

    PubMed

    McGregor, Stephen J; Erickson, Andrew J

    2003-09-01

    5alpha-Androst-1-ene-3beta,17beta-diol (1) was detected in extracts from fat of Sus scrofa L. (pig) by comparison with the commercially available synthetic compound, using gas chromatography-mass spectrometry. This observation is unprecedented because 1 is currently sold as a nutritional supplement, yet has not been previously reported as naturally occurring in the food supply. PMID:14510586

  5. Origin and palaeoenvironmental significance of C25 and C27n-alk-1-enes in a 25,000-year lake-sedimentary record from equatorial East Africa

    NASA Astrophysics Data System (ADS)

    van Bree, L. G. J.; Rijpstra, W. I. C.; Cocquyt, C.; Al-Dhabi, N. A.; Verschuren, D.; Sinninghe Damsté, J. S.; de Leeuw, J. W.

    2014-11-01

    We studied the distribution of long-chain alkenes (n-C23 to n-C31) in well-dated sediments from Lake Challa, a deep crater lake near Mt. Kilimanjaro in equatorial East Africa, to reveal signatures of palaeo-environmental and palaeo-climatic changes affecting the production of these compounds during the last 25 kyr. The apolar fractions of organic sediment extracts dated to the last 16 kyr showed an unusual dominance of δ13C-depleted n-C25:1 and n-C27:1 alk-1-enes. These alkenes were not detected in soil and litter from near the shoreline and from the inner rim of the crater, pointing to an autochthonous, aquatic source. Analysis of suspended particulate matter indicated that the n-alk-1-enes are produced in the well-oxygenated upper 30 m of the water column, indicating a phytoplanktonic origin. Sedimenting particles collected monthly from December 2006 to November 2007 showed increased fluxes of n-alk-1-enes following the locally prominent short rain season in November-December. Green algae and/or cyanobacteria were identified as candidate sources of these alkenes. Production of the n-C25:1 and n-C27:1 alkenes in Lake Challa was much reduced during the Last Glacial Maximum and early late-glacial period, suggesting a temperature or CO2 effect on habitat suitability. We explored the potential of n-alk-1-ene accumulation rates, and of a derived Alkene Index [n-C27:1]/([n-C25:1] + [n-C27:1]), to record longer-term climatic changes. The Alkene Index record of Lake Challa over the past 25 kyr shows clear periodicity with a dominant frequency of ∼2.3 kyr, potentially indicative of monsoon variability directly or indirectly forced by variation in solar radiation.

  6. "Grafting to" of RAFTed Responsive Polymers to Glass Substrates by Thiol-Ene and Critical Comparison to Thiol-Gold Coupling.

    PubMed

    Biggs, Caroline I; Walker, Marc; Gibson, Matthew I

    2016-08-01

    Surface-grafted polymers have been widely applied to modulate biological interfaces and introduce additional functionality. Polymers derived from reversible addition-fragmentation transfer (RAFT) polymerization have a masked thiol at the ω-chain end providing an anchor point for conjugation and in particular displays high affinity for gold surfaces (both flat and particulate). In this work, we report the direct grafting of RAFTed polymers by a "thiol-ene click" (Michael addition) onto glass substrates rather than gold, which provides a more versatile surface for subsequent array-based applications but retains the simplicity. The immobilization of two thermoresponsive polymers are studied here, poly[oligo(ethylene glycol) methyl ether methacrylate] (pOEGMA) and poly(N-isopropylacrylamide) (pNIPAM). Using a range of surface analysis techniques the grafting efficiency was compared to thiol-gold and was quantitatively compared to the gold alternative using quartz crystal microbalance. It is shown that this method gives easy access to grafted polymer surfaces with pNIPAM resulting in significantly increased surface coverage compared to pOEGMA. The nonfouling (protein resistance) character of these surfaces is also demonstrated. PMID:27409356

  7. Selective Cell Adhesion and Biosensing Applications of Bio-Active Block Copolymers Prepared by CuAAC/Thiol-ene Double Click Reactions.

    PubMed

    Oyman Eyrilmez, Gizem; Doran, Sean; Murtezi, Eljesa; Demir, Bilal; Odaci Demirkol, Dilek; Coskunol, Hakan; Timur, Suna; Yagci, Yusuf

    2015-09-01

    N-Acetyl-l-cysteine (NAC)-capped poly(methyl methacrylate)-b-polycaprolactone block copolymer (PMMA-b-PCL-NAC) was prepared using the previously described one-pot photoinduced sequential CuAAC/thiol-ene double click procedure. PMMA-b-PCL-NAC had previously shown good applicability as a matrix for cell adhesion of cells from the Vero cell line (African green monkey kidney epithelial). Here, in this work, PMMA-b-PCL-NAC served as an excellent immobilization matrix for biomolecule conjugation. Covalent binding of RGD (R: arginine, G: glycine, and D: aspartic acid) peptide sequence onto the PMMA-b-PCL-NAC-coated surface was performed via EDC chemistry. RGD-modified PMMA-b-PCL-NAC (PMMA-b-PCL-NAC-RGD) as a non-toxic cell proliferation platform was used for selective "integrin αvβ3-mediated cell adhesion and biosensing studies. Both optical and electrochemical techniques were used to monitor the adhesion differences between "integrin αvβ3" receptor positive and negative cell lines on to the designed biofunctional surfaces. PMID:25974890

  8. “Grafting to” of RAFTed Responsive Polymers to Glass Substrates by Thiol–Ene and Critical Comparison to Thiol–Gold Coupling

    PubMed Central

    2016-01-01

    Surface-grafted polymers have been widely applied to modulate biological interfaces and introduce additional functionality. Polymers derived from reversible addition–fragmentation transfer (RAFT) polymerization have a masked thiol at the ω-chain end providing an anchor point for conjugation and in particular displays high affinity for gold surfaces (both flat and particulate). In this work, we report the direct grafting of RAFTed polymers by a “thiol–ene click” (Michael addition) onto glass substrates rather than gold, which provides a more versatile surface for subsequent array-based applications but retains the simplicity. The immobilization of two thermoresponsive polymers are studied here, poly[oligo(ethylene glycol) methyl ether methacrylate] (pOEGMA) and poly(N-isopropylacrylamide) (pNIPAM). Using a range of surface analysis techniques the grafting efficiency was compared to thiol–gold and was quantitatively compared to the gold alternative using quartz crystal microbalance. It is shown that this method gives easy access to grafted polymer surfaces with pNIPAM resulting in significantly increased surface coverage compared to pOEGMA. The nonfouling (protein resistance) character of these surfaces is also demonstrated. PMID:27409356

  9. Biocomposites from Natural Rubber: Synergistic Effects of Functionalized Cellulose Nanocrystals as Both Reinforcing and Cross-Linking Agents via Free-Radical Thiol-ene Chemistry.

    PubMed

    Parambath Kanoth, Bipinbal; Claudino, Mauro; Johansson, Mats; Berglund, Lars A; Zhou, Qi

    2015-08-01

    Natural rubber/cellulose nanocrystals (NR/CNCs) form true biocomposites from renewable resources and are demonstrated to show significantly improved thermo-mechanical properties and reduced stress-softening. The nanocomposites were prepared from chemically functionalized CNCs bearing thiols. CNCs served as both reinforcing and cross-linking agents in the NR matrix, and the study was designed to prove the cross-linking function of modified CNCs. CNCs were prepared from cotton, and the cross-linkable mercapto-groups were introduced onto the surface of CNCs by esterification. Nanocomposite films were prepared by dispersing the modified CNCs (m-CNCs) in NR matrix by solution casting. The cross-links at the filler-matrix (m-CNCs-NR) interface were generated by photochemically initiated thiol-ene reactions as monitored by real-time FTIR analysis. The synergistic effects of reinforcement and chemical cross-linking at the m-CNCs-NR interface on structure, thermo-mechanical, and stress-softening behavior were investigated. Methods included field emission scanning electron microscopy (FE-SEM), swelling tests, dynamic mechanical analysis, and tensile tests. Compared to biocomposites from NR with unmodified CNCs, the NR/m-CNCs nanocomposites showed 2.4-fold increase in tensile strength, 1.6-fold increase in strain-to-failure, and 2.9-fold increase in work-of-fracture at 10 wt % of m-CNCs in NR. PMID:26151647

  10. Mechanistic investigations into the enantioselective Conia-ene reaction catalyzed by cinchona-derived amino urea pre-catalysts and Cu(I).

    PubMed

    Sladojevich, Filippo; Fuentes de Arriba, Ángel L; Ortín, Irene; Yang, Ting; Ferrali, Alessandro; Paton, Robert S; Dixon, Darren J

    2013-10-11

    The enantioselective Conia-ene cyclization of alkyne-tethered β-ketoesters is efficiently catalyzed by the combination of cinchona-derived amino-urea pre-catalysts and copper(I) salts. The reaction scope is broad and a series of substrates can be efficiently cyclized with high yields and enantioselectivities. Herein, we present a detailed mechanistic study based on experimental considerations and quantum mechanical calculations. Several variables, such as the nature of the organic pre-catalyst and the metal-ion source, have been thoroughly investigated. Kinetic studies, as well as kinetic isotope effects and deuterium labeling experiments have been used to gain further insights into the mechanism and prove the cooperative nature of the catalytic system. Our studies suggest that the rate-limiting step for the reaction involves the β-ketoester deprotonation and that the active species responsible for the enantiodeterming step is monomeric in amino-urea pre-catalyst. Computational studies provide a quantitative understanding of the observed stereoinduction and identify hydrogen bonding from the urea group as a crucial factor in determining the observed enantioselectivity. PMID:24009075

  11. Impact of 3,4-dideoxyglucosone-3-ene (3,4-DGE) on cytotoxicity of acidic heat-sterilized peritoneal dialysis fluid.

    PubMed

    Tomo, Tadashi; Okabe, Eiji; Yamamoto, Takashi; Namoto, Shinji; Iwashita, Tomohiko; Matsuyama, Kazuhiro; Kadota, Jun-ichi

    2007-01-01

    Of the glucose degradation products (GDPs) in glucose-rich peritoneal dialysate, we investigated the influence of 3,4-dideoxyglucosone-3-ene (3,4-DGE) on the cytotoxicity of acidic heat-sterilized peritoneal dialysis fluid (L-H PDF) using human peritoneal mesothelial cells (HPMC). We prepared acidified filtration-sterilized PDF (glucose concentration 3.86%) containing eight types of added GDP [3,4-DGE, glyoxal (GO), methylglyoxal (MGO), 3-deoxyglucosone (3-DG), formaldehyde (FA), acetaldehyde (AA), 5-hydroxymethyl-2-furaldehyde (5-HMF), and furfural (FF)] or seven types of GDP (GO, MGO, 3-DG, FA, AA, 5-HMF, and FF). HPMC were exposed to these two types of solution and acidic heat-sterilized PDF (glucose concentration 3.86%, L-H 3.86) for 4 h. Cell viability was determined by 3,(4,5-dimethythiazol-2-yl)2,5-diphenyl-terazolium bromide (MTT) assay. MTT viability was decreased significantly compared with the control when treated with L-H 3.86 or acidified neutral filtration-sterilized PDF (glucose concentration 3.86%) containing eight GDPs. However, no significant decrease in MTT viability was observed when HPMC were treated with acidified neutral filtration-sterilized PDF (glucose concentration 3.86%) containing seven GDPs. Thus, 3,4-DGE strongly affects the cytotoxicity of L-H PDF. It is suggested that the cytotoxicity of L-H PDF is based on the presence of 3,4-DGE. PMID:17380297

  12. Thiol-ene Michael-type formation of gelatin/poly(ethylene glycol) biomatrices for three-dimensional mesenchymal stromal/stem cell administration to cutaneous wounds

    PubMed Central

    Xu, Kedi; Cantu, David Antonio; Fu, Yao; Kim, Jaehyup; Zheng, Xiaoxiang; Hematti, Peiman; Kao, W. John

    2013-01-01

    Mesenchymal stromal/stem cells (MSCs) are considered promising cellular therapeutics in the fields of tissue engineering and regenerative medicine. MSCs secrete high concentrations of immunomodulatory cytokines and growth factors, which exert paracrine effects on infiltrating immune and resident cells of the wound microenvironment that could favorably promote healing after acute injury. However, better spatial delivery and improved retention at the site of injury are two factors that could improve the clinical application of MSCs. In this study, we utilized thiol-ene Michael-type addition for rapid encapsulation of MSCs within a gelatin/poly(ethylene glycol) biomatrix; this biomatrix was also applied as a provisional dressing to full-thickness wounds in Sprague-Dawley rats. The three-way interaction of MSCs, gelatin/poly(ethylene glycol) biomatrices, and host immune cells and adjacent resident cells of the wound microenvironment favorably modulated wound progression and host response. In this model we observed attenuated immune cell infiltration, lack of foreign giant cell (FBGC) formation, accelerated wound closure and re-epithelialization, as well as enhanced neovascularization and granulation tissue formation by 7 days. The MSC-entrapped gelatin/poly(ethylene glycol) biomatrix localized the presentation of MSCs adjacent to the wound microenvironment and thus, mediated early resolution of inflammatory events and facilitated proliferative phases in wound healing. PMID:23811217

  13. Engineering Thiol-Ene Click Chemistry for the Fabrication of Novel Structurally Well-Defined Multifunctional Cyclodextrin Separation Materials for Enhanced Enantioseparation.

    PubMed

    Yao, Xiaobin; Zheng, Hao; Zhang, Yang; Ma, Xiaofei; Xiao, Yin; Wang, Yong

    2016-05-01

    The preparation of two novel multifunctional cyclodextrin (CD) separation materials and their ultimate enantioseparation performances in high performance liquid chromatography are reported. A mild thiol-ene click reaction was used to anchor 1-allylimidazolium-per(p-methyl)phenylcarbamoylated-β-CD and 1-allylimidazolium-per(p-chloride)phenylcarbamoylated-β-CD onto thiol-modified porous silica giving structurally well-defined stable cationic multifunctional CD chiral stationary phases (CSP1 and CSP2 respectively). These covalently bonded CD phases have typical interaction modes such as H-bonding, π-π effect, electrostatic and dipole-dipole interactions as well as steric effects which result in superior chiral resolution for a variety of chiral compounds in different separation modes. In a reverse-phase mode, both CSPs exhibited excellent separation abilities for isoxazolines, flavonoids, β-blockers, and some other neutral and basic racemates. In a polar-organic mode, isoxazolines and flavonoids were well resolved. CSP1 with an electron-rich phenyl substitution on the CD rims gave a better resolution for isoxazolines whereas CSP2 with an electron-deficient phenyl substitution on the CD rims gave better resolution for flavonoids. Among isoxazolines, 4ClPh-OPr gained a high selectivity and resolution up to 18.6 and 38.7, respectively, which is an amazing result for CD enantioseparation materials. PMID:27058612

  14. Facile "one-pot" synthesis of poly(methacrylic acid)-based hybrid monolith via thiol-ene click reaction for hydrophilic interaction chromatography.

    PubMed

    Lv, Xumei; Tan, Wangming; Chen, Ye; Chen, Yingzhuang; Ma, Ming; Chen, Bo; Yao, Shouzhuo

    2016-07-01

    A novel sol-gel "one-pot" approach in tandem with a radical-mediated thiol-ene reaction for the synthesis of a methacrylic acid-based hybrid monolith was developed. The polymerization monomers, tetramethoxysilane (TMOS) and 3-mercaptopropyl trimethoxysilane (MPTS), were hydrolyzed in high-concentration methacrylic acid solution that also served as a hydrophilic functional monomer. The resulting solution was then mixed with initiator (2, 2'-azobis (2-methylpropionamide) dihydrochloride) and porogen (urea, polyethylene glycol 20,000) in a capillary column and polymerized in water bath. The column had a uniform porous structure and a good permeability. The evaluation of the monolith was performed by separation of small molecules including nucleosides, phenols, amides, bases and Triton X-100. The calibration curves for uridine, inosine, adenosine and cytidine were determined. All the calibration curves exhibited good linear regressions (R(2)≥0.995) within the test ranges of 0.5-40μg/mL for four nucleosides. Additionaliy, atypical hydrophilic mechanism was proved by elution order from low to high according to polarity retention time increased with increases in the content of the organic solvent in the mobile phase. Further studies indicated that hydrogen bond and electrostatic interactions existed between the polar analytes and the stationary phase. This was the mechanism of retention. The excellent separation of the BSA digest showed good hydrophility of the column and indicated the potential in separation of complex biological samples. PMID:27264742

  15. A p-menth-1-ene-4,7-diol (EC-1) from Eucalyptus camaldulensis Dhnh. triggers apoptosis and cell cycle changes in Ehrlich ascites carcinoma cells.

    PubMed

    Islam, Farhadul; Khanam, Jahan Ara; Khatun, Mahbuba; Zuberi, Natasha; Khatun, Laboni; Kabir, Syed Rashel; Reza, Md Abu; Ali, M M; Rabbi, M A; Gopalan, Vinod; Lam, Alfred King-Yin

    2015-04-01

    Anticancer activities of p-menth-1-ene-4,7-diol (EC-1) isolated from Eucalyptus camaldulensis Dhnh. were studied on Ehrlich ascites carcinoma (EAC) cells by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. Anticancer activities also analyzed in EAC-bearing mice by assessment of cancer growth inhibition, changes in cancer volume, changes in life span, and hematological parameters. Apoptosis was analyzed by fluorescence microscope, DNA fragmentation assay, and flow cytometry. The expression of apoptosis-related genes, Bcl-2, Bcl-X, PARP-1, p53, and Bax, were analyzed using polymerase chain reaction (PCR). EC-1 significantly inhibited proliferation of EAC cells in vivo and restored the altered hematological parameters of EAC-bearing mice. Cytological observation by fluorescence microscope showed apoptosis of EAC cells upon treatment with EC-1. Also, DNA fragmentation assay revealed EAC cells' apoptosis following EC-1 treatment. Increased mRNA expressions of p53 and Bax genes and negative expressions of Bcl-2 and Bcl-X were observed in cells treated with EC-1. These findings confirmed the induction of apoptosis by EC-1. In addition, MTT assay showed dose-dependent anticancer activity of EC-1 against EAC cell. Cell cycle analysis revealed that EC-1 treatment caused suppression of EAC cells at S phase. To conclude, EC-1 is a novel anticancer compound and showed antiproliferative and apoptotic activities in cellular and mice models. PMID:25583285

  16. Photoinduced intramolecular charge transfer and photophysical characteristics of (2Z)-3-[4-(dimethylamino) phenyl]-2-(2-methylphenyl) prop-2-ene-nitrile (DPM) in different media

    NASA Astrophysics Data System (ADS)

    Asiri, Abdullah M.; El-Daly, Samy A.; Alamry, Khalid A.; Arshad, Muhammad Nadeem; Pannipara, Mehboobali

    2015-10-01

    A new fluorophore, (2Z)-3-[4-(dimethylamino) phenyl]-2-(2-methylphenyl) prop-2-ene-nitrile (DPM), was synthesized by knoevenagel condensation of 4-(dimethylamino) benzaldehyde and 2-methylbenzyl cyanide in ethanol using NaOH as base. The electronic absorption and emission characteristic of DPM was studied in different solvents. The X-ray crystallographic structure of DPM was also investigated. A crystalline solid of DPM gives a strong green emission at about 533 nm; these phenomena are important for the application of DPM dye in organic photo emitting diode. DPM exhibits a red shift in its emission spectrum as solvent polarity increases, indicating a large change in the dipole moment of dye molecule upon excitation due to intramolecular charge transfer in excited DPM*. The fluorescence quantum yield depends strongly on the properties of the solvents, which was attributed to positive and negative solvatokinetic effects. The DPM dye displays solubilization in cationic (CTAB) micelle and could be used as a probe to determine the critical micelle concentration (CMC) of CTAB.

  17. Identification and Structure-Activity Relationships of a Novel Series of Estrogen Receptor Ligands Based on 7-Thiabicyclo[2.2.1]hept-2-ene-7-oxide1

    PubMed Central

    Wang, Pengcheng; Min, Jian; Nwachukwu, Jerome C.; Cavett, Valerie; Carlson, Kathryn E.; Guo, Pu; Zhu, Manghong; Zheng, Yangfan; Dong, Chune; Katzenellenbogen, John A.; Nettles, Kendall W.; Zhou, Hai-Bing

    2012-01-01

    To develop estrogen receptor (ER) ligands having novel structures and activities, we have explored compounds in which the central hydrophobic core has a more three-dimensional topology than typically found in estrogen ligands and thus exploit the unfilled space in the ligand-binding pocket. Here, we build upon our previous investigations of 7-oxabicyclo[2.2.1]heptene core ligands, by replacing the oxygen bridge with a sulfoxide. These new 7-thiabicyclo[2.2.1]hept-2-ene-7-oxides were conveniently prepared by a Diels-Alder reaction of 3,4-diarylthiophenes with dienophiles in the presence of an oxidant and give cycloadducts with endo stereochemistry. Several new compounds demonstrated high binding affinities with excellent ERα selectivity, but unlike oxabicyclic compounds, which are transcriptional antagonists, most thiabicyclic compounds are potent, ERα-selective agonists. Modeling suggests that the gain in activity of the thiabicyclic compounds arises from their endo stereochemistry that stabilizes an active ER conformation. Further, the disposition of methyl substituents in the phenyl groups attached to the bicyclic core unit contribute to their binding affinity and subtype selectivity. PMID:22283328

  18. Enteroviruses harness the cellular endocytic machinery to remodel the host cell cholesterol landscape for effective viral replication

    PubMed Central

    Ilnytska, Olha; Santiana, Marianita; Hsu, Nai-Yun; Du, Wen-Li; Chen, Ying-Han; Viktorova, Ekaterina G.; Belov, Georgy; Brinker, Anita; Storch, Judith; Moore, Christopher; Dixon, Joseph L.; Altan-Bonnet, Nihal

    2013-01-01

    Cholesterol is a critical component of cellular membranes, regulating assembly and function of membrane-based protein/lipid complexes. Many RNA viruses, including enteroviruses, remodel host membranes to generate organelles with unique lipid blueprints on which they assemble replication complexes and synthesize viral RNA. Here we find that clathrin-mediated endocytosis (CME) is harnessed by enteroviruses to traffic cholesterol from the plasma membrane (PM) and extracellular medium to replication organelles where cholesterol then regulates viral polyprotein processing and facilitates genome synthesis. When CME is disrupted, cellular cholesterol pools are instead stored in lipid droplets; cholesterol cannot be trafficked to replication organelles; and replication is inhibited. In contrast, replication is stimulated in cholesterol-elevated cells like those lacking caveolins or those from Niemann-Pick disease patients. Our findings indicate cholesterol as a critical determinant for enteroviral replication and outline roles for the endocytic machinery in both the enteroviral lifecycle and host cell cholesterol homeostasis. PMID:24034614

  19. [Social marketers' lack of success in using CSM discipline to harness commercial resources and increase contraceptive prevalence].

    PubMed

    Davies, J

    1984-01-01

    Social marketers have certainly shown that the CSM discipline can quickly and cost-effectively harness commercial resources to increase contraceptive prevalence. But why hasn't the social marketing idea caught on in more countries? According to Social Marketing Forum, only a tiny number of countries have active programs after more than a decade of effort. The most likely reason for this lack of success is doubt and fear on the part of both developing countries' officials and donor agencies about allowing marketing enthusiasts--with our very noticeable advertising methods--to join the family planning fight. And what has our answer been? Usually, a head-on retort such as, "But look at all the condoms we've sold]" And that gets us nowhere, because the successful peddling of 1 not-so-impressive method doesn't begin to balance the fears of a possible backlash that brash condom promotions could bring down on official heads. The lesson we should be learning is that social marketers possess to narrow an outlook and promote a small range of products that don't enthuse decisionmakers. Hence, we are often perceived as condom salesmen--and not much more. What should we be doing? We should be selling the idea of using private sector experience to assist national development. That means social development, particularly improved health, family planning and women's education. These 3 activities have proven effective in reducing fertility and would add up to a marketing opportunity--a longterm challenge that should enthuse dicisionmakers, private sector entrepreneurs and donor agencies alike. Further, our model--the commercial sector--is renowned for branching out and secceeding in a broad range of endeavors. As an example, Procter and Gamble uses separate divisions to market different products. Initiatives already exist in many countries to harness the private sector as a development tool. Social marketers should be leading the initiative--and benefitting from it, too. PMID

  20. Heats of formation of [2.2]paracyclophane-1-ene and [2.2]paracyclophane-1,9-diene - an experimental study.

    PubMed

    de Meijere, Armin; Kozhushkov, Sergei I; Rauch, Karsten; Schill, Heiko; Verevkin, Sergey P; Kümmerlin, Martin; Beckhaus, Hans-Dieter; Rüchardt, Christoph; Yufit, Dmitrii S

    2003-12-10

    The enthalpies of formation [Delta(g)] of tricyclo[8.2.2.2(4,7)]hexadeca-1(13),2,4(16),5,7(15),10(14),11-heptaene (2, 1,2-dehydro[2.2]paracyclophane or [2.2]paracyclophane-1-ene) and tricyclo[8.2.2.2(4,7)]hexadeca-1(13),2,4(16),5,7(15),8,10(14),11-octaene (3, 1,2,9,10-dehydro[2.2]paracyclophane or [2.2]paracyclophane-1,9-diene) have been determined by measuring their heats of combustion in a microcalorimeter and their heats of sublimation by the transpiration method. Values of the strain energies (SE) [SE(2) = 34.7 kcal mol(-)(1), SE(3) = 42.0 kcal mol(-)(1)] have been derived from the gas-phase heats of formation and are compared with those from MM3 and PM3 calculations and with the corresponding value SE(1) = 30.1 kcal mol(-)(1) for the parent tricyclo[8.2.2.2(4,7)]hexadeca-1(13),4(16),5,7(15),10(14),11-hexaene (1, [2.2]paracyclophane). The higher strain energies of 2 and 3 (by 4.6 and 11.9 kcal mol(-)(1)) are in accord with the well-known increased reactivities of their aromatic rings as a consequence of their increased bending. As revealed by an X-ray crystal structure analysis, the bending in the monoene 2 corresponds to that of 1 and 3 at one of two bridging corners. PMID:14653746

  1. Why are chlorinated pollutants so difficult to degrade aerobically? Redox stress limits 1,3-dichloprop-1-ene metabolism by Pseudomonas pavonaceae

    PubMed Central

    Nikel, Pablo I.; Pérez-Pantoja, Danilo; de Lorenzo, Víctor

    2013-01-01

    Chlorinated pollutants are hardly biodegradable under oxic conditions, but they can often be metabolized by anaerobic bacteria through organohalide respiration reactions. In an attempt to identify bottlenecks limiting aerobic catabolism of 1,3-dichloroprop-1-ene (1,3-DCP; a widely used organohalide) in Pseudomonas pavonaceae, the possible physiological restrictions for this process were surveyed. Flow cytometry and a bioluminescence reporter of metabolic state revealed that cells treated with 1,3-DCP experienced an intense stress that could be traced to the endogenous production of reactive oxygen species (ROS) during the metabolism of the compound. Cells exposed to 1,3-DCP also manifested increased levels of d-glucose-6-P 1-dehydrogenase activity (G6PDH, an enzyme key to the synthesis of reduced NADPH), observed under both glycolytic and gluconeogenic growth regimes. The increase in G6PDH activity, as well as cellular hydroperoxide levels, correlated with the generation of ROS. Additionally, the high G6PDH activity was paralleled by the accumulation of d-glucose-6-P, suggesting a metabolic flux shift that favours the production of NADPH. Thus, G6PDH and its cognate substrate seem to play an important role in P. pavonaceae under redox stress caused by 1,3-DCP, probably by increasing the rate of NADPH turnover. The data suggest that oxidative stress associated with the biodegradation of 1,3-DCP reflects a significant barrier for the evolution of aerobic pathways for chlorinated compounds, thereby allowing for the emergence of anaerobic counterparts. PMID:23479756

  2. Occurrence of (Z)-3,4-Dideoxyglucoson-3-ene in Different Types of Beer and Malt Beer as a Result of 3-Deoxyhexosone Interconversion.

    PubMed

    Hellwig, Michael; Nobis, Arndt; Witte, Sophia; Henle, Thomas

    2016-04-01

    In beer, 3-deoxyglucosone (3-DG) and 3-deoxygalactosone (3-DGal) are important sugar degradation products, but little is known about the relevance of the interconversion reaction between these compounds in different types of beer. In the present study, 3-DG was quantitated at concentrations of 12.9-52.7 mg/L and 3-DGal at concentrations of 6.0-26.4 mg/L in different types of beer (pilsner, wheat, bock, dark, and alcohol-free beers). The concentrations in malt beer tended to be higher. Largely overlapping concentration ranges precluded a classification of beers by their 3-deoxyglycosone contents. 3,4-Dideoxyglucoson-3-ene (3,4-DGE) was identified as an important intermediate and quantitated in beer and malt beer for the first time. The E and Z isomers of the corresponding quinoxaline were synthesized by a new synthetic approach and isolated by semipreparative HPLC. An assay was developed for quantitation of (E)- and (Z)-3,4-DGE by HPLC-MS/MS, and the Z isomer was determined at concentrations of 0.3-1.7 mg/L in beer and 0.5-4.8 mg/L in malt beer samples. The E isomer was shown to be of little importance. Concentrations of 5-hydroxymethylfurfural (HMF) were twice as high as those of (Z)-3,4-DGE in beer samples (0.4-3.7 mg/L) but much higher in malt beer samples (1.6-336 mg/L). PMID:26984557

  3. Harness: Heterogeneous Adaptable Reconfigurable Networked Systems -- U.S. Department of Energy Grant DE-FG02-99ER25379 Final Project Report

    SciTech Connect

    Vaidy Sunderam

    2003-07-02

    Issues in reconfigurability and adaptability in heterogeneous distributed systems for high-performance computing are the focus of the work funded by this grant. Our efforts are part of an ongoing research project in metacomputing and are a follow on to the DOE funded PVM system that has witnessed over a decade of use at numerous institutions worldwide. The current project, termed Harness, investigates novel methodologies and tools for distributed metacomputing, focusing on dynamically reconfigurable software frameworks. During the first phase, we defined the metacomputing architecture embodied in Harness and developed prototype subsystems as proof of concept exercises. Subsequently, we designed and developed a complete software framework manifesting the Harness architecture, and also developed several tools and subsystems that demonstrated the viability and effectiveness of our proposed model for next generation metacomputing. We then used this substrate to emulate multiple programming environments on Harness, and conducted performance evaluation and tuning exercises. The main research results from these efforts include the establishment of software metacomputing systems as viable and cost-effective alternatives to MPPs; the demonstration of dynamic and reconfigurable platforms as effective methods of tailoring parallel computing environments; the development of methodologies to construct plugin modules for component-based distributed systems; contributions to performance modeling and optimization in emulated software environments; and software architectures for multi- and mixed-paradigm parallel distributed computing. Details and specifics on these and other results have been reported in numerous publications, and are manifested in software systems, all of which may be accessed at or via the website http://www.mathcs.emory.edu/harness/

  4. Design of thiol–ene photoclick hydrogels using facile techniques for cell culture applications† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c4bm00187g Click here for additional data file.

    PubMed Central

    Sawicki, Lisa A.

    2014-01-01

    Thiol–ene ‘click’ chemistries have been widely used in biomaterials applications, including drug delivery, tissue engineering, and controlled cell culture, owing to their rapid, cytocompatible, and often orthogonal reactivity. In particular, hydrogel-based biomaterials formed by photoinitiated thiol–ene reactions afford spatiotemporal control over the biochemical and biomechanical properties of the network for creating synthetic materials that mimic the extracellular matrix or enable controlled drug release. However, the use of charged peptides functionalized with cysteines, which can form disulfides prior to reaction, and vinyl monomers that require multistep syntheses and contain ester bonds, may lead to undesired inhomogeneity or degradation under cell culture conditions. Here, we designed a thiol–ene hydrogel formed by the reaction of allyloxycarbonyl-functionalized peptides and thiol-functionalized poly(ethylene glycol). Hydrogels were polymerized by free radical initiation under cytocompatible doses of long wavelength ultraviolet light in the presence of water-soluble photoinitiators (lithium acylphosphinate, LAP, and 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone, Irgacure 2959). Mechanical properties of these hydrogels were controlled by varying the monomer concentration to mimic a range of soft tissue environments, and hydrogel stability in cell culture medium was observed over weeks. Patterns of biochemical cues were created within the hydrogels post-formation and confirmed through the incorporation of fluorescently-labeled peptides and Ellman's assay to detect free thiols. Human mesenchymal stem cells remained viable after encapsulation and subsequent photopatterning, demonstrating the utility of the monomers and hydrogels for three-dimensional cell culture. This facile approach enables the formation and characterization of hydrogels with well-defined, spatially-specific properties and expands the suite of monomers available for

  5. Harnessing genomics to improve health in the Eastern Mediterranean Region – an executive course in genomics policy

    PubMed Central

    Acharya, Tara; Rab, Mohammed Abdur; Singer, Peter A; Daar, Abdallah S

    2005-01-01

    Background While innovations in medicine, science and technology have resulted in improved health and quality of life for many people, the benefits of modern medicine continue to elude millions of people in many parts of the world. To assess the potential of genomics to address health needs in EMR, the World Health Organization's Eastern Mediterranean Regional Office and the University of Toronto Joint Centre for Bioethics jointly organized a Genomics and Public Health Policy Executive Course, held September 20th–23rd, 2003, in Muscat, Oman. The 4-day course was sponsored by WHO-EMRO with additional support from the Canadian Program in Genomics and Global Health. The overall objective of the course was to collectively explore how to best harness genomics to improve health in the region. This article presents the course findings and recommendations for genomics policy in EMR. Methods The course brought together senior representatives from academia, biotechnology companies, regulatory bodies, media, voluntary, and legal organizations to engage in discussion. Topics covered included scientific advances in genomics, followed by innovations in business models, public sector perspectives, ethics, legal issues and national innovation systems. Results A set of recommendations, summarized below, was formulated for the Regional Office, the Member States and for individuals. • Advocacy for genomics and biotechnology for political leadership; • Networking between member states to share information, expertise, training, and regional cooperation in biotechnology; coordination of national surveys for assessment of health biotechnology innovation systems, science capacity, government policies, legislation and regulations, intellectual property policies, private sector activity; • Creation in each member country of an effective National Body on genomics, biotechnology and health to: - formulate national biotechnology strategies - raise biotechnology awareness - encourage

  6. Fire, Earth, Water, Iron: Harnessing the Elements to Study Nature's Most Elusive Elementary Particles (458th Brookhaven Lecture)

    SciTech Connect

    Bishai, Mary

    2010-06-30

    Scientists are harnessing the properties of immense natural powers to capture and learn more about one of the most minute particles ever known: the neutrino. Ghostlike neutrinos pour continuously in billions per second through the earth and everything on it, yet they interact so weakly with all other material that they pass almost without trace. Already, many years of experiments have yielded great discoveries about the neutrino. For example, there are three types: electron, tau, and muon neutrinos -- one for each generation of the lepton family of particles -- and they can oscillate, or change from one type to another. Yet deep mysteries remain. What is the mass of the electron neutrino? Could neutrino research shed light on the origin of the matter/anti-matter asymmetry in our Universe? Are there only three generations of leptons? Neutrinos come from many sources, including the fiery heart of the sun. She will describe how in a huge underground body of water in Super-Kamiokande, Japan, scientists proved that neutrinos from cosmic rays change from one type to another. She will also talk about her work with colleagues in ongoing experiments such as MINOS at the Fermi National Accelerator Laboratory in Illinois and the Soudan Mine, Minnesota, Daya Bay in China, and the planned Long Baseline Neutrino Experiment stretching between Fermilab and South Dakota, in which earth, iron and other elements play essential roles.

  7. Harnessing microbial gene pools to remediate persistent organic pollutants using genetically modified plants--a viable technology?

    PubMed

    Rylott, Elizabeth L; Johnston, Emily J; Bruce, Neil C

    2015-11-01

    It has been 14 years since the international community came together to legislate the Stockholm Convention on Persistent Organic Pollutants (POPs), restricting the production and use of specific chemicals that were found to be environmentally stable, often bioaccumulating, with long-term toxic effects. Efforts are continuing to remove these pollutants from the environment. While incineration and chemical treatment can be successful, these methods require the removal of tonnes of soil, at high cost, and are damaging to soil structure and microbial communities. The engineering of plants for in situ POP remediation has had highly promising results, and could be a more environmentally-friendly alternative. This review discusses the characterization of POP-degrading bacterial pathways, and how the genes responsible have been harnessed using genetic modification (GM) to introduce these same abilities into plants. Recent advances in multi-gene cloning, genome editing technologies and expression in monocot species are accelerating progress with remediation-applicable species. Examples include plants developed to degrade 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), trichloroethylene (TCE), and polychlorinated biphenyls (PCBs). However, the costs and timescales needed to gain regulatory approval, along with continued public opposition, are considerable. The benefits and challenges in this rapidly developing and promising field are discussed. PMID:26283045

  8. Functionally distinct NEAT (NEAr Transporter) domains within the Staphylococcus aureus IsdH/HarA protein extract heme from methemoglobin.

    PubMed

    Pilpa, Rosemarie M; Robson, Scott A; Villareal, Valerie A; Wong, Melissa L; Phillips, Martin; Clubb, Robert T

    2009-01-01

    The pathogen Staphylococcus aureus uses iron-regulated surface determinant (Isd) proteins to scavenge the essential nutrient iron from host hemoproteins. The IsdH protein (also known as HarA) is a receptor for hemoglobin (Hb), haptoglobin (Hp), and the Hb-Hp complex. It contains three NEAT (NEAr Transporter) domains: IsdH(N1), IsdH(N2), and IsdH(N3). Here we show that they have different functions; IsdH(N1) binds Hb and Hp, whereas IsdH(N3) captures heme that is released from Hb. The staphylococcal IsdB protein also functions as an Hb receptor. Primary sequence homology to IsdH indicates that it will also employ functionally distinct NEAT domains to bind heme and Hb. We have used site-directed mutagenesis and surface plasmon resonance methods to localize the Hp and Hb binding surface on IsdH(N1). High affinity binding to these structurally unrelated proteins requires residues located within a conserved aromatic motif that is positioned at the end of the beta-barrel structure. Interestingly, this site is quite malleable, as other NEAT domains use it to bind heme. We also demonstrate that the IsdC NEAT domain can capture heme directly from Hb, suggesting that there are multiple pathways for heme transfer across the cell wall. PMID:18984582

  9. Inspiration in the harness of daily labor. Darwin, botany, and the triumph of evolution, 1859-1868.

    PubMed

    Bellon, Richard

    2011-09-01

    Charles Darwin hoped that a large body of working naturalists would embrace evolution after the Origin of Species appeared in late 1859. He was disappointed. His evolutionary ideas at first made painfully little progress in the scientific community. But by 1863 the tide had turned dramatically, and within five years evolution became scientific orthodoxy in Britain. The Origin's reception followed this peculiar trajectory because Darwin had not initially tied its theory to productive original scientific investigation, which left him vulnerable to charges of reckless speculation. The debate changed with his successful application of evolution to original problems, most notably orchid fertilization, the subject of a well-received book in 1862. Most of Darwin's colleagues found the argument of the Origin convincing when they realized that it functioned productively in the day-to-day work of science-and not before. The conceptual force of the Origin, however outwardly persuasive, acquired full scientific legitimacy only when placed "in the harness of daily labour". PMID:22073768

  10. Cycloart-24-ene-26-ol-3-one, a New Cycloartane Isolated from Leaves of Aglaia exima Triggers Tumour Necrosis Factor-Receptor 1-Mediated Caspase-Dependent Apoptosis in Colon Cancer Cell Line

    PubMed Central

    Loong, Xe-Min; Cheah, Foo Kit; Supratman, Unang; Litaudon, Marc; Mustafa, Mohd Rais; Awang, Khalijah

    2016-01-01

    Plants in the Meliaceae family are known to possess interesting biological activities, such as antimalaral, antihypertensive and antitumour activities. Previously, our group reported the plant-derived compound cycloart-24-ene-26-ol-3-one isolated from the hexane extracts of Aglaia exima leaves, which shows cytotoxicity towards various cancer cell lines, in particular, colon cancer cell lines. In this report, we further demonstrate that cycloart-24-ene-26-ol-3-one, from here forth known as cycloartane, reduces the viability of the colon cancer cell lines HT-29 and CaCO-2 in a dose- and time-dependent manner. Further elucidation of the compound’s mechanism showed that it binds to tumour necrosis factor-receptor 1 (TNF-R1) leading to the initiation of caspase-8 and, through the activation of Bid, in the activation of caspase-9. This activity causes a reduction in mitochondrial membrane potential (MMP) and the release of cytochrome-C. The activation of caspase-8 and -9 both act to commit the cancer cells to apoptosis through downstream caspase-3/7 activation, PARP cleavage and the lack of NFkB translocation into the nucleus. A molecular docking study showed that the cycloartane binds to the receptor through a hydrophobic interaction with cysteine-96 and hydrogen bonds with lysine-75 and -132. The results show that further development of the cycloartane as an anti-cancer drug is worthwhile. PMID:27070314

  11. Sea floor topography and backscatter intensity of the Historic Area Remediation Site (HARS), offshore of New York, based on multibeam surveys conducted in 1996, 1998, and 2000

    USGS Publications Warehouse

    Butman, Bradford; Danforth, W.W.; Knowles, S.C.; May, Brian; Serrett, Laurie

    2000-01-01

    An area offshore of Sandy Hook, New Jersey, has been used extensively for disposal of dredged and other materials, derived from the New York/New Jersey Harbor and surrounding areas, since the late 1800's (Figure 1). Between 1976 and 1995, the New York Bight Dredged Material Disposal Site, also known as the Mud Dump Site (Figure 2), received on average about 6 million cubic yards of material each year from federal and private maintenance dredging and from harbor deepening activities (Massa and others, 1996). In September 1997 the Mud Dump Site (MDS) was closed as an official ocean disposal site by the U.S. Environmental Protection Agency (http://www.epa.gov/), and the MDS and surrounding areas were designated as the Historic Area Remediation Site (HARS). The HARS is subdivided into a Primary Remediation Area (PRA, subdivided into 9 cells), a Buffer Zone, and a No-Discharge Zone (Figure 2). The sea floor of the HARS, approximately 9 square nautical miles in area, is being remediated by placing at least a one-meter cap of Category I (clean) dredged material on top of the existing surface sediments that exhibit varying degrees of degradation. (See http://www.nan.usace.army.mil/business/prjlinks/dmmp/benefic/hars.htm)(Category I sediments have no potential short or long-term impacts and are acceptable for unrestricted ocean disposal (EPA, 1996)). About 1.1 million cubic yards of dredged material for remediation was placed in the HARS in 1999, and 2.5 million cubic yards in 2000. Three multibeam echosounder surveys were carried out to map the topography and surficial geology of the HARS. The surveys were conducted November 23 - December 3, 1996, October 26 - November 11, 1998, and April 6 - 30, 2000. The surveys were carried out as part of a larger survey of the Hudson Shelf Valley and adjacent shelf (Butman and others, 1998, (http://pubs.usgs.gov/openfile/of98-616/). This report presents maps showing topography, shaded relief, and backscatter intensity (a measure of sea

  12. A comparative evaluation of methicillin-resistant staphylococci isolated from harness racing-horses, breeding mares and riding-horses in Italy

    PubMed Central

    Mallardo, Karina; Nizza, Sandra; Fiorito, Filomena; Pagnini, Ugo; De Martino, Luisa

    2013-01-01

    Objective To investigate the prevalence of methicillin-resistant staphylococci (MRS) which is a potencial risk factor of transmission between animals and humans in different types of horses (harness racing-horses, breeding mares and riding-horses) and to compare the antimicrobial resistance of the isolates. Methods A total of 191 healthy horses, housed at different locations of the Campania Region (Italy), were included in the study. Nasal swab samples were collected from each nostril of the horses. The mecA gene was detected by a nested PCR technique. Antibiotic susceptibility was tested for each isolate. Results MRS was isolated from nasal samples of 68/191 (35.6%; 95% CI: 28.9%-42.9%) healthy horses. All isolates were coagulase-negative with the exception of two coagulase-positive MRS strains, identified as Staphylococcus aureus and Staphylococcus pseudintermedius, 2/83 (2.4%; 95% CI: 0.4%-9.2%). Interestingly, both coagulase-positive MRS isolates were from harness racing-horses. These horses also presented a significantly higher positivity for MRS (53.3%; 95% CI: 40.1%-66.1%) than the breeding mares and riding-horses groups. Antibiotic susceptibility testing showed difference between isolates due to different origins except for an almost common high resistance to aminopenicillins, such as ampicillin and amoxicillin. Conclusions It can be concluded that harness racing-horses may act as a significant reservoir of MRS as compared to breeding mares and riding-horses. PMID:23620832

  13. Paleoenvironmental significance of aluminum phosphate-sulfate minerals in the upper Cretaceous ooidal ironstones, E-NE Aswan area, southern Egypt

    NASA Astrophysics Data System (ADS)

    Salama, Walid

    2014-09-01

    Aluminum phosphate-sulfate (APS) minerals are present as small, disseminated crystals in the upper Cretaceous shallow marine ooidal ironstones, E-NE Aswan area, southern Egypt. Their association with the ironstones is considered as a proxy of subaerial weathering and post-diagenetic meteoric water alteration. The mineralogical composition of the ooidal ironstones was investigated by optical and scanning electron microscopes, X-ray diffraction, Fourier transform infrared and Raman spectroscopy. The ooidal ironstones are composed mainly of ooids and groundmass, both of which consist of a mixture of detrital (quartz) and diagenetic (fluorapatite, chamosite and pyrite) mineral assemblages. These mineral assemblages are destabilized under acidic and oxidizing, continental conditions. These conditions resulted from the oxidation of pyrite and probably organic matter under warm and humid, tropical climate followed the Santonian Sea regression and subaerial exposure. These pedogenic conditions promoted corrosion of quartz, dissolution of chamosite and apatite and hydrolysis of feldspars of the nearby exposed granitoids. The released Si, Al and Sr from quartz, chamosite and feldspars; Fe and S from pyrite and P, Ca and light rare earth elements (LREE) from apatite are reprecipitated as hematite, kaolinite, apatite and APS minerals from the pore fluids or along fractures. The paragenetic sequence and textural relationships of this post-diagenetic mineral assemblage indicate that hematite was formed by replacement of chamosite followed by formation of a secondary generation of pore filling chlorapatite and APS minerals and finally the precipitation of kaolinite in the remaining pore spaces. The formation of APS minerals and chlorapatite is simultaneous, but APS minerals are stable at shallow depths under acidic to neutral pH conditions, whereas chlorapatite is stable under alkaline pH conditions. Alkaline conditions were maintained at greater depths when the infiltrated

  14. Biological inspiration in optics and photonics: harnessing nature's light manipulation strategies for multifunctional optical materials (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kolle, Mathias; Sandt, Joseph D.; Nagelberg, Sara N.; Zarzar, Lauren D.; Kreysing, Moritz; Vukusic, Peter

    2016-03-01

    The precise control of light-matter interactions is crucial for the majority of known biological organisms in their struggle to survive. Many species have evolved unique methods to manipulate light in their environment using a variety of physical effects including pigment-induced, spectrally selective absorption or light interference in photonic structures that consist of micro- and nano-periodic material morphologies. In their optical performance, many of the known biological photonic systems are subject to selection criteria not unlike the requirements faced in the development of novel optical technology. For this reason, biological light manipulation strategies provide inspiration for the creation of tunable, stimuli-responsive, adaptive material platforms that will contribute to the development of multifunctional surfaces and innovative optical technology. Biomimetic and bio-inspired approaches for the manufacture of photonic systems rely on self-assembly and bottom-up growth techniques often combined with conventional top-down manufacturing. In this regard, we can benefit in several ways from highly sophisticated material solutions that have convergently evolved in various organisms. We explore design concepts found in biological photonic architectures, seek to understand the mechanisms underlying morphogenesis of bio-optical systems, aim to devise viable manufacturing strategies that can benefit from insight in biological formation processes and the use of established synthetic routines alike, and ultimately strive to realize new photonic materials with tailor-made optical properties. This talk is focused on the identification of biological role model photonic architectures, a brief discussion of recently developed bio-inspired photonic structures, including mechano-sensitive color-tunable photonic fibers and reconfigurable fluid micro-lenses. Potentially, early-stage results in studying and harnessing the structure-forming capabilities of living cells that

  15. Harnessing Online Peer Education (HOPE): Integrating C-POL and Social Media to Train Peer Leaders in HIV Prevention

    PubMed Central

    Jaganath, Devan; Gill, Harkiran K.; Cohen, Adam Carl; Young, Sean D.

    2011-01-01

    Novel methods, such as Internet-based interventions, are needed to combat the spread of HIV. While past initiatives have used the Internet to promote HIV prevention, the growing popularity, decreasing digital divide, and multi-functionality of social networking sites, such as Facebook, make this an ideal time to develop innovative ways to use online social networking sites to scale HIV prevention interventions among high-risk groups. The UCLA HOPE [Harnessing Online Peer Education] study is a longitudinal experimental study to evaluate the feasibility, acceptability, and preliminary effectiveness of using social media for peer-led HIV prevention, specifically among African American and Latino Men who have Sex with Men (MSM). No curriculum currently exists to train peer leaders in delivering culturally aware HIV prevention messages using social media. Training was created that adapted the Community Popular Opinion Leader (C-POL) model, for use on social networking sites. Peer leaders are recruited who represent the target population and have experience with both social media and community outreach. The curriculum contains the following elements: discussion and role playing exercises to integrate basic knowledge of HIV/AIDS, awareness of sociocultural HIV/AIDS issues in the age of technology, and communication methods for training peer leaders in effective, interactive social media-based HIV prevention. Ethical issues related to Facebook and health interventions are integrated throughout the sessions. Training outcomes have been developed for long-term assessment of retention and efficacy. This is the first C-POL curriculum that has been adapted for use on social networking websites. Although this curriculum has been used to target African American and Latino MSM, it has been created to allow generalization to other high-risk groups. PMID:22149081

  16. Harnessing Fluorine–Sulfur Contacts and Multipolar Interactions for the Design of p53 Mutant Y220C Rescue Drugs

    PubMed Central

    2016-01-01

    Many oncogenic mutants of the tumor suppressor p53 are conformationally unstable, including the frequently occurring Y220C mutant. We have previously developed several small-molecule stabilizers of this mutant. One of these molecules, PhiKan083, 1-(9-ethyl-9H-carbazole-3-yl)-N-methylmethanamine, binds to a mutation-induced surface crevice with a KD = 150 μM, thereby increasing the melting temperature of the protein and slowing its rate of aggregation. Incorporation of fluorine atoms into small molecule ligands can substantially improve binding affinity to their protein targets. We have, therefore, harnessed fluorine–protein interactions to improve the affinity of this ligand. Step-wise introduction of fluorines at the carbazole ethyl anchor, which is deeply buried within the binding site in the Y220C–PhiKan083 complex, led to a 5-fold increase in affinity for a 2,2,2-trifluoroethyl anchor (ligand efficiency of 0.3 kcal mol–1 atom–1). High-resolution crystal structures of the Y220C–ligand complexes combined with quantum chemical calculations revealed favorable interactions of the fluorines with protein backbone carbonyl groups (Leu145 and Trp146) and the sulfur of Cys220 at the mutation site. Affinity gains were, however, only achieved upon trifluorination, despite favorable interactions of the mono- and difluorinated anchors with the binding pocket, indicating a trade-off between energetically favorable protein–fluorine interactions and increased desolvation penalties. Taken together, the optimized carbazole scaffold provides a promising starting point for the development of high-affinity ligands to reactivate the tumor suppressor function of the p53 mutant Y220C in cancer cells. PMID:27267810

  17. Harnessing data structure for recovery of randomly missing structural vibration responses time history: Sparse representation versus low-rank structure

    NASA Astrophysics Data System (ADS)

    Yang, Yongchao; Nagarajaiah, Satish

    2016-06-01

    Randomly missing data of structural vibration responses time history often occurs in structural dynamics and health monitoring. For example, structural vibration responses are often corrupted by outliers or erroneous measurements due to sensor malfunction; in wireless sensing platforms, data loss during wireless communication is a common issue. Besides, to alleviate the wireless data sampling or communication burden, certain accounts of data are often discarded during sampling or before transmission. In these and other applications, recovery of the randomly missing structural vibration responses from the available, incomplete data, is essential for system identification and structural health monitoring; it is an ill-posed inverse problem, however. This paper explicitly harnesses the data structure itself-of the structural vibration responses-to address this (inverse) problem. What is relevant is an empirical, but often practically true, observation, that is, typically there are only few modes active in the structural vibration responses; hence a sparse representation (in frequency domain) of the single-channel data vector, or, a low-rank structure (by singular value decomposition) of the multi-channel data matrix. Exploiting such prior knowledge of data structure (intra-channel sparse or inter-channel low-rank), the new theories of ℓ1-minimization sparse recovery and nuclear-norm-minimization low-rank matrix completion enable recovery of the randomly missing or corrupted structural vibration response data. The performance of these two alternatives, in terms of recovery accuracy and computational time under different data missing rates, is investigated on a few structural vibration response data sets-the seismic responses of the super high-rise Canton Tower and the structural health monitoring accelerations of a real large-scale cable-stayed bridge. Encouraging results are obtained and the applicability and limitation of the presented methods are discussed.

  18. Harnessing and storing visible light using a heterojunction of WO3 and CdS for sunlight-free catalysis.

    PubMed

    Kim, Seonghun; Park, Yiseul; Kim, Wooyul; Park, Hyunwoong

    2016-08-01

    CdS and WO3 (CdS/WO3) bilayer film electrodes are fabricated to harness solar visible light (λ > 420 nm) and store photogenerated electrons for possible use during periods of unavailable sunlight. The overall film thickness is approximately 50-60 μm, while the CdS underlayer is slightly thinner than WO3 owing to a packing effect. The energetics of CdS and WO3 determined by optical and electrochemical analyses enables cascaded electron transfer from CdS to WO3. The open circuit potential (EOCP) of CdS/WO3 under visible light (approximately -0.35 V vs. SCE) is nearly maintained even in the absence of light, with a marginal decrease (∼0.15 V) in ∼20 h of darkness. Neither CdS nor WO3 alone exhibits such behavior. The electron lifetimes (τ) of CdS and WO3 are each less than 100 s, whereas coupling of the two increases τ to ∼2500 s at the EOCP. In the absence of dissolved O2, τ further increases, suggesting that O2 is the primary electron acceptor. In spite of oxic conditions, CdS/WO3 is capable of continuously reducing Cr(6+) to Cr(3+) and Ag(+) to Ag(0) after removal of visible light. The number of utilized (i.e., stored) electrons in the reductions of Cr(6+) and Ag(+) are estimated to be ∼1.08 × 10(17) and ∼0.87 × 10(17), respectively. The primary role of CdS is to be a visible-light absorber in the 420-565 nm wavelength range, transferring the photogenerated electrons to WO3. The electrons stored in WO3 are gradually released to electron acceptors with suitable redox potentials. PMID:27411566

  19. Harnessing Fluorine-Sulfur Contacts and Multipolar Interactions for the Design of p53 Mutant Y220C Rescue Drugs.

    PubMed

    Bauer, Matthias R; Jones, Rhiannon N; Baud, Matthias G J; Wilcken, Rainer; Boeckler, Frank M; Fersht, Alan R; Joerger, Andreas C; Spencer, John

    2016-08-19

    Many oncogenic mutants of the tumor suppressor p53 are conformationally unstable, including the frequently occurring Y220C mutant. We have previously developed several small-molecule stabilizers of this mutant. One of these molecules, PhiKan083, 1-(9-ethyl-9H-carbazole-3-yl)-N-methylmethanamine, binds to a mutation-induced surface crevice with a KD = 150 μM, thereby increasing the melting temperature of the protein and slowing its rate of aggregation. Incorporation of fluorine atoms into small molecule ligands can substantially improve binding affinity to their protein targets. We have, therefore, harnessed fluorine-protein interactions to improve the affinity of this ligand. Step-wise introduction of fluorines at the carbazole ethyl anchor, which is deeply buried within the binding site in the Y220C-PhiKan083 complex, led to a 5-fold increase in affinity for a 2,2,2-trifluoroethyl anchor (ligand efficiency of 0.3 kcal mol(-1) atom(-1)). High-resolution crystal structures of the Y220C-ligand complexes combined with quantum chemical calculations revealed favorable interactions of the fluorines with protein backbone carbonyl groups (Leu145 and Trp146) and the sulfur of Cys220 at the mutation site. Affinity gains were, however, only achieved upon trifluorination, despite favorable interactions of the mono- and difluorinated anchors with the binding pocket, indicating a trade-off between energetically favorable protein-fluorine interactions and increased desolvation penalties. Taken together, the optimized carbazole scaffold provides a promising starting point for the development of high-affinity ligands to reactivate the tumor suppressor function of the p53 mutant Y220C in cancer cells. PMID:27267810

  20. Harnessing the Risk-Related Data Supply Chain: An Information Architecture Approach to Enriching Human System Research and Operations Knowledge

    NASA Technical Reports Server (NTRS)

    Buquo, Lynn; Johnson-Throop, Kathy

    2010-01-01

    NASA's Human Research Program (HRP) and Space Life Sciences Directorate (SLSD), not unlike many NASA organizations today, struggle with the inherent inefficiencies caused by dependencies on heterogeneous data systems and silos of data and information spread across decentralized discipline domains. The capture of operational and research-based data/information (both in-flight and ground-based) in disparate IT systems impedes the extent to which that data/information can be efficiently and securely shared, analyzed, and enriched into knowledge that directly and more rapidly supports HRP's research-focused human system risk mitigation efforts and SLSD s operationally oriented risk management efforts. As a result, an integrated effort is underway to more fully understand and document how specific sets of risk-related data/information are generated and used and in what IT systems that data/information currently resides. By mapping the risk-related data flow from raw data to useable information and knowledge (think of it as the data supply chain), HRP and SLSD are building an information architecture plan to leverage their existing, shared IT infrastructure. In addition, it is important to create a centralized structured tool to represent risks including attributes such as likelihood, consequence, contributing factors, and the evidence supporting the information in all these fields. Representing the risks in this way enables reasoning about the risks, e.g. revisiting a risk assessment when a mitigation strategy is unavailable, updating a risk assessment when new information becomes available, etc. Such a system also provides a concise way to communicate the risks both within the organization as well as with collaborators. Understanding and, hence, harnessing the human system risk-related data supply chain enhances both organizations' abilities to securely collect, integrate, and share data assets that improve human system research and operations.

  1. Interleukin-15 Dendritic Cells Harness NK Cell Cytotoxic Effector Function in a Contact- and IL-15-Dependent Manner

    PubMed Central

    Van den Bergh, Johan; Willemen, Yannick; Goossens, Herman; Van Tendeloo, Viggo F.; Smits, Evelien L.; Berneman, Zwi N.; Lion, Eva

    2015-01-01

    The contribution of natural killer (NK) cells to the treatment efficacy of dendritic cell (DC)-based cancer vaccines is being increasingly recognized. Much current efforts to optimize this form of immunotherapy are therefore geared towards harnessing the NK cell-stimulatory ability of DCs. In this study, we investigated whether generation of human monocyte-derived DCs with interleukin (IL)-15 followed by activation with a Toll-like receptor stimulus endows these DCs, commonly referred to as “IL-15 DCs”, with the capacity to stimulate NK cells. In a head-to-head comparison with “IL-4 DCs” used routinely for clinical studies, IL-15 DCs were found to induce a more activated, cytotoxic effector phenotype in NK cells, in particular in the CD56bright NK cell subset. With the exception of GM-CSF, no significant enhancement of cytokine/chemokine secretion was observed following co-culture of NK cells with IL-15 DCs. IL-15 DCs, but not IL-4 DCs, promoted NK cell tumoricidal activity towards both NK-sensitive and NK-resistant targets. This effect was found to require cell-to-cell contact and to be mediated by DC surface-bound IL-15. This study shows that DCs can express a membrane-bound form of IL-15 through which they enhance NK cell cytotoxic function. The observed lack of membrane-bound IL-15 on “gold-standard” IL-4 DCs and their consequent inability to effectively promote NK cell cytotoxicity may have important implications for the future design of DC-based cancer vaccine studies. PMID:25951230

  2. Harnessing the Community.

    ERIC Educational Resources Information Center

    O'Reilly, Robert R.; And Others

    The Willow Creek School Division in southern Alberta (Canada) invited leaders of various community agencies to serve on a task force to examine how changes in the local society were affecting children. The division serves approximately 2,700 rural-based students in several small rural communities. The task force was composed of the leaders of a…

  3. Harnessing natural ventilation benefits.

    PubMed

    O'Leary, John

    2013-04-01

    Making sure that a healthcare establishment has a good supply of clean fresh air is an important factor in keeping patients, staff, and visitors, free from the negative effects of CO2 and other contaminants. John O'Leary of Trend Controls, a major international supplier of building energy management solutions (BEMS), examines the growing use of natural ventilation, and the health, energy-saving, and financial benefits, that it offers. PMID:23678661

  4. A new series of bis(ene-1,2-dithiolato)tungsten(IV), -(V), -(VI) complexes as reaction centre models of tungsten enzymes: preparation, crystal structures and spectroscopic properties.

    PubMed

    Sugimoto, Hideki; Hatakeda, Kohei; Toyota, Kazuo; Tatemoto, Susumu; Kubo, Minoru; Ogura, Takashi; Itoh, Shinobu

    2013-03-01

    The carbomethoxy substituted dithiolene ligand (L(COOMe)) enabled us to develop a series of new bis(ene-1,2-dithiolato)tungsten complexes including W(IV)O, W(IV)(OSiBuPh(2)), W(VI)O(2), W(VI)O(OSiBuPh(2)) and W(VI)O(S) core structures. By using these tungsten complexes, a systematic study of the terminal monodentate ligand effects has been performed on the structural, spectroscopic properties and reactivity. The structure and spectroscopic properties of the tungsten complexes have also been compared to those of the molybdenum complexes coordinated by the same ligand to investigate the effects of the metal ion (W vs. Mo). X-ray crystallographic analyses of the tungsten(IV) complexes have revealed that the tungsten centres adopt a distorted square pyramidal geometry with a dithiolene ligand having an ene-1,2-dithiolate form. On the other hand, the dioxotungsten(VI) complex exhibits an octahedral structure consisting of the bidentate L(COOMe) and two oxo groups, in which π-delocalization was observed between the W(VI)O(2) and ene-1,2-dithiolate units. The tungsten(IV) and dioxotungsten(VI) complexes are isostructural with the molybdenum counter parts. DFT calculation study of the W(VI)O(S) complex has indicated that the W=S bond of 2.2 Å is close to the bond length between the tungsten centre and ambiguously assigned terminal monodentate atom in aldehyde oxidoreductase of the tungsten enzyme. Resonance Raman (rR) spectrum of the W(VI)O(S) complex has shown the two inequivalent L(COOMe) ligands with respect to their bonding interactions with the tungsten centre, reproducing the appearance of two ν(C=C) stretches in the rR spectrum of aldehyde oxidoreductase. Sulfur atom transfer reaction from the W(VI)O(S) complex to triphenylphosphines has also been studied kinetically to demonstrate that the tungsten complex has a lower reactivity by about one-order of magnitude, when compared with its molybdenum counterpart. PMID:23160484

  5. Crystal structure of 5''-benzyl-idene-1'-methyl-4'-phenyl-tri-spiro-[ace-naphthyl-ene-1,2'-pyrrolidine-3',1''-cyclo-hexane-3'',2'''-[1,3]dioxane]-2,6''-dione.

    PubMed

    Chandralekha, Kuppan; Gavaskar, Deivasigamani; Sureshbabu, Adukamparai Rajukrishnan; Lakshmi, Srinivasakannan

    2016-03-01

    In the title compound, C36H31NO4, two spiro links connect the methyl-substituted pyrrolidine ring to the ace-naphthyl-ene and cyclo-hexa-none rings. The cyclo-hexa-none ring is further connected to the dioxalane ring by a third spiro junction. The five-membered ring of the ace-naphthylen-1-one ring system adopts a flattened envelope conformation with the ketonic C atom as flap, whereas the dioxalane and pyrrolidine rings each have a twist conformation. The cyclo-hexa-none ring assumes a boat conformation. Three intra-molecular C-H⋯O hydrogen bonds involving both ketonic O atoms as acceptors are present. In the crystal, C-H⋯O hydrogen bonds connect centrosymmetrically related mol-ecule into chains parallel to the b axis, forming rings of R 2 (2)(10)and R 2 (2)(8) graph-set motifs. PMID:27006814

  6. Transformations of the molecular complex of hydroiodide of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene and 5,5‧-dibromo-2,2‧-biphenol between crystal and solutions

    NASA Astrophysics Data System (ADS)

    Wojciechowski, Grzegorz; Ratajczak-Sitarz, Małgorzata; Katrusiak, Andrzej; Brzezinski, Bogumil

    2005-05-01

    A complex of 5,5'-dibromo-2,2'-biphenol with 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene hydroiodide has been studied by X-ray diffraction, FT-IR, and 1HNMR spectroscopy. In the crystal structure, the iodide anion is hydrogen-bonded to the MTBDH + cation and to two hydroxyl groups of two 5,5'-dibromo-2,2'-biphenol molecules. In chloroform and acetonitrile the structure of the complex assumes a new structure due to almost complete dissociation of the protonated MTBD molecule. In chloroform the MTBDH + cation is hydrogen bonded to 5,5'-dibromo-2,2'-biphenol whereas in acetonitrile it is free and solvated by the solvent. In both cases the 5,5'-dibromo-2,2'-biphenol molecule is hydrogen bonded to the iodide anion. In chloroform the iodide ion interacts strongly with the solvent.

  7. Hydroxylation of DHEA, androstenediol and epiandrosterone by Mortierella isabellina AM212. Evidence indicating that both constitutive and inducible hydroxylases catalyze 7α- as well as 7β-hydroxylations of 5-ene substrates.

    PubMed

    Kołek, Teresa; Milecka, Natalia; Świzdor, Alina; Panek, Anna; Białońska, Agata

    2011-08-01

    The course of transformation of DHEA, androstenediol and epiandrosterone in Mortierella isabellina AM212 culture was investigated. The mentioned substrates underwent effective hydroxylation; 5-ene substrates--DHEA and androstenediol--were transformed into a mixture of 7α- and 7β- allyl alcohols, while epiandrosterone was converted into 7α- (mainly), 11α- and 9α- monohydroxy derivatives. Ketoconazole and cycloheximide inhibition studies suggest the presence of constitutive and substrate-induced hydroxylases in M. isabellina. On the basis of time course analysis of the hydroxylation of DHEA and androstenediol, the oxidation of allyl C(7)-H(α) and C(7)-H(β) bonds by the same enzyme is a reasonable assumption. PMID:21655574

  8. 6 alpha-Fluoro- and 6 alpha,9 alpha-difluoro-11 beta,21-dihydroxy-16 alpha,17 alpha-propylmethylenedioxypregn-4-ene-3,20-dione: synthesis and evaluation of activity and kinetics of their C-22 epimers.

    PubMed

    Thalén, B A; Axelsson, B I; Andersson, P H; Brattsand, R L; Nylander, B; Wickström, L I

    1998-01-01

    It is generally accepted that the anti-inflammatory effect of glucocorticosteroids cannot be separated from their adverse effects at the receptor level. However, modification of the pharmacokinetics through structural alterations could provide steroids with a better therapeutic index than those currently used. Thus, new 16 alpha,17 alpha-acetals between butyraldehyde and 6 alpha-fluoro- or 6 alpha,9 alpha-difluoro-16 alpha-hydroxycortisol were synthesized and studied. Acetalization of the corresponding 16 alpha,17 alpha-diols or transacetalization of their 16 alpha,17 alpha-acetonides in dioxane produced mixtures of C-22 epimers, which were resolved by preparative chromatography. Alternatively, an efficient method was used to produce the 22R-epimer stereoselectively through performing the acetalization and transacetalization in a hydrocarbon with an inert material present. The C-22 configuration of (22R)-6 alpha,9 alpha-difluoro-11 beta,21-dihydroxy-16 alpha,17 alpha-propylmethylenedioxypregn-4-ene-3,20-dione was unambiguously established by single crystal X-ray diffraction. The present compounds, especially the 22R-epimer just mentioned, bind to the rat thymus glucocorticoid receptor with high potency. The C-22 epimers of the 6 alpha,9 alpha-difluoro derivatives showed a 10-fold higher biotransformation rate than the budesonide 22R-epimer when incubated with human liver S9 subcellular fraction. The high receptor affinity in combination with the high biotransformation rate indicates that (22R)-6 alpha,9 alpha-difluoro-11 beta,21-dihydroxy-16 alpha,17 alpha-propylmethylenedioxypregn-4-ene-3,20-dione may be an improved 16 alpha,17 alpha-acetal glucocorticosteroid for therapy of inflammatory diseases, in which the mucous membranes are involved, such as those in the intestinal tract as well in the respiratory tract. PMID:9437793

  9. Further development of the pneumatic method to harness hydropower and its experimental implementation in the State of Maine. Final report, [February 15, 1990--February 14, 1993

    SciTech Connect

    Gorlov, A.M.

    1994-03-01

    This report contains conclusive results of the research project entitled ``Further Development of the Pneumatic Method to Harness Hydropower and its Experimental Implementation in the State of Maine`` sponsored by the US Department of Energy (Contract DE-FG02-91ER12113). The results obtained by this research are considerably beyond the original goals anticipated by the contract which were a theoretical study of the method only and its possible applications. In fact, the success of the analytical research program has allowed us to move on to development, construction and testing of a physical model of the hydro-air power converter and, subsequently, to development of a well equipped hydro-pneumatic power laboratory at Northeastern University. Photographs la and 2a show both the laboratory and the model. Good performance of the model proves that the hydro-pneumatic concept holds much promise for development of an ecologically safe and commercially attractive novel approach to harnessing ultra low-head hydropower. As a result, private companies have started to support this new technology, and to invest money in its further development and construction of demonstration power plants (Appendix 1). Visitors at the Northeastern University laboratory often praise this new technique, as is attested by the articles in the Wall Street Journal (Appendix 2) and the Technology Review (Appendix 3).

  10. Solution structure of the NEAT (NEAr Transporter) domain from IsdH/HarA: the human hemoglobin receptor in Staphylococcus aureus.

    PubMed

    Pilpa, Rosemarie M; Fadeev, Evgeny A; Villareal, Valerie A; Wong, Melissa L; Phillips, Martin; Clubb, Robert T

    2006-07-01

    During infections the pathogen Staphylococcus aureus procures the essential nutrient iron from its host using iron-regulated surface determinant (Isd) proteins, which scavenge heme bound iron from host hemoproteins. Four Isd proteins are displayed in the cell wall, where they function as receptors for host proteins and heme. Each of the receptors contains one or more copies of a recently discovered domain called NEAT (NEAr Transporter) that has been shown to mediate protein binding. Here we report the three-dimensional solution structure of the NEAT domain from the IsdH/HarA protein, which is the hemoglobin receptor in the Isd system. This is the first structure of a NEAT domain and reveals that they adopt a beta sandwich fold that consists of two five-stranded antiparallel beta sheets. Although unrelated at the primary sequence level, our results indicate that NEAT domains belong to the immunoglobulin superfamily. Binding studies indicate that two IsdH/HarA NEAT domains bind a single molecule of methemoglobin, while the distantly related NEAT domain from the S. aureus IsdC protein binds only heme. A comparison of their primary sequences in light of the new structure is used to predict the hemoglobin and heme binding surfaces on NEAT domains. PMID:16762363

  11. Cryogenic on-orbit liquid depot storage acquisition and transfer (COLD-SAT) experiment subsystem instrumentation and wire harness design report

    NASA Technical Reports Server (NTRS)

    Edwards, Lawrence G.

    1994-01-01

    Subcritical cryogens such as liquid hydrogen (LH2) and liquid oxygen (LO2) are required for space based transportation propellant, reactant, and life support systems. Future long-duration space missions will require on-orbit systems capable of long-term cryogen storage and efficient fluid transfer capabilities. COLD-SAT, which stands for cryogenic orbiting liquid depot-storage acquisition and transfer, is a free-flying liquid hydrogen management flight experiment. Experiments to determine optimum methods of fluid storage and transfer will be performed on the COLD-SAT mission. The success of the mission is directly related to the type and accuracy of measurements made. The instrumentation and measurement techniques used are therefore critical to the success of the mission. This paper presents the results of the COLD-SAT experiment subsystem instrumentation and wire harness design effort. Candidate transducers capable of fulfilling the COLD-SAT experiment measurement requirements are identified. Signal conditioning techniques, data acquisition requirements, and measurement uncertainty analysis are presented. Electrical harnessing materials and wiring techniques for the instrumentation designed to minimize heat conduction to the cryogenic tanks and provide optimum measurement accuracy are listed.

  12. Rhodium-catalyzed [5 + 2 + 1] cycloaddition of ene-vinylcyclopropanes and CO: reaction design, development, application in natural product synthesis, and inspiration for developing new reactions for synthesis of eight-membered carbocycles.

    PubMed

    Wang, Yi; Yu, Zhi-Xiang

    2015-08-18

    Practical syntheses of natural products and their analogues with eight-membered carbocyclic skeletons are important for medicinal and biological investigations. However, methods and strategies to construct the eight-membered carbocycles are limited. Therefore, developing new methods to synthesize the eight-membered carbocycles is highly desired. In this Account, we describe our development of three rhodium-catalyzed cycloadditions for the construction of the eight-membered carbocycles, which have great potential in addressing the challenges in the synthesis of medium-sized ring systems. The first reaction described in this Account is our computationally designed rhodium-catalyzed two-component [5 + 2 + 1] cycloaddition of ene-vinylcyclopropanes (ene-VCPs) and CO for the diastereoselective construction of bi- and tricyclic cyclooctenones. The design of this reaction is based on the hypothesis that the C(sp(3))-C(sp(3)) reductive elimination of the eight-membered rhodacycle intermediate generated from the rhodium-catalyzed cyclopropane cleavage and alkene insertion, giving Wender's [5 + 2] cycloadduct, is not easy. Under CO atmosphere, CO insertion may occur rapidly, converting the eight-membered rhodacycle into a nine-membered rhodacycle, which then undergoes an easy C(sp(2))-C(sp(3)) reductive elimination process and furnishes the [5 + 2 + 1] product. This hypothesis was supported by our preliminary DFT studies and also served as inspiration for the development of two [7 + 1] cycloadditions: the [7 + 1] cycloaddition of buta-1,3-dienylcyclopropanes (BDCPs) and CO for the construction of cyclooctadienones, and the benzo/[7 + 1] cycloaddition of cyclopropyl-benzocyclobutenes (CP-BCBs) and CO to synthesize the benzocyclooctenones. The efficiency of these rhodium-catalyzed cycloadditions can be revealed by the application in natural product synthesis. Two eight-membered ring-containing natural products, (±)-asterisca-3(15),6-diene and (+)-asteriscanolide, have been

  13. Probabilistic Modeling of High-Temperature Material Properties of a 5-Harness 0/90 Sylramic Fiber/ CVI-SiC/ MI-SiC Woven Composite

    NASA Technical Reports Server (NTRS)

    Nagpal, Vinod K.; Tong, Michael; Murthy, P. L. N.; Mital, Subodh

    1998-01-01

    An integrated probabilistic approach has been developed to assess composites for high temperature applications. This approach was used to determine thermal and mechanical properties and their probabilistic distributions of a 5-harness 0/90 Sylramic fiber/CVI-SiC/Mi-SiC woven Ceramic Matrix Composite (CMC) at high temperatures. The purpose of developing this approach was to generate quantitative probabilistic information on this CMC to help complete the evaluation for its potential application for HSCT combustor liner. This approach quantified the influences of uncertainties inherent in constituent properties called primitive variables on selected key response variables of the CMC at 2200 F. The quantitative information is presented in the form of Cumulative Density Functions (CDFs). Probability Density Functions (PDFS) and primitive variable sensitivities on response. Results indicate that the scatters in response variables were reduced by 30-50% when the uncertainties in the primitive variables, which showed the most influence, were reduced by 50%.

  14. A Phenylbutenoid Dimer, cis-3-(3',4'-Dimethoxyphenyl)-4-[(E)-3''',4'''-Dimethoxystyryl] Cyclohex-1-ene, Exhibits Apoptogenic Properties in T-Acute Lymphoblastic Leukemia Cells via Induction of p53-Independent Mitochondrial Signalling Pathway.

    PubMed

    Anasamy, Theebaa; Abdul, Ahmad Bustamam; Sukari, Mohd Aspollah; Abdelwahab, Siddig Ibrahim; Mohan, Syam; Kamalidehghan, Behnam; Azid, Mohd Zulkhairi; Muhammad Nadzri, Nabilah; Andas, A Reenaa Joys; Kuan Beng, Ng; Hadi, A Hamid A; Sulaiman Rahman, Heshu

    2013-01-01

    The current study was designed to evaluate the in vitro cytotoxicity effect of a phenylbutenoid dimer, cis-3-(3',4'-dimethoxyphenyl)-4-[(E)-3 (‴) ,4 (‴) -dimethoxystyryl]cyclohex-1-ene (ZC-B11) isolated from the rhizome of Zingiber cassumunar on various cancer cell line, and normal human blood mononuclear cells, and to further investigate the involvement of apoptosis-related proteins that leads, to the probable pathway in which apoptosis is triggered. Cytotoxicity test using MTT assay showed selective inhibition of ZC-B11 towards T-acute lymphoblastic leukemia cells, CEMss, with an IC50 value of 7.11 ± 0.240  μ g/mL, which did not reveal cytotoxic effects towards normal human blood mononuclear cells (IC50 > 50  μ g/mL). Morphology assessments demonstrated distinctive morphological changes corresponding to a typical apoptosis. ZC-B11 also arrested cell cycle progression at S phase and causes DNA fragmentation in CEMss cells. Decline of mitochondrial membrane potential was also determined qualitatively. In the apoptosis-related protein determination, ZC-B11 was found to significantly upregulate Bax, caspase 3/7, caspase 9, cytochrome c, and SMAC and downregulate Bcl-2, HSP70, and XIAP, but did not affect caspase 8, p53, and BID. These results demonstrated for the first time the apoptogenic property of ZC-B11 on CEMss cell line, leading to the programmed cell death via intrinsic mitochondrial pathway of apoptosis induction. PMID:23710242

  15. N-O Chemistry for Antibiotics: Discovery of N-Alkyl-N-(pyridin-2-yl)hydroxylamine Scaffolds as Selective Antibacterial Agents Using Nitroso Diels-Alder and Ene Chemistry

    PubMed Central

    Wencewicz, Timothy A.; Yang, Baiyuan; Rudloff, James R.; Oliver, Allen G.; Miller, Marvin J.

    2011-01-01

    The discovery, syntheses, and structure-activity relationships (SAR) of a new family of heterocyclic antibacterial compounds based on N-alkyl-N-(pyridin-2-yl)hydroxylamine scaffolds are described. A structurally diverse library of ~100 heterocyclic molecules generated from Lewis acid-mediated nucleophilic ring opening reactions with nitroso Diels-Alder cycloadducts and nitroso ene reactions with substituted alkenes was evaluated in whole cell antibacterial assays. Compounds containing the N-alkyl-N-(pyridin-2-yl)hydroxylamine structure demonstrated selective and potent antibacterial activity against the Gram-positive bacterium Micrococcus luteus ATCC 10240 (MIC90 = 2.0 μM or 0.41 μg/mL) and moderate activity against other Gram-positive strains including antibiotic resistant strains of Staphylococcus aureus (MRSA) and Enterococcus faecalis (VRE). A new synthetic route to the active core was developed using palladium-catalyzed Buchwald-Hartwig amination reactions of N-alkyl-O-(4-methoxybenzyl)hydroxylamines with 2-halo-pyridines that facilitated SAR studies and revealed the simplest active structural fragment. This work shows the value of using a combination of diversity-oriented synthesis (DOS) and parallel synthesis for identifying new antibacterial scaffolds. PMID:21859126

  16. Regioselective synthesis and molecular modeling study of vasorelaxant active 7,9-dioxa-1,2-diaza-spiro[4.5]dec-2-ene-6,10-diones.

    PubMed

    Girgis, Adel S; Ismail, Nasser S M; Farag, Hanaa; el-Eraky, Wafaa I; Saleh, Dalia O; Tala, Srinivasa R; Katritzky, Alan R

    2010-09-01

    Nitrilimines (PhC(-):N(+):NR') generated in situ from hydrazonoyl chlorides 2a,b reacted regioselectively with 5-arylidene-2,2-dimethyl[1,3]dioxane-4,6-diones 1a-f to afford 1,3,4-triaryl-8,8-dimethyl-7,9-dioxa-1,2-diaza-spiro[4.5]dec-2-ene-6,10-diones 3a-l. In vitro vasodilation activity screening of the synthesized compounds using isolated thoracic aortic rings of male Wister rats pre-contracted with norepinephrine hydrochloride revealed considerable vasodilation activity; compounds 3f and 3j had IC(50) (concentration necessary for 50% reduction of maximal norepinephrine hydrochloride induced contracture) of 0.325, 0.321 mM, respectively. Molecular modeling, including fitting to a 3D-pharmacophore model using Discovery studio 2.1 programs and their docking into optimized alpha(1)-AR homology models as alpha(1)-AR antagonist showed high-docking score and fit values. The experimental in vitro vasodilation activity of compounds 3a-l was consistent with the molecular modeling. PMID:20615586

  17. Vibrational spectroscopy investigation using ab initio and density functional theory analysis on the structure of 5-chloro-10-oxa-3-thia-tricyclo[5.2.1.0 1,5]dec-8-ene-3,3-dioxide

    NASA Astrophysics Data System (ADS)

    Arslan, Hakan; Demircan, Aydın; Göktürk, Ersen

    2008-01-01

    The IR spectra of 5-chloro-10-oxa-3-thia-tricyclo[5.2.1.0 1,5]dec-8-ene-3,3-dioxide (COTDO) has been recorded in the region 4000-525 cm -1. The optimized molecular geometry, frequency and intensity of the vibrational bands of COTDO in the ground state has been calculated using the Hartree-Fock and density functional using Becke's three-parameter hybrid method with the Lee, Yang, and Parr correlation functional methods with 6-31G(d,p) and 6-311G(d,p) basis sets. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental IR spectra. The calculated geometrical parameters and harmonic vibrations are predicted in a very good agreement with the experimental data. The theoretical vibrational spectra of the title compound were interpreted by means of potential energy distributions (PEDs) using VEDA 4 program. With the help of this modern technique we were able to complete the assignment of the vibrational spectra of the title compound.

  18. Cooperative hydrogen-bonded chain in molecular ionic complex of 5,5'-dibromo-2,2'-biphenol with 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene hydrofluoride

    NASA Astrophysics Data System (ADS)

    Wojciechowski, Grzegorz; Ratajczak-Sitarz, Małgorzata; Katrusiak, Andrzej; Brzezinski, Bogumil

    2002-08-01

    A complex of 5,5'-dibromo-2,2'-biphenol (DBBPh) with 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) hydrofluoride has been studied using X-ray diffraction, FT-IR, and 1H NMR spectroscopy. The formula unit of the crystal structure consists of a MTBDH + cation, a fluoride anion, and one neutral molecule of 5,5'-dibromo-2,2'-biphenol. In the solid state the F - anion is an acceptor in two very short O-H⋯F - intermolecular hydrogen bonds of 2.487 and 2.390 Å involving the hydroxyl groups. One oxygen atom of these groups forms also an N +-H⋯O intermolecular hydrogen bond of 2.775 Å with the MTBDH + cation. In chloroform and acetonitrile, the structures of the complexes are comparable with those studied previously for 5,5'-dibromo-2,2'-biphenol with MTBD, because the hydrogen fluoride goes into the gas phase during the solution process.

  19. Structural, spectroscopic and theoretical studies of the 2:2 complex of 5,5'-dibromo-2,2'-biphenol with 1,5,7-triazabicyclo[4.4.0]dec-5-ene

    NASA Astrophysics Data System (ADS)

    Wojciechowski, G.; Brzezinski, B.; Naumov, P.; Chantrapromma, S.; Ibrahim, A. R.; Fun, H.-K.; Ng, S. W.

    2001-12-01

    In the crystal of the 2:2 complex of 1,5,7-triazabicyclo[4.4.0]dec-5-ene with 5,5'-dibromo-2,2'-biphenol a cooperative inter-intra-molecular hydrogen-bonded system is formed. The intermolecular hydrogen bonds are relatively long [2.708(6) and 2.895(7)] and do not show large proton polarizability. The intramolecular OHO - hydrogen bond is relatively short [2.489(6)]. The structure of the complex is very well reflected in its FT-IR spectrum in the solid. On the basis of the FT-IR and 1H NMR studies of the complex in chloroform and in acetonitrile a structure different than in the solid is proposed. DFT structures of both isolated ions in their ground electronic states at the B3LYP/6-31++G(d,p) level are employed to follow the effects of the hydrogen bonding on the intrinsic ionic structures.

  20. Crystal and molecular structure of a complex formed between the hydrochloride of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene and 5,5'-dibromo-2,2'-biphenol

    NASA Astrophysics Data System (ADS)

    Bartoszak-Adamska, E.; Wojciechowski, G.; Jaskólski, M.; Brzezinski, B.

    2001-09-01

    A complex of 5,5'-dibromo-2,2'-biphenol with 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) hydrochloride has been studied using X-ray diffraction, FT-IR, and 1H NMR spectroscopy. The compound crystallises in the space group P2 1/ c with a=9.738(2), b=12.100(2), c=18.347(4) Å, β=92.62(3)° (at 100 K), and Z=4. In the crystal structure, the MTBDH + cation, a chloride anion, and one molecule of 5,5'-dibromo-2,2'-biphenol are present. In the solid state the Cl - anion is an acceptor in N +-H⋯Cl -, O-H⋯Cl - and C-H⋯Cl - intermolecular hydrogen bonds. In chloroform the structure of the complex is comparable with that in the solid, whereas in acetonitryle the complex assumes a new structure owing to the almost complete dissociation of the protonated MTBD molecule. The 5,5'-dibromo-2,2'-biphenol molecule is hydrogen-bonded with the chloride anion. Within this complex the OH⋯OH hydrogen bond shows very large proton polarisability indicated by the continuous absorption in the FTIR spectrum.

  1. Molecular structure of a complex formed between hydrobromide of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene and 5,5'-dibromo-2,2'-biphenol in crystal and solutions

    NASA Astrophysics Data System (ADS)

    Wojciechowski, Grzegorz; Ratajczak-Sitarz, Małgorzata; Katrusiak, Andrzej; Brzezinski, Bogumil

    2002-08-01

    A complex of 5,5'-dibromo-2,2'-biphenol with 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene hydrobromide has been studied using X-ray diffraction, FT-IR, and 1H NMR spectroscopy. In the crystal structure, a bromide anion is hydrogen-bonded with MTBDH + cation and two hydroxyl groups of two 5,5'-dibromo-2,2'-biphenol molecules. In the solid state, the Br - anion is an acceptor in N +-H⋯Br -, and two O-H⋯Br - intermolecular hydrogen bonds. In chloroform and acetonitrile, the structure of the complex assumes a new structure due to almost complete dissociation of protonated MTBD molecule. In chloroform, the MTBDH + cation is hydrogen-bonded with 5,5'-dibromo-2,2'-biphenol whereas in acetonitrile it is free and solvated by the solvent. In both cases, the 5,5'-dibromo-2,2'-biphenol molecule is hydrogen-bonded to the bromide anion.

  2. Synthesis and structure elucidation of potential 6-oxygenated metabolites of (22R)-6alpha,9alpha-difluoro-11beta,21-dihydroxy-1 6alpha,17alpha-propyl methylenedioxypregn-4-ene-3,20-dione, and related glucocorticosteroids.

    PubMed

    Thalén, A; Wickström, L I

    2000-01-01

    (22R)-6alpha,9alpha-Difluoro-11beta,21-dihydroxy-16 alpha,17alpha-propylmethylenedioxypregn-4-ene-3,20-dione (rofleponide) is a synthetic glucocorticosteroid with high affinity for the rat thymus glucocorticoid receptor and a very high biotransformation rate demonstrated through incubation with a human liver S9 subcellular fraction. Because oxidation in the 6-position is an important metabolic pathway of glucocorticosteroids, the potential 6beta-hydroxy and 6-oxo metabolites of rofleponide were synthesized to be used as reference compounds. Three alternative routes were used to reach the 6-hydroxy compound: (a) a one-step procedure involving allylic oxidation of rofleponide by selenium dioxide, (b) selenium dioxide oxidation of the corresponding 1,4-diene followed by selective 1,2-hydrogenation using Wilkinson's catalyst, and (c) autoxidation of a 3-methoxypregna-3,5-diene derivative. All three routes proceeded stereospecifically. Routes (a) and (c) gave approximately the same overall yield of the 6beta-hydroxy epimer, whereas the overall yield from route (b) was much lower, primarily because of incomplete 1,2-hydrogenation. The 6-oxo compound was prepared through Pfitzner/Moffat oxidation of the 6-hydroxy compound. The stereochemistry of the 6-hydroxy substituent is discussed on the basis of 1H-NMR spectroscopy and supplementary 2D NOESY experiments. PMID:10624832

  3. Molecular structure, FT-IR, vibrational assignments, HOMO-LUMO, MEP, NBO analysis and molecular docking study of ethyl-6-(4-chlorophenyl)-4-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate

    NASA Astrophysics Data System (ADS)

    Sheena Mary, Y.; Yohannan Panicker, C.; Sapnakumari, M.; Narayana, B.; Sarojini, B. K.; Al-Saadi, Abdulaziz A.; Van Alsenoy, Christian; War, Javeed Ahmad

    2015-03-01

    The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of ethyl-6-(4-chlorophenyl)-4-(4-fluoro-phenyl)-2-oxocyclohex-3-ene-1-carboxylate have been investigated experimentally and theoretically using Gaussian09 software. The title compound was optimized using the HF and DFT levels of theory. The geometrical parameters are in agreement with the XRD data. The stability of the molecule has been analyzed by NBO analysis. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. Molecular electrostatic potential was performed by the DFT method. As can be seen from the MEP map of the title compound, regions having the negative potential are over the electro negative atoms, the region having the positive potential are over the phenyl rings and the remaining species are surrounded by zero potential. First hyperpolarizability is calculated in order to find its role in non linear optics. The title compound binds at the active sites of both CypD and β-secretase and the molecular docking results draw the conclusion that the compound might exhibit β-secretase inhibitory activity which could be utilized for development of new anti-alzheimeric drugs with mild CypD inhibitory activity.

  4. Molecular structure, FT-IR, vibrational assignments, HOMO-LUMO, MEP, NBO analysis and molecular docking study of ethyl-6-(4-chlorophenyl)-4-(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate.

    PubMed

    Sheena Mary, Y; Yohannan Panicker, C; Sapnakumari, M; Narayana, B; Sarojini, B K; Al-Saadi, Abdulaziz A; Van Alsenoy, Christian; War, Javeed Ahmad

    2015-03-01

    The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of ethyl-6-(4-chlorophenyl)-4-(4-fluoro-phenyl)-2-oxocyclohex-3-ene-1-carboxylate have been investigated experimentally and theoretically using Gaussian09 software. The title compound was optimized using the HF and DFT levels of theory. The geometrical parameters are in agreement with the XRD data. The stability of the molecule has been analyzed by NBO analysis. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. Molecular electrostatic potential was performed by the DFT method. As can be seen from the MEP map of the title compound, regions having the negative potential are over the electro negative atoms, the region having the positive potential are over the phenyl rings and the remaining species are surrounded by zero potential. First hyperpolarizability is calculated in order to find its role in non linear optics. The title compound binds at the active sites of both CypD and β-secretase and the molecular docking results draw the conclusion that the compound might exhibit β-secretase inhibitory activity which could be utilized for development of new anti-alzheimeric drugs with mild CypD inhibitory activity. PMID:25463053

  5. 8β-hydroxy-3-oxopimar-15-ene exerts anti-inflammatory effects by inhibiting ROS-mediated activation of the TRAF6-ASK1-p38 signaling pathway.

    PubMed

    Cho, Jae-Heung; Lee, Jong Hyun; Lee, Eun-Jung; Nam, Dongwoo; Shim, Bum Sang; Song, Mi-Yeon; Kim, Sung-Soo; Kim, Sung-Hoon; Jung, Sang Hoon; Chung, Won-Seok; Ahn, Kwang Seok

    2013-10-01

    The flying squirrel's droppings (Pteropus pselaphon) have been used for improving the blood circulation, arresting bleeding to treat hematological disorders, and reducing pain. Here, 8β-hydroxy-3-oxopimar-15-ene (OXO), one of main constituents of P. pselaphon, was examined for its anti-inflammatory activity in murine macrophages. We found that OXO significantly suppressed LPS-induced nitric oxide (NO) without exerting cytotoxic effects on RAW 264.7 cells. OXO inhibited the expression of LPS-induced iNOS and COX-2 protein and their mRNA in a dose-dependent manner. Also, TNF-α, IL-6, and PGE2 secretion was decreased by OXO in LPS-stimulated macrophages. These inflammatory biomarkers were attributed to the suppression of LPS-induced activation of p38 MAPK and subsequent activation of two components of AP-1 (c-Jun and c-Fos), but not of ERK, JNK, NF-κB. Moreover, OXO inhibited LPS-induced intracellular reactive oxygen species (ROS) production and co-incubation of OXO and hydrogen peroxide (H2O2) suppressed the phosphorylation of p38 in a concentration-dependent manner. In addition, OXO completely disrupted the formation of TRAF6-ASK complex in the cells. Therefore, we demonstrate here that OXO can potentially inhibit several biomarkers related to inflammation through inhibition of ROS-mediated activation of TRAF6-ASK1-p38 pathway. PMID:23914844

  6. 2β, 3β, 23-trihydroxy-urs-12-ene-28-olic acid (TUA) isolated from Actinidia chinensis Radix inhibits NCI-H460 cell proliferation by decreasing NF-κB expression.

    PubMed

    Cheng, Qi-Lai; Li, Hong-Liang; Huang, Zhi-Qin; Chen, Yi-Jian; Liu, Ta-Si

    2015-10-01

    A natural ursolic compound, 2β, 3β, 23-trihydroxy-urs-12-ene-28-olic acid (TUA) was isolated from the root of Actinidia chinensis Planch (A. chinensis Radix). Since a large number of triterpenoid compound has marked anticancer effects toward various types of cancer cell lines in vitro, this study was carried out to investigate the anticancer effect of TUA in non-small cell lung cancer cells (NSCLCCs) and the underlying apoptotic mechanism of TUA was examined in NCI-H460 cell lines. Cell proliferation, apoptosis and cell cycle were measured using a cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. The activity of transcription factor NF-κB was determined by EMSA method. The expression of apoptosis- and proliferation-related proteins was determined by western blotting. The effect of TUA on NF-κB mRNA expression in NCI-H460 cells was detected by RT-PCR. TUA significantly suppressed the viability of NCI-H460 cells. Also, TUA significantly increased the sub G1 population by cell cycle analysis and in a concentration dependent manner in NCI-H460 cells. Such an effect was accompanied by p65 (NF-κB subunit) inactivation by an inhibition of IκBα phosphorylation, and by inhibition of p65 mRNA expressions. Consistently Overall, our findings suggest that TUA induces apoptosis via inhibition of NF-κB (p65) expression level and activation of IκBα in NCI-H460 cells as a potent anticancer candidate for lung cancer treatment. PMID:26134000

  7. Inquiry of the electron density transfers in chemical reactions: a complete reaction path for the denitrogenation process of 2,3-diazabicyclo[2.2.1]hept-2-ene derivatives.

    PubMed

    Safont, Vicent S; González-Navarrete, Patricio; Oliva, Mónica; Andrés, Juan

    2015-12-28

    A detailed study on all stages associated with the reaction mechanisms for the denitrogenation of 2,3-diazabicyclo[2.2.1]hept-2-ene derivatives (DBX, with X substituents at the methano-bridge carbon atom, X = H and OH) is presented. In particular, we have characterized the processes leading to cycloalkene derivatives through migration-type mechanisms as well as the processes leading to cyclopentil-1,3-diradical species along concerted or stepwise pathways. The reaction mechanisms have been further analysed within the bonding evolution theory framework at B3LYP and M05-2X/6-311+G(2d,p) levels of theory. Analysis of the results allows us to obtain the intimate electronic mechanism for the studied processes, providing a new topological picture of processes underlying the correlation between the experimental measurements obtained by few-optical-cycle visible pulse radiation and the quantum topological analysis of the electron localization function (ELF) in terms of breaking/forming processes along this chemical rearrangement. The evolution of the population of the disynaptic basin V(N1,N2) can be related to the experimental observation associated with the N=N stretching mode evolution, relative to the N2 release, along the reaction process. This result allows us to determine why the N2 release is easier for the DBH case via a concerted mechanism compared to the stepwise mechanism found in the DBOH system. This holds the key to unprecedented insight into the mapping of the electrons making/breaking the bonds while the bonds change. PMID:26584857

  8. A mutant form of 3-ketosteroid-Δ(1)-dehydrogenase gives altered androst-1,4-diene-3, 17-dione/androst-4-ene-3,17-dione molar ratios in steroid biotransformations by Mycobacterium neoaurum ST-095.

    PubMed

    Shao, Minglong; Zhang, Xian; Rao, Zhiming; Xu, Meijuan; Yang, Taowei; Li, Hui; Xu, Zhenghong; Yang, Shangtian

    2016-05-01

    Mycobacterium neoaurum ST-095 and its mutant M. neoaurum JC-12, capable of transforming phytosterol to androst-1,4-diene-3,17-dione (ADD) and androst-4-ene-3,17-dione (AD), produce very different molar ratios of ADD/AD. The distinct differences were related to the enzyme activity of 3-ketosteroid-Δ(1)-dehydrogenase (KSDD), which catalyzes the C1,2 dehydrogenation of AD to ADD specifically. In this study, by analyzing the primary structure of KSDDI (from M. neoaurum ST-095) and KSDDII (from M. neoaurum JC-12), we found the only difference between KSDDI and KSDDII was the mutation of Val(366) to Ser(366). This mutation directly affected KSDD enzyme activity, and this result was confirmed by heterologous expression of these two enzymes in Bacillus subtilis. Assay of the purified recombinant enzymes showed that KSDDII has a higher C1,2 dehydrogenation activity than KSDDI. The functional difference between KSDDI and KSDDII in phytosterol biotransformation was revealed by gene disruption and complementation. Phytosterol transformation results demonstrated that ksdd I and ksdd II gene disrupted strains showed similar ADD/AD molar ratios, while the ADD/AD molar ratios of the ksdd I and ksdd II complemented strains were restored to their original levels. These results proved that the different ADD/AD molar ratios of these two M. neoaurum strains were due to the differences in KSDD. Finally, KSDD structure analysis revealed that the Val(366)Ser mutation could possibly play an important role in stabilizing the active center and enhancing the interaction of AD and KSDD. This study provides a reliable theoretical basis for understanding the structure and catalytic mechanism of the Mycobacteria KSDD enzyme. PMID:26886757

  9. Harnessing Protocolized Adaptation in Dissemination: Successful Implementation and Sustainment of the Veterans Affairs Coordinated-Transitional Care Program in a Non-Veterans Affairs Hospital.

    PubMed

    Kind, Amy J H; Brenny-Fitzpatrick, Maria; Leahy-Gross, Kris; Mirr, Jacquelyn; Chapman, Elizabeth; Frey, Brooke; Houlahan, Beth

    2016-02-01

    The Department of Veterans Affairs (VA) Coordinated-Transitional Care (C-TraC) program is a low-cost transitional care program that uses hospital-based nurse case managers, inpatient team integration, and in-depth posthospital telephone contacts to support high-risk patients and their caregivers as they transition from hospital to community. The low-cost, primarily telephone-based C-TraC program reduced 30-day rehospitalizations by one-third, leading to significant cost savings at one VA hospital. Non-VA hospitals have expressed interest in launching C-TraC, but non-VA hospitals differ in important ways from VA hospitals, particularly in terms of context, culture, and resources. The objective of this project was to adapt C-TraC to the specific context of one non-VA setting using a modified Replicating Effective Programs (REP) implementation theory model and to test the feasibility of this protocolized implementation approach. The modified REP model uses a mentored phased-based implementation with intensive preimplementation activities and harnesses key local stakeholders to adapt processes and goals to local context. Using this protocolized implementation approach, an adapted C-TraC protocol was created and launched at the non-VA hospital in July 2013. In its first 16 months, C-TraC successfully enrolled 1,247 individuals with 3.2 full-time nurse case managers, achieving good fidelity for core protocol steps. C-TraC participants experienced a 30-day rehospitalization rate of 10.8%, compared with 16.6% for a contemporary comparison group of similar individuals for whom C-TraC was not available (n = 1,307) (P < .001). The new C-TraC program continues in operation. Use of a modified REP model to guide protocolized adaptation to local context resulted in a C-TraC program that was feasible and sustained in a real-world non-VA setting. A modified REP implementation framework may be an appropriate foundational step for other clinical programs seeking to harness

  10. Simultaneous all-optical half-adder, half-subtracter, comparator, and decoder based on nonlinear effects harnessing in highly nonlinear fibers

    NASA Astrophysics Data System (ADS)

    Singh, Karamdeep; Kaur, Gurmeet; Singh, Maninder Lal

    2016-07-01

    A multifunctional combinational logic module capable of performing several signal manipulation tasks all-optically, such as half-addition/subtraction, single-bit comparison, and 2-to-4 decoding simultaneously is proposed. Several logic functions (A+B¯, A.B, A¯.B, A.B¯, A⊕B, and A⊙B) between two input signals A and B are implemented by harnessing a number of nonlinear effects, such as cross-phase modulation (XPM), cross-gain modulation (XGM), and four-wave mixing (FWM) inside only two highly nonlinear fibers (HNLF) arranged in a parallel structure. The NOR gate (A+B¯) is realized by the means of XPM effect in the first HNLF, whereas, A‾.B, A.B¯, and A.B logics have relied on utilization of XGM and FWM processes, respectively, in parametric medium made up of the second HNLF of parallel arrangement. The remaining A⊕B and A⊙B logics required for successful implementation of the proposed simultaneous scheme are attained by temporally combining previously achieved (A‾.B and A.B‾) and (A.B and A+B‾) logics. Quality-factor ≥7.4 and extinction ratio ≥12.30 dB have been achieved at repetition rates of 100 Gbps for all logic functions (A+B‾, A.B, A¯.B, A.B¯, A⊕B, and A⊙B), suggesting successful simultaneous implementation.

  11. Harnessing endogenous miR-181a to segregate transgenic antigen receptor expression in developing versus post-thymic T cells in murine hematopoietic chimeras.

    PubMed

    Papapetrou, Eirini P; Kovalovsky, Damian; Beloeil, Laurent; Sant'angelo, Derek; Sadelain, Michel

    2009-01-01

    MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression by targeting complementary sequences, referred to as miRNA recognition elements (MREs), typically located in the 3' untranslated region of mRNAs. miR-181a is highly expressed in developing thymocytes and markedly downregulated in post-thymic T cells. We investigated whether endogenous miR-181a can be harnessed to segregate expression of chimeric antigen receptors (CARs) and TCRs between developing and mature T cells. Lentiviral-encoded antigen receptors were tagged with a miR-181a-specific MRE and transduced into mouse BM cells that were used to generate hematopoietic chimeras. Expression of a CAR specific for human CD19 (hCD19) was selectively suppressed in late double-negative and double-positive thymocytes, coinciding with the peak in endogenous miR-181a expression. Receptor expression was fully restored in post-thymic resting and activated T cells, affording protection against a subsequent challenge with hCD19+ tumors. Hematopoietic mouse chimeras engrafted with a conalbumin-specific TCR prone to thymic clonal deletion acquired peptide-specific T cell responsiveness only when the vector-encoded TCR transcript was similarly engineered to be subject to regulation by miR-181a. These results demonstrate the potential of miRNA-regulated transgene expression in stem cell-based therapies, including cancer immunotherapy. PMID:19033646

  12. To Twitter to Woo: Harnessing the power of social media (SoMe) in nurse education to enhance the student's experience.

    PubMed

    Sinclair, Wendy; McLoughlin, Moira; Warne, Tony

    2015-11-01

    This paper explores some of the difficulties, challenges and rewards for student nurses and nurse academics when harnessing social media (SoMe) as part of the overall learning experience. The paper draws upon data in the form of student voices, captured through an online planned Twitter chat. This data analysis provides the basis of a case study on the student experience in practice placements. A planned 1 h Twitter chat took place in June 2013, specifically aimed at student nurses. What transpired was an illuminating debate, eliciting responses from around the globe about learning in practice, mentors, and student support that lasted over 3 h. More importantly, the Twitter chat also included qualified nurses and mentors, listening and responding in real time, offering thoughts and solutions to how support and mentoring could be improved. This was in contrast to how students, locally, currently use a paper based questionnaire to give feedback in isolation. The authenticity of this feedback is often compromised by university link lecturers' who often provide a more sanitised version of this feedback to clinical placement. This paper explores whether it is possible to facilitate a realignment and capture the zeitgeist in order to provide the opportunity for enhancing learning in practice. PMID:26119057

  13. Use of a domestic Korean black goat (Capra hircus coreanae) with its chest crayon-harnessed in detecting estrus of Himalayan tahrs (Hemitragus jemlahicus)

    PubMed Central

    Yong, Hwanyul

    2014-01-01

    The reliability of a Korean black goat (Capra hircus coreanae) to detect estrus in Himalayan tahrs (Hemitragus jemlahicus) for an artificial breeding program was investigated. Estrus in six female Himalayan tahrs was synchronized using fluorogestone acetate (FGA) sponges. Thirteen days later, 200 IU of PMSG and 100 IU of hCG were injected before removing the sponges and simultaneously injecting 5 mg of PGF2α the next day. Penetration of the cervical canal and the thickness and location of red crayon marks were examined 40~43 h later. Two females treated with sponges containing 60 or 45 mg of FGA had estrogen levels of 8.7 and 11.1 pg/mL, respectively. No red marks were found on the backs of these two tahrs. The remaining females had higher levels of estradiol, and the red crayon marks were clearly shown. The cervical folds of these tahrs were readily penetrated and the insemination gun was smoothly inserted into the uterine body. In conclusion, a Korean domestic goat with its chest crayon-harnessed was successfully used to detect estrus of Himalayan tahrs. This technique might be utilized as a part of breeding programs for wild goats and avoid the need for a vasectomy of conspecific males. PMID:24690603

  14. Crystal structures of three anhydrous salts of the Lewis base 1,8-di-aza-bicyclo-[5.4.0]undec-7-ene (DBU) with the ring-substituted benzoic acid analogues 4-amino-benzoic acid, 3,5-di-nitro-benzoic acid and 3,5-di-nitro-salicylic acid.

    PubMed

    Smith, Graham; Lynch, Daniel E

    2016-03-01

    The anhydrous salts of the Lewis base 1,8-di-aza-bicyclo-[5.4.0]undec-7-ene (DBU) with 4-amino-benzoic acid [1-aza-8-azoniabi-cyclo-[5.4.0]undec-7-ene 4-amino-benzoate, C9H17N2 (+)·C7H6NO2 (-) (I)], 3,5-di-nitro-benzoic acid [1-aza-8-azoniabi-cyclo-[5.4.0]undec-7-ene 3,5-di-nitro-benzoate, C9H17N2 (+)·C7H3N2O6 (-), (II)] and 3,5-di-nitro-salicylic acid (DNSA) [1-aza-8-azoniabi-cyclo-[5.4.0]undec-7-ene 2-hy-droxy-3,5-di-nitro-benzoate, C9H17N2 (+)·C7H3N2O7 (-), (III)] have been determined and their hydrogen-bonded structures are described. In both (II) and (III), the DBU cations have a common disorder in three of the C atoms of the six-membered ring moieties [site-occupancy factors (SOF) = 0.735 (3)/0.265 (3) and 0.686 (4)/0.314 (4), respectively], while in (III), there is additional rotational disorder in the DNSA anion, giving two sites (SOF = 0.72/0.28, values fixed) for the phenol group. In the crystals of (I) and (III), the cation-anion pairs are linked through a primary N-H⋯Ocarbox-yl hydrogen bond [2.665 (2) and 2.869 (3) Å, respectively]. In (II), the ion pairs are linked through an asymmetric three-centre R 1 (2)(4), N-H⋯O,O' chelate association. In (I), structure extension is through amine N-H⋯Ocarbox-yl hydrogen bonds between the PABA anions, giving a three-dimensional structure. The crystal structures of (II) and (III) are very similar, the cation-anion pairs being associated only through weak C-H⋯O hydrogen bonds, giving in both overall two-dimensional layered structures lying parallel to (001). No π-π ring associations are present in any of the structures. PMID:27006813

  15. Crystal structures of three anhydrous salts of the Lewis base 1,8-di­aza­bicyclo­[5.4.0]undec-7-ene (DBU) with the ring-substituted benzoic acid analogues 4-amino­benzoic acid, 3,5-di­nitro­benzoic acid and 3,5-di­nitro­salicylic acid

    PubMed Central

    Smith, Graham; Lynch, Daniel E.

    2016-01-01

    The anhydrous salts of the Lewis base 1,8-di­aza­bicyclo­[5.4.0]undec-7-ene (DBU) with 4-amino­benzoic acid [1-aza-8-azoniabi­cyclo­[5.4.0]undec-7-ene 4-amino­benzoate, C9H17N2 +·C7H6NO2 − (I)], 3,5-di­nitro­benzoic acid [1-aza-8-azoniabi­cyclo­[5.4.0]undec-7-ene 3,5-di­nitro­benzoate, C9H17N2 +·C7H3N2O6 −, (II)] and 3,5-di­nitro­salicylic acid (DNSA) [1-aza-8-azoniabi­cyclo­[5.4.0]undec-7-ene 2-hy­droxy-3,5-di­nitro­benzoate, C9H17N2 +·C7H3N2O7 −, (III)] have been determined and their hydrogen-bonded structures are described. In both (II) and (III), the DBU cations have a common disorder in three of the C atoms of the six-membered ring moieties [site-occupancy factors (SOF) = 0.735 (3)/0.265 (3) and 0.686 (4)/0.314 (4), respectively], while in (III), there is additional rotational disorder in the DNSA anion, giving two sites (SOF = 0.72/0.28, values fixed) for the phenol group. In the crystals of (I) and (III), the cation–anion pairs are linked through a primary N—H⋯Ocarbox­yl hydrogen bond [2.665 (2) and 2.869 (3) Å, respectively]. In (II), the ion pairs are linked through an asymmetric three-centre R 1 2(4), N—H⋯O,O′ chelate association. In (I), structure extension is through amine N—H⋯Ocarbox­yl hydrogen bonds between the PABA anions, giving a three-dimensional structure. The crystal structures of (II) and (III) are very similar, the cation–anion pairs being associated only through weak C—H⋯O hydrogen bonds, giving in both overall two-dimensional layered structures lying parallel to (001). No π–π ring associations are present in any of the structures. PMID:27006813

  16. SURVIVAL EFFICACY OF THE PEGYLATED G-CSFS MAXY-G34 AND NEULASTA IN A MOUSE MODEL OF LETHAL H-ARS, AND RESIDUAL BONE MARROW DAMAGE IN TREATED SURVIVORS

    PubMed Central

    Chua, Hui Lin; Plett, P. Artur; Sampson, Carol H.; Katz, Barry P.; Carnathan, Gilbert W.; MacVittie, Thomas J.; Lenden, Keith; Orschell, Christie M.

    2013-01-01

    In an effort to expand the worldwide pool of available medical countermeasures (MCM) against radiation, the PEGylated G-CSF (PEG-G-CSF) molecules Neulasta and Maxy-G34, a novel PEG-G-CSF designed for increased half-life and enhanced activity compared to Neulasta, were examined in a murine model of the Hematopoietic Syndrome of the Acute Radiation Syndrome (H-ARS), along with the lead MCM for licensure and stockpiling, G-CSF. Both PEG-G-CSFs were shown to retain significant survival efficacy when administered as a single dose 24hr post-exposure, compared to the 16 daily doses of G-CSF required for survival efficacy. Furthermore, 0.1 mg kg−1 of either PEG-G-CSF effected survival of lethally-irradiated mice that was similar to a 10-fold higher dose. The one dose/low dose administration schedules are attractive attributes of radiation MCM given the logistical challenges of medical care in a mass casualty event. Maxy-G34-treated mice that survived H-ARS were examined for residual bone marrow damage (RBMD) up to 9mo post-exposure. Despite differences in Sca-1 expression and cell cycle position in some hematopoietic progenitor phenotypes, Maxy-G34-treated mice exhibited the same degree of hematopoietic stem cell (HSC) insufficiency as vehicle treated H-ARS survivors in competitive transplantation assays of 150 purified Sca-1+cKit+lin-CD150+ cells. These data suggest that Maxy-G34, at the dose, schedule, and time frame examined, did not mitigate RBMD, but significantly increased survival from H-ARS at one-tenth the dose previously tested, providing strong support for advanced development of Maxy-G34, as well as Neulasta, as MCM against radiation. PMID:24276547

  17. Survival efficacy of the PEGylated G-CSFs Maxy-G34 and neulasta in a mouse model of lethal H-ARS, and residual bone marrow damage in treated survivors.

    PubMed

    Chua, Hui Lin; Plett, P Artur; Sampson, Carol H; Katz, Barry P; Carnathan, Gilbert W; MacVittie, Thomas J; Lenden, Keith; Orschell, Christie M

    2014-01-01

    In an effort to expand the worldwide pool of available medical countermeasures (MCM) against radiation, the PEGylated G-CSF (PEG-G-CSF) molecules Neulasta and Maxy-G34, a novel PEG-G-CSF designed for increased half-life and enhanced activity compared to Neulasta, were examined in a murine model of the Hematopoietic Syndrome of the Acute Radiation Syndrome (H-ARS), along with the lead MCM for licensure and stockpiling, G-CSF. Both PEG-G-CSFs were shown to retain significant survival efficacy when administered as a single dose 24 h post-exposure, compared to the 16 daily doses of G-CSF required for survival efficacy. Furthermore, 0.1 mg kg of either PEG-G-CSF affected survival of lethally-irradiated mice that was similar to a 10-fold higher dose. The one dose/low dose administration schedules are attractive attributes of radiation MCM given the logistical challenges of medical care in a mass casualty event. Maxy-G34-treated mice that survived H-ARS were examined for residual bone marrow damage (RBMD) up to 9 mo post-exposure. Despite differences in Sca-1 expression and cell cycle position in some hematopoietic progenitor phenotypes, Maxy-G34-treated mice exhibited the same degree of hematopoietic stem cell (HSC) insufficiency as vehicle-treated H-ARS survivors in competitive transplantation assays of 150 purified Sca-1+cKit+lin-CD150+cells. These data suggest that Maxy-G34, at the dose, schedule, and time frame examined, did not mitigate RBMD but significantly increased survival from H-ARS at one-tenth the dose previously tested, providing strong support for advanced development of Maxy-G34, as well as Neulasta, as MCM against radiation. PMID:24276547

  18. De novo der(X)t(X;10)(q26;q21) with features of distal trisomy 10q: case report of paternal origin identified by late replication with BrdU and the human androgen receptor assay (HAR).

    PubMed Central

    Garcia-Heras, J; Martin, J A; Witchel, S F; Scacheri, P

    1997-01-01

    We describe an 11 year old girl with a de novo unbalanced t(X;10) that resulted in a deletion of Xq26-->Xqter and a trisomy of 10q21-->10qter. Her clinical features were of distal trisomy 10q, but she lacked the cardiovascular and renal malformations observed in duplications of 10q24-->10qter and had only moderate mental retardation. X inactivation was assessed on peripheral blood lymphocytes by late replication with BrdU (LR) and the human androgen receptor assay (HAR). By LR the der(X) was inactive without spreading to 10q21-->10qter in all cells. The HAR assay showed skewed methylation of the paternal allele (90%). The correlation of HAR and LR suggests that the der(X) was paternally inherited and is consistent with data from other de novo balanced and unbalanced X;autosome translocations detected in females. This is the first report of parental origin of a de novo trisomy 10q. Images PMID:9132498

  19. Thermodynamic properties and ideal-gas enthalpies of formation for 2-aminoisobutyric acid (2-methylalanine), acetic acid, (Z)-5-ethylidene-2-norbornene, mesityl oxide (4-methyl-3-penten-2-one), 4-methylpent-1-ene, 2,2{prime}-bis(phenylthio)propane, and glycidyl phenyl ether (1,2-epoxy-3-phenoxypropane)

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Cowell, A.B.; Knipmeyer, S.E.; Nguyen, A.

    1997-11-01

    The results of a study aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic substances are reported. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor-pressure measurements, and differential scanning calorimetric (DSC) heat-capacity measurements. Ideal-gas enthalpies of formation of acetic acid, (Z)-5-ethylidene-2-norbornene, mesityl oxide (4-methyl-3-penten-2-one), 4-methylpent-1-ene, glycidyl phenyl ether (1,2-epoxy-3-phenoxypropane), and 2,2{prime}-bis(phenylthio)propane are reported. An enthalpy of formation of 2-aminoisobutyric acid (2-methylalanine) in the crystalline phase was determined. Using a literature value for the enthalpy of sublimation of 2-aminoisobutyric acid, a value for the ideal-gas enthalpy of formation was derived. An enthalpy of fusion was determined for 2,2{prime}-bis(phenylthio)propane. Two-phase (solid + vapor) or (liquid + vapor) heat capacities were determined from 300 K to the critical region or earlier decomposition temperature for all the compounds except acetic acid. For mesityl oxide and 4-methylpent-1-ene, critical temperatures and critical densities were determined from the DSC results and corresponding critical pressures derived from the fitting procedures. Group-additivity parameters and ring strain energies useful in the application of group-contribution correlations were derived.

  20. Harness the Energy of Collaboration

    ERIC Educational Resources Information Center

    Lieberman, Ann; Miller, Lynne

    2016-01-01

    As they write about the Learning Communities standard in "Reach the Highest Standard in Professional Learning: Learning Communities," authors Ann Lieberman and Lynne Miller consider why communities have gained widespread attention and support and summarize the established research base about them. They also describe three contexts in…

  1. Harnessing science for environmental regulation

    SciTech Connect

    Graham, J.D.

    1991-01-01

    An introductory chapter by Graham frames the issues to be discussed; then the following three chapters describe the formation and character of three organizations. These chapters are written by authors who have each had an active management role in the organization they are writing about: Terry F. Yosie, now at the American Petroleum Institute, who staffed the SAB (Science Advisory Board) while he was at EPA; Robert A. Neal, who headed CIIT (Chemical Industry Institute of Toxicology) before leaving for a position at Vanderbilt University; and Thomas P. Grumbly, former executive director of HEI (Health Effects Institute) now president of Clean Sites, Inc. While these chapters are well written and make a vital contribution to the overall development of the book's themes, the most valuable and enjoyable parts of the book are the succeeding five chapters, which present case studies dealing with EPA's regulatory efforts on unleaded gasoline, perchloroethylene, formaldehyde, nitrates in drinking water, and carbon monoxide. Each of these case studies, nominally historical accounts of how one or more of these (three) organizations participated in the regulatory controversy, offer insight into the broader issues of dealing with, and incorporating into regulations scientific information that has high uncertainty. One of the richest aspects of the five case studies is the extensive use of referenced interviews with identified participants from all aspects of the regulatory process. This material illuminates the motivation, emotions, and goals of the different players, helping the reader to understand their positions and other issues, such as why industry pursues, and EPA and the environmental movement appear to resist, good science; what underlies EPA's preferences for one regulatory option over another; and why scientists are histant to give yes-or-no answers in accord with the real time needs of the regulatory agency.

  2. Harnessing Computer Games in Education

    ERIC Educational Resources Information Center

    Jong, Morris S. Y.; Shang, Junjie; Lee, Fong-Lok; Lee, Jimmy H. M.

    2008-01-01

    Besides the ability of making learning more interesting, educators and researchers have been exploring other pedagogical potentials of computer games. How to employ games for constructivist learning and teaching has become an attention in the field of education and game design in recent years. This article gives an introduction to game-based…

  3. Harnessing Critical Incidents for Learning

    ERIC Educational Resources Information Center

    Patahuddin, Sitti Maesuri; Lowrie, Tom

    2015-01-01

    A critical incident is a situation or event that holds significance for learning, both for the students and teachers. This paper presents four examples of critical incidents from a Year 7 teacher's lesson excerpts in Indonesia involving teaching of fractions, to show how they shaped classroom situation, brought forward elements of conflict, and…

  4. Re-Harnessing the Genie

    NASA Astrophysics Data System (ADS)

    Lagowski, J. J.

    1996-06-01

    Fifty years ago Vannevar Bush, with the aid of the Federal Government, released the academic research genie. It was argued at the time, and it still may be true, that only academic laboratories could provide the research and trained personnel needed to sustain American's scientific and technological needs. As history has shown, Bush's instinctive distrust of industrial laboratories as a potential training ground was basically correct. In those days, the country's needs were associated with warfare-the end of WWII and the collective hostile activities historically described as the "cold war." Today the country's needs derive from attempts to stay globally competitive. The government's decision to have universities turning out the bulk of the nation's basic research and to use those universities as a venue for developing research talent has created a network of more than 100 research-intensive universities, the output of which is the envy of the world. But, now there is another growing national need-improving the quality of science, mathematics, engineering, and technology (SMET) education throughout the educational system. The genie released 50 years ago, either has to go back into the bottle, or it needs to be re-purposed. The former is highly unlikely, which leaves only the latter as a viable strategy. Indeed, the National Science Foundation, which could be described as the master of the genie, is attempting to do just that. In the past several years, the budget for NSF's suite of "undergraduate" programs has grown to the point where the Foundation currently spends about $180 million on such projects. These programs represent initiatives at the pre-college and undergraduate college levels that are focused on instructional activities (teacher preparation, curriculum development, faculty enhancement, etc.) and research-oriented activities to compliment undergraduate education in a variety of traditional nonresearch environments. These programs are an attempt by NSF to start redressing the imbalance between research and teaching that the Foundation has actively promoted during most of its 50 years of existence. Now, the NSF strategy is to tell the scientists it has supported in the past, and those who will be supported in the future, that what they do in the classroom is as important as what they do in the laboratory; indeed, some would argue it is the most important activity that NSF has to sustain in the current environment. Since NSF is part of the problem, it has an obligation to be part of the solution, which is the essence of a report of an advisory panel. The draft report also has suggestions to universities on how to revise their approach to SMET teaching. It recommends that departments should set goals for what their students should learn, hold faculty members accountable for students' performance, change the academic reward system to incorporate good teaching, and give science faculty members a bigger role in the education of K-12 teachers. The basic problem is that 65% of all undergraduates, including many who will become the nation's precollege teachers, do not attend the more than 100 research intensive institutions that are so heavily supported by NSF's research efforts. In effect, those students have no access to SMET education in a world of growing technical complexity. The report suggests that NSF would do well to redress this imbalance by shifting more of its resources into undergraduate and precollege programs that focus on teaching. This point of view grows out of a 1986 review which centered on how NSF could help science majors. Now, the Foundation is being asked to address the SMET-related problems of all undergraduate students. Clearly, there is danger in attempting to use a system, the relatively meager resources of which have been aimed at about 10% of the population of undergraduates, to serve the entire population. Still, NSF can send a clear message that teaching is important in research-intensive universities. A message that might have a catalytic effect on all institutions. JJL

  5. Harnessing science to improve safety.

    PubMed

    Baillie, Jonathan

    2011-01-01

    Examining the effectiveness of various wet surface cleaning methods in combating harmful microorganisms in a hospital ward, understanding different healthcare cleaning regimes' impact on reducing slips and trips, evaluating the protection offered by surgical masks against influenza bioaerosols, and independently testing tower crane safety following a number of fatal incidents, are among the broad spectrum of recent projects undertaken by the Buxton-headquartered Health and Safety Laboratory (HSL). As HEJ editor Jonathan Baillie discovered from the organisation's healthcare and patient safety lead, Darren Whitehouse, with around 350 scientists skilled in everything from microbiology to occupational psychology, the range of scientific guidance, expertise, advice, testing, training, and investigation, that the HSL can offer to the healthcare sector is perhaps unrivalled throughout Europe. PMID:22053356

  6. Solar Radiation: Harnessing the Power

    ERIC Educational Resources Information Center

    Rowland, Teri; Chambers, Lin; Holzer, Missy; Moore, Susan

    2009-01-01

    My NASA Data (Chambers et al. 2008) is a teaching tool available on NASA's website that offers microsets of real data in an easily accessible, user-friendly format. In this article, the authors describe a lesson plan based on an activity from My NASA Data, in which students explore parts of the United States where they would want to live if they…

  7. Harnessing the Power of Data

    ERIC Educational Resources Information Center

    Reese, Susan

    2009-01-01

    There is great demand at the federal, state and local levels for hard, cold facts to demonstrate the effectiveness of education programs. In this article, the author discusses ways to utilize data in making the case for career and technical education (CTE). The right information, gathered from internal and external sources, can arm CTE program…

  8. Harnessing the Age of Information.

    ERIC Educational Resources Information Center

    Oettinger, Anthony G.

    Drawing in part on experiences from Harvard University's Program in Information Resources Policy, this paper looks at societal implications of changes in information resources and suggests concomitant changes in education. Commercial and geopolitical effects of the expansion in the range and versatility of information and communications products…

  9. Lithium: for harnessing renewable energy

    USGS Publications Warehouse

    Bradley, Dwight; Jaskula, Brian

    2014-01-01

    Lithium, which has the chemical symbol Li and an atomic number of 3, is the first metal in the periodic table. Lithium has many uses, the most prominent being in batteries for cell phones, laptops, and electric and hybrid vehicles. Worldwide sources of lithium are broken down by ore-deposit type as follows: closed-basin brines, 58%; pegmatites and related granites, 26%; lithium-enriched clays, 7%; oilfield brines, 3%; geothermal brines, 3%; and lithium-enriched zeolites, 3% (2013 statistics). There are over 39 million tons of lithium resources worldwide. Of this resource, the USGS estimates there to be approximately 13 million tons of current economically recoverable lithium reserves. To help predict where future lithium supplies might be located, USGS scientists study how and where identified resources are concentrated in the Earth’s crust, and they use that knowledge to assess the likelihood that undiscovered resources also exist.

  10. Harnessing nanoparticles for immune modulation

    PubMed Central

    Getts, Daniel R.; Shea, Lonnie D; Miller, Stephen D.; King, Nicholas J.C.

    2015-01-01

    Recent approaches using nanoparticles engineered for immune regulation have yielded promising results in preclinical models of disease. The number of nanoparticle therapies is growing, fueled by innovations in nanotechnology and advances in understanding of the underlying pathogenesis of immune-mediated diseases. In particular, recent mechanistic insight into the ways in which nanoparticles interact with the mononuclear phagocyte system and impact its function during homeostasis and inflammation have highlighted the potential of nanoparticle-based therapies for controlling severe inflammation while concurrently restoring peripheral immune tolerance in autoimmune disease. Here we review recent advances in nanoparticle-based approaches aimed at immune-modulation, and discuss these in the context of concepts in polymeric nanoparticle development, including particle modification, delivery and the factors associated with successful clinical deployment. PMID:26088391

  11. Harnessing neuroplasticity for clinical applications

    PubMed Central

    Sur, Mriganka; Dobkin, Bruce H.; O'Brien, Charles; Sanger, Terence D.; Trojanowski, John Q.; Rumsey, Judith M.; Hicks, Ramona; Cameron, Judy; Chen, Daofen; Chen, Wen G.; Cohen, Leonardo G.; deCharms, Christopher; Duffy, Charles J.; Eden, Guinevere F.; Fetz, Eberhard E.; Filart, Rosemarie; Freund, Michelle; Grant, Steven J.; Haber, Suzanne; Kalivas, Peter W.; Kolb, Bryan; Kramer, Arthur F.; Lynch, Minda; Mayberg, Helen S.; McQuillen, Patrick S.; Nitkin, Ralph; Pascual-Leone, Alvaro; Reuter-Lorenz, Patricia; Schiff, Nicholas; Sharma, Anu; Shekim, Lana; Stryker, Michael; Sullivan, Edith V.; Vinogradov, Sophia

    2011-01-01

    Neuroplasticity can be defined as the ability of the nervous system to respond to intrinsic or extrinsic stimuli by reorganizing its structure, function and connections. Major advances in the understanding of neuroplasticity have to date yielded few established interventions. To advance the translation of neuroplasticity research towards clinical applications, the National Institutes of Health Blueprint for Neuroscience Research sponsored a workshop in 2009. Basic and clinical researchers in disciplines from central nervous system injury/stroke, mental/addictive disorders, paediatric/developmental disorders and neurodegeneration/ageing identified cardinal examples of neuroplasticity, underlying mechanisms, therapeutic implications and common denominators. Promising therapies that may enhance training-induced cognitive and motor learning, such as brain stimulation and neuropharmacological interventions, were identified, along with questions of how best to use this body of information to reduce human disability. Improved understanding of adaptive mechanisms at every level, from molecules to synapses, to networks, to behaviour, can be gained from iterative collaborations between basic and clinical researchers. Lessons can be gleaned from studying fields related to plasticity, such as development, critical periods, learning and response to disease. Improved means of assessing neuroplasticity in humans, including biomarkers for predicting and monitoring treatment response, are needed. Neuroplasticity occurs with many variations, in many forms, and in many contexts. However, common themes in plasticity that emerge across diverse central nervous system conditions include experience dependence, time sensitivity and the importance of motivation and attention. Integration of information across disciplines should enhance opportunities for the translation of neuroplasticity and circuit retraining research into effective clinical therapies. PMID:21482550

  12. Harnessing the Power of PLCs

    ERIC Educational Resources Information Center

    DuFour, Richard

    2014-01-01

    The first time the author was responsible for planning a districtwide professional development day, DuFour secured a funny speaker, provided plenty of doughnuts, and made sure everyone could return to their classrooms in the afternoon. "The day was considered a huge success," he notes. "There was absolutely no evidence that the day…

  13. Pen and Pal Are Nucleotide-Sugar Dehydratases That Convert UDP-GlcNAc to UDP-6-Deoxy-d-GlcNAc-5,6-ene and Then to UDP-4-Keto-6-deoxy-l-AltNAc for CMP-Pseudaminic Acid Synthesis in Bacillus thuringiensis*♦

    PubMed Central

    Li, Zi; Hwang, Soyoun; Ericson, Jaime; Bowler, Kyle; Bar-Peled, Maor

    2015-01-01

    CMP-pseudaminic acid is a precursor required for the O-glycosylation of flagellin in some pathogenic Gram-negative bacteria, a process known to be critical in bacterial motility and infection. However, little is known about flagellin glycosylation in Gram-positive bacteria. Here, we identified and functionally characterized an operon, named Bti_pse, in Bacillus thuringiensis israelensis ATCC 35646, which encodes seven different enzymes that together convert UDP-GlcNAc to CMP-pseudaminic acid. In contrast, Gram-negative bacteria complete this reaction with six enzymes. The first enzyme, which we named Pen, converts UDP-d-GlcNAc to an uncommon UDP-sugar, UDP-6-deoxy-d-GlcNAc-5,6-ene. Pen contains strongly bound NADP+ and has distinct UDP-GlcNAc 4-oxidase, 5,6-dehydratase, and 4-reductase activities. The second enzyme, which we named Pal, converts UDP-6-deoxy-d-GlcNAc-5,6-ene to UDP-4-keto-6-deoxy-l-AltNAc. Pal is NAD+-dependent and has distinct UDP-6-deoxy-d-GlcNAc-5,6-ene 4-oxidase, 5,6-reductase, and 5-epimerase activities. We also show here using NMR spectroscopy and mass spectrometry that in B. thuringiensis, the enzymatic product of Pen and Pal, UDP-4-keto-6-deoxy-l-AltNAc, is converted to CMP-pseudaminic acid by the sequential activities of a C4″-transaminase (Pam), a 4-N-acetyltransferase (Pdi), a UDP-hydrolase (Phy), an enzyme (Ppa) that adds phosphoenolpyruvate to form pseudaminic acid, and finally a cytidylyltransferase that condenses CTP to generate CMP-pseudaminic acid. Knowledge of the distinct dehydratase-like enzymes Pen and Pal and their role in CMP-pseudaminic acid biosynthesis in Gram-positive bacteria provides a foundation to investigate the role of pseudaminic acid and flagellin glycosylation in Bacillus and their involvement in bacterial motility and pathogenicity. PMID:25414257

  14. catena-Poly[[[(2,2′-bipyridine-κ2 N,N′)cobalt(II)]-μ-(E)-3,3′-(but-2-ene-2,3-di­yl)dibenzoato-κ4 O,O′:O′′,O′′′] hemihydrate

    PubMed Central

    Li, Zong-Sheng; Ng, Seik Weng

    2011-01-01

    The title coordination polymer, {[Co(C18H14O4)(C10H8N2)]·0.5H2O}n, features a helical polymeric chain that runs along the b axis. The Co atoms are chelated by the carboxyl­ate groups of two 3,3′-(but-2-ene-2,3-di­yl)dibenzoate ligands and the N atoms of a 2,2′-bipyridine ligand. The lattice water mol­ecule is disordered about a center of inversion and is connected to the chain by an O—H⋯O hydrogen bond. The CoII atom shows a distorted octa­hedral coordination. PMID:22219789

  15. Ethyl 7'-(6-benz-yloxy-2,2-dimethyl-tetra-hydro-furo[3,2-d][1,3]dioxol-5-yl)-2-oxo-5',6',7',7a'-tetra-hydro-1'H,2H-spiro-[acenaphthyl-ene-1,5'-pyrrolo-[1,2-c][1,3]thia-zole]-6'-carboxyl-ate.

    PubMed

    Jagadeesan, G; Sethusankar, K; Prasanna, R; Raghunathan, R

    2012-08-01

    In the title compound, C(34)H(35)NO(7)S, the acenaphthyl-ene unit is essentially planar (r.m.s. deviation = 0.0335 Å). The pyrrolo-thia-zole ring system is folded about the bridging N-C bond; the thia-zolidine and pyrrolidine rings adopt S- and C-envelope conformations, respectively, with a 'butterfly' angle between the mean planes of 51.38 (10)°. The dioxolane and tetra-hydro-furan rings adopt O- and a C-envelope conformations, respectively, with a 'butterfly' angle between the mean planes of 57.12 (10)°. Two C atoms are each disordered over two positions with site-occupancy factors of 0.450 (7) and 0.550 (7). The crystal packing is stabilized by C-H⋯O inter-actions, generating an R(2) (2)(14) graph-set ring motif. PMID:22904945

  16. The photochemical thiol–ene reaction as a versatile method for the synthesis of glutathione S-conjugates targeting the bacterial potassium efflux system Kef† †Electronic supplementary information (ESI) available: Further experimental details and NMR spectra. See DOI: 10.1039/c5qo00436e Click here for additional data file.

    PubMed Central

    Rasmussen, Tim; Miller, Samantha; Booth, Ian R.

    2016-01-01

    The thiol–ene coupling reaction is emerging as an important conjugation reaction that is suitable for use in a biological setting. Here, we explore the utility of this reaction for the synthesis of glutathione-S-conjugates (GSX) and present a general, operationally simple, protocol with a wide substrate scope. The GSX afforded are an important class of compounds and provide invaluable molecular tools to study glutathione-binding proteins. In this study we apply the diverse library of GSX synthesised to further our understanding of the structural requirements for binding to the glutathione-binding protein, Kef, a bacterial K+ efflux system, found in many bacterial pathogens. This system is vital to the survival of bacteria upon exposure to electrophiles, and plays an essential role in the maintenance of intracellular pH and K+ homeostasis. Consequently, Kef is an appealing target for the development of novel antibacterial drugs. PMID:27110363

  17. Core functionalization of semi-crystalline polymeric cylindrical nanoparticles using photo-initiated thiol–ene radical reactions† †Electronic supplementary information (ESI) available: Further methods, polymer and nanostructure characterization. See DOI: 10.1039/c5py01970b Click here for additional data file.

    PubMed Central

    Sun, Liang; Pitto-Barry, Anaïs; Thomas, Anthony W.; Inam, Maria; Doncom, Kay

    2016-01-01

    Sequential ring-opening and reversible addition–fragmentation chain transfer (RAFT) polymerization was used to form a triblock copolymer of tetrahydropyran acrylate (THPA), 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC) and l-lactide. Concurrent deprotection of the THPA block and crystallization-driven self-assembly (CDSA) was undertaken and allowed for the formation of cylindrical micelles bearing allyl handles in a short outer core segment. These handles were further functionalized by different thiols using photo-initiated thiol–ene radical reactions to demonstrate that the incorporation of an amorphous PMAC block within the core does not disrupt CDSA and can be used to load the cylindrical nanoparticles with cargo.

  18. Thermodynamic properties and ideal-gas enthalpies of formation for dicyclohexyl sulfide, diethylenetriamine, di-n-octyl sulfide, dimethyl carbonate, piperazine, hexachloroprop-1-ene, tetrakis(dimethylamino)ethylene, N,N{prime}-bis-(2-hydroxyethyl)ethylenediamine, and 1,2,4-triazolo[1,5-a]pyrimidine

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Smith, N.K.

    1997-11-01

    The results of the study are aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic substances. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor-pressure measurements, and differential scanning calorimetric (DSC) heat-capacity measurements. Ideal-gas enthalpies of formation of hexachloroprop-1-ene, N,N{prime}-bis(2-hydroxyethyl)ethylenediamine, dimethyl carbonate, di-n-octyl sulfide, dicyclohexyl sulfide, diethylenetriamine, tetrakis(dimethylamino)ethylene, piperazine, and 1,2,4-triazolo[1,5-a]pyrimidine are reported. Enthalpies of fusion were determined for N,N{prime}-bis(2-hydroxyethyl)ethylenediamine, piperazine and 1,2,4-triazolo[1,5-a]pyrimidine. Two-phase (solid + vapor) or (liquid + vapor) heat capacities were determined from 300 K to the critical region or earlier decomposition temperature for each compound studied. Liquid-phase densities along the saturation line were measured for N,N{prime}-bis(2-hydroxyethyl)ethylenediamine, dimethyl carbonate, and dicyclohexyl sulfide. For dimethyl carbonate and piperazine, critical temperatures and critical densities were determined from the DSC results and corresponding critical pressures derived from the fitting procedures. Fitting procedures were used to derive critical temperatures, critical pressures, and critical densities for hexachloroprop-1-ene, di-n-octyl sulfide, dicyclohexyl sulfide, and diethylenetriamine. Group-additivity parameters and 1,4-interaction terms useful in the application of group-contribution correlations were derived.

  19. Thiol-ene and H-phosphonate-ene reactions for lipid modifications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The addition of H-E (E= -SR, -P(O)(OR)2 or -P(O)R2) to the carbon-carbon double bonds in lipids is a way to create new materials: lubricants, additives, polymers. In the current chapter, the radical addition of thiols (E= SR) and H-phosphonates (E= P(O)(OR)2) will be reviewed in detail. The kinetics...

  20. Crystal structure of catena-poly[bis(formato-κO)bis­[μ2-1,1′-(1,4-phenyl­ene)bis­(1H-imidazole)-κ2 N 3:N 3′]cobalt(II)

    PubMed Central

    Xu, Guo-Wang; Wang, Ye-Nan; Xia, Hong-Xu; Wang, Zhong-Long

    2015-01-01

    A red block-shaped crystal of the title compound, [Co(HCOO)2(C12H10N4)2]n, was obtained by the reaction of cobalt(II) nitrate hexa­hydrate, formic acid and 1,1′-(1,4-phenyl­ene)bis­(1H-imidazole) (bib) mol­ecules. The asymmetric unit consists of one CoII cation, one formate ligand and two halves of a bib ligand. The central CoII cation, located on an inversion centre, is coordinated by two carboxyl­ate O atoms and four N atoms from bib ligands, completing an octa­hedral coordination geometry. The CoII centres are bridged by bib ligands, giving a two-dimensional net. Topologically, taking the CoII atoms as nodes and the bib ligands as linkers, the two-dimensional structure can be simplified as a typical sql/Shubnikov tetra­gonal plane network. The structure features C—H⋯O hydrogen-bonding inter­actions between formate and bib ligands, resulting in a three-dimensional supra­molecular network. PMID:26396863